• Title/Summary/Keyword: Limits

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A Study on the Establishments of Aircraft Noise Abatement Procedures in Gimpo International Airport (김포공항 항공기 저소음 운항절차 수립을 위한 연구)

  • Kim, Yeon-Myung;Park, Jin-Woo;Kim, Young-Il;Son, Jung-Gon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.5 s.122
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    • pp.379-390
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    • 2007
  • The final purpose of this study is to develop noise abatement procedures for minimizing damages caused by aircraft noise, to establish appropriate noise limits and to suggest a plan for imposing surcharges and penalties on aircraft infringing the noise limits. This study establishes noise abatement procedures and suggests a plan to complement and improve upon NMS in Gimpo International Airport by reviewing the NMS structure. In addition, this study establishes a noise limit at each noise monitoring system and a verification system to discriminate infringing aircraft. Finally, this study suggests a control plan for aircraft Infringing the noise limit.

Robust control charts based on self-critical estimation process

  • 원형규
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.15-18
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    • 1996
  • Shewhart control chart is a basic technique to monitor the state of a process. We observe observations of a group of size four or five in a rational way and plot some statistics (e.g., means and ranges) on the chart. When setting up the control chart, the control limits are calculated based on preliminary 20-40 samples, which were supposedly obtained from stable operating conditions. But it may be hard to believe, especially at the beginning of constructing the chart for the first time, whether the process is stable and hence all samples were generated under the homogeneous operating conditions. In this report we suggest a mechanism to obtain robust control limits under self-criticism. When outliers are present in the sample, we obtain tighter control limits and hence increase the sensitivity of the chart. Examples will be given via simulation study.

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A Study on Estimation of Lower Explosive Limits of Alcohol Compounds (알코올화합물의 폭발하한계 추산에 관한 연구)

  • Dong-Myeong Ha;Yong-Chan Choi;Haejin Oh;Su-kyung Lee
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 2002.11a
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    • pp.291-296
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    • 2002
  • Flammable compounds are indispensible in domestic as well as in industrial fields as fuel, solvent and raw materials. The fire and explosion properties necessary for safe storage, transport, process design and operation of handling flammable substances are lower explosive limits(LEL), upper explosive limits(UEL), flash point, fire point, AIT(auto ignition temperature), MIE(minimum ignition energy), MOC(minimum oxygen concentration) and heats of combustion.

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The Measurement and Investigation of Fire and Explosion Properties for Acetone (아세톤의 화재 및 폭발 특성치 측정 및 고찰)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.25 no.4
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    • pp.30-35
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    • 2010
  • For the safe handling of acetone, the flash point, the explosion limit at $25^{\circ}C$ and the temperature dependence of the explosion limits were investigated. And the AIT for acetone were experimented. By using the literatures data, the lower and upper explosion limits of acetone recommended 2.5 vol% and 13.0 vol%, respectively. In this study, the lower flash points of acetone recommended $-20^{\circ}C$. This study was determined relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for acetone, and the experimental AIT of acetone was $565^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of acetone is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

Investigation of Combustible Characteristics for Risk Assessment of Benzene (벤젠의 위험성 평가를 위한 연소 특성치 고찰)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.24 no.5
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    • pp.28-33
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    • 2009
  • The thermochemical parameters for safe handling, storage, transport, operation and process design of flammable substances are explosion limit, flash point, autoignition temperatures(AITs), minimum oxygen concentration(MOC), heat of combustion etc.. Also it is necessary to know explosion limit at high temperature and pressure. For the safe handling of benzene, lower explosion limit(LEL) at $25^{\circ}C$, the temperature dependence of the explosion limits and flash point were investigated. And the AITs for benzene were experimented. By using the literatures data, the lower and upper explosion limits of benzene recommended 1.3 vol% and 8.0 vol%, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for benzene, and the experimental AIT of benzene was $583^{\circ}C$. The new equations for predicting the temperature dependence of the explosion limits of benzene is proposed. The values calculated by the proposed equations were a good agreement with the literature data.

Stabilization Characteristics of Diffusion Flame with Auxiliary Fuel Supply through a Bluff Body (보조연료의 공급이 확산화염의 보염특성에 미치는 영향)

  • An, J.G.;Song, K.K.
    • Journal of the Korean Society of Combustion
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    • v.1 no.1
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    • pp.11-18
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    • 1996
  • The stabilization characteristics of diffusion flame formed behind a bluff body with fuel injection slits was experimentally investigated by varying main fuel injection angles and auxiliary fuel injection conditions. The flame stability limits, temperature and length of recirculation zone, direct and schlieren photographs of flames were measured in order to study the stabilization mechanism of the diffusion flame. The results of this investigation are as follows. The stability limits can be improved by the condition of the kind and quanity of the injected auxiliary fuel. The length and temperature decrease with injection of auxiliary fuel, and these phenomena are remarkable when LPG is injected into the recirculation zone. When the LPG is injected into the recirculation zone, flame remains sooty. Fluctuation of fuel and main stream is generated actively by air injection.

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Establishing residue limits and GAP in the use of pesticides (농약사용에서의 잔류기준 설정과 GAP)

  • Lee, Su-Rae
    • The Korean Journal of Pesticide Science
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    • v.9 no.2
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    • pp.113-121
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    • 2005
  • Consumer protection and prevention of foodborne diseases are essential elements of food safety program for every country The food safety program proposed by WHO was introduced and the importance of GAP in establishing residue limits of intentional additives in food production was emphasized. The procedures and differences in establishing maximum residue limits of pesticides on food crops by Codex Alimentarius Commission and Korea were explained. Finally, considerations in harmonization of Korean standards with Codex MRLs were suggested.

The Effect of Estimated Control Limits

  • JaiWook Baik;TaiYon Won
    • Communications for Statistical Applications and Methods
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    • v.5 no.3
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    • pp.645-657
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    • 1998
  • During the start-up of a process or in a job-shop environment conventional use of control charts may lead to erroneous results due to the limited number of subgroups used for the construction of control limits. This article considers the effect of using estimated control limits based on a limited number of subgroups. Especially we investigate the performance of $\overline{X}$ and R control charts when the data are independent, and X control chart when the data are serially correlated in terms of average run length(ARL) and standard deviation run length(SDRL) using simulation. It is found that the ARL and SDRL get larger as the number of subgroups used for the construction of the chart becomes smaller.

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Monitoring for β-agonist residues in raw meat in Seoul (식육에서 베타아고니스트계 약물 잔류 연구)

  • Choi, Yoon-Hwa;Kim, Mi-Ran;Kim, Young-Seob;Lee, Ju-Hyeong
    • Korean Journal of Veterinary Service
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    • v.40 no.1
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    • pp.79-82
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    • 2017
  • We investigated the residues of ${\beta}-agonist$ (zilpaterol, ractopamine and clenbuterol) using LC-MS/MS in raw meat in Seoul. The recoveries ranged between 76.7~89.9% in beef respectively. The limits of detection were $0.01{\sim}0.09{\mu}g/kg$ and the limits of quantification were $0.03{\sim}0.28{\mu}g/kg$ respectively. Residues of ${\beta}-agonist$ drugs which exceeded maximum residue limits (MRL) were not exceed in any of the 267 samples.

INVESTIGATION ON PREDICTION OF FORMING LIMIT FOR COLD UPSETTING BY UTILIZING ENERGY FRACTURE CRITERION

  • Lee Rong-Shean;Wang Shui-To;Chen Jih-Hsing
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10b
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    • pp.22-25
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    • 2003
  • The forming limits are studied for cold upsetting of high strength aluminium alloy in the present paper. Different geometry ratio and frictional conditions are investigated in the forgeability test to evaluate the forming limits and also to obtain the various strain paths. The critical fracture value can be obtained by integrating along the strain path till free surface crack initiation. To predict the damage evolution of cold upsetting, the computer-aided evaluation of forming limits is obtained by using the finite-element software DEFORM-3D and the modified Cockcroft-Latham criterion. The predicted theoretical limit strains agree quite well with the experimental results.

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