• Communications for Statistical Applications and Methods
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• 제26권3호
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• pp.261-272
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• 2019

In this paper, we propose a procedure to build a prediction interval of the sum of dependent binary random variables over a graph to account for the dependence among binary variables. Our main interest is to find a prediction interval of the weighted sum of dependent binary random variables indexed by a graph. This problem is motivated by the prediction problem of various elections including Korean National Assembly and US presidential election. Traditional and popular approaches to construct the prediction interval of the seats won by major parties are normal approximation by the CLT and Monte Carlo method by generating many independent Bernoulli random variables assuming that those binary random variables are independent and the success probabilities are known constants. However, in practice, the survey results (also the exit polls) on the election are random and hardly independent to each other. They are more often spatially correlated random variables. To take this into account, we suggest a spatial auto-regressive (AR) model for the surveyed success probabilities, and propose a residual based bootstrap procedure to construct the prediction interval of the sum of the binary outcomes. Finally, we apply the procedure to building the prediction intervals of the number of legislative seats won by each party from the exit poll data in the $19^{th}$ and $20^{th}$ Korea National Assembly elections.

• Macromolecular Research
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• 제14권5호
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• pp.517-523
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• 2006

The effects of particle content, size and shape on the thermal conductivity (k) and adhesion properties of thermally conductive, pressure-sensitive adhesives (PSAs) were investigated. The matrix resins were thermally crosslinkable, 2-ethylhexyl acrylic polyol and ultraviolet (UV)-curable, random copolymer consisting of acrylic oligomer and various acrylates. We found that k increased with increasing diameter and particle aspect ratio, and was further enhanced due to the reduction of the interfacial thermal barrier when the coupling agent, which increases the adhesion between particles and the matrix resin, was used. On the other hand, adhesion properties such as peel strength and tack of the thermally crosslinkable resin decreased sharply with increasing particle content. However, for UV curable resin, increased particle addition inhibited the decrease in adhesion properties.

• Structural Engineering and Mechanics
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• 제2권2호
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• pp.157-171
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• 1994

A general approach to the dynamic time-history analysis of the reactor core is presented in this paper as a part of the fuel assembly qualification program. Several detailed core models are set up to reflect the placement of the fuel assemblies within the core shroud. Peak horizontal responses are obtained for each model for the motions induced form earthquake. The dynamic responses such as fuel assembly deflected shapes and spacer grid impact loads are carefully investigated. Also, the sensitivity responses are obtained for the earthquake motions and the fuel assembly non-linear response characteristics are discussed.

• 의정연구
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• 제15권1호
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• pp.5-38
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• 2009

이 연구는 민주화 이후 국회-대통령-정당관계를 역사적으로 살펴봄으로써 이를 상생적인 관계로 이끌어가기 위한 조건들에 대하여 고찰하고자 하였다. 연구자는 정당 내부의 권력집중도와 정당기율의 정도가 국회-대통령관계의 상생성에 결정적 영향을 미친다고 보고 이를 분석의 중심틀로 적용하였다. 2002년 이전까지 한국 정당은 권력집중형에 강한 기율이 특징이었다. 대통령 정당은 그의 의제실현을 목적으로 한 입법도구였고, 야당은 반대자로만 존재하는 집단적 대립과 교착의 시대였다. 2002-4년이후 정당정치에서 권력을 분산시키고 기율을 약화시키는 미국식 원내정당화를 포함하여 다양한 제도 개혁이 이루어졌으나 현재까지는 상생정치가 별로 진전되지 않고 있다. 개혁의 결과는 의원들 개인보다는 파벌의 중요도를 증진하였다. 그런데 파벌정치가 (잠재적)대권후보를 중심으로 강하게 응집함으로써 국회는 여전히 정당간의 당론들만이 격돌하는 입법전쟁터로 존재할 뿐이다. 분석을 토대로 연구자는 상생정치 발전을 위해서 현재 정당 및 하위 파벌들의 집단적 행태를 더욱 해체하는 방향으로의 제도 개선을 제안하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.15-17
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• 2022

볼 베어링 선택조립 시스템에서 잉여부품을 최소화하기 위해서는 각 부품의 치수 분포를 파악하여 선택 확률을 최적화하여야 하지만, 복잡한 시스템은 생산 공정에 지연이 일으킨다. 본 논문에서는 볼 베어링 선택조립 시스템에서 빠르고 간단하게 선택 우선순위를 결정할 수 있는 군집 우선 선택 알고리즘을 제안한다. 그리고 실제 볼 베어링 선택조립 공정에서 수집한 데이터로 모의 상황을 가정하고, 군집 우선 선택 알고리즘과 기존 알고리즘을 시뮬레이션하여 잉여부품 발생률과 연산소요시간을 평가한다. 시뮬레이션 결과, 군집 우선 선택 알고리즘이 기존 알고리즘에 비하여 83.8% 적은 잉여부품을 발생하였고, 연산소요시간도 39.7% 단축되었다.

• 한국고분자학회지:고분자과학과기술
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• 제24권5호
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• pp.512-516
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• 2013

• 산업경영시스템학회지
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• 제29권4호
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• pp.34-42
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• 2006

This paper considers an assembly-type flowshop scheduling problem in which each job is assembled with two types of components. One type of the components is outsourced with positive lead time but the other type is fabricated in-house at the first stage. The two types of the components should be prepared at the first stage before starting the assembly operation for each job at the second stage. The objective is to schedule the jobs so that the makespan is minimized. Some solution properties and lower bounds are derived and incorporated into a branch and bound algorithm. Also, an efficient heuristic is developed. The performances of the proposed branch and bound algorithm and heuristic are evaluated through computational experiments.

• 보건행정학회지
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• 제26권4호
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• pp.279-288
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• 2016

Graphic health warning on the tobacco product package is a cost-effective tobacco control policy to convey information on harmful effect of tobacco use to health, and it is known not only to motivate smokers to quit but also to deter adolescents from start smoking. In case of Korea, amendments to National Health Promotion Act requiring implementation of graphic health warning had been submitted 13 times, from 2002 to May 2015. In May 2015, the amendment had been approved by the National Assembly and it enters into force on December 23, 2016. This research analyzed the discussions from Health and Welfare Committee of the National Assembly during the implementation of the graphic health warning in order to study decision making process of legislators. Study found that there was a shift from a general opposition on implementing graphic health warning at first to a harsh conflict over relaxation of the regulation once discussing the implementation in earnest. Particularly, while the group supporting the implementation of the graphic health warning or opposing relaxation advocated the amendment with scientific and knowledge-based evidences including the World Health Organization Framework Convention on Tobacco Control, the group opposing the adoption of the amendment itself or suggesting relaxation tended to defend their position with empathy on smokers or tobacco industries.

• 한국유체기계학회 논문집
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• 제18권6호
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• pp.5-11
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• 2015

In a pressurized water reactor (PWR), control rod assembly (CRA) falls into the guide tubes of a fuel assembly due to gravity for scram. Various theoretical approaches and numerical analyses have been performed because its shape is simple and its design was completely developed several decades ago. A control rod assembly for a sodium-cooled faster reactor (SFR) which is geometrically more complicated is being actively developed in Korea nowadays. Drop time and impact velocity of a CRA are important parameters with respect to reactivity insertion time and the mechanical robustness of a CRA and a guide duct. In this paper, computational method considering simultaneously the equation of motion for rigid body and the Navier-Stokes equations for fluid is suggested and verified by comparison with theoretical analysis results. Through this valuable CFD analysis method, drop time and impact velocity of initially designed SFR CRA are evaluated before performing scram tests with it.

• Korean Chemical Engineering Research
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• 제50권6호
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• pp.1082-1085
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• 2012

CdTe 나노입자로부터 형성된 나노리본은 독특한 광학적 특성을 나타낸다. 용액 내 CdTe의 $Te^{2-}$ 이온의 산화는 나노입자에 불규칙적인 결함을 유발하며 이때 여러 층의 나노결정으로 구성된 나노리본을 형성하게 된다. 본 연구에서는 자기조립 된 CdTe 나노입자가 나노리본을 형성하는 과정에서 빛을 조사하였다. 빛은 용액 내 CdTe 나노입자의 표면에 위치한 $Te^{2-}$의 산화를 촉진시키는 촉매 역할을 수행한다. 합성된 3차원 나노리본의 형태와 특성을 투과전자현미경(TEM)으로 조사하였다. TEM 결과 안정제가 완전히 제거된 부분에서 부분적으로 접힌 꼬인 형태의 다결정 나노리본을 관찰할 수 있었다. Photoluminescence (PL) 측정 결과 550 nm에서 544 nm로 나노입자가 나노리본으로 형성될 때 Blue shift 되었음을 확인하였다. 본 연구에서 제안된 새로운 합성법은 나노물질을 합성하는 새로운 대안을 제시한다.