Advantages Of Bus Topology Computer Science Essay

Advantages Of Bus Topology Computer Science Essay A topology is defined as the layout of the network i.e. how the nodes are connected. This describes how the network physically looks or how the network is physically designed. The concept of a topology is important because each network card is designed to work with a specific topology. Conversely, if your network cable is already installed and you want to use existing wiring, you must select your network cards based on the preexisting physical topology. Ideally, you can design your network from scratch. Then you can choose your topology, cabling, and network cards based on what best meets your needs. Physically, a bus topology uses a linear segment of cable to connect all network devices. Devices typically connect to the bus (the cable) through T-connectors. At each end of the bus are terminators. Each terminator absorbs the signal when it reaches the end of the cable. Without a terminator, a signal would bounce back and cause network errors. The physical bus topology uses a logical bus to transmit data on the cable in both directions. In a logical bus topology, only one transmission can occur at any given moment. Otherwise, two transmissions would collide and cause network errors. Termination ensures that the signal is removed from the cable when it reaches either end, preventing possible network errors. Fig. 4.1 Bus Topology Advantages of Bus Topology : The benefits of a bus topology include the following: 1. This is less expensive topology because it requires less cable for networking because using only one cable it is possible to connect many computers. 2. It is an easy way to network a small number of computers. Disadvantages of Bus Topology : The drawbacks of a bus topology include the following: 1. One break in cable cause entire failure in network. 2. It is very difficult to correct the errors because the cable is not related to only one machine. 3. On a medium-sized to large network, reconfiguration is more difficult than the cable Management of a star topology. Star Topology The star topology looks like a star. The hub is at the center of the star, and all devices attach to the hub via a cable. Logically, the physical star topology operates as a logical bus topology by sending the data signal to all nodes at once. The hub at the center of the star works as a signal splitter, which means the signal is split and sent to all computers at the same time, with one exception-it is not sent back to the computer from which the signal sent. The signal is terminated at each network card, thereby preventing the signal from accidentally reentering the network. If this were to happen, data packets would travel the network endlessly-seriously slowing down network performance. Fig. 4.2 Star Topology Advantages of Star Topology : The benefits of a star topology include the following: 1. A star topology is more fault tolerant than other topologies, because a cable break does not bring down the entire network. 2. Reconfiguring the network, or adding nodes, is easy because each node connects to the central hub independent of other nodes. 3. Isolating cable failures is easy because each node connects independently to the central hub. Disadvantages of Star Topology : The disadvantages of a star topology are: 1. If the central hub fails, the entire network becomes unavailable. 2. This topology is more expensive than others to install because of the additional cable and equipment involved. Ring Topology: Physically, the ring topology is shaped in a ring. Cables pass from computer to computer until the ring is complete. When data is transmitted, each workstation receives the signal and then passes it on when the workstation is done with the data. Other than Fiber Distributed Data Interface (FDDI), no current networks use a physical ring topology, because a break in the ring makes the entire network unavailable. Logically, a ring topology works by passing the signal, traditionally called a token, from one node to another until it reaches all the way around the ring. Token-passing schemes use the logical ring topology. Fig. 4.3 Ring Topology Advantages of Ring Topology : A logical ring topology ensures access to the network without the risk of collisions, which can occur in logical star or bus topologies. Disadvantages of Ring Topology : The drawbacks of a ring topology include the following: 1. If there is a break in the cable of a physical ring topology, the network becomes unavailable. 2. Physical ring topologies are difficult to troubleshoot. 3. Physical ring topologies are hard to reconfigure. 4. There is limited support for ring networks. 5. The costs for a ring network are significantly higher than for star or bus. Tree Topology Also known as a hierarchy network, The type of network topology in which a central root node (the top level of the hierarchy) is connected to one or more other nodes that are one level lower in the hierarchy (i.e., the second level) with a point-to-point link between each of the second level nodes and the top level central root node, Fig. 4.4 Tree Topology While each of the second level nodes that are connected to the top level central root node will also have one or more other nodes that are one level lower in the hierarchy (i.e., the third level) connected to it, also with a point-to-point link, the top level central root node being the only node that has no other node above it in the hierarchy (The hierarchy of the tree is symmetrical.) Each node in the network having a specific fixed number, of nodes connected to it at the next lower level in the hierarchy, the number, being referred to as the branching factor of the hierarchical tree. This tree has individual peripheral nodes. 1.) A network that is based upon the physical hierarchical topology must have at least three levels in the hierarchy of the tree, since a network with a central root node and only one hierarchical level below it would exhibit the physical topology of a star. 2.) A network that is based upon the physical hierarchical topology and with a branching factor of 1 would be classified as a physical linear topology. 3.) The branching factor, f, is independent of the total number of nodes in the network and, therefore, if the nodes in the network require ports for connection to other nodes the total number of ports per node may be kept low even though the total number of nodes is large à ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬ this makes the effect of the cost of adding ports to each node totally dependent upon the branching factor and may therefore be kept as low as required without any effect upon the total number of nodes that are possible. 4.) The total number of point-to-point links in a network that is based upon the physical hierarchical topology will be one less than the total number of nodes in the network. 5.) If the nodes in a network that is based upon the physical hierarchical topology are required to perform any processing upon the data that is transmitted between nodes in the network, the nodes that are at higher levels in the hierarchy will be required to perform more processing operations on behalf of other nodes than the nodes that are lower in the hierarchy. Such a type of network topology is very useful and highly recommended Mesh Topology Mesh The value of fully meshed networks is proportional to the exponent of the number of subscribers, assuming that communicating groups of any two endpoints, up to and including all the endpoints, is approximated by Reeds Law. Fig. 4.5.1 Fully connected mesh topology The number of connections in a full mesh = n(n 1) / 2 Fully connected Note: The physical fully connected mesh topology is generally too costly and complex for practical networks, although the topology is used when there are only a small number of nodes to be interconnected. Fig. 4.5.2 Partially connected mesh topology Partially connected The type of network topology in which some of the nodes of the network are connected to more than one other node in the network with a point-to-point link à ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬ this makes it possible to take advantage of some of the redundancy that is provided by a physical fully connected mesh topology without the expense and complexity required for a connection between every node in the network. In most practical networks that are based upon the physical partially connected mesh topology, all of the data that is transmitted between nodes in the network takes the shortest path (or an approximation of the shortest path) between nodes, except in the case of a failure or break in one of the links, in which case the data takes an alternative path to the destination. This requires that the nodes of the network possess some type of logical routing algorithm to determine the correct path to use at any particular time.

Management Concepts Essay

Case for critical thinking: A flood of decisions 1. What information sources (or potential information sources) could have been used to assist with the decision-making process for Wivenhoe Dam in this case? Potential information sources that could have been used to assist with the decision-making process for Wivenhoe Dam -SEQWater -Sought advice from Water Grid Manager -Water Commission -DERM (Department of Environmental Resource Management) Managerial decision-making Problem avoiders Problem solvers Problem seekers Approaches to decision making Classical decision model Behavioral decision model Judgmental decision model 2. With references to decision-making theory covered in the chapter, describe the type of managerial decision-making evident in this case, and the conditions under which decisions were made. Managerial Decision Making *Problem avoidably *Problem solvers *Problem seekers Decision conditions: *Certain environment *Risk environment *Uncertain environment 3. Evaluate the decisions made in the case in relation to the classical, behavioural and judgmental heuristics approaches to decision-making that are outlined in the chapter. Which model do you believe best describes the situation and subsequent decision-making process in this case? Justify your answer? Approaches to decision making ^Classical decision model ^Behavioral decision model ^Judgmental decision model Case decision *Classical decision model Problem: it was the flood that damage Brisbane and Ipswich Possible alternative: Not releasing flood waters. Consequently threatened stability of dam Optimizing decision: Release of flood waters being aware of potential damage. SWOT Analysis: Strengths: *New technology *They set priorities *Manage time Weakness: Lack of communication Misunderstanding Misconduct Problem solving Crisis Opportunities: *Professional engineer *Employment Threats: Natural disaster (climate change) Damage roads and homes. Conclusion People should make wise decision to save the lifes of the others.

Reading strategy Essay

The SQ3R strategy which stands for survey, question, read, recite, and review. This five step strategy can be integrated into many areas. students can learn more effectively by engaging in the pre-reading, during-reading, and post-reading steps of this strategy. There are five strategy of reading to better understand the material. The strategy contain survey, question, read,recite and review. In survey, it contains chapter titles, introductory paragraphs, bold face, italicized headings and summary paragraphs. Question includes turn section headings into questions; have questions for which answers are expected to be found in the passage. In read purpose is to answer the questions. In recite also allow to answer question without referring to the text or notes. In review includes reviewing the material by reading parts of the text or notes to verify answers.The SQ3R is great way to actively read difficult material. It does not promise to make it student love or even like the subject but it facilitate the student to reading and ultimately, teach learning. with time and practice find this approach great study skill to develop.These students can benefit from using the SQ3R because it requires them to activate their thinking and review their understanding throughout their reading. It also helps students from waiting and then cramming for tests since the five steps requires them to review information and create notes during their initial reading. Their notes from the initial reading become their study guides. The SQ3R strategy which stands for survey, question, read, recite, and review. This five step strategy can be integrated into many areas. students can learn more effectively by engaging in the pre-reading, during-reading, and post-reading steps of this strategy. There are five strategy of reading to better understand the material. The strategy contain survey, question, read,recite and review. In survey, it contains chapter titles, introductory paragraphs, bold face, italicized headings and summary paragraphs. Question includes turn section headings into questions; have questions for which answers are expected to be found in the passage. In read purpose is to answer the questions. In recite also allow to answer question without referring to the text or notes. In review includes reviewing the material by reading parts of the text or notes to verify answers.The SQ3R is great way to actively read difficult material. It does not promise to make it student love or even like the subject but it facilitate the student to reading and ultimately, teach  learning. with time and practice find this approach great study skill to develop.These students can benefit from using the SQ3R because it requires them to activate their thinking and review their understanding throughout their reading. It also helps students from waiting and then cramming for tests since the five steps requires them to review information and create notes during their initial reading. Their notes from the initial reading become their study guides.

The Iliad by Homer - 1383 Words

Many years ago in ancient Greece, Plato initiated a debate about the usefulness of literature by declaring that poetry had no place in the ideal society, mainly because it was full of lies and because it evoked undesirable emotions. His pupil Aristotle, however, took the opposing side of this dispute and argued that literature was, in fact, useful. Aristotle agreed with Plato that literature induces undesirable emotions, but he stated that it only does so in an attempt to purge us of these harmful sentiments, a process which he termed â€Å"catharsis†. The events in Homer’s Iliad, while used by both Plato and Aristotle to defend their theories about literature, lend themselves to the defense of Aristotle’s ideas more so than Plato’s.†¦show more content†¦But it is not so much the pain to come of the Trojans that troubles me [†¦] as troubles me the thought of you† (Iliad book 6 lines 447-454). Obviously, Hektor shows himself in book six to be a man firmly in touch with the unalterable human condition of mortality. He understands that Ilion is fated to fall, and that he himself will be murdered by the Greeks leaving his wife a widow and his young child, Astyanax, fatherless. As the Trojan army becomes more and more successful in battle, however, Hektor seems to lose this insight about his own mortality and about the ultimate end of the Trojan War. After Hektor sees Diomedes the great Greek warrior retreat from the battle front, he taunts the son of Tydeus, saying, â€Å"Oh, if I only could be as this in all my days immortal and ageless and be held in honor as Athene and Apollo are honored as surely as this oncoming day brings evil to the Argives† (Iliad book 8 lines 538-541). With these four lines, Homer depicts a man who has lost sight of his human limitations. By showing his desire for immortality, Hektor is essentially showing how close he is to death. His insatiable desire for Kleos, timà ©, and victory force him to completely forget all of the predictions he made about the fall of Ilion only two books earlier. In bookShow MoreRelatedThe Iliad By Homer1654 Words   |  7 Pages The Iliad is a collection of poems by Homer describing the 10-year siege on Troy by Greeks in what is now famously referred to as the Trojan War. Several Greek and Trojan characters are worth a special mention in these Homeric poems because of the roles they played in the battles before the war was won, how they conducted themselves to help eventually win the war for their side. This paper specifically investigates the writings in the Homeric poems to look are important in the overall text. TheRead MoreThe Iliad By Homer892 Words   |  4 Pages The Iliad by Homer depicts the great struggle by Agamemnon and the Greeks to take the mighty city state of Troy and return Helen to her rightful husband, Menelaus. 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In orderRead MoreThe Iliad By Homer2007 Words   |  9 PagesThe Iliad is a collection of poems written by Homer describing the 10-year siege of the city of Troy by Greeks in what is now famously known as the Trojan War. Several characters stand out in the series of poems because of the roles they played in the war, how they behaved and the acts they took to help eventually win the war for the Greeks (then known as Akhaians). This paper specifically investigates the writings in Books two, four, thirteen, sixteen and seventeen and why the events in these booksRead MoreThe Iliad, by Homer855 Words   |  4 PagesIn Homers epic Iliad, the poet emphasizes the control of the gods in the war he describes. He creates literary devices around these well-known deities to illustrate their role in the action, conveying to his audience that this war was not just a petty conflict between two men over a woman, but a turbulent, fiery altercation amongst the gods. To an audience which had likely lost their fathers, brothers, or husbands to the Trojan War, it would be a welcome relief to hear that the whole affair wasRead MoreThe Iliad By Homer2191 Words   |  9 PagesThe Iliad By Homer was created in the late 5th-early 6th century A.D. This Epic was a best seller, but the publishing date and publisher is unknown, due to the story being so old. The Iliad is around 576 pages long. Some facts that have to do with the Iliad that are not well knows include the name Homer resembling the greek word for â€Å"hostage.† Also, taking place after the events of the Iliad, Aeneas supposedly survives the war and goes on to become the founder of roman culture. Going on to a differentRead MoreIliad by Homer1216 Words   |  5 Pagesin Homer’s Iliad, to be a hero is to be â€Å"publicly recognized for ones valour on the battlefield† and to have a prize with it (Sale). In other words, a hero is someone who fights for his own fame and glory. However, the modern perception of a hero is quite different. A hero is someone who do not endeavor to become a hero, but someone who act in admirable ways, often for the better of everyone else. The modern concept of heroism is what defines a true hero. Achilles is a hero in the Iliad, because ofRead MoreThe Iliad Of The Homer s Iliad Essay1475 Words   |  6 PagesThe Iliad ranks as one of the most important and most influential works in terms of world literatures since its establishment. Between the underlying standard to which the Iliad offers us as audience members, along with the plethora of writers that have followed in the footsteps to which Homer’s Iliad paved, the impact that the Iliad has played is remarkable in itself. 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