• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.282-286
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• 2000

In this paper, magneto-rheological(MR) damper is studied for vibration control of large infra structures under earthquake. Generally, active control devices need a large control force and a high power supply system to reduce the vibration effectively. Large and miss tuned control force may induce the dangerous situation such that the generated large control force acts to amplify the structural vibration. Recently, to overcome the weaknesses of the active control, the semi-active control method is suggested by many researchers. Semi-active control uses the passive control device of which the characteristics can be modified. Control force of the semi-active device is not generated from the actuator with power supply. It is generated as a dynamic reaction force of the device same as in the passive control case, so the control system is inherently stable and robust. Unlike the case of passive control, control force of semi-active control is adjusted depending on the measured response of the structure, so the vibration can be reduced more effectively against various unknown environmental loads. Magneto-rheological(MR) damper is one of the semi-active devices. Dynamic characteristics of the MR material can be changed by applying the magnetic fields. So the control of MR damper needs only small power. Response time of MR to the input voltage is very short, so the high performance control is possible. MR damper has a high force capacity so it is adequate to the vibration control of large infra structure. Because MR damper has a nonlinear property, normal control method used in active control may not be effective. Clipped optimal control, modified bang-bang control etc. have been suggested to MR damper by many researchers. In this study, sliding mode fuzzy control(SMFC) is applied to MR damper. Genetic algorithm is used for the controller tuning. To verify the applicability of MR damper and suggested algorithm, numerical simulation on the aseismic control is carried out. Simulation model is three-story building structure, which was used in the paper of Dyke, et al. The control performance is compared with clipped optimal control. The present results indicate that the SMFC algorithm can reduce the earthquake-induced vibration very effectively.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.263-263
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• 2000

Electromagnetic Suspension(EMS) System produces no noise, friction and heat through non-contacting operation Therefore, the applicable device using EMS system has a lot of attraction in case of the high-speed and non-contacting transmission EMS with nonlinear properties requires a precise airgap position control and stable kinematics characteristics under the disturbances, In this study, the nonlinear system was linearized by a Nonlinear Feedback Lineariztion(NFL) method. The NFL method requires that the modelling should be exact, and the state variables should be measured and a rapidly operating controller be necessary on account of a heavy data calculating In the experiments. the ideal control characteristics of the NFL was acquired through simulation at first. then the characteristics of the actual system were compared with those of simulation. In addition, the results by NFL were examined and analysed considering the characteristics of the PID control. The Control by NFL shows much stable control characteristics than the PID control. Whereas, the steady state errors occur for various disturbances. hence a robust control design is remained for a further study.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4741-4745
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• 2016

Background and Objective: Any role of human papillomavirus (HPV) in the development of breast cancer is conjectural. The aim of this study was to investigate possible links between HPV and breast cancer in women, Sanandaj, Iran. Methods: In this case-control study, 70 formalin fixed and paraffin embedded blocks of breast malignant tumors as a case group and 70 blocks of lesions without malignancy were selected as controls. Sections about $10{\mu}m$ thick were prepared. After removing the paraffin, DNA was extracted. Samples were tested by PCR using general and high-risk specific HPV primers. Results: All 70 malignant breast tumors (cases) were invasive ductal carcinomas, and of the 70 controls, 17 (24.3%) were fibrocystic tumors and 53 (75.7%) fibroadenomas. The age range of women in the case group was 25-72 years old and in the control group It was13-66 years. Using HPV general primers two samples were positive in the case group, confirmed to be HPV-18 using high-risk specific primers. Conclusion: No statistically significant association was found between breast cancer and HPV. It is necessary to confirm this result by further investigations in other populations.

• Journal of Korean Academy of Nursing
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• v.29 no.5
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• pp.1103-1112
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• 1999

In the last few years, psychiatric nurse practitioners have shown a growing an interest in community psychosocial rehabilitation, caring for chronic psychiatric patients as case manager in South Korea. The purpose of this study was to evaluate the effectiveness of a community psychiatric rehabilitation nursing program on self-care activity and quality of life and to suggest this program as an effective nursing intervention in a group of chronic home-based psychiatric patients in a poor town. A nonequivalent control group, pretest-posttest design was used. Of the twenty women that started the program, sixteen finished it. The data were analyzed by the Wilcoxon Rank Sum Test. The program included the process of case management which consisted of four phases: the first was an active case finding and pre-test, the second was home visiting and contacted by phone. the third was group activity therapy of 12 sessions, and the fourth phase was terminal and post-test. The effects of the program were assessed by quality of life and self-care activity. The quality of life and the self-care activity, especially, area of nutrition. elimination, dressing. leisure activity, and follow-up clinic visiting showed greater improvement than those of the control group. The results of this study suggest that this program was effective in improving the quality of life of chronic home-based psychiatric patients.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.6
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• pp.599-607
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• 2004

The purpose of this study is to reevaluate the performance of Hanji as an architectural material. Hanji has good things in controlling indoor space comfortably. Particularly, ability of controlling humidity of Hanji affects indoor space comfort and human health. The major focuses of this experimental research are (1) how much of water vapor passes through Hanji, (2) how much of water vapor is absorbed into Hanji. In the first case, indoor humidity is higher than outdoor humidity. In this case, approximately 38 g of water vapor passes through Hanji 1, genarally utilized in window paper (Changhoji), per square meter in one hour. And approximately 4 g of water vapor is absorbed into Hanji 2, genarally utilized in wallpaper, per square meter. In the second case, outdoor humidity is higher than indoor humidity. In this case, Hanji passes water vapor to inner space at first, but when indoor relative humidity reach approximately 66%, although outdoor humidity is higher than indoor humidity, water vapor doesn't pass through Hanji. If Hanji is utilized in window material and wallpaper, indoor space is maintained comfortably without mechanical devices in humidity control.

• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.115-119
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• 1983

The purpose of this study was to compare the solubility of enamel and dentin to an etchant after fluoride application. Specimens were collected from extracted anterior and bicuspid and each tooth was cut into several pieces. These specimen were allocated in 7 group; 1%, 2%, 3% NaF, 1%, 8%, 20% $SnF_2$, and control group. Five specimens in each group was exposed to pre-determined fluoride solution for 3 minutes, and washed with running water. These specimens were etched by Hipol (commercial label) etchant for 30 seconds. Following are the findings obtained through S.E.M. 1. All specimens with acid etching revealed preferential removal of prism periphery leaving prism core. 2. Specimens treated with 1%, 2% NaF solution showed that the shape of prism tip was thin and sharp like a needle. The case of 3% NaF showed rather round shape at prism end. 3.1% of $SnF_2$ case showed similar findings with the control group but 8% and 20% $SnF_2$ case revealed needle shape at the prism and was less clear than NaF case. Preferential removal of prism periphery was partialy observed and un decalcified area is fused to prism forming reidge. 4. Dentine treated by fluoride compound in low concentration showed the orifice of dentinal tubule was clearly enlarged whereas in high concentration the orifice was not widened.

• The Korea Journal of Herbology
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• v.37 no.2
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• pp.23-31
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• 2022

Objectives : The purpose of this research was to find out the efficacy of Castanea crenata Inner Shell (CCIS) on the skin by comparing the difference effect between only MTS (microneedle therapy system) and the CCIS essence application after MTS treatment. Methods : The present author performed once a week and total 3 times of MTS treatment. The treatment time took about 5 ~ 10 minutes and the depth of the needle was adjusted according to the participant's skin condition. In the control group, essence base was applied after MTS and in the experimental group, CCIS powder dissolved essence was applied. One week after each treatment, the change of skin condition was measured. Two weeks after the end of the clinical trial, the skin condition was checked again. Results : In the case of the test group and the control group, there was a significant decrease in thermography temperature and there was a significant increase in skin tone. In the case of pores and pigmentation, there was no significant difference on both group. In the case of moisture, there was a significant increase only in the test group. Conclusion : The MTS treatment itself showed good effects on thermography temperature and skin tone. But in the case of the moisture effect, it was much better when the CCIS essence was applied to the skin after MTS treatment. This study suggests that CCIS essence increases the efficacy of MTS on the point of moisture.

• The Journal of Internal Korean Medicine
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• v.29 no.3
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• pp.675-683
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• 2008

Objectives : This study was designed to examine the effects of hyperbaric oxygen therapy on cerebral infarction. Methods : Fifty-five patients with acute or subacute cerebral infarction were classified into two groups, the study group and control group. The study group was treated by hyperbaric oxygen therapy(HBOT) for 2 weeks(5 times/week) and the control group wasn't treated by HBOT. We compared the score of National Institutes of Health Scale(NIHSS scale) between two groups. We subdivided the study group by TOAST classification and onset stage, and compared the results. All of this data was analyzed by statistical method. Results : The study group patients who were treated by hyperbaric oxygen therapy saw more improvement than the control group patients in NIHSS score, and there was significant consideration. Among the study group patients, we saw more improvement during the first week period than in the course of the second week, and there was significant consideration. Conclusion : These results suggest that hyperbaric oxygen therapy(HBOT) could be a useful medical treatment to treat cerebral infarction. Further studies are needed on more cases to make sure that hyperbaric oxygen therapy (HBOT) is surely effective for cerebral infarction.

• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.816-829
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• 2007

Objectives : This study investigated warning signs and stroke presymptoms and their relationship with acute stroke patients in each stroke type. Methods : 217 patients with first-ever acute stroke within 2 weeks as the case group, 146 people without four major risk factors (hypertension, diabetes mellitus, hyperlipidemia and ischemic heart disease) as the healthy control group (Normals), and 160 people as the general control group (Controls) were recruited at the Stroke Medical Center in Daejeon University Oriental Medicine Hospital from July 2005 to March 2007 for this case-control study. We analyzed the odds ratio of each warning sign or presymptom by multivariate logistic analysis and evaluated each stroke type, as well as general characteristics such as age, sex, etc. Results : Paralysis or weakness of the face and limbs, visual field disorder or loss of vision or blurred and double vision in eyes or both eyes, and sudden difficulty in speaking or dysarthria showed significant increase respectively in each stroke type. In contrast, numbness or tingling sensation or lowering sensation of the face and limbs, numbness or dead sensation of 1st and 2nd fingers, tension at cervical lesion, blepharospasm, facial spasm, etc. had no significant relation with stroke occurrence. Conclusions : In this study we demonstrated that each presymptom have an influence on each stroke type and have different odds ratio for stroke. We believe this may contribute to interpreting the importance of warning signs or presymptoms for each type of stroke, and more prospective studies are needed.

• The Journal of Internal Korean Medicine
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• v.22 no.3
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• pp.423-430
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• 2001

Objects: The purpose of this case-control study was done to examine the relationship between stroke prevalence and the anthropometric indices(body mass index(BMI), modified Broca's method(Broca's index), waist circumference(WC), waist-hip ratio(WHR)), dyslipidemia, past medical history(heart disease, hypertension, diabetes mellitus(DM)), life-style factors(smoking, drinking) in Korean adults. Methods : The study group consisted of neurologically confirmed 116 stroke patients as the case group and 116 non-stroke patients as control group. Obesity were defined as $BMI{\geq}25kg/m^2,\;Broca's\;index{\geq}30%$, WC >94cm in male and WC >80cm in female, $WHR{\geq}0.9$ in male and $WHR{\geq}0.8$ in female. Oyslipidemia were defined as total $cholesterol{\geq}200mg/dl,\;triglyceride{\geq}200mg/dl,\;HDL-cholesterol {\leq}35mg/dl,\;LDL-cholesterol{\geq}160mg/dl$. Information on life-style factors and past medical history was obtained from personal interview. The analysis of the data was done by means of chi-square test(Pearson's chi-square test, Fisher's exact test) and student t-test. Results: The results were as follow. In the study group: Hypertension had a 4:05 odds ratio, Broca's $index{\geq}30%$ had a 1.98 odds ratio, WC >94cm in male had a 2.17 odds ratio, WC >80cm in female had a 2.80 odds ratio, $WHR{\geq}0.9$ in male had a 4.66 odds ratio, $WHR{\geq}0.8$ in female had a 5.35 odds ratio, but heart disease, DM, life-style factors, serum lipid and 8MI had no direct relationship with odds ratio(nonsignificant). By student t-test, risk factors for stroke were found to be total cholesterol(p=0,025), LDL-cholesterol(p=0.013), WC(p=0.000) and WHR(p=0.000). Conclusions: This study suggests that people should be advised to control hyperlitension, hyperlipidemia and obesity since these carry a risk of stroke.