Thursday, October 31, 2019
The shift from specific social science subjects to current Essay
The shift from specific social science subjects to current multidisciplinary approaches - Essay Example The changes this is creating leads into a different set of definitions of what it means to receive a specific education while having the correct approaches to learning within the classroom. Exploring the understanding of movement from social studies and sciences into multidisciplinary approaches to learning within the classroom also conveys a deeper understanding of how education can work from a variety of perspectives and in terms of the necessary components of teaching, education and how learning can be enhanced by using a variety of approaches. However, a variety of perspectives and studies all relate to different factors which change the understanding and outcome of social sciences and learning with multidisciplinary approaches. The traditional approach to teaching the social sciences is based on offering historical facts and figures while moving through highlighted events within history. This particular approach in the curriculum is one which is now being recognized as ineffective. While the historical facts and figures are developed with student retention, there is often little to no association with the facts and figures to the current events. This is combined with the lack of understanding of how the particular historical events affect those who are a citizen of a particular country. The ideology of multidisciplinary learning challenges the concept of traditional learning to an expanded curriculum. The ideology is to create a personal relationship to the materials while expanding the awareness of students with the material that is being learned. Multidisciplinary ideologies consist of everything from adding in personal and social relationships to the material to combining the curriculum with other format s of teaching, such as other topics or literature. The initiative which is taken is based on a re-examination of the materials which are being taught and what this means to students when they are beginning to understand the philosophies of social studies and the importance which this holds (Clark, 2008). Citizenship Education The first approach which is now considered with multidisciplinary education and social studies is citizenship education. There are many which are showing that the concept of history is not only to learn about historical facts and figures. There is also a direct correlation between the approach with citizenship to a country and the way in which oneââ¬â¢s perspective alters toward the country. If there is not the ability to understand the historical factors within a country, then one cannot become a responsible citizen while having different opinions, social responsibilities and political actions which are taken. By changing the curriculum to incorporate socia l responsibility and citizenship, there is also the ability to begin altering the way in which social and cultural movements occur in terms of political terms and conditions. Changing the approaches to teaching so it correlates with meaning behind being a citizen is one which is then able to develop a different alternative in terms of educational development as well as the relationship which one holds to the historical ideologies which are taking place through current events. There are a variety of factors which show that social studies are not only linked to the main topic and sets of facts but also to other multidisciplinary approaches. The first is with the understanding of citizenship and what it means to be a part of a nation. The concept of being a citizen within a nation becomes an important term. It links directly to the understanding of the country, relationships to different historical facts and the responsibility which one takes in turn of being a citizen. However, this c annot be
Tuesday, October 29, 2019
Psychology 14 Essay Example | Topics and Well Written Essays - 250 words
Psychology 14 - Essay Example Kohlbergs moral stages are applicable in different spheres of life. In explaining the situation facing the Christians, the six stages in all the three levels are used. According to Kohlberg (1984), the first level, known as Preconventional or the premoral is concerned with an individualsââ¬â¢ level of responsiveness to both rules their evaluative labels. It views them in terms of either their pleasant or unpleasant consequences of action. Characteristics of the first stage include obedience and punishment orientation, which major concern is on the objectiveness of the responsibility. With reference to this stage, the Christians disobeyed the law and therefore liable for punishment. The second stage, which Kohlberg described as naively egoistic orientation defines the right action as a parsonââ¬â¢s means through which they can personally satisfy their needs as well as that of others. With personal satisfaction being essential in this stage, the actions taken by the Christians we re justified. The second level is defined by conventional or role conformity. In this level, it points out that the moral values guide a person in performing the right role in maintaining the conventional order as well as accomplishing the desire of other people but still maintaining his own right. In this level, the third stage defines the good boy or the good girl orientation, geared towards pleasing other people (Nisha, 2006). There was no need to intentions of the Christians in pleasing Nero and this meant that they were not wrong in their actions. Evaluation of the action taken by an individual is in terms of the personal orientations. The fourth stage, authority and social-order-maintaining orientation, means that the orientation of showing any form of respect to the people as a duty and maintain any form of social order did not justify the actions of these Christians in any way, and thus were supposed to be punished. The third level, the postconventional or
Sunday, October 27, 2019
Mcdonalds Corporation Is The Worlds Largest Chain Marketing Essay
Mcdonalds Corporation Is The Worlds Largest Chain Marketing Essay McDonalds Corporation is the worlds largest chain of fast food restaurants, serving nearly 47 million customers daily through more than 31,000 restaurants in 119 countries worldwide. McDonalds sells various fast food items and soft drinks including, burgers, chicken, salads, fries, and ice cream. Many McDonalds restaurants have included a playground for children and advertising geared toward children, and some have been redesigned in a more natural style, with a particular emphasis on comfort: introducing lounge areas and fireplaces, and eliminating hard plastic chairs and tables. Each McDonalds restaurant is operated by a franchisee, an affiliate, or the corporation itself. The corporations revenues come from the rent, royalties and fees paid by the franchisees, as well as sales in company-operated restaurants. McDonalds revenues grew 27% over the three years ending in 2007 to $22.8 billion, and 9% growth in operating income to $3.9 billion.à [1]à History analysis: The business began in 1940, with a restaurant opened by brothers Dick and Mac McDonald in San Bernardino, California. Their introduction of the Speedee Service System in 1948 established the principles of the modern fast-food restaurant. The original mascot of McDonalds was a man with a chefs hat on top of a hamburger shaped head whose name was Speedee. Speedee was eventually replaced with Ronald McDonald in 1963. The present corporation dates its founding to the opening of a franchised restaurant by Ray Kroc, in Des Plaines, Illinois on April 15, 1955 , the ninth McDonalds restaurant overall. Kroc later purchased the McDonald brothers equity in the company and led its worldwide expansion and the company became listed on the public stock markets in 1965. With the expansion of McDonalds into many international markets, the company has become a symbol of globalization and the spread of the American way of life. Its prominence has also made it a frequent topic of public debates about obesity, corporate ethics and consumer responsibility.à [2]à Vision To be the best and leading fast food provider around the globe Mission McDonalds brand mission is to be our customers favorite place and way to eat, and improve our operations to provide the most delicious fast food that meet our customers expectations. Values Our values summarized in Q.S.C. V.. Provide good quality, services to customer. Have a cleanliness environment when customer enjoys their meal. The value of food product makes every customer is smiling. Suppliers Substitutes Buyers Potential entrants Competitive rivalryThe Five Forces Framework The Threat of Entrants Large established companies with strong brand identities such as McDonalds BKC, YUM, and WEN do make it more difficult to enter and succeed within the marketplace; new entrants find that they are faced with price competition from existing chain restaurants. Bargaining Power of Buyers Low bargaining power of buyers. Bargaining power of suppliers Bargaining power of suppliers within the fast food industry would be relatively small, unless the main ingredient of the product is not readily available. Threat of Substitutes This could range from a competitive fast food restaurant to family restaurant to a home cooked meal. Competitive Rivalry The strength of competition in this industry is very high; the main rivals are BKC, YUM, and WEN. They compete with international, national, regional, local, retailers of food products (restaurants, quick service, pizza, coffee shops, and supermarkets). PESTEL Framework: Political: The international operations of McDonalds are highly influenced by the individual state policies enforced by each government. Economic: McDonalds has the tendency to experience hardship in instances where the economy of the respective states is hit by inflation and changes in the exchange rates. Market leader. Very high target market. Low cost and more incomes. The rate at which the economy of that particular state grows determines the purchasing power of the consumers in that country. Social: Working within many social groups. Increase employments. Technological Advanced technology development. Quality standards. Environmental: Quality packing. Local manufacture using foreign supplies. Legal: Legislation for product. Sustained logo. SWOT ANALYSIS Opportunities Threats Growing health trends among consumers Globalization, expansion in other countries (especially in China India). Diversification and acquisition of other quick-service restaurants. Growth of the fast-food industry. Worldwide deregulation. Low cost menu that will attract the customers. Freebies and discounts. Health professionals and consumer activists accuse McDonalds of contributing to the countrys health issue of high cholesterol, heart attacks, diabetes, and obesity. The relationship between corporate level McDonalds and its franchise dealers. McDonalds competitors threatened market share of the company both internationally and domestically. Anti-American sentiments. Global recession and fluctuating foreign currencies. Fast-food chain industry is expected to struggle to meet the expectations of the customers towards health and environmental issues. Strength Weakness Strong brand name, image and reputation. Large market share. Strong global presence. Specialized training for managers known as the Hamburger University. McDonalds Plan to win focuses on people, products, place, price and promotion. Strong financial performance and position. Unhealthy food image. High Staff Turnover including Top management Customer losses due to fierce competition. Legal actions related to health issues; use of trans fat beef oil. Uses HCFC-22 to make polystyrene that is contributing to ozone depletion. Ignoring breakfast from the menu. COMPARISION McDonalds Burger King Yum Brands Wendys Critical Success Factors Weight Rating Weighted Score Rating Weighted Score Rating Weighted Score Rating Weighted Score Price 0.15 4 0.60 3 0.45 3 0.45 3 0.45 Financial Position 0.08 4 0.32 3 0.32 3 0.24 2 0.16 Consumer Loyalty 0.10 4 0.40 3 0.40 3 0.30 2 0.20 Advertising 0.10 3 0.30 3 0.30 4 0.40 2 0.20 Product Quality 0.10 4 0.40 3 0.40 4 0.40 2 0.20 Innovation 0.15 3 0.45 3 0.45 3 0.45 2 0.30 Market Share 0.10 4 0.40 2 0.20 3 0.30 2 0.20 Management 0.07 4 0.28 3 0.21 3 0.21 3 0.21 Global Expansion 0.15 4 0.60 2 0.30 3 0.45 1 0.15 Total 1 3.75 3.03 3.20 2.07 External Factor Evaluation (EFE) Matrix Key External Factors Weight Rating Weighted Score Opportunities Growing health trends among consumers 0.08 3 0.24 Globalization, expansion in other countries (especially in China India). 0.12 4 0.48 Diversification and acquisition of other quick-service restaurants. .04 3 0.12 Growth of the fast-food industry. .10 3 0.30 Worldwide deregulation .04 2 0.08 Low cost menu that will attract the customers. .08 2 0.16 Freebies and discounts. .08 1 0.08 Threats Health professionals and consumer activists accuse McDonalds of contributing to the countrys health issue of high cholesterol, heart attacks, diabetes, and obesity. 0.10 3 0.30 The relationship between corporate level McDonalds and its franchise dealers. 0.09 3 0.27 McDonalds competitors threatened market share of the company both internationally and domestically. 0.12 4 0.48 Anti-American sentiments. .07 2 .14 Global recession and fluctuating foreign currencies. .04 3 .12 Fast-food chain industry is expected to struggle to meet the expectations of the customers towards health and environmental issues. .04 2 .08 Total 1.00 2.85 Financial Ratio Analysis 12/2007 Growth Rates % McDonalds Industry SP 500 Sales (Qtr vs year ago qtr) -3.30 4.20 -3.80 Net Income (YTD vs YTD) 84.70 47.90 8.40 Net Income (Qtr vs year ago qtr) -22.60 -59.90 -94.80 Sales (5-Year Annual Avg.) 6.53 8.14 13.26 Net Income (5-Year Annual Avg.) 23.39 15.30 14.45 Dividends (5-Year Annual Avg.) 32.36 22.36 12.30 Price Ratios Current P/E Ratio 14.7 14.2 13.0 P/E Ratio 5-Year High N/A 9.5 12.5 P/E Ratio 5-Year Low N/A 4.7 2.0 Price/Sales Ratio 2.62 1.88 1.47 Price/Book Value 4.62 3.54 3.00 Price/Cash Flow Ratio 11.20 10.00 9.00 Profit Margins % Gross Margin 36.7 32.1 39.4 Pre-Tax Margin 26.2 17.2 13.2 Net Profit Margin 18.3 12.0 9.1 5Yr Gross Margin (5-Year Avg.) 33.9 33.3 39.1 5Yr PreTax Margin (5-Year Avg.) 19.8 14.2 16.6 5Yr Net Profit Margin (5-Year Avg.) 13.7 9.8 11.45 Financial Condition Debt/Equity Ratio 0.76 .80 1.03 Current Ratio 1.4 1.2 1.4 Quick Ratio 1.3 1.1 1.1 Interest Coverage N/A 1.2 29.9 Leverage Ratio 2.1 -5.3 1.9 Book Value/Share 12.00 10.00 19.75 Investment Returns % Return On Equity 32.2 44.4 27.9 Return On Assets 14.9 11.3 8.1 Return On Capital 17.0 13.7 11.2 Return On Equity (5-Year Avg.) 19.7 22.8 20.6 Return On Assets (5-Year Avg.) 10.0 8.98 8.5 Return On Capital (5-Year Avg.) 11.4 11.0 11.5 Management Efficiency Income/Employee 10,783 9,401 91,499 Revenue/Employee 58,806 98,207 1,000,000 Receivable Turnover 23.7 44.7 15.8 Inventory Turnover 125.7 98.7 12.3 Asset Turnover 0.8 1.1 1.0 Internal Factor Evaluation (IFE) Matrix Key Internal Factors Weight Rating Weighted Score Strengths Strong brand name, image and reputation. 0.12 4 0.48 Large market share. 0.10 4 0.40 Strong global presence. 0.04 3 0.12 Specialized training for managers known as the Hamburger University. 0.04 3 0.12 McDonalds Plan to Win focuses on people, products, place, price and promotion 0.12 4 0.48 Strong financial performance and position. 0.08 4 0.32 Introduction of new products. 0.06 4 0.24 Customer focus (centric). 0.06 4 0.24 Strong performance in the global marketplace. 0.08 4 0.32 Weaknesses Unhealthy food image. 0.08 1 0.08 High Staff Turnover including Top management 0.04 1 0.10 Customer losses due to fierce competition. 0.04 1 0.04 Legal actions related to health issues; use of trans fat beef oil. 0.04 2 0.08 McDonalds uses HCFC-22 to make polystyrene that is contributing to ozone depletion. 0.04 2 0.08 Ignoring breakfast from the menu. 0.06 1 0.06 Total 1.00 3.16 SPACE Matrix Financial Strength Rating Environmental Stability Rating Return on investment 4 Rate of inflation -3 Leverage 4 Demand Changes -3 Net Income 6 Price Elasticity of demand -1 EPS 5 Competitive pressure -3 ROE 5 Barriers to entry new markets -3 Cash Flow 4 Risk involved in business -2 Average 4.67 Average -2.5 Y-axis 2.17 Competitive Advantage Rating Industry Strength Rating Market share -1.00 Growth potential 5 Product Quality -1.00 Financial stability 5 Customer Loyalty -1.00 Ease of entry new markets 4 Control over other parties -2.00 Resources utilization 4 Profit potential 5 Demand variability 3 Average -1.25 Average 4.33 X-axis 3.08 Directional vector point is ðŸ⢠3.08, 2.17) Conservative Aggressive Competitive Defensive FS IS CA ES Grand Strategy Matrix Quadrant II Quadrant I Quadrant IV Quadrant III Rapid Market Growth Strong Competitive Position Weak Competitive Position Slow Market Growth The Boston Consulting Group (BCG) Matrix Question Marks Cash Cows Dogs Relative Market Share Position Industry Sales Growth Rate Stars MCD The Internal-External (IE) Matrix The IFE Total Weighted Score Strong Average Weak 3.0 to 4.0 2.0 to 2.99 1.0 to 1.99 III II I High 3.0 to 3.99 VI V IV The EFE Total Weighted Score McDonaldsMedium 2.0 to 2.99 IX VIII VII Low 1.0 to 1.99 The Quantitative Strategic Planning Matrix (QSPM) Strategy 1 Expand further in Asia by adding 500 restaurants Strategy 2 Applying 0 grams Trans fat in all worldwide McDonalds restaurants Key Internal Factors Weight AS TAS AS TAS Strengthsà Strong brand name, image and reputation 0.12 4 0.48 4 0.48 Large market share 0.10 4 0.40 2 0.20 Strong global presence 0.04 4 0.12 2 0.08 Specialized training for managers known as the Hamburger University 0.04 McDonalds Plan to Win focuses on people, products, place, price and promotion 0.12 4 0.48 4 0.48 Strong financial performance and position 0.08 4 0.32 4 0.32 Introduction of new products 0.06 Customer focus (centric) 0.06 1 0.06 4 0.24 Strong performance in the global marketplace 0.08 3 0.24 1 0.08 Weaknesses Unhealthy food image 0.08 1 0.08 4 0.32 High Staff Turnover including Top management 0.10 Customer losses due to fierce competition 0.04 3 0.12 1 0.04 Legal actions related to health issues; use of trans fat beef oil 0.04 1 0.04 4 0.16 Uses HCFC-22 to make polystyrene that is contributing to ozone depletion 0.04 SUBTOTAL 1.00 2.34 2.40 Strategy 1 Expand further in Asia by adding 500 restaurants Strategy 2 Applying 0 grams Trans fat in all worldwide McDonalds restaurants Key External Factors Weight AS TAS AS TAS Opportunities Growing health trends among consumers 0.08 1 0.08 4 0.32 Globalization, expansion in other countries (especially in China India) 0.12 4 0.48 1 0.12 Diversification and acquisition of other quick-service restaurants 0.04 Growth of the fast-food industry 0.10 4 0.40 4 0.40 Worldwide deregulation 0.04 4 0.16 1 0.04 Low cost menu that will attract the customers 0.08 Freebies and discounts 0.08 Threats Health professionals and consumer activists accuse McDonalds of contributing to the countrys health issue of high cholesterol, heart attacks, diabetes, and obesity 0.10 1 0.10 4 0.40 The relationship between corporate level McDonalds and its franchise dealers 0.09 4 0.36 1 0.09 McDonalds competitors threatened market share of the company both internationally and domestically 0.12 4 0.48 4 0.48 Anti-American sentiments 0.07 Global recession and fluctuating foreign currencies 0.04 Fast-food chain industry is expected to struggle to meet the expectations of the customers towards health and environmental issues 0.04 1 0.04 4 0.16 SUBTOTAL 1.00 2.10 2.01 SUM TOTAL ATTRACTIVENESS SCORE 4.44 4.41 . Conclusion McDonalds faces some difficult challenges. Key to its future success will be maintaining its core strengths-an unwavering focus on quality and consistency-while carefully experimenting with new options. These innovative initiatives could include launching higher-end restaurants under new brands that wouldnt be saddled with McDonalds fast-food image. The company could also look into expanding more aggressively abroad where the prospects for significant growth are greater.à The companys environment efforts, while important, should not overshadow its marketing initiatives, which are what the company is all about. Recommendations Expand further into Asia markets over a 2-year period by adding 500 restaurants per year at a cost of $4 billion annually, and applying 0 grams Trans fat in all worldwide McDonalds restaurants.
Friday, October 25, 2019
Retrocasualty in Time Travel Essay -- Science
ââ¬Å"Can the future affect the present, and can the present affect the past?â⬠(1) This is the question posed by the philosophical concept of retrocasualty ââ¬â the product of time travel to the past. Time travel has been a common staple in science fiction writing, so many of its explanations owe their origins to tales of protagonists discovering its often confusing implications. Many people may already have a great understanding of a few hypothesized behaviors of time travel due to popular media, such as Back to the Future, Star Trek, and many other works of fiction. Currently, scientific knowledge is too premature to know if time travel is possible, no less how it behaves, so questions and answers are open for anybody to contemplate. The most famous question of time travel is the one posed by the temporal paradox, in which the time traveler invokes a condition which causes the circumstances that led up to time travel, or the time travelerââ¬â¢s presence, to become impo ssible. Many theories have attempted to answer this paradox, introducing behaviorally diverse concepts such as merging time lines, multiple dimensions, or a nature of time where everything is predestined. The act of time travel can produce radically different effects, depending on which solution to the temporal paradox is applied. The largest difference between expressed solutions to the temporal paradox is in what degree they assume deterministic behavior of the time line. The time line protection hypothesis(2) is a rigidly deterministic solution to the temporal paradox, one that hypothesizes that any action that can cause a paradox will ultimately fail, due to some unforeseen twist of fate. This paradox assumes that all time travel to the past is (or will) become part of t... ... then, it will remain an elusive tool for science fiction and philosophical contemplation. Works Cited ââ¬Å"Retrocasualty.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 2) ââ¬Å"Temporal Paradox ââ¬â Time Line Protection Hypothesis.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 3) ââ¬Å"Temporal Paradox ââ¬â Harmony Theory.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 4) ââ¬Å"Temporal Paradox ââ¬â Temporal Merging Hypothesis.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 5) ââ¬Å"Temporal Paradox ââ¬â Time Line Protection Hypothesis.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 Retrocasualty in Time Travel Essay -- Science ââ¬Å"Can the future affect the present, and can the present affect the past?â⬠(1) This is the question posed by the philosophical concept of retrocasualty ââ¬â the product of time travel to the past. Time travel has been a common staple in science fiction writing, so many of its explanations owe their origins to tales of protagonists discovering its often confusing implications. Many people may already have a great understanding of a few hypothesized behaviors of time travel due to popular media, such as Back to the Future, Star Trek, and many other works of fiction. Currently, scientific knowledge is too premature to know if time travel is possible, no less how it behaves, so questions and answers are open for anybody to contemplate. The most famous question of time travel is the one posed by the temporal paradox, in which the time traveler invokes a condition which causes the circumstances that led up to time travel, or the time travelerââ¬â¢s presence, to become impo ssible. Many theories have attempted to answer this paradox, introducing behaviorally diverse concepts such as merging time lines, multiple dimensions, or a nature of time where everything is predestined. The act of time travel can produce radically different effects, depending on which solution to the temporal paradox is applied. The largest difference between expressed solutions to the temporal paradox is in what degree they assume deterministic behavior of the time line. The time line protection hypothesis(2) is a rigidly deterministic solution to the temporal paradox, one that hypothesizes that any action that can cause a paradox will ultimately fail, due to some unforeseen twist of fate. This paradox assumes that all time travel to the past is (or will) become part of t... ... then, it will remain an elusive tool for science fiction and philosophical contemplation. Works Cited ââ¬Å"Retrocasualty.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 2) ââ¬Å"Temporal Paradox ââ¬â Time Line Protection Hypothesis.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 3) ââ¬Å"Temporal Paradox ââ¬â Harmony Theory.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 4) ââ¬Å"Temporal Paradox ââ¬â Temporal Merging Hypothesis.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010 5) ââ¬Å"Temporal Paradox ââ¬â Time Line Protection Hypothesis.â⬠Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 22 July 2004. Web. 05:51, 11 October 2010
Thursday, October 24, 2019
Internetworking End-to-End Requirements Essay
ââ¬â Hence such characteristics as: performance, reliability, scalability, mobility, and QoS of DS are impacted by the underlying network technology and the OS ? Principles of computer networking ââ¬â Every network has: ? An architecture or layers of protocols ? Packet switching for communication ? Route selection and data streaming ? Comm Subsystems (network technologies rest on): ââ¬â Transmission media: wires, cables, fiber, wireless (sat, IR, RF, mwave) ââ¬â Hardware devices: routers, switches, bridges, hubs, repeaters, network interfaces/card/transceivers. ââ¬â Software components: protocol stacks, comm handlers/drivers, OS primitives, network-focus APIs ? Hosts ââ¬â The computers and end-devices that use the comm subsystem ââ¬â Subnet: A single cluster or collection of nodes, which reach each other on the same physical medium and capable of routing outgoing and incoming messages ââ¬â The Internet is a collection of several subnets (or intranets) ? Networking issues for distributed systems ââ¬â Initial requirements for DS applications: ftp, rlogin, email, newsgroup ââ¬â Subsequent generation of DS applics. : on-line shared resources. ââ¬â Current requirements: performance, reliability, scalability, mobility, security, QoS, multicasting ? Performance ââ¬â Key: time to deliver unit(s) of messages between a pair of interconnected computers/devices ââ¬â point-to-point latency (delay) from sending out of outgoing-buffer and receiving into incoming-buffer. Usually due to software overheads, traffic load, and path selection ââ¬â Data transfer/bit rate: speed of data transfer between 2 computers (bps). Usually due to physical properties of the medium. ? Message trans time = latency + length/bit-rate ? Bandwidth vs. bit-rate. ââ¬â The total system bandwidth (volume of data sent and received in a unit time, e. g. , per sec. ) is a measure of its throughput ââ¬â Bit rate or transfer rate is restricted to the mediumââ¬â¢s ability to propagate individual bits/signals in a unit time ââ¬â In most LANs, e. g. , Ethernetââ¬â¢s, when full transmission capacity is devoted to messaging (with little or no latency), then bandwidth and bit-rate are same in measure ââ¬â Local memory vs network resources: ? Applications access to shared resources on same network usually under msec ? Applications access to local memory usually under msec (1000x faster)? However, for high speed network web-server, with caches, the access time is much faster (than local disk access due to hard disk latency) ? Scalability (Internet and DSs) ââ¬â Future growth of computing nodes of Internet (hosts, switches) in 109ââ¬â¢s (100ââ¬â¢s of 106 hosts alone) ââ¬â Requires substantial changes to routing and addressing schemes (more later! ) ââ¬â Current traffic (load) on Internet approx. measured by the latencies (see www. mids. org), which seem to have reduced (with advances in medium and protocol types). ââ¬â Future growth and sustainability depend on economies of use, charge rate, locality/placement of shared resource? Reliability ââ¬â Failures are typically, not due to the physical medium, but at the end-end (at host levels) software (application-level), therefore, error detection/correction is at the level ââ¬â Suggesting that the communication subsystem need not be error-free (made transparent/hidden to user) because reliability is somewhat guaranteed at the send/receiver ends (where errors may be caused by, e. g. , buffer overflow, clock drifts causing premature timeouts) ? Security ââ¬â Most intranets are protected from external (Internet-wide) DSs by firewall. ââ¬â A firewall protects all the resources of an organized from unlawful/malicious access by external users, and control/monitoring of use of resources outside the firewall ââ¬â A firewall (bundle of security software and network hardware) runs on a gateway ââ¬â the entry/exit point of the corporate intranet ââ¬â A firewall is usually configured based on corporate security policy, and filters incoming and outgoing messages. ââ¬â To go beyond firewalls, and grant access to world- or Internet-wide resources, end-to-end authentication, privacy, and security (Standards) are needed to allow DSs to function ââ¬â E. g., techniques are Cryptographic and Authentication ââ¬â usually implemented at a level above the communication subsystem ââ¬â Virtual Private Network (VPN) security concept allows intranet-level protection of such features/devices as local routers and secure links to mobile devices ? Mobility ââ¬â Need wireless to support portable computers and hand-held devices ââ¬â Wireless links are susceptible to, e. g. , eavesdropping, distortions in medium, out-of-sight/range transmitters/receivers ââ¬â Current addressing and routing schemes are based on ââ¬Ëwiredââ¬â¢ technologies, which have been adapted and, therefore, not perfect and need extensions? QoS (Quality of Service) ââ¬â Meeting deadlines and user requirements in transmitting/processing streams of real-time multimedia data ââ¬â E. g. , QoS requirements: guaranteed bandwidth, timely delivery or bounded latencies, or dynamic readjustments to requirements ? Multicasting ââ¬â Most transmissions are point-to-point, but several involve one-to-many (either one-to-all ââ¬â broadcast or selective broadcast ââ¬â multicast) ââ¬â Simply sending the same message from one node to several destinations is inefficient ââ¬â Multicasting technique allows single transmission to multiple destination (simultaneously) by using special addressing scheme 3. Multimedia Transmission and Internetworking Heterogeneous Systems ? Types of Networks ââ¬â LANs: (confined to smaller, typically, 2. 5km diameter spread) ? higher speed, single medium for interconnection (twisted pair, coax, opt), no routing within ââ¬Ësegmentsââ¬â¢ ââ¬â all point-to-point (from hub), inter-segment connections via switches/hubs, low latency, low error rate ? E. g. , Ethernet, token ring, slotted ring protocols, wired. (1) Ethernet: 1970 with bandwidth of 10Mbps, with extended versions of 100/1000Mbps, lacking latency and bandwidth QoS for DSs: (2) ATM ââ¬â using frame cells and optical fills the gap but expensive for LAN, newer high-speed Ethernets offer improvement and cost-effective ââ¬â MANs: (confined to extended, regional area, typically, up to 50km spread) ? Based on high-bandwidth copper and fiber optics for multimedia (audio/video/voice), ? E. g. , technologies: ATM, high-speed Ethernet (IEEE 802. 6 ââ¬â protocols for MANs), DSL (digital subscriber line) using ATM switches to switch digitized voice over twisted pair @ 0. 25-6Mbps within 1. 5km, cable modem uses coax @ 1. 5Mpbs using analog signaling on TV networks and longer distances than DSL ââ¬â WANs: (worldwide, lower speeds over sets of varying types of circuits with routers) ? High latency (due to switching and route searching) between 0. 1-0. 5s, signaling speed around 3x105km/s (bounds latency) plus propagation delay (round-trip) of about 0. 2s if using satellite/geostationary dishes; generally slower at 10-100kbps or best 1-2Mbps ââ¬â Wireless: (connecting portable, wearable devices using access points) ? Common protocol ââ¬â IEEE 802. 11 (a, b, and now g) (WaveLAN) @ 2-11Mbps (11gââ¬â¢s bandwidth near 54Mbps) over 150m creating a WLANs, some mobiles connected to fixed devices ââ¬â printers, servers, palmtops to create a WPANs (wireless personal area networks) using IR links or low-powered Bluetooth radio network tech @ 1-2Mbps over 10m. ? Most mobile cell phones use Bluetooth tech. e. g. , European GSM standard and US, mostly, analog-based AMP cellular radio network, atop by CDPD ââ¬â cellular digital packet data communication system, operating over wider areas at lower speed 9. 6-19. 2kbps.? Tiny screens of mobiles and wearables require a new WAP protocol ââ¬â Internetworks ? Building open, extendible system for DSs, supporting network heterogeneity, multi-protocol system involving LANs, MANs, WLANs, connected by routers and gateways with layers of software for data and protocol conversions ââ¬â creating a ââ¬Ëvirtual networkââ¬â¢ using underlying physical networks ? E. g. , the Internet using TCP/IP (over several other physical protocols) ââ¬â Comparisons ? Range of performance characteristics: ? Frequency and types of failures, when used for DS applics? Packet delivery/loss, duplicates (masked at TCP level to guarantee some reliability and transparency to DSs; but may use UDP ââ¬â faster but less reliable and DS applicââ¬â¢s responsibility to guarantee reliability) Diagram 3. 2 Network Principles â⬠¢ Packet Transmission â⬠¢ Packet transmission superseded telephone/telegraph switched network â⬠¢ Messages are packetized and packets are queued, buffered (in local storage), and transmitted when lines are available using asynchronous transmission protocol â⬠¢ Data Streaming â⬠¢ Multimedia data canââ¬â¢t be packetized due to unpredicted delays. AV data are streamed at higher frequency and bandwidth at continuous flow rate â⬠¢ Delivery of multimedia data to its destination is time-critical / low latency ââ¬â requiring end-to-end predefined route â⬠¢ E. g. networks: ATM, IPv6 (next generation ââ¬â will separate ââ¬Ësteamedââ¬â¢ IP packets at network layer; and use RSVP (resource reserv. protocol) resource/bandwidth prealloc and RTP play-time/time-reqs (real-time transp protocol) at layers 3 & 1, respectively) to work ? Switching Schemes ââ¬â 4 Kinds of switching methods typically used. ââ¬â Broadcast ââ¬â no switching logic, all nodes ââ¬Ëseeââ¬â¢ signals on circuits/cells (e.g. , Ethernet, wireless networks) ââ¬â Circuit Switching ââ¬â Interconnected segments of circuits via switches/exchange boxes, e. g. , POTS (Plain Old Telephone System) ââ¬â Packet Switching ââ¬â Developed as computing tech advanced with processors and storage spaces using store-and-forward algorithms and computers as switches. Packets are not sent instantaneously, routed on different links, reordered, may be lost, high latency (few msec ââ¬â msecs). Extension to switch audio/video data brought integration of ââ¬Ëdigitizedââ¬â¢ data for computer comm. , telephone services, TV, and radio broadcasting, teleconferencing. ââ¬â Frame Relay ââ¬â PS (not instantaneous, just an illusion! ), but FR, which integrates CS and PS techniques, streams smaller packets (53 byte-cells called frames) as bits at processing nodes. E. g. , ATM ââ¬â Protocols ââ¬â ââ¬â Protocols ââ¬â implemented as pairs of software modules in send/receive nodes, ââ¬â Specify the sequence of messages for transmission ââ¬â Specify the format of the data in the messages ââ¬â Protocols Layers ââ¬â layered architecture, following the OSI suite ââ¬â packets are communicated as peer-to-peer transmission but effected vertically across layers by encapsulation method over a physical medium Protocols Suites ââ¬â The 7-layered architecture of the ISO-OSI â⬠¢ Each layer provides service to the layer above it and extends the service provided by the layer below it â⬠¢ A complete set of protocol layers constitute a suite or stack â⬠¢ Layering simplifies and generalizes the software interface definitions, but costly overhead due to encapsulations and protocol conversions Diagram 3. 3 4. Service Provider Management On the Internet, a management service provider (MSP) is a company that manages information technology services for other companies. For example, a company could hire an MSP to configure and administer its business computers and related systems on a continuing basis, saving the company. An MSP is a service provider that offers system and network management tools and expertise. An MSP typically has its own data center that runs advanced network management software such as HP OpenView or Tivoli. It uses these tools to actively monitor and provide reports on aspects of its customerââ¬â¢s networks, including communication links, network bandwidth, servers, and so on. The MSP may host the customerââ¬â¢s Web servers and application servers at its own site. The services provided by MSPs have been called ââ¬Å"Web telemetryâ⬠services. The MSP Association defines MSPs as follows: Management Service Providers deliver information technology (IT) infrastructure management services to multiple customers over a network on a subscription basis. Like Application Service Providers (ASPs), Management Service Providers deliver services via networks that are billed to their clients on a recurring fee basis. Unlike ASPs, which deliver business applications to end users, MSPs deliver system management services to IT departments and other customers who manage their own technology assets. TriActive is an example of an MSP. It provides management and monitoring of PCs, servers, networks, and Web sites from its own NOC (network operations center), which is hosted by Exodus Communications. Exodus ensures that the NOC has fully redundant power, network connectivity, routing, and switching to ensure maximum reliability and integrity. A ââ¬Å"microagentâ⬠interacts with customer systems to provide system management. The agent is lightweight and designed for use over the Internet. It acts as a universal agent invoking and managing other agents and programs as required for specific actions. The service is delivered via the Web through a secure Internet portal that lets customers view management information, based on their role in the organization. For example, CIOs can view overall management information while help desk technicians can check call queues, escalations, and open ticket status. Systems analysts can conduct asset inventories and view virus reporting. Objective Systems Integrators is another management service provider that provides software solutions for unified network, service application, and process management. OSI was recently acquired by Agilent Technologies. A list of other MSPs may be found at the MSP Association Web site. Web application and infrastructure monitoring and management have suddenly become critical, yet the tools to do them are lacking. Management service providers (MSP), the latest addition to the current slew of service providers, claim to offer products and services that will oversee your Web operations. Companies staking claims as early MSPs include Candle Corp. in Santa Monica, Calif. ; InteQ Corp. in Burlington, Mass. ; and Nuclio Corp. in Skokie, Ill. What makes MSPs distinctive is that their products and services are provided over the Internet on a subscription basis. That means ââ¬Å"MSPs can achieve economies of scale that companies who license software cannot,â⬠says Christopher Booth, head of technical operations at FreightWise Inc. , a Forth Worth, Texas-based online transportation exchange. Though he declined to say how much his company is paying to use Nuclioââ¬â¢s MSP, Booth did say that the service has been ââ¬Å"very advantageous. â⬠The cost savings that MSPs can pass on may help them catch on with corporate customers. Gartner Group Inc. in Stamford, Conn., estimates that the $90 million MSP market will balloon to more than $3. 25 billion by 2005. 5. Programmable/Cognitive Networks A key strength of the Internet has been to reduce the intelligence within the network to that required placed at strategic places within the network such as at administrative boundaries, or at locations where there is a large mismatch between bandwidth, or where the certain location specific services can be used. Others believe that the entire architecture should be rethought as a computational environment, in which everything can be programmed, and the entire network becomes active. The research in this area is aimed at discovering how viable it is to open up such elements of the communications architecture as the routing table. A fundamental question raised by both the active service and the active network approaches is how to ensure that the shared resource of the network remains safe and is protected from misbehaving programs. Programs can abuse the network by generating packet explosions and can abuse the shared processor by using all the memory and the processor cycles. Worse, they may subvert the working of correct programs so that they too break. If network programmability is going to be available to the application designers, we need to ensure that they do not break things by accident, let alone by intention. Traditional systems approaches to protection are based upon what a program should be able to do, then using runtime checks to ensure that the program doesnââ¬â¢t exceed these bounds. This leads to the sandbox model of protection, as used in Java and enhanced to provide protection for Active Networks. However, there are major problems with this approach. First, each runtime check reduces the performance of the system, increasing the overhead of each use of system resources. Second, it is very difficult to ensure that the protection mechanisms are correct, and cannot be subverted in any way. An alternative approach is to use compile time checks upon what the program is doing. This uses the type system to represent predicates about program functionality and if a program is well-typed, then it proves the program to obey the policies implemented in the type system. This approach has been used to allow users to run programs within the kernel as in Spin, and in protecting access to router functionality in the Switchware project. â⬠¢ To provide a network programming language based on Internet `best effortââ¬â¢ communication. â⬠¢ To provide scaleable high-level communication based on `remote spawnââ¬â¢ from which other communication can be built. â⬠¢ To make use of types as safety properties, to ensure that the safety and security policies of the network are maintained. â⬠¢ To rapidly prototype tools such as compilers and simulators in order to drive the development of the language by examples. Best-effort distributed programming In the Internet, an application transmits a packet, which is sent to the next router on the way to the destination. At this router, the arrival of the packet causes code to run, which calls other code dependent upon the fields in the header of the packet. This code may access and modify local state stored in the router and then copy or create one or more packets to be sent out from the router. These packets are then routed on output links depending upon the destination for each packet, and so on until the packets reach their destination, or are destroyed within the network for whatever reason. In our programming model, we have attempted to replicate this basic structure of packet transmission. In the Internet, the arrival of a packet initiates some thread of control which uses the data within the packet to decide upon the disposition of the packet. In our model, a packet becomes a thread of control, carrying the code to be run and the names or values of any data referenced within that code. When a thread arrives at a Safetynet-aware router or end system, the thread code is instantiated within the runtime and runs within a de_ned scheduling class. The thread of control may call other code to be run on its behalf. The other code is encapsulated within classes, which are either present in the router, or are dynamically loaded from elsewhere. Threads can spawn other threads, either locally or on the next hop to some destination. 6. Design of an Internetwork We will discuss about the networking especially the internetworking. In this case we will need to discuss some topics related with the Internet Infrastructure, Internet routing, domain name and address resolution, internet protocol and the applications. Internet Infrastructure: The Internet backbone is made up of many large networks which interconnect with each other. These large networks are known as Network Service Providers or Naps. Some of the large Naps are UUNet, Cerf Net, IBM, BBN Planet, Sprint Net, PSINet, as well as others. These networks peer with each other to exchange packet traffic. Each NSP is required to connect to three Network Access Points or NAPs. At the NAPs, packet traffic may jump from one NSPââ¬â¢s backbone to another NSPââ¬â¢s backbone. NSPs also interconnect at Metropolitan Area Exchanges or MAEs. MAEs serve the same purpose as the NAPs but are privately owned. NAPs were the original Internet interconnects points. Both NAPs and MAEs are referred to as Internet Exchange Points or IXs. NSPs also sell bandwidth to smaller networks, such as ISPs and smaller bandwidth providers. Below is a picture showing this hierarchical infrastructure. Diagram 4 This is not a true representation of an actual piece of the Internet. Diagram 4 is only meant to demonstrate how the NSPs could interconnect with each other and smaller ISPs. None of the physical network components are shown in Diagram 4 as they are in Diagram 3. This is because a single NSPââ¬â¢s backbone infrastructure is a complex drawing by itself. Most NSPs publish maps of their network infrastructure on their web sites and can be found easily. To draw an actual map of the Internet would be nearly impossible due to its size, complexity, and ever-changing structure. The Internet Routing Working: It is general phenomenon that No computer knows where any of the other computers are, and packets do not get sent to every computer. The information used to get packets to their destinations is contained in routing tables kept by each router connected to the Internet. The Routers are called the packet switches. A router is usually connected between networks to route packets between them. Each router knows about its sub-networks and which IP addresses they use. The router usually doesnââ¬â¢t know what IP addresses are ââ¬Ëaboveââ¬â¢ it. Examine Diagram 5 below. The black boxes connecting the backbones are routers. The larger NSP backbones at the top are connected at a NAP. Under them are several sub-networks, and under them, more sub-networks. At the bottom are two local area networks with computers attached. Diagram 5 When a packet arrives at a router, the router examines the IP address put there by the IP protocol layer on the originating computer. The router checks its routing table. If the network containing the IP address is found, the packet is sent to that network. If the network containing the IP address is not found, then the router sends the packet on a default route, usually up the backbone hierarchy to the next router. Hopefully the next router will know where to send the packet. If it does not, again the packet is routed upwards until it reaches a NSP backbone. The routers connected to the NSP backbones hold the largest routing tables and here the packet will be routed to the correct backbone, where it will begin its journey ââ¬Ëdownwardââ¬â¢ through smaller and smaller networks until it finds its destination. Domain Names and Address Resolution. But what if you donââ¬â¢t know the IP address of the computer you want to connect to? What if the you need to access a web server referred to as www. anothercomputer. com? How does your web browser know where on the Internet this computer lives? The answer to all these questions is the Domain Name Service or DNS. The DNS is a distributed database which keeps track of computerââ¬â¢s names and their corresponding IP addresses on the Internet. Many computers connected to the Internet host part of the DNS database and the software that allows others to access it. These computers are known as DNS servers. No DNS server contains the entire database; they only contain a subset of it. If a DNS server does not contain the domain name requested by another computer, the DNS server re-directs the requesting computer to another DNS server. Diagram 6 The Domain Name Service is structured as a hierarchy similar to the IP routing hierarchy. The computer requesting a name resolution will be re-directed ââ¬Ëupââ¬â¢ the hierarchy until a DNS server is found that can resolve the domain name in the request. Figure 6 illustrates a portion of the hierarchy. At the top of the tree are the domain roots. Some of the older, more common domains are seen near the top. What is not shown are the multitude of DNS servers around the world which form the rest of the hierarchy? When an Internet connection is setup (e. g. for a LAN or Dial-Up Networking in Windows), one primary and one or more secondary DNS servers are usually specified as part of the installation. This way, any Internet applications that need domain name resolution will be able to function correctly. For example, when you enter a web address into your web browser, the browser first connects to your primary DNS server. After obtaining the IP address for the domain name you entered, the browser then connects to the target computer and requests the web page you wanted. The Disable DNS in Windows If youââ¬â¢re using Windows 95/NT and access the Internet, you may view your DNS server(s) and even disable them. If you use Dial-Up Networking: Open your Dial-Up Networking window (which can be found in Windows Explorer under your CD-ROM drive and above Network Neighborhood). Right click on your Internet connection and click Properties. Near the bottom of the connection properties window press the TCP/IP Settingsâ⬠¦ button. If you have a permanent connection to the Internet: Right click on Network Neighborhood and click Properties. Click TCP/IP Properties. Select the DNS Configuration tab at the top. You should now be looking at your DNS serversââ¬â¢ IP addresses. Here you may disable DNS or set your DNS servers to 0. 0. 0. 0. (Write down your DNS serversââ¬â¢ IP addresses first. You will probably have to restart Windows as well. ) Now enter an address into your web browser. The browser wonââ¬â¢t be able to resolve the domain name and you will probably get a nasty dialog box explaining that a DNS server couldnââ¬â¢t be found. However, if you enter the corresponding IP address instead of the domain name, the browser will be able to retrieve the desired web page. (Use ping to get the IP address prior to disabling DNS. ) Other Microsoft operating systems are similar. Internet protocols: As hinted to earlier in the section about protocol stacks, one may surmise that there are many protocols that are used on the Internet. This is true; there are many communication protocols required for the Internet to function. These include the TCP and IP protocols, routing protocols, medium access control protocols, application level protocols, etc. The following sections describe some of the more important and commonly used protocols on the Internet. Higher-level protocols are discussed first, followed by lower level protocols. Application Protocols: HTTP and the World Wide Web One of the most commonly used services on the Internet is the World Wide Web (WWW). The application protocol that makes the web work is Hypertext Transfer Protocol or HTTP. Do not confuse this with the Hypertext Markup Language (HTML). HTML is the language used to write web pages. HTTP is the protocol that web browsers and web servers use to communicate with each other over the Internet. It is an application level protocol because it sits on top of the TCP layer in the protocol stack and is used by specific applications to talk to one another. In this case the applications are web browsers and web servers. HTTP is a connectionless text based protocol. Clients (web browsers) send requests to web servers for web elements such as web pages and images. After the request is serviced by a server, the connection between client and server across the Internet is disconnected. A new connection must be made for each request. Most protocols are connection oriented. This means that the two computers communicating with each other keep the connection open over the Internet. HTTP does not however. Before an HTTP request can be made by a client, a new connection must be made to the server. When you type a URL into a web browser, this is what happens: If the URL contains a domain name, the browser first connects to a domain name server and retrieves the corresponding IP address for the web server. The web browser connects to the web server and sends an HTTP request (via the protocol stack) for the desired web page. The web server receives the request and checks for the desired page. If the page exists, the web server sends it. If the server cannot find the requested page, it will send an HTTP 404 error message. (404 mean ââ¬ËPage Not Foundââ¬â¢ as anyone who has surfed the web probably knows. ) The web browser receives the page back and the connection is closed. The browser then parses through the page and looks for other page elements it needs to complete the web page. These usually include images, applets, etc. For each element needed, the browser makes additional connections and HTTP requests to the server for each element. When the browser has finished loading all images, applets, etc.the page will be completely loaded in the browser window. Retrieving a Web Page Using HTTP: Telnet is a remote terminal service used on the Internet. Its use has declined lately, but it is a very useful tool to study the Internet. In Windows find the default telnet program. It may be located in the Windows directory named telnet. exe. When opened, pull down the Terminal menu and select Preferences. In the preferences window, check Local Echo. (This is so you can see your HTTP request when you type it. ) Now pull down the Connection menu and select Remote System. Enter www. google. com for the Host Name and 80 for the Port. (Web servers usually listen on port 80 by default. ) Press Connect. Now type GET / HTTP/1. 0 And press Enter twice. This is a simple HTTP request to a web server for its root page. You should see a web page flash by and then a dialog box should pop up to tell you the connection was lost. If youââ¬â¢d like to save the retrieved page, turn on logging in the Telnet program. You may then browse through the web page and see the HTML that was used to write it. Most Internet protocols are specified by Internet documents known as a Request for Comments or RFCs. RFCs may be found at several locations on the Internet. See the Resources section below for appropriate URLââ¬â¢s. HTTP version 1. 0 is specified by RFC 1945. Application Protocols: SMTP and Electronic Mail: Another commonly used Internet service is electronic mail. E-mail uses an application level protocol called Simple Mail Transfer Protocol or SMTP. SMTP is also a text-based protocol, but unlike HTTP, SMTP is connection oriented. SMTP is also more complicated than HTTP. There are many more commands and considerations in SMTP than there are in HTTP. When you open your mail client to read your e-mail, this is what typically happens: The mail client (Netscape Mail, Lotus Notes, Microsoft Outlook, etc.) opens a connection to its default mail server. The mail serverââ¬â¢s IP address or domain name is typically setup when the mail client is installed. The mail server will always transmit the first message to identify itself. The client will send an SMTP HELO command to which the server will respond with a 250 OK message. Depending on whether the client is checking mail, sending mail, etc. the appropriate SMTP commands will be sent to the server, which will respond accordingly. This request/response transaction will continue until the client sends an SMTP QUIT command. The server will then say goodbye and the connection will be closed. Transmission Control Protocol: Under the application layer in the protocol stack is the TCP layer. When applications open a connection to another computer on the Internet, the messages they send (using a specific application layer protocol) get passed down the stack to the TCP layer. TCP is responsible for routing application protocols to the correct application on the destination computer. To accomplish this, port numbers are used. Ports can be thought of as separate channels on each computer. For example, you can surf the web while reading e-mail. This is because these two applications (the web browser and the mail clien.
Wednesday, October 23, 2019
The Basis of Economics
Japan has performed a miracle. The country's economic performance following its crushing defeat in World War II is nothing short of astounding. The economic expansion of Japan is second to none. All of the elements are in place for Japan to continue increasing its share of the world's wealth as America's gradually declines. The country is on track to becoming the world's largest economy. How did Japan do it? There are many theories and studies that have traced the Japanese miracle without success. The answer to the mystery can by examining Japan's culture, education, and employment system. Japan's success is not just a case of good technique and technology in business, but a real recognition and development of the necessary human skills. A better understanding of the Japanese society provides the framework to understanding the workings of Japanese business (and possibly the Japanese mind. ) The ayes of the Japanese provide a foundation for their economic adaptability in modern times. Japan is a culture where human relations and preservation of harmony are the most important elements in society. It is their sense of identity and destiny, which gives their industrial, machines its effectiveness. Among the Japanese, there exists an instinctive respect for institutions and government, for the rules of etiquette and service, for social functions and their rituals of business. Japan is a traditionally crowded island; the people are forced to share the limited space with each other and to live in harmony. The Japanese are very protective of their culture. They are very conservative to outside intrusion. Their distinctive ways are a source of pride and national strength. Japan's striving for purity is very different form a North American idea of open doors and diversity as strength. Accordingly, one of the main sources of Japan's strength is its people's willingness to sacrifice, to be regimented and homogenized, and to subordinate personal desires to the harmony of the working group. The Japanese people have had to become a group-oriented society. While in the western world, individuality and independence are highly valued, Japanese society emphasizes group activity and organization. The people accept that they will belong to one social group and work for one company for life. The crowded island conditions have driven society to value conformity. The culture that Japanese people are brought up in causes them to recognize that they have to work together to succeed. Only harmony will provide improvement. This development of the human nature and attitude relates directly to Japan's business practice and provides a basis for good business relations. Japan's education system has grabbed the world's attention as it is specifically designed to teach the children skills and aptitudes to give them an edge in the business world. The educational system, based on the principle of full equality of educational opportunity, is widely recognized as having greatly contributed to the prosperity of Japan by providing a highly qualified work force supplemented by extensive in training programs by many of the major employers. The primary and secondary educational system is probably the most comprehensive and most disciplined in the world. Where North American students attend school 175 days a year, Japanese students attend 240 days. Japanese students attend elementary and secondary school six days a week and for two months longer each year than North American students. In addition, they have long hours of homework. A large majority of Japanese students attend Juki, or preparatory schools, in the evenings and on Sundays. In higher education, while lacking the strong University system which exists in North America, the curriculum is equally rigorous, and Japan is graduating 75 000 engineers per year, 3 000 more than the U. S. , from a University population one fifth the size. The education system itself is a unifying force. It molds children into group oriented beings by demanding uniformity and conformity form the earliest ages. The attainment of excellence within this complex environment, and the importance it holds for one's future is stressed early. This emphasis places a great burden on the young to perform well in school a to earn admittance to high status universities. The public school system not only produces good, obedient citizens, it produces good workers. A willingness to give oneself to the corporation's best interest, to arrive early and stay late, and to produce good work is attributes learned in the Japanese schools. Those who cannot learn these skills do not do well in school or do not rise in the ranks of the corporate world. The education system is an excellent example of how the Japanese recognize and develop the necessary human skills that are needed in society and stressed in the business world.
Tuesday, October 22, 2019
Audre Lorde, Black Lesbian Feminist Poet
Audre Lorde, Black Lesbian Feminist Poet Audre Lorde Facts Known for:à poetry, activism. While some of her poetry is known for being romantic or erotic, sheââ¬â¢s better known for her more political and angry poetry, especially around racial and sexual oppression. She identified through most of her career as a black lesbian feminist. Occupation:à writer, poet, educatorDates:à February 18, 1934 ââ¬â November 17, 1992Also known as: Audre Geraldine Lorde, Gamba Adisa (adopted name, meaning Warrior ââ¬â She Who Makes Her Meaning Known) Background, Family: Mother: Linda Gertrude Belmar LordeFather: Frederic Byron Husband: Edwin Ashley Rollins (married March 31, 1962, divorced 1970; attorney) Children: Elizabeth, Jonathan Partner: Frances Clayton ( - 1989)Partner: Gloria Joseph (1989 ââ¬â 1992) Education: Catholic schools, Hunter High School (New York City)Hunter College, B.A., 1960.à Library Science.National University of Mexico, 1954.Columbia University, M.L.S., 1962. Library Science. Religion: Quaker Organizations: Harlem Writers Guild, American Association of University Professors, Sisterhood in Support of Sisters in South Africa Audre Lorde Biography: Audre Lordeââ¬â¢s parents were from the West Indies: her father from Barbados and her mother from Grenada.à Lorde grew up in New York City, and began writing poetry in her teen years. The first publication to publish one of her poems was Seventeen magazine. She traveled and worked for several years after graduating from high school, then came back to New York and studied at Hunter College and Columbia University. She worked in Mount Vernon, New York, after graduating from Columbia University, moving on to become a librarian in New York City.à Then she began an educational career, first as a lecturer (City College, New York City; Herbert H. Lehman College, Bronx), then associate professor (John Jay College of Criminal Justice), then finally professor at Hunter College, 1987 ââ¬â 1992.à She served as visiting professor and lecturer around the United States and the world. She was aware early of her bisexuality, but by her own description confused about her sexual identity, given the times. Lorde married an attorney, Edwin Rollins, and had two children before they divorced in 1970. Her later partners were women. She published her first book of poems in 1968. Her second one, published in 1970, includes explicit references to love and an erotic relationship between two women.à Her later work became more political, dealing with racism, sexism, homophobia and poverty. She also wrote about violence in other countries, including Central America and South Africa. One of her more popular collections was Coal, published in 1976. She characterized her poems as expressing her ââ¬Å"duty to speak the truth as I see itâ⬠including ââ¬Å"not just the things that felt good, but the pain, the intense, often unmitigating pain.â⬠à She celebrated differences among people. When Lorde was diagnosed with breast cancer, she wrote about her feelings and experience in journals which were published as The Cancer Journals in 1980. Two years later she published a novel, Zami: A New Spelling of My Name, which she described as ââ¬Å"biomythographyâ⬠and which reflects her own life. She founded Kitchen Table: Women of Color Press in 1980s with Barbara Smith. She also founded an organization to support black women in South Africa during the time of apartheid. In 1984, Lorde was diagnosed with liver cancer. She chose to ignore the advice of American physicians, and instead sought experimental treatment in Europe. She also moved to St. Croix in the U.S. Virgin Islands, but continued to travel to New York and elsewhere to lecture, publish and engage in activism. After Hurricane Hugo left St. Croix with devastating damage, she used her fame in mainland cities to raise funds for relief. Audre Lorde won many awards for her writing, and was named New York State Poet Laureate in 1992. Audre Lorde died of liver cancer in 1992 in St. Croix. Books by Audre Lorde The First Cities.à Introduction by Diane di Prima. Poets Press. 1968.Cables to Rage.à Broadside Press. 1970.From a Land Where Other People Live.à Broadside Press. 1973.The New York Head Shop and Museum.à Broadside Press. 1974.Coal.à Norton. 1976.Between Our Selves.à Eidolon. 1976.The Black Unicorn.à Norton. 1978.The Cancer Journals. Spinsters Ink. 1980.Zami: A New Spelling of My Name. Crossing Press. 1982.Chosen Poems Old and New.à Norton. 1982.Sister Outsider. Crossing Press. 1984.Our Dead behind Us.à Norton. 1986.A Burst of Light.à Firebrand Books. 1988.Need: A Chorale for Black Women Voices.à Women of Color Press. 1990.Undersong: Chosen Poems Old and New.à Norton. 1992.The Marvelous Arithmetics of Distance.à Norton. 1993.The Collected Poems ofà Audre Lorde.à Norton. 1997.
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