• Journal of the Korea Safety Management & Science
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• v.8 no.3
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• pp.11-25
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• 2006

It is necessary to deal with the process capability index carefully because it has been developed with certain assumptions. Companies make a decision on processes through the results obtained by using and treating data extracted from the processes. However if they have incorrect or wrong results, they cannot lead to proper outputs but also bring to loss of the competition in quality. Therefore, this study will show a method to analysis Cp (process capability ; CP) and an idea of mass-production on Pp (process performance ; PP) based on the Sigma Estimate which is one of the uncertainty in the process capability index and makes a lot of error. To apply this method, it is essential to understand and to analyze the processes exactly. Especially, it is required to establish the more accurate process capability index that can quickly and properly respond to changes on processes to recognize the small changes on the process which lies in specification in mass production system that the continual monitoring of quality managers is required.

• Journal of the Korean Institute of Plant Engineering
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• v.23 no.4
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• pp.29-38
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• 2018

Through process quality information, the time required for process quality analysis has been drastically shortened, the process defect rate has been reduced, and the manufacturing lead time has been shortened and the on-time delivery rate has been improved. Therefore, The purpose of this study is to develop a quality information analysis system model that effectively shortens the time required for process quality analysis in automobile safety belt parts manufacturing process. As a result of experiments on communication operation between manufacturing execution system (MES) quality server, injection machine control computer, injection machine programmable logic controller (PLC) and terminal, in analyzing quality information, the conventional handwriting input method took an average of 20 minutes, but the new multi-network method took about 2 minutes on average. In addition, the process defect rate was reduced by 13% and the manufacturing lead time was shortened from 28 hours to 20 hours. The delivery compliance rate improved from 96 to 99%.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.64-69
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• 2012

The concept of SIL is applied in the most of all standards relating to functional system safety. However there are problems for the people to apply SIL to their plants. as these standards don't include sufficient informations. In this regards, this paper will suggest the direction of SIL application and concept based on IEC 61508 and IEC 61511. A Safety Integrity Level(SIL) is the discrete level(one out of possible fours), corresponding to a range of the probability of an E/E/PE (Electric/Electrical/Programmable Electrical) safety-related system satisfactorily performing the specific safety functions under all the stated conditions within a stated period of time. SIL can be divided into the target SIL(or required SIL) and the result SIL. The target SIL is determined by the risk analysis at the analysis phase of safety lifecycle and the result SIL is calculated during SIL verification at the realization phase of safety lifecycle. The target SIL is determined by the risk analysis like LOPA(Layer Of Protection Analysis), Risk Graph, Risk Matrix and the result SIL is calculated by HFT(Hardware Fault Tolerance), SFF(Safe Failure Fraction) and PFDavg(average Probability of dangerous Failure on Demand). SIL is applied to various areas such as process safety, machinery(road vehicles, railway application, rotating equipment, etc), nuclear sector which functional safety is applied. The functional safety is the part of the overall safety relating to the EUC and the EUC control system that depends on the correct functioning of the E/E/PE safety-related systems and other risk reduction measures. SIL is applied only to the functional safety of SIS(Safety Instrumented System) in safety. EUC is the abbreviation of Equipment Under Control and is the equipment, machinery, apparatus or plant used for manufacturing, process, transportation, medical or other activities.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.89-96
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• 2015

The weapon systems development has some distinct characteristics in that a big size of government budget (derived from national tax) has been expended frequently and the completion of the development projects seems to take long. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks. As such, proper management of project risk has been one of crucial subjects in the weapon systems development. Although a variety of methods can be considered, an approach based on the test and evaluation (T&E) process has been selected in this paper in order to appropriately handle those potential risks. In the study of the underlying T&E process, the safety consideration (for instance, explosiveness) of weapon systems is also included. To achieve the objective of the paper, a step-by-step procedure is first presented in the analysis of the T&E process. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored based on a design structure matrix method. The case study of a tank development is also discussed.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.59-69
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• 2021

Malfunctions and failures linked to medical devices may result in significant damage for human being. Thus, in order to ensure that safety of medical device is achieved, it should be established and applied the international standard. It is required to integrate and customize activities at standards, owing to reference relationship between standards, especially, activities based safety analysis is too expensive. This paper proposes a integration process that integrate activities of development lifecycle and safety process. Additionally, we derived a guidance based on STPA for integration process. As a result, we can be performed systematically from early stage of the development and increased effectiveness of integration process by the guidance.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.221-225
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• 2013

Sustainability, in general, means the protection of environmental resources and economic prosperity, with the consideration of the social, economic and environmental effect, as well as human health and the enhancement of life. Profound consideration about sustainability has to handle the overall cycle of feedstock, resource extraction, transportation and production in addition to the environmental effect. Sustainable development of the chemical industries should be carried out complementarily by strengthening the chemical process safety of the industries. In this respect, chemical process safety can be called an opportunity to enhance the compatibility internationally. Changing new paradigm in chemical process safety is formed from the overall life cycle considering basic design of existing systems and production processes. To improve the chemical process safety, the integrated smart system is necessary, comprising various chemical safety database and knowledge base and improved methods of quantitative risk analysis, including management system. This paper discussed the necessity of overall life cycle in chemical process safety and proposed new technology to improve the sustainability. To develop the sustainable industries in process systems engineering, three S, which include Safety, Stability and Security, will have to be combined appropriate.

• Journal of the Korea Safety Management & Science
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• v.2 no.4
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• pp.19-32
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• 2000

Assignable causes producing temporary deviation from the underlying system can influence on process adjustment and process monitoring in dynamic feedback control system. In this paper, the impact of assignable causes on EWMA forecasts and process adjustment which is based on the EWMA forecasts are derived for optimum control methods.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.457-463
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• 2008

In this study, the mean time to failures of a system under shock models are derived. The system receives shocks according to a stochastic process. The expected system lifetime under homogeneous Poisson shock process, nonhomogeneous Poisson shock process, and a general renewal shock process are derived. Some numerical examples are presented.

• Proceedings of the Korean Reliability Society Conference
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• 2004.07a
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• pp.262-267
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• 2004

In designing and evaluating a new product, the company needs to give thought to the entire spectrum of produceability, usability, and ultimate reliability, as well as safety of users. For each design review(DR) stage, a formal, systematic, documented review and evaluation of a product design is conducted to assure that the product is safe and reliable, that costs and materials have been optimized, and that the design complies with its specifications and requirements. This paper presents how to improve development process for product's safety and reliability. The process requires gathering the appropriate information, determining the limits of the product, estimating risk associated with the task-hazard combinations, and reducing risk according to a prioritized procedure.

• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.24-30
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• 2021

Heat is generated during the synthesis and mixing process of chemical compounds due to a change in activation energy during the reaction. A runaway reaction occurs when sufficient heat is not removed during the heat control process within a reactor, rapidly increasing the temperature, reaction speed, and rate of heat generation inside the reactor. A risk assessment was executed using an RC-1 (Reaction Calorimeter) during Friedel-Crafts acylation. Friedel-Crafts acylation runs the risk of rapid heat generation during Active Pharmaceutical Ingredient (API) manufacturing; it was used to confirm the risk of a runaway reaction at each synthesis stage and during the mixing process. This study used experimental data to develop a safety efficiency improvement plan to control the risks of runaway and other exothermic reactions, which was implemented at the production site of a chemical plant.