• Title/Summary/Keyword: Load Patterns

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Various Models of Fuzzy Least-Squares Linear Regression for Load Forecasting (전력수요예측을 위한 다양한 퍼지 최소자승 선형회귀 모델)

  • Song, Kyung-Bin
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.7
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    • pp.61-67
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    • 2007
  • The load forecasting has been an important part of power system Accordingly, it has been proposed various methods for the load forecasting. The load patterns of the special days is quite different than those of ordinary weekdays. It is difficult to accurately forecast the load of special days due to the insufficiency of the load patterns compared with ordinary weekdays, so we have proposed fuzzy least squares linear regression algorithm for the load forecasting. In this paper we proposed four models for fuzzy least squares linear regression. It is separated by coefficients of fuzzy least squares linear regression equation. we compared model of H1 with H4 and prove it H4 has accurately forecast better than H1.

Modeling and Analysis of Load-Balancing Based on Base-Station CoMP with Guaranteed QoS

  • Feng, Lei;Li, WenJing;Yin, Mengjun;Qiu, Xuesong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.9
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    • pp.2982-3003
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    • 2014
  • With the explosive deployment of the wireless communications technology, the increased QoS requirement has sparked keen interest in network planning and optimization. As the major players in wireless network optimization, the BS's resource utilization and mobile user's QoS can be improved a lot by the load-balancing technology. In this paper, we propose a load-balancing strategy that uses Coordinated Multiple Points (CoMP) technology among the Base Stations (BS) to effectively extend network coverage and increase edge users signal quality. To use universally, different patterns of load-balancing based on CoMP are modeled and discussed. We define two QoS metrics to be guaranteed during CoMP load balancing: call blocking rate and efficient throughput. The closed-form expressions for these two QoS metrics are derived. The load-balancing capacity and QoS performances with different CoMP patterns are evaluated and analyzed in low-dense and high-dense traffic system. The numerical results present the reasonable CoMP load balancing pattern choice with guaranteed QoS in each system.

Design of Main Transformer Fault Restoration Strategy Based on Pattern Clustering Method in Automated Substation (패턴 클러스터링 기법에 기반한 배전 변전소 주변압기 사고복구 전략 설계)

  • Ko, Yun-Seok
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.10
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    • pp.410-417
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    • 2006
  • Generally, the training set of maximum $m{\times}L(m+f)$ patterns in the pattern recognition method is required for the real-time bus reconfiguration strategy when a main transformer fault occurs in the distribution substation. Accordingly, to make the application of pattern recognition method possible, the size of the training set must be reduced as efficient level. This Paper proposes a methodology which obtains the minimized training set by applying the pattern clustering method to load patterns of the main transformers and feeders during selected period and to obtain bus reconfiguration strategy based on it. The MaxMin distance clustering algorithm is adopted as the pattern clustering method. The proposed method reduces greatly the number of load patterns to be trained and obtain the satisfactory pattern matching success rate because that it generates the typical pattern clusters by appling the pattern clustering method to load patterns of the main transformers and feeders during selected period. The proposed strategy is designed and implemented in Visual C++ MFC. Finally, availability and accuracy of the proposed methodology and the design is verified from diversity simulation reviews for typical distribution substation.

Shear mechanism and bearing capacity calculation on steel reinforced concrete special-shaped columns

  • Xue, J.Y.;Chen, Z.P.;Zhao, H.T.;Gao, L.;Liu, Z.Q.
    • Steel and Composite Structures
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    • v.13 no.5
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    • pp.473-487
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    • 2012
  • An experimental study was performed to investigate the seismic performance of steel reinforced concrete (SRC) special-shaped columns. For this purpose, 17 steel reinforced concrete special-shaped column specimens under low-cyclic reversed load were tested, load process and failure patterns of the specimens with different steel reinforcement were observed. The test results showed that the failure patterns of these columns include shear-diagonal compression failure, shear-bond failure, shear-flexure failure and flexural failure. The failure mechanisms and characteristics of SRC special-shaped columns were also analyzed. For different SRC special-shaped columns, based on the failure characteristics and mechanism observed from the test, formulas for calculating ultimate shear capacity in shear-diagonal compression failure and shear-bond failure under horizontal axis and oblique load were derived. The calculated results were compared with the test results. Both the theoretical analysis and the experimental results showed that, the shear capacity of T, L shaped columns under oblique load are larger than that under horizontal axis load, whereas the shear capacity of +-shaped columns under oblique load are less than that under horizontal axis load.

Finite Element Analysis of Stress Distribution around the Micro-Patterned Implants (마이크로패터닝을 부여한 임플란트 주변골에서의 하중 분포에 관한 유한요소분석법적 연구)

  • Hur, Bae-Young;Kim, Dae-Gon;Park, Chan-Jin;Cho, Lee-Ra
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.1
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    • pp.67-76
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    • 2008
  • Implant requires long lasting, strong osseointegration using bio-mechanical interlocking by bone ingrowth. In regarding the size level for bone ingrowth, the micro-patterning would enhance bone response. Micro-patterning can increase the area contacting the bone tissues. Therefore, it may distribute the load to the surrounding bone tissue, more effectively. This study compared and analyzed the load distributing effect with the shape and number of micro-patterning. For the optimal comparison of threads, the assumptions different from general finite element analysis model were made. It was assumed that the implant was axisymmetric and infinitely long. The implant was assumed to be completely embedded in the infinitely long cortical bone and to have 100% bone apposition. The implant-bone interface had completely fixed boundary conditions and received an infinitely big axial load. The condition of threads were as follows. The reference model 1 had conventional thread. Model 2 had 2 micro-patterns on the upper flank of the thread. Model 3 had 2 micro-patterns on the lower flank of the thread. Model 4 had 2 micro-patterns on the upper and lower flanks of the thread. Model 5 had 3 micro patterns on the upper and lower flanks of the thread. The results were as follows: 1. The thread with micro-patterns distributed stress better than the conventional thread. 2. The thread with micro-patterns on the lower flank distributed stress better than that with micro-patterns on the upper flank. 3. The thread with 3 micro-patterns distributed stress better than that with 2 micro-patterns, However, an area with stress concentration occurred.

The Estimation of Incomplete Information in Electricity Markets by Using Load Pattern Changes (부하패턴을 이용한 전력시장 정보의 불완비성 추정에 관한 연구)

  • Shin, Jae-Hong;Lee, Kwang-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.5
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    • pp.848-853
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    • 2007
  • This paper presents a methodology of estimating incomplete information in electricity markets for analyzing the gaming behavior of Generating Companies (GENCOs). Each GENCO needs to model its opponents' unknown information of strategic biddings and cost functions. In electricity markets with complete information, each GENCO knows its rivals' payoff functions and tries to maximize its own profit at Nash equilibriurnl Nli) by acknowledging the rivals' cost function. On the other hand, in the incomplete information markets, each GENCO lacks information about its rivals. Load patterns can change continuously due to many factors such as weather, price, contingency, etc. In this paper, we propose the method of the estimation of the opponents' cost function using market price, transaction quantities. and customer load patterns. A numerical example with two GENCOs is illustrated to show the basic idea and effectiveness of the proposed methodology.

Analysis on learning curves of end-use appliances for the establishment of price-sensitivity load model in competitive electricity market (전력산업 경쟁 환경에서의 요금부하모델 수립을 위한 부하기기의 학습곡선 분석)

  • Hwang, Sung-Wook;Kim, Jung-Hoon;Song, Kyung-Bin;Choi, Joon-Young
    • Proceedings of the KIEE Conference
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    • 2001.07a
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    • pp.386-388
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    • 2001
  • The change of the electricity charge from cost base to price base due to the introduction of the electricity market competition causes consumer to choose a variety of charge schemes and a portion of loads to be affected by this change. Besides, it is required the index that consolidate the price volatility experienced on the power exchange with gaming and strategic bidding by suppliers to increase profits. Therefore, in order to find a mathematical model of the sensitively-responding-to-price loads, the price-sensitive load model is needed. And the development of state-of-the-art technologies affects the electricity price, so the diffusion of high-efficient end-uses and these price affect load patterns. This paper shows the analysis on learning curves algorithms which is used to investigate the correlation of the end-uses' price and load patterns.

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Development of Energy Demand Models for Hospitals (병원 건물의 에너지 부하모델 개발)

  • Park, Hwa-Choon;Chung, Mo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.11
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    • pp.636-642
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    • 2009
  • Energy consumption data are surveyed and measured to develop energy demand models for hospital buildings as part of a complete package. Daily consumption profiles for electricity, heating, cooling and hot water are surveyed for 14 carefully chosen hospitals to establish energy demand patterns for a time span of a year. Then the hourly demand patterns of the 4 loads are field-measured for different seasons and statistically analyzed to provide higher resolution models. Used in conjunction with energy demand models for other types of buildings, the high resolution of 8760 hour energy demand models for a hospital for a typical year will serve as building blocks for the comprehensive model that allows the estimation of the combined loads for arbitrary mixtures of buildings.

The Effect of surface roughness on Finished Surface orientation of Friction Characteristics (가공방향의 마찰특성에 대한 표면거칠기 영향)

  • 유응대;김태완;조용주
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.11a
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    • pp.267-272
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    • 2001
  • The effect of characteristic of surface roughness and roughness patterns on frictioin was studied experimentally in boundary lubrication with reciprocating tribometer. Roughness was changed from Ra=0.2 $\mu\textrm{m}$ to Ra=1.2 $\mu\textrm{m}$. Three roughness patterns-transverse, oblique, longitudinal- were tested for various load. Ra=1.0 $\mu\textrm{m}$ roughness showed lower friction coefficient and transversal pattern showed lower friction and high scuffing load in the test conditions.

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The Size of Crowd Pressure According to Loading Patterns (가력유형별 군중하중의 크기에 관한 실험적 연구)

  • Kim, Jin-Sik;Shin, Yun-Ho;Choi, Soo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.128-129
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    • 2016
  • This study is to categorize the loading of multiple persons on a vertical building elements into three types to test the size of crowd pressure under each loading patterns. The loading patterns is divided under the combination of loading method and loading persons. The loading method is categorized into the method of instantaneous loading of hand on a force plate and the method of continuous loading. The loading persons has been composed of 1~5 persons under the loading patterns. The loading patterns is also divided into lateral loading, longitudinal loading, and agglomeration loading. The subject group has been composed of 12 males in 20s. The load measurement device(size 1800×600×36mm, capacity 20kN, rigidity 28kN/cm) has been designed and manufactured directly. To eliminate the difference of individual, the size of crowd pressure has been converted into the strength to weight ratio (maximum load/weight) for computation. The strength to weight ratio in lateral loading was about 0.91 under instantaneous loading and about 0.47 under continuous loading. The strength to weight ratio in longitudinal loading was about 0.65 under instantaneous loading and about 0.36 under continuous loading. The strength to weight ratio in agglomeration loading was about 0.65 under instantaneous loading and about 0.36 under continuous loading.

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