• Title/Summary/Keyword: Demand Performance

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Mid-Term Energy Demand Forecasting Using Conditional Restricted Boltzmann Machine (조건적 제한된 볼츠만머신을 이용한 중기 전력 수요 예측)

  • Kim, Soo-Hyun;Sun, Young-Ghyu;Lee, Dong-gu;Sim, Is-sac;Hwang, Yu-Min;Kim, Hyun-Soo;Kim, Hyung-suk;Kim, Jin-Young
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.127-133
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    • 2019
  • Electric power demand forecasting is one of the important research areas for future smart grid introduction. However, It is difficult to predict because it is affected by many external factors. Traditional methods of forecasting power demand have been limited in making accurate prediction because they use raw power data. In this paper, a probability-based CRBM is proposed to solve the problem of electric power demand prediction using raw power data. The stochastic model is suitable to capture the probabilistic characteristics of electric power data. In order to compare the mid-term power demand forecasting performance of the proposed model, we compared the performance with Recurrent Neural Network(RNN). Performance comparison using electric power data provided by the University of Massachusetts showed that the proposed algorithm results in better performance in mid-term energy demand forecasting.

The Performance of Time Series Models to Forecast Short-Term Electricity Demand

  • Park, W.G.;Kim, S.
    • Communications for Statistical Applications and Methods
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    • v.19 no.6
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    • pp.869-876
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    • 2012
  • In this paper, we applied seasonal time series models such as ARIMA, FARIMA, AR-GARCH and Holt-Winters in consideration of seasonality to forecast short-term electricity demand data. The results for performance evaluation on the time series models show that seasonal FARIMA and seasonal Holt-Winters models perform adequately under the criterion of Mean Absolute Percentage Error(MAPE).

Mental States in Information Search Process (정보검색과정에서의 정신적 상태)

  • Na, Kyoungsik;Choi, Wontae
    • Journal of Korean Library and Information Science Society
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    • v.48 no.3
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    • pp.281-302
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    • 2017
  • This study examined the differences in a searcher's mental states of a complex information search and retrieval task during information search process between the two groups: participants who were exposed to mental demand manipulation and those not exposed. Data from the experiments and questionnaires were analyzed. Based on qualitative approach and quantitative analyses, the results indicated that the participants exposed to mental demand required more thoughts; addressed negative emotions more often; reduced a searcher's efforts; and interrupted search performance than those not exposed. These results suggest that mental demand contributed to a searcher's perceived thought, emotion, effort, and performance, although these mental states differed in relative contribution of information search process. Significant differences were found between the two groups with respect to the component of mental demand, performance, and frustration of the NASA-TLX subjective cognitive load. These results have implications for search user interface design and information search systems among others.

Provision of Two-area Automatic Generation Control by Demand-side Electric Vehicle Battery Swapping Stations

  • Xie, Pingping;Shi, Dongyuan;Li, Yinhong
    • Journal of Electrical Engineering and Technology
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    • v.11 no.2
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    • pp.300-308
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    • 2016
  • Application of demand-side resources to automatic generation control (AGC) has a great significance for improving the dynamic control performance of power system frequency regulation. This paper investigates the possibility of providing regulation services by demand-side energy storage in electric vehicle battery swapping stations (BSS). An interaction framework, namely station-to-grid (S2G), is presented to integrate BSS energy storage into power grid for giving benefits to frequency regulation. The BSS can be regarded as a lumped battery energy storage station through S2G framework. A supplementary AGC method using demand-side BSS energy storage is developed considering the vehicle user demand of battery swapping. The effects to the AGC performance are evaluated through simulations by using a two-area interconnected power grid model with step and random load disturbance. The results show that the demand-side BSS can significantly suppress the frequency deviation and tie-line power fluctuations.

Intensity measure-based probabilistic seismic evaluation and vulnerability assessment of ageing bridges

  • Yazdani, Mahdi;Jahangiri, Vahid
    • Earthquakes and Structures
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    • v.19 no.5
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    • pp.379-393
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    • 2020
  • The purpose of this study is to first evaluate the seismic behavior of ageing arch bridges by using the Intensity Measure - based demand and DCFD format, which is referred to as the fragility-hazard format. Then, an investigation is performed for their seismic vulnerability. Analytical models are created for bridges concerning different features and these models are subjected to Incremental Dynamic Analysis (IDA) analysis using a set of 22 earthquake records. The hazard curve and results of IDA analysis are employed to evaluate the return period of exceeding the limit states in the IM-based probabilistic performance-based context. Subsequently, the fragility-hazard format is used to assess factored demand, factored capacity, and the ratio of the factored demand to the factored capacity of the models with respect to different performance objectives. Finally, the vulnerability curves are obtained for the investigated bridges in terms of the loss ratio. The results revealed that decreasing the span length of the unreinforced arch bridges leads to the increase in the return period of exceeding various limit states and factored capacity and decrease in the displacement demand, the probability of failure, the factored demand, as well as the factored demand to factored capacity ratios, loss ratio, and seismic vulnerability. Finally, it is derived that the probability of the need for rehabilitation increases by an increase in the span length of the models.

Ductility Demand-Based Seismic Design and Seismic Performance Evaluation of Urban Railway Bridge Pier (도시철도 고가교 및 교량 교각의 연성도 내진설계와 내진성능 평가)

  • Park, Seung-Hee;Nam, Min-Jun;Yoon, Jong-Ku;Kim, Jin-Ho
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1220-1226
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    • 2011
  • The purpose of this study is to assess the seismic performance of a reinforced concrete pier using ductility demand-based seismic design method and nonlinear earthquake analysis. A computer program named MIDAS/Civil(MIDAS IT,2009) for the analysis of the reinforced concrete pier was used. The bridge pier was designed by the ductility demand-based seismic design. In addition, a seismic performance was evaluated through both capacity spectrum method and nonlinear time history method. In order to determine the seismic performance of the bridge pier, the maximum response values from the capacity spectrum method and nonlinear time history analysis were compared each other.

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A Study on Some Major Clauses of a Payment Guarantee in International Transactions (국제거래에서 대금지급보증서(payment guarantee)의 주요 조항에 대한 연구)

  • Kim, Sang Man
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.58
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    • pp.179-213
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    • 2013
  • While a performance type guarantee is required as a security for non-performance risk by a seller, a payment guarantee is used as a security for non-payment risk by a buyer(or a borrower in a loan agreement). A payment guarantee is a type of independent bank guarantee, bank guarantee, bond, demand guarantee, or standby letter of credit. A guarantor accepts a credit risk of a principal which is normally a buyer in a contract for sale of goods. A payment guarantee is independent of the underlying relationship between the applicant and the beneficiary. The guarantor is only empowered to examine the beneficiary's demand and determine the payment on its face to the terms of the guarantee. A payment guarantee is thus different from a suretyship. The principle of independence carries a significant advantages for a guarantor as well as for a beneficiary. While a documentary credit requires B/L, commercial invoice, packing list, inspection certificate, etc., a typical payment guarantee does not require any evidence for a seller's performance of the underlying contract other than written demand. In this respect payment guarnatee can be a more secured facility than a documentary credit. A payment guarantee normally comes into force from the issuing date and shall remain in effect until all sums guaranteed shall be paid in full by a buyer(or a borrower) or by a guarantor. Although a guarantor shall pay a demand made in accordance with the terms and conditions of the payment guarantee, a payment demand may be denied when it is determined to be abusive or unfair.

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A Study on the Preference Design and the Demand Performance for Adult Men's Suit (성인 남성의 신사복에 대한 선호 디자인 및 요구 성능)

  • Park, Young-Hee;Han, Seung-Hee
    • The Research Journal of the Costume Culture
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    • v.18 no.1
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    • pp.1-12
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    • 2010
  • This study diagnosed difference of preference about demand performance with design of men's suit according to demographic characteristic and figured out Needs of adult man consumers for men's suit. This study is survey research. In order to collect data, a questionnaire was used. To analyze the collected data, fact analysis, $\chi^2$, ANOVA, Duncan's multiple comparisons and the rest were carried out with using SPSS 14.0. Result of this study could get as following. According to silhouette and color, there was difference to age, attainments in scholarship and preference according to job. Also young people preferred fitted-silhouette and in occasion of color, all of them preferred best black. It was no difference according to demographic characteristic in preferring pattern but preferred best solid on the whole. Demand performance of men's suit appeared by five main causes of design, practicality, comfort, appearance appropriateness, another person awareness and functional materials. And most main causes showed difference according to demographic characteristic.

Forecasting Model of Air Passenger Demand Using System Dynamics (시스템다이내믹스를 이용한 항공여객 수요예측에 관한 연구)

  • Kim, Hyung-Ho;Jeon, Jun-woo;Yeo, Gi-Tae
    • Journal of Digital Convergence
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    • v.16 no.5
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    • pp.137-143
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    • 2018
  • Korea's air passenger traffic has been growing steadily. In this paper, we propose a forecasting model of air passenger demand to ascertain the growth trend of air passenger transportation performance in Korea. We conducted a simulation based on System Dynamics with the demand as a dependent variable, and international oil prices, GDP and exchange rates as exogenous variables. The accuracy of the model was verified using MAPE and $R^2$, and the proposed prediction model was verified as an accurate prediction model. As a result of the demand forecast, it is predicted that the air passenger demand in Korea will continue to grow, and the share of low cost carriers will increase sharply. The addition of the Korean transportation performance of foreign carriers in Korea and the transportation performance of Korean passengers due to the alliance of airlines will provide a more accurate forecast of passenger demand.

Policy Direction in Responses to Demand for Apartment Remodeling (공동주택 리모델링 수요에 대응한 정책 추진방안)

  • Lee, Yeo-Kyung;Kim, Eun-Hee
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.1
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    • pp.125-136
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    • 2020
  • This study aims to seek a proper policy direction in response to the demand for apartment remodeling. As the research methods, we diagnosed the current status of the remodeling policy and analyzed the demand for apartment remodeling nationwide. According to the result of analysis, we suggested the fundamental direction and tasks for remodeling policies to be pursued at the government level. The results of the study are summarized as follows. First, the result of analysis showed that the demand for environmental improvement(performance improvement) remodeling project was much higher than other types of remodeling projects. The percentage of unit increased-type remodeling that can secure business feasibility is about 10% and only 30% when it comes to reducing project costs. The remaining 70-90% need to be promoted in environmental improvement remodeling projects which dependent on the residents' payment. Second, in order to prepare a policy action plan in response to the demand for apartment remodeling, it is necessary to set up clear policy goals and strategies for apartment remodeling in advance at the national level. Along with proactive goals and strategies, graded policy support should be accompanied per type of remodeling and business demand. We also suggest to simplify administrative procedures and support the R&D research to develop technologies. It would help to utilize the unit increased-type remodeling. On the other hand, for utilizing the environmental improvement remodeling which takes up a relatively high proportion, the policy should take care of as follows: offering housing performance information, rationalizing long term repair reserve, fostering small companies and experts. Finally, apartment management system should be advanced from the perspectives of managing old apartments and institutional foundations such as new construction and customized regulations for differentiated remodeling should be accompanied.