• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.259-266
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• 2005

Recently data centric routing or application dependent routing protocols are emerged in mobile ad hoc networks. In this paper, we propose a routing method for query processing in MANET(Mobile Ad hoc NETwork) environment, called road-based query routing, with consideration on real time traffic information of large number of vehicles. In particular, we focus on the method that process arrival time dependent shortest path query in MANET without a central server on the road networks. The main idea of our approach lies in a routing message that includes query predicates based on the road connectivity and on data gathering method in real time from vehicles on the road by ad-hoc network. We unify route discovery phase and data delivery(query processing) phase in our mechanism and reduce unnecessary flooding messages by pruning mobile nodes which are not on the same or neighboring road segments. In order to evaluate the performances of the proposed method, we established a model of road networks and mobile nodes which travel along the roads. The measurement factor is the number of nodes to whom route request is propagated according to each pruning strategy. Simulation result shows that road information is a dominant factor to reduce the number of messages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.537-544
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• 2016

National Competency Standards (NCS) need to be introduced to train newly hired staff and to gradually improve employees' work performance in the information security industry. In particular, the introduction of a new NCS curriculum for new hires is important in order to retain and efficiently manage professionals in the information security field. However, the legacy NCS is not clearly designed for the information security field. So a formal curriculum has been suggested for institutions training the information security workforce. Therefore, this study establishes a competency unit based on the types of personnel, their duties, and required knowledge. To select the competency unit, this study reviewed prior research to understand the required skills and work knowledge, and reviewed recruitment-based NCS that public agencies and public and private companies have carried out, including them in the study. The selected competency unit was classified into a required competency unit and an elective competency unit based on the importance of the duties and the demands of training. Through a verification process for the new, licensed career path model in the NCS information and communications field, this study suggests updated NCS competency units and required courses to provide an appropriate NCS curriculum for newly hired employees in the information security industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.133-140
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• 2017

This study was conducted to determine the casual relationship among family support, social support, workplace spirituality, and quality of life (QOL) for middle-aged, male office workers, as well as the effects of family support, and social support on their QOL with the mediation of workplace spirituality. The participants were 288 middle-aged, male office workers, and the data were collected from 14 October to 30 November, 2016, through questionnaires. The data were analyzed with descriptive statistics and Pearson's correlations using PASW 21.0, while the AMOS 18.0 program was used for structural equation modeling (SEM), and the fitness of the final model was determined using RMSEA .05, GFI .98, AGFI .94 and NFI .96. The results of this study can be summarized as follows. There were correlations between family support, social support, workplace spirituality, and QOL for the middle-aged, male office workers. Second, family support (${\beta}=.60$, p<.001) and social support (${\beta}=.47$, p<.001) had a direct effect on their workplace spirituality. Third, family support had direct (${\beta}=.12$, p=.002) and indirect (${\beta}=.10$, p<.001), while social support also had direct (${\beta}=.12$, p<.001) and indirect (${\beta}=.08$, p<.001) effects on their QOL. The findings also suggested that workplace spirituality had a partial mediating effect between the family support, social support, and QOL of the middle-aged, male office workers.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.4
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• pp.421-426
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• 2010

Due to the ease of deployment and the extended coverage, wireless mesh networks (WMNs) are gaining popularity and research focus. For example, the routing protocols that enhance the throughput on the WMNs and the link quality measurement schemes are among the popular research topics. However, most of these works assume that the locations of the mesh routers are predetermined. Since the operators in an Indoor mesh network can determine the locations of the mesh routers by themselves, it is essential to the WMN performance for the mesh routers to be initially placed by considering the performance issues. In this paper, we propose a mesh router placement scheme based on genetic algorithms by considering the characteristics of WMNs such as interference and topology. There have been many related works that solve similar problems such as base station placement in cellular networks and gateway node selection in WMNs. However, none of them actually considers the interference to the mesh clients from non-associated mesh routers in determining the locations of the mesh routers. By simulations, we show that the proposed scheme improves the performance by 30-40% compared to the random selection scheme.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.239-248
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• 2017

According to the structure, solenoid valve can be categorized as spool valve or poppet valve. While various research on spool valve which has simple structure and fine susceptibility to contamination has been conducted, poppet valve which has less susceptibility to contamination and advantage in a long time operation still need much research because of its complicated structure. In order to design the poppet valve, various parameters such as the diameter of the poppet, the angle of the poppet, the diameter of the disk, the spring stiffness, the spring preload and flow path structure should be considered. Conventional studies on poppet valve usually take only one design parameters and did not much focused on the effect of the parameters on flow characteristics. In this paper, the change of the flow characteristics according to the design parameters of the poppet valve for 3/2Way solenoid valve is analyzed. The previous studies and the results of initial model analysis was referred for the selection of the design parameters. The effects of design parameters on maximum pressure, minimum pressure, and pressure drop was examined using analysis of means(ANOM).

• Culinary science and hospitality research
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• v.22 no.7
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• pp.158-172
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• 2016

This study engaged food-service industry workers in Busan (casual dining restaurants and buffets) to investigate the moderating effect of job satisfaction on the influence of emotional labor on turnover intention and job burnout. To accomplish the goal of this study, the statistical programs SPSS 21.0 and AMOS 21.0 were employed for frequency analysis, factor analysis, reliability, and confirmatory factor analysis of responses from f 278 respondents. An examination was conducted to prove the hypothesis based on a structural equation model. There are two sub factors of emotional labor, surface acting and deep acting. According to the result of this study, surface acting has a positive influence (+) on job burnout (exhaustion) while deep acting has a negative influence(-). In addition, job burnout showed a positive influence (+) on turnover intention. It has been revealed that job satisfaction has a moderating effect on the path from deep acting to job burnout. Having considered that job burnout of food-service workers in Busan was related to deep acting, one of sub factors of emotional labors, promoting deep acting appears to be the way of reducing both job burnout and the number of people with turnover intention. Therefore, it is necessary for restaurant owners and CEOs to implement employee training and improve employee benefits in order to promote the deep acting of their employees.

• Korean Journal of Social Welfare
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• v.60 no.4
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• pp.175-203
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• 2008

It has been well known and empirically supported that many persons with psychiatric disabilities experience recovery in the community. The sense of recovery is experienced while they recognize and manage mental illness and cope with everyday life utilizing personal and social resources. In order to explore ways in which the sense of recovery is enhanced, this study investigated the structure of relationships among the mental health state, optimism, positive emotions, quantity and quality of the social relationships, coping, and recovery of 460 persons with psychiatric disabilities through structural equation modeling. Of findings, first, in the results of path estimates of measurement and theoretical model, especially optimism and positive emotions demonstrated significant effects on the social relationship, coping, and the recovery, while, by contraries, positive emotions showed no significant direct effects on coping, neither the social relationships did on the recovery. Second, on the recovery optimism and positive emotions had direct effects, while quantity and quality of the social relationships had only indirect effects. It is particularly noted that positive emotions showed stronger effects on the recovery than optimism, and also had direct and indirect effects on the social relationships. Finally, partial mediating effects of coping were found between optimism and the recovery, between quality of the social relationships and recovery, and between quantity and quality of the social relationships; another partial mediating effects of quality of social relationships between quantity of social relationships and coping, and between positive emotions and coping; and the last same effects of quantity of the social relationships between positive emotions and coping. According to these results, discussions and implications for social work practice and practice research were suggested regarding the differential effects of positive cognitions and emotions on the recovery and different mechanisms of the quality and quantity of the social relationships, and the relationships among the resources, coping, and the recovery of persons with psychiatric disabilities.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.438-444
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• 2004

The intelligent robots that will be needed in the near future are human-friendly robots that are able to coexist with humans and support humans effectively. To realize this, robots need to recognize their position and posture in known environment as well as unknown environment. Moreover, it is necessary for their localization to occur naturally. It is desirable for a robot to estimate of his position by solving uncertainty for mobile robot navigation, as one of the best important problems. In this paper, we describe a method for the localization of a mobile robot using image information of a moving object. This method combines the observed position from dead-reckoning sensors and the estimated position from the images captured by a fixed camera to localize a mobile robot. Using the a priori known path of a moving object in the world coordinates and a perspective camera model, we derive the geometric constraint equations which represent the relation between image frame coordinates for a moving object and the estimated robot's position. Since the equations are based or the estimated position, the measurement error may exist all the time. The proposed method utilizes the error between the observed and estimated image coordinates to localize the mobile robot. The Kalman filter scheme is applied for this method. its performance is verified by the computer simulation and the experiment.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.92-104
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• 2014

CM services have been increasingly practiced over the two decades in the Korean construction industry, and recent efforts focus on further development in advanced CM capabilities and expansion to overseas market. However, there has been lack of holistic research to investigate current status and future direction of CM industry in Korea. In this context, the purposes of this study are 1) to analyze current status of Korean CM industry in terms of owners, market, CM firms, contracts, and work scopes, 2) to define different types of CM practices, and 3) to propose growth models for Korean CM firms based on the defined CM project types. An extensive literature review and statistical analysis of 2012 CM contracts were performed in order to analyze the CM status. Based on the analyses, ten different CM types are defined, and growth paths of CM firms are illustrated. Implications and lessons learned during the statistical analysis and workshops are briefly introduced as well.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.531-554
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• 2020

In order to provide explanations of the practice of the abductive inquiry-based outdoor geological fieldwork education, this study examined the characteristics of students' performance in geological fieldwork before and after the introduction of explicit learning of geologic knowledge and inquiry. To this end, a 21st-class program was developed in the order of pre-evaluation, initial fieldwork, explicit learning of geologic knowledge and inquiry, and post-evaluation and applied to nine middle school students. As research data, outdoor geological fieldwork class recording data and students' activity sheets were collected and analyzed qualitatively. As a result, during the initial fieldwork, students caught clues of low geological importance and used everyday experience and/or general scientific knowledge as a rule when asked to generate hypotheses about the origin of the clues. Also, students evaluated their hypotheses by the scientific accuracy of the rule or their own criterion. Meanwhile, during the final fieldwork, students frequently caught key clues in geologic perspectives and generated geological event hypotheses related to the clues by borrowing geologic knowledge as a rule. Furthermore, students scientifically evaluated their hypotheses based on the consistency of evidence and rules. Combining these results, the effects of learners' geological knowledge and inquiry (abduction) abilities as a path model were presented in order to help students carry out a proficient abductive inquiry in geological fieldwork.