• Journal of Korean Neurosurgical Society
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• 제62권4호
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• pp.414-421
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• 2019

Objective : To evaluate 3-dimensional magnetic resonance imaging (MRI) of Kambin's safe zone to calculate maximum cannula diameter permissible for safe percutaneous endoscopic lumbar discectomy. Methods : Fifty 3D MRIs of 19 males and 31 females (mean, 47 years) were analysed. Oblique, axial and sagittal views were used for image analysis. Three authors calculated the inscribed circle (cannula diameter) individually, within the neural (original) and bony Kambin's triangle in oblique views, disc heights on sagittal views and root to facet distances at upper and lower end plate levels on axial views and their averages were taken. Results : The mean root to facet distances at upper end plate level measured on axial sections increased from $3.42{\pm}3.01mm$ at L12 level to $4.57{\pm}2.49mm$ at L5S1 level. The mean root to facet distances at lower end plate level measured on axial sections also increased from $6.07{\pm}1.13mm$ at L12 level to $12.9{\pm}2.83mm$ at L5S1 level. Mean maximum cannula diameter permissible through the neural Kambin's triangle increased from $5.67{\pm}1.38mm$ at L12 level to $9.7{\pm}3.82mm$ at L5S1 level. The mean maximum cannula diameter permissible through the bony Kambin's triangle also increased from $4.03{\pm}1.08mm$ at L12 level to $6.11{\pm}1mm$ at L5S1 level. Only 2% of the 427 bony Kambin's triangles could accommodate a cannula diameter of 8mm. The base of the bony Kambin's triangle taken in oblique view (3D MRI) was significantly higher than the root to facet distance at lower end plate level taken in axial view. Conclusion : The largest mean diameter of endoscopic cannula passable through "bony" Kambin's triangle was distinctively smaller than the largest mean diameter of endoscopic cannula passable through "neural" Kambin's triangle at all levels. Although proximity of exiting root to the facet joint is always taken into consideration before PELD procedure, our 3D MRI based anatomical study is the first to provide actual maximum cannula dimensions permissible in this region.

• 비파괴검사학회지
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• 제33권2호
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• pp.147-153
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• 2013

최근 가압경수로형 원전의 가압기 노즐과 안전단 사이의 이종용접부에서 일차수응력부식균열에 대한 건전성 확보가 중요한 관심사항으로 대두되고 있다. 가압기 노즐은 SA508 Gr.3 저합금강이며 안전단은 F316L 스테인리스강으로, 이들 두 재료 사이에 용접재로는 Alloy 82/182가 사용되었다. 재료 결함에 대한 건전성 평가를 위해서는 재료의 기계적 물성치, 특히 인장물성과 파괴물성이 확보되어야 한다. 그러나, 일반적인 재료 규격과 시험성적서에서는 상온의 인장물성이 제공되지만 고온의 인장물성과 파괴인성이 제공되지 않는다. 따라서, 본 논문에서는 상온과 원전 운전온도에서 SA508 Gr.3과 F316L 스테인리스강에 대한 인장시험과 J-R 파괴인성시험을 수행하고 그 결과를 수록하였다.

• Journal of the Korean Wood Science and Technology
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• 제32권1호
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• pp.52-58
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• 2004

참나무는 소나무와 함께 우리나라의 대표적 수종이나 아름다운 목리에도 불구하고 건조가 어려워 다양하게 사용되지 못하였다. 본 연구를 통해 굴참나무 판재와 원판의 효율적 건조방법을 찾고자 노력하였다. 먼저 마구리 도포제 효과를 조사한 결과 4가지 마구리 도포제 중 PVAc 접착제를 두껍게 도포한 것이 가장 좋은 효과를 나타냈다. 천연건조속도는 1.2%MC/일로 미농무성(USDA)의 안전건조속도(safe drying rate) 1-3%MC/일을 초과하지 않았다. 본 연구에 사용된 USDA의 참나무 열기건조 스케쥴은 천연건조된 국산굴참나무재를 내부 할열없이 함수율 8%까지 건조하는데 효과적이었다. pallet형 잔목을 사용하여 참나무 원판의 V-크랙을 막고자 하였으나 성공하지 못했다. 그러나 일반 잔목 건조에 비해 V-크랙의 갈라진 면이 깨끗했으며 다른 할열은 거의 발생하지 않았다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권3호
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• pp.927-932
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• 2015

Background: Breast and cervical cancers are the most common causes of cancer mortality among women in India, but actually they are largely preventable diseases. Although early detection is the only way to reduce morbidity and mortality, there are limited data on breast and cervical cancer knowledge, safe practices and attitudes of teachers in India. The purpose of this study is to assess the level of awareness and impact of awareness programs in adoption of safe practices in prevention and early detection. Materials and Methods: This assessment was part of a pink chain campaign on cancer awareness. During cancer awareness events in 2011 at various women colleges in different parts in India, a pre-test related to cervical cancer and breast cancer was followed by an awareness program. Post-tests using the same questionnaire were conducted at the end of the interactive session, at 6 months and 1 year. Results: A total of 156 out of 182 teachers participated in the study (overall response rate was 85.7 %). Mean age of the study population was 42.4 years (range- 28-59 yrs). There was a significant increase in level of knowledge regarding cervical and breast cancer at 6 months and this was sustained at 1 year. Adoption of breast self examination (BSE) was significantly more frequent in comparison to CBE, mammography and the Pap test. Magazines and newspapers were sources for knowledge regarding screening tests for breast cancer in more than 60% of teachers where as more than 75% were educated by doctors regarding the Pap test. Post awareness at 6 months and 1 year, there was a significant change in alcohol and smoking habits. Major reasons for not doing screening test were found to be ignorance (50%), lethargic attitude (44.8%) and lack of time (34.6%). Conclusions: Level of knowledge of breast cancer risk factors, symptoms and screening methods was high as compared to cervical cancer. There was a significant increase in level of knowledge regarding cervical and breast cancer at 6 months and this was sustained at 1 year. Adoption of BSE was significantly greater in comparison to CBE, mammography and the Pap test. To inculcate safe practices in lifestyle of people, awareness programmes such as pink chain campaign should be conducted more widely and frequently.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1392-1395
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• 2004

In order to successfully develop attitude and orbit control subsystem(AOCS), AOCS engineer performs hardware selection, controller design and analysis, control logic and interface verification on electrical test bed, integrated system test, polarity test, and finally verification on orbit after launching. Attitude and orbit control subsystem for KOMPSAT-2 consists of standby mode, sun mode, maneuver mode, science mode, and power safe mode to stabilize and to control the spacecraft for performing the mission. The sun mode is usually divided into sun point submode, earth search submode and safe hold submode. The maneuver mode is divided into attitude hold submode and ${\triangle}$ V submode, while the science mode divided into science coarse submode and science fine submode. Moreover, it is added to back-up mode which uses wheels as an actuator for sun mode and maneuver mode. In this paper, we describe the controller design process and the performance of the design results with respect to the sun mode and the maneuver mode based on thrusters as an actuator using on flexible model.

• 한국가스학회지
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• 제15권5호
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• pp.31-36
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• 2011

In this paper, an analytical model of a cantilever beam having a midpoint load is considered for structural optimization and design. This involves creation of the geometry through a parametric study of all design variables. For this purpose, the optimization of the cantilever beam was elaborated in order to find the optimum geometry which minimizes its volume eventually for minimum weight by FEM (finite element method) analysis. Such geometry can be obtained by different combinations of width and height, so that the beam may have the same cross-sectional area, yet different dynamic behavior. So for optimum safe design, besides minimum volume it should have minimum vibration as well. In order to predict vibration, different dynamic analyses were performed simultaneously to identify the resonant frequencies and mode shapes belonging to the lowest three modes of vibration. Next, by introducing damping effects, the tip displacement and bending stress at the fixed end was evaluated under dynamic loads of varying frequency. Investigation of the results clearly shows that only structural analysis is not enough to predict the optimum values of dimension for safe design it must be aided by dynamic analysis as well.

• 한국도로학회논문집
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• 제18권3호
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• pp.127-134
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• 2016

PURPOSES : Low visibility caused by dark surroundings at nighttime affects the likelihood of accidents, and various efforts, such as installing road safety facilities, have been made to reduce accidents at night. Despite these efforts, the nighttime severity index (SI) in Korea was higher than the daytime SI during 2011-2014. This study determined the factors affecting daytime and nighttime accident severity through a discriminant analysis. METHODS : Discriminant analysis. RESULTS : First, drowsiness, lack of attention, and lighting facilities affected both daytime and nighttime accident severity. Accidents were found to be caused by a low ability to recognize the driving conditions and a low obstacle avoidance capability. Second, road conditions and speeding affected only the daytime accident severity. Third, failure to maintain a safe distance significantly affected daytime accident severity and nonsignificantly affected nighttime accident severity. The majority of such accidents were caused by rear-end collisions of vehicles driving in the same direction; given the low relative speed difference in such cases, the shock imparted by the accidents was minimal. CONCLUSIONS : Accidents caused by a failure to maintain a safe distance has lower severity than do accidents caused by other factors.

• 동력기계공학회지
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• 제20권6호
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• pp.80-86
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• 2016

In this study, The watertight damper was designed to improve conventional DN 350A butterfly valve. The FSI(Fluid-Structure Interaction) analysis has performed to investigate the safety factor for the watertight damper. When watertight damper of disk was closed, the disk of pressure value is constant. However depending on the opening angle of disk, the flow velocity and pressure are changed. The maximum velocity was appeared at the end of disk on the small outlet area of duct. When the opening angel of disk is $90^{\circ}$, the maximum velocity was appeared at the center of ending disk. So we were found the opening angle of disk is bigger, the flow rate is increased and velocity is also increased from the result of FSI analysis. We can find the least deformation and stress when the opening angel of damper is $90^{\circ}$. When the $45^{\circ}$ opening angle of disk, the largest deformation and stress was found and the minimum safety factor 1.3 was calculated. As a result, we found that the structure of watertight damper is safe enough irrespective of opening angel.

• 대한한방내과학회지
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• 제39권5호
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• pp.964-972
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• 2018

Introduction: The aim of this study is to report the effect of Yukmijiwhang-tang-gamibang on the treatment of hypersensitivity vasculitis. Case presentation: A patient with hypersensitivity vasculitis was treated with herbal medicine (3 times a day) and dressing (once per day) for 16 days. The severity of hypersensitivity vasculitis was assessed using the numeral rating scale (NRS) and pruritus score. After treatment, pain and itching symptoms were reduced, the NRS score improved from 5 to 1, and the pruritus score improved from 2 to 0. No adverse reactions were noted and no relapse of hypersensitivity vasculitis occurred within 38 days after the end of treatment. This result shows that herbal medicine could be effective and safe for treating hypersensitivity vasculitis. Conclusion: According to the results, Korean medicine such as Yukmijiwhang-tang-gamibang can be effective and safe for the treatment of hypersensitivity vasculitis.

• 한국안전학회지
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• 제20권1호
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• pp.143-147
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• 2005

Immediate responsibilities for occupational health and safety (OHS) management reside in business proprietors and supervisors whose voluntary participation in OHS educational programs, not legal sanctions, may thus lead to safe and pleasant work environments. This study investigates how to promote the effectiveness of OHS educational programs to draw voluntary participations in such programs in Korea To this end, drawbacks of current practices in OHS education are first analyzed, and then OHS related policies in advanced countries in the area of disaster prevention such as United States and Germany, are also scrutinized. Based on the preliminary investigations, the following propositions are made to lay out the foundation for promoting effective OHS educational programs in Korea: improvement of government regulations, revitalizing job training initiatives, on-site OHS education, compensation and incentive programs for OHS education. These propositions may also facilitate the deployment of disaster prevention activities across the organization and prevent various occupational disorders (for example, musculoskeletal disorders). This study emphasizes that monolithic OHS education systems led by regulatory agencies may not be efficient to ensure healthy and safe work environments. Globally competitive OHS educational systems may be established only when they are based on the health and safety requirements specified by proprietors and workers.