• Title/Summary/Keyword: Average Travel Distance

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Assignment Problem Based Vehicle Dispatching for a Semiconductio FAB (반도체 라인 물류시스템에서의 할당문제 기반 차량 배차)

  • Kim, Byung-In;Shin, Jae-Joon;Jeong, Sang-Won
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.525-528
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    • 2006
  • This paper considers the vehicle dispatching problem in the automated material handling system (AMHS) of a large scale semiconductor fabrication line, which consists of 18 bays, 468 equipments and uses more than 130 overhead hoist transporters (OHT). We propose an assignment problem based vehicle dispatching approach to take advantage of simultaneous vehicle reassignment based on up-to-date system status. The proposed approach compares fsvorably with the shortest travel distance first rule and with the reassignment based rule which was recently proposed by the authors, in the number of vehicles required and the average lead time.

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Safety Factors in Mega Event

  • Hyun-Jee Park;Young-Sul Park;Young-Guk Kwon
    • Proceedings of the Safety Management and Science Conference
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    • 2001.11a
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    • pp.161-168
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    • 2001
  • Global tourism has increased throughout the 1990s, with the biggest surge occurring in the Asia-Pacific region. Long-distance travel is also increasing, and at a rate faster than the global average. The opportunities for event tourism appear to be strong almost everywhere, although we know from recent history that recessions like IMF impacted on these destinations. Along with this upward trend, competition for more desirable tourists is also surging, so destinations cannot be complacent (Getz, i997). Event tourism is appearing as the powerful method In the fierce competition around the tourism industry. This paper investigated the safety factors considered by visitors of 2000 Gyeongju World Culture Expo in Korea and analyzed the correlation between the safety factors and the demographic characteristic of the visitors.

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Changes of Time-Distance Accessibility by Year and Day in the Integrated Seoul Metropolitan Public Transportation Network (서울 대도시권 통합 대중 교통망에서 연도별 및 요일별 시간거리 접근도 변화)

  • Park, Jong Soo;Lee, Keumsook
    • Journal of the Economic Geographical Society of Korea
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    • v.21 no.4
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    • pp.335-349
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    • 2018
  • This study analyzes the effect of the changes in traffic environments such as transportation speeds on the time-distance accessibility for the public transportation passengers. To do this, we use passenger transaction databases of the Seoul metropolitan public transportation system: one week for each of the three years (2011, 2013, and 2015). These big data contain the information about time and space on the traffic trajectories of every passenger. In this study, the time-distances of links between subway stations and bus stops of the public transportation system at each time are calculated based on the actual travel time extracted from the traffic-card transaction database. The changes in the time-distance accessibility of the integrated transportation network from the experimental results can be summarized in two aspects. First, the accessibility tends to decline as the year goes by. This is because the transportation network becomes more complicated and then the average moving speed of the vehicles is lowered. Second, the accessibility tends to increase on the weekend in the analysis of accessibility changes by day. This tendency is because the bus speeds on bus routes on the weekend are faster than other days. In order to analyze the accessibility changes, we illustrate graphs of the vehicle speeds and the numbers of passengers by year and day.

Trip Assignment for Transport Card Based Seoul Metropolitan Subway Using Monte Carlo Method (Monte Carlo 기법을 이용한 교통카드기반 수도권 지하철 통행배정)

  • Meeyoung Lee;Doohee Nam
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.2
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    • pp.64-79
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    • 2023
  • This study reviewed the process of applying the Monte Carlo simulation technique to the traffic allocation problem of metropolitan subways. The analysis applied the assumption of a normal distribution in which the travel time information of the inter-station sample is the basis of the probit model. From this, the average and standard deviation are calculated by separating the traffic between stations. A plan was proposed to apply the simulation with the weights of the in-vehicle time of individual links and the walking and dispatch interval of transfer. Long-distance traffic with a low number of samples of 50 or fewer was evaluated as a way to analyze the characteristics of similar traffic. The research results were reviewed in two directions by applying them to the Seoul Metropolitan Subway Network. The travel time between single stations on the Seolleung-Seongsu route was verified by applying random sampling to the in-vehicle time and transfer time. The assumption of a normal distribution was accepted for sample sizes of more than 50 stations according to the inter-station traffic sample of the entire Seoul Metropolitan Subway. For long-distance traffic with samples numbering less than 50, the minimum distance between stations was 122Km. Therefore, it was judged that the sample deviation equality was achieved and the inter-station mean and standard deviation of the transport card data for stations at this distance could be applied.

Effects of Urban Compactness and Residential Density on Trip Generation: Focusing on Work Trips in Seoul, Korea (도시 압축도와 주거밀도가 통행발생에 미치는 영향에 관한 연구: 서울시 출근 통행을 중심으로)

  • Mahriyar, Muhammad. Zia;RHO, Jeonghyun
    • Journal of Korean Society of Transportation
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    • v.35 no.1
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    • pp.1-10
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    • 2017
  • The compact city usually provides good accessibility of residents with multiple transportation modes. However, in a compact city, annual average of travel distance per household by car is relatively short due to more congested traffic condition and larger travel cost than disperse city. As a result, total travel demand is decreasing when the region becomes more compact. Therefore compact development is regarded as one of the sustainable choices for future urban planning in many countries. This study aims at an empirical analysis of the relationship between urban compactness and travel demand based upon land-use and travel data for city of Seoul. In this study, 424 sub-districts with the mixed land-use patterns are assessed in a hexagonal diagram. The measurement is based on the relative deviation of each sector's characteristics including numbers of residence, manufacture, and trade & service. Multiple linear regression models are developed to analyze the effects of urban compactness on zonal trip generations. As a result, the trip generation rate in the residence-intensive and mixed-use areas is found to be relatively low. Furthermore, residents in high-compact areas tend to use public transport more often than residents in less compact areas.

Study for Habitat Usage of Spot-billed Duck in Korea, Using GPS-Mobile Telemetry (WT-200) (위치추적기(WT-200)를 이용한 흰뺨검둥오리의 서식지 이용에 관한 연구)

  • Shin, Yong-un;Shin, Man-Seok;Lee, Han-soo;Kang, Yong-myung;Moon, Oun-Kyong;Park, Hong-shik;Oh, Hong-shik
    • Korean Journal of Environment and Ecology
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    • v.30 no.2
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    • pp.146-154
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    • 2016
  • In this study, understanding the habitats on spot-billed duck that wintering-breed in the korea, which using the GPS-Mobile based Telemtry (WT-200), I tried to take advantage as the basic data of the protection and management of the habitats of the waterbirds of Korea. Study area is Gyeonggi-do Bokhacheon, Chonmichon, Chungcheongnam-do Gokugyochon, Chungcheongbuk-do Byeongcheoncheon, Jeollabuk-do Mangyunggang, which Five rivers and Jeju Island reservoir, I have attached the tracking of the location(WT -200) to the twenty-five spot-billed ducks. among twenty five ducks, twelve ducks moved to overseas countries, the arrival site was China, North Korea, Russia. Moving average distance was 683km, the largest distance was 1,238km. The average northbound starting date was April 26. The average daily movement distance of thirteen ducks remaining in the domestic country is $1.0{\pm}0.89km$, maximum travel distance was 23.8km. The average daily movement distance of wintering prior to average going north dating is a 0.9km, is the largest 14.6km, the breeding season is an average 1.3km, maximum was 14.4km. Spot-billed duck used the rivers in domestic country most frequently, following was rice field, a filed, reservoir. It used the river most frequently during the wintering period, in the breeding season it used paddy paddies most frequently. While wintering, during the day and night's utilization rate was the highest in the river, but utilization rate was incleased on filed, paddy filed at night. During breeding season, daytime and night's utilization rate was the highest but, utilization rate was increased on river and utilization rate was decreased on river. In accordance with time change, spot-billed duck showed different tendency in paddy fields, and they utilized the filed adjacent to rivers mostly.

Calculation of the Peak-hour Ratio for Road Traffic Volumes using a Hybrid Clustering Technique (혼합군집분석 기법을 이용한 도로 교통량의 첨두율 산정)

  • Kim, Hyung-Joo;Chang, Justin S.
    • Journal of Korean Society of Transportation
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    • v.30 no.1
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    • pp.19-30
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    • 2012
  • The majority of daily travel demands concentrate at particular time-periods, which causes the difficulties in the travel demand analysis and the corresponding benefit estimation. Thus, it is necessary to consider time-specific traffic characteristics to yield more reliable results. Traditionally, na$\ddot{i}$ve, heuristic, and statistical approaches have been applied to address the peak-hour ratio. In this study, a hybrid clustering model which is one of the statistical methods is applied to calculate the peak-hour ratio and its duration. The 2009 national 24-hour traffic data provided by the Korea institute of Construction Technology are used. The analysis is conducted dividing vehicle types into passenger cars and trucks. For the verification for the usefulness of the methodology, the toll collection system data by the Korea Express Corporation are collected. The result of the research shows lower errors during the off-peak hours and night times and increasing error ratios as the travel distance increases. Since the method proposed can reduce the arbitrariness of analysts and can accommodate the statistical significance test, the model could be considered as a more robust and stable methodology. It is hoped that the result of this paper could contribute to the enhancement of the reliability for the travel demand analysis.

Evaluation of On-Road NOx Emission from a Light Duty Diesel Vehicle using a Portable Emissions Measurement System (이동식 배출가스 측정장비를 이용한 소형 경유 자동차의 실도로 질소산화물 배출특성 분석)

  • Lee, Tae-Woo;Lee, Jong-Tae;Kim, Jeong-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.1
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    • pp.94-104
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    • 2012
  • The purpose of this research is to quantify the compliance of on-road emission from a light duty diesel vehicle, based on a comparison to emission regulation standard. $NO_x$, CO and THC emissions were measured using a portable device on a selected real-world driving route with a length of approximately 22 km. On-road measurements were repeated by 10 times on a same route to reflect variability in traffic conditions. A test route was divided into 22 road links with length of 1 km to analyze emission results with higher spatial resolution. The average emissions of $NO_x$, CO and THC over total travel distance, which is approximately 220 km, were quantified to be in compliance with emission regulation standards. Under higher spatial resolution, $NO_x$ concentration exceeded a standard in 92 links out of 220 links. The extended time in stop period and the stop-and-go driving cycle were identified as two important reasons for increased $NO_x$ emissions in observed cases. Heavy traffics showed higher $NO_x$ emissions than free flow. These results indicate that the real-world vehicle emissions might exceed the compliance level associate with traffic conditions. Another interesting observation of this research is that the on-road emission characteristics can be independent to the average speed of road links with higher spatial resolution. Variability in on-road emission might not be fully described by solely relying on an average speed, because variability in traffic conditions and road conditions can influence on real-world vehicle emissions.

Pick & Place Module consist of Linear Motor using Cogging Force Reduction Method (코깅힘 저감 방법을 적용한 선형모터로 구성되는 Pick & Place 모듈)

  • Chung, Myung-Jin
    • Journal of IKEEE
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    • v.24 no.3
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    • pp.735-742
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    • 2020
  • The pick & place module is used as a core module in the process equipment for producing and inspecting semiconductor components. The conventional pick & place module has the disadvantage that the precision and durability of the system are reduced and the size and weight of the module are increased by using a conversion device that converts rotary motion into linear motion. In this study, we proposed a pick & place module that implements up-and-down linear motion without a conversion device by improving such disadvantage and employs a linear motor with no limit on average thrust and travel distance. Design parameter values, that can reduce cogging force while maintaining average thrust by selecting parameters for designing a core type linear motor with a large thrust to volume ratio and analyzing the effect of cogging force according to design parameter changes through magnetic analysis, was selected. Average thrust and cogging force were measured for the pick & place module composed of the manufactured linear motor and compared with the design values.

Longitudinal Control of Acceleration Lanes and its Impact on Congestion Alleviation (가속차로의 길이 제어와 고속도로 접속부 혼잡저감 효과)

  • Shin, Chi-Hyun;Kim, Kyu-Ok
    • Journal of Korean Society of Transportation
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    • v.23 no.5 s.83
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    • pp.169-176
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    • 2005
  • This paper introduces the dynamic control of acceleration lanes at freeway-ramp junctions. The feasibility of operation with flexible length of acceleration lane was tested with most possible traffic conditions. The operational qualify was also evaluated using average speed and total thru-put at both ramp section and freeway section. A CORSIM microscopic simulation model was used to evaluate the operation quality with a variety or volume conditions and three acceleration lanes, each representing different length categories. In addition, tollgate O-D data including travel times were obtained for two sections on the Gyeong-bu Freeway where an effective merging distance has been largely reduced. Its effect was analyzed and compared to the simulation results. Finally, the effects of acceleration lane are discussed and operational improvement at junctions is presented as research findings.