• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.405-412
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• 2015

The procurement of public construction, which has been selected mainly on the basis of the work experience of a department of public agencies that award construction contracts or those in charge of ordering, has not been executed through an objective selection process considering the construction types or characteristics. Thus, as a preliminary study on developing a model for the selection of contract methods, this study intends to analyze and present the key factors affecting the selection of procurement methods in public construction. Through a literature review on the existing methods, foundational factors were first presented, based on the analysis of these factors, the final influence factors were proposed. As a result, 6 factors contractor's characteristics, the environment of the construction market, relevant organization, the characteristics of a project, costs, and responsibility factors were determined, and 14 sub-factors were selected. The factors presented in this study will be used as base data for developing a decision making support model for the selection of contract methods in public construction.

• Asia pacific journal of information systems
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• v.27 no.1
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• pp.1-17
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• 2017

The need for effective information systems that can help in efficient transportation management has become essential. This study presents the potential benefits of developing a decision support system used by a trucking company for routing and scheduling. Our study investigates how customer exibility factors affect the utilization of transportation resources and establishes a vehicle scheduling model for better allocation of transportation resources with a time window. The results show vehicle savings from 25% up to 70% per day given different levels of exibility in delivery times. Increased capacity utilization can be achieved by considering only customer exibility in the model. Our study implies that incorporating customer exibility into the information system can help transportation organizations have the capability to gain control over management to cut costs and improve service.

• The Journal of Information Systems
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• v.14 no.3
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• pp.63-70
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• 2005

Compared with land logistics and sea logistics, air logistics takes not only less transportation time, but also makes just-in-time delivery possible. Because of this, in spite of high freight rates, many shippers make good use of airlines. To cope with borderless competition in this global age, most shippers using air logistics want to receive diverse information including just-in-time cargo delivery and dangerous situation as well as convenience and speed in job handling. Nevertheless, most domestic forwarders, who perform many kinds of important businesses for air logistics, mainly put emphasis on demanding information from overseas partners through their business agreements, that is, focusing on horizontal integration, instead of sharing information or improving job performance among air logistics participants. As a result, it is almost impossible to satisfy the needs of shippers. Airline users want to remove the uncertainties over their cargo movement. And in time of emergency, they want to take immediate measures through speedy information sharing and decision-making. In order to satisfy shipper's needs, all the organizations participating in the air logistics supply chain-cargo senders, cargo receivers, forwarders, transporters, licensed customs brokers, airlines as well as foreign partners-have to set up a vertical cooperation system. For effective air logistics SCM, it is very important to remove overlapping jobs, strengthen the efficiency of job handling, and provide online monitoring on cargo information in order to support decision-making. To this end, this paper has applied the concept of RTE (Real Time Enterprise), a new business management system, which tries to maximize competitiveness by removing many hindrance factors on an ongoing basis in managing and fulfilling core business processes based on up-to-the-minute information. In order to realize RTE-based information system for air logistics SCM, this paper has analyzed the information required by business process and by air logistics participant, and suggested the method for information sharing, point of time for information input and output, and its means.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.51-59
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• 2017

Due to the rapid change of global business environment, the growth of China's steel industry and the inflow of cheap products, domestic steel industry is faced on downward trend. The change of business paradigms from a quantitative growth to a qualitative product is needed in this steel industry. In this environment, it is very important for domestic steel distribution companies to secure their competitiveness by selecting good supply companies through a efficient procurement strategy and effective method. This study tried to find out the success factors of steel distribution industry based on survey research from experts. Weighted values of each factors were found by using AHP (analytic hierarchy process) analysis. The weighted values were applied to DEA(data envelopment analysis) model and eventually the best steel supply company were selected. This paper used 29 domestic steel distribution firms for case example and 5 steps of decision process to select good vendors were suggested. This study used quality, price, delivery and finance as a selection criteria. Using this four criterions, nine variable were suggested. Which were product diversity, base price, discount, payment position, average delivery date, urgency order responsibility and financial condition. These variables were used as a output variable of DEA. Sales and facilities were used as an input variable. Pairwise comparison was conducted using these variables. The weighted value calculated by AHP pairwise comparison were used for DEA analysis. Through the analysis of DEA efficiency process, good DMU (decision making unit) were recommended as a steel supply company. The domestic case example was used to show the effectiveness of this study.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.2
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• pp.168-175
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• 2024

Due to the complexity of urban area, the city vehicle routing problem has been a difficult problem. The problem has involved factors such as parking availability, road conditions, and traffic congestion, all of which increase transportation costs and delivery times. To resolve this problem, one effective solution can be the use of parcel lockers located near customer sites, where products are stored for customers to pick up. When a vehicle delivers products to a designated parcel locker, customers in the vicinity must pick up their products from that locker. Recently, identifying optimal locations for these parcel lockers has become an important research issue. This paper addresses the parcel locker location problem within the context of urban traffic congestion. By considering dynamic environmental factors, we propose a Markov decision process model to tackle the city vehicle routing problem. To ensure more real situations, we have used optimal paths for distances between two nodes. Numerical results demonstrate the viability of our model and solution strategy.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.426-426
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• 1999

;There are many sources of uncertainty in a typical production and inventory system. There is uncertainty as to how many items customers will demand during the next day, week, month, or year. There is uncertainty about delivery times of the product. Uncertainty exacts a toll from management in a variety of ways. A spurt in a demand or a delay in production may lead to stockouts, with the potential for lost revenue and customer dissatisfaction. Firms typically hold inventory to provide protection against uncertainty. A cushion of inventory on hand allows management to face unexpected demands or delays in delivery with a reduced chance of incurring a stockout. The proposed strategies are used for the design of a probabilistic inventory system. In the traditional approach to the design of an inventory system, the goal is to find the best setting of various inventory control policy parameters such as the re-order level, review period, order quantity, etc. which would minimize the total inventory cost. The goals of the analysis need to be defined, so that robustness becomes an important design criterion. Moreover, one has to conceptualize and identify appropriate noise variables. There are two main goals for the inventory policy design. One is to minimize the average inventory cost and the stockouts. The other is to the variability for the average inventory cost and the stockouts The total average inventory cost is the sum of three components: the ordering cost, the holding cost, and the shortage costs. The shortage costs include the cost of the lost sales, cost of loss of goodwill, cost of customer dissatisfaction, etc. The noise factors for this design problem are identified to be: the mean demand rate and the mean lead time. Both the demand and the lead time are assumed to be normal random variables. Thus robustness for this inventory system is interpreted as insensitivity of the average inventory cost and the stockout to uncontrollable fluctuations in the mean demand rate and mean lead time. To make this inventory system for robustness, the concept of utility theory will be used. Utility theory is an analytical method for making a decision concerning an action to take, given a set of multiple criteria upon which the decision is to be based. Utility theory is appropriate for design having different scale such as demand rate and lead time since utility theory represents different scale across decision making attributes with zero to one ranks, higher preference modeled with a higher rank. Using utility theory, three design strategies, such as distance strategy, response strategy, and priority-based strategy. for the robust inventory system will be developed.loped.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.5
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• pp.1992-2008
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• 2018

Mobile opportunistic network is a kind of ad hoc networks, which implements the multi-hop routing communication with the help of contact opportunity brought about by the mobility of the nodes. It always uses opportunistic data transmission mode based on store-carry-forward to solve intermittent connect problem of link. Although many routing schemes have been proposed, most of them adopt the greedy transmission mode to pursue a higher delivery efficient, which result in unfairness extremely among nodes. While, this issue has not been paid enough attention up to now. In this paper, we analyzed the main factors that reflect fairness among nodes, modeled routing selection as a multiple attribute decision making problem, and proposed our Fairness-aware Routing Strategy, named FARS. To evaluate the performance of our FARS, extensive simulations and analysis have been done based on a real-life dataset and a synthetic dataset, respectively. The results show that, compared with other existing protocols, our FARS can greatly improve the fairness of the nodes when ensuring the overall delivery performance of the network.

• Journal of Korean Society for Quality Management
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• v.33 no.4
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• pp.21-41
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• 2005

This study analyzes the Internet utilization pattern of customer by comprehensively investigating the previous studies on the behavior pattern of customer in terms of Internet business. Based on the analysis, this study develops research framework that supports strategic decision-making for resource allocation in Internet business. Such research framework would be helpful for providing the typology of Internet business model that can be specialized by each industry. As a result of the simulation analysis, it was found that the optimal resource allocation portfolio providing maximum profits to the Internet bookstore involves large-scale investment on delivery service and customer support service which are the key factors for post-purchase customer satisfaction, regardless of the growth pattern or size of Internet bookstore market. Consequently, from the above analysis, the investment ratio of resources for the profit maximization of Internet bookstore was drawn. Conclusively, based on the comprehensive examination of the results, this study provided a framework for dynamic resource allocation decision-making, and proposed a management strategy which allows consumers to shop under more favorable environment, and simultaneously enables the Internet bookstore to accomplish management objectives such as continuous growth and profit maximization.

• Journal of Construction Engineering and Project Management
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• v.7 no.3
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• pp.15-25
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• 2017

The existence of material price volatility in construction projects puts forward substantial risks for all parties involved. Depending on the parties involved in the project, type of contracts, and state of the market various risk management strategies are practiced by contracting parties to manage project risks related to price volatility. Unfortunately, in many cases companies fail to select an adequate approach to better manage volatilities of material prices due to the lack of a decision support system to aid in the selection of an appropriate strategy based on the project characteristics. The aim of this study is to identify critical project factors and align them to documented strategies to manage price volatility based on an extensive literature review and industry interviews. This study found Integrated Project Delivery (IPD) as the ideal strategy with respect to project duration; quantitative risk management methods with respect to the cost; and Price Adjustment Clauses (PAC) with respect to the risk allocation, as the top price volatility management strategies.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.101-113
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• 1995

In pipeline planning, the systematic and reasonal management of topographical and spatial data are needed in order to omprove the availibilities for data analysis and the effective combinations of spatial informations. According to that fact, DBMS (Database Management System) and DSS(Decision making Support System) have to be developed for the planning of water supply system Also, the economic selection for harmonious delivery of water to target area, since the alternatives of pre-designed pipeline are influenced by hydraulic stability and geographic characteristics. In this study, GIS technique for water supply planning and management which stores graphic features and attributes as digital data sets is considered and engineering application programs are integrated for effective planning of water supply system. Decision making support system based on analyzing technical, Social and economical aspects is developed for the extension of water supply facilities and pipeline configurations. Especially, Hydraulic, land-use and economic influences are considered as important factors for the purpose of developing the system. Hydraulic analysis program(SAPID) for pipeline flow which is already developed in Water Resources Research Institute and economic analysis program(ECOVEL) are integrated with GIS for resonable decision making. Every possible aspects in pipeline planning for water supply is reviewed and the applicabilities of developed system into the field are evaluated.