• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.411-412
• /
• 2006

It is very difficult to analyze the dynamic characteristic because railway vehicle is a very complex system which are connected various mass element with railway vehicle system. To realize and analyze actual phenomenon has restriction that usual commercial software calculates creep force under creep theory about wheel-rail contact mechanism as basic analyzing, and approach about contact point are based on two dimensional non-linear contact theory and simplified Hertzian contact which considers just displacement change on the YZ plain. Therefore, to solve these problems there should be a new approach difference with existing one. In this research, a new algorithm for finding wheel-rail contact position, calculation method of contact force and applied force will be presented.

• Journal of the Korea Safety Management & Science
• /
• v.11 no.3
• /
• pp.121-129
• /
• 2009

Today, many companies will be isolated in competition if they do not have competitive power to overcome quick change and big crisis of market. Nowadays, globally high-grade companies have done their best for increasing their competitive power through a many kinds of methods in keen competition for making of pacesetting position. This study focuses on distribution with the domains like capacity, layout, amount of location, assignment of product, operation procedure and operation rule in order to improve these domains, we make a further application of eight analysis ways based on DMAIC method for improving operation of processes of distribution center as the third profit source. The purpose of this study is to seek an approach that can easily adopt of Lean Six Sigma in operational management of distribution center by a kind of data, analysis method and template.

• Proceedings of the KSR Conference
• /
• 2003.05a
• /
• pp.604-609
• /
• 2003

The fire precautions regulation for Rolling stock in England, France and America concentrate on ensuring of safety in respect of material choosing method and consideration of design. In order to guarantee fire safety in Korean Rolling stocks, it is necessary to establish the fire precautions regulation at the two respects. Korean Standard of product classifies only incombustibility or not. It is not sufficient to classify various materials by testing method for incombustibility of material. Korean Standard to be reserved should be able to cover the smoke density test for small size and classification of the detail grade of material against the reaction to fire

• Journal of the Korean Society of Safety
• /
• v.11 no.4
• /
• pp.10-15
• /
• 1996

In studying the fatigue strength of fillet welded the section of pressure vessel pad, this study was to evaluate the effect of weld toe notch and to compare the results of numerical analysis with the results of fatigue experiments of fillet welded A5l6 grade 60 steel specimens. The fatigue life for the Bead welded specimen was about 1.4 times as much it as the 1Pad welded specimen. Also, The fatigue life for the 2Pad welded specimen was about 1.5 times as much it as the 1Pad welded specimen. In $da/dN-{\Delta}K$ curve, the fatigue crack growth rate for the 1Pad welded specimen appeared higher than that of the 2Pad welded specimen in the same initial region of ${\Delta}K$, had a similar Inclination In the stabled region.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10a
• /
• pp.655-657
• /
• 2004

본 논문은 안전등급 제어 기 기(Programmable Logic Controller) 에서 동작하는 실시간 운영체제의 안전성을 요구사항 단계에서 평가할 수 있는 검토항목을 개발하고 HAZOP(Hazard and Operability) 을 이용하여 현재 개발중인 PLC 운영체제에 적용한 경험 을 기술한다. HAZOP은 화학공장과 같은 산업에서 안전성을 평가하기 위한 방법으로 사용했던 방법론이다. 원자력발전소에 적용하기 위해 운영체제가 갖추어야 할 안전성 요건은 NUREG-0800의 BTP-14(Branch Technical Position)의 소프트웨어 기능특성 및 공정특성에 기술되어 있다. 이러한 기능적인 특성을 정확도, 신뢰성, 타이밍/사이징, 기능성, 강인성, 보안성 항목으로 나누고 세부적인 검토리스트를 만들어 HAZOP을 적용하여 평가하였다.

• Proceedings of the KIEE Conference
• /
• 1995.07a
• /
• pp.451-454
• /
• 1995

Increasing the transfortation efficiency is very important issue in railway system. Speed-up of train and shortage of headway can be its solution. Headway can vary with blocksection length, characteristics of the railway and signalling systems. Safety braking distance needed for passenger's safety is very important factor in block section division method. In this study, basic block section division program was developed with the differential ratio of braking distance resulted by grade value of the track. More complete block section division program is going to be developed by the help of experienced experts.

• Journal of Korean Elementary Science Education
• /
• v.38 no.3
• /
• pp.305-316
• /
• 2019

Most research on verbal interaction in school has used general frameworks, not including general sense that encompass 'elementary' and 'science'. Considering the current framework, we developed a new framework containing items such as safety and science terms. In this study, we compared 2 beginner teachers and 2 career teachers using new frameworks. After preliminary experiments, we recorded 4 classes per each person and recorded all interaction. It was revealed that the career teachers shows more convergent question and agreement to students. And in experimental class the career teachers give more attention for safety. This study may present that it is necessary for beginner teachers to be trained focusing differences.

• International Journal of Highway Engineering
• /
• v.13 no.3
• /
• pp.157-165
• /
• 2011

With respect to the trend of highway traffic accident, highway accident is in decline, whileas, the fatality is on an increasing trend. Thus, many efforts to decrease highway traffic accidents and improve the safety, are required. In particular, in case of highway, the management standard by grade for accident black spot is designated. Thus, investing the effect factors by grade for highway traffic accident is required in detail. Thus, in this study, the factors affecting the traffic accidents among the environmental factors based on the graded data for the accident black spot in the applicable section targeting the Seoul-Pusan Express Highway, were reviewed; accident forecasting model which would analyze the characteristics of the accidents for determining the accident grade, was developed. As a result of establishing a model by using Quantification Theory of Type II, considering the characteristics of the dependent and independent variables based on the geometric structure, 'the fixed variable' among the variables relating to the accident, for the variables influencing over the accident grade, 'the type of vans, a chassis and people', 'the trailers, special vehicles and chassis people' and 'the negligence of watching and cloudy weather' were analyzed as common factors, in case of 'horizontal alignment', 'longitudinal slope' and, 'barricade' respectively.

• Journal of the Korean Arthroscopy Society
• /
• v.9 no.2
• /
• pp.180-185
• /
• 2005

Purpose: To purpose of this study is to evaluate the clinical and radiological results of arthroscopic meniscus repair using Rapid Loc device. Materials and Methods: A retrospective study was performed on 44 cases which had been turned out longitudinal tear without degeneration. We repaired all cases with Rapid Loc device. Patients were evaluated using clinical examination, Orthopaedische Arbeitsgemeinschaft Knie (OAK) scheme, and MRI. We regarded patients with joint line tenderness, swelling or McMurray positive test as clinical failure. Results: A mean age was 33.3 years and follow-up period was average 15 months. Clinical results were excellent 15 cases(34.1%), good 20 cases(45.5%), fair 7 cases(15.9%), poor 2 cases(4.5%). MRI showed grade 115 cases(33.3%), grade II 22 cases(50%), grade III 7 cases(16.7%). Clinical failures were 8 cases and only one complication was developed. Conclusion: Rapid Loc device showed the excellent results in meniscus repair. We regard it has a lot of advantages in safety, softness, ease, ability to control tension at repair site.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.11
• /
• pp.6883-6888
• /
• 2013

Background: Platinum based concurrent chemo-radiation is the de-facto standard of care in the non-surgical management of locally-advanced head and neck cancer of squamous origin. Three-weekly single agent cisplatin at 100 $mg/m^2$ concurrent with radical radiotherapy has demonstrated consistent improvement in loco-regional control and survival. This improvement is however at the cost of considerable hematologic toxicity and poor overall compliance. The routine use of this regime is improbable in developing countries with limited resources. We therefore aimed to determine the safety and efficacy of an alternative regime of weekly cisplatin and concurrent radiotherapy in such patients. Materials and Methods: January-05 and April-12, 188 patients of locally-advanced head and neck cancer of squamous origin were treated with concurrent weekly-cisplatin at $35mg/m^2$ and conventional radiotherapy 60-66Gy/30-33 fractions/5days per week. Results: Overall, 95% patients received planned doses of RT while 74% completed within the stipulated overall treatment time of <50 days. Eighty-two percent received at-least 5 weekly cycles. Grade-III/IV mucositis was seen in 58%/9% respectively, which resulted in mean weight loss of 9.2% from a pre-treatment mean of 54.5 kg. Grade-III hematologic toxicity-0.5%; grade II nephrotoxicity-2.5% and grade III emesis-3% were also seen. Grade-III/IV subcutaneous toxicity-10%/1% and grade-III/IV xerostomia-10%/0% were observed. Complete responses at the primary site, regional nodes and overall disease were seen in 86%, 89% and 83% patients respectively. The median and 5-years disease-free survival were 26 months and 39.4% respectively, while the median and overall survival were 27 months and 41.8% respectively. Conclusions: Weekly-cisplatin at 35 $mg/m^2$ when delivered concurrently with conventional radical RT (at-least 66y/33 fractions) in locally-advanced head and neck cancer is well tolerated with minimal hematologic and neprologic toxicity and can be routinely delivered on an out-patient basis. It is an effective alternative to the standard 3-weekly cisplatin especially in the context of developing countries.