• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9A
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• pp.856-867
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• 2006

This paper proposes a new algorithm for opportunistic scheduling that take advantage of both multiuser diversity and power control. Motivated by the multicast RTS and priority-based CTS mechanism of OSMA protocol, we propose an opportunistic packet scheduling with power control scheme based on IEEE 802.11 MAC protocol. The scheduling scheme chooses the best candidate receiver for transmission by considering the SINR at the nodes. This mechanism ensures that the transmission would be successful. The power control algorithm on the other hand, helps reduce interference between links and could maximize spatial reuse of the bandwidth. We then formulate a convex optimization problem for minimizing power consumption and maximizing net utility of the system. We showed that if a transmission power vector satisfying the maximum transmission power and SINR constraints of all nodes exist, then there exists an optimal solution that minimizes overall transmission power and maximizes utility of the system.

• Journal of Distribution Science
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• v.11 no.11
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• pp.49-55
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• 2013

Purpose - This study examined the effects of susceptibility to global consumer culture (SGCC) on the brand attitude of consumers of the global SPA brand in South Korea. Research Design, Data, and Methodology -Questionnaires were used, and the sample that was extracted by the convenience sampling method comprised 703 males and females, aged 20-36. The data were analyzed with SPSS 16.0 and Amos 5.0 for frequency analysis, exploratory factor analysis, confirmatory factor analysis, reliability analysis, correlation analysis, and structural equation modeling analysis. Results - First, conformity to consumption trends was found to have a significant effect on all four variables of SPA brand attitude (brand favorability, uniqueness, ethicality, and economic utility). Second, quality perception was found to have a significant effect on brand favorability, uniqueness, ethicality, and economic utility. Third, social prestige was found to have a positive effect on uniqueness. Conclusions - The results show that consumers' susceptibility to global culture is a significant factor in their attitude to the global SPA brand. Therefore, it would be more effective if the global SPA brand develops recognition among consumers that its products play a role in sharing new trends and global lifestyles.

• Journal of Communications and Networks
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• v.18 no.5
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• pp.784-795
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• 2016

In this paper, we investigate the resource allocation problem in time-varying heterogeneous wireless networks (HetNet) with multi-homing user equipments (UE). The stochastic optimization model is employed to maximize the network utility, which is defined as the difference between the HetNet's throughput and the total energy consumption cost. In harmony with the hierarchical architecture of HetNet, the problem of stochastic optimization of resource allocation is decomposed into two subproblems by the Lyapunov optimization theory, associated with the flow control in transport layer and the power allocation in physical (PHY) layer, respectively. For avoiding the signaling overhead, outdated dynamic information, and scalability issues, the distributed resource allocation method is developed for solving the two subproblems based on the primal-dual decomposition theory. After that, the adaptive resource allocation algorithm is developed to accommodate the timevarying wireless network only according to the current network state information, i.e. the queue state information (QSI) at radio access networks (RAN) and the channel state information (CSI) of RANs-UE links. The tradeoff between network utility and delay is derived, where the increase of delay is approximately linear in V and the increase of network utility is at the speed of 1/V with a control parameter V. Extensive simulations are presented to show the effectiveness of our proposed scheme.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.156-162
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• 2004

In this paper, a technique that estimate the optimal capacity of the solar-wind hybrid power system for minimizing the total monthly electric power expenses is presented. The hybrid power system is assumed to be operated in connection with the utility power system and electric bill be paid for the power not covered by the hybrid system generation. Monthly generation cost is estimated based on total life-cycle cost analysis. The monthly utility power bill is assumed to be increased quadratically in proportion with the net utility power consumption which is the difference between the total monthly load minus the hybrid system generations. Test results demonstrate applications potential of the proposed technique.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.109-121
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• 2009

In these OECD countries, left-wingers Government focus on unemployment, but right -wingers Government cares more about inflation. It is that inflation and unemployment don't have differential effects across rich and poor and the happiness levels of these two groups are unaffected by identity of the Government in power. The poor people choose to left-wingers Government, but rich people prefer to right -wingers Government. I estimate whether above opinion is correct or not. Especially I check how my results change when I control for aggregate economy activity and government consumption, two variables that could be correlated with inflation and unemployment and affect each Government's happiness differentially. This paper, and I believe much of the happiness literature, can be understood as an application of experienced utility, a conception that emphasis the pleasures derived from private consumption and sentiment of it. In Granger Causality test, private consumption sentiment index related with industrial production interactively in Korea. The business cycles affect on private consumption sentiment index.

• Journal of Families and Better Life
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• v.28 no.5
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• pp.209-223
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• 2010

This research how self-esteem and consumption behavior for adolescent consumers are differentiated different psychological home environment and how the psychological home environment during adolescence self-esteem and consumption behavior. The result of the research as follows. First, when the psychological home environment categorized in 4 subgroups, accomplishment-non-accomplishment zone had average 3 points sense of non-accomplishment. Setting the aspiration level and striving to achieve such level were reviewed to be low. In autonomous-heteronomous, it is thought that with more allowance more responsible for actions and autonomous actions such as respecting personal opinions. Secondly, all 5 sub-groups of the self-esteem level for adolescent consumers showed average of approximately 3 points, a normal standard self-esteem When the overall school score is high self-esteem was also given high points. It can be thought that the school scores provide positive or negative effect on pride, future and surrounding situations. When psychological home environment was deemed positive in the relationship between psychological home environment and self-esteem, evaluation and the faith how other people recognize one were also thought positively. Thirdly, 4 subgroups of the consuming behavior for adolescent consumers had under 3 points for trend pursuit, showing a less severe trend pursuit by adolescents then expected. Consumer behavior for different psychological home environment and self-esteem showed that consumers selected a utility, while trendy and unique consumer behavior was found with middle level of open-closeness when a sense of accomplishment was significant among the psychological home environment.

• Journal of Environmental Policy
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• v.11 no.4
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• pp.131-154
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• 2012

Existing researches on tax efficiency of environmental taxes mostly focuses on taxes imposed on the consumption process of the final output, or goods that create pollution during the input process of intermediate goods. The assumption here is that there is a significant relation between the consumption of polluting goods and the pollution itself. However, in reality they are not identical. This signifies that the above assumption may distort the actual results. This study classifies environmental tax into two different forms, output tax and emission tax. Theformer is the tax that is imposed on the consumption of polluting goods, while the latter is directly levied onto the emission of pollution. It then compares the efficiency of these taxes through the computational general equilibrium simulations. After analyzing the simulation, it was proven that the direct imposition on pollution, or environmental tax as emission tax, was more effective in terms of tax efficiency. Furthermore, these results were revealed as irrelevant to the assumption of homotheticity in utility function. Thus, if market-distortionary tax already exist, then the effectiveness of revenue neutral environmental tax reform will be sensitive to the assumption of homotheticity for utility function. However, environmental taxes as emission taxes have been shown to be more effective in tax efficiency than output taxes.

• The Korean Journal of Financial Management
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• v.2 no.1
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• pp.55-75
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• 1986

This article is to analyse the economic efficiency of capital market, which plays a role of resource allocation in terms of financial claims such as stock and bond. It provides various contributions to the welfare theoretical aspects of modern capital market theory. The key feature that distinguishes the theory described here from traditional welfare theory is the presence of uncertainty. Securities has time dimensions and the state and outcome of the future are really uncertain. This problem resulting from this uncertainty can be solved by complete market, but it has a weak power to explain real stock market. Capital Market is faced with the uncertainity because it is a kind of incomplete market. Individuals and firms in capital market made their consumption-investment decision by their own criteria, i. e. the maximization of expected utility form intertemporal consumption and the maximization of the market value of firm. We noted that allocative decisions that had to be made in the economy could be naturally subdivided into two groups. One set of decisions concerned the allocation of first-period resources among consumption $C_i$, investment in risky firms $I_j$, and riskless investment M. The other decisions concern the distribution among individuals of income available in the second period $Y_i(\theta)$. Corresponing to this grouping, the theoretical analysis of efficiency has also been dichotomized. The optimality of the distribution of output in the second period is distributive efficiency" and the optimality of the allocation of first-period resources is 'the efficiency of investment'. We have found in the distributive efficiency that the conditions for attainability is the same as the conditions for market optimality. The necessary and sufficient conditions for attainability or market optimality is that (1) all utility functions are such that -$\frac{{U_i}^'(Y_i)}{{U_i}^"(Y_i)}={\mu}_i+{\lambda}Y_i$-linear risk tolerance function where the coefficients ${\mu}_i$ and $\lambda$ are independent of $Y_i$, and (2) there are homogeneous expectations, i. e. ${\Large f}_i(\theta)={\Large f}(\theta)$ for every i. On the other hand, the efficiency of investment has disagreement about optimal investment level. The investment level for market rule will not generally lead to Pareto-optimal allocation of investment. This suboptimality is caused by (1)the difference of Diamond's decomposable production function and mean-variance valuation model and (2) the selection of exelusive investment or competitive investment. In conclusion, this article has made an analysis of conditions and processes of Pareto-optimal allocation of resources in capital marker and tried to connect with significant issues in modern finance.

• Journal of Service Research and Studies
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• v.12 no.4
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• pp.82-93
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• 2022

The food service industry is a major driver of global sustainable food consumption. By understanding food consumption behavior, restaurant managers can forecast demands and reduce pre-consumer food waste. This study investigates the relationship between influencing factors and the number of customers at restaurants and cafés. These factors are weather-related factors, including rain and temperature, and school-related factors, including exams and the day of the week. Based on these four factors, 24 possible combinations were created. Three representtive days were chosen for each weekday combination. Besides, one representative day was chosen for each weekend combination. In total, 48 days were sampled throughout the year. Customer data were collected from six restaurants and cafes on a Korean university campus. Conjoint analysis was used to determine the relative importance of each variable to customer numbers. Following that, utility scores were standardized and mapped to determine the best condition when the number of customers was at its peak. In addition, each store's sales were compared using Pearson's Correlation Coefficient. The findings support that temperature and rain influences are correlated with the number of customers. Furthermore, we discovered that temperature was far more significant than rain in determining the number of customers. The paper discusses the implications of weather to forecast food and beverage demand and predict meal choices.

• International Journal of Human Ecology
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• v.14 no.1
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• pp.13-27
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• 2013

Consumer perception of the meaning of 'green' and 'green products' as well as how they use green claims (including terms, certifications, and marks) should be examined to help consumers pursue green behavior in everyday life. This study investigates what type of green claims prevail in the Korean consumer market and how consumers perceive the meaning of 'green' and green claims. For these purposes, media analysis, in-context research (shop visit) and a survey were conducted to collect green claims (including green terms and certified/noncertified green marks). Green claims in the consumer market were first summarized and analyzed; subsequently, the most frequently used 7 green marks and 15 green terms were selected to construct a consumer survey questionnaire on consumer perceptions of green claims. An online survey was performed via Embrain and the survey respondents consisted of 500 adult consumers over the age of 20. The field research results showed frequent green claims in the Korean consumer market. However, certified (and hence trustworthy green product information labels) were uncommon in the market. The only green claim widely known and used by consumers was the energy consumption efficiency label. Consumers were interested in the green information label not because it affected their utility cost nor because it was important for environment protection.