• 한국정밀공학회지
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• 제16권12호
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• pp.152-160
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• 1999

The weld quality of $CO_2$ arc welding is closely related to the arc stability. As the characteristics of the arc are excessively complex and nonlinear, it is not easy to make the arc model as mathematical form and to control the arc state to be stabilized. This paper was aimed to estimate the arc stability and to control for stabilizing the arc state in short circuit metal transfer mode of $CO_2$ arc welding. For these purposes, the behaviors of arc stability was investigated at different welding conditions using Mita's arc stability index, and the fuzzy control algorithm which uses the arc stability index as control imput and the arc voltage as control output was developed. In the control of the arc stability, the experiments of two cases were performed; the case of setting an initial welding voltage arbitrarily, the case of the step change in workpiece shape. Obtained results were as follows; Mita's arc stability index was able to be estimated qualitatively in the case of using the inverter type welding power source and the control performance for stabilizing the arc status was excellent in the case of existing step change disturbance.

• 대한방사선기술학회지:방사선기술과학
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• 제24권2호
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• pp.41-47
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• 2001

This study was undertaken to examine the differences between normal vocal technique and abnormal vocal technique because of diseases in respiratory system(emphysema). The breath control for vocalizing with diaphragmatic respiration must be sustained clearly. But if there is an abnormality in lung(emphysema), it is not sustained to hold diaphragmatic respiration when we sing. In order to examine the differences of the width in diaphragmatic respiration among professional singer's case, non professional case and the case of respiratory disturbance, Shimadzu X-ray remote control TV system was used. The results obtained were summerized as follows: When we vocalize, breath control is very important not only to sustain a resonance but also to form focus for being scattered to cranial resonance. We must know the differences between normal and abnormal diaphrogmatic respiration in order to teach vocal technique right. professional singer's vocal technique with Piaphragmatic respiration was better than that compared with non professional case and respiratory disturbance. Non professional case was very similar to the case of respiratory disturvance in diaphragmatic respiration until 10 sec. after full inhalation, but diaphragmatic respiration in the case of 20 sec. after full inhalation was very different.

• PNF and Movement
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• 제13권4호
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• pp.203-213
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• 2015

Purpose: Deficits in lower-extremity function and trunk control ability have a negative impact on individuals with hemiplegia. This case report aimed to describe the effect of trunk stability exercises using proprioceptive neuromuscular facilitation (PNF) on trunk control ability, balance, and gait in a patient with hemiplegia. Methods: A 77-year-old man with hemiplegia and trunk and lower extremity impairment participated in this four-week training intervention. Results: The patient demonstrated improvements in trunk control ability, balance, and gait performance. Outcome measures (Fugl-Meyer Assessment Lower Extremity (FMA-LE), Trunk Control Test, Berg Balance Scale, Timed Up and Go test, 10 Meter Walk test) were measured before and after the training program. Conclusion: The results of this case suggest that a trunk stability exercise using a PNF program may improve trunk control ability, balance, and gait in a patient with hemiplegia.

• Journal of Electrical Engineering and information Science
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• 제1권1호
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• pp.29-38
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• 1996

To improve the reliability of control systems, certain robustness to plant uncertainties and disturbance inputs is required in terms of well founded mathematical basis. Robust control theory was set up and developed until now from this motivation. In this field, H$_2$or H\ulcorner norm performance measures are frequently used nowadays. Moreover a mixed H$_2$/H\ulcorner control problem is introduced to combine the merits of each measure since H$_2$control usually makes more sense for performance while H\ulcorner control is better for robustness to plant perturbations. However only some partial analytic solutions are developed to this problem under certain special cases at this time. In this paper, the mixed H$_2$/H\ulcorner control problem is considered. The analytic(or semi-analytic) solutions of (sub)optimal mixed H$_2$/H\ulcorner state-feedback controller are derived for the scalar plant case and the multivariable plant case, respectively. An illustrative example is given to compare the proposed analytic solution with the existing numerical one.

• 한국컴퓨터정보학회논문지
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• 제11권2호
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• pp.121-129
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• 2006

퍼지기법을 이용한 룰-기반(rule-based) 전문가 시스템에서는 사용자의 조건입력에 따라 여러 가지의 룰(rule)들을 추론하여, 가장 적절한 신호주기를 산출해낸다. 그러나 입력조건을 사용자의 판단에만 의존함으로 해서 객관성을 잃을 수 있는 단점이 있다. 본 논문에서는 케이스-기반시스템(case-based system)의 기법을 추가함으로써 그러한 객관성의 문제를 보완하고자 한다. 기존의 통계치로 각 요일별, 각 계절별, 여러 상황들에 대한 케이스(case)를 시스템에 저장함으로써 적절히 활용할 수 있도록 교통신호 제어 전문가 시스템의 모델을 제안한다.

• 혜화의학회지
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• 제11권1호
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• pp.85-90
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• 2002

From June 1th to December 31th 2001, the study was carried out 285 person who came to the Daejon oriental hospital for the examination of CVA. The result was as follows : 1. Hyperlipidemia patient is 41%, 50's is the highest. 2. In the case of Hyperlipidemia patient, Taeyum type is 49%, Soyang type is 36% and Soyum type is 15%. but in the Control group Taeyum type is 36%, Soyang type is 44% and Soyum type is 20%. 3. In the case of Abnormal EKG, Hyperlipidemia group is 34%, Control group is 32%. 4. In the case of Liver disease, Hyperlipidemia group is 17%, Control group is 9%. 5. In the case of Diabet mellitus, Hyperlipidemia group is 30%, Control group is 7%. 6. In the case of Hypertension, Hyperlipidemia group is 50%, Control group is 42%.

• 한방비만학회지
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• 제2권1호
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• pp.25-36
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• 2002

Objective: The purposes of this study are to know the relations of abdominal obesity and ischemic stroke and to know what index could represent the abdominal obesity appropriately. Methods. We have done case-control study and recruited 97 ischemic stroke patients and 117 controls. Case is matched by control by individual matching. All participants had questionnaire, interview and then were examined waist-hip ratio, waist circumference and body mass index. Results : WC, WHR and Hypertension history had differences in two groups, case and control groups. But BMI and other factors weren't significant. According to Quartile of Waist Circumference, the two groups had the differences in hypertension history, diabetes history, smoking status, WHR, BMI, and weight and in the Quartile of Waist-Hip Ratio Quartile, past history of hypertension and diabetes, WC, BMI and weight had the significances. Sex, Age Adjusted and Multivariate Odds Ratio (95% Confidence Interval) of WC Quartile are 2.083, 1.628, 4.491 and 4.418, 4.964, 12.306, and in WHR, the Ors are 2.252, 5.743, 15.776 and 2.632, 8.918, 23.596. Conclusions: We knew from these results that abdominal obesity is very important risk factor of ischemic stroke and WHR more than WC is a good indicator of abdominal obesity, so we should reduce the WHR to prevent of ischemic stroke.

• Genomics & Informatics
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• 제3권1호
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• pp.1-7
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• 2005

Case-control studies are widely used for disease gene mapping using individual genotyping data. However, analyses of large samples are often impractical due to the expense of individual genotyping. The use of DNA pooling can significantly reduce the number of genotyping reactions required; hence reducing the cost of large-scale case-control association studies. Here, we discuss the design and analysis of DNA pooling genetic association studies.

• 대한간호학회지
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• 제42권6호
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• pp.771-782
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• 2012

Purpose: This study was conducted to develop and implement a case-based small group learning program on the care of children with infectious disease, and to examine its effects on knowledge, attitude and preventive practice behaviors of daycare center teachers compared to a control group. Methods: Based on the need assessment, the case-based learning program for the management of infectious children was developed. For this quasi-experimental study, 69 teachers were recruited from 14 child daycare centers in a city located in J province. Thirty four teachers were assigned to experimental group and participated in the case-based small group learning once a week for 5 weeks. Data were analyzed using the SPSS 18.0 program to perform ${\chi}^2$-test and t-tests. Analysis of covariance was used to treat the covariate of the number of assigned children between experimental and control groups. Results: The experimental group showed significantly higher posttest scores in knowledge, attitude and preventive practice behaviors than those of control group (p<.001). Conclusion: These findings indicate that case-based small group learning is an effective educational strategy for daycare center teachers to learn infection management through the emphasis of self-reflection and discussion.

• 가정간호학회지
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• 제17권1호
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• pp.28-35
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• 2010

Purpose: The study compared the hypertension care efficacy of a case management intervention program for registered clients. Methods: The nonequivalent control group pretest-posttest design involved 53 registered hypertensive patients of a customized visiting health care service in S-city(n=28 experimental group, n=25 control group). Data collection and case management intervention were carried out from April to July, 2009. The experimental group had six home visits and two phone calls, and the control group had two home visits during the 8-week period. Outcome variables for test hypotheses were changes in physiologic index (blood pressure and total cholesterol) and degree of self-management performance and confidence. Results: Repeated measure ANOVA and t-test of means revealed significant differences before and after program for systolic and diastolic blood pressure and self-management performance and confidence, but no significant difference concerning total cholesterol. Conclusion: A case management program can have positive effects on blood pressure control and self management. However, research is needed to create a more effective case management for vulnerable patient populations.