• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.153-162
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• 2017

Weapon systems have been developed with high technology electronic equipment due to technology growth. In addition, the capital, operational and maintenance costs of weapon systems have all increased. However, cost of operation and maintenance for weapon systems has been decreased relatively compared to the increased capital cost of weapon systems. Therefore, the defense industry needs to research the life cycle cost of weapon systems that have high operational and maintenance costs. This paper focuses on maintenance equipment for the operation and maintenance of weapon systems. Recently, it seems that the weapon systems that have periodic calibration with maintenance equipment are valid. The equipment requires periodic calibration by the manufacturer to check its own validation. Basically, customers demand high reliability devices from foreign companies that have qualified in the global market. Therefore, the tools need to be calibrated overseas. In other words, weapon systems are not available when the equipment has to be calibrated overseas because the systems require validation with valid maintenance equipment. A purpose of this paper is to compare the loss costs that arise from the calibration of the equipment overseas and the purchasing cost of the tools. Finally, the research shows the number of equipment that customers need to minimize the cost. This research will help to improve the efficiency of operation of weapon systems and solve the problems associated with the need for maintenance overseas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.345-353
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• 2020

On conventional railway lines, trains with different speeds are operated. Therefore, trains moving on curved sections with cants must accept various ranges of balanced cants, cant deficiency, and cant excess, which is essential for the comfort and safety of train operation. In this study, the correlation between the curve radius, cant, and train speed on a track was analyzed to check the cant range that satisfies the criteria of train types, operation speed, cant deficiency, and cant excess. Also, the range of setting the cant by the curve radius and balanced cant were calculated by a regression analysis of train speed according to the frequency of operation in the case of mixed trains. The results could make it possible to improve the speed of the operation route, reduce the loss of ride quality, reduce the risk of derailing caused by cant deficiency, and minimize the load deflection by excess cant. This will ensure the safety of trains running on curves and improve the efficiency of track maintenance.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.70-77
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• 2012

The Ladle Furnace Slag, about 20% of the electric arc furnace slag, has high content of free CaO and free MgO, which generates the expansion collapse by hydration reaction. Although many researchers have been endeavoring to recycle the EAF reducing slag in construction fields, there is not found the effective recycling method up to now. However, the LFS(Ladle Furnace Slag) contains mineral composition of the system of calcium aluminate with high-reactivity. Therefore, it is possible to developed the quick setting property and the high strength at the early age by the rapid cooling. This study aimed to check the reactive minerals and predict the reactivity with water on the LFS discharged from different steel product plants. The test results show that many types of LFS has hydration reactivity and can use in construction field as a inorganic binder with the rapid setting property.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.261-266
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• 1979

This experiment was carried out to evaluate the sanitary quality of cultured vegetables and to check the removing rate of bacteria by treating methods such as washing with tap water or commercial detergent, or blanching. Samples collected from farm land located at Busan suburbs and markets were Fragaria chiloensis var. ananasa, Lycopersicum esculentum, Capsium longum, Cucumis sativus, Lactuca scariola var. sativa leaf of Perilla frutescens var, japonica, Oananthe stolonifera and Allium odoium. Fecal coliform MPN was ra god from less than 30 to 430,000 per 100 grams of samples examined while plate count was $7.2\times10^3\;to\;2.2\times10^7$ per gram. Usually contamination rate of fecal coliform of leaf vegetal)les was much higher than that of fruit vegetables. Removing rate of bacterial density of vegetables by washing three times with tap water was about $70\%$ in fruit vegetables, about $20\%$ in leaf vegetables but it was about $80\%$ in leaf vegetables by washing with a commercial detergent. Sirvival rate of viable cell count of leaf vegetables was less than $0.1\%$ after blanching for one minutes in boiling tap water, Composition of coliform was $18\%$ Escherichia coli group, $22\%$ Citrobacter freundii group and $60\%$ Klebsiella aerogenes group, among Escherichia coli, type I being $16\%$ in total. The coliform detection from BGLB gas positive tubes being planted with various vegetables was about $80\%$ in the result of IMViC reaction.

• Journal of the Society of Disaster Information
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• v.10 no.3
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• pp.420-430
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• 2014

Firefighters performing disaster response activities such as Fire Suppression Rescue First Aid in fire are being exposed in various adverse factors, heat, smoke, toxic gases, emotional stress, biological toxic factors and physical overload by unnatural ergonomic posture required for firefighters. But so far, there is the study for this problem only separately. There is no study about comprehesive analysis of exposed adverse factors in fire-related disaster response activities and countermeasures. The purpose of this study is to contiribute to solving the health problems and prevention of accidents of firefighters by extracting hazardous agents in disaster such as fire and by proposing countermeasures. After analyzing circumstances such as fire-suppression, rescue first aid and life-environment, exposure factors of fire are derived and exposure status is suggested according to physical chemical biological psychological aspects. The countermeasure against the noise of the physical exposure factors are proposed. The countermeasures such as protective equipment and clean room in chemical factors, infection prevention education, vaccination and periodic check system in biological factors, PTSD alleviation booth and mentoring in psychological factors are proposed.

• Archives of design research
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• v.14
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• pp.109-119
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• 1996

One of the most important factors in the work environment of the industrial design is the design process which can systematically synthesize the informations of related fields. Because the computer technology is being radically developed, industrial should not only positively be able to cope with new technologies, but also should positively be able to take part in the development of the integrated system for the process by the new technologies. Recently in the industrial design field, designers are often using the computer~applied-3D modeling techniques in the development process of industrial design products, especially in the visualization level of the design development. In this paper, we studied the workstation modeling process to understand the computer~applied-3D modeling and presented the methods of transfer of the 3D-modeling data of a workstation(SGI) to the AutoCAD data of a personal computer which is generally being used as a drawing tool in mechanism parts. Through the development process of an electronic taxi meter as a practical case study, we check the possibility whether the 3D-modeling data transferred from an industrial design part to a mechanism part can directly be used as the mechanism data. For this, we transferred the 3D-modeling data of an electronic taxi meter created with a workstation(SGI) to the AutoCAD data of a personal computer and checked the usefulness of data transferred from an industrial design part to a mechanism part. Through these processes of data transfer, we aimed to find out the basic principles which can be rationally applied to a mechanism part or a production part.

• Journal of Science Education
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• v.40 no.1
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• pp.72-89
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• 2016

The purpose of this study is to investigate current trends of research in STEAM education through the analysis of published articles in Korea on STEAM education between 2011~2014. By looking into the research trend, this study check out research's achievements for four years and suggest guiding light to determine the direction of the research of STEAM education. The number of papers of STEAM education had continuously increased from 2011 to 2014 but the increase in research tended to stall by 2014. In 2014 the research for kindergartens started to increase and research for slow learning students and special students was done. With regard to the number of studies published relating to the curriculum, many studies centered in the study of the actual and science curriculum which took a large portion since the adoption. In the kindergarten and university level, the study based on art showed the highest while in elementary, middle and high school level, the actual and science curriculum took a major portion in its studies. The general academic associations continue to expand their research area with regard to STEAM education while the academic related associations show a 16% decline in its number of studies published when comparing 2014 to 2013. A higher proportion of qualitative research methods such as case studies are needed to be addressed in the future while more research should be done on education policies for the establishment of a system to share the program that contains the distribution of the education programs and its utilization. In addition, a long-term research should be conducted to verify the effectiveness of the education of teachers for teaching candidates and school teachers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.159-169
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• 2016

Objectives: The objective of this study was to evaluate the generating characteristics of VOCs and the exposure effect to chemicals among laundry workers and to identify the current status of occupational safety and health through health check-ups. Methods: During the six-month period from April to September 2015, this study quantitatively measured seven VOCs in ten laundries and carried out health examinations on 35 workers. Results: Comparing the monitoring results for the ten laundries, they were classified into three groups by ventilation system, dry-cleaning and size of shop. The average concentration of toluene, chlorobenzene, xylene, ethylbenzene, benzene, styrene and TCE were 23.9, 15.6, 5.5, 2.8, 0.9, 0.3 and $1.3{\mu}g/m^3$, respectively. During dry-cleaning, VOC concentrations were 1.3-8.9 times higher than usual. On the other hand, at night the concentrations of toluene, chlorobenzene, xylene, ethylbenzene, benzene, styrene and TCE were 64.3, 41.5, 12.2, 6.3, 1.1, 1.2 and $6.6{\mu}g/m^3$, respectively. The health checkup results for the 35 workers showed that 13 workers were diagnosed as normal, while 22 workers were diagnosed as requiring continuous monitoring or re-checkup of liver and hematogenous functions. Conclusions: Although the results of exposure evaluation to VOCs did not exceed reference value and items had a low correlation with health checkup items, it is necessary to improve indoor air quality due to VOC volatilization from clothes.

• Journal of Internet Computing and Services
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• v.10 no.5
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• pp.195-209
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• 2009

The embedded software has been become more important than the hardware in mobile systems in ubiquitous society. The improvement models such as CMMI(Capability Maturity Model Integration) and SPICE(Software Process Improvement and Capability dEtermination) are used to improve the quality of software in general systems. Software process improvement is also necessary for mobile embedded software development to improve its quality. It is not easy to apply the general software improvement model to the mobile embedded software development due to the high cost effectiveness and heavy process. On the other hand, XP has the characteristics on focused communications with customers and iteration development. It is specially suitable for mobile embedded software development as depending on customer's frequent requirement changes and hardware attributes. In this paper, we propose a framework for development small process improvement based XP(eXtreme Programming)'s practice in order to accomplish CMMI level 2 or 3 in mobile embedded software development at the small organizations. We design and implement the Mobile Embedded Software Process Improvement System(MESPIS) to support process improvement. We also suggest the evaluation method for the mobile embedded software development process improvement framework with CMMI coverage check by comparing other process improvement model. In the future, we need to apply this proposed framework to real project for practical effectiveness and the real cases quantitative. It also include the enhance the functionality of MESPIS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4802-4808
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• 2014

A plate-fin tube type heat exchanger has a lighter weight, approximately 30%, than the conventional circular-fin type condenser of household refrigerator. Because the low weight means low cost, it can have significant effects on the growth of related businesses if similar performance can be guaranteed. To check the possibility of the use of such a plate fin-tube condenser, experimental evaluations were performed in this study. Four different condensers including a conventional circular fin-tube condenser were used for the test. A well designed refrigerant supply system was used to supply similar conditions with a refrigerator, and the heat transfer rate and pressure drops of air side were measured precisely. As a result, the plate fin-tube type condensers showed a lower heat transfer rate of more than 13% than the conventional circular fin-tube type condenser, but the air side pressure drop was reduced and the heat transfer per unit weight was increased. Therefore, it shows the possibility of the use of a plate fin-tube type condenser after optimizing the air flow path and increasing the air flow to make a similar heat transfer rate.