• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1664-1670
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• 1991

For kinematically redundant manipulators, conventional dynamic control methods of local torque optimization showed the instability which resulted in physically unachievable torque requirements. In order to guarantee stability of the null space vector method which resolves redundancy at the acceleration level, Maciejewski[1] analyzed the kinetic behavior of homogeneous solution component and proposed the condition to identify regions of stability and instability for this method. 'In this paper, a modified null space vector method is first presented based on the Maciejewski's condition which is a function of a manipulator's configuration. Secondly, a new control method which is based on the concept of aspects is proposed. It was shown by computer simulations that the modified null space vector method and the proposed method have a common property that a preferred aspect is preserved during the execution of a task. It was also illustrated that both methods demonstrate a drastic reduction of torque loadings at the joints in the tracking motion of a long trajectory when compared with the null space vector method, and thus guarantee the stability of joint torque.

• 한국화재소방학회논문지
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• 제16권4호
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• pp.49-58
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• 2002

최근 국내·외에서 지하철 공사현장 가스폭발, 지하 공동구 화재, 지하가 화재 폭발 등 지하공간에서의 사고가 다수 발생하고 있다. 이러한 사고는 재산의 손실 뿐 아니라 전력, 통신망 마비로 도시 기능을 무력화시키고, 인명 피해의 대형화를 동반함으로서 도시민의 안전을 위협하고 있다. 본 연구에서는 지하공간이 잠재적으로 갖고 있는 연소확대 위험성을 확률을 이용하여 평균 연소손실면적 예측치를 산출하고, 화재시 화재확산 경로 및 피해 크기를 산출하여 각 방재 대책의 효과를 상대적으로 비교 평가할 수 있는 시스템을 개발하고자 한다.

• 항공우주정책ㆍ법학회지
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• 제14권
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• pp.87-110
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• 2001

This Article examines a structure of two Conventions of Space Station, compares 1988 Convention and 1998 Convention, and tries to apply "model" to it. The structure of 1988 Convention shows us three phases: the Convention as a framework, the bilateral memorandum of understanding and the legislation by domestic process of United States. There were many advantageous provisions for United States. In 1998 Convention, however, those provisions are dampened and provisions become impartial, for example, the criminal jurisdiction, the right of intellectual property and the codes of conducts in Space Station. On the other hand, we sets the "model" up, that is "input of national benefits and ideas ${\Rightarrow}$ process of law-making ${\Rightarrow}$ output of common benefits, universal ideas and wastes." In the case of applying this "model" to 1988 and 1998 Conventions, we are convinced of enough possibility to understand and explain the legal system of Space Station by this "model." This result awakes us that study of legal system of Space Station according to the "model" influences the fundamental theory of International Law Study: the relation between international law and domestic law. This "model" has possibility to change the theory of relation between from "international law and domestic law" to "domestic law and domestic law through international legal system." In the end, we should reconsider on "policy-oriented jurisprudence" by professor McDougal to use his key words for explanation of concepts in the "model," because his theory contains important suggestions to the study of law-making process and legal system for outer space activities in the near future.

• 한국실내디자인학회논문집
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• 제14권1호
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• pp.118-125
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• 2005

A leisure culture in the modern society is the measure of a value in one's life and has a symbolic meaning which reflects the aspect of a society where an individual belongs to. Therefore, the leisure is not a simple pleasure but has an critical meaning of expressing the culture of a country. In particular, the theme park leads the public amusement in the modern society using the cutting-edge equipments on a large scale in the postmodernism society being lead by the public. Nonetheless, Korea imports the theme parks of the same type as the Disney land of the Western Europe so that Korea depends on the foreign country in the leisure field. Therefore, in this study, the basic property of the theme park is investigated and the issues of Korean theme park will be revealed through the comparison of Korean theme park to foreign theme parks. In order to solve these issues, it points out that the concept of Korean traditional leisure space has inclusive and upgraded characteristics with many meanings, compared with the concept of the leisure space of foreign countries. . Based on this, the new concept of Korean theme park's space will be proposed. Specially, it is empathized that Korean own originality and credit should be preserved and Korean traditions should be succeeded.

• 천문학회보
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• 제36권2호
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• pp.102.1-102.1
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• 2011

In this study we use three-dimensional magnetohydrodynamic simulations to investigate how the dynamic state of emerging magnetic field is related to the twist of field lines. Emerging magnetic field forms a magnetic structure on the Sun where various kinds of activity such as solar flares, jets, and coronal mass ejections are observed. To understand the physical mechanism for producing such activity, we have to know the dynamic nature of this structure. Since flares are the manifestation of rapidly dissipating electric current in the corona, we also investigate the distribution of current density inside the structure and examine how it depends on the field-line twist. To demonstrate the dynamic structure of emerging magnetic field, we focus on the factors characterizing the geometric property and stratification of emerging magnetic field, such as the curvature of field line and the scale height of field strength. These two factors show that emerging field forms a two-part structure in which the central part is close to a force-free state while the outer marginal part is in a fairly dynamic state where magnetic pressure force is dominant. We discuss how the field-line twist affects the two-part structure and also explain a possible relation between electric current structure and sigmoid observed in a preflare phase.

• 한국주거학회논문집
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• 제25권6호
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• pp.1-10
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• 2014

The purpose of this study is to gain an in-depth understand of the dwelling needs of residents who are interested in Cohousing. To do this, we interviewed 18 urban residents who wanted a community life; investigated consciousness of neighbor relationships; and analyzed their consciousness of Cohousing residences, preference types, and spatial needs. At first the research has revealed that the neighbor relationships of the participants were not very close and that there was a difference in awareness levels between a 'good neighbor' and 'strange neighbor' with regard to neighbors, though all of the participants required a vitalization of these relationships. Second, Cohousing residence types could be divided into the 'life preferred type' and 'space preferred type', depending on the differences of pursued dwelling interests. These could be further segmented into the 'leisure life preferred type' and 'daily life preferred type', 'public space preferred type' and 'individual space preferred type'. Thirdly, preferences for Cohousing types varied depending on differences in priority with regard to important concepts of the social-physical environment (e.g., community property, effectiveness, naturalness, economic feasibility, and individuality). Finally, we found that the greatest needs were for public gardens and exercise space as aspects of the common spaces. Agreements pertaining to special use were considered as most important during the design process of the common spaces.

• 한국항해항만학회지
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• 제37권5호
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• pp.543-549
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• 2013

본 연구는 부산을 대표하는 수변공간으로서, 인지도가 높은 7곳(해운대, 민락공원, 광안리, APEC나루공원, 다대포, 자갈치, 태종대)을 선정하여 사전 표본 설문조사를 실시하였다. 그 결과를 바탕으로 특성이 가장 뚜렷하게 나타난 2곳(해운대, 자갈치)을 대상으로 설문조사를 다시 실시하여, 방문자가 수변공간에 대해서 느끼는 수변공간의식을 조사하였다. 그 결과, 해운대는 이용자의 81.5%(163명)가 '바다바람을 느낀다.'로 응답하였으며, 자갈치는 55.8%(111명)가 '해산물을 먹을 수 있다.' 로 응답하였다. 또 수변공간의식을 중심으로 각각 연령대별, 희망 활동별로 수변공간의 전체적인 만족도에 대한 분석을 실시하였다.

• 한국정보통신학회논문지
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• 제25권12호
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• pp.1826-1834
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• 2021

본 논문에서는 지상의 광학 관측 시스템에서 미지 우주물체를 짧은 주기로 촬영할 때의 연속 추적 가능성을 확인해 본다. 저궤도영역으로 한정된 대상 표적에 대해 모의 관측 데이터를 생성하였고, 표적특성을 고려하여 예측 오차의 성능지수를 설정하였다. 칼만 필터를 이용하여 표적의 다음 위치를 예측하였고, 등속도/등가속도 표적 기동 모델이 미지 우주물체의 방위각/고도각 두 축에 적용되었다. 몬테카를로 시뮬레이션을 수행한 결과, 최대 비선형구간의 최대 오차 비율이 2% 미만으로 나타나 연속적인 추적을 보장할 수 있다고 판단할 수 있었다. 등가속도 모델이 케이스별 예측 오차값의 변화가 적어서, 미지 우주물체의 추적에 더 적합하였다. 이러한 분석은 광학 관측을 이용한 미지 우주물체 궤도 결정의 기초를 제공할 수 있다.

• 한국전산구조공학회논문집
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• 제21권2호
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• pp.199-208
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• 2008

본 논문에서는 초기값을 갖는 비동질 반무한 평면문제를 비례경계유한요소법으로 해석하기 위하여 무한요소를 이 해석법에 도입하였다. 초기값을 갖는 반무한 평면의 자유면은 비례경계좌표계의 원주방향의 좌표를 이용하여 모델링하였고 무한요소는 이 자유면이 나타내는 무한한 영역을 모사하기 위해 사용되었다. 반무한 평면의 물성치(탄성계수)에 대한 초기값은 비례중심의 위치와 비례경계좌표계에서의 반지름 멱함수를 이용하여 나타내었다. 사상형 무한요소를 사용하여 일관된 정식화가 가능하였고, 제안된 해석법에 대한 적용성과 성능을 두 수치예제를 통하여 보였다.

• Structural Engineering and Mechanics
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• 제46권5호
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• pp.645-672
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• 2013

The differential settlements and rotations among footings cannot be avoided when the frame-footing-soil system is subjected to seismic/dynamic loading. Also, there may be a situation where column(s) of a building are located near adjoining property line causes eccentric loading on foundation system. The strap beams may be provided to control the rotation of the footings within permissible limits caused due to such eccentric loading. In the present work, the seismic interaction analysis of a three-bay three-storey, space frame-footing-strap beam-soil system is carried out to investigate the interaction behavior using finite element software (ANSYS). The RCC structure and their foundation are assumed to behave in linear manner while the supporting soil mass is treated as nonlinear elastic material. The seismic interaction analyses of space frame-isolated footing-soil and space frame-strap footing-soil systems are carried out to evaluate the forces in the columns. The results indicate that the bending moments of very high magnitude are induced at column bases resting on eccentric footing of frame-isolated footing-soil interaction system. However, use of strap beams controls these moments quite effectively. The soil-structure interaction effect causes significant redistribution of column forces compared to non-interaction analysis. The axial forces in the columns are distributed more uniformly when the interaction effects are considered in the analysis.