• Journal of Chest Surgery
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• v.45 no.5
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• pp.295-300
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• 2012

Background: With growing attention to the aortopathy associated with aortic valve diseases, the number of candidates for accompanying ascending aorta and/or root replacement is increasing among the patients who require aortic valve replacement (AVR). However, such procedures have been considered more risky than AVR alone. This study aimed to compare the surgical outcome of isolated AVR and AVR combined with aortic procedures. Materials and Methods: A total of 86 patients who underwent elective AVR between 2004 and June 2010 were divided into two groups: complex AVR (n=50, AVR with ascending aorta replacement in 24 and the Bentall procedure in 26) and simple AVR (n=36). Preoperative characteristics, surgical data, intra- and postoperative allogenic blood transfusion requirement, the postoperative clinical course, and major complications were retrospectively reviewed and compared. Results: The preoperative mean logistic European System for Cardiac Operative Risk Evaluation (%) did not differ between the groups: $11.0{\pm}7.8%$ in the complex AVR group and $12.3{\pm}8.0%$ in the simple AVR group. Although complex AVR required longer cardiopulmonary bypass ($152.4{\pm}52.6$ minutes vs. $109.7{\pm}22.7$ minutes, p=0.001), the quantity of allogenic blood products did not differ ($13.4{\pm}14.7$ units vs. $13.9{\pm}11.2$ units). There was no mortality, mechanical circulatory support, stroke, or renal failure requiring hemodialysis/filtration. No difference was found in the incidence of bleeding (40% vs. 33.3%) which was defined as red blood cell transfusion ${\geq}5$ units, reoperation, or intentional delayed closure. The incidence of mediastinitis (2.0% vs. 0%), ventilator ${\geq}24$ hours (4.0% vs. 2.8%), atrial fibrillation (18.0% vs. 25.0%), mean intensive care unit stay (34.5 hours vs. 38.8 hours), and median hospital stay (8 days vs. 7 days) did not differ, either. Conclusion: AVR combined with additional aortic or root replacement showed an excellent outcome and recovery course equivalent to that after isolated AVR.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.124-131
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• 2016

Baseline correction is very important due to influence on performance of spectral analysis in application of spectroscopy. Baseline is often estimated by parameter selection using visual inspection on analyte spectrum. It is a highly subjective procedure and can be tedious work especially with a large number of data. For these reasons, it is an objective and automatic procedure is necessary to select optimal parameter value for baseline correction. Asymmetrically reweighted penalized least squares (arPLS) based on penalized least squares was proposed for baseline correction in our previous study. The method uses a new weighting scheme based on the generalized logistic function. In this study, we present an automatic selection of optimal parameter for baseline correction using arPLS. The method computes fitness and smoothness values of fitted baseline within available range of parameters and then selects optimal parameter when the sum of normalized fitness and smoothness gets minimum. According to the experimental results using simulated data with varying baselines, sloping, curved and doubly curved baseline, and real Raman spectra, we confirmed that the proposed method can be effectively applied to optimal parameter selection for baseline correction using arPLS.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.6
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• pp.607-611
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• 2001

Ultrasonic inspection system consist of the operator, equipment and procedure. The reliability of results in ultrasonic inspection is affected by its ability. Furthermore, the reliability of nondestructive testing is influenced by the inspection environment, materials and types of defect. Therefore, it is very difficult to estimate the reliability of NDT due to the various factors. In this study, the probability of detection by logistic probability model and Monte Carlo simulation is used for the reliability assessment of ultrasonic inspection. The utility of the NDT reliability assesment is verified by the analysis of the data from round robin test nth these models.

• Korean Journal of Head & Neck Oncology
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• v.22 no.2
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• pp.117-122
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• 2006

Background and Objectives : Thyroid carcinoma is the sixth commonest cancer in Korea and the papillary carcinoma is the most common type(88%) of the malignant thyroid tumors. Bulky DNA adducts formed by the carcinogens are repaired by DNA repair process, but failure to repair this DNA damage can cause mutations in oncogenes and tumor suppressor genes resulting in tumor formation. The xeroderma pigmentosum group C(XPC) gene is essential for this repair procedure and the XPC-PolyAT(PAT) polymorphisms may alter DNA repair capacity(DRC) and genetic susceptibility to cancer. Subjects and Methods : In a case-control study of 113 Korean patients with pathologically diagnosed thyroid papillary carcinoma and 65 control subjects, we investigated the association between the three XPC-PAT gene polymorphisms and thyroid papillary cancer susceptibility. Results : The frequency of the variant XPC-PAT allele was lower in the cases(0.349) than in the controls (0.423), but the difference was not significant(p=0.140). Using logistic regression adjusting for age and sex, risk for thyroid papillary cancer was not increased in the XPC-PAT-/+ and XPC-PAT+/+ compared to XPCPAT-/-(adjusted overall odds ratio[95% confidence intervals;95%CI]=0.52[0.26-1.03] and 0.62 [0.22-1.75], respectively; trend test, p=0.167). Conclusion : There are no relationship between the XPC-PAT polymorphism and the risk of thyroid papillary carcinoma in Korean population. Based on our results, XPC-PAT polymorphism do not modulate genetic susceptibility to thyroid papillary cancer.

• Journal of Preventive Medicine and Public Health
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• v.32 no.4
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• pp.538-545
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• 1999

Objective : To compare the predictive power of International Classification of Diseases 10th Edition(ICD-10) based International Classification of Diseases based Injury Severity Score(ICISS) with Trauma and Injury Severity Score(TRISS) and International Classification of Diseases 9th Edition Clinical Modification(ICD-9CM) based ICISS in the injury severity measure. Methods : ICD-10 version of Survival Risk Ratios(SRRs) was derived from 47,750 trauma patients from 35 Emergency Centers for 1 year. The predictive power of TRISS, the ICD-9CM based ICISS and ICD-10 based ICISS were compared in a group of 367 severely injured patients admitted to two university hospitals. The predictive power was compared by using the measures of discrimination(disparity, sensitivity, specificity, misclassification rates, and ROC curve analysis) and calibration(Hosmer-Lemeshow goodness-of-fit statistics), all calculated by logistic regression procedure. Results : ICD-10 based ICISS showed a lower performance than TRISS and ICD-9CM based ICISS. When age and Revised Trauma Score(RTS) were incorporated into the survival probability model, however, ICD-10 based ICISS full model showed a similar predictive power compared with TRISS and ICD-9CM based ICISS full model. ICD-10 based ICISS had some disadvantages in predicting outcomes among patients with intracranial injuries. However, such weakness was largely compensated by incorporating age and RTS in the model. Conclusions : The ICISS methodology can be extended to ICD-10 horizon as a standard injury severity measure in the place of TRISS, especially when age and RTS were incorporated in the model. In patients with intracranial injuries, the predictive power of ICD-10 based ICISS was relatively low because of differences in the classifying system between ICD-10 and ICD-9CM.

• Journal of Trauma and Injury
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• v.25 no.2
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• pp.37-43
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• 2012

Purpose: A tube thoracostomy is an invasive procedure that places patients at risk for complications. Tube thoracostomies are frequently performed by emergency medicine residents. Thus, the purpose of the study was to assess both the complication rate for tube thoracostomies performed by emergency medicine residents and the factors associated with these complications. Methods: A retrospective chart review of all patients who had undergone a tube thoracostomy performed by emergency medicine residents between January 2008 and February 2009 was conducted at a university hospital. Complications were divided into major and minor complications and into immediate and delayed complications. Complications requiring corrective surgical intervention, requiring the administration of blood products, or involving situations requiring intravenous antibiotics were defined as major. Complications that were detected within 2 hours were defined as immediate. Results: Tube thoracostomies were performed in 189 patients, and 70 patients(37%) experienced some complications. Most complications were immediate and minor. In multiple logistic regressions, BMI, hypotension and resident seniority were significantly associated with complications. Conclusion: The prevalence of complications was similar to these in previous reports on the complications of a tube thoracostomy. Most complications from tube thoracostomies performed by emergency medicine residents were immediate and minor complications. Thus, emergency medicine residents should be allowed to perform closed tube thoracostomies instead of thoracic surgeons.

• Journal of Preventive Medicine and Public Health
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• v.50 no.5
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• pp.320-327
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• 2017

Objectives: The purpose of our study was to evaluate the association between the intensity of physical activity (PA) and prevalence of cardiovascular disease (CVD) using Korean representative data. Methods: We analyzed 39 804 participant data from the Korea National Health and Nutrition Examination Survey, 2007-2013. Exposure variable was three levels of PA (low, medium, and high) in a week, and outcome variable was prevalence of CVD based on patient self-recognition and doctor's diagnosis. Complex logistic regression analysis was performed to evaluate the relationship between level of PA and CVD adjusted by body mass index, hypertension, hypercholesterolemia, diabetes mellitus, stress recognition, household income, smoking, and current drinking. The indices of association w ere estimated as crude prevalence odds ratio (POR), adjusted POR, and their 95% confidence interval (CI). All statistical analyzes were performed using complex sample analysis procedure of the SPSS version 23.0. Results: When all variables were adjusted, only high level PA in women showed a significant association with stroke (adjusted POR by patient's self-recognition, 0.57; 95% CI, 0.32 to 0.99, adjusted POR by doctor's diagnosis, 0.55; 95% CI, 0.34 to 0.87) and CVD (adjusted POR by doctor's diagnosis, 0.68; 95% CI, 0.48 to 0.96). Conclusions: High level PA in women has a significant reverse association with prevalence of stroke and CVD in Korea. Further study for elucidating the mechanism will be needed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2689-2692
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• 2014

Purpose: To investigate the risk factors for appendiceal metastasis of epithelial ovarian cancer and compare findings with the previous studies. Materials and Methods: One hundred and thirty-four patients with epithelial ovarian cancer were assessed in this study. All of them had undergone a surgical procedure including appendectomy. Of these, 21 (15.7%) patients who had appendiceal metastasis were analyzed as the case group and the patients with no metastasis were the controls, compared according to stage, grade, histology of tumor, preoperative Ca125 levels, presence of ascites, peritoneal cytology, diameter and site of tumor considered as risk factors. Results: We found statistically significant differences between the groups in terms of stage, grade, right-sided tumor location, presence of ascites, diameter of tumor${\geq}10cm$ and positive peritoneal cytology (p<0.05). In the logistic regression model, stage, grade, presence of ascites, right-sided location and diameter of tumor were independent risk factors. ROC curve analysis showed that stage, grade and diameter of the tumor were discriminative factors for appendiceal metastasis. Conclusions: In epithelial ovarian cancer, stage, grade, presence of ascites, right-sided location and large tumor size have importance for estimation of risk of appendiceal metastasis. As we compare our findings with previous studies, there is no definite recommendation for the risk factors of appendiceal metastasis in epithelial ovarian cancer and more studies are needed.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.249-257
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• 2009

The purpose of this study is to find a classification method with high accuracy in regard with sasang constitutional diagnosis. The BMI, blood pressure, pulse wave, and Sasang constitution diagnosed by a specialist was collected from 2848 subjects who were apparently healthy. Through a selective procedure, the data of 1635 subjects was used in the analysis. The results with the classification methods such as the discriminant analysis, regression, decision tree and neural network were compared with the diagnosis of a Sasang constitutional specialist. In result, the discriminant analysis method was hard to qualify the assumption of the equality of covariance matrices within constitutional groups. Moreover, without BMI, the decision tree and neural network methods were very sensitive to the change of the analysis data. Therefore, the Logistic regression and the decision tree is recommended on condition that the decisive factors of constitution are well concerned.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1055-1060
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• 2009

In this paper, we design an e-Learning system for the Driver's License Teste studying through the Internet. The proposed system make users to be arrived at the goal for the license in a shorter time by offering learning contents and items according to the item-responses made by the users based on the Item Response Theory. Moreover we design the scheme to give the optimum items and the most necessary content to the user during the learning procedure in the form of concept-based objects. All the items in the problem bank DB maintain their difficulties, discriminations, and guessing parameters as is the case of 3-parameter logistic model. In addition user profile DB stores users' status informations, item responses, and ability parameters. Using these structures and combining agents, we can offer the optimum learning process or dynamic personalized studying structure to the user. We can construct interface agent and content selection and feedback agent with the DB's described above. User can study without any awareness of system operations or personal fitting scheme.