• Journal of Biosystems Engineering
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• v.32 no.6
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• pp.422-429
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• 2007

To prevent deterioration of agricultural products during cold transportation, optimized temperature control is essential. Because the control of temperature and thermal uniformity of transported products are mainly governed by cooling air flow pattern in the transportation equipment, the accurate understanding and removal of appearance of stagnant air zone by poor ventilation is key to design of optimized cooling environment. The objectives of this study were to develop simulation model to predict the airflow and heat transfer phenomena in the cold container and to evaluate the effect of fan blowing velocity on the temperature level and uniformity of products using the CFD approach. Comparison of CFD prediction with PIV measurement showed that RSM turbulent model reveals the more reasonable results than standard $k-{\varepsilon}$ model. The increment of fan blowing velocity improved the temperature uniformity of product and reduced almost linearly the averaged temperature of product.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.88-95
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• 2021

In Korea, which achieved economic growth due to export industries, the economic importance of the foreign port transportation industry is very great. The government took the initiative in fostering the foreign port transportation industry, and as a result, it developed into one of the top 10 foreign port transport countries in the world. However, due to the poor management of the small and medium-sized foreign port transport business and the trade dispute between countries, the foreign port transportation industry has faced a long-term invasion. Therefore, in order for these companies to recover again, they will, among other things, have to reorganize their operational inefficiency to carry out efficient production activities. In this study, we want to analyze the management efficiency of the top 10% companies in the unlisted domestic outbound shipping industry, present the project value of inefficient enterprises, and confirm the reference collection of companies that may be subject to benchmarking. For this purpose, a total of 10 foreign port transportation industry were analysed for efficiency and scale profitability (RTS) of the CCR and BCC models. The analysis showed that there were a total of six entities with BCC efficiency and five entities with CCR efficiency. In addition, there were a total of five entities with both BCC and CCR efficiency.

• Korean Journal of Social Welfare Studies
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• v.42 no.1
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• pp.305-331
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• 2011

This study analyzes the consumption patterns of the poor households. The first objective of this analysis is to show that the group living in poverty get not one consumption pattern but several types of consumption patterns. The second objective is to understand what factors effect the consumption patterns. This study use the data of Korea Welfare Panel Study in 2008 & 2009. In oder to achieve first goal, We conduct factor analysis and cluster analysis. And to achieve second goal, We conduct multinomial logistic Analysis. Major findings are as follows. First we find six patterns of consuming types of the poor households. They are education oriented consuming type, diet oriented type, social network oriented type, transportation-communication oriented type, health & medical oriented type, and housing expenditure oriented type. Second we find these consumption patterns are effected by not economic factors but socio-populational factors, especially by life cycle of members of household.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.755-764
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• 2017

The current review seeks to highlight the concerns that have been raised on pre-slaughter stress, contributing factors and its consequent effects on cattle behavioural responses and the quality of beef; inter-linking the activities involved from birth to slaughter. Such information is crucial in light of the consumer concerns on overall animal welfare, quality of meat and food security. Slaughter animals are exposed to different conditions during production and transportation to abattoirs on a daily basis. However; the majority of studies that have been done previously singled out different environments in the meat production chain, while conclusions have been made that the welfare of slaughter animals and the quality of meat harvested from them is dependent on the whole chain. Behaviour is a critical component used to evaluate the animals' wellbeing and it has been reported to have an effect on product quality. Apart from the influence of on-farm, transportation and abattoir conditions, the genetic background of the animal also affects how it perceives and responds to certain encounters. Stress activates the animals' hypothalamic-pituitary-adrenal activity, triggering release of various stress hormones such as catecholamines and cortisol, thus glycogen depletion prior slaughter, elevated ultimate pH and poor muscle-meat conversion. Pre-slaughter stress sometimes results to cattle attaining bruises, resulting to the affected parts of the carcass being trimmed and condemned for human consumption, downgrading of the carcass and thus profit losses.

• Journal of Korean Society of Transportation
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• v.33 no.3
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• pp.276-283
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• 2015

Pedestrians have been exposed to dangerous traffic environments, in which walking spaces in a city decrease without improved facilities even though cars increase. Such poor walking environments are deadly dangerous to the vulnerable as well as the non-vulnerable. This study analyzed the road facilities use characteristics according to a type of vulnerability in order to improve traffic safety and walking environment for vulnerable pedestrians. This study surveyed the vulnerable in terms of issues that they encountered on existing walkways and conducted the analytic hierarchy process (AHP), which took all quantitative and qualitative variables into account. The results of Level-3 analysis were showed that the elderly and the disabled were partially similar; both felt most inconvenient at enter-exit sections, steep walkway and bad paved walkway. Unlike those results, people with children and/or infants answered that overpass or underpass walkways without lifting facilities were most inconvenient walking environments.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.415-422
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• 1994

Recent new town construction project proouced large numbers of apartment houses using precast concrete (P. C.) panels. l'bst construction companies involved in this project put their management focus on to the individual control of P.C. panel producing plants and the job sites. Little attention was paid to the integrated management of the production. transportation. and im;tallation of P. C. panels. Numerous job site delays experienced in the new town project were largely based on the poor coordination between these three key disciplines of the P. C. apartment construction. This stlldy was initiated with an .intention to improve coordination between these disciplines. Activities of these disciplines were identified and related data were gathered. This was performed through the interv:iews with the personnel involved in P. C. constructlon and through the analy::;is of the related documents and publications. Based on this information. the authors are nolol developing a model IoIhich will provide a foundation for opt:iJnal.ly coorc.inated control of the proouction. transportation, and installation of P. C. panels for apartment construction. In this paper. the authors briefly present intermediate results of this study.

• Journal of the Korean housing association
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• v.3 no.2
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• pp.89-99
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• 1992

We discussed the change of housing environmental problems from the early 1900s to the present in Study(I). This study(II) which secendly research of study(I) analyzed the fixing precess of a lavatory centering around a excretion which was a serious housing environmental problem in 1920 to 1940. The documentary research method was used for this study. Articles of content analysis(N=185) were published in 1920 to 1990 which were The Deng-A daily news article about a excretion and a lavatory. The main content of this study was examined the change, such as the number of whole article, the column number of article by time series. and the content of article by subject. 1. The number of whole article by time series was collected mainly in1920s-1930s. In 1940s-1960s, one-two column of article was appeared generally and three-four, five column of article was appeared in 1970-1980. 2. Contents of article was divided into two classes, excretion and lavatory. Contents of excretion was 1) a use of fertilizer 2) the method of transportation 3) a cost of gathering 4) a place of disposal 5) the problem of cleaning. Contents of lavatory was 1) a public lavatory 2) a flush toilet 3) a sanitary conditions 3. 1) A use of fertilizer was concentrated in 1920s-1930s, and problems of it was solved more or less by change of management method. Transportation of excretion developed such as \ulcornerGue\ulcorner->a coach of tank style->underground transportation->a dung car of absorption style. Disposal place of excretion was a cause of dissatisfaction in 1920s and it is serious problem Today. A duty of excretion gathering was transfered to a private worker in 1978. The accunulation problem of excretion was continued until 1940s-1950s. The management law of waste matters was proclaimed in 1986. 2) A public lavatory was planned in 1924 for the first time, and it is insufficient in these days, A settlement of public lavatory in building which has upward of 20pyung became obligation in 1973. The problem of water contamination which by poor septic tank was happened in 1970s-1980s.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.3
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• pp.1-17
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• 2022

Accurate analysis of the causes of metro rail traffic congestion provides a means of addressing issues arising from metro rail traffic congestion in metropolitan areas. Currently, congestion analysis based on counting, weight detection, CCTVs, and mobile Wi-Fi is limited by poor accuracies or because studies have been restricted to single routes and trains. In this study, a train congestion analysis model was used that includes the transfer and multi-path behavior of metro passengers and train operation plans for metropolitan urban railroads. Analysis accuracy was improved by considering traffic patterns in which passengers must wait for next trains due to overcrowding. The model updates train crowding levels every 10 minutes, provides information to potential passengers, and thus, is expected to increase the social benefits provided by the Seoul metropolitan subway

• Korean Journal of Materials Research
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• v.32 no.3
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• pp.132-138
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• 2022

Zintl phase Mg₃Sb₂ is a promising thermoelectric material in medium to high temperature range due to its low band gap energy and characteristic electron-crystal phonon-glass behavior. P-type Mg₃Sb₂ has conventionally exhibited lower thermoelectric properties compared to its n-type counterparts, which have poor electrical conductivity. To address these problems, a small amount of Sn doping was considered in this alloy system. P-type Mg₃Sb₂ was synthesized by controlled melting, pulverizing, and subsequent vacuum hot pressing (VHP) method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate phases and microstructure development during the process. Single phase Mg₃Sb₂ was successfully formed when 16 at.% of Mg was excessively added to the system. Nominal compositions of Mg_3.8Sb_2-xSn_x (0 ≤ x ≤ 0.008) were considered in this study. Thermoelectric properties were evaluated in terms of Seebeck coefficient, electrical conductivity, and thermal conductivity. A peak ZT value ≈ 0.32 was found for the specimen Mg_3.8Sb_1.994Sn_0.006 at 873 K, showing an improved ZT value compared to intrinsic one. Transport properties were also evaluated and discussed.

• Journal of the Korea Society for Simulation
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• v.24 no.1
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• pp.35-43
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• 2015

This research proposed a new method to evaluate the objective validity to launch smart transportation services that various stakeholders are complicatedly inter-connected. First of all, we have designed the fundamental business model to form the smart transportation services and defined the stakeholders taking part in the services. Also, the criteria to evaluate the economical validity has been proposed based on the relationship among stakeholders. Especially, in the case EV drivers and charging service providers, the economical validity depends on the scale of spreading. Therefore, we have compared the two extreme scenarios, the poor and stable level of EV spreading. According to the result, it may be said that EV drivers and charging service providers cannot be guaranteed the economical validity due to the burden of initial investment. On the contrary to this, suppliers of EV and charging gears may secure more than a certain level of profit. In addition, the government may have great profit due to reducing the CO2 emission and cost for importing energy sources. Therefore, it is needed to enhance the level of supporting EV drivers and charging service providers at the first stage. Also, the impact of the ratio of EV and charging service stations on the economical validity of smart transportation should be further investigated.