• Korea Trade Review
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• v.41 no.3
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• pp.27-42
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• 2016

This study is to investigate seaport clustering by using meta-frontier and cross-efficiency models. Data covers the 13 Asian ports during 2009, 2010 and 2013 with 3 inputs(depth, total area, and number of cranes) and 1 output(TEU). Correlations coefficient from cross-efficiency matrix are used for measuring clustering dendrogram. After that, meta-frontier analysis for investigating whether the clustering using cross-efficiency method increases the meta-efficiency. Empirical main results are as follows: First, group efficiencies of Busan, Incheon, and Gwangyang ports are increased. Second, meta and group efficiencies of China ports are greater than those of Korean ports. Third, distortion of technology gap of Gwangyang is lower than that of Busan and Incheon. Fourth, Gwangyang, clustering with Ningbo, Chingtao, Tokyo and Caosung ports in 2009 and with Dubai port in 2013 can increase the efficiency. Fifth, to enhance the efficiency, Busan port should be clustered to group 2 in 2010 and group 1 in 2013, and Incheon port clustered to group 2 in 2010 and 2013. Fifth, it is empirically investigated that Busan, Incheon and Gwangyang ports can increase the efficiency by using Cross-efficiency and Meta-frontier models. Port policy planner should promote the clustering policy for Busan with Hong Kong, Shanghai, and Singapore, Incheon and Gwangyang with Chingtao, Nagoya, Ningbo, Tokyo, and Kaoshung ports.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.10-20
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• 2024

The conservation and restoration of wetlands are essential tasks for the sustainable development of human society and the environment, providing vital benefits such as biodiversity maintenance, natural disaster mitigation, and climate change alleviation. This study aims to analyze the strategic interactions and interests among various stakeholders using game theory and to provide significant grounds for policy decisions related to wetland restoration and development. In this study, hypothetical scenarios were set up for three types of cities: large, medium, and small. Stakeholders such as governments, development companies, environmental groups, and local residents were identified. Strategic options for each stakeholder were developed, and a payoff matrix was established through discussions among wetland ecology experts. Subsequently, non-cooperative game theory was applied to analyze Nash equilibria and Pareto efficiency. In large cities, strategies of 'Wetland Conservation' and 'Eco-Friendly Development' were found beneficial for all stakeholders. In medium cities, various strategies were identified, while in small cities, 'Eco-Friendly Development' emerged as the optimal solution for all parties involved. The Pareto efficiency analysis revealed how the optimal solutions for wetland management could vary across different city types. The study highlighted the importance of wetland conservation, eco-friendly development, and wetland restoration projects for each city type. Accordingly, policymakers should establish regulations and incentives that harmonize environmental protection and urban development and consider programs that promote community participation. Understanding the roles and strategies of stakeholders and the advantages and disadvantages of each strategy is crucial for making more effective policy decisions.

• Journal of Digital Convergence
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• v.11 no.2
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• pp.299-307
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• 2013

The aim of this paper is the improvement of identification performance and the reduction of computational quantities in the face recognition system based on SIFT-Grid. Firstly, we propose a composition method of integrated template by removing similar SIFT keypoints and blending different keypoints in variety training images of one face class. The integrated template is made up of computation of similarity matrix and threshold-based histogram from keypoints in a same sub-region which divided by applying SIFT-Grid of training images. Secondly, we propose a computation method of similarity for identify of test image from composed integrated templates efficiently. The computation of similarity is performed that a test image to compare one-on-one with the integrated template of each face class. Then, a similarity score and a threshold-voting score calculates according to each sub-region. In the experimental results of face recognition tasks, the proposed methods is founded to be more accurate than both two other methods based on SIFT-Grid, also the computational quantities are reduce.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.301-306
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• 2012

We propose a method for accurate image acquisition in a machine vision system in the present study. The most important feature is required by the various lenses to implement real and of the same high quality image-forming optical role. The input of the machine vision system, however, is generated due to the aberration of the lens distortion. Transformation defines the relationship between the real-world coordinate system and the image coordinate system to solve these problems, a mapping function that matrix operations by calculating the distance between two coordinates to specify the exact location. Tolerance Focus Lens caused by the lens aberration correction processing to Galvanometer laser precision machining operations can be improved. Aberration of the aspheric lens has a two-dimensional shape of the curve, but the existing lens correction to linear time-consuming calibration methods by examining a large number of points the problem. How to apply the Bilinear interpolation is proposed in order to reduce the machining error that occurs due to the aberration of the lens processing equipment.

• Journal of Digital Convergence
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• v.10 no.5
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• pp.67-78
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• 2012

Recently, the interesting of customers in online auto insurance is rapidly increasing. The one of major reasons is economical benefit. offline auto insurance products as a service formed high price. However, online auto insurance relatively formed low price. Thanks to these characteristics of online auto insurance has gained great popularity. Therefore, in purchasing online auto insurance, consumers carefully buy products of auto insurance. In this study, we classified the $2{\times}2$ matrix (online preference group, economic pursuit group, convenience oriented group, and carefulness approach group) in online auto insurance consumers focusing on the perceived benefits and price acceptance. From an economic point of view of consumers around the perceived benefits and price acceptance, we analyzed the relationships among easy of use, usefulness, attitude, and purchase intention in automobile e-shopping mall. The results of this study will provide the useful implications for the planing CRM(customer relationship management) strategy for improving purchase intention of customers to online insurance companies.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.97-104
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• 2018

Regarding seaport operation, a higher quality performance and increasing competitiveness are main goals to adapt to the evolution of international trade. This paper discusses about the competition among Southern Vietnam seaports concerning the strategic positioning analysis, by applying BCG method. This technique describes the performance of business based on two variables such as relative market share and average growth rate. The finding shows up different performances of 21 seaports and how the strategic positioning of each port changes in the period 2007-2016. After analyzing, this research pointed out the growth in strategic positioning of ports in Cai Mep-Thi Vai complex, gradually replacing Ho Chi Minh City-Dong Nai-Binh Duong and becoming the transportation hub of Southern Vietnam. Also, The results obtained would be helpful for port administrators and operators to establish short and long-term strategies to improve competitiveness in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1036-1057
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• 2013

Wireless body area network (WBAN) is a promising candidate for future health monitoring system. Nevertheless, the path to mature solutions is still facing a lot of challenges that need to be overcome. Energy efficient scheduling is one of these challenges given the scarcity of available energy of biosensors and the lack of portability. Therefore, researchers from academia, industry and health sectors are working together to realize practical solutions for these challenges. The main difficulty in WBAN is the uncertainty in the state of the monitored system. Intelligent learning approaches such as a Markov Decision Process (MDP) were proposed to tackle this issue. A Markov Decision Process (MDP) is a form of Markov Chain in which the transition matrix depends on the action taken by the decision maker (agent) at each time step. The agent receives a reward, which depends on the action and the state. The goal is to find a function, called a policy, which specifies which action to take in each state, so as to maximize some utility functions (e.g., the mean or expected discounted sum) of the sequence of rewards. A partially Observable Markov Decision Processes (POMDP) is a generalization of Markov decision processes that allows for the incomplete information regarding the state of the system. In this case, the state is not visible to the agent. This has many applications in operations research and artificial intelligence. Due to incomplete knowledge of the system, this uncertainty makes formulating and solving POMDP models mathematically complex and computationally expensive. Limited progress has been made in terms of applying POMPD to real applications. In this paper, we surveyed the existing methods and algorithms for solving POMDP in the general domain and in particular in Wireless body area network (WBAN). In addition, the papers discussed recent real implementation of POMDP on practical problems of WBAN. We believe that this work will provide valuable insights for the newcomers who would like to pursue related research in the domain of WBAN.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.509-516
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• 2015

Intangibility, measurement difficulty and irreversibility, which are the characteristics of service, have such problems as obscurity and uncertainty in quality evaluation. Technical entrepreneurship education, a sort of public service, also contains such characteristics of service. To objectively evaluate the service quality of technical entrepreneurship education, this paper drew up factors as hierarchical structure, centered on FAHP technique, and conducted pre-processing, inputted those factors into triangular fuzzy number fuzzy judgement matrix, and calculated their weights. In this manner, this paper proposed a TESE system, through which an analysis can be conducted by drawing relative importance and priorities of the factors. The proposed system can efficiently evaluate the qualitative technical start-up education service quality factors quantitatively in the diversely changing technical start-up environment in view of the highest result quality (41%), which means performance in the relative importance of major factors. Namely, this paper confirmed that clear decision making can be made through an experiment.

• Journal of Digital Convergence
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• v.16 no.8
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• pp.351-359
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• 2018

This study tries to figure out the precarious communication types between parents and their children. For this, the linguistic behavioral characteristics of the main characters in the movie "Daughter" were extracted from their dialogues with the matrix analysis and were conceptualized. These conceptual features were analyzed in the convergence way combined with Transactional analysis and Satir's communication theory. The result shows that the dysfunctional communication between parents and children deteriorates their relation and even could collapse it. Thus. for their whole relation, it is important that they keep the functional communication between them. The study suggested the need for the parental education and youth personality education which let them know how to facilitate their communication.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.311-317
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• 2015

It is important to analyze and offer specialized start-ups effect factors for collegians in order to systematically and successfully support technology-centered start-ups of collegians, whose social experience is insufficient. However, consistently changing start ups environmental analysis is difficult, which can be a problem, because technology-centered start-ups factor analysis is carried out depending on statistical package. This paper proposes an ATSA system that demonstrates effect factors on technology-centered start-ups decision making as a hierarchial structure by using AHP, inputs the effect factors to judgment matrix after pre-processing, calculates standardized values and weights, verifies consistency, and draws priorities through weights integration. It was confirmed that the ATSA system can efficiently support decision making for technology-centered start-ups by quantitatively analyzing qualitative factors through experiments by applying multi-criteria decision making to the analyses of start-ups founders' internal and external factors and various start-ups environments.