• Journal of Korean Neurosurgical Society
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• v.62 no.4
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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.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.2
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• pp.147-153
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• 2013

Recently the primary water stress corrosion cracking(PWSCC) has occurred in the dissimilar metal weld region between pressurizer nozzle and safe-end in nuclear power plants(NPPs). As material of the pressurizer nozzle, SA508 Gr. 3 low alloy steel was used. F316L stainless steel and Alloy 82/182 were used as safe-end and weld metal, respectively. Although mechanical properties are needed for evaluation of the structural integrity against flaw in the material, material specification and standard don't supply those properties. Therefore, the present study conducted tensile and fracture toughness tests on SA508 Gr.3 and F316L stainless steel at ambient temperature and operating temperature of NPPs and reported the tested results.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.52-58
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• 2004

Oak is one of major species in this country as well as pine, but has been less utilized because of its refractory properties. The purpose of this study is to develope an effective method for drying the boards and disks of Quercus variabilis. Among four end-coaters used in this study thick coating with polyvinyl acetate chrolide glue (PVAc) was proved as the most effective. The average air-drying rate of boards was 1.2%MC/day, which did not exceed the safe drying rate recommended by United States Department of Agriculture (USDA). The kiln drying schedule used in this study gave a good result in drying the air-dried boards to 8%MC without any internal checks. An attempt to prevent oak disks from V-cracking during air-drying using special pallet-type stickers was not successful.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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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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• 2004.08a
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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.

• Journal of the Korean Institute of Gas
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• v.15 no.5
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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.

• International Journal of Highway Engineering
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• v.18 no.3
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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.

• Journal of Power System Engineering
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• v.20 no.6
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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.

• The Journal of Internal Korean Medicine
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• v.39 no.5
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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.

• Journal of the Korean Society of Safety
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• v.20 no.1 s.69
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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.