만성 알코올 중독성 기억장애의 세부적 특성에 관한 연구

심주식,김홍근,김용숙 한국건강심리학회 2012 한국심리학회지 건강 Vol.17 No.1

본 연구는 만성 알코올 중독성 환자에서 나타나는 기억장애의 세부적 특징을 살펴보고자 수행되었다. 이를 위해 알코올 의존 환자 28명과 정상인 26명에게 ‘Rey-Kim 기억검사’와 K-WAIS를 실시하였다. 알코올 의존군이 보여주는 기억장애의 주요 특성은 다음과 같았다. 첫째, 기억기능을 즉시기억(immediate memory), 최근기억(recent memory), 옛날기억(remote memory)으로 구분하여 살펴본 결과 최근기억에만 결손이 있었고 즉시기억과 옛날기억은 정상 수준이었다. 둘째, 최근기억의 내용을 언어기억(verbal memory)과 시각기억(visual memory)으로 구분하여 살펴본 결과 언어기억과 시각기억 모두에 결손이 있었다. 셋째, 최근기억의 인지적 과정을 등록(encoding), 유지(retention), 인출(retrieval) 단계로 구분하여 살펴본 결과 등록과 인출 단계에만 결손이 있었고 유지 단계는 정상 수준이었다. 넷째, 최근기억과 일반지능에서 결손된 정도를 비교한 결과 최근기억의 결손이 유의하게 더 심하였다. 이 결과는 최근기억의 장애가 일반화된(generalized) 인지장애가 아니라 기억에 특이한(specific) 인지장애임을 시사한다. 마지막으로, 최근기억장애를 개인별 수준에서 살펴본 결과 다수가 경증이었고 중증은 약 20% 정도에 해당하였다. 종합적으로, 본 연구의 결과들은 만성 알코올 중독성 기억장애의 학술적 이해와 임상적 관리에 유용한 정보를 제공한다. The purpose of the present study was to investigate specific characteristics of memory deficits, associated with chronic alcoholism. To this end, we administered Rey-Kim memory test and K-Wechsler Adult Intelligence Scale to a sample of 28 alcohol dependent patients and 26 normal controls. The alcohol dependent group showed the following characteristics in their memory deficits. First, their memory deficits involved recent memory, but not immediate or remote memory. Second, their recent-memory deficits involved both verbal and visual memory. Third, their recent-memory deficits involved problems in registration and retrieval stage, but not in retention stage. Fourth, their deficits in recent memory were more severe than their deficits in general intelligence, suggesting that the memory deficits were not part of generalized cognitive dysfunction, but a memory-specific dysfunction. Finally, about 20% of the patients evidenced severe memory decline, whereas other patients showed mild to moderate decline. These results provide useful data for the understanding of alcoholic memory deficits and their clinical managements.

Study on the Performance Evaluation and Analysis of Mobile Cache Memory

이상민,김종완,김지영,오덕신 한국컴퓨터정보학회 2020 韓國컴퓨터情報學會論文誌 Vol.25 No.6

In this paper, we analyze the characteristics of mobile cache, which is used to improve the data access speed when executing applications on mobile devices, and verify the importance of mobile cache through a cache data access experiment. The mobile device market has grown at a fast pace over the past decade; however, battery limitations and size, price considerations restrict the usage of fast hardware. Thus, their performance are supplemented by using a memory buffer structure such as the cache memory. The analysis mainly focuses on cache size, hierarchical structure of cache, cache replacement policy, and the effect these features has on mobile performance. For the experimental data, we applied a data set from a microprocessor system study, originally used to test the cache performance. In the experimental results, the average data access speed on a mobile device showed a performance improvement of up to 10 times with the presence of cache memory than without. Accordingly, the cache memory was helpful for the performance improvement of a mobile device when the specifications were identical.

Cyclic behavior of extended end-plate connections with shape memory alloy bolts

Nader Fanaie,Morteza N. Monfared 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.60 No.3

The use of shape memory alloys (SMAs) has been seriously considered in seismic engineering due to their capabilities, such as the ability to tolerate cyclic deformations and dissipate energy. Five 3-D extended end-plate connection models have been created, including one conventional connection and four connections with Nitinol bolts of four different prestress forces. Their cyclic behaviors have been investigated using the finite element method software ANSYS. Subsequently, the moment-rotation responses of the connections have been derived by subjecting them to cyclic loading based on SAC protocol. The results obtained in this research indicate that the conventional connections show residual deformations despite their high ductility and very good energy dissipation; therefore, they cannot be repaired after loading. However, while having good energy dissipation and high ductility, the connections equipped with Nitinol bolts have good recentering capability. Moreover, a connection with the mentioned specifications has been modeled, except that only the external bolts replaced with SMA bolts and assessed for seismic loading. The suggested connection shows high ductility, medium energy dissipation and very good recentering. The main objective of this research is to concentrate the deformations caused by cyclic loading on the connection in order to form super-elastic hinge in the connection by the deformations of the shape memory alloy bolts.

자동복원이 가능한 댐퍼의 이력거동 특성 연구

김영찬,허종완 한국복합신소재구조학회 2018 복합신소재구조학회 학술발표회 Vol.2018 No.04

This study investigates a new type of recentering damper system combining a shape memory alloy bar with initial tension force is proposed to improve the recentering of frictional damper dissipating energy. The recentering damper is a damper device with improved energy dissipation capability as well as a reduction in maintenance and reinforcement cost, and can be said to be a low-cost, high-efficiency damper device conforming to domestic reality. For the implementation of the theoretical mechanism for the recentering damper device, various parameters were selected and the theoretical and detailed design were carried out. In order to verify the design validity of the recentering damper, a high dimensional finite element analysis model was fabricated and analyzed using cyclic load. As a result of comparing and analyzing the behavior response of the recentering damper, it proved its superiority in terms of energy dissipation ability and stability. Based on these results, we propose an optimized system design method of recentering damper.

기억유산으로서 세계유산 문화경관의 등재 이후 현상 분석

박리디아,강동진 한국경관학회 2024 한국경관학회지 Vol.16 No.1

본 연구는 세계유산으로 등재된 문화경관들 중 기억유산에 해당하는 21건을 대상으로, 유산과연관된 기억에 대한 보존관리의 현상 도출을 연구 목적으로 한다. 분석 기준은 세계유산의 탁월한 보편적 가치와 기억 간의 관계성, 기억 공유의 방식, 미래 전승의 방식 등이며 이에 준하여사례별 분석을 시행한다. 기억이 문화경관으로 연결되어 존재하는 경우 전반적으로 기억을 공유하고 전승하려는 노력이 전개되나, 부분적으로 기억을 은폐, 축소, 미화하는 현상이 나타나고 있는 것으로 분석되었다. 결과적으로 과거 사건으로 인한 기억임에도 이해당사자들의 관점과 문화경관에 대한 해석 전략, 그리고 유산을 둘러싼 상황 변화에 따라 기억이 변할 수 있다는 가능성과 이를 올바르게 제어할 수 있는 보존관리의 필요성을 확인하였다. The purpose of this study is to derive trends in conservation management of memories related to heritage, targeting 21 cases of sites of memory among cultural landscapes inscribed as World Heritage. The analysis criteria are the relationship between outstanding universal value and memory, the method of memory sharing, and the method of future transmission, and a case-by-case analysis is conducted accordingly. When memories exist in connection with the cultural landscape, efforts are made to share and transmit memories overall, but it has been analyzed that the phenomenon but it has been analyzed that the phenomenon of partially concealing, reducing, and beautifying memories is occurring. As a result, although it is a memory due to past events, it was confirmed that the memory can change according to the perspectives of stakeholders, interpretation strategies for cultural landscape, and changes in the situation surrounding the heritage, and the need for conservation management to in the situation surrounding the heritage, and the need for conservation management to properly control this.

Seismic analysis and parametric study of SDOF lead-rubber bearing (LRB) isolation systems with recentering shape memory alloy (SMA) bending bars

Jong Wan Hu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.7

Base isolation has been considered one of aseismic design methodologies based on belief that it is feasible to separate the superstructure from the supporting ground, thereby preserving structural members and their internal contents from damage caused by earthquake motions. Although remarkable progress was achieved in this isolation technique towards the end of the century, a number of catastrophic building failures are still found where earthquake with severe ground motion attacked. In particular, high-rise buildings that have been currently constructed in urban area are very vulnerable when exposed to such impulsive events, and thus large relative displacement occurs at the isolator interface. The obstacles in or in the vicinity of the isolator interface destroy seismic performance. In this study, the innovative isolation systems incorporated with superelastic Shape memory alloy (SMA) bars functioning as seismic restrainers are suggested in order to more effectively maintain structural integrity. The superelastic SMA bending bars supply recentering force to the base isolator that accordingly makes a significant contribution to reducing permanent deformation over entire structure. The base Lead-rubber bearing (LRB) isolators with superelastic SMA bars are considered as inelastic behavior reproduced by component spring elements. The response of the proposed base isolators are compared with those of the conventional LRB isolators. Through the observation of the analysis results, it can be concluded that recentering LRB isolators create the improvement of seismic performance in terms of strength, energy dissipation, and recentering effect.

초탄성 형상기억합금을 이용한 원상 복원 X형 철골 가새 골조

이성주,김주우,Lee, Sung Ju,Kim, Joo-Woo 한국공간구조학회 2018 한국공간구조학회지 Vol.18 No.2

In this paper a systematic numerical analysis is performed to obtain the energy dissipation and re-centering capacities of diagonal steel braced frames subjected to cyclic loading. This diagonal steel bracing systems are fabricated with super-elastic SMA (Shape Memory Alloy) braces in order to develop a recentering seismic resistance system without residual deformation. The three-dimensional nonlinear finite element models are constructed to investigate the horizontal stiffness, drifts and failure modes of the re-centering bracing systems.

Seismic response of steel braced frames equipped with shape memory alloy-based hybrid devices

Salari, Neda,Asgarian, Behrouz Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5

This paper highlights the role of innovative vibration control system based on two promising properties in a parallel configuration. Hybrid device consists of two main components; recentering wires of shape memory alloy (SMA) and steel pipe section as an energy dissipater element. This approach concentrates damage in the steel pipe and prevents the main structural members from yielding. By regulation of the main adjustable design parameter, an optimum performance of the device is obtained. The effectiveness of the device in passive control of structures is evaluated through nonlinear time history analyses of a five-story steel frame with and without the hybrid device. Comparing the results proves that the hybrid device has a considerable potential to mitigate the residual drift ratio, peak absolute acceleration and peak interstory drift of the structure.

SMA 적용 역V형 가새골조의 내진 원상복원 효과

윤승한,김주우,Yoon, Seung Han,Kim, Joo Woo 한국공간구조학회 2020 한국공간구조학회지 Vol.20 No.3

This paper presents a systematic numerical analysis to obtain the re-centering and energy dissipation capacities of Chevron braced steel frames subjected to seismic loadings. In order to develop a recentering seismic resistance system excluding a residual deformation, the chevron braced steel frames are assembled using super-elastic SMA (Shape Memory Alloy) braces. The three-dimensional nonlinear finite element models are constructed to investigate the horizontal stiffness, hysteretic behaviors, and failure modes of the re-centering Chevron bracing system.

Numerical simulation for the behavior of superelastic shape memory alloys

허종완 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.2

Superelastic shape memory alloys (SMAs) are unique metallic materials that undergo substantial plastic deformations and recover their original conditions when stresses are only removed without any heat treatment. SMAs have currently become prevalent for application in structural engineering because this superelastic property contributes to entire construction system by mitigating the problem of permanent deformation. Notwithstanding many structural advantages, there exist relatively few investigations on the numerical modeling of these smart materials, which had been mostly used for nonlinear analyses. For this reason, this study mainly focuses on a one-dimensional (1D) constitutive model able to simulate the inherent behavior of superelastic SMAs, taking into account phase transformation between austenite and martensite. After discussing a possible approach for the solution scheme, numerical simulation results are compared to experimental data obtained from pull-out tests that are performed on SMA bars in order to validate the adequacy for the 1D constitutive material model presented. Furthermore, the user material model based on the solution algorithm of reproducing this superelastic behavior is applied to the structural analysis with a view to assure adequacy in practical use.