• 한국전산구조공학회논문집
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• 제20권4호
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• pp.493-499
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• 2007

본 연구에서는 미분 가능한 함수가 Taylor 전개로 표현되고 그 계수들은 주어진 함수와 미분에 대한 근사값을 제공할 수 있다는 점에 착안하여 m차 Taylor 다항식을 구성하고 이동최소제곱법을 이용하여 그 계수들을 구했다. 계산된 근사함수와 미분을 콜로케이션 개념을 바탕으로 균열 문제를 포함하는 고체문제에 대한 지배 미분방정식에 적용하여 차분식 형태의 이산화된 계방정식을 구성하였다. 본 연구의 해석기법은 격자망(grid)에 의존적이고 근사함수가 없는 유한차분법과 형상함수의 미분과 약형식의 적분산정, 필수경계조건 처리가 어려운 Galerkin법 기반의 무요소법의 단점을 효과적으로 극복한 새로운 수치기법이다.

• 복식문화연구
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• 제23권2호
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• pp.294-309
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• 2015

This study aims to clarify the aesthetic values between emotion of human and expression of technology in contemporary fashion as it analyzes formative characteristics of related cases in fashion based on principles of 3D Printing technology and the viewpoint of mechanic aesthetics. The conclusions of this study are as follows. First, 3D Printing fashion is not only expressed diverse variations by its principles of formative methods, materials and properties, but also changes of silhouette by applying system of designers. Second, general characteristics of 3D Printing fashion is represented by various applications in SLS system, and it can be specifically explained application to a portion of clothing, decorative roles of clothing, complicated pattern making through crossing fabrics using 3D scanner and displaying a certain object changing fashion styles, and so forth. Third, the formative characteristics of 3D Printing fashion from the perspective of mechanic aesthetics is as follows. It can be analyzed as the integration of metaphysical values through compared symbolization of natural feature and technical evolution, partial dynamics and interactive velocity-based, formative combinations for abstract expression using architectural components, cosmos images and substantialized structures through images of organic space interacted human shapes. As the mention above, 3D Printing technology can creative a diverse area of fashion, and express images of new technological fashion through various works with continuous development of techniques.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.214.2-214.2
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• 2013

Device performance for the 45 and 32 nm node CMOS technology requires the integration of ultralow-k materials. To lower the dielectric constant for PECVD and spin-on materials, partial replacement of the solid network with air (k=1.01) appears to be more intuitive and direct option. This can be achieved introducting of second "labile" phase during depositoin that is removed during a subsequent UV curing and annealing step. Besides, with shrinking line dimensions the resistivity of barrier films cannot meet the International Technology Roadmap for Semiconductors (ITRS) requirements. To solve this issue self-forming diffusion barriers have drawn attention for great potential technique in meeting all ITRS requirments. In this present work, we report a Cu-V alloy as a materials for the self-forming barrier process. And we investigated diffusion barrier properties of self-formed layer on low-k dielectrics with or without UV curing treatment. Cu alloy films were directly deposited onto low-k dielectrics by co-sputtering, followed by annealing at various temperatures. X-ray diffraction revealed Cu (111), Cu (200) and Cu (220) peaks for both of Cu alloys. The self-formed layers were investigated by transmission electron microscopy. In order to compare barrier properties between V-based interlayer on low-k dielectric with UV curing and interlayer on low-k dielectric without UV curing, thermal stability was measured with various heat treatment temperature. X-ray photoelectron spectroscopy analysis showed that chemical compositions of self-formed layer. The compositions of the V based self-formed barriers after annealing were strongly dominated by the O concentration in the dielectric layers.

• Advances in aircraft and spacecraft science
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• 제8권4호
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• pp.345-372
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• 2021

The analysis of nonlinear vibrations, buckling, post-buckling, flutter boundary determination and post-flutter behavior of a homogeneous curved plate assuming cylindrical bending is conducted in this article. Other assumptions include simply-supported boundary conditions, supersonic aerodynamic flow at the top of the plate, constant pressure conditions below the plate, non-viscous flow model (using first- and third-order piston theory), nonlinear structural model with large deformations, and application of mechanical and thermal loads on the curved plate. The analysis is performed with constant environmental indicators (flow density, heat, Reynolds number and Mach number). The material properties (i.e., coefficient of thermal expansion and modulus of elasticity) are temperature-dependent. The equations are derived using the principle of virtual displacement. Furthermore, based on the definitions of virtual work, the potential and kinetic energy of the final relations in the integral form, and the governing nonlinear differential equations are obtained after fractional integration. This problem is solved using two approaches. The frequency analysis and flutter are studied in the first approach by transferring the handle of ordinary differential equations to the state space, calculating the system Jacobin matrix and analyzing the eigenvalue to determine the instability conditions. The second approach discusses the nonlinear frequency analysis and nonlinear flutter using the semi-analytical solution of governing differential equations based on the weighted residual method. The partial differential equations are converted to ordinary differential equations, after which they are solved based on the Runge-Kutta fourth- and fifth-order methods. The comparison between the results of frequency and flutter analysis of curved plate is linearly and nonlinearly performed for the first time. The results show that the plate curvature has a profound impact on the instability boundary of the plate under supersonic aerodynamic loading. The flutter boundary decreases with growing thermal load and increases with growing curvature.

• 한국조경학회지
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• 제40권5호
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• pp.51-62
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• 2012

서울 금호동은 응봉의 산자락에 위치한 재개발 주거지역으로, 지형적 문제와 대규모 아파트단지의 조성, 부분적인 재개발사업의 시행 등 다양한 원인에 의해 주민들의 물리적, 사회적 단절이 심각한 곳이다. 본 연구는 이러한 금호동의 단절된 커뮤니티를 회복하기 위한 방안으로, 일상적 장소인 오픈스페이스의 기능과 이의 원활한 네트워크의 가능성에 주목하고자 한다. 연구를 위하여 우선 다양한 유형의 오픈스페이스를 점 또는 면적인 '거점'과 선적인 '통로'로 단순화하여 구분하고, 전체적인 맥락에서 네트워크 현황을 분석하였다. 분석 결과, 거점과 통로의 연결거리가 500m 이상인 구간이 전체의 반수 이상을 차지했으며, 유치권 안에 포함되지 않은 지역도 다수 나타났다. 축선도에 의한 연결도와 통합도 분석을 통해 연계가 취약한 구간을 점검하였으며, 추가로 거점이 필요한 구간도 산정하였다. 또한 거점과 통로의 질을 개선하기 위해 현장 조사를 실시, 문제점을 진단하고 해결 가능성을 검토하였다. 이상의 분석 결과들을 바탕으로 거점과 통로의 수적, 질적인 확보를 위한 금호동의 오픈스페이스 네트워크 계획을 수립하였다. 대상지 중심부에 주요 거점을 추가하고 6개의 보조 거점도 신규로 설치하였으며, 낙후된 보조 거점의 환경을 개선할 수 있는 방안을 마련하였다. 또한 연계가 힘든 대현산지역 근린공원 주변에 연결 통로를 확보하여 주요 통로로 기능하게 하고, 일부 구간을 중심으로 통로의 환경이 개선되도록 하였다. 네트워크 계획의 결과, 연결거리는 상당부분 줄어들었고, 연결도와 통합도는 증가하였으며, 유치권도 적절하게 확보될 수 있었다. 본 연구는 네트워크를 위한 법적, 제도적 뒷받침과 정량적인 지표화 과정 등의 한계점을 가지나, 복잡한 오픈스페이스의 유형을 단순하고 명확하게 정립하고, 이의 유기적인 관계를 정량적, 정성적으로 조명함으로써 전체적인 네트워크 구축을 위한 보다 합리적이고 실질적인 계획 방향을 제안하였다는 점에 그 의의를 갖는다.

• Smart Structures and Systems
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• 제3권3호
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• pp.281-298
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• 2007

The load carrying capacity of a bridge needs to be properly assessed to operate the bridge safely and maintain it efficiently. For the evaluation of load carrying capacity considering the current state of a bridge, static and quasi-static loading tests with weight-controlled heavy trucks have been conventionally utilized. In these tests, the deflection (or strain) of the structural members loaded by the controlled vehicles are measured and analyzed. Using the measured data, deflection (or strain) correction factor and impact correction factor are calculated. These correction factors are used in the enhancement of the load carrying capacity of a bridge, reflecting the real state of a bridge. However, full or partial control of the traffic during the tests and difficulties during the installment of displacement transducers or strain gauges may cause not only inconvenience to the traffic but also the increase of the logistics cost and time. To overcome these difficulties, an alternative method is proposed using an excited response part of full measured ambient acceleration data by ordinary traffic on a bridge without traffic control. Based on the modal properties extracted from the ambient vibration data, the initial finite element (FE) model of a bridge can be updated to represent the current real state of a bridge. Using the updated FE model, the deflection of a bridge akin to the real value can be easily obtained without measuring the real deflection. Impact factors are obtained from pseudo-deflection, which is obtained by double-integration of the acceleration data with removal of the linear components on the acceleration data. For validation, a series of tests were carried out on a steel plategirder bridge of an expressway in Korea in four different seasons, and the evaluated load carrying capacities of the bridge by the proposed method are compared with the result obtained by the conventional load test method.

• 한국컴퓨터정보학회논문지
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• 제17권10호
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• pp.117-127
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• 2012

급변하는 웹과 모바일 환경에서 사용자 요구사항을 효율적으로 찾아내고 올바르게 시스템에 반영하는 것은 매우 중요하다. 본 연구는 모바일 프로그램에서 사용되는 댓글, Q&A, 불편사항 신고 등의 사용자 요구사항을 기반으로 웹과 모바일 프로그램을 변경하기 위한 요구사항을 정제하고, 정제된 요구사항의 우선순위를 결정하기 위한 전략을 제안한다. 요구사항을 정제하기 위하여 소프트웨어사업선진화포럼의 표준화 방안, 기 개발된 프로그램 구성도를 활용하여 요구사항을 그룹화 하였으며, 이를 PIECES 에 맵핑하여, 정제된 요구사항이 시스템에 유효하게 반영될 수 있는지 여부를 확인하고 정제하였다. 정제된 요구사항의 우선순위를 결정하기 위하여 첫째, 소프트웨어의 구조, 요구사항, PIECES 카테고리에 상대적인 가중치를 부여하고, 둘째, 각 요구사항에 대한 통합 점수를 구하여 부문 및 전체 점수의 상대적인 값을 구한다. 제안한 기법의 가능성을 검증하기 위해서 S 대학교에서 서비스하는 모바일 애플리케이션의 변경 요구사항을 15명의 업무 관련 이해당사자에게 설문한 결과로 그 유효성을 입증하였다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2000년도 International Symposium on Bioinformatics
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• pp.21-22
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• 2000

Expressed sequence tags (EFTs) are the partial segments of cDNA produced from 5 or 3 single-pass sequencing of cDNA clones, error-prone and generated in highly redundant sets. Advancement and expansion of Genomics made biologists to generate huge amount of ESTs from variety of organisms-human, microorganisms as well as plants, and the cumulated number of ESTs is over 5.3 million, As the EST data being accumulate more rapidly, it becomes bigger that the needs of the EST analysis tools for extraction of biological meaning from EST data. Among the several needs of EST analyses, the extraction of protein sequence or functional motifs from ESTs are important for the identification of their function in vivo. To accomplish that purpose the precise and accurate identification of the region where the coding sequences (CDSs) is a crucial problem to solve primarily, and it will be helpful to extract and detect of genuine CD5s and protein motifs from EST collections. Although several public tools are available for EST analysis, there is not any one to accomplish the object. Furthermore, they are not targeted to the plant ESTs but human or microorganism. Thus, to correspond the urgent needs of collaborators deals with plant ESTs and to establish the analysis system to be used as general-purpose public software we constructed the pipelined-EST analysis system by integration of public software components. The software we used are as follows - Phred/Cross-match for the quality control and vector screening, NCBI Blast for the similarity searching, ICATools for the EST clustering, Phrap for EST contig assembly, and BLOCKS/Prosite for protein motif searching. The sample data set used for the construction and verification of this system was 1,386 ESTs from human intrathymic T-cells that verified using UniGene and Nr database of NCBI. The approach for the extraction of CDSs from sample data set was carried out by comparison between sample data and protein sequences/motif database, determining matched protein sequences/motifs that agree with our defined parameters, and extracting the regions that shows similarities. In recent future, in addition to these components, it is supposed to be also integrated into our system and served that the software for the peptide mass spectrometry fingerprint analysis, one of the proteomics fields. This pipelined-EST analysis system will extend our knowledge on the plant ESTs and proteins by identification of unknown-genes.

• Journal of Periodontal and Implant Science
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• 제32권3호
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• pp.539-554
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• 2002

It has been approximately 40 years since $Br{{\aa}}nemark$ first introduced osseo-integration for implants in the early 1960s. Unlike crown and bridge or denture treatment, implant treatment helps preserve existing bone and improve masticatory functions. Thus, the awareness of implant treatment has grown rapidly among dentists and patients alike in Korea, as it becomes a widely accepted treatment. The following results on patients type and implant distribution were compiled from 1814 implant cases of 640 patients treated at the periodontal dept. of Y University Hospital during 1992 to 2001. 1. There are no dissimilarities between men and women, with patients in their 40,50s accounting for 49% of patients and 56% of implant treatments; the largest share of patients and implant treatments. 2. Mn. posterior area accounted for 59% of implant treatments followed by Mx. posterior area(21%), Mx anterior area(l4%) and Mn anterior area 2%. 3. Partial edentulous patients treated by single crown and bridge-type prosthesis accounted for 98% and fully edentulous patient accounted for the remaining 2% 4. The major cause of tooth loss is periodontal disease, followed by dental caries, trauma and congenital missing. Compared to women, men are more likely to suffer from tooth loss due to periodontal disease. Also, older people are more likely to suffer from tooth loss due to periodontal disease rather than dental caries. 5. The distribution of bone quality for maxillae was 52% for type III, followed by 23% for type II, 20% for type IV and 0% for type I. As for mandible, the distribution was 52% for type II, followed by 37% for type III, 7% for type IV and 4% for type I. 6. The distribution of bone quantity for maxillae was 49% for type C, followed by 34% for type B, 14% for type D, 3% for type A, and 0% for type E. As for mandible, the distribution was 52% for type B, followed by 35% for type C, 6% for type D, 3% for type A and 0% for type E. 7. The majority of implants were those of 10-14mm in length (80%) and regular diameter in width (79%). The results provided us with basic data on patient type, implant distribution, bone condition, etc. We wish that our results coupled with other research data helps assist in the further study for better implant success/survival rates, etc.

• 디자인학연구
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• 제15권1호
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• pp.309-318
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• 2002

시각디자인(visual communication design)에서 이미지의 표현은 전통적으로 여러 표현매체(Media)의 매커니컬한 부분과 깊은 관계가 있다. 특히 디지털방식을 이용한 이미지 표현에서는 회화적인 표한 도면작성, 광학적인 표현, 영상이미지 등 다양한 형식의 이미지들이 디지털데이터로 전환됨으로써 이미지의 변환이 쉬워졌다. 한편 디지털형식으로 각종 표현매체가 통합됨으로써 여러 형식의 시각이미지들간의 함성이 활성화됨으로써 이미지표현의 범위가 다양해지고 있으며, 나아가 기존의 평면적인 표현에서 3D, 4D 등 다양한 차원의(dimensional) 표현들이 디지털디자인의 이미지표현에서 종합되고 있는 경향을 보이고 있다. 또한 이렇게 여러 이미지형식들이 종합되는 과정에서 부분적이거나 전체적인 이미지의 변환이 자주 발생하고 있으며, 그 변환은 크게 조형적인 측면과 기술적인 측면의 두 가지 요인으로 요약된다. 본 논문에서는 조형적 측면으로 기존의 회화적 표현과 사진술로 대표되는 광학적 표한 그리고 컴퓨터그래픽에서의 이미지 변환 원리를 유형화하고 기술적인 측면으로 데이터형식에 따른 이미지의 변환과 디멘션에 따른 세부적인 내용을 기술하였다. 이 중 특히 기술적이고 정량적인 측정이 필요한 내용에 대해서는 컴퓨터를 이용한 간단한 시뮬레이션을 통해 객관적이고 실증적인 결과를 요약하였고, 연구내용의 세부적인 결과를 실제 시각디자인 작업에서 활용하는 방안을 사안별로 제시했다.