• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1491-1494
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• 2003

Video adaptation in response to dynamic resource conditions and user preferences is required as a key technology to enable universal multimedia access (UMA) through heterogeneous networks by a multitude of devices in a seamless way. Although many adaptation techniques exist, selections of appropriate adaptations among multiple choices are often ad hoc. To provide a systematic solution, we present a general conceptual framework to model video entity, adaptation, resource, utility, and relations among them. It allows for formulation of various adaptation problems as resource-constrained utility maximization. We apply the framework to a practical case of dynamic bit rate adaptation. Furthermore, we present a description tool, which has been accepted as a part of the MPEG-21 Digital Item Adaptation (DIA), along with a brief overview of the .elated descriptors to support terminal and network quality of service (QoS).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.792-812
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• 2022

Multi-agent systems often need to achieve the goal of learning more effectively for a task through coordination. Although the introduction of deep learning has addressed the state space problems, multi-agent learning remains infeasible because of the joint action spaces. Large-scale joint action spaces can be sparse according to implicit or explicit coordination structure, which can ensure reasonable coordination action through the coordination structure. In general, the multi-agent system is dynamic, which makes the relations among agents and the coordination structure are dynamic. Therefore, the explicit coordination structure can better represent the coordinative relationship among agents and achieve better coordination between agents. Inspired by the maximization of social group utility, we dynamically construct a factor graph as an explicit coordination structure to express the coordinative relationship according to the utility among agents and estimate the joint action values based on the local utility transfer among factor graphs. We present the application of such techniques in the scenario of multiple intelligent vehicle systems, where state space and action space are a problem and have too many interactions among agents. The results on the multiple intelligent vehicle systems demonstrate the efficiency and effectiveness of our proposed methods.

• 한국조경학회지
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• 제24권3호
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• pp.109-114
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• 1996

Generally, the size of our recreation sites is selected through use demand at the peak day. At same time, scale economic and diseconomic are applied to a recreation site. If you are a rational decision-maker, you would like to select the size of your park at profit-maximization point. This study is the first try for modelling a Gain-Loss by the size options of a theme park. For testing the validity of a financial model to select the size of theme parks. Ever-Land, Seoul-Land, Dream-Land's operating size was analyzed. By the size options, the revenue of each park was compared with cost. The profit-maximization point and break-even point of each park were found. Ever-Land and Dream-Land's size was selected between the profit-maximization point and the break-even point. In contrast with Ever-Land and Dream-Land's, Seoul-Land's was selected upper the break-even point. To increase the utility of this model in selecting the size of a theme park, a decision-maker must keep in mind a few limits of this study. That is, 1) this model can not be applied at public parks. 2) Sometimes the others can be more important than financial revenue and cost. Finally, there is the validity of Gain-Loss Model in estimating only the financial revenues and costs through the size options.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.40-45
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• 2013

It is known that Reliability Differentiated Pricing (RDP) can improve the efficiency and benefits of consumers and producers. This paper examines the long-run social welfare maximization problem of the utility and presents a long-term reliability differentiated prices for firm capacity, based on customer outage costs. Then the applicability of the proposed pricing scheme is verified with a case study.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 1998년도 가을 학술발표논문집 Vol.25 No.2 (2)
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• pp.360-362
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• 1998

In the original mixtures of experts framework, the parameters of the network are determined by gradient descent, which is naturally slow. In [2], the Expectation-Maximization(EM) algorithm is used instead, to obtain the network parameters, resulting in substantially reduced training times. This paper presents the new EM algorithm for prediction. We show that an Efficient training algorithm may be derived for the HME network. To verify the utility of the algorithm we look at specific examples in time series prediction. The application of the new EM algorithm to time series prediction has been quiet successful.

• 기술사
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• 제34권5호
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• pp.29-33
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• 2001

This paper summarizes the design and construction of the roof canopy structure for the SEOUL 2002 World Cup Main Stadium with a design inspired by Korean traditional beauty emphasizing images of the Pangpae kite. The stadium has also been designed for maximization of its post-World Cup utility to be used on as every basis by the citizens. The stadium canopy is a unique spatial network of truss members with a tensile membrane roof suspended from 16 masts. The canopy covers 40,950 ㎡. which is clad with a pre-stressed tensile membrane of PTFE coated fiberglass fabric and the glass.

• 한국병원경영학회지
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• 제10권4호
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• pp.75-97
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• 2005

The research objective is to empirically investigate the compensation packages maximizing the utilities of internal customers by applying the market segmentation theory. Data was collected from four Korean hospitals in Seoul, Busan and Gyunggi-do. The research is designed to seek the compensation package maximizing the utility of doctors by mixture regression model, which has been applied as latent structure and other type of finite mixture models from various academic fields since early 1980s. The mixture regression model shows the optimal segments number and fuzzy classification for each observation by EM(expectation-maximization algorism). The finite mixture regression model is to unmix the sample, to identify the groups, and to estimate the parameters of the density function underlying the observed data within each group. The doctors were segmented into 5 groups by their preference for the compensation package. The results of this study imply that the utility of doctors increases with differentiated compensation package segmented by their preference.

• 무역상무연구
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• 제35권
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• pp.41-69
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• 2007

This study analyzes some important implications for the forthcoming revision of eUCP through the methodology of expected utility maximization theory. The overall results are as follows. First, beneficiary with an initial wealth has a risk-averse utility in traditional letter of credit transaction, and he would be more risk-averse in eUCP transaction. Secondly, the beneficiary who has risk-averse utility will pay for the risk premium to reduce the risk of corruption of an electronic record by means of cost of loss reduction activities. Thirdly, the cost of loss reduction activities is represented by a convex cost function, Fourthly, a risk averse beneficiary pursues loss reducing activities to the point where the expected marginal product of loss reduction is less than its marginal cost. Fifthly, a more risk-averse eUCP beneficiary will always select a higher level of loss reduction as long as the effectiveness of loss reduction is certain. Sixthly, when the effectiveness of loss reduction is uncertain, the more risk-averse eUCP beneficiary does not necessarily choose a higher level of loss reducing activities. Finally, it would be more reasonable that eUCP Article 11 should protect eUCP beneficiary who pursues a higher level of loss reducing activities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4848-4863
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• 2016

The explosive wireless data service requirement accompanied with carbon dioxide emission and consumption of traditional energy has put pressure on both industria and academia. Wireless networks powered with the uneven and intermittent generated renewable energy have been widely researched and lead to a new research paradigm called green communication. In this paper, we comprehensively consider the total generated renewable energy, QoS requirement and channel quality, then propose a utility based renewable energy allocation policy. The utility here means the satisfaction degree of users with a certain amount allocated renewable energy. The energy allocation problem is formulated as a constraint optimization problem and a heuristic algorithm with low complexity is derived to solve the raised problem. Numerical results show that the renewable energy allocation policy is applicable not only to soft QoS, but also to hard QoS and best effort QoS. When the renewable energy is very scarce, only users with good channel quality can achieve allocated energy.

• Journal of Information Processing Systems
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• 제17권2호
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• pp.306-317
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• 2021

The unbalance between system ergodic sum rate and high fairness is one of the key issues affecting the performance of non-orthogonal multiple access (NOMA) system. To solve the problem, this paper proposes a power allocation algorithm to realize the ergodic sum rate maximization of NOMA system. The scheme is mainly achieved by the construction algorithm of fair model based on α fair utility function and the optimal solution algorithm based on the interior point method of penalty function. Aiming at the construction of fair model, the fair target is added to the traditional power allocation model to set the reasonable target function. Simultaneously, the problem of ergodic sum rate and fairness in power allocation is weighed by adjusting the value of α. Aiming at the optimal solution algorithm, the interior point method of penalty function is used to transform the fair objective function with unequal constraints into the unconstrained problem in the feasible domain. Then the optimal solution of the original constrained optimization problem is gradually approximated within the feasible domain. The simulation results show that, compared with NOMA and time division multiple address (TDMA) schemes, the proposed method has larger ergodic sum rate and lower Fairness Index (FI) values.