• Title/Summary/Keyword: Safety Estimation

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Estimation of Wind Speeds for Return Period in Cellularized District of Basan by the Recent Meteorological Data (최근 기상 자료에 의한 부산의 세분화된 지역별 재현기대 풍속 산정)

  • An, Jae-Hyeok
    • Journal of the Korean Society of Safety
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    • v.27 no.5
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    • pp.158-163
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    • 2012
  • This study is concerned with the estimation of wind speeds for return period in cellularized district of Busan by the recent meteorological data. Recently standard of the wind load in Busan area is determined by using meteorological wind speed data which is observed on Automated Synoptic Observing System(ASOS) only. Applying the existing basic wind speed that is 40m/s to the construction design of Busan area is inefficient. Because the wind speeds of Busan area show different amounts depend on the location of cellularized district. This research analyze the observed data of wind speeds of cellularized district in Busan based on Automate Weather System(AWA). In addition that we compute regional wind speeds for return period by using Gumbel distribution and study and compare with the existing basic wind speeds after evaluating appropriateness by Hazen's plot method.

Design of Lane Keeping Steering Assist Controller Using Vehicle Lateral Disturbance Estimation under Cross Wind (횡풍하의 차량 외란 추정을 이용한 차선 유지 조향 보조 제어기 설계)

  • Lim, Hyeongho;Joa, Eunhyek;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.3
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    • pp.13-19
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    • 2020
  • This paper presents steering controller for unintended lane departure avoidance under crosswind using vehicle lateral disturbance estimation. Vehicles exposed to crosswind are more likely to deviate from lane, which can lead to accidents. To prevent this, a lateral disturbance estimator and steering controller for compensating disturbance have been proposed. The disturbance affecting lateral motion of the vehicle is estimated using Kalman filter, which is on the basis of the 2-DOF bicycle model and Electric Power Steering (EPS) module. A sliding mode controller is designed to avoid unintended the lane departure using the estimated disturbance. The controller is based on the 2-DOF bicycle model and the vision-based error dynamic model. A torque controller is used to provide appropriate assist torque to driver. The performance of proposed estimator and controller is evaluated via computer simulation using Matlab/Simulink.

A Study on the Improvement Scheme of the Total Water Pollution Load Management Plan (수질오염총량관리 계획수립의 개선방안에 관한 연구)

  • Kim, Young-Il;Yi, Sang-Jin
    • Journal of Korean Society on Water Environment
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    • v.22 no.6
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    • pp.977-981
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    • 2006
  • In order to improve water quality in drinking water sources, Ministry of Environment (MOE) was implemented total water pollution load management (TWPLM) in all the major river basins. From the experience of the application of TWPLM, we could find some problems relating the target watershed, standard operating procedure (SOP) of establishment and implementation plan, water quality and flow rate, design flow, water quality model, margin of safety (MOS), and estimation of wasteload were found. The authors were reviewed ongoing TWPLM and presented the improvement schemes for a successful TWPLM. For the application of these suggestions, further detailed studies should be done to implement TWPLM in the future.

A Development of a Reliability Prediction Program Using the Field Failure (필드고장을 이용한 신뢰성예측 프로그램 개발)

  • Baek, Jae-Jin;Rhie, Kwang-Won
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.2
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    • pp.1-7
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    • 2012
  • A Failure data from operating condition includes various failures. Reliability evaluation by operating condition is more correct than test condition. Additional, the evaluation result by operating condition is widely used for quality assurance, forecasting amount of manufacturing at EOL. To discover valuable things from the failure data, arrangement of the failure data and information technique to handle data is needed among many failure data. This paper introduces a reliability prediction program to solve this problem based on the failure. And new technologies for parameters estimation with method of Graphic-Wizard-Parameters-Estimation and Genetic Algorithm are introduced.

The Characteristics of Water Quality in Mokpo Harbour(II) - Centering on eutrophication summer - (목포항의 수질특성 - 하계의 부영양화를 중심으로 -)

  • 김광수
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.3 no.S1
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    • pp.77-90
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    • 1997
  • the observations in situ and the seawater analyses were conducted in July and August, 1996 for the purpose of evaluating the characteristics of seawater quality centered on eutrophication in Mokpo harbour. By applying the OECD standards of trophic classification to the parameters such as secchi depth, total inorganic nitrogen, phosphate phosphorus and chlorophyll-a, the trophic level of seawater in Mokpo harbour was evaluated to be in eutrophic state in summer. By the estimation of pollution index with relation to eutrophication, the seawater quality of Mokpo harbour was evaluated to be under the regular grades and this evaluation was found to be different from the results of evaluation obtained by the environmental index of single parameter, chemical oxygen demand. By the estimation of eutrophication index, the seawaters of Mokpo harbour were shown to have the high potentiality of red tide occurrence.

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The Characteristics of Water Quality in Mokpo Harbour(II) -Centering on eutrophication in summer- (목포항의 수질특성(II) - 하계의 부영양화를 중심으로 -)

  • 김광수
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.3 no.2
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    • pp.51-61
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    • 1997
  • The in situ observations and the seawater analyses were conducted in July and Auguse, 1996 for the purpose of evaluating the characteristics of seawater quality centered about eutrophication in Mokpo harbour. By applying the OECD standards of trophic classification to the parameters such as secchi depth, total inorganic nitrogen, phosphate phosphorus and chlorophyll-a, the trophic level of seawater in Mokpo harbour was evaluated to be in eutrophic state in summer. The estimation of pollution index by eutrophication showed the seawater quality of Mokpo harbour to deteriorate and fall under the regular grades. The results of eutrophic index estimation showed the high otentiality of red tide occurrence in Mokpo harbour.

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Capacity Analysis for the Railway Investment and Operation (철도투자 및 운영을 위한 용량분석에 관한 연구)

  • Kim Dong-Hee;Hong Soon-Heum;Kim Jae-Hee
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.197-203
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    • 2004
  • Railway system is consisted of various resources such as rail-line, signal, and railcar. It is necessary to efficiently utilize these limited and expensive resources as much as possible up to given line capacity. So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present an improved systematic line capacity model. The proposed model has three main components ; TPS(lain performance simulator), PES(parameter evaluation simulator), LCS(line capacity simulator). The concept of each sub-component is described, including the evaluation method of capacity parameters. And capacity parameter evaluation and estimation results using sample line section data are presented.

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Overview of Reliability Rank Measures for Small Sample (소표본인 경우 신뢰성 순위 척도의 고찰)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.9 no.2
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    • pp.161-169
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    • 2007
  • This paper presents three methods for expression of reliability measures for large and small data. First method is to express parametric estimation of cardinal reliability measure data for large sample, which requires numerous sample. Second is to obtain nonparametric distribution classification of ordinal reliability measure data for small sample. However it is difficult for field user to understand this method. Last method is to acquire parametric estimation of ordinal reliability measure data for small data. Because this method requires small sample and is comprehensive, we recommend this one among the proposed methods. Various reliability rank measures are presented.

Added Mass Estimation of Square Sections Coupled with a Liquid Using Finite Element Method

  • Jeong, Kyeong Hoon;Jhung, Myung Jo
    • Nuclear Engineering and Technology
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    • v.49 no.1
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    • pp.234-244
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    • 2017
  • Natural frequencies of immersed square sections decrease due to a contribution of added mass to the movement of square sections. In this study, natural frequencies of square sections are obtained as a function of gap size between the square section and a rigid square wall using the finite element method. Additionally, they are used to extract the added mass effect on translational and rotation motions. Published information and studies on the translational and torsional vibration of square beams are also examined for practical use. D coupling of a square section is also investigated for multiple square sections. The suggested added mass estimation can be applicable to the spent fuel storage design of a pressurized light water modulated nuclear power plant.

A Study on Endurance Estimation of ultra Precision Reverse-Locking Clutches under Contact Condition (접촉상태에 있는 초정밀 역전방지클러치의 내구성 평가에 관한 연구)

  • Suh Jeong Se;Lee Seok Soon;Lee Tae Sun;Choi Jung Hoan;Lee Sang Bum
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6 s.171
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    • pp.47-54
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    • 2005
  • A dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOKNANOTECH corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque from input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element method and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test method when applied rated torque.