• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.35-43
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• 2011

Cognitive Radio (CR) ad hoc network is highly considered as one of promising future ad hoc networks, which enables opportunistic access to under-utilized licensed spectrum. Similarly to other CR networks, the spectrum sensing is a prerequisite in CR ad hoc network. Collaborative spectrum sensing can help increasing sensing performance. For such an infrastructureless network, however the coordination for the sensing collaboration is really complicated due to the lack of a central controller. In this paper, we propose a novel collaborative spectrum sensing scheme in which the final decision is made by the node with the highest data reliability based on a sequential Dempster Shafer theory. The collaboration of sensing data is also executed by the proposed contention-aware reporting mechanism which utilizes the sensing data reliability order for broadcasting spectrum sensing result. The proposed method reduces the collecting time and the overhead of the control channel due to the efficiency of the ordered sequential combination while keeping the same sensing performance in comparison with the conventional cooperative centralized spectrum sensing scheme.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.254-266
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• 2011

Wired and mobile Internet has led to increase in online broadcasting content market size. In particular, the fast-growing smart devices like smart phone and tablet PC in mobile Internet market has accelerated the growth of online broadcasting content service market. Meanwhile, the illegal distribution of online broadcasting content has been widespread in this market. There are also significant transaction costs, search costs, contracting and coordination costs in online broadcasting content market. MCP(Master content provider) which is a content distributor has been playing a critical role in preventing illegal content distribution, reducing costs and removing inefficiencies of online broadcasting content market. Thus, the purpose of this study is to investigate the competency of MCP to streamline the online broadcasting contents market from the resource- based view. And this study conducted a case study to explain the status of online broadcasting content market and define what kinds of problems and issues are there in the market in a systematic way. The case study also showed how MCP competency plays an important role in reducing administrative and transaction costs and in solving illegal content distribution and other inefficiencies of the online broadcasting contents market.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.305-312
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• 2012

This study was conducted to elucidate the seasonal prevalence of adult mosquitoes and occurrence of anopheline larvae in Gimpo, Gyeonggi province, Republic of Korea. Sampling of adult mosquitoes was carried out 18 times from May to September in 2008, using light traps at six sites. A total of 48,919 individuals belonging to 16 species and 8 genera were collected. Aedes vexans nipponii (43%) was the most frequently collected, followed by Anopheles sinensis (34%) and Culex tritaeniorhynchus (14%). The seasonal prevalence of anopheline mosquitoes had a different occurrence compared to that of Cx. tritaeniorhynchus. Anopheline larvae were collected using a standard dipper (size = of 350 ml) at eight habitat types of 203 point locations. Anopheline larvae were confirmed from 138 points (63%). The average larval population per dipper was highest in the lotus plantation (6.9 individuals), followed by irrigation channel (4.5 ind.), dropwort field (3.4 ind.), fallow field (3.1 ind.), paddy field (1.8 ind.), swamp (1.4 ind.), and stream (0.2 ind.). There was no significant relationship observed between larval density and DO, pH, salinity, or distance from blood meal hosts (cowshed, pigsty, chicken-house). In the results of average nearest neighbor analysis (ANNA), the distribution of whole points for mosquito larval collection was clustered, and points with over 4.0 larvae per dipper were randomly distributed. Within the study area Haseong-myeon, those points where over 3.0 larvae were collected were of a dispersed distribution.

• Journal of the Korean Society of Fashion and Beauty
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• v.3 no.2 s.2
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• pp.55-64
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• 2005

The purpose of this study is to investigate consumers' knowledge and preference towards functional cosmetics. Through the beauty advisors' surveys, their own selling styles and consumer behaviors recognized by beauty advisors were analyzed. It was intended to help extend and strengthen the functional cosmetic market which has continued to grow rapidly since the approved goods under cosmetic law in 2001. For this study, the data was collected through questionnaires the professional consumer counselors confirmed from Korean women over the age. of twenty old living in the Seoul and Kyoungki areas. After pre-research was implemented on 45 women, 328 samples were analyzed as final samples. In addition,46 samples, which were collected through the questionnaires from beauty advisors were analyzed. Samples were analyzed by frequency, percentage, T-test, ANOVA using the SPSS program. The results of study were as follows: First consumers recognized whether functional cosmetics or not. According to the beauty advisor's surveys, consumers regard the functional cosmetic boundary as being wider than real functional cosmetic boundary according to cosmetic law. So, there is a gap between consumers' opinions and real law. Second, regarding the purchasing channels, the largest channel is the cosmetic store. As far as consumers are concerned the most important factor when buying cosmetics, is the suitability of their own skin types. The second factor is product quality and the third factor is price. Functional cosmetics non-experienced group are more concerned with price compared to experienced group. Related to purchasing products, functional cosmetics experienced group buy set products compared to non-experienced group buy one product. Third, the ultraviolet filter cosmetics portion is the largest in the functional cosmetics market the second largest portion is bleaching cosmetics and the third largest portion is the anti-senility cosmetics. However, Most preferred by consumers is the anti-senility cosmetics. Moreover, preference for ultraviolet filter cosmetics is the least. Finally, the level of satisfaction for functional cosmetics is high and dissatisfaction is low. Consumers feel that beauty advisors are simply pushing high priced products without recognizing the consumers' real needs. In conclusion, to develop the functional cosmetic market continually in the future, it needs to extend various products and advertise them until consumers are more aware.

• Journal of Distribution Science
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• v.10 no.2
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• pp.29-41
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• 2012

This paper undertakes a conceptual review of transaction cost to broaden the understanding of the transaction cost analysis (TCA) approach. More than 40 years have passed since Coase's fundamental insight that transaction, coordination, and contracting costs must be considered explicitly in explaining the extent of vertical integration. Coase (1937) forced economists to identify previously neglected constraints on the trading process to foster efficient intrafirm, rather than interfirm, transactions. The transaction cost approach to economic organization study regards transactions as the basic units of analysis and holds that understanding transaction cost economy is central to organizational study. The approach applies to determining efficient boundaries, as between firms and markets, and to internal transaction organization, including employment relations design. TCA, developed principally by Oliver Williamson (1975,1979,1981a) blends institutional economics, organizational theory, and contract law. Further progress in transaction costs research awaits the identification of critical dimensions in which transaction costs differ and an examination of the economizing properties of alternative institutional modes for organizing transactions. The crucial investment distinction is: To what degree are transaction-specific (non-marketable) expenses incurred? Unspecialized items pose few hazards, since buyers can turn toalternative sources, and suppliers can sell output intended for one order to other buyers. Non-marketability problems arise when specific parties' identities have important cost-bearing consequences. Transactions of this kind are labeled idiosyncratic. The summarized results of the review are as follows. First, firms' distribution decisions often prompt examination of the make-or-buy question: Should a marketing activity be performed within the organization by company employees or contracted to an external agent? Second, manufacturers introducing an industrial product to a foreign market face a difficult decision. Should the product be marketed primarily by captive agents (the company sales force and distribution division) or independent intermediaries (outside sales agents and distribution)? Third, the authors develop a theoretical extension to the basic transaction cost model by combining insights from various theories with the TCA approach. Fourth, other such extensions are likely required for the general model to be applied to different channel situations. It is naive to assume the basic model appliesacross markedly different channel contexts without modifications and extensions. Although this study contributes to scholastic research, it is limited by several factors. First, the theoretical perspective of TCA has attracted considerable recent interest in the area of marketing channels. The analysis aims to match the properties of efficient governance structures with the attributes of the transaction. Second, empirical evidence about TCA's basic propositions is sketchy. Apart from Anderson's (1985) study of the vertical integration of the selling function and John's (1984) study of opportunism by franchised dealers, virtually no marketing studies involving the constructs implicated in the analysis have been reported. We hope, therefore, that further research will clarify distinctions between the different aspects of specific assets. Another important line of future research is the integration of efficiency-oriented TCA with organizational approaches that emphasize specific assets' conceptual definition and industry structure. Finally, research of transaction costs, uncertainty, opportunism, and switching costs is critical to future study.