• Title/Summary/Keyword: LOCATION FACTOR

Search Result 1,462, Processing Time 0.026 seconds

New Fault Location Algorithms by Direct Analysis of Three-Phase Circuit Using Matrix Inverse Lemma for Unbalanced Distribution Power Systems

  • Park, Myeon-Song;Lee, Seung-Jae
    • KIEE International Transactions on Power Engineering
    • /
    • v.3A no.2
    • /
    • pp.79-84
    • /
    • 2003
  • Unbalanced systems, such as distribution systems, have difficulties in fault locations due to single-phase laterals and loads. This paper proposes new fault locations developed by the direct three-phase circuit analysis algorithms using matrix inverse lemma for the line-to-ground fault case and the line-to-line fault case in unbalanced systems. The fault location for balanced systems has been studied using the current distribution factor, by a conventional symmetrical transformation, but that for unbalanced systems has not been investigated due to their high complexity. The proposed algorithms overcome the limit of the conventional algorithm using the conventional symmetrical transformation, which requires the balanced system and are applicable to any power system but are particularly useful for unbalanced distribution systems. Their effectiveness has been proven through many EMTP simulations.

Estimating People's Position Using Matrix Decomposition

  • Dao, Thi-Nga;Yoon, Seokhoon
    • International journal of advanced smart convergence
    • /
    • v.8 no.2
    • /
    • pp.39-46
    • /
    • 2019
  • Human mobility estimation plays a key factor in a lot of promising applications including location-based recommendation systems, urban planning, and disease outbreak control. We study the human mobility estimation problem in the case where recent locations of a person-of-interest are unknown. Since matrix decomposition is used to perform latent semantic analysis of multi-dimensional data, we propose a human location estimation algorithm based on matrix factorization to reconstruct the human movement patterns through the use of information of persons with correlated movements. Specifically, the optimization problem which minimizes the difference between the reconstructed and actual movement data is first formulated. Then, the gradient descent algorithm is applied to adjust parameters which contribute to reconstructed mobility data. The experiment results show that the proposed framework can be used for the prediction of human location and achieves higher predictive accuracy than a baseline model.

A Numerical Study on Slip Factor Variations in Centrifugal Compressor Impellers (원심압축기 임펠러의 미끄럼계수 변화에 관한 수치연구)

  • Oh, Jongsik
    • The KSFM Journal of Fluid Machinery
    • /
    • v.2 no.3 s.4
    • /
    • pp.17-23
    • /
    • 1999
  • In the present numerical analysis, investigation of the effect of blade loadings from design shape on the slip factor variation was studied. Both the Eckardt radial bladed impeller and the backswept impeller were analyzed. In addition, a new design of the blade profile was arbitrarily attempted to generate a center-loading pattern in the original backswept impeller. Three dimensional compressible Navier-Stokes flow analysis with the Baldwin-Lomax turbulence model was applied to get the numerical slip factor at each impeller exit plane using the mass-averaging technique. The numerical slip (actors are in good agreement with the experimental ones and the Wiesner's slip factors deviate further from the numerical and experimental ones in both backswept impellers. Deviation angles and meridional channel loadings are found in no relation with the trend of change of the slip factor. Blade-to-blade loadings in midspan location are, however, found to have a direct relationship, especially at the sections where maximum loadings we to be expected. That information can be utilized in establishing an improved expression for slip factors in the future.

  • PDF

Store Preference on the Clothing Involvement and Body Cathexis of Elderly Women (노년기 여성의 신체만족도와 의복관여도에 따른 점포선호에 관한 연구)

  • 홍병숙
    • Journal of the Korean Home Economics Association
    • /
    • v.34 no.4
    • /
    • pp.245-256
    • /
    • 1996
  • The purpose of this study were 1) to understand clothing involvement and body cathexis of elderly women, 2) to examine differences between store atmosphere factor on clothing involvement and body cathexis, 3) to find out its relationship with clothing involvement and body cathexis. Data were collected by questionnaire of 248 elderly women. Frequency, factor analysis, Chi-square, t-test, F-test, F-test, correlation and Duncan's multiple range test were used in data analysis. As a result, 1) clothing involvement of elderly women were classified with importance, fashion and interest, symbolism factor and there was significant differences with display, comfort, interior, convenience factor. 2) Elderly women were not satisfied with their body sufficiently and there was significant differences only display factor(store location, show window, display). 3) Clothing involvement was significant differences variables were found in relationship to body cathexis except income. 4) There was positive correlation between clothing involvement and body cathexis. The higher body cathexis, the more interest clothing.

  • PDF

Application of inverse reliability method to estimation of flutter safety factors of suspension bridges

  • Cheng, Jin;Dong, Fenghui
    • Wind and Structures
    • /
    • v.24 no.3
    • /
    • pp.249-265
    • /
    • 2017
  • An efficient and accurate algorithm is proposed to estimate flutter safety factor of suspension bridges satisfying prescribed reliability levels. Uncertainties which arise from the basic wind speed at the bridge deck location, critical flutter velocity, the wind conversion factor from a scaled model to the prototype structure and the gust speed factor are incorporated. The proposed algorithm integrates the concepts of the inverse reliability method and the calculation method of the critical flutter velocity of suspension bridges. The unique feature of the proposed method is that it offers a tool for flutter safety assessment of suspension bridges, when the reliability level is specified as a target to be satisfied by the designer. Accuracy and efficiency of this method with reference to three example suspension bridges is studied and numerical results validate its superiority over conventional deterministic method. Finally, the effects of various parameters on the flutter safety factor of suspension bridges are also investigated.

Analysis of correlation between activity factor ash and chemical composition by location and lot in fly ash (플라이애시 생산지 및 로트별 화학조성과 모르타르 활성도 지수의 상관관계 분석)

  • Kim, Hwan-Soo;Park, Kwang-Hoon;Song, Yong-Soon;Kang, Suck-Hwa
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2010.05a
    • /
    • pp.307-308
    • /
    • 2010
  • In this study we've tested on correlation between activity factor and locaton and lot in fly ash, which fundamental reserch for concrete compressive strength developments by quality propeties in fly ash.

  • PDF

Estimation of Angular Location and Directivity Compensation of Split-beam Acoustic Transducer for a 50 kHz Fish Sizing Echo Sounder (50 kHz 체장어군탐지기용 분할 빔 음향 변환기의 지향성 보정 및 위치각 추정)

  • Lee, Dae-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.44 no.4
    • /
    • pp.423-430
    • /
    • 2011
  • The most satisfactory split-beam transducer for fish sizing maintains a wide bearing angle region for correct fish tracking without interference from side lobes and lower sensitivity to fish echoes outside of the main lobe region to correctly measure the angular location of free-swimming fishes in the sound beam. To evaluate the performance of an experimentally developed 50 kHz split-beam transducer, the angular location of a target was derived from the electrical phase difference between the resultant signals for the pair of transducer quadrants in the horizontal and vertical planes consisting of 32 transducer elements. The electrical phase difference was calculated by cross-spectral density analysis for the signals from the pair of receiving transducer quadrants, and the directivity correction factor for a developed split-beam transducer was estimated as the fourth-order polynomial of the off-axis beam angle for the angular location of the target. The experimental results demonstrate that the distance between the acoustic centers for the pair of receiving transducer quadrants can be controlled to less than one wavelength by optimization with amplitude-weighting transformers, and a smaller center spacing provides a range of greater angular location for tracking of a fish target. In particular, a side lobe level of -25.2 dB and an intercenter spacing of $0.96\lambda$($\lambda$= wavelength) obtained in this study suggest that the angular location of fish targets distributing within a range of approximately ${\pm}28^{\circ}$ without interference from side lobes can be measured.

A Study on the Suggestion of a Lighting Control System Applying General Illumination and Technology of User and Location Awareness (전반조명 기반 사용자 및 위치인식기술 적용 조명제어 시스템 제안 연구)

  • Park, Juil;Lee, Haengwoo;Seo, Janghoo;Kim, Yongseong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.27 no.10
    • /
    • pp.527-536
    • /
    • 2015
  • Studies for the reduction of lighting energy have been done using technologies such as user and location awareness. However, the focus of current research on location-based lighting control has been on energy reduction, which can lead to other issues including an imbalance in indoor illumination. This study proposes a lighting control system applying general illumination and technology for user and location awareness. The proposed lighting control system reduced lighting energy by 72.1%, 66.5% and 62.3% for 1, 2 and 3 users, respectively, compared to the On/Off lighting control system. This lighting control system causes an increase in lighting energy of 35.8% and 10.9% for 1 and 2 users compared to the lighting control system with user and location awareness, while a reduction of 9.4% was seen for 3 users. This means that the proposed system provides more effective energy reduction for a room with multiple occupants as it is based on the general lighting control scheme. The lighting control system applying general illumination and technology of user and location awareness improved the uniformity factor by 32.0%, 39.4% and 33.4% for 1, 2 and 3 users, respectively.

Red Ginseng Quality and Characteristics of KG101 a Promising Line of Panax Ginseng C.A. Meyer (인삼 우수계통 KG101의 생육과 홍삼품질)

  • 권우생;강제용
    • Journal of Ginseng Research
    • /
    • v.22 no.4
    • /
    • pp.244-251
    • /
    • 1998
  • KG101 was developed by the Korea Ginseng & Tobacco Research Institute. We reported about yield trials and local adaptability test. Growth characteristics and red ginseng quality of KG101 in local performance test can be summarized as follows. Aerial parts growth, stem and leaf, was similar about KG101 and Jakyungjong, 4-year old and 6-year old ginseng. Emergence rate of KG101 was higher than Jakyungjong in the 3 location of local performance test. Taproot diameter of KG101 was smaller than Jakyungjong and taproot shape of KG101 had fitted characteristics, radish type and human body type, to manufactured red ginseng. Raw ginseng grade, 1st and 2nd of KG101 was higher than Jakyungjong's. Chun, Jeesam ratio to manufacture of 2nd grade of raw ginseng of KG101 was 25%, Jakyungjong was 6-13% in 3 location of local performance test. Distribution of red ginseng weight of Jakyungiong was heavier than KG101 in 2 location, Kongju and Jungup, but KG101 was heavier than Jakyungjong in Ichon. Red ginseng quality of KG101 was better than Jakyungiong. Main degrade factor of red ginseng quality was inside cavity and inside white, was not different lines and location.

  • PDF

Modified Transmission Line Protection Scheme in the Presence of SCC

  • Naeini, Ehsan Mostaghimi;Vaseghi, Behrouz;Mahdavian, Mehdi
    • Journal of Electrical Engineering and Technology
    • /
    • v.12 no.2
    • /
    • pp.533-540
    • /
    • 2017
  • Distance relay identifies the type and location of fault by measuring the transmission line impedance. However any other factors that cause miss calculating the measured impedance, makes the relay detect the fault in incorrect location or do not detect the fault at all. One of the important factors which directly changes the measured impedance by the relay is series capacitive compensation (SCC). Another factor that changes the calculated impedance by distance relay is fault resistance. This paper provides a method based on the combination of distance and differential protection. At first, faulty transmission line is detected according to the current data of buses. After that the fault location is calculated using the proposed algorithm on the transmission line. This algorithm is based on active power calculation of the buses. Fault resistance is calculated from the active powers and its effect will be deducted from calculated impedance by the algorithm. This method measures the voltage across SCC by phasor measurement units (PMUs) and transmits them to the relay location via communication channels. The transmitted signals are utilized to modify the voltage signal which is measured by the relay. Different operating modes of SCC and as well as different faults such as phase-to-phase and phase-to-ground faults are examined by simulations.