• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1283-1288
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• 2015

In general, IC chip circuit which is operating a cryptographic computation tends to radiate stronger electromagnetic signal to the outside. By using a power detecter such as a loop antenna near cryptographic device, the encryption key can be identified by probing a electromagnetic signal. To implement a method against non-invasive type attack, multi dielectric slab structure on IC chip to suppress radiated electromagnetic signal was introduced. Multiple dielectric slab was implemented by suitably configured to have the Bragg reflection characteristics, and then the reflection response was computed and verified its effectiveness. As a result, the thickness of the dielectric coating was 2mm and the reflection response characteristics for the vertical incidence was achieved to be 91% level.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.333-334
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• 2011

본 논문에서는 안경식 스테레오스코픽 3DTV에 대한 효율적인 주관적 화질평가 방법에 대한 논의를 한다. 3DTV의 주관적 화질평가는 시각피로나 신체적 불편감을 유발하는 요인들을 규명하고 평가하여 사용자가3D 영상물을 관람할 때 이들을 최소화하면서 컨텐츠 제공자가 의도한 입체 깊이를 시청자가 지각 할 수 있도록 도와 줄 수 있도록 가이드라인을 제공하기 위해 이루어진다. 주관적 화질평가를 위해 적절한 깊이감을 갖는 카메라기반의 실영상과 컴퓨터 그래픽 기반의 3D컨텐츠를 사용하였다. 설문은 디스플레이 자체와 3D컨텐츠에 대한 화질평가 구분을 하고, 전문가와 일반인들을 대상으로 이루어졌다. 주관적 평가에 앞서 평가결과에 대한 객관성을 유지하기 위해 Random-dot Stereogram을 이용하여 개인별 입체시 평가를 하였다. 일반인들의 경우 전문가들에 비해 상대적으로 응답편차가 많이 발생하였으나 전문가 집단과 일반인 집단의 설문응답 경향은 대체적으로 일치하였다. 전문가 그룹의 주관적 평가 결과를 적절히 반영하고 일반인들의 응답편차를 줄임으로써 3DTV에 대한 주관적 평가에 대한 시간과 비용을 효율적으로 줄일 수 있을 것으로 기대된다.

• Journal of Korean Library and Information Science Society
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• v.32 no.1
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• pp.1-31
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• 2001

University libraries need the development of a common Internet-based reference request system in order to prevent duplicated investment and provide interoperability among them. This paper proposes a standard of Internet-based reference recluest system that serves reference request-responses and that provides reference source sites on the world wide web. Using this system, university libraries can cooperate other libraries with reference databases and may perform tasks of reference service efficiently.

• Journal of Korean Association for Spatial Structures
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• v.11 no.4
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• pp.37-47
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• 2011

This article aims to analytically research for influence of residual stresses on bending moment responses against welded steel pipes subjected to quasi -static or dynamic loadings. The residual stresses of the welded steel pipe are computed by three-dimensional welding simulation. The bending moment responses of the welded and seamless steel pipes are determined by using three-dimensional dynamic elastoplastic FE analysis as a function of loading rate. It is seen from analytical results that the welded steel pipe shows lower moment response comparing to the seamless steel pipe, and moment difference between seamless and welded steel pipes tends to decrease as loading rate increases.

• Journal of the KSME
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• v.20 no.5
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• pp.387-391
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• 1980

일반적으로 내진 설계라 함은 지진에 의하여 발생된 지진동이 특정한 구조물에 작용할 때 이 지 진동의 경향하에서도 구조물의 정상적인 기능을 추진할 수 있도록 설계하는 것을 말하는 바, 원자력발전소의 내진설계에 있어서도 원칙적으로는 동일한 개념이나 실시하는 규정이 타구조물에 비하여 훨씬 엄격한 것이 다른 점이라 하겠다. 현재 우리나라의 경우 원자력 발전소는 1기(고리 #1)가 가동중이고 2기(월성 #1, 고리 #2)가 거의 완공단계에 있으며 7기(고리 #3, #4, 월성 #2, 계마 #1, #2, 부구 #1, #2)가 건설작업중인 바 이중 부구의 경우만 프랑스(\ulcorner)에서 건설 예정이고 기타는 모두 미국 및 카나다에서 건설하였거나 건설 예정이므로 따라서 그 설계에 있어서도 제 규정은 대체로 미국것을 준용하고 있는 형편이다. 그러므로 본고에서 는 미국에서 시행되고 있는 방법 또는 규정에 의거하여 내진설계용 입력지진에 대하여 설명하고자 한다. 내진설계에 입력 으로 사용되는 지진을 설계기준지진(design basis earthquake, DBE)이라고 통칭하며 이 지진은 미국 규정에 의하면 응답스펙트럼(response spectrum)으로 정의되게 되어 있으며 또한 이 응답 스펙트럼에 준하는 인공정인 지진의 시간기득(artificial time history)을 작성 또는 선정하여 이를 발전소 구조물의 내진 해석 및 내진 시험 입력으로 사용하게 되어 있다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1992.06a
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• pp.77-81
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• 1992

스퀴즈 필름 댐퍼 (Squeeze Film Damper, SFD)는 구조가 단순하면서도 감쇠성능이 우수하여 구름베어링에 지지된 고속회전체의 댐퍼로 이용되고 있으며 특히 대부분의 항공기용 터보엔진에 장착되어 고속회 전체의 댐퍼로서의 우수성을 보여주고 있다. 또한 동력기계의 단위 무게당 고출력화 경향으로 인하여 회전체의 경량화와 고속회전은 더욱 절실히 요구되고 있다. 이에따라 기계의 회전속도를 제 1차 또는 제 2차 위험속도(critical speed)이상까지 상승시켜야 하므로 SFD의 활용범위는 앞으로도 점차 증가할 것이다. 본 논문에서는 Swift-Stieber 경계조건을 적용하여, 공동현상이 발생하는 무한 폭 SFD의 유막력과 감쇠계수를 구한 후 강성 및 유연회전체의 정상상태 응답을 해석함으로써 공동현상이 회전체-SFD계의 진동에 미치는 영향을 연구하고자 한다.

• Korean Journal of Psychosomatic Medicine
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• v.18 no.1
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• pp.19-29
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• 2010

Objectives：Authors hypothesized that bipolar tendency of non-psychiatric person would be associated with stress vulnerability. To test the hypothesis, we compared perceived stress level, Type A Behavioral Pattern (TABP) and unhealthy lifestyle between person with and without bipolar tendency. Methods：The study cohort consisted of 1987 subjects without past and current psychiatric history. In this study, bipolar tendency was determined by MDQ response which requires endorsement of at least 7 of the 13 "yes or no" questions. We compared the scores of Perceived Stress Scale, A/B lifestyle questionnaire, and unhealthy lifestyle(alcohol, smoking, lack of exercise, irregular meal) between MDQ positive and negative respondents. Results：We identified the bipolar tendency group determined by the MDQ positive response were 329 subjects(16.6%). The overall score of the bipolar tendency group was significantly high on the A/B lifestyle questionnaire compared to the non-bipolar tendency group(125.4 vs. 115.9, p<0.001), and the rate of the subjects defined as TABP was also significantly high(41.3% vs. 30.1%, p<0.001). In comparison of subjectively perceived stress level, the bipolar tendency group was observed to be significantly higher than the non-bipolar tendency group (18.5% vs. 16.5%, p<0.001). The bipolar tendency group was significantly higher than the non-bipolar tendency group on the rate of answering：'irregular eating habit' (20.1% vs. 14.3%, p=0.002), '4-or-more-times alcohol intake per week' (29.8% vs. 16.5%, p<0.001), 'currently smoking' (41.9% vs. 23.0%, p<0.001), '2-or-less-times physical exercises per week' (63.2% vs. 55.1%, p=0.007). Conclusion：By clinical diagnosis, even a person who does not meet the criteria of bipolar disorder has a high risk of stress-related behavioral pattern, and perceived stress when possessing bipolar tendencies such as the (hypo) maniac tendency or affective instability. Such individual has significantly higher risk of having unhealthy life-style such as smoking, drinking, irregular eating habit and lack of exercise compared to non-bipolar tendency group. Since these risk factors lead to increase the risk of obesity, metabolic syndrome, diabetes, and cardiovascular diseases, the individual with the bipolar tendency requires a more effort to manage stress and to maintain healthy lifestyle.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.82-89
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• 2016

In this study, we proposed a pier of pontoon-type, "Very Large Floating Structure" (VLFS), with the length of 500m, breadth of 200 m and height of 2 m in Yeosu domestic port. Since this structure ought to endure wave loads for long periods at sea, it is essential to analyze the wave response characteristics. Direct-method is used to analyze the fluid-structure problem and the coupled motion of equation is used to obtain response results. The structural part is calculated by using finite element method (FEM) and the fluid part is analyzed by using boundary element method (BEM). Dynamic responses caused by the elastic deformation and rigid motion of structure are analyzed by numerical calculation. To investigate response characteristics of the pier in regular waves, several factors such as the wavelength, water depth, wave direction and flexural rigidity of structure are considered. As a result, wave response of pier changed at the point of $L/{\lambda}$ 1.5 and represented the torsional phenomenon according to the various incident waves. And the responses showed increasing tendency as the water depths increase at the incident point in case of $L/{\lambda}=8.0$ and peak point of vertical displacement amplitude moved from side to side as the flexural rigidity of structure changes.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.1
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• pp.11-20
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• 2008

In probabilistic seismic analysis of nonlinear structural system, dynamic analysis is performed to obtain the distribution of the response estimate using input ground motion time histories which correspond to a given seismic hazard level. This study investigates the differences in the distribution of the responses and the failure probability according to input ground motion models. Two types of input ground motion models are considered: real earthquake records scaled to specified intensity level and artificial input ground motion fitted to design response spectrum. Simulation results fir a nonlinear SDOF system demonstrate that the spectrum matched input ground motion produces larger failure probability than those of scaled input ground motion due to biased responses. Such tendency is more remarkable in the site of soft soil conditions. Analysis results show that such difference of failure probability is due to the conservative estimation of design response spectrum in the range of long period of ground motion.

• 한국노년학
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• v.40 no.4
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• pp.639-657
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• 2020

The purpose of this study is to analyze the effect of individual differences in recognition of retirement responsibility on financial preparedness for retirement and to examine moderating effect of income-level on the relationships between the two variables, using the 7th Korean Retirement and Income Study(KReIS). Two research methods, descriptive analysis and hierarchical multiple logistic regression(HMLR) analysis, have been conducted. The total number of sample was 3,869 subjects with an average age of 58.9 years and 55.3% males. The results show that only 35.8% of the respondents make financial plans for retirement, and 64.2% did not. Main findings are as follows. First, 65% of respondents take a responsibility for financial preparedness for retirement, compared to 37% in European countries. Second, people with responsibility for their own retirement are more likely to have a financial preparation for retirement than people who think others(family, society, government) have to take a responsibility for retirement instead of them. Third, there is a significant moderating effect of income-level on relationships between recognition of retirement responsibility and financial preparedness for retirement. As income level decreases, the moderating effect reduces the positive effect of recognition of retirement responsibility on financial preparedness for retirement and vice versa. Fourth, as income level increases and educational level is higher, the tendency to prepare financially for retirement is also increasing. Low-income and low-educated people are less likely to have a financial preparation for retirement than their counterparts. The findings suggest that it is necessary to design an effective incentive scheme for financial preparedness for retirement for low-income and low-educated people and to develop various policies and services to encourage them to prepare financially for retirement.