Daniel Sadoc

Physical memory = 32 frames Certainly, we need 5 bits to select one of the frames. Besides, we also need 10 bits to identify one of the 2^10 positions within the frame . Physical address size = 15 bits

Be careful! Satisfability of boolean equations with more than 2 variables is NP-Complete! Satisfability of first order predicates is undecidable. 2-SAT is Polynomial.

Physical memory = 32 frames Logical memory = 8 pages x 1024 words Logical address points to 2 ^ 13 words. Therefore, it needs 13 bits. What about the physical address? Certainly, it needs 5 bits for the frame. But what's the size of each frame? One page has the same size as one frame? If so, physical address needs to address 2^10 positions within a frame. Physical address size = 15 bits

Thank you very much! :tup:

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Topic: "The best ideas arise from a passionate interest in commonplace things." Present your perspective on the issue below, using relevant reasons and/or examples to support your views. Your Answer: Modern society places a key role on ideas. Therefore, nowadays a very complex and debated topic concerns the process of creation and development of good ideas, also know as creativity. Some people think that the best ideas arise from a passionate interest in commonplace things, while others argue that good ideas are generated when people think out of the box about things that are not related to common issues. Let us analyze each of these perspectives in details. Consider, for instance, the well known biologist Mayanard Smith. In the last century, he made a breakthrough in the Biology literature, proposing a new mathematical model in order to understand the conflicts of interest among species. The model that he proposed is able to capture when and why does the cooperation emerge among birds and mamals. When asked about the source of his ideas, Smith replied that he usually talked with the animals that he was trying to analyze. He of course had a very solid background in mathematics and biology. However, the passionate interest that he had for his object of study permitted him to establish a new landmark in his field. In general, people who make important contributions have a very strong interest in the subject that they are dealing with. Nevertheless, subjects such as physics and mathematics sometimes require a passionate interest in things that are not commonplace. For example, consider the studies about the Big Bang. The best theories about how the universe was created are very abstract. However, even in these cases it is possible to derive analogies with common things in order to explain or develop the concepts. After all, there is no work that is completly uncorrelated to commonplace things. Indeed, generally best ideas arise when people are able to see commonplace things through a new perspective. As another example, Charles Darwin developed the abstract theory about the evolution of the species based on passionate observations that he made about the animals around him. Clearly, he wasn't able to reproduce the process throught which species evolve, which lingers for millions of years. Nevertheless, observing commonplace things he figured out an abstract and broad theory in order to explain the reality. To sum up, the creative process is very complex since it involves knowledge and emotion. In essence, a passionate interest in commonplace things is generally the motivation that guides managers, scientists and researchers to develop new ideas. In fact, the capacity of dealing with common things through an uncommon perspective is one of the most important capacities developed by creative people.

Maybe I diverted from the topic... Topic: "It is important for higher education to challenge established traditions and values." Present your perspective on the issue below, using relevant reasons and/or examples to support your views. Your Answer: Efficient forms of education are one of the most fundamental problems debated by the modern society. Indeed, the progresses that will be made by the next generations depend strongly on the education that new students receive. Therefore, it is very important to study and understand the questions instrinsict to this complex problem of devising an excelent educational method. One of the topics involved in this discussion is whether students should be encouraged to challenge established traditions or not. This discussion leads to psychological, social and cultural issues. First, it is important to notice that different people have different levels of maturity at a certain age. In order to challenge traditions and values, it is necessary to have a solid background about what has been tried by the former generations. Hence, it is essencial to first thoroughly study the established traditions so as to develop a critical sense about them. Only after that people may have insights that are truly original. According to the society where people live they may develop their critical sense earlier or later. In the oriental societies, such as in China, people are motivated to absorb the knowledge during a long period of time, and just after that they start to receive incentives to challenge their teachers. In the western society, on the other hand, people are encouraged to challenge the established traditions and values very early. Each of these approaches has its pros and cons. If people challenge established traditions and values too early, they may become lost. Besides, they may think that they are challenging the traditions and values, when in fact what they are doing is repeating what others have done in the past. So, it is essential that people study the references and cultures to be aware of what were the errors and successes achieved by the former generations. On the other hand, if people pass a long time studying the existing traditions and values, they may not develop their critical senses properly. If one is not incentivated to think critically about what he reads or hears, h/she may never develop his/her own ideas. Consequently, it extremely important that, at the proper time, people start challenging the existing traditions and values. To sum up, it is important for higher education to challenge established traditions. The unique way of promoting the progress is challenging the status quo. However, in order to develop a critical sense about the reality it is fundamental that people study the existing traditions. In essence, there is a tradeoff between allocating time to better understand the reality and using the time to challenge the current traditions and devising new ways of thinking. To deal with this tradeoff requires a wise and mature reasoning.

Topic: Hospital statistics regarding people who go to the emergency room after roller-skating accidents indicate the need for more protective equipment. Within this group of people, 75 percent of those who had accidents in streets or parking lots were not wearing any protective clothing (helmets, knee pads, etc.) or any light-reflecting material (clip-on lights, glow-in-the-dark wrist pads, etc.). Clearly, these statistics indicate that by investing in high-quality protective gear and reflective equipment, roller skaters will greatly reduce their risk of being severely injured in an accident. Discuss how well reasoned you find this argument. Your Answer: Protective gears and reflective equipment have recently been focus of attention. The author of an article about these protective equipment argues that roller skaters should use them more frequently so as to reduce the risks of being severly injured in accidents. His reasoning is based on statistics. However, the argument is not convincing, since (a) the author does not distinguish clearly the utility of the protective gears and the reflective equipment, (b) the statistics presented may be biased and © the level of injury of those who went to the hospital is not mentioned. Let us discuss each of these aspects more precisely. First, the author does not distinguish clearly the fact that protective gears are used to decrease the level of injuries of the accidents, while reflective equipment are used to avoid accidents. Although protective gears and reflective equipment are devised to increase the safety of the skatter, the effects of their usage are completely different. From the arguments presented, it is not possible to distinguish what is the most important equipment, and what is the real impact of using them. Besides that, the statistics presented may be biased. The author does not state neither the source of the data collected nor the number of people interviewed. He mentions that within the group of people that went to the emergency room of some hospitals, "75 percent of those who had accidents (...) were not wearing any protective clothing". However, he does not state how many and which were the hospitals analyzed. He also does not mention how many people have gone to the hospitals but did not went to the emergency room. Also, it is not discussed the total number of people who had accidents but did not go to the hospital. Regarding the level of injury of those who went to the hospital, the author should have mentioned how helmets, knee and pads have decreased the harm caused by the accidents. However, he just cites the number of people who went to the emergency room. He does not compare the level of injury of those who were using helmets and those who were not. To sum up, the author argues that skatters should invest in high-quality protective gear and reflective equipment. Nevertheless, he does not give adequate support to his argument, weaking the soundness of his reasoning. The impacts of the protective clothing and light-reflecting material are not clearly stated and distinguished, the statistics may be biased and the level of injury of those who were in the accidents is not discussed. To improve the quality of the argument, the author needs to consider these extra issues.

Hi People, My test is tomorrow. Please, I would like to know how to improve the composition below. E-Rater gave me a score of 5.0. The feedback was: - style: repetition of word ("accident") - organization and developmnet: e-rater has identified only one main idea. How should I clearly expose the three ideas in the composition? - statistics: 430 words, 22 sentences Best regards, Daniel Topic: Six months ago the region of Forestville increased the speed limit for vehicles traveling on the region's highways by ten miles per hour. Since that change took effect, the number of automobile accidents in that region has increased by 15 percent. But the speed limit in Elmsford, a region neighboring Forestville, remained unchanged, and automobile accidents declined slightly during the same six-month period. Therefore, if the citizens of Forestville want to reduce the number of automobile accidents on the region's highways, they should campaign to reduce Forestville's speed limit to what it was before the increase. Discuss how well reasoned you find this argument. Your Answer: The speed limit in the region of Forestville has recently been focus of critics. The author of a critic argues that the speed limit should be decreased. His argument is based on statistics that compare the number of accidents in Forsetville and Elmsford. However, his reasoning is not convincing, since (a) the statistics considered may be biased, (b) the author does not mention what is the speed limit in Elmsford and © there is no clear relationship of cause and effect between the speed limit and the number of accidents. Let us analyze each of these issues in details. First, the author presents statistics showing that the number of automobile accidents increased by 15 percent in Forestville during the last semester. But he does not mention what was the absolute number of accidents in Forestville and in Elmsford. This information is essential, since if the number of accidents in Elmsford used to be huge and the number of accidents in Elmsford is small, both a slight decline in the number of accidents in Elmsford and a 15 percent increase in the number of accidents in Forestville are insignificant. Second, the author mentions that "the speed limit in Elmsford (...) remained unchanged, and automobile accidents declined". Nevertheless, he does not mention what is the speed limit in Elmsford. It is possible that the Forestville increase of the speed limit was done so as to make it equal to the one used in Elmsford. In that case, it is possible that in the short run, during a period of adaptation, the number of car accidents in Forestville increased. In the long run, the number of car accidents may become stable, or even decrease. Third, it is possible that during the six months considered the number of accidents historically has been greater compared to the other semester. For instance, during winter the number of car accidents may increase because of snow. So, the author needs to give more data about how automobile accidents were distributed among the months during the last years. If the number of accidents usually increases by more than 15 percent during the six months considered, than the speed limit had a positive effect, and not the opposite. To sum up, the author argues that the limit speed for vehicles in Forestville should be decreased. However, he does not give adequate support to his argument, and that destroys its soundness. The statistics showed are incomplete, the comparisons made are nebulous and the implicit cause-effect relationship established is not clear. The author needs to reconsider these details in order to better support his theory.

Topic: A recent survey of dental patients showed that people who use Smile-Bright toothpaste are most likely to have capped teeth---artificial but natural-looking protective coverings placed by dentists on individual teeth. Those people who had begun using Smile-Bright toothpaste early in life were more likely to have capped teeth than were people who had begun using Smile-Bright later in life. In addition, those who reported brushing their teeth more than twice a day with Smile-Bright toothpaste were more likely to have caps on their teeth than were those who reported brushing with Smile-Bright less frequently. Therefore, people wishing to avoid having their teeth capped should not use Smile-Bright toothpaste. Discuss how well reasoned you find this argument. Your Answer: The author concludes that people should avoid using Smile-Bright toothpaste if they don't want to have their teeth capped. His reasoning is based on the statistics relating the frequency of usage of the Smile-Bright toothpaste and the likeliness of having capped teeth. Altough the ideas are clearly stated, the argument is not convincing because the source of the data presented is not mentioned, the relation between the causes and effects showed are not evident and nothing is stated about non Smile-Bright toothpastes. Let us consider each of these aspects in details. First, the statistics presented may be biased. The author does not mention how many people were interviewed, how frequently have they used the Smile-Bright toothpaste, and when did they started using it. He uses vague expressions, such as "later in life" and "early in life" to describe those who have used the toothpaste in the short run and in the long run, respectively. Besides that, the author implies that there is a relation of cause and effect between using the Smile-Bright toothpaste and having teeth capped. However, nothing is stated in order to support this theory. The fact that more people who used Smile-Bright had their teeth capped may be caused by lots of reasons. For instance, those who use Smile-Bright toothpaste may be more concerned with their health and teeth. Therefore, they go more frequently to dentists, and have a greater probability of having their teeth capped. In addition, the author does not discuss the differences between the Smile-Bright toothpastes and the other toothpastes. It is not clear that other toothpastes would cause less harm to the health than the Smile-Bright toothpaste. Indeed, the other toothpastes may have chemical substances that are even worse compared to those contained in the Smile-Bright toothpaste. To sum up, the author argues that Smile-Bright toothpaste should not be used so as to avoid having the teeth capped. However, he does not give proper arguments to support the fact that Smile-Bright toothpastes are the real causes of having the teeth capped. He also doe not discuss the properties of other kinds of toothpastes available in the market. Therefore, more data needs to be collected in order to better understand what are the pros and cons of the Smile-Bright toothpaste, and to give a final judgement about whether it should be avoided or not.

Another approach: ( 13C4 + 13C4 + 13C4 + 13C4 ) / ( 52C4 ) 4 . ( 13 . 12 . 11 . 10 ) / ( 4 . 3. 2 ) _______________________________ = ( 52 . 51. 50. 49 ) / ( 4 . 3. 2 ) = ( 12/51 ) ( 11/50 ) ( 10/49 ) Another approach: 52 x 51 x 50 x 49 ways of selecting 4 cards 52 x 12 x 11 x 10 ways of selecting 4 cards of the same suit answer = 52 x 12 x 11 x 10 _______________ = 52 x 51 x 50 x 49 12 x 11 x 10 _____________ 51 x 50 x 49

bf + bc + fc = (number of people that play exactly two sports) + 3 (number of people that play three sports) = (number of people that play at least two sports) + 2 (number of people that play three sports) = 8 + 2 x 1 = 8 + 2 = 10

where is the circle?

Another approach: Use the inclusion/exclusion principle http://mathworld.wolfram.com/Inclusion-ExclusionPrinciple.html n = b + f + c - ( bf + bc + fc ) + bfc + none n = 20 + 30 + 25 - ( 8 + 2 ) + 1 + none = 67 none = 67 - 75 + 10 - 1 = 1

Thanks. I've corrected it. ;)