• Environmental and Resource Economics Review
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• v.20 no.1
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• pp.119-153
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• 2011

This study reviews various aspects of model formulating processes of dichotomous choice responses of the contingent valuation method (CVM), which has been increasingly used in the preliminary feasibility test of Korea public investment projects. The theoretical review emphasizes the consistency between WTP estimation process and WTP measurement process. The empirical analysis suggests that two common parametric models for dichotmous choice responses (RUM and RWTP) and two commonly used probability distributions of random components (probit and logit) resulted in all most the same empirical WTP distributions, as long as the WTP functions are specified to be a linear function of the bid amounts. However, the efficiency gain of DB response compared to SB response were supported on the ground that the two CV responses are derived from the same WTP distribution. Moreover for the exponential WTP function which guarantees the non-negative WTP measures, sample mean WTP were quite different from median WTP if the scale parameter of WTP function turned out to be large.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.639-645
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• 2015

Recently, a study on the commercialization of Rope type Platform Safe Door (RPSD) technology has commenced. The study focuses on RPSD, in which a rope screen ascends to allow safe passage from the platform to the transit vehicle in aboveground stations. Currently, a pilot installation has taken in place with Daegu Metro Line 2 in MoonYang station starting from March of 2013. However, there is a need to select an appropriate pilot installation's object for the improvement in the future RPSD. An appropriate designation would correspond with the needs of the railroad corporation and as a historic railway platform with safe facilities. This study tried to usa Analytic Hierarchy Process (AHP) to determine the priority of the KTX stations to attain a list of appropriate designations for future RPSD installations by analyzing the followings: management of the facilities, operational risks, and intent of business projects. As a case study, it was applied to the evaluation of the KTX stations. For the application, it used relative measurement to calculate the weight of upper level structuring, and absolute measurement for low level structuring instead of pairwise comparisons.

• The Journal of the Korea Contents Association
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• v.19 no.11
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• pp.33-45
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• 2019

The operation of the theater's seasonal program is an important service for the stability of theater management and audience development. However, the domestic theater season system has been around for 20 years, but still has not been established in practice compared to overseas theaters, and academic research is also lacking. Therefore, in this study, the government wanted to draw out elements of 'season system' program services and additional services provided by domestic and foreign theaters, and to calculate the importance of each attribute to suggest a plan to operate a seasonal service suitable for the actual conditions in Korea. Thus, through the analysis of seven theater seasonal programs, a study model consisting of two higher, seven median and 23 lower factors was derived. Based on this survey, 14 theater experts were asked to compare the priorities of each factor. Studies have shown that the composition of packages and works in program services is important, and that monetary factors are important in additional services. In other words, an important element in the seasonal system is judged to be the need to upgrade program services and selectively operate a small number of additional services with large audience needs to attract audiences.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.55-59
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• 2016

Conventional RF energy harvesting systems can harvest energy and decode information from same source as an Hybirid-AP (H-AP). However, harvesting efficiency is seriously dependent on distance between users and H-AP. Therefore, in this paper, we proposed a transmission model for RF harvesting consisting of information and power source separately called Decoupled RF Energy harvesting networks. Main purpose of this paper is to maximize energy efficiency under various constraints of transmit power from H-AP and power beacon (PB), minimum quality of service and quality of harvested power of each users. To measure proposed model's performance, we proposed optimal time scheduling algorithms for energy efficiency (EE) maximization using Lagrangian dual decomposition theory that locally maximizes the EE by obtaining suboptimal values of three arguments : transmit power of H-AP, transmit power of PB, frame splitting factor. Experiment results show that the proposed energy-efficient algorithms converge within a few iterations with its optimality and greatly improve the EE compared to that of baseline schemes.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.417-429
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• 2015

Evaluation of traffic data quality is a backbone of better traffic information and management systems because it directly affects the reliability of traffic information. This study developed an integrated index for evaluating the quality of archived intelligent transportation systems (ITS) data. Two novel indices including spatio-temporal consistency and severity of missing data were devised and integrated with existing indices such as availability and completeness. An evaluation framework was proposed based on the developed integrated index. Both analytical hierarchical analysis (AHP) technique and entropy method were adopted to derive mixed weighting values to be used for the integrated index. It is expected that the proposed methodology would be effectively used in enhancing the quality of traffic data as a part of traffic information system.

• Journal of Technology Innovation
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• v.27 no.3
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• pp.83-112
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• 2019

As more and more patents for new technology are issued, companies and organizations are interested in managing patents systematically so that the patents should be a valuable asset rather than burden. In this study we propose the method to select superior patents effectively using QFD. First, what firms want in the patents that have long been accumulated is identified and appropriate patent indices are derived to illustrate how the firm's requirements are satisfied. Then the importance of firm's requirements and their relationship with patent indices are determined through AHP's pairwise comparison. Finally, the results are analyzed and demonstrated with the case of a real company, which shows that patents are sorted out well according to the firm's requirements.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.10
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• pp.936-942
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• 2015

This paper suggests the significant strategies and their priority to deal with space transportation market trends. First, market trends related with technical improvement and change in demand are analyzed by the literature research. The three key trends are obtained: 'Increasing Demand of High-Performance Launch Vehicles', 'Rising of Low-Price Launch Vehicles', and 'Rising of Dual/Multi-Launch'. And then, strategies for developing the launch vehicle industry in Korea are selected from several studies about commercialization of Korean launch vehicle. The strategies are evaluated by the experts through pairwise comparison matrix and the criteria for this process is how significantly does the strategy effect on the launch vehicle industry through market assessment. As a result, reliable order of priority among the strategies are obtained. Under the three key trends, strategy to enhance reliability is most important. And, strategy to have price competitiveness has secondary priority to deal with 'Rising of Low-Price Launch Vehicles' trend and 'Rising of Dual/Multi-Launch' trend. On the contrary, strategy of government's support is secondary under 'Increasing Demand of High-Performance Launch Vehicles' trend.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.107-117
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• 2011

Smartphones are widely used as a mobile communication devices with more advanced computing ability and connectivity than a contemporary feature phone. As the market expands, many brand-new smartphones are released and chosen by (potential) smartphone users. In spite of smartphone's popularity, little research of the factors affecting the evaluation of smartphones and their influences on smartphone choice have been performed. Therefore, we aim to analyze evaluation factors of smartphone selection and use in this research. We use Fuzzy Analytic Hierarchy Process method, a Multi-Criteria Decision Making (MCDM) model, to find the relative importance among the factors considering the fuzziness of pair-wise comparison using AHP. After reviewing related works and interviewing the focus group, we extract the five independent factors influencing the choice and use of a smartphone. Pair-wise comparison and triangle fuzzy numbers are used to calculate the relative importance of factors. We analyze not only the whole interviewees' responses, but the differences between smartphone users and non-users. Practical implications are delivered in concluding remarks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12C
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• pp.764-773
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• 2011

Despite enormous performance gain with multi-antenna transmission in the single cell environment, its gain diminishes out in the multi-cell environment due to interference. It is also very hard to solve the efficient downlink beamforming with low complexity in multi-cell environment. First, this paper shows that the asymptotically sum rate optimal downlink beamformings at low and high SNR are maximum ratio transmit (MRT) and zero forcing (ZF) beamforming in the multi-cell system, respectively. Secondly, exploiting the asymptotically optimal downlink beamforming, we develop simple two types of near optimal downlink beamforming schemes having the form of minimum mean squared error (MMSE) beamforming obtained from the dual uplink problem. For each type, three different subclasses are also considered depending on the computational complexity. The simulation results show that the proposed near optimum algorithms provide the trade-off between the complexity and the performance.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.183-195
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• 2014

This study aims at identifying and prioritizing the application areas for business development of IoT(Internet of Things). In specific, we collected the opinions of the experts on IoT in Korea through the survey based on pairwise comparison, and then we analyzed them using AHP(analytic hierarchy process). As a result, we found that 'Public Safety & Security', 'Automotive & Transportation', and 'Utility & Energy' are the most promising area in realizing IoT-related businesses. Also, we found that the experts had different views according to the positions of their industry in IoT value chain. The analysis showed that the device industry prioritizes 'Public Safety & Security', whereas the network industry does 'Automotive & Transportation'. The experts from the service industry were found to regard 'Utility and Energy' as the most promising commercialization area of IoT.