• 한국가스학회지
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• 제27권2호
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• pp.32-38
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• 2023

수도권 내 화학공장에서 부식성 유체를 펌프로 저장탱크에 공급하던 도중 수위파악이 정확히 되지 않아 상부 배기벤트로 부식성유체가 누출되는 사고가 발생하였다. 누출 사고가 발생한데는 다양한 원인이 있지만 직접 원인인 레벨게이지의 수위 지시계가 고착되는 것에 초점을 맞추었다. 분석 결과 사고가 발생한 사업장에서 사용되는 수위 지시계를 임의로 교체하였으며, 사고발생인 여름에 Tubular 방식의 레벨게이지는 열팽창이 쉽게 일어나서 다른 형태보다 고착이 발생될 수 있는 것으로 파악되었다. 또한 국내에는 저장탱크에 설치되는 계측기기의 설치기준이 명확치 않아 적정설치 검토에 어려움이 있었다. 따라서 본 연구에서는 사고사례 및 해외기준을 바탕으로 저장탱크 계측기기류 설치 시 유의사항에 대해 검토하였다.

• 아동학회지
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• 제31권1호
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• pp.163-177
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• 2010

The purpose of this study was to examine the maintenance of an evaluation accreditation indicator according to child care center teachers' participation in decision making. The subjects of this study were 139 teachers from 12 accredited national, public, private, and corporate child care centers in Seoul and North Gyeongsang Province. The TIP-2 (Teacher Involvement and Participation Scale V.2) and Accreditation Indicator for Child Care Centers were used to measure teachers' participation in decision making and accreditation indicator maintenance. Frequency, mean, standard deviation, one-way ANOVA and scheffe test were used for data analyses. The results revealed that the teachers who rated middle and high level in terms of their participation in decision-making showed higher levels of maintenance of the evaluation accreditation indicator than those with low levels of participation. This finding suggests that teachers' participation in decision making is an important factor for maintaining the quality of child care centers.

• Communications for Statistical Applications and Methods
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• 제14권3호
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• pp.483-495
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• 2007

In a general fractional factorial design, the n-levels of a factor are coded by the $n^{th}$ roots of the unity. Pistone and Rogantin (2007) gave a full generalization to mixed-level designs of the theory of the polynomial indicator function using this device. This article discusses the optimal blocking scheme for nonregular designs. According to hierarchical principle, the minimum aberration (MA) has been used as an important criterion for selecting blocked regular fractional factorial designs. MA criterion is mainly based on the defining contrast groups, which only exist for regular designs but not for nonregular designs. Recently, Cheng et al. (2004) adapted the generalized (G)-MA criterion discussed by Tang and Deng (1999) in studying $2^p$ optimal blocking scheme for nonregular factorial designs. The approach is based on the method of replacement by assigning $2^p$ blocks the distinct level combinations in the column with different blocks. However, when blocking level is not a power of two, we have no clue yet in any sense. As an example, suppose we experiment during 3 days for 12-run Plackett-Burman design. How can we arrange the 12-runs into the three blocks? To solve the problem, we apply G-MA criterion to nonregular mixed-level blocked scheme via the mixed-level indicator function and give an answer for the question.

• 한국수산과학회지
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• 제56권5호
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• pp.721-727
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• 2023

This study was conducted to evaluate the level of microbial contamination in smoked salmon products sold in hypermarkets in major metropolitan cities in Korea. Listeria monocytogenes is the primary cause of smoked and raw salmon product recalls. Here, we used L. monocytogenes as a bacterial hygiene indicator and investigated the microbial contamination level of frozen/refrigerated smoked salmon products collected from hyper markets. Contamination levels were analyzed by seasons, manufacturers, and consumption regions. For hygiene indicator bacteria, total bacteria count, coliforms, and Escherichia coli were examined according to the food code established by the Ministry of Food and Drug Safety, and polymerase chain reaction (PCR) was performed to detect Listeria sp. The highest contamination level was observed in spring in Busan among five consumption regions. Listeria was detected at a level of 2.1% among all samples collected. And especially L. monocytogenes was detected in two cases from the samples collected from Daegu and Daejeon. Sanitary standards and specifications should be established according to the contamination level of smoked salmon products investigated in this study, and continuous monitoring is necessary.

• 한국환경농학회지
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• 제40권4호
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• pp.248-259
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• 2021

BACKGROUND: Contaminated water was a major source of food-borne pathogens in various recent fresh produce-related outbreaks. This study was conducted to investigate the microbial contamination level and correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water by logistic regression analysis. METHODS AND RESULTS: Agricultural water was collected from 457 sites including surface water (n=300 sites) and groundwater (n=157 sites) in South Korea from 2018 to 2020. Sanitary indicator bacteria (total coliform, fecal coliform, and Escherichia coli) and food-borne pathogens (pathogenic E. coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were analyzed. In surface water, the coliform, fecal coliform, and E. coli were 3.27±0.89 log CFU/100 mL, 1.90±1.19 log CFU/100 mL, and 1.39±1.26 log CFU/100 mL, respectively. For groundwater, three kinds of sanitary indicators ranged in the level from 0.09 - 0.57 log CFU/100 mL. Pathogenic E. coli, Salmonella and Listeria monocytogenes were detected from 3%-site, 1.5%- site, and 0.6%-site water samples, respectively. According to the results of correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens by logistic regression analysis, the probability of pathogen detection increased individually by 1.45 and 1.34 times as each total coliform and E. coli concentration increased by 1 log CFU/100mL. The accuracy of the model was 70.4%, and sensitivity and specificity were 81.5% and 51.7%, respectively. CONCLUSION(S): The results indicate the need to manage the microbial risk of agricultural water to enhance the safety of fresh produce. In addition, logistic regression analysis is useful to analyze the correlation between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water.

• 한국의류학회지
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• 제26권11호
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• pp.1605-1614
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• 2002

The purpose of this study was to identify the consumers who use the level of price as the indicator of the product quality. In order to implement the purpose of this study, Jeans market had been segmented by the mixture regression model, and price response function was calibrated for each segment. Based on the types of price response function, segments were allocated into one of two groups; the group using the level of price as the quality indicator or the group not using the level of price as that. Then, characteristics of both groups were compared in terms of product attributes and demographic variables. Data were co]looted from the sample of the 23o undergraduate and graduate students in Seoul. For the data analysis, mixture regression model, conjoint analysis, and t-test were used. As a result, jeans market was divided into 5 segments. Segment 1,2,3 were allocated into the group not using the level of price as the quality indicator while segment 4,5 were done into the other group. Significant differences existed between two groups in product attributes, not in demographic variables. Mixture model and conjoint analysis were proved to be an effective set of tools in market segmentation.

• 한국의료질향상학회지
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• 제7권2호
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• pp.204-216
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• 2000

Background : There has been a concern that the quality of care provided to end-stage renal disease (ESRD) patients in the United States may not be as good as recommended. This paper illustrates a composite measure to assess, the quality of care received by ESRD patients undergoing in-center hemodialysis by incorporating outcomes for 4 major treatment areas. The 4 treatment areas are: dialysis treatments, anemia control, nutritional management, and blood pressure control. Methods : The major data source for the study was the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Study Wave 1 (DMMS-1) d Sixteen categories of a composite quality indicator were constructed by combining 4 dichotomous variables (16=2*2*2*2). representing the optimal vs. less than optimal level of outcome for each of the 4 treatment outcome measure respectively. Optimal outcome level for each treatment area was defined based on the recommendation from the National Kidney Foundation: (a) delivered dialysis doses (Kt/V) ${\geq}$ 1.2; (b) hematocrit level ${\geq}$ 30%; (c) serum albumin concentration ${\geq}$ 3.8g/dl ; and (d) blood pressure of <140 / <90mmHg. The 16 quality indicator were ranked according to their relative quality weights, which were estimated from its association with the relative risk of survival, adjusting for patient's baseline severity and dialysis facility characteristics. Results : Out of the entire sample of 2,179 patients, only 229 (10%) meet th recommended outcome levels for all 4 treatment areas. Overall, the study patients were distributed evenly over the 16 quality indicators, indicating a great variation in the quality of ESRD care. It appears that the rank of the 16 quality-indicators is driven by serum albumin concentration, suggesting that serum albumin concentration may be the most powerful predictor of ESRD patient survival among the 4 outcome measures. Conclusion : The developed quality indicator has the advantage of describin a range of care for dialysis patients and thus providing a more complete picture of care as compared to previous studies that have focused on only single or few components of the ESRD care.

• 한국지역지리학회지
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• 제13권3호
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• pp.235-253
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• 2007

본 연구에서는 우리나라 7대 대도시를 대상으로 지속가능발전성을 비교 평가하였다. 국가지속가능발전지표 목록 등을 참고하여 3개 부문, 14개 지표군, 42개 하위지표를 선정하여 정량적 지표체계를 구축하였다. 대도시간 비교분석을 위해 지표별로 7대 대도시의 평균값을 기준으로 지속가능성을 상대평가 하였으며, 이 때 필요시 역기능지표를 순기능 지표화 하여 모든 지표를 동일한 스케일로 비교 가능하도록 하였다. 그 결과 서울이나 울산과 같이 특정산업이 집중한 도시에서 경제적 지속가능성이 높았으나 환경적 지속가능성은 낮았고, 지역경제가 낙후된 광주에서 환경적 지속가능성이 높은 것으로 나타났다. 부산, 대구, 인천은 전반적으로 지속가능성이 낮은 반면, 대전은 3개 부문 모두에서 조화롭게 지속가능성이 높아 대도시 중 통합적 지속가능성이 제일 높은 것으로 나타났다.

• 정보교육학회논문지
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• 제13권2호
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• pp.145-158
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• 2009

본 연구는 국가 교육정책과 관련, 교육정보화의 측면에서 교육 관련 당사자라 할 수 있는 학생, 교사, 학부모의 교육정보화 수준 측정 지표를 개발하였다. 그리고 각 집단별 지표에 대한 준거를 설정하였다. 분석 결과, 첫째, 교육정보화 지수 설정을 위한 지표 개발 결과, 4개 영역, 10개 요소, 24개의 세부 지표를 산출하였다. 그리고 각 집단별 특성을 고려하여 영역, 요소, 지표별 각각 다른 가중치를 설정하였다. 둘째, 개발된 교육정보화 지표를 토대로 전문가들이 산출한 교육정보화 수준의 준거는 100점 만점으로 환산할 때, 학생은 80.64점, 교사는 80.90점, 학부모는 76.52점으로 학부모 집단에 대한 준거가 가장 낮았다. 따라서 본 연구는 향후 교육정보화 방향을 설정할 때, 어느 측면을 보다 집중적으로 지원해야 하는지에 대한 방향 모색에 기여할 수 있을 것으로 판단된다.

• 한국환경과학회지
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• 제14권11호
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• pp.985-994
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• 2005

Recently, Environmental friendliness and sustainability become the main concern of residential area planning. This paper deals with the estimation indicator system for environmentally friendliness of residential areas. An interview survey was carried out for resident groups by the type of housing. 'Environmentally friendly residential site' is defined as 'A site of sustainable development with low undesirable impact on environment, friendliness to natural environments such as green areas and waters, and amenity, health & hygiene of residents' Totally, nineteen individual indicators, six categories and three principles(Low Impact, High Contact, Amenity & Health) were proposed as estimation indicator system. Residents showed high importance on principle of 'amenity & health'. Individual indicators such as 'garbage segregated collection', 'secure green areas' and 'cleanness of water and air' showed high weighting value by each principles. Satisfaction level of residents for individual indicators, such as 'garbage segregated collection', 'common gardens', and 'cleanness of residential areas', were comparatively high. By the result of factor analysis, the proposed model for indicator system was valid.