Objective.To introduce the properties of Chinese type A botulinum toxin(CBTXA,made by Lanzhou Institute of Biological Products),and its long?term effect for focal dystonia and hemifacial spasm.Method.The purity and re...Objective.To introduce the properties of Chinese type A botulinum toxin(CBTXA,made by Lanzhou Institute of Biological Products),and its long?term effect for focal dystonia and hemifacial spasm.Method.The purity and recovery of crude and crystalline toxin were tested.Long?term data from305patients with hemifacial spasm(HFS),blepharospasm(BS)and cervical dystonia(CD)were evalu-ated and subgroups of patients received CBTXA injections between1994and2000in at least six sepa-rate treatment sessions,with follow up for2～8years.The therapeutic results of the last session CBTXA injections were analyzed in comparison with the first session.Result.CBTXA purity was high[(2.55～2.60)×10 7 LD50/mgPr ,A260/A280≤0.55,high molecular substance accounted for99.2%of total proteins].Long term treatment with CBTXA in patients with focal dystonia and HFS was not associated with any decline in benefit,and efficacy may improve slightly with repeat treatments.CBTXA is an excellent long-term treatment of HFS,BS and CD.Conclusion.We conclude that Chinese type A botulinum toxin is of botulinum toxin therapy quality standard according to results obtained from the basic study and long?term clinical applications.The re?injection of CBTXA significantly improves the quality of life of most patients and is a safe,effective and comparatively economical treatment for patients with focal dystonia and HFS.展开更多
It has been proven that longwall faces can be moved safely and efficiently. However,abutment pressures and poor ground control conditions can halt operations and be hazardous to coal miners. Recently at a mine in Sout...It has been proven that longwall faces can be moved safely and efficiently. However,abutment pressures and poor ground control conditions can halt operations and be hazardous to coal miners. Recently at a mine in Southwestern Pennsylvania,roof material collapsed above shields that created two large voids and caused major challenges for shield recovery. A unique,engineering solution was developed that utilized a modified concrete material to fill the voids,creating stability in the affected area. The many phases of this project included the construction phase,void pumping,cutting out,and bolting of the concrete material. This project eliminated the hazards associated with bolting the recovery face and removing shields in adverse conditions,making it possible for the mine operator to safely complete the longwall move.展开更多
Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics o...Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains＇ movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and reseheduling trains on the rail network.展开更多
The universality of the application of wireless sensor networks( WSN) makes more attention be paid on the security problem. Node authentication is not only the basis of network security,but also the premise of key man...The universality of the application of wireless sensor networks( WSN) makes more attention be paid on the security problem. Node authentication is not only the basis of network security,but also the premise of key management and secure routing protocol. Although the signature mechanism based on symmetric encryption is high in energy efficiency,it is vulnerable to be attacked and there is a time delay during authentication. Traditional public key encryption mechanism with improvement in security brings in complex algorithm and costs much time,which is not suitable for WSN. In this paper,a signature authentication mechanism,an optimized variant Bellare Namprempre Neven( OvBNN) is presented to quickly complete the authentication by mutual cooperation between nodes so as to make the nodes use the intermediate calculation results of their neighbor nodes directly.Simulation results show that the proposed mechanism is superior to traditional authentication mechanisms both in energy consumption and authentication time.展开更多
Plenty of dams in China are in danger while there are few effective methods for underwater dam inspections of hidden problems such as conduits,cracks and inanitions.The dam safety inspection remotely operated vehicle(...Plenty of dams in China are in danger while there are few effective methods for underwater dam inspections of hidden problems such as conduits,cracks and inanitions.The dam safety inspection remotely operated vehicle(DSIROV) is designed to solve these problems which can be equipped with many advanced sensors such as acoustical,optical and electrical sensors for underwater dam inspection.A least-square parameter estimation method is utilized to estimate the hydrodynamic coefficients of DSIROV,and a four degree-of-freedom(DOF) simulation system is constructed.The architecture of DSIROV's motion control system is introduced,which includes hardware and software structures.The hardware based on PC104 BUS,uses AMD ELAN520 as the controller's embedded CPU and all control modules work in VxWorks real-time operating system.Information flow of the motion system of DSIROV,automatic control of dam scanning and dead-reckoning algorithm for navigation are also discussed.The reliability of DSIROV's control system can be verified and the control system can fulfill the motion control mission because embankment checking can be demonstrated by the lake trials.展开更多
In Wireless Sensor Networks (WSNs), it is necessary to predict computational overheads of security mechanisms without final implementations to provide guidelines for system design. This paper presents an accurate and ...In Wireless Sensor Networks (WSNs), it is necessary to predict computational overheads of security mechanisms without final implementations to provide guidelines for system design. This paper presents an accurate and flexible model to predict overheads of these mechanisms. This model is based on overheads of basic operations frequently used in cryptography algorithms, which are essential elements of security mechanisms. Several popular cryptography algorithms and security mechanisms are evaluated using this model. According to simulation results, relative prediction errors are less than 7% for most cryptography algorithms and security mechanisms.展开更多
文摘Objective.To introduce the properties of Chinese type A botulinum toxin(CBTXA,made by Lanzhou Institute of Biological Products),and its long?term effect for focal dystonia and hemifacial spasm.Method.The purity and recovery of crude and crystalline toxin were tested.Long?term data from305patients with hemifacial spasm(HFS),blepharospasm(BS)and cervical dystonia(CD)were evalu-ated and subgroups of patients received CBTXA injections between1994and2000in at least six sepa-rate treatment sessions,with follow up for2～8years.The therapeutic results of the last session CBTXA injections were analyzed in comparison with the first session.Result.CBTXA purity was high[(2.55～2.60)×10 7 LD50/mgPr ,A260/A280≤0.55,high molecular substance accounted for99.2%of total proteins].Long term treatment with CBTXA in patients with focal dystonia and HFS was not associated with any decline in benefit,and efficacy may improve slightly with repeat treatments.CBTXA is an excellent long-term treatment of HFS,BS and CD.Conclusion.We conclude that Chinese type A botulinum toxin is of botulinum toxin therapy quality standard according to results obtained from the basic study and long?term clinical applications.The re?injection of CBTXA significantly improves the quality of life of most patients and is a safe,effective and comparatively economical treatment for patients with focal dystonia and HFS.
文摘It has been proven that longwall faces can be moved safely and efficiently. However,abutment pressures and poor ground control conditions can halt operations and be hazardous to coal miners. Recently at a mine in Southwestern Pennsylvania,roof material collapsed above shields that created two large voids and caused major challenges for shield recovery. A unique,engineering solution was developed that utilized a modified concrete material to fill the voids,creating stability in the affected area. The many phases of this project included the construction phase,void pumping,cutting out,and bolting of the concrete material. This project eliminated the hazards associated with bolting the recovery face and removing shields in adverse conditions,making it possible for the mine operator to safely complete the longwall move.
基金Supported by the National Natural Science Foundation of China under Grant No. 70901006Research Foundation of Beijing Jiaotong University under Grant Nos. 2011JBM158, 2011JBM162Research Foundation of State Key Laboratory of Rail Traffic Control and Safety under Grant Nos. RCS2009ZT001, RCS2010ZZ001
文摘Based on the discrete time method, an effective movement control model is designed for a group of high- speed trains on a rail network. The purpose of the model is to investigate the specific traffic characteristics of high-speed trains under the interruption of stochastic irregular events. In the model, the high-speed rail traffic system is supposed to be equipped with the moving-block signalling system to guarantee maximum traversing capacity of the railway. To keep the safety of trains＇ movements, some operational strategies are proposed to control the movements of trains in the model, including traction operation, braking operation, and entering-station operation. The numerical simulations show that the designed model can well describe the movements of high-speed trains on the rail network. The research results can provide the useful information not only for investigating the propagation features of relevant delays under the irregular disturbance but also for rerouting and reseheduling trains on the rail network.
基金Support by the National High Technology Research and Development Program of China(2012AA120802)the National Natural Science Foundation of China(61771186)+1 种基金the Postdoctoral Research Project of Heilongjiang Province(LBH-Q15121) the Undergraduate University Project of Young Scientist Creative Talent of Heilongjiang Province(UNPYSCT-2017125)
文摘The universality of the application of wireless sensor networks( WSN) makes more attention be paid on the security problem. Node authentication is not only the basis of network security,but also the premise of key management and secure routing protocol. Although the signature mechanism based on symmetric encryption is high in energy efficiency,it is vulnerable to be attacked and there is a time delay during authentication. Traditional public key encryption mechanism with improvement in security brings in complex algorithm and costs much time,which is not suitable for WSN. In this paper,a signature authentication mechanism,an optimized variant Bellare Namprempre Neven( OvBNN) is presented to quickly complete the authentication by mutual cooperation between nodes so as to make the nodes use the intermediate calculation results of their neighbor nodes directly.Simulation results show that the proposed mechanism is superior to traditional authentication mechanisms both in energy consumption and authentication time.
基金Project(20100480964) supported by China Postdoctoral Science FoundationProjects(2002AA420090,2008AA092301) supported by the National High Technology Research and Development Program of China
文摘Plenty of dams in China are in danger while there are few effective methods for underwater dam inspections of hidden problems such as conduits,cracks and inanitions.The dam safety inspection remotely operated vehicle(DSIROV) is designed to solve these problems which can be equipped with many advanced sensors such as acoustical,optical and electrical sensors for underwater dam inspection.A least-square parameter estimation method is utilized to estimate the hydrodynamic coefficients of DSIROV,and a four degree-of-freedom(DOF) simulation system is constructed.The architecture of DSIROV's motion control system is introduced,which includes hardware and software structures.The hardware based on PC104 BUS,uses AMD ELAN520 as the controller's embedded CPU and all control modules work in VxWorks real-time operating system.Information flow of the motion system of DSIROV,automatic control of dam scanning and dead-reckoning algorithm for navigation are also discussed.The reliability of DSIROV's control system can be verified and the control system can fulfill the motion control mission because embankment checking can be demonstrated by the lake trials.
基金Supported by 863 Project of China (No.2006AA01Z224)
文摘In Wireless Sensor Networks (WSNs), it is necessary to predict computational overheads of security mechanisms without final implementations to provide guidelines for system design. This paper presents an accurate and flexible model to predict overheads of these mechanisms. This model is based on overheads of basic operations frequently used in cryptography algorithms, which are essential elements of security mechanisms. Several popular cryptography algorithms and security mechanisms are evaluated using this model. According to simulation results, relative prediction errors are less than 7% for most cryptography algorithms and security mechanisms.
