• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.772-774
• /
• 2005

Interstate electric power system, as an alternative for energy cooperation under regional economic bloc, has been hotly debated before progressing the restructure in electric power industry and rapidly expanded in many regions after 1990s. Especially, since northeast asia has strong supplementation in resource, load shape, fuel mix etc., electric power system interconnection in this region may bring considerable economic benefits. Moreover, since Korean electric power system has a great difficulty in a geographical condition to interrupt electricity transaction with other countries, it has been expanded as an independent system to supply all demand domestically. As a result, Korean electric power system makes considerable payment for maintaining system security and reliability and expands costly facilities to supply a temporary summer peak demand. Under this inefficiency, if there are electricity transactions with Russia via the North Korea route then economic electric power system operation may be achieved using seasonal and hourly differences in electricity price and/or load pattern among these countries. In this paper, we estimate price cap of transacted electricity via interstate electric power system in northeast asia. For this study, we perform quantitative economic analysis on various system interconnection scenarios.

• Proceedings of the KIEE Conference
• /
• 2005.11b
• /
• pp.162-164
• /
• 2005

This paper presents an hour-ahead System Marginal Price (SMP) forecasting framework based on a neural network. Recently, the deregulation in power industries has impacted on the power system operational problems. The bidding strategy of market participants in energy market is highly dependent on the short-term price levels. Therefore, short-term SMP forecasting is a very important issue to market participants to maximize their profits. and to market operator who may wish to operate the electricity market in a stable sense. The proposed hybrid neural network is composed of tow parts. First part of this scheme is pattern classification to input data using Kohonen Self-Organizing Map (SOM) and the second part is SMP forecasting using back-propagation neural network that has three layers. This paper compares the forecasting results using classified input data and unclassified input data. The proposed technique is trained, validated and tested with historical date of Korea Power Exchange (KPX) in 2002.

• Journal of Energy Engineering
• /
• v.11 no.2
• /
• pp.142-148
• /
• 2002

The variations of real time electric price in competitive electricity markets have influence on electric power demands of the consumers. Residential, commercial, and industrial consumers with different characteristics cause the different price elasticity of the demand due to changing the pattern of consumption. Therefore, this paper analyze the effects of spot pricing for the change of the electric power demand based on the demand elasticity of each loads in competitive electricity market.

• Health Policy and Management
• /
• v.3 no.2
• /
• pp.27-80
• /
• 1993

It is widely known that patients' utilization pattern for medical care facilities and the patientflow are influenced by multi-factors, such as demographic characteristics, structural characteristics of society, socio-psychological characteristics(value, attitude, norms, culture, health behavior, etc.), economic characteristics(income, medical price, relative price, physician induced demand, etc.), geographical accessibility, systematic characteristics(health care delivery system, payment methods for physician fees, form of health care security, etc.), and characteristics of medical facilities(reliability, quality of medical care, convenience, kindness, tec.). This study was conducted to research the mechanism of patient-flow according to changes of health care system(implementation of national health insurance, health care referral system and regionalization of health care utilization, etc.) and characteristics of medical facilities(ownership of hospital, characteristics of medical services, non-medical characteristics, etc.). In this study, the fact could be ascertained that the patient-flow had been influenced by changes of health care system and characteristics of medical facilities.

• Journal of the Korean Home Economics Association
• /
• v.42 no.1
• /
• pp.153-166
• /
• 2004

The purpose of this study was to examine the internet shoppers' new purchase behavior, to examine the general purchase behavior(i.e., purchase pattern, preference), and to examine the related factors to promotion strategies(i.e., e-mail, event) of internet shopping mall. Focus group interviews were done with 40 internet shopping-mall users on May, 2003 for the data collection. Data were analyzed by content analysis and descriptive statistics(i.e., frequency, percent). The results of this study were as following. First, competitive price, accurate product and service information and convenience were considered as important factors in the new purchase behavior among internet shoppers. Second, the more frequent purchasing time through the internet shopping mall were on weekdays rather than weeekends and the most preferred information search engine were category type, item type, and price type in order. Third, e-mails from internet shopping mall were most likely opened by internet shoppers, that is to say, e-mail can be the efficient communication tool as well as the possible promotion strategies. Specifically, the title of email was considered as an important factor to approach the target consumers.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.524-526
• /
• 2001

The variations of real time electric price in competitive electricity markets have influence on electric power demands of the consumers. Residential, commercial, and industrial consumers, with different characteristics cause the different price elasticity of the demand due to changing the pattern of consumption. Therefore, this paper calculate the elasticity of each loads and analysis the effects of electric power demands and spot pricing as a function of elasticity in competitive electricity market.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2003.05a
• /
• pp.255-263
• /
• 2003

A multi-agent system designed to represent newly deregulated electricity markets in the USA is aimed at testing the capability of the multi-agent model to replicate the observed price behavior in the wholesale market and developing a smart business intelligence which quickly searches the optimum offer strategy responding to the change in market environments. Simulation results show that the optimum offer strategy is to withhold expensive generating units and submit relatively low offers when demand is low, regardless of firm size; the optimum offer strategy during a period of high demand is either to withhold capacity or speculate for a large firm, while it is to be a price taker a small firm: all in all, the offer pattern observed in the market is close to the optimum strategy. From the firm's perspective, the demand-side participation as well as the intense competition dramatically reduces the chance of high excess profit.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.6
• /
• pp.122-130
• /
• 2013

The demand and the supply are increasing sharply in accordance with the growth of the Memory Semiconductor Industry. The Flash Memory above all is being utilized substantially in the Industry of smart phone, the tablet PC and the System on Chip (SoC). The Flash Memory is divided into the NOR-type Flash Memory and the NAND-type Flash Memory. A lot of study such as the Built-In Self Test (BIST), the Built-In Self Repair (BISR) and the Built-In Redundancy Analysis (BIRA), etc. has been progressed in the NOR-type fash Memory, the study for the Built-In Self Test of the NAND-type Flash Memory has not been progressed. At present, the pattern test of the NAND-type Flash Memory is being carried out using the outside test equipment of high price. The NAND-type Flash Memory is being depended on the outside equipment as there is no Built-In Self Test since the erasure of block unit, the reading and writing of page unit are possible in the NAND-type Flash Memory. The Built-In Self Test equipped with 2 kinds of finite state machine based structure is proposed, so as to carry out the pattern test without the outside pattern test equipment from the NAND-type Flash Memory which carried out the test dependant on the outside pattern test equipment of high price.

• Journal of Energy Engineering
• /
• v.22 no.4
• /
• pp.370-375
• /
• 2013

This paper attempts to estimate the city gas demand function in Korea over the period 1981-2012. As the city gas demand function provides us information on the pattern of consumer's city gas consumption, it can be usefully utilized in predicting the impact of policy variables such as city gas price and forecasting the demand for city gas. We apply lagged dependent variable model and ordinary least square method as a robust approach to estimating the parameters of the city gas demand function. The results show that short-run price and income elasticities of the city gas demand are estimated to be -0.522 and 0.874, respectively. They are statistically significant at the 1% level. The short-run price and income elasticities portray that demand for city gas is price- and income-inelastic. This implies that the city gas is indispensable goods to human-being's life, thus the city gas demand would not be promptly adjusted to responding to price and/or income change. However, long-run price and income elasticities reveal that the demand for city gas is price- and income-elastic in the long-run.

• Journal of Energy Engineering
• /
• v.22 no.3
• /
• pp.245-249
• /
• 2013

This paper attempts to estimate the kerosene demand function in Korea over the period 1981-2012. As the kerosene demand function provides us information on the pattern of consumer's kerosene consumption, it can be usefully utilized in predicting the impact of policy variables such as kerosene price and forecasting the demand for kerosene. We apply least absolute deviations and least median squares estimation methods as a robust approach to estimating the parameters of the kerosene demand function. The results show that short-run price and income elasticities of the kerosene demand are estimated to be -0.468 and 0.409, respectively. They are statisitically significant at the 1% level. The short-run price and income elasticities portray that demand for kerosene is price- and income-inelastic. This implies that the kerosene is indispensable goods to human-being's life, thus the kerosene demand would not be promptly adjusted to responding to price and/or income change. However, long-run price and income elasticities reveal that the demand for kerosene is price- and income-elastic in the long-run.