• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.349-354
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• 2009

In this paper, a new motion compensation scheme to reduce external memory access frequency which is one of the major bottlenecks for real-time decoding is proposed. Most H.264/AVC decoders store reference pictures in external memories due to the large size and reference blocks are read into the decoder core as needed during decoding. If the reference data access is done for each reference block in decoding sequence, the memory bandwidth can be unacceptable for real-time decoding. This paper presents a memory access scheme for motion compensation to read as many reference data as possible with reduced memory access frequency by analyzing reference data access pattern for each macroblock. Experimental results show that the proposed motion compensation scheme leads to approximately 30% improvement in memory bandwidth requirement.

• Smart Media Journal
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• v.4 no.4
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• pp.56-63
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• 2015

Modern GPU can execute mass parallel computation by exploiting many GPU core. GPGPU architecture, which is one of approaches exploiting outstanding computational resources on GPU, executes general-purpose applications as well as graphics applications, effectively. In this paper, we investigate the impact of memory-efficiency and performance according to number of CTAs(Cooperative Thread Array) on a SM(Streaming Multiprocessors), since the analysis of relation between number of CTA on a SM and them provides inspiration for researchers who study the GPU to improve the performance. Our simulation results show that almost benchmarks increasing the number of CTAs on a SM improve the performance. On the other hand, some benchmarks cannot provide performance improvement. This is because the number of CTAs generated from same kernel is a little or the number of CTAs executed simultaneously is not enough. To precisely classify the analysis of performance according to number of CTA on a SM, we also analyze the relations between performance and memory stall, dram stall due to the interconnect congestion, pipeline stall at the memory stage. We expect that our analysis results help the study to improve the parallelism and memory-efficiency on GPGPU architecture.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.141-145
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• 2021

Various types of memory architectures have been developed, and various compiler optimization techniques have been studied to efficiently use them. In particular, since a memory is a major component that determines performance in mobile computing devices, various optimization techniques have been developed to support them. Recently, a lot of research on hybrid type memory architecture is being conducted, so various compiler techniques are being studied to support it. Existing compiler optimization techniques can be used to achieve the required minimum performance and constraint on low power according to market requirements. References for determining the low-power effect and the degree of performance improvement using these optimization techniques are not properly provided yet. This study was conducted to provide the experimental results of the existing compiler technique as a reference for the development of multibank memory architecture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.83-92
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• 2019

This qualitative study employed focused group interviews to collect data on the forgetfulness experienced by elderly persons (over the age of 65) who suffer with subjective memory impairment. The participants were ten elderly persons who participated in the cognitive function improvement program at an elderly welfare center in D city. They were divided into three groups that were comprised of three/four people each, and each group was interviewed for 40~60 minutes. The results showed that "difficulties in human relations", "feeling uncomfortable in daily life", "exposure to a safety risk", "inexpressible ambivalence" and "family effort to overcome forgetfulness" were all expressed in the interviews. The elderly who participated in this study and who complained of subjective memory impairment had both feelings of anxiety and anxiety about non-dementia, and they were making efforts to overcome forgetfulness themselves. Based on this study, we suggest that interventions should be developed that reflect the individual needs of elderly people with subjective memory impairment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.822-828
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• 2019

An Augmented Reality(AR) provides virtual information with a real environment, and the processor needs to access the memory for the AR system. However, the processor has the heavy workload as the technology improvement leads to increase the size of data. We need a specific module to reduce the workload to overcome the limitation. In this paper, we propose a Direct Memory Access(DMA) controller displaying image instead of the processor. We implemented the proposed DMA controller on a Field Programmable Gate Array(FPGA) and demonstrated the functionality of the DMA controller based on an Avalon Memory Mapped(Avalon-MM) interface. Also, the DMA controller is fabricated by using Magnachip/Hynix 0.35um CMOS technology and verified the feasibility of the embedded system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.32 no.6
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• pp.375-383
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• 2018

This study was conducted to investigate the cognitive improvement and memory recovery effects of Korean and Chinese Crataegus pinnatifida ethanolic extracts on scopolamine-induced memory impairment in mice. In vivo studies were carried out with mice treated with Korean Crataegus pinnatifida extracts (KCF) and Chinese Crataegus pinnatifida extracts (CCF) in doses of 5 and 50 mg/kg (p.o.) and scopolamine was injected 30 min before the behavioral testing. Antioxidant activity was assessed by 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, and acetylcholinesterase inhibition by Ellman's modified method. The chlorogenic acid and hyperoside as marker compounds of KCF and CCF was quantified by ultra-performance liquid chromatography analysis (UPLC). Results showed that KCF was more contained high content of chlorogenic acid and hyperoside than CCF. In addition, KCF was more exerted free radical (DPPH and ABTS) scavenging activity and blocked AChE activity than CCF. In vivo studies also showed that KCF administration has a further improved the memory of scopolamine-treated mice than CCF in Y-maze test, passive avoidance test and Morris water maze test. These results revealed that KCF more prevents scopolamine-induced memory impairments through antioxidant and acethylcholinesterase inhibition effect compared CCF.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.09a
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• pp.78-78
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• 2005

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.376-382
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• 2010

It has been shown that BF-7 enhances short- and long-term memory and attention in normal person. BF-7 was addressed to clinical study for children if BF-7 is also effective to children, since accumulated verification of safety and effectiveness is needed for young ages, in special. We administered BF-7 and a placebo control to two different groups of children (7-12 years old, 9.78 on averages). Their memory enhancement was tested with Rey-Kim Memory Test for Children before and after the administration of BF-7 and a placebo, in a double blinded way. The results showed that long- and short-term memories were significantly improved by the administration of BF-7. Interestingly, the degree of memory preservation, the ability of memory application and awareness of complex thing were also significantly improved. These results indicate that BF-7 is a promising substance from natural resource improving learning and memory of children as well as cognitive function of adults

• Journal of Korean Neurosurgical Society
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• v.56 no.3
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• pp.188-193
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• 2014

Objective : Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease of unknown etiology. In addition, the neurocognitive impairment of adults with MMD is infrequently reported and, to date, has not been well described. We attempted to determine both the neurocognitive profile of adult moyamoya disease and whether a superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis can improve the neurocognitive impairment in exhibiting hemodynamic disturbance without stroke. Methods : From September 2010 through November 2012, 12 patients with angiographically diagnosed MMD underwent STA-MCA anastomosis for hemodynamic impairment. Patients with hypoperfusion and impaired cerebrovascular reserve (CVR) capacity but without evidence of ischemic stroke underwent a cognitive function test, the Seoul Neuropsychological Screening Battery (SNSB). Five patients agreed to undergo a follow-up SNSB test. Data from preoperative and postoperative neurocognitive function tests were compared and analyzed. Results : Five of 12 patients were enrolled. The median age was 45 years (range, 24-55 years). A comparison of preoperative to postoperative status of SNSB, memory domain, especially delayed recall showed significant improvement. Although most of the domains showed improvement after surgery, the results were not statistically significant. Conclusion : In our preliminary study, large proportions of adult patients with MMD demonstrate disruption of cognitive function. This suggests the possibility of chronic hypoperfusion as a primary cause of the neurocognitive impairment. When preoperative and postoperative status of cognitive function was compared, memory domain showed remarkable improvement. Although further study is needed, neurocognitive impairment may be an indication for earlier intervention with reperfusion procedures that can improve cognitive function.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.4
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• pp.203-209
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• 2023

Harmony search(HS) does not use the evaluation of individual harmony when referring to HM when constructing a new harmony, but particle swarm optimization(PSO), on the contrary, uses the evaluation value of individual particles and the evaluation value of the population to find a solution. However, in this study, we tried to improve the performance of the algorithm by finding and identifying similarities between HS and PSO and applying the particle improvement process of PSO to HS. To apply the PSO algorithm, the local best of individual particles and the global best of the swam are required. In this study, the process of HS improving the worst harmony in harmony memory(HM) was viewed as a process very similar to that of PSO. Therefore, the worst harmony of HM was regarded as the local best of a particle, and the best harmony was regarded as the global best of swam. In this way, the performance of the HS was improved by introducing the particle improvement process of the PSO into the HS harmony improvement process. The results of this study were confirmed by comparing examples of optimization values for various functions. As a result, it was found that the suggested HS-PSO was much better than the existing HS in terms of accuracy and consistency.