• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.2
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• pp.335-344
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• 2016

It is known that power analysis is one of the most powerful attack in side channel analysis. Among power analysis single trace attack is widely studied recently since it uses one power consumption trace to recover secret key of public cryptosystem. Recently Sim et al. proposed new exponentiation algorithm for RSA cryptosystem with higher attack complexity to prevent single trace attack. In this paper we analyze the vulnerability of exponentiation algorithm described by Sim et al. Sim et al. applied message blinding and random exponentiation splitting method on $2^t-ary$ for higher attack complexity. However we can reveal private key using information exposed during pre-computation generation. Also we describe modified algorithm that provides higher attack complexity on collision attack. Proposed algorithm minimized the reuse of value that are used during exponentiation to provide security under single collision attack.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.2-2
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• 2010

텐덤형 태양전지는 다양한 에너지 대역을 동시에 흡수할 수 있도록 제작할 수 있어 단일접합 태양전지에 비해 높은 에너지변환효율을 기대할 수 있다. 본 연구에서는 GaAs를 기반으로 양자점 혹은 양자우물 구조를 이용한 고효율 텐덤형 태양전지를 설계하고, 완충층 및 활성층의 특성을 분석하였다. 분자선 단결정 성장 장비를 이용하여 GaAs 기판 위에 메타모픽 (metamorphic)성장법을 이용하여 convex, linear, concave 형태로 조성을 변화시켜 $In_xAl_1-_xAs$ 경사형 완충층을 성장한 후 그 특성을 비교하였다. 또한, 최적화된 경사형 완충층 위에 1.1 eV와 1.3 eV의 에너지 대역을 각각 흡수할 수 있는 적층 (5, 10, 15 층)된 InAs 양자점 구조 또는 InGaAs 양자우물구조를 삽입하여 p-n 접합을 성장하였다. 그리고 GaAs/AlGaAs층을 이용한 터널접합에서는 GaAs층의 두께 (20, 30, 50 nm)에 따른 터널링 효과를 평가하였다. 그 결과, 경사형 완충층을 통해 조성 변화로 인한 결함을 최소화하여 다양하게 조성 변화가 가능한 고품위의 구조를 선택적으로 성장할 수 있었으며, 적층의 양자점 구조 및 양자우물 구조를 이용해 고효율 텐덤형 태양전지의 구현 가능성을 확인하였다.

• Therapeutic Science for Rehabilitation
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• v.2 no.2
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• pp.67-75
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• 2013

Objective : This study aims to investigate the effect of listening to music for the reduction of unilateral neglect in stroke patients. Methods : This study used a single subject (A-B) design for a stroke patient with unilateral neglect. The subject was trained for 12 sessions in total. Unilateral neglect was measured using a line bisection test and catherine bergego scale. Results : The line bisection test showed decreased mean error scores of treatment period(B) compared with baseline period(A). and catherine bergego scale showed slightly decreased total scores of treatment period(B) compared with baseline period(A). Conclusion : The listening to music showed a beneficial effect for the reduction of unilateral neglect.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.4
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• pp.63-68
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• 2005

In this paper, the single coaxial fed and circularly polarized patch antenna for the RFID system in 2.45GHz ISM band has been fabricated. The simulation by HFSS, electro-magnetic field simulator was executed in order to decide the location of feed which is difficult to be analysed. The simulated result has the same tendency as the measured one in the view of input impedance with the variation of feed location. VSWR of fabricated antenna is low($\leq$1.2) even in comparatively high dielectric loss epoxy substrate(FR4), and this value is enough for the application of RFID reader antenna.

• Therapeutic Science for Rehabilitation
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• v.2 no.1
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• pp.57-65
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• 2013

Objective : This study aims to investigate the effect of listening to music for the reduction of unilateral neglect in stroke patients. Methods : This study used a single subject (A-B) design for a stroke patient with unilateral neglect. The subject was trained for 12 sessions in total. Unilateral neglect was measured using a line bisection test and catherine bergego scale. Results : The line bisection test showed decreased mean error scores of treatment period(B) compared with baseline period(A). and catherine bergego scale showed slightly decreased total scores of treatment period(B) compared with baseline period(A). Conclusion : The listening to music showed a beneficial effect for the reduction of unilateral neglect.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.65-71
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• 2022

Recently, multi-material structural topology optimization is more critical because it provides reasonable solution to weight reduction challenges and can as well provide effective conceptual design. For conventional multi-material topology optimization (MMTO), the number of design variable increases when the number of candidate materials increases, and accordingly, a significant increase in computational time occurs. Therefore, MMTO with a single design variable, such as the phase section method (PSM) was proposed. This research is focused on improving the PSM, considering three major limitations: the composition ratio does not represent the area or volume ratio, design variables are not sufficiently concentrated to target values, and certain materials are created less than they are required. To address such limitations, the redefined composition ratio and adjusted parameters for better convergence are proposed. The validation of proposed modifications is verified via two- and three-dimensional numerical examples.

• Korean Journal of Social Welfare
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• v.58 no.4
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• pp.291-312
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• 2006

Incentive-Therapy approach on substance abuser has a solid theoretical base in Behavior Psychology and shows the effectiveness empirically in US. The purpose of this exploratory study was to evaluate the effectiveness of Incentive-Therapy on two alcohol abusers using ABA Single System Design in a community welfare agency, Korea. It proceeded for 12 week-baseline stage, 6-week intervention stage and 4-week postintervention stage through scanning whether alcohol abuser drinks or not by the alcohol analyzer as a target behavior. As a results, this study showed that two abusers' drinking were decreased in the middle of intervention stage in incentive-therapy but they showed differently in the postintervention stage : One sustained his abstinence and the other recurred to drink. Thus, we concluded Incentive-Therapy had better adaptability in community welfare agency in that alcohol abusers were driven to motivate for abstinence and then had an opportunity for psycho-social counseling and social welfare intervention consistently.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.04a
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• pp.328-332
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• 1998

인간의 정보전달 방식이 텍스트와 같은 단일 미디어 중심에서 텍스트, 이미지, 음성, 영상 등의 멀티미디어 중심으로 바뀌어 감에 따라 멀티미디어 응용에 대한 관심이 고조되고 있다. 그러나, 멀티미디어 응용의 대표적 갈래인 VOD(Video On Demand) 시스템은 그 특성 및 구조에 대해 축적된 연구가 많은 반면, NOD(News On Demand) 시스템은 그 연구가 거의 없는 실정이다. 이 점에 착안하여 본 논문에서는 NOD 데이터 및 시스템의 특성을 우선적으로 살펴보고, 아울러 NOD 시스템 전체에 대한 구조를 제시함으로써 NOD 시스템에 대한 이해를 돕고자 한다. 뿐만 아니라, 차등적인 QoS를 제공함으로써 여러 가지 비정상적인 상황에 대처하는 서버의 능력을 높이고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.549-551
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• 2012

본 논문에서는 기존의 화소값 차영상 기법이 저속으로 움직이는 물체의 동작정보 감지에 취약한 점을 보완하기 위하여 실시간 영상 처리를 목적으로 연속된 프레임(Frame)에서 움직임이 있는 프레임을 찾아내고, 움직임 영역을 추출하는 움직임 검출에 관한 연구를 통해 웹캠 기반의 객체 감지시스템을 제안하였다. 제안 시스템은 단일 객체뿐 아니라 다중 객체의 움직임까지 파악할 수 있다는 장점을 가지고 있다.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.5
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• pp.373-378
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• 2001

The optimization method based on an enhanced genetic algorithms is for multimodal function optimization in this paper. This method is consisted of two main steps. The first step is a global search step using the genetic algorithm(GA) and function assurance criterion(FAC). The belonging of an population to initial solution group is decided according to the FAC. The second step is to decide the similarity between individuals, and to research the optimum solutions by single point method in reconstructive search space. Four numerical examples are also presented in this papers to comparing with conventional methods.