• Journal of Welding and Joining
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• 제31권2호
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• pp.4-15
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• 2013

The laser/arc hybrid welding process is a new process combining the laser beam and the arc as welding heat source. The laser beam and arc influence and assist one another. By application of hybrid welding, synergistic effects are achievable, and disadvantage of the respective processes can be compensated. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. This review analyses the recent advances in the fundamental understanding of hybrid welding processes using the works of the data base of Web of Science (SCI-Expanded) since the 2000 year. The research activity on the hybrid welding has been become more actively since 2006, especially in China, presenting the most research papers in the world. Since the hybrid welding process was adopted in manufacturing of the automobile in Europe in the early of 2000's, its adopting is widely expanded in the field of manufacturing of automobile, ship building, steel construction and the other various industry. The hybrid welding process is expected to advance toward higher productivity, higher precision, higher reliability through the mixing of high power and flexible fiber laser or disk laser and digitalized pulsed arc source.

• 한국기계가공학회지
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• 제16권5호
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• pp.31-39
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• 2017

Research in the machine tool industry has focused on ICT-based smart machines rather than hardware technologies related to machine tools. Real-time tool-status monitoring is representative of this type of technology and has become important for measuring sensors during cutting processes. In this paper, we studied several research areas and used a round bar to conduct fundamental research into the axial displacement of the main spindle of a tool when it was subjected to a machining load. We were able to use the gap sensor to detect the axial displacement indirectly by using grooves with various shapes on the round bar and sensing the gaps between the grooves. We then determined the optimal groove shape for monitoring the tool state.

• 대한인간공학회지
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• 제32권2호
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• pp.199-205
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• 2013

Objective: The aim of this study is to investigate the job rotation implementation at medium- or small-industries and to identify the viewpoint on job rotation as preventive activity of work-related musculoskeletal disorders(WMSDs). Background: Job rotation has been implemented in many industrial areas in order to prevent the WMSDs as one part of ergonomic program. Generally, the cases of implementation of ergonomic program or successful cases of job rotation were reported on the side of major or large company. Therefore, this study tried to inspect the current state of job rotation implementation at medium- or small-industries. Method: Survey was carried out for randomly contacted forty seven mangers responsible for safety. Survey contained the questionnaires on the general state of company, shift-work and job rotation. Results: The ratio of work-shift in medium- and small-industry was 34.0% and the ratio of job rotation was 19.1%. For manufacturing industry, the ratio was 37.9% and 17.2%, respectively. Conclusion: The implementation ratio of job rotation was relatively low considering the results of previous studies. Many managers appealed the quality decreasing of goods and the injuries of workers due to job rotation, though agreed to train the multi-functional worker and to prevent the WMSDs. Application: The results can be used for the fundamental data how the job rotation will be properly implemented in medium- and small-industry as an administrative control for MSDs.

• 산업경영시스템학회지
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• 제39권3호
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• pp.147-155
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• 2016

Industry 4.0's goal is the 'Smart Factory' that integrates and controls production process, procurement, distribution and service based on the fundamental technology such as internet of the things, cyber physical system, sensor, etc. Basic requirement for successful promotion of this Industry 4.0 is the large supply of semiconductor. However, company I who produces dicing blades has difficulty to meet the increasing demand and has hard time to increase revenue because its raw material includes high price diamond, and requires very complex and sensitive process for production. Therefore, this study is focused on understanding the problems and presenting optimal plan to increase productivity of dicing blade manufacturing processes. We carried out a study as follows to accomplish the above purposes. First, previous researches were investigated. Second, the bottlenecks in manufacturing processes were identified using simulation tool (Arena 14.3). Third, we calculate investment amount according to added equipments purchase and perform economic analysis according to cost and sales increase. Finally, we derive optimum plan for productivity improvement and analyze its expected effect. To summarize these results as follows : First, daily average blade production volume can be increased two times from 60 ea. to 120 ea. by performing mixing job in the day before. Second, work flow can be smoother due to reduced waiting time if more machines are added to improve setting process. It was found that average waiting time of 23 minutes can be reduced to around 9 minutes from current process. Third, it was found through simulation that the whole processing line can compose smoother production line by performing mixing process in advance, and add setting and sintering machines. In the course of this study, it was found that adding more machines to reduce waiting time is not the best alternative.

• 한국산업보건학회지
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• 제6권2호
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• pp.249-264
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• 1996

This study was conducted for the purpose of obtaining the fundamental data on improvement of working environment and contributing to health improvement of workers who dealed with metal by assessing the metal concentration in air of industries located in Chang-Won Industrial Complex. Authors measured the concentration of metals(Al, Cd, Cr, Cu, Mn, Ni, Pb, Sn and Zn) is the air to 25 working processes of 73 industries by flame atomic absorption spectrometry from February to December 1994. Personal air sampler was used for air sampling with mixed cellulose-ester membrane filter. The results were as follows : 1. The geometric means(range) of metal concentration; 1) Al: $0.1505mg/m^3$ ($0.0147-18.6100mg/m^3$) 2) Cd: $0.0077mg/m^3$ ($0.0003-7.0710mg/m^3$) 3) Cr: $0.0163mg/m^3$ ($0.0013-1.1510mg/m^3$) 4) Cu: $0.0097mg/m^3$ ($0.0009-0.4950mg/m^3$) 5) Mn: $0.0412mg/m^3$ ($0.0006-4.7877mg/m^3$) 6) Ni: $0.0088mg/m^3$ ($0.0001-1.0170mg/m^3$) 7) Pb: $0.0152mg/m^3$ ($0.0015-0.4499mg/m^3$) 8) Sn: $0.0486mg/m^3$ ($0.0037-0.1500mg/m^3$) 9) Zn: $0.1911mg/m^3$ ($0.0122-8.2920mg/m^3$) 2. The geometric mean of lead exceeded TWA in assembling process of other general purpose machinery not elsewhere classified products manufacturing industries.

• 한국표면공학회지
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• 제57권3호
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• pp.165-178
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• 2024

In semiconductor memory device manufacturing, the capability for high aspect ratio contact (HARC) etching determines the density of memory device. Given that there is no standardized definition of "high" in high aspect ratio, it is crucial to continuously monitor recent technology trends to address technological gaps. Not only semiconductor memory manufacturing companies such as Samsung Electronics, SK Hynix, and Micron but also semiconductor manufacturing equipment companies such as Lam Research, Applied Materials, Tokyo Electron, and SEMES release annual reports on HARC etching technology. Although there is a gap in technological focus between semiconductor mass production environments and various research institutes, the results from these institutes significantly contribute by demonstrating fundamental mechanisms with empirical evidence, often in collaboration with industry researchers. This paper reviews recent studies on HARC etching and the study of dielectric etching in various technologies.

• 한국생산제조학회지
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• 제22권5호
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• pp.767-773
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• 2013

A high-pressure, high-pressure drop control valve, which transforms the power transfer of a system by reducing the inlet pressure of 345bartothe outlet pressure of 112bar, is a fundamental component in an offshore plant process. With the increasingly growing market share of the maritime industry, this valve has been expected to be a high-value-added product. This study not only analyzes the relation between pressure drop and fluid velocity in a trim by using fluid analysis, but also examines the possibility of cavitation in a valve in addition to the plot for the extension of lifespan. Based on the analysis results, the design and production method of the valve are established, and accordingly, performance evaluation is carried out. It is demonstrated that the pressure drop from 345bar to 112bar is more feasible in the presence of the trim, which can induce a continuous and diminutive pressure drop in order to prevent cavitation in a high-pressure drop control valve. Furthermore, despite the fluid velocity near a seatring being found to be over 30m/s, the lifespan of the valve is determined to be adequate considering the operation condition of a prototype valve of 80%.

• 한국생산제조학회지
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• 제22권2호
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• pp.223-227
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• 2013

Dust collecting performance of cyclone collector for oil mist was alalyzed in the study. The purposes of using cutting fluid during cutting have been colling, lubricating, chip washing and anti-corroding. However, the present manufactaring industry restricts the use of cutting fluid because cutting fluid confains poisonous substances which are harmful to the human body. Also, the optimum design oil-mist collector. The new oil mist collector was designed. In the near future, this device must be tested in the real machining center and CNC machine. Cutting using oil-mist showed better cutting characteristics than dry, air and fluid cutting with respect to by cutting force, tool wear and surface roughness. The model(A, B Type cyclone) of the set of fixture and alveolus are made by using a CAE software. Finally, we have obtained a model A Type solution by using orthogonal array. Therefore, it could be confirmed that as the model-A was increased and model-B was decreased, cut diameter was decreased.

• 대한안전경영과학회지
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• 제26권1호
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• pp.25-30
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• 2024

Considering the difficulties of the manufacturing industry by improving production efficiency in the era of high wages and aging in domestic automation facilities, automation facilities are considered an irreversible trend, but many serious related disasters are occurring due to the problems of increasing automation facilities due to the enlargement of manufacturing processes, line-up, and automation. The purpose of this study is to review the usage conditions and safety measures for industrial robots that are experiencing serious industrial accidents and are expected to continue to increase in facilities among automation facilities at the automation industrial site and propose ways to ensure the fundamental safety of the facilities at all times The suggestions are as follows. The purpose is to prevent safety accidents in advance by applying safety door aids to industrial sites and installing additional safety devices in safety slide door lock systems applied to safety fence doors of new and already installed facilities to detach safety keys and ensure that workers carry them at all times.

• 한국경영과학회지
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• 제30권2호
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• pp.41-61
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• 2005

The concept of revenue management (RM) has been used widely in the air-transportation industry, and proven as a good system for managing perishable assets. While the airlines are the oldest and most sophisticated users of RM, these practices have been an enormously important innovation in other service industries such as the travel, the railway, the internet and the manufacturing industries. In this paper, reviewing several studies on RM, we introduce the fundamental concepts and the major models of RM covering seat allocation with multiple fare classes and overbooking. Future research directions also are suggested.