• Journal of the Korea Society for Simulation
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• v.11 no.1
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• pp.11-22
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• 2002

In this paper, a RAID system is modeled and simulated by using the DEVS formalism. The RAID system interacts with a host system by using the high-speed Fibre channel protocol and stores data in an array of IDE disks. The DAVS formalism specifies discrete event systems in a hierarchical, modular manner. The RAID system model is composed of three units: primary-PCI unit, secondary-PCI unit and MCU unit. The primary-PCI unit interfaces with the host system and I/O data caches. The secondary-PCI unit includes disks. The MCU unit controls overall system. The control algorithm of MCU and PCI transactions are analyzed and modeled, From the analysis of simulation events, we can conclude that the proposed model satisfies given requirements.

• Journal of the Korean Society of School Health
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• v.24 no.1
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• pp.81-88
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• 2011

Purpose: The main purpose of this study was to explore the influences of adolescents' smoking on the stress level according to gender. Methods: We used the data from the 2008 Korea National Health and Nutrition Examination Survey conducted by the Korea Centers for Disease Control and Prevention between the period of Jan. and Dec. 2008. The target population of this study is 805 adolescents in the 12~19 years old. Results: 22.0% of male adolescents and 11.8% of female adolescents were current smokers. Hierarchical regression analysis showed that stress level was associated with self-reported health status, drinking, and smoking among males. Among females, stress level was associated with BMI. Conclusion: The results of this study would help to develop smoking prevention programs and health promotion strategies for adolescents.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.114-120
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• 2021

This study aims to discover how self-esteem and social competence in early childhood affect school adjustment in elementary school. This study used the 7th year (2014) and 10th year (2017) of the panel study on Korean children, which are longitudinal research data from the Korea Institute of Child Care and Education (KICCE). Pearson's correlation analysis and hierarchical regression analysis were used as the main statistical analysis methods. The analysis was performed using the the Spss 21.0 program. As a result of this study, peer acceptance among early childhood's self-esteem, assertion, cooperation, and self-control among social competence have influences on adjustment to elementary school life. This study is meaningful in that it is a longitudinal study conducted with a time difference for 3 years with the same subjects in order to investigate the influence of the inner factors of early childhood on school adjustment in elementary school.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3595-3603
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• 2022

Nuclear safety-class DCS is used for nuclear reactor protection function, which is one of the key facilities to ensure nuclear power plant safety, the maintenance for DCS to keep system in a high reliability is significant. In this paper, Nuclear safety-class DCS system developed by the Nuclear Power Institute of China is investigated, the model of reliability estimation considering nuclear power plant emergency trip control process is carried out using Markov transfer process. According to the System-Subgroup-Module hierarchical iteration calculation, the evolution curve of failure probability is established, and the preventive maintenance optimization strategy is constructed combining reliability numerical calculation and periodic overhaul interval of nuclear power plant, which could provide a quantitative basis for the maintenance decision of DCS system.

• International Journal of Computer Science & Network Security
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• v.22 no.10
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• pp.137-144
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• 2022

Wireless community networks (WCNs) are considered another form of ownership of internet protocol (IP) networks, where community members manage and own every piece of equipment in a decentralized way, and routing for traffic is done in a cooperative manner. However, the current routing protocols for WCNs suffer from stability and scalability issues. In this paper, an enhanced routing protocol is proposed based on the optimized link state routing (OLSR) protocol to meet the standards of efficiency in terms of stability and scalability. The proposed routing protocol is enhanced through two phases: multicasting expansion and multipoint relay (MPR) selection based on an analytical hierarchical process (AHP). The experimental results demonstrate that the proposed routing protocol outperforms the OLSR protocol in terms of network control overhead and packet delivery ratio by 18% and 1% respectively.

• Journal of IKEEE
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• v.27 no.3
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• pp.239-245
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• 2023

Whitelist-based ransomware solution is known as being vulnerable to false impersonation attack using DLL injection attack. To solve this problem, it is proposed to monitor DLL injection attack and to integrate the monitoring result to ransomware solutions. In this paper, we show that attackers can easily bypass the monitoring mechanism and then illegally access files of a target system. It means that whitelist-based ransomware solutions are still vulnerable.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.389-390
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• 2020

본 논문은 DC 마이크로그리드에서 배터리 에너지 저장 장치의 SoC(State-of-Charge)를 기반으로 한 계층 제어 기법을 제안한다. DC 마이크로그리드의 안정적인 운영을 위해 계층 구조의 제어방식이 필요하다. 제안하는 계층 제어 기법은 2 레벨로 구성된다. 1차 제어에서는 SoC에 의해 드룹 계수가 조정되고 충·방전 전류가 제어되어 SoC 밸런싱이 이루어진다. 2차 제어는 1차 제어에 의해 발생하는 배전망 전압강하를 보상한다. 제안하는 SoC 기반 계층 제어를 적용한 에너지 저장 장치는 일정 SoC 운용범위에서 동작하고 배전망 전압을 일정하게 유지하여 DC 마이크로그리드의 안정적인 전력관리가 가능해진다. 본 논문에서는 PSIM 시뮬레이션을 통해 제안하는 기법의 유효성을 검증하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.4
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• pp.51-62
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• 2004

Fuzzy supervisory control technique for the seismic response control of cable-stayed bridges subject to earthquakes is studied. The proposed technique is a hybrid control method, which adopts a hierarchical structure consisting of several sub-controllers and a fuzzy supervisor. Sub-controllers are independently designed to reduced the responses to be controlled of a cable-stayed bridge, and a fuzzy supervisor achieves improved seismic control performance by tuning the pre-designed sub-controllers. It is realized by converting static gains of the sub-controllers into time-varying dynamic gains through the fuzzy inference mechanism. To evaluate the feasibility of the proposed technique, the benchmark control problem of cable-stayed bridge proposed by Dyke et al. is adopted. The control variables for the seismic response control of the cable-stayed bridge are determined to be t도 shear forces and bending moments at the base of the towers, the longitudinal displacements at the top of the towers, the relative displacements between the deck and the tower, and the tensions in the stay cables. Comparative results between the fuzzy supervisory controller and LQG controller demonstrate the effectiveness of the proposed control technique.

• Korean Journal of Childcare and Education
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• v.11 no.4
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• pp.271-292
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• 2015

The purpose of this study was to examine the mediating effect of young children's self-control in the relationship between mother's affectionate parenting psychological behavioral control and young children's problem behaviors. The subjects of this study were 368 mothers whose young children were 3 to 5years old and attending to 3 private kindergartens and 2 child-care centers located in Chunkbuk. Data were analyzed by frequency, percentage, Primary factor analysis, Cronbach's ${\alpha}$, t-test, F-test, Pearson's correlation, and hierarchical regression, using the SPSS 12.0 program. The results of this study were as follows: First, young children's self control partially mediated when mother's affectionate parenting affected young children's internalizing and externalizing problem behaviors. Second, young children's self control partially mediated when mother's psychological control affected young children's internalizing and externalizing problem behaviors. Third, young children's self control did not show a mediating effect on the relationship between mother's behavioral control and young children's internalizing and externalizing problem behaviors. In conclusion, young children's internalization of mother's psychological control and behavioral control as well as affectionate parenting have its effect on problem behaviors.

• Korean Journal of Human Ecology
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• v.17 no.2
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• pp.207-221
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• 2008

This study examined different individual, family factors and classroom environment that affect children's perceived competency. For an analysis, achievement motivation, intrinsic locus of control and anxiety were included in individual variables. For family factors, parental support and marital conflict were examined. For classroom psycho-social environment, teacher support, peer relations, classroom involvement and teacher control were used. The sample consisted of 565 fifth and sixth grade children. Statistics and methods used for the data analysis were Cronbach's alpha, Factor analysis, frequency, percentage, t-test, Pearson's correlation, and Hierarchical Regression. Several major results were found from the analysis. First, boy's perceived academic competency was higher than girl's. And no sex difference was in children's social and athletic competency. Second, boy's and girl's perceived academic and social competency and boy's perceived athletic competency had a positive correlation with achievement motivation, intrinsic locus of control, parental support, teacher support, peer relations and classroom involvement. And girl's perceived athletic competency had a positive correlation with achievement motivation, intrinsic locus of control, parental support and peer relations. But boy's and girl's perceived academic and social competency and boy's perceived athletic competency had a negative correlation with anxiety and parental marital conflict. Third, the most important variable predicting boy's and girl's perceived academic competency was achievement motivation. The most important variable predicting boy's and girl's perceived social competency was peer relations. And the most important variable predicting boy's perceived athletic competency was peer relations. On the other hand, the most important variable predicting girl's perceived athletic competency was father's support.