Environmental Protection Agency Essay Example | Topics and Well Written Essays - 1000 words

Environmental Protection Agency - Essay Example With the wide scope and scale of EPA’s thrusts and issues spanning practically all facets of the environment, evaluation of specific policies to determine whether some identified programs promote business investment or discourages it need to focus on a specific focus. To achieve the aim of the essay, the cleanup activities promoted by the Superfund, would be used to evaluate policies that either promote or undermine business investment. Superfund Background The Superfund is specifically designed to address the cleanup activities needed for hazardous wastes. The scope of the policies and guiding procedures to govern operations and activities under the Superfund are likewise vast encompassing areas such as the cleanup process and the site activities. Under the cleanup process, there are 10 major classifications with 44 indicated enforcement policies and guidance for implementation and direction. The site activities include 10 areas such as contacts and agreements, enforcements, worker health and safety, institutional controls, among others, that each have respective regulations and policies for due evaluation and implementation. Assessment of Policies As revealed by Gale Encyclopedia of Espionage and Intelligence, â€Å"EPA provides outreach and educational activities for communities surrounding the toxic waste sites to raise awareness of risks, prevention and avoidance strategies, and to promote direct involvement in cleanup activities† (The Gale Group, Inc., 2004). The EPA, through the Office of Enforcement and Compliance Assurance (OECA), as one of the policy enforcement agencies, â€Å"aggressively goes after pollution problems that make a difference in communities through vigorous civil and criminal enforcement that targets the most serious water, air and chemical hazards. OECA also advances environmental justice by protecting vulnerable communities† (EPA: OECA 2011, par. 1). The agency’s success in policy design and in enforcemen t relies on the joint collaboration and participation of other agencies, particularly with the Office of Administration and Policy (OAP) that â€Å"recommends national policy on issues pertaining to enforcement and compliance. OAP provides a wide range of administrative support services which includes: human resources, labor relations, budget, finances, contracts, grants, records management and management of the compliance and enforcement information on the Agency’s Web site† (EPA: OECA 2011, par. 13). The govening office in charge of policy design works in coordination with other offices to ensure that their policies are appropriately implemented and other appointed agencies monitor compliance to these regulations. The other crucial agencies that participate in enforcement of policies include the Office of Civil Enforcement, Office of Criminal Enforcement, Forensics and Training (OCEFT), Office of Compliance (OC), Office of Environmental Justice (OEJ), Office of Feder al Activities (OFA), Federal Facilities Enforcement Office (FFEO), and Office of Site Remediation Enforcement (OSRE). With the clarity of explicitly stated policies, regulations and governing compendium, as well as the specific regulating offices tasked with enforcement and monitoring of compliance to

Six Degrees Could Change the World Essay Example | Topics and Well Written Essays - 500 words

Six Degrees Could Change the World - Essay Example One scene from the movie seemed harmless enough. It was merely a vineyard estate producing wine-quality grapes in England. It may seem harmless, but in reality, this is a compelling evidence of global warming effects already occurring around the world. Only a few years ago, it was truly impossible to cultivate wine-quality grapes in a weather environment such as ones in England. As favorable as this weather transformation is for English wine industry, such a transformation signals the end of the world for observers of universal weather modifications. Wine grapes budding in England is a clear indication that its regular daily temperature has augmented perhaps by a couple of degrees already. The documentary brings forward numerous actual examples and instances of early global warming. In addition, Bowman's direction is most solid in this part of the film. Baldwin's telling together with these illustrations of global warming in addition to the end of time situations of what might and wi ll happen if temperature continues to increase make Six Degrees Could Change the World among the best of 2008's ecological documentary films.With this, the film has definitely moved and changed the perspective and outlook of its viewers such as myself about the reality the world is facing right now. Without any remarkable change from our own selves, with the determination and will to actually save our planet, our home, the world will be destroyed. We must be the change that will stop the destruction of our only beautiful and amazing world.

Liquid Fluoride Thorium Reactor Essay Example for Free

Liquid Fluoride Thorium Reactor Essay Recently the spotlight has been set on renewable energies to assist with weaning off of greenhouse gas emissions, solving issues with energy independence, and to exploit their inherent renewability. Unfortunately our technology is not quite up to speed economically with our wish to rely completely on renewable energy, thus many non- renewable energies are recognized as viable options to power our economy (Fraser, 2011). The United States current position on diversifying with non-renewables onsists of oil, natural gas, coal, and the less spoken of, nuclear power. Nuclear power is the process by which a reactor contains a slow explosion called fission, which gives Offa positive net amount of energy that can be harvested. Of course the social stigma around nuclear is so strong that even if there were an undiscovered completely safe type of nuclear power plant, Justifying the complex science would be challenging. After events such as Fukushima, Chernobyl, and Three Mile Island, the vast majority of society believes nuclear energy is nothing more than a death wish. Contrary to popular belief, a safer alternative in nuclear energy has been discovered and has been gaining popularity over the past few years despite the recent tragedy in Japan (Sorensen, 2011). Though newly rekindled, the non-mainstream nuclear power known as Molten Salt Reactor (MSR) was discovered in the 1960s and had been proved to be a very attractive option to the more popular Light Water Reactor (LWR). It all began with nuclear physicist Alvin Weinberg, who would graduate from the University of Chicago soon become research director at the Oak Ridge National Laboratory (ORNL). Weinberg was given the freedom to experiment with designing multiple types of nuclear reactors including the prominent LWRs that are in commercial use today. Subsequently Weinberg had noted the potential danger of a LWR and moved on to designing a safer nuclear power technology that he would end up supporting for the rest of his life. His research team at ORNL created a fluid fuel in a MSR, opposed to the traditional solid fuel in LWRs, in order to decrease the pressure and overall danger of the system. To Weinbergs delight, although this rototype MSR had corrosive issues because of the salt involved, Weinberg deemed this technology far more superior to LWR. Furthermore, the worst part about current hatred for LWRs is that although it can be a dangerous process, the technology is revolutionary and its power has potential that we are seriously unaware of. For now with our current state of knowledge about nuclear power combined with our worlds predicament with how we generate power so ineffectively, MSRs must be and should have always been the governments number one priority (Sorensen, 2011). This pecific type of nuclear reactor is certainly on the minds of at least China, India, Brazil, Indonesia, South Korea, and Australia (Furukawa, 2008). Since these countries showed interest at least by 2008 it can be assumed that they are already in the process of construction. An example for our worst-case scenario would be for the United States to simply stand back and watch as the rest ot the world capi talizes on the best power generating technology known to man. A technology that of course the United States developed and had in operation fifty years ago, but the idea simply aded away. As the majority of the US would like to go green, it may not be too early to claim the MSR as green nuclear power. Nuclear reactors do not emit greenhouse gases taking care of one of the three major concerns with the future of energy. Though observing an entire life cycle of Thorium and materials to make the power plant, there are transportation emissions involved. It turns out however, that Thorium is extremely accessible in the US as it is already mined concurrently with other rare earth minerals but is typically discarded for lack of utility. The United States has omewhere in the order of 15% of the worlds total Thorium stockpile at around 15 million tons (Bonometti, 2008). Even if we were to run out of Thorium, the Moon has even greater amounts that by the time we begin to hit peak Thorium it will surely be so far in the future that extracting moon materials would not be a challenge. As an investor this further assures a safe bet, but what is so safe about the LFTR design is that a meltdown or explosion is so much more unlikely to occur than in LWR systems. Since the carrier of thorium is a liquid, liquid fluoride, it allows standard pressure at igh temperatures. Traditionally, in LWR, water had to cool down the solid fuel since it couldnt handle the high temperatures because of high pressure, which had always been a fine line behind meltdowns (Sorensen, 2011). In the LFTR, the system can naturally correct an over heated system by melting a frozen salt plug at the base of the system to enter into an emergency cooling tank. If LFTR technology has already been proved, proved to be safe, proved to be powerful, and proved to be available and cheap, then why doesnt the world run on it? The technology itself seems to be a it mysterious itself or maybe doubtful since it has already been ignored once before. What it comes down to is the timescale that nuclear reactors had been created. Back at Oak Ridge Laboratory where Weinberg had designed nuclear power he first designed the LWR, which happened to be more dangerous, but nevertheless reported his results. Quickly academics and politicians alike were astounded by the amount of power that could be generated through nuclear fission. Academics such as Weinberg understood the dangerous design of the LWR and proceeded to design afer alternatives, hence the MSR. Politicians on the other hand, had deadlines to meet, people to please, Jobs to create, and the LWR went commercial. There is even a specific phone call between President Nixon and a California LWR director expressing swift actions to commercialize the technology before elections (Sorensen, 2011). As Weinberg fought the Nixon administration to stop continuing with LWRs he was soon fired from the Oak Ridge Lab and so did the MSR department. Thus many scientists have since seen and admired his work and have finally had reason to express its arious benefits once the inevitable failures of LWR ensued, for example, Fukushima. In addition, it is important to note how resultant issues with LWR nuclear plants in the past have all been due to the intrinsic difficulty with handling a solid fuel at its required high pressure for fission to take place. In other words, none of those accidents would have happened if they would have simply listened to their founder, Weinberg, and chose to go with an MSR design. As the public is informed with this somewhat difficult science I imagine it will take about as long to understand the itterence in types ot nuclear reactors as it did tor the majority ot the population to understand the science behind the greenhouse effect. This is based on the fact that the same oil and coal industries will be threatened along with ill-educated environmentalists who will viciously support only renewable energy.

A Gllance At Information And Communication Technology Essay Example for Free

A Gllance At Information And Communication Technology Essay Information and communication technology (ICT) has become an important tool in all aspects of life. With the development of technology, the introduction of ICT as a tool has essentially brought tremendous revolution to the practices and procedures of nearly all forms of endeavor within business and governance during the past decades. Consequently, the importance of ICT project management cannot be overemphasized since it is the catalyst for successfully carrying out the ICT project. A critical research on the factors influencing the performance of ICT has been conducted as well as the introduction of different evaluation models or frameworks, which are used determine if an ICT project is successfully implemented. The last but not the least, a conclusion and a recommendation are given to prove that the potential values and benefits will be brought by elaborately analyzing those related factors before implementation and regularly evaluation on the ICT project. Table of content Introduction Recently, the role of Information and communication technology (ICT) has become more and more important in any forms of organizations and businesses. According to Daniels (2002) ICT has evolved to be one of the basic tool but pervasive among the public within such a short time. Besides, understanding the operational mechanism of ICT and mastering the fundamental skills and concepts of ICT are regarded as the basic knowledge that people now should equip with. However, it seems that many people have the wrong perceptions of what ICTs are; it’s commonly that ICTs generally be referred to ‘computers and computing related activities’ before the definition of ICT officially clarified by a United Nations report (1999). Also, according to UNESCO ICT could be understood in the way that which is the combination of ‘Informatics technology’ with other related technology, such as communication technology in particular. In other words, ICT is a more extended than information technology (IT), ICT not only emphasizes the technology itself, but also highlights the unified communications and the integration of telecommunications, computers; furthermore, by using these products such as the enterprise software, middleware, storage, and audio-visual systems, users will be able to access, store, transmit, and manipulate information. Now, we can find the radio broadcasts, audio conferencing, teleconferencing, email, interactive voice response system, audiocassettes and CD ROMs etc., are vari ous kinds of ICT products available, and those ICT products have been used for different purposes in our daily life, work environment, or common business practices. There are more and more people become aware of the benefits and efficiency brought by the ICT. With that in mind, people are starting paying more attentions on the ICT management issues, such as how to better manage ICT projects, what are those key factors determining the performance of ICT project, or how to adequately evaluate the performance of ICT project. Discussion Just as the other project management is, there are various success/failure factors related to the ICT project management. Here we discuss the roles of attitudes and the alignment between ICT and business, which are regarded as two of the most important key factors in ICT project management. A corresponding literature review is also preformed in order to better understand the background. The Roles of Attitudes Based on recent researches on the acceptance and use of ICT project, and related ICT design and development, ICT only brings values to the organization if it is accepted, applied and widely applied by those targeted users. From one of the research (Zhang, P. 2007), the author mentioned two different theories, which the inconformity between these two theories lays in the concepts behind and effects behavioral intention. The theories mentioned are Attitude toward ICT as an object (ATO) and Attitude toward using ICT as a behavior (ATB). By definition, ATO is â€Å"a psychological tendency that is expressed by evaluating a particular entity with some degree of favor or disfavor† (Eagly et al. 1998) or, as a combination of evaluative judgments about an object (Crites et al. 1994), while ATB is defined as â€Å"an individual’s positive or negative feelings (evaluative affect) about performing the target behavior.† (Fishbein et al. 1975) And the conceptual confusions whether attitudes play important role in the context of ICT project acceptance and use has been clarified, and there is an interesting evidence showing that the roles of attitudes can change as the users’ use of the ICT increases. The Alignment between business and ICT The literature related to the information and communication technology (ICT) demonstrated that alignment between ICT and business will influence the business performance and effectiveness of the organization in a positive way. (Cumps, B., Viaene, S., Dedene, G., Vandenbulcke, J 2006) Furthermore, the alignment of business and ICT of an organization is one of the fundamental sustainable factors, which can also be an advantage for an organization. In that case, the organizations should consider establishing specific ICT management routines in order to obtain better alignment performance scores. Since the role of ICT cannot be underestimated, more and more people want to know whether the ICT really brings values, whether the ICT substantially improved the efficiency, or whether the ICT works as expected. Based on the research, there are several more comprehensive ICT management capability maturity framework developed, such as the ICT management capability maturity framework and ICT Per formance Reference Model. The differences between these two frameworks or models are the focus and the content. ICT management capability maturity framework The framework is a ‘spider diagram’, which includes seven indicators: ICT Applications, Business-ICT relationship, ICT strategy alignment, ICT user profile, ICT managerial paradigm, ICT governance and ICT organization. Before applying the ICT management capability maturity framework, the users should firstly define the critical processes of their ICT management for each indicator. For each indicator, there are specific process-orientated evaluation standards, and the users should make judgments for each standard to see whether it fits to the organization’s characters, needs, and specific industry. For each applied standard, there are different dimensionalities to assess the maturity of capability. The key function of this framework is to be used as an evaluating tool and a improvement roadmaps that can point out directions for the senior management on ICT and business management in strategies planning in order to sustainably improve, develop, and manage the ICT capability in support of optimized business value delivery. From this capability maturity framework, we can clearly see the ICT management capability maturity of an organization as well as its improvement footprint. At the same time, with the use of such framework, the organization can be evaluated on its overall ICT management capability, the comparison analysis between different organizations can be conducted, and even the industrial benchmark can als o be made to see the ranking of the organization in the certain industry. ICT Performance Reference Model ICT Performance Reference Model is a model using the reference model principles in the area of ICT management. For better understanding of the meaning of reference model, here the definition of the reference model that â€Å"Reference model contains relevant structures and relationships among the model elements (process structures, levels, document structures) and also the predefined knowledge (best practice examples) already included in these structures.† is used. ICT Performance Reference Model combines the strengths of mathematical and data modeling techniques for its structure and knowledge management principles for its content; namely, it represents the best practices and knowledge in the formalized model structure, and therefore allows easier knowledge replication. The framework of ICT Performance Reference Model includes ICT Management Process, ICT Performance management Methodologies, ICT Performance Measurement Processes, ICT Performance Measures and ICT Performance m anagement Tools and Applications. The performance of ICT project is then be evaluated through these dimensions. With the implication of ICT Performance Reference Model, it would be easier to address ICT management related issues including application functionality overlap, technology and knowledge heterogeneity, and constantly changing business pressures. Conclusion From the discussion part, we can see that there are different success/failure factors relate to the Information and Communication Technology project management. Each factor cannot be left out from consideration whenever applying an ICT project, namely, the importance of each factor cannot be overestimated, or there would possibly result in an unpleasant outcome. On the other hand, it is also necessary to have the ICT project to be reviewed, or assessed the related management capability maturity periodically. With the regular evaluation, the organization will have better understanding about the current state of the implementation of ICT project, the acceptance level of related personnel, the operation results compared to expected results, and the continuing alignment with organization’s strategies. Recommendations As we all know that the management of ICT in the enterprise has been increasing in importance and nowadays it is one of the critical success factors of any type of business. In order to ensure sustainable growing of an organization, the use of ICT cannot be avoidable. After the careful research, I recommend the organization should look into every success/failure factors corresponding with the ICT project before implementation, which will largely reduce the risk of carrying out a project and ending in nothing. At the same time, with careful elaboration on each success/failure factors, the organization will have better understanding of its status quo, its strengths and weakness, which can be a great headstone for the design and implementation of the ICT project. In addition to the prior-art research, the ongoing assessment is also important for an ICT project management. In that case, the organization should choose adequate evaluation model or framework with some customized changes in order to fit into the needs of the organization. By doing the regular inspection, the organization can notice the wrong behavior in time and make certain modifications accordingly. Without such safeguard monitor mechanism, it may be too late when the organization realizes the mistakes happening. References Becker, J., Knackstedt, R., Pà ¶ppelbuß, D. W. I. J. (2009). Developing maturity models for IT management. Business Information Systems Engineering, 1(3), 213-222. Cumps, B., Viaene, S., Dedene, G., Vandenbulcke, J. (2006, January). An empirical study on business/ICT alignment in European organisations. InSystem Sciences, 2006. HICSS06. Proceedings of the 39th Annual Hawaii International Conference on (Vol. 8, pp. 195a-195a). IEEE. Donnellan, B., Sheridan, C., Curry, E. (2011). A capability maturity framework for sustainable information and communication technology. IT professional, 13(1), 33-40. Novotnà ½, O. (2009). ICT performance reference model in the context of corporate performance management systems. IDIMT-2009 System and Humans–A complex Relationship. Linz: Trauner Verlag Universitat, 13-16. Silvius, A. G. (2009, April). Business and IT Alignment: What We Know and What We Dont Know. In Information Management and Engineering, 2009. ICIME09. International Conference on (pp. 558-563). IEEE. Zhang, P., Aikman, S. (2007). Attitudes in ICT acceptance and use. In Human-Computer Interaction. Interaction Design and Usability (pp. 1021-1030). Springer Berlin Heidelberg.

Cable Modem Cloning Hacking Communication Computer Science Essay

Cable Modem Cloning Hacking Communication Computer Science Essay Cable modem is a communication device. This device allows us to connect our PC or laptop to cable Television line and receive data from operator at speed of 1.5 Mpbs or more. Data rate is much more then telephone modems (28.8 or 56 kbps) and 128 kbps given by ISDN (integrated services Digital Network). It is almost equal to Digital Subscriber Line (DSL) telephone service. Cable modem can is combined with set top box. With this combination channels could be watched on TV and internet could be accessed. In most cased cable modem are given by operator. They are not purchased by customers. Cable modem has two connectors. One connecter is connected to cable wall outlet. Other connected to personal computer or laptop. In some cased second connector is connected to set top box for TV channels. Cable modems do conversation between analog signals and digital signals. In other words it performs the task of modulations and demodulation. Although it do modulation and demodulation but it is a very complex device then telephone modem. Cable modem can be individual external device or it can be integrated with a personal computer of set top box. Cable modem is connected to a laptop or personal computer with a standard 10BASE-T Ethernet card. Cable modems are connected to cable operator with a coaxial cable line. Through this coaxial cable cable modem communicates to Cable Modem Termination System located at cable operator office. Cable modems can send or receive signals to Cable Modem Termination System. But cable modem cannot send or receive signal to other cable modems on line. Internet service bandwidth over cable TV line can be 27 Mpbs or more for downstream and 2.5 Mpbs or more on reverse direction. But main factor in speed is cables from operator office to customers homes and actual speed that operator has. If operator is only connected to internet at speed of 1.5 Mpbs in this case data rate at customer end would be near 1.5 Mpbs. Main cable TV providers are using cable modems to bring internet at customer home. Cable modems are used to provide internet service to individuals and business customers. Fast internet connection can be provided by cables modems as well cable modem is a continuous connection. How cable modems work News, entertainment and educational programs are brought by television in millions of homes. Many peoples watch TV through cable TV in short known as CATV. Cable TV operator provides many channels and in very good picture quality. If customer wants cable TV operator can also provide access to internet with high speed. Cable modems are able to give competition to asymmetrical digital subscriber lines (ADSL).it is very interesting to how these both competitors works. In next topic I will try to explain how many TV channels and web sites flow on single coaxial cable. 1.1.1 More Space Coaxial cable used by cable operators is able to carry hundreds of megahertz of signals and each channel that travels on coaxial cable is given 6 megahertz of total electrical space or bandwidth.it means coaxial cable can carry many more channels then we can or wants to watch. Cable TV operator sends signals of various channels each channel gets six MHz slice of coaxial cables available total bandwidth. There could be two types of distribution of cable network. In first one coaxial cable is installed from operators office till customer home. In second type fiber-optic cable is installed from operators office till different areas then from these different locations coaxial cable is installed till customer home. 1.1.2 Streams If a company provides facility of internet then internet service can also use same coaxial cable. This work is done by Cable Modem by putting downstream data (data that is sent from internet to customer) on a six MHz channel. So internet data is just like a TV channel on cable. Same amount of total cable bandwidth is taken by internet downstream data as by a single TV channel. Internet service is a combination of downstream and upstream (data that is sent to internet from customer) .it means upstream also need bandwidth of cable. It takes only 2 MHz slice of space from total available space because it is assumed that customers download more data as they upload. To put these two types of streams (downstream and upstream) cable operator needs only two devices. One device at customer end that is called Cable Modem and other one at operator end called Cable Modem termination system. Computer networking and internet access management takes place in between these two devices. 1.1.3 inside the cable modem As mentioned earlier Cable modem can be external or internal to computer. Some operators provide Cable Modems those are integrated with set top box. Cable Modems can be different from their outer look but all of them have same components inside. Components are given below 1. Demodulator 2. Media Access Control Device 3. Microprocessor 4. Modulator 5. Tuner 1.1.3.1 Tuner The tuner is connected to cable outlet. In some cases tuner is connected to a splitter. Splitter separates channels used for data from channels used for cable TV channels. Tuner collects data from internet channel. Data comes in form of digital modulated signal. Tuner receives this data and passes this data to demodulator. In some Cable Modems tuner contain one other component known as diplexer.it allows tuner to divide frequencies into two sets. First set is used for downstream traffic ad second one is used for upstream traffic. Range of frequencies used for upstream is between 5 to 42 MHz. Range used for downstream frequencies is between 42 to 850 MHz. In some other cases Cable Modem tuner is only used for downstream data and for upstream traffic dial up telephone modem is used. In any case tuner passes data to demodulator. 1.1.3.2 Demodulator Typically Demodulator performs four functions. First function is to convert radio frequency signal in to simple signal that can be processed by analog to digital converter. Radio frequency signal contains information in it by varying amplitude and phase of wave. Second function is performed by analog to digital converter. It takes signal from quadrature amplitude modulation demodulator in turns in series of 1s and 0s. These 1s and 0s are in digital form. Third function is performed by error correction module. It receives information from analog to digital converter and checks this information against a already known standard for possible errors. Main function of this module is to find problems in transmission and to fix them. At this stage data is in groups and these groups are called frames. Frames can be MPEG format. So MPEG synchronizer does its duty to make sure that frames are in order and in line as they were transmitted. 1.1.3.3 Modulator Modulator do reverse job as done by demodulator. It converts digital data into radio frequency signals. So that they can be transmitted on cable. Nature of traffic that flow between user and internet is irregular. Typically this component has they parts 1. Digital to analog converter 2. Quadrature amplitude modulator 3. Error correction information inserter 1.1.3.4 MAC Cable modem has two portions upstream and downstream.MAC is lactated between these two portions. It works as interface between hardware and software portions of different network protocols. Every network device has MAC. Cable modem MAC performs much more complex task then normal MACs. Because it performs much more complex tasks it work load is given to CPU of Cable Modem or to CPU of user personal computer or laptop. 1.1.3.5 Microprocessor Job of Microprocessor depends on for what cable modem is designed. Cable modem can be designed only to provide internet access or it can be designed to be a part of large computer system. If Cable modem is used only for internet access then Microprocessor of Cable mode does most of function of MAC. In case Cable modem is used to be part of large computer system Microprocessor of computer performs most function of MAC. 1.2 Cable Modem Termination System At CMTS end traffic comes from different users in groups. Function of CMTS is take all traffic on a single channel and route this all traffic to internet service provider for connection to internet. on CMTS end service provider could have set up different servers for performing following functions 1. Account and Log management 2. Dynamic Host Configuration Protocol 3. Administration of IP Addresses of users 4. Servers for Data over Cable Service Interface Specifications Downstream data reaches to connected users. It is same like in a Ethernet network. Individual connection has to think that it is for him or not. It is totally different in case of upstream data. Data send from one user to internet is not seen by other users on network. As we know there is not so much bandwidth for upstream. Total available bandwidth is divided into time slices. Time slices are in milliseconds. Time slices are given to different user to send data to internet. Time slices works very well for send short commands, queries and address those are send from users to internet. Typically CMTS allow 1,000 users to connect to internet on a single six MHz channel. Normally single channel have capacity of 30 to 40 megabits per second. So it clear that Cable modem is able to give speed to customers which is much more then dial up modems. Single channel concept could also lead to some issues those customers can face. 2. History of Cable Modems At stating of year 1990 world started to know about stuff that could be possible with digital communication. At that time internet was known just as a tool. Engineers were trying to discover a method to shuttle digital signals between two computers. Same stuff is available for us today in form of internet, email and much more. Technology was invented but not for sending receiving email or surfing web instead it was invented to transmit television channel signals. Channels like ORF, ATV, Plus 4. These channels were transmitted on high capacity wires. At user end a TV box was used to handle these channels and deliver to TV. It was starting of cable TV. To get more TV channels so much efforts are done in last many years. Physical network of coaxial cable and fiber optic cable are installed in many kilometers. These physical networks are installed either underground or some feets over ground using wooden or iron poles. And of course these networks have worked very well to full fill their purpose. Cable TV was born in U.S. but it has rapidly migrated to other continents. Now a day cable TV networks are pumping more than hundred TV channels to homes. One of leading cable operator in Vienna is delivering 132 TV programs including 23 HD programs.[upc.at] Later on inventors wanted to use cable TV network for other purposes. That was time when computer network started to stand on its feet. Means computer networks were started to build in organizations and in educational institutions. Some organization had proved that two or more computer connected to each other can do amazing things. Data or information that was only in individuals computer can be shared between others also can be enhanced by other users. Books were made free from library and published so that all can see. To make it possible that two computers can talk to each other so much was done by inventors. Communication protocols were developed. Languages to develop protocol were invented. Standards of communication were developed. Names were given to standards such as Novell and Ethernet. This all was rising of local area network. At this time engineers and investors started to think about increase boundaries of this information communication network. They wanted to share that was going on in computer of an organization at a wider geographical area. They were thinking to share information of a computer with another computer located at other end of same city. They wanted to transform a local area network in metropolitan area network. All these idea needed transmission medium installed within a city.so that information or data can be send or received on wide spread transmission medium. One solution was to transmit information on copper wires of telephone networks. But copper wires used in telephone network were not able to provide speed that was provided by LANs. Fast speed transmission was provided by advance version of telephone system called TI ,T3 or ISDN. But these solutions of high speed information transmission were very expensive. Luckily same types of cables used for local area networks named coaxial cables were already been installed in all over the city by cable operators to provide TV channels to customers. With some more engineering this cable can be used as very power full media for information transmission. A electronic device was demanded by many organizations and educational institutes. Private and government organizations, schools, hospitals, were looking for a way to send and receive text file, images, across town. Some of them rented expensive lease lines from telephone companies and some of them created their own pipes to transfer data or information across town. But peoples were not aware that there was a medium that was able to data with high speed as well it capable to transfer data on very high speed. This medium was not far away it was just outside in street. Cable TV operators had built a network across city. It was supposed that it was only for transmission of TV channels. But it was very much suited for information as well. It took many years to discover that cable TV network can be used for transfer data across city. LANcity discovered technology that became mile stone for so called Cable Modem. In other words It was just a box that was attached to cable television that was able to transfer coaxial cable a medium to transfer TV channels to medium to transfer data. As many people wished about its speed it was outstanding. It was a big coincidence that almost on same time an another force that attracted attention of peoples was introduced. Its name was internet. Typically cable modem technology was developed so that peoples can share files between offices those were located across city. Combination of internet and cable modem technology connected households with high speed. As it happens to all most all technologies same was with cable modems that it took many years to come in shape that is available for us today. Modems those were made in its early days were big metal boxes and were very heavy to pick up. In early years size of cable modem was almost same as rack of our cupboard. Main idea was they were not made for homes or residential use. They were made for schools, offices and for educational institutions. Not at all for homes. In those days internet was just a linking of government offices and educational institutions. Speed of internet was very slow over dialup phone lines. Computer monitors were also black and white. Operating system of systems was also DOS. It was not windows. There was no world wide web available. Internet was a toy for peoples who were interested in technology or of peoples who were interested to explore new technology. Internet has nothing for everyone. Those days were starting days of internet. 2.1 Development of Cables Nothing would be wrong to say that in those days personal computer were babies. But cable television networks were in their 30s. There was more than one cable operator in same area. Most of cable operators were offering more than 50 channels. Some of cable operators were providing service with basic TV channels on the other hand some were providing TV channels with basic channels as well premium TV channels. Architecture of cable network was totally different as it is today. In these days fiber optics is being used and it has increased speed of transmission lines. Noise that was introduced by amplifiers has reduced. Combination of fiber optics and coaxial cable are doing a under full job. But at starting some peoples believed this combination will never work. With time there are many changes have taken place in technology but still one technology is still same. Pictures of TV channels are taken from air as they are broadcast from satellites. At operator end TV channels are captured from air then they are passed through a so called mixer it place them on a single cable on different frequency bands. Now they are ready to travel on coaxial cable. But after traveling some miles they should be amplified. But here is a problem amplifiers also amplify or boost noise as well. This noise introduced by amplifiers make the picture worse. In 1980 cable networks were like branches of tree. It means from main office of cable operator thick cables were going to all four directions. After a particular distance in each direct less thick cable were used till different branches of cable operator. Thin cables were used till customer home from branch office. This was architecture of cable TV networks. It was perfect to transmit TV channels on it. There were many reasons that this network was not suitable for data communication. In a sense it was one way network. As we mentioned there where many reasons one of them was TV signals were sent only in one direct means from cable operator office to customer homes. To send signal in other direction means from customer to home cable TV operator was not possible. This network could work with data transmission if there would a method that customer or users can also send data to operator office and from operator office to destination of data it could in same city or in same country or could in other country for example world wide web. Till 1980 most of cable operator had not started to make path for customer to send data toward operator office. It was called upstream. Downstream was already possible as channels were sending from operator office to customer homes. Operator were not thinking about it one reason behind was there was not enough demand of it. So without any demand operators were not ready to invest their money in this technology to make path from customer home toward operator office. But it has not affected developers in any way. They continued their inventions in this technology that could make coaxial cable more useable. It was their main interest to make this cable TV network useable for information transmission. Information can travel in both directions not only in one direction. There was a requirement of an electronic device that could combination all stuff of data communication with cables used for TV channels. This electronic device should combine whole architecture of cable network with data c ommunications. So lot of efforts was required to transform cable TV network in to data network. Cable modems those were invented in 1980. Typically were not addressed a Cable Modems. They were so called radio frequency modems. They were not made for home users. They were used only by engineers. They were cable able to perform of modulation and demodulation. Information transmitted by them was 1s and 0s. It was not video means were not TV channels. Information was transmitted in coaxial cable within same boundaries of frequencies. Cable modems those were invented in their early days were used for different purposes. As cable networks owned by cable operators. Only some of cable operator agreed to negotiate within a city to link different buildings. These building can be educational institutions, police stations. These building can send or receive messages to each other by using existing cable network. At that time cable modems were only capable to deliver a speed of 19.2 kbps. But it was still faster than speed given by telephone modems that was around 1200 bps. Interesting thing is after 30 years we can enjoy speed of Mpbs. Cable Modems made in starting days were not so complex as modems those we have now a day. They were very less sophisticated as compared to todays modems. Let us suppose there are two computers in two different buildings attached to each other with cable modems over cable network coaxial cable. A message is sent from first computer. Computer handovers message to modem. Modem hand over this message to destination computer on downstream frequency without any processing. Basically it is broadcasted to all computers over network. Destination computer gets message through cable modem. As well all other computers on network get the message. But they cannot see messages because address of computer does not correlate with messages destination address. Transmission was based on a simple logic. One computer wants to send message to other computer so called Mr. ABC it will send message to all assuming that all are Mr. ABC but only Mr. ABC will receive message because other computers are not Mr. ABC. Till this time cable TV operators started to recognize capabilities of their wide spread coaxial cable network. They started to use cable modem for their own communications. Some of main branch offices were not near to telephone lines. Cable operators had covered remote areas as well mountains. But telephone lines were not available on these places. So cable operators thought they will use their own cables for communication on these remote areas rather than paying to telephone companies for installing telephones line in those remote areas. They have one choice to use cable modem on both end of their cable network. It was cable modem that allowed to cable engineers to set up internet PBX using cable network. Till now a day in some places those modems are used for telephone service. This was the time when data was available with phone and TV channels were already available. After some time developers of cable modem discovered a modem that was able to provide speed of 1.544 Mpbs speed over cable network. They took advantage of it started service of leased line known as T1 for businesses. T1 lines needed bandwidth on cable as equal to one TV channel. Luckily some of cable operator have free channel available. Those operators do not have vacant channels thought to replace some of channels so that give service of private data network to their customers. Research done on history of cable modem shows that it took 15 years and then cable modem became main stream. Main three problems were faced in long path of development of cable modems. First problem was transmission of traffic in both directions. It was possible with cable network to transmit information from operator office to customer homes but transmission of information from customers toward operator office was not possible. Till late 1990 cable operstor were capable to transmit information in both directions. Second problem was with business model. As already mentioned data transmission was made possible by cable modems but it was only use full for organizations or educational institutions like universities or schools. It was not available for home users. At that time it only looked as a business have only cost but no profit. Third problem was modem itself. In most cased it was built by different companies according to their requirement for single application. It was property of supplier. Modems from different suppliers were not able to communication with each other means no interoperable. In simple words it means cable companies were investing in such a technology that have no standard and it can be overcome anytime or other technology. Answer of these questions was given by DOCSIS. DOCSIS stands for Data Over Cable Service Interface Specification. It defined that cable modems are for cable industry. They are not for researchers or developers. DOCSIS helped for development of cable modems in direction of economy and volume. 2.1.1 DOCSIS Till mid of 1990, three problems those occurred for acceptance of cable modem were being solved. Upstream path from customer homes to operator office were being added to coaxial cable network. News from Cambridge and Castro valley encouraged cable operators to know more about cable modem technology.it also helped them to explore business model. Use of cable modem in telecommunications business was also favorable for cable modem development. Internet was rising day by day. Cable TV and telephone companies had tuff competitions. Companies were trying to get each other customers. Companies were able to provide TV channel service as well telephone service. At this time there was a new business for these companies it was internet service for customers at high speed. But still there was one barrier for companies. It was device interoperability. There was a lack of standard in modem industry. It was not possible to get interoperability without standards. Cable modem market could not be emerged without standards. Cable modem developers had a feeling of fear without standards to manufacture a big volume of cable modems. Because of production of less quantity price was high and it directly affected customers. It was well understandable and as well expected that electronic devices should work no matter of their location. In other words if we buy a modem from Vienna it should also work in Graz without any trouble. Because lack of interoperability if a modem purchased from Vienna and then customer moves to some other city where cable service is provided by another operator and this modem will not work there. I would like to give a sweet example here may be you have experienced of different power outlet in different countries. It is obvious no retailer would like to sell such products those give trouble to face angry customers. Interoperability was main issue at that time and it depended on technologies those developers had chosen those days. Some manufactures were selling asymmetrical modems. It means information moved faster from operator office toward customer home as it moved from customer home to operator office. Reason behind was a click to get a page from web needed less bandwidth as required by webpage itself. Some other manufactures had different ideas they were producing symmetrical cable modems as broadband user were increasing. Their idea was that home user would need more upstream speed to send information toward word wide web. Cable modem suppliers were growing with same speed as high speed internet grew. Every supplier was bit different from other. Some big names of electronic devices like Cisco Systems. HP, IBM, Motorola jumped in industry of cable modems. There were also small manufactures in cable modem industry. When big companies entered in market, small manufactures where afraid because big manufactures can produce modem like cookies. They could offer price very much attractive for customers. Still small suppliers tried to move on as quickly it was possible for them. This all was happening in non-standardized environment. In 1995 only one mantra was on everyones tongue and it was standards for their technology. When it did not worked as it was in mind of big manufactures like HP and IBM they step back from scene. In those days standards for cable industry were only concern. Because it was related to electronic devices those were used in homes. Cable operators has only fitted cables and modems in their offices and at customers end only from short listed providers of cable and modems. It made possible coexistence of both suppliers and cable service provider. Main suppliers have full control over selecting pricing and features of cable modems. It totally up to them to decide when older version would be discontinued and newer version would be introduced to market. At end of year 1995 some of cable modem engineers started to does private meetings about a chip call MIcroUnity. Same like other chips it was also reprogrammable. They decided to use this chip in cable modems as well in set top boxes and later on if required it can be updated with software. It was an alternative for if new services are introduced then cable operator should change box. It have double cost first cost was of box and second one was to send one to install new box. At that time there were two main players in cable technologies. Both of them thought enough about this MicroUnity chip that was reprogrammable then they decided to invest in this chip. They formed a private company that would lead for use of chip in cable hardware. This company was called Cable Multimedia Cable Network System in short MCNS. Motivation behind MCNS was to attract more hardware suppliers in cable industry. So that pricing can be bring down and to introduce more features. Only reason to do so was to bring interoperability among cable device producers. only solution of Interoperability between devices from different operators was to develop standards. Later on MCNS became DOCSIS Data Over Cable Service Interface Specification. It is pronounced as dock sis. In year 1996 Developers put it on fast track and they decided to complete specification written till end of year 1996. At mid of 1997 specification were being completed. Lab test can be performed on specifications. Intension of these tests was give sample to vendor and to test specifications. It was September month of year 1997 when a detailed certification program was released. Responsibility was given to a board to review certification. It was also responsibility of board to approve products if they meet specifications. An agreement was made that Cable Modem Termination Systems would be check to qualify specifications and vendors would be tested to give me certificate. As certificate they will get DOCSIS certificate sticker. 2.1.2 Certification Two years and to clear three certification test were necessary for any vendor to get DOCSIS certificate. On 20 march 1999 cisco system got qualification for their CMTS. First certificate for modem was issued to Toshiba and Thomson companies. After some months modems from 3Com and Arris passed certification. In coming some months many products get DOCSIS certificate. Now a day in many country cable companies lead DSL reson behind is speedy efforts done to make DOCSIS standard. Meanwhile stories of success of cable modem and high speed internet were coming continuously. Peoples who adopted cable modem in its early days were satisfied from their decision. Cable modem industry was afraid if they would be able to full fill high demand. Because of fast progress of cable modem technicians were also in high demand. Two persons were need first one to handle cable modem and second one for handling personal computer. At end of year 2002 in North America there were around 16 million customers. Cost of cable modem was also reduced from 1990 since 2001. In year 2001 cost of a cable modem was around $120 while in year 1990 it was $500. There is no dispute either on success stories of cable or on its high demand. Investment banker signed agreements with leading cable companies to build backbone network and content infrastructure to support high speed cable modem technology. Development of DOCSIS is still continuing. Now a day Circuit of cable modem is available on personal computer cards. In Europe cable modem circuit is available in set top box. With the time successor of DOCSIS were released. Quality of service has in improved in successors of DOCSIS. They are able to support coming generation of high speed internet service. DOCSIS has also played very important role in development of internet protocols. Latest version of DOCSIS is DOCSIS 3.0 that is able to provide download speed of 1.5 Gbit/s and upload speed of 1150 Mbit/s. Trial version of DOCSIS 3.0 was announced o

cloning :: essays research papers

Cloning humans and organs could only yield new technologies that will be beneficial to society. Organ cloning is something that would be extremely beneficial to society. For example, if we could clone human organs there would be no need for waiting lists for people looking for donors. Scientist could make a clone of a patient’s organ, that their body would be more likely to accept, without the imperfections of their previous organ. This way, another person who was on the waiting list could receive the organ. In America there are thousands of people on waiting lists to receive new organs that will help prolong their life. Many of these people will die because there is not a suitable donor that matches their needs. Imagine the lives that will be saved if an individual can clone their own liver, or any other organ that is needed to survive an illness. The process is fairly uncomplicated. When a child is conceived, doctors will take a few cells from it and clone them. These cells will then be placed in a national tissue bank until needed. There they are readily available. If the child gets hurt, or contracts a disease, it will have a â€Å"repair kit† to fall back on. Most of the controversy is over whether or not we will be killing another human in order to get these parts. In a sense, we would. The frozen embryo would be placed in a surrogate mother. There it needs only a mere week to grow. It can then be removed, and the needed organ singled out. Then, this organ can be grown in a lab, where scientists can speed up the process greatly. Yes, we did create the beginnings of a human, but it was only one week old. Whether or not people believe in the "art" of cloning you have to agree that there are definitely good things that can come from all of this research. Researchers say that within 5-10 years we will actually be able to grow headless human clones. I’m not saying that this should be ethical to everyone, but just imagine the possibilities. No more waiting lists, and nearly uliminating organ rejection should be and exiting prospect to everyone. This type of technology could save thousands of lives. Using just the embryonic cloning, we could drastically improve many people’s chance to live. . Cloning has the ability to change the face of the planet forever. cloning :: essays research papers Cloning humans and organs could only yield new technologies that will be beneficial to society. Organ cloning is something that would be extremely beneficial to society. For example, if we could clone human organs there would be no need for waiting lists for people looking for donors. Scientist could make a clone of a patient’s organ, that their body would be more likely to accept, without the imperfections of their previous organ. This way, another person who was on the waiting list could receive the organ. In America there are thousands of people on waiting lists to receive new organs that will help prolong their life. Many of these people will die because there is not a suitable donor that matches their needs. Imagine the lives that will be saved if an individual can clone their own liver, or any other organ that is needed to survive an illness. The process is fairly uncomplicated. When a child is conceived, doctors will take a few cells from it and clone them. These cells will then be placed in a national tissue bank until needed. There they are readily available. If the child gets hurt, or contracts a disease, it will have a â€Å"repair kit† to fall back on. Most of the controversy is over whether or not we will be killing another human in order to get these parts. In a sense, we would. The frozen embryo would be placed in a surrogate mother. There it needs only a mere week to grow. It can then be removed, and the needed organ singled out. Then, this organ can be grown in a lab, where scientists can speed up the process greatly. Yes, we did create the beginnings of a human, but it was only one week old. Whether or not people believe in the "art" of cloning you have to agree that there are definitely good things that can come from all of this research. Researchers say that within 5-10 years we will actually be able to grow headless human clones. I’m not saying that this should be ethical to everyone, but just imagine the possibilities. No more waiting lists, and nearly uliminating organ rejection should be and exiting prospect to everyone. This type of technology could save thousands of lives. Using just the embryonic cloning, we could drastically improve many people’s chance to live. . Cloning has the ability to change the face of the planet forever.

Teaching: A Priceless Profession Essay -- Teachers Education Essays

Teaching: A Priceless Profession What if there was a career that not only inspired people to be lawyers and brain surgeons, but was also responsible for motivating the average fast food employee to take just as much pride and initiative in their work? Although most people underestimate the profound role that educators play in today’s society, teachers have a tremendous responsibility. They have the opportunity to not only challenge their students intellectually, but they can teach them how to gear what they have learned toward positive goals and how to use their knowledge for good. As a potential educator, it is my hope I can provide a stronger educational background for my students, but more importantly, they will leave my classroom with a strong sense of who they are. I hope to teach them to have compassion and a regard for others. My goal is to help students understand that it does not matter what occupation they end up pursuing. All that matters is that they do their job to the best of their ability. Although a certain career may not pay as much as another, in many other ways, it can be just as rewarding. I want my students to understand that even though they may be labeled as unimportant by other people, they can still accomplish great things. I have found these principles to be very true after watching the life of my grandfather. He was not a doctor or a great business man, instead, he was a coal miner. In all of the movies, West Virginia’s coal miners are portrayed as leading uneducated and unhappy lifestyles. My grandpa proved that this certainly was not the case. He was one of the smartest men I have ever known and although his job may not have appeared to be of any great importance, he proved that he could acc... ... from experience and the teacher is only a guide or a supervisor of their learning. I prefer progressivism over any other philosophy because education should be geared more towards the needs and interests of the students. My overall teaching philosophy is to be a good role model for the students, to teach them that everybody is unique, and that they are all of equal importance. Teaching may not be the best paying profession, but I feel that if do my best, I can achieve great things. It does not matter how much the salary will be. What matters the most is that teaching can be an everyday adventure and it is extremely rewarding to know that you have made such an impact on someone else. As an educator, I hope to not only prepare students to move on to the next level, but to teach them values and principles that they will carry with them for the rest of their lives.