• Journal of Information Processing Systems
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• v.20 no.1
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• pp.38-52
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• 2024

The 5G is the 5th generation mobile network that provides enhanced mobile broadband, ultra-reliable & low latency communications, and massive machine-type communications. New services can be provided through multi-access edge computing, network function virtualization, and network slicing, which are key technologies in 5G mobile communication. However, these new technologies provide new attack paths and threats. In this paper, we analyzed the overall threats of 5G mobile communication through a literature review. First, defines 5G mobile communication, analyzes its features and technology architecture, and summarizes possible security issues. Addition, it presents security threats from the perspective of user devices, radio access network, multi-access edge computing, and core networks that constitute 5G mobile communication. After that, security requirements for threat factors were derived through literature analysis. The purpose of this study is to conduct a fundamental analysis to examine and assess the overall threat factors associated with 5G mobile communication. Through this, it will be possible to protect the information and assets of individuals and organizations that use 5G mobile communication technology, respond to various threat situations, and increase the overall level of 5G security.

• Journal of the Korea Society for Simulation
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• v.17 no.2
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• pp.91-103
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• 2008

In order to simulate the behavior of automated manufacturing systems, the performance of material handling systems should be measured dynamically. Multi-Agent technology could be well adapted for the development of simulator for distributed and intelligent manufacture systems. A multi-agent system is composed of one coordination agent and multiple application agents. Issues in AGVS simulator can be classified by the set-up and operating problems. Decisions on the number of vehicles, bi- or uni-directional guide-path, etc. are fallen into the set-up problem category, while deadlock tree algorithm and conflict resolution are in operating problem. In this paper, a multi-agent based deadlock-free simulator for automated guided vehicle system(AGVS) are proposed through the use of multi-agent technologies and the development of deadlock-free algorithm. In this AGVS simulator proposed, well-known Floyd algorithm is used to create AGVS Guide path, through which AGVS move. Also, AGVs avoid vehicle conflict and deadlock using check path algorithm. And Moving vehicle agents are operated in real-time control by coordination agent. AGV position is dynamically calculated based on the concept of rolling time horizon. Simulator receives and presents operating information of vehicle in AGVS Gaunt chart. The performance of the proposed algorithm and developed simulator based on multi-agent are validated through set of experiments.

• Korean Journal of Culture and Social Issue
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• v.20 no.1
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• pp.45-65
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• 2014

This study was designed to look into whether there is any mediated effect of psychological well-being and empowerment on the path of the negative emotions of mothers from multi-cultural families turning into the life satisfaction and tried to demonstrate empirically factors to mitigate the decline in the life satisfaction due to negative emotions of mothers from multi-cultural families. In addition, we verified the differences of psychological factors according to the characteristics of the sociology of population of mothers from multi-cultural families. For this, the survey was conducted with 400 mothers from multi-cultural families across the nation. The results are as follows. First, in case of negative emotions, there were differences among groups depending on ages, years of marriage and educational background. In case of psychological well-being and empowerment, there were differences among groups with different age, years of marriage, their own or their spouse's educational background. Second, as a result of looking into the path through which negative emotions turned into life satisfaction, there were the path effects between negative emotions and empowerment, between negative emotions and life satisfaction, and between psychological well-being and life satisfaction. This means that dealing properly with negative emotions can have positive impacts on the three dimensions of psychological well-being, empowerment, and eventually the life satisfaction. This study is meaningful in that it took psychological factors of mothers from multi-cultural families into consideration and the results can be used as useful data to come up with political measures for mothers from multi-cultural families in the future.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.519-524
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• 2007

One of the most important issues on the sensor network with resource limited sensor nodes is prolonging the network lifetime by effectively utilizing the limited node energy. The most representative mechanism to achieve a long lived sensor network is the clustering mechanism which can be further classified into the single hop mode and the multi hop mode. The single hop mode requires that all sensor nodes in a cluster communicate directly with the cluster head(CH) via single hop md, in the multi hop mode, sensor nodes communicate with the CH with the help of other Intermediate nodes. One of the most critical factors that impact on the performance of the existing multi hop clustering mechanism is the cluster size and, without the assumption on the uniform node distribution, finding out the best cluster size is intractable. Since sensor nodes in a real sensor network are distributed non uniformly, the fixed size mechanism may not work best for real sensor networks. Therefore, in this paper, we propose a new dynamic size multi hop clustering mechanism in which the cluster size is determined according to the distance from the sink to relieve the traffic passing through the CHs near the sink. We show that our proposed scheme outperforms the existing fixed size clustering mechanisms by carrying out numerical analysis and simulations.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.11
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• pp.43-53
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• 2010

Wide deployment of high resolution video services leads to active studies on high speed video processing. Especially, prevalent employment of multi-core systems accelerates researches on high resolution video processing based on parallelization of multimedia software. In this paper, we propose a novel parallel H.264/AVC decoding scheme on a multi-core platform. Parallel H.264/AVC decoding is challenging not only because parallelization may incur significant synchronization overhead but also because software may have complicated dependencies. To overcome such issues, we propose a novel approach called Multi-Threaded Parallelization(MTP). In MTP, to reduce synchronization overhead, a separate thread is allocated to each stage in the pipeline. In addition, an efficient memory reuse technique is used to reduce the memory requirement. To verify the effectiveness of the proposed approach, we parallelized FFmpeg H.264/AVC decoder with the proposed technique using OpenMP, and carried out experiments on an Intel Quad-Core platform. The proposed design performs better than FFmpeg H.264/AVC decoder before the parallelization by 53%. We also reduced the amount of memory usage by 65% and 81% for a high-definition(HD) and a full high-definition(FHD) video, respectively compared with that of popular existing method called 2Dwave.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.2
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• pp.116-127
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• 2015

The phenomenon of international migration since the 1980s comes to be born 'multi-cultural families support law' due to the foreign workers' inflow into labor market and to a rise in married female immigrants caused by globalization and diversification. Accordingly, the purpose of this study is to examine who are participants? given being led to the enactment of 'multi-cultural families support law' by which the social issue called multi-cultural family is highlighted as the public agenda. Also, the mobilization will be selected and explained among three types in mobilization model, outside initiative model, and inside access model in the process of driving by confirming it as the government's formal agenda out of social issues. With having the case characteristics in mind, the aim is to research by choosing a case analysis method that uses research theses & books, newspaper, daily newspaper, election pledges, civic group, internet, and seminar data based on the existing theory and model. The temporal scope is limited to the one from the time as saying "revise the Overseas Korean Act of opposing the banishment of migrant workers" in November 2003 to February 2008 when 'multi-cultural families support bill(alternative plan)' is legislated with agreement by the 7th plenary session for the 271th provisional session of the National Assembly.

• Journal of Families and Better Life
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• v.25 no.6
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• pp.43-57
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• 2007

The objective of this study is to identify the significance of haying many children, their motive of childbirth, patterns of investment in human capital, and their expectations of their children. For this purpose, thirteen mothers of multi-child families have been interviewed in depth. Key findings of the study are as follows. First, the significance of children in many-child families varied. The fundamental features were: symbol of strong ties between God and humans, proud existence displayable to others about their level of happiness, and a means of defining their identity. Second, the typical motives of the majority of interviewees to have many children were "unplanned" but "natural accommodation and adaptation." Third, striking aspects, in terms of many-child families' investment in human capital were to consider many-child families to be a community in itself as a great environment of teaming and to have to deal with issues of limits and impartiality when allocating resources of a limited income and parents' time. Fourth, expectations of parents for their children were "normal growth" and mediocrity, and they cited intangible human assets as the greatest gift to their children. This study will hopefully offer a new analytical perspective to the growing concerns of low birth rates and excessive zeal of parents for their children's education, and thereby lay the groundwork of methodological approaches for resolving such social problems.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.8
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• pp.689-696
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• 2001

Large-scale Multi-disciplinary Systems(LMS) such as transportation, aerospace, defense etc. are complex systems in which there are many subsystems, interfaces, functions and demanding performance requirements. Because many contractors participate in the development, it is necessary to apply methods of sharing common objectives and communicating design status effectively among all of the stakeholders. The processes and methods of systems engineering which includes system requirement analysis; functional analysis; architecting; system analysis; interface control; and system specification development provide a success-oriented disciplined approach to the project. This paper shows not only the methodology and the results of model-based systems engineering to Automated Guided Transit(AGT) system as one of LMS systems, but also propose the extension of the model-based tool to help manage a project by linking WBS (Work Breakdown Structure), work organization, and PBS (Product Breakdown Structure). In performing the model-based functional analysis, the focus was on the operation concept of an example rail system at the top-level and the propulsion/braking function, a key function of the modern automated rail system. The model-based behavior analysis approach that applies a discrete-event simulation method facilitates the system functional definition and the test and verification activities. The first application of computer-aided tool, RDD-100, in the railway industry demonstrates the capability to model product design knowledge and decisions concerning key issues such as the rationale for architecting the top-level system. The model-based product design knowledge will be essential in integrating the follow-on life-cycle phase activities. production through operation and support, over the life of the AGT system. Additionally, when a new generation train system is required, the reuse of the model-based database can increase the system design productivity and effectiveness significantly.

• Journal of Communications and Networks
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• v.18 no.5
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• pp.784-795
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• 2016

In this paper, we investigate the resource allocation problem in time-varying heterogeneous wireless networks (HetNet) with multi-homing user equipments (UE). The stochastic optimization model is employed to maximize the network utility, which is defined as the difference between the HetNet's throughput and the total energy consumption cost. In harmony with the hierarchical architecture of HetNet, the problem of stochastic optimization of resource allocation is decomposed into two subproblems by the Lyapunov optimization theory, associated with the flow control in transport layer and the power allocation in physical (PHY) layer, respectively. For avoiding the signaling overhead, outdated dynamic information, and scalability issues, the distributed resource allocation method is developed for solving the two subproblems based on the primal-dual decomposition theory. After that, the adaptive resource allocation algorithm is developed to accommodate the timevarying wireless network only according to the current network state information, i.e. the queue state information (QSI) at radio access networks (RAN) and the channel state information (CSI) of RANs-UE links. The tradeoff between network utility and delay is derived, where the increase of delay is approximately linear in V and the increase of network utility is at the speed of 1/V with a control parameter V. Extensive simulations are presented to show the effectiveness of our proposed scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.9
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• pp.8-15
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• 2009

Although traditional single-hop cellular networks had been serving well in past years, they are no longer economically feasible in supporting high data-rate, multimedia services of $4^{th}$Generation (4G) communications due to the requirement of high transmission power By contrast, multi-hop cellular networks (MCN) are capable of dramatically saving the transmission power by overlaying the capability of ad hoc networking among mobile terminals on the cellular network infrastructure. To achieve this performance gain as well as enable 4G services, an efficient routing protocol needs to be designed for MCN. In this paper, we propose a reactive route discovery protocol for MCN that uses directional information to the base station in the route discovery process. Our analysis/simulation results have demonstrated that the proposed protocol significantly reduces flooding overheads. In addition, we consider issues for 4G services in MCN and applications of the proposed protocol.