Cement Lifecycle Review

Life Cycle Review of Cement and Concrete Manufacturing Table of Contents Introduction3 Concrete Overview3 Life Cycle Stages4 Portland Cement4 Raw Material Extraction5 Crushing Process5 Kiln Processing6 Clinker Cooling and Storage7 Clinker Grinding7 Packaging and Shipping7 Concrete Processing8 Recycling and Landfill8 Environmental Considerations Throughout Life Stages9 Inputs: Consumption9 Outputs: Waste10 Air Quality and Pollution11 Land Quality and Biodiversity12 Alternative Suggestions in Minimizing Environmental Impact13Solutions for Minimising Ecological Footprint13 Solutions for Improving Air Quality13 Solutions for Minimising Land Degradation14 References15 Introduction A life-cycle assessment (LCA), as described by the US Environmental Protection Agency, is â€Å"a technique to assess environmental impacts associated with all the stages of a products life from cradle-to-grave†(USPA 2010). Therefore, an assessment of a product’s life cycle endeavors to analyze its existence from raw material extraction, to manufacturing, through to disposal.This report will not provide adequate data for the purpose of undertaking an LCA, however, it is aimed at â€Å"thinking† about the life cycle, and collecting information from past LCA studies to undertake a report on concrete production, particularly focusing on the life-cycle of cement, a critical component of concrete. Therefore, the following â€Å"life cycle thinking† review will endeavor to utilize previous LCA studies in order gain an insight about the major environmental impacts throughout each lifestage, chiefly centering on cement manufacturing.Correspondingly, it will also discuss alternative strategies of delivering cement and concrete as a building material with fewer environmental impacts. Concrete Overview Concrete is a multifaceted construction material, which is assembled mainly from cement, water and aggregate (Reding et al 1977). Concrete is one of the most durable buildin g materials, which allows it to exhibit many functions, including; precast elements, underwater construction, infrastructure formation and residential housing.In view of the fact that the life cycle stages and environmental impacts differ between manufacturing for each function concrete withholds, this report will focus on concretes function as a building material for residential housing and apartments (Anonymous 2012). Concrete is labeled one of the most durable building materials; therefore concrete structures withhold an elongated service life (Reding et al 1977. As a result of this, concrete is the most extensively used construction material in the world and has contributed momentously to the built environment throughout history. Life Cycle StagesIn a straightforward description, as mentioned above, concrete consists of three basic components, including cement, aggregates and water. Although there are various cement blends used for different purposes, this lifecycle review will focus particularly on Portland cement manufacturing, which is frequently utilized for industrial purposes (Anonymous 2012). In observing a life cycle of concrete manufacturing, the production of cement generally takes place separately, which is then transported to the selected building location, where water and aggregates are added to bind all components into one homogenous material – concrete (Anonymous 2012).Although there are obviously procedures in obtaining the water and aggregate for concrete production, the life-cycle discussed in this report will focus primarily on Portland Cement production (Reding et al 1977). Portland Cement The major raw materials extracted for cement production include limestone, sand, shale and clay. These feedstock ingredients provide calcium carbonate, alumina, silica and ferric oxide, which are critical elements of cement (Anonymous 2012). Figure 1: Proportion of cement components (CCAA 2010) Raw Material ExtractionThe initial stage of Portla nd cement production is the extraction of the raw materials by either quarrying or mining (Anonymous 2012). This withholds an adverse risk to land quality, potentially effecting fauna and flora within close proximity. Quarrying and mining are undertaken by operations such as drilling, blasting, excavating, handling, loading, hauling, and crushing (Reding et al 1977). The fragmented material, which can reach meters in length, is then transported via dump trucks to the cement plant, which is generally located nearby (Anonymous 2012). Crushing ProcessWhen transferred to the plant, the rock material is fed through a primary crusher, which breaks it down into smaller pieces up to six inches in size (Anonymous 2012). Subsequently, the rock is then transported via a conveyor to the secondary crushing stage, which accordingly, crushes the rock down to sizes of three inches or less. Following these essential crushing processes, all raw material undergoes a mixing and grinding process, where additional silica and iron may be added (Anonymous 2012). Within this stage, particulate emissions are profoundly emitted into the atmosphere.The mixing process can either be wet or dry, depending on the plant, however, the Cement Industry Federation states in their most recent Environmental Report that wet process plants in Australia now only account for less then 15% of total production, as wet processes have momentous water consumption (CIF 2010). In the instance of a wet mixing and grinding process, large impact dryers completely dry out the materials whilst grinding is undertaken, however if a wet process is embarked on, water is added during the grinding process which turns the mix into the form of a â€Å"slurry† (Anonymous 2012).Kiln Processing This process involves the slurry or the finely ground dry material to be fed into a high-temperature, cylindrical rotary kiln, heated to about 2700 degrees F (Anonymous 2012). Kilns are mounted with the axis slightly inclined f rom the horizontal and can reach up to 180m long, with a six meter diameter, thus it can take up to two hours for the material to travel through. The upper end of the kiln provides the entrance for the material, whereas the lower end comprises a roaring blast of flame, fueled by either coal or natural gas.During this process, any water contained in a â€Å"slurry† mix is lost through evaporation (Reding et al 1977). Ultimately, as the mixture travels through the kiln, it transforms both physically and chemically into grey pebble-like substances called clinker (Anonymous 2012). During kiln processing, particulate and GHG emissions are released. This stage also consumes the most energy, as fossil fuels are incinerated to provide extreme heat. Clinker Cooling and StorageThe clinker is expelled from the lower end of the kiln and is then transported onto a conveyer through a cooling system where large fans and water are utilized to cool the temperature (Anonymous 2012). The United Kingdom Environmental Agency state in their Environmental Performance Evaluation, that the vast majority of cement plants around the world now transfer the heated air from the coolers back towards the kiln as a means of saving fuel (UKEA 2010).Once the clinker is cooled, it is deposited into a storage area where it awaits until it is required for it’s final stage of grinding. Clinker Grinding The clinker is finally transported via a conveyor to its final crushing stage and is ground into a fine powder. This is carried out by steering the product through rotating tube mills with rolling crushers, which grind the cement into a fine powder. During this stage, other materials conveying analogous characteristics are added.Gypsum is also combined with the mix, as it assists in regulating the setting time of the final concrete product (Anonymous 2012). The continuous rolling assists in distributing the materials and gypsum throughout the cement evenly, and also separates the cement particles according to size (Reding et al 1977) . The material that has not been ground to the adequate size is deflected through the system again, however the final product is guided to the final storage silo (Anonymous 2012). Packaging and ShippingThe final product is either mechanically or hydraulically hauled out from its storage silo and is either packaged in paper sacks or supplied in bulk where it is then transported via truck, rail car or ship to the location of utilization (Anonymous 2012). Transportation must still be taken into consideration in contributing to the manufacturing air emissions. Concrete Processing Once transported to the building location, the addition of water to the cementitious material forms a thick cement paste, through the method of hydration (Anonymous 2012).Both fine and course aggregates; consisting of natural gravel, sand and soft stone are also commonly added to the cement paste, to create bulk and a strong, high resistant concrete (CCAA 2010). Aggregates are granular materials such as sand, gravel or crushed stone, which are usually dredged from a river, lake, pit or seabed (CCAA 2010). Prior to combining the aggregate in the cement, it undergoes a washing process to remove any unwanted silt, dust, clay or organic matter that could potentially interfere with the bonding reaction with the cement (Cement Industry Australia 2003).Similarly to the cement manufacture process, the aggregate is also sorted into different granular sizes (Anonymous 2012). This is undertaken by passing the material through a screen containing different size openings. Once arranged into adequate sizing, the aggregate is transported to the building site where it congregates with the cement (CCAA 2010). Thorough combining of cement, water and aggregate is crucial for the invention of high quality, uniform concrete, therefore equipment and methods such as cement trucks and on site mixers are utilized (CCAA 2010).Once all the constituents are thoroughly combined, it is molded or positioned as anticipated and then left to harden. Recycling and Landfill When a concrete building structure reaches the end of it’s life, either recycling or landfill is an option (CCAA 2010). The process of demolition of a concrete structure involves pulling it down either mechanically or manually through the utilization of excavators or bulldozers (Chen et al 2010). Larger buildings however, may require more powerful equipment.Following, the shattered concrete fragments are either transported by trucks to landfills for disposal or collected from the annihilation site and transported to a crushing facility, where it is fed through a crushing machine to be broken down and used for aggregate of new concrete (Cement Australia 2003). In conjunction with quarries, landfills also hold significant environmental consequences, as it can destroy or alter species habitat. Environmental Considerations Throughout Life Stages Inputs: ConsumptionThe Cement Indus try Federation (CIF) states in their 2003 environmental report, that the cement manufacturing process is extremely energy and resource intensive, therefore, it withholds a significant environmental footprint (CIF 2003). As displayed in the life-cycle diagram (figure 2), raw materials, energy and in some instances water, are the chief inputs associated with the manufacturing process, therefore, their consumption levels are predominantly to blame for the industries heightened environmental footprint (Anonymous 2012).Cement Australia (2010) states that on average, water utilization of a modern dry cement plant is between one hundred to two hundred litres per tonne of clinker produced (Cement Australia 2010). This water consumption is primarily used for cooling heavy equipment and exhaust gas. Although this appears quite high, Chen et al (2010) mentions that it is a dramatic improvement from earlier, yet still subsisting wet process cement plants (Chen et al 2010). The addition of water in cement to create the final product of concrete also consumes a large quantity of water.Similarly, the cement industry is highly energy intensive, especially during the kiln life stage (CIF 2003). Generally, cement plants today use natural gas, heavy oil and coal for fuel (Chen et al 2010). However, as coal accounts for almost 40 per cent of manufacturing costs, the utilization of fossil fuels in cement production has decreased since 1990 and has been partly substituted by alternative fuels (CIF 2003). The impact the high consumption of fossil fuels possesses on the environment is accelerated greenhouse releasement into the atmosphere, thus contributing to global warming (Chen et al 2010).Therefore, environmental consideration of adequate selection of alternative fuels is crucial in minimizing the environmental footprint. Outputs: Waste Furthermore, the outputs within each life stage also exhibit environmental issues throughout the entire cycle, from resource extraction through t o landfill (Chen et al 2010). The outputs fluctuate and vary between atmospheric emissions, waterbourne wastes, solid wastes and other co-product releases (CIF 2003).These outputs, in conjunction with the reasonably high input consumption, are the causes of the evident impacts the industry posses on the environment. Lemay & Leed (2011), mention in a broad perspective that air emissions leading to climate change, resource depletion, water consumption, ecotoxicity, eutrophocation, human health criteria, habitat alteration, smog formation and acidification are the main documented impacts that occur throughout the cement manufacturing process, whether it be instant or over time (Lemay & Leed 2011).Although there is clearly a vast array of impacts associated with cement manufacturing and concrete assembly, the impact on air quality and land quality appear to be considered by numerous LCAs to be a vital issue associated with manufacture, therefore they will be analyzed in more thorough de tail. Air Quality and Pollution Air pollution is highly likely to occur throughout each life stage of cement production, whether it is a result of fuel combustion or particulates from raw and finished materials (CIF 2003).Eco Tech (2011) mentions in its Cement Industry Report, that the uttermost crucial impacts associated with air pollution include; hydrocarbons and particulates which posses a threat to human health and environmental quality, and greenhouse gas emissions accelerating climate change (EcoTech 2011). In relation to Greenhouse gas emissions, Chen et al (2010) scrutinized in his Cement Plant Evaluation, that different Portland cement plants around the world is under close inspection these days because of the large volumes of CO2 emitted (Chen et al 2010).The report also continues to address that almost one tonne of CO2 is released for every one tonne of cement produced in the industry, which appears to be momentous considering in the year 2010, the world produced approxi mately 3. 6 billion tonnes of cement (Rosenwald 2011). Contrary to greenhouse gas emissions, dust emissions are at their highest peak at the initial quarrying stage and the final building demolition stage, as a result of forceful blasting and obliterating (Chen et al 2010).Other sources of dust emissions, however, are raw mills, kilns/ clinker coolers and cement mills. The Cement Industry Federation (2003) states that transportation of raw materials from the quarry to the site and stockpiles of raw materials contribute significantly to dust emissions (CIF 2003). Overall, the dust emissions released throughout the different life stages impact momentously on air quality, thus it threatens human health and overall environmental quality. Dust is the most common and extensive air pollutant from a quarry (CIF 2010).It has different origins in a quarry site such as mechanical handling operations that include crushing and grading process; haulage with which is related to the vehicle, and th e nature and condition of the way; blasting; additional manufacturing operations and wind blow from paved areas, stockpiles (Chen et al 2010) . Land Quality and Biodiversity The central issue of cement production upon land quality comes from quarrying, atmospheric deposition, disposal of wastes and storage of raw material (CIF 2003).These issues, predominantly atmospheric deposition, arise from merely every life stage of cement manufacturing; therefore it is an issue that must be taken into great consideration (Chen et al 2010). Quarrying and landfill have both direct and indirect environmental impacts on land and its surrounding biodiversity (Chen et al 2010). The direct impacts include habitat destruction thus biodiversity loss, dust inhalation and noise from rock drilling and blasting (CIF 2010). Subsequently, the effects of cement works on habitats are difficult to quantify, however the potential harm is much greater in vulnerable areas.The US Environmental Protection Agency (20 02), states in their report that two large operating cement plants in England are located on the edge of National Parks, therefore site selection must be considered in depth prior to implementation (USEA 2002). On the other hand, indirect impacts can potentially cause different catastrophes such as landslides and flashfloods in and around quarry sites (Chen et al 2010) . Furthermore, dust particulate has physical effects on plants, such as damage and blockage to the leaf surface, which may lead to death if photosynthesis is unable to occur (Chen et al 2010).Chemical effects on the other hand, can potentially produce changes in soil chemistry, which ultimately leads to changes in the long term associated with plant chemistry alterations, species competition and community structure (CIF 2010). Dust particulates from quarrying and wastes also affect waterways, as supplementary sedimentation may cause nearby reservoirs to dry out or flood (Chen et al 2010) . Alternative Suggestions in M inimizing Environmental Impact Solutions for Minimising Ecological FootprintDue to the significant amount of energy consumed in cement manufacturing, the cement industry has considerably focused over a long period on escalating plant efficiency and decreasing energy consumption. Cement Australia (2010) affirms that the Australia Cement Industry has seen a 23% decrease in CO2 emissions in the period between 1990-2009 (Cement Australia 2010). Although this is a significant decrease, further methods could potentially be utilized to further cutback consumption. Firstly, energy could be more efficiently recycled and transferred within the plant system.For example, excess heat from the clinker cooler being transferred back to the kiln stage to prevent energy waste should be implemented in all modern cement plants (Lemay & Leed 2011). Secondly, alternative fuels should be enhanced, especially in clinker manufacture. Alternative fuels may include items such as tyres, oils and tarrow. Soluti ons for Improving Air Quality As mentioned earlier, air emissions for GHG release has improved over the last decade as a result of utilization of alternative fuels.This however, has the potential to be further improved, therefore complete replacement of fossil fuels to alternative fuels could potentially take place to completely eradicate GHG releasement (Lemay & Leed 2011). In addition, the Cement Industry Federation (2010) asserts that improvement techniques for dust collection such as baghouse dust collectors has also been implemented over the past century (CIF 2010). Although there have been improvements, likewise, the potential for further development still remains. Perhaps aspects of the layout design could be improved, as a means of stockpile design and transportation throughout the system.Containment of conveyors could be implemented and perhaps pipelines, which substitute transport to and from the quarry to the plant, could be considered to prevent particulate emissions bei ng released (Lemay & Leed 2011). In addition, the moistening of the raw material throughout the crushing stages via sprays could also potentially to instigated to minimize dust release (CIF 2010). Filters and collectors could also be applied within each stage so the dust gathered can be sent through to the kiln for clinker production Solutions for Minimising Land DegradationUnfortunately quarrying and landfill in any form will impact on land quality, however methods such as buffer zones between workings and alternative habitats for defined species could be considered in an attempt to conserve biodiversity within or around the sites (Lemay & Leed 2011). Rehabilitation programs to restore once existing biodiversity on site could also be considered when the quarry material is completely exploited. Additionally, as displayed in the life cycle review, recycling of the final concrete material is an option as opposed to landfill.Perhaps the promotion of further cement and concrete recyclin g could be considered to avoid the amount of quarrying required. This would also minimize the amount of product discarded into landfill, thus retaining natural habitat. References Abdul-Wahab S. 2006. â€Å"Impact of fugitive dust emissions from cement plants on nearby communities†. Ecological Modelling. Vol: 195. Issue: 3-4. Page 338-348. Anonymous. 2012. â€Å"How Portland Cement is Made†. Portland Cement Association. Available: www. cement. org/basics/howmade. asp. (Last Accessed 7/10/12) Cement Australia. 2010. Environmental Performance†. Cement Australia. Available: www. cementaustralia. com. au/wps/wcm/connect/website/cement/home/sustainable-development/environmental-performance (Last Accessed 10/10/12) Cement Concrete and Aggregates Australia (CCAA). 2010. â€Å"Sustainable Concrete Materials†. CCAA. Available: www. concrete. net. au/sustainability/documents/documents2. pdf. (Last Accessed 7/10/12) Chen C, Habert G, Bouzidi Y, Jullie A. 2010.  "Environmental impact of cement production: detail of the different processes nd cement plant variability evaluation†. Journal of Cleaner Production.Vol: 18. Issue: 5. Page 478-485 Lemay L, Leed A. 2011. â€Å" Life Cycle Assessment of Concrete Buildings†. Concrete Sustainability Report. Available: www. nrmca. org/sustainability/CSRO4%20-%Life%20Cycle%20Assessment%20Concrete. pdf (Last Accessed 10/10/12 Nisbet M. 1996. â€Å"The Reduction of Resource Input and Emissions Achieved by Addition of Limestone to Portland Cement† Research and Development Information. Portland Cement Association. Canada Obajana Cement Project. 2005. â€Å"Social and Environmental Impact Assessment† Obajana Cement Project. Available: www. jaspers. uropa. eu/attachments/pipeline/1191_social_eia_en. pdf (Last Accessed 10/10/12) Park L, Tae S, Kim T. 2012. â€Å"Life Cycle CO2 Assessment of Concrete by Compressive Strength on Construction Site in Korea† Renewable and Sustainabl e Energy Reviews. Vol: 16. Issue: 5. Pages 2940 – 2946. Reding J, Muehlberg P, Shepherd B. 1977. â€Å"Industrial Process Profiles for Environmental Use† The Cement Industry. Chapter 21. Available: http://www. inece. org/mmcourse/chapt6. pdf. (Last Accessed 7/10/12) Rosenwald M. 2011. â€Å"Building a Better World with Green Cement†. Science and Nature.Available: http://www. smithsonianmag. com/science-nature/Building-a-Better-World-With-Green-Cement. html (Last Accessed 10/10/12) The Energy Conservation Center (ECC). 1994. â€Å"Output of a Seminar on Energy Conservation in Cement Industry†. United Nations Industrial Development Organisation (UNIDO). Available: www. unido. org/fileadmin/import/userfiles/puffk/cement. pdf. (Last Accessed 10/10/12) US Environmental Protection Agency (USEPA). 2010. â€Å"Defining Life Cycle Assessment (LCA). US Environmental Protection Agency. Available: www. gdrc. org/uem/lca/ (Last Accessed 11/10/12)

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Should the Canadian Government Use Monetary and Fiscal Policy to Term Paper

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Agriculture in the next 30 years Assignment Example | Topics and Well Written Essays - 750 words

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The ban on the advertising of convenience foods - Essay Example This article provides a counter response to such calls and it takes a supportive stand on behalf of the advertisers as there seems to be no clear-cut evidence to prove that such advertisements could also be a cause for the supposed epidemic of ill-health and obesity among these children. The article aims to bring out the positive effects of such advertising stating that it would actually be educative for the children. There is no compelling language used in the text. The article states that children like any others have the right to view such advertisements and thereby make their own food choices. The first two premises aim to counter the media claims by using survey reports that convenience and tasty food advertising are a reason for the supposed ill-health epidemic and obesity among children. In the third premise, there is a highlight on how food companies like the McDonalds not only promote healthy food for children but also contribute to the growth of children by sponsoring junio r level sporting activities. The next premise explains about the unproven link between health problems like diabetes due to consumption of fast foods. The fifth premise adds a note on the actual purpose of such advertising and makes a reference to the situation in the US. The final premise stresses that every child must have the right to information on food products which would help them make their own food choices and ends on a positive statement emphasizing the freedom that needs to be given to the advertising world in a democratic society.

Discuss the most common challenges faced by management in an Essay

Discuss the most common challenges faced by management in an international context - Essay Example Besides the common challenges the management faces, globalization and the rise of multinational organizations have created challenges from communicational dimensions. In this essay, four main communication barriers will be discussed; they are cultural barriers, distance barriers, trust barrier (inner barrier), and the language barrier. In the process of international management, cultural understanding is a crucial factor to create opportunities for economic growth and development. To create cultural understanding, the manager is challenged with the task of learning and comprehending other cultures and contexts. This serves to reduce as much cultural difference as possible, and avoid communication breakdowns wherever the company or organization may encounter it. For example, while Arabs treat their leaders as heroes and worship them as long as they remain in power, Iranians expect their leaders to exhibit power and strength. (Phatak, 2005, p.5) Most common cultural differences are broadly categorized based on the following factors- power distance, uncertainty avoidance, human orientation, collectivism, assertiveness, gender egalitarianism, future orientation, and performance orientation. (Phatak, 2005, p.5) It is the management’s responsibility to analyze other cultures and minimize any cultural problems to maximize efficiency. This results in better business expansion, improved production and better image for the company. A manager who has a better understanding of the various cultural factors will be able to adopt appropriate management techniques and procedures that adapt to differing cultural values and beliefs. For this to occur, it is important that the manager accurately analyses the situation and acts accordingly or it may lead to a sharp decline in efficiencies. In leadership at every level possible, the most important factor is ‘trust’. Without trust in

Refubrishment of the UK industrial buildings Literature review

Refubrishment of the UK industrial buildings - Literature review Example In major constructions in the UK and Wales, industrial buildings are generally one-story, multi-span, rectangular in design and equipped with crane for lifting heavy materials. Moreover, some of the buildings have translucent roofing materials which provide natural ventilation and lighting. Such industrial buildings are mainly manifested in enterprises which are specialised in machine use, metalworking, ferrous metallurgy, and the construction-materials industry (Pastor, 2005). When industrial processes involve substantial emission of heat or hazardous gases, the roof structure of such industrial buildings is developed aerodynamically, and big enough to provide an enabling environment for easier elimination of heated or contaminated air. Most of the industrial buildings whose operations involve such processes have adequate space to avoid air pollution through wind or thermal pressure vents and chimneys in the roof. Richardson and Chaloner (1996) indicated that when production process es involve particular prescribed and controlled conditions of temperature, air moisture, and uncontaminated air, industrial building with single-story multi-spans are have higher ceilings. The main function of the ceilings is to separate the ground where machinery and infrastructure lines are built from the central area for work within the building, which is normally protected from adverse environmental conditions. Such industrial buildings normally lack natural systems and are fitted with artificial ventilation materials, mechanical lighting, and air conditioners. Industrial buildings made in such large designs are mainly meant for the development of electronic equipment, and precision tools (Beaudry, & Swann, 2009). Chemical industrial buildings are also designed in similar ways to aid the manufacture of synthetic fabric and fibres. 2). Under which regulations most of them have been built? In Britain, and Wales, the Building Act 1984 guides the establishment of industrial building s. The statute traces back to the advent of Industrial Revolution when industrial accidents were rife, in an attempt to guarantee safety. The regulations contained in the law, basically guards against fire accidents (Boleat, 1986). Under the regulations, most industrial buildings in the country were built through an initial form of compartments blended with stone materials. Moreover, industrial buildings in UK and Wales are sited away from residential areas or highly congested downtown areas. The site for every industrial building requires the approval of the government before construction process begins. The buildings have wide exits for escape in case of any disaster. Stairways should be made of fire resistant materials and be wide enough to allow easy exits and evacuations of any emergency. Industrial buildings were to be made without obstructed isles and stairways for easier and faster escape. Additionally, all the buildings were supposed to be at most 15 meters from any of the fire escapes (Boleat, 1986). In light of this, every staircase built on the building had to be adequately ventilated from a spacious room to avoid fire outbreaks or suffocation during operations. 3). What are their energy issues? Owing to the inability of ancient industrial buildi

Video games and time wasting Essay Example for Free

Video games and time wasting Essay There is a fine line between using your time to your advantage and one of which you’re on a couch watching the latest Hannah Montana episode. I plan on explain how you use video games to achieve that maximum goal. Many adults over the age of 40 don’t take the classic controller or the player seriously and from that you get the hate and criticism you see today. From here on out I will take you on an in-depth tour of the latest video games and how they apply to different subjects. Firstly, this is my thought in the matter; video games are not a waste of time. Video games help you relax, they are just for fun. What most people fail to see when they say things like, video games are a total waste of time is that they too have areas of their life which could be deemed pointless. They however do not see it this way. This is because whatever their time-waste is has something to offer that person. Do you like to watch movies? Few would say no, yet what have you gotten done after an hour and half of sitting in a chair, staring at a screen? Yet these same people can attack video games. True, there are those who play way too much, (I am not one of them), and there is a point where it becomes a problem. The fact is that every form of media has something you can glean from it. This includes movies, games, T. V, books, ect. Movies contain inspiration, Books and T. V contain knowledge, relaxation and humor. Games likewise contain a mixture of all of them, and throw in strategy and interactions to boot. Many people say they are a waste of time, but really they are about as much waste of time as say reading a magazine or a taking a walk in the park. You might not be accomplishing much, but it is entertainment. It’s Simple as that. Let me brief you up on the history at the start of the video game era. The first commercially available video game was Computer Space in 1971, which laid the foundation for a new entertainment industry in the late 1970s within the United States, Japan, and Europe. The arcade game industry entered its Golden Age in 1978 with the release of Space Invaders by Taito, a success that inspired dozens of manufacturers to enter the market. In 1979, Atari released Asteroids. Color arcade games became more popular in 1979 and 1980 with the arrival of titles such as Pac-Man. The Golden Age had a prevalence of arcade machines in shopping malls, traditional storefronts, restaurants and convenience stores. The first home console system was developed by Ralph Baer and his associates. The system was released in the USA in 1972 by Magnavox, called the Magnavox Odyssey. At the end of 1983, the industry experienced losses more severe than the 1977 crash. This was the crash of the video game industry, as well as the bankruptcy of several companies that produced North American home computers and video game consoles from late 1983 to early 1984. It brought an end to what is considered to be the second generation of console video gaming. Causes of the crash include the production of poorly designed games such as Custers Revenge, E. T. the Extra-Terrestrial and Pac-Man for the Atari 2600 that suffered due to extremely tight deadlines. It was discovered that more Pac-Man cartridges were manufactured than there were systems sold. In addition, so many E. T. the Extra-Terrestrial cartridges were left unsold that Atari allegedly buried thousands of cartridges in a landfill in New Mexico. The new decade (2010) has seen rising interest in the possibility of next generation consoles being developed in keeping with the traditional industry model of a five-year development cycle. However, in the industry there is believed to be a lack of desire for another race to produce such a console. Reasons for this include the challenge and massive expense of creating consoles that are graphically superior to the current generation, with Sony and Microsoft still looking to recoup development costs on its current consoles. The focus for new technologies is likely to shift onto motion-based peripherals, such as Microsofts Kinect and Sonys PlayStation Move. One new console is Nintendos new handheld: the successor to the Nintendo DS known as the Nintendo 3DS. The system is due for release by the end of the fiscal year (March 2011). The system will incorporate 3D graphics and effects without the need for using 3D glasses. Other features include three cameras (one internal and a dual 3D external set), a motion sensor, a gyro sensor and a Slide Pad that allows 360-degree analog input. Sony is also using 3D technology, with some PS3 games compatible with their 3D TV, the Sony Bravia, also using 3D glasses So you see video games have been around for a long time and I don’t see a point where the will become obsolete. Secondly, videogames have genres much like books. There are several different kind of genres. For example; Role-Playing, First Person Shooter or Third Person Shooter, Adventure, Puzzle, and Education, etc. are all genres of videogames. Many just provide fun and entertainment but they all provide learning one way or another. The learning comes from these topics; hand-eye coordination, problem solving skills, teamwork, tactics, reflex improvement, vocabulary, cash management, multi-tasking, etc. A famous video game is Call of Duty. There are many different variations but it will always give you a little history lesson. Like in the 5th one; World at War, it puts you in the place of an American soldier in World War Two. There is also a softer side of videogames such as the Wii console. There are many videogames for the young gamers such as; Brothers Sesame St: Elmos A to Z Adventure for Nintendo Wii, Math Blaster for the Pc, Magic School bus, and plenty more. As a matter of fact I was walking down an isle at a Toys R Us and picked up a copy of World of Warcraft and a lot of younger kids recognized it. Videogames also have a lot of backstory in it. People get paid just to re-write history straight out of a textbook, script it, then code to where it’s a game that you can play. Burger King also released a videogame a while ago that came with the big kids’ meal. It consisted of some cheap coding and crappy graphics. Strategy Games have you devise methods to solve a goal which is working your mind, thus making you smarter. Same goes with puzzle games like Bejeweled. There are also games that can test your reflexes like that one app for the iPod touch. Of the topic of puzzle games there is one that can be played off of the screen and on a piece of paper. It’s called Sudoku. Sudoku is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9? 9 grid with digits so that each column, each row, and each of the nine 3? 3 sub-grids that compose the grid. Many accomplished surgeons come from a video game background. The hand eye coordination practice they received from games is the reason they succeeded. Although gaming is a great past-time it also has some serious downfalls that you need to take into consideration. 1. An increased rate of aggression or violence because of the graphic content and violent images games. 2. A sedimentary lifestyle can result in childhood obesity. 3. Seizures or epilepsy. Those are the many side effects from gaming. Although those may seem serious, playing games for only an hour or two at a time is relatively healthy and stimulates brain activity. So if you read everything carefully you have come to understand that videogames are not a waste of time and are simply just a past time. Just imagine you could be improving your reflexes instead of catching up on the latest Oprah show. I hope this essay enlightened you.

Lesson Plan Assignment Example

Lesson Plan Assignment Example Each student will create a lesson plan for his/her area of interest (i.e., primary, elementary, secondary, etc.) between kindergarten and grade 12, in a chosen content area, using https://planbook.com. The lesson is to last approximately 60 minutes. Lessons must include the following elements:   title, grade level, materials, Common Core or Maryland standard (depending on the content area), objective, anticipatory set/warm-up, instructional input, guided practice, independent practice, closure, and assessment. Make sure your lesson plan aligns. Does your assessment test what it is setting out to assess which are your objectives? Your lesson plan is to be written for a forty-five minute class. Effective teachers employ a number of instructional strategies in their classrooms. These strategies are prescriptive approaches to teaching, designed to help students acquire a deep understanding of specific forms of knowledge.   Direct Instruction, Constructivism, Discovery Learning, and Cooperative Learning strategies are discussed in our textbook and it is expected that one of these strategies will be detailed in the instructional input portion of your lesson. You will need to do some additional research on the strategy you choose to showcase before writing your procedure, as the lesson must align with the strategy. When writing your lesson provide a lot of detail. The goal is that you could hand your lesson plan to a substitute and have it taught exactly as you envision it. Also, it is very important that you integrate activities that engage all the learning styles in your classroom. Therefore, I will be looking for activities that engage the visual, auditory, and kinesthetic learners. You can include childrens books, reference books, pictures, web resources, any poems, songs, learning centers or games, manipulates, and/or motivational theme related ideas. Title/Grade: The title of lesson and the grade level that the plan is designed to teach. Subject: discipline being taught Materials: items/supplies needed to implement the lesson. Consider: What items and supplies will be needed by both the instructor and the students in order to accomplish the stated learning objectives? What equipment will I need in order to utilize as many learning modalities as possible? (visual, audio, tactile, kinesthetic, etc.) How can I use materials creatively? What can I borrow from other teachers? Common Core/Maryland Standard: Define what students should understand and be able to accomplish. Common Core standards focus on reading, writing, language, and math skills, while all other content areas are MD standards. Objective: Precise goals for what you want your students to be able to accomplish after the lesson is completed. These must align with common core and/or state standards. SWBAT (Students will be able to) is the acronym that we use when stating an objective. For the lessons in this unit, you will be focusing on only one objective per lesson. Anticipatory Set: What would be said and/or presented to your students before the direct instruction of the lesson begins. Purpose of Anticipatory Set Provide continuity from previous lessons, if applicable Allude to familiar concepts and vocabulary as a reminder and refresher Tell the students briefly what the lesson will be about- this is not the actual lesson Gauge the students level of collective background knowledge of the subject to help inform your instruction Activate the students existing knowledge base Whet the classs appetite for the subject at hand Briefly expose the students to the lessons objectives and how you will get them to the end result Instructional Input: (What knowledge will you communicate to the studenttell, lecture, stand up and deliver so that the student will understand the objective.) This portion of the lesson is the main part if the instruction and where you will include information about the instructional strategy that the lesson focuses on. Use your textbook and research on your own to explain the use of this strategy. How will new information be disseminated and what activities are employed to achieve the stated objectives? Guided Practice: Precise goals for what you want your students to be able to accomplish after the lesson is completed. These must align with common core and/or state standards. SWBAT (Students will be able to) is the acronym that we use when stating an objective. For the lessons in this unit, you will be focusing on only one objective per lesson. Examples of Guided Practice in Your Lesson Plan Students will split into pairs to work together on drawing. On a piece of paper, students will draw a picture of plants, incorporating characteristics they learned about in this lesson (listed on board). On the other side of the paper, students will draw a picture of animals, incorporating characteristics they learned about in this lesson (listed on board). Students complete a book review that corresponds to what they are reading. Independent Practice: Through Independent Practice, students have a chance to reinforce skills and synthesize their new knowledge by completing a task on their own and away from the teachers guidance. It is the part of the lesson where students are given the opportunity to practice what they have just learned. In writing the Independence Practice section, consider the following questions: Based on observations during Guided Practice, what activities will students be able to complete on their own? How can I provide a new and different context in which the students can practice their new skills? How can I offer Independent Practice on a repeating schedule so that the learning is not forgotten? How can I integrate the learning objectives from this particular lesson into future projects? Closure: The closure is the time when you wrap up a lesson plan and help students organize the information in a meaningful context in their minds. Examples of Closure in a Lesson Plan Discuss new things that the students learned about plants and animals. Summarize the characteristics of plants and animals and how they compare and contrast. Ask what information from the lesson the students will find important three years from now and why. Ask the students to summarize the lesson to explain to someone who missed the class. Give them a couple of minutes and then either have them turn them in for you to read or have a few presented to the class. Assessment: Standards and objectives must be assessed in every lesson and every child must have documentation to prove their performance as it relates to the mastery of that standard and objective. This can be done through many means, but a few ways to assess are quizzes, tests, independently performed worksheets, cooperative learning activities with independently scored rubrics, hands-on experiments with specific documentation, oral discussion in which anecdotal notes or another method of recording is used, question-and-answer sessions, or other concrete means.   Most importantly, ensure that the Assessment activity is directly and explicitly tied to the stated learning objective. In the learning objective section, you specified what students would accomplish and how well they would have to be able to perform a task in order to consider the lesson satisfactorily accomplished.

Quantization effects in digital filters

Quantization effects in digital filters ABSTRACT: Quantization effects in digital filters can be divided into four main categories: quantization of system coefficients, errors due to A-D conversion, errors due to roundoffs in the arithmetic, and a constraint on signal level due to the requirement that overflow must be prevented in the comparison. The effects of quantization on implementations of two basic algorithms of digital filtering-the first-or second-order linear recursive difference equation, and the fast Fourier transform (FFT) are studied in some detail. For these algorithms, the differing quantization effects of fixed point, floating point, and block floating point arithmetic are examined and compared. The ideas developed in the study of simple recursive filters and the FFT are applied to analyze the effects of coefficient quantization, roundoff noise, and the overflow constraint in two more complicated types of digital filters frequency sampling and FFT filters. Realizations of the same filter design, by means of the frequency sampling and FFT methods, are compared on the basis of differing quantization effects. All the noise analyses in the report are based on simple statistical models for roundoff and A-D conversion errors. Experimental noise measurements testing the predictions of these models are reported, and the empirical results are generally in good agreement with the statistical predictions INTRODUCTION: Digital filters are widely used in modern signal-transmission systems. The first-order filters are used for extracting lower-frequency or upper-frequency signals. Quantization errors due to the finite number of binary digits in the representation of numbers are typical of digital filters. Quantization is a representation of data samples with a certain number of bits per sample after rounding to a suitable level of precision. Quantization errors in a Digital Signal Processing (DSP) system can be introduced from three sources; one source is input quantization, a second is coefficient quantization and the third is the finite precision in the arithmetic operations. The quantization error in the arithmetic operations can be controlled by carefully selecting the size of buffer registers according to the input word length. Quantization errors from input and filter samples are considered in this article. The effects of quantization errors and the tradeoffs required between precision and hardware resources are discussed in relation to the implementation of the DSP in Field Programmable Gate Array (FPGA). This article is divided into three main sections; quantization effects for upconversion, quantization noise due to rounding off arithmetic and quantization effects for digital beamforming (DBF). Fixed length samples cause reduction in the filter dynamic range and gain resolution. Quantization In digital signal processing, quantization is the process of approximating (mapping) a continuous range of values (or a very large set of possible discrete values) by a relatively small (finite) set of (values which can still take on continuous range) discrete symbols or integer values. For example, rounding a real number in the interval [0,100] to an integer 0,1,2,100. In other words, quantization can be described as a mapping that represents a finite continuous interval I = [a,b] of the range of a continuous valued signal, with a single number c, which is also on that interval. For example, rounding to the nearest integer (rounding  ½ up) replaces the interval [c .5,c + .5) with the number c, for integer c. After that quantization we produce a finite set of values which can be encoded by say binary techniques. A. QUANTIZATION EFFECTS ON UPCONVERSION: In multirate systems, upconvcersion can be achieved with oversampling and filtering techniques. For the proposed digital TIGER system, input Gaussian pulses are upsampled to produce higher order Nyquist zones. A high pass FIR filter is employed to acquire a spectral zone at the expanded band edge. In this case, higher efficiency is possible by exploiting filter symmetry. For a higher throughput rate, polyphase implementation of the FIR filters can be employed. Since signal amplification is performed in the analog domain, a high speed 14 bit DAC is used for digital to analog conversion. Finite precision causes similar effects in the input data samples and filter coefficients. Fixed word length effects on filter coefficients, filter length and dynamic range are described in the following sections. 1. Sensitivity of Filter Coefficients to Quantization Finite precision plays a significant role in the dynamic range of filter gain and DC offset. A large number of quantization levels will decrease the quantization error; on the other hand it requires larger silicon space to implement the design. The quantization affects the input Gaussian pulse and the filter coefficients. The pole and zero maps show perturbations in Figure 1 when samples are restricted to finite word length. The filter coefficients in the lower parts are constrained to 14 bit quantized samples and the length of the filter is 100 taps. This constraint arises from the fast DAC of 14 bit width used for converting a digital signal into the analog domain. Since the dynamic range of the quantizer is less than that of the filter coefficients, the quantized coefficients are disturbed from the unit circle. The gain of the quantized filter response is displayed in Figure 1 which is distinctly less than that for the infinite precision filter. For these simulations infinite prec ision representation is regarded as floating point, which provides significantly better precision than the quantization levels discussed here. The zeros around Z = -1 are responsible for passband attenuation and are less displaced. As the dynamic range of the quantizer is increased to match the filter coefficients, the signal to quantization noise ratio (SNR) improves, but at the cost of increased hardware resources. Similar results can be obtained for the input Gaussian pulse when quantized to specified fourteen bit word lengths. Finite precision is hardware efficient since the system data width is less than the infinite precision (or floating point) case. Quantization reduces a few out of 100 coefficients to zero, which will further ameliorate the memory cell and arithmetic processing requirement. Quantization also reduces the filter gain compared to infinite precision samples; however this reduction is acceptable as long as it remains within an attenuation limit. The fourteen bit quantizer provides more than 80dB attenuation which is better than the standard of 60dB used by many communication systems. 2. Quantization Effects on Filter Order For direct conversion transmission, a cascaded design performs better than a single stage. This is because quantization errors are reduced with a lower filter order. Secondly a lower order design requires less logic resources. Quantization errors vary with the length of a filter and we now study the effects of the filter order on the quantization error. A simulated result is shown in Figure 2, where quantization error is plotted against variable filter order. The quantization is performed by rounding the infinite precision samples to the closest fixed point value. The quantization error increases with increased filter order, since the highest power index in the filter polynomial is the most affected by the rounding. When the quantizer is increased with one more bit in the precision, the error is reduced by approximately 6dB as would be expected. The lower order filter provides better dynamic range than the higher order for eight and nine bit quantizers. This fact is also evident in Figure 2. At lower filter order of fifty, accumulative quantization error is around -43dB and at higher order of 200, it is -31dB. The 12dB difference is equivalent to two additional bits in quantization. Non-linear effects of the quantization can be reduced using a smaller filter order in the modulator. Since the cascaded design comprises a filter of lower order, compared with the single model, it introduces less quantization error than the single stage. 3. Quantization and Word length The dynamic range of the scaled filter depends on the number of bits assigned to the quantizer. For maximum signal power, the quantizer range should be equal to the signal magnitude. An FIR filter with filter variance 2 f s and quantization noise variance 2 n s has a signal to noise ratio of This expression can be used to estimate the appropriate word length for the FPGA implementation. A comparison of SNR versus word precision using the above expression has been calculated and is shown in Figure 3. From this graph it is evident that for each bit added to the word length, there is approximately a six decibel improvement in the SNR. For a higher precision level, a system can still be implemented, but at the cost of increased FPGA logic resources. B. QUANTIZATION NOISE DUE TO ROUNDING OF ARITHMETIC: In the poly phase filter, like in any other filter, quantization has to be performed on the result of any arithmetic operation. This is because any such operation requires more bits to represent the result than is required for each of the operands. If the Word length were always to be adjusted to store the data in full precision, this would be impractical, as there would soon be too many bits required to be stored in the available memory. Therefore, the word length of the internal data, has to be chosen, and the result of any arithmetic operation has to be constrained back to using the quantization scheme chosen from the ones shown in the previous section, as appropriate for the given application. The quantization operation may cause a disturbance to the result of the arithmetic operation. For normal filtering operations, such a quantization disturbance can usually be successfully considered as white noise and modeled as an additive noise source at the point of the arithmetic operation with the quantization step equal to the LSB of the internal data, . This certainly is not the case for zero-valued or constant input signals. However, modeling the quantization has-in most cases-the purpose of determining the maximum noise disturbance in the system. Hence, even if the additive quantization noise model gives overestimated values of the noise for very specific signals, this fact does not decrease the usefulness of the approach. After the shape of the quantization noise power spectral density (NPSD) is found, it can be used to identify regions that might cause overloading or loss of precision due to arithmetic noise shaping; also the required input signal scaling and the required internal arithmetic word length can be estimated for a given noise performance. The standard methods of estimating the maximum signal level at a given node are L1-norm (modulus of the impulse response-worst-case scenario), L2-norm (statistical mean-square), and L -norm (peak in frequency domain giving the effect of the input spectral shaping). These norms can be easily estimated for the given node from the shape of the NPSD. The quantization noise injected at each adder and multiplier, originally spectrally flat, is shaped by the noise shaping function (NSF), , calculated from the output of the filter to the input of each of the noise sources, i.e., to the output of each of the arithmetic operators. These functions were calculated for all of the all pass filter structures are shown in Fig. 2. The shapes of the nontrivial of the NFS are shown in Fig. 3. The accumulated quantization NPSD transferred to the output, , is obtained by shaping the uniform NPSD from each of the quantization noise sources by the square of the magnitude of the NFS corresponding to the given noise injection point and can be described by The results show that all structures perform in a way very distinct from the other ones. Structure (a)has the best performance at dc, half-Nyquist , and Nyquist , where the NPSD falls toward minus infinity. Its two maxima are symmetric about and independent of the coefficient value. The peaks are distant from for small coefficient values and approaches it as the coefficient increases. Structure (b) has uniform noise spectral distribution as all the arithmetic operations are either at the filter input-then noise is shaped by the allpass characteristic of the whole filter-or at its output. Structure (d) also has a minimum at v=0.25 . Its average noise power level decreases as the value of the all pass coefficient increases. Structure (c), the best from the point of view of the required guard bits, has its maximum at v=0.25 going toward infinity for coefficient values approaching one. This effect is a result of the denominator of the Nth-order all pass filter causing the poles of the filter to move toward the unit circle at normalized frequencies of v=2pik/N,k=0.N-1 for the coefficient approaching one. If there is no counter effect of the numerator, like for the case of P1(Z) for structure (c) and for structure (a), then the function goes to infinity. Even though structure (c) goes to infinity at v=0.25 for alfa=1, it has the lowest average noise power from all the structures. This structure has a big advantage in terms of the number of required guard bits and ease of cascading a number of them into higher order all pass filters. If the filter coefficients appro ach one, then the increase in quantization noise power could be countered with few additional bits. Using other structures would only replace the problem of dealing with an increase in the quantization noise with the problem of having to increase the number of guard bits required to deal with an increase of the peak gains. The NPSD of the quantization noise at the output of the poly phase structure can be calculated as the sum of the NPSD at the output of all all pass filters in the filter scaled by the 1/N factor N, being the number of paths. If the filter is cascaded with another filter, the NPSD of the first one will also be shaped by the square of the magnitude of the second filter. sources. The intention was to check the correctness of the theoretical equations by applying the white noise sources instead of quantization and by performing the quantization after addition and multiplication (rounding and truncating) to verify the shaping of the quantization noise and its level both for white input noise sources and real-life signals. The shape of the output quantization noise accumulated from all arithmetic elements for a wide-band input signal assuming, for simplicity, no correlation between the noise sources, is shown for all considered all pass structures in Fig. 4. The solid curve indicates the theoretical NSF that is very well matching the median of the quantization noise (curves lying on top of each other). The quantization noise power increase calculated for the given coefficient was 8.5 dB for structure (a), 6 dB for structure (c), 7.3 dB for structure (d), and 9 dB for structure (b). It is clear that the quantization noise differs from the assumed white n oise characteristic. However, the approximation still holds with an accuracy of around 5-10% depending on the structure of the input signal. An example of more accurate modeling of the quantization noise caused by arithmetic operations can be found in (a). The arithmetic quantization noise certainly decreases the accuracy of the filter output. The value of the arithmetic word length has to be chosen such that the quantization noise power is smaller than the stop band attenuation of the filter and the stop band ripples. In certain cases, the design requirements have to be made more stringent to allow some unavoidable distortion due to the arithmetic word length effects. For the case of decimation filters for the based A/D converters, the quantization noise adds to the one originating from the modulator. In such a case, each stage of the decimator has to be designed so that it filters out this noise as well. The verification of the peak gain analysis was performed by applying single-tone signals at the characteristic frequencies- where functions from Fig. 2 have their extremes-and by using wideband signals to make sure that the estimates are accurate. The experimental results confirmed the theoretical calculations. The results of the simulation for the white noise input signal of unity power are given in Fig. 8. The simulation was performed for a white noise input signal of unity power in order to have a uniform gain analysis across the whole range of frequencies. The theoretical shape of the gain is shown by a solid line that is very closely matching the median value of the signal at the test points. C. QUANTIZATION EFFECTS ON DIGITAL BEAMFORMING: The quantization of infinite precision samples into fixed word length degrades the phased signals. As was discussed in the previous section, the use of more levels for higher precision decreases the quantization error at the expense of larger hardware resources. For a reduced precision level, quantization error is spread to the main beams and to the grating lobes as well. In this section we present effects of quantization on beam resolution and associated grating lobes. 1. Quantization effects on Beam Pattern Phased signals have similar quantized effects on main beam resolution as the filter samples. However non-linearity arises in the sidelobes since the quantizer is not of adequate resolution to represent small changes that affect the sidelobe levels. In order to investigate the quantization effects, an example is presented with fixed word length delay samples. The coefficients of the time vector are quantized into four and ten bits; the increased number of bits will reduce the quantization effect. For an actual design the fixed bit width will depend on available hardware resources. The quantized beam in Figure 1 shows that a four bit fixed number does not adequately represent the beam pattern and thus introduces quantization noise. The ten bit numbers will also introduce quantization error, but at a lower level as shown in Figure 1(b). As can be seen from this simple example, the four bit quantization compromises the sidelobes at the 20dB level, while the ten bit quantization provides a reasonably faithful reconstruction of the theoretical sidelobes at this level. Therefore we conclude that for the 14 bit DAC of the proposed system, the sidelobe level will be essentially unaffected by the quantization at the -20dB level. 2. Sensitivity of Sidelobe Levels to Quantization Quantization causes gain errors in sidelobe levels. Higher resolution in quantization introduces lower quantization error. The graph in Figure 1 shows that the four bit samples result in a quantization error which reduces the first sidelobe gain while producing a gain error in the second sidelobe. The quantization error changes the dynamic range of the grating lobes and degrades the adjacent beam resolution for multiple beam systems. A simulated graph is displayed in Figure 2 to demonstrate non-linear behavior of the quantizer in the sidelobe resolution. For a lower order quantizer, the quantization step is not perfectly matched with the sidelobe levels. For the first sidelobe, the quantized resolution is less than the infinite precision case, although it approaches the floating point value with increasing quantized levels. Figure 2(a) shows that for a three bit quantizer, the first sidelobe resolution is at -18dB, while at ten bits it approaches the infinite precision value of -13.5dB. Unlike the first sidelobe, the second sidelobe exhibits higher resolution error at a lower precision level, since the quantizer can not represent the dynamic range adequately. Again, quantization error reduces with an increase in the number of bits. CONCLUSION: In this paper, effect of fixed word lengths on signal upconversion, quantization noise due to round of arithmetic and quantization effects on digital beam forming have been discussed. For the digital up conversion process, the quantization error can be described using pole/zero filter and frequency response plots. Filter resolution and stop band attenuation are degraded when quantization is introduced. For an increase in filter order, the quantization error increases as the highest order in filter polynomial is effected the most. To overcome this limitation, the number of precision levels of a quantizer can be increased, however this will require increased logic resources for FPGA implementation. Quantization effects in phasing are more complex than in the filter quantization since finite precision degrades the side lobe resolution. For lower precision levels, the quantization error exhibits non-linear behavior in the second side lobe. The quantization error is higher for lower precision levels. In order to overcome these non-linear effects, a precision level of more than eight bits is required. Performance of the proposed digital system will be effectively unaffected by the fixed word length limitations since a system data bus of at least 14 bits is suggested. REFERENCES: A. B. Sripad and D. L. Snyder, A Necessary and Sufficient Condition for Quantization Errors to be Uniform and White P. P. Vaidyanathan, On coefficient-quantization and computational roundoff effects in lossless multirate filter banks. 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Diversity in Management Essay -- BTEC Business Marketing GCSE Coursewo

Diversity in Management Diversity in management, or lack thereof, is having the same mixture of women, blacks, and other minorities in management positions as there is in that local population. What this paper will talk about is some of the facts that business will have to face in regards to diversifying there workforce and there management. Also, it will discuss that while our workforce is becoming more diverse, the upper and middle management of many companies are not. We have to remember that having diversified workforce is not something a company should have, actually it is some thing that has happened or is soon going to happen due to the fact that we have a more diversified population. (Sutherland, 1996) This is why it is important that we train our management to deal with this inevitability. To the extent of the lack of diversity in management, it is somewhat alarming to see that while we have a rapid increase in the diversity of our population on Long Island, and a pretty diversified workforce, we don’t have well-diversified management in most companies on the island. On Long Island, two-thirds of the companies surveyed in conjunction with a recent Newsday article have no blacks, Hispanics, or Asians at anything above the vice president level. Also, of all the companies surveyed only 13 percent of them said that they had more than one minority in their executive suite. Also while women have seen an increase that has actually out numbered the number of men in professional ranks, women only account for a mere 10 percent of the total number of executive officers in the top 25 companies on Long Island. While women are getting the short end of the stick in the respect to jobs, women and other minorities are also not getting paid as much as men are. Of the 500 highest paid executives on the island and queens only 19 of them were female. That works out to be about 3.8 percent of the 500 executives. In the highest paid and the fastest growing type of business which happens to be technology, management here is represented less than in any other type of business. All women and most minorities excluding Asian Americans hold few to no jobs in this field that includes the manufacturing of computers, communication devices, and other kinds of electronic equipment. Along with technology, the stock brokerage field and securities firms all al... ...at broadcasters must now reach out more into minority communities when hiring new workers. (www.diversityonline.com) While where has been some progress in helping diversify our workforce and management it is obvious that we have a long way to go before the amount of minorities and women in a given local area equal the amount of minorities and women in managerial roles in a given company. It is unfortunate that there is such a lack of diversity because if we continue to limit the number of minorities in management positions and the number of minorities in a given community continue to rise than companies might not be able to meet the needs of their customers. That it is why it is imperative that more companies incorporate some form of a diversity program. If companies don’t start using programs like this it will not only hurt that company and community but it will also hurt the economy. Works Cited 1. www.diversiryonline.com. The Diversity Monitor, February 2000. 2. Gordon, Craig. Newsday Vol.60 No.219. Sunday, April 9, 2000 3. Sutherland, Tyler. April 1996, http://cctr.umkc.edu/wicc/wdpaper.html 4. The Workplace Diversity Initiative, http://www.shrm.org/diversity/

Gendre Stereotyping :: essays research papers

In the year 2000, the average person is spending more of his/her leisure time watching television, or using their computer. The shows on TV and the information available to us available through all types of media influence our decision process. An individuals perception of the world is ever-changing as he/she recieves more and more information. Although being informed is good, it can be very dangerous. TV influences every aspect of our lives; our life style, what we wear, how we look, and how we act. Children are more susceptible to the influence of television compared to adults. This is true because of a lack of maturity. Children often identify with a popular movie or television character although both adults and children are influenced by television. Information acquired through all media can be destructive. We know information can be harmful when we use the terms "tomboy" and "sissy". These terms automatically make the accused party an outcast. The term "tomboy" is used when referring to a girl who may seem slightly masculine, whereas the term "sissy" is used to describe a boy whe may seem slightly feminine. The socially accepted despcription of what it is to be masculine is to be strong, to be able to support a family, and to have high stamina. On the other hand, what it is to be feminine is to be a loving mother, and to stay home with their kids. Men and women have very specific and very different dress codes. Men must where suits and women must wear dresses. Men must stay away from feminine colours such as purple and pink. Whoever crosses the gendre based lines may be made fun of or shunned by others. We are not only trying to fit in the gendre molds ourselves, but also tend to pass them on to our own children. We attempt to protect them from being shunned by society by setting the mold for them as well. The key differences between men and women seem to have been existing since the beginning of time. This is because from birth, a boy is dressed in blue and a girl wears pink. Children even have much different toys. Boys play with trucks and violence oreinted toys, and girls play with dolls. Since men and women are conditioned to be different from birth, it is not surprising that there is a huge gender gap. Gender gaps are common in sports, because sports are traditionally regarded as masculine activities.

Appearance Vs. Reality Of Modern Music Affect On Teenagers :: essays research papers

Appearance vs. Reality of Modern Music Affect on Teenagers In today's society the teenager has had more rights than ever before, along with these rights comes responsibility, independence and good judgment. All of those mentioned have been destroyed in many teenagers lives by these "Rock Stars". The modern teenager is exposed to many different things that may affect their lives as they choose to live it, non quite as strong of a force than the effect of music, it is the teens outlet to expression, rebellion and popularity all of which are very important to the average teenager, but often in cases the teen who is trying to conform becomes subject to the "Rock Star's" manipulation, and that is when obsession kicks in. Then not only is the teenager subject to power corruption but so is the "rock star". This is the important thing to remember when dealing with the subject at hand. There are many reasons why teenagers cling to "rock stars", but there are always more popular reasons than others. One main reason that this occurs is because of the accessibility of what these "rock stars" are publishing. Think of all the things that teenagers have in front of them day-in, day-out; radio, television, clothes of peers etc. All of which are covered with popular musicians. So if they are so accessible then most people are aware of this so they start to pay attention to it, they see these extravagant people with no boundaries, limits or regulations. Most of modern "rock stars" have a catch something that stands out from the rest which leads to peoples attention. Also most "rock stars" these days have a relationship with the teens, the teens see themselves (or what they want to call themselves) in the "rock stars" presentation of their selves, but they take it to extremes so the teens say "hey they are like me but better" so it becomes an obsession to conform. These are some reasons why teens are obsessed by "rock stars". Out of all the different age groups on this planet why do teens seem to be the only ones who do this? Well teenagers have a great amount of time to read so much into things. Its the first age in most peoples lives where real independence is given, so they are desperate for something new to be controlled by. The one main reason why teens are the only age group subject to the manipulation of "rock stars" is because most of these "rock stars" are still in a teenage state of mind, so the real teenagers are already adapted to the Appearance Vs. Reality Of Modern Music Affect On Teenagers :: essays research papers Appearance vs. Reality of Modern Music Affect on Teenagers In today's society the teenager has had more rights than ever before, along with these rights comes responsibility, independence and good judgment. All of those mentioned have been destroyed in many teenagers lives by these "Rock Stars". The modern teenager is exposed to many different things that may affect their lives as they choose to live it, non quite as strong of a force than the effect of music, it is the teens outlet to expression, rebellion and popularity all of which are very important to the average teenager, but often in cases the teen who is trying to conform becomes subject to the "Rock Star's" manipulation, and that is when obsession kicks in. Then not only is the teenager subject to power corruption but so is the "rock star". This is the important thing to remember when dealing with the subject at hand. There are many reasons why teenagers cling to "rock stars", but there are always more popular reasons than others. One main reason that this occurs is because of the accessibility of what these "rock stars" are publishing. Think of all the things that teenagers have in front of them day-in, day-out; radio, television, clothes of peers etc. All of which are covered with popular musicians. So if they are so accessible then most people are aware of this so they start to pay attention to it, they see these extravagant people with no boundaries, limits or regulations. Most of modern "rock stars" have a catch something that stands out from the rest which leads to peoples attention. Also most "rock stars" these days have a relationship with the teens, the teens see themselves (or what they want to call themselves) in the "rock stars" presentation of their selves, but they take it to extremes so the teens say "hey they are like me but better" so it becomes an obsession to conform. These are some reasons why teens are obsessed by "rock stars". Out of all the different age groups on this planet why do teens seem to be the only ones who do this? Well teenagers have a great amount of time to read so much into things. Its the first age in most peoples lives where real independence is given, so they are desperate for something new to be controlled by. The one main reason why teens are the only age group subject to the manipulation of "rock stars" is because most of these "rock stars" are still in a teenage state of mind, so the real teenagers are already adapted to the

Final study guide

Final Exam Study Guide Know these people Carl Linnaeus- Swedish botanist who established a system for naming species that is still in use today; two-part name unique to each type of organism Jean Baptists Lamarckian-proposed that individuals change in response to challenges posed by the environment and the changed traits are then passed on to offspring Charles Darwin- said that species change over time but do not progress; individual variation is important and variation is what drives evolution Biodiversity How many species have been described? Approximately 1. 5 million (114 of all species) How many species remain to be described? What animals account for the greatest amount of species diversity? Insects How do we estimate biodiversity? Genetic diversity, species diversity, ecosystem diversity, change through time -variety and variability of life on earth, measured by species What are ecosystem services? Processes that increase the quality of the biotic environment -atmosphere and c limate, freshwater, nutrient cycling, pollination, pest population, disease What is an ecological footprint?How many additional planet earths would be required if all humans had the ecological footprint of an American? 4 planets Why is biodiversity important? Why study biodiversity? Economical and biological benefits Science What is a theory and how does it differ from a hypothesis? Well a hypothesis is a possible or tentative explanation for scientific findings that a scientist discovered during research. A theory is a tested by other scientists who get the same results as the previous scientists hypothesis Evolution and Natural Selection Why did Darwin delay the publication of The Origin of Species?Because of â€Å"special creation† was still very popular What is unfamiliarity's and how does it relate to the process of Natural Selection? Their ideas both relied on low changes over time rather than cataclysmic events that caused sudden upheaval or change What is a geometric progression;- -is a sequence of numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the common ratio -population growth what is an arithmetic progression? -increases by a constant difference (e. . , units of 1 or 2 or 3) -food supply -supply gradually increases with large population jumps How do these relate to populations and natural selection? – lack of resources causes competition Review the medium ground finch study (Gasping forties). What type of selection? Directional selection What influenced beak size? Since only big seeds became available, individuals with particularly large and deep beaks were more likely to crack these fruits efficiently enough to survive How did this relate to rainfall? He drought cause the sources of seeds as food to decline What are the conditions necessary for Natural Selection? – individuals vary -some variations are heritable -more offspring are produced than can survive - individuals with traits that confer an advantage are more likely to survive and reproduce What are the agents of evolutionary change – review notes on tuition, coneflower, nonrandom mating, genetic drift.Mutation-constantly introduces new alleles at all loci -increases genetic diversity in population -ultimate source of all genetic variability -random with respect to fitness Gene Flow- the movement of alleles from one population to another -random with respect to fitness -tends equalize allele frequencies among populations Nonrandom matting- nonrandom mating between relatives -causes inbreeding depression -helps selection weed out deleterious alleles Genetic Drift- any change in the allele frequencies in a population that is due o chance (luck, sampling error) ;causes allele frequencies to drift up and down randomly over time What is fitness? The ability of an individual to survive and reproduce, relative to other individuals in that population What is artificial selection? S elective breeding of domesticated plants and animals to produce offspring with desired genetic traits How does natural selection produce major change? Trial selection is the tendency of the ones best suited to survive in their environment to survive longer and pass on their genes more often – those genes then become more common and the harmful rations die out, gradually reshaping all life and fine-tuning it to it's environment. What is homology? The occurrence of similar features in different species because they both inherited the trait from a common ancestor What is the most common cause Of homophony? -convergent evolution -occurs when natural selection favors similar solutions to problems posed by a similar way of life What is a vestigial structure? Any rudimentary structure of unknown or minimal function that is homologous to functioning structures in other species -are thought to reflect evolutionary history How do imperfect structures relate to the theory of evolution b y Natural Selection?If evolution is true, then â€Å"imperfect design† is expected, because natural selection works to make an organism well-adapted, but not perfectly adapted, to their environment What is convergent evolution? Review the fish ichthyology example from class and the text. Process by which unrelated organisms independently evolve similarities when adapting to similar environments. Starting about 200 million years ago, these marine reptiles evolved body plans (and behavioral patterns) strikingly similar to those of odder dolphins and bluffing tuna (great example of convergent evolution) Be able to recognize disruptive, directional, stabilizing selection.Disruptive both extremes are favored, and the average phenotype is selected against – relatively rare -maintains genetic variation -plays a role in speciation-the generation of new species Directional- one extreme is favored, and the average phenotype (and the other extreme) is selected against -changes th e average value of a trait Stabilizing- reduces genetic variation -the average phenotype is favored, and both extremes are selected against – he average value of the trait does not change over time What is the difference between macroeconomics- Large-scale evolution occurring over geologic time that results in the formation of new taxonomic groups. ND microinstruction – evolution resulting from small specific genetic changes that can lead to a new subspecies Hardy-Weinberg You will not be asked to do any Hardy-Weinberg calculations What is the basic tenet of the Hardy-Weinberg Theorem? When alleles are transmitted via meiosis and random combination of gametes, their frequencies do not change over time -for evolution to occur, some other actor or factors must come into play -if the frequencies of alleles AH and AH in a population are given by p and q, then the frequencies of genotypes AH AH , AH AH, and AAA will be given by pa, ops, and sq for generation after generatio n What are the assumptions of the H-W Theorem? O natural selection -no genetic drift (no random allele frequency changes) -no gene flow via immigration or emigration -no mutation -random mating (with respect to the gene in question) pa -the predicted frequency of the offspring AH AH genotype* ops-the predicted frequency of the offspring AI genotype + sq -the predicted regency of the offspring AAA genotype= 1 : what are the allele frequencies, what are the genotype frequencies in a non-evolving population? Frequency of dominant allele the frequency of the recessive allele frequency of AAA (homozygous dominant) ops= frequency of AAA (heterozygous) sq= frequency of AAA (homozygous recessive) How do you recognize a population not in H-W equilibrium? If it does not equal one Why would a population not be in H-W equilibrium? B/c changes would occur and that would not be realistic Species and speciation Review the Biological Species Concept. Cost widely accepted concept -defines species as a population or group whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring Be able to differentiate between Predating/Precocity-individuals of different species are prevented from mating, Postdating/Precocity and Posthypnotic- when individuals from different populations do mate, but species will have low fitness or fitness or offspring will be sterile barriers. What are the predating-Factors which cause species to mate with their own kind (assertive mating) and postdating barriers-Genomic incompatibility, hybrid amiability or sterility What are posthypnotic barriers? What is a hybrid?Temporal isolation-populations are isolated because they breed at different times Habitat Isolation- populations are isolated because they breed in different habitats Behavioral Isolation- populations do not interbreed because their courtship displays differ Gametes Barrier- mating fail because eggs and sperm are incompatible Mechanical Isolatio n- mating fail because male and female reproductive structures are incompatible Hybrid Viability- hybrid offspring do not develop normally and die as embryos Hybrid Sterility- hybrid offspring mature but are sterile as adults Hybrid-the offspring of parents from two different strains, populations, or species In very general terms what does the Biological Species Concept state about the nature of species? What are some of the problems with the Biological Species Concept? Tot applicable to asexual or fossil species; difficult to assess if populations do not overlap geographically Be able to define the terms symmetric-occurs even though gene flow is possible; is rare or nonexistent – even though symmetric populations are not physically isolated, they may be isolated by preferences for different habitats and allophonic- begins with physical isolation via either dispersal or vicariate What is the phylogeny species concept? -based on reconstructing the evolutionary history of popul ations What is the morphological species concept? Identifies evolutionary independent lineages by differences in morphological features – based on the idea that distinguishing features are most likely to arise if populations are independent and isolated from gene flow The Fossil Record and Mass extinctions What are the different types of facsimiled materials?Thousandth Microfossils- first animals on Earth -include tiny sponges Dedicated faunas- -include sponges, jellyfish, and comb jellies as well as facsimiled burrows, tracks, and other traces from unidentified animals -small, have no shells, limbs, heads, mouths, or feeding appendages -sat immobile on the seafloor, or floated in the Water Burgess Shale Faunas- sponges, jellyfish, and comb jellies, arthropods, and mollusks -tremendous increase in the size and morphological complexity of animals occurred, accompanied by diversification in how they made a living Fossil Intermediate- we can see the bridge between where we start ed and here we are now with these intermediate fossils How are rocks in fossils preserved?What are fossil intermediates? What was the Cambrian Explosion? When did it occur? About 563 million years ago What is a mass extinction? How many are there in the paleontologist record? Result from extraordinary, sudden, and temporary changes in the environment , 5 records What is the sixth mass extinction? The ongoing extinction of Earth's creatures caused by humans What are some of the putative causes for the Permian mass extinction? When did it occur? What percentage of species went extinct? 0% 251 million years ago When was the KIT mass extinction? 65 million What is the evidence that points to an asteroid strike as the trigger of the KIP extinction?Sedimentary rocks that formed at the KIT boundary contain very high amounts of iridium (rare on Earth, common in meteorites) -In Haiti, shocked quartz and micrometeorites are abundant in rock layers from this time period -The huge crater off th e coast of Mexico Yucatan Peninsula Review the timing and general characterizations of the Paleozoic-saw the origin and initial diversification of the animals, land plants, and fungi, as well as the appearance of land animals, Pre-Cambrian-life was exclusively unicellular for most Of Earth's history -oxygen was virtually absent from the oceans and atmosphere for almost 2 billion years after the origin of life, Mesozoic- extinction of dinosaurs -in terrestrial environments of the Mesozoic, gymnosperms were the most important plants and dinosaurs were the most important vertebrates, Cenozoic-on land, angiosperms were the most important plants and mammals were the most important vertebrates and Cambrian Phylogeny How does the principle of parsimony apply to phylogeny reconstruction? Deer parsimony, the most likely explanation or pattern is the one that implies the least amount of change -a computer compares the branching patterns that are theoretically possible and counts the number of changes in DNA sequences required to produce each pattern Define the following terms: contemporary-a trait found in certain groups of organisms that exists in no others -homologous trait (inherited from a common ancestor), Primitive A structure which is NOT exclusively shared only by all members of a group by virtue of descent from a common ancestor -cannot be used to extinguish between members of a group because all actually or ancestrally possess the Structure -Example: Vertebrae are possessed by all birds but also by all other vertebrates.Possession of vertebrae cannot be used to distinguish the birds from other batteries since all batteries including birds share that trait, ancestral-A trait shared by all members of a group through a common ancestor. , derived-A structure which IS exclusively shared ONLY by all members of a group by virtue of descent from a common ancestor -Example: Among vertebrates, feathers are possessed by all birds ND by NO OTHER VERTEBRATE -Possession of feathers CAN be used to didst anguish the birds from other batteries since no batteries except birds share that trait.. Of the above which provide the only real evidence for relationship? Derived Trait How do you establish if a character is derived or ancestral (hint: outgrip and ingrown)- Assume that the character in the outgrip is ancestral.Fifth character is different in the ingrown, then it is considered derived -To determine whether a character is ancestral or derived compare the character in the ingrown with that of the outgrip Define: monopolistic-an evolutionary unit that includes an ancestral population and all of its descendants but no others (also called a clawed or lineage), paralytic-an evolutionary unit that includes an ancestral population and some but not all of its descendants -meaningful unit in evolution, polytechnic-composed of unrelated organisms descended from more than one ancestor. Be able to recognize the above terms within the context of a phylogeny tree. O f the above terms which one is preferred? – monopolistic group Which is most likely the reality of any group? Reparability group Prokaryote (study sections 28. And 28. 3) What feature has contributed significantly to bacterial diversity? Be able to differentiate been gram-positive- have cell walls composed of a thick layer of pedagogical -bacteria that look purple when treated with a gram strain and gram-negative-bacteria that look pink when treated with a gram stain bacteria have a cell wall composed of a thin layer of pedagogical and an outer phosphoric layer bacteria. Review bacterial metabolic diversity (heterodox-acquire carbon containing compounds from other organisms, lithograph-oxidize inorganic ions such as ammonia or methane to fuel cellular aspiration etc. What features distinguish Reach-no nuclear envelope -circular chromosome -all unicellular -flagella spin like bacterial flagella, but in a distinctive molecular composition have unique phosphoric in their plasma membranes, Bacteria-no nuclear envelope -have pedagogical in their cell walls -flagella spin like propeller -almost all unicellular and Eukaryote-nuclear envelope -flagella undulate back and forth? Are prokaryote monopolistic-yes, because there are two main lineages that diverged very early in the history of life Protests (study sections 29. 1 , 29. 2 and 29. ) What is the domain Eukaryote? What is the endometriosis origin of eukaryote – who proposed it and what is the evidence supporting it?Mitochondria are most closely related to what group of bacteria – to what group are chloroplasts most closely related? Do protests form a monopolistic group? What groups must be included? Land Plants (study sections 30. 1 and 30. 3) What group is most closely related to land plants? Green Algae What features were the main features that allowed plants to inhabit and subsequently diversify on land? Terrestrial habitats have more sunlight and more CA than aquatic habitats -Preventing water loss: cuticle and stomata -upright growth and vascular tissue Review the general features of land plant phylogeny. What were the major features to evolve over the course of land plant history?