Improving Cache Performance by Selective Cache Bypass

In traditional cache-based computers, all memory references are made through cache. However, a significant number of items which are referenced in a program are referenced so infrequently that other cache traffic is certain to “bump” these items from cache before they are referenced again. I n such cases, not only is there no benefit in placing the item in cache, but there is the additional overhead of “bumping” some other item out of cache to make room for this useless cache entry. Where a cache line is larger than a processor word, there is an additional penalty in loading the entire line from memory into cache, whereas the reference could have been satisfied with a single word fetch. Simulations have shown that these effects typically degrade cache-based system performance (average reference time) by 10% to 30%. This performance loss is due to cache pollution; by simply forcing “polluting” references to directly reference main memory — bypassing the cache — much of this performance can be regained. The technique proposed in this paper involves the use of new hardware, called a Bypass-Cache, which, under program control, will determine whether each reference should be through the cache or bypassing the cache and referencing main memory directly. Several inexpensive heuristics for the compiler to determine how to make each reference are given

Compiler-Driven Cache Policy (Known Reference String)

Increasing cache hit-ratios has proved to be instrumental in improving performance of cache-based computers. This is particularly true for computers which have a high cache-miss/cache-hit memory reference delay ratio. Although software policies are often used for main vs. secondary memory caching , the speed required for an implementation of a CPU vs. main memory cache policy has prompted only investigation of policies which can be implemented directly in hardware. Based on compile-time analysis, it is possible to predict program behavior, thereby increasing the hit-ratio beyond the capability of pure run-time (hardware) techniques. In this report, compiler-driven techniques for this kind of cache policy are described. The SCP Model (software cache policy model) provides an optimal cache prefetch and placement/replacement policy when given an arbitrary memory reference string. In addition to suggesting a simplified cache hardware model, the SCP Model can be applied to various cache organizations such as direct mapping, set associative, and full associative. Analytic results demonstrate significant improvements in cache performance. The current work discusses an optimal cache policy which applies where the string of references is known at compile time. However, this constraint can be relaxed to encompass reference strings which are known only statistically, i.e., reference strings in which data aliases make the target of some references ambiguous. Companion reports, currently in preparation, detail the extension of the SCP Model to incorporate aliases, code incorporating loops, and conditional branches

Consideration of Data Security and Privacy Using Machine Learning Techniques

As artificial intelligence becomes more and more prevalent, machine learning algorithms are being used in a wider range of domains. Big data and processing power, which are typically gathered via crowdsourcing and acquired online, are essential for the effectiveness of machine learning. Sensitive and private data, such as ID numbers, personal mobile phone numbers, and medical records, are frequently included in the data acquired for machine learning training. A significant issue is how to effectively and cheaply protect sensitive private data. With this type of issue in mind, this article first discusses the privacy dilemma in machine learning and how it might be exploited before summarizing the features and techniques for protecting privacy in machine learning algorithms. Next, the combination of a network of convolutional neural networks and a different secure privacy approach is suggested to improve the accuracy of classification of the various algorithms that employ noise to safeguard privacy. This approach can acquire each layer's privacy budget of a neural network and completely incorporates the properties of Gaussian distribution and difference. Lastly, the Gaussian noise scale is set, and the sensitive information in the data is preserved by using the gradient value of a stochastic gradient descent technique. The experimental results showed that a balance of better accuracy of 99.05% between the accessibility and privacy protection of the training data set could be achieved by modifying the depth differential privacy model's parameters depending on variations in private information in the data

Patriotism or conciliation in Sion-British relations, 1839-1848: Lin Tse-Hsu and Ch'i-Ying

Every nation lives with its past, even if unaware. The Chinese remember with pride the time when they were respected as a great civilisation and were a great power; they also remember with bitterness the time when they were despised as an inferior race. Chinese communists firmly believe Lenin's saying: "Imperialism means aggres¬ sion and war." In their memory, imperialism from the beginning of modern Chinese history (the Opium War) first sapped China of her wealth and her people of their health, later it detached her vassal states, and eventually turned her into a "semi-colonial state."In this thesis, I propose to examine the genesis of Lin's policy of resistance during the Opium war and its influence contending with Ch'i-ying's conciliatory policy in the post-war period. By analysing Lin's victory and Ch'i-ying's failure, we can observe that China's management of its foreign relations during and after the Opium War .suffered from pride, prejudice and hatred against the Westerners. These elements jeopardized the conciliatory policy of those open-minded persons who insisted that must be in order to prevent conflicts between China and the West. My basic sources of information are furnished by Chinese materials both published and unpublished, specially the F0682 Canton archives of from the yamen of the governor-general^Kuang-tung and Kuang-si in the Public Record Office, London, supplemented by the rich western accounts and archives. Before embarking on a detailed scrutiny of the happenings of the period covered by this thesis, it will be well to describe these elements before the Opium War

The effects of sulphur and copper on hot-workability of pure iron

The independent effects of sulphur, copper and their combinations on the hot-workability of pure iron free from other elements was studied, with special emphasis on the red-short phenomenon. Electrolytic pure iron with the addition of 0.023 cent sulphur, 0.33 per cent copper and 0.024 per cent sulphur plus 0.032 per cent copper along with a heat of only electrolytic pure iron was melted under vacuum, and cast under helium pressure. The specimens machined from the forged bars were tested at various temperatures by the hot twist-test and by the constant energy single blow drop forging test to evaluate the hot-workability and red-shortness. The red-short temperature range starts from not too far above the eutectic point of the iron-sulphur system and extends up to a certain temperature at which the solubility of sulphur in gamma iron is much more than sufficient to absorb all the sulphur content. The red-short range starts and ends gradually rather than suddenly, especially at the upper end of the red short range. The red-short range can be illustrated by the grain boundary strength curve, which dips down to lower than the grain strength at this temperature; this provides an easy way to evaluate the red-short range, by plotting the deformation or torque curve of the iron in question along with that of the normal one. Copper itself proved not to induce any red-shortness nor make the sulphur effect worse at the amount of 0.33 per cent copper content in this investigation, but indicates beneficial effects --Abstract, page 6

The Investigation of Platinum-Tellurium/Aluminum-Oxide and Platinum-Antimony/Aluminum-Oxide Bimetallic Reforming Catalysts.

PtTe/Al\sb2O\sb3 and PtSb/Al\sb2O\sb3 bimetallics were characterized as possible reforming catalysts by kinetic studies, mechanistic investigations, and spectroscopic measurements. The results were compared with Pt/Al\sb2O\sb3 with the aim to understand the effects of tellurium and antimony on the platinum function. Coimpregnated PtTe/Al\sb2O\sb3 and PtSb/Al\sb2O\sb3 catalysts exhibited an increase in selectivity for the isomerization of n-hexane. This enhancement in selectivity can be caused either by electronic effects, which increase the specific activities for isomerization, or by geometric effects, which reduce the rate of hydrocracking. The results of the kinetic experiments, along with FTIR spectroscopy of adsorbed carbon monoxide using the isotopic dilution method, suggest that electronic effects can be identified with Te/Pt alloying in catalysts of low (Te/Pt $\u3c$ 0.06) tellurium content, while geometric effects predominate in catalyst formulations more concentrated in the post-transition metal for both PtTe/Al\sb2O\sb3 and PtSb/Al\sb2O\sb3. The cyclohexane dehydrogenation turnover frequencies were also enhanced at low Te/Pt ratio; in this respect the dehydrogenation and isomerization reactions are similar. Direct six-member ring closure, rather than ring expansion by way of an adsorbed methylcyclopentane intermediate, accounted for most of the production of benzene. The isomerization reactions of carbon-13 labeled 2-methylpentane were used to determine the relative contributions of cyclic and bond shift mechanisms. n-Hexane was formed primarily by a C\sb5 cyclic mechanism on the platinum surface, while 3-methylpentane was produced by both cyclic and bond shift mechanisms. Isomerization via bond shifts increases when tellurium or antimony is added to Pt/Al\sb2O\sb3. The reaction of benzene and deuterium at 110 and 250\sp\circC showed that carbon-hydrogen bond breaking/making is extremely fast. Since diffusion may affect the deuterium levels in the hydrocarbon molecules, no other firm conclusions may be drawn. PtTe/Al\sb2O\sb3 catalysts were also prepared by vapor deposition of tellurium onto Pt/Al\sb2O\sb3. These catalysts exhibited selectivities which were influenced by the type of carrier gas used to deposit the tellurium. A carrier gas containing n-hexane improved the selectivity relative to hydrogen or helium carrier gases. The mechanism of this selectivity effect is unknown but possibly due to carbon incorporation into a Pt-Te alloy

A Study of School Achievement Among Elementary School Students with Working and Nonworking Mothers

Statement of Problem Most parents face the question of whether the wife should seek employment outside the home during the years that their children are attending elementary school. Many families have no choice since the costs of daily living make it necessary to pursue a double income. A large portion of parents do, however, have a choice as to whether the mother should go to work. In many homes the second income goes toward obtaining some of the extra-things not normally available due to financial limitations. Mothers who work outside of the home will have less time to stay home relatively and take care of their children. Furthermore, after she returns from her place of employment, her strength will compare unfavorable maybe even be exhausted. This may affect on her care of children. Cyrus (1952) found that the working mother\u27s child is more irritable. Now Taiwan, Republic of China is stepping into industrialized society, and the number of working mothers is increasing; therefore, this topic needs to studied what is the effect of maternal employment on the scholastic performance of children? Purpose of This Study The purpose of this investigation was to determine if children with working mothers do in fact differ from children with nonworking mothers in school achievement as numerous educators and sociologists profess. More specifically, answers to the following questions were sought: 1. Is there a difference in school achievement among children from homes where the mother works full-time, part-time, or not at all? 2. Do boys and girls differ in school achievement among the maternal employment groups? Conclusions 1. Maternal Employment And Intelligence. There is no difference in intelligence among children from homes where the mothers works full-time, part-time, or not at all. 2. Maternal Employment And School Achievement. There is no difference in school achievement among children from homes where the mothers works full-time, part-time, or not at all i.e. hypothesis 1,2,3, and 4 were rejected. The reason why might be that early elementary children were too young to quality to have achievement effected by the maternal employment status. 3. Sex Difference Of School Achievement Were Concluded As Follows: (a) There is no significant sex difference in first semester of first year. (b) In second semester of the first year, girls\u27 grade point was higher than boys\u27 for Chinese Language Arts and grade point average of 3 courses, but there was no difference on Arithmetic and Social Studies. (c) In the whole first year, girls\u27 grade point was higher than boys\u27 on Chinese Language Arts and grade point average, but Arithmetic and Social Studies are not significant. (d) In the first semester of second year, girls\u27 grade point was higher than boys\u27 on Chinese Language Arts and Arithmetic, but Social Studies and grade point average were not. (e) In the second semester of second year, there were significant differences between boys and girls on all 3 courses and grade point average. Girls were higher. (f) In the whole second year there were significant differences between boys and girls except for Social Studies, with girls being higher. (g) In the whole two years, girls were higher than boys on all 3 courses and grade point average. There was no significant interaction among boys and girls i.e. boys and girls did not differ in school achievement among the maternal employment groups at any period or for any courses in the first two years of elementary school. Hypothesis 5,6,7, and 8 were accepted. Recommendations 1. One of the findings of this investigation was that there is no difference in school achievement among maternal employment groups. The wise woman surely does not use all other ability outside of home, but she still faithfully carries out her duties in the home as well. 2. There are sex differences in school achievement of early elementary school children. The teacher should pay attention to the sex differences in his/her instruction. 3. The subjects of the present study were first two grade students of elementary school. If we want to understand the entire situation, we should continue studying what happens with the older students of elementary schools, high school students and college students. 4. This study only gives heed to the maternal employment status, and did not notice to the kind of profession, the official position, the children caring, the level of satisfaction of working mother, and the attitude of children toward maternal employment etc. Those factors should be noticed in the further studies. 5. There were some studies found where boys were higher than girls on mathematics and social studies, but the results of this study were opposite. The reason why has not been answered by the author. Is there a racial difference or not? That needs to be studied