• 대한토목학회논문집
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• 제26권5C호
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• pp.313-322
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• 2006

지반 액상화는 대표적인 지진 피해의 한 형태로 이 연구에서는 이러한 지반 액상화 가능성 평가를 위한 확률적 접근 방법을 제시하였다. 일정한 사용기간 동안의 지진에 의한 액상화 발생확률을 구하기 위하여 액상화 취약도와 지진재해도를 결합하여 액상화 위험도를 산정할 수 있도록 하였다. 현재 국내에서는 결정론적인 방법이 많이 이용되고 있으나, 이러한 방법은 지반 물성치에 포함되어 있는 많은 불확실성을 합리적으로 다루기 어려운 단점이 있다. 두 가지 형태의 확률적 접근 방법을 제시하였는데, 첫번째는 설계지진에 대한 확률적 신뢰도 해석 방법이고, 두번째는 주어진 지반조건에 대하여 일정한 사용기간 동안 액상화가 발생할 수 있는 가능성을 평가한 위험도 해석 방법이다. 기존의 결정론적 방법과 확률적 방법에 의하여 매립지반의 액상화를 평가하였으며, 위험도 해석에 의한 액상화 가능성 평가기법을 지속적으로 적용하고, 설계기준이 제시된다면 보다 합리적이고, 정량적인 지반 액상화 가능성 평가기법이 될 수 있음을 검증하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.491-492
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• 1989

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.333-333
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• 1999

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권1호
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• pp.131-147
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• 2020

RFID (Radio Frequency Identification) identifies a specific object by radio signals. As the tag provides a unique ID for the purpose of identification, RFID technology effectively solves the ambiguity and occlusion problem that challenges the laser or camera-based approach. This paper proposes an approach to track a moving object based on the integration of RFID and laser ranging information using a particle filter. To be precise, we split laser scan points into different clusters which contain the potential moving objects and calculate the radial velocity of each cluster. The velocity information is compared with the radial velocity estimated from RFID phase difference. In order to achieve the positioning of the moving object, we select a number of K best matching clusters to update the weights of the particle filter. To further improve the positioning accuracy, we incorporate RFID signal strength information into the particle filter using a pre-trained sensor model. The proposed approach is tested on a SCITOS service robot under different types of tags and various human velocities. The results show that fusion of signal strength and laser ranging information has significantly increased the positioning accuracy when compared to radial velocity matching-based or signal strength-based approaches. The proposed approach provides a solution for human machine interaction and object tracking, which has potential applications in many fields for example supermarkets, libraries, shopping malls, and exhibitions.

• 방사선산업학회지
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• 제17권2호
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• pp.143-150
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• 2023

A graded approach applies safety requirements differentially, depending on the risk potential. An advantage of applying a graded approach is that safety assessments can be conducted repeatedly by focusing on areas with relatively higher risk than on those with low risk when decommissioning a nuclear power plant (NPP). The International Atomic Energy Agency (IAEA) recommends applying a graded approach to decommissioning NPPs worldwide. In Korea, the definition of the graded approach requires to be clarified. This study compared the decommissioning method used in Korean NPPs with the IAEA graded approach and examined whether the graded approach can be applied to decommissioning NPPs in Korea. As a result of the comparison, the preliminary decommissioning plan for Shin-Kori Units 5 and 6 showed that the decommissioning method for Korean NPPs is similar to the five-step IAEA graded approach.

• The Journal of Asian Finance, Economics and Business
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• 제7권6호
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• pp.133-143
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• 2020

The purpose of this study is to investigate the economic potential of the regions from the mining sector of North Morowali, Central-Sulawesi, Indonesia, and the formulation of pro-business regional development management that aims to create synergy between the local government and mining sector entrepreneurs. This study uses a descriptive qualitative approach by taking data in the form of primary data from FGD and secondary data observations from statistical bureau data in the North Morowali, Indonesia. The analysis unit uses SWOT analysis to determine the economic potential of the North Morowali and Location Quotient (LQ) to analyze the economic potential of the mining sector. The research period covers one year (2018-2019) in North Morowali, Indonesia. All the mining products have considerable potential as a financing unit in North Morowali, while mining potential has not been maximally exploited. The absence of regulations, facilities such as road access, and optimal land and sea transportation are the causes of the difficulty of optimization and access to explore mining products comprehensively. As a new province at Central Sulawesi, more efforts and the role of government are needed to focus attention to North Morowali as an area with great potential in the mining sector.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권5호
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• pp.502-506
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• 2008

최근에 제안된 강화 학습 기법인 "potential-based" reinforcement learning(RL) 기법은 다수 학습들과 expert advice들을 감독 지식으로 강화 학습 알고리즘에 융합하는 것을 가능하게 했고 그 효용성은 최적 정책으로의 이론적 수렴성 보장으로 증명되었다. 본 논문에서는 potential-based RL 기법을 셀룰러 네트워크에서의 채널 할당 문제에 적용한다. Potential-based RL 기반의 동적 채널 할당 기법이 기존의 fixed channel assignment, Maxavail, Q-learning-based dynamic channel assignment 채널 할당 기법들보다 효율적으로 채널을 할당한다. 또한, potential-based RL 기법이 기존의 강화 학습 알고리즘인 Q-learning, SARSA(0)에 비하여 최적 정책에 더 빠르게 수렴함을 실험적으로 보인다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2360-2362
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• 1998

This paper presents a new collison-free trajectory problem for SCARA robot manipulator. we use artificial potential field for collison detection and avoidance. The potential function is typically defined as the sum of attractive potential pulling the robot toward the goal configuration and a repulsive potential pushing the robot away from the obstacles. In here, end-effector of manipulator is represented as a particle in configuration space and moving obstacles is simply represented, too. we consider not fixed obstacle but moving obstacle in random. So, we propose new distance function of artificial potential field with moving obstacle for SCARA robot. At every sampling time, the artificial potential field is update and the force driving manipulator is derived from the gradient vector of artificial potential field. To real-time path planning, we apply very simple modeling to obstacle. Some simulation results show the effectiveness of the proposed approach.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.662-668
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• 2015

A suspension of titanium nanoparticles (Ti NPs) in liquid sodium (Na) has been proposed as a method to mitigate the violent sodium-water reaction (SWR). The interparticle potential between Ti NPs in liquid Na may play a significant role in the agglomeration of NPs on the reaction surface and in the bulk liquid Na, since the potential contributes to a reduction in the long-term dispersion stability. For the effective control of the SWR with NPs, a physical understanding of the molecular dynamics of NPs in liquid Na is key. Therefore in this study, the nonretarded Van der Waals model and the solvation potential model are employed to analyze the interparticle potential. The ab initio calculation reveals that a strong repulsive force driven by the solvation potential exceeds the interparticle attraction and predicts the agglomeration energy required for two 10-nm Ti NPs to be $4{\times}10^{-17}J$. The collision theory suggests that Ti NPs can be effective suppressors of the SWR due to the high energy barrier that prevents significant agglomeration of Ti NPs in quiescent liquid Na.

• 한국정보시스템학회지:정보시스템연구
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• 제30권2호
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• pp.29-56
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• 2021

Purpose Cyber deviance of adolescents has become a serious social problem. With a widespread use of smartphones, incidents of cyber deviance have increased in Korea and both quantitative and qualitative damages such as suicide and depression are increasing. Research has been conducted to understand diverse factors that explain adolescents' delinquency in cyber space. However, most previous studies have focused on a single theory or perspective. Therefore, this study aims to comprehensively analyze motivations of juvenile cyber deviance and to develop a predictive model for delinquent adolescents by integrating four different theories on cyber deviance. Design/methodology/approach By using data from Korean Children & Youth Panel Survey 2010, this study extracts 27 potential factors for cyber deivance based on four background theories including general strain, social learning, social bonding, and routine activity theories. Then this study employs econometric analysis to empirically assess the impact of potential factors and utilizes a machine learning approach to predict the likelihood of cyber deviance by adolescents. Findings This study found that general strain factors as well as social learning factors have positive effects on cyber deviance. Routine activity-related factors such as real-life delinquent behaviors and online activities also positively influence the likelihood of cyber diviance. On the other hand, social bonding factors such as community commitment and attachment to community lessen the likelihood of cyber deviance while social factors related to school activities are found to have positive impacts on cyber deviance. This study also found a predictive model using a deep learning algorithm indicates the highest prediction performance. This study contributes to the prevention of cyber deviance of teenagers in practice by understanding motivations for adolescents' delinquency and predicting potential cyber deviants.