• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.24-32
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• 2006

This paper is to analyze the effectiveness of multistatic sonar network based on detection performance. The multistatic sonar network is a distributed detection system that places a source and multi-receivers apart. So it needs a detection technique that relates to decision rule and optimization of sonar system to improve the detection performance. For this we propose a data fusion procedure using Bayesian decision and optimal sensor arrangement by optimizing a bistatic sonar. Also, to analyze the detection performance effectively, we propose the environmental model that simulates a propagation loss and target strength suitable for multistatic sonar networks in real surroundings. The effectiveness analysis on the multistatic sonar network confirms itself as a promising tool for effective allocation of detection resources in multistatic sonar system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.766-774
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• 2004

The future mobile communication system can support not only voice but also multimedia applications such as data, image and video. It requires greater resources than the voice-oriented mobile system. Efficient resource reservation and hand-over schemes are necessary to maintain the same QoS of transmitted multimedia traffic because the QoS may be defected by some delay and information loss during hand-over. This paper proposes a resource reservation scheme to accommodate multimedia traffics in mobile multimedia networks. In our scheme the position of mobile is estimated in two steps, that is, sector estimation and zone estimation. With this position information, the moving direction is determined. According to simulation results, our scheme provides a better performance than conventional methods.

• Journal of Technology Innovation
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• v.10 no.1
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• pp.22-37
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• 2002

The importance of selecting the strategic research field is increasingly emphasized by research manager and technology policy-maker in perspective of the strategic allocation of R&D resources, employing the R&D personnel, and formulating technology policy. Among various methods for selecting the strategic research field, it is, however, very difficult to find the method that involves the path-dependant trend, and interdisciplinary nature of technology development. This study suggests modified technology cluster analysis (TCA) as a method for selecting strategic research field in order to include the recent technology trend in quantitative approach. TCA is the method that groups the near technologies of which the innovation pattern is similar. TCA model can be a very necessary method for multidisciplinary government research institutes (GRIs) which conduct multi research field with forward oriented positioning. It is more difficult for them to select the strategic research field mainly due to their diversity and intangibility of research scope. In this study, we applied this method to Korea Institute of Science and Technology (KIST) which represents the most adequate research institute in terms of research diversity and forwardness. As a result of the application, we found that seven main technology groups come from TCA analysis, coincide with the technology topics of KIST's recent R&D planning. Even though this method designed for multidisciplinary research institutes, but it also can be used for establishing the research strategy of other (private or public) Research Institute which have the similar mission and scope of research.

• Korean System Dynamics Review
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• v.16 no.3
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• pp.77-96
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• 2015

This study aims to forecast of the number of smart phone addicted youths and to evaluate the effect of rehabilitation programs. A system dynamics model is developed to describe the processes of addiction and transits between phases as well as the diffusion of smart phones. The youths are grouped into non users, general users, potential risky users, and high risky users. The model utilizes the population distributions over ages for the next 30 years forecasted by Korean Government. The number of youths decreases for the next decade or so, and the number of youths who owns smart phone will reach maximum at 2017. As for the rehabilitation programs, the model includes the preventive education for general users, counseling for potential risky users, and professional therapy for high risky users. The preventive education restricts the transit from general users to potential risky users. Counseling increases the transit from potential risky users to general users while it decreases the transit to high risky users. Professional therapy improves transit to potential risky users and to general users. Although the model cannot be validated the accuracy owing to the lack of data, it describes these transit within the reasonable ranges and can be used to study the allocation of the limited resources to maximize the outcome.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1642-1661
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• 2015

Wireless mesh networks are a special type of broadcast networks which cover the qualifications of both ad-hoc as well as infrastructure mode networks. These networks offer connectivity to the last mile through hop to hop communication and by comparatively reducing the cost of infrastructure in terms of wire and hardware. Channel assignment has always been the focused area for such networks specifically when using non-overlapping channels and sharing radio frequency spectrum while using multiple radios. It has always been a challenge for mesh network on impartial utilization of the resources (channels), with the increase in users. The rational utilization of multiple channels and multiple radios, not only increases the overall throughput, capacity and scalability, but also creates significant complexities for channel assignment methods. For a better understanding of research challenges, this paper discusses heuristic methods, measurements and channel utilization applications and also examines various researches that yield to overcome this problem. Finally, we highlight prospective directions of research.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.885-892
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• 2020

The purpose of this study was to determine the social engagement network in Sido Muncul's CSR, the partnership program with farmers, and how the implementation of corporate social entrepreneurship in the program is carried out. The research design uses qualitative methods with a grounded theory approach that tests the validity and reliability of the data using triangulation of data sources and methods, namely, data obtained through documentation and the results of surveys and interviews to more than one observation unit. Data was obtained from surveys and interviews with Sido Muncul's Public Relations and CSR Division, as well as partner farmers. The results of this study indicate that the social engagement network in Sido Muncul's partnership program is related to the role of farmer groups, farmer cooperatives, government, NGOs, universities, and private companies as facilitators and control functions, thus creating mutually beneficial relationships with one another. The process of implementing corporate social entrepreneurship in Sido Muncul's CSR for the partnership program with farmers consists of nine stages: problem identification, coordination with related parties, allocation of resources and commitments, collaboration with NGOs, local entrepreneurs and government, social innovation and the creation of new businesses, documentation of activities, reporting, monitoring and evaluation, as well as publications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1501-1505
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• 2004

The authentication system of high-speed internet in IP-infra is not warm enough to administration of systematic authentication information for user's legalization, connection right and resources allocation in order to both methods of authentication-unauthentication connection system according to transmission method . Also unauthentication connection raises a difficulty condition to user's needs satisfaction in order to a load weighting of system and network and a drop of transmission speed. Accordingly, this study brings forth authentication system construction in a high-speed IP infrastructure using spam sever able to construct the suitable network condition according to unifying authentication-unauthentication system for single authentication system.

• Nuclear Engineering and Technology
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• v.40 no.5
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• pp.327-348
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• 2008

A risk-informed regulatory approach implies that risk insights be used as supplement of deterministic information for safety decision-making purposes. In this view, the use of risk assessment techniques is expected to lead to improved safety and a more rational allocation of the limited resources available. On the other hand, it is recognized that uncertainties affect both the deterministic safety analyses and the risk assessments. In order for the risk-informed decision making process to be effective, the adequate representation and treatment of such uncertainties is mandatory. In this paper, the risk-informed regulatory framework is considered under the focus of the uncertainty issue. Traditionally, probability theory has provided the language and mathematics for the representation and treatment of uncertainty. More recently, other mathematical structures have been introduced. In particular, the Dempster-Shafer theory of evidence is here illustrated as a generalized framework encompassing probability theory and possibility theory. The special case of probability theory is only addressed as term of comparison, given that it is a well known subject. On the other hand, the special case of possibility theory is amply illustrated. An example of the combination of probability and possibility for treating the uncertainty in the parameters of an event tree is illustrated.

• Journal of Communications and Networks
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• v.8 no.3
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• pp.330-338
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• 2006

Many web cache systems and policies concerning them have been proposed. These studies, however, consider large objects less useful than small objects in terms of performance, and evict them as soon as possible. Even if this approach increases the hit rate, the byte hit rate decreases and the connections occurring over congested links to outside networks waste more bandwidth in obtaining large objects. This paper puts forth a client-cluster approach for improving the web cache system. The client-cluster is composed of the residual resources of clients and utilizes them as exclusive storage for large objects. This proposed system achieves not only a high hit rate but also a high byte hit rate, while reducing outgoing traffic. The distributed hash table (DHT) based peer-to-peer lookup protocol is utilized to manage the client-cluster. With the natural characteristics of this protocol, the proposed system with the client-cluster is self-organizing, fault-tolerant, well-balanced, and scalable. Additionally, the large objects are managed with an index based allocation method, which balances the loads of all clients well. The performance of the cache system is examined via a trace driven simulation and an effective enhancement of the proxy cache performance is demonstrated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10A
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• pp.1512-1520
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• 2000

The wireless communication network is evolving toward IMT-2000 for providing various multimedia services. In order to accomplish this ultimate goal the effective schemes are required which can dynamically utilize the limited wireless resources based on different traffic characteristics of various services. This paper proposes a novel bandwidth allocation and call admission control scheme to transmit multimedia traffic based on the bandwidth reservation procedure using direction estimation in the IMT-2000 This scheme estimates the position of mobiles based on the mliticriteria decision making in which uncertain parameters such as RSS(Received Signal Strength), the distance between mobile and base station the moving direction and the previous location are participated in the decision process using aggregation function in fuzzy set theory. Its effectiveness is investigated by simulation.