• 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.

• 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.

• 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.

• 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.

• 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.

• 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.

• 한국직업건강간호학회지
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• 제24권2호
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• pp.122-131
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• 2015

Purpose: The purpose of this study was to investigate what factors are affecting job-seeking stress in nursing students. Methods: Subjects were 463 students from two 3-year and two 4-year colleges of nursing in K-Province in Korea. Data was collected from self-administered questionnaires. t-test, ANOVA, Pearson's and Spearman's correlation coefficients, and hierarchical multiple regression with dummy variables were used for statistical analysis of data. Results: Job-seeking stress was significantly different by school system (t=2.76, p=.006), family economic status (F=3.40, p=.005), characteristics (t=1.99, p=.047), academic achievement (F=6.54, p=.002), current weight control status (t=2.23, p=.026), times of cosmetic surgery (r=.11, p=.022), self-esteem (r=-.47, p<.001) and appearance stress (r=.40, p<.001). However, after controlling for general characteristics, self-esteem, and perceived appearance stress, job-seeking stress was significantly different by grade (1st vs 3rd, ${\beta}=0.163$, p<.001), academic achievement (low vs. high, ${\beta}=-0.121$, p=.0321), self-esteem (${\beta}=-0.224$, p<.001), and appearance stress (${\beta}=0.099$, p<.001). The explanation power of self-esteem on job-seeking stress was greater compared with that of appearance stress. Conclusion: Results of this study suggest that it is necessary for nursing students to develop intervention program aimed at reducing job-seeking stress, and it would be effective to focus on improving self-esteem for them.

• 한국시뮬레이션학회논문지
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• 제20권3호
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• pp.69-78
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• 2011

대규모 센서 네트워크를 구성하는 센서 노드는 개방된 무인 환경에서 동작한다. 악의적인 공격자는 일부 센서 노드를 탈취 하여 허위 보고서를 주입할 수 있다. 통계적 여과 기법은 이러한 허위 보고서 주입 공격에 대응하기 위한 기법으로 보고서 전달 과정 중에 허위 보고서를 검출하고 여과할 수 있는 방법을 제안하였다. 통계적 여과 기법에서는 적절한 전달 경로 설정을 통하여 허위 보고서 검출 성능 향상뿐만 아니라 에너지 효율 또한 높일 수 있다. 하지만 네트워크의 위상 변화와 노드의 에너지고갈 등의 다양한 환경 변화로 인하여 전달 경로를 재설정해야 하는 경우가 빈번히 발생한다. 빈번한 경로 재설정은 과도한 에너지 소모를 유발하므로 적절한 경로 재설정 주기를 결정하는 것은 매우 중요하다. 본 논문에서는 센서 네트워크의 제안된 에너지를 효율적으로 사용하기 위한 영역별 경로 재설정 주기 결정 기법을 제안한다. 제안 기법은 퍼지 시스템을 이용해 각 영역의 경로 재설정 주기를 동적으로 결정한다. 또한 주기가 결정된 영역에 대해 적절한 보안 수준을 결정하고 해당 영역은 이를 적용하여 경로를 재설정한다. 시뮬레이션을 통하여 제안 기법이 경로 재설정에 사용되는 에너지 소모량을 최대 50% 이상 감소시켰음을 확인하였다.

• 한국수자원학회논문집
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• 제35권1호
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• pp.25-36
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• 2002

1998년 여름철, 기상레이더와 레이더 주위의 고밀도 우량계 관측자료를 이용하여 $Z_{e}-R$ 관계식을 산출하기 위하여 관악산 레이더 자료와 강우강도 자료의 확률밀도함수를 구해 확률이 같은 지점을 매치시키는 Window Probability Matching Method(WPMM)라는 통계적 방법을 사용하였다. 레이더 반사도의 확률 분포는 약 15dBZ에서 가장 많은 빈도 분포를 보였고 강우강도의 확률분포는 대부분의 영역에서 시간당 10mm 이하의 비가 내리는 것으로 나타났다. WPMM을 이용한 $Z_{e}-R$ 관계식은 로그 좌표계에서 곡선형의 분포를 가지고 있어 직선형의 분포를 가지는 멱급수 형태의 관계식에 비해 반사도를 강우량으로 전환하는데 있어 더 나은 것으로 나타났다. 특히, 3개월 동안의 누적 강수량 산출시 $Z=200R^{1.6}$ 식은 실제 우량계 강수량의 44%만을 추정하는데 반해 WPMM의 경우는 실제 강수량의 80%까지 근접하는 것으로 나타났다.

• 한국수자원학회논문집
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• 제45권1호
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• pp.75-89
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• 2012

본 논문에서는 한반도에서 발생했던 과거 가뭄사상의 통계학적 특성을 분석하기 위하여 SPI (Standardized Precipitation Index)와 PDSI (Palmer Drought Severity Index)를 선정하였고, 기상청 산하의 59개 기상관측소의 1980~2009년까지의 기상자료를 수집하여 월평균 가뭄지수를 산정하였다. 산정된 가뭄지수를 이용하여 지수별 경향성 분석, 주기성 분석 및 가뭄기간(Drought Spell) 조사를 통하여 과거 한반도 가뭄의 통계학적 특성을 분석하였다. 한반도 가뭄의 유역별 경향성을 분석한 결과, SPI3와 SPI6는 봄과 겨울에는 모든 유역에서 가뭄이 심화되는 경향을 보였고 여름철에는 가뭄이 완화되는 경향을 보였으나, SPI12와 PDSI의 경우 짧은 지속기간의 가뭄지수와는 다소 다른 경향을 나타내었다. 한편, 유역별 가뭄의 주기성을 분석한 결과 1~2년 또는 6년 내외의 주기 성분이 유의한 것으로 나타났으며, SPI3의 분석결과 유역 전반에서 1~2년의 주기성을 보였고, SPI6와 SPI12는 유역별로 다소 차이를 보이기는 했으나 4~6년에서 강한 주기성을 나타냈다. 또한 PDSI도 마찬가지로 6년 내외의 주기성을 보였다. 가뭄기간 조사에서도 금강, 영산강, 낙동강 유역에 위치하는 관측소를 중심으로 극심한 가뭄이 많이 나타났던 것으로 분석되었으며, 한반도의 중부지방 보다 남부지방이 극심한 가뭄에 취약했던 것으로 나타났다.