• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2469-2490
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• 2019

A low-energy adaptive clustering hierarchy (LEACH) protocol is a low-power adaptive cluster routing protocol which was proposed by MIT's Chandrakasan for sensor networks. In the LEACH protocol, the selection mode of cluster-head nodes is a random selection of cycles, which may result in uneven distribution of nodal energy and reduce the lifetime of the entire network. Hence, we propose a new selection method to enhance the lifetime of network, in this selection function, the energy consumed between nodes in the clusters and the power consumed by the transfer between the cluster head and the base station are considered at the same time. Meanwhile, the improved FTBA algorithm integrating the curve strategy is proposed to enhance local and global search capabilities. Then we combine the improved BA with LEACH, and use the intelligent algorithm to select the cluster head. Experiment results show that the improved BA has stronger optimization ability than other optimization algorithms, which the method we proposed (FTBA-TC-LEACH) is superior than the LEACH and LEACH with standard BA (SBA-LEACH). The FTBA-TC-LEACH can obviously reduce network energy consumption and enhance the lifetime of wireless sensor networks (WSNs).

• Journal of Korean Academy of Nursing
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• v.42 no.3
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• pp.311-321
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• 2012

Purpose: This study was designed to construct and test a structural equation modeling on specific domain health status and the Selection Optimization Compensation (SOC) strategy affecting successful aging in elderly people. Methods: The model construction was based on the SOC model by Baltes and Baltes. Interviews were done with 201 elderly people aged 65 or older. Interview contents included demographics, functional health status, emotional health status, social health status, SOC strategies, and successful aging. Data were analyzed using SPSS 15.0 and AMOS 7.0. Results: Model fit indices for the modified model were GFI=.93, CFI=.94, and RMSEA=.07. Three out of 7 paths were found to have a significant effect on successful aging in this final model. Functional health status had a direct and positive effect on successful aging. Emotional health status influenced successful aging through SOC strategies. Conclusion: This study suggests that interventions for improving functional health status and for strengthening SOC strategies are critical for successful aging. Continuous development of a variety of successful aging programs using SOC strategy is suggested.

• Journal of IKEEE
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• v.22 no.3
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• pp.570-577
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• 2018

With the increasing number of network nodes, traditional client/server node selection mechanisms are under tremendous pressure. In order to select efficient cooperative nodes in a highly dynamic P2P network topology, this article uses greedy algorithm to translate the overall optimization into multiple local optimal problems, and to quickly select service nodes. Therefore, the service node with the largest comprehensive capacity is selected to reduce the transmission delay and improve the throughput of the service node. The final simulation results show that the node selection strategy based on greedy algorithm can effectively improve the overall performance of P2P streaming media system.

• International Commerce and Information Review
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• v.12 no.4
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• pp.279-302
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• 2010

A better selection model on management innovative enterprises is needed since the Korean government provides multi benefits to those selected enterprises. However, the selection model's propriety is suspicious because of the shortage of consideration of assessment items. In particular, the most important two assessment items, strategy and performance are suspected of multicollinearity because of high correlation scores. No consideration on multicollinearity among those items leads to erroneous selection which doubly counts the same components with different item names. The principle component analysis is applied to factor out the uncorrelated items. Using the resulted principle components, the new estimations are carried out. The comparison between estimated results from using principle components and non principle components shows that the present selection model overly considers the performance items compared to the real effect of items, which is a result of multicollinearity between performance and strategy.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.591-597
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• 2001

In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control school is based on clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.

• Research in Mathematical Education
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• v.15 no.4
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• pp.357-371
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• 2011

In mathematical problem solving, students may make various errors. In order to draw useful lessons from the errors, and then correct them, we surveyed 24 eighth-grade students' performances in geometrical problem solving according to Casey's hierarchy of errors. It was found that: 1. Students' effect can lead to errors at the stage of "comprehension", "strategy selection", and "skills manipulation"; and 2. Students' geometric schemas also influenced their strategy selection".

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.217-231
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• 2019

The purpose of this study is to analyze the factors influencing consumers' selection of web-toon service through AHP (Analytic Hierarchy Process) analysis and to provide the strategy of web-toon service. To accomplish this study, theories, existing research and references related to AHP were sufficiently examined and selected the factors in the selection criteria. Surveys from consumers who used the web-toon service were conducted with selected factors. Through this, the results were analyzed by AHP analysis to find out the weighting values and the differences were examined and analyzed. The highest weighting factor in the first layer that consists of web-toon service was cinematic quality. The cinematic quality was the most important factor in the selection criteria of customers who use the web-toon service regardless of their preferred genre. Furthermore, it was confirmed that the weighting value or ranking changed in the second layer by genre. In this study, the effective basis of strategy were suggested by ranking the quantitative selection factors according to the preferred genre of consumers using web-toon services. In addition, This research provides some practical implications. That is, the web-toon service provider can easily recognize and respond to the customer's requirements, which factors are important when the customer selects a specific genre from the web-toon genre.

• East Asian Journal of Business Economics (EAJBE)
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• v.4 no.2
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• pp.48-60
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• 2016

This study analyzes what effects does restaurant's well-being attribute selection have on word-of-mouth intention. Based on the result, this study aims to provide basic data for establishing Korean restaurant's service strategy and marketing strategy. The researchers surveyed 350 customers who visited a Korean restaurant located in Kangbook, Seoul. We encoded gathered data and analyzed them using SPSS 17.0 statistics package program. Following are the analyzed results. First, under hypothesis 1 - Korean restaurant's well-being attribute selection will have a positive influence on re-visitation intention - it is shown that sufficiency, healthiness, and steadiness have similar influence on re-visitation intention. Second, under hypothesis 2 - Korean restaurant's well-being attribute selection will have a positive influence on word-of-mouth intention - it is shown that sufficiency, healthiness, environment, and steadiness have similar influence on word -of-mouth intention. Third, under hypothesis 3 - Korean restaurant's re-visitation intention will have a positive influence on word -of-mouth intention - it is considered that eliciting customer's re-visitation intention also has influence on word-of-mouth intention. We will be necessary to consult how to derive customer's re-visitation intention or word-of-mouth intention by considering factors which customers of traditional Korean restaurant value.

• Journal of Korea Port Economic Association
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• v.33 no.4
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• pp.37-58
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• 2017

The implicit assumption of port selection studies based on survey and respondents' perceptions is that the preference of the port selection attributes is proportional to the selection behavior. Further, the straight lines of the port selection attributes could also have non-linear properties. This study confirms nonlinear characteristics of selection attributes by using Kano model. The findings of this study showed that several properties of carriers were evaluated as nonlinear characteristics, such as the intermodal links and network accessibility, and size of port and terminal. Hence, port service providers such as port authorities and terminal operating companiesl, should construct a port operation strategy that reflects the non-linear port selection characteristics of shipping companies. Since this study aimed at exploring the forms of port selection characteristics, long-term additional verification studies on ports and stakeholders at domestics and abroad were needed. The Kano model and importance-selection analysis method used for analysis and strategy establishment also need to be improved to capture evident characteristics and to present strategic guidelines.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.9
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• pp.1513-1527
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• 2011

This paper investigates the capacity rate problems for a joint decode-and-forward (JDF) based two-way relaying with network coding. We first characterize the achievable rate region for a conventional three-node network scenario along with the calculation of the corresponding maximal sum-rate. Then, for the goal of maximizing the system sum-rate, opportunistic relay selection is examined for multi-relay networks. As a result, a novel strategy for the implementation of relay selection is proposed, which depends on the instantaneous channel state and allows a single best relay to help the two-way information exchange. The JDF scheme and the scheme using relay selection are analyzed in terms of outage probability, after which the corresponding exact expressions are developed over Rayleigh fading channels. For the purpose of comparison, outage probabilities of the amplify-and-forward (AF) scheme and those of the scheme using relay selection are also derived. Finally, simulation experiments are done and performance comparisons are conducted. The results verify that the proposed strategy is an appropriate method for the implementation of relay selection and can achieve significant performance gains in terms of outage probability regardless of the symmetry or asymmetry of the channels. Compared with the AF scheme and the scheme using relay selection, the conventional JDF scheme and that using relay selection perform well at low signal-to-noise ratios (SNRs).