• Journal of the Korean Data and Information Science Society
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• 제21권6호
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• pp.1225-1235
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• 2010

개인신용평점에서 항목그룹화의 과정은 연속형 특성변수를 밴드로 분할하고 이산형 특성변수는 그룹으로 분할하는 것이다. 또한 평점표는 시간이 지나감에 따라 성능이 떨어지게 되고, 따라서 사용되고 있는 승인점을 조정하여야 한다. 그러나 개인신용평점에서 항목그룹화와 승인점의 조정은 매우 복잡하고 번거로운 과정이라고 할 수 있다. 따라서 본 논문에서는 비주얼베이직을 사용하여 개인신용평점에서 항목그룹화와 모형평가를 위한 소프트웨어를 개발하였다. 개발된 소프트웨어를 활용하면 항목그룹화에서 최적의 분할과 모형평가에서 최적의 승인점을 쉽게 찾을 수 있다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.365-370
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• 2001

In order to minimize unstable flow occurred at a multiblade fan/scroll system, optimal angle and shape of cut-off was determined by using two-dimensional turbulent fluid field analyses and neural network. The results of CFD analyses were used for learning as data of input and output of neural network. After learning neural network optimization process was accomplished for design variables, the angle and the shape of cut-off, in the design domain. As a result of optimization, the optimal angle and shape were obtained as 71 and 0.092 times the outer diameter of impeller, respectively, which are very similar values to previous studies. Finally, it was verified that the fluid field is very stable for optimal angle and shape of cut-off by two-dimensional CFD analysis.

• 한국가정과학회지
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• 제4권1호
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• pp.36-45
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• 2001

This study was performed to determine the changes of maternal iron status during pregnancy cross sectionally, and to evaluate the appropriateness of the cut-off points of hemoglobin (Hb). hematocrit (Hct), serum transferrin receptor (sTfR) and sTfR : ferritin ratio for assessing iron deficiency status based on serum ferritin level (< 12${\mu}g$/L). Serum Hb concentrations in the first trimester were significantly higher (p < 0.05) than those in the second and third trimester. Serum levels of iron and ferritin in the third trimester were significantly lower (p < 0.05) than those in the first and second trimester. On the other hand, sTfR:ferritin ratios in the third trimester were significantly higher (p < 0.05) than those in the first and second trimester. sTfR concentrations did not change significantly during pregnancy. The appropriate cut-off points of Hb were 11.5g/dL for whole period of pregnancy. 12.0g/dL for 1st trimester. and 11.5g/dL for both 2nd and 3rd trimester. The good cut-off points of Hct were 34% for whole period of pregnancy. 36% for 1st trimester. and 34% for both 2nd and 3rd trimester The suitable cut-off points of TIBC were 400${\mu}g$/dL for whole period of pregnancy. 360${\mu}g$/dL for 1st trimester, and 400${\mu}g$/dL for both 2nd and 3rd trimester. Any cut-off point of sTfR could not be selected because of its low sensitivity and specificity. The proper cut-off point of sTfR : ferritin ratio was 600 or 650 for all the periods determined except the first trimester. In conclusion, there were no reliable cut-off levels of sTfR and those of sTfR : ferritin ratio showed low specificity. The cut-off values of Hb and Hct for assessing iron deficiency were slightly higher than the values used to evaluate anemia. Thus, if appropriate cut-off levels were applied, Hb. Hct, or TIBC might be useful indices for evaluating iron deficiency as well as anemia.

• Clinical and Experimental Pediatrics
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• 제48권4호
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• pp.387-394
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• 2005

목 적 : 선천성 갑상선기능저하증에 대한 신생아 선별검사결과의 이상빈도는 실제 임상적으로 진단되는 질환의 발생빈도보다 훨씬 높다. 본원에서 시행되는 선천성 갑상선기능저하증에 대한 신생아 선별검사의 위양성률과 소환율을 알아보고 재태기간과 출생체중에 따른 검사결과치를 비교하여 각각의 결과에 따라 cut-off value를 재평가함으로써 임상에서 신생아 선별검사의 결과를 해석하고 질환을 진단하는데 도움을 주고자 하였다. 방 법 : 2000년 5월부터 2003년 1월까지 단국대학교병원에서 출생한 2,133명의 신생아를 대상으로 정상분만의 경우 생후 3일째, 제왕절개인 경우 생후 5일째, 신생아중환자실에 입원한 미숙아인 경우 생후 $14.3{\pm}12.4$일(5-79일) 이내에 신생아의 발뒤꿈치를 천자하여 모세혈을 검사용 채혈지에 묻혀 갑상선자극호르몬과 유리 $T_4$를 효소면역법으로 분석하였고 각각의 기존참고치인 $20{\mu}IU/mL$ 이상, 1 ng/dL 미만일 경우 소아과 외래로 불러 재검하였으며 이때 이학적 검사 및 주산기적 병력, 약물력, 모체질환 등의 여부를 조사하였고 혈청을 이용해 면역형광법에 의한 갑상선기능검사를 시행하였다. 결 과 : 1) 다른 질병이 없었던 1,749명의 갑상선자극호르몬과 유리 $T_4$의 평균${\pm}$표준편차는 각각 $9.01{\pm}5.82{\mu}IU/mL$, $1.99{\pm}0.90ng/dL$이었고 성별, 분만형태, 아프가 점수에 따른 차이는 없었다. 2) 재태연령과 출생체중에 따라 갑상선자극호르몬의 수치는 의미있는 차이가 없었고 유리 $T_4$의 수치는 의미있는 차이가 있었다(P<0.01). 3) 다른 질병이 있었던 384명의 갑상선자극호르몬과 유리 $T_4$의 평균${\pm}$표준편차는 각각 $9.17{\pm}7.22{\mu}IU/mL$, $1.52{\pm}0.75ng/dL$이었고, 건강한 신생아와 비교시 갑상선자극호르몬의 수치는 의미있는 차이가 없었고 유리 $T_4$의 수치는 의미있는 차이가 있었다(P<0.01). 4) 신생아 선별검사에서 131명이 소환되었고 재소환율은 7.48%이었으며, 이중 추적관찰이 가능했던 87명의 갑상선기능이 정상화된 기간은 출생체중과 의미있는 관계는 없었고, 출생주수와는 음의 상관관계를 보였다(P=0.042, Pearson 상관계수 -0.177). 5) 신생아 선별검사에서 재소환되어 선천성 갑상선기능저하증을 진단받은 환아는 모두 4명으로 2명은 갑상선자극호르몬 수치만 $20{\mu}IU/mL$ 이상이었고 2명은 유리 $T_4$ 수치만 1 ng/dL 미만이었으며, 3명은 건강한 신생아에, 1명은 질병이 있었던 군에 속했다. 6) Cut-off value를 본 연구에서 시행되었던 기준인 갑상선 자극호르몬이 $20{\mu}IU/mL$ 이상이거나 또는 유리 $T_4\;1\;ng/dL$ 미만인 경우 소환율, 양성예측률, 민감도, 특이도는 각각 7.48%, 2.29%, 75%, 92.6%이었다. 갑상선자극호르몬이 $20{\mu}IU/mL$ 이상이거나 유리 $T_4\;0.64\;ng/dL$ 미만인 경우에 소환율, 양성예측률, 민감도, 특이도가 각각 4.8%, 3.57%, 75%, 95.3%이었다. 결 론 : 결론적으로 선천성 갑상선기능저하증에 대한 신생아 선별검사에서 갑상선자극호르몬 및 유리 $T_4$ 모두를 선별검사로 사용하는 것은 타당하고, 현재의 cut-off value가 소환율이 높기는 하나 검사의 민감도를 고려할 때 cut-off를 바꾸기에는 문제가 있을 것으로 생각되며 향후 더 큰 대상군을 바탕으로 한 재평가가 필요하리라 생각된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.345-349
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• 2015

Background: To determine the cut-off values of the preoperative risk of malignancy index (RMI) used in differentiating benign or malignant adnexal masses and to determine their significance in differential diagnosis by comparison of different systems. Materials and Methods: 191 operated women were assessed retrospectively. RMI of 1, 2, 3 and 4; cut-off values for an effective benign or malignant differentiation together with sensitivity, specificity, negative and positive predictive values were calculated. Results: Cut-off value for RMI 1 was found to be 250; there was significant (p<0.001) compatibility at this level with sensitivity of 60%, positive predictive value (PPV) of 75%, specificity of 93%, negative predictive value (NPV) of 88% and an overall compliance rate of 85%. When RMI 2 and 3 was obtained with a cut-off value of 200, there was significant (p<0.001) compatibility at this level for RMI 2 with sensitivity of 67%, PPV of 67%, specificity of 89%, NPV of 89%, histopathologic correlation of 84% while RMI 3 had significant (p<0.001) compatibility at the same level with sensitivity of 63%, PPV of 69%, specificity of 91%, NPV of 88% and a histopathologic correlation of 84%. Significant (p<0.001) compatibility for RMI 4 with a sensitivity of 67%, PPV of 73%, specificity of 92%, NPV of 89% and a histopathologic correlation of 86% was obtained at the cut-off level 400. Conclusions: RMI have a significant predictability in differentiating benign and malignant adnexal masses, thus can effectively be used in clinical practice.

• 한국어병학회지
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• 제24권2호
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• pp.95-102
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• 2011

Normalized resistance interpretation (NRI) analysis for tetracycline was applied to generate information on the epidemiological cut-off value for Vibrio ichthyoenteri isolated from diseased olive flounder (Paralichthys olivaceus) larvae. Thus, 42 strains of V. ichthyoenteri were used to determine minimum inhibitory concentration (MIC) values of tetracycline using Etest. Also, 11 tetracycline resistance related genes were investigated by PCR method. Most tetracycline-resistant strains harbored both tetB and tetM with a few exceptions. NRI-derived mean and 2 SD above the mean of theoretical normal distributions of susceptible isolates were 0.33 mg/L and 1.66 mg/L, respectively. The epidemiological cut-off value for V. ichthyoenteri from the calculations could be set to S ${\leq}$ 2 mg/L. Of the 42 strains, 15 were classified as non-wild type (NWT), and MIC values of the NWT strains vary regardless of tetB and tetM detection, suggesting that there may be other mechanisms involved in tetracycline resistance in this Vibrio species.

• 사상체질의학회지
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• 제34권4호
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• pp.27-37
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• 2022

Objectives The purpose of this study is to propose a method to more specifically identify Sasang constitutional risk factors of metabolic syndromes by adjusting the cut-off value of Korea Sasang Constitutional Diagnostic Questionnaire (KS-15). Methods Data of 1997 participants in Korean medicine Daejeon Citizen Cohort study (KDCC) were analyzed. Metabolic syndrome was defined according to the NCEP-ATP III, lifestyle information, and hematologic information including KS-15 and demographic characteristics were used as covariates. Results The 179 subjects with metabolic syndrome accounted for 9.0% of the total. As a result of determining the Sasang constitution for the KS-15 response based on the cut-off values (approximate 0.33), 0.5, and 0.6 of the constitutional score, when performed at the 0.6 cut-off model, the odds ratio of TE was 2.46 which showed a statistically significantly higher risk than the borderline group. For the accuracy of the model and the Area under the curve (AUC), the model accuracy based on the original cut-off of the KS-15 was 0.902 and AUC was 0.737. The accuracy of the model with cut-off of 0.5 and with of 0.6 were 0.904 and 0.902, respectively, and the AUCs were 0.687 and 0.741, respectively. Conclusion In this study, we confirmed that it is effective to increase the cut-off value of KS-15 to 0.6 in the metabolic syndrome risk model. It is expected that this could increase the accuracy of identifying high-risk groups for metabolic syndrome.

• 중환자간호학회지
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• 제12권2호
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• pp.26-38
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• 2019

Purpose : The aims of this study were to identify the incidence of pressure ulcers and to compare the predictive validities of pressure ulcer risk assessment scales among trauma patients. Methods : This was a prospective observational study. A total of 155 patients admitted to a trauma intensive care unit in a university hospital were enrolled. The predictive validity of the Braden, Cubbin & Jackson, and Waterlow scales were assessed based on the sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC). Results : Of the patients, 14 (9.0%) subsequently developed pressure ulcers. The sensitivity, specificity, positive predictive values, and negative predictive values were 78.6%, 75.9%, 24.4%, and 97.3%, respectively, for the Braden scale (cut-off point of 12); 85.7%, 68.8%, 21.4%, and 98.0%, respectively, for the Cubbin & Jackson scale (cut-off point of 26); and 71.4%, 87.2%, 35.7%, and 96.9%, respectively, for the Waterlow scale (cut-off point of 18). The AUCs were 0.88 (Waterlow), 0.86 (Braden), and 0.85 (Cubbin & Jackson). Conclusion : The findings indicate that the predictive validity values of the Waterlow, Braden, and Cubbin & Jackson scales were similarly high. However, further studies need to also consider clinical usefulness of the scales.

• Safety and Health at Work
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• 제3권4호
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• pp.287-293
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• 2012

Objectives: Metabolic syndrome has received attention as a risk factor for cardiovascular disease, with particular importance attached to visceral fat accumulation, which is associated with lifestyle-related diseases and is strongly correlated with waist circumference. In this study, our aim is to propose waist circumference cut-off values that can be used as a marker for fatty liver based on a sample of workers receiving health checkups in Japan. Methods: This study was conducted in a total of 21,866 workers who underwent periodic health checkups between January 2007 and December 2007. The mean age of the subjects was 47.4 years for men (standard deviation [SD]: 8.0) and 44.7 years for women (SD: 6.9). Evaluation included abdominal ultrasound and measurement of waist circumference, body mass index, fasting blood glucose, triglycerides, high-density lipoprotein cholesterol, and blood pressure. Results: Based on receiver operating characteristic curve analysis, the optimal waist circumference cut-off values were shown as 85.0 cm (sensitivity 0.72, specificity 0.69) for men and 80.0 cm (sensitivity 0.75, specificity 0.78) for women. Conclusion: Abdominal ultrasound is the most efficient means of diagnosing fatty liver, but this examination seldom occurs because the test is not routinely performed at workers' health checkups. In people found to have a high risk of fatty liver, recommendations can be made for abdominal ultrasound based on the waist circumference cut-off values obtained in this study. That is, waist circumference can be used in high risk individuals as an effective marker for early detection of fatty liver.

• 한국자동차공학회논문집
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• 제11권1호
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• pp.225-231
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• 2003

In order to improve efficiency of a system with three-dimensional flow characteristics, this paper presents a new method that overcomes three-dimensional effects by using two-dimensional CFD and response surface method. The method was applied to shape optimization of cut-off in a multi-blade fan/scroll system. As the entrance conditions of two-dimensional CFD, the experimental values at the positions out of the inactive zone were used. In order to examine the validity of the two-dimensional CFD the distributions of velocity and pressure obtained by two-dimensional CFD were compared with those of three-dimensional CFD and experimental results. It was found that the distributions of velocity and pressure show qualitatively similarity. The results of two-dimensional CFD were used for constructing the objective function with design variables using response surface method. The optimal angle and radius of cut-off were determined as $72.4^{\circ}$ and 0.092 times the outer diameter of impeller, respectively. It is quantified the previous report that the optimal angle and radius of cut-off are approximately $72^{\circ}$ and 0.08 times the outer diameter of impeller, respectively.