• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.376-386
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• 2020

The aim of this study was to develop a new efficient strategy that uses the Vector form Intrinsic Finite-element (VFIFE) method to conduct the static and dynamic analyses of marine pipes. Nonlinear problems, such as large displacement, small strain, and contact and collision, can be analyzed using a unified calculation process in the VFIFE method according to the fundamental theories of point value description, path element, and reverse motion. This method enables analysis without the need to integrate the stiffness matrix of the structure, because only motion equations of particles established according to Newton's second law are required. These characteristics of the VFIFE facilitate the modeling and computation efficiencies in analyzing the nonlinear dynamic problem of flexible pipe with large deflections. In this study, a three-dimensional (3-D) dynamical model based on 3-D beam element was established according to the VFIFE method. The deep-sea flexible pipe was described by a set of spatial mass particles linked by 3-D beam element. The motion and configuration of the pipe are determined by these spatial particles. Based on this model, a simulation procedure to predict the 3-D dynamical behavior of flexible pipe was developed and verified. It was found that the spatial configuration and static internal force of the mining pipe can be obtained by calculating the stationary state of pipe motion. Using this simulation procedure, an analysis was conducted on the static and dynamic behaviors of the flexible mining pipe based on a 1000-m sea trial system. The results of the analysis proved that the VFIFE method can be efficiently applied to the static and dynamic analyses of marine pipes.

• 한국주거학회논문집
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• 제16권6호
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• pp.121-128
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• 2005

This study investigates the design features of pilotis applied to 20 high-rise apartment housings in Korea, completed between January 2000 and August 2005. It analyzes the design characteristics of pilotis on the basis of its spatial configuration and the residents' behavior and suggests the directions of pilotis design in the future. The study finds the followings. 1) The pilotis spaces in foreign apartment housings are used mainly for communal functions such as the passages between buildings for both pedestrians and vehicles. Compared with this public use of pilotis in foreign counterparts, the pilotis spaces in Korean apartment housings are semi-private and have multiple purposes. 2) The pilotis design can be classified on the basis of the spatial configuration elements and the patterns of residents' behavior. The spatial configuration elements consist of ceiling, column, wall, and floor; the residents' behavior can be classified as viewing, resting and playing, driving and parking, and keeping privately-owned objects such as motorcycle and bicycle. 3) Two spatial configuration elements, the wall and the ceiling and two behavioral patterns, 'resting and playing' and 'viewing' are getting more attention by designers in the apartment housings analyzed in this study.

• 한국실내디자인학회논문집
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• 제29호
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• pp.120-127
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• 2001

The study aims at finding out the spatial configuration of a small art museums through the analysis of visual Perception in spatial layouts. In so doing to analyze the characteristics of spatial perception in visual layouts and identity of space to evaluate the spatial construction with relation to the role of small art museums. Purpose of this study is to offer basic data to contribute effectiveness of the architectural planning of a small art museums by understanding of visual element of design and ultimately to make efficient use of space.

• 한국공간구조학회논문집
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• 제17권2호
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• pp.63-70
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• 2017

In Korea, the occurrence frequency of earthquakes has recently increased, compared with the past. So, the various damages for cultural properties due to earthquake can be expected, and especially fortress structure is vulnerable to earthquake. Therefore, the resonable seismic characteristics evaluation is required to secure the safety for fortress structure with the various construction and configuration types. Also, we should consider the various applied load conditions as design variables. To this end, this study classifies fortress structures according to the construction and configuration types, and then applies the discrete element method to model and analyze fortress structures. Finally, the seismic characteristics is evaluated through slip condition due to the analysis results considering the various design variables.

• 전산구조공학
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• 제11권1호
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• pp.179-190
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• 1998

두개의 케이블요소를 이용한 3차원 케이블망의 정적 비선형 유한요소해석기법을 제시한다. 먼저, 공간 트러스요소와 탄성현수선 케이블요소(elastic catenary cable element)의 접선강도행렬과 질량행렬을 유도하는 과정을 간략히 요약한다. 지점 변위를 일으키고 자중을 받는 케이블망의 초기평형 상태를 결정하기 위하여, Newton-Raphson 반복법에 근거한 하중증분법과 현수케이블요소를 적용하는 경우에 viscous damping을 고려한 dynamic relaxation법을 제시한다. 또한 초기의 정적평형상태를 기준으로 추가하중에 대한 케이블망의 정적 비선형해석을 수행한다. 지점변위와 외력을 받는 케이블 구조에 대하여 비선형해석을 수행하고, 해석결과들을 기존의 문헌의 결과와 비교, 검토하므로써 본 논문에서 제시한 이론 및 해석방법의 타당성을 입증한다.

• 대한건축학회논문집:계획계
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• 제35권9호
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• pp.65-75
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• 2019

This study aims at analyzing the therapeutic design characteristics implemented in the indoor atriums of the outpatient areas in four children's hospitals in London and San Francisco. A mixed-method approach was used to examine the spatial configurations and design elements in the atriums, while a literature review was conducted to understand the therapeutic design characteristics relevant to atrium spaces and children's healthcare facilities. The spatial design and the pattern of use of the atrium in each hospital were studied during field visits and interviews with the hospital management staff. Based on the literature review and the observations from the field study, a Visibility Graphic Analysis was chosen to examine the visibility, accessibility, and intelligibility of the spatial configurations in the atriums of each hospital. In addition, the openness, restfulness, and vibrant ambience of the design elements in the atriums of each hospital were investigated by surveying fifty-two design professionals on the quality of the design elements in the atriums. A spatial configuration analysis, confirmed that all the atrium spaces had high visibility, accessibility, and intelligibility due to their high connectivity, integration, intelligibility, and because the atriums were laid out in the open lobby space, along the major circulation axis, or in the circulation intersection. In the survey of the design element evaluation, all atriums proved to be appropriate in terms of openness, while the adequacy of restfulness and vibrant ambience differed depending on the hospitals. Notably, location and orientation, access, natural light, outdoor view, and play facilities were found significant environmental design elements determining the successful implementation of the therapeutic design in the atriums. The observations from the aforementioned are further discussed to enhance the therapeutic design quality of atrium spaces in children's hospitals.

• 한국디지털건축인테리어학회논문집
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• 제9권3호
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• pp.95-102
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• 2009

An architectural space can be considered a life form that interconnects a number of architectural elements such as the humans who live in it. It is difficult to understand and evaluate the complexity of the interrelation between each element, but there have been various attempts to understand and evaluate this architectural space. The Space Syntax that emerged in 1980s has been studied and used more frequently than other methods. Space Syntax is the space analysis tool that analyzes the physical structure of space and represents it as a graph. Space syntax enables its various applications in space analysis by quantifying each spatial property of a whole structure, analyzing it systemically and objectively based on mathematical logic, and representing the results as a quantitative value. Integration of Space Syntax, a widely used index, reflects human behavior in spatial configuration. Meanwhile, there have been various studies in the field of architectural environmental psychology about the relationships between space and human behavior by applying behavioral science to architectural plan. One of the most widely used one is spatial behavior simulation which uses models and simulates the behavioral characteristics to anticipate practical situations and investigate the behavior related spatial problems. In this study, which focuses on the accessibility of the space syntax model, the usefulness of space will be analyzed through the simulation of human behavior that moves through each space. Furthermore, the validity of index will be verified by displaying several examples and compared with integration in space syntax, which represents the usefulness of space.

• Journal of Magnetics
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• 제18권2호
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• pp.212-215
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• 2013

This paper deals with torque harmonic characteristics and its reduction design of induction motors for electric vehicle (EV) propulsion. For calculating the stator harmonic flux of squirrel-cage induction motor, the numerical methods have been employed on the structural configuration design of stator and rotor teeth. In particular, torque ripples including spatial harmonics are obtained by Finite Element Method (FEM), and their individual harmonic components are identified with Fast Fourier Transform (FFT). In this paper, design modification on the teeth surface gives rise to the significant reduction of torque ripples including spatial torque harmonics, which have been obtained with FEM.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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• pp.134-141
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• 1997

A geometrically non-linear finite element formulation of spatial cable networks is presented using three cable elements. Firstly, derivation procedures of tangent stiffness and mass matrices for the space truss element and the elastic catenary cable element, and the isoparametric cable element are summarized. The load incremental method based on Newton-Raphson iteration method and the dynamic relaxation method are presented in order to determine the initial static state of cable nets subjected to self-weights and support motions. Furthermore, static non-linear analysis of cable structures under additional live loads are performed based on the initial configuration. Challenging example problems are presented and discussed in order to demonstrate the feasibility of the present finite element method and investigate static non-linear behaviors of cable nets.

• 대한의용생체공학회:의공학회지
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• 제32권4호
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• pp.305-311
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• 2011

For effective stimulation with tDCS, spatial focality of induced electrical field(EF) and current density(CD) is one of the important factors to be considered. Recently, there have been some studies to improve the spatial focality via different types of electrodes and their new configurations: some improvements using ring electrodes were reported over the conventional pad electrodes. However, most of these studies assumed isotropic conductivities in the head. In this work, we have investigated the effect of tissue anisotropy on the spatial focality of tDCS with the 4 + 1 ring electrode configuration via a 3-D high-resolution finite element(FE) head model with anisotropic conductivities in the skull and white matter. By examining the profiles of the induced EF from the head models with isotropic and anisotropic conductivities respectively, we found that the spatial focality of the induced EF significantly drops and get diffused due to tissue anisotropy. Our analysis suggests that it is critical to incorporate tissue anisotropy in the effective stimulation of the brain via tDCS.