• Advances in Energy Research
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• v.4 no.1
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• pp.87-106
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• 2016

In this research, optimum design of the combined solar collector, geothermal heat pump and thermal seasonal storage system for heating and cooling a sample greenhouse is studied. In order to optimize the system from technical point of view some new control strategies and functions resulting from important TRNSYS output diagrams are presented. Temperatures of ground, rock bed storage, outlet ground heat exchanger fluid and entering fluid to the evaporator specify our strategies. Optimal heat storage is done with maximum efficiency and minimum loss. Mean seasonal heating and cooling COPs of 4.92 and 7.14 are achieved in series mode as there is no need to start the heat pump sometimes. Furthermore, optimal parallel operation of the storage and the heat pump is studied by applying the same control strategies. Although the aforementioned system has higher mean seasonal heating and cooling COPs (4.96 and 7.18 respectively) and lower initial cost, it requires higher amounts of auxiliary energy either. Soil temperature around ground heat exchanger will also increase up to $1.5^{\circ}C$ after 2 years of operation as a result of seasonal storage. At the end, the optimum combined system is chosen by trade-off between technical and economic issues.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.10
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• pp.695-702
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• 2007

In this paper, the ventilation efficiencies of an underground sewage disposal plant were investigated for ventilating system without fan, ventilating system with eleven cross flow fans and ventilating system with sixteen cross flow fans by numerical method. It has been found that the air change effectiveness of the system without fan was predicted 0.44. It means that an additional ventilating equipment is needed to maintain good indoor air quality. For the ventilating system with sixteen cross flow fans, the air change effectiveness was predicted 0.55. The air change effectiveness of the ventilating system with eleven cross flow fans was predicted 0.51. It is known that the air change effectiveness above 0.5 is enough to eliminate pollutant and bad smell in the indoor. Therefore, it is recommended to select the ventilating system with eleven cross flow fans for the underground sewage disposal plant in an economic point of view.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1051-1060
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• 2008

The use of the coal ash for surcharge material, in a view of the environmental aspect, can decrease amount of the reclamation through recycling waste materials as well as prevent a destruction of the ecosystem attributed to sand picking. In addition, it can reduce both unit cost of material and construction expenses. In this study, new construction material as alternative surcharge material using coal ash, which is by-product from thermoelectric power plant, were developed. Mixing ratios of fly ash and bottom ash derived from the coal ash in Samchunpo thermoelectric power plants were determined. Furthermore, mixing conditions depending on the ratios of the cement and gypsum used for chemical additive were determined too. Uniaxial compression strength tests were conducted at different mixing conditions and Design graph of optimum mixing ratio at each required strength for economic efficiency is indicated in this paper.

• Journal of the Korean housing association
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• v.26 no.6
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• pp.61-69
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• 2015

Current criticism regarding the "uniformity" of Korean apartments has shown not only tendencies of emotional and unscholarly criticism, but also lack of academic discourse. They tend to stay at the common-sense level and be quite subjective without supporting facts. This research began with questioning the phenomenon of seeing Korean apartments as an object of negative criticism. The research questions for this study are: 1. Of the living space of so-called apartment houses, what elements should be called uniform?; 2. How should the implications of the findings be interpreted? In this context, this study aims to reinterpret criticisms on the uniformity of apartments from a new point of view. First, literature review is done to examine characteristics of Korean apartments in the social-cultural, economic, and physical contexts. Next, existing non-academic, abstract criticisms are classified into three trends, to show that the way of understanding architectural spaces by those criticisms are limited and weighted towards visual perceptions focused only on the shape of architectural structures. Finally, it is argued that the viewpoints of space and residents' experience should be treated as important for the reinterpretation of criticisms on the uniformity. This is validated through presenting relevant cases such as changes of space uses, diversified lifestyles being accepted, and the expansion of living space.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.77
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• pp.285-304
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• 2018

With the development of market economy, it has been a legislative trend to establish a system for vicarious liability of employers. China also established Tort Liability Law of People's Republic of China in 2009 and ruled responsibility of the employers for the acts for their employees through Art. 35. First, the employer's right to indemnity to an employee should be recognized, because employer's superintendence is much weak and economic power is similar between them. Second, an employer should take a responsibility for an unpaid employee as vicarious liability, because the Law did not exclude them from employees. Lastly, in case the Law conflicts with Interpretation of the Supreme People's Court on Certain Issues Concerning the Application of Law in Trying Cases Involving Compensation for Personal Damage, the Law should be regarded it has priority based on several related Principles. Regarding these matters, this study guides you to an analysis of vicarious liability of employers in China, benefits with a view to the perfection of the vicarious liability regime.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.139-142
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• 2000

Excessive inventories result from poor scheduling, planning, and controls, and the converse is also same. With adequate inventories, supplies can transport products to customers in time without excessive delivering cost. So efficient inventory control is vital for successful logistics management operation. In terms of mass discount retailers such as Wal-Mart, Carrefour, E-Mart, and so on, they require the high-quality services such as a small-amount and a high-frequency delivery because of having small warehouse and wanting possess much more various goods. In the opposite, manufactures ask mass discount retailer to delivery more lots of goods because of reducing the number of deliveries. It goes without saying that both wish to prevent stockout(lack of inventories). Usually, mass discount retailers have the power more than manufactures. This paper proposed how to manage inventory and how many to order in view of the TPLC and supplier. We considered the economic order quantity models for multiple items so as to prevent urgent deliveries as possible as. And the tradeoff stockout costs and delivering costs.

• International Journal of Costume and Fashion
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• v.13 no.2
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• pp.15-29
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• 2013

Today's technology enables consumers to trade millions of dollars, conduct online banking, access entertainment, and do countless other activities at the click of a button. Online social networks (OSN) have become a cultural phenomenon that allows for individualistic consumerism. Consumers are increasingly utilizing OSN to share ideas, build communities, and contact fellow consumers who are similar to themselves. The relevance of online communities to the music is immense especially because musicians are now using social media to build global audiences. Not only is information about music and performance disseminated online, but musical commodities are sold and traded online. Online music communities allow consumers to elect and create new identities online through the purchase of subcultural commodities. Given the growing economic importance of online music communities it is important to get a holistic view of subcultural communities online. This study utilized content analysis of online music community websites using the Netnography methodology as developed by Kozinet for data collection to analyze consumers' purchasing and consumption behavior of subcultural commodities online as related to the formation of subcultural identities. Findings showed that subcultural items are predominantly purchased online, especially digital music, and there is a need for more custom craft items. The authors presented a new conceptual taxonomy of online subcultural consumer classifications based on online behavior patterns.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2189-2195
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• 1992

The performance of heat exchanger as an energy conversion device can be described by the available energy output and efficiency. The efficiency is defined as the ratio of the available energy output and the exergy of the heat source flow. In present study, a counterflow heat exchanger is analyzed and the conditions to obtain maximum output is numerically determined. As a result, the avilable energy obtained by the cold flow can be determined as functions of the heat capacity flow, the cold flow inlet temperature and the heat transfer capacity of heat exchanger. At the maximum output condition the heat capacity flow of the cold fluid is larger than that of the heat source, and the heat capacity flow ratio is equal to the ratio of the cold flow inlet temperature and the atmospheric temperature. And the avilable energy output increases as the heat transfer capacity of the heat exchanger become larger, but in the economic point of view there is also an optimum heat transfer capacity for a given heat source flow.

• Asia pacific journal of information systems
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• v.20 no.3
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• pp.33-49
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• 2010

We empirically examine the impact of online auction knowledge and category-specific knowledge on the final price of online auctions. Specifically, we question how the relationship between buying and selling experiences affects the final prices of online auctions. Related to the trust between buyers and sellers, we examine the multiple interactions between a buyer-seller pairand aim to identify how these repeated transactions influence the final price. To contrast these effects with other product related factors, we focus on so called 'common value' auctions of vintage stamps on eBay, in which the ex-post value of the product is the same among participating agents’ perceived value. Online auction of stamps provides a representative setting to examine the relationship between market experience and the auction participation behavior in the common value auction, as it provides the book value of stamp as well as price variation across individual buyers with different expertise levels. Our analysis of over 3000 stamps auctions on eBay indicates a significantly high frequency of buyer-seller (pair) interactions, thus suggesting a 'relationship view' of auctions. The work validates five hypotheses derived from the existing theory in economics, marketing, and information systems. Through the common-value auction data, we find that seller's online auction experience and category-specific experience favor sellers by increasing the final price. However, buyer's online auction experience does not affect the final price, but buyer's category-specific experience favors buyers by decreasing the final price. We find that the trust between two trading parties increases the final price.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.3
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• pp.387-394
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• 2009

It has been observed that coated steel structures are rapidly deteriorated than designed lifetime due to acid rain caused by air pollution etc.. Therefore improvement of corrosion resistance of anti-corrosive paint is very important in terms of safety and economic point of view. In this study corrosion resistance for five kinds of anti-corrosive paints including acryl, fluorine and epoxy resin series were investigated with electrochemical methods such as corrosion potential, polarization curves, impedance and cyclic voltammogram measurements etc.. There were somewhat good relationships between values measured by electrochemical methods such as corrosion current density obtained by cathodic and anodic polarization curves, value of impedance estimated with AC impedance, and polarization resistance on the cyclic voltammogram, for example, corrosion current density was decreased with increasing of values of impedance and polarization resistance on the cyclic voltammogram. However their relationships between corrosion current density and corrosion potential were not well coincided each other. Consequently it is considered that although a corrosion potential of F101 of fuoric resin series shifted to negative direction than other anti-corrosive paints, its corrosion resistance, indicating on the cathodic and anodic polarization curves, AC impedance curves and cyclic voltammogram, was the most superior to other paints, whereas A100 containing arcylic resin showed a relatively poor corrosion resistance compared to other paints.