• Journal of the Korea Safety Management & Science
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• v.6 no.4
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• pp.171-181
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• 2004

A multi axis whetstone polishing system, which uses the flow system of the stone polishing machine head, has been developed. The test results show that the defect by line contact polishing does not occur in both ends of the stone and that it came to trim smoothly. In terms of the surface roughness, the corresponding index was decreased by 3.6 times, improving the polishing effect greatly. It decreased significantly the dust and noise with the wet polishing. The factors of the duty evasion at production site can thus be solved with the work environment improvement against the polishing process of the stone industry and work intensive reduction.

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.165-170
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• 2004

It used the flow system of the stone polishing machine head and it developed a multi axis whetstone polishing system. With the result, the defect by line contact polishing does not occur in both ends of the stone, and it came to trim smoothly. As the index of the surface roughness decreased to 3.6 times, the polishing effect improved greatly. It decreased greatly the dust and a noise with the wet polishing, and the factors of the duty evasion at production site were solved with the work environment improvement against the polishing process of the stone industry and work intensive reduction.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.145-150
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• 2013

As a recent global trend, the majority of mega-size plant projects are delivered through EPC (Engineering, Procurement and Construction) contracts, where a single contract is awarded for engineering, procurement, and construction. Under this contracting mechanism, it is challenging for contractors to carry out the projects under traditional project management processes used in design-bid-build projects. A new EPC Plant, the POSCO Special Steel Plant in Changwon, was built successfully at the beginning of 2012 and it is currently in full-scale production. The project has encountered a number of major difficulties however, with some technical and managerial issues through its development process. As summarized in this paper, the authors (as project participants with the contractor) investigated it as a post construction analysis and recorded the Lessons-learned for future project management improvement.

• Journal of Information Technology Services
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• v.10 no.2
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• pp.61-74
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• 2011

SMEs(Small and Medium-sized Enterprises) have implemented the various IT-based Production Information Systems(PIS) to cope with the highly competitive environment as well as to improve their competitiveness and productivity. For the efficient development of PIS In SMEs, standardizing the system development process is required. Methodology for the development of PIS is especially important for the systematic and efficient implementation to communicate among the SI companies, SMEs, and a supervision agency. TIPA(Korea Technology and Information Promotion Agency for SMEs) has developed PSDM(Production System Development Methodology), and supplies it to the SI companies. The research goal of this paper is to explore the productivity improvement by adopting the PSDM with the cases of SI companies applied PSDM. The results show that such benefits as risk management, productivity improvement, easy system implementation and maintenance are perceived by PSDM Users. This research could be the first case study reveal the effectiveness of PSDM. For further research, the survey could be carried out with more samples.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.74-84
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• 2023

This paper is the result of a comparative analysis of crew members' workloads using the EMG and OWAS methods according to the fishing process before and after the improvement of the operating system of the experimental vessel, with the aim of improving operational efficiency and safety work of coastal improved stow net fishing vessels. The target crew members were three people with at least five years of experience on board the same fishing vessel as the experimental vessel. After improving the operating system, such as installing a power block crane and two capstans, change the location of the ball-roller, the time required for setting and hauling work decreased (p < .01), and the evaluation results by OWAS showed that the overall workload for setting and hauling net work decreased. The results of muscle activity analysis showed a decrease in lashing anchor work (p < .01) in the case of hauling net and in anchor dropping work in the case of setting net (p < .001). It is judged that the use of ball rollers in net handling has been reduced; consequently, work safety has been improved.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.411-418
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• 1992

Recently, onset of bacterial disease, especially infiltration of chronic respiratory diseases have been increasing at high rate. The main cause of these diseases are originated from inappropriate sanitary management and slow progress in introducing system and herd free system, which are the base of productivity improvement in bigger pig management, Methods for the prevention and removal of these diseases, are divided into four categories. The first category includes prevention and removal of infectious diseases by organizing strict animal quarantine, enforcing vaccination, and legal regulation and disposal at the time of outbreak. The second category includes improvement of production systems. This purpose can be achieved by discontinuing the open herd system, which brings on the invasion of foreign pathogens and replacing the system by the closed type of farm. To Continue eradication process step-wisely by performing the all-in all-out system at every pig pen or herd level is also effective for this purpose. The third category includes introduction of herd free system can be achieved by repopulating conventional pigs with SPF pigs. If these means are unrealizable from economic or technical viewpoint, medicated early weaning system is perfomed. This system consists of disinfection of pigsty at pre-postpartum stage, application of drugs to pregnant sows and newborn piglets in accordance with the medication program, and early weaning and rearing of newborn piglets in isolation. The fourth category is sanital leading by veterinarians, aimed to eliminating incentives for diseases through diagnoses. Their main activities include periodical monitoring and improvement leading on each responsible subject.

• Environmental Engineering Research
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• v.16 no.2
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• pp.103-109
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• 2011

This work experimentally determined the effect of thermal and microwave pretreatments on the anaerobic digestion of mixtures of municipal primary and secondary sludges in semi-continuous mesophilic digesters at hydraulic retention times (HRT) of 20, 15, 10, 7, and 5 days. The ratio of soluble chemical oxygen demand (COD) to total COD in thermally pretreated and microwaved sludges at $80^{\circ}C$ was 2.7 and 3.2 times higher than that of raw sludge, respectively. The volatile solids (VS) and COD removal efficiencies in all three digesters fed with raw (control), thermally pretreated (TM), and microwaved (MW) sludges decreased as the HRT was reduced. The highest relative improvement in VS removal compared to the control occurred at the HRT of 5 days in the TM and MW (29 and 41% higher than the control, respectively). At this HRT, improvement in the COD removal efficiencies in the TM and MW compared to the control was 28 and 53%, respectively. Improvements in biogas production compared with the control increased in both the TM and MW as the HRT was reduced to 5 days. The relative improvement in daily biogas production compared to the control from the TM and MW was 33 and 53% higher than the control at the HRT of 5 days, respectively. The results show that microwave pretreatment is more effective than thermal pretreatment in increasing the solubilization degree and mesophilic anaerobic biodegradability of sewage sludge.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.437-451
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• 2019

Purpose: The purpose of this study is to improve the quality of the PGM system by improving the structure and production process of slip-ring rotary joint for radar. Methods: The improvement measures for each cause are established through failure analysis of broken items. Specifically, changing in the housing to improve the heating system. Changing the transportation method to prevent damage to equipment during transport. Changing work process of the attenuator ring to prevent damage. etc. Results: The results of this study are as follows; improving the heating system reduces heat generated by the attenuator by about 7 degrees and obtain additional temperature margins. Reduction of defect rate because of adding X-band rotary joint run-out measurement test, ESS of slip-ring rotary joint and Transportation improvement(reinforced flight boxes, tube protection, etc). Getting stable VSWR values by improving work process of attenuator overheating due to a bad bonding process. Conclusion: Through this study, improvements were made to slip-ring rotary joint that failed repeatedly for various reasons. As a result of the application of the improvements, the same fault does not occur until now, so we can see that the quality of PGM has improved.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.15 no.26
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• pp.77-84
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• 1992

This paper constructs Croup Technology process-based learning curve model adjusted to a Group Technology environment which accounts for shared learning that occurs when multiple products utilize some of the same process steps. Through this constructed model, the estimated times and productivity of labor calculated by the Group Technology process-based learning curve model are compared with those generated by employing product-based 1 earning curve model. For sensitivity analysis of the model, the impact of learning rate and the ordered production quantity on the ratio differences between Group Technology process-based learning curve model and product-based learning curve model are examined. These results indicate the critical importance of employing Group Technology process-based learning curve model when a process spans multiple products.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.74-80
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• 1999

Recently, manufacturing work has been transformed to small scale production form with various types to act up to user's expectation from mass production with a little items required in the past. Then FMS using NC type machinaries has been applied actively also in domestic manufacturing line to meet thus tendency, but there are many machining troubles occured during work process not be settled yet. Nowdays high efficiently has been required no less than high precision in grinding work for the improvement of productivity. In this study, to represent more advance FMS can be adapted to thus situation In-process type monitoring method using AE and Current sensors is suggested to investigate the machining condition in grinding process. As results form this experimental study, it is recognized well that grinding conditions and dressing point of in time cab be estimated effectively using monitoring method suggested. Furthermore, surface shape of grinding wheel on voluntary point of in time can be predicted indirectly through the observation and comparison of AE signal waveform obtained as performance of continuous dressing work.