• Steel and Composite Structures
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• 제48권3호
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• pp.353-365
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• 2023

Shape memory alloys (SMAs) have emerged as a novel functional material that is being increasingly applied in diverse fields including medical, aeronautical and structural engineering to be used in the active, passive and semi-active structural control devices. This paper is mainly aimed at evaluating the ductility and response modification factor of the steel plate shear wall (SPSW) frames with and without the Ni-Ti shape memory alloys. To this end, different configurations were utilized, in which the walls were used in the first, third, middle, and all stories. The models were numerically analyzed using OpenSees Software. The obtained results indicate that improving the shape memory properties of alloys can greatly enhance the ductility and response modification factor. Furthermore, the model whose first and third stories are equipped with the SMA shear wall was found to be 290% more ductile, with a greater response modification factor compared to the unequipped frame.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2020년도 추계학술발표대회
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• pp.12-15
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• 2020

Data access characteristics can directly affect the efficiency of the system execution. This research is to design an accurate predictor by using historical memory access information, where highly accessible data can be migrated from low-speed storage (SSD/HHD) to high-speed memory (Memory/CPU Cache) in advance, thereby reducing data access latency and further improving overall performance. For this goal, we design a locally weighted linear regression prefetch scheme to cope with irregular access patterns in large graph processing applications for a DARM-PCM hybrid memory structure. By analyzing the testing result, the appropriate structural parameters can be selected, which greatly improves the cache prefetching performance, resulting in overall performance improvement.

• 정보처리학회논문지A
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• 제9A권4호
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• pp.405-412
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• 2002

임베디드 시스템은 일반 PC(Personal Computer)나 워크스테이션에 비해 느린 CPU와 작은 메모리 공간을 사용하고 있다. 따라서 임베디드 운영체제는 제한된 자원을 효과적으로 사용하도록 설계되어져야 한다. 그런데 임베디드 리눅스의 가상 메모리 관리 기법에서 페이지 폴트가 발생할 경우 스왑 디바이스로 페이지를 이동하는 과정에서 성능 저하가 발생한다. 본 논문에서는 가상 메모리 기법의 효율성을 놀이며 메모리 공간의 효율성을 향상시킬 수 있는 가상 메모리 압축 기법을 구현하였다. 가상 메모리 압축 기법은 임베디드 리눅스의 가상 메모리 관리 기법에서 스왑핑이 발생할 경우 스왑 디바이스로 이동하는 페이지들을 압축하여 이동시킴으로서 스왑핑에서 발생하는 성능저하를 감소시키며, 압축된 스왑 디바이스의 운영으로 메모리의 공간 효율성을 높인 수 있다. 또한 본 논문에서는 메모리 내의 소량의 데이터 압축에 적합한 알고리즘을 고안하여, 압축률의 효율성과 시스템 성능을 향상시키고자 하였다.

• 대한한의학회지
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• 제25권4호
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• pp.51-60
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• 2004

Objective : The effect Saenggitang (GT), which has been used for amnesia, in Oriental Medicine, on memory and learning ability, was investigated. Methods : Hot water extracts (HWE) of SGT were used for the studies. In passive avoidance performances (step through test), active avoidance performances (lever press test), Motor activity, pentobarbital-induced sleep, 20 and 50 mg/100g of SGT-HWE ameliorated the memory retrieval deficit induced by 40% ethanol. Results : The SGT-HWE did not affect the ambulatory activity of normal mice in normal condition. 20 and 50 mg/100g of SGT-HWE enhanced contextual fear memory, but not cued fear memory in a fear conditioning task, which requires the activation of the NMDA (N-methyl-D-aspartase) receptor. SGT-HWE did not affect the motor activity measured by the titling type ambulometer test performed immediately and 24 hr after the administration. SGT-HWE prolonged the sleeping time induced by 50 mg/kg pentobarbital in mice and decreased SMA (spontaneous motor activity) in active avoidance performances (lever press test). Conclusion : These results indicate that the SGT-HWE have an improving effect on the memory retrieval disability induced by ethanol and may act as a stimulating factor for activating the NMDA receptor. and the SGT-HWE has a tranquilizing and anti-anxiety action.

• 동의신경정신과학회지
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• 제10권2호
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• pp.115-126
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• 1999

This study was conducted to find out the effects of Woohwangchungsimwon on learning and memory in the NOS inhibitor treated rats. The Morris water maze was used in evaluating them. The result of the study was summarized as follows. 1. In the learning test, three groups have showed a gradual improvement of learning ability by repeating the trials in Morris water maze. WHCS group have showed statistical improvement than control group at 4,5,6 trial(p<0.05, p<0.01, p<0.01). 2. In the memory test, the first latency of WHCH group was statistically shortened than that of control group(p<0.05). 3. In the memory test, there was no statistical difference in the entry number between WHCH group and control. 4. In the memory test, there was no statistical difference in the memory score between WHCH group and control. The result of this experimental study presents that Woohwangchungsimwon has the improving effect on impaired learning and memory in NOS inhibitor treated rats, and implies that Woohwangchungsimwon may be one of the useful prescription for the treatment of vascular dementia after cerebral ischemia.

• 전기전자학회논문지
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• 제4권2호
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• pp.212-224
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• 2000

본 논문에서는 영상 응용프로그램의 처리 속도를 향상하기 위한 병렬처리 시스템을 제안한다. 병렬처리 시스템은 Pipelined SIMD 구조를 갖고 있으며, 다수개의 처리기와 다중접근 기억장치로 구성된다. 다중접근 기억장치는 메모리 모듈들과 메모리 제어부로 구성되며, 메모리 제어부는 메모리 모듈 선택 모듈, 데이터 라우팅 모듈, 그리고 주소 계산 및 라우팅 모듈로 구성되어 있으며, 블록, 행, 그리고 열 내의 데이터를 동시에 접근할 수 있는 기능을 제공한다. 제안한 병렬처리 시스템을 검증하기 위해서 형태학적 필터를 적용하여 기능 검증 및 처리속도를 확인하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권4호
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• pp.262-269
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• 2005

Semiconductor scientists and engineers ideally desire the faster but the cheaper non-volatile memory devices. In practice, no single device satisfies this desire because a faster device is expensive and a cheaper is slow. Therefore, in this paper, we use heterogeneous non-volatile memories and construct an efficient hierarchy for them. First, a small RAM device (e.g., MRAM, FRAM, and PRAM) is used as a write buffer of flash memory devices. Since the buffer is faster and does not have an erase operation, write can be done quickly in the buffer, making the write latency short. Also, if a write is requested to a data stored in the buffer, the write is directly processed in the buffer, reducing one write operation to flash storages. Second, we use many types of flash memories (e.g., SLC and MLC flash memories) in order to reduce the overall storage cost. Specifically, write requests are classified into two types, hot and cold, where hot data is vulnerable to be modified in the near future. Only hot data is stored in the faster SLC flash, while the cold is kept in slower MLC flash or NOR flash. The evaluation results show that the proposed hierarchy is effective at improving the access time of flash memory storages in a cost-effective manner thanks to the locality in memory accesses.

• 동의생리병리학회지
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• 제19권2호
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• pp.434-440
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• 2005

This study was conducted to find out the effect of Bojungikgitanggamibang(BIT) on growth, learning and memory of rats. The effects of BIT on learning and memory performance were examined in normal or memory impaired mice by using water maze task. Memory was impaired by 192 saporin. Body weight and growth of bone and tail of sample group were not significant compared with those of control groups. Acquisition test of water maze revealed that acqusitive ability of sample group significantly improved on 4,5th day compared with control group, while retentive ability of sample group was not significant. ChAT cell numbers of medial septum of sample group was significant compared with control group, and so was those of CA1, CA2 parts of hippocampus. On ChAT cell numbers of hippocampus, in CA2 part. These results suggest that BIT has an improving effect on the impaired learning through the effects on memory registration and retrieval.

• 대한통합의학회지
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• 제1권3호
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• pp.79-95
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• 2013

Purpose : This study aims to investigate the effect of the Snoezelen and Rehacom programs on improvement of attention and memory, and the effect of the Snoezelen program on stress reduction. Method : This study was targeted at 11 subjects in the Snoezelen experimental group, 11 subjects in the Rehacom group and 11 subjects in the non-experimental group. As the initial evaluation, all the subjects took electroencephalography. Then, the Snoezelen group and Rehacom group did Snoezelen training and Rehacom training, respectively total 12 times(for 20 minutes twice per week for six weeks), but no training was applied to the control group. Three weeks after the training, the interim was carried out, and four weeks after the training, the final evaluation was carried out. Results : Subjects' attention increased to $58.15{\pm}4.96$ from $43.75{\pm}4.69$ during the Snoezelen training, and increased to $49.85{\pm}1.91$ from $43.28{\pm}2.71$ during the Rehacom training, which means the Snoezelen training was more effective in improving attention(P<0.05). Subjects' memory increased to $56.14{\pm}1.26$ from $43.19{\pm}3.46$ during the Snoezelen training, and increased to $50.94{\pm}4.0$ from $43.07{\pm}2.58$ during the Rehacom training. This also implies that the Snoezelen training was more effective in improving memory(P<0.05). Conclusion : Though both of the Snoezelen training and Rehacom training improved attention and memory, the Snoezelen program was more effective, and it also influenced stress resistance and physical arousal.

• 정보과학회 논문지
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• 제44권11호
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• pp.1130-1137
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• 2017

하나의 메모리 셀에 여러 비트의 정보를 저장하는 다치화 기법은 공정 미세화와 함께 낸드 플래시 메모리의 집적도를 크게 향상시켰지만, 그 반대급부로 MLC 낸드 플래시 메모리의 평균 쓰기 성능은 SLC 낸드 플래시 메모리 대비 두 배 이상 하락하였다. 본 논문에서는 MLC 낸드 플래시 기반 저장장치의 성능 향상을 위해 제안되었던 기존의 계층 교차적 최적화 기법들을 소개하고, 두 기법의 상호 보완성을 분석하여 해당 기법들의 한계점을 극복하는 새로운 통합 기법을 제안한다. MLC 낸드 플래시 디바이스에 존재하는 성능 비대칭성을 플래시 변환 계층 수준에서 최대한 활용함으로써, 제안하는 기법은 인가되는 다수의 쓰기 명령을 SLC 낸드 플래시 디바이스의 성능으로 처리하여 저장장치의 성능 향상을 도모한다. 실험 결과, 제안하는 기법은 기존 기법 대비 평균 39%의 성능 향상을 달성할 수 있음을 확인하였다.