This paper presents an approach for estimating power of the score test, based on an asymptotic approximation to the power of the score test under contiguous alternatives. The method is applied to the problem of power ...This paper presents an approach for estimating power of the score test, based on an asymptotic approximation to the power of the score test under contiguous alternatives. The method is applied to the problem of power calculations for the score test of heteroscedasticity in European rabbit data （Ratkowsky, 1983）. Simulation studies are presented which indicate that the asymptotic approximation to the finite-sample situation is good over a wide range of parameter configurations.展开更多
This paper describes a conceptual design study for the circuit configuration of the Error Field Correction Coil （EFCC） power supply （PS） to maximize the expected performance with reasonable cost in JT-60SA. The EF...This paper describes a conceptual design study for the circuit configuration of the Error Field Correction Coil （EFCC） power supply （PS） to maximize the expected performance with reasonable cost in JT-60SA. The EFCC consists of eighteen sector coils installed inside the vacuum vessel, six in the toroidal direction and three in the poloidal direction, each one rated for 30 kA-turn. As a result, star point connection is proposed for each group of six EFCC coils installed cyclically in the toroidal direction for decoupling with poloidal field coils. In addition~ a six phase inverter which is capable of controlling each phase current was chosen as PS topology to ensure higher flexibility of operation with reasonable cost.展开更多
The growing problems of harmonic pollution on coal mine power lines caused by high-power DC drive systems has increased the use of active power filters.We analyzed compensation errors caused by the time lag in the det...The growing problems of harmonic pollution on coal mine power lines caused by high-power DC drive systems has increased the use of active power filters.We analyzed compensation errors caused by the time lag in the detecting circuits of an active power filter based on DSP control.We derived a mathematical model for the compensation error starting from the error estimation when a single distortion frequency is present.This model was then extended to the case where multiple frequencies are present in the distortion.A formula for a general theory of compensation error with fixed load and fixed lag time is presented.The theoretical analysis and experimental results show that the delay time of an active power filter mainly arises from the sampling time.Lower sampling frequencies introduce larger compensation errors in the active power filter reference current.展开更多
Error-tolerant IR(international relation)theory is constructed on the base of error-tolerant powers paradigm and error-tolerant economics.Error-tolerant powers paradigm takes the integration between trial and error an...Error-tolerant IR(international relation)theory is constructed on the base of error-tolerant powers paradigm and error-tolerant economics.Error-tolerant powers paradigm takes the integration between trial and error and anarchy as the starting point of IR theory and upholds that the power to trial and error is an original power,for which states compete.So the core concept of realism should be the original power to trial and error;error-tolerant economics argues that liberal IR theory enables hegemonic powers to compete for their original power to trial and error in an implicit way.Error-tolerant powers paradigm regards that states who truly control original powers to trial and error can define identities and create shared knowledge,which is the core of constructivism.Besides taking the original power to trial and error as the core concept,error-tolerant IR theory can unify three major schools of realism,liberalism,and constructivism by relative right-doing and trial-and-error capabilities,and corresponding costs as endogenous drives.展开更多
Short-term power flow analysis has a significant influence on day-ahead generation schedule. This paper proposes a time series model and prediction error distribution model of wind power output. With the consideration...Short-term power flow analysis has a significant influence on day-ahead generation schedule. This paper proposes a time series model and prediction error distribution model of wind power output. With the consideration of wind speed and wind power output forecast error’s correlation, the probabilistic distributions of transmission line flows during tomorrow’s 96 time intervals are obtained using cumulants combined Gram-Charlier expansion method. The probability density function and cumulative distribution function of transmission lines on each time interval could provide scheduling planners with more accurate and comprehensive information. Simulation in IEEE 39-bus system demonstrates effectiveness of the proposed model and algorithm.展开更多
A generalized form of the error function, Gp(x)=pΓ(1/p)∫0xe−tpdt, which is directly associated with the gamma function, is evaluated for arbitrary real values of p>1and 0x≤+∞by employing a fast-converging power...A generalized form of the error function, Gp(x)=pΓ(1/p)∫0xe−tpdt, which is directly associated with the gamma function, is evaluated for arbitrary real values of p>1and 0x≤+∞by employing a fast-converging power series expansion developed in resolving the so-called Grandi’s paradox. Comparisons with accurate tabulated values for well-known cases such as the error function are presented using the expansions truncated at various orders.展开更多
The energy model was founded to calculate the critical power of keyhole formation by using the limit principle in CW （ continuous wave ） Nd： YAG laser deep penetration welding process. The model was validated by ex...The energy model was founded to calculate the critical power of keyhole formation by using the limit principle in CW （ continuous wave ） Nd： YAG laser deep penetration welding process. The model was validated by experiments. The results show that ＇.there are two errors between the calculated critical power of keyhole formation and that of experiments ： one is that the calculated results is less than those of experiments, which is caused by not considering the energy loss by heat conduction in the model of keyhole formation. The other is that there is 0. 9 mm error between the axis of the calculated curve of critical power with location of laser focus and that of experimental curve, which is induced by the excursion of laser focus in laser deep penetration welding. At last, the two errors were revised according to the analyses of the errors.展开更多
智能电能表在复杂电网环境下的计量精度易受非线性误差影响。为提高其准确性,提出一种融合非线性自回归外生输入(nonlinear auto-regressive with exogenous inputs,NARX)模型与畸变功率的误差校正方法。利用NARX模型构建电能表的非线...智能电能表在复杂电网环境下的计量精度易受非线性误差影响。为提高其准确性,提出一种融合非线性自回归外生输入(nonlinear auto-regressive with exogenous inputs,NARX)模型与畸变功率的误差校正方法。利用NARX模型构建电能表的非线性误差模型,以捕捉其动态特性;从测量数据中分离基波与谐波电能,并计算谐波电能比差以量化谐波影响;引入畸变功率概念,构建以谐波电能比差和畸变功率为输入的误差校正模型,对非线性误差进行补偿。实验结果表明:经所提方法校正后,在不同谐波含量(5%、10%、20%)条件下,智能电能表的最大计量误差由校正前的2.4%、3.1%、10.3%均降至0.5%左右,同时非线性误差预测结果的拟合度得到了提升,有效提高了谐波环境下的计量精度。展开更多
基金Supported by SSFC（04BTJ002）,the National Natural Science Foundation of China（10371016） and the Post-Doctorial Grant in Southeast University.
文摘This paper presents an approach for estimating power of the score test, based on an asymptotic approximation to the power of the score test under contiguous alternatives. The method is applied to the problem of power calculations for the score test of heteroscedasticity in European rabbit data （Ratkowsky, 1983）. Simulation studies are presented which indicate that the asymptotic approximation to the finite-sample situation is good over a wide range of parameter configurations.
基金supported within the framework of the "Broader Approach Internationals Agreement"
文摘This paper describes a conceptual design study for the circuit configuration of the Error Field Correction Coil （EFCC） power supply （PS） to maximize the expected performance with reasonable cost in JT-60SA. The EFCC consists of eighteen sector coils installed inside the vacuum vessel, six in the toroidal direction and three in the poloidal direction, each one rated for 30 kA-turn. As a result, star point connection is proposed for each group of six EFCC coils installed cyclically in the toroidal direction for decoupling with poloidal field coils. In addition~ a six phase inverter which is capable of controlling each phase current was chosen as PS topology to ensure higher flexibility of operation with reasonable cost.
基金provided by the National Basic Research Program of China (No.2005CB221505)
文摘The growing problems of harmonic pollution on coal mine power lines caused by high-power DC drive systems has increased the use of active power filters.We analyzed compensation errors caused by the time lag in the detecting circuits of an active power filter based on DSP control.We derived a mathematical model for the compensation error starting from the error estimation when a single distortion frequency is present.This model was then extended to the case where multiple frequencies are present in the distortion.A formula for a general theory of compensation error with fixed load and fixed lag time is presented.The theoretical analysis and experimental results show that the delay time of an active power filter mainly arises from the sampling time.Lower sampling frequencies introduce larger compensation errors in the active power filter reference current.
文摘Error-tolerant IR(international relation)theory is constructed on the base of error-tolerant powers paradigm and error-tolerant economics.Error-tolerant powers paradigm takes the integration between trial and error and anarchy as the starting point of IR theory and upholds that the power to trial and error is an original power,for which states compete.So the core concept of realism should be the original power to trial and error;error-tolerant economics argues that liberal IR theory enables hegemonic powers to compete for their original power to trial and error in an implicit way.Error-tolerant powers paradigm regards that states who truly control original powers to trial and error can define identities and create shared knowledge,which is the core of constructivism.Besides taking the original power to trial and error as the core concept,error-tolerant IR theory can unify three major schools of realism,liberalism,and constructivism by relative right-doing and trial-and-error capabilities,and corresponding costs as endogenous drives.
文摘Short-term power flow analysis has a significant influence on day-ahead generation schedule. This paper proposes a time series model and prediction error distribution model of wind power output. With the consideration of wind speed and wind power output forecast error’s correlation, the probabilistic distributions of transmission line flows during tomorrow’s 96 time intervals are obtained using cumulants combined Gram-Charlier expansion method. The probability density function and cumulative distribution function of transmission lines on each time interval could provide scheduling planners with more accurate and comprehensive information. Simulation in IEEE 39-bus system demonstrates effectiveness of the proposed model and algorithm.
文摘A generalized form of the error function, Gp(x)=pΓ(1/p)∫0xe−tpdt, which is directly associated with the gamma function, is evaluated for arbitrary real values of p>1and 0x≤+∞by employing a fast-converging power series expansion developed in resolving the so-called Grandi’s paradox. Comparisons with accurate tabulated values for well-known cases such as the error function are presented using the expansions truncated at various orders.
文摘The energy model was founded to calculate the critical power of keyhole formation by using the limit principle in CW （ continuous wave ） Nd： YAG laser deep penetration welding process. The model was validated by experiments. The results show that ＇.there are two errors between the calculated critical power of keyhole formation and that of experiments ： one is that the calculated results is less than those of experiments, which is caused by not considering the energy loss by heat conduction in the model of keyhole formation. The other is that there is 0. 9 mm error between the axis of the calculated curve of critical power with location of laser focus and that of experimental curve, which is induced by the excursion of laser focus in laser deep penetration welding. At last, the two errors were revised according to the analyses of the errors.
文摘智能电能表在复杂电网环境下的计量精度易受非线性误差影响。为提高其准确性,提出一种融合非线性自回归外生输入(nonlinear auto-regressive with exogenous inputs,NARX)模型与畸变功率的误差校正方法。利用NARX模型构建电能表的非线性误差模型,以捕捉其动态特性;从测量数据中分离基波与谐波电能,并计算谐波电能比差以量化谐波影响;引入畸变功率概念,构建以谐波电能比差和畸变功率为输入的误差校正模型,对非线性误差进行补偿。实验结果表明:经所提方法校正后,在不同谐波含量(5%、10%、20%)条件下,智能电能表的最大计量误差由校正前的2.4%、3.1%、10.3%均降至0.5%左右,同时非线性误差预测结果的拟合度得到了提升,有效提高了谐波环境下的计量精度。
