Objective:To evaluate the correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma(SBA).Methods:46 patients with solitary bronchogenic adenocarci...Objective:To evaluate the correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma(SBA).Methods:46 patients with solitary bronchogenic adenocarcinomas (SBA)(diameter≤4 cm)underwent multi-location dynamic contrast material-enhanced(nonionic contrast material was administrated via the antecubital vein at a rate of 4 mL/s by using an autoinjector 90 mL,4×5 mm or 4×2.5 mm scanning mode with stable table were performed)serial CT.Precontrast and postcontrast attenuation on every scan was recorded.Perfusion (PBA),peak height(PHBA),ratio of peak height of the SPN to that of the aorta(BA-to-A ratio)and mean transit time(MTT)were calculated.The correlation between peak height of the aorta(PHA)and parameters of the SBA(PHBA,BA-to-A ratio,PBA,and MTT)and those among parameters of the SBA were assessed by means of linear regression analysis.Regression equation among parameters of the SBA were obtain by means of stepwise regression.Results:The correlation between the SBA peak height(PHBA,36.78 HU±12.02)and the aortic peak height(PHA)was significant(r=0.506,P<0.0001).No significant cor- relation was found between the BA-to-Apeak height ratio(15.33%±4.55)and the aortic peak height(r=0.130,P=0.388> 0.05)as it was between the SBA perfusion(PBA,31.86 mL/min/100 g±9.74)and the aortic peak height(r=0.049,P=0.749 >0.05).The SBA perfusion correlated with the PHBA and the BA-to-A peak height ratio(r=0.394,P=0.007<0.05;r=0.407, P=0.005<0.05).The PHBA correlated positively with the BA-to-A peak height ratio(r=0.781,P<0.0001).Mean transit time was 14.84 s±5.52.PBA=18.500+0.872×BA-to-A ratio.BA-to-A ratio=4.467+0.295×PHBA.Conclusion:The linear correlation between the SBA perfusion and BA-to-Aratio and that between BA-to-Aratio and PHBA can be expressed by equation. It is possible to design a simpler scanning procedure of investigation of bronchogenic adenocarcinoma angiogenesis.展开更多
Objective： To evaluate the correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in malignant solitary pulmonary nodules and tumor size. Methods： Sixty-eight patients with mal...Objective： To evaluate the correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in malignant solitary pulmonary nodules and tumor size. Methods： Sixty-eight patients with malignant solitary pulmonary nodules （SPNs） （diameter 〈4 cm） underwent multi-location dynamic contrast material-enhanced （nonionic contrast material was administrated via the antecubitai vein at a rate of 4mL/s by using an autoinjector, 4×5 mm or 4×2.5 mm scanning mode with stable table were performed）. Precontrast and postcontrast attenuation on every scan was recorded. Blood flow （BF）, peak, height （PHSPN）, ratio of peak height of the SPN to that of the aorta （SPN-to-A ratio） and mean transit time （MTT） were calculated. The correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in malignant solitary pulmonary nodules and tumor size were assessed by means of linear regression analysis. Results： No significant correlations were found between the tumor size and each of the peak height （PHSPN） （35.79±10.76 Hu）, ratio of peak height of the SPN to that of the aorta （SPN-to-A ratio）, （14.27%±4.37） and blood flow （BF） （30.18 mL/min/100 g±9.58） （r=0.180, P=0.142〉0.05; r=0.205, P=0.093〉0.05; r=0.008, P=0.947〉0.05）. Conclusion： No significant correlations were found between the tumor size and each of the quantifiable parameters of blood flow pattern derived with dynamic CT in malignant solitary pulmonary nodules.展开更多
A brief account of basic connotation and evaluation indexes system of harmonious leadership teams is given. On this basis, a simulation model is built by using the ARENA simulation software and the quantified simulati...A brief account of basic connotation and evaluation indexes system of harmonious leadership teams is given. On this basis, a simulation model is built by using the ARENA simulation software and the quantified simulation is carried out for the factors of harmonization of aerospace enterprise leadership teams. Moreover, by taking the characteristics of aerospace enterprise leadership teams into consideration, the comparison of harmonization quantified results of several typical leadership teams, especially on the comparative analysis of influencing degrees of moral characters and capabilities on the leadership teams overall harmonization is emphatically discussed. Finally, a conclusion is drawn.展开更多
A new parallel architecture for quantified boolean formula(QBF)solving was proposed,and the prediction model based on machine learning technology was proposed for how sharing knowledge affects the solving performance ...A new parallel architecture for quantified boolean formula(QBF)solving was proposed,and the prediction model based on machine learning technology was proposed for how sharing knowledge affects the solving performance in QBF parallel solving system,and the experimental evaluation scheme was also designed.It shows that the characterization factor of clause and cube influence the solving performance markedly in our experiment.At the same time,the heuristic machine learning algorithm was applied,support vector machine was chosen to predict the performance of QBF parallel solving system based on clause sharing and cube sharing.The relative error of accuracy for prediction can be controlled in a reasonable range of 20%30%.The results show the important and complex role that knowledge sharing plays in any modern parallel solver.It shows that the parallel solver with machine learning reduces the quantity of knowledge sharing about 30%and saving computational resource but does not reduce the performance of solving system.展开更多
This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem b...This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem between overlay path delay and access bandwidth at Multicast Server Nodes (MSN) for real-time ap-plications over Internet. Besides implementing a dynamic priority to MSNs by weighing the size of its service clients for better efficiency, QCost-Balanced tradeoffs these two metrics by a unified tradeoff metric based on quantitative analysis. Simulation experiments demonstrate that the scheme achieves a better tradeoff gain in both two metrics, and effective performance in metric quantitative control.展开更多
Objective To evaluate the utility of virtual reality system in quantitative comparison for cavernous sinus surgical approach. Methods Image data of CT and MRI scan performed in five adult cadaver heads was inputted in...Objective To evaluate the utility of virtual reality system in quantitative comparison for cavernous sinus surgical approach. Methods Image data of CT and MRI scan performed in five adult cadaver heads was inputted into the Destroscope virtual reality system to build 3-D model of cavernous sinus.展开更多
In this paper,the author first reviews the history of Hilbert’s Tenth Problem,and then study mixed quantifier prefixes over Diophantine equations with integer variables.For example,the author proves that■^(2)■^(4) ...In this paper,the author first reviews the history of Hilbert’s Tenth Problem,and then study mixed quantifier prefixes over Diophantine equations with integer variables.For example,the author proves that■^(2)■^(4) over Z is undecidable,that is,there is no algorithm to determine for any P(x_(1),···,x_(6))∈Z[x_(1),···,x_(6)]whether■x_(1)■x_(2)■x_(3)■x_(4)■x_(5)■x_(6)(P(x_(1),···,x_(6))=0),where x_(1),···,x_(6) are integer variables.The author also has some similar undecidable results with universal quantifies bounded,for example,■^(2)■^(2)■^(2) over Z with ■ bounded is undecidable.The author conjectures that■^(2)■^(2) over Z is undecidable.展开更多
A method using quantifier-elimination is proposed for automatically generating program invariants/inductive assertions. Given a program, inductive assertions, hypothesized as parameterized formulas in a theory, are as...A method using quantifier-elimination is proposed for automatically generating program invariants/inductive assertions. Given a program, inductive assertions, hypothesized as parameterized formulas in a theory, are associated with program locations. Parameters in inductive assertions are discovered by generating constraints on parameters by ensuring that an inductive assertion is indeed preserved by all execution paths leading to the associated location of the program. The method can be used to discover loop invariants-properties of variables that remain invariant at the entry of a loop. The parameterized formula can be successively refined by considering execution paths one by one; heuristics can be developed for determining the order in which the paths are considered. Initialization of program variables as well as the precondition and postcondition, if available, can also be used to further refine the hypothesized invariant. The method does not depend on the availability of the precondition and postcondition of a program. Constraints on parameters generated in this way are solved for possible values of parameters. If no solution is possible, this means that an invariant of the hypothesized form is not likely to exist for the loop under the assumptions/approximations made to generate the associated verification condition. Otherwise, if the parametric constraints are solvable, then under certain conditions on methods for generating these constraints, the strongest possible invariant of the hypothesized form can be generated from most general solutions of the parametric constraints. The approach is illustrated using the logical languages of conjunction of polynomial equations as well as Presburger arithmetic for expressing assertions.展开更多
For a parametric algebraic system in finite fields, this paper presents a method for computing the cover and the refined cover based on the characteristic set method. From the cover, the author knows for what parametr...For a parametric algebraic system in finite fields, this paper presents a method for computing the cover and the refined cover based on the characteristic set method. From the cover, the author knows for what parametric values the system has solutions and at the same time presents the solutions in the form of proper chains. By the refined cover, the author gives a complete classification of the number of solutions for this system, that is, the author divides the parameter space into several disjoint components, and on every component the system has a fix number of solutions. Moreover, the author develops a method of quantifier elimination for first order formulas in finite fields.展开更多
Facing constraints imposed by storage and bandwidth limitations,the vast volume of phasor meas-urement unit(PMU)data collected by the wide-area measurement system(WAMS)for power systems cannot be fully utilized.This l...Facing constraints imposed by storage and bandwidth limitations,the vast volume of phasor meas-urement unit(PMU)data collected by the wide-area measurement system(WAMS)for power systems cannot be fully utilized.This limitation significantly hinders the effective deployment of situational awareness technologies for systematic applications.In this work,an effective curvature quantified Douglas-Peucker(CQDP)-based PMU data compression method is proposed for situational awareness of power systems.First,a curvature integrated distance(CID)for measuring the local flection and fluc-tuation of PMU signals is developed.The Doug-las-Peucker(DP)algorithm integrated with a quan-tile-based parameter adaptation scheme is then proposed to extract feature points for profiling the trends within the PMU signals.This allows adaptive adjustment of the al-gorithm parameters,so as to maintain the desired com-pression ratio and reconstruction accuracy as much as possible,irrespective of the power system dynamics.Fi-nally,case studies on the Western Electricity Coordinat-ing Council(WECC)179-bus system and the actual Guangdong power system are performed to verify the effectiveness of the proposed method.The simulation results show that the proposed method achieves stably higher compression ratio and reconstruction accuracy in both steady state and in transients of the power system,and alleviates the compression performance degradation problem faced by existing compression methods.Index Terms—Curvature quantified Douglas-Peucker,data compression,phasor measurement unit,power sys-tem situational awareness.展开更多
Based on the intuitionistic first order predicate calculusH given by Thomason with the modal machinery of MIPC put forward by Prior this paper obtains the intuitionistic quantified modal logic system MIPC*, gives it a...Based on the intuitionistic first order predicate calculusH given by Thomason with the modal machinery of MIPC put forward by Prior this paper obtains the intuitionistic quantified modal logic system MIPC*, gives it a semantic interpretation and proves its strong (thus also weak) completeness theorem and soundness theorem with respect to that semantic. Since Zorn lemma plays a decisive role in our discussion, methodologically, it was even farther from the intuitionistic point of view than Thomason's result.展开更多
Let S be a propositional modal system and S~* be the quantification of S, then we can prove the algebraic semantic completeness theorem of the kind of Rasiowa-Sikorski for S~* by showing that S has the property (E)giv...Let S be a propositional modal system and S~* be the quantification of S, then we can prove the algebraic semantic completeness theorem of the kind of Rasiowa-Sikorski for S~* by showing that S has the property (E)given in [1]. But except for a few cases, it is very difficult to show thara system S has the property (E). So for most quantified modal systems,展开更多
Solving a quantified constraint satisfaction problem(QCSP)is usually a hard task due to its computational complexity.Exact algorithms play an important role in solving this problem,among which backtrack algorithms are...Solving a quantified constraint satisfaction problem(QCSP)is usually a hard task due to its computational complexity.Exact algorithms play an important role in solving this problem,among which backtrack algorithms are effective.In a backtrack algorithm,an important step is assigning a variable by a chosen value when exploiting a branch,and thus a good value selection rule may speed up greatly.In this paper,we propose two value selection rules for existentially and universally quantified variables,respectively,to avoid unnecessary searching.The rule for universally quantified variables is prior to trying failure values in previous branches,and the rule for existentially quantified variables selects the promising values first.Two rules are integrated into the state-of-the-art QCSP solver,i.e.,QCSP-Solve,which is an exact solver based on backtracking.We perform a number of experiments to evaluate improvements brought by our rules.From computational results,we can conclude that the new value selection rules speed up the solver by 5 times on average and 30 times at most.We also show both rules perform well particularly on instances with existentially and universally quantified variables occurring alternatively.展开更多
Traditional first-order logic has four definitions for quantifiers,which are defined by universal and existential quantifiers.In L_(3)-valued(three-valued)first-order logic,there are eight kinds of definitions for qua...Traditional first-order logic has four definitions for quantifiers,which are defined by universal and existential quantifiers.In L_(3)-valued(three-valued)first-order logic,there are eight kinds of definitions for quantifiers;and corresponding Gentzen deduction systems will be given and their soundness and completeness theorems will be proved.展开更多
Continuous-scale trusted safety efficiency evaluation is crucial for the agile development and robust validation of autonomous vehicle intelligence.While the UN R157 Regulation evaluates automated lane-keeping system(...Continuous-scale trusted safety efficiency evaluation is crucial for the agile development and robust validation of autonomous vehicle intelligence.While the UN R157 Regulation evaluates automated lane-keeping system(ALKS)performance baselines through safe collision plots(SCPs)in various scenario clusters,quantifying the specific ALKS safety efficiency remains challenging.We propose a spectrum quantification approach to evaluate the safety efficiency of autonomous vehicles in cut-in scenarios.First,we collected speed-distance data under different cut-in scenarios and extracted essential spectral features to indicate the vehicle motion parameters during the cut-in process.Second,by utilizing Fourier analysis,a spectral analysis model was built to quantify and analyze the vehicle motion characteristics,providing insights into scenario safety.Finally,we created approximate analytical equations for the normalized disturbance frequencies in the nonlinear response scenarios of autonomous driving systems by combining the SCP with a frequency spectrum analysis model.The results showed that the normalized disturbance frequency in the cut-in scenario was approximately 0.2.When the relative longitudinal distance and speed of the vehicle are the same,if the cut-in speed of the cut-in vehicle is larger,the normalized disturbance frequency is higher,indicating that the cut-in process of the autonomous vehicle is more dangerous and may trigger a collision.展开更多
Quantifying tree resources is essential for effectively implementing climate adaptation strategies and supporting local communities.In the Sahel,where tree presence is scattered,measuring carbon becomes challenging.We...Quantifying tree resources is essential for effectively implementing climate adaptation strategies and supporting local communities.In the Sahel,where tree presence is scattered,measuring carbon becomes challenging.We present an approach to estimating aboveground carbon(AGC)at the individual tree level using a combination of very high-resolution imagery,field-collected data,and machine learning algorithms.We populated an AGC database from in situ measurements using allometric equations and carbon conversion factors.We extracted satellite spectral information and tree crown area upon segmenting each tree crown.We then trained and validated an artificial neural network to predict AGC from these variables.The validation at the tree level resulted in an R^(2)of 0.66,a root mean square error(RMSE)of 373.85 kg,a relative RMSE of 78.6%,and an overestimation bias of 47 kg.When aggregating results at coarser spatial resolutions,the relative RMSE decreased for all areas,with the median value at the plot level being under 30%in all cases.Within our areas of study,we obtained a total of 3,900 Mg,with an average carbon content per tree of 330 kg.A benchmarking analysis against published carbon maps showed that 9 out of 10 underestimate AGC stocks,in comparison to our results,in the areas of study.An additional comparison against a method using only crown area to determine AGC showed an improved performance,including spectral signature.This study improves crown-based biomass estimations for areas where unmanned aerial vehicle or height data are not available and validates at the individual tree level using solely satellite imagery.展开更多
文摘Objective:To evaluate the correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma(SBA).Methods:46 patients with solitary bronchogenic adenocarcinomas (SBA)(diameter≤4 cm)underwent multi-location dynamic contrast material-enhanced(nonionic contrast material was administrated via the antecubital vein at a rate of 4 mL/s by using an autoinjector 90 mL,4×5 mm or 4×2.5 mm scanning mode with stable table were performed)serial CT.Precontrast and postcontrast attenuation on every scan was recorded.Perfusion (PBA),peak height(PHBA),ratio of peak height of the SPN to that of the aorta(BA-to-A ratio)and mean transit time(MTT)were calculated.The correlation between peak height of the aorta(PHA)and parameters of the SBA(PHBA,BA-to-A ratio,PBA,and MTT)and those among parameters of the SBA were assessed by means of linear regression analysis.Regression equation among parameters of the SBA were obtain by means of stepwise regression.Results:The correlation between the SBA peak height(PHBA,36.78 HU±12.02)and the aortic peak height(PHA)was significant(r=0.506,P<0.0001).No significant cor- relation was found between the BA-to-Apeak height ratio(15.33%±4.55)and the aortic peak height(r=0.130,P=0.388> 0.05)as it was between the SBA perfusion(PBA,31.86 mL/min/100 g±9.74)and the aortic peak height(r=0.049,P=0.749 >0.05).The SBA perfusion correlated with the PHBA and the BA-to-A peak height ratio(r=0.394,P=0.007<0.05;r=0.407, P=0.005<0.05).The PHBA correlated positively with the BA-to-A peak height ratio(r=0.781,P<0.0001).Mean transit time was 14.84 s±5.52.PBA=18.500+0.872×BA-to-A ratio.BA-to-A ratio=4.467+0.295×PHBA.Conclusion:The linear correlation between the SBA perfusion and BA-to-Aratio and that between BA-to-Aratio and PHBA can be expressed by equation. It is possible to design a simpler scanning procedure of investigation of bronchogenic adenocarcinoma angiogenesis.
文摘Objective： To evaluate the correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in malignant solitary pulmonary nodules and tumor size. Methods： Sixty-eight patients with malignant solitary pulmonary nodules （SPNs） （diameter 〈4 cm） underwent multi-location dynamic contrast material-enhanced （nonionic contrast material was administrated via the antecubitai vein at a rate of 4mL/s by using an autoinjector, 4×5 mm or 4×2.5 mm scanning mode with stable table were performed）. Precontrast and postcontrast attenuation on every scan was recorded. Blood flow （BF）, peak, height （PHSPN）, ratio of peak height of the SPN to that of the aorta （SPN-to-A ratio） and mean transit time （MTT） were calculated. The correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in malignant solitary pulmonary nodules and tumor size were assessed by means of linear regression analysis. Results： No significant correlations were found between the tumor size and each of the peak height （PHSPN） （35.79±10.76 Hu）, ratio of peak height of the SPN to that of the aorta （SPN-to-A ratio）, （14.27%±4.37） and blood flow （BF） （30.18 mL/min/100 g±9.58） （r=0.180, P=0.142〉0.05; r=0.205, P=0.093〉0.05; r=0.008, P=0.947〉0.05）. Conclusion： No significant correlations were found between the tumor size and each of the quantifiable parameters of blood flow pattern derived with dynamic CT in malignant solitary pulmonary nodules.
文摘A brief account of basic connotation and evaluation indexes system of harmonious leadership teams is given. On this basis, a simulation model is built by using the ARENA simulation software and the quantified simulation is carried out for the factors of harmonization of aerospace enterprise leadership teams. Moreover, by taking the characteristics of aerospace enterprise leadership teams into consideration, the comparison of harmonization quantified results of several typical leadership teams, especially on the comparative analysis of influencing degrees of moral characters and capabilities on the leadership teams overall harmonization is emphatically discussed. Finally, a conclusion is drawn.
基金Project(61171141)supported by the National Natural Science Foundation of China
文摘A new parallel architecture for quantified boolean formula(QBF)solving was proposed,and the prediction model based on machine learning technology was proposed for how sharing knowledge affects the solving performance in QBF parallel solving system,and the experimental evaluation scheme was also designed.It shows that the characterization factor of clause and cube influence the solving performance markedly in our experiment.At the same time,the heuristic machine learning algorithm was applied,support vector machine was chosen to predict the performance of QBF parallel solving system based on clause sharing and cube sharing.The relative error of accuracy for prediction can be controlled in a reasonable range of 20%30%.The results show the important and complex role that knowledge sharing plays in any modern parallel solver.It shows that the parallel solver with machine learning reduces the quantity of knowledge sharing about 30%and saving computational resource but does not reduce the performance of solving system.
文摘This paper focuses on the quantitative analysis issue of the routing metrics tradeoff problem, and presents a Quantified Cost-Balanced overlay multicast routing scheme (QCost-Balanced) to the metric tradeoff problem between overlay path delay and access bandwidth at Multicast Server Nodes (MSN) for real-time ap-plications over Internet. Besides implementing a dynamic priority to MSNs by weighing the size of its service clients for better efficiency, QCost-Balanced tradeoffs these two metrics by a unified tradeoff metric based on quantitative analysis. Simulation experiments demonstrate that the scheme achieves a better tradeoff gain in both two metrics, and effective performance in metric quantitative control.
文摘Objective To evaluate the utility of virtual reality system in quantitative comparison for cavernous sinus surgical approach. Methods Image data of CT and MRI scan performed in five adult cadaver heads was inputted into the Destroscope virtual reality system to build 3-D model of cavernous sinus.
基金supported by the National Natural Science Foundation of China under Grant No.12371004。
文摘In this paper,the author first reviews the history of Hilbert’s Tenth Problem,and then study mixed quantifier prefixes over Diophantine equations with integer variables.For example,the author proves that■^(2)■^(4) over Z is undecidable,that is,there is no algorithm to determine for any P(x_(1),···,x_(6))∈Z[x_(1),···,x_(6)]whether■x_(1)■x_(2)■x_(3)■x_(4)■x_(5)■x_(6)(P(x_(1),···,x_(6))=0),where x_(1),···,x_(6) are integer variables.The author also has some similar undecidable results with universal quantifies bounded,for example,■^(2)■^(2)■^(2) over Z with ■ bounded is undecidable.The author conjectures that■^(2)■^(2) over Z is undecidable.
基金This research was partially supported by an National Science Foundation(NSF)Information Technology Research(ITR)award CCR-0113611an NSF award CCR-0203051.
文摘A method using quantifier-elimination is proposed for automatically generating program invariants/inductive assertions. Given a program, inductive assertions, hypothesized as parameterized formulas in a theory, are associated with program locations. Parameters in inductive assertions are discovered by generating constraints on parameters by ensuring that an inductive assertion is indeed preserved by all execution paths leading to the associated location of the program. The method can be used to discover loop invariants-properties of variables that remain invariant at the entry of a loop. The parameterized formula can be successively refined by considering execution paths one by one; heuristics can be developed for determining the order in which the paths are considered. Initialization of program variables as well as the precondition and postcondition, if available, can also be used to further refine the hypothesized invariant. The method does not depend on the availability of the precondition and postcondition of a program. Constraints on parameters generated in this way are solved for possible values of parameters. If no solution is possible, this means that an invariant of the hypothesized form is not likely to exist for the loop under the assumptions/approximations made to generate the associated verification condition. Otherwise, if the parametric constraints are solvable, then under certain conditions on methods for generating these constraints, the strongest possible invariant of the hypothesized form can be generated from most general solutions of the parametric constraints. The approach is illustrated using the logical languages of conjunction of polynomial equations as well as Presburger arithmetic for expressing assertions.
基金supported by the National 973 Program of China under Grant No.2011CB302400the National Natural Science Foundation of China under Grant No.60970152
文摘For a parametric algebraic system in finite fields, this paper presents a method for computing the cover and the refined cover based on the characteristic set method. From the cover, the author knows for what parametric values the system has solutions and at the same time presents the solutions in the form of proper chains. By the refined cover, the author gives a complete classification of the number of solutions for this system, that is, the author divides the parameter space into several disjoint components, and on every component the system has a fix number of solutions. Moreover, the author develops a method of quantifier elimination for first order formulas in finite fields.
基金supported by the National Natural Sci-ence Foundation of China(No.52077195).
文摘Facing constraints imposed by storage and bandwidth limitations,the vast volume of phasor meas-urement unit(PMU)data collected by the wide-area measurement system(WAMS)for power systems cannot be fully utilized.This limitation significantly hinders the effective deployment of situational awareness technologies for systematic applications.In this work,an effective curvature quantified Douglas-Peucker(CQDP)-based PMU data compression method is proposed for situational awareness of power systems.First,a curvature integrated distance(CID)for measuring the local flection and fluc-tuation of PMU signals is developed.The Doug-las-Peucker(DP)algorithm integrated with a quan-tile-based parameter adaptation scheme is then proposed to extract feature points for profiling the trends within the PMU signals.This allows adaptive adjustment of the al-gorithm parameters,so as to maintain the desired com-pression ratio and reconstruction accuracy as much as possible,irrespective of the power system dynamics.Fi-nally,case studies on the Western Electricity Coordinat-ing Council(WECC)179-bus system and the actual Guangdong power system are performed to verify the effectiveness of the proposed method.The simulation results show that the proposed method achieves stably higher compression ratio and reconstruction accuracy in both steady state and in transients of the power system,and alleviates the compression performance degradation problem faced by existing compression methods.Index Terms—Curvature quantified Douglas-Peucker,data compression,phasor measurement unit,power sys-tem situational awareness.
文摘Based on the intuitionistic first order predicate calculusH given by Thomason with the modal machinery of MIPC put forward by Prior this paper obtains the intuitionistic quantified modal logic system MIPC*, gives it a semantic interpretation and proves its strong (thus also weak) completeness theorem and soundness theorem with respect to that semantic. Since Zorn lemma plays a decisive role in our discussion, methodologically, it was even farther from the intuitionistic point of view than Thomason's result.
文摘Let S be a propositional modal system and S~* be the quantification of S, then we can prove the algebraic semantic completeness theorem of the kind of Rasiowa-Sikorski for S~* by showing that S has the property (E)given in [1]. But except for a few cases, it is very difficult to show thara system S has the property (E). So for most quantified modal systems,
基金We would like to thank Dr.Peter Nightingale for the source code of QCSP-Solve.The work described in this paper was supported by the National Natural Science Foundation of China(Granted Nos.61972063,61763003,61672122,61602077,61402070)the Fundamental Research Funds for the Central Universities(3132019029,3132019355).
文摘Solving a quantified constraint satisfaction problem(QCSP)is usually a hard task due to its computational complexity.Exact algorithms play an important role in solving this problem,among which backtrack algorithms are effective.In a backtrack algorithm,an important step is assigning a variable by a chosen value when exploiting a branch,and thus a good value selection rule may speed up greatly.In this paper,we propose two value selection rules for existentially and universally quantified variables,respectively,to avoid unnecessary searching.The rule for universally quantified variables is prior to trying failure values in previous branches,and the rule for existentially quantified variables selects the promising values first.Two rules are integrated into the state-of-the-art QCSP solver,i.e.,QCSP-Solve,which is an exact solver based on backtracking.We perform a number of experiments to evaluate improvements brought by our rules.From computational results,we can conclude that the new value selection rules speed up the solver by 5 times on average and 30 times at most.We also show both rules perform well particularly on instances with existentially and universally quantified variables occurring alternatively.
基金the Open Fund of the State Key Laboratory of Software Development Environment(SKLSDE-2010KF-06)Beijing University of Aeronautics and Astronautics,and by the National Basic Research Program of China(973 Program)(2005CB321901).
文摘Traditional first-order logic has four definitions for quantifiers,which are defined by universal and existential quantifiers.In L_(3)-valued(three-valued)first-order logic,there are eight kinds of definitions for quantifiers;and corresponding Gentzen deduction systems will be given and their soundness and completeness theorems will be proved.
基金the National Key R&D Program of China(Grant No.2021YFB1600403)the National Natural Science Foundation of China(Grant Nos.51805312 and 52172388).
文摘Continuous-scale trusted safety efficiency evaluation is crucial for the agile development and robust validation of autonomous vehicle intelligence.While the UN R157 Regulation evaluates automated lane-keeping system(ALKS)performance baselines through safe collision plots(SCPs)in various scenario clusters,quantifying the specific ALKS safety efficiency remains challenging.We propose a spectrum quantification approach to evaluate the safety efficiency of autonomous vehicles in cut-in scenarios.First,we collected speed-distance data under different cut-in scenarios and extracted essential spectral features to indicate the vehicle motion parameters during the cut-in process.Second,by utilizing Fourier analysis,a spectral analysis model was built to quantify and analyze the vehicle motion characteristics,providing insights into scenario safety.Finally,we created approximate analytical equations for the normalized disturbance frequencies in the nonlinear response scenarios of autonomous driving systems by combining the SCP with a frequency spectrum analysis model.The results showed that the normalized disturbance frequency in the cut-in scenario was approximately 0.2.When the relative longitudinal distance and speed of the vehicle are the same,if the cut-in speed of the cut-in vehicle is larger,the normalized disturbance frequency is higher,indicating that the cut-in process of the autonomous vehicle is more dangerous and may trigger a collision.
基金funded by Intermon Oxfam Spain,and under Industrial PhD grants AGAUR(2021 DI 121)and DIN2020-010982 financed by MCIN AEI 10.13039/501100011033 and by European Union“NextGenerationEU/PRTR”Aitor Ameztegui is funded by a Serra-Húnter fellowship from Generalitat de Catalunyasupported by the ESA Network of Resources Initiative.
文摘Quantifying tree resources is essential for effectively implementing climate adaptation strategies and supporting local communities.In the Sahel,where tree presence is scattered,measuring carbon becomes challenging.We present an approach to estimating aboveground carbon(AGC)at the individual tree level using a combination of very high-resolution imagery,field-collected data,and machine learning algorithms.We populated an AGC database from in situ measurements using allometric equations and carbon conversion factors.We extracted satellite spectral information and tree crown area upon segmenting each tree crown.We then trained and validated an artificial neural network to predict AGC from these variables.The validation at the tree level resulted in an R^(2)of 0.66,a root mean square error(RMSE)of 373.85 kg,a relative RMSE of 78.6%,and an overestimation bias of 47 kg.When aggregating results at coarser spatial resolutions,the relative RMSE decreased for all areas,with the median value at the plot level being under 30%in all cases.Within our areas of study,we obtained a total of 3,900 Mg,with an average carbon content per tree of 330 kg.A benchmarking analysis against published carbon maps showed that 9 out of 10 underestimate AGC stocks,in comparison to our results,in the areas of study.An additional comparison against a method using only crown area to determine AGC showed an improved performance,including spectral signature.This study improves crown-based biomass estimations for areas where unmanned aerial vehicle or height data are not available and validates at the individual tree level using solely satellite imagery.
