• 제목/요약/키워드: Statistical Power

검색결과 1,618건 처리시간 0.026초

몬테카를로방법을 이용한 V2B(Vehicle to Building) 운용 제로에너지빌딩의 액티브 요소 예측 연구 (Forecast study for active factor of V2B(Vehicle to Building) operation zero energy building using monte carlo method)

  • 김영일;김인수
    • 에너지공학
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    • 제26권4호
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    • pp.29-34
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    • 2017
  • 제로에너지빌딩의 요소는 크게 액티브 요소와 패시브 요소 두 가지로 나뉘며, 패시브 요소의 경우 단열, 창호, 차양, 외부분 등 건물의 단열, 열교 성능 등을 나타내는 요소들을 지칭하며, 액티브 요소의 경우는 에너지생산량 및 효율 계수 등을 나타내는 요소이다. 액티브 요소의 에너지생산량은 일반적으로 신재생에너지 발전을 통해 이루어진다. 본 연구에서는 신재생에너지 발전이 아닌 V2B(Vehicle to Building)라는 전기차의 양방향 충방전 기술이 제로에너지빌딩에 액티브 요소로 적용될 경우 어느 정도의 영향을 미칠지에 대해 예측하였다. 신재생발전의 경우 지리, 기후환경에 따라 발전량이 예측될 수 있지만 V2B의 경우 전기차 이용자의 방전의사, 가용 충전기의 대수 등 여러 가지 입력변수를 고려하여 예측하여야 한다. 예측한 결과에 따라 V2B가 제로에너지빌딩의 액티브 요소에 얼마나 기여할 수 있는지 확인 할 수 있으며, 해당 예측은 통계자료가 부족한 실정이기에 확률적 방법을 이용하여 예측해야한다. 본 연구에서는 해당 확률적 방법 중 몬테카를로 방법을 이용하여 DR(Demand Response)발령 시간대를 기준으로 충방전 패턴의 변화를 예측하였다.

정보영재아동의 학년별 차이 비교 분석에 관한 연구 (A Study on Grade Comparison Difference Analysis of the Gifted Children in IT)

  • 전우천;홍석기
    • 인터넷정보학회논문지
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    • 제15권5호
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    • pp.25-32
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    • 2014
  • 현대 지식정보사회에서 한 나라의 경제력은 IT 산업과 기술에 크게 의존하고 있다. 이러한 관점에서 대부분의 국가들은 새롭고 혁신적인 IT 기술을 개발함으로써 IT 산업을 부흥시키려고 노력하고 있다. 전통적으로 IT 산업에 있어서는 단지 소수의 뛰어난 인재가 전체 산업을 주도하고 있다. 따라서, 조기에 정보영재를 판별하고 양성하는 것은 IT산업의 육성에 있어서 매우 중요하며 필요하다. 본 논문의 목적은 정보영재아동의 학년별 학업능력을 조사하는 것이다. 이러한 목적을 위해 본 연구는 초등학교 4학년, 5학년 및 6학년 정보영재아동에 초점을 두고 있다. 본 연구에서는 정보영재의 다양한 능력 가운데서 프로그래밍 능력과 논리적 사고력에 중점을 두었다. 현재까지 정보영재아동의 학년별 차이를 비교하고 분석한 연구는 없었다. 이러한 연구목적을 위해 서울시의 한 대학부설 과학영재교육원에 재학한 정보영재아동들을 대상으로 연구하였으며, 8년 동안의 성적이 분석되었다. 통계처리결과로부터 정보영재아동의 프로그래밍 능력과 논리적 사고력에 있어서 4학년, 5학년 및 6학년 간에 유의미한 차이는 없다고 결론을 내릴 수 있다. 이 연구결과는 향후 정보영재교육에 있어서 교육내용, 교육과정 및 법과 제도를 제안하는 데 있어서 도움이 될 것으로 기대한다.

전자책 시장 활성화를 위한 기업 요구사항과 CPND 가치사슬 분석 (Study on analysis of the Corporate requirements and CPND Value chain for e-book Market Activation)

  • 나윤빈;유종선;이승하
    • 디지털융복합연구
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    • 제14권4호
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    • pp.163-171
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    • 2016
  • 본 연구는 국내 전자책 시장 활성화를 위해 전자책 기업들의 요구사항과 CPND 가치사슬을 분석하여 정책적 시사점을 도출하였다. 먼저 30개 기업에게 전자책 시장 전망, 제작 및 유통 현황, 서비스 활용인식, 정책지원의 요구사항 등에 대해 질문하였다. 그 결과, 기업에게 필요한 지원사항은 '시장진입 및 판로개척을 위한 홍보 마케팅 지원'(27%) 항목이 가장 높았고, 다음으로 '인건비, 사업비 등 재정지원'과 '해당 분야별 전문성을 길러주는 인력 재교육 지원' 항목이 각각 22%로 높았다. 전자책 기업에 대해 유효한 지원사항은 외부 지원 프로그램(35%), 자금지원(30%)의 순으로 높게 나타났다. 가치사슬 측면에서는 플랫폼 비즈니스를 중심으로 기존 종이책 시장의 일직선상 체계와는 다른 구조를 나타냈다. 특히 공동도서관과 글로벌 유통사의 서비스가 주요 변수로 작용할 것으로 예상되었다. 이러한 연구결과를 종합하면, 국내 전자책 기업의 경쟁력 확보를 위해서는 1)e-pub3 저작도구 및 SNS 마케팅의 활용교육 2)유통판매망의 통계 구축 3)과금체계의 다양화 4)전자책 콘텐츠 품질 인증 등이 필요한 것으로 나타났다.

치기공과 재학생의 건강관련 심신 자각증상에 관한 연구 (A study of the psychosomatic self-reported symptoms of the dental technology students)

  • 권순석
    • 대한치과기공학회지
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    • 제35권2호
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    • pp.157-171
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    • 2013
  • Purpose: This study aims to present a database for the development of a healthcare management program based on the survey and analysis of self reported psychosomatic symptoms among the current dental technology students. Methods: Subjects of our study are 480 dental technology major students enrolled in a third year college located Gyeonggi, Chungcheong, and Gangwon province. Using a random sampling, we conducted a self-report survey from August 30, 2011 to October 28, 2011 and 418 reports were collected as feedback and we put an analysis on them. Results: 1. The average physical self symptom was 20.49, which is higher than the average mental self symptom(18.54). Of the subcategories of psychosomatic self symptom, we observed multiple subjective symptoms as the highest one(37.77), and aggression as the lowest(13.77). 2. As to gender, both physical and mental self symptom were statistically significant with the scale score of(p<.001). The scale score of subcategories is as follows; multiple subjective symptoms(I, p<.001), eye and skin(B, p<.001), digestive(C, p<.001), impulsiveness(H, p<.001), lie scale(L, p<.001), mental instability(J, p<.001), depression(K, p<.001), aggression(F, p<.001), irregularity of life(G, p<.001), mouth and anal(D, p<.05), nervousness(E, p<.05). 3. As for obesity, statistical significance was shown with the scale scores of physical self symptom(p<.001), multiple subjective symptoms(I, p<.001), digestive(C, p<.001), aggression(F, p<.001), depression(K, p<.01), irregularity of life(G, p<.01), respiratory(A, p<.05), eye and skin(B, p<.05), impulsiveness(H, p<.05), mental instability(J, p<.05). The scale scores in the environmental quality and life satisfaction were shown as follows; depression(K, p<.001), lie scale(L, p<.01), and irregularity of life(G, p<.05). 4. We employed multiple regression analysis to take account of general factors affecting psychosomatic self symptoms, and drew that the explanatory power of the model was proved with the scales of physical self symptom(4.1%) and mental self-symptom(3.6%). Obesity was a factor that affects physical self symptom with the scale score of(p<.01), and environmental quality and life satisfaction(p<.01) and obesity(p<.05) affect mental self symptom. Conclusion: In this analysis we observed obesity of dental technology students can influence their psychosomatic self symptoms. In this sense, it would be reasonable to develop a healthcare management and education programs that help the students maintain a healthy weight and promote their health.

ANALYSIS OF THE TRANSPORTATION LOGISTICS FOR SPENT NUCLEAR FUEL IN KOREA

  • Lee, Hyo-Jik;Ko, Won-Il;Seo, Ki-Seok
    • Nuclear Engineering and Technology
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    • 제42권5호
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    • pp.582-589
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    • 2010
  • As a part of the back-end fuel cycle, transportation of spent nuclear fuel (SNF) from nuclear power plants (NPPs) to a fuel storage facility is very important in establishing a nuclear fuel cycle. In Korea, the accumulated amount of SNF in the NPP pools is troublesome since the temporary storage facilities at these NPP pools are expected to be full of SNF within ten years. Therefore, Korea cannot help but plan for the construction of an interim storage facility to solve this problem in the near future. Especially, a decision on several factors, such as where the interim storage facility should be located, how many casks a transport ship can carry at a time and how many casks are initially required, affect the configuration of the transportation system. In order to analyze the various possible candidate scenarios, we assumed four cases for the interim storage facility location, three cases for the load capacity that a transport ship can carry and two cases for the total amount of casks used for transportation. First, this study considered the currently accumulated amount of SNF in Korea, and the amount of SNF generated from NPPs until all NPPs are shut down. Then, how much SNF per year must be transported from the NPPs to an interim storage facility was calculated during an assumed transportation period. Second, 24 candidate transportation scenarios were constructed by a combination of the decision factors. To construct viable yearly transportation schedules for the selected 24 scenarios, we created a spreadsheet program named TranScenario, which was developed by using MS EXCEL. TranScenario can help schedulers input shipping routes and allocate transportation casks. Also, TranScenario provides information on the cask distribution in the NPPs and in the interim storage facility automatically, by displaying it in real time according to the shipping routes, cask types and cask numbers that the user generates. Once a yearly transportation schedule is established, TranScenario provides some statistical information, such as the voyage time, the availability of the interim storage facility, the number of transported casks sent from the NPPs, and the number of transported casks received at the interim storage facility. By using this information, users can verify and validate a yearly transportation schedule. In this way, the 24 candidate scenarios could be constructed easily. Finally, these 24 scenarios were compared in terms of their operation cost.

전처리 방법에 따른 참외와인의 품질특성과 항산화능 (Quality characteristics and antioxidant capacities of oriental melon wine depending on pretreatments)

  • 황희영;하형태;하세비;성기운;황인욱;정신교
    • 한국식품저장유통학회지
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    • 제22권3호
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    • pp.421-427
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    • 2015
  • 고품질 참외와인을 제조하기 위하여 브랜칭 및 착즙 처리를 하여 발효와 숙성에 따른 이화학적 특성 및 항산화능을 조사하였다. 발효 중 참외와인의 이화학적 특성은 모든 처리구가 유사한 추이를 보였으며, 브랜칭 및 착즙 처리가 알코올 발효에 영향을 미치지 않았다. 숙성 후 이화학적 특성을 측정한 결과는 알코올 함량, 가용성 고형분 함량, 환원당 함량, 적정 산도, pH가 각각 11.5~11.8%, 10.7~11.2%, 0.25~0.49 g/100 mL, 0.60~0.81%, 3.75~3.89 범위로 나타났으며, 숙성 전에 비하여 가용성 고형분, 환원당, 알코올 함량, 적정산도는 감소하고 pH는 증가하는 것으로 나타났다. 항산화능은 DPPH 라디칼 소거 활성, FRAP 활성이 각각 $563.00{\sim}785.00{\mu}M\;TE$, $504.60{\sim}811.93{\mu}M\;TE$ 범위로 나타났으며, 브랜칭 처리구의 항산화 활성이 높았다. 총페놀성 화합물 함량은 287.53~312.08 mg/L 범위로 전처리 방법에 따른 유의적인 차이가 나타나지 않았으며(p<0.05), 총플라보노이드 함량은 39.06~141.03 mg/L 범위로 브랜칭 처리구의 함량이 높았다. 또한 QDA profile 결과는 색, 맛, 풋내, 이취, 종합적 기호도 항목에서 모두 브랜칭 처리구가 더 높은 점수를 얻었다. 브랜칭 처리는 참외와인의 항산화능을 증가시키고 기호성을 좋게 하는 반면, 착즙 처리는 참외와인 제조 시 영향을 미치지 않는 것으로 나타났다.

지하철 근로자의 직장 내 폭력과 정신건강과의 관련성에 대한 융복합 연구 (Convergence Study on Relationship between Workplace Violence and Mental Health for Subway Workers)

  • 최숙경
    • 디지털융복합연구
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    • 제14권11호
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    • pp.379-388
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    • 2016
  • 본 연구는 서울시 소재 지하철 근로자 876명을 대상으로 직장 내 폭력경험 실태를 파악하고, 직장 내 폭력과 정신건강과의 관련성을 파악하고자 실시하였다. 자료수집은 구조화된 설문지로 웹 사이트에서 하였고, 자료분석은 SPSS 20.0 통계프로그램을 이용하여 다중선형회귀분석을 실시하였다. 연구결과, 직장 내 폭력경험 실태에서 신체적 폭력, 언어적 폭력, 성희롱 및 인격무시 모두에서 폭력의 주체가 '고객'으로 나타났다. 직장 내 폭력과 정신건강과의 관련성에서는 직장 내 폭력유형인 신체적 폭력, 언어적 폭력, 성희롱 및 인격무시 모두에서 정신건강의 하위영역과 통계적으로 유의한 차이가 있었다. 직장 내 폭력이 정신건강에 미치는 영향에서는 신체적 폭력, 성희롱 및 인격무시에서 유의한 차이가 있는 것으로 나타났으며, 설명력은 8.3%이었다. 본 연구는 지하철 근로자를 대상으로 직장 내폭력 경험 실태를 파악한 것과 정신건강에 미치는 영향을 통계분석을 통하여 이들 간의 관계를 분석하였다는데 의의가 있다. 향후 지하철 근로자의 직장 내 폭력을 예방할 수 있는 고객응대 가이드라인 마련과 근무환경에 맞는 구체적인 폭력예방대책을 마련하여 적용할 것을 제안한다.

Assessment of Respiratory Problems in Workers Associated with Intensive Poultry Facilities in Pakistan

  • Yasmeen, Roheela;Ali, Zulfiqar;Tyrrel, Sean;Nasir, Zaheer Ahmad
    • Safety and Health at Work
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    • 제11권1호
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    • pp.118-124
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    • 2020
  • Background: The poultry industry in Pakistan has flourished since the 1960s; however, there are scarce data regarding the impact of occupational exposure on the pulmonary health of farm workers in terms of years working in the industry. The objective of the present study was to assess the effect of poultry environment on the health of occupationally exposed poultry farmers in countries of warm climatic regions, such as Pakistan. This study will also show the effect of exposure to poultry facilities on the health of poultry farmers in the context of low-income countries with a relatively inadequate occupational exposure risk management. Materials and methods: The lung function capacity of 79 poultry workers was measured using a spirometer. Along with spirometry, a structured questionnaire was also administrated to obtain information about age, height, weight, smokers/nonsmokers, years of working experience, and pulmonary health of farm workers. The workers who were directly involved in the care and handling of birds in these intensive facilities were considered and divided into four groups based on their years of working experience: Group I (3-10 months), Group II (1-5 years), Group III (6-10 years), and Group IV (more than 11 years). The forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio were considered to identify lung function abnormalities. Statistical analysis was carried out using independent sample t test, Chi-square test, Pearson's correlation, and linear regression. Results: Based on the performed spirometry, 68 (86 %) of workers were found normal and healthy, whereas 11 (14 %) had a mild obstruction. Of the 11 workers with mild obstruction, the highest number with respect to the total was in Group IV (more than 11 years of working experience) followed by Group III and Group II. Most of the workers were found healthy, which seems to be because of the healthy survivor effect. For the independent sample t test, a significant difference was noticed between healthy and nonhealthy farmers, whereas Chi-square test showed a significant association with height, drugs, and working experience. Linear regression that was stratified by respiratory symptoms showed for workers with symptoms, regression models for all spirometric parameters (FVC, FEV1, and FEV1/FVC) have better predictive power or R square value than those of workers without symptoms. Conclusion: These findings suggest that lung function capacity was directly related to years of working experience. With increasing number of working years, symptoms of various respiratory problems enhanced in the poultry workers. It should be noted that most of the poultry workers were healthy and young, the rationale being that there is a high turnover rate in this profession. The mobility in this job and our finding of 86% of the healthy workers in the present study also proposed healthy worker survivor effect.

대구지역 대학생의 영양섭취상태, 체형만족도, 체력상태 및 그 관련성 (Relations among Nutrient Intake, Body Image Satisfaction, and Physical Fitness of College Students in Taegu)

  • 최미자;류숙희;김기진
    • 동아시아식생활학회지
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    • 제9권3호
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    • pp.325-335
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    • 1999
  • The aim of the present study was to evaluate the relations among nutrient intake. self body image and satisfaction, and physical fitness of college students in Taegu. A total of 213 apparently healthy college students living in Taegu were selected for the study. The following anthropometric measurements were made on all participants : weight, height: waist and hip circumferences, and bioimpedence. Using weight and height, the body mass index (kg/$m^2$) was calculated. The 24-hour recall were obtained from subjects. Dietary habits and energy expenditure were examined through questionnaires. Nutrients intake were analyzed by computer aided nutritional analysis program. Variables of Physical fitness were consisted of body fat, muscular strength and endurance, agility. power, flexibility, cardiorespiratory function, physical efficiency index(PEI). Data were analyzed by computer using the SAS 6.12(Statistical Analysis System). The mean heights and weights of these students were similar to those reported for the 50th percentile in a national survey. Nutrient intake of the college students in Taegu was considerably lower than RDA. The male subjects' mean intake of two nutrients, vitamin B$_2$ and calcium, were less than 55% of the RDAs. the female subjects' mean intake of two nutrients, iron and calcium, were less than 55% of the RDAs. A most variables of physical fitness except sit and reach in male students showed a significant higher values than those of female students. There was a significant positive relationship between PEI and the intake of animal protein, fat, Ca. and B$_2$ in male students. Also there was a significant positive relationship between exercise duration of PWC 170 and protein, fat, iron, vitamin A, B$_2$, niacin, and energy intake in female students. The muscular strength showed the significant correlation with weight, height, and waist circumference in male and female students. The cardiorespiratory function and Physical efficiency index showed significantly negative correlation with tricep and subscapular skin thickness in the female students. There were significantly positive correlations between WHR and body efficiency index in male students, and significantly positive correlations between WHR and the cardiorespiratory function in female students. There was no significant level of correlation between the degree of satisfaction of body image and physical efficiency index. However. there was a significant positive correlation between waist circumference (and weight) and physical efficiency index in male and female students and almost all of the surveyed male and female college students wanted less waist circumference or weight even though they were in the criteria of standard waist circumference or weight. In conclusion, a beneficial effect of adequate nutrient intake on physical fitness was found, college students must increase their energy and nutrient intake if it is below than the RDA for improving their physical fitness.

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임피던스 변환 회로를 이용한 건식능동뇌파전극 개발 (Development of an Active Dry EEG Electrode Using an Impedance-Converting Circuit)

  • 고덕원;이관택;김성민;이찬희;정영진;임창환;정기영
    • Annals of Clinical Neurophysiology
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    • 제13권2호
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    • pp.80-86
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    • 2011
  • Background: A dry-type electrode is an alternative to the conventional wet-type electrode, because it can be applied without any skin preparation, such as a conductive electrolyte. However, because a dry-type electrode without electrolyte has high electrode-to-skin impedance, an impedance-converting amplifier is typically used to minimize the distortion of the bioelectric signal. In this study, we developed an active dry electroencephalography (EEG) electrode using an impedance converter, and compared its performance with a conventional Ag/AgCl EEG electrode. Methods: We developed an active dry electrode with an impedance converter using a chopper-stabilized operational amplifier. Two electrodes, a conventional Ag/AgCl electrode and our active electrode, were used to acquire EEG signals simultaneously, and the performance was tested in terms of (1) the electrode impedance, (2) raw data quality, and (3) the robustness of any artifacts. Results: The contact impedance of the developed electrode was lower than that of the Ag/AgCl electrode ($0.3{\pm}0.1$ vs. $2.7{\pm}0.7\;k{\Omega}$, respectively). The EEG signal and power spectrum were similar for both electrodes. Additionally, our electrode had a lower 60-Hz component than the Ag/AgCl electrode (16.64 vs. 24.33 dB, respectively). The change in potential of the developed electrode with a physical stimulus was lower than for the Ag/AgCl electrode ($58.7{\pm}30.6$ vs. $81.0{\pm}19.1\;{\mu}V$, respectively), and the difference was close to statistical significance (P=0.07). Conclusions: Our electrode can be used to replace Ag/AgCl electrodes, when EEG recording is emergently required, such as in emergency rooms or in intensive care units.