为解决皮带式检重分级装备,在高速工作时检重精度低的问题,首先对检重系统进行建模,研究检重秤在静止、空载运行、加载工作下的系统状态,对检重秤采集的信号进行时频分析,找出干扰源和干扰频段,分析其产生原因及变化趋势,确定滤波指标...为解决皮带式检重分级装备,在高速工作时检重精度低的问题,首先对检重系统进行建模,研究检重秤在静止、空载运行、加载工作下的系统状态,对检重秤采集的信号进行时频分析,找出干扰源和干扰频段,分析其产生原因及变化趋势,确定滤波指标。依指标,设计FIR数字滤波器提高数据信噪比。降噪后采用2种方式进行重量值估计:(1)非对称切尾均值(Trimmed-mean mass estimator,TME),取去噪后的最后N个采样数据按大小排序,对排序后的数据进行非对称切尾,找出准确的观测区间,然后对该区间取平均值;(2)算数平均重量估计(Average mass estimation,AME),截取最后N个数据取平均值。结果表明:TME方式所得检重误差低于0.3%,平均误差0.155%;AME平均误差为0.758%。FIR滤波可快速去噪,TME重量估计能令检重精度更高。展开更多
In this paper, we establish a differential equation about scalar curvature of conformally flat K-contact manifolds, and prove that a conformally symmetric K-contact manifold is a Riemann manifold with constant curvatu...In this paper, we establish a differential equation about scalar curvature of conformally flat K-contact manifolds, and prove that a conformally symmetric K-contact manifold is a Riemann manifold with constant curvature 1. At the same time, the results on Sasaki manifolds which are given by Miyazaawa and Yamagushi are generalized to K-contact manifolds.展开更多
We combine the tanh function method with the symmetry group method to construct new type of solutions of Davey-Stewartson equation and implemente it in a computer algebraic system. As a result, some new types of solut...We combine the tanh function method with the symmetry group method to construct new type of solutions of Davey-Stewartson equation and implemente it in a computer algebraic system. As a result, some new types of solutions are obtained. This method is also applied to other differential equations if the nonlinear evolution equations admit nontrivial one-parameter group of transformation.展开更多
The influence of summer monsoon on tropical cyclone (TC) genesis over the Bay of Bengal (BoB) is explored using an empirical genesis potential (GP) index. The annual cycle of cyclogenesis frequency over the BoB shows ...The influence of summer monsoon on tropical cyclone (TC) genesis over the Bay of Bengal (BoB) is explored using an empirical genesis potential (GP) index. The annual cycle of cyclogenesis frequency over the BoB shows an asymmetric bimodal pattern with the maximum genesis number appearing in late October and the second largest in early May. The two peaks correspond to the withdrawal and onset of the BoB summer monsoon, respectively. The semimonthly GP index calculated without TC days over the BoB is consistent with TC genesis frequency, indicating that the index captures the monsoon-induced changes in the environment that are responsible for the seasonal variation of TC genesis frequency. Of the four environmental variables (i.e., low-level vorticity, mid-level relative humidity, potential intensity, and vertical wind shear) that enter into the GP index, the potential intensity makes the largest contribution to the bimodal distribution, followed by vertical wind shear due to small wind speed during the summer monsoon onset and withdrawal. The difference in TC genesis frequency between autumn and late spring is mainly owing to the relative humid-ity difference because a divergence (convergence) of horizontal moisture flux associated with cold dry northerlies (warm wet wester-lies) dominates the BoB in late spring (autumn).展开更多
As one of the most severe typhoons in the year 2005,Typhoon Longwang is chosen as a case study in this article.Throughout its life,two surveillance flights are carried out on it.Different from previous studies,GPS(glo...As one of the most severe typhoons in the year 2005,Typhoon Longwang is chosen as a case study in this article.Throughout its life,two surveillance flights are carried out on it.Different from previous studies,GPS(global positioning system)Dropwinsonde data collected from the Dropwinsonde Observations for Typhoon Surveillance near the Taiwan Region is chosen to present the thermodynamic and kinetic structure at its two different stages of development.This study suggests that not only kinetic structure but also thermodynamic structure of Longwang are more robust in the second surveillance than the first surveillance,with stronger and larger circulation and a warmer core.Further research shows that the environmental vertical wind shear mainly contributes to the asymmetric structure of the typhoon.The strong vertical wind shear not only results in the distinct asymmetric structure,but also restrains the development of the typhoon.展开更多
The buyer-supplier relationship plays a great role in most economic systems. The buying firm usually tries to find a new supplier who provides products with satisfying quality and lower price. A broad branch of litera...The buyer-supplier relationship plays a great role in most economic systems. The buying firm usually tries to find a new supplier who provides products with satisfying quality and lower price. A broad branch of literature deals with the development of buyer-supplier relationships, but limited research is on the circumstances under which a buyer should terminate such a relationship and switch to a new supplier. In this paper, the incentive compatibility constraint (IC) which induces the entrant supplier to report his true cost is considered, and the participation constraint (PC) which ensures the entrant supplier to get at least reservation profit is taken into account. Then the supplier switching model is set up to minimize the buying firm's total procurement cost which includes the transfer payment to the incumbent supplier, the payment to the entrant supplier and the switching cost, and the buying firm's switching cost is considered as a function of the switching quantity. With the theoretical analysis of IC, PC and the proposed model, the optimal supplier switching strategy can be obtained. Finally, a numerical example is given to illustrate the effectiveness of the proposed model and the switching strategy.展开更多
Objective： To investigate the clinical features and treatment strategy of dissymmetric bilateral frontal contusion, and to summarize our experience in treating these patients by minimally invasive surgery. Methods：...Objective： To investigate the clinical features and treatment strategy of dissymmetric bilateral frontal contusion, and to summarize our experience in treating these patients by minimally invasive surgery. Methods： Over the past 3 years, we have treated a total of 31 patients with dissymmetric bilateral frontal contusion using endoscopy-assisted unilateral cerebral falx incision. ~ ~ther 30 patients treated by routine bilateral approaches within the same period were taken as control. Results： Seventeen cases （54.8%） in the unilateral operation group survived and were in good condition, 8 （25.8%） had moderate disability, 4 （12.9%） had severe disability, 1 （3.2%） was in vegetative state, and 1 （3.2%） died. Compared with the control group, the Glasgow Out- come Scale score was not significantly different in the uni-lateral operation group, but the operation time, blood trans- fusion volume, the length of hospital stay, the incidences of mental disorder and olfactory nerve injury were greatly reduced in the unilateral operation group. Conclusions： Endoscopy-assisted unilateral cerebral falx incision can shorten the operation time, reduce surgical trauma and complications in treatment of patients with dissymmetric bilateral frontal contusion. It can obviously diminish the chance of delayed intracerebral hematoma and subsequently minimize the incidences of subfalcial and centrencephalic herniation.展开更多
文摘为解决皮带式检重分级装备,在高速工作时检重精度低的问题,首先对检重系统进行建模,研究检重秤在静止、空载运行、加载工作下的系统状态,对检重秤采集的信号进行时频分析,找出干扰源和干扰频段,分析其产生原因及变化趋势,确定滤波指标。依指标,设计FIR数字滤波器提高数据信噪比。降噪后采用2种方式进行重量值估计:(1)非对称切尾均值(Trimmed-mean mass estimator,TME),取去噪后的最后N个采样数据按大小排序,对排序后的数据进行非对称切尾,找出准确的观测区间,然后对该区间取平均值;(2)算数平均重量估计(Average mass estimation,AME),截取最后N个数据取平均值。结果表明:TME方式所得检重误差低于0.3%,平均误差0.155%;AME平均误差为0.758%。FIR滤波可快速去噪,TME重量估计能令检重精度更高。
文摘In this paper, we establish a differential equation about scalar curvature of conformally flat K-contact manifolds, and prove that a conformally symmetric K-contact manifold is a Riemann manifold with constant curvature 1. At the same time, the results on Sasaki manifolds which are given by Miyazaawa and Yamagushi are generalized to K-contact manifolds.
基金The project partially supported by the State Key Basic Research Program of China under Grant No. 2004CB318000
文摘We combine the tanh function method with the symmetry group method to construct new type of solutions of Davey-Stewartson equation and implemente it in a computer algebraic system. As a result, some new types of solutions are obtained. This method is also applied to other differential equations if the nonlinear evolution equations admit nontrivial one-parameter group of transformation.
基金supported by the National Basic Research Program of China(973Program:2012CB955604)National Natural Science Foundation of China(No.40975038,40830106)the CMA Program(GYHY200906008)
文摘The influence of summer monsoon on tropical cyclone (TC) genesis over the Bay of Bengal (BoB) is explored using an empirical genesis potential (GP) index. The annual cycle of cyclogenesis frequency over the BoB shows an asymmetric bimodal pattern with the maximum genesis number appearing in late October and the second largest in early May. The two peaks correspond to the withdrawal and onset of the BoB summer monsoon, respectively. The semimonthly GP index calculated without TC days over the BoB is consistent with TC genesis frequency, indicating that the index captures the monsoon-induced changes in the environment that are responsible for the seasonal variation of TC genesis frequency. Of the four environmental variables (i.e., low-level vorticity, mid-level relative humidity, potential intensity, and vertical wind shear) that enter into the GP index, the potential intensity makes the largest contribution to the bimodal distribution, followed by vertical wind shear due to small wind speed during the summer monsoon onset and withdrawal. The difference in TC genesis frequency between autumn and late spring is mainly owing to the relative humid-ity difference because a divergence (convergence) of horizontal moisture flux associated with cold dry northerlies (warm wet wester-lies) dominates the BoB in late spring (autumn).
基金project of the National Science Foundation of China(40830958,40905020)project of National Basic Research Program of China(2009CB421502)+1 种基金project of the Special Scientific Research for Public Interest(GYHY201006007)project of the Specialized Research Fund for the Doctoral Program of Higher Education of China(20090091120038)
文摘As one of the most severe typhoons in the year 2005,Typhoon Longwang is chosen as a case study in this article.Throughout its life,two surveillance flights are carried out on it.Different from previous studies,GPS(global positioning system)Dropwinsonde data collected from the Dropwinsonde Observations for Typhoon Surveillance near the Taiwan Region is chosen to present the thermodynamic and kinetic structure at its two different stages of development.This study suggests that not only kinetic structure but also thermodynamic structure of Longwang are more robust in the second surveillance than the first surveillance,with stronger and larger circulation and a warmer core.Further research shows that the environmental vertical wind shear mainly contributes to the asymmetric structure of the typhoon.The strong vertical wind shear not only results in the distinct asymmetric structure,but also restrains the development of the typhoon.
基金Supported by National Natural Science Foundation of China (No. 61004015 and No. 71071106)Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1028)
文摘The buyer-supplier relationship plays a great role in most economic systems. The buying firm usually tries to find a new supplier who provides products with satisfying quality and lower price. A broad branch of literature deals with the development of buyer-supplier relationships, but limited research is on the circumstances under which a buyer should terminate such a relationship and switch to a new supplier. In this paper, the incentive compatibility constraint (IC) which induces the entrant supplier to report his true cost is considered, and the participation constraint (PC) which ensures the entrant supplier to get at least reservation profit is taken into account. Then the supplier switching model is set up to minimize the buying firm's total procurement cost which includes the transfer payment to the incumbent supplier, the payment to the entrant supplier and the switching cost, and the buying firm's switching cost is considered as a function of the switching quantity. With the theoretical analysis of IC, PC and the proposed model, the optimal supplier switching strategy can be obtained. Finally, a numerical example is given to illustrate the effectiveness of the proposed model and the switching strategy.
文摘Objective： To investigate the clinical features and treatment strategy of dissymmetric bilateral frontal contusion, and to summarize our experience in treating these patients by minimally invasive surgery. Methods： Over the past 3 years, we have treated a total of 31 patients with dissymmetric bilateral frontal contusion using endoscopy-assisted unilateral cerebral falx incision. ~ ~ther 30 patients treated by routine bilateral approaches within the same period were taken as control. Results： Seventeen cases （54.8%） in the unilateral operation group survived and were in good condition, 8 （25.8%） had moderate disability, 4 （12.9%） had severe disability, 1 （3.2%） was in vegetative state, and 1 （3.2%） died. Compared with the control group, the Glasgow Out- come Scale score was not significantly different in the uni-lateral operation group, but the operation time, blood trans- fusion volume, the length of hospital stay, the incidences of mental disorder and olfactory nerve injury were greatly reduced in the unilateral operation group. Conclusions： Endoscopy-assisted unilateral cerebral falx incision can shorten the operation time, reduce surgical trauma and complications in treatment of patients with dissymmetric bilateral frontal contusion. It can obviously diminish the chance of delayed intracerebral hematoma and subsequently minimize the incidences of subfalcial and centrencephalic herniation.
