• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1367-1372
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• 2009

A proprietary device is adopted to break out the membrane of cell in the rigid polyurethane foam. As it is known, the membrane of cell is hardly tearing-off thoroughly in a mechanical way due to both its elastic characteristic and micro sized pores. In this study, a novel experimental approach is introduced to burst out all gases inside the cells of the rigid polyurethane foam by abrasively grinding micro-cells completely into fine powder. The biggest advantage of this approach is to be capable of releasing all gases out from the cell even in the micro pores. As clearly reflected from the repeatability, the accuracy of the result is highly improved and high confidence in the data sets as well. For the measurements of not only gas composition but partial pressure for each gas simultaneously as well, a precision gas mass spectrometer is used in-line directly to the abrasive grinding device. To control the starting point of the polyurethane foam, all samples were prepared on site in the laboratory. Manufactured time is one of the most critical factors in characterization of cell gas composition because it is known that one of gas composition, especially, carbon dioxide, is diffused out dramatically in a short period of time as soon as it is foamed.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1098-1105
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• 2001

There is little information on smallholder dairy farming in Zimbabwe. With such inadequate knowledge, no meaningful decisions on how to improve these systems can be made. A study was, therefore, carried out in Nharira communal area and Lancashire small-scale commercial area to provide information on the viability of dairy farms. This paper is based on data obtained through participatory monitoring of 13 smallholder dairy farms in 1996 and 1997. All the four farms in Lancashire were found to be viable in both years. In Nharira, two out of the nine farms in 1996 and three farms in 1997 failed to break even. There were considerable inter-farm differences in the contribution of milk sales towards total income from dairy farming, ranging from 41% to 99% in Nharira and 71% to 81% in Lancashire in 1996. Corresponding estimates in 1997 were 51-95% and 72-78%, respectively. Expenses on cattle feeds contributed 36-84% in 1996 and 37-80% in 1997 towards total variable costs in Nharira. In Lancashire, the respective estimates were 15-33% and 22-36%. Seven out of the nine studied farms in Nharira and three out of four in Lancashire realized higher gross margin (GM) in 1997 than in 1996. All these farming households had conserved considerable amounts of farm-grown feeds. It was concluded that feed costs, number of cows and sizes of land holdings were the main factors determining viability of smallholder dairy farming. The major challenge to smallholder dairy farming in Nharira, in particular, was to develop low-cost feeding strategies.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.227-230
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• 2001

This paper divides the factors of an accident into two parts, that are electrical deterioration and thermal deterioration, to analyze a characteristic of the factor of an accident which can break out in the capacitor of metal vaporized polypropylene film. For the purpose of creating capacitor which is caused by electric deterioration, we applied DC overvoltage, induced self-healing and breakdown from element. We applied gradual heat to get an element which is cause by thermal deterioration. The chemical structure of the shape and surface is analyzed by thermogravimetric analyzer (TGA), Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectrometer(FT-IR). As a result, the peak of methylene group came out, in case of electrical deterioration, as observing the self-healing point. However, the peak is disappeared in the heat treated element by 500[$^{\circ}C$], and the peak of carbonyl group which has C=O came out in case of thermal deterioration.

• Journal of Biosystems Engineering
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• v.19 no.4
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• pp.318-328
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• 1994

This study was carried out to find out the possibility of continuity of the Farming Service Company (FSC), which has been founding since 1991 by the public administration to obtain the scale economy in the rice production, through the only financial analysis of the FSC. The results obtained were as follows. 1. The FSC's business is forward to the off-farm business rather than farm business. Based on the profit ratio, the profit ratio of off-farm business is more than that of farm business. It may cause the difficulty of policy to obtain the scale economy in the farming through the FSC. 2. Without subsidies the average net profit of the FSC was negative, which may provide the motives to the FSC to seek out the way to survive through the off-farm business, unless the FSC's could break up. 3. After all, the possibility of continuity of the FSC through the only financial analysis seems to be very little. Therefore the public administration should reconsider the present policy which is to found the more FSC continuously. If government wants to support the FSC continuously, government should focus on the conglomeration of farm land to increase the productivity of farming and on the subsidy of off-farm business to increase the profit ratio of the FSC.

• Nuclear Engineering and Technology
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• v.35 no.2
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• pp.91-107
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• 2003

Since DBA(Design Basis Accidents) has been studied rather separately from SA(Severe Accidents) in the conventional nuclear reactor safety analysis, the thermal hydraulics during transition between DBA and SA has not been identified so much as each accident itself. Thus, in this study, the thermal hydraulic behavior from DBA to the commencement of SA has been experimentally and analytically investigated for the long-term cooling phase of LB-LOCA(Large-Break Loss-of-Coolant Accident). Experiments were conducted for both cases of the loop seal open and closed in an integral test loop, named as SNUF (Seoul National University Facility), which was scaled down to l/6.4 in length and 1/178 in area of the APR1400 (Advanced Power Reactor 1400MWe). The core mixture level was a main measured value since it took major role in the fuel heat-up rate, the location of fuel melting initiation and the channel blockage by melting material during SA. Experimental results were compared to MAAP4.03 to assess its model of calculating the core mixture level. MAAP4.03 overestimates the core two- phase mixture level because sweep-out and spill-over and the measures to simulate the status of loop seal are not included, which is against the conservatism. Thus, it is recommended that MAAP4.03 should be improved to simulate the thermal hydraulic phenomena, such as sweep-out, spill-over and the status of loop seal.

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.579-587
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• 2017

Objective: The purpose of this study is to measure the workload of Korea coastal ship crew members, to investigate whether they are following work-break time regulations and to identify the main causes of their workload. Background: According to the US Coast Guard, about 33% of human casualties are reported to be due to fatigue, and 30% of marine casualties reported by the British Marine Accident Investigation Agency (MAIB) are attributed to crew fatigue. But the coastal ship are not managed for business hours and breaks despite the harsh environment. Method: The workload of duty crew members on the 100 domestic coastal vessels was measured. It was also investigated whether they are following domestic and international work-break time regulations. Finally, the marine accidents resulted from the fatigue of the crew was analyzed. Results: As a result of workload analysis, the workload on the 42~62% of the vessels exceeded the standard of working time on the related regulation. The workload increased with the number of inbound and outbound ports. Especially, in the system where there are two seafarers, the workload exceeded the working time requirement. As a result of the marine accidents analysis on 100 vessels, it was found that collision and grounding occurred due to fatigue, workload and drowsiness in 7 marine accidents out of 30 marine accidents. Conclusion: It is necessary for the shipping companies to introduce an operation management manual for the management of the crews' workload and reasonable crew arrangement. It is also required for crew members to easily record work times and for shipping companies to manage the record. It would be possible to prevent many marine accidents by providing adequate rest to the crews and flexibly adjusting their working hours. Application: The results of this study can be used as fundamental data to manage crews' fatigue and to make job management manuals.

• Ocean and Polar Research
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• v.33 no.4
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• pp.409-419
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• 2011

Semi-diurnal internal tides and near-inertial waves are investigated using moored current meter measurements at four sites along the shelf break of the East China Sea during August 1987 and May-June 1988. Each mooring is equipped with four current meters spanning from near surface to near bottom. Spectral analyses of all current data reveal dominant spectra at the semi-diurnal frequency band, where the upper and lower current measurements show out-of-phase relationship between them with significant coherences. These are consistent with typical characteristics of the first-mode semi-diurnal internal tide. Strong intensification of the near-bottom baroclinic currents is observed only at one site, where the ratio of the bottom slope to the slope of the internal-wave characteristics at the semi-diurnal frequency is close to unity. An energetic near-inertial wave event is observed during the first half of May-June 1988 observation at two mooring sites. Rotary spectra reveal that the most dominant signal is clockwise rotating motion at the near-inertial frequency band. Upward phase and downward energy propagations, shown in time-depth contour plots of near-inertial bandpass filtered currents, are confirmed by cross correlations between the upper- and lower-layer current measurements. The upward-propagating phase speed is estimated to be about 0.13 cm $s^{-1}$ at both sites. Significant coherences and in-phase relationships of near-inertial currents at the same or similar depths between the two sites are observed in spite of their long distance of about 110 km.

• Korean Journal of Animal Reproduction
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• v.17 no.2
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• pp.75-83
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• 1993

Purine has been identified in the preparation of follicular fluid and shown an activity in maintaining oocyte meiotic arrest. Therefore this study was performed to examine the inhibitory effect of purine on germinal vesicle break down(GVBD) in the presence and absence of human fetal cord serum(HFCS) or human mature follicular fluid(HMFF), as a protein source, in vitro culture. Immature oocytes(GV stage) were collected from ovaries of 21∼28 days old ICR mice by puncturing the antral follicles with a fine needle, at 48 hrs after PMSG injection. Some of the oocytes were denuded by drawing the cumulus-enclosed(complex) oocytes in and out of a pasteur pipet. Complex oocytes and denuded oocytes were cultured 3 hrs. in T6 media containing 0.75mM adenosine or/and 4mM hypoxanthine, with HFCS or HMFF. Their GVBD rates were observed at every 1 hr. during the culture time. Both adenosine and hypoxanthine have shown a time-dependent inhibitory effect on GVBD in complex and denuded oocytes and the inhibitory effect was maximized in culture medium containing hypoxanthine and adenosine. HFCS and HMFF increased the GVBD rates in the presence of the purines, thus HFCS and HMFF may contain a factor that could reverse the inhibitory effect of purines. Also complex oocytes were more sensitive to not only the inhibitory effect of purines but the promoting action of HMFF on GVBD than denuded oocytes. Therefore it was reconfirmed that granulosa cells play an important part in meiotic arrest and resumption.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.399-410
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• 2019

The purpose of this study was to find out the types and characteristics of 'good camping' on the base of camping participant's recognition with Q-methodology. The subjects were selected 15 Q population and did 1:1 interview on them. With those statements, this study was selected 45 P samples and performs Q sort with them. The Q sort result was analyzed by using QUANL program. The results of this study, First, the characteristics of company·break type can be defined with comfort break in nature and the companion except family. Second, family activity type can be defined with the various activities with family. Third, nature·activity can be defined with free hobby activities in nature.

• Korean journal of food and cookery science
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• v.23 no.6
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• pp.891-898
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• 2007

This study was carried out to determine the quality characteristics of grape jellies made with various gelling agents such as agar, $\kappa$-carrageenan, and gellan gum for consumption by elderly women. The concentrations of agar were 0.25, 0.35, and 0.45%, and those of the $\kappa$-carrageenan and gellan gum were 0.15, 0.3, and 0.4%, respectively. The color values, gelling temperatures, melting temperatures, break down rates, textural properties, and consumer acceptance of the grape jellies were measured. The average age of the subjects participating in the acceptance test was 82. The lightness of the grape jelly made with agar was the highest, and its redness was the lowest among the jellies. The gelling and melting temperatures for the grape jelly made with gellan gum were higher than those of the other jellies, and the melting temperatures were 37, 43, and $47^{\circ}C$ based on 0.15, 0.3, and 0.4% gellan gum content, respectively. The break down rate of the grape jelly made with gellan gum was the lowest among the jellies. These results indicate that the stability of the grape jelly made with gellan gum was superior among the jellies. The hardness, adhesiveness, and springiness of the grape jelly made with agar were lowest among the jellies, and the grape jellies made with agar(0.25% and 0.35%) and gellan gum(0.15% and 0.3%) had the highest consumer acceptance among the jellies. However, the gellan gum was deemed an inappropriate gelling agent with regard to the acceptability due to its sour and moldy taste as perceived by the participants.