[Objective] The study was to analyze functional components in improved barley grains. [Method] Genetic variations of functional components in grains among 629 barley improved lines from four continents were determined...[Objective] The study was to analyze functional components in improved barley grains. [Method] Genetic variations of functional components in grains among 629 barley improved lines from four continents were determined with DU640-type ultraviolet spectrophotometry (BECKMAN). [Result] The contents (mg/100 g) of total flavones and GABA in grains of Asian barley lines (123.09±29.56, 9.49±4.34) were significantly higher than that of American barley lines (103.85±22.33, 7.38±3.59), while no significant difference was observed between Asia/Americas and Europe (115.47±11.41, 9.66±3.98) and Australia (104.20±4.76, 8.83±3.41); furthermore, there was no significant difference of resistant starch content (%) in barley grains among four continents [Asia (1.63±1.44), America (1.54±1.13), Europe (1.20±0.85) and Australia (0.27±0.26)]. The contents (%) of resistant starch in grains of two-rowed barley (ssp. Hordeum distichon Koern., 1.45±1.20) was significantly lower than that of poly-rowed barley (ssp. Hordeum vulgare Orlov., 1.95±1.24). On the contrary, the content of total flavones in two-rowed lines (111.43±27.79 mg/100 g) was significantly higher than that of poly-rowed lines (102.15±14.95 mg/100 g), and the content of GABA in two-rowed lines (8.55±3.73 mg/100 g) was also significantly higher than that of poly-rowed lines (5.96±3.95 mg/100 g). There was the most significant correlation between GABA content and resistant starch (-0.21**)/total flavones content (0.12**, P<0.01, n=629). There were great genotype differences among the functional components in barley grains. The coefficient of variation (78.60%) and range (0-9.29%) of resistant starch (1.56±1.22%) were relatively large, including 11 high-resistant starch lines above 5%; the coefficient of variation (49.00%) and range (0-30.67 mg/100g) of GABA (8.00±3.92 mg/100 g) were also relatively large, including 26 lines with GABA higher than 15 mg/100 g; the coefficient of variation (23.63%) and range (58.44-236.91 mg/100 g) of total flavones (109.44±25.85 mg/100 g) was relatively small, including 14 lines with total flavones higher than 176 mg/100 g. [Conclusion] There are zonal and genotypic differences in the contents of of functional components in barley grains.展开更多
Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model＇s three-dimensional variational assimilation system, t...Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model＇s three-dimensional variational assimilation system, this study compares the be- havior of two momentum control variable options-streamfunction velocity potential （ψ-χ） and horizontal wind components （U-V）-in radar wind data assimilation for a squall line case that occurred in Jiangsu Province on 24 August 2014. The wind increment from the single observation test shows that the ψ-χ control variable scheme produces negative increments in the neighborhood around the observation point because streamfunction and velocity potential preserve integrals of velocity. On the contrary, the U-V control variable scheme objectively reflects the information of the observation itself. Furthermore, radial velocity data from 17 Doppler radars in eastern China are assimilated. As compared to the impact of conventional observation, the assimilation of radar radial velocity based on the U-V control variable scheme significantly improves the mesoscale dynamic field in the initial condition. The enhanced low-level jet stream, water vapor convergence and low-level wind shear result in better squall line forecasting. However, the ψ-χ control variable scheme generates a discontinuous wind field and unrealistic convergence/divergence in the analyzed field, which lead to a degraded precipitation forecast.展开更多
Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the lev...Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.展开更多
Over the past seven decades, the grain yield of maize(Zea mays L.) has increased continuously in China, mostly due to hybridization innovations, particularly recent genetic improvements in photosynthesis. In order to ...Over the past seven decades, the grain yield of maize(Zea mays L.) has increased continuously in China, mostly due to hybridization innovations, particularly recent genetic improvements in photosynthesis. In order to reveal photosynthetic characters of elite inbred lines in different ears, a field experiment was conducted at the North China Plain of Shandong Province in China. Six parental lines of maize introduced in three eras(the 1960 s, 1980 s, and 2000 s) were investigated diurnal variation of gas exchange, chlorophyll fluorescence, and photosynthetic response characteristic at the grain filling stage. Compared to earlier parental lines, the 2000 s parental lines always had higher net photosynthetic rate(Pn) throughout the day, especially at noon, and a mid-day depression in Pn did not occur in all hybrids parental lines. Moreover, the stomatal conductance(Gs) and water use efficiency(WUE) of the 2000 s’ lines showed higher value than those of the 1960 s’ and 1980 s’ lines. The inbred lines differences in photosynthetic parameters were partly owing to their different quantum carboxylation efficiencies and light synthase activities. Simultaneously, the 2000 s parental lines exhibited lower light and CO2 compensation points, and their higher apparent quantum yield, and carboxylation efficiency. These suggested that the modern parental lines required lower light intensity and less CO2 to maintain a relatively high photosynthetic capacity, substantially increasing leaf physical quality and stress resistance. It provided crucial information of high photo-efficiency and stress-resistance breeding in maize.展开更多
Plumb line variations (PLV) of points at Tangshan and Midu during 1985-1998 are determined by using the 46 batch repeated gravity observations of the Beijing-Tangshan network and 32 batch repeated gravity observations...Plumb line variations (PLV) of points at Tangshan and Midu during 1985-1998 are determined by using the 46 batch repeated gravity observations of the Beijing-Tangshan network and 32 batch repeated gravity observations of the West-Yunan network. As for Tangshan region, relation between underground matter change (UMC) and the PLV on ground are discussed and approach of determining the UMC by a derived regional PLV is found. The UMC before and after earthquake(1995.10.05, Mb 5.0)in Tangshan region, as an example, is studied, giving the location and depth of the mass center of underground disturbing body as well as its mass quantity.展开更多
Efficient estimation of line spectral from quantized samples is of significant importance in information theory and signal processing,e.g.,channel estimation in energy efficient massive MIMO systems and direction of a...Efficient estimation of line spectral from quantized samples is of significant importance in information theory and signal processing,e.g.,channel estimation in energy efficient massive MIMO systems and direction of arrival estimation.The goal of this paper is to recover the line spectral as well as its corresponding parameters including the model order,frequencies and amplitudes from heavily quantized samples.To this end,we propose an efficient gridless Bayesian algorithm named VALSE-EP,which is a combination of the high resolution and low complexity gridless variational line spectral estimation(VALSE)and expectation propagation(EP).The basic idea of VALSE-EP is to iteratively approximate the challenging quantized model of line spectral estimation as a sequence of simple pseudo unquantized models,where VALSE is applied.Moreover,to obtain a benchmark of the performance of the proposed algorithm,the Cram′er Rao bound(CRB)is derived.Finally,numerical experiments on both synthetic and real data are performed,demonstrating the near CRB performance of the proposed VALSE-EP for line spectral estimation from quantized samples.展开更多
The arc-suppression coil(ASC)in parallel low resistance(LR)multi-mode grounding is adopted in the mountain wind farm to cope with the phenomenon that is misoperation or refusal of zero-sequence protection in LR ground...The arc-suppression coil(ASC)in parallel low resistance(LR)multi-mode grounding is adopted in the mountain wind farm to cope with the phenomenon that is misoperation or refusal of zero-sequence protection in LR grounding wind farm.If the fault disappears before LR is put into the system,it is judged as an instantaneous fault;while the fault does not disappear after LR is put into the system,it is judged as a permanent fault;the single-phase grounding fault(SLG)protection criterion based on zerosequence power variation is proposed to identify the instantaneous-permanent fault.Firstly,the distribution characteristic of zero-sequence voltage(ZSV)and zero-sequence current(ZSC)are analyzed after SLGfault occurs in multi-mode grounding.Then,according to the characteristics that zero-sequence power variation of non-fault collector line is small,while the zero-sequence power variation of fault collector line can reflect the active power component of fault resistance,the protection criterion based on zero-sequence power variation is constructed.The theoretical analysis and simulation results show that the protection criterion can distinguish the property of fault only by using the single terminal information,which has high reliability.展开更多
Rate of exserted stigmas (RES), ie. the ratio of glumes with exserted stigmas to the total glumes is one of the most important characteristics which affects the out-crossing rate of its combinations. Sixteen P(T) GMS ...Rate of exserted stigmas (RES), ie. the ratio of glumes with exserted stigmas to the total glumes is one of the most important characteristics which affects the out-crossing rate of its combinations. Sixteen P(T) GMS lines with different ecotypes were used to study the variations of RES during their stable sterile period in Wuhan from 1992—1993. Ten healthy panicles were randomly selected at full anthesis. Their colour and the number of glumes showing one-side or two-side exserted of stigmas were investigated. Table 1 showed that there were a great variations of RES among the 16 lines tested in two consecutive years (c.v.=43.38%) and among the展开更多
Eight lines of temperature-responsive leaf colormutants induced by applying 300 Gy Gamma-ray irradiation to Thermo-sensitive genic malesterile line 2177s,were obtained through con-tinuous selection in seven generation...Eight lines of temperature-responsive leaf colormutants induced by applying 300 Gy Gamma-ray irradiation to Thermo-sensitive genic malesterile line 2177s,were obtained through con-tinuous selection in seven generations..Theleaves of these lines started to become greenafter the fourth leaf extension,and except展开更多
As the feature size of the CMOS integrated circuit continues to shrink, process variations have become a key factor affecting the interconnect performance. Based on the equivalent Elmore model and the use of the polyn...As the feature size of the CMOS integrated circuit continues to shrink, process variations have become a key factor affecting the interconnect performance. Based on the equivalent Elmore model and the use of the polynomial chaos theory and the Galerkin method, we propose a linear statistical RCL interconnect delay model, taking into account process variations by successive application of the linear approximation method. Based on a variety of nano-CMOS process parameters, HSPICE simulation results show that the maximum error of the proposed model is less than 3.5%. The proposed model is simple, of high precision, and can be used in the analysis and design of nanometer integrated circuit interconnect systems.展开更多
Based on a differentiable merit function proposed by Taji, et al in “Mathematical Programming, 1993, 58： 369-383”, a projected gradient trust region method for the monotone variational inequality problem with conve...Based on a differentiable merit function proposed by Taji, et al in “Mathematical Programming, 1993, 58： 369-383”, a projected gradient trust region method for the monotone variational inequality problem with convex constraints is presented. Theoretical analysis is given which proves that the proposed algorithm is globally convergent and has a local quadratic convergence rate under some reasonable conditions. The results of numerical experiments are reported to show the effectiveness of the proposed algorithm.展开更多
Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can b...Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can be achieved by employing short-and long-term storage plants buffering and complementing renewable energy sources. A representative grid consists of a natural-gas-fired plant serving as frequency leader, long-term storage plant, wind-power farm with associated short-term storage plantfor energy buffering, and photovoltaic farm with associated short-term storage plant interconnected by a long transmission line to two load circuits. Transient analysis is performed with Mathemafica solving the differential equation system for frequency variation. Powerflow through the AC transmission line is limited by its impedance. The long transmission line must be segmented to achieve stability and voltage control over an 800 km distance. The renewable plants must be operated together with the storage plants in order tominimize frequency variations by smoothing the power output of renewable plants, achieving step-wise control of the transmission-line power. Although to date only AC Iransmission lines in Germany exist, it is anticipated that within the next 10 years these will beaugmented by DC high-voltage lines.展开更多
By using Fukushima's differentiable merit function,Taji,Fukushima and Ibaraki have given a globally convergent modified Newton method for the strongly monotone variational inequality problem and proved their metho...By using Fukushima's differentiable merit function,Taji,Fukushima and Ibaraki have given a globally convergent modified Newton method for the strongly monotone variational inequality problem and proved their method to be quadratically convergent under certain assumptions in 1993.In this paper a hybrid method for the variational inequality problem under the assumptions that the mapping F is continuously differentiable and its Jacobian matrix Δ F(x) is positive definite for all x∈S rather than strongly monotone and that the set S is nonempty,polyhedral,closed and convex is proposed.Armijo type line search and trust region strategies as well as Fukushima's differentiable merit function are incorporated into the method.It is then shown that the method is well defined and globally convergent and that,under the same assumptions as those of Taji et al.,the method reduces to the basic Newton method and hence the rate of convergence is quadratic.Computational experiences show the efficiency of the proposed method.展开更多
文摘[Objective] The study was to analyze functional components in improved barley grains. [Method] Genetic variations of functional components in grains among 629 barley improved lines from four continents were determined with DU640-type ultraviolet spectrophotometry (BECKMAN). [Result] The contents (mg/100 g) of total flavones and GABA in grains of Asian barley lines (123.09±29.56, 9.49±4.34) were significantly higher than that of American barley lines (103.85±22.33, 7.38±3.59), while no significant difference was observed between Asia/Americas and Europe (115.47±11.41, 9.66±3.98) and Australia (104.20±4.76, 8.83±3.41); furthermore, there was no significant difference of resistant starch content (%) in barley grains among four continents [Asia (1.63±1.44), America (1.54±1.13), Europe (1.20±0.85) and Australia (0.27±0.26)]. The contents (%) of resistant starch in grains of two-rowed barley (ssp. Hordeum distichon Koern., 1.45±1.20) was significantly lower than that of poly-rowed barley (ssp. Hordeum vulgare Orlov., 1.95±1.24). On the contrary, the content of total flavones in two-rowed lines (111.43±27.79 mg/100 g) was significantly higher than that of poly-rowed lines (102.15±14.95 mg/100 g), and the content of GABA in two-rowed lines (8.55±3.73 mg/100 g) was also significantly higher than that of poly-rowed lines (5.96±3.95 mg/100 g). There was the most significant correlation between GABA content and resistant starch (-0.21**)/total flavones content (0.12**, P<0.01, n=629). There were great genotype differences among the functional components in barley grains. The coefficient of variation (78.60%) and range (0-9.29%) of resistant starch (1.56±1.22%) were relatively large, including 11 high-resistant starch lines above 5%; the coefficient of variation (49.00%) and range (0-30.67 mg/100g) of GABA (8.00±3.92 mg/100 g) were also relatively large, including 26 lines with GABA higher than 15 mg/100 g; the coefficient of variation (23.63%) and range (58.44-236.91 mg/100 g) of total flavones (109.44±25.85 mg/100 g) was relatively small, including 14 lines with total flavones higher than 176 mg/100 g. [Conclusion] There are zonal and genotypic differences in the contents of of functional components in barley grains.
基金jointly supported by the National Fundamental Research(973)Program of China(Grant Nos.2015CB452801 and 2013CB430100)the Jiangsu Meteorological Bureau Research Fund Project for the Youth(Grant Nos.Q201514 and Q201407)+3 种基金the Shandong Institute of Meteorological Sciences Research Fund Project(Grant No.SDQXKF2015M10)the Jiangsu Provincial Key Technology R&D Program(Grant No.BE2013730)the Jiangsu Meteorological Bureau Key Research Fund Project(Grant No.KZ201502)the National Key Technology R&D Program(Grant No.2014BAG01B01)
文摘Different choices of control variables in variational assimilation can bring about different influences on the analyzed atmospheric state. Based on the WRF model＇s three-dimensional variational assimilation system, this study compares the be- havior of two momentum control variable options-streamfunction velocity potential （ψ-χ） and horizontal wind components （U-V）-in radar wind data assimilation for a squall line case that occurred in Jiangsu Province on 24 August 2014. The wind increment from the single observation test shows that the ψ-χ control variable scheme produces negative increments in the neighborhood around the observation point because streamfunction and velocity potential preserve integrals of velocity. On the contrary, the U-V control variable scheme objectively reflects the information of the observation itself. Furthermore, radial velocity data from 17 Doppler radars in eastern China are assimilated. As compared to the impact of conventional observation, the assimilation of radar radial velocity based on the U-V control variable scheme significantly improves the mesoscale dynamic field in the initial condition. The enhanced low-level jet stream, water vapor convergence and low-level wind shear result in better squall line forecasting. However, the ψ-χ control variable scheme generates a discontinuous wind field and unrealistic convergence/divergence in the analyzed field, which lead to a degraded precipitation forecast.
基金supported by grants from the National High Technology Research and Development Program (2012AA10A405-6)National Natural Science Foundation of China (31372524)Special Fund for Independent Innovation of Shandong Province (2013CX80202)
文摘Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.
基金funded by the National Key Research and Development Program of China (2016YFD0300103)the earmarked fund for China Agriculture Research System (CARS-02-12)
文摘Over the past seven decades, the grain yield of maize(Zea mays L.) has increased continuously in China, mostly due to hybridization innovations, particularly recent genetic improvements in photosynthesis. In order to reveal photosynthetic characters of elite inbred lines in different ears, a field experiment was conducted at the North China Plain of Shandong Province in China. Six parental lines of maize introduced in three eras(the 1960 s, 1980 s, and 2000 s) were investigated diurnal variation of gas exchange, chlorophyll fluorescence, and photosynthetic response characteristic at the grain filling stage. Compared to earlier parental lines, the 2000 s parental lines always had higher net photosynthetic rate(Pn) throughout the day, especially at noon, and a mid-day depression in Pn did not occur in all hybrids parental lines. Moreover, the stomatal conductance(Gs) and water use efficiency(WUE) of the 2000 s’ lines showed higher value than those of the 1960 s’ and 1980 s’ lines. The inbred lines differences in photosynthetic parameters were partly owing to their different quantum carboxylation efficiencies and light synthase activities. Simultaneously, the 2000 s parental lines exhibited lower light and CO2 compensation points, and their higher apparent quantum yield, and carboxylation efficiency. These suggested that the modern parental lines required lower light intensity and less CO2 to maintain a relatively high photosynthetic capacity, substantially increasing leaf physical quality and stress resistance. It provided crucial information of high photo-efficiency and stress-resistance breeding in maize.
文摘Plumb line variations (PLV) of points at Tangshan and Midu during 1985-1998 are determined by using the 46 batch repeated gravity observations of the Beijing-Tangshan network and 32 batch repeated gravity observations of the West-Yunan network. As for Tangshan region, relation between underground matter change (UMC) and the PLV on ground are discussed and approach of determining the UMC by a derived regional PLV is found. The UMC before and after earthquake(1995.10.05, Mb 5.0)in Tangshan region, as an example, is studied, giving the location and depth of the mass center of underground disturbing body as well as its mass quantity.
基金supported by National Natural Science Foundation of China(No.61901415)。
文摘Efficient estimation of line spectral from quantized samples is of significant importance in information theory and signal processing,e.g.,channel estimation in energy efficient massive MIMO systems and direction of arrival estimation.The goal of this paper is to recover the line spectral as well as its corresponding parameters including the model order,frequencies and amplitudes from heavily quantized samples.To this end,we propose an efficient gridless Bayesian algorithm named VALSE-EP,which is a combination of the high resolution and low complexity gridless variational line spectral estimation(VALSE)and expectation propagation(EP).The basic idea of VALSE-EP is to iteratively approximate the challenging quantized model of line spectral estimation as a sequence of simple pseudo unquantized models,where VALSE is applied.Moreover,to obtain a benchmark of the performance of the proposed algorithm,the Cram′er Rao bound(CRB)is derived.Finally,numerical experiments on both synthetic and real data are performed,demonstrating the near CRB performance of the proposed VALSE-EP for line spectral estimation from quantized samples.
基金This paper is supported in part by the National Natural Science Foundations of China,and the Major Science and Technology Projects in Yunnan Province under Grant Nos.51667010,51807085,and 202002AF080001.
文摘The arc-suppression coil(ASC)in parallel low resistance(LR)multi-mode grounding is adopted in the mountain wind farm to cope with the phenomenon that is misoperation or refusal of zero-sequence protection in LR grounding wind farm.If the fault disappears before LR is put into the system,it is judged as an instantaneous fault;while the fault does not disappear after LR is put into the system,it is judged as a permanent fault;the single-phase grounding fault(SLG)protection criterion based on zerosequence power variation is proposed to identify the instantaneous-permanent fault.Firstly,the distribution characteristic of zero-sequence voltage(ZSV)and zero-sequence current(ZSC)are analyzed after SLGfault occurs in multi-mode grounding.Then,according to the characteristics that zero-sequence power variation of non-fault collector line is small,while the zero-sequence power variation of fault collector line can reflect the active power component of fault resistance,the protection criterion based on zero-sequence power variation is constructed.The theoretical analysis and simulation results show that the protection criterion can distinguish the property of fault only by using the single terminal information,which has high reliability.
文摘Rate of exserted stigmas (RES), ie. the ratio of glumes with exserted stigmas to the total glumes is one of the most important characteristics which affects the out-crossing rate of its combinations. Sixteen P(T) GMS lines with different ecotypes were used to study the variations of RES during their stable sterile period in Wuhan from 1992—1993. Ten healthy panicles were randomly selected at full anthesis. Their colour and the number of glumes showing one-side or two-side exserted of stigmas were investigated. Table 1 showed that there were a great variations of RES among the 16 lines tested in two consecutive years (c.v.=43.38%) and among the
文摘Eight lines of temperature-responsive leaf colormutants induced by applying 300 Gy Gamma-ray irradiation to Thermo-sensitive genic malesterile line 2177s,were obtained through con-tinuous selection in seven generations..Theleaves of these lines started to become greenafter the fourth leaf extension,and except
基金Project supported by the National Natural Science Foundation of China(Grant Nos.60725415 and 60971066)the National Science&Technology Important Project of China(Grant No.2009ZX01034-002-001-005)The National Key Laboratory Foundation(Grant No.ZHD200904)
文摘As the feature size of the CMOS integrated circuit continues to shrink, process variations have become a key factor affecting the interconnect performance. Based on the equivalent Elmore model and the use of the polynomial chaos theory and the Galerkin method, we propose a linear statistical RCL interconnect delay model, taking into account process variations by successive application of the linear approximation method. Based on a variety of nano-CMOS process parameters, HSPICE simulation results show that the maximum error of the proposed model is less than 3.5%. The proposed model is simple, of high precision, and can be used in the analysis and design of nanometer integrated circuit interconnect systems.
基金Supported by the National Natural Science Foundation of China (10871130)the Ph.D.Foundation of China Education Ministry (0527003)+1 种基金Shanghai Educational Development Foundationthe Science Foundation of Shanghai Education Committee(06A110)
文摘Based on a differentiable merit function proposed by Taji, et al in “Mathematical Programming, 1993, 58： 369-383”, a projected gradient trust region method for the monotone variational inequality problem with convex constraints is presented. Theoretical analysis is given which proves that the proposed algorithm is globally convergent and has a local quadratic convergence rate under some reasonable conditions. The results of numerical experiments are reported to show the effectiveness of the proposed algorithm.
文摘Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can be achieved by employing short-and long-term storage plants buffering and complementing renewable energy sources. A representative grid consists of a natural-gas-fired plant serving as frequency leader, long-term storage plant, wind-power farm with associated short-term storage plantfor energy buffering, and photovoltaic farm with associated short-term storage plant interconnected by a long transmission line to two load circuits. Transient analysis is performed with Mathemafica solving the differential equation system for frequency variation. Powerflow through the AC transmission line is limited by its impedance. The long transmission line must be segmented to achieve stability and voltage control over an 800 km distance. The renewable plants must be operated together with the storage plants in order tominimize frequency variations by smoothing the power output of renewable plants, achieving step-wise control of the transmission-line power. Although to date only AC Iransmission lines in Germany exist, it is anticipated that within the next 10 years these will beaugmented by DC high-voltage lines.
基金Project supported by the National Natural Science Foundation of China (1 9971 0 65)
文摘By using Fukushima's differentiable merit function,Taji,Fukushima and Ibaraki have given a globally convergent modified Newton method for the strongly monotone variational inequality problem and proved their method to be quadratically convergent under certain assumptions in 1993.In this paper a hybrid method for the variational inequality problem under the assumptions that the mapping F is continuously differentiable and its Jacobian matrix Δ F(x) is positive definite for all x∈S rather than strongly monotone and that the set S is nonempty,polyhedral,closed and convex is proposed.Armijo type line search and trust region strategies as well as Fukushima's differentiable merit function are incorporated into the method.It is then shown that the method is well defined and globally convergent and that,under the same assumptions as those of Taji et al.,the method reduces to the basic Newton method and hence the rate of convergence is quadratic.Computational experiences show the efficiency of the proposed method.
