Computer Network

Computer Network also called Network is a group of computers and other devices connected to each other to share resources electronically. Networks can be as small as two computers or many thousand computers that are connected to one another. These computers are usually connected to one another through wires, satellite, and modems. Each device connected to the network is called a â€Å"node†, and the computer that is connected to the network is called a workstation.There are several ways to connect networks together, the way the Network is laid out is called Topology, and there are several types of topologies, Bus Topology, Star Topology, Ring Topology. There are several types of network, Peer to Peer Network, Client/Server Network. Depending on the size of networks they are divided into several categories and have different terms that specify these networks, LAN (Local Area Network), MAN (Metropolitan Area Network), and WAN (Wide Area Network). One of the primary reasons to ne twork is to increase productivity and cut all the unnecessary costs.By connecting their office people can get the advantages of managing their data, all the data can be stored in a server computer instead of storing them in each workstations hard disk. This way you can easily back-up and manage your data. And whenever someone makes changes to files it will updated and everyone will have the access to the same updated file. The network administrator will decide to whom grant the access to the files. Another advantage of network is that it makes data transfer easy so you don’t have to transport files into Floppy disk, or USB device and walk over to your co-workers desk.Networking also will allow you to share the equipment like printer, if there are several hundred computers in an office building you don’t have to buy different printers for each computers instead you can just buy one or two printers that can be shared between all computers on a network. You can save on so ftware too many software companies offer businesses software deals that are more affordable than purchasing separate software license for each computer, it also can save time when the time to upgrade to a new version of a software you can just update it on a server instead of doing it on each computer.Another way of saving money is that you can share the internet too. As you can see networking computers has many advantages and it is recommended to network. As I mentioned above the way the networks are laid out are called topology, today you will come across the networks that laid out uniquely using one type of topology or combination of different types of topologies these kind of topologies are also called a â€Å"Hybrid Topology†:1. Bus.2. Star.3. Ring.The Bus Topology is older topology that is not seen that often and almost never used in modern networks.It is very easy to set up because all the computers are connected to each other using a single cable which is called a bac kbone or segment. Because all the computers connected to a bus network to one cable only one computer can send packets of data (which are electronic signals) at a time. Bus topologies have some advantages they are easy to set up, and since they are on one line of cable if one computer fails it does not crash the entire network. They are also very inexpensive to set up because less cable is used.Despite the advantages of a bus topology there disadvantages too. One of the disadvantages of a bus topology is that if the cable used breaks, the entire cable needs to be replaced, and if the cable is too long it will hard to find out where the cable is broken. The bus topology is also not very scalable if you have a small network it will be hard to expand it. It is also not very secure network. Even though the Bus topology is very easy to set up and inexpensive I t is very outdated, it should not be used in a modern networks.The Star Topology is a topology mostly used in modern networks alt hough it is an older topology too, many modifications has been made to it to handle all the modern networking needs. In a star topology all the computers are connected separately to the Hub or Switch, and all computers have their own cable. When a computer sends the packets of data to other computers in the network it is sent through the cable to the hub or switch, then it passes the data packet to other computers that are connected to it.Since the computers in a star topology are connected to the switch separately and all the computers have their own cables, in case it brakes it is easy to configure the problem. The computer that breaks down is the only computer that will not have access to the network, and all the other computer are not affected because they have their own cables connected to the switch. Another benefit the star topology has is that it is scalable and can be expanded anytime. The star topology is the most used topology in modern networks and it is recommended to u se the star topology if you are setting up a network.

Assignment1 Essay Example | Topics and Well Written Essays - 1000 words - 1

Assignment1 - Essay Example Its major function is to carry the genetic information to the cytoplasm for the protein synthesis process. However, DNA is present in the nucleus mainly to store the genetic information. DNA is short lived and double stranded while mRND is single stranded and has a short lifespan. A DNA chemical test can be carried out to observe their performance in genetic synthesis. c. Starch and cellulose are polymers having very similar characteristics. They have similar glucose based repeat units and are made up of the same monomer. However, all the repeated units in starch are oriented in one direction while in cellulose; every successive unit of glucose is rotated 180 degrees of around the axis of the backbone chain of the polymer. In experiments, starch is soluble in warm water while cellulose is tough and can only be broken down into simpler units when treated with acids at high temperatures. Starch is therefore used as a major source of energy in human food while cellulose is used in making fibre materials (Markussen et al., 2002). d. Amylose is a D-glucose unit polysaccharide that forms 20-30% of the total starch structure while Amylopectin forms the remaining percentage of the cell starch structure. In experiments, the amylase components do not dissolve in water while Amylopectin dissolves in water. Structurally, Amylose can appear in a pair of distinct helical forms or in a distorted amorphous confirmation. Amylopectin , however, has a non-random branching determined by enzymes and glucose residues (Markussen et al., 2002). e. Myoglobin is a monomer that binds oxygen more tightly than hemoglobin as reflected when oxygen is in the bloodstream is observed to move from hemoglobin to myoglobin. On the other hand, hemoglobin is a tetramer made up of a pair of related subunits of alpha and beta. Their functional difference can be observed in an oxygen uptake experiment under similar conditions for oxygen

Digital Video Production Reflective Commentary on Trailer Produced Essay

Digital Video Production Reflective Commentary on Trailer Produced - Essay Example This scene signifies the beginning of a relationship representing all things positive and tender and affectionate, which is disrupted by this explosion, which represents the disturbances that life represents - some of which the relationship may survive, but more importantly, sets the tone for the wife to be prepared for her new husband to leave her in an instant to deal with these disturbances. The film line revolves around Vargas, the 'hero' and his weakness in balancing his personal and professional responsibilities. On a broader level, this opening scene is a microcosm for the theme of the rest of the film: the ever raging and seemingly endless battle between good and evil, within the characters themselves as well as between them. (Tom Dirk, Film site review) The title Orson Welles appears in the 9th second who introduces t... d us and he appears almost larger than life until he reaches his full height and balance within the camera which indicates that he is only human, after-all. This scene represents the progression of his character through the movie: he begins as a seemingly powerful man that will stop at nothing to achieve his goal (of catching the 'bad guys') and cannot be stopped by any force known to man. As his character progresses through the film, we see a leveling out that suggests that even all-powerful men ultimately have to live within the boundaries of life - and if you choose not to, justice will eventually prevail to maintain the balance between good and evil. The next title is consistent with the first (black with the credit appearing in a white outline for an elegant and classic feel) and appears in the 11th second: 'Touch of Evil' that heralds in the next scene is actually the crux of the film as it begins to unfold. The sound overlaid on the credit, for but a second, is meant to represent mystery. In seconds 12 to 16, Quinlan sports a self-satisfied and smug look and the sound begins: "Vargas himself has a theory that the murder was committed outside our jurisdiction" and the camera cuts to Vargas who looks confident and also somewhat suspicious of this 'theory'. The scene then cuts to the increasing tension and friction between Vargas and Quinlan: the tone is being set for a battle between these two and the battle between good and evil that ensues. The body language of the group of men who proposed Vargas' 'theory' seems to be in support of Quinlan and blinded by the reality of his methods of investigation. Vargas is in alien territor y and the representative of justice will have to fight his battle single-handedly, as justice always needs to win against all odds. In

The United Nations And Human Right Essay Example | Topics and Well Written Essays - 2000 words

The United Nations And Human Right - Essay Example Upholding those rights are considered as having peace, justice, and freedom in the world. The laws and fundamental principles for upholding these rights are in place and so does the overall mechanism and infrastructure to actually enforce these rights. Over the period of time, UN has been able to reduce the number of human rights violations across the whole world and that it has been able to put in place different resources which helped it to achieve this objective. However, UN also failed to properly enforce human rights across the whole world as millions of people are still being put through brutalities and gross human rights violations. Not only governments are committing crimes against the basic human rights but smaller and individual groups are also involved too in such incidents. This paper will debate whether United Nations has been able to ensure human rights for all or not by presenting arguments in favor and against the same. Human Rights and United Nations As discussed abo ve, human rights are universal in nature and are available to everyone equally. These are the rights which we enjoy as humans and violations of the same can attract penalties and other punishments for those who violate the human rights. The overall movement for the protection of human rights started to become significant after the World War-II. The overall mandate given to UN is given by the countries who acquire the membership of the UN. Membership of UN is considered as the admission of any individual country towards the international community. UN, therefore, has been implementing and enforcing human rights either through charter based or treaty-based implementations. Both these mechanisms not only provide UN a proper mechanism but structure also to implement and influence countries to implement human rights. The overall atrocities and violations of human rights become common after World War II and as a result of this, United Nations General Assembly met in Paris with the objecti ve of adapting Universal Declaration of Human Rights. In 1948, a universal declaration of human rights was adopted by General Assembly of United Nations and as such overshadowed all other human rights declaration which was prevailing in ancient times. Article 1 of the universal declaration suggests that all human beings are born equal and with the same level of dignity. The United Nation Article 1 on human rights states that all human beings are equal and born free in dignity and rights (Smith, 2009, p. 54). The laws were made to ensure that every person has a right to life and this right should be legally protected.

Criminal Justice Questionaires Essay Example | Topics and Well Written Essays - 500 words

Criminal Justice Questionaires - Essay Example After a rough draft is created, the researcher then analyzes the questions to see which ones are related to the variables list. The variables list contains the key concepts or theoretical constructs that are contained in the research question. Care is taken to ensure that questions cover every concept, and there is no duplication or excessive coverage of any one concept. (Hagan, 2000). For example, I am interested in studying the relationship of childrearing, self-control, and crime. Before I would formulate the questions to constitute my questionnaire, I would do some literature search. I would try to find out if there is a research gap or a strong reason for trying to study this topic. I would exploit a theory connected to these three constructs for my study, if feasible (Converse &Presser, 1986). Self-control theory has received extensive empirical attention in the past decade, but most studies have not tested its arguments about the effects of parenting on self-control and delinquency (Hay, 2001). Latimore, Tittle & Grasmick (2006) wrote that there is an emerging body of research suggesting that self-control may be dependent on things other than the childhood caregiving identified in self-control theory. They have examined Gottfredson & Hirschi's model of caregiving to produce high self-control using survey data from a city population of adults. Meanwhile, Carter Hay (2001) tried to test self-control theory in a possible relationship between parent

Calcium Element Chemistry Research Paper Example | Topics and Well Written Essays - 750 words

Calcium Element Chemistry - Research Paper Example Calcium occurs naturally only in compounds, and this is because it is so reactive. (Environmental Chemistry Website) It is derived from minerals such as limestone and gypsum where it occurs in combination with sodium, magnesium and aluminium There are also vast sedimentary deposits in the fossilized remains of marine life, such as shells. These minerals and sedimentary deposits containing calcium can be found all over the world. Calcium is often found in the compound calcite, which is the principal constitute of the rock limestone. (Enghag, p. 333) Chemists denote calcium with the symbol Ca and the atomic number 20, and it has the atomic weight 40.078. (Helmenstine, p.1) It is classified along with beryllium Be, magnesium Mg, strontium Sr, barium Ba and radium Ra as one of the alkaline earth metals. (Enghag, p. 323) The properties of calcium are that it has an atomic radius of 2.00A, and ionic radius of 1.14A, a melting point of 842?C and a boiling point of 1484? and it has a flame c olor of orange-red. Section 2. 10 compounds formed by Calcium. Calcium hydroxide (slaked lime) is made by heating limestone to a temperature of above 825?C and then adding water to it. (Wikipedia). Calcium sulphate (CaSO4 ·2H2O) is a powdery white material which is safe to handle. Calcium carbonate CaCO3 comprises more than 4% of the earth’s crust and comes in three main natural forms: chalk, limestone and marble. These are identical in chemical terms the have different purity, thicknes and homogeneity. (IMA-NA website, 2011) Calcium nitrate Ca(NO3)2 also called Norwegian saltpetre is obtained by â€Å"dissoving limestone in nitric acid or through the absorption of nitrous gases by milk of lime.† (Pubchem, 2011) Calcium chloride (CaCl2) can be produced from seawater, but this is inefficient and produces impure compounds. A better way of obtaining this compound is by combining high purity limestone and salt brine. (Morris chemicals Inc Website) Calcium carbide   (Ca C2) is a colorless compound produced at an extremely high temperature in a furnace from a mixture of lime and coke. (Wikipedia) Calcium hypochlorite  (Ca(OCl)2) is a yellow white solid which emits a strong smell from the chlorine part of its constitution. Calcium permanganate  (Ca(MnO4)2). This compound consists of calcium plus two permanganate ions. Calcium stearate  (Ca(C18H35O2)2) is a non-toxic compound of calcium with various solid organic acids such as stearic. Stearic acid is a naturally occurring fatty acid such as that found in animal fats and palm oil. Calcium arsenate  (Ca3(AsO4)2) is a â€Å"white flocculent powder which is practically insoluble in water.† Pohanish, p. 522. It is toxic to humans due to the arsenic component in it. Section 3. 4 Uses in everyday life. Calcium is used in making cheese, and it adds a valuable dietary contribution to many foods, or as a vitamin supplement combined with less reactive materials in tablet form. Another use of calc ium is in the steel industry, where it is as a deoxidizer used to help purify other metals in the heating process. A third use of calcium is in the production of cement. Calcium is used as an ingredient in many fertilizers and bleaching agents, including in textile and paper production. It is hardly ever handled in its pure form, but in its compounds (see sections 2 and 4). Section 4. 5 compounds and their everyday use. Calcium nitrate Ca(NO3)2 is a compound made with nitrogen which is used to fertilize plants. It was first applied in

Serving Newton Essay Example for Free

Serving Newton Essay At the start of the years University Physics 1 degree course, the Physics Professor looked at the motley crew filling the lecture theatre. He knew some students were destined to survive, while others would drop-out. In a rather callous way, the professor wrote-off the previous twelve years of the students scientific education before introducing the course. Writing on the board just four symbols, he continued saying The single most important equation in the Universe is, F = m a . The experience could be likened to watching the rector at church, singing the praises of the most exalted one. From this equation he said, everything else, all other forces are derived, forces including motion, gravity, electrostatics and magnetism. This can be experimentally proven over-and-over again as a Law of Nature, as a Universal truth. But this was no rector, this was the bishop, the professor himself outlining Newtons laws of motion, showing the magic relationships that exist in the sciences. The Universe seemed to make sense at that moment, but then his reverent attitude turned. He introduced into this overview scheme of things, three body gravitational systems. At this point, he stated that Newtons laws failed, for this is where Einsteins approximations come into their own, for only they can accurately predict and solve the forces that exist between three or more bodies in the Universe. Something appeared to be very incorrect; for this did not ring true. It seemed impossible that a law of Nature, a known Universal Truth, could be wrong? The professor was expressing the common cosmological opinion that Newtons laws of gravity are deeply troubled, if not wrong, yet he found it amusing that cosmologists could not suggest any mechanism to explain gravity or to improve gravitational theory. To conclude his introduction to Physics 1, the professor said, Terrestrially, the laws of Physics work, but when one talks about matters cosmological, Newtons laws fail miserably, giving-way to Einsteins relativity. This statement appeared to be more contradiction than Science. The Earth exists as a tiny speck of dark matter, orbiting with the Moon around a rather common star. As the Earth is part of the Solar System, located in The Galaxy, situated in the Universe, what then, makes the Earth so different to any other cosmological body? How can Newtons laws only apply here? Surely, if Newtons laws fail miserably in the rest of the cosmos, they must fail here? For any law to be a Natural law, then the law must apply universally, throughout the entire cosmos, where-ever there is matter. How can Newtons laws be called Natural laws when they fail? Only one theory can be true, or the accepted theories must be wrong. If both are incorrect then some other law must universally apply. It is important to contemplate some historical facts about Newtons laws of motion. Sir Isaac Newton (1642-1747) was a man and as such made mistakes, not just in life, but also in his mathematics, language and science. At the start of his academic career, the Great Plague (1666) closed the Universities, so he left Cambridge to work on his own in the country. Newton taught himself mathematics from just four books and within a year, was making valuable contributions to mathematics and science. When it came to logarithms and The Calculus, Newton had to invent them, developing his own ideas and concepts, or he had to encompass, correct and modify the works of others. Words like mass and energy were not contemplated in this period. There was no one available to teach Newton how to use these methods and equally, there was no-one who could correct or confirm his work. Newton sourced much theory from the works of others and when they seemed true, accepted such mistakes as well. He modified their concepts and ideas into his own constructs. His laws of motion corrected the discoveries of Galileus Galileus (the English xenoym is Galileo Galilei), using deduction and fluxions (The Calculus). Galileus did not include the objects initial motion u. t when he wrote the distance equation s = 1/2 at 2. Newtons correction made sense, where a minor change , s = ut + 1/2 at 2 , bestowed credit on him. Prior to Galileus discovery, the belief was that when a cannon fired a shot, the shell was given impetus by the detonation of the gunpowder. The shell would use up all this impetus as it rose, then fall to the ground when the impetus ran out.