• Title/Summary/Keyword: network flow model

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Optimization of the Transportation of International Container Cargoes Considering Short Sea Shipping (근해운송을 고려한 국제컨테이너 화물운송의 최적화)

  • Kim, Hwa-Joong;Chang, Young-Tae;Lee, T.W.
    • Proceedings of the Korea Port Economic Association Conference
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    • 2007.10a
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    • pp.161-173
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    • 2007
  • This paper considers the problem of determining the cargo flow and the transportation mode in each trade route while satisfying the demand. Especially, the problem incorporates short sea shipping in Korea, which is becoming more important in order to improve efficiency of Logistics. The objective is to minimize the sum of shipping and inland transportation costs. To solve optimally the problem, this paper employs a linear programming model, which is an operations research technique for optimization. The problem is formulated by extending the well-known network design problem by considering capacity at seaport and limitation of total number of vehicles. The model is solved using CPLEX, a commercial linear program software. The test results using a real cargo flow data in Korea show that the model represents closely the real situation.

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Design of Simulation System for Port Resources Availability in Logistics Supply Chain (항만자원 계획 적합성 검증을 위한 시뮬레이션 시스템 설계)

  • Lee, Tae-Woo;Park, Nam-Kyu;Lee, Dong-Won
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.11a
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    • pp.53-61
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    • 2002
  • This paper aims to apply a supply chain modeling and its analysis framework to the supply chain in the port industry, each of which has its own objective. The simulation approach serves two purposes: to model a supply chain network in quantity approach and to evaluate its supply chain performance based on proposed strategies. The simulation model will be applied to quantifying the flow of a supply chain, the involved information and material flow and conducted to simulate the supply chain operations. The model will also be used which strategic and operational policies are the most effective in smoothing the variations in the supply chain.

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Fan Noise Prediction Method of Air Cooling System (공기 냉각 시스템의 홴 소음 예측 기법)

  • Lee, Chan;Kil, Hyun-Gwon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.9
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    • pp.952-960
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    • 2008
  • Fan noise prediction method is presented for air conditioning, automobile and electronic cooling system applications where fan acts as an internal equipment having very complicated flow interaction with other various system components. The internal flow paths and distribution in the fan-applied systems such as computer or air conditioner are analyzed by using the FNM(flow network modeling). Fan noise prediction method comprises two models for the discrete frequency noise due to rotating steady aerodynamic lift and blade interaction and for the broadband noise due to turbulent boundary layer and wake vortex shedding. Based on the fan operation point predicted from the FNM analysis results and fan design parameters, the present far noise model predicts overall sound pressure level and spectrum. The predictions for the flow distribution, the fan operation and the noise level in air cooling system by the present method are well agreed with 3-D CFD and actual noise test results.

Research on ANN based on Simulated Annealing in Parameter Optimization of Micro-scaled Flow Channels Electrochemical Machining (미세 유동채널의 전기화학적 가공 파라미터 최적화를 위한 어닐링 시뮬레이션에 근거한 인공 뉴럴 네트워크에 관한 연구)

  • Byung-Won Min
    • Journal of Internet of Things and Convergence
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    • v.9 no.3
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    • pp.93-98
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    • 2023
  • In this paper, an artificial neural network based on simulated annealing was constructed. The mapping relationship between the parameters of micro-scaled flow channels electrochemical machining and the channel shape was established by training the samples. The depth and width of micro-scaled flow channels electrochemical machining on stainless steel surface were predicted, and the flow channels experiment was carried out with pulse power supply in NaNO3 solution to verify the established network model. The results show that the depth and width of the channel predicted by the simulated annealing artificial neural network with "4-7-2" structure are very close to the experimental values, and the error is less than 5.3%. The predicted and experimental data show that the etching degree in the process of channels electrochemical machining is closely related to voltage and current density. When the voltage is less than 5V, a "small island" is formed in the channel; When the voltage is greater than 40V, the lateral etching of the channel is relatively large, and the "dam" between the channels disappears. When the voltage is 25V, the machining morphology of the channel is the best.

A Study on Link Travel Time Prediction by Short Term Simulation Based on CA (CA모형을 이용한 단기 구간통행시간 예측에 관한 연구)

  • 이승재;장현호
    • Journal of Korean Society of Transportation
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    • v.21 no.1
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    • pp.91-102
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    • 2003
  • There are two goals in this paper. The one is development of existing CA(Cellular Automata) model to explain more realistic deceleration process to stop. The other is the application of the updated CA model to forecasting simulation to predict short term link travel time that takes a key rule in finding the shortest path of route guidance system of ITS. Car following theory of CA models don't makes not response to leading vehicle's velocity but gap or distance between leading vehicles and following vehicles. So a following vehicle running at free flow speed must meet steeply sudden deceleration to avoid back collision within unrealistic braking distance. To tackle above unrealistic deceleration rule, “Slow-to-stop” rule is integrated into NaSch model. For application to interrupted traffic flow, this paper applies “Slow-to-stop” rule to both normal traffic light and random traffic light. And vehicle packet method is used to simulate a large-scale network on the desktop. Generally, time series data analysis methods such as neural network, ARIMA, and Kalman filtering are used for short term link travel time prediction that is crucial to find an optimal dynamic shortest path. But those methods have time-lag problems and are hard to capture traffic flow mechanism such as spill over and spill back etc. To address above problems. the CA model built in this study is used for forecasting simulation to predict short term link travel time in Kangnam district network And it's turned out that short term prediction simulation method generates novel results, taking a crack of time lag problems and considering interrupted traffic flow mechanism.

An Application of Dynamic Route Choice Model Using Optimal Control Theory (최적제어이론을 이용한 동적 통행배정 모형의 적용에 관한 연구)

  • 전경수;오세현
    • Journal of Korean Society of Transportation
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    • v.13 no.4
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    • pp.5-29
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    • 1995
  • Advanced Traveler Inoformation Systems*ATIS) , as a subsystem of ITS influence the travel choices of dreivers by providing them with historical, real-time and predictive information to supprot travel decisions and consequently improves the speed and quality of travel. For thesuccessul accomplishment of ATIS, the time-dependent variations of traffic in a road network and travel times of vehicles during their journey must be predicted . The purpose of this study is to evaluate the past developments in the dynamic route choice models and to apply the instantaneous dynamic user optimal route choice model. recently formulated with flow propagation constraints by Ran, Boyce and LeBlanc, to the real transportation network of Seocho-Ku in Seoul. As input data for this application, the time-dependent travel rates are estimated and the link travel time function is derived. The modelis validated from three view points : the efficiency of model itself the ability to predict traffic volume and travel time on links, and the optimal traffic control.

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Automatic Estimation of 2D Facial Muscle Parameter Using Neural Network (신경회로망을 이용한 2D 얼굴근육 파라메터의 자동인식)

  • 김동수;남기환;한준희;배철수;권오흥;나상동
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.1029-1032
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    • 1999
  • Muscle based face image synthesis is one of the most realistic approach to realize life-like agent in computer. Facial muscle model is composed of facial tissue elements and muscles. In this model, forces are calculated effecting facial tissue element by contraction of each muscle strength, so the combination of each muscle parameter decide a specific facial expression. Now each muscle parameter is decided on trial and error procedure comparing the sample photograph and generated image using our Muscle-Editor to generate a specific face image. In this paper, we propose the strategy of automatic estimation of facial muscle parameters from 2D marker movement using neural network. This also 3D motion estimation from 2D point or flow information in captered image under restriction of physics based face model.

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NBC Hazard Prediction Model using Sensor Network Data (센서네트워크 데이터를 활용한 화생방 위험예측 모델)

  • Hong, Se-Hun;Kwon, Tae-Wook
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.5
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    • pp.917-923
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    • 2010
  • The local area weather information is very important element to estimate where the air-pollutant will flow. But the existing NBC hazard prediction model does not consider the local area weather information. So, in this paper, we present SN-HPM that uses the local area wether information to perform more accurate and reliable estimate, and embody it to program.

Monitoring and Tracking Model of Logistics Based on ICT network

  • Cho, Sokpal;Chung, Heechang
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.10a
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    • pp.489-492
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    • 2016
  • Transportation in the logistics, many business organizations are engaged in monitoring and tracking the vehicles in order to improve logistics services, reduce expenses and secure security in cargo transportation. It is saving time and money by tracking and monitoring vehicles which transport cargo in supply chain of logistics. Therefore the main issue of delivery flow is to improve services, and ensure the safety in transportation system. This article suggests the tracking and monitoring model to keep safety transports on ICT network. It focuses on precise delivery control by monitoring and tracking vehicles to save time and costs. The status of product movement is analyzed for proper decision making. The vehicle embedded with RFID is automatically tracked in the movement process by tracking and monitoring model. The main role keeps safety tracking to reduce costs and to deliver products at proper time and location.

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A Study on the Water Resources Geographical Information System Based on Network Component (Network 컴포넌트 기반의 수자원지리정보시스템에 관한 연구)

  • Kim, Kyung Tak;Kim, Joo Hun;Choi, Yun Seok;Park, Dong Sun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.6 no.4
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    • pp.122-134
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    • 2003
  • In recent, different kinds of nationwide thematic map have been developed based on NGIS, and each related research field has tried to develop GIS by utilizing this map. Also, Many researches on the geographic information data model has been conducted to improve the compatibility of developed system. The developed system in water resource field should reflect the dynamic characteristics of river flow. Because it should be considered from the design of data model, this study suggests the datamodel for designing geographical information database on water resources which is possible to linear reference capacity based on stream network. In order to examine the applicability of the suggested model, network component based system has developed. Finally, the river network based system shows the superiority in terms of its applicability comparing with other system.

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