• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.1057-1073
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• 2015

In this paper, we consider cooperative D2D communications in cellular networks. More precisely, a cellular user leases part of its spectrum to facilitate the D2D communication with a goal of improving the energy efficiency of a D2D pair. However the D2D pair is untrusted to the cellular user, such resource sharing may result in the information of this cellular user unsecured. In order to motivate the cellular user's generosity, this D2D pair needs to help the cellular user maintain a target secrecy rate. To address this issue, we formulate a joint spectrum and power allocation problem to maximize the energy efficiency of the D2D communication while guaranteeing the physical layer security of the cellular user. Then, a theorem is proved to indicate the best resource allocation strategy, and accordingly, an algorithm is proposed to find the best solution to this resource allocation problem. Numerical results are finally presented to verify the validity and effectiveness of the proposed algorithm.

• 한국전자통신학회논문지
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• 제5권4호
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• pp.406-411
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• 2010

지난 수년간 Honeynet은 공격자의 공격 도구, 공격 기법 및 공격동기를 배울 수 있는 보안 메커니즘으로서의 가치가 충분히 입증되었다. 이러한 정보는 다양한 위협에 대한 조직의 대응을 위한 핵심 정보로 활용되어 보다 효율적인 보안을 위한 기초자료가 되고 있다. 그러나 Honeynet활용의 문제점 중 하나는 구축에 많은 자원이 요구되며, 구축 및 운영관리가 어렵다는 문제이다. Honeynet 구축을 위해서는 다수의 시스템들과 다양한 보안 메커니즘을 필요로 한다. 본 논문에서는 최근 IT분야의 화두로 떠오르고 있는 가상화(Virtualization) 기술을 이용하여 기존의 Honeynet의 가치를 그대로 유지하면서도 기존 Honeynet의 자원문제, 구축 및 운영관리문제를 줄일 수 있는 Virtual Honeynet 모델을 제시하고자 한다.

• The Journal of Korean Physical Therapy
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• 제16권1호
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• pp.1-13
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• 2004

Airway clearance technique are used to aid in mucus clearance in a variety of disease states. In this review I discuss airway physiology including airway mucus, action of airways, and airway resistance and review the literature and theory regarding forced expiratory technique, active cycle of breathing technique, and autogenic drainage. Also, I look at the appropriate device such as positive expiratory pressure mask(PEP mask), Flutter, and HFCWO(Vest system) which can be applied in the field of respiratory physical therapy. This study is provided as the basic resource regarding the application method of respiratory physical therapy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.5701-5722
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• 2018

The continuous increase in the cost of energy production and concerns for environmental sustainability are leading research communities, governments and industries to amass efforts to reduce energy consumption and global $CO_2$ footprint. Players in the information and communication industry are keen on reducing the operational expenditures (OpEx) and maintaining the profitability of cellular networks. Meanwhile, network virtualization has been proposed in this regard as the main enabler for 5G mobile cellular networks. In this paper, we propose a generic framework of slice resource provisioning and customized physical resource allocation for energy-efficiency and quality of service optimization. In resource slicing, we consider user demand and population resources provisioning scheme aiming to satisfy quality of service (QoS). In customized physical resource allocation, we formulate this problem with an integer non-linear programming model, which is solved by a heuristic algorithm based on minimum vertex coverage. The proposed algorithm is compared with the existing approaches, without consideration of slice resource constraints via system-level simulations. From the perspective of infrastructure providers, traffic is scheduled over a limited number of active small-cell base stations (sc-BSs) that significantly reduce the system energy consumption and improve the system's spectral efficiency. From the perspective of virtual network operators and mobile users, the proposed approach can guarantee QoS for mobile users and improve user satisfaction.

• ETRI Journal
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• 제43권1호
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• pp.53-63
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• 2021

Cloud computing has drastically reduced the price of computing resources through the use of virtualized resources that are shared among users. However, the established large cloud data centers have a large carbon footprint owing to their excessive power consumption. Inefficiency in resource utilization and power consumption results in the low fiscal gain of service providers. Therefore, data centers should adopt an effective resource-management approach. In this paper, we present a novel load-balancing framework with the objective of minimizing the operational cost of data centers through improved resource utilization. The framework utilizes a modified genetic algorithm for realizing the optimal allocation of virtual machines (VMs) over physical machines. The experimental results demonstrate that the proposed framework improves the resource utilization by up to 45.21%, 84.49%, 119.93%, and 113.96% over a recent and three other standard heuristics-based VM placement approaches.

• 가족자원경영과 정책
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• 제5권1호
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• pp.49-60
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• 2001

This research examined elderly’s quality of life(q/l). In order to explore the elderly’s q/l, it was conceptualized into 8 dimensions tapping macro and micro aspects of elderly’s life: physical & mental health, self-esteem, anxiety, social support, family solidarity, economic state, and physical environment. The primary purposes were to describe dimensions of q/l by the elderly’s sociodemographic variables. And the intercorrelations among q/l dimensions were examined and then the effects of q/l sub-dimensions on psychological well-being were analyzed by using multiple regression. Based on the data collected for 677 subjects residing in rural and urban areas, the basic issues hypothesized were explored. The findings appeared that the psychological well-being was a positive function of physical and mental health, self-esteem, social support, and economic state and a negative one of social anxiety, controlling for subjects’s sociodemographic variables.

• 가족자원경영과 정책
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• 제12권4호
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• pp.47-62
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• 2008

This study investigated the experience of physical violence among adolescents and the domestic variables explaining sibling violence. Data were collected from 501 adolescents in 2007 and analyzed using SPSS 16.0. The statistics used for analysis were the T-Test, two-way ANOVA, and regression. Findings indicated that 45% of the sample population had experienced sibling violence and the most common acts were "hit with hand or objects". The violence of parents toward their children, gender, and the frequency of conflict between siblings were associated with sibling violence. From these results, the study proposed that education about sibling violence should be included in social work programs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권8호
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• pp.2626-2646
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• 2014

This study presents a power and Physical Resource Blocks (PRBs) joint allocation algorithm to coordinate uplink (UL) interference in the device-to-device (D2D) underlaying Long Term Evolution-Advanced (LTE-A) networks. The objective is to find a mechanism to mitigate the UL interference between the two subsystems and maximize the weighted sum throughput as well. This optimization problem is formulated as a mixed integer nonlinear programming (MINLP) which is further decomposed into PRBs assignment and transmission power allocation. Specifically, the scenario of applying imperfect channel state information (CSI) is also taken into account in our study. Analysis reveals that the proposed PRBs allocation strategy is energy efficient and it suppresses the interference not only suffered by the LTE-A system but also to the D2D users. In another side, a low-complexity technique is proposed to obtain the optimal power allocation which resides in one of at most three feasible power vectors. Simulations show that the optimal power allocation combined with the proposed PRBs assignment achieves a higher weighted sum throughput as compared to traditional algorithms even when imperfect CSI is utilized.

• 디지털융복합연구
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• 제14권10호
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• pp.303-310
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• 2016

인터넷의 경직성으로 인하여 다양한 서비스를 제공하기 어려운 문제를 해결하기 위한 가장 효과적인 방법이 네트워크 가상화 방안이다. 공통의 물리 네트워크 자원을 공유하는 가상 네트워크를 효율적으로 생성하기 위해서는 자원을 효율적으로 사용할 수 있는 방안이 필요하다. 이러한 한정된 물리 자원을 효율적으로 사용하기 위하여 본 논문에서는 사용중인 자원이라도 더 높은 서비스 우선순위를 갖는 가상 네트워크에 할당하는 방법을 제안한다. 높은 우선순위의 네트워크 생성 요청을 위하여 운용중인 낮은 우선순위의 가상 네트워크에서 효율적으로 대역폭을 회수하는 알고리즘을 제안한다. 제안하는 대역폭 할당 알고리즘은 낮은 우선순위를 갖는 가상 네트워크에서 서비스 지속성을 유지하면서 할당된 대역폭을 회수할 수 있다. 제안한 알고리즘의 실험을 통하여 약 8%정도의 가상 네트워크 생성 수락률의 향상을 확인하였다.

• Child Health Nursing Research
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• 제12권1호
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• pp.15-24
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• 2006

Purpose: This study was done to define nursing behavior in neonatal intensive care units so as to estimate resource-based relative value-. Method: Participating in this study were 292 nurses in neonatal intensive care units. The study surveyed physical and mental labor, stress and time involved in nursing work. Tool used in this study was a nursing labor per relative value tool. For analyzes, the relative value of each nursing behavior was calculated, where the mean value of the three components, labor intensity and component-by-component explanatory power were in percentage terms. Results: 1. Nursing behaviors in neonatal intensive care unit were classified and defined at three levels: 5 main domains, 17 mid-domains, and 42 small domains. 2. The per component explanatory power of intensity involved in nursing labor showed physical effort to be 32.45%, mental 32.86%, and stress 34.69%. 3. The reliability of nursing labor factors was very strong, Cronbach's alpha value of 0.96. Conclusion: In this research, which is a first in defining nursing behavior in neonatal intensive care units, individual nursing behavior were broken down using resource-based relative value for nursing cost, and each nursing behavior was successfully translated to a numerical value.