• Title/Summary/Keyword: Speculative History

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Branch Prediction with Speculative History and Its Effective Recovery Method (분기 정보의 추측적 사용과 효율적 복구 기법)

  • Kwak, Jong-Wook
    • The KIPS Transactions:PartA
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    • v.15A no.4
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    • pp.217-226
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    • 2008
  • Branch prediction accuracy is critical for system performance in modern microprocessor architectures. The use of speculative update branch history provides substantial accuracy improvement in branch prediction. However, speculative update branch history is the information about uncommitted branch instruction and thus it may hurts program correctness, in case of miss-speculative execution. Therefore, speculative update branch history requires suitable recovery mechanisms to provide program correctness as well as performance improvement. In this paper, we propose recovery logics for speculative update branch history. The proposed solutions are recovery logics for both global history and local history. In simulation results, our solution provides performance improvement up to 5.64%. In addition, it guarantees the program correctness and almost 90% of additional hardware overhead is reduced, compared to previous works.

A Branch Predictor with New Recovery Mechanism in ILP Processors for Agriculture Information Technology (농업정보기술을 위한 ILP 프로세서에서 새로운 복구 메커니즘 적용 분기예측기)

  • Ko, Kwang Hyun;Cho, Young Il
    • Agribusiness and Information Management
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    • v.1 no.2
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    • pp.43-60
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    • 2009
  • To improve the performance of wide-issue superscalar processors, it is essential to increase the width of instruction fetch and the issue rate. Removal of control hazard has been put forward as a significant new source of instruction-level parallelism for superscalar processors and the conditional branch prediction is an important technique for improving processor performance. Branch mispredictions, however, waste a large number of cycles, inhibit out-of-order execution, and waste electric power on mis-speculated instructions. Hence, the branch predictor with higher accuracy is necessary for good processor performance. In global-history-based predictors like gshare and GAg, many mispredictions come from commit update of the branch history. Some works on this subject have discussed the need for speculative update of the history and recovery mechanisms for branch mispredictions. In this paper, we present a new mechanism for recovering the branch history after a misprediction. The proposed mechanism adds an age_counter to the original predictor and doubles the size of the branch history register. The age_counter counts the number of outstanding branches and uses it to recover the branch history register. Simulation results on the SimpleScalar 3.0/PISA tool set and the SPECINT95 benchmarks show that gshare and GAg with the proposed recovery mechanism improved the average prediction accuracy by 2.14% and 9.21%, respectively and the average IPC by 8.75% and 18.08%, respectively over the original predictor.

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형이상학과 수학적 추상에 관한 소고

  • 이건창
    • Journal for History of Mathematics
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    • v.15 no.3
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    • pp.49-58
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    • 2002
  • The present paper aims to show basic substitution between metaphysics and mathematical abstraction in the philosophy of mathematics. The general troths of metaphysics and the truths particularly relevant to tile nature of mathematical abstraction serve as speculative guides in ordering the content and discussing the nature of the multiple questions which lie between the disputed frontiers of metaphysics and mathematical abstraction.

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수학적 추상의 본질에 관한 소고

  • 이건창
    • Journal for History of Mathematics
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    • v.14 no.2
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    • pp.69-76
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    • 2001
  • This paper aims to show an inner, basic harmony between metaphysics and current directions in mathematics and in the philosophy of mathematics. In this attempt, the general truths of metaphysics and the truths particularly relevant to the nature of mathematical abstraction serve as speculative guides in ordering the content and discussing the nature of the multiple questions lie between and disputed frontiers of metaphysics and mathematics.

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Simple Recovery Mechanism for Branch Misprediction in Global-History-Based Branch Predictors Allowing the Speculative Update of Branch History (분기 히스토리의 모험적 갱신을 허용하는 전역 히스토리 기반 분기예측기에서 분기예측실패를 위한 간단한 복구 메커니즘)

  • Ko, Kwang-Hyun;Cho, Young-Il
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.6
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    • pp.306-313
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    • 2005
  • Conditional branch prediction is an important technique for improving processor performance. Branch mispredictions, however, waste a large number of cycles, inhibit out-of-order execution, and waste electric power on mis-speculated instructions. Hence, the branch predictor with higher accuracy is necessary for good processor performance. In global-history-based predictors like gshare and GAg, many mispredictions come from commit update of the history. Some works on this subject have discussed the need for speculative update of the history and recovery mechanisms for branch mispredictions. In this paper, we present a simple mechanism for recovering the branch history after a misprediction. The proposed mechanism adds an age_counter to the original predictor and doubles the size of the branch history register. The age_counter counts the number of outstanding branches and uses it to recover the branch history register. Simulation results on the Simplescalar 3.0/PISA tool set and the SPECINTgS benchmarks show that gshare and GAg with the proposed recovery mechanism improved the average prediction accuracy by 2.14$\%$ and 9.21$\%$, respectively and the average IPC by 8.75$\%$ and 18.08$\%$, respectively over the original predictor.

An Essay on Philosophy of Mathematics-Education with an Episode (라플라스변환 사례를 통한 수학교육철학(數學敎育哲學) 모색 시론)

  • Oh, Chae-Hwan
    • Journal for History of Mathematics
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    • v.23 no.2
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    • pp.59-74
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    • 2010
  • Though considering of philosophy of mathematics can be optional to theoretical mathematicians, that of philosophy of mathematics-education is supposed to be indispensible to mathematics-educators. So it is natural for mathematics-educators to ask what kind of philosophy might be more desirable for mathematics-education. In this context, this essay reviews two kinds of major philosophy of mathematics, Platonism and formalism. However it shows that humanism could be more plausible alternative philosophy of mathematicseducation. In the course of entailing such a result it introduces an episode of lecture for Laplace-transformation as a speculative evidence from experience.

Mechanical Amusement Culture Phenomenon and the Context of Pre-Game Period in 1960s (1960년대 기계오락문화현상과 전(前)게임기의 맥락)

  • Jeon, Gyongran
    • Journal of Korea Game Society
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    • v.15 no.4
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    • pp.111-120
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    • 2015
  • The purpose of this study is to understand the sociocultural context of the pre-game period, and how the context influenced on the identity formation of games. Games did not develop with the fixed and stable identities. Instead, games is the outcome which is conceived in the history of articulation of various discourses, technologies and social factors. The mechanical amusement devices was consumed for the urban entertainment, and made a strained relations with the society for the speculative and pathological characteristics. The mechanical amusement has extended to the electronic games in 1970s, and reached the present digital game culture.

Recovery Modules for Speculative Update Branch History (분기 정보의 투기적 사용에 대한 효율적인 복구 기법)

  • Kwak Jong Wook;Kim Ju-Hwan;Jhang Seong Tae;Jhon Chu Shik
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.766-768
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    • 2005
  • 분기 영령어의 예측 정확도는 시스템 전체 성능에 중대한 영향을 미친다. 여러 분기 예측 방식 가운데 하나인 "분기 정보의 투기적 사용" 은 분기 명령어의 가장 최근 기록을 일관되게 사용할 수 있도록 도와줌으로 해서 분기 예측의 정확도 향상에 크게 기여한다. 하지만 이와 같은 기법은 미완료 분기에 대한 히스토리를 투기적으로 사용하는 방식이다. 따라서 사용되는 정보가 올바르지 못할 수 있으며, 이런 경우 적절한 복구 기법을 필요로 한다. 본 논문에서는 분기 정보의 투기적 사용에 대한 필요성과 효율적인 복구 기법을 제안한다. 제안된 기법은 이전 연구와 비교하여 상당한 하드웨어 요구량의 감소를 가져왔으며, 또한 프로그램 수행의 정확성을 해치지 않으면서 최대 $3.3\%$의 성능향상을 보였다.

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Giambattista Vico: His View on Language and History (지암바티스타 비코의 언어관과 역사관)

  • 문경환
    • Lingua Humanitatis
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    • v.6
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    • pp.51-75
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    • 2004
  • Is there a pattern in history? How and why does social change occur? Are we to distinguish between the methods to be employed in the study of man and the study of nature? How does linguistic, or 'philological', knowledge contribute to unearthing historical facts? These are the queries that Vico grappled with throughout his life. Vico, however, was an outsider to the intellectual atmosphere of his own day, dismissed as obscure, speculative, and unsound. Only after his death did he begin to inspire enthusiasm among diverse readers, and as long as we remain concerned with the queries mentioned above, Vico's reflections will come alive with contemporary relevance. Actually he has been regarded as the founder--unrecognized by his contemporaries--of the philosophy of history and as a thinker whose ideas anticipated such later intellectual movements as historicism, pragmatism, existentialism, and structuralism. There are many among modern minds who find Vico fascinating for his view of myth as concrete thought and of an age of myth as a necessary age in the intellectual evolution of the human race. James Joyce, for one, was deeply impressed by Vico's view on myth, on metaphor, on Homer, on language, on psychology, and much else besides. 'My imagination grows when I read Vico,' he once confessed, 'as it doesn't when I read Freud or Jung.' Some philosophers, critics, psychologists, social scientists and even geographers would describe themselves as 'Vichians', sharing the view that Vico was a poet and a lawyer, a platonist and a baconian rolled into one. His refusal to be confined within any one discipline, his imaginative effort to understand different cultures, and his insight in dealing with some fundamental problems in the study of humanity all compel admiration and deserve to be emulated in our age--an age when the split between the literary and the scientific approaches to the understanding of society is widening into a chasm. Vico has left some of his most important ideas underdeveloped or even undeveloped, to be excavated and polished by us afier our own fashion. It is surprising that Vico is still a man of obscure name in the academia of our country, Korea.

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Developing Cryptocurrency Trading Strategies with Time Series Forecasting Model (시계열 예측 모델을 활용한 암호화폐 투자 전략 개발)

  • Hyun-Sun Kim;Jae Joon Ahn
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.46 no.4
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    • pp.152-159
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    • 2023
  • This study endeavors to enrich investment prospects in cryptocurrency by establishing a rationale for investment decisions. The primary objective involves evaluating the predictability of four prominent cryptocurrencies - Bitcoin, Ethereum, Litecoin, and EOS - and scrutinizing the efficacy of trading strategies developed based on the prediction model. To identify the most effective prediction model for each cryptocurrency annually, we employed three methodologies - AutoRegressive Integrated Moving Average (ARIMA), Long Short-Term Memory (LSTM), and Prophet - representing traditional statistics and artificial intelligence. These methods were applied across diverse periods and time intervals. The result suggested that Prophet trained on the previous 28 days' price history at 15-minute intervals generally yielded the highest performance. The results were validated through a random selection of 100 days (20 target dates per year) spanning from January 1st, 2018, to December 31st, 2022. The trading strategies were formulated based on the optimal-performing prediction model, grounded in the simple principle of assigning greater weight to more predictable assets. When the forecasting model indicates an upward trend, it is recommended to acquire the cryptocurrency with the investment amount determined by its performance. Experimental results consistently demonstrated that the proposed trading strategy yields higher returns compared to an equal portfolio employing a buy-and-hold strategy. The cryptocurrency trading model introduced in this paper carries two significant implications. Firstly, it facilitates the evolution of cryptocurrencies from speculative assets to investment instruments. Secondly, it plays a crucial role in advancing deep learning-based investment strategies by providing sound evidence for portfolio allocation. This addresses the black box issue, a notable weakness in deep learning, offering increased transparency to the model.