• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.93-100
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• 2002

Vertical reinforcement of soft soils using the deep mixing method has received increasing applications. In this study, the theory of elasticity and plasticity including the upper bound theorem of limit analysis were used to derive the equations for obtaining composite elastic properties and shear strength parameters. The developed equations were validated using the finite element computer program SAGE CRISP. The analysis involved 4 different cases-two different type of soil and replacement ratios. Tile results of the analysis show that the proposed equations could determine the properties of composite material for practical applications.

• 분석과학
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• 제12권4호
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• pp.312-317
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• 1999

저농도, 고농도의 BOD, COD, TN, TP 항목에 대해 13개 기관을 대상으로 정도관리를 실시하였다. 정도관리 평가값은 6회에 걸쳐 주기적으로 반복측정한 평균치로 정하였으며, 이 값은 실제 조제한 값으로부터 오차율이 5%이내였으며, 표준편차도 0.44 (BOD, 저농도), 2.15 (BOD, 고농도), 0.12 (COD 저농도), 1.63 (COD 고농도), 0.35 (TN 저농도), 1.99 (TN 고농도), 0.05 (TP, 저농도), 0.14 (TP, 고농도)으로 정밀도가 아주 우수한 것으로 나타났다. 6회에 걸쳐 주기적으로 반복측정하여 허용상하한값과 경고상하한값을 구하여 정도관리차트를 얻었으며, 이 차트에 따라 평가한 결과 BOD 저농도의 경우 3개 기관이 5.30, 9.70, 5.30 mg/L로 허용상하한값을 벗어났으며, 고농도는 5개 기관이 허용상하한값을 벗어나 BOD 측정분석의 신뢰도가 다소 좋지 않은 것으로 나타났다. COD 저농도의 경우 4개 실험실, 고농도는 2개 기관이 41.00, 30.60 mg/L로 허용상하한값을 벗어났으며, 그외의 11개 기관은 신뢰할 수 있는 측정분석 결과를 산출하였다. TN 저농도의 경우 1개 기관만이 0.70 mg/L로 허용 하한값을 벗어났지 그외의 11개 기관은 거의 평가값에 가까운 우수한 측정분석 결과를 산출하였으며, 고농도는 거의 대부분인 11개 기관이 허용상하한값의 범위를 벗어나 측정분석 결과에 대한 신뢰도 향상에 보다 더 중점을 두어야 할 것으로 나타났다. TP 저농도의 경우 4개 기관이 1.14, 0.45, 0.64, 1.49 mg/L로 허용 상하한값을 벗어났으며, 고농도는 7개 기관이 허용 상하한값을 벗어나 TP 측정 분석의 신뢰도가 다소 좋지 않은 것으로 나타났다.

• 한국안전학회지
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• 제8권3호
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• pp.50-55
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• 1993

A new model for predicting upper flammability limits( UFL ) of paraffinic hydrocarbons is developed, based on statistics and numerical simulation. With the proposed model, UFL have been calculated for 24 compounds, and when compared with experimental data, this model produced average percent error of 2.96%. When compared to established methods published by Spakowski and Zabetakis, this model produced more accurate results.

• 한국화재소방학회논문지
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• 제25권2호
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• pp.114-119
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• 2011

폭발한계와 인화점은 가연성물질의 화재 및 폭발의 위험성을 결정하는데 중요한 연소특성치이다. 본 연구에서는 산류와 케톤류의 폭발상한계를 예측하기 위해서, 평형상태에서 인화점을 측정하는 Setaflash 밀폐식 장치(ASTM D3278)를 사용하여 이들의 상부인화점을 측정하였다. 측정된 상부인화점을 이용하여 Antoine 식에 의한 계산된 폭발상한계는 기존의 문헌값들보다 약간 낮게 나타났다. 본 연구에서 제시한 실험 및 예측 방법을 이용하여 다른 가연성물질의 폭발상한계 예측이 가능해 졌다.

• 대한조선학회논문집
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• 제40권4호
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• pp.53-58
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• 2003

Design of the corrugated watertight bulkhead for a bulk carrier is principally determined by the permissible limit of Classification requirements. As the weight of upper and lower stool has considerable portion of the total weight of the transverse bulkhead, optimum design including the stool geometry and size will play an important role on economic shipbuilding. The purpose of this study is focused on the minimization of steel weight using the design variables, which are the shape and the size of the corrugation as well as the upper and lower stools. Discrete variables are used as design variables for the practical design. In this study, the evolution strategies (ES), which can highly improve the possibility of leaching the global minimum point, are selected as an optimization method. Usefulness of this study is verified by comparison with the proven type ship design. As objective function, total weight of the transverse bulkhead including the upper and lower stools is used.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.77-86
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• 2005

In urban areas, new tunnel construction work is often taking place adjacent to existing piled foundations. In this case, careful assessment for the pile-soil-tunnel interaction is required. However, research on this topic has not been much reported, and currently only limited information is available. In this study, the complex pile-soil-tunnel interaction is investigated using the upper and lower bound methods based on kinematically possible failure mechanism and statically admissible stress field respectively. It is believed that the limit theorem is useful in understanding the complicated interaction behaviour mechanism and applicable to the pile-soil-tunnel interaction problem. The results are compared with numerical analysis. The material deformation patterns and strain data from the FE output are shown to compare well with the equivalent physical model tests. Admissible stress fields and the failure mechanisms are presented and used to develop upper and lower bound solutions to assess minimum support pressures within the tunnel.

• 대한임상검사과학회지
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• 제39권1호
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• pp.31-36
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• 2007

The purpose of the clinically reportable range (CRR) in clinical chemistry is to estimate linearity in working range. The reportable range includes all results that may be reliably reported, and embraces two types of ranges: the analytical measurement range (AMR) is the range of analyte values that a method can directly measure on the specimen without any dilution, concentration, or other pretreatment not part of the usual assay process. CAP and JCAHO require linearity on analyzers every six months. The clinically reportable range is the range of analyte values that a method can measure, allowing for specimen dilution, concentration, or other pretreatment used to extend the direct analytical measurement range. The AMR cannot exceed the manufacturer's limits. Establishing AMR is easily accomplished with Calibration Verification Assessment and experimental Linearity. For example: The manufacturer states that the limits of the AST on their instrument are 0-1100. The lowest level that could be verified is 2. The upper level is 1241. The verified AMR of the instrument is 2-1241. The lower limit of the range is 2, because that is the lowest level that could be verified by the laboratory. The laboratory could not use the manufacturer's lower limit of 2 because they have not proven that the instrument values below 2 are valid. The upper limit of the range is 1241, because although the lab has shown that the instrument is linear to 1241, the manufacturer does not make that claim. The laboratory needs to demonstrate the accuracy and precision of the analyzer, as well the validation of the patient AMR. Linearity requirements have been eliminated from the CLIA regulations and from the CAP inspection criteria, however, many inspectors continue to feel that linearity studies are a part of good lab practice and should be encouraged. If a lab chooses to continue linearity studies, these studies must fully comply with the calibration/calibration verification requirements of CLIA and/or CAP. The results of lower limit and upper limit of clinically reportable range were total protein (2.1 - 79.9), albumin (1.3 - 39), total bilirubin (0.2 - 106.2), alkaline phosphatase (13 - 6928.2), aspartate aminotransferase (24 - 7446), alanine aminotransferase (13 - 6724.2), gamma glutamyl transpeptidase (16.64 - 9904.2), creatine kinase (15.26 - 4723.8), lactate dehydrogenase (127.66 - 13231.8), creatinine (0.4 - 129.6), blood urea nitrogen (8.67 - 925.8), uric acid (1.6 - 151.2), total cholesterol (48.52 - 3162), triglycerides (36.91 - 3367.8), glucose (31 - 4218), amylase (21 - 6694.2), calcium (3.1 - 118.2), inorganic phosphorus (1.11 - 108), HDL (11.74 - 666), NA (58.3 - 1800), K (1.0 - 69.6), CL (38 - 1230).

• Journal of Preventive Medicine and Public Health
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• 제7권2호
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• pp.395-401
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• 1974

In order to figure out the normal range, lower limit of hypertension and upper limit of hypotension of the blood pressure of Korean, authors had measured blood pressure according to Korotkow's method for 31,897 healthy persons as samples who were occupied different levels of the social class except cases who would seem to be the essential hypertension and had the diseases affecting to secondary hypertension. A following conclusion was induced by actual measurement and statistical reasoning. 1. The normal range and limits of hypo- and hypertension by sex and age groups of Korean were demonstrated in Table 1 and Figure 1. 2. The more aging the higher value of blood pressure in both sexes, especially women rather than men and systolic as to diastolic. 3. Generally, blood pressure values of female were lower than male, after 55 years of age, however, the crossing phenomenon was recognizable. 4. To settle the normal and abnormal ranges of the blood pressure of Korean, it was attempted that $M{\pm}1.282{\sigma}$ as normal range, $M+2{\sigma}$ as lower limit of hypertension and $M-2{\sigma}$ as upper limit of hypotension were calculated, and regression lines were drawn to adjust the biological variables and derive continuity from each age class. (Fig. 2 and 3) 5. The blood pressure levels were becoming elevated as to getting increased of the body weight, particularly diastolic value at 40-49 age group in male and systolic value at 30-39 age group in female.

• 응용통계연구
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• 제23권5호
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• pp.967-975
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• 2010

데이터마이닝 분야에서의 회귀모형에는 연관성이 높은 설명변수들이 포함되어 다중공선성을 유발하는 경우가 많은데, 다중공선성이 야기하는 문제를 해결하기 위하여 주성분회귀분석을 적용할 수 있다. 이 분석에서는 적절한 주성분을 선정하는 과정이 핵심인데, 기존의 선정방법들은 다중공선성을 잘 해결하지 못하거나 모형의 적합성을 저하시킨다는 지적을 받고 있다. 따라서 본 논문에서는 다중공선성 문제와 적합성 저하 현상을 동시에 해결할 수 있는 새로운 선정방법을 제안하였다. 다중공선성에 의해 최소제곱추정량의 분산이 팽창되는 문제를 주성분회귀에 의해 해결할 수 있지만, 주성분의 일부를 선정함에 따라 발생하는 편의도 동시에 통제해야 한다. 따라서 주성분회귀추정량의 평균제곱오차를 최소가 되게 하는 상태지수를 측정하고, 이 값에 영향을 미치는 주요 요인들을 컨조인트분석에 의해 파악하여 주성분 선정기준 모형을 구축하였다. 선정기준의 상한과 하한을 설정하고, 상태지수가 상한을 초과하면 해당 주성분을 제외시키고, 하한에 미달하면 해당 주성분을 포함시킨다. 그리고 상한과 하한 사이의 상태지수에 대응하는 주성분들에 대해서는 일반화선형검정을 순차적으로 적용하여 주성분을 선정하는 방법이다.

• 한국안전학회지
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• 제33권4호
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• pp.8-14
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• 2018

In the industrial chemical process involving combustible materials, reliable safety data are required for design prevention, protection and mitigation measures. The accurate combustion properties are necessary to safely treatment, transportation and handling of flammable substances. The combustion parameters necessary for process safety are lower flash point, upper flash point, fire point, lower explosion limit(LEL), upper explosion limit(UEL)and autoignition temperature(AIT) etc.. However, the combustion properties suggested in the Material Safety Data Sheet (MSDS) are presented differently according to the literatures. In the chemical industries, tetralin which is widely used as a raw material of intermediate products, coating substances and rubber chemicals was selected. For safe handling of tetralin, the lower and flash point, the fire point, and the AIT were measured. The LEL and UEL of tetralin were calculated using the lower and upper flash point obtained in the experiment. The flash points of tetralin by using the Setaflash and Pensky-Martens closed-cup testers measured $70^{\circ}C$ and $76^{\circ}C$, respectively. The flash points of tetralin using the Tag and Cleveland open cup testers are measured $78^{\circ}C$ and $81^{\circ}C$, respectively. The AIT of the measured tetralin by the ASTM E659 apparatus was measured at $380^{\circ}C$. The LEL and UEL of tetralin measured by Setaflash closed-cup tester at $70^{\circ}C$ and $109^{\circ}C$ were calculated to be 1.02 vol% and 5.03 vol%, respectively. In this study, it was possible to predict the LEL and the UEL by using the lower and upper flash point of tetralin measured by Setasflash closed-cup tester. A new prediction method for the ignition delay time by the ignition temperature has been developed. It is possible to predict the ignition delay time at different ignition temperatures by the proposed model.