• 한국환경과학회지
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• 제31권7호
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• pp.593-607
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• 2022

Climate change has recently become a serious global issue, and carbon emissions and energy consumption are increasing, particularly in cities where economic activities and populations are concentrated. Accordingly, various countries worldwide are promoting the Green New Deal and promoting urban-centered climate change response policies with the aim of carbon neutrality. In Korea, following the "smart green city" project that creates a city where humans and the environment coexist, a similar "carbon neutral green city" policy is set to be introduced. Therefore, in this study, implications and directions for the sustainable introduction of the carbon neutral green city policy will be derived by comparing and analyzing the State and Tribal Assistance Grants of the U.S. bipartisan infrastructure law and the smart green city of the Korean new deal.

• Wind and Structures
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• 제22권4호
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• pp.429-454
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• 2016

In this paper, a shear deformation plate theory based on neutral surface position is developed for free vibration analysis of functionally graded material (FGM) plates. The material properties of the FGM plates are assumed to vary through the thickness of the plate by a simple power-law distribution in terms of the volume fractions of the constituents. During manufacture, defects such as porosities can appear. It is therefore necessary to consider the vibration behavior of FG plates having porosities in this investigation. The proposed theory is based on assumption that the in-plane and transverse displacements consist of bending and shear components, in which the bending components do not contribute toward shear forces and, likewise, the shear components do not contribute toward bending moments. The neutral surface position for a functionally graded plate which its material properties vary in the thickness direction is determined. The equation of motion for FG rectangular plates is obtained through Hamilton's principle. The closed form solutions are obtained by using Navier technique, and then fundamental frequencies are found by solving the results of eigenvalue problems. Numerical results are presented and the influences of the volume fraction index and porosity volume fraction on frequencies of FGM plates are clearly discussed.

• 한국심리학회지:법
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• 제12권2호
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• pp.99-120
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• 2021

본 연구는 정신병질 특성을 가지고 있는 집단이 정서적 얼굴을 처리하는 데 있어서 어떤 차이가 있는지 알아보았다. 정신병질적 성격 검사 개정판에 따라 15명의 정신병질 특성집단과 15명의 통제집단을 선별하였다. 실험 참여자들은 화남, 공포, 슬픔으로 구성된 부정적 얼굴과 무표정인 중성적 얼굴이 자극으로 사용된 과제를 수행하였다. 피험자가 자극의 성별을 판단하는 암묵적 과제와 정서를 판단하는 외현적 과제를 수행하는 동안 사건관련전위가 측정되었다. 정서처리과정에서 나타나는 정신병질 특성집단과 통제집단의 차이를 조사하기 위해 LPP(late positive potentials) 진폭을 분석하였다. 암묵적 과제에서는 두 집단 간 유의미한 차이가 나타나지 않았다. 그러나 외현적 과제에서는 집단과 정서 간 유의미한 상호작용이 전두중심영역에서 나타났다. 부정적 얼굴과 중성적 얼굴에서 비슷한 LPP 진폭을 보인 통제집단과 다르게 정신병질 특성집단은 부정적 얼굴에 비해 중성적 얼굴에서 더 큰 진폭을 보였다. 이러한 결과는 정신병질 특성집단이 가지는 정서 처리의 비정상성을 반영한다고 볼 수 있다.

• 해양안보
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• 제5권1호
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• pp.85-112
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• 2022

전쟁에 있어서 해상봉쇄는 결정적인 전투행위를 담당하지는 않아도 적의 해상수송을 마비시키는 역할을 통해 경제전을 위한 가교 역할을 담당한다는 점에서 오랜시간 동안 전쟁의 수단으로 활용되어왔고, 한국전쟁에서도 유엔군은 클라크 라인을 통한 제한적 해상봉쇄로 전쟁에서 상당한 효과를 거두었다. 하지만 해상봉쇄의 중요성에도 불구하고 중국이 강력한 해군력을 바탕으로 해양강대국으로 부상한 현 상황을 고려할 때 한반도에서 다시금 전쟁이 발발한다면 어떻게 봉쇄선을 설정하여 해상활동을 차단할 것인지, 특히 중립국 선박이나 전시금제품을 수송하는 선박에 대해 어떻게 대응할 것인지에 대한 검토가 부족하다. 또한 봉쇄는 중립국과의 이해관계가 존재한다는 점에서 예민하고 융통성 있는 해군력 투사 수단으로 활용되어야 하므로 봉쇄의 합법성을 보장하기 위한 원칙을 고려하여 신중하고 합리적인 판단을 통해 활용될 때에만 그 목적을 달성할 수 있다는 점에서 그 실행에 앞서 신중한 검토가 필요하다. 따라서 본 연구에서는 해상봉쇄법 적용의 변천 과정을 재조명하고, 이를 통해 해상봉쇄의 합법성을 보장하는 기본원칙을 도출하고자 한다. 그리고 전시 한반도 근해에서 이러한 기본원칙의 적용방안과 함께 중립국 선박과 전시금제품 운반선박에 대해서는 어떤 대응이 필요한지를 검토함으로서 연구질문에 대한 답을 제시하고, 우리에게 주는 함의를 고찰하였다.

• Advances in nano research
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• 제8권3호
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• pp.191-202
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• 2020

The article brings the study of nonlocal, surface and the couple stress together to apparent the frequency retaliation of FG nanobeams (Functionally graded). For the examination of frequency retaliation, the article considers the accurate spot of neutral axis. This article aims to enhance the coherence of proposed model to accurately encapsulate the significant effects of the nonlocal stress field, size effects together with material length scale parameters. These considered parameters are assimilated through what are referred to as modified couple stress as well as nonlocal elasticity theories, which encompasses the stiffness-hardening and softening influence on the nanobeams frequency characteristics. Power-law distribution is followed by the functional gradation of the material across the beam width in the considered structure of the article. Following the well-known Hamilton's principle, fundamental basic equations alongside their correlated boundary conditions are solved analytically. Validation of the study is also done with published result. Distinct parameters (such as surface energy, slenderness ratio, as nonlocal material length scale and power-law exponent) influence is depicted graphically following the boundary conditions on non-dimensional FG nanobeams frequency.

• Wind and Structures
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• 제24권5호
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• pp.465-480
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• 2017

Modelling an equilibrium atmospheric boundary layer (ABL) in computational wind engineering (CWE) and relevant areas requires the boundary conditions, the turbulence model and associated constants to be consistent with each other. Among them, the inflow boundary conditions play an important role and determine whether the equations of the turbulence model are satisfied in the whole domain. In this paper, the idea of modeling an equilibrium ABL through specifying proper inflow boundary conditions is extended to the SST $k-{\omega}$ model, which is regarded as a better RANS model for simulating the blunt body flow than the standard $k-{\varepsilon}$ model. Two new sets of inflow boundary conditions corresponding to different descriptions of the inflow velocity profiles, the logarithmic law and the power law respectively, are then theoretically proposed and numerically verified. A method of determining the undetermined constants and a set of parameter system are then given, which are suitable for the standard wind terrains defined in the wind load code. Finally, the full inflow boundary condition equations considering the scale effect are presented for the purpose of general use.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3703-3708
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• 2013

The scaling relationship of the longest relaxation time of a single chain of semiflexible biological polyelectrolyte has been investigated by performing well-established coarse-grained Brownian dynamics simulations. Two kinds of longest relaxation times were estimated from time-sequences of chain trajectories, and their behaviors were interpreted by applying the scaling law for different molecular weights of polyelectrolyte and Debye lengths. The scaling exponents for longest stress relaxation and rotational relaxation are found in the ranges of 1.67-1.79 and 1.65-1.81, respectively, depending on the physicochemical interaction of electrostatic Debye screening. The scaling exponent increases with decreasing screening effect, which is a special feature of polyelectrolytes differing from neutral polymers. It revealed that the weak screening allows a polyelectrolyte chain to follow the behavior in good solvent due to the strong electrostatic repulsion between beads.

• 가정과삶의질연구
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• 제9권2호
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• pp.345-366
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• 1991

The concrete purpose of this study is to examine the possibility of applying S.Minuchin's structural family therapy theory to each clinical families so that it can solve efficiently the clinical problems Korean family. The test results are as follows: 1)The Results of Question I : Types of Korean family problems can be divide into six. Then the most frequent type of problem was marital problem. 2) The Results of Question II: Korean normal family showed rater difussed boundary and higher rate of wife dominant type than that of husband dominant type in aspect of boundary and power, and had low tendency toward alignment and neutral adjustment. 3)The Results of Quesion III; Amidst the clinical families, family structural traits of the families which have marital problems showed a clear boundary, the tendency toward alignment, and higher tate of husband dominant type than that of wife dominant type. And family structural traits of children problem family had the tendency of alignment and showed little wife-dominanted families in power. Finally, mother-in -law and daughter-in-law problemed family had several characters such as diffused boundary, the tendency of alignment and high adjustment. 4)The Results of Question IV : As a result of camparing problemed families with normal families in family structure, there was high adaptability of S.Minuchin's structural theory to the two family groups; the groups of marital problems and those of children problem.

• 가정과삶의질연구
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• 제30권3호
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• pp.1-11
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• 2012

The purpose of this study is to analyze the effects of attitudes toward reasons for which abortion is permitted on needs for abortion prevention policies among 232 unmarried female students at the middle schools, high schools, and universities located in Seoul. The respondents were requested to complete the self-administered questionnaire, and the principal component analysis, t-tests, Pearson's correlations, and hierarchical multiple regression analyses were performed for analyzing data. The major findings of this study were as follows: First, the principal component analysis identified three reasons for which abortion is permitted. These are reasons under the maternal & child health law, socioeconomic reasons, and normatively unqualified reasons. Second, the female students showed permissive attitudes toward reasons for abortion under the maternal & child health law, disapproval attitudes toward socioeconomic reasons for abortion, and neutral attitudes toward abortion by normatively unqualified reasons. Students also showed high levels of needs for abortion prevention policies. Finally, hierarchical regression analyses revealed that female students' attitudes toward reasons for which abortion is permitted significantly predicted levels of needs for abortion prevention policies, after controlling their sciodemographic characteristics. The implications of the study results are discussed.

• Journal of Mechanical Science and Technology
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• 제18권1호
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• pp.82-91
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• 2004

This article deals with a minimum energy control law of S-CVT connected to a dc motor. The S-CVT can smoothly transit between the forward, neutral, and reverse states without any brakes or clutches, and its compact and simple design and its relatively simple control make it particularly effective for mechanical systems in which excessively large torques are not required. And such an S-CVT equipped power transmission has the advantage of being able to operate the power sources in their regions of maximum efficiency, thereby improving the energy efficiency of the transmission system. The S-CVT was intended to primarily for use in small power capacity transmissions, thus a dc motor was considered here as the power source. We first review the structure and operating principles of the S-CVT, including experimental results of its performance. And then we describe a minimum energy control law of S-CVT connected to a do motor. To do this, we describe the results of an analysis of the dynamics of an S-CVT equipped power transmission and the power efficiency of a DC motor. The minimum energy control design is carried out via B-spline parameterization. And we show numerical results obtained from simulations illustrate the validity of our minimum energy control design, benchmarked with a computed torque control algorithm for S-CVT.