Asynchronous Transfer Mode Description and Development Essay

Asynchronous Transfer Mode Description and Development - Essay Example ATM was originally conceived as a solution for completely integrating the entire set of communication technologies, starting from the Local Area Network to the IP based systems and the broad band voice and data communication systems. ATM was proposed as the final and ultimate protocol to take care of all the requirements of all communication systems in the world. However, it was found that ATM could satisfy only some of these like ADSL could make full use of it. ATM was not used in its original form on the other devices. The best features and proposals of ATM were incorporated in a number of other standards that came about, typically, MPLS kind of systems. However, ATM has taken a rebirth in terms of the standards that are currently being developed IEC 62365 which provides for both audio and video over IP using ATM technologies. The aim of this paper is to present the asynchronous transfer mode as a standard protocol, its description and development over a period of time. The paper will also look at the places were this is being employed and to what extent these were successful in implementing the systems that are needed for the users. Asynchronous Transfer mode systems integrate Voice, Video and Data. Since it is connected oriented technology, one packet with the same source and destination will travel through the same route. This employs best effort delivery system which would enable performance and bandwidth on demand. Figure 1: Aimed at providing best service (IEC, 2005) ATM as per the standards defined would employ connection oriented, packet-like switching and multiplexing model. It starts by defining the fixed sized cell that comprises of 48 bytes of data and 5 bytes of header together making up the 53 bytes of cell information. ATM is fundamentally connection oriented. Therefore, it does multiplexing and reserves a route for a specific user on getting a request from the user. Multiplexing such lines over a network either from a user to a destination or from one switch to another would optimize the usage of the network to a great extent. This would save the cost of switching when requests are made one after the other and switch keeps changing the route. ATM also specifies a number of standards on how an user would get connected to an ATM network depending upon the speed of the network. ATM to User interface standards are governed by the ATM UNI standards. ATM has the following three layers: 1. The physical layer 2. ATM Layer 3. ATM adaptation layer The physical layer consists of various media that make up the transmission system, which would eventually transmit from kilobits per second to gigabits per second. The ATM layer defines the cells that make up the data transfer along with the other components; multiplexer that would switch the cell to the specific route that it should take, switches that would transmit data over a high speed switching hardware so that the transmission speed is achieved and finally have necessary software or hardware to take care of the issues that concern the traffic and do traffic management. In the ATM adaptation layer, four different types of data transfer is provided for the ATM system. AAL Type 1 Constant bit rate services AAL Type 2 Variable bit rate services AAL Type 3 / 4 Connectionless services and data protocols AAL Type 5 High Speed

World Cup Impact on South Africas Tourism Sector Essay

World Cup Impact on South Africas Tourism Sector - Essay Example The FIFA 2010 world cup contributed to a massive increase in the number of international tourists arrivals. In this regard Francheska (2011) stated that most of South Africa’s tourists are drawn from other African countries and Europe, which offers the country the highest number of tourists arrivals annually. Among the major tourists, attractions in South Africa include the country’s national parks, world heritage sites, and cultural and historic sites. Additionally, the country has a vibrant wine sector that has also been able to attract high number of tourists and even the Robben Island where the country’s iconic figure, Mr. Nelson Mandela was imprisoned for twenty-five years has been a key attraction sites mostly for scholars in the field of history, this is according to Mattner et al. (2012). Equally, it is of essence to that the tourism sector in the country has substantially contributed to the country’s growth in terms of job creation, infrastructure development, and source of foreign exchange. The weather pattern affects South Africa’s tourism sector in equal measures as it does in other countries. This is to say that during harsh climatic conditions such as winter the tourism sector usually experience low activities or low tourists arrivals while during favorable climatic conditions such as summer it experience a boom in the sector. Altbeker (2009) stated that the key factor that negatively affects the South Africa’s tourism sector is the crime level in the country, which makes many international tourists shy away from visiting the country for fear of their own safety. Â  

Final writing exercise Essay Example for Free

Final writing exercise Essay There are three phases whereby each has a different crystal structure at three different temperatures. At room temperature (298K), Phase III is present whereby Cs3H(SeO4)2 has a crystal structure of a monoclinic with a space group of C2/m. At 400K, Phase II is present whereby Cs3H(SeO4)2 has a crystal structure of a monoclinic-A2/a symmetry. At 470K, Phase I is present whereby Cs3H(SeO4)2 has a crystal structure of a trigonal with a space group of R3-m. In Phase III, as we can see in Figure 2(a), the positioning of the tetrahedrons is parallel to the a-axis, and in between these SeO4 tetrahedrons are the hydrogen bonds. Looking at a 2dimensional perspective, we can also see that there is a translation movement of the SeO4 tetrahedrons along the a-axis; hence the symmetry operator would be a glide line parallel to a-axis. In a 3-dimensional perspective, we can see that Phase III has a 2-fold rotation axis and contains glide planes. In Phase II, from Figure 2(b), we can see that the positioning of the SeO4 tetrahedrons are along the approximate direction [310]. Observing the schematic of the crystal structure in Phase II, we can see that there is a vertical mirror line in between the SeO4 tetrahedrons. There is also an a-glide reflection vertically. In Phase I, from Figure 2(c), the positioning of SeO4 tetrahedron is similar to that of Phase II, however the difference is the crystal structure and the hydrogen bonding. Comparing both Phase II and Phase III crystal structures of the compound, Phase II contains two-fold screw axis, inversion center and a two-fold rotation axis, which is the sole reason for Phase II to be twice of that of Phase III in terms of geometrical  arrangement of hydrogen bonds. From the above analysis of the symmetry of the crystals structures in different phases, we can tell that Phase III has the most symmetry operators and hence achieving the highest crystal symmetry generating a low geometrical arrangement of hydrogen bonds. Due to the low geometrical arrangement of hydrogen bonds, the mobility of protons decreases giving the result of ferroelasticiy. The drastic change from superprotonic conductivity to ferroelasticty happens when there is a change from Phase II to Phase III. The major difference between theses 2 phases is the hydrogen bond arrangement. Paragraph 2 Under the optical microscope, we can observe that the polymorphic domains will alter at each phase transition to a different extent. We can see in phase III that the domains in the Cs3H(SeO4)2 crystal are made up of polydomains separated by two kinds of domain boundaries. The two kinds of domain boundaries are categorized as the planes of {311} and {11n}, where n is determined by the strain compatibility condition. The domains at the sides of each domain boundary are related to the reflective symmetry or the rotational symmetry on that boundary itself. Furthermore, we can observe that the angle between any domain and its neighboring domains is approximately 120 °, which is very close to the theoretical values calculated using the lattice parameters. As we move on from phase III to phase II, we can observe that the domain structure alters slightly by the phase transition of TII–III. Similarly, the reflective symmetry and rotational symmetry also changes at the same phase transition. However, the kinds of domain and domain boundary remain the same as those in phase III despite a change in domain pattern. This could be due to the slight change in alignment of hydrogen bonding between the SeO4 tetrahedrons when the existing hydrogen bonds were broken to form new weaker  ones. This might explains why their lattice parameters a and b do not really change appreciably. Compared to phase III previously, the angle between any domain and its neighboring domains in phase II is also approximately 120 ° and is justified by the theoretical values determined from the same equation we used for phase III. Hence, this suggest a slight change in the Cs3H(SeO4)2 crystal structure at the phase transition of TII–III. From phase II to phase I, the domain boundaries is observed to have disappear just before the curie temperature of the phase transition of TI–II and the crystal structure changes from  optically biaxial to optically uniaxial. This could be due to an external stress caused by the atomic rearrangement of the SeO4 tetrahedrons in the Cs3H(SeO4)2 crystal as a result of breaking the hydrogen bonds between them. Paragraph 3 Higher temperatures for most material will enable atoms to move to low energy sites, fitting into a perfect crystal symmetry. Cs3H(SeO4)2 however behaves differently. As the temperature increases (above 396K), its crystal symmetry decreases when it changes phase from III to II. The orientation of the hydrogen bond for phase II and III differs. For phase II, the orientation is along [310] and [3-10] direction whereas for phase III, it is parallel to the aaxis. As the transition from phase III to II occurs, the precursor of the superprotonic conductivity is observed. In order for movement of proton to occur, the breaking and then recombination of hydrogen bonds are required. For phase III, in order for the movement of one proton, the breaking of 2 hydrogen bonds is needed. The reason as to why 2 hydrogen bond is needed to be broken and recombined again is because for the movement of one proton to occur, it must break the hydrogen bond it resides in and then change its orientation, recombining at another site; the mirroring effect of opposite hydrogen bond is required to maintain the crystal symmetry i.e. to say that the another hydrogen bond parallel to the previous hydrogen bond site needs to be broken and recombined at other site parallel to the newly  recombined hydrogen bond. In this way, in phase III, the recombination of two hydrogen bonds is simultaneously needed for one proton transport. Phase II however, behaves differently. The movement of the proton is independent of the other protons at other hydrogen site. The crystal structure allows for this flexibility of the proton motion, which the superprotonic conduction takes place. The mechanism in which proton transportation occurs in the polymorphs is by the diffusion of protons through a hydrogen bond network, by the cleaving and formation of the hydrogen bonds. However, in certain phases, the cleavage and formation of the hydrogen bond might differ. The fuel cell works on the basis of the movement of protons. The movement of electrons should be disallowed as it would short circuit the fuel cell. Hence, a membrane is used to allow only the movement of protons across and not electrons and gases. On top of that, in order for a superprotonic effect to occur, the flexibility for proton motion must be allo wed. Hence, the lesser symmetrically patterned the phases the protons reside in, the higher this flexibility.

Looking At Heroic Code In The Iliad English Literature Essay

Looking At Heroic Code In The Iliad English Literature Essay In book 9 of The Iliad, the greatest example of heroes, Achilles, questions in mid-way about the heroic code. However, it is just a shattering start for the process in seeking another point of view about what and how to construct a real hero. Through a miserable loss and ability to relate to other characters in the book, finally, Achilles ends up that process with a lesson: Rather than the honor gained in the battle, a hero is also inspired by the connectedness to other people, fighting for the survival of their city, families and companions. Achilless suspicion about the true value of heroic code brings up a new perspective to the Iliads readers, showing them how the heroic world may look from the position outside it. Initially, it seems to make sense that Nothing is worth my life, not all the riches/ They say Troy held before the Greeks came, (9.415-16) Achilles said, when he has plenty of possession, and those honor-conferring material gifts are not a worth-while compensation for the loss of his life on the battle. Also, it is hard to object when he criticizes the pointlessness of the heroic system: Coward and hero get the same reward:/You die whether you slack off or work. (9.326-27) However, those arguments are only subjective and associated with blindness. The speech of Phoenix, one of the ambassadors and Achilles beloved old tutor, fully answers Achilles concern and points out what Achilles cannot see. He tells the story of Meleager, a man who was wronged and refused to defend his country. He retired in his room wi th his beloved wife and stayed out of the fighting until the moment when his city was about to be destroyed. He realized that his wifes safety could be threatened if his country lost in the war. Therefore, he returned to battle and fought for his city, but at that point Meleager just won little honor. Phoenixs story responds to Achilles accusation that gifts are inadequate compensation for fighting by showing that there are still other reasons besides honor why people lose their lives for fighting. That is because of their family, their close friends, and any bonds of friendship in a small community. At this point, the family concept and the interrelation between individuals become revealing as an integral aspect of heroic code. This idea slowly develops in further Book through Achilles relationship to others on a personal basis. It is only after Patroclus death that Achilles realizes what is missing in his previous accusation, which also highlights those above newfound perspectives of human connectedness. A hero, of course, must fulfill his status in combat on the battlefield, to get honored for himself; besides, it is stressed that he has to respect his family, show loyalty to his friends, and protect his comrades. Achilles learns this precious lesson after a miserable loss: A mist black grief enveloped Achilles/He scooped up fistfuls of sunburnt dust/And poured it on his head, fouling/His beautiful face à ¢Ã¢â€š ¬Ã‚ ¦ (18.23-26) The word envelope is used sophisticatedly as, like a letter is covered underneath another thick paper, Achilles gets stuck in a confusing thinking stream about if his own honor is an ultimate purpose he is seeking for throughout all his lie, or his close relationship with companions matters more to his true heroic value. He gets lost. He conflicts with himself. The image of self-w illed man with strong accusation at the beginning disappears; instead, that man is acting unconsciously: He scooped up fistfuls of sunburnt dust/And poured it on his head, fouling/His beautiful face à ¢Ã¢â€š ¬Ã‚ ¦ (18.24-26) Beautiful face is a nice metaphor for the image of an ideal hero which Achilles mistakenly overvalues for himself, and dust can be understood as the force for Achilles to break against that monument and reach the underneath true heroic code. Now, Achilles begins to see life and relationships with other people from a mortal point of view. Patrocluss death is a strong reminder of those other reasons for fighting that Achilles forgets in his initial undermining of honor. In a material human world, heroes may treasure the reward and social status as a consequence of winning the fighting, but they are also motivated by the patriotism for the city they protect and by the love for family and friend they deeply involve. Family and deep bond of friendship also take part in constructing the moral aspect in a real heros character. This excites the readers profoundly besides many bloody brutal killing scenes throughout the book. In the scene Priam takes ransom to demand Hectors corpse back for a proper burial, the readers can witness a new side in Achilles behavior that never plays out before: full of sincere kindness and sympathy. Compared with the intense savagery when Achilles cruelly drags Hectors corpse around the walls of Troy, this move entirely surprises the readers. Priam huddled in grief at Achilles feet, cried/ And moaned softly for his man-slaying Hector. (24.547-49) Homer uses the verb huddle, somehow in contrast with high status of Priam, a king, to demonstrate that death is no barrier to the honor and glory achieved in life. Priams begging does not dishonor him; instead, he does that in the name of his family member. This action truly captures Achilles pity and breaks down his resistance. Achilles knows that his fate is to die at Troy and never return home in Phthia. He realizes how desperate his father, Peleus, feels once he knows that heart-breaking news of his son, which might happens to Priam if Achilles does not return Hectors corpse to him. And Achilles cried for this father and/ For Patroclus. The sound filled the room. (24.550-51) Just only any object that is visible and have weight can fill up a space, but Homer uses that verb for the sound to show that, this time, Achilles tear has value because he already learns his mistake in self-absorption and changes himself to care for other peoples feelings. Finally, he reaches to his identity as a mortal, letting go of his previous bitter outrage, and sharing the grief of loss with other mortals. Generosity, or forgiveness, also constructs a real hero. This is a precious lesson that Achilles learns till the end. The Iliad, set aside all of the brutal killing scenes, is a work deeply concerned with the true value of heroic system. Specifically, the questioning of Achilles in Book 9 brings up a new insight for the Iliads readers. The heros brilliant performance in the battlefield is fundamental to maintain his status. Furthermore, he had to fulfill his responsibility in accordance with his family, friends, and community in general.

Enlightenment and Tartuffe :: Free Essays Online

Enlightenment and Tartuffe The ideals of the Enlightenment can be found in many of the writings from this time period. There are a few characteristics that are commonly associated with the Enlightenment. This was the age of reason. People at this time began to apply rational thoughts to figure out and understand nature and to guide their human existence. In Moliere’s Tartuffe, this ideal is expressed through the character of the king. In the end, Tartuffe has brought an officer of the king back to take Orgon away. However, in Tartuffe’s attempt to get Orgon arrested, the king saw through him and reasoned that Tartuffe was the one to be accused and put to trial. Another defining characteristic is the desire for equality and dignity for all, the thought that all have a set of basic human rights. The Enlightenment also challenged many of the former ideologies, one of which was ignorance. Tartuffe exemplifies these characteristics through the character Dorine. Dorine is Mariane’s lady-maid, in other words, someone with a low social standing because she is a member of the working class, and presumably ignorant because of this low social status. However, in the story, she is much smarter than Orgon and also a lot more reasonable. This shows that it does not matter what social class one comes from to determine their level of intelligence. Her closeness and acceptance by the family, with the exception of Orgon, shows that people can be viewed for their own worth and value. Dorine is someone from a lower social standing than the family, but yet, is able to socialize and befriend the family she works for. Another challenge is to superstition, deception, and oppressive traditions. Tartuffe is a character that is related to the church and yet is a very deceptive, hypocritical character. He is able to con Orgon into letting him into his home. Furthermore, Orgon is deceived into disinheriting his own son and leaving all the inheritances to Tartuffe. Orgon is an example of the oppressive person who tries to maintain complete control.

Growth of Internet Business :: essays research papers

Introduction The history of the Internet traces its roots to the United States government. The original use of the information system was to maintain communication during the cold war, with the Soviet Union in 1969, by the Department of Defense, incase of a nuclear attack or a major catastrophe. The National Science foundation created the Internet based on the ARPAnet. The first mass connection was between the University of California Santa Barbara, Stanford Research Institute, the University of Utah and the University of California Los Angeles.Ray Tomlinson develops E-mail in 1972.The ARPAnet became obsolete in 1982, but the basis for the program is still used at the present time. The Web began in 1989;it wasn’t released to the world till the early 90’s that’s when it became the World Wide Web. In 1993 Marc Andressen created software for the Internet to publish text, images and sound. Andressen also introduced the first graphical Web browser, called Mosaic, sti ll in use today. The United States runs most of the access to the Internet with 62% of all the routers, next closest is the United Kingdom with 5.2%. That is just an example of what America controls much on the Internet. 70% of the writing on the Internet is in English, next is Japanese. Statistics say 1 in 3 people use the Internet for E- Mail, 1 in 6 use it because they want to find out how it works, 1 in 8 want business information and 1 in 2 go to the Internet for education, hobbies, job listings, and entertainment. In 1993 less than 1% of users paid for use of the Internet. By 1995, it rose to over 200% due to the profits companies made from the providing this service. This became a common change that businesses have made since the beginning of the information highway. It was then clear that the Internet wasn’t going anywhere anytime soon. This stared a trend, which is still being felt today and into the near future. Because of the demand for the Internet around the Worl d, and the amount of capital a business could make that provides this service, is astounding, a good example of this is Cisco, a once Silicon Valley based business, which is now a Internet technology provider, reaped in $10 billion in 1986 without an IPO (initial public offering), and this is 14 years before the Internet became what it is today.

Swot: Shopping Mall and Similar Stalls

. SWOT Matrix |STRENGTHS |WEAKNESS | |FEATURES OF USB WATCH |MARKETING SERVICES AGENCIES | |As the USB watch has the USB the watch can also have an alarm and |As the product is new to the market it would be difficult to | |timer. increase the sales because people still don’t know about the | | |product and if they would accept the product. | |DISTRIBUTION OF THE PRODUCT |FORMS OF USB | |The product is not yet known to most of the people and making it |The product remains vulnerable to the possibility that innovation | |distributed in Alabang especially in Festival Mall and Alabang |may falter over time. |Town Center that are commonly known to them. The product can be | | |sold at CD-R King or any similar stalls. | | |FASHIONABLE WATCH | | |The USB watch has different styles and colors that make the wearer| | |stylish. | |OPPORTUNITIES |THREATS | |JOINT VENTURES OR STRATEGIC ALLIANCES |WEAK BRAND NAME | |Joining CD-R king and other similar stalls that allow the product|As a new in the industry in producing a USB watch competing with | |to be introduced in the market and knowing that they are easily |a known brand like Timex. |found on malls. | | |MATERIALS ARE RECYCLED |FAST CHANGING ENVIRONMENT | |If the product can be made through recycled parts of a computer |As the people are changing what they think would be needed in | |it could make our product in a cheaper cost. |making their life convenient and having many alternatives in the | | |form of USB like pens. | |FINANCIAL CRISIS | | |As the economy slows the purchasing power of people would decline| | |and they would prefer buying their primary need. |