• Journal of Korea Foundry Society
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• v.41 no.3
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• pp.252-259
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• 2021

The magnesium is one of the important alloying elements in the conventional aluminum alloys. The addition of magnesium to aluminum is well known to increase the mechanical strength of the aluminum without the trade-off of the decreased elongation. However, the content of magnesium in aluminum alloys has been limited to be lower than about 5wt.% because of the high oxidation tendency of magnesium element during the manufacturing processes such as casting, hot-forming and post heat-treatments, which can deteriorate the quality and properties of the final products. In this study, new 'ECO-Almag6~9' (containing 6~9wt%Mg) alloys were investigated to be made of the ECO-Mg master alloy, which has been invented to reduce the oxidation tendency of itself. It was successfully demonstrated that ECO-Almag6~9 alloys can be fabricated through the mass-production facilities of DC casting and extrusion routes without the problems of magnesium oxidation. In addition, it was confirmed that the strength and ductility were simultaneously improved due to the addition of high magnesium contents.

• International Area Studies Review
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• v.16 no.1
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• pp.53-74
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• 2012

The bundling of multiple products/services at a set price has become a popular marketing strategy. However, little is known on how effects of bundling strategy influence tourists' evaluation of tour packages. Tourists evaluate a tour package based on the trade-off between the perceived benefits and costs involved in purchasing the tour package. In other words, the perceived value of the tour package influenced whether tourists to purchase a tour package or not. This study tested a tour package based on the theory of bundling, taking a moderating approach with perceived value. The data for this study wascollected by subjects who live Seoul Metropolitan Area and Gyeonggi Province and 4234 respondents, potential tourists to northeastern U.S.A/Canada. Results show that bundling taken by travel agencies include how many product items to put in a tour package and what degree of discount for the tour package. Also explaining functional relationship among product items in the tour package. Result show that tourists expect a discount, large or small, from purchasing a tour package. And the larger the number of products in a tour packages, the larger the discount size, and low functional relationship among items tourists expect to get.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.239-246
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• 2021

Unification means the change of the economic system from 'Planned Economy' of the North Korea to 'Market Economy' of the South Korea. Therefore, it may cause confusions and difficulties for North Koreans who have been under planned economy for ages. So, we need to take the perspective of behavioral economics for the effective education. First of all, it is about overall finance, which contains the record of financial transactions, effect of inflation, investors' bounded rationality, and choice difficulty of financial products. Second, it is about borrowings, which includes the credit management, interest rate of difference among financial institutions. Third, it is about investment on financial products, which includes the effect of cost on returns, difference between compound interest and simple interest, trade-off between expected return and risk, market and non-market risks, the importance of diversification, and passive & aggressive investments.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.129-142
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• 2022

Nutrition dictates nearly all biological processes and determines Darwinian fitness in all living organisms, including insects. Research on insect nutrition has a long history in the field of insect physiology and the importance of understanding insect nutrition has become increasingly apparent with the growing need for producing insects as food and feed. Nevertheless, it is only in recent years that we have witnessed a major breakthrough in our knowledge of insect nutrition. The multivariate, interactive, and dynamic nature of nutrition has long hampered our complete understanding of insect nutrition. However, the challenge posed by such nutritional complexity has been overcome with the advent of the Nutritional Geometry, which is an integrative and multidimensional framework that enabled us to model complex interactions between multiple nutrients. In this review, we introduce the basic concepts and principles of the Nutritional Geometry and describe how this innovative framework has revolutionized the field of insect nutrition and has placed nutrition in the centre of the interface between physiology, ecology, and evolution. We close this review by discussing potentially fertile research areas that can benefit tremendously from the application of this powerful nutritional paradigm in the future.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.134-153
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• 2022

Regardless of a trade-off relationship between energy density and safety, it is essential to improve both properties for future lithium secondary batteries. Especially, to improve the energy density of batteries further, not only thickness but also weight of separators including ceramic coating layers should be reduced continuously apart from the development of high-capacity electrode active materials. For this purpose, an attempt to replace conventional slurry coating methods with a deposition one has attracted much attention for securing comparable thermal stability while minimizing the thickness and weight of ceramic coating layer in the separator. This review introduces state-of-the-art technology on ceramic-coated separators (CCSs) manufactured by the deposition method. There are three representative processes to form a ceramic coating layer as follows: chemical vapor deposition (CVD), atomic layer deposition (ALD), and physical vapor deposition (PVD). Herein, we summarized the principle and advantages/disadvantages of each deposition method. Furthermore, each CCS was analyzed and compared in terms of its mechanical and thermal properties, air permeability, ionic conductivity, and electrochemical performance.

• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.39-47
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• 2009

Recently, the threat of DDoS attacks is increasing and many companies are planned to deploy the DDoS defense solutions in their networks. The DDoS attack usually transmits heavy traffic data to networks or servers and they cannot handle the normal service requests because of running out of resources. Since it is very hard to prevent the DDoS attack beforehand, the strategic plan is very important. In this work, we have conducted modeling and simulation of the DDoS attack by changing the number of servers and estimated the duration that services are available. In this work, the modeling and simulation is conducted using OPNET Modeler. The simulation result can be used as a parameter of trade-off analysis of DDoS defense cost and the service's value. In addition, we have presented a way of estimating the cost effectiveness in deployment of the DDoS defense system.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.73-80
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• 2010

A wireless sensor network which is deployed in hostile environment can be easily compromised by attackers. The selective forwarding attack can jam the packet or drop a sensitive packet such as the movement of the enemy on data flow path through the compromised node. Xiao, Yu and Gao proposed the checkpoint-based multi-hop acknowledgement scheme(CHEMAS). In CHEMAS, each path node enable to be the checkpoint node according to the pre-defined probability and then can detect the area where the selective forwarding attacks is generated through the checkpoint nodes. In this scheme, the number of hops is very important because this parameter may trade off between energy conservation and detection capacity. In this paper, we used the fuzzy rule system to determine adaptive threshold value which is the number of hops for the ACK packets. In every period, the base station determines threshold value while using fuzzy logic. The energy level, the number of compromised node, and the distance to each node from base station are used to determine threshold value in fuzzy logic.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.711-717
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• 2009

This study develops model for analysis of relationship between major node (Interchange in expressway) and land price formation of apartments along with Seoul Belt Expressway by using CHAID analysis. The results show that first, regions(outer side: Gyeongido, inner side: Seoul) on the line of Seoul Belt Expressway are different and a graph generally show llinear relationships between land price and traffic node but it does not; second, CHAID analysis shows two different spatial distribution at the point of 2.6km in the outer side, but three different spatial distribution at the point of 1.4km and 3.8km in the inner side. In other words, traffic access does not necessarily guarantee high housing price since the graphs shows land price related to composite spatial distribution. This implies that residential environments (highway noise and regional discontinuity) and traffic accessibility cause mutual interaction to generate this phenomenon. Therefore, the highway IC landprice model will be beneficial for calculation of land price in New Town which constantly is being built along the highway.

• The Korean Journal of Franchise Management
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• v.9 no.4
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• pp.21-31
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• 2018

Purpose - Recently, the franchise business has made remarkable progress, but many conflicts have occurred. From this perspective, this paper explains how to improve the long - term relationship between franchisor and franchisee by integrating the relationship between franchisor of franchise business and franchisee. This study aims to identify the franchisee's economic and social satisfaction and to examine their influences on calculative and affective commitment, and loyalty. At the end of this paper, theoretical and managerial implication were suggested. Research design, data, and methodology - The data were collected from owners and store managers in franchisees located in Seoul, Korea. The trained researchers contacted owners and managers of the franchise stores. The questionaires were distributed to owners and managers consented to respond. The collected questionnaires were used for the final analysis of 324 copies(243 store owners and 81 store managers), except for 26 copies of the untrustworthy response out of 350 copies. The data were analyzed with SPSS, 21.0 and SmartPls 3.0 Result - The results of the study are as follows. First, economic satisfaction effects both calculative and affective commitment, but social satisfaction does not. Second, both calculative and affective commitment have positive effects on loyalty. Third, economic satisfaction has a positive impact on loyalty, but social satisfaction does not. Conclusions - The implications of this study are following as: From the theoretical perspective, this study analyze the satisfaction and commitment of the franchisee from the multidimensional perspective by analyzing the effects of the franchisee on two dimensions of economic and social satisfaction and on calculative and affective commitment. That is, this study explains the trade-off between economica and social satisfaction, and between calculative and affective commitment. From the managerial perspective, the results of this study suggest that the economic satisfaction of the franchise headquarters felt by franchisees should be prioritized over social satisfaction. Especially at the early stage of the contract, economic satisfaction should be given priority over social satisfaction. However, since affective and calculative commitment have a significant effect on loyalty, social satisfaction factors should not be excluded by focusing on only economic ones. In other words, the franchisors should not only think of franchisees as a source of sales and profits, but should respect franchisees and maintain loyal relationships with friends.

• Asia Marketing Journal
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• v.15 no.1
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• pp.83-105
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• 2013

During recent decades, the number of mixed attribute products (henceforth mixed products), which have both utilitarian and hedonic benefits, has increased dramatically. Despite these products' growing popularity, academic research has paid little attention to them, and there remains a gap between theory and the real world. Hence, our study was undertaken to understand consumers' perceptions about and behaviors toward mixed products, as well as factors affecting the evaluation and choice of these products. We divided mixed attribute products into two categories: mixed utilitarian products (utilitarian products adding hedonic attributes) and mixed hedonic products (hedonic products adding utilitarian attributes). We then showed how adding different attributes affects consumers' perception, willingness to pay (WTP), and the choice of mixed attribute products compared to pure utilitarian or pure hedonic products. We conducted an experiment using a within-subject design. A total of 160 office workers and college students participated in the study. The pure utilitarian product used in the study was orange juice, and the mixed utilitarian product was carbonated orange juice. The pure hedonic product was chocolate, and the mixed hedonic product was polyphenol enriched chocolate. Results showed that consumers perceived a mixed utilitarian product to be less utilitarian, less pleasurable and more guilty than a pure utilitarian product. On the other hand, a mixed hedonic product was perceived to be more utilitarian, less pleasurable and less guilty than a pure hedonic product. Also, WTP for a mixed hedonic product was higher than WTP for a pure hedonic product, but WTP was lower for a mixed utilitarian product than for a pure utilitarian product. Furthermore, mixed hedonic products were likely to be evaluated more favorably when they were presented together with pure hedonic products, more so than when they were presented alone. Finally, when compared to low self-control participants, high self-control participants chose mixed hedonic products more frequently. The present study contributes to the existing literature on utilitarian and hedonic consumption by adding to the sparse literature on the consumption of products that have both utilitarian and hedonic purposes. Also, our research findings provide several useful implications for practitioners in related fields. First, the current study provides marketers with a useful guide for understanding consumers' perceptions of these types of products, and helps to predict how adding different attributes influences these products. Second, this study has examined the conditions that may moderate the evaluation and choice of hedonic base products and this finding will serve as a good reference for marketers of mixed hedonic products in marketing communication strategy, in-store marketing and targeting. Specifically, comparative advertising with a pure hedonic product will be beneficial for a mixed hedonic product. Also, displaying mixed hedonic products near pure hedonic products may enhance the effectiveness of in-store marketing of mixed hedonic products.