• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.119-122
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• 1996

The recently proposed control method using a Lyapunov-like function can give global asymptotic stability to a system with mismatched uncertainties if the uncertainties are bounded by a known function and the uncontrolled system is locally and asymptotically stable. In this paper, we modify the method so that it can be applied to a system not satisfying the latter condition without deteriorating qualitative performance. The assured stability in this case is uniform ultimate boundedness which is as useful as global asymptotic stability in the sense that it is global and the bound can be taken arbitrarily small. By the proposed control law we can deal with both matched and mismatched uncertain systems. The above facts conclude that Lyapunov-like control method is superior to any other Lyapunov direct methods in its applicability to uncertain systems.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 2001년도 춘계 심포지움 연제집
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• pp.82-82
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• 2001

• Journal of Preventive Medicine and Public Health
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• 제22권2호
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• pp.181-188
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• 1989

In this study an attempt was made to determine the factors affecting anemia in female industrial workers. The population was identified through the records of screening examinations given by Kosin Medical Center to the industrial workers in Sasang Industrial Complex during the period from March 1987 to October 1988. One hundred twenty eight cases were selected from the records screening examination of 155 anemic patients. A case-control study was carried out using matched 128 anemic cases and 128 non-anemic workers who were selected by simple random sampling. Age was matched, and their occupational history, general characteristics, physical characteristics and health status were analyzed. The results were; 1. In the anemic group, educational level was lower, and the frequencies of irregular menstruation and poor appetite were higher than in the control group but these differences were statistically not significant. 2. The percentage of workers working with organic solvents, working hours and years of service (total years exposed to organic solvents) were significantly higher in the anemic group than those in the control group. 3. A career exposed to organic solvents was more influential factor affecting anemia in the female industrial workers rather than menstruation amount of other factors, and it was statistically significant.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7595-7600
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• 2013

Cervical cancer is a serious public health problem in developing countries. We investigated possible risk factors for cervical cancer in rural areas of Wuhan China using a matched case-control study with 33 women diagnosed with cervical cancer and 132 healthy women selected from the same area as matched controls. A questionnaire, which included questions about general demography conditions, environmental and genetic factors, the first sexual intercourse, first marriage age, age at first pregnancy, pregnancy first child's age, female personal health history, social psychological factors, dietary habits, smoking and alcohol status and other living habits was presented to all participants. At the same time, HPV infection of every participant was examined in laboratory testing. Results showed HPV infection (P<0.000, OR=23.4) and pregnancy first child's age (P<0.000, OR=13.1) to be risk factors for cervical cancer. Menopause (P=0.003, OR=0.073) was a protective factor against cervical cancer. However, there was no indication of associations of environmental (drinking water, insecticide, disinfectant) genetic (cancer family history), or life-style factors (smoking status, alcohol status, physical training, sleep quality), including dietary habits (intake of fruit and vegetable, meat, fried food, bean products and pickled food) or social psychological factors with cervical cancer. The results suggest that the risk of cervical cancer in Chinese rural women may be associated with HPV infection, menopause and the pregnancy first child's age.

• Asian Pacific Journal of Cancer Prevention
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• 제17권8호
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• pp.3979-3982
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• 2016

Background: Thailand remains a primarily agricultural country and Thai farmers are heavy users of pesticides. Coincidentally the incidence of cholangio carcinoma (CCA) is high in parts of the country, but no previous study has examined any association between the two. Materials and Methods: The present matched, case-control study covered patients admitted to Srinagarind Hospital, Khon Kaen University, Thailand. The case group comprised 210 cases diagnosed with CCA and the control group 840 diagnosed with other diseases. Cases and controls were matched for sex, age within five years, and date of admission within three months. Multiple conditional logistic regression was used for the analysis. Results: After adjusting for potential confounders, pesticide use as compared with never used pesticide was not associated with CCA (ORadj=1.11, 95% CI: 0.77, 1.60) and neither was there any significant relationship between CCA and duration of pesticide use, type or number of types pesticide use. Conclusions: The current study thus found no association between pesticide use and CCA.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5895-5900
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• 2014

Background: Metabolic syndrome (MS) is a cluster of complicated disorders caused by the interactive influencing factors of heredity and environment, which predisposes to many cnacers. Results from epidemic research indicate that stress is tightly related to the pathogenesis of MS and neoplasia. This paper aims to investigate the association between psychological stress and MS with respect to the tumor necrosis factor alpha (TNF${\alpha}$) and neuropeptide Y (NPY) genes in the Han and Hui ethnic groups. Methods: All subjects for this case-control study matched strict enrollment criteria (nationality, gender and age) and lived in the city of Wu Zhong of Ningxia Province in China. The enrolled group contained 102 matched pairs of Hui ethnic individuals and 98 matched pairs of Han ethnic individuals. Enrolled subjects completed the general Symptom Checklist-90 (SCL-90). The TNF${\alpha}$-308G/A variant and NPYrs16147 polymorphism were detected in case (81 males, 119 females) and control (81 males, 119 females) groups by polymerase chain reaction (PCR) amplification. Results: Nine factors of the SCL-90 were found to be statistically different (p<0.05) between case and control groups. The homozygous mutant genotype (AA) and the mutant allele (A) of the TNF${\alpha}$-308G/A gene were less frequently observed in the control population compared to the case group. The odds ratio (95% confidence interval) in "Allele" for MS was 2.28 (1.47-3.53), p=0.0001, while "OR" was 1.11 (0.83-1.47), p=0.15, for the NPYrs16147 gene polymorphism. Conclusions: Psychological stress has been positively associated with MS. A previous study from our group suggested there were differences in the level of psychological stress between Hui and Han ethnic groups. Furthermore, we found that the stress-related TNF${\alpha}$ gene was associated with MS for both Han and Hui ethnic groups. In contrast, NPY may be a possible contributor to MS and associated cancer for the Han ethnic group.

• 한국환경보건학회지
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• 제41권3호
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• pp.182-190
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• 2015

Objectives: To introduce a protocol of Mobi-kids study which was aimed to examine an association between radiofrequency (RF) radiation exposure by mobile phone use and brain tumor risk in children and adolescents. Methods: The Mobi-kids study was a multinational matched case control study using a standardized protocol with the number of subjects targeted about 1,000 cases and 2,000 controls aged 10 to 24. In Mobi-Kids Korea, the source population was restricted to Seoul, Incheon, and Gyeonggi-do province. Eligible cases of primary brain tumor (glioma, meningioma, and others) were diagnosed from January 2012 to June 2015. Eligible controls were appendicitis patients operated during the study period. Two controls were matched on age, gender, and study region for 1 case. Information about pattern and history of mobile phone use and other covariates were obtained by face to face interview by trained interviewer. The Mobi-kids study has been involved in Mobi-expo as a validation study about mobile phone use, XGridmaster to localize tumor in the brain for RF energy calculation, and histological review for validation of diagnosis. Results: The Mobi-kids was the first and largest study in children and adolescents to estimate risk of brain tumor in association with the RF energy absorption in the brain estimated by mobile phone use. Forty-six-cases and 54 controls were collected as of September 2014 in Korea. Conclusions: The meaningful results of the study were expected because of the largest sample size, high validity of EMF exposure assessment as well as the susceptible study populationof children and adolescents.

• Clinical Endoscopy
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• 제56권1호
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• pp.75-82
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• 2023

Background/Aims: The etiology of superficial non-ampullary duodenal epithelial tumors (SNADETs) remains unclear. Recent studies have reported conflicting associations between duodenal tumor development and Helicobacter pylori infection or endoscopic gastric mucosal atrophy. As such, the present study aimed to clarify the relationship between SNADETs and H. pylori infection and/or endoscopic gastric mucosal atrophy. Methods: This retrospective case-control study reviewed data from 177 consecutive patients with SNADETs who underwent endoscopic or surgical resection at seven institutions in Japan over a three-year period. The prevalence of endoscopic gastric mucosal atrophy and the status of H. pylori infection were compared in 531 sex- and age-matched controls selected from screening endoscopies at two of the seven participating institutions. Results: For H. pylori infection, 85 of 177 (48.0%) patients exhibited SNADETs and 112 of 531 (21.1%) control patients were non-infected (p<0.001). Non-atrophic mucosa (C0 to C1) was observed in 96 of 177 (54.2%) patients with SNADETs and 112 of 531 (21.1%) control patients (p<0.001). Conditional logistic regression analysis revealed that non-atrophic gastric mucosa was an independent risk factor for SNADETs (odds ratio, 5.10; 95% confidence interval, 2.44-8.40; p<0.001). Conclusions: Non-atrophic gastric mucosa, regardless of H. pylori infection status, was a factor independently associated with SNADETs.

• 한국간담췌외과학회지
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• 제27권1호
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• pp.87-94
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• 2023

Backgrounds/Aims: Central pancreatectomy (CP) is associated with a higher rate of postoperative pancreatic fistula (POPF), and it is less preferred over distal pancreatectomy (DP). We compared the short- and long-term outcomes between CP and DP for low-grade pancreatic neck and body tumors. Methods: This was a propensity score-matched case-control study of patients who underwent either CP or DP for low-grade pancreatic neck and body tumors from 2003 to 2020 in a tertiary care unit in southern India. Patients with a tumor >10 cm or a distal residual stump length of <4 cm were excluded. Demographics, clinical profile, intraoperative and postoperative parameters, and the long-term postoperative outcomes for exocrine and endocrine insufficiency, weight gain, and the 36-Item Short Form Survey (SF-36) quality of life questionnaire were compared. Results: Eighty-eight patients (CP: n=37 [cases], DP: n=51 [control]) were included in the unmatched group after excluding 21 patients (meeting exclusion criteria). After matching, both groups had 37 patients. The clinical and demographic profiles were comparable between the two groups. Blood loss and POPF rates were significantly higher in the CP group. However, Clavien-Dindo grades of complications were similar between the two groups (p = 0.27). At a median follow-up of 38 months (range = 187 months), exocrine sufficiency was similar between the two groups. Endocrine sufficiency, weight gain, SF-36 pain control score, and general health score were significantly better in the CP group. Conclusions: Despite equivalent clinically significant morbidities, long-term outcomes are better after CP compared to DP in low-grade pancreatic body tumors.