• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.93-104
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• 1999

Existing composting system was improved to have a high performance for organic degradation, deodorization and energy reduction. Compared with conventional devices, this developed system uses the heat recovered from platinum catalytic tower by three times heat exchange in which 65% of exhaust gas was recirculated. Evaporation of water was made easy by maintaining negative pressure in entire system. It was possible for reaction to be maintained steadily by microorganism agent. The optimum mixing volume ratio of garbage to sawdust was 15:1 contrary to 20:1 in conventional one. Moreover, aerobic condition was maintained efficiently. Effects obtained by using a inner circulation system were as follows. It was possible to reduce the ammonia causing offensive odor and verified that consumption of electricity cut down to 1/3 with reduction of exhaust gas inflowing. According to this inner circulation, the optimum air flow was $0.44m^3$ to 100kg treatment capacity. The electricity consumption was changed in proportion to inflowing air volume.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.740-753
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• 2013

The purpose of this study was to examine present condition of social work field education, students' stress/stress coping strategies in their field practicum, and to find out the difference according to the factors related field education. This study carried out a survey targeting 202 students who finished their social work field practicum and took their course work in 2012, from 4 different universities in the northern Gyeonggi province & Seoul. As the result, in the area of stress, the highest rank was the lack of professional knowledge/skills, the second was the environment of field practicum, and the third was the burden of tasks that they had to perform. About the coping strategies, it was found that students utilized 'problem-solving focused' the most, pursuing 'social support' as the second, and 'avoidance' strategies as the least. Factors influencing on differences of stress level depending on field work experiences were whether they had previous field experience, how much time they participated in previous volunteer activities, whether they attended orientation for their field practicum, regularity/frequency of supervision, the satisfaction on their social work/welfare major, and the satisfaction on their field practicum or supervision. Based on the results, suggestions for development in field education system were presented.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.4
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• pp.1-18
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• 2012

With the enormous growth and various applications of private brands, national brand manufacturers are confronted with a dilemmatic situation. That is, paradoxically, some manufacturers have come to produce private brands of retailers which are potential competitors to their own brands. This study reveals why manufacturers with their own brands let themselves do the consignment production of retailers' private brands although those private brands may become strong competitors of their own brands and then investigates the condition in which manufacturers may benefit from such consignment production. Through an analysis of a game theoretical model assuming a monopoly market, the present study presents the theoretical backgrounds and provides new insights about consignment production of manufacturer with its own brand for retailer's private brand. First, such consignment production can play a role in mitigating the loss in the consignee manufacturer's own brand sales caused by the private brand in the competitive environment. Second, the effectiveness of such role is affected by the quality of the private brand produced under consignment. In other word, only if the consignee manufacturer keeps the quality of the private brand low, the manufacturer can maintain the benefit from its own brand. In addition, a consigner retailer needs to consider the final objective of launching its private brand, when it chooses its consignee manufacturer of the brand. Finally, a manufacturer with its own brand may consider consignment production as not merely an unavoidable option compelled by a retailer's power but a reasonable strategic choice to reduce the risk from competition.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.131-135
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• 2005

Under sulfur deprived conditions, PS II and photosynthetic $O_2$ evolution by Chlamydomonas reinhardtii UTEX 90 are inactivated, resulting in shift from aerobic to anaerobic condition. This is followed by hydrogen production catalyzed by hydrogenase. We hypothesized that the photosynthetic capacity and the accumulation of endogenous substrates such as starch for hydrogen production might be different according to cell age. Accordingly, we investigated (a) the relationships between hydrogen production, induction time of sulfur deprivation, increase of chlorophyll after sulfur deprivation, and residual PS II activity, and (b) the effect of initial cell density upon sulfur deprivation. The maximum production volume of hydrogen was 151 ml $H_2$/l with 0.91 g/l of cell density in the late-exponential phase. We suggest that the effects of induction time and initial cell density at sulfur deprivation on hydrogen production, up to an optimal concentration, are due to an increase of chlorophyll under sulfur deprivation.

• Journal of Korean Medical classics
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• v.24 no.4
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• pp.175-193
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• 2011

In present-day Korea, a climatic change is causing various changes to the life of people and their body. The climate is more and more warm, so the internal environment of people's body is exchanging to warm. The climatic change's range is big and the speed is fast. So the harmony of human body is being destroyed and the human body's adaptation ability is becoming low. At this condition, diseases more frequently occur. So doctor must expect the occur of diseases and practice early treatment. And in present-day Korea, a life environmental change is being advanced. The life environmental change is causing big changes to the people's body and having influences to the occur of diseases. To this problem, doctor must expect and practice early treatment. This thesis would like to interpret about present-day Korea's climatic changes and life environmental changes in Korean Medicine point of view, and try to present the method of Korean Medicine early treatment. And comment on present-day Korea's early treatment method especially on health supplement or functional food and vaccination.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.216-222
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• 1988

This study was conducted to investigate the effect of meteorological factors on the diameter growth and Key-year in Pinus koraiensis and Pinus densiflora trees grown in Chuncheon and Hongcheon. The results obtained were summarized as follows : 1. The diameter growth of Pinus koraiensis was better than that of Pinus densiflora grown in the same meteorological condition and site environment. 2. The influence of meteorological factors on the diameter growth of Pinus koraiensis was the highest in the descending order fog, hours of sunshine, precipitation, relative humidity, warm index, and evaporation. 3. The influence of meteorological factors on the diameter growth of Pinus densiflora was the highest in the descending order fog, hours of sunshine, relative humidity, precipitation, and warm index. But evaporation was not significant. 4. The Key-years for Pinus koraiensis and Pinus densiflora trees appeared in 1964 and 1913 when the diameter growth was influenced by the specific climate change.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1500-1506
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• 2017

Objective: High $NH_3$ emissions from poultry houses are reported to have negative impacts on health, welfare and safety of birds and humans, and on the environment. Objective of the present study was to determine the effects of two litter amendments on the $NH_3$ levels in broiler closed houses under hot-humid conditions. Methods: Giving a completely randomize design, nine closed houses, each housed 32,500 birds on paddy husk litter, were randomly allocated into two treatment (Mizuho; a bacterial culture mix and Rydall OE; an enzymatic biocatalyst) and control groups. $NH_3$ levels were determined thrice a day (0600, 1200, and 1800 h), at three heights from the litter surface (30, 90, and 150 cm), at 20 predetermined locations of a house, from day 1 to 41. Results: Rydall significantly reduced the $NH_3$ level compared to control and Mizuho. $NH_3$ levels at 30 cm were significantly higher than that of 90 and 150 cm. The $NH_3$ levels at 30 cm height were higher than 25 ppm level from day 9, 11, and 13 in Mizuho, control, and Rydall groups, respectively to day 41. $NH_3$ levels at 150 cm height were higher than maximum threshold limit of 50 ppm for human exposure from day 12, 14, and 15 in Mizuho, control, and Rydall groups, respectively to day 33. Being significantly different among each other, the $NH_3$ level was highest and lowest at 0600 and 1800 h. Litter amendments had no significant effects on growth performance. Rydall significantly increased the litter N content on day 24. Conclusion: It was concluded that the $NH_3$ levels of closed house broiler production facilities under tropical condition are so high that both birds and workers are exposed to above recommended levels during many days of the growing period. Compared to microbial culture, the enzymatic biocatalyst was found to be more effective in reducing $NH_3$ level.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1714-1720
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• 2018

Objective: This study was conducted to analyze the effects of stocking density on growth and carcass quality, and behavior of Hanwoo cattle to conform with global trends, targeting animal welfare production through the practice of environmentally friendly condition. Methods: Thirty six steers were randomly assigned to three treatment groups (C: 5 heads, T1: 4 heads, T2: 3 heads) and reared in separate pens with a constant stocking density of $50m^2$ (C: $10m^2/head$, T1: $12.5m^2/head$, T2: $16.67m^2/head$) per group from 12 to 30 month of age. Growth performance, behavior and carcass quality traits of each steer were recorded and compared between the treatment groups. Results: In general, the average daily gain during the fattening period was lower in group T2 than in T1 and the control groups. However, carcass weight and dressing percentage was lower in the control group than in T1 or T2 groups (p<0.05). Also, marbling score at 30 months of age was the lowest in the control group (p<0.05), while the three heads group (T2) had the greatest longissimus muscle area and marbling score (p<0.05). The behavior of walking time was the greatest in T2 group, while self-grooming and fighting occurred with the most frequency in the control group (p<0.05). Conclusion: Our results show that the steers in more spacious stocking density had better carcass quality and wellbeing related behaviors, indicating that a lower density has a positive effect on raising management and carcass quality. Thus it is a need to install appropriate pens fitted to welfare-oriented management practices from growing to fattening period in Hanwoo cattle.

• Journal of Korea Multimedia Society
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• v.3 no.4
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• pp.389-398
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• 2000

The focus of this study is to investigate how personal display system - Head Mounted Display(HMD) and VDU-affect to the body in virtual environments. This prediction was tested by a comparing of playing 3D games while wearing a HMD and monitoring a VDU for an hour. As quantitative measuring and analyzing tools, SSQ, RSSQ, pre and post posture stability test and vision test are used. The results showed that SSQ and RSSQ total score (TS) are related with the results of pre and post posture stability test and SSQ and RSSQ TS of HMD is higher than TS of VDU by one point five times. Especially, TS of MRG3C, having large field of view, has a possibility by two times of simulator sickness (SS). And in order to investigate the degree of SS regarding to the simulator control condition, two conditions, subjective-passive and subjective-active environments were compared. However, there was no significant difference between two environments. The repetition of the same environment has no effect to reduce the SS. Disorientation and oculomotor scores of the SSQ and RSSQ are higher than that of another symptoms. In addition, RSSQ score of strain/confusion is higher than that of nausea. Therefore, we assume that personal fear could possibly increase the simulator sickness in virtual environments.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.77-82
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• 2005

According as the quantity of goods transported by ship is increasing, a port environment is rapidly changing To meet this situation successfully, the development of the next generation port loading and unloading system(LMTT) is studied A Frame of shuttle car for LMTT(Linear Motor-based Transfer Technology) consists of three parts which are outer beam, inner beam and cross beam In this study, we carried out the finite element analysis for the effect of cross beam on the strength and stiffness of the frame according to the number of cross beam, loading position of container, the distance ratio of inner beam from center. The result is as follow ; When the load is applied on outer beam and inner beam concurrently and the number of cross beam is 5, that is the optimum condition in frame design.