• 한국생산제조학회지
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• 제9권1호
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• pp.24-29
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• 2000

This paper is experimental study of machining characteristics about martensitic heat resisting steel STR11. Machining characteristics are different according to internal quality(chemical compositions, microscopic structure and nonmetallic inclusion) mechanical properties(tensile strength value impact value and hardness) and dynamic cutting force. Following are the results : 1. In analyzing internal quality test materials have typical martensite structure and a minute needle-shaped structure. 2. Tensile strength and reduction of area and hardness are larger. But values of elongation and impact values are smaller. Fracture surface of tensile specimen is ductile. 3, Cutting force is decreasing with cutting speed increasing 4. Cutting force is increasing with feed speed increasing.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.1073-1077
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• 1997

In this paper, we have studied internal quality including chemical compositions, microscopic structure and nonmetalic inclusion of test materials. We have analyzed machining characteristics including tensile strength value, impact value, hardness value etcs. Test materials are usd martensitic heat resisting steel, STR11 and STS420J2. The obtined results are as follows : 1. In analyzing internal quality, STR11 and STR420J2 have typical martensite structure and a minute needle-shaped structure. 2. Tensile strength and reduction of area and hardness value are large STR11 than STS420J2. But elongation impact are smaller STR11 than STS420J2. 3. Fracture surface of tensile speciman is ductile in STR11 and STS420J2.

• Smart Structures and Systems
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• 제21권6호
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• pp.751-759
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• 2018

Glass fibre reinforced polymers (GFRP) are widely exploited in many industrial branches. Due to this Structural Health Monitoring systems containing embedded fibre optics sensors are applied. One of the problems that can influence on composite element durability is water contamination that can be introduced into material structure during manufacturing. Such inclusion can be a damage origin significantly decreasing mechanical properties of an element. A non-destructive method that can be applied for inspection of an internal structure of elements is THz spectroscopy. It can be used for identifications of material discontinuities that results in changes of absorption, refractive index or scattering of propagating THz waves. The limitations of THz propagation through water makes this technique a promising solution for detection of a water inclusion. The paper presents an application of THz spectroscopy for detection and localisation of a water drop inclusion embedded in a GFRP material between two fibre optics with fibre Bragg grating sensors. The proposed filtering method allowed to determine a 3D shape of the water drop.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.48-54
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• 2006

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid) has been used as feed additives in poultry industries to improve production and control coccidiosis. The effect of high dietary levels of Roxarsone (ROX) on the performance and function of internal organs and the kinetics of recovery as well as its after-effects were examined in laying hens. The inclusion rates of ROX were 0, 100, 200, 300, and 400 mg per kg feed. Inclusion up to 200 mg did not show any adverse effects (p>0.05), whereas in the 300 and 400 mg groups, significant effects, particularly in the latter, were observed for three weeks after ROX addition (p<0.05). Recovery of the physical appearance occurred soon after ROX addition was withdrawn. Recovery of performance and internal organs, however, appeared to be dependent on the amount of residual ROX in the body; as the amount of ROX decreased, the toxic effect of ROX also decreased. In the third week after the withdrawal of ROX, complete recovery was observed in the lower dosage groups (100 or 200 mg groups) (p>0.05), whereas in the higher dosage groups (300 or 400 mg groups), recovery took at least five weeks; when complete recovery was observed in egg production and in liver weight (p>0.05). On the other hand, ROX might have damaged the liver and other tissues. The recovery of liver weight was probably due to accumulation of fatty particles rather than repair. It appeared, therefore, there were little after-effects of ROX on the hen's physical appearance, but some internal organs were probably damaged.

• 한국해안해양공학회지
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• 제8권4호
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• pp.287-296
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• 1996

해저 riser관내에 내부유체 금이 발생한 때 그 흐름으로 인해 riser system의 자유진동에 미치는 영향을 조사하기 위해 수학적 모델이 유도된다. System의 고유진동수를 계산하기 위해 조화함수 확장을 적용하여 고유치 방정식을 유도하는 부분해석적 방법을 사용하였다. 그리고 이 방법론은 기존 해석론에 의해 비교 검증된다. 컴퓨터 프로그램을 위한 알고리즘이 개발되어 내부유체 흐름이 system 고유진동수에 미치는 영향을 상부인장력, 내부 유체흐름 속도 등과 같은 인자의 변화에 따라 조사하였다 분석결과 내부유체흐름의 영향은 상부인장력에 의해 지배되나 심해저 riser와 같은 장대 riser의 경우에 설계시 세심한 주의가 요구된다.

• 대한한방내과학회지
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• 제21권5호
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• pp.765-771
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• 2000

Objectives : To evaluate the pain control effect of combination treatment of Oriental Medicine on patients who suffered from thalamic pain syndrome caused by thalamic stroke. Methods : We reviewed the medical records and brain imaging data of all patients with thalamic stroke from September 1998 to August 2000 who visited to Department of Oriental Internal Medicine, National Medical Center. We evaluated clinical features of thalamic pain syndrome, including incidence, onset interval from stroke, nature, pain distribution, and assessed the pain control effect of combination treatment by Visual Analog Scale(VAS). Results : 64 cases were selected under the inclusion criteria, and 17 patients(26.5%) with thalamic pain syndrome were identified from 64 thalamic strokes. VAS proved combination treatment effective to control pain of thalamic pain syndrome. In 12 cases(70.5%), pain onset was within the first week poststroke. The patients with allodynia were 6(35.3%). In 12 cases(70.5%), the lesion was mainly located in the posterolateral areas of thalamus. Conclusion : We conclude that combination treatment of the Oriental Medicine modalities have pain control effectiveness on thalamic pain syndrome.(t=-5.47, p=0.0001)

• 대한한방내과학회지
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• 제31권3호
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• pp.612-619
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• 2010

Background : Low level laser therapy may be an effective method to protect tissue damage in acute stroke. Recently, series of clinical studies on the basis of animal experiments report efficacy and safety of laser therapy at early stages of acute stroke. Laser promotes mitochondrial ATP synthesis to reduce cell death by ischemic infarction. Objectives : To report possibility of non-invasive laser therapy for acute stroke by reviewing literature about its effectiveness, safety and mechanism. Methods : We searched papers using PubMed and 'Web of Knowledge' of Thomson ISI, using the keywords "Laser Therapy, Low-Level" and "Stroke". Limitations were last 10 years of publications and only in English. Search range includes RCTs, clinical reports, reviews and animal experiments. Papers not matched with inclusion criteria were excluded. Results : A total 223 studies were found, 203 excluded during title and extract screening. After scanning 20 papers the final 2 serial RCTs were selected and analyzed. They reported that transcranial laser therapy led in neuroprotective effect for acute stroke patents. Clinical evaluation factors showed favorable trend and initial safety. Conclusions : Non-invasive laser secured safety of clinical application. It may be a favorable choice for the acute stage of stroke.

• 대한한방내과학회지
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• 제29권3호
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• pp.800-809
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• 2008

Objective : Although chronic prostatitis/chronic pelvic pain syndrcme(CP/CPPS) is a common disease, there is no consensus on the etiology or pathology and treatment. This was a double-blinded, placebo-controlled, randomized clinical trial, investigating the therapeutic effects of the traditional Korean medicine, Bosingunyang-tang(BSGYT). Method : Participants who met US National Institutes of Health (NIH) consensus criteria for CP/CPPS were entered after applying inclusion/exclusion criteria. They were randomized to the BSGYT or placebo group. and treated three times a day for 6 weeks. NIH-Chronic Prostatitis Symptom Index (NIH-CPSI) was used to estimate the clinical symptoms of CP/CPPS. Prostaglandin E2 and ${\beta}$-endorphin in prostatic fluid, collected by 2-glass pre-massage and post-massage test, were analyzed as factors associated with pain and inflammation. Result : The mean decrease in NIH-CPSI total score of the BSGYT group was 11.0 points, which is 5.7 points more than the placebo group. (Mann Whitney test P=0.038) Also the BSGYT group showed three times higher response rate than the placebo group in NIH-CPSI pain subscale score. (Fisher's exact test P=0.027) In those responders, prostaglandin E2 decreased significantly. (Wilcoxon's signed-ranks test P=0.037). No specific side effects were observed. Conclusion : After a 6-week treatment period, BSGYT improved clinical symptoms of CP/CPPS patients by decreasing PGE2 level in prostatic fluid.

• 한국안전학회지
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• 제9권3호
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• pp.3-12
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• 1994

This study employed the Eshelby's equivalent inclusion method incorporated with mean field theory to investigate the Internal stress of short fiber-reinforced metal matrix composites during static loading and the dynamic finite element analysis by using alternative unit cell model to investigate the impact behaviors during the impact loading. Using the 2124 Al-SiC system as an example, the general effects of parameters such as fiber's aspect ratio, content and modulus were examined.

• 동의생리병리학회지
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• 제22권6호
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• pp.1390-1396
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• 2008

The aim of this study is to analyze literatures researching changes of liver function parameters after administration of herbal medicine and the safety of herbal medicine on hepato-biliary system. Eight Korean databases were searched for researches on the safety of oriental herbal medicine. According to inclusion criteria, nineteen studies were selected and analyzed. As a result, seventy outcomes in five parameters(aspartate transaminase, alanine transaminase, gamma(${\gamma}$)-glutamyl transferase, alkaline Phosphatase, total bilirubin) were obtained. After administration, parameters decreased or sustained in fifty seven outcomes. In thirteen outcomes, parameters slightly increased. In two outcomes, parameters increased but not severely. The change of liver function parameters after administration of herbal medicine is expected to be harmless. But it requires additional large scale studies and modification in method to corroborate the safety of herbal medicine.