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- Marked by Teachers essays 2
Linux memory management. Linux uses demand paging where the virtual pages are only loaded into physical memory when needed by the process. Swapping occurs when a process needs to bring data from the virtual memory to the physical memory,
Each of these pages has a page frame number (PFN). Linux uses demand paging where the virtual pages are only loaded into physical memory when needed by the process. Swapping occurs when a process needs to bring data from the virtual memory to the physical memory, if there is no space available an old page is swapped out of memory to bring in the new one. Linux the Least Recently Used (LRU) technique to efficiently choose pages which are to be removed from the system.
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IT Security. In this practical we focus on digital signing based on RSA and ElGamal. We also look at the Digital Signature Standard and the use of hashing when signing.
Determine if Bob should accept the signed message as valid. Solution. Bob checks by computing 5444 (mod 5023) = 4678 and also ybbg (mod p) =3796229422943740 = 728. So no, Bob should not accept the message as being validly signed by Alice. C. The questions in this section deal with attacking the El Gamal scheme. 1. In this case, Oscar, the attacker, uses Alice's scheme set-up parameters p = 5023, a = 5 and y = 5a = 3796. Oscar picks random , r1 = 205 and r2 = 1021.
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And for the most part, it is. There are many concepts that Farrell ploughs through to try and explain to the reader, many of which don't help in answering the question posed in the title. One example of this would be Farrell's divergence to explaining the two MUA integrated protocols, S/MIME and OpenPGP, and how these have not been incorporated mainstream MUA program operations. He doesn't entirely describe why the protocols "remain unused" (though he partly answers this under the following section), but how "these protocols are deployed" (Farrell 2009, p.83).
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A laser printer is a high-speed, high-quality nonimpact printer. Laser printer are available in both black-and-white and colour models. Figure 1 Laser printers are available in both black-and-white and colour models. The objective of this article is to give more knowledge about the functions of laser printers. Details and specifications of these printers will also be provided. Furthermore, it also shows the benefits and disadvantages of this kind of printer, and help users to choose a printer to purchase. 2. Specification Of Laser Printers Laser printers print text and graphics in high-quality resolutions, usually 1200 dpi for black-and-white printers and up to 2400 dpi for colour printers.
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Experiment A: Chanalyzer After inserting the 'dongle' in the USB port and running the Chanalyzer u will be able to see several access points and channels which match with those found using Netstumbler. Access Points and Channels as seen in Network stumbler Chanalyzer provides three different views to guide us manage issues with Wi-Fi networks: * Spectral View: depicts bandwidth use over time with a graph that plots the time period chosen against the range of frequencies, with each point colour-coded where red is high and blue is low.
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NetStumbler or Network Stumbler is a Windows tool that facilitates discovery of Wireless local area networks using the 802.11b, 802.11a and 802.11g Wireless LAN standards
A site survey typically includes finding out what existing items (microwave ovens, cordless phones, radio hams) are using the radio frequencies as the wireless LAN. Before installing a wireless LAN a survey should be done and after installation some subsequent surveys should be performed. Hardware such as an RF spectrum analyzer is generally used for a full site survey, but Netstumbler can also be for surveying a site partially. Turn the Auto Reconfigure on, to ensure that as many wireless LANs as possible are detected.
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hostile environments * there are considerable advantages in reaching an accurate answer quickly http://library.thinkquest.org/11534/expert.htm How are they different from a conventionally coded system? Expert systems are differ from conventionally coded system because expert system can do lot of things then a normal conventionally coded system. Also a expert system are able to perform more than one tasks at a time but the conventionally coded system does not allow to perform that way they are just using a basic programming language. Describe the architecture/Design of a typical Expert System 2) http://www.cee.hw.ac.uk/~alison/ai3notes/subsection2_5_2_1.html The above diagram shows the importance of a rule base system.
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Asynchronous data transmission is fine if the volume of data to be transferred is low. However, owing to the high overhead incurred, transferring large volume of data asynchronously is very slow. Also the lack of timing information sent with data the data restricts asynchronously transmission to low data rates. Asynchronous character representation Star bit 1 bit 7-bit ASCII character Parity bit 1 bit Stop bit 1 bit Synchronous Communication Synchronous data transmission is used to overcome these limitations. With synchronous transmission, rather than sending individual characters, a block of characters is sent.
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Example: Mary is angry with Peter and she doesn't want to talk to him. When he tries to engage her in conversation, she might: 1. stare ostentatiously at the ceiling. 2. open a newspaper and start to read it. 3. look angrily at Peter and clamp her mouth shut. 4. look angrily at Peter, put a finger to her lips and whisper `Shh`. 5. say `I m deaf and dumb`. 6. say `I won't talk to you`. * What do Mary's actions communicate to Peter? * Which, if any, of Mary's actions encode some part of her meaning?
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The hospital today is striving to achieve the best handling of patients' historical records as well as the common problem how to provide the best medical care to thousands of patients that receive care from multiple physicians
Other problems are as followings: * Physicians and staff have to wait for the delivery of patient's record. * The hospital operated with paper only. Dictated documents and lab results often took weeks to reach the patient's chart. * The paper filing process was not conductive to ensure that most recent information was available. * Many of historical data regarding to service involved can be lost. * The work flow resulted in manual process lead to frequent inefficiencies, such as delays in returning patient phone calls , scheduling appointed to re-diagnose or follow up their symptom.
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This wastes space and makes updating more time-consuming. A database system minimises these effects. Data independence is another benefit of the database approach. In short, data independence means that the data is held in such a way that changes to the structure of the database do not affect any of the programs used to access the data. Other advantages that organizing information in a database brings are integrity of data and greater security of data. With a database management system (DBMS), users are provided with the ability to specify constraints on data such as making a field entry essential or using a validation routine.
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CPU scheduling deals with the issue of deciding which of the processes in the ready queue is to be allocated the CPU. Many different scheduling algorithms exist and these are the most important ones:
� Response time: Measures the time from the submission of a request until the first response is produced. SCHEDULING ALGORITHMS: CPU scheduling deals with the issue of deciding which of the processes in the ready queue is to be allocated the CPU. Many different scheduling algorithms exist and these are the most important ones: First Come First served (FCFS): This is the simplest scheduling algorithm, where the process that requests the CPU first is allocated the CPU first; it generates an average waiting time that varies significantly according to the CPU burst times. But it produces a "convoy effect", where all the other processes wait for the one big process to get off the CPU.
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However, this ease of use can be misleading. This sort of developer is often an office worker with little or no training in application or data design. Because Access makes it possible even for such developers to create usable systems, many are misled into thinking that the tool itself is limited to such applications. 2. The tasks/process, it is specifically designed for. Professional application developers use Access for rapid application development, especially for the creation of prototypes and standalone applications that serve as tools for on-the-road salesmen. Access does not scale well if data access is via a network, so applications that are used by more than a
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Around 5 evaluators can usually discover 75% of a systems usability faults according to Nielsen (2003). Abowd (1994) describes heuristic evaluation as a "design time evaluation technique", as it is easier to fix many problems with a system at the design stage. In relation to the statement "heuristic evaluation is an essential element of systems' development" and its relevance, it is best to first look at the benefits of using a heuristic evaluation. UsabilityNet (2003) outlines the five following benefits of this technique: 1. The method provides quick and relatively cheap feedback to designers. The results generate good ideas for improving the user interface.
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This report focuses on how the OSI (Open System Interconnection) and TCP/IP (Transmission Control Protocol/Internet Protocol) compare and contrast.
Main Body: Both TCP/IP and OSI relate to the networking system divided into layers. Each layer performs a certain function, interacting directly only with the layer beneath or above it. The laying of both models is the following: OSI TCP/IP Application (Layer 7) Application Presentation (Layer 6) Session (Layer 5) Transport Transport (Layer 4) Network (Layer 3) Internet Data link (Layer 2) Network Access Layer Physical (Layer 1) Both models adhere to the same principle. Data is being passed from the application layer dawn the stack when it is being sent over the network (Physical Layer).
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The main Computer (CUSSBASE) has to keep record of every cardholder's identity. The CUSSENSEs have to be powerful enough to cover every possible area. For the moment, City University operates with a swipe-card and manual card check system. People who enter the buildings are asked to show their City University ID to a member of staff. To enter certain areas such as the computer labs, people have to swipe their card, and if their ID is valid, the door will unlock.
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In order to reach the stage of the final Entity Related diagram (I shall call this the ERM) I had to go through quite a large amount of data and processes. The first process being normalization, done through the nine forms given to us
To start with at this first stage I just introduced a name and a primary key. This is where I encountered the first main problem, what to use as a primary key? Some of the tables of data didn't have an obvious key, so where absolutely necessary I created my own for example, Order Number on the Order Form (see page two). From here the initial information can (normally) be broken down, for example figure one below is part of a normalization table (Ingredients Forecast, page one) showing an initial split from UNF to First Normal Form (FNF), (Blue=Name, violet=Primary Key and orange=Foreign Key)
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It is a hybrid of the FPTP system and the Party List system. The operation of the AMS system Two key points which characterise the system: 1. Each voter casts two votes at the same time - one for a constituency MP and the other for a party. 2. There are two different types of MPs elected - constituency MPs and the 'additional members' (those elected using the party lists). The voter casts one vote for a constituency MP. This process is identical to the FPTP system as it operates on a simple majority basis.
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Science fiction writers came up with all kinds of machines like "The Terminator", which led people to believe that such machines were just round the corner. "2001: A space odyssey" that talked about the existence of such machines in the early 21st century. But when computer scientists actually got down to creating such machines, they realized the problem was much larger than they had imagined. Conventional computers find it very difficult to do basic things that people do. When we look at the picture of a Hyundai Accent or a Tata Indica, we have no trouble identifying it as a car.
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It can look as if the Tsar was more a dictator than a monarch. The other consequences of the Tsars hold on Russia were the failing and ineffective administration that eventually led to the Tsarist systems downfall. A centrally appointed bureaucracy ruled Russia itself. The size of Russia made a unitary system completely ineffective, for example on the Western borders were Polish Jews yet in the Far East were peoples of Oriental origin at Vladivostok. No centralised government could understand the needs of all these peoples at the same time. The actual size of the country itself also made administration difficult as messages took a long time to pass from border to border.
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E-mail also has the advantage of being less expensive, for most people, than regular mail. Many people have access to e-mail for free through their work or school. And while some people may pay for e-mail through an online service, there is no increase in cost relative to the number of messages sent. It is the same price to send one message to one person as it is to send several messages to a hundred people. There is no question that e-mail is convenient. It allows us to send the same message to many people at the same time with little more effort than it takes to send a message to one person.
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Linz describes two main features of presidentalism: the first, "president's strong claim to democratic, even plebiscitarian, legitimacy" and "the second is his fixed term in office". The second argument is really seemed stronger to argue against presidentalism. Because, during four or five years until next elections the other political groups - "the losers" have not any opportunity to participate in executive power. Moreover, as Linz describes, in case of president's death or incapacity person who is not elected by direct popular vote or who has not elected by citizens can come to power.
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If the machine that the converting does not have a math co processor it would take a very long time to complete a conversion, or in most cases be impossible to complete in real time. LPC is very sensitive to high frequencies and clipping caused by a microphone with an input level set to high, this is even more apparent when a person with a high frequency voice uses the compression as LPC removes a lot of the high frequency data, making their message (in the case of voice mail)
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