• Title/Summary/Keyword: Top Down Method

검색결과 390건 처리시간 0.028초

각관 추진 굴착시 궤도노반의 침하경향 실험분석 (Test and analysis of settlement pattern of trackbed during pipe roof excavation)

  • 정관동;엄기영;최찬용;조수익;황인환
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.895-902
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    • 2010
  • The method in a bid to make better use of limited urban space amidst increasingly expanding urban area have been attempted in various ways. Efficient using underground space is one of the examples. The pipe roof and excavation for underground crossing implemented in this study was the part of evaluation of such attempt. However, the pipe roof method for underground crossing may cause the ground surface to be uplifted or settled down, having effect on structure above the ground. Thus in this study, a laboratory model test designed to evaluate the effect on surface during implementing pipe roof and excavation was carried out. The ground displacement during pipe roof advancing and excavation is usually occurred in a radial shape but as the study focused on trackbed, the evaluation included ground settlement only. Thus, appropriately-scaled model was selected considering domestic geological characteristics and operation characteristics of traditional and high-speed rail trains and the qualitative evaluation of displacement was carried out with a certain ground loss depending on excavation after categorizing trackbed settlement pattern depending on depth of top soil.

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트리패턴매칭기법의 재목적 가능한 중간코드 최적화 시스템 (Retargetable Intermediate Code Optimization System Using Tree Pattern Matching Techniques)

  • 김정숙;오세만
    • 한국정보처리학회논문지
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    • 제6권8호
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    • pp.2253-2261
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    • 1999
  • ACK에서는 패턴 테이블 생성기와 핍홀 최적화기에서 스트링 패턴 매칭 기법을 이용하여 EM 중간 코드에 대한 최적화 코드를 생성한다. 하지만 이 스트링 패턴 매칭 방법은 패턴 결정 시에 반복적으로 많은 비교 동작이 이루어지므로 비효율적이다. 본 논문은 ACK의 중간 코드 최적화기를 개선하기 위해 EM 트리 생성기, 최적화 패턴 테이블 생성기, 트리 패턴 매칭기로 구성된 트리 패턴 매칭 알고리즘을 이용한 EM 중간 코드 최적화 시스템을 설계하고 구현하였다. 이러한 트리 패턴 매칭 알고리즘은 EM 트리를 하향식으로 순회하면서 트리 구조를 가진 패턴 테이블을 참조하여 루트 노드를 중심으로 패턴 매칭을 수행한다. 트리 패턴 매칭 동작은 궁극적으로 ACK의 스트링 패턴 매칭에 비해 최적화 패턴을 찾는데 걸리는 시간을 평균 10.8% 감소시킬 수 있는 효과를 보였다.

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조직공학용 세포담체 제작을 위한 플라즈마-표면개질이 포함된 바이오프린팅 시스템 (A 3D bioprinting system and plasma-surface modification to fabricate tissue engineering scaffolds)

  • 김근형
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2017년도 춘계학술대회 논문집
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    • pp.3-23
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    • 2017
  • The achievement of tissue engineering can be highly depending on the capability to generate complicated, cell seeded three dimensional (3D) micro/nano-structures. So, various fabrication techniques that can be used to precisely design the architecture and topography of scaffolding materials will signify a key aspect of multi-functional tissue engineering. Previous methods for obtaining scaffolds based on top-down are often not satisfactory to produce complex micro/nano-structures due to the lack of control on scaffold architecture, porosity, and cellular interactions. However, a bioprinting method can be used to design sophisticated 3D tissue scaffolds that can be engineered to mimic the tissue architecture using computer aided approach. Also, in recent, the method has been modified and optimized to fabricate scaffolds using various natural biopolymers (collagen, alginate, and chitosan etc.). Variation of the topological structure and polymer concentration allowed tailoring the physical and biological properties of the scaffolds. In this presentation, the 3D bioprinting supplemented with a newly designed plasma treatment for attaining highly bioactive and functional scaffolds for tissue engineering applications will be introduced. Moreover, various in vivo and in vitro results will show that the fabricated scaffolds can carry out their structural and biological functionality.

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방죽포 쇄파대생태계의 수용력과 수산자원방류 (Carrying Capacity and Fishery Resources Release in the Bangjukpo Surfzone Ecosystem)

  • 강윤호
    • 한국수산과학회지
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    • 제36권6호
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    • pp.669-675
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    • 2003
  • To increase fishery resources in coastal waters, juvenile fish and bivalves are artificially released every year in Korea. This study provides a methodology to estimate an optimal release quantity based on the carrying capacity of the receiving basins. Carrying capacity was defined by E.p. Odum's theory of ecosystem development as the upper limit of biomass, where total system respiration equals total primary production. The Ecopath trophic ecological model was used to determine carrying capacity in the surfzone ecosystem of Bangjukpo on the southern coast of Korea. Using a top-down control method, various biomasses of fish groups were given to the simulation, with primary production constant and no catch. The results showed that biomass of selected fish groups increased by two orders of magnitude, yielding a five-fold increase in overall consumer biomass. The resultant values are 10 times higher than those estimated in open seas. This can be explained by higher primary production in the Bangjukpo surfzone ecosystem. This method can be used for strategic releases and ecosystem management, particularly when based on an ecological background.

A design of multi-width HTS magnets considering both wire consumption and field homogeneity

  • Yang, Hongmin;Ahn, Minchul
    • 한국초전도ㆍ저온공학회논문지
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    • 제23권2호
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    • pp.24-27
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    • 2021
  • This paper presents a design methodology of high-temperature superconducting (HTS) magnets. The magnet consists of several double pancake coils with a variety of wire width. This technique, named Multi-Width, is well known to make efficient use of the superconducting wire. It is common for design of high-temperature superconducting magnets to not only reduce wire consumption used, but also consider the homogeneity of the magnetic field. In this paper, we study a design method that efficiently reduces wire usage while considering magnetic field homogeneity. The design is carried out by calculating the critical current and the critical magnetic field according to the configuration of arranging the thickness of the wire to determine the number of windings. The width of wire comprising the magnet was set to 4 - 12 mm, and the number of double pancake coils was set to an even number to consist of top-down symmetry. To verify the validity of the design, we compared the progress of the design code with a complete enumeration survey. As a case study, we designed a magnet that generates a central magnetic field of 3 T or more in a 240 mm bore in diameter. Optimality can be evaluated by weighing wire consumption and field homogeneity according to the magnet's use or user preference.

국제비즈니스에서 비교문화 연구의 재검토 (Cross-cultural Studies Revisited in International Business)

  • 조호현
    • 이베로아메리카
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    • 제12권1호
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    • pp.407-439
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    • 2010
  • Growth of researches addressing cross-culture in international business is exponential. This article reviews the extant researches around the national culture and describes the various conceptualization of culture through discussion of some of popular models of national culture. This article presented some of the most important issues in international business surrounding globalization, especially convergence and divergence of cultures and cultural changes. Global rapid changes in international business environment request the reconsideration of the assumption of cultural stability and the simple view of culture, which tends to examine the static influence of a few cultural factors in isolation form other cultural factors and contextual elements. This paper identifies a valid cultural grouping and proposes the following typology of the possible methodologies in international business; Ethnological description, Use of proxies, Direct values inference, and Indirect values inference. Rather than selecting a single methodology, it appears to be more appropriate to use multi-method in the cross-cultural international business research. It has been shown that cultural change is intertwined with socioeconomic-institutional variables, and that these variables may also add to determine culture contemporarily. This paper also explained the dynamics of culture as multi-level, multi-layer constructs. According to this model, we may understand how the dynamic nature of culture conveys the top-down-bottom-up processes where one cultural level affects changes in other level of culture.

계층적 영상구조에서 통계적 방법에 의한 영상분할 (A Statistical Image Segmentation Method in the Hierarchical Image Structure)

  • 최성진
    • 방송공학회논문지
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    • 제1권2호
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    • pp.165-175
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    • 1996
  • 본 논문에서는 영상분할에 이용되는 대부분의 기존방법들에서의 문제점을 해결하기 위해 입력 영상으로부터 형성된 계층적 피라밋 영상구조를 이용하여 영상을 분할하는 방법을 제안하였다. 제안된 방법은 통계적 방식에 의한 물체검출 및 묘사과정으로 이루어져 있다. 물체검출 방법에서는 계층적 영상구조에서 발생하는 클러스터링의 유효성 문제를 해결하기 위해 통계적 IFSVR 알고리듬과 FSVR 알고리듬을 제안하였고, 이를 이용하여 관심대상 화소를 검출하였다. 물체묘사 방법은 고해상도 레벨로 검출된 최적 물체화소를 투사하고 처리하기 위해 톱다운 추적방식인 반복 알고리듬을 제안하였다. 시뮬레이션을 통하여 2진 영상과 실영상 모두에서 제안된 분할방법을 분석하였고, 그 결과 계층적 피라밋구조에 기초를 둔 접근방법이 영상분할에 대한 유용한 특성을 가지고 있음을 입증하였으며, 병렬처리기에서 처리된다면 각 알고리듬이 n${\times}$n 영상에 대해 0(log n)의 계산량이 요구된다.

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텍스트 네트워크 분석을 활용한 농촌 주거환경 연구 동향 (Rural residential environment: Identifying trends through text network analysis)

  • 이차희
    • 농촌계획
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    • 제26권1호
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    • pp.39-49
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    • 2020
  • The study analyzed the frequency of simultaneous occurrence of keywords presented in a total of 805 papers published in domestic journals from 1995 to 2019 by social network analysis(SNS) method, and examined core keywords of each period(5 years), in order to understand the research trends of the rural residential environment. The main results are as follows. First, as a result of the analysis of centrality, 'Community', 'Tourism' and 'Comprehensive Rural Village Development Project' were the top 3 keywords. Second, examined by each period, the top keywords are 'Eco Friendly' in 2000~2004, 'Tourism' in 2005~2009 and 2010~2014, 'Community' in 2015~2019. Third, comparing the structural characteristics of core keywords 2nd, 3rd, and 4th period, a network centering on 'Tourism' was clearly formed in the 2nd period. 'Tourism' was divided into 'Community' and a movement to form a separate group appeared in the 3rd period. In the 4th period, 'Community' was found to form a network without direct connection with 'Tourism'. The results of this study suggest the trend change of viewpoint for the rural area in the domestic research on rural residential environment. It has been confirmed that while the research had been carried out with the viewpoint of rural area as a 'tourist attraction' or 'sightseeing spot' for the urban citizens until the mid-2010s, in the research of late 2010s the viewpoint has settled down as a 'residential space' or 'space for new economic activities' of a variety of rural residents.

물리적 차원 지각에 대한 감성 메타포 (Affective Metaphor of Dimensional Perception)

  • 문성철;황민철;이정년;김종화;김지혜
    • 대한인간공학회지
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    • 제30권1호
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    • pp.187-193
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    • 2011
  • Objective: The aim of this study was to investigate the association between conceptual metaphors of affect and physical dimensions. Background: The evidence that affect is unconsciously linked to physical dimensions(e.g., position and color) has been obtained in western cultures. However, in eastern cultures, especially, in Korea, it has been seldom tested. It is indispensable to examine whether or not cultural differences exist for better understanding of the conceptual metaphors. Method: 50 positive and 50 negative words were adopted from previous studies in order to determine the relationship between physical domains and abstract affect. Three hypotheses were tested in this study: (1) Good is up. (2) Good is bright. (3) Good is right(for right-handers). The automatic association between valence(positive vs. negative) and vertical position (up vs. down) was investigated in experiment 1, in which 100 words were randomly presented on either the top or the bottom of a LCD screen and the evaluation time of the presented word was recorded. The unconscious association between valence and color(white and black) was examined in experiment 2, where each word was randomly presented in either white or black. Lastly, we tested whether right-handers tend to associate rightward space with positive ideas and leftward space with negative ideas. Results: Reaction time was faster when words were presented in metaphor congruent domains(e.g., 'positive words on the top, in bright color, and on right space vs. negative words on the bottom, in dark color, and on left region) than when they were shown in metaphor incongruent domains. Conclusion: The results might give the groundwork for various directions in further understanding perception, emotion, and behavior. Application: This study may provide useful points to GUI designers and service developers if further studies enhanced in validity and reliability are followed.

골프 스윙동작의 운동학적 분석 (A Kinematic analysis of Golf Swing Motion)

  • 신성휴;고석곤
    • 한국운동역학회지
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    • 제13권2호
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    • pp.101-114
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    • 2003
  • The purpose of this study was to examine the major kinematicak variance to Increase the club head velocity during the driver swing two PGA prp-golfers utilizing 3-dimensional Image analyzing linear velocity of the club-head during the impact quantiatively. To achive these purpose, two high speed camera in 120 field/s and one high-speed camera in 500 field/s were used in this study. The program made by Younghoo Kwon(1944) was used to analysis the digitalization of reference point, digitalization of joint venter, synchronization, calculation of 3-Dimensional coordinate by DLT method, and smoothing. Through this study, the conclusions are as follow. 1. During the drivel swing, in the percentile of the total time, two pro-golfer showed 0.925, 0.929 second from adress to top-swing, 0.236, 0.929 second from top-swing to impact. 2. During the driver swing, in the displacement of the center of the body, two pro-golfer showed 45.3, 45.23% from adress, 44.3, 44.24% front impact. 3. In the velocity variance, The maximum club-head velocity two pro-golfer showed 43.36, 43.24m/s respectively the down swing. The ball velocity showed 63.12, 63.06m/s. 4. In the rotational angle of the shoulder joint. two pro-golfer showed $-13.5,-13.53^{\circ}$, during the back swing respectively. Two subject adressed opening status og upper body. 5. In the rotational angle of the right knee angle showed $156.3,154.7^{\circ}$ from the adress.