• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1522-1545
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• 2012

Call admission control (CAC) plays an important role in mobile cellular network to guarantee the quality of service (QoS). In this paper, a dynamic hybrid CAC scheme with integrated cutoff priority and handoff queue for mobile cellular network is proposed and some performance metrics are derived. The unique characteristic of the proposed CAC scheme is that it can support any number of service types and that the cutoff thresholds for handoff calls are dynamically adjusted according to the number of service types and service priority index. Moreover, timeouts of handoff calls in queues are also considered in our scheme. By modeling the proposed CAC scheme with a one-dimensional Markov chain (1DMC), some performance metrics are derived, which include new call blocking probability ($P_{nb}$), forced termination probability (PF), average queue length, average waiting time in queue, offered traffic utilization, wireless channel utilization and system performance which is defined as the ratio of channel utilization to Grade of Service (GoS) cost function. In order to validate the correctness of the derived analytical performance metrics, simulation is performed. It is shown that simulation results match closely with the derived analytic results in terms of $P_{nb}$ and PF. And then, to show the advantage of 1DMC modeling for the performance analysis of our proposed CAC scheme, the computing complexity of multi-dimensional Markov chain (MDMC) modeling in performance analysis is analyzed in detail. It is indicated that state-space cardinality, which reflects the computing complexity of MDMC, increases exponentially with the number of service types and total channels in a cell. However, the state-space cardinality of our 1DMC model for performance analysis is unrelated to the number of service types and is determined by total number of channels and queue capacity of the highest priority service in a cell. At last, the performance comparison between our CAC scheme and Mahmoud ASH's scheme is carried out. The results show that our CAC scheme performs well to some extend.

• Journal of the Korea Society of Computer and Information
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• v.24 no.9
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• pp.59-67
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• 2019

The service composition based on Service-Oriented Architecture(SOA) can make us view various machines or its functionalities in the Web or Internet-of-Things environment as 'service', and efficiently create new value-added services that users want by compositing different services if there is no service to satisfy the client. The service composition problem with respect to behavioral descriptions deals with the automatic synthesis of a coordinator service that controls a set of services to reach a goal state. Despite its importance, however, solving the service composition problem with only partial observations remains to be doubly exponential in the number of variables in service descriptions, rendering any attempts to compute an exact solution for modest size impractical. Toward this challenge, in this paper, we propose novel approximation-based approaches using abstraction methods. We empirically validate that our proposals can solve realistic problems efficiently.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1385-1391
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• 2016

Background: To investigate the prevalence of and factors associated with performance of annual mammography by women above 40 years of age. Materials and Methods: This cross-sectional retrospective study was conducted at an oncology reference service in Southern Brazil from October 2013 to October 2014 with 525 women aged 40 years or older. Results: The prevalence of annual mammography was 54.1%; annual mammographic screening was performed for women without private medical insurance, who were under hormone replacement therapy and who had used contraception in the past. An association was found between non-performance of breast clinical and self-examination and non-performance of mammographic screening. Conclusions: Use of mammography for breast cancer screening in the public health care setting proved to be accessible; nevertheless, the proportion of screened women was low, and they exhibited poor adherence to the basic measures of care recommended for breast assessment. Thus, control of breast cancer requires implementing actions targeting the population most vulnerable to non-adherence to screening in addition to continuously monitoring and assessing that population to reduce the prevalence of this disease.

• The Journal of Korea Robotics Society
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• v.19 no.2
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• pp.196-202
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• 2024

The ability to understand given environments and plan a sequence of actions leading to goal state is crucial for personal service robots. With recent advancements in deep learning, numerous studies have proposed methods for state representation in planning. However, previous works lack explicit information about relationships between objects when the state observation is converted to a single visual embedding containing all state information. In this paper, we introduce graph-based state representation that incorporates both object and relationship features. To leverage these advantages in addressing the task planning problem, we propose a Graph Neural Network (GNN)-based subgoal prediction model. This model can extract rich information about object and their interconnected relationships from given state graph. Moreover, a search-based algorithm is integrated with pre-trained subgoal prediction model and state transition module to explore diverse states and find proper sequence of subgoals. The proposed method is trained with synthetic task dataset collected in simulation environment, demonstrating a higher success rate with fewer additional searches compared to baseline methods.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.3
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• pp.147-163
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• 2022

The relocation policy of public Institutions throughout provincial areas that implemented for the purpose of "balanced national development" finished in 2019 with the last relocation of the Korea Institute of Science & Technology Evaluation and Planning, which moved to Chungbuk Innovation City. Electric power public corporations also completed relocation program over eight regions across the nation. This study was conducted empirically to identify the structural relationship between the public service motivation and job attitude. In this, the relationship of organizational change, particularly occurred by the regional relocation, with the psychological state of these organization members (experienced direct changes and got substantial impacts in various aspects such as psychological, economic and living environment, etc.,) was studied. This study aims to seek early organizational stabilization ideas for electric power public corporations after relocation, and to present some implications that can contribute to the secondary relocation of public institutions to local areas. This study shows the statistically significant relationship between the psychological state occurred by relocation and organizational commitment. The result shows that the higher the expectation levels, the higher the degree of organizational commitment, while anxious psychological state has no relation with that. Additionally, expectation level has no significant functional relation with turnover intention. Followings are the major conclusions revealed in this study; The stronger the anxious psychological state, the higher the turnover inducement goes up. The higher the expectation levels, the higher the public service motivation grows, and the higher the anxiety psychological state, the public service motivation lowers. The organizational commitment grows according to the public service motivation proportionally, but the turnover inducement intention is weak. The moderating effect of public service motivation between the expectation of organizational change and turnover intention was not significant, but it was analyzed that the moderating effect of public service motivation formed a significant relationship with other anxiety psychology. The expectation levels of employees of electric power public corporations has grown up after moving to provincial areas. Relationship between the expectation mind and the turnover inducement has decreased after local relocation.

• Fashion, Industry and Education
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• v.15 no.2
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• pp.53-63
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• 2017

The growing significance of corporate social responsibility in the fashion industry has shed light on the importance of preparing fashion students to become socially responsible professionals. In spite of numerous benefits of service-learning, the teaching/learning method has been rarely employed in the fashion design and merchandising context. Therefore, the purpose of the study was first, to examine the concept and models of service-learning and compare different types of service-learning programs, and second, to discuss service-learning projects that were adopted in a visual design class as examples that service-learning can be effectively integrated into the fashion design and merchandising curriculum. This study provides the opportunity to share successful service-learning implementation with other educators to help with effective incorporation of the pedagogical program into the curriculum.

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.192-193
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• 2005

• Journal of Digital Convergence
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• v.9 no.6
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• pp.39-55
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• 2011

Since telecommunications reforms began around world in the 1980s, many scholars have attempted to uncover its effects on the telecommunications sector. Nevertheless, research focusing largely on the impact of privatization on universal service has been relatively less frequent than other research on telecommunications reform such as the effect of competition on efficiency, investment, and universal service, and the impact of privatization on efficiency. From this perspective, this study attempted to explain the impact of the privatization of a state-owned telecommunications enterprise on universal service in Korea. This work may contribute to providing policy-makers and scholars in telecommunications with some useful policy suggestions by concretely illustrating how the privatization of Korea Telecom has influenced universal service policy formulation and the universal service system in Korea.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.183-191
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• 2016

Most recent trend reveals broader state of provision of NFC service as NFC technology was applied on smartphones which has become core communication tools by providing integrated services such as payment, medical, and personal authentication. Moreover, with integration of original service and NFC technology, new service providers now can handle personal information of original service or can handle other personal information with transition of previous service provider to NFC service provider. Considering current state of security industry along with NFC technology and service, we would like to analyze current stage of security threats and plan the counter strategies to create NFC service structure.

• Journal of Korean Society of Rural Planning
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• v.18 no.3
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• pp.91-101
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• 2012

The purposes of this study were to identify the living environment in rural fishing area and to suggest checking methods for implementation performance. Rural service standard is the key factor of rural development in Korea. In 2012. The first Implementations of performance was announced. The results were presented to the unit by the City and the County. Because of Fishing villages exists as a unit by the haengjeongri. It is difficult to know the status of the fishing villages by the Rural service standard. In order to look for the actual conditions in rural fishing village it was investigated in the 100 Eochongye. The data used in the analysis is 577 questionnaires. Analysis showed that rural fishing areas were superior to general state of rural in the 8 items of rural service standard. Especially housing, transportation and health care sector in rural fishing area wes better than general state of rural. But Public safety and order is relatively poor. This is because Fishing village contains islands. Presenting to improve rural service standard based on the results of research. The items of rural service standard should be measured the actual residents' accessibility than opportunity of the public service, and after setting the rural service standard clearly related to the quality of life of residents in each sector. Accessibility aspects of the customer for the public services should be considered. Checking the performance for the unit by the City and the County should be replaced as a living zone in order to consider the facilities using nearby.