• Title/Summary/Keyword: power curve

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Random Point Blinding Methods for Koblitz Curve Cryptosystem

  • Baek, Yoo-Jin
    • ETRI Journal
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    • v.32 no.3
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    • pp.362-369
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    • 2010
  • While the elliptic curve cryptosystem (ECC) is getting more popular in securing numerous systems, implementations without consideration for side-channel attacks are susceptible to critical information leakage. This paper proposes new power attack countermeasures for ECC over Koblitz curves. Based on some special properties of Koblitz curves, the proposed methods randomize the involved elliptic curve points in a highly regular manner so the resulting scalar multiplication algorithms can defeat the simple power analysis attack and the differential power analysis attack simultaneously. Compared with the previous countermeasures, the new methods are also noticeable in terms of computational cost.

A Study on a Methodology of Determining an Appropriate Load Power Factor Effectively by the Use of Reactive Power Sensitivity and Load Duration Curve (무효전력 민감도와 부하지속곡선을 활용한 적정 부하역률의 효과적인 산정 기법에 관한 연구)

  • Lee, Byung Ha;Hwang, Sung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.12
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    • pp.1782-1790
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    • 2012
  • In this paper, a methodology to use load duration curve and the reactive power factor sensitivity of generation cost is proposed for analyzing the effects of load power factor effectively. A great deal of cases of power systems are classified into several patterns according to the characteristics using load duration curve, and the overall effects of load power factor are assessed by integrating the analysis results of load power factor in all the patterns. The reactive power sensitivity of generation cost and the integrated costs such as generation cost, investment cost, voltage variation penalty cost and CO2 emission cost are used for determining an appropriate load power factor. A systematic procedure for effective analysis of load power factor is presented. It is shown through the application to the practical power system of KEPCO(Korea Electric Power Corporation)that the effects of load power factor can be analyzed effectively using load duration curve and reactive power factor sensitivity.

Measured AEP Evaluations of a Small Wind Turbine using Measured Power Curve & Wind Data (측정 출력곡선과 기상자료를 이용한 소형 풍력발전기 연간 발전량 비교평가)

  • Kim, Seokwoo
    • Journal of the Korean Solar Energy Society
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    • v.33 no.6
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    • pp.32-38
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    • 2013
  • In an efforts to encourage renewable energy deployment, the government has initiated so called 1 million green homes program but the accumulated installation capacity of small wind turbine has been about 70kW. It can be explained in several ways such that current subsidy program does not meet public expectations, economic feasibility of wind energy is in doubt or acoustic emission is significant etc. The author investigated annual energy production of Skystream 3.7 wind turbine using measured power curve and wind resource data. The measured power curve of the small wind turbine was obtained through power performance tests at Wol-Ryoung test site. AEP(Annual Energy Production) and CF(Capacity Factor) were evaluated at selected locations with the measured power curve.

Flexible Prime-Field Genus 2 Hyperelliptic Curve Cryptography Processor with Low Power Consumption and Uniform Power Draw

  • Ahmadi, Hamid-Reza;Afzali-Kusha, Ali;Pedram, Massoud;Mosaffa, Mahdi
    • ETRI Journal
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    • v.37 no.1
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    • pp.107-117
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    • 2015
  • This paper presents an energy-efficient (low power) prime-field hyperelliptic curve cryptography (HECC) processor with uniform power draw. The HECC processor performs divisor scalar multiplication on the Jacobian of genus 2 hyperelliptic curves defined over prime fields for arbitrary field and curve parameters. It supports the most frequent case of divisor doubling and addition. The optimized implementation, which is synthesized in a $0.13{\mu}m$ standard CMOS technology, performs an 81-bit divisor multiplication in 503 ms consuming only $6.55{\mu}J$ of energy (average power consumption is $12.76{\mu}W$). In addition, we present a technique to make the power consumption of the HECC processor more uniform and lower the peaks of its power consumption.

Power Curve Measurements on the 6kW Wind Turbine (6kW 풍력발전기의 출력곡선 측정)

  • Yoo, Neung-Soo;Nam, Yoon-Su;Lee, Jung-Wan;Cho, Joo-Suk
    • Journal of Industrial Technology
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    • v.25 no.B
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    • pp.149-157
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    • 2005
  • The power performance monitoring system for a small class of wind turbine is established. The wind turbine power performance characteristics are determined by measured power curve and the estimated annual energy production (AEP). The measured power curve is determined by collecting simultaneous measurements of wind speed and power output at the test site under varying wind conditions. In order to determine the power performance characteristics of the wind turbine accurately, the data are of sufficient quantity and quality shall be corrected according to defined criteria. In this study, the 6kW wind turbine made by Germany Inventus GmbH is examined.

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A Direct Expansion Algorithm for Transforming B-spline Curve into a Piecewise Polynomial Curve in a Power Form. (B-spline 곡선을 power 기저형태의 구간별 다항식으로 바꾸는 Direct Expansion 알고리듬)

  • 김덕수;류중현;이현찬;신하용;장태범
    • Korean Journal of Computational Design and Engineering
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    • v.5 no.3
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    • pp.276-284
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    • 2000
  • Usual practice of the transformation of a B-spline curve into a set of piecewise polynomial curves in a power form is done by either a knot refinement followed by basis conversions or applying a Taylor expansion on the B-spline curve for each knot span. Presented in this paper is a new algorithm, called a direct expansion algorithm, for the problem. The algorithm first locates the coefficients of all the linear terms that make up the basis functions in a knot span, and then the algorithm directly obtains the power form representation of basis functions by expanding the summation of products of appropriate linear terms. Then, a polynomial segment of a knot span can be easily obtained by the summation of products of the basis functions within the knot span with corresponding control points. Repeating this operation for each knot span, all of the polynomials of the B-spline curve can be transformed into a power form. The algorithm has been applied to both static and dynamic curves. It turns out that the proposed algorithm outperforms the existing algorithms for the conversion for both types of curves. Especially, the proposed algorithm shows significantly fast performance for the dynamic curves.

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Test of Normality Based on the Normalized Sample Lorenz Curve

  • Kang, Suk-Bok;Cho, Young-Suk
    • Communications for Statistical Applications and Methods
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    • v.8 no.3
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    • pp.851-858
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    • 2001
  • Using the normalized sample Lorenz curve which is introduced by Kang and Cho (2001), we propose the test statistics for testing of normality that is very important test in statistical analysis and compare the proposed test with the other tests in terms of the power of test through by Monte Carlo method. The proposed test is more power than the other tests except some cases

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Stability Analysis of Jeju Power System with Wind Turbine Generators and HVDC (풍력발전설비 및 HVDC가 도입된 제주도 계통에 대한 안정도 해석)

  • Kim, Do-Hyung;Kim, Jae-Eon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.11
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    • pp.1897-1904
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    • 2008
  • In this paper, the method for effective stability analysis of Jeju power system in 2011 is proposed. The stability analysis of Jeju power system was carried out by using proposed method In case of Jeju power system with wind turbine generators or without wind turbine generators, including CSC HVDC or VSC HVDC. The steady-state stability is validated by SCR and ESCR, PV curve, QV curve. And the transient stability is analyzed by CCT(Critical Clearing Time). VSC HVDC has more advantages than CSV HVDC on the stability. Also, Jeju power system without wind turbine generators has more advantages than Jeju power system with Wind Turbine Generators on the stability.

Changes of Recloser's TC Curve for the Improvement of Distribution Line Protection Coordination (배전선로 보호협조 개선을 위한 리클로져 TC커브 변경)

  • Lee, Jung-Ho;Ha, Bok-Nam;Cho, Ham-Hun
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.964-966
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    • 1998
  • The TC curve of recloser which used in KEPCO's distribution line is a little different in a pattern with the TC curve of sub-station OCR. So it sometimes fails in protection coordination. And the recloser sometimes does mis-open/close owing to the inrush current of CB reclosing when a fault occurred on the source-side of the recloser. The mis-open/close is another trouble maker. This Paper Present a new delay TC curve of recloser which has the same pattern with the TC curve of OCR, and a new instantaneous TC curve of recloser which doesn't mal-function to the inrush current. In addition, this paper present another two TC curves for the serial positioning of 2 reclosers. So we accomplished the simple protection coordination of OCR-recloser-fuse.

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The Power Performance Testing for 3MW Wind turbine System (3MW 풍력발전시스템 출력성능평가에 관한 연구)

  • Ko, Suk-Whan;Jang, Moon-Seok;Park, Jong-Po;Lee, Yoon-Su
    • Journal of the Korean Solar Energy Society
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    • v.31 no.4
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    • pp.19-26
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    • 2011
  • We are carried out power performance testing for 3MW wind turbine system at Je-ju wind turbine testing Site and analyzed measured data which was stored through monitoring system. In this paper, we described the power performance testing results and analyzed an uncertainty of measured data sets. The power curve with measured power data is closely coincide with designed power curve except for the low wind speed sections(4m/s~7m/s) and the annual energy production which is given Ray leigh distribution was included with 1.5~5.9% of uncertainty in the wind speed region as 4~11m/s. Although the deviation of curve between measured power and designed power is high, the difference of annual energy production is low in the low wind speed region.