• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제19권4호
• /
• pp.417-428
• /
• 2015

Although, in general, the random fluctuation of interest rates gives a limited impact on portfolio optimization, their stochastic nature may exert a significant influence on the process of selecting the proportions of various assets to be held in a given portfolio when the stochastic volatility of risky assets is considered. The stochastic volatility covers a variety of known models to fit in with diverse economic environments. In this paper, an optimal strategy for portfolio selection as well as the smoothness properties of the relevant value function are studied with the dynamic programming method under a market model of both stochastic volatility and stochastic interest rates.

• 정보기술과데이타베이스저널
• /
• 제4권2호
• /
• pp.21-32
• /
• 1998

A primary concern of physical database design has been efficient retrieval and update of a record because predictable performance of a DBMS is indispensable to time-critical missions. To maintain such phenomenal performance, database manages often spends more than or as much as the goal of an organization can warrant. The motivation of this research stems from the fact that even predictable performance of a physical database can be hampered by stochastic query processing time, physical configurations of a database, and random arrival processes of queries. They all together affect the overall performance of a DBMS. In particular, if there are queuing delays due to limited capacity or during on-peak congestion, this paper suggest to prioritize database services. A surprising finding of this paper is that such a transition from a non-priority system to a corresponding priority-based system can be Pareto-improving in the sense that no users in the system will be worse off after the transition. Thus prioritizing database services can be a viable option for efficient database management.

• ETRI Journal
• /
• 제32권3호
• /
• pp.447-456
• /
• 2010

Asymmetric regulation as applied to mobile termination rates refers to regulatory arrangements in which different mobile operators charge different termination rates, even though the services provided are essentially identical. The asymmetric regulation has been frequently used as a regulatory tool to support new entrants to a mobile market. This paper examines the economic effects of asymmetric regulation of mobile termination rates using a theoretical model and its simulation. The result shows that when there is no noticeable difference in brand loyalty between mobile operators with the high degree of substitutability between services provided by mobile operators, and the costs of new entrants are low, a reduction in the asymmetry of mobile access prices results in an enhancement of consumer welfare. These findings provide positive evidence for the argument that in certain situations asymmetric pricing of mobile access services may be counterproductive for consumer welfare.

• Journal of Information Technology Applications and Management
• /
• 제9권2호
• /
• pp.33-56
• /
• 2002

This paper shows that internet retailers adjust the total expenses of their customer's purchase by the nominal price of each product and the delivery fee of the purchase. This paper compares the total expenses of purchasing a bundle of goods in the internet market against the total expenses of purchasing the same bundle of goods in the traditional market. The results show that the type of goods and the total expenses of a purchase, together with their interaction, determine up to 60% or 80% of the variance of the difference between the expenses up the same purchase in the two markets. The results also show that neither the expenses of a purchase nor its interaction with the product type affects the dispersion of total purchase expenses in the internet market.

• 대한전기학회논문지:전력기술부문A
• /
• 제51권7호
• /
• pp.311-316
• /
• 2002

It has been a basic model for the present electric power industry that more than two generators compete, and thereby the market clearing price and the generation schedules are determined through the bid process. In order for this paradigm to be applicable to real electric power systems and markets, it is necessary to reflect many physical and economic constraints related to frequency and transmission in the dispatching schedule. The paper presents an approach to deriving a Nash bargaining solution in a competitive electricity market where multiple generators are playing with the system operator who mitigates the transmission congestion to minimize the total transaction cost. In this study, we take the effect of the line flows and the role of system operator into the Game. Finally, a case study has been demonstrated to verify the proposed cooperative game.

• 한국병원경영학회지
• /
• 제15권1호
• /
• pp.13-26
• /
• 2010

A Health Promotion Center (HPC) whose capacity is partially idle causes inefficiency in resource usage of a country as well as the hospital itself. Meanwhile, Increased demand in HPC would lead to increased revenue for the HPC as well as reduced national expenditures on healthcare. We introduced a way to enhance revenue by Revenue Management (RM) on HPC services, in which demand forecasting and pricing strategies are considered. In addition, a real data analysis had been performed to evaluate the usefulness of the proposed approach.

• 대한산업공학회지
• /
• 제27권2호
• /
• pp.181-189
• /
• 2001

The proliferation of the Internet and related technologies and applications has led to a new form of market place known as the electronic store. In this paper, we study competition between two shopping channels, an electronic store and traditional retailers. Based on the circular spatial market model, we derive the Nash and Stackelberg equilibria as a function of the efficiency of the electronic store. The result shows that the Stackelberg equilibrium is always superior to the Nash equilibrium for both channels. It is also shown that, in some cases, the electronic store has incentive to decrease its efficiency to gain more profit.

• 한국조리학회지
• /
• 제14권2호
• /
• pp.30-45
• /
• 2008

The objective of this study is to examine how the factors influence each other by determining the appropriate measurement standard in fast food restaurants based on the evaluation of attributes, perceived pricing, value, satisfaction and intention of revisit, and present an effective marketing strategy for fast food restaurants based on the analytical results by patrons and market segmentations. The study surveyed 195 subjects and processed the result using SPSS for Win. V. 12.0. For statistical analysis, Frequency, Factor Analysis, Reliability Analysis, and Regression Analysis were put into operation. As a result of the Factor Analysis of the evaluation of attributes, 3 factors have been extracted. The results showed that restaurant attribution evaluation had a positive effect on the perceived value($R^2adj=0.357$, p=0.000), satisfaction($R^2adj=0.346$, p=0.000) and intent of revisiting($R^2adj=0.389$, p=0.000); perceived pricing had a positive affect on the perceived value($R^2adj=0.464$, p=0.000), satisfaction($R^2adj=0.113$, p=0.000) and intention of revisit($R^2adj=0.276$, p=0.000); perceived value had a positive affect on satis-faction($R^2adj=0.327$, p=0.000) and intention of revisit($R^2adj=0.515$, p=0.000); and satisfaction had a positive affect on intention of revisit($R^2adj=0.442$, p=0.000).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권1호
• /
• pp.58-73
• /
• 2021

Cloud Service Providers (CSPs) enable their users to access Cloud computing and storage services from anywhere in quick and flexible manners through the Internet. With the basis of 'pay-as-you-go' model, it makes the interactions between CSPs and the users play a vital role in shaping the Cloud computing market. A pool of virtualized and dynamically scalable Cloud services that delivered on demand to the users is associated with guaranteed performance and cost-provisioning. It needed a costing scheme for determining suitable charges in order to secure lease pricing of the Cloud services. However, it is hard to meet the satisfied prices for both CSPs and users due to their conflicting needs. Furthermore, there is lack of Service Level Agreements (SLAs) that allowing the users to take part into price negotiating process. The users may lose their interest to use Cloud services while reducing CSPs profit. Therefore, this paper proposes a generic costing scheme for Cloud services using General Equilibrium Theory (GET). GET helps to formulate the price function for various services' factors to match with various demands from the users. It is initially determined by identifying the market circumstances that a general equilibrium will be hold and reached. Specifically, there are two procedures of agreement made in response to (i) established equilibrium supply and demand, and (ii) service price formed and constructed in a price range. The SLAs in our costing scheme is integrated to satisfy both CSPs and users' needs while minimizing their conflicts. The price ranging strategy is deliberated to provide prices' options to the users with respect their budget limit. Meanwhile, the CSPs can adaptively charge based on users' preferences without losing their profit. The costing scheme is testable and analyzed in multi-tenant computing environments. The results from our simulation experiments demonstrate that the proposed costing scheme provides better users' satisfaction while fostering fairness pricing in the Cloud market.

• 유통과학연구
• /
• 제13권9호
• /
• pp.37-45
• /
• 2015

Purpose - This paper's aim is to investigate whether or not gross profitability explains the cross-sectional variation of the stock returns in the Korean stock market. Gross profitability is an alternative profitability measure proposed by Novy-Marx in 2013 to predict cross-sectional variation of stock returns in the US. He shows that the gross profitability adds explanatory power to the Fama-French 3 factor model. Interestingly, gross profitability is negatively correlated with the book-to-market ratio. By confirming the gross profitability premium in the Korean stock market, we may provide some implications regarding the well-known value premium. In addition, our empirical results may provide opportunities for the fund distribution industry to promote brand new styles of funds. Research design, data, and methodology - For our empirical analysis, we collect monthly market prices of all the companies listed on the Korea Composite Stock Price Index (KOSPI) of the Korea Exchanges (KRX). Our sample period covers July1994 to December2014. The data from the company financial statementsare provided by the financial information company WISEfn. First, using Fama-Macbeth cross-sectional regression, we investigate the relation between gross profitability and stock return performance. For robustness in analyzing the performance of the gross profitability strategy, we consider value weighted portfolio returns as well as equally weighted portfolio returns. Next, using Fama-French 3 factor models, we examine whether or not the gross profitability strategy generates excess returns when firmsize and the book-to-market ratio are controlled. Finally, we analyze the effect of firm size and the book-to-market ratio on the gross profitability strategy. Results - First, through the Fama-MacBeth cross-sectional regression, we show that gross profitability has almost the same explanatory power as the book-to-market ratio in explaining the cross-sectional variation of the Korean stock market. Second, we find evidence that gross profitability is a statistically significant variable for explaining cross-sectional stock returns when the size and the value effect are controlled. Third, we show that gross profitability, which is positively correlated with stock returns and firm size, is negatively correlated with the book-to-market ratio. From the perspective of portfolio management, our results imply that since the gross profitability strategy is a distinctive growth strategy, value strategies can be improved by hedging with the gross profitability strategy. Conclusions - Our empirical results confirm the existence of a gross profitability premium in the Korean stock market. From the perspective of the fund distribution industry, the gross profitability portfolio is worthy of attention. Since the value strategy portfolio returns are negatively correlated with the gross profitability strategy portfolio returns, by mixing both portfolios, investors could be better off without additional risk. However, the profitable firms are dissimilar from the value firms (high book-to-market ratio firms); therefore, an alternative factor model including gross profitability may help us understand the economic implications of the well-known anomalies such as value premium, momentum, and low volatility. We reserve these topics for future research.