• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.85-94
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• 2005

The scale and operating conditions of logistical systems very sensitively varies according to the variation of traffic intensity that is affected by the arrival characteristics of trucks and the attributes of loading/unloading services in logistics facilities. More exactly, logistics costs are incurred according to variations of traffic intensity. which are intimately linked with in a given time period. Also. although traffic intensity changes minutely, the range of cost variation is wide. Nevertheless, with regard to operating logistics systems, the existing studies make no attempt to analyze these factors. Therefore, it was the purpose of this study to determine the optimal traffic intensity to minimize excessive logistics costs resulting from the generation of unnecessary costs such as waiting costs and overcosts in operating a facility. For the purposes of this analysis. a determination model of optimal traffic intensity was constructed according to queuing theory. The inflow/outflow conditions of trucks and the terminal operational conditions were collected from an off-dock container terminal in Busan. On the basis of this data. the optimal traffic intensity that could off-set excessive waiting and operating costs was determined quantitatively. Also. using the optimal traffic intensity to be determined. we consider the improvements of operating system in the logistics facilities.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.81-89
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• 2005

Real-time bus arrival information within the Bus Information System (BIS) is an invaluable resource for users that demand accurate and up-to-date bus headway information while waiting at a bus stop. The associated benefits of such a system come in two folds, that is to 1) resolve the psychological uncertainty caused by the lack of real-time bus arrival information and 2) empower the user waiting at bus stops with the ability to reliably coordinate various tasks and errands, such as a quick trip into a convenience store or restroom without fear of missing a bus pick-up. This paper discusses the appropriate methodology with which to measure the economic value of reliable bus arrival information, with particular emphasis on the psychological uncertainty in users associated with the lack of real-time headway information at bus stops. Data regarding bus transit users' willingness to pay for such a service is obtained through questionnaire surveys, and the Contingent Valuation Method is used to analyze and derive the associated economic value. Our findings indicate the monetary value associated with a real-time bus arrival information system is approximately 132.5 won/min at the 0.3 significance level.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.6
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• pp.1-8
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• 2018

In this paper, we implement the signboard voice guidance service for visually impaired person using virtual beacon. The new location to provide a location-based service can be added easily by using virtual beacons, which are locating by Wi-fi, GPS, and so on, instead of physical beacons, which are locating by physical devices. We provide the voice service for guiding information of the captured signboard for the visually impaired when he arrived at the location registered through the virtual beacon.

• IE interfaces
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• v.14 no.4
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• pp.365-373
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• 2001

It is discussed how to determine time windows for pickups and deliveries, which have been assumed to be given in all most of previous studies on traveling salesman problems with time window, vehicle routing problems with time window, vehicle scheduling and dispatching problems, and so on. First, time windows are classified into four models (DR, DA, AR, and AA) by customers‘ polices. For each model, it is shown how a time window is related to various cost terms of suppliers and customers. Under the assumption of collaborative supplier-customer relationship, an integrated cost model for both supplier and customer is constructed for determining boundaries of time windows. The cost models in this paper consists of cost terms that depend on waiting time, early arrival time, late arrival time, and rejection of receipt. A numerical example is provided and results of the sensitivity analysis for some parameters are also provided to help intuitive understanding about the characteristics of the suggested models.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.109-112
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• 2023

본 논문에서는 정보화 시대의 바쁜 현대인들에게 일상생활 속 필요한 정보들을 거울과 IOT 기술을 접목하여 인포그래픽(inforgraphics) 형태로 제공하는 개인용 스마트 미러를 제작하였다. 제공되는 정보는 날짜 및 시간, 일정, 날씨, 뉴스 속보, 실시간 버스 도착 정보, 실시간 지하철 도착 정보가 있으며 Google Assistant SDK를 활용하여 시각적 정보제공의 한계를 개선하였다.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.147-155
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• 2005

The purpose of this paper is to develop a method for estimation of reliable path-travel time using data obtained from the toll collection system on freeways. The toll collection system records departure and arrival time stamps as well as the identification numbers of arrival and destination tollgates for all the individual vehicles traveling between tollgates on freeways. Two major issues reduce accuracy when estimating path-travel time between an origin and destination tollgate using transaction data collected by the toll collection system. First, travel time calculated by subtracting departure time from arrival time does not explain path-travel time from origin tollgate to destination tollgate when a variety of available paths exist between tollgates. Second, travel time may include extra time spent in service and/or rest areas. Moreover. ramp driving time is included because tollgates are installed before on-ramps and after off-ramps. This paper describes an algorithm that searches for arrival time when departure time is given between tollgates by a Progressive Iterative Forward and Backward (PIFAB) search method. The algorithm eventually produces actual path-travel times that exclude any time spent in service and/or rest areas as well as ramp driving time based on a link-based procedure.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.113-127
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• 2018

This study develops a fusion priority signal control algorithm to pass without delay in emergency events. Fusion priority signal control is method combined center control with local control. The center control method applies signal times for each signalized intersection on the emergency vehicle's route when an emergency call is received. As signals are controlled before the emergency vehicle leaves for its destination, it is possible to clear the queues at each intersection more effectively. However, since the traffic information (speed, position) of the real-time emergency vehicle is not used, the intersection arrival time predicted by center control and actual arrival time of the emergency vehicle may be different from each other. In the case, it is possible to experience a delay caused by the signal. Local control method operate priority signal use the real-time information of EV, but there is a limitation that queue elimination time can not be reflected. In this study, fusion(center+local) control algorithm is proposed to compensate the disadvantages of center and local control also maximizing its advantages. Proposed algorithm is expected to decrease delay time of EV in emergency situation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.51-58
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• 2022

This paper proposes new measures to aid the uses of pubic transport buses by visually impaired people. Many visually impaired people have difficulty using public buses, but current guidance systems and braille blocks are not useful enough, according to a national survey(2017). In this paper, we develop a system with three functions that help to increase the bus accessibility and mobility of visually impaired people: (1)bus reservation using smart phone applications, (2)arrival notification, and (3)wireless bus stop button using Beacon. Experiments have confirmed that our system supports bus reservation, boarding and getting off the bus efficiently.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2646-2648
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• 2005

열차는 타 교통수단에 비하여 정시성과 안전성이 우수하다는 장점을 가지고 있다. 이러한 열차의 정시성을 유지하는데 있어서 열차 경합에 대한 대응은 매우 중요한 용소이다. 열차 경합은 열차와 열차간의 충돌로 정의된다. 이러한 열차의 경합은 두 열차의 각 역에서의 도착 및 출발시각을 변경함으로써 해결할 수 있다. 본 논문에서는 전문가 시스템 및 제약조건 만족 기법을 이용하여 열차 경합을 해소하는 알고리즘을 제시한다.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.9
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• pp.169-193
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• 2004

In simultaneous interpreting, if the syntactic structure of the source language and the target language are very different, interpreters have to wait before being able to reformulate the source text segments into a meaningful utterance in target language. It is inevitable to adapt the target language structure to that of the source language so as not to unduly increase the memory load and to minimize the pause. While such adaptation enables simultaneous interpretating, it results in damaging the perspective coherence of the text. Discovering when such perspective coherence is impaired, and how the problem can be relieved, will enable interpreters to enhance their performance. This paper analyses the reasons for perspective coherence damage by looking at some examples of German-Korean simultaneous interpreting.