Browsing by Author "Hwang, HY"

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Aggressive scheduling for memory accesses of CISC superscalar microprocessors
(2001-09-01)
Shiu, RM
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Hwang, HY
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Shann, JJJ
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資訊工程學系
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Department of Computer Science
For CISC microprocessors, the proportion of memory access instructions is relatively high, and a specific address is likely to be accessed repeatedly in a short period of time because of register-to-memory or memory-to-memory instruction set architectures and limited register sets. As superscalar architectures advance, an aggressive scheduling policy for memory access becomes crucial. In this paper, we examine the scheduling policies of loads/stores on CISC superscalar processors and develop an aggressive scheduling policy called preload. The preload scheduling policy allows loads to precede the earlier unsolved pending stores, and delays the checking of conflict and forwarding of data until the data is loaded, thereby allowing greater tolerance of the latency for address generation. Because of its popularity, we focus our attention on the x86 instruction set. Simulation results show that the preload achieves a higher performance in comparison with the traditional scheduling policies such as load bypassing and load forwarding. Furthermore, by reducing the pipeline stages, the preload can achieve even higher performance.
An X86 load/store unit with aggressive scheduling of load/store operations
(1998)
Hwang, HY
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Shiu, RM
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Shann, JJJ
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資訊工程學系
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Department of Computer Science
Because of register-memory instruction set architecture and limited register set, there are significant amounts of memory access instructions in x86 microprocessors. As the higher issue degree of superscalar microprocessor is provided, an aggressive scheduling policy of load/store operations becomes crucial. In this paper, we examine the scheduling policies of loads/stores on x86 superscalar microprocessors and propose a new aggressive scheduling policy called load speculation, which allows loads to precede the previous unsolved pending stores. Simulation results show that the load speculation achieves the higher performance in comparison with the traditional scheduling policies such as load bypassing and load forwarding. Furthermore, by reducing the pipeline stages, the load speculation can achieve even higher performance.
Fuzzy GIS assisted landfill siting analysis
(1996)
Lin, HY
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Kao, JJ
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Li, KC
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Hwang, HY
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交大名義發表
This paper presents a prototypical fuzzy geographical information system (GIS) developed to facilitate landfill siting analysis. Landfill siting requires extensive effort to process massive spatial information, to evaluate various factors, and to review numerous criteria and regulations. A computerized GIS, although capable of effectively manipulating spatial information, generally lacks the ability to evaluate the suitability levers of candidate sites based on factors/criteria with some degree of imprecision and/or uncertainty. Because of their imprecision/uncertainty, many siting factors/criteria are not appropriate to be evaluated with a binary assessment, e.g., yes/no. Fuzzy set algorithms are therefore applied to overcome this difficulty. With proper membership functions assigned to imprecise/uncertain factors/criteria, the suitability score of a candidate site can be determined by a series of fuzzy calculations. The algorithms are incorporated into a previously developed landfill siting GIS to assist an engineer in improving siting decisions. This article, in addition to the description of the prototype, presents a case study to demonstrate the effectiveness of the developed Fuzzy GIS.
Self-aligned tantalum oxide nanodot arrays through anodic alumina template
(2006-04-01)
Wu, CT
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Ko, FH
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Hwang, HY
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材料科學與工程學系奈米科技碩博班
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Graduate Program of Nanotechnology , Department of Materials Science and Engineering
A novel strategy for fabricating the ordered nanodot arrays of tantalum oxide with anodic alumina film is proposed to serve the template. Anodic oxidation of Al on TaN film has been performed in oxalic acid and sulfuric acid electrolytes at various applied voltages for porous alumina formation. Anodising reaction proceeds in the sequence of growth of porous anodic alumina when the aluminum layer is consumed up to the underlying TaN, and the growth of tantalum oxide under the bottoms of the alumina pores occurred simultaneously. The nanostructure of the nanodot arrays was studied by scanning electron microscopy, and the chemical composition of nanodots was analyzed by X-ray photoelectron spectroscopy. The nanodots are composed of nonstoichiometric TaOx. The nanodot diameter demonstrated here ranges between 15 nm and 70 nm and density ranges between 10(11) /cm(2) and 10(10)/cm(2). (c) 2006 Elsevier B.V. All rights reserved.