• 제목/요약/키워드: Fundamental Diagram

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차간시간(Time Gap) 변수를 이용한 교통기본도(Fundamental Diagram)의 미시적 해석 (A Microscopic Analysis on the Shapes of Fundamental Diagram Using Time Gap)

  • 김태완;김상구;김영호;손영태
    • 대한교통학회지
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    • 제22권3호
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    • pp.95-105
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    • 2004
  • 교통기본도(Fundamental Diagram)는 교통류와 관련된 다양한 연구에서 중요한 요소로 생각되어져 왔다. 지금까지 다양한 형태의 교통기본도가 제시되었고 실제 데이터를 가장 잘 설명하는 교통기본도의 형태에 대해 많은 논의가 이루어졌지만, 서로 다른 형태의 교통기본도를 결정하는 원인에 대한 분석이 충분히 이루어지지 않고 있다. 본 연구는 서로 다른 지점과 교통조건에서 운전자의 행태차이를 이해하는데 중요한 파라메타로서 차간시간(time gap)을 소개하였고, 차간시간과 교통기본도의 형태와의 연관성을 분석하였다. 개별차량 검지기 자료를 토대로, 차간시간은 확률분포를 따르고 평균값은 지점에 따라 변화하는 것과 다른 통행속도에서 다른 차간시간을 보이는 것으로 분석되었다. 또한, 차간시간-속도 분포도의 3가지 형태들이 확인되었고 이것들은 교통류율-밀도 교통기본도로 전환되면 기존의 Greenberg, 역 ${\lambda}$, 전도된 V형태의 교통기본도와 일치하였다. 본 연구는 미시적 교통변수인 차간시간을 이용하여 교통기본도의 특징을 해석하였고, 운전자들의 행태에 관한 특성을 교통조건과 도로의 기하구조에 따라 설명하였다.

교통기본도와 운전자 행태에 대한 미시적 분석 (A Microscopic Analysis on the Fundamental Diagram and Driver Behavior)

  • 김태완
    • 한국도로학회논문집
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    • 제14권6호
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    • pp.183-190
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    • 2012
  • PURPOSES : The fundamental diagram provides basic information necessary in the analysis of traffic flow and highway operation. When traffic flow is congested, the density-flow points in the fundamental diagram are widely scattered and move in a stochastic manner. This paper investigates the pattern of density-flow point transitions and identifies car-following behaviors underlying the density-flow transitions. METHODS : From a microscopic analysis of 722 fundamental diagrams of NGSIM data, a total of 20 transition patterns of fundamental diagrams are identified. Prominent features of the transition patterns are explained by the behavior of the leader and follower. RESULTS : It is found out that the average speed and the speed difference between the leader and the follower critically determine the density-flow transition pattern. The density-flow path is very sensitive to the values of vehicle speed and spacing especially at low speed and high density such that most fluctuations in the fundamental diagram in the congested regime is due to the noise of speed and spacing variations. CONCLUSIONS : The result of this study suggests that the average speed, the speed difference between the leader and the follower, and the random variations of speed and spacing are dominant factors that explain the transition patterns of a fundamental diagram.

Divide and conquer algorithm for a voronoi diagram of simple curves

  • Kim, Deok-Soo;Hwang, Il-Kyu;Park, Bum-Joo
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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    • pp.691-700
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    • 1994
  • Voronoi diagram of a set of geometric entities on a plane such as points, line segments, or arcs is a collection of Voronoi polygons associated with each entity, where Voronoi polygon of an entity is a locus of point which is closer to the associated entity than any other entity. Voronoi diagram is one of the most fundamental geometrical construct and well-known for its theoretical elegance and the wealth of applications. Various geometric problems can be solved with the aid of Voronoi diagram. For example, the maximum tool diameter of a milling cutter for rough cutting in a pocket can be easily found, and the pocketing tool path can be efficiently generated from Voronoi diagram. In PCB design, the design rule checking can be easily done via Voronoi diagram, too. This paper discusses an algorithm to construct Voronoi diagram of a simple polygon which consists of simple curves such as line segments as well as arcs in a plane with O(nlogn) time complexity by employing the divide and conquer scheme.

Fundamental Approach to Capacity Prediction of Si-Alloys as Anode Material for Li-ion Batteries

  • Kim, Jong Su;Umirov, Nurzhan;Kim, Hyang-Yeon;Kim, Sung-Soo
    • Journal of Electrochemical Science and Technology
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    • 제9권1호
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    • pp.51-59
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    • 2018
  • Various Si-Fe-Al ternary alloys were prepared with the same amount of Si by the melt spinning technique. The feasibility of the capacity prediction approach based on the estimation of the active amount of Si using the phase diagram was practically examined and reported. These predictions were verified by the electrochemical test of fabricated coin cells and other characterization methods. The capacity prediction approach using the phase diagram might be a fundamental and efficient method to accelerate the practical application of Si-based alloys as the anode material for Li-ion batteries. The details on the prediction procedure were discussed.

DSRC 기반 프로브 자료를 이용한 거시 교통류 모형 추정 방법 (Deriving Macroscopic Fundamental Diagrams Using Probe Vehicle Data Based on DSRC)

  • 심지섭;여지호;이수진;장기태
    • 한국ITS학회 논문지
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    • 제16권6호
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    • pp.29-41
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    • 2017
  • 본 연구에서는 개별 차량의 주행정보를 이용하여 대구광역시 도심부에서 네트워크 스케일의 거시 교통류 모형(Macroscopic Fundamental Diagram, MFD)을 추정하는 방법에 대해 고찰한다. 이를 위해 근거리 전용 통신(Dedicated Short Range Communication, DSRC) 방식으로 수집된 개별 차량의 원시 데이터 처리 방법 및 통행 정의 방법을 분석하고, 해당 자료를 활용하는 새로운 활용 방안을 제시한다. 이를 위해 프로브 자료인 DSRC 데이터와 교통량 조사 자료를 이용해 표본율을 산정하고 대구광역시 네트워크 내 MFD를 도출하는 방법을 설명한다. 도출된 MFD를 통해 시간적 재현성(reproducibility)의 확인과 선행 연구 가정 사항들에 대한 데이터 기반 검증을 수행하였으며, DSRC 자료의 새로운 활용 방법을 제시하고자 한다.

6 속 자동변속기용 레펠레티아 유성 치차의 동력 해석에 관한 연구 (A Study on Power-Flow Analysis of The Lepelletier 6-Speed Automatic Transmission)

  • 박진홍;심재경;강봉수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.652-655
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    • 2004
  • In gear-train design, power-flow analysis is a very important process. The method for power-flow analysis apply the power balance equation and torque balance equation to each fundamental circuit. Then, the equation are solved simultaneously to determine the power-flow in planetary gear train. In this paper we perform power-flow analysis of a 6-speed automatic transmission. With this results are used to represent block diagram. In addition, the efficiencies of epicyclic inversion of the 6-speed automatic transmission is obtained.

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A Network Partition Approach for MFD-Based Urban Transportation Network Model

  • Xu, Haitao;Zhang, Weiguo;zhuo, Zuozhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권11호
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    • pp.4483-4501
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    • 2020
  • Recent findings identified the scatter and shape of MFD (macroscopic fundamental diagram) is heavily influenced by the spatial distribution of link density in a road network. This implies that the concept of MFD can be utilized to divide a heterogeneous road network with different degrees of congestion into multiple homogeneous subnetworks. Considering the actual traffic data is usually incomplete and inaccurate while most traffic partition algorithms rely on the completeness of the data, we proposed a three-step partitioned algorithm called Iso-MB (Isoperimetric algorithm - Merging - Boundary adjustment) permitting of incompletely input data in this paper. The proposed algorithm was implemented and verified in a simulated urban transportation network. The existence of well-defined MFD in each subnetwork was revealed and discussed and the selection of stop parameter in the isoperimetric algorithm was explained and dissected. The effectiveness of the approach to the missing input data was also demonstrated and elaborated.

MVRDV의 건축에 나타난 공간 구성 수법에 관한 연구 (A Study on Spacial Characterristics of MVRDV's Architecture)

  • 조영배
    • 한국실내디자인학회논문집
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    • 제17권1호
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    • pp.77-83
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    • 2008
  • MVRDV is most important architect as created interesting architectural space in contemporary architecture, and so they applies to the unique theory in their architecture. They used to architectural diagram, program, datascape, density as a design tool. Especially, they have create new architectural space and form in using architectural diagram, program, datascape, density, and void. So, this study is purposed to explain how they use as architectural tool to make composition of it's architectural space and is purpose to explain what is their main concept in architectural space. MVRDV's architectural space has fundamental methodology. That is Datascape on uncertainty and continuity between urban space and architectural space. The former consist in using diagram and architectural program and the latter consist in operating architectural void and inner continuity surface. The conclusion is follows 1. The mode of spacial composition by architectural void is correspond density of city as MVRDV's architectural thinking. 2. The mode of spacial composition by architectural program is ambiguous to the boundary between inner and exterior space by transparency. 3. The mode of spacial composition by architectural diagram make to generate the architectural form and space, through the reinterpretation and relocation of architectural program. 4. The mode of spacial composition inner continuity plane is make relative between site and inner space.

현대건축에 적용된 액티비티 다이어그램에 관한 연구 - 마누엘 고사, 벤 반 버클, 비센떼 구아이야르의 프로젝트를 중심으로 - (A Study on Activity Diagrams in Contemporary Architecture - Focusing on the Projects by Manuel Gausa, Ben Van Berkel and Vicente Guallart -)

  • 김종진
    • 한국실내디자인학회논문집
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    • 제15권1호
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    • pp.20-29
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    • 2006
  • The concept of a 'place' in contemporary cities has been fundamentally challenged by the social, economical changes as well as the global digital network. The complex and multi-layered contemporary everyday life blur the boundaries of the existing architectural programs. In contemporary architecture, various proposals have attempted to overcome the physical limitations. 'Activity Diagram' is one of them. Activity diagram is a diagrammatized design process In which the given program is analyzed into individual activities, then it is re-organized and finally spatialized based on the analysis. In many projects by Manuel Gausa, Ben Van Berkel and Vicente Guallart, the activity diagram is applied in various forms and they are explained with theoretical backgrounds. Based on how the given program is re-organized into assembly of activities and how diagram is applied, five analytical elements were selected to critically analyze three chosen architects' case projects. In this study, it is found that architects attempt to construct an open networked world where diverse activities are freely interconnected in spite of some fundamental limitations of activity diagrams.