• Geophysics and Geophysical Exploration
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• v.22 no.1
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• pp.1-11
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• 2019

Well logging technologies are used to measure the physical properties of reservoirs through boreholes. These technologies have been utilized to understand reservoir characteristics, such as porosity, fluid saturation, etc., using equations based on rock physics models. The analysis of well logs is performed by selecting a reliable rock physics model adequate for reservoir conditions or characteristics, comparing the results using the Archie's equation or simandoux method, and determining the most feasible reservoir properties. In this study, we developed a joint inversion algorithm to estimate physical properties in shaly sandstone reservoirs based on the pre-existing algorithm for sandstone reservoirs. For this purpose, we proposed a rock physics model with respect to shale volume, constructed the Jacobian matrix, and performed the sensitivity analysis for understanding the relationship between well-logging data and rock properties. The joint inversion algorithm was implemented by adopting the least-squares method using probabilistic approach. The developed algorithm was applied to the well-logging data obtained from the Colony gas sandstone reservoir. The results were compared with the simandox method and the joint inversion algorithms of sand stone reservoirs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.242-248
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• 2019

This study was conducted to examine the effects of a smart home (electronic control unit, ECU) on the performance and satisfaction of activities of daily living of wheelchair users. A total of 15 wheelchair users (10 patients with spinal cord injury and 5 patients with stroke) were investigated. Smart homes were equipped with ECU technology, which consisted of automation of furniture and products. The products and facilities were integrated and controlled by a smart device or voice. Performance and satisfaction of activities of daily living were measured by the Canadian Occupational Performance Measure (COPM) before and after residence in a smart home. All participants showed a higher COPM (performance score ${\geq}3$, satisfaction score ${\geq}4$) during residence in a smart home compared to residence in the current home. In addition, the COPM scores differed significantly before and after residence in a smart home. These results provide evidence of the applicability of smart homes based on high technology. However, additional studies of more smart home participants should be conducted to improve the quality of the results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.589-598
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• 2019

This study was conducted to build a structural equation model explaining factors that affect hemodialysis patients' quality of life to test the goodness of fit of the model and identify directly and indirectly significant paths. To accomplish this, 230 patients receiving hemodialysis registered at study hospitals in G Metropolitan City and M City were randomly selected, and 201 were used in the final analysis. Data were collected using a self reporting questionnaire from February 1 to March 31, 2014. SPSS WIN 18.0 was used for descriptive statistics and correlation analysis of the general characteristics and for reliability analysis of the research tools. In addition, AMOS 18.0 was used for confirmatory factor analysis of latent variables, to determine the goodness of fit of the hypothetic model, and hypotheses testing. The results of this study were as follows: the fit of the modified model was 41.32, GFI = .96, AGFI = .92, RMR = .04, NFI = .96, CFI = .91 and TLI = .95. Twelve out of the 22 research hypotheses that were improved and improved were statistically significant. The results indicated that hemodialysis patients' quality of life was influenced directly by self-efficacy, depression, and self-care behavior, and indirectly by sleep disturbance, stress, fatigue, and family support. These variables explained 58.6% of the variation in quality of life. Overall, these findings suggest that nursing interventions for hemodialysis patients require strategies for managing patient depression and for increasing self-efficacy and self-care behavior to improve quality of life.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.370-381
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• 2021

This study examines the perceptions and demands of pre-service early childhood teachers about the Demonstration of simulated instruction for 350 students in early childhood education at 3-4 years university located in Busan, Ulsan, and Gimhae. And through this, the purposes of study are to provide basic data based on the current level of pre-school teachers for instructors leading simulated instruction and to seek effective management plans for simulated instruction to improve teaching ability. As a result of the study, pre-service early childhood teachers recognized that simulated instructions were necessary in teacher training course and helped to improve teaching ability, but they did not actively agree to expand simulated instructions and were not very satisfied with the methods of instructors in demonstration of simulated instruction. They wanted to receive feedback from instructors who have practical teaching knowledge and skills based on field experience at least two times during preparation stage and evaluation stage of the simulated instructions. And they wanted to be guided specifically on principles and methods of preparing educational plans, effective interactions and questions with young children. They wanted the feedback, the most preferred form of feedback is form of participations by all class members and instructors. In addition to instructor's feedback, they required experience of simulated instruction in which infants and toddlers participate together.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.45-51
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• 2021

The purpose of this study was to investigate the effect of applying whole body vibration exercise at 30 Hz on the thickness and mechanical properties of the erector spinae. The study population included 24 adults (11 male and 13 female) in the N region. The subjects were divided into two groups, a 30Hz whole body vibration exercise(WG, n=12) and an LSG(12 subjects). Changes in the thickness and mechanical properties of the erector spinae were analyzed before the exercises and after four and eight weeks of exercises using a two-way repeated analysis of variance with a statistical significance level of α=0.05. When there was an interaction between the groups and measurement times, post hoc analyses were conducted at a statistical significance level of α=0.01. The thickness, frequency, stiffness and strain of the erector spinae muscles were significantly different in each time period and in the interaction between time period and the group (P<0.05), and recovery was significantly different only in each time period (P<0.05). Thus, 30Hz whole body vibration exercise had a positive effect on the thickness and mechanical properties of the erector spinae. The results of this preliminary study suggest that whole body vibration exercise may find a place as a lumbar stabilization exercise in clinical practice in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.583-592
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• 2020

This study assessed source depletion in the vadose zones of contaminated sites. The possible range of infiltration rate in Korea was statistically analyzed. The results showed a trend of decreasing leachate concentration of 13 pollutants used for risk assessment. Among them, benzene, ethylbenzene, toluene, and xylene showed a lower leachate concentration in groundwater over time due to their low distribution coefficient and also possible biodegradation effects. The average values of the relative concentration could be taken as a default index due to a very small range of uncertainties. In the case of heavy metals, it was shown that the leachate concentration in a pollutant does not decrease over time. Considering the annually different infiltration, a site-specific source-depletion scenario was applied to Cheongju in North Chungcheong Province. The result was expressed as a time series of the relative concentration of the leachate concentration, and this was compared to the trend by averaged Korean infiltration. Finally, an open-source code that used Python was used to help calculate the leachate concentration by this site-specific infiltration scenario.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.697-706
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• 2021

The purpose of this study is to find out whether the many start-up support programs provided by a college can actually help students start a business, and to discuss what role colleges should have as facilitators of student entrepreneurship. To this end, a qualitative study was conducted with seven students who wished to start a business by utilizing start-up education and support programs provided by College Y. As a result of the study, the participants first mentioned parallel and administrative inefficiency in entrepreneurship and the entrepreneurship programs. Second, the implications for the role of colleges in fostering start-up content are systematic planning and guidance for start-up programs operated by the college, concise administrative procedures, mentoring in various start-up items, and securing a test market. It can be said that the concept of a common office in which students can work together is necessary. The study is significant in that it can help to establish a start-up support plan by suggesting what role colleges should play in relation to entrepreneurship, but its limitation is that its scope includes only one specific major.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.67-76
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• 2011

In this present study, to evaluate a behavior characteristics of the sea dyke coastal covering stone by sea waves. sea waves act on coastal structures as an impact load. During impact loading, erosion and bluff slumping occur in the coastal structures. Also, the covering stone are worn down by wave impact. The sea dyke has been used near coastal region for protection of infra-structure since 1970s in Korea. The sea dyke consist of dredged sand and covering stone mainly. The damage type of covering stone has been reported since 1970s. However, the interaction of impact load by sea wave with the covering stone has not been investigated yet properly. Mainly damage type of covering stone is an abrasion. But the study of covering stone abrasion is not sufficient. Hence, In this study, it was analyzed the interaction of impact load by sea wave and the covering stone during sea wave action on coastal structures. In order to analyze the behavior characteristics of coastal covering stone considering the magnitude and period of impact loading and to evaluate the displacement increment of covering stone during impact load, numerical analysis was carried out considering impact loading by sea wave.

• The Southeast Asian review
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• v.20 no.3
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• pp.183-222
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• 2010

본 연구의 목적은 2008년 후반에 발생한 국제금융위기에 대응하여 조직 개편을 선택한 기업과 그 기업 내의 근로자들 실태 파악을 하는데 있다. 특히 기업구조조정 명목으로 단행된 해고를 모면한 근로자들 (생존자)의 상태를 그들이 지각하는 각 개인의 관리자에 대한 만족도와 그들의 직무관련태도인 직무만족, 조직적 몰입 그리고 이직 의도 간의 관계 관점에서 살피고자 한다. 관리자에 대한 만족도는 근로자들의 직무 관련 태도 변수와 관련되어 사회적 선행변수로 선택되었으며 직무관련태도는 결과변수로 선택하였다. 본 연구를 통해 생존자들의 조직 내 직무관련태도에 관한 이해를 높이는데 필요한 정보를 표출해내어 그들의 실태를 파악하는데 하나의 목적을 두었으며 그들의 관리자와의 사회적 관계가 그들에게 미치는 영향을 파악하는 것이 또 하나의 목적이라 하겠다. 이상과 같은 관계 파악을 통해 얻은 정보로 관련기업이 단기적으로 성공적인 자립을 하여 장기적으로 경쟁력 있는 조직으로 성장할 수 있는 인적자원전략을 제공하는데 2차적인 목적을 두고 있다. 본 연구는 이상과 같은 목적을 달성하고자 그 유의성이 증명된 현존하는 설문을 활용한 조사기법을 채택하여 실증연구를 하였다. 수집한 자료는 SPSS 17.0과 LISREL 8.5을 사용하여 연구모형과 연구의 가설들을 검증하였다. 연구목적을 달성하고자 채택된 가설들은 기존의 문헌연구를 토대로 세워졌다. 연구대상은 태국 북부지역의 대표도시인 치앙마이 내 관광호텔 종사자들로서 외부적으로는 2008년 국제금융위기와 그에 따른 경제침체, 내부적으로는 극심한 정치적 사회적 불안에 의한 관광객의 급감소와 조직의 자구책으로 행해진 조직재구조 차원에서의 해고를 이겨낸 근로자들, 즉 생존자들이었다. 가설검증을 통해 입증된 연구결과에 의하면 1) 근로자들의 관리자에 대한 만족은 그들의 직무만족, 정서적 조직몰입과 지속적 조직몰입에 영향을 미치는 것으로 검증됐다. 2) 근로자들의 관리자에 대한 만족은 그들의 이직의도에는 영향을 미치지 못하는 것으로 검증됐다. 3) 근로자들의 직무만족은 그들의 이직의도에 영향을 미치는 것으로 검증되었다. 4) 근로자들의 조직적 몰입과 이직의도 간의 관계에 있어서는 오직 경제적 성격의 지속적 조직몰입만 영향을 미치는 것으로 검증되었다. 이러한 연구 결과는 기존의 타 연구 결과와 기본적인 맥락은 같게 나왔으나 근로자들의 정서적인 면의 부재는 2008년 후반 당시의 독특한 태국의 사회적, 경제적 그리고 문화적 실태를 보여주는 것이 아닌 가 사료된다. 특히 근로자들이 그들의 직장과의 관계와 관련된 의사결정을 가치가 아닌 경제적인 요소에 의존한다는 결과 그리고 상관인 관리자가 이러한 태도에 전혀 영향력을 미치지 못한다는 결과는 전통적으로 감성적이며 집단주의적인 동양적 문화가 지배하리라고 예상했던 태국에서는 이례적인 결과였다. 그러나 관리자들이 그들의 직무만족 그리고 조직적 몰입에 영향을 주며 직무만족이 이직 의도에 영향을 미친다는 결과와 지속적 조직몰입이 이직의도에 영향을 미친다는 결과는 장기적으로 적극적인 관리자 교육을 통해 근로자들을 조직에 정서적으로도 올바르게 안착시키고 긍정적인 구성원으로 존재하면서 조직에 기여할 수 있는 그들의 역할을 기대할 수 있다고 볼 수도 있다. 이 점은 매우 중요한데 그 이유는 해고를 이겨낸 근로자들은 그 조직이 미래를 짊어지는 마지막 기대변수이기 때문이다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.5
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• pp.109-119
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• 2004

The home network environment can be defined as a network environment, connecting digital home devices such as computer systems, digital appliances, and mobile devices. In this kind of home network environments, there will be numerous local/remote interactions to monitor and control the home network devices and the home gateway. Such an environment may result in communication bottleneck. By applying the mobile agents that can migrate among the computing devices autonomously and work on behalf of the user, remote interactions and network traffics can be reduced enormously. The mobile agent authentication is necessary to apply mobile agent concept to the home network environments, as a prerequisite technology for authorization or access control to the home network devices and resources. The existing mobile agent systems have mainly used the public key based authentication scheme, which is not suitable to the home network environments, composed of digital devices of limited computation capability. In this paper, we propose a shared key based mobile agent authentication scheme for single home domain and expand the scheme to multiple domain environments with the public key based authentication scheme. Application of the shared key encryption scheme to the single domain mobile agent authentication enables to authenticate the mobile agent with less overhead than the public key based authentication scheme.