• Journal of Communications and Networks
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• v.9 no.1
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• pp.67-74
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• 2007

The performance of dual diversity receivers operating over correlated Ricean fading channels is analyzed. Using a previously derived rapidly converging infinite series representation for the bivariate Ricean probability density function, analytical expressions for the statistics of dual-branch selection combining, maximal-ratio combining, and equal-gain combining output signal-to-noise ratio (SNR) are derived. These expressions are employed to obtain novel analytical formulae for the average output SNR, amount of fading, average bit error probability, and outage probability. The proposed mathematical analysis is used to study various novel performance evaluation results with parameters of interest the fading severity, average input SNRs, and the correlation coefficient. The series convergence rate is also examined verifying the fast convergence of the analytical expressions. The accuracy of most of the theoretical performance evaluation results are validated by means of computer simulations.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.108-113
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• 2012

Routing paths are mightily important for the network security in WSNs. To maintain such routing paths, sustained path re-selection and path management are needed. Region segmentation based path selection method (RSPSM) provides a path selection method that a sensor network is divided into several subregions, so that the regional path selection and path management are available. Therefore, RSPSM can reduce energy consumption when the path re-selection process is executed. However, it is hard to guarantee optimized secure routing path at all times since the information using the path re-selection process is limited in scope. In this paper, we propose partial path selection method in each subregion using preselected partial paths made by RSPSM for routing path optimization in SEF based sensor networks. In the proposed method, the base station collects the information of the all partial paths from every subregion and then, evaluates all the candidates that can be the optimized routing path for each node using a evaluation function. After the evaluation process is done, the result is sent to each super DN using the global routing path information (GPI) message. Thus, each super DN provides the optimized secure routing paths using the GPI. We show the effectiveness of the proposed method via the simulation results. We expect that our method can be useful for the improvement of RSPSM.

• The KSFM Journal of Fluid Machinery
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• v.10 no.3 s.42
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• pp.33-38
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• 2007

Fan selection procedure and fan noise evaluation method are presented for the system electronic cooling by combining FNM(Flow Network Model) and fan noise correlation model. Internal flow paths and distribution in electronic system we analyzed by using the FNM with the flow resistances for flow elements of the system. Based on the fan operation point predicted from the FNM analysis results, the present fan noise model predicts overall sound power, pressure levels and spectrum. The predictions of the flow distribution, the fan operation and the noise level in electronic system by the present method are well agreed with 3-D CFD and actual test results.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.830-836
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• 2007

This paper is concerned with identifying the importance of the pre-qualification factors used in selecting contractors and also in determining the importance of various criteria used for the award of contract. The study was carried out through questionnaire survey administered to a population of 60 respondents in consultancy and client's organisation. The data analysis included a statistical comparison of means and interpretation. The result of this study showed that experience of the contractor is the most important prequalification factor while technical expertise is the most important criteria in the award of contract. The result of this study will enable clients, consultants and contractors to lay emphasis on the influencing factors in terms of pre-qualification and award of contract.

• Journal of the Ergonomics Society of Korea
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• v.31 no.3
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• pp.437-444
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• 2012

The purpose of this study was to suggest appropriate human model for ergonomic evaluation considering working postures on 3D space. Background: Traditionally extreme design rules have been widely utilized at the stage of designing products. Body size of 5th percentile and 95th percentile in stature has been generally selected for controllability and clearance evaluation, respectively. However, these rules had limitations in reflecting working posture in ergonomic evaluation. Method: In order to define working posture on 3D space, not only sagittal plane but also lateral plane was considered. Kinematic linkage body model was utilized for representation of working posture. By utilizing the anthropometric data of 2,836 South Korean male populations, the point cloud for end points of linkage models was derived. The individuals who were lacking in certain controllability were selected as human models for the evaluation. Result: In case of standing posture it was found that conventional approach is proper for all controllability evaluations. Contrary to standing posture, tall people had less controllability on control location below shoulder point in sitting posture. Conclusion: From the derived proper range on controllability, ergonomic evaluation rule was suggested according to working posture especially in standing and sitting. Application: The results of the study are expected to aid in selection of appropriate human model for ergonomic evaluation and to improve the usability of products and work space.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.37-40
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• 2001

This paper describes the selection and evaluation of RP processes. Major rapid prototyping processes such as SLS, SLA, FDM and LOM, which are wide spread in use are selected. A test part, which includes various primitives, is designed in order to evaluate these RP processes. Measurement of the test part is automated by using a CMN program. To visualize and analyze measured data, Microsoft Access and Visual C++ are used. Also, from measured data obtained, TOPSIS, one of the decision making methods, and Shannon Entropy is used to select an appropriate RP process for specific application.

• Korean Management Science Review
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• v.18 no.2
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• pp.73-85
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• 2001

Recently increasing amount of efforts has been devoted to the improvement of logistics in the marine products industry. Yet, few studios have been conducted on the development of site selection models of marine products centers. This paper Proposes a systematic assessment model for the decision making, which is composed of a set of evaluation criteria and an appropriate evaluation method. In choosing criteria we consider completeness and comprehensiveness to reach a right solution. For more flexibility of the model in the future, this study proposes two sets of criteria according to the size of planned centers. The Analytic Hierarchy Process (AHP) is adopted in this study, since the criteria incorporate both subjective factors and objective factors and the AHP is known effective in the situation. This study then illustrates the model application with plausible alternatives. Finally, a dependency problem in the decision criteria is discussed and the Analytic Network Process (ANP) is recommended, in the context, as e solution method.

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.226-235
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• 1999

The purpose of this study is to present models for evaluation and selection of Electronic Commerce systems suppliers. The Major concern of management is that almost all decision problems have multiple, usually conflicting, criteria. The fuzzified multi-objective programming models are given to accommodate the aspiration level and satisfaction level of decision makers. The proposed models are classified into three types, that is, min-operator. additive and pre-emptive priority. Numerical Examples illustrating each type of model are presented and the implications of these models are discussed.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.102-115
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• 2019

This study aims to establish and apply a drought vulnerability assessment plan including various factors related to drought. The evaluation technique consisted of three stages: evaluation factor and weight selection, evaluation data database construction, evaluation data and weight combination, and Delphi investigation method was applied to evaluation factor and weight selection. As the evaluation method, the TOPSIS method, which is a widely used MCDM method, was used. The results of the drought vulnerability assessment were applied to the administrative districts of Sigun-gu, Korea from March 2016 to September 2019. As a result of the evaluation, drought vulnerable areas were identified in Chungcheongbuk-do, Gyeongsangnam-do, and Jeollanam-do, and it was analyzed that it is necessary to establish drought response plans for these areas.

• Journal of Korea Society of Industrial Information Systems
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• v.2 no.2
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• pp.159-179
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• 1997

Traditionally, the evaluation and selection of suppliers have been a major purchasing function. A growing concern for just in-time purchasing, global sourcing, and long-term partnership between buyers and suppliers makes selecting a righ supplier become more critical decision making process. Consequently, a rigorous and systematic method for evaluation suppliers is a must. However, assessing the values of factors(e.g. qulaity , delivery, and service) selected for evaluating suppliers contains elements of uncertainty. Although several methods have been developed for uncertainty analysis, they may not be proper tools for evaluating suppliers under uncertainty. In this paper, a methodology using a fuzzy-set approach in combination with a multicriterion decision-making (MCDM) technique is developed to use as a tool for evaluating suppliers under uncertainty. An numerical example is presented to demonstrate the method in practice.