• 한국물환경학회지
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• 제22권3호
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• pp.437-443
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• 2006

The Water usage is relationship which is close with the administrative cost from industrial facility. It is not easy to reduce a water usage. This research is the optimization of the waste water quantity which process waste water integration of the standard thermal power plant in system operate time. The turbine rotates by force of the steam and it produces an electricity. Demineralization Water is manufacture purity manufacturing equipment and it is supplied in power plant channel. We knew a possibility of reducing from pure control process. When it is reduced the Back Washing time, Rinsing time of the gravity filter and the activated carbon filter. Also, It is possible even from regeneration phase in Condensate Polishing Demineralization System. In addition, There is also the water which the drain of the sampling water for watching the condition of power plant process will be able to use. Integrates these processes it will be able to reduce an annual 30,000 ton degree. The research is want to use the fundamental data for the water curtailment of the power plant.

• 한국컴퓨터정보학회논문지
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• 제24권2호
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• pp.179-184
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• 2019

As the tendency of children's overdependence on smart phones increased, it was obligatory to carry out preventive education more than once a year in kindergarten and day care center, but there is no specific guidance on contents and method of preventive education. This is due to the lack of prior studies on the actual use of smartphones and the influence variables of infants and young children. The purpose of this study was to investigate the effects of use time, frequency of use, and sociological background variables on the actual situation of smartphone usage and overdependency on smartphone among 3-5 year old children nationwide. For the analysis, the frequency of the use of smartphone for 3-5 year old children was analyzed by frequency analysis, and the influence variables were correlated and multiple regression analysis. Research shows that smartphone overdependence of 3-5 year old children have an influence on the use time and frequency of use. The results should include content that restricts the use time and frequency of use of smartphones and prevention education programs for 3-5 year olds and young children. Suggesting a need for a transition to the educational method used.

• 한국인터넷방송통신학회논문지
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• 제16권3호
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• pp.187-201
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• 2016

본 연구는 20세에서 23세 사이의 대학생 7명을 대상으로 스마트폰 사용에 대한 경험 구조를 분석하고자 총 4회에 걸친 인터뷰를 실시하였다. Giorgi의 현상학적방법을 이용하여 분석한 결과 4개의 일반적 구조문장과 28개의 주제로 작성할 수 있었다. 일반적 구조문장은 스마트폰 사용의존, 스마트폰 사용현상, 스마트폰 사용결과, 스트레스와 스마트폰과의 관계이었고 주제는 양가감정, 스마트폰에 대한 긍정적 감정, 분리불안, 스마트폰에 대한 부정적 감정, 스마트폰에 의존되어 있는 감정, 스마트폰과의 일체감, 생활의 보조 역할, 깊게 삶에 관여함, 일상생활에 유용함, 학습 소통 휴식과 건강관리, 인간관계 유지, 가장 중요한 존재, 깊이가 얕은 관계의 속상함, 대인관계 방해, 부정적인 대인관계 형성, 사적인 부분 침해, 부정확한 인맥 구축, 어쩔 수 없이 참여, 개선하지 않으려는 인간관계, 집중력 저하, 학업에 방해, 학업에 도움, 심층학습 성취에는 한계적 도움, 스트레스 도피 공간, 스트레스 증폭, 강박적 집중, 괴리감, 시간낭비이었다. 결론적으로, 현재 대학생에게 스마트폰의 사용은 스마트폰에 의존하게 되었고, 인간관계와 학업에 있어서 부정적인 영향을 미치고 있었으며, 스트레스를 증폭시켰다. 이에 따라 스마트폰 사용의 원칙이 필요하고, 합리적인 스마트폰 사용을 위한 문화 구축을 제언한다.

• 대한임베디드공학회논문지
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• 제12권3호
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• pp.121-130
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• 2017

NAND flash memory has advantages of non-volatility, little power consumption and fast access time. However, it suffers from inability that does not provide to update-in-place and the erase cycle is limited. Moreover, the unit of read/write operation is a page and the unit of erase operation is a block. Therefore, erase operation is slower than other operations. The AGC, the proposed garbage collection policy focuses on not only garbage collection time reduction for real-time guarantee but also wear-leveling for a flash memory lifetime. In order to achieve above goals, we define three garbage collection operating modes: Fast Mode, Smart Mode, and Wear-leveling Mode. The proposed policy decides the garbage collection mode depending on system CPU usage rate. Fast Mode selects the dirtiest block as victim block to minimize the erase operation time. However, Smart Mode selects the victim block by reflecting the invalid page number and block erase count to minimizing the erase operation time and deviation of block erase count. Wear-leveling Mode operates similar to Smart Mode and it makes groups and relocates the pages which has the similar update time. We implemented the proposed policy and measured the performance compare with the existing policies. Simulation results show that the proposed policy performs better than Cost-benefit policy with the 55% reduction in the operation time. Also, it performs better than Greedy policy with the 87% reduction in the deviation of erase count. Most of all, the proposed policy works adaptively according to the CPU usage rate, and guarantees the real-time performance of the system.

• Human Ecology Research
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• 제61권2호
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• pp.169-182
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• 2023

This study aimed to investigate the mediating effect of the screen media time of young children on the relationship between mothers' reasons for allowing young children to use screen media and their children's ability to regulate screen media. The participants consisted of 614 children aged 5-6 (312 boys and 302 girls), and all the survey questions were answered by their mothers. Descriptive statistics, Pearson's correlation, structural equation modeling, and bootstrapping analysis were employed to analyze the data using SPSS 25.0 and Mplus 8.6. The results were as follows. First, mothers' educational and ritualized reasons for allowing young children to use screen media and children's screen media time directly affected young children's ability to regulate screen media. Second, children's screen media time mediated the relationship between mothers' educational and ritualized reasons for allowing their children to use screen media and children's ability to regulate screen media. When mothers permitted their children to use screen media for educational purposes, their children were likely to spend less time on screen media usage which, in turn, increased their ability to regulate screen media. Conversely, the more mothers allowed their children to use screen media for ceremonial purposes, the more time their children spent on screen media and the less ability they had to regulate screen media usage. These outcomes suggest that, to improve children's screen media regulation ability, mothers must not routinely allow their children to use screen media and should manage their children's screen media time.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.199-202
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• 2009

Adaptive memory management is a serious issue in data stream management. Data stream differ from the traditional stored relational model in several aspect such as the stream arrives online, high volume in size, skewed data distributions. Data skew is a common property of massive data streams. We propose the predicted allocation strategy, which uses predictive processing to cope with time varying data skew. This processing includes memory usage estimation and indexing with timestamp. Our experimental study shows that the predictive strategy reduces both required memory space and latency time for skewed data over varying time.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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• pp.11-11
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• 2010

Recently, annual usage of energy is dramatically increasing by industrialization is going faster and more electricity is needed due to various electronic devices. This paper present relationships between the Vmax, $V_T$, load and time constant of solar cell charge and discharge curve. Charging and discharging recording where the external resistance will become larger Vmax, $V_T$ is decrease and the time increases and decreases there is a possibility of knowing.

• 대한지역사회작업치료학회지
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• 제9권3호
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• pp.21-30
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• 2019

목 적 : 본 연구는 작업 균형(Occupational Balance)과 성공적인 노화연구(Well Elderly Research Study)를 이론적 근거로 라이프스타일 재설계 프로그램을 적용하여 뇌졸중 노인의 시간 사용과 삶의 질에 미치는 효과를 확인하고자 하였다. 연구방법 : 요양병원에 거주하는 뇌졸중 노인 총 40명(실험군 20명, 대조군 20명)을 대상으로 통제집단 사전사후검사 설계(pretest-posttest control group design)를 시행하였다. 라이프스타일 재설계 프로그램에 참여하기 전 2주 동안 사전평가를 실시하였고, 이 후 10주 동안 주 7회 라이프스타일 재설계 프로그램을 적용하였으며, 이 후 1주 동안은 사후 평가를 실시하였다. 대상자의 시간 사용은 통계청(2009) 생활시간 조사표를 사용하였고, 삶의 질의 경우 세계보건기구 삶의 질 평가도구(WHOQOL-BREF)를 사용하였다. 결과 : 프로그램 적용 전과 후의 시간 사용량 비교 결과 실험군의 경우 휴식과 수면(t=-4.89, p<.001), 여가(t=-4.67, p<.001)에서 통계적으로 유의한 차이를 확인할 수 있었다. 또한 집단 간 비교 결과 역시 휴식과 수면(t=-2.24, p<.01) 그리고 여가(t=3.57, p<.01)에서 통계적으로 유의한 차이가 나타났다. 삶의 질 비교 결과 두 그룹 간 통계적으로 유의한 차이가 나타났다(t=6.80, p<.001). 삶의 질 하위영역을 살펴보면 신체적 건강영역(t=6.08, p<.001), 심리적 건강영역(t=5.21, p<.001), 생활 환경영역(t=3.60, p<.01)에서 통계적으로 유의한 차이를 확인할 수 있었다. 결론 : 라이프스타일 재설계 프로그램은 요양병원에 거주하는 뇌졸중 노인의 휴식과 수면의 시간 사용은 줄이고, 여가생활에 참여하는 시간 사용을 늘려주었으며, 그로 인해 삶의 질이 향상되는 결과를 나타내었다.

• 한국정보통신학회논문지
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• 제24권4호
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• pp.536-545
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• 2020

모바일 스마트 장치 배터리의 잔여 시간을 예측하기 위해 범용 통계적 회귀 기법을 적용한 경우, 배터리 잔량별 배터리 사용 시간의 편차가 커질수록 범용 통계적 회귀 기법의 예측 정확도가 낮아진다. 따라서 범용 통계적 회귀 기법의 예측 정확도를 향상시키기 위해서는 배터리 잔량별 배터리 사용 시간의 편차가 큰 원 측정 데이터를 가공 처리하여 정제된 데이터로 변환시키는 작업이 필요하다. 이에 본 논문에서는 원 측정 데이터를 정제된 데이터로 가공 처리하는 데이터 전처리 프레임워크를 제안하였다. 제안한 프레임워크를 통해 가공 처리하여 정제된 데이터를 범용 통계적 회귀 기법에 적용한 결과, 범용 통계적 회귀 기법의 예측 정확도가 향상됨을 확인하였다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제34권3호
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• pp.175-180
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• 2023

Objectives: The coronavirus disease 2019 (COVID-19) pandemic has led to a decrease in face-to-face classes worldwide, affecting the mental health of children and their parents. The global pandemic has increased children's overall use of electronic media. This study analyzed the effect of children's screen time on problematic behaviors during the COVID-19 pandemic. Methods: A total of 186 parents from Suwon, South Korea, were recruited to participate in an online survey. The mean age of the children was 10.14 years old, and 44.1% were females. The questionnaire included questions on children's screen time, problematic behaviors, and parental stress. Children's behavioral problems were evaluated using the Behavior Problem Index, whereas the Parental Stress Scale was used to estimate parental stress. Results: The mean smartphone usage frequency of the children was 5.35 days per week, and the mean smartphone screen time was 3.52 hours per day. Smartphone screen time (Z=4.49, p<0.001) and usage frequency (Z=2.75, p=0.006) were significantly correlated with children's behavioral problem scores. The indirect effect of parental stress on this relationship was also statistically significant (p=0.049, p=0.045, respectively). Conclusion: This study suggests that children's smartphone screen time has affected problematic behaviors during the COVID-19 pandemic. Furthermore, parental stress is related to the relationship between children's screen time and problematic behaviors.