• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.367-374
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• 2000

This study investigates the effect of hysteretic characteristics to the Inelastic Demand Spectrum (IDS) which was expressed by an acceleration(Sa) and a displacement response spectrum (Sd). Elasto Perfectly Plastic(EPP) model is used in this study and inelastic demand spectrum (Sa vs, Sd) are obtained from a given target ductility ratio. For a given target ductility ratio IDS can be obtained by using nonlinear time history analysis of single degree of system with forth five recorded earthquake ground motions for stiff soil site. The effect EPP model under demand spectrum is investigated by ductility factor and natural frequency. According to the results obtained in this study IDS has dependency on ductility factor and natural frequency.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.615-617
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• 2003

In electricity market with a imperfect competition, participants make plans of biddings and transaction strategies to maximize their own profits. The market price and the quantity are determined by bidding systems and market demands. Practically the characteristics of power demand have rather two forms; elastic region and inelastic region, than constant slope elasticity. Furthermore the price cap in the market can be modelled as a region of perfect elasticity in the demand function. This paper analyses supplier's bidding strategies which are reflected the characteristics of practical demand. Equilibrium strategies are solved by using the Bertrand model and payoff matrices.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.235-237
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• 1996

This paper shows a reasonable power demand method and load characteristics in underground streets, that was made by the systematic and statistical way considering actual conditions, such as investigated electric equipment capacity, electric power consumption, load characteristics, etc for 13 underground streets.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.61
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• pp.213-245
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• 2014

This study has significance in examining the formation requirements and notes for concluding the guarantee contract of minimizing interests and conflicts with the concerned parties by examining issues related to the legal relation and demand payment in the concerned parties and by figuring out the provisions of conformity related to the requirements for demand payment pertinent to the documentary provision in relation to characteristics of demand guarantee. What the concerned parties of using demand guarantee grasp the requirements for demand payment of being compliant with the essence and the guarantee condition of the demand guarantee will lead to possibly preventing a dispute caused by disagreement and being secured the fulfillment of underlying contract. To fulfill a underlying contract that is the objective of issuing the demand guarantee, an effort is needed that minimizes a contract-based risk and a cost by being fully aware of a relevant rule that will be recorded in the terms of payment in the demand guarantee, by reflecting the interests between the concerned parties, and by discussing the payment terms.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1765-1773
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• 2012

The accuracy of load forecast is very important from the viewpoint of economical power system operation. In general, the weekdays' load demand pattern has the continuous time series characteristics. Therefore, the conventional methods expose stable performance for weekdays. In case of special days or weekends, the load demand pattern has the discontinuous time series characteristics, so forecasting error is relatively high. Especially, weekdays near the thanksgiving day and lunar new year's day have the mixed load profile characteristics of both weekdays and weekends. Therefore, it is difficult to forecast these days by using the existing algorithms. In this study, a new load forecasting method is proposed in order to enhance the accuracy of the forecast result considering the characteristics of weekdays and weekends. The proposed method was tested with these days during last decades, which shows that the suggested method considerably improves the accuracy of the load forecast results.

• ETRI Journal
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• v.44 no.4
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• pp.624-640
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• 2022

Taxi-demand forecasting and hotspot prediction can be critical in reducing response times and designing a cost effective online taxi-booking model. Taxi demand in a region can be predicted by considering the past demand accumulated in that region over a span of time. However, other covariates-like neighborhood influence, sociodemographic parameters, and point-of-interest data-may also influence the spatiotemporal variation of demand. To study the effects of these covariates, in this paper, we propose three models that consider different covariates in order to select a set of independent variables. These models predict taxi demand in spatial units for a given temporal resolution using linear and ensemble regression. We eventually combine the characteristics (covariates) of each of these models to propose a robust forecasting framework which we call the combined covariates model (CCM). Experimental results show that the CCM performs better than the other models proposed in this paper.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.816-822
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• 2010

A comprehensive review for the selection of urban rail vehicle systems that best suit Gimpo railway line is taking place with consideration of the project area characteristics in light of line planning, passenger demand, supply of rolling stock, and railway construction and operation. Various aspects of vehicle systems including passenger demand on concerned lines, regional characteristics, vehicle types, and railway construction and operational settings should be taken into consideration. In addition, request for the introduction of customized vehicle systems reflecting the convenience of transit users such as wide and hospitable inner space, low noise, flexible operation of 2 to 4 car train-set and eye catching slim bridge piers is increasing. A study on alternatives to place an order to opt for optimum rolling stock systems considering line characteristics of Gimpo City's urban railway and future passenger demand while meeting the needs of Gimpo City has been conducted.

• Journal of the Korean Regional Science Association
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• v.40 no.2
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• pp.75-89
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• 2024

As the problem of lowering the efficiency of urban services in small and medium-sized cities in the non-metropolitan area intensifies, the necessity of developing a railway station area is being emphasized to form a compressed urban space through regional bases. Although major station areas in large cities are being developed in the form of complex, the analysis of the development location characteristics of the small and medium-sized city station areas is insufficient. The purpose of this study is to analyze the characteristics of development project conditions and potential demand in the high-speed rail station areas across the country, identify the differences in locational characteristics according to the type of city, such as 'metropolitan city', 'large city in non-metropolitan city', 'medium and small city in non-metropolitan city', and find out the appropriate development method. As a result of the analysis, it was analyzed that the 'metropolitan area metropolitan area' has high potential demand and poor business conditions. On the other hand, in the case of the non-metropolitan area, it was analyzed that the 'small and medium-sized city station area' has good business conditions and low potential demand characteristics, and the 'large city station area' has intermediate characteristics. This suggests the need for different development methods in the development of metropolitan and small and medium-sized city station areas. The analysis results of this study show that it is desirable to encourage private participation in large-scale metropolitan station areas, which require large-scale input, to maximize potential demand, and to encourage private participation through public-led projects based on favorable business conditions or development based on regional characteristics.

• Journal of Preventive Medicine and Public Health
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• v.52 no.2
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• pp.72-81
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• 2019

Objectives: The current study presents a new conceptual framework for physician-induced demand that comprises several influential components and their interactions. Methods: This framework was developed on the basis of the conceptual model proposed by Labelle. To identify the components that influenced induced demand and their interactions, a scoping review was conducted (from January 1980 to January 2017). Additionally, an expert panel was formed to formulate and expand the framework. Results: The developed framework comprises 2 main sets of components. First, the supply side includes 9 components: physicians' incentive for pecuniary profit or meeting their target income, physicians' current income, the physician/population ratio, service price (tariff), payment method, consultation time, type of employment of physicians, observable characteristics of the physician, and type and size of the hospital. Second, the demand side includes 3 components: patients' observable characteristics, patients' non-clinical characteristics, and insurance coverage. Conclusions: A conceptual framework that can clearly describe interactions between the components that influence induced demand is a critical step in providing a scientific basis for understanding physicians' behavior, particularly in the field of health economics.

• Structural Engineering and Mechanics
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• v.70 no.3
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• pp.289-301
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• 2019

Hysteretic energy is defined as energy dissipated through inelastic deformations during a ground motion by the system. It includes frequency content and duration of ground motion as two remarkable parameters, while these characteristics are not seen in displacement spectrum. Since maximum displacement individually cannot be the appropriate criterion for damage assessment, hysteretic energy has been evaluated in this research as a more comprehensive seismic demand parameter. An innovative methodology has been proposed to establish a new equivalent linear model to estimate hysteretic energy spectrum for bilinear SDOF models under two different sets of earthquake excitations. Error minimization has been defined in the space of equivalent linearization concept, which resulted in equivalent damping and equivalent period as representative parameters of the linear model. Nonlinear regression analysis was carried out for predicting these equivalent parameter as a function of ductility. The results also indicate differences between seismic demand characteristics of far-field and near-field ground motions, which are not identified by most of previous equations presented for predicting seismic energy. The main advantage of the proposed model is its independency on parameters related to earthquake and response characteristics, which has led to more efficiency as well as simplicity. The capability of providing a practical energy based seismic performance evaluation is another outstanding feature of the proposed model.