• 한국보육지원학회지
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• 제15권3호
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• pp.61-81
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• 2019

Objective: This study aimed to examine the effects of collaborative activities by utilizing picture books in order to improve the self-regulation and perspectivetaking abilities among four-year-olds. Methods: A total of 52 four-year-olds(control group 26, experimental group 26) attending two classes at D kindergarten located in B city participated in this study. Before and after the activities, all participants individually took a social perspective taking ability instrument and rated their self-regulation with a teacher. Data were analyzed by conducting ANCOVA in the way of setting pre-test scores as the covariate and post-test scores as the dependent variable. Results: First, the total and subarea of self-regulation in the experimental group was higher than the control group. Second, the cognitive and emotional perspective taking abilities in the experimental group were higher than the control group in all cares. Conclusion/Implications: The results of this study suggest that collaborative activities using picture books are effective in improving young children's selfregulation and perspective-taking abilities.

• 한국표면공학회지
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• 제57권3호
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• pp.179-191
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• 2024

This study focuses on improving the photocatalytic degradation efficiency by synthesizing a TiO₂/WO₃ composite. Given the environmental significance of photocatalysis and the limitations posed by TiO₂'s large bandgap and high electron recombination rate, we explored doping, surface modification, and synthesis strategies. The composite was created using a ball mill process and heat treatment, analyzed with field emission scanning electron microscope, high resolution X-ray diffraction, Raman microscope, and UV-Vis/NIR spectrometer to examine its morphology, composition and absorbance. We found that incorporating WO₃ into the TiO₂ lattice forms a W_x-Ti_1-x-O₂ solution, with optimal WO₃ content reducing the band gap and enhancing sterilization efficiency by inhibiting the anatasese to rutile transition. This contributes to the field by offering a way to overcome TiO₂'s limitations and improve photocatalytic performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권5호
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• pp.1223-1237
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• 2024

Autonomous vehicles use onboard sensors to sense the surrounding environment. In complex autonomous driving scenarios, the detection and recognition capabilities are constrained, which may result in serious accidents. An efficient way to enhance the detection and recognition capabilities is establishing collaborations with the neighbor vehicles. However, the collaborations introduce additional challenges in terms of the data heterogeneity, communication cost, and data privacy. In this paper, a novel personalized federated learning framework is proposed for addressing the challenges and enabling efficient collaborations in autonomous driving environment. For obtaining a global model, vehicles perform local training and transmit logits to a central unit instead of the entire model, and thus the communication cost is minimized, and the data privacy is protected. Then, the inference similarity is derived for capturing the characteristics of data heterogeneity. The vehicles are divided into clusters based on the inference similarity and a weighted aggregation is performed within a cluster. Finally, the vehicles download the corresponding aggregated global model and train a personalized model which is personalized for the cluster that has similar data distribution, so that accuracy is not affected by heterogeneous data. Experimental results demonstrate significant advantages of our proposed method in improving the efficiency of collaborative perception and reducing communication cost.

• 한국컴퓨터정보학회논문지
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• 제25권10호
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• pp.51-58
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• 2020

DDS 디스커버리는 같은 도메인을 사용하고, 다른 노드에 존재하는 DDS 객체를 찾는 과정이다. 한 노드에서 DDS 디스커버리 과정이 실패한다면, DDS 디스커버리가 실패한 노드에서 정상적인 DDS 데이터 송수신이 불가능하여 시스템 운용에 큰 영향을 미칠 수 있다. 그렇기 때문에, DDS 디스커버리의 성능을 향상시켜 DDS 디스커버리 과정을 빠르게 완료하고, 네트워크 부하와 컴퓨터 자원 사용량을 줄여서 DDS 디스커버리가 실패할 수 있는 가능성을 줄일 수 있다면 전체 시스템의 성능 향상에 큰 영향을 줄 수 있다. 본 논문에서는 대용량 시스템에서 DDS 디스커버리 시간과 네트워크 부하, 컴퓨터 자원 사용량을 줄일 수 있는 성능 향상을 위한 새로운 방법을 제안하고, 시험을 통하여 제안한 방법의 효율성을 증명한다.

• 한국지반신소재학회논문집
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• 제11권3호
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• pp.53-58
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• 2012

국내에는 약 17,531개의 소규모 농업용 댐과 저수지가 있다. 댐의 95%는 필댐이며, 심한 파손 또는 수리 또는 보수가 필요하다. 그러므로 댐을 평가하고 문제점을 도출해야 한다. 또한 댐은 보수의 시기가 적절해야 한다. 댐의 안전성 평가는 소규모 농업용 댐과 저수지의 적절한 기능을 보증하고 손상을 최소화하기 위하여 수행한다. 본 논문에서는 농업용 저수지의 체계적인 유지관리를 위한 유지관리 규정을 정립하고, 시 군 구에서 관리하고 있는 농업용 저수지 현황 분석을 통하여 소규모 저수지의 안전관리의 개선 방향을 모색하고자 하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.460-463
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• 2008

A large part of the overall industrial energy is dissipated as waste heat despite of much development in the utilization of thermal energy. A mean efficiency is reported to be only around 30 to 35%. The existing waste heat recovery technology has reached its limit and consequently, the development of a new technology is necessary. Improving efficiency using thermoelectric technology has recently come into the spotlight because of its unique way to recover thermal energy. In fact, thermoelectric generator directly converts thermal energy into electric energy by a solid state without any moving parts. Futhermore remarkable improvement in the thermoelectric energy conversion efficiency has been achieved. In this study, a thermoelectric generator was made using commercialized thermoelectric modules. With thermoelectric modules attached on a duct surface, hot air was blown into the duct using a hot air blower. On the other side of the module, a water jacket was attached to cool the module. With different air inlet temperatures and water flowrates, the electrical power of the thermoelectric generator was measured.

• 한국보건간호학회지
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• 제25권1호
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• pp.38-47
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• 2011

Purpose: The study investigated the effects of 9 weeks of group music rope-jumping training on health-related physical fitness and blood lipid in obese elementary school boys and girls. Method: Subjects were randomly assigned to either a training group (37 boys and 18 girls) or control group (36 boys and 19 girls). The training group exercised for 1 hour, 2 days per week during the 9-week supervised music rope-jumping training program. The control group was asked to maintain their normal daily physical activities. The effects of the interventions on physical fitness and blood lipids were analyzed by two-way repeated measures ANOVA (group ${\times}$ time). Results: There were significant group ${\times}$ time interaction effects on body weight (p<.023), %body fat (p=.09), body mass index (p=.018), and body fat mass (p=.019) in school girls. However, there was not an interaction effect on serum lipids in both genders. Conclusion: The 9-week music rope-jumping training program used was effective for improving body composition in obese elementary school girls.

• 한국실내디자인학회논문집
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• 제21권2호
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• pp.223-230
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• 2012

These days, hospitals in Korea have great interests in healthcare accreditation. The criteria of this accreditation has been established by management, but development of the management system without facility improvement has limits. Therefore this study reclassified domestic and foreign healthcare accreditation focusing on facilities and has purpose on proposing facility elements that can be adopted in hospitals. Also, the study is relevant to the study on architecture planning of hospital according to 'Patient safety' which will be suggested in the future and has significance for establishing basis of healthcare facility planning and for improving the existing facilities. The study selected facility lists from 'healthcare accreditation' and reclassified them based on departments in the hospital. Using these lists, the study divided the hospital that has obtained 'healthcare accreditation' into departments and investigated and analyzed them. On the basis of the analysis, the study suggested facility lists involved in hand washing, waste disposal, equipment washing, quarantine, goods-movement, establishing clean/polluted area, emergency exit-way, and restricted zone.

• 한국건설관리학회논문집
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• 제2권4호
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• pp.48-61
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• 2001

본 연구에서는 작업 신뢰도 향상의 한 방안으로 기존 공정 관리 기법 상의 한계점을 분석하여 이를 보완하고자 하였다. 그 결과로써 린 생산 원리를 적용한 건설 생산 공정 개선 모델인 CPAM(Construction Process Analysis Model)을 제시하였다. CPAM의 변이 관리 기법을 통해 작업 변이를 최소화시켜 공정계획의 신뢰도 향상 및 생산 효율을 증대시킬 수 있도록 하였고 CPAM에서 제시된 세부작업 일정 계획과 주간작업계획을 통해 건설 현장의 작업 흐름에서 나타날 수 있는 자재, 장비, 인력등의 재고(Inventory or Work In Process, WIP)를 감소시킬 수 있도록 하였다. 또한 본 연구는 건설 생산을 작업 흐름의 관점으로 분석함으로써 기존의 분석에서 놓치기 쉬운 작업 흐름상에서의 불확실성을 최소화시키고 작업 처리량을 최대화시킬 수 있는 대안을 제시하는 데 그 의의가 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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• pp.194-196
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• 2001

Light dimming is based on adjusting the voltage which gets to the lamp. Light dimming has been possible for many decades by using adjustable power resistors and adjustable transformers. The power electronics have proceeded quietly since 1960. Between 1960-1970 thyristors and triacs came to market. Using those components it was quite easy to make small and inexpensive light dimmers which have goof efficiency. This type of electronic light dimmers became available after 1970 and are nowadays used in very many locations like homes, restaurants, conference rooms and in stage lighting. But the problem of thyristor dimmer have been that it has poor efficiency and voltage drop. Recently IGBT(Insulated Gate Bipolar Transistor) control is a new way to do light dimming for improving this problems. IGBT dimmer has many other advantages over traditional thyristor dimmer there are no huge current spikes and EMI caused by turn on Using IGBT it is possible to make the turn-off rate relatively slot to achieve quite operations in terms of EMI and acoustical or incandescent lamp filament noise. For the development of IGBT dimmer. This paper shows the effects of IGBT dimmer compared with thyristor dimmer through a simulation using EMTDC.