• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.1
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• pp.35-57
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• 2014

Multi-criteria decision making (MCDM) algorithms play an important role in ensuring quality of service in an integrated HetNets (Heterogeneous Networks). The primary objective of this paper is to develop a multi-criteria vertical handoff decision algorithm (VHDA) for best access network selection in an integrated Wireless Local Area Network (WLAN)/Universal Mobile Telecommunications System (UMTS)/Worldwide Interoperability for Microwave Access (WiMAX) system. The proposed design consists of two parts, the first part is the evaluation of an Analytic Hierarchy Process (AHP) to decide the relative weights of handoff decision criteria and the second part computes the final score of the weights to rank network alternatives using Simple Additive Weighting (SAW). SAW ranks the network alternatives in a faster and simpler manner than AHP. The AHP-SAW mathematical model has been designed, evaluated and simulated for streaming video type of traffic. For other traffic type, such as conversational, background and interactive, only simulation results have been discussed and presented in brief. Simulation results reveal that the hierarchical modelling and computing provides optimum solution for access network selection in an integrated environment as obtained results prove to be an acceptable solution to what could be expected in real life scenarios.

• Journal of Korean language education
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• v.28 no.1
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• pp.173-196
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• 2017

Writing is a subjective and performative activity. Writing ability has multi-facets and compoundness. To understand the examinees's writing ability accurately and provide effective writing scores, raters first ought to have the competency regarding assessment. Therefore, this study is significant as a fundamental research about rater's characteristics on the TOPIK writing assessment. 150 scripts of the 47th TOPIK examinees were selected randomly, and were further rated independently by 20 raters. The many-facet Rasch model was used to generate individualized feedback reports on each rater's relative severity and consistency with respect to particular categories of the rating scale. This study was analyzed using the FACETS ver 3.71.4 program. Overfit and misfit raters showed many difficulties for noticing the difference between assessment factors and interpreting the criteria. Writing raters appear to have much confusion when interpreting the assessment criteria, and especially, overfit and misfit teachers interpret the criteria arbitrarily. The main reason of overfit and misfit is the confusion about assessment factors and criteria in finding basis for scoring. Therefore, there needs to be more training and research is needed for raters based on this type of writing assessment characteristics. This study is recognized significantly in that it collectively examined writing assessment characteristics of writing raters, and visually confirmed the assessment error aspects of writing assessment.

• Journal of Auto-vehicle Safety Association
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• v.4 no.2
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• pp.5-10
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• 2012

Whiplash is the most frequent injury among occupants in low speed rear-end car collision. The aim of this paper is to analyze thecorrelation between influence parameters of head restraints and whiplash injury criteria.In this paper, DFSS (Design for Six Sigma) method is used for optimum design of head restrains. Four control factors of head restraints have selected by function matrix method. The effects of the control factors have been experimentally evaluated by using a sled pulse from 16km/h relative velocity which is suggested by KNCAP (Korean New Car Assessment Program). In order to reduce the noise factors of dynamic tests, whiplash tests were repeated twice. By using DFSS, the correlation between control factors and injury criteria has been comprehended.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.769-776
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• 2006

A mathematical model is developed in this paper to define the interaction between the occupant and vehicle passenger compartment and to predict the occupant dynamic response during a sudden impulse load. Two different types of occupants are considered in this study, child and adult occupants. The occupants are considered as lumped masses connected to the child seat and vehicle's body masses by means of restraint systems. In addition, the occupant restraint characteristics of seat belt and airbag are represented by stiffness and damping elements. To obtain the dynamic response of the occupant, the equations of motion of the occupants during vehicle collisions are developed and analytically solved. The occupant's acceleration and relative displacement are used as injury criteria to interpret the results. It is demonstrated from the numerical simulations that the dynamic response and injury criteria are easily captured and analyzed. It is also shown that the mathematical models are flexible, useful in optimization studies and it can be used at initial design stage.

• Proceedings of the Safety Management and Science Conference
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• 2006.04a
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• pp.123-131
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• 2006

Multi-criteria decision making is deducing the relative importance in the criterion of decision making and each alternative which is able to making a variety of choices measures the preferred degree in the series of low-raking criterions. Moreover, this is possible by synthesizing them systematically. In general, a fundamental problem decision maker solve for multi-criteria decision making is evaluating a set of activities which are considered as the target logically, and this kind of work is evaluated and synthesized by various criterions of the value which a chain of activities usually hold in common. In this paper, we are the eigenvector methods in weights calculating. For the purpose of making optimal decision, the data of five different car models are used. For computing, we used Visual Numerica Version 1.0 software package.

• Korean Management Science Review
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• v.16 no.1
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• pp.75-85
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• 1999

In recent, an unfaithful construction bring about many social problems. The bidding process considering bidding price firstly is one of the reasons raising an unfaithfull construction work. Thus, we should consider many other criteria including bidding price in the bidder selection process. This paper suggests an analytic hierarchy process(AHP) model for selecting the best bidder of a large construction project. A questionnaire was used to obtain domain experts' opinion about criteria to be considered in the bidding process. A hierarchical structure of the AHP model is formed using criteria obtained in the survey. The model consists of bidding price, construction capability, financial status, faith, and their 17 sub-attributes. The relative importance of bidders are judged by pairwise comparison or absolute measurement. An illustrative example is given to show the process selecting the best bidder using the suggested AHP model.

• Journal of the Korea Safety Management & Science
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• v.8 no.4
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• pp.205-218
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• 2006

Multi-criteria decision making is deducing the relative importance in the criterion of decision making and each alternative which is able to making a variety of choices measures the preferred degree in the series of town ranking criterions. Moreover, this is possible by synthesizing them systematically. In general, a fundamental problem decision maker solve for multi-criteria decision making is evaluating a set of activities which an considered as the target logically, and this kind of work is evaluated and synthesized by various criterions of the value which a chain of activities usually hold in common. In this paper, we use the compensatory models for the optimal decision making. For the purpose of optimal decision making, the data of five different car models are used in Europe.

• Journal of Energy Engineering
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• v.11 no.4
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• pp.359-369
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• 2002

Nuclear power plant is a huge system with multidisciplinary technology. So, R & D prioritization is a not a simple task and the relative importance of each prioritization criterion is not well established. This study built a technology classification chart for nuclear power plant operation and maintenace, established the relative importance of prioritization criteria and assigned the relative importance of each technology at each level. Analytical Hierarchy Process was used for the prioritization and the result was validated with Consistency Index and outcomes of fields interview.

• Journal of Environmental Impact Assessment
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• v.18 no.5
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• pp.301-312
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• 2009

Recently, habitat fragmentation and shrinkage has occurred because of increased road construction. As a measures mitigating the adverse effect such as eco-island by road construction, Korea has been installed eco-corridors since 1995. Using the Analytic Hierarchy Process (AHP), this study analyzed the importance of assessment items and the criteria to determine which areas require eco-corridors the most. First, related literature reviews, preliminary surveys, and expert interviews were carried out to develop assessment items and criteria for constructing the hierarchy. Second, experts were surveyed in order to determine the relative importance of the assessment items by applying the AHP. As a result, it found that the restoration of the ecological network was the most important assessment item, followed by wild animal resources in the Level 3. In the Level 4, the eighteen items were ranked in the order of their relative weight and it was found that the 'Baekdudaegan Mountain Range (0.189)' was the highest ranked item. Therefore, this approach can be applied to effective selection of the priority areas in planning eco-corridors in the national scale.

• Asia Marketing Journal
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• v.17 no.2
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• pp.97-125
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• 2015

In this study, we tried to evaluate the relative importance and find out the differences in consumer perceptions regarding service recovery strategies and the service provider in the distribution industry by using AHP (Analytic Hierarchy Process) analysis method. Therefore in this study, we tried to systematize various recovery strategies which were considered very important during service failure process in the distribution industry and analyze the relative importance for each recovery strategy. We set hierarchy composed of four items of monetary, action-oriented, psychological, and assured level as primary selection criteria and a total of 16 items(indemnity, refund, gift, gift certificate, prompt resolution, exchange, manager support, explanation, apology, empathy, acknowledge, kindness, assortment, after service, manage subcontractor, manage employee) as secondary selection criteria. We tried to take one step further from the service sector and study service recovery strategies specialized in distributor services. This study suggests various implications about service recovery strategies of distributors. First, this study can provide practical implications - e.g. service recovery efforts should be applied differently depending on service channels. There is a perceptual difference with respect to the importance of the types of service recovery strategies between service provider and final customer. Second, we can find theoretical implications in terms of identifying the priorities through hierarchy design of new recovery strategies and comparison of each element from the classifications of the current fractional recovery strategies. We hope to help service providers to build more efficient recovery strategy system based on the results of this study.