• Journal of Gifted/Talented Education
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• v.26 no.3
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• pp.541-559
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• 2016

This study investigated a relationship among facilitating discourse, students' perceived challenge, and learning outcomes(persistent intention and learning achievement) in an online science gifted education program. Two hundreds and forty-two middle school students participated in the study. A survey questionnaire which was consisted of 6 items of facilitating discourse from teaching presence questionnaire(Shea, Swan, & Pickett, 2005) and 5 items of challenge from Student Perceptions of Classroom Quality(Gentry & Owen, 2004) was administered. First, the findings of this study showed that students' perceived facilitating discourse as a part of teaching presence was positively related to students' perceived challenge in an online course. Second, students' perceived facilitating discourse were positively related to persistent intention, but were negatively related to students' achievement. Third, students' perceived challenge was positively related to persistent intention and achievement. Finally, challenge mediated the relationship between students' perceived facilitating discourse and persistent intention, and the relationship between students' perceived facilitating discourse and students' achievement as well. This results suggested that online program should be designed to increase the levels of facilitating discourse.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.3
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• pp.43-49
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• 2019

In this study, a new approach using graphene oxide (GO) powder-composited Sn-3.0Ag-0.5Cu(in wt.%) solder paste for improving the bending reliability of solder joints between a flexible substrate and small outline package (SOP) was suggested. The GO addition slightly affected the melting temperature, however, the change in the melting temperature was not significant. Meanwhile, we observed the addition of GO could suppress IMC growth and IMC thickness of solder joint during the reflow process. Moreover, the cyclic bending test was also performed for evaluation of reliability in solder joint and we could improve the cyclic bending reliability of solder joint by adding GO powders. For 0.2 wt.% of GO added to the solder joint, the bending lifetime was increased to 20% greater than that without GO. Pull strength and ductility of the solder joint with GO were also higher than those of the joint without GO and it was assumed that this effect by adding GO could contribute to improve cyclic bending reliability of solder joint.

• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.61-73
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• 2018

In the defense modeling and simulation, for the detailed analysis of the communication system, many studies have carried out the analysis under the C3 SoS(system of systems) which consists of C2(command and control) and C(communication). However, it requires time and space constraints of the C2 system. To solve this problem, this paper proposes a communication analysis method in the standalone system environment which is combined with the C system after abstracting the C2 system. In the abstraction process, we hypothesize the traffic model and mobility model for C system analysis and learn the parameters in the model based on machine learning. Through the proposed method, it is possible to construct traffic and mobility model with different output according to the battlefield. This case study shows how the process can be applied to the C3 SoS and the enhanced accuracy than the existing method. We expect that it is possible to carry out the efficient communication analysis against many experimental scenarios with various communication parameters.

• Annals of Geriatric Medicine and Research
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• v.22 no.4
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• pp.167-175
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• 2018

Sarcopenia, a common clinical syndrome in older adults, is defined as decreased muscle mass, strength, and physical performance. Since sarcopenia is associated with the incidence of functional decline, falls, and even mortality in older adults, researchers and health care providers have been keen to accumulate clinical evidence to advocate the screening and prevention of sarcopenia progression in older adults. The factors that may accelerate the loss of muscle mass and function include chronic diseases, inactivity, and deficiency in appropriate nutritional support. Among these, nutritional support is considered an initial step to delay the progression of muscle wasting and improve physical performance in community-dwelling older adults. However, a nationwide study suggested that most Korean older adults do not consume sufficient dietary protein to maintain their muscle mass. Furthermore, considering age-associated anabolic resistance to dietary protein, higher protein intake should be emphasized in older adults than in younger people. To develop a dietary protein recommendation for older adults in Korea, we reviewed the relevant literature, including interventional studies from Korea. From these, we recommend that older adults consume at least 1.2 g of protein per kg of body weight per day (g/kg/day) to delay the progression of muscle wasting. The amount we recommend (1.2 g/kg/day) is 31.4% higher than the previously suggested recommended daily allowance (i.e., 0.91 g/kg/day) for the general population of Korea. Also, evidence to date suggests that the combination of exercise and nutritional support may enhance the beneficial effects of protein intake in older adults in Korea. We found that the current studies are insufficient to build population-based guidelines for older adults, and we call for further researches in Korea.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.658-666
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• 2018

The purpose of this study is to verify the effects of yoga and meditation-focused forest healing programs on profiles of mood states and stress reactions of adults. We tested 17 adults who agreed to participate in the experiments that were conducted for 2 nights and 3 days between September 8 to 10, 2017 in the healing forest located at Hongcheon-gun, Gangwon-do. The test used the simplified version of the inventory for the profile of mood states (K-POMS-B: Korean version of Profile of Mood States-Brief) and the stress response inventory as the measuring tools. For data analysis, we examined the differences in the profile of mood states and stress response of subjects before and after participation in the program through the paired T-tests with the SPSS 24.0 program. The analysis of the impact of the yoga and meditation-focused forest healing program on the profile of mood states of the test subjects showed the statistically significant reduction of the total score of the profile of mood states. Although the vigor among sub-level inventories increased, it was not statistically significant. But the tension, depression, anger, fatigue, and confusion showed a statistically significant reduction. The analysis of the impact of the yoga and meditation-focused forest healing program on the stress response of the test subjects showed a statistically significant reduction. Among sub-level inventories, the tension, somatization, anger, depression, fatigue, and frustration showed a statistically significant reduction, but the aggressiveness did not. It is expected that the results of this study can be utilized in the future as reference data for clarifying the effects of yoga and meditation-focused forest healing programs.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.667-675
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• 2018

This study was conducted to reveal the effects of forest healing programs on recovery resilience and happiness of university employees. Fourteen people who agreed on experiments were selected as the study subject, with seven people classified the experimental group and seven people into the controlled group. The subjects in the experimental group participated in the forest healing program consisting of four 60-minute long weekly sessions from October 27 to November 17, 2015 in a forest managed by University C located in Cheongju-si of Chungcheongbuk-do. For data analysis, we examined the differences in recovery resilience and happiness before and after participation in the programs through the paired t-test using the SPSS 21.0 program, and the analysis results confirmed that the forest healing program helped to increase the recovery resilience and happiness of the university employees. Although there was no statistically significant change of the controlled group, the recovery resilience and happiness of the experimental group showed a statistically significant increase. The results of this study are expected to be utilized as reference data for clarifying the effects of forest healing programs for university employees.

• Journal of the Korean Geotechnical Society
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• v.34 no.11
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• pp.21-31
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• 2018

Bucket foundations are widely used in offshore areas due to their various benefits such as easy and fast installations. A bucket is installed using self-weight and the hydraulic pressure difference across the lid generated by pumping out water from inside the bucket. When buckets are installed in high permeable soil such as sands, upward seepage flow occurs around the bucket tip and interior, leading to a decrease in the effective stress in the soil inside the buckets. This process reduces the penetration resistance of buckets. However, the soil inside and outside the bucket can be disturbed due to the upward seepage flow and this can change the soil properties around the bucket. Moreover, upward seepage flow can create significant soil plug heave, thereby hindering the penetration of the bucket to the target depth. Despite of these problems, soil disturbance and soil plug heave created by suction installation are not well understood. This study aims to investigate the behavior of soil during suction installation. To comprehend the phenomena of soil plug heave during installation, a series of small-scale model tests were conducted with different testing conditions. From a series of tests, the effects of tip thickness of bucket, penetration rate, and self-weight were identified. Finally, soil properties inside the bucket after installation were approximated from the measured soil plug heave.

• Journal of Software Engineering Society
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• v.28 no.1
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• pp.1-6
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• 2019

Google released an initial version of Android that runs Dex(Dalvik Executable) through the Dalvik Runtime. Since Dalvik Runtime is based on interpreter, JIT(Just-in-time) compilation has been applied to improve performance. After Lollipop(Android 5.0) Dalvik Runtime has replaced with ART Runtime which support AOT (Ahead-of-time) compilation of Dex into Native Code. The late st Android has a problem that the application execution speed is slow until the AOT compilation is completed according to the actual usage record after the installation of the app. To improve the problem we have investigate the characteristics of profile that can improve the execution speed of the application and generate the profile automatically. Finally we propose a method that can optimize the application at install time. With the proposed method we can optimize selectively at install time and can help improving the execution speed of the app from the initial execution.

• The Journal of Korean Association of Computer Education
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• v.22 no.5
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• pp.51-65
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• 2019

This study aims to provide educational implications for more strategic online software education by the types of online learning according to learners' self-regulated learning characteristics in the online software education environment and examining the characteristics of each type. For this, variables related to self-regulated learning characteristic were extracted from the log data of 809 students participating in the online software learning program of K University, and then analyzed using hierarchical cluster analysis. Based on hierarchical cluster analysis learner clusters according to the characteristics of self-regulated learning were derived and the differences between learners' learning characteristics and learning results according to cluster types were examined. As a result, the types of self-regulated learning of online software learners were classified as 'high level self-regulated learning type (group 1)', 'medium level self-regulated learning type (group 2)', and 'low level self-regulated learning type (group 3)'. The achievement level was found to be highest in 'high-level self-regulated learning type (group 1)' and 'low-level self-regulated learning type (group 3)' was the lowest. Based on these results, the implications for effective online software education were suggested.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.13-26
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• 2019

There is a growing interest in the entrepreneurial activity that has long been considered essential for sustainable economic development and value creating. Although it is strongly encouraged by focusing on the positive aspects of venturing, less has been paid attention to entrepreneurial failure, which is the biggest cause of hesitation in starting a business. The uncertain and risky nature of entrepreneurship implies a considerable possibility of failure. Even if it fails, the experience and knowledge of entrepreneurs acquired through entrepreneurship indeed offers valuable lessons for the re-venturing, which can serve as an important social asset that should not be lost. It has been argued that re-entering the same industry for the subsequent venture maximizes the learning effect through utilizing potential benefits from industry-specific knowledge. Although the re-startup after entrepreneurial failure is a very important topic in the studies on serial entrepreneurs, there is a paucity of systematic empirical investigation. This study responds to calls for more research on the re-startup after entrepreneurial failure, and specifically complements existing studies on serial entrepreneurs. Focusing on the entrepreneurs' attribution for the failure, we conducted an empirical analysis of how this affects the re-startup process. Moreover, we also examined the moderating effects of entrepreneurial self-efficacy and resilience. For the analyses, we surveyed the entrepreneurs who tried to re-start the subsequent business after the entrepreneurial failure through the "Revitalization Center for Strained Entrepreneur". The results found that failed entrepreneurs who blamed internal factors for their previous venture failures were likely to keep the same industry for their subsequent business. In addition, the positive effect of internal attribution on maintaining the same industry for the re-startup was found to be stronger when entrepreneurial self-efficacy and resilience were high.