• Title/Summary/Keyword: Case-control study

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A study on the H_$\infty$ robust controller of induction motors (유도전동기의 H_$\infty$강인제어에 관한 연구)

  • 김민찬;박승규;진승오
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1448-1451
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    • 1997
  • In this paper, a speed control of nin-servo induction motor is considered. In this case, it is difficult to satisfy precise control performance. SO H.inf. robust controller is designed for this problem by usign polynomial approach and Youla parameterization.

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The Effect of Safety Education on Accident Proneness Prospect in Preschooler (안전교육이 학령전기 아동의 사고경향 예측에 미치는 효과)

  • Kim Shin Jeong;Lee Jung Eun
    • Child Health Nursing Research
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    • v.6 no.3
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    • pp.372-386
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    • 2000
  • The purpose of this study was to provide basic data on preschool children for accident prevention and improve their health through sound, safe living environment with safety education established through more systematic method. Data were collected from 300 preschoolers(150 preschooler are assigned to experimental group and 150 preschoolers are assigned to control group) from 4 to 6 years old using APP paper test which consists of questions and drawings. To experimental group, safety education were done 4 times within the time of 30 minutes per 1 time using education books, video, OHP, slide. The findings of this study are as follows: 1. There were significant difference in behavioral character between experimental group and control group(χ2=11.690, p= 0.003). So, safety education have effect on the behavioral character of preschooler. 2. In the accident proneness on preschooler between experimental group and control group according to general characteristics, it proved significant difference in the case of accident prevention education were done, movement stability(χ2=8.844, p=0.012) and behavioral character(χ2=6.699, p=0.035), in the case of housing pattern is mixed-type, behavioral character(χ2=10.37, p=0.006), in the case of subjects' age is 4 years old, watchfulness(χ2=9.525, p=0.009), in the case of subjects' age is 5 years old, behavioral character(χ2=7.324, p=0.026), in the case of children's order is second, behavioral character(χ2=14.31, p=0.001), in the case of children's sex is boy, living safety(χ2=7.981, p=0.018), movement speed (χ2=6.661, p=0.036), bihavioral character(χ2=8.837, p=0.012), in the case of children's sex is girl, reasoning power(χ2 =9.78, p=0.008), in the case of childrens have no past accidental experience, behavioral character(χ2=9.862, p=0.007), in the case of nuclear family, movement speed(χ2=6.341, p=0.042) and behavioral character(χ2=9.326, p=0.009), in the case of mothers' age is under thirty behavioral character(χ2=16.40, p=0.000), in the case of mothers' school career is under high school graduate, behavioral character(χ2 =8.375, p=0.015), in the case of mothers' school career is beyond college graduate, reasoning power(χ2=9.803, p=0.007) and behavioral character(χ2=6.205, p=0.045), in the case of mothers' job is part time, movement speed(χ2=10.99, p=0.004), in the case of mothers have no job, movement stability(χ2=8.490, p=0.014) and behavioral character(χ2=10.11, p=0.006). The difference of accident proneness between experimental group and control group according to general characteristics, it also showed that there were significant difference in behavioral character compared to other area.. From this findings, we can guess that safety education change and guide preschoolers' behavioral character to desirable direction.

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A STUDY ON THE SPEED CONTROL OF A LOW SPEED-LONG STROKE MARINE DIESEL ENGINE (저속 장행정 박용디젤기관의 속도제어에 관한 연구)

  • 유영호;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • v.13 no.3
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    • pp.26-36
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    • 1989
  • Recently digital governor system is commonly adapted for the speed control of the marine diesel engine because of too much fluctuation of rpm resulted by the low speed, long stroke, high efficiency and a small number of cylinder of it, and versatile studies on the development of digital governor system are progressed. On this subject the new control method in which the fuel is controlled by feedforwarding the change of load as well as the feedback of angular velocity in case of disregarding the engine dead time and influence of scavenging air was proposed by the authors, and found the method has shown quite a good control performance in comparision to the conventional control method by the simulation using a digital computer for various load change. In this paper the speed control system of a diesel engine is simulated in case of regarding the engine dead time by the proposed method, and also confirm a good control performance of it under even more realistically simulated environment.

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Analysis of a network for control systems in nuclear power plants and a case study (원자력 발전소 제어계통을 위한 네트워크의 해석과 사례 연구)

  • Lee, Sung-Woo;Yim, Han-Suck
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.6
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    • pp.734-743
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    • 1999
  • In this paper, a real-time communication method using a PICNET-NP(Plant instrumentation and Control Network for Nuclear Power plant) is proposed with an analysis of the control network requirements of DCS(Distributed Control System) in nuclear power plants. The method satisfies deadline in case of worst data traffics by considering aperiodic and periodic real-time data and others. In addition, the method was used to analyze the data characteristics of the DCS in existing nuclear power plant. The result shows that use of this method meets the response time requirement(100ms).

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The Effectiveness of WBI(Web-Based Instruction) on the Knowledge and Attitude of Traffic Safety among Middle School Students (웹기반 교육이 중학생의 교통안전 지식과 태도에 미치는 효과 연구)

  • 장시원;이명선
    • Korean Journal of Health Education and Promotion
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    • v.21 no.3
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    • pp.101-116
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    • 2004
  • Korea has the highest traffic accident occurrence rate in the world. It means that we are forced to face a tremendous amount of economic loses and great cost of life. Even though this phenomenon consistently has arose as a public issue every year and many researchers have emphasized the importance of safety education as the fundamental solution, we are still trying to make a long-lasting and effective traffic safety education programs for children and adolescents. The purpose of this study was to test the effectiveness of web-based learning for traffic safety in Korea middle school. For this purpose, the instructive model was constructed based on the ASSURE model and a special web-site of education was developed on behalf of practical use of multi-media learning materials for the traffic safety. The research subject was represented by 259 students from second grade in 2 middle schools located in Seoul Korea. The traffic safety education program using web-site was preceded to the 136 students as a case group for 45 minutes total 3 times. Other 126 students are control group those who did not get with this program. The survey was conducted before and after the education. The results of this study were as follow: 1. The knowledge analysis from the comparison between before and after of the lesson showed case group and control group scored average at 11.25 points and 10.97 points. However, after they attended programs, case group scored 13.57 points and control group scored 10.85 points. The difference from the result of the case group was statistically significant(p<0.001). 2. The attitude analysis from the comparison between before and after of the lesson showed case group and control group scored averages at 29.59 points and 28.21 points. However, after they attended program, case group scored 37.23 points and control group scored 32.71 points. The difference from the result of the case group was statistically significant(p<0.05). 3. Regarding the domain analysis by means of web-based traffic safety education, only the case group had a statistically significant score in the case of knowledge 'safe utilization of bicycle' and 'The Characteristic of Automobile and Safer Mode of Walking for Pedestrian'(p<0.01, p< 0.001), and in the case of attitude 'safe walking and crossing' 'The Characteristic of Automobile and Safer Mode of Walking for Pedestrian'(p<0.01, p<0.001). 4. Web based instruction for traffic safety was effective in terms of improving students' knowledge and attitude for traffic safety.

Effects of an Integrated Case Management Program on Medication Adherence, Pain, Physical Function and Depression among Korean Medical Aid Beneficiaries with Osteoarthritis (의료급여 관절염환자의 복약순응향상을 위한 통합중재프로그램의 효과)

  • Ahn, Yang Heui
    • Journal of Korean Public Health Nursing
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    • v.28 no.1
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    • pp.32-45
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    • 2014
  • Purpose: The purpose of this study was to test the effectiveness of an eight session integrated case management program for improvement of medication adherence, physical function, pain, and depression among medical aid beneficiaries with osteoarthritis. Method: A nonequivalent control group pre-posttest design was employed. Participants were 55 medical aid beneficiaries who agreed to participate in this study, and were assigned to an experimental group (n=28) or control group (n=27). The framework of this research derived from Cox's Interaction Model of Client Health Behavior guided the overall intervention and the components. The program led by a case manager with a medication calendar, motivating interviewing and coaching strategies and collaboration with a pharmacist. Analysis included change in scores, ${\chi}^2$-test, and t-test. Result: The results showed significant increase in medication adherence, physical function and decrease joint pain, joint stiffness and depression in the experimental group compared to the control group. Conclusion: The eight session integrated case management program indicated an effect on medication adherence, pain, physical function, and depression. Partnership with a pharmacist is recommended for medication adherence and conduct of further studies will be needed in order to determine the long-term effect of an extended integrated program on health outcomes.

Influence of Water Hardness on Accumulation of Heavy Metals in Kidneys and Livers of Rats (물의 경도가 흰쥐의 신장, 간에서 중금속 축적에 미치는 영향)

  • 한돈희
    • Journal of Environmental Health Sciences
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    • v.14 no.2
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    • pp.51-64
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    • 1988
  • It has been suggested that calcium is only one of many metals that compete with toxic metals in the body. Therefore, this study was carried out to determine the influence of water hardness on accumulation of heavy metals in rats. The seventy-five rats were divided into control and case groups. Case group was subdivided into four subgroups in proportion to the concentration of water hardness respectively, such as, 0, 250, 500, 1000ppm. Control group was fed on only deionized water, but case groups were fed on hard water with ionized heavy metals (Cd 150mg + Pb 300mg + Cu 300mg/l) for 20, 40, 60 days. The concentrations of cadmium, lead and copper were measured by atomic absorption spectrophotometry (Perkin Elmer 2380) in livers and kidneys. The results of the study are summarized as following 1. The concentration of cadmium accumulation showed the tendency of decrease in proportion to water hardness in both livers and kidneys of rats having been fed for only 60 days, respectively. 2. In only livers of rats having been fed for 60 days, essential metal, copper had the tendency of decrease according as hardness in water. 3. It was impossible to compare case with control about the tendency of lead accumulation because there was no difference between the two in livers and kidneys respectively.

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Lifestyle factors related to glucose control for diabetes management strategies: Nested case control design using KNHANES data (당뇨병 관리전략을 위한 혈당조절 관련 생활습관 요인: 국민건강영양조사 활용 코호트내 환자-대조군 연구)

  • Kim, Yunjung;Cho, Eunhee
    • Journal of the Korea Convergence Society
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    • v.10 no.11
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    • pp.501-510
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    • 2019
  • This study aimed to find health related lifestyle factors that influence glycemic control for diabetes mellitus (DM) management strategies. This study used nested case-control design with matching variables that were not controlled by individuals such as age, sex, insulin or oral hypoglycemic agent (OHA) use, disease duration, education level and household income. This study analyzed 983 subjects with type 2 DM who enrolled in the $7^{th}$ (2016-2017) Korean National Health and Nutrition Examination Survey (KNHANES). The target HbA1c level of controlled glucose was defined as less than 6.5%, and 289 (30%) were achieved. Conditional multivariable logistic regression analysis was performed to find self-control factors associated with HbA1c levels. The results statistically significant for variables such as duration of diabetes, insulin or OHA use in overall cohort and body mass index (BMI), smoking and fundus Examination in matched cohort. These results are expected to provide as evidence for the intensive care criteria(disease duration, drug use) and lifestyle management strategy(BMI, smoking, fundus examination).

Case-Control Study on Some Risk Factors of Cerebrovascular Diseases in Rural Community - Matched Analysis with One Control per Case- (일부 농촌지역에서 뇌졸중의 위험요인에 관한 연구 -환자 대조군 연구-)

  • Han, Sung-Hyun;Lee, Sung-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.21 no.1 s.23
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    • pp.82-88
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    • 1988
  • The main objectives of this study were to know the prevalence of cerebrovascular diseases, to find the important risk factors of cerebrovascular diseases. This study is a part of Eumseong Community Health Project supportes by GTZ(West German Goverment). 116 perceived cases of cerebrovascular diseases were first screened by health interview and examinations and 80 cases were diagnosed as a cerebrovascular group. For comparison, 80 cases were matched with their neighbor controls of the same sex and the similar age. 1. The prevalence rate for cerebrovascular diseases was 476.3 per 100,000 population which is considered to be very high compared with that of other countries. Age adjusted rate for cerebrovascular diseases was 261.6 per 100,000. 2. Among the risk factors examined for the association with cerebrovascular diseases by case-control study, and analysed by paired marginal test(McNemar's $X^2$-test) and odds ratio, only hypertension showed high significant statistical association.

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Nutrient Intake and Breast Cancer Risk in Korean Women : A case - control study

  • Do, Min-Hee;Lee, Sang-Sun;Jung, Pa-Jong;Lee, Min-Hyuk
    • Nutritional Sciences
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    • v.6 no.2
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    • pp.106-112
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    • 2003
  • To investigate the association between breast cancer risk and nutrient intake in Korean women, a case-control study was carried out. Incident cases (n=224) were identified through cancer biopsy between february 1999 and December 2000 at two university hospitals in Seoul. Hospital-based controls (n=250) were selected from patients in the same hospitals, during the same periods. food intake was investigated with semi-quantitative food frequency questionnaire (98 items) by a trained dietitian. Subjects were asked to indicate the average intake, for a 12-month period of three years prior to the baseline phase. In this study, no apparent association was found between fat intake level and breast cancer risk. High fiber intake showed a significant inverse association only among premenopausal women. In terms of antioxidant vitamins, $\beta$-carotene and vitamin C among premenopausal women and vitamin C intake among postmenopausal women was significantly associated with a decreasing risk of breast cancer. A protective effect of high calcium consumption was observed among postmenopausal women. In conclusion, our findings support epidemiological evidence that antioxidant vitamin intake could lower the breast cancer risk in Korea.