• 품질경영학회지
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• 제24권4호
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• pp.190-206
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• 1996

In case measurements are made on units of production in time order, it is reasonable to expect that the measurement errors will sometimes be first order autocorrelated, and a technique to test such autocorrelation is required to give good control of the productive process. Tool-wear process provide an example for which regression model can sometimes be useful in modeling and controlling the process. For the control of such process, we present a simple method for testing first order autocorrelation in regression errors. The method is based on Bayesian test method via Bayes factor and derived by observing that in general, a Bayes factor can be written as the product of a quantity called the Savage-Dickey density ratio and a correction factor ; both terms are easily estimated from Gibbs sampling technique. Performance of the method is examined by means of Monte Carlo simulation. It is noted that the test not only achieves satisfactory power but eliminates the inconvenience occurred in using the well-known Durbin-Watson test.

• 대한가정학회지
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• 제48권2호
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• pp.113-120
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• 2010

Quality characteristics effects of adding four different amounts (0%, 1%, 2%, 3%) of Ulleung-Maesil (Prunus mume fruit) powder cookie doughs were examined. pH, water content & bulk density of dough, spread factor, color value, hardness and consumer acceptability of maesil cookies were measured. The pH and water content of freezedried Ulleung-Maesil powder were 2.01 and 6.26%, respectively, while the L, a, b values were 76.14, -1.66 and 28.65, respectively. Although bulk density of the 3% powder group of cookie dough was the highest, its pH value was the lowest compared to the other groups (p < 0.05). Spread factor of the 3% group showed the lowest value among all groups (p < 0.05). Hardness of the control group (i.e, 0%) was significantly higher than the 1%, 2%, 3% groups (p < 0.05), which showed no significant difference among themselves. The ${\Delta}E$ value of cookies increased significantly with increasing Maesil powder content (p < 0.05). The consumer acceptability scores for control and 1% Maesil cookie groups ranked significantly higher than the 2% and 3% groups in overall acceptability, taste, flavor and texture (p < 0.05). In conclusion, our study suggests that small amounts of Ulleung-maesil can add positive attributes to cookies.

• 한국환경과학회지
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• 제13권3호
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• pp.233-244
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• 2004

This study was conducted to evaluate water quality in the Mankyung River using multivariate analysis. The analysis data which was surveyed from January 1996 to December 2002 in Mankyung river was aquired by the ministry of environment. Twelve water quality parameters were determined on each survey. The results were summarized as follow; Water quality in the Mankyung River could be explained up to 74.90% by four factors which were included in loading of organic matter and nutrients by the tributaries(43.28%), seasonal variation(10.40%), loading of pathogenic bacteria by domestic sewage of Gapcheon (12.41%) and internal metabolism in river(8.81%). The result of cluster analysis by station was classified into three group that has different water quality characteristics. Especially, Iksan river was appeared to considerable water quality characteristics against other station. In monthly cluster analysis, three group was classified by seasonal characteristics. Also, in yearly cluster analysis, three group was classified. It is necessary to control the pollutant loadings by domestic sewage and livestock waste for water quality management of Mankyung river.

• 성인간호학회지
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• 제19권4호
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• pp.644-655
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• 2007

Purpose: The purposes of this study were to describe the pattern of type D personality, to compare the life style and quality of life between type D personality and non-type D personality patients, and to investigate the factors influencing quality of life in patients with hypertension. Methods: A cross sectional, descriptive study was used. The participants in this study were 193 outpatients who were diagnosed with hypertension at two university hospitals in urban area, Korea. The data was collected from December, 2006 to January, 2007. Type D personality was measured by the DS-14 scale. Results: The prevalence of type D personality was 83.9%. Patients of type D personality were significantly different in educational status, monthly income, fat intake and exercise, and had a lower overall quality of life than patients of non-type D personality. Under controlled general characteristics and life style factors, multiple linear regression analysis was performed. The most significant factor influencing quality of life in hypertensive patients was type D personality, and this factor explained their quality of life with a variance of 14.8%. Conclusions: Various programs for psychological intervention are required to control for the distressed personality of patients with hypertension. Further studies should be conducted prospectively on a larger patient population.

• 치위생과학회지
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• 제9권1호
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• pp.53-59
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• 2009

치과위생사의 감염관리 실천도를 측정하는 척도를 개발하고 타당화하기 위해 254명의 치과위생사를 대상으로 설문조사를 실시하였다. 예비척도는 리커트 4점 척도로서 21개의 문항으로 구성되었으며, 신뢰도 분석, 탐색요인분석, 확인요인분석을 통해 척도의 차원과 항목을 축소하고 신뢰도와 타당도를 검증하였다. 1. 탐색요인분석과 신뢰도 분석을 통해 4개 요인과 12개의 항목으로 척도를 수정하였다. 수정된 척도의 요인은 '예방접종 및 정기검진'(2항목), '기구 소독 및 멸균'(3항목), '손위생 관리'(4항목), '개인 보호'(3항목)가 추출되었으며, 전체분산 중 58.296%를 설명하고 있다. 예비척도 중 '환경 관리' 요인이 제외되었다. 2. 확인요인분석을 통해 한 문항을 제외하였다. 최종적인 측정모형은 4개 요인과 11개 항목으로 구성되었으며, 모형의 적합도는 $x^2$= 79.593(df = 38, 0 = 0.000), RMR= 0.045, GFI = 0.940, CFI = 0.904, AGFI = 0.896, NFI = 0.837, TLI = 0.861, RMSEA = 0.67로 나타나 대체로 기준을 충족하였다. 모든 측정변수의 요인부하량은 유의하였으나(p < 0.001), 세 변수만이 0.7 이상으로 나타났다. 평균분산추출값과 구성개념신뢰도는 대체로 기준을 충족하지 못하였으나, 모든 요인의 평균분산추출값은 각 요인간 상관관계제곱값 보다 크게 나타났다. 3. 요인분석을 통해 추출한 네 개의 요인이 치과위생사의 '감염관리 실천률 인식'에 미치는 영향을 알아보기 위해 네 요인을 독립변수로 선정하고 실천률 인식을 종속변수로 선정하여 회귀분석을 실시하였다. $R^2$는 0.304, 수정된 $R^2$은 0.431, F = 25.813, p = 0.000이며, '손위생 관리'를 제외한 세 변수의 회귀계수는 통계적으로 유의하게 나타났다.

• 상하수도학회지
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• 제20권1호
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• pp.94-103
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• 2006

The pollution in closing water can be caused by not only artificial factor like sewage but also natural factor like elution from sediment. In this study we analyzed Sediment Oxygen Demand (SOD) for verification of sediment purification effect and sediment elution experiment as well as general items like COD, TN, TP, SS to complement and assess the effect of sediment and water quality. The experiment result showed that the release rate of OSD system were 4 times and 3 times as large as control for P and Fe respectively. SOD for operated OSD system and control were $12.18gO_2{\cdot}m^{-2}{\cdot}d^{-1}$ and $47.95gO_2{\cdot}m^{-2}{\cdot}d^{-1}$. From water qualities analyzed by COD, TN, TP, SS, chlorophyll-a, the removal efficiency increase of TN, TP, chlorophyll-a and COD were about 10~20%, 40~50% and 10% respectively. In conclusion, OSD can contribute to improvement of both the waterbody and the sediment environment effectively.

• 한국식품조리과학회지
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• 제25권1호
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• pp.98-105
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• 2009

This study examined the effects of adding four different amounts (0%: control, 4%: M-4, 8%: M-8, 12%: M-12) of button mushroom (Agaricus bisporous) powder on the quality characteristics of cookies. The bulk density and pH of the dough, and firmness, color, spread factor, consumer acceptability of cookies, and total phenol compound content and free radical scavenging activity of mushroom powder and cookies were measured. While the bulk density and pH of the dough as well as spread factor of the cookies significantly decreased, the firmness, L values and total phenol compound contents and free radical scavenging activity of the cookies significantly increased with increasing mushroom powder content(p<.05). The consumer acceptability scores for the button mushroom cookie groups ranked significantly(p<.05) higher than those of the control group in general acceptability, appearance, flavor, color, taste, and texture. This study suggests that button mushroom powder is a good ingredient for increasing the acceptability and functionality of cookies.

• International Journal of Automotive Technology
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• 제8권1호
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• pp.111-117
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• 2007

The nonlinear characteristics of a suspension is directly related to the ride quality of a passenger car. In this study, the nonlinear characteristics of a spring and a damper of a passenger car is analyzed by dynamic experiments using the MTS single-axial testing machine. Also, a mathematical nonlinear dynamic model for the suspension is devised to estimate the ride quality using the K factor. And the effect on the variation of the parameters of the suspension is examined. The results showed that the dynamic viscosity of the oil in a damper was the parameter that most influeced the ride quality of a passenger car for the ride quality of a passenger car.

• Food Science and Biotechnology
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• 제18권3호
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• pp.745-748
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• 2009

Sensory quality variations of jajang sauce were monitored by the $\bar{X}-chart$ and capability analysis based on specifications of each sensory attributes. For sensory quality control (QC) of the sauce which has a strong sweetness and sourness, the ratio of sourness/sweetness was examined as a necessary QC factor to maintain the balance of sweetness and sourness. For the sensory QC factors, all the sensory data were divided into individual sensory score of reference which was a pack of sauce manufactured a week ago. The ratio form of sensory data was useful for decreasing individual variations and for increasing normality of data measured by category scale. The overall proportion of out-spec products under normal manufacturing conditions was obtained by capability analysis of sensory data with normal distribution. Out-spec samples were monitored by the $\bar{X}-chart$ of each sensory attributes.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.327-328
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• 2021

In the manufacturing process of ready-mixed concrete, quantity management directly affects the workability and strength of concrete. Therefore, water quantity is the most important management factor for water quality control of ready-mixed concrete. It can be said that the number of unit water in the mix design, the water quantity due to the surface water contained in the aggregate used, and the water quantity taking into account the concentration of sludge contained in the recycling water when using the recycling water are factors that affect the quantity management of ready-mixed concrete. In this study, as a stable quality control method of ready-mixed concrete, a quantity management method by aggregate surface water and a sludge concentration management method according to the use of recycling water were proposed. Thus, we tried to suggest an efficient quantity management method for stabilizing the quality of ready-mixed concrete.