• Title/Summary/Keyword: T-test analysis

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Investigating Dynamic Mutation Process of Issues Using Unstructured Text Analysis (부도예측을 위한 KNN 앙상블 모형의 동시 최적화)

  • Min, Sung-Hwan
    • Journal of Intelligence and Information Systems
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    • v.22 no.1
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    • pp.139-157
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    • 2016
  • Bankruptcy involves considerable costs, so it can have significant effects on a country's economy. Thus, bankruptcy prediction is an important issue. Over the past several decades, many researchers have addressed topics associated with bankruptcy prediction. Early research on bankruptcy prediction employed conventional statistical methods such as univariate analysis, discriminant analysis, multiple regression, and logistic regression. Later on, many studies began utilizing artificial intelligence techniques such as inductive learning, neural networks, and case-based reasoning. Currently, ensemble models are being utilized to enhance the accuracy of bankruptcy prediction. Ensemble classification involves combining multiple classifiers to obtain more accurate predictions than those obtained using individual models. Ensemble learning techniques are known to be very useful for improving the generalization ability of the classifier. Base classifiers in the ensemble must be as accurate and diverse as possible in order to enhance the generalization ability of an ensemble model. Commonly used methods for constructing ensemble classifiers include bagging, boosting, and random subspace. The random subspace method selects a random feature subset for each classifier from the original feature space to diversify the base classifiers of an ensemble. Each ensemble member is trained by a randomly chosen feature subspace from the original feature set, and predictions from each ensemble member are combined by an aggregation method. The k-nearest neighbors (KNN) classifier is robust with respect to variations in the dataset but is very sensitive to changes in the feature space. For this reason, KNN is a good classifier for the random subspace method. The KNN random subspace ensemble model has been shown to be very effective for improving an individual KNN model. The k parameter of KNN base classifiers and selected feature subsets for base classifiers play an important role in determining the performance of the KNN ensemble model. However, few studies have focused on optimizing the k parameter and feature subsets of base classifiers in the ensemble. This study proposed a new ensemble method that improves upon the performance KNN ensemble model by optimizing both k parameters and feature subsets of base classifiers. A genetic algorithm was used to optimize the KNN ensemble model and improve the prediction accuracy of the ensemble model. The proposed model was applied to a bankruptcy prediction problem by using a real dataset from Korean companies. The research data included 1800 externally non-audited firms that filed for bankruptcy (900 cases) or non-bankruptcy (900 cases). Initially, the dataset consisted of 134 financial ratios. Prior to the experiments, 75 financial ratios were selected based on an independent sample t-test of each financial ratio as an input variable and bankruptcy or non-bankruptcy as an output variable. Of these, 24 financial ratios were selected by using a logistic regression backward feature selection method. The complete dataset was separated into two parts: training and validation. The training dataset was further divided into two portions: one for the training model and the other to avoid overfitting. The prediction accuracy against this dataset was used to determine the fitness value in order to avoid overfitting. The validation dataset was used to evaluate the effectiveness of the final model. A 10-fold cross-validation was implemented to compare the performances of the proposed model and other models. To evaluate the effectiveness of the proposed model, the classification accuracy of the proposed model was compared with that of other models. The Q-statistic values and average classification accuracies of base classifiers were investigated. The experimental results showed that the proposed model outperformed other models, such as the single model and random subspace ensemble model.

A Kinematics Analysis of Uchi-mata(inner thigh reaping throw) by Kumi-kata types and Two different Opponent's Height in Judo[II] (유도 맞잡기 타입과 받기의 신장에 따른 허벅다리걸기의 Kinematic 분석[2])

  • Kwon, Moon-Seok;Kim, Eui-Hwan;Cho, Dong-Hee
    • Korean Journal of Applied Biomechanics
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    • v.12 no.2
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    • pp.143-157
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    • 2002
  • This study was to analyze the kinematic variables when the subjects performing Uchi-mata(inner thigh reaping throw) by Kumi-kata types((How to grasp A or B?) and two different opponent's height in Judo. Kinematic variables were temporal, posture. Data analysis was collective comparison of two-way ANOVA, t-test by type A&B and two different opponent's height. There were significant difference of Kumi-kata types(p<.05) in the time elapsed on Kake phase(KP : throwing phase) and hip, knee, ankle-angle of the attacking foot in the 1st stage of KP and knee, ankle-angle of the attacking foot and hip, knee ankle-angle of the supporting foot in the 2nd stage of KP. There were significant difference of two opponent's(p<.05) in the time elapsed on KP and hip-angle of the supporting foot in 1st stage of KP. Therefore, the interaction effect(p<.05) were in the time elapsed on KP and hip-angle of the supporting foot in the 2nd stage of KP. So, It could be suggested that Judoka hold on the part-behind neck lapel(type A) at the sleeve with the other of Judogi jacked when opponent's height was short. Because the time elapsed on KP of type B was not so fast as type A(p<.05) during performed Uchi-mata, and also the bigger hip-angle of the supporting foot in the 2nd stage of KP grew, the faster the time elapsed on KP became.

Evaluation on the Usefulness of Filter in Sentinel Lymphoscintigraphy Using $^{99m}Tc$-Phytate (Phytate를 이용한 감시림프절 검사 시 Filter의 유용성 평가)

  • Jeong, Yeong-Hwan;Seo, Han-Kyung;Shim, Cheol-Min;Lim, Seong-Dong;Han, Dong-Hyeon;Park, Yung-Sun;Kim, Dong-Yun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.35-39
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    • 2010
  • Purpose: The aim of this study was to investigate distribution of particle size in phytate kit and compare filtered method with non-filtered method using 200 nm filter for sentinel lymphoscintigraphy (SLS). Materials and Methods: Five phytate kit of having the same available period was measured by particle size analyzer. For in-vivo experiment, $^{99m}Tc$-phytate was injected intradermally at both foot to perform lymphoscintigraphy. Imaging was acquired at 1hour after injection. Region of interest (ROI) was drawn in inguinal and background area for analysis. RAW 264.7 cells (Murine macrophage cell) were prepared for measurement of celluar uptake as a representative of macrophages. Paired t-test was performed using SPSS (SPSS Inc, USA) for statistical analysis. Results: The size of most particle in Techne phytate kit was distributed in 130~650 nm(90.5 %). In-vivo study, the ROI analysis showed similar result between filtered and non-filtered sample, and the numerical value of count/pixel were $58.3{\pm}5.97$ and $60.2{\pm}4.88$. In-vitro study, cellular uptake study also showed no difference between filtered and non-filtered sample by gamma counting. Conclusion: The present study demonstrates that there was no meaning of 200 nm filtered method for SLS using $^{99m}Tc$-phytate.

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Comparative analysis of RN-BSN Program in Korea and U. S. A. (간호학사 편입학제도의 교과과정 비교분석)

  • Lee Ok-Ja;Kim Hyun-Sil
    • The Journal of Korean Academic Society of Nursing Education
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    • v.3
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    • pp.99-116
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    • 1997
  • In response of the increasing demand for professional degree in nursing, some university in Korea offers RN-BSN program for R. N. from diploma in nursing. However, RN-BSN program in Korea is in formative period. Therefore, the purpose of this survey study is for the comparative analysis of RN-BSN curriculum in Korea and U.S.A. In this study, subjects consisted of 18 department of nursing in university and 5 RN-BSN programs in Korea and 18 department of nursing in university and 12 RN-BSN programs in U.S.A. For earn the degree of Bachelor of Science in Nursing, the student earns 134 of mean credits in U.S.A., whereas 150.3 of mean credits in Korea. The mean credit for clinical pratice is 30.1 in U.S.A., whereas 23.9 in Korea. Students are assigned to individually planned clinical experiences under the direction of a preceptor in U.S.A. In RN-BSN program, total mean credits through lecture and clinical practice for earn the degree of BSN is 35.5(lecture : 27.7, practice ; 7.8)in U.S.A., whereas,48.1 (lecture;42.1, practice;6.0) in Korea. RN-BSN program can be taken on a full-or-part time basis in U.S.A., whereas didn't in Korea. Especially, emphasis is place on the advanced nursing practicum that focus on the role of the professional nurse in providing health care to individuals, families, and groups in community setting in U.S.A. 27.7 of mean credits was earned through lecture in U.S.A., whereas 42.1 of mean credits in Korea. It means that RN-BSN program in Korea is the lesser development in teaching method and appraisal method than in U.S.A. Students of RN-BSN program in U.S.A. can earns credit through CLEP, NLN achievement test, portfolio review session etc as well as lecture. Therefore, the authors suggests some recommendations for the development of curriculum of RN-BSN program in Korea based on comparative analysis of RN-BSN curricula in U.S.A. and Korea. 1. The curriculum of RN-BSN Program in nursing was required to do some alterations. Nursing care, today, is complex and ever changing. According to change of public need, RN-BSN curriculum intensified primary care program in community setting, geriatric nursing, marketing skill, computer language. 2. The various and new methods of earning credit should be developed. That is, the students will earn credits through the transfer of previous nursing college credits, accredited examination of university, advanced placement examination, portfolio review session, case study, report, self-directed learning and so on. Flexible teaching place should ile offered. 3. Flexible teaching place should be offered. The RN-BSN curriculum should accommodate each RN student's geographical needs and school/work schedule. Therefore, the university should search a variety of teaching places and the RN students can obtain their degrees comfortably throughout the teaching place such as lecture room inside the health care agency and establishment of the branch school in each student's residence area. 4. The RN-BSN program should offer a long distance education to place-bound RN student in many parts of Korea. That is, from the main office of university, the RN-BSN courses are delivered to many areas by Internet, EdNet (satellite telecommunication) and other non-traditional methods. 5. For allowing RN student to take nursing courses, program length should be various, depending upon the student's study/work schedule. That is, the various term systems such as semester, three terms, quarter systems and the student's status like full time or part time should be considered. Therefore, the student can take advantage of the many other educational and professional opportunities, making them available during the school year.

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Dietitians' Customer Orientation at Contract Foodservice Management Company (위탁급식전문업체 영양사의 고객지향성 분석)

  • Shin, Seo-Young;Kim, Hee-Yeon;Choi, Mi-Kyung;Yang, Il-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.6
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    • pp.801-808
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    • 2006
  • The purposes of this study were to measure customer orientation of dietitians engaged in contract foodservice management companies, and to examine the impacts of personal characteristics and organizational characteristics on the customer orientation of dietitians. The questionnaires developed for this study were distributed to 230 dietitians of contract foodservice management companies, including 4 major companies, in Seoul and Gyeonggi areas. A total of 187 (81.3%) questionnaires were used for analysis, and statistical analyses were conducted using SPSS (Win 11.5) for descriptive analysis, correlation analysis, t-test and ANOVA. The average customer orientation score of the dietitians was 3.77 (SD=0.40) and it seemed that most respondents evaluated themselves as customer-oriented. Further analyses revealed significant differences in customer orientation among different position (p<0.05) and payroll (p<0.01) groups.'Type of menu' also affected the customer orientation (p<0.01). Overall, it is needed to design efficient training programs that improve service skills and customer orientation of dietitians, and the understandings on variables affecting customer orientation would help it.

Result of Radiation Therapy of Cerebellar Medulloblastoma - with Emphasis on the Neuraxis Dose - (전중추신경계 조사선량을 중심으로 한 수아세포종의 방사선치료성적)

  • Kim Joo Young;Kim Il Han;Ha Sung Whan;Park Charn Il
    • Radiation Oncology Journal
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    • v.11 no.1
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    • pp.69-77
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    • 1993
  • Treatment of cerebellar medulloblastoma has been much improved with modern surgical technique for gross total tumor removal and adequate radiation therapy for the whole craniospinal axis. Questions have been arosen about the optimal radiation dose for the preventive treatment of whole cranium and whole spinal axis. Recently, many authors have reported their treatment results as comparable to older data, using lower than conventional dose of 3,600 cGy-4,000 cGy. For 50 patients treated between 1981 and 1990 at the Department of Radiation Therapy of SNUH, retrospective analysis was done for the treatment result, especially the neuraxis control, by radiation dose for the presymptomatic area of the disease. Analysis only by total spinal dose did not give any significant difference. But further analysis by following patient group; 3,600 cGy/150 cGy (n=6), 3,000 cGy/150 cGy (n=10), 2,400 cGy/150 cGy (n=17) and 2,400 cGy/100-120 cGy (n=11) showed significant improvement of neuraxis control by decreasing order (p =0.003). There was no significant difference in overall survival between the groups. For the 19 patients who had been confirmed initially as having no neuraxis disease, TDF 30 was the cur-off value that could prevent neuraxis failure (p =0.004). We couldn't define any TDF value that give reasonable control for the patient group with positive CSF study at initial diagnosis.

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The Clinical Usefulness Measurement of the Whole Body Percent Fat Calculated by the Part Bone Mineral Density Measurement (부분골밀도 측정을 통해 산출되는 체지방률의 임상적 유용성에 대한 평가)

  • Kang, Young-Eun;Kim, Eun-Hye;Kim, Ho-Sung;Choi, Jong-Sook;Choi, Woo-Jun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.1
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    • pp.3-9
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    • 2011
  • Purpose: Generally dual energy X-ray absorptiometry has been used for the purpose of evaluation of osteoporosis and treatment. Recently the interest of obesity came to be high and body percent fat test is increasing. Existing measure of body fat have to scan the whole body can be evaluated, but only lumbar spine and hip measurements was assumed to be whole body fat as well as improving the software. It tries to check whether the part measured value not being whole body measurement has the validity or not compared with the value calculated with the method that it is different, it forgives through a correlation with a (BIA) and (BMI). Materials and Methods: In 2010, the body percent fat was measured among the examinee coming to the Asan Medical Center public health care center from March till August against 90 females more than 40 years old through (DXA) and BIA. BMI utilized the value which wrote an hight and weight measured through the body measuring instrument in the examinee information and is automatically calculated. In addition, it classified as the low weight ($13-18.5kg/m^2$), normal ($18.5-25kg/m^2$), and corpulence ($25-30kg/m^2$) based on BMI and so that it could check whether there was the difference according to the weight or not BMI and BIA and correlation between DXA were analyzed in each group. The statistical program for the analysis used SPSS 12.0. Results: The comparison of DXA at 3 which it divides into the low weight and normal and corpulence groups and BIA did not show the difference noted statistically in all groups and the between group comparison was exposed to do not have a meaning. The body percent fat measured by the correlation analysis result DXA at the state that it doesn't divide into the group showed the high correlation (r=0.908, p0.01) noted statistically compared with BMI and showed the high correlation noted statistically in a comparison with BIA (r=0.927, p0.01). Conclusion: It confirmed that the whole body percent fat presumed from the part bone density measurement showed the excel correlation compared with BIA and BMI and information is high. There is still no clear standard about the presumed whole body percent fat and it is difficult to evaluate the fat evaluation by the bone mineral density measurement. However, it is determined that the information offering which is more objective through the comparative study with the body percent fat which is very efficient and in that it can obtain till the information about a fat as well as diagnosis of the osteoporosis through the bone density checkup is measured by the afterward telegraph bone density checkup and is clinically useful is possible.

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Usefulness of Prone Position on PET-CT in Breast Cancer (유방암 PET-CT 검사에서 Prone(복와위)자세의 유용성 평가)

  • Park, Hoon-Hee;Kim, Sei-Yung;Kim, Jung-Yul;Park, Min-Soo;Lim, Han-Snag;Jung, Suk;Kang, Chun-Goo;Kim, Jae-Sam;Lee, Chang-Ho;Lee, Yung-Joo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.1
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    • pp.44-48
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    • 2008
  • Purpose: In FDG-PET/CT of breast cancer, a sensitivity was 80~96% and a specificity was 75~95% commonly. It was valuable to identify a cancer in early stage been difficult in Mammography. Most of the PET/CT scans have been examined on supine position, so, the image of breast has been acquired by reconstructed whole body scan image. However, using prone position with a compensator, a shape of breast was reassembly shown to be real by gravity. Therefore, the purpose of this study was to evaluate diagnostic value of prone position in FDG PET-CT of breast cancer. Materials and Methods: 30 female patients with doubtful or positive breast cancer were examined. The PET-CT whole body scan was acquired at 60 minutes after $^{18}F$-FDG injection on Supine position. Then, regional breast spot scan was progressed on prone position using a compensator. Each image was evaluated by physicians blinded to patient's data, and statistical analysis did through SUVs measured in PET-CT images. Results: In 27 of 30 patients, prone position was shown accurate discrimination and diagnostic value, but in another 3 patients had a lesion 1cm below, PET-CT couldn't detect it, unlike MRI. Consequently, prone position distinguished a lesion better than Supine position, because of low degree of metamorphosis by gravity. The SUVs analysis of each position was significant (p value=0.004). Conclusion: In PET-CT of breast cancer, prone position could detect micrometastasis as well as primary lesion, better than supine position. Therefore, this study proposes that any technical change considered morphological feature like prone position can offer adequate and useful diagnostic information, together with complementary quantitative analysis.

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The Organization Commitment and Perception of Human Resource Management by Employment Types of School Foodservice Employees (학교급식 직원의 고용유형에 따른 인적 자원 관리 활동에 대한 인식과 조직 몰입도)

  • Lee, Ok;Cho, Minju;Chang, Hyeja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.1
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    • pp.162-171
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    • 2014
  • As the foodservice industry is labor intensive, the efficient management of human resources is an essential element for improving operational efficiency. This study was designed to investigate the performance level of human resource management in self-operated school foodservices and to examine the relationship between human resource management, organizational commitment, and productivity. Whether these factors rated differently by employment and job types was also examined. Data were collected through questionnaires distributed to 60 dieticians and 240 cooks in Seongnam and Yongin. Frequency analysis, factor analysis, the t-test and multiple regression analysis were tested using Minitab. Human resource management practices rated highly in the dimension of employee training (3.51), followed by working environment (3.39), and turnover management (3.37). In contrast, reward management (1.73) and working condition (1.56) received the lowest score. Organizational commitment scored 3.65 points, and showed that dedication (3.82) was the highest score; however, self-esteem (3.50) was the lowest score. For human resource management, there were significant differences between employment types as full time workers (3.85) rated management more highly than part-time worker (3.43). Overall productivity was fairly high, especially in high school foodservices. Only the performance appraisal had an influence on organizational commitment (${\beta}$=0.292, P<0.05). Productivity was positively correlated with human resource management (r=0.432, P<0.001) and organizational commitment (r=0.36, P<0.01). In conclusion, school foodservices need to establish objective performance standards, and increase employee morale by enhancing reward systems and working conditions. In particular, irregular employees require training with job performance standards and given a proper reward program, depending on their performance, to improve organizational commitment.

Need Assessment for Enlargement of Oriental Medical Care Service Room in Rural Community Health Center (농촌지역 보건소 한방진료실 확대설치 요구도 및 관련요인 - 일개 군 보건소 한방진료실 내소자를 대상으로 -)

  • Kim, Dae-Feel;Song, Mi-Sook;Song, Hyun-Jong
    • Journal of agricultural medicine and community health
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    • v.28 no.1
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    • pp.39-51
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    • 2003
  • Objectives: The oriental medical care has been getting popular in community health centers because of uniqueness, changing of disease patterns, and increasing of elderly population. From 1998, oriental medical doctors has been working in several rural community health centers for their military obligations. At this point of time, it is necessary to evaluate the oriental public health doctors system. This study was performed to investigate the utilization patterns, the degree of satisfactions, needs of oriental medical care service provided by community health center in a designated Gun area. This study focused on the need for extending over Myun area of community health center's oriental medical care services. Methods: Person-to-person interview survey method through a structured questionnaire was done by a personnel at a oriental medical care service room in a Gun community health center. The major statistical method used for the analysis were the t-test, ANOVA, and logistic analysis. Results: The total number of responded subjects in this study was 163 residents. Among these 65.0% were aged 61 or over, and only 13.5% recognized themselves were healthy. 73.7% of the respondents demanded establishment of more oriental medical care services provided by community health center to other Myun area. Factors affecting the need for enlargement of oriental medical care service room were education level, subjective awareness of access to community health center, and cost satisfaction of oriental medical service provided by community health center. Thus, a resident who had graduation of middle school achievement or above(OR=3.35), had a long way to center(OR=2.47), satisfied with oriental medical service cost(OR=2.78) had demonstrated increased chance of need by logistic regression analysis.

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