• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.119-126
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• 2006

Though safety signs are important since they transmit hazard information even after diverse accident prevention treatments, their functional effectiveness were never tested in Korea so that even those provided by Occupational Safety & Health Act(OSHAct) could not accomplish their objectives, "effective accident prevention", This research was carried out to understand confronted problems and improvement direction for safety signs provided by OSHAct. For them, current safety signs were analyzed with a semiotic view on one hand, and a questionnaire survey was conducted with safety-related people in industrial fields on the other hand. To summarize problems in semiotic aspects, geometric simplicity of pictograms in safety signs seemed to be so emphasized that they might fail to induce realistic action, and their esthetic sensation seemed to be lower than those of developed countries. And according to present questionnaire survey, it was pointed out that; 1) legal systems related with safety signs were not classified appropriately, 2) safety signs were recognized as difficult to understand and inapplicable to industrial fields, and eventually 3) safety signs were not effectively utilized for industrial accident prevention. Therefore, discussions for improving confronted problems and relation to international standards were added at the end.

• International Journal of Quality Innovation
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• v.1 no.1
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• pp.89-96
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• 2000

Evolutionary operation (EVOP) is a continuous improvement system which explores a region of process operating conditions by deliberately creating some systematic changes to the process variable levels without jeopardizing the product. It is aimed at securing a satisfactory operating condition in full-scale manufacturing processes, which is generally different from that obtained in laboratory or pilot plant experiments. Information on how to improve the process is generated from a simple experimental design. Traditional EVOP procedures are established on the assumption that the variance of the response variable should be small and stable in the region of the process operation. However, it is often the case that process noises have an influence on the stability of the process. This process instability is due to many factors such as raw materials, ambient temperature, and equipment wear. Therefore, process variables should be optimized continuously not only to meet the target value but also to keep the variance of the response variables as low as possible. We propose a scheme to achieve robust process improvement. As a process performance measure, we adopted the mean square error (MSE) of the replicate response values on a specific operating condition, and used the Kruskal-Wallis test to identify significant differences between the process operating conditions.

• Korean Journal of Materials Research
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• v.13 no.12
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• pp.850-854
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• 2003

The abrasion wear behavior on the hardfacing weld was investigated by performing abrasion wear, hardness, and microstructural tests. The gas metal arc(GMA) weld was produced by using the cored wire which was filled with the hard metal, i.e., the recycled tungsten carbide (WC) reinforced metal matrix composite. For 30% addition of the hard metal, the abrasion wear resistance was significantly improved comparing with that for 20% addition of the hard metal. Above 30% addition of the hard metal, however, there was no significant improvement of the wear resistance. The improvement of the wear resistance was due to the increased amount of eutectic carbides(W$_{6}$C) which was formed during GMA welding. For the weld in which the hard metal was added to 30-40%, an optimum level of abrasion wear resistance was performed.

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.167-179
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• 2009

In this era of knowledge and information of the 21st century, the source of a nation's competitive power consists of human resources and material resources and the importance of human resources appreciates highly. The number of small and medium enterprises which are the core of national economy covers over 98% among whole domestic enterprises of Korea. Competitive power of small and medium enterprises comes from human resources development. For the development of human resources, small and medium enterprises are trying to expand their learning organizations in the company. The analysis of outcomes of administering the existing learning organizations shows that learning organizations contribute highly to the improvement of the productivity of small and medium enterprises. And the analysis also shows that the participants of learning organizations and middle management and executives who support and encourage them recognize the necessity of learning organizations and that it should be disseminated throughout other enterprises. Therefore government's supports to establish learning organizations in a company are required to expand.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.152-161
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• 2015

Until a recent date, Toyota Production System (called TPS) was introduced by many domestic companies to remove waste and reduce manufacturing cost. However, cases of substantial and effective improvement after the introduction are not much. Even though many companies have actively conducted TPS during that time, the outcome is not satisfactory. In this paper, we show the problems and core contents to consider in applying of TPS as follows. First, the innovative organizational culture formed by active participation of employees and leadership of the CEO is very important for a successful introduction of TPS above all. Second, it is necessary to prepare various training programs optimized for the field in order to continuously improve the competency of employees in each class, and to train skilled personnel through that programs. Third, it is necessary to improve the maturity level of TPS application through the construction of correct evaluation system on accomplishment of the production system. In addition, the problems that occur should be solved through the continuous improvement activities. These results will help to TPS introduction of the domestic small-medium companies. Therefore, this study will contribute to strengthen and improve the global competitiveness in the related industries.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.2
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• pp.137-145
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• 2020

Various elements of Fabrication (FAB), mass production of existing products, new product development and process improvement evaluation might increase the complexity of production process when products are produced at the same time. As a result, complex production operation makes it difficult to predict production capacity of facilities. In this environment, production forecasting is the basic information used for production plan, preventive maintenance, yield management, and new product development. In this paper, we tried to develop a multiple linear regression analysis model in order to improve the existing production capacity forecasting method, which is to estimate production capacity by using a simple trend analysis during short time periods. Specifically, we defined overall equipment effectiveness of facility as a performance measure to represent production capacity. Then, we considered the production capacities of interrelated facilities in the FAB production process during past several weeks as independent regression variables in order to reflect the impact of facility maintenance cycles and production sequences. By applying variable selection methods and selecting only some significant variables, we developed a multiple linear regression forecasting model. Through a numerical experiment, we showed the superiority of the proposed method by obtaining the mean residual error of 3.98%, and improving the previous one by 7.9%.

• Journal of the Korean institute of surface engineering
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• v.48 no.1
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• pp.1-6
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• 2015

Amino-carboxyl acid as a complexing agent in acid copper sulfate solution was utilized to improve the adhesion of immersion copper layer for steel wire. According to the tape test results, regardless of alloy composition of the wire, the adhesion of immersion copper layer was improved with the addition of amino-carboxyl acid. The incorporation of H and Fe in the plating layer was analyzed by TOF-SIMS. The H and Fe were detected at the entire coating layer without any addition of amino-carboxyl acid. However, with addition of amino-carboxyl acid, the H and Fe were scarcely detected at the coating layer.

• Journal of the Korea Safety Management & Science
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• v.23 no.3
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• pp.1-9
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• 2021

Crane is an important equipment for the transport of heavy goods in industrial sites, but it is also known as one of the most fatal machines. In order to reduce crane accidents, it is necessary to minimize human errors during crane operations. To achieve this, ergonomic design principles are recommended to be reflected from the crane design stage. The study analyzed the safety certification standards for crane that should be fulfilled at the crane design and manufacturing stage. This study selected five representative ergonomic design principles (feedback, compatibility, consistency, full-proof, and fail-safe) by surveying heuristic evaluation principles that are widely used for usability evaluation in early design stage. Next, the principles were applied to the safety certification standards to identify insufficient clauses. This study identified 12 insufficient clauses out of 119 in the current safety certification standards for crane and discussed their improvement directions to comply the ergonomic principles. The analysis results of this study can help of improving the safety certification standards and the method used in this study can also be applied to identify insufficient clauses in the safety certification standards for other industrial machines such as press machine and lift.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.2
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• pp.78-85
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• 2019

High variance observed in the measurement system can cause high process variation that can affect process capability badly. Therefore, measurement system analysis is closely related to process capability analysis. Generally, the evaluation for measurement system and process variance is performed separately in the industry. That is, the measurement system analysis is implemented before process monitoring, process capability and process performance analysis even though these analyses are closely related. This paper presents the effective concurrent evaluation procedure for measurement system analysis and process capability analysis using the table that contains Process Performance (Pp), Gage Repeatability & Reproducibility (%R&R) and Number of Distinct Categories (NDC). Furthermore, the long-term process capability index (Pp), which takes into account both gage variance and process variance, is used instead of the short-term process capability (Cp) considering only process variance. The long-term capability index can reflect well the relationship between the measurement system and process capability. The quality measurement and improvement guidelines by region scale are also described in detail. In conclusion, this research proposes the procedure that can execute the measurement system analysis and process capability analysis at the same time. The proposed procedure can contribute to reduction of the measurement staff's effort and to improvement of accurate evaluation.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.203-210
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• 2023

As the environment changes become more complex, learners should establish the learning strategy for the 4th industrial era and the post-COVID-19, also change. This paper focuses on the importance of self-regulated learning. Through this learning strategy, learners will form more positive attitudes and reduce negative attitudes toward the 4th industrial era. This attitude change will lead to an improvement in learners' career decision-making efficacy as a sense of future efficacy. As a result of the study, it was demonstrated that self-regulated learning improves career decision-making efficacy through the mediating effect of positive attitude formation toward the fourth industry. This article emphasizes the necessity of self-regulated learning as a valid learning strategy for the new era. The effect of self-regulated learning is explained as an improvement in attitude toward the future and a sense of efficacy. Through this learning strategy, learners' future performance could be improved.