• 제목/요약/키워드: multi-deterioration

검색결과 163건 처리시간 0.024초

CFS 입지에 따른 경제적 효과 평가 (Evaluation of Effect on CFS Location)

  • 송용석;남기찬;곽규석
    • 한국항해항만학회지
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    • 제28권1호
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    • pp.69-74
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    • 2004
  • Container Freight Station(CFS)은 터미널의 내부 또는 외부에 배치되어 여러 화주의 소량(Less than Container Load ; LCL) 화물을 컨테이너화시키거나, 수입된 컨테이너에서 내품을 인출하여 여러 화주에게 분산시키는 기능을 담당하고 있다. 하지만 CFS가 터미널 내부에 배치될 경우에는 LCL화물을 운송하기 위한 일반차량의 운행이 증가하여 터미널 주변의 교통 혼잡, 높은 사회 비용 및 물류비용의 발생, 장치장의 장치 여건 악화 등과 같은 문제를 초래한다. 본 연구는 현재 개발 중인 부산신항만을 대상으로 CFS를 각 터미널 내부에 개별적으로 배치하는 경우와 북측 컨테이너 부두 배후지에 거점화할 경우에 대해 총 비용 관점(사회적 비용과 물류비용)에서 경제성을 평가하는 것을 그 목적으로 한다.

다기준 의사결정기법을 이용한 공간위험 순위산정 (Identifying Spatial Hazard Ranking Using Multicriteria Decision Making Techniques)

  • 정은성;이길성
    • 한국수자원학회논문집
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    • 제40권12호
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    • pp.969-983
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    • 2007
  • 본 연구에서는 도시화로 인해 왜곡된 물순환을 치수, 이수, 수질관리 등의 측면에서 건전화시키기 위해 지속가능한 유역통합관리 계획을 수립하기 위한 10단계의 절차와 적용방법을 개발하여 제시하였으며 이 중 Step 2에 해당하는 문제점 도출 및 우선순위 결정 단계를 수행하였다. 유역의 잠재적인 위험도를 나타내는 홍수피해잠재능(PFD), 건천잠재능(PSD), 수질오염잠재능(PWQD), 유역평가지수(WEI)를 산정하기 위해 다기준 의사결정기법과 지속가능성평가지수 개념을 사용하였다. 사용된 다기준 의사결정 기법들은 복합계획법, 타협계획법, Regime, ELECTRE II, EVAMIX 방법이며 자료의 가용성과 목적(예비타당성, 타당성)에 따라 다르게 사용될 수 있다.

윈도우즈 기반 영상 감시 시스템에서의 Tearing 현상 개선 (A Study on the Improvement of Tearing Artifact for Windows-Based Visual Monitoring Systems)

  • 정연권;이동학;정선태
    • 한국통신학회논문지
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    • 제27권11C호
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    • pp.1097-1105
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    • 2002
  • 아날로그 모니터를 사용하는 디스플레이 시스템의 경우, 프레임 버퍼의 영상 정보 갱신 주기와 모니터 주사 주기가 맞지 않는 경우, 장면 변화가 심한 동영상 디스플레이시에 화면이 상단과 하단으로 다른 영상이 나타나는 tearing 현상이 발생한다. 다중 카메라 채널을 디스플레이하여야 하는 영상 감시 시스템인 DVR(Digital Video Recorder) 시스템에서는 프레임 버퍼 갱신율이 매우 높기 때문에 tearing 현상이 심하게 된다. 본 논문에서는 윈도우즈 기반 DVR에서 디스플레이 속도 성능의 저하가 별로 없으면서, tearing 현상을 방지한 개선된 디tm플레이 시스템 구조를 제안한다. 제안된 디스플레이 시스템의 효율성은 실험을 통하여 입증하였다.

유한요소법을 이용한 3차원 염해 침투 예측 모델의 개발 (Development of Three Dimensional Chloride Ion Penetration Model Based on Finite Element Method)

  • 최원;김한중
    • 한국농공학회논문집
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    • 제57권5호
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    • pp.43-49
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    • 2015
  • Most of agricultural structures located in seashore could not avoid rapid deterioration of concrete because chloride-ion and $CO_2$ gradually penetrate into concrete. However, since most of models can be able to describe the phenomenon of penetration by using one or two dimensional models based on finite difference method (FDM), those modes can not simulate the real geometry and it takes a lot of computational time to complete even the calculation. To overcome those weaknesses, three dimensional numerical model considering time dependent variables such as surface concentration of chloride and diffusion coefficient of domain based on finite element method (FEM) was suggested. This model also included the neutralization occurred by the penetration of $CO_2$. Because the model used various sizes of tetrahedral mesh instead of equivalent rectangular mesh, it reduced the computational time to compare with FDM. As this model is based on FEM, it will be easily extended to execute multi-physics simulation including water evaporation and temperature change of concrete.

아파트의 내부 생활소음레벨 및 소음종류 실태 (Present Condition on Noise Level and Types Including Residents' Living Noise in Apartment Units)

  • 최윤정
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2008년도 춘계학술발표대회 논문집
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    • pp.427-430
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    • 2008
  • The present study is a preliminary research improving the dwelling quality of apartment house as a kind of multi-family housing. The purpose of the study is to find out the present condition on noise level and types including residents' living noise in apartment units. The method was field survey consisted of field measurements on equivalent noise level, observation on noise type, and interview on residents' responses. The results are as follows. 1) Averages of indoor noise levels of subject houses were measured as $43.9{\sim}62.2\;dB(A)_{Leq5min}$, the average of each house except one was higher than the permissible level, 45 dB(A). 2) The noise types observed were mostly residents' living noise and classified as 'water hammer', 'living equipment noise', 'noise by family', 'hood noise', and 'kitchen noise' in own unit, 'walking and talking noise in stairs and corridors', 'noise by neighborhood house', 'noise by the upper story' in building, and outdoor noise. 3) The residents show slightly non-positive responses at 'noise by the upper story', 'noise by neighborhood house', 'water hammer', and 'noise by family'. Therefore, it is required to plan for preventing deterioration of the sound environment quality by residents' living noise in own unit as well as by neighborhood houses.

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3온스 물 삼킴검사 이후 정상 노년층의 음질 변화: 음향학적 분석 (Voice quality of normal elderly people after a 3oz water-swallow test: An acoustic analysis)

  • 이솔희;최홍식;최성희;김향희
    • 말소리와 음성과학
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    • 제10권2호
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    • pp.69-76
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    • 2018
  • The elderly are at increased risk of developing dysphagia due to aging and illnesses. The aim of the current study was to analyze, via an acoustic study, the change in the voice quality of normal elderly people after a 3oz water-swallow test. Subjects included a group of 60 normal elderly people (age: $mean{\pm}SD=76.9{\pm}6.66$) and 60 healthy young adults (age: $mean{\pm}SD=25.1{\pm}2.36$). Every participant produced a five-second /a/ phonation pre- and post-swallowing, and the fractioned two-second sections were analyzed using the MDVP (multi dimensional voice program) analysis. The elderly group demonstrated a post-swallowing increase in the following related acoustic parameters: fundamental frequency, fundamental frequency variation, amplitude-variation, and noise in both two-second sections. However, the younger group showed an increase only in frequency related acoustic parameters (i.e., STD ) in the first two-second section. The significant changes in values in the post-swallowing parameters might indicate temporary irregularities in pitch and amplitude along with higher amounts of noise in the voice. The results could be attributed to water residues in the vocal fold and vocal tract, as well as a deterioration of the motor and sensory functions caused by anatomical and physiological changes that result from aging.

선박외판 문자 자동용접 시스템의 개발 (Development of a Automatic Welding System for Various Marks on the Hull of Vessels)

  • 윤훈성;양종수;김호경;최영달
    • 대한조선학회 특별논문집
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    • 대한조선학회 2008년도 특별논문집
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    • pp.90-95
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    • 2008
  • The letters and marks on the hull of vessels are marked by welding bead or steel plate to resist the corrosion environment. It has done by manual work. So, it cause deterioration of welding quality and process delay and so on. The automated welding device for draft mark has developed partially in the field of shipbuilding. But it can be used for draft mark only. And it has caused a few problems about that workablity and movablity are decreased owing to the size and weight of device. So we developed the automated welding device that can be used for most letters and marks on the hull. It designed to 3 axises mobile robot include to ratoation axis and stand alone type controller with multi GUI base on imbedded windows.

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멀티미디어 콘텐츠의 QoS를 개선한 전송 메커니즘 (Transmission Scheme for Improving QoS of Multimedia Contents)

  • 김선호;송병호
    • 정보처리학회논문지B
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    • 제12B권2호
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    • pp.167-172
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    • 2005
  • 웹 사용자와 대용량 콘텐츠의 급증으로 웹 서버와 네트워크의 부하가 가중되고 웹 서비스의 질이 떨어지는 문제가 발생하였으며 이러한 문제를 해결하기 위해 콘텐츠를 다수의 지역서버에 복사하고 가까운 지역서버로 하여금 클라이언트의 요청을 처리하도록 하여 웹 서버의 부하를 줄이고 트래픽을 분산하는 콘텐츠 분산 네트워크 기술이 대두되고 있다. 본 연구에서는 이러한 분산 네트워크의 지역서버를 이용하여 클라이언트 그룹의 콘텐츠 요청을 가까운 지역서버가 담당하도록 하며, 전송에 있어서는 MDC 코딩과 다중채널에 의한 전송으로 전송 중 오류를 줄이고 지연시간을 단축할 수 있는 전송 메커니즘을 제안한다. 이러한 연구는 멀티미디어 웹 서비스의 성능 개선에 기여할 수 있을 것이다.

퍼지이론을 이용한 유고감지 알고리즘

  • 이시복
    • 대한교통학회:학술대회논문집
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    • 대한교통학회 1995년도 제28회 학술발표회
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    • pp.77-107
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    • 1995
  • This paper documents the development of a fuzzy logic based incident detection model for urban diamond interchanges. Research in incident detection for intersections and arterials is at a very initial stage. Existing algorithms are still far from being robust in dealing with the difficulties related with data availability and the multi-dimensional nature of the incident detection problem. The purpose of this study is to develop a new real-time incident detection model for urban diamond interchanges. The development of the algorithm is based on fuzzy logic. The incident detection model developed through this research is capable of detecting lane¬blocking incidents when their effects are manifested by certain patterns of deterioration in traffic conditions and, thereby, adjustments in signal control strategies are required. The model overcomes the boundary condition problem inherent in conventional threshold-based concepts. The model captures system-wide incident effects utilizing multiple measures for more accurate and reliable detection, and serves as a component module of a real-time traffic adaptive diamond interchange control system. The model is designed to be readily scalable and expandable for larger systems of arterial streets. The prototype incident detection model was applied to an actual diamond interchange to investigate its performance. A simulation study was performed to evaluate the model's performance in terms of detection rate, false alarm rate, and mean time to detect. The model's performance was encouraging, and the fuzzy logic based approach to incident detection is promising.

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Detection of flaw in steel anchor-concrete composite using high-frequency wave characteristics

  • Rao, Rajanikant;Sasmal, Saptarshi
    • Steel and Composite Structures
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    • 제31권4호
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    • pp.341-359
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    • 2019
  • Non-monolithic concrete structural connections are commonly used both in new constructions and retrofitted structures where anchors are used for connections. Often, flaws are present in anchor system due to poor workmanship and deterioration; and methods available to check the quality of the composite system afterward are very limited. In case of presence of flaw, load transfer mechanism inside the anchor system is severely disturbed, and the load carrying capacity drops drastically. This raises the question of safety of the entire structural system. The present study proposes a wave propagation technique to assess the integrity of the anchor system. A chemical anchor (embedded in concrete) composite system comprising of three materials viz., steel (anchor), polymer (adhesive) and concrete (base) is considered for carrying out the wave propagation studies. Piezoelectric transducers (PZTs) affixed to the anchor head is used for actuation and the PZTs affixed to the surrounding concrete surface of the concrete-anchor system are used for sensing the propagated wave through the anchor interface to concrete. Experimentally validated finite element model is used to investigate three types of composite chemical anchor systems. Studies on the influence of geometry, material properties of the medium and their distribution, and the flaw types on the wave signals are carried out. Temporal energy of through time domain differentiation is found as a promising technique for identifying the flaws in the multi-layered composite system. The present study shows a unique procedure for monitoring of inaccessible but crucial locations of structures by using wave signals without baseline information.