حل تشریحی سوالات زبان تخصصی (انگلیسی) - کنکور ارشد مهندسی کامپیوتر 1401

PART C: Reading Comprehension Directions: Read the following three passages and answer the questions by choosing the best choice (1), (2), (3), or (4). Then mark the correct choice on your answer sheet. PASSAGE 1: When a user enters a query into a search engine (typically by using keywords), the engine examines its index and provides a listing of best-matching web pages according to its criteria, usually with a short summary containing the document title and sometimes parts of the text. The index is built from the information stored and the method by which the information is indexed. The usefulness of a search engine depends on the relevance of the results set it gives back. For instance, there may be millions of web pages that include a particular word or phrase, but some pages may be more relevant, popular, or authoritative than others. Most search engines employ methods to rank the results to list the "best" results first. How a search engine decides which pages are the best matches, and in what order the results should be presented, varies widely from one engine to another. Also, search engine ranking methods change over time as the way users interact with internet services changes and new techniques evolve. Many search engines, such as Google and Bing provide customized results based on the user's activity history. This leads to an effect that is called a filter bubble. The term describes a phenomenon in which websites use algorithms to selectively guess what information a user would like to see, based on information about the user (such as location, past click behavior and search history). As a result, websites tend to show only information that agrees with the user's past viewpoint, effectively isolating the user in a bubble that tends to exclude contrary information.

PART C: Reading Comprehension Directions: Read the following three passages and answer the questions by choosing the best choice (1), (2), (3), or (4). Then mark the correct choice on your answer sheet. To "recover" data from a bad sector, one would simply need to issue the Read Long command instead of the "normal" Read Sectors command. That is really it! It is so simple that any software developer who is familiar with hard drives can do it. And sure enough, more and more data recovery tools now come with a Bad Sector Recovery option. In fact, if a tool does not have a bad sector recovery feature, it automatically falls into a second-grade category. Error checking and correction algorithms were implemented for a reason, which is data integrity. When a hard drive reads a sector with the Read Long command, it disables these algorithms and hence there is no way to prove that you get valid data. Instead, you get something, which may or may not resemble your customer's data. Tests in our lab had shown that this approach allows you to get much more random bytes than anything else. Yes, there are cases where this approach allows recovering original data from a sector. But these cases are extremely rare in real data recovery scenarios, and even then, only a part of the recovered sector will contain valid data. There are tools that claim better bad sector recovery. But they utilize a statistical approach, an algorithm where the tool reads the bad sector a number of times and then reconstructs the "original" sector by locating the bits that occur most often in the sector. While these tools claim this approach could improve the outcome, there is no evidence to back up the validity of such claims. Furthermore, re-reading the same spot many times while the hard drive is failing is a reliable way to cause permanent damage to the media or heads.

PART C: Reading Comprehension Directions: Read the following three passages and answer the questions by choosing the best choice (1), (2), (3), or (4). Then mark the correct choice on your answer sheet. There are two important types of packet networks: connectionless packet networks and connection-oriented packet networks. Connectionless packet networks operate in a way analogous to the post office. Connectionless networks offer best effort packet• delivery service. Connectionless packets are launched into the network with a large and powerful header that contains all the information necessary to deliver the packet, whatever its destination. As a by-product of their connectionless nature, it is not possible to guarantee performance or reserve network resources for any particular communication, so connectionless networks do not support real-time services reliably. The switches in the network are stateless. When the network is subjected to overload, packets are buffered for later delivery. If the buffer capacity is exceeded, the packets are discarded. In connectionless networks there is no guarantee that all packets will traverse the same network path and be subject to the same delays. If a communication requires the transmission of a series of packets, it is up to the end stations to ensure that the sequence is preserved. Connection-oriented packet networks have similarities with both circuit networks and packet networks. They are like circuit networks in that a connection, called a virtual circuit, must be established before data can be transported. Network nodes are prepared to support virtual circuits, and they devote resources to them. The resources include buffer memory and link bandwidth. Assumptions are made about the traffic likely to be contributed by a11 the sources, and the network may overload if a11 sources begin sending packets at their peak rate. Occasional pileups of traffic are to be expected and are handled by maintaining local memory to buffer packets until it is possible to transmit them. The network is not stateless. When all the resources are committed, the network may deny requests to establish new virtual circuits. The headers of connection-type packet networks can be shorter than those of connectionless networks because the addressing portion of the header needs only to distinguish each virtual circuit from each other established on common links and switch ports.