• Management Science and Financial Engineering
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• v.18 no.1
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• pp.27-37
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• 2012

This paper is motivated by a military cargo-plane routing problem which is a pickup-and-delivery problem in which load splits and node revisits are allowed (PDPLS). Although this recent evolution of a VRP-model enhances the efficiency of routing, a solution method is more of a challenge since the node revisits entail closed walks in modeling vehicle routes. For such a case, even a compact IP-formulation is not available and an effective method had been lacking until Nowak et al. (2008b) proposed a heuristic based on a tabu search. Their method provides very reasonable solu-tions as demonstrated by the experiments not only in their paper (Nowak et al., 2008b) but also in ours. However, the computation time seems intensive especially for the class of problems with dynamic transportation requests, including the military cargo-plane routing problem. This paper proposes a more scalable algorithm hybridizing a tabu search for pricing subproblem paused as a single-vehicle routing problem, with a column generation approach based on Dantzig-Wolfe decomposition. As tested on a wide variety of instances, our algorithm produces, in average, a solution of an equiva-lent quality in 10~20% of the computation time of the previous method.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.75-81
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• 2017

PURPOSES : So far, aged cement concrete pavement on express highways has been rehabilitated mainly with asphalt concrete inlay. However, potholes were the major problem, and they shortened the life of the inlay mainly owing to the poor drainage of water once it infiltrated the interface of the concrete and asphalt. The purpose of this study is to compare the performance and economic efficiency of asphalt overlay and inlay. METHODS : Overlay and inlay were compared through accelerated pavement testing, and a life-cycle cost analysis was conducted in this study using the CA4PRS program. RESULTS and CONCLUSIONS : It was found from accelerated pavement testing that the overlay exhibited reflective crack resistance that was more than twice as effective as that of inlay. The total cost (construction cost + user cost) within the analysis period (20 years) of the overlay was 37% lower than that of the inlay.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.83-95
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• 2017

PURPOSES : The purpose of this study is to develop a regression model to predict the International Roughness Index(IRI) and Surface Distress(SD) for the estimation of HPCI using Expressway Pavement Management System(PMS). METHODS : To develop an HPCI prediction model, prediction models of IRI and SD were developed in advance. The independent variables considered in the models were pavement age, Annual Average Daily Traffic Volume(AADT), the amount of deicing salt used, the severity of Alkali Silica Reaction(ASR), average temperature, annual temperature difference, number of days of precipitation, number of days of snowfall, number of days below zero temperature, and so on. RESULTS : The present IRI, age, AADT, annual temperature differential, number of days of precipitation and ASR severity were chosen as independent variables for the IRI prediction model. In addition, the present IRI, present SD, amount of deicing chemical used, and annual temperature differential were chosen as independent variables for the SD prediction model. CONCLUSIONS : The models for predicting IRI and SD were developed. The predicted HPCI can be calculated from the HPCI equation using the predicted IRI and SD.

• Journal of the Korea Safety Management & Science
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• v.22 no.4
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• pp.87-100
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• 2020

Economic Development Zone(EDZ) in the province is one of the foreign policy for economic development of North Korea. North Korea has promulgated 27 Economic Development Zones(5 EDZs as central level and 22 EDZs as provincial level) to promote economic growth through the expansion of external opening policy. EDZs of the provinces play an important role in North Korea's national and regional economic growth. The purpose of this study is to select analytical criteria that can be quantified when considering the location conditions of North Korean economic development zones when domestic companies advance into North Korea according to the progress of inter-Korean economic cooperation, and derive the relative importance between the criteria. After that, based on this, we intend to quantify the evaluation of the location priority of the economic development zone. In this study, through AHP analysis results, when domestic companies enter North Korea, we derive the importance and preference of location selection factors when considering the location conditions of North Korean economic development zones. Taking into account the reality of North Korea when the Korean company entered the North economic development zone following location for evaluation. That is, logistics and transportation, industrial infrastructure, competitiveness, and management incentives. And 14 sub-factors were selected and AHP analysis was performed.

• Industrial Engineering and Management Systems
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• v.12 no.4
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• pp.351-358
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• 2013

This paper proposes a multiobjective model describing the trade-offs involved in selecting the locations of drop-off boxes for collecting used products and transporting these products to designated locations. We assume the following reverse flow of used products. Owners of used products (cellular phones, digital cameras, ink cartridges, etc.) take them to the nearest drop-off box when the distance is reasonably short. We also assume that owners living closer to drop-off boxes dispose of more used products than do owners living farther from drop-off boxes. Different types of used products are collected, with each type requiring its own drop-off box. A transportation destination for each product is specified. Three objectives are considered: maximizing the volume of used products collected at drop-off boxes; minimizing the cost of transporting collected products to designated locations; and minimizing the cost of allocating space for drop-off boxes. We formulate the above model as a multiobjective integer programming problem and generate the corresponding set of Pareto optimal solutions. We apply the model to an area using population data for Chofu City, Tokyo, Japan, and analyze the trade-offs between the objectives.

• Electronics and Telecommunications Trends
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• v.35 no.2
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• pp.28-37
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• 2020

Recently, the focus of research interest in artificial intelligence technology has shifted from algorithm development to application domains. Industrial sectors such as smart manufacturing, transportation, and logistics venture beyond automation to pursue digitalization of sites for intelligence. For example, smart manufacturing is realized by connecting manufacturing sites, autonomous reconfiguration, and optimization of manufacturing systems according to customer requirements to respond promptly to market needs. Currently, KSB Convergence Research Department is developing BeeAI-an on-site end-to-end intelligence platform. BeeAI offers end-to-end service pipeline configuration and DevOps technologies that can produce and provide intelligence services needed on-site. We are hopeful that in future, the BeeAI technology will become the base technology at various sites that require automation and intelligence.

• Journal of radiological science and technology
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• v.43 no.4
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• pp.289-295
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• 2020

This study investigated the feasibility of establishing a college of medicine in the western region of Chungnam to fill the gap in the medical doctor in charge of essential medical care in the region. Currently, the level of medical services in Chungnam is low compared to provinces across the country and in particular, 7 cities and towns, which account for 760,000 people, one-third of Chungnam's population, are located in the western regions of Chungnam. Because of this, in the event of an emergency patients, it is necessary to travel to Cheonan, Daejeon, Seoul, etc. where the regional emergency medical center is located for more than 1 hour and 30 minutes. In the case of critically ill and emergency patients transfer, it is a situation that misses the golden time and causes valuable loss of life. In order to improve the medical environment in the western region of Chungnam and improve the lives of residents in vulnerable areas of medical services, it is believed that establishing a college of medicine in the western region of Chungnam is essential.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.185-186
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• 2009

According to increase of container transportation, demands of empty container handling has been increasing, so research of empty container has been studied steadily. However, the handling of containers and empty containers is not handled simultaneously. Moreover, as Korean ICD(Inland Container Depot) and ODCY(Off-Dock Container Yard), the inland depot in many environments, relocation research due to demand of empty container has not been studied sufficiently. This paper formulates and analyzes logical mathematical relocation model according to demands of empty container which are required in container terminal, ICD, and ODCY as cargo depots. This paper also aims to help reduce cost by improving q current empty container relocation as same as the past procedure.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.83-89
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• 2016

As the world's industrial development quickens, the highways and regional expressways have been expanding to serve the logistics and transportation needs of people. The burgeoning road construction has led to a growing interest in roadside installations. These must have reliable performance over long periods, reduced maintenance and high durability. Steel roadside barriers are prone to corrosion and other compromises to their functionality. Therefore, using high anti-corrosion steel material is now seen as a viable solution to this problem. Thus, the objective of this paper is to expand the scope of applications for high anti-corrosion steel material for roadside barriers. This paper assesses the impact safety such as structural performance, occupant protection performance and post-impact vehicular response performance by a simulation review on roadside barriers built with high strength anti-corrosion steel materials named as hot-dip zinc-aluminium-magnesium alloy-coated steel. The simulation test results for the roadside barriers built with high strength anti-corrosion steels with reduced sectional thickness meet the safety evaluation criteria, hence the proposed roadside barrier made by high strength and high anti-corrosion hot-dip zinc-aluminium-magnesium alloy-coated steel will be a good solution to serve safe impact performance as well as save maintenance cost.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.5
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• pp.253-263
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• 2021

Traffic data collected using advanced equipment are highly valuable for traffic planning and efficient road operation. However, there is a problem regarding the reliability of the analysis results due to equipment defects, errors in the data aggregation process, and missing data. Unlike other detectors installed for each vehicle lane, radar detectors can yield different error types because they detect all traffic volume in multilane two-way roads via a single installation external to the roadway. For the traffic data of a radar detector to be representative of reliable data, the error factors of the radar detector must be analyzed. This study presents a field survey of variables that may cause errors in traffic volume collection by targeting the points where radar detectors are installed. Video traffic data are used to determine the errors in traffic measured by a radar detector. This study establishes three types of radar detector traffic errors, i.e., artificial, mechanical, and complex errors. Among these types, it is difficult to determine the cause of the errors due to several complex factors. To solve this problem, this study developed a radar detector traffic volume error analysis model using a multiple linear regression model. The results indicate that the characteristics of the detector, road facilities, geometry, and other traffic environment factors affect errors in traffic volume detection.