• Clean Technology
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• v.8 no.4
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• pp.205-215
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• 2002

Can industry has grown up with growth of packing industry and its recycling activation in recent years. But profit has became low by oversupply. Therefore, can industry needs a reduction of environmental load and official loss by an optimization of process in order to maintain its competitiveness. In this study, the main issues of aluminium can production was investigated by life cycle assessment. As a result of LCA, it examined closely by main issues that reduce defective cans and remove tramp oil. In the present work, it was recommended that setup of R/O system, sterillizing tramp oil separation, and heating system of DI water. The ROI investigated 6.4 months. The operating cost with the advanced processes could be reduced annually by 300 million won.

• Journal of Engineering Education Research
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• v.17 no.2
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• pp.50-58
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• 2014

This study reviews recently developed perspectives within Science and Technology Studies (STS) and engineering education including engineering ethics and engineering design, focusing on defining why interdisciplinary collaboration between those two areas is required and how it can be realized. The disconnection between those areas is closely related to the chronic diseases that has brought the mono-disciplinary, segmented educational system of 20th century: fragmented perception of reality and gradual loss of academic influence. This study consists of two sections: the first section reviews new movements among STS, engineering ethics and engineering design; the second section analyses how their combination is developing and what significance it represents. Recently, some scholars attach more importance to scalable scholarship of STS, that is, strategic expansion of the range of STS. This kind of attempts is gradually producing satisfactory results as it is combined with innovative efforts arising from the field of engineering education. This study emphasizes that, when STS and engineering education are combined and interact more with each other, it will broaden our prospects about engineering and society; it will, particularly, contribute to enhance our engineering education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.779-783
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• 2012

In this paper, we studied the design and fabrication of $2{\times}2$ array-type microstrip patch antenna to be used in wireless communication systems operating at around 5GHz band. To obtain wide bandwidth and high gain, antenna parameters such as patch size, inter patch space are simulated by HFSS(High Frequency Structure Simulator). From these parameters, the $2{\times}2$ array-type microstrip patch antenna is fabricated using FR-4 substrate. The measured results of the antenna are as follows: The center frequency of 5.06GHz, insertion loss of -44dB, bandwidth of 200MHz, and VWSR of 1.1.

• IE interfaces
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• v.25 no.1
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• pp.40-51
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• 2012

Today, many manufacturing companies realize that collaboration is crucial for their survival. Especially, in the perspective of quality, the importance of collaboration is emphasized because economic loss increases exponentially while defective parts go through the process in supply chain. However, the manufacturing companies are facing two main difficulties in implementing collaborative relationships with their suppliers. First, it is difficult for the suppliers to produce reliable products due to their obsolete facilities. The problem gets worse for second- or third-tire vendors. Second, the companies experience the lack of universally understandable set of terminology and effective methodologies for knowledge representation. Ontology is one of the best approaches to expressing and processing a domain knowledge. In this paper, we propose the manufacturing ontology-based quality prediction framework to represent and share the knowledge of industrial environment and to predict product quality in manufacturing processes. In addition, we develop the ontology-based quality prediction system based on the proposed framework. We carried out a series of experiments for an injection molding process at an automotive part supplier. The experimental results demonstrated that the proposed framework and system can be successfully applicable in manufacturing industry.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.76.1-76.1
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• 2010

Recently, many efforts to solve the durability problem of PEM fuel cell are carried on constantly. However, despite this attention, durability researches of gas diffusion layer (GDL) are not much reported yet. Generally, GDL of PEM fuel cell experiences three external attacks, which are dissolution of water, erosion of gas flow, corrosion of electric potential. In this study, among these degradation factors, carbon corrosion of electric potential was focused and investigated with accelerated carbon corrosion test. Through the test, it is confirmed that carbon corrosion occurred at GDL, and corroded GDL decreased a performance of operating fuel cell. The property changes of GDL were measured with various methods such as air permeability meter, pore distribution analyzer, thermo gravimetric analyzer, and tensile stress test to discover the effects of carbon corrosion. Carbon corrosion caused not only loss of weight and thickness, but also degradation of mechanical strength of GDL. In addition, to analysis the reason of GDL property changes, a surface and a cross section of GDL were observed with scanning electron microscope. After 100 hours test, the GDL showed serious damage in center of layer.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1721-1726
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• 2005

The characteristic smell of cow milk was suppressed when herbs were consumed by lactating dairy cows. But it is unclear whether or not peppermint ingestion affects the nutritional and milk production parameters in lactating dairy cows. The objective of this study was to examine the effect of peppermint feeding to lactating dairy cows on nutrient digestibility, energy metabolism, ruminal fermentation and milk production. Eight Holstein cows were given a diet supplemented with or without 5% of dried peppermint per diet on a dry matter basis. The digestion of nutrients from cows fed the diet with peppermint was significantly lower than that of the control group. Energy loss as methane and methane released from cows receiving the peppermint treatment was significantly lower than that in the control cows. Peppermint feeding to cows resulted in the promotion of thermogenesis. However, ruminal fermentation and milk production were not affected by peppermint feeding. In conclusion, peppermint ingestion by lactating dairy cows reduces the nutrient digestibility and methanogenesis, and changes energy metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.4
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• pp.299-303
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• 1990

Twenty-four Harnai lambs 6 to 7 month old, weighing $16{\pm}2kg$ were used in a completely randomized design in growth and digestibility trials to study fourwing saltbush ratio supplemented with cotton seed cake. The animal were divided at random into three groups of 8 animals each. Three iso-nitrogenous (10.5% CP) experimental rations (1, 2 and 3) containing wheat straw + lucerne hay (24:76); fourwing saltbush (Atriplex canescens) + cotton seed cake (71:29); and wheat straw + cottonseed cake (41:59); respectively, were allotted to each group randomly. All the animals were taken out for grazing in a dormant native range for about 3 hours in the afternoon during the growth trial. The growth trial lasted for 8 weeks followed by a digestibility trial. At the end of 8 weeks lambs on ration 3 had gained significantly (p<0.10) more weight compared to those on rations 1 and 2 which maintained their body weight. The crude protein digestibility of the fourwing saltbush based ration was comparable with the other two treatments (71 vs 70 and 71%). However, the digestibility of dry matter (41%), acid detergent fibre (13%) and neutral detergent fibre (22%) of this ration was significantly lower (p<0.10) than the other two diets. The results suggest that lambs can be maintained on fourwing saltbush during winter without significant loss in body weight with 30% extra protein concentrate supplementation.

• Journal of East-West Nursing Research
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• v.23 no.1
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• pp.18-25
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• 2017

Purpose: The purpose of this study was to identify factors which effect to female college student' reproductive health promoting behavior in female college students. Methods: The design of this study was correlational study and subjects were 127 female college students from two colleges in B metropolitan city. The data collection was carried out from June 1, 2016 to June 30, 2016. Data were collected using questionaires of characteristics of the subjects, sexual knowledge, sexual behavior, and self-efficacy(KGSE). Results: The subjects' reproductive health promoting behavior differed according to the grade, major, smoking, and experience of weight loss of more than 10 kg within the last 3 months. The subjects' reproductive health promoting behavior had positive correlations with sexual knowledge (r=.39, p<.001) and self-efficacy (r=.34, p<.001), and negative correlation with sexual behavior (r=-.23, p=.011). Sexual knowledge and sexual behavior were influencing factors on reproductive health promoting behavior accounting for 23.0%. Conclusion: This study showed that sexual knowledge and sexual behavior were factors affecting female college students' reproductive health promoting behavior and the most influential factor was sexual knowledge.

• Corrosion Science and Technology
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• v.19 no.5
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• pp.239-249
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• 2020

The characteristics of cavitation-erosion damage with changes in the amplitude of 5052-O aluminum alloy for ships were investigated in a seawater environment. In the cavitation-erosion experiment, the cavitation environment was created using a vibration-generating device with a piezo-electric effect. The amplitudes of 5 ㎛, 10 ㎛, and 30 ㎛ were created by changing the geometric shape of the cavitation horn. The resistance characteristics of cavitation-erosion damage were evaluated by weight loss and pitting area. The damaged surface was analyzed using scanning electron microscopy (SEM) and 3D optical microscopy. As the amplitude increased, the amount of damage and the area of the damaged surface increased, and the damage was concentrated at the center and edge of the specimen. The pit was created after the initial incubation period with increasing experimental time, and then the pits were merged to grow and propagate into craters, and eventually, the surface was detached and damaged. The cavitation-erosion damage after 30 minutes with amplitude of 10 ㎛ and 30 ㎛ was 1.48 and 2.21 times compared to 5 ㎛, respectively.

• Journal of Korean Academy of Nursing
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• v.46 no.4
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• pp.562-571
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• 2016

Purpose: In this study the costs and benefits of a home health care program were examined to evaluate the economic feasibility of the program. Methods: The study participants included 349 patients in the community who had been registered at a home health care center for 5 years. The costs and benefits of the program were analyzed using performance data and health data. The benefits were classified as the effects of pressure ulcer care, skin wound care and catheters management. The program effect was evaluated on the change of progress using transition probability. Benefits were divided into direct benefit such as the savings in medical costs and transportation costs, and indirect benefits which included saving in productivity loss and lost future income. Results: Participants had an average of 1.82 health problems. The input cost was KRW 36.8~153.3 million, the benefit was KRW 95.4~279.7 million. Direct benefits accounted for 53.4%~81.2%, and was higher than indirect benefits. The net benefit was greater than 0 from 2006 to 2009, and then dropped below 0 in 2010. Conclusion: The average net benefit during 5 years was over 0 and the benefit cost ratoi was over 1.00, indicating that the home health care program si economical.