• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.99-102
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• 2003

Computing environments of Embedded Systems are different from those of desktop computers so that they have resource constraints such as CPU processing, memory capacity, power, and etc.. Thus, when a desktop S/W is ported into embedded systems, optimization should be seriously considered. In this paper, we investigate several S/W optimization techniques to be considered for porting H.263 encoder into a high performance DSP, TMS320C6711. Through experiments, it is found that optimization techniques employed can make a big performance improvement.

• 전자공학회논문지A
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• 제33A권5호
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• pp.108-116
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• 1996

A semiconductor process imulator operated in windows$^{TM}$ environment has been developed. two-dimensional process simulation in personal computer has been enabled due to the improvement of CPU speed and the efficient use of memory. The process simulator in this paper is capable of calculating diffusion, oxidation, ion implantation, etching and deposition in two-dimensional manner. In addition, graphic-user-friendly editor, parser, and multi-dimensional graphical routine is also available in the devloped simulator.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2004년도 춘계학술발표대회논문집
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• pp.354-357
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• 2004

자바는 스마트 카드 상의 다중 애플리케이션 기능을 지원하기 위한 가장 유용한 프로그래밍 언어이다. $\lrcorner$CVM(Java Card Virtual Machine)은 자바 언어로 작성된 프로그램들을 스마트 카드 상에서 동작 가능하게 한다. 현재 스마트 카드는 작은 프로세서를 가지고 있으며 이런 제한적인 환경에서의 JCVM 성능 향상은 매우 중요한 이슈 중의 하나이다 그리고 기존의 스마트 카드는 쓰기 속도가 느린 EEPROM에 객체를 생성하여 사용함으로 JCVM의 성능 저하를 가져왔다. 본 논문에서는 스마트 카드 메모리 관리, 즉, EEPROM에서 RAM으로 객체를 이동시킴으로써 JCVM 성능을 보다 향상시키는 알고리즘에 관해 제안하고자 한다.

• International Journal of Advanced Culture Technology
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• 제9권4호
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• pp.282-287
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• 2021

A multicore system must be able to take full advantage of the program's instruction and data parallelism. This study introduces the data replication technique as a support technique to maximize the program's instruction and data parallelism. Instruction level parallelism can be limited by data dependency. In this case, if data is replicated to each processor core and used, instruction level parallelism can be used to the maximum. The technique proposed in this study can maximize the performance improvement effect when applied to scientific applications such as matrix multiplication operation.

• 동의생리병리학회지
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• 제24권2호
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• pp.228-235
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• 2010

This study was performed to investigate the memory enhancing effect of Poria cocos Wolf (Hoelen cum radix) against scopolamine-induced amnesia in Sprague-Dawley (SD) rats. To induce amnesia, scopolamine (0.75 mg/kg) was intraperitonically injected into SD rats 30 min before starting behavior tests. We have conducted Morris water-maze and Y-maze tests to monitor learning and memory functions. Poria cocos effectively reversed scopolamine-induced memory impairment in SD rats which was represented by an improvement of mean escape latency in water-maze test and spontaneous alterations in Y-maze test. To elucidate possible molecule mechanism, we have measured mRNA as well as protein expression of acetylcholine esterase (AchE), choline acetyltransferase (ChAT), muscarinic acetylcholine receptor (mAchR), and brain-derived neurotrophic factor (BDNF) using RT-PCR and Western blot analysis, respectively. Poria cocos increased mRNA levels of ChAT and mAchR in rat hippocampus compared with those in the scopolamine-injected amnesic group. In addition, protein expression of ChAT and BDNF was also elevated by Poria cocos intake. Furthermore, as an upstrem regulator, the activation of cAMP response element-binding protein (CREB) was assessed by immunohistochemistry. In this immunohistochemical analysis, the phosphorylation of CREB (p-CREB) was reduced by scopolamine injection, which was restored back to control levels by administration of Poria cocos. These results suggest that Poria cocos may improve memory and cognitive deficit in amnesia and have therapeutic potentials through up-regulation of ChAT, mAchR, and BDNF, which seemed to be mediated by activation of CREB.

• Korean Journal of Acupuncture
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• 제19권2호
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• pp.63-78
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• 2002

Kupunggibodan(KU), Gamisamul-tang(GA) and Whangryunhaedok-tang(WH) are clinically the most popular prescriptions as an herbal medicine in the treatment of ischemia. In order to compare and evaluate their protective effects on the ischema-induced cognitive deficits by middle cerebral artery occlusion (MCAO), we examined its ability to improve ischemia-induced cell loss and impairements of learning and memory in the Morris water maze and eight-arm radial arm maze. Focal cerebral ischemia produced a marked cell loss, decrease in acetylcholinesterase(AchE) reactivity in the hippocampus, and learning and memory deficits in two behavioral tasks. Pretreatment with WH (100 mg/kg, p.o.) produced a substantial increase in acquisition in the Morris water maze. Pretreatment with KU increased the perfomance of the resention test in the Morris water maze. WH, KU and GA caused a significant improvement in choice accuracy in radial arm maze test. WH was superior to KU and GA in perfomance of the radial arm maze test. Consistent with behavioral data, staining with cresyl violet showed that pretreatments with WH, but not KU and GA significantly recovered the ischemia-induced cell loss in the hippcampal CA1 area. In addition, pretreatments with WH and KU recovered the ischemia-induced reduction of AchE reactivity in the hippocampal CA1 area. These results demonstrated that KU, GA and WH have protective effects against ischimea-induced learning and memory impairments and that the efficacy was the order of WH>KU>GA in tratment of ischemia induced memory deficits. The present studies provide an evidence of KU, GA and WH as putative treatment of vascular dementia. Supported by a fund from the Ministry of Health and Welfare(HMP-00-OO-04-0004), and the Brain Korea 21 Project from Korean Ministry of Education, Korea.

• 한국컴퓨터정보학회논문지
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• 제26권11호
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• pp.1-9
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• 2021

3D-NAND 플래시 메모리는 평면적 구조인 2D-NAND 셀을 적층하는 방식으로 단위 면적당 고용량을 제공한다. 하지만 적층 공정의 특성상 각 레이어별 또는 물리적인 셀 위치에 따라 오류 발생 빈도가 달라질 수 있는 문제가 있다. 이와 같은 현상은 플래시 메모리의 쓰기/지우기(P/E) 횟수가 증가할수록 두드러진다. SSD와 같은 대부분의 플래시 기반 저장장치는 오류 교정을 위하여 ECC를 사용한다. 이 방법은 모든 플래시 메모리 페이지에 대하여 고정된 데이터 보호 강도를 제공하므로 물리적 위치에 따라 오류 발생률이 각기 다르게 나타나는 3D NAND 플래시 메모리에서는 한계를 보인다. 따라서 본 논문에서는 오류 발생률 차이를 보이는 페이지와 레이어를 K-means 머신러닝 알고리즘을 통해 군집으로 분류하고, 각 군집마다 차별화된 데이터 보호강도를 적용한다. 본 논문에서는 페이지와 레이어별로 오류 발생률이 현저하게 달라지는 내구성 테스트가 끝난 시점에서 측정된 오류 발생 횟수를 바탕으로 페이지와 레이어를 분류하고 오류에 취약한 영역에 대해서는 스트라이프에 패리티 데이터를 추가하여 차별화된 데이터 보호 강도 제공을 예시로 보인다. 본 논문에서는 기존의 ECC 또는 RAID 방식의 데이터 보호 구조와 비교하여 제안하는 차별화된 데이터 보호정책이 3D NAND 플래시 메모리의 신뢰성과 수명향상에 기여할 수 있음을 보인다.

• 대한중풍순환신경학회지
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• 제19권1호
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• pp.21-30
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• 2018

■ Objectives This case study is to report the two cases of Gami-Guibitang on cognitive impairment after stroke with improved recall memory. ■ Methods We used Korean medicine treatments including Gami-guibitang, acupuncture and moxibustion to treat patients who had cognitive impairment after stroke for at least two months. We observed the changes of symptoms by measuring Korean version of Mini-mental status examination (MMSE-K), Clinical Dementia Rating (CDR) and Global Detration Scale (GDS). ■ Results After treatment, the patient's symptoms were improved including MMSE-K, CDR and GDS. Improvement appeared to be prominent in recall memory. The general condition were also improved after treatment. ■ Conclusion This clinical case study suggests that Korean medicine including Gami-guibitang could be used to treat patients who had cognitive impairment after stroke especially suffering from degraded recall memory.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.133-136
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• 2002

This paper presents a new method of Huffman decoding which gives a significant improvement of processing efficiency based on the reconstruction of an efficient one-dimensional array data structure incorporating the numeric interpretation of the accrued codewords in the binary tree. In the Proposed search method, the branching address is directly obtained by the arithematic operation with the incoming digit value eliminating the compare instruction needed in the binary tree search. The proposed search method gives 30% of improved Processing efficiency and the memory space of the reconstructed Huffman table is reduced to one third compared to the ordinary ‘compare and jump’ based binary tree. The experimental result with the six MPEG-2 AAC test files also shows about 198% of performance improvement compared to those of the widely used conventional sequential search method.

• 디지털산업정보학회논문지
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• 제5권3호
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• pp.19-28
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• 2009

Computer system performance has always had the possibility of affecting business profitability, but with the advent of the World Wide Web where customers interact directly with Web servers, response time can have a direct and dramatic impact on business revenue. This paper is written in the operation environment and system analysis of HTS(Home Trading System) running K Securities. This paper also shows the method for performance improvement through investigation and analysis for the overall systems resources whether HTS has an appropriate performance or not. Performance analysis includes specially CPU analysis, Memory analysis, Disk Input/Output analysis and application analysis. Besides providing more detailed server specification for expansion from now on, system performance can be maintained with effect in the future. Through this study it is possible to manage the performance of HTS more easily and to solve problems such as a bottleneck more quickly.