Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperatu...Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.展开更多
To improve the accuracy of strapdown inertial navigation system(SINS) for long term applications,the rotation technique is employed to modulate the errors of the inertial sensors into periodically varied signals,and,a...To improve the accuracy of strapdown inertial navigation system(SINS) for long term applications,the rotation technique is employed to modulate the errors of the inertial sensors into periodically varied signals,and,as a result,to suppress the divergence of SINS errors.However,the errors of rotation platform will be introduced into SINS and might affect the final navigation accuracy.Considering the disadvantages of the conventional navigation computation scheme,an improved computation scheme of the SINS using rotation technique is proposed which can reduce the effects of the rotation platform errors.And,the error characteristics of the SINS with this navigation computation scheme are analyzed.Theoretical analysis,simulations and real test results show that the proposed navigation computation scheme outperforms the conventional navigation computation scheme,meanwhile reduces the requirement to the measurement accuracy of rotation angles.展开更多
This letter introduces a 4th order active RC complex filter with 1.SMHz center frequency and 1MHz bandwidth. The total harmonic distortion of the filter is less than -60dB and the image rejection ratio is greater than...This letter introduces a 4th order active RC complex filter with 1.SMHz center frequency and 1MHz bandwidth. The total harmonic distortion of the filter is less than -60dB and the image rejection ratio is greater than 60dB. A novel technique is also proposed in this letter to automatically adjust the variation of the time constant. The advantages of the proposed method are its high precision and simplicity. Using 5bits control words, the tuning error is less than ±1.6%.展开更多
In order to integrate heterogeneous location-aware systems into pervasive computing environment,a novel pervasive computing location-aware model based on ontology is presented.A location-aware model ontology(LMO)is co...In order to integrate heterogeneous location-aware systems into pervasive computing environment,a novel pervasive computing location-aware model based on ontology is presented.A location-aware model ontology(LMO)is constructed.The location-aware model has the capabilities of sharing knowledge,reasoning and adjusting the usage policies of services dynamically through a unified semantic location manner.At last,the work process of our proposed location-aware model is explained by an application scenario.展开更多
It is still a laborious work to consult massive multidisciplinary geological maps which are scattered in different geological departments,and hard to give full play to the potential application value of geological map...It is still a laborious work to consult massive multidisciplinary geological maps which are scattered in different geological departments,and hard to give full play to the potential application value of geological map. Along with the network,the development of communication and computer technology,especially with the Web2.0 technology arisen,provides opportunities to the web for sharing of geological maps. Web fast sharing platform of massive geological maps( WSPGM) is based on the Flex technology development,using B/S architecture,with map navigation,search,display,security and other functions of the software system. Through the map pretreatment and asynchronous communication the system can display any size of geological map,and through the range limits,rights management,sharing system and watermark logo to take effective security on geological map. On the basis of this system,with the Jilin University web sharing system of geological map,the system can greatly improve the efficiency of using geological map. for research.展开更多
Simulation and optimization are the key points of virtual product development (VPD). Traditional engineering simulation software and optimization methods are inadequate to analyze the optimization problems because of ...Simulation and optimization are the key points of virtual product development (VPD). Traditional engineering simulation software and optimization methods are inadequate to analyze the optimization problems because of its computational inefficiency. A systematic design optimization strategy by using statistical methods and mathematical optimization technologies is proposed. This method extends the design of experiments (DOE) and the simulation metamodel technologies. Metamodels are built to in place of detailed simulation codes based on effectively DOE, and then be linked to optimization routines for fast analysis, or serve as a bridge for integrating simulation software across different domains. A design optimization of composite material structure is used to demonstrate the newly introduced methodology.展开更多
The present work makes the exhibition of a manfacturing cell for didactic pulposes, implemented as part of evaluation in the last cycle of mechatronics engineering formation within Technological University of North Ag...The present work makes the exhibition of a manfacturing cell for didactic pulposes, implemented as part of evaluation in the last cycle of mechatronics engineering formation within Technological University of North Aguascalientes. It includes the motivation that led to plnning and subsequent implementation of manufacturing system described, the characteristics of particular processing operations that it was decided to include, methodology to achieve joint work and synchronization of each operation performed, the results of operation obtained and their comparison with initial expectations, as well as the conclusions derived from process, which lead to considering such a project as an ideal model to verify the formation of the future mechatroonics engineers, when faced with applications of their area of exercise, reviewing operating principle of mechanical, electronic, control and computing systems to achieve their synergy in a mechatronic system.展开更多
To strike a tradeoff between the security and the consumption of energy,computing and communication resources in the nodes,this paper presents an efficient authentication scheme based on one-way key chain for sensor n...To strike a tradeoff between the security and the consumption of energy,computing and communication resources in the nodes,this paper presents an efficient authentication scheme based on one-way key chain for sensor network. The scheme can provide immediate authentication to fulfill the latency and the storage requirements and defends against various attacks such as replay,impersonation and denial of service. Meanwhile,our scheme possesses low overhead and scalability to large networks. Furthermore,the simple related protocols or algorithms in the scheme and inexpensive public-key operation required in view of resource-starved sensor nodes minimize the storage,computation and communication overhead,and improve the efficiency of our scheme. In addition,the proposed scheme also supports source authentication without precluding in-network processing and passive participation.展开更多
The development of computer information technology makes the information of the audited unit more and more high. The introduction of accounting computerization information system makes the processing of enterprise eco...The development of computer information technology makes the information of the audited unit more and more high. The introduction of accounting computerization information system makes the processing of enterprise economic business more convenient and efficient. Here came the computer controlled environment audit new risks, of course, the computer technology applied to the audit work to improve the audit efficiency by a lot, but also increased the complex information technology environment audit risk. Starting from the concept of computer audit risk, this paper analyzes and discusses the new risks and causes of audit under the computer condition, and puts forward some constructive risk control measures.展开更多
With the rapid development of animation design and other computer science techniques, the application of computer based design pattern is urgently appreciated. In this paper, we conduct research on the similarities an...With the rapid development of animation design and other computer science techniques, the application of computer based design pattern is urgently appreciated. In this paper, we conduct research on the similarities and differences between Flash ActionScript based animation design technique and traditional design pattern. Current computer animation technology has developed rapidly at home and abroad, in the production of 2D and 3D animation, creating many new methods, new technology, using the computer aided animation in different degree to replace the manual animation technology, computerized gradually. We could significantly conclude from the user interface and the sample example of the pattern of computer based animation design. In the future, we plan to research more to touch the latest techniques related to flash technique.展开更多
Developing nations, like Nigeria, whose financial systems and infrastructural base are not yet fully developed face data rendition challenges which may hamper the representativeness of their interest rate statistics.A...Developing nations, like Nigeria, whose financial systems and infrastructural base are not yet fully developed face data rendition challenges which may hamper the representativeness of their interest rate statistics.A critical component of any credible interest rate data compilation framework relates to the sampling procedure.In Nigeria, no work has been done with regards to employing alternatives sampling techniques in the computation of interest rate statistics largely because of the small number of deposit money banks in the country. Leveraging on existing literature and established statistical methods, the study examines two sampling techniques for generating credible and reliable interest rates in Nigeria. The current interest rate compilation framework in the country is presented and alternative sampling procedures were explored with a view to investigating their appropriateness for Nigeria＇s interest rate computation. The interest rates generated based on the current population-based compilation method is compared with those of the alternative approaches. This paper recommends the use of purposive sampling method that covers Deposit Money Banks （DMBs） which account for about 70.0 per cent of the banking sector total assets as an appropriatealternative.展开更多
文摘Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.
基金Project(60604011) supported by the National Natural Science Foundation of China
文摘To improve the accuracy of strapdown inertial navigation system(SINS) for long term applications,the rotation technique is employed to modulate the errors of the inertial sensors into periodically varied signals,and,as a result,to suppress the divergence of SINS errors.However,the errors of rotation platform will be introduced into SINS and might affect the final navigation accuracy.Considering the disadvantages of the conventional navigation computation scheme,an improved computation scheme of the SINS using rotation technique is proposed which can reduce the effects of the rotation platform errors.And,the error characteristics of the SINS with this navigation computation scheme are analyzed.Theoretical analysis,simulations and real test results show that the proposed navigation computation scheme outperforms the conventional navigation computation scheme,meanwhile reduces the requirement to the measurement accuracy of rotation angles.
基金Supported by the Key Project of the National Natural Science Foundation of China (No.60437030) the Tianjin Natural Science Foundation (No.05YFJMJC01400).
文摘This letter introduces a 4th order active RC complex filter with 1.SMHz center frequency and 1MHz bandwidth. The total harmonic distortion of the filter is less than -60dB and the image rejection ratio is greater than 60dB. A novel technique is also proposed in this letter to automatically adjust the variation of the time constant. The advantages of the proposed method are its high precision and simplicity. Using 5bits control words, the tuning error is less than ±1.6%.
基金The Key Project of Chinese Ministry of Education(No.104086)
文摘In order to integrate heterogeneous location-aware systems into pervasive computing environment,a novel pervasive computing location-aware model based on ontology is presented.A location-aware model ontology(LMO)is constructed.The location-aware model has the capabilities of sharing knowledge,reasoning and adjusting the usage policies of services dynamically through a unified semantic location manner.At last,the work process of our proposed location-aware model is explained by an application scenario.
文摘It is still a laborious work to consult massive multidisciplinary geological maps which are scattered in different geological departments,and hard to give full play to the potential application value of geological map. Along with the network,the development of communication and computer technology,especially with the Web2.0 technology arisen,provides opportunities to the web for sharing of geological maps. Web fast sharing platform of massive geological maps( WSPGM) is based on the Flex technology development,using B/S architecture,with map navigation,search,display,security and other functions of the software system. Through the map pretreatment and asynchronous communication the system can display any size of geological map,and through the range limits,rights management,sharing system and watermark logo to take effective security on geological map. On the basis of this system,with the Jilin University web sharing system of geological map,the system can greatly improve the efficiency of using geological map. for research.
文摘Simulation and optimization are the key points of virtual product development (VPD). Traditional engineering simulation software and optimization methods are inadequate to analyze the optimization problems because of its computational inefficiency. A systematic design optimization strategy by using statistical methods and mathematical optimization technologies is proposed. This method extends the design of experiments (DOE) and the simulation metamodel technologies. Metamodels are built to in place of detailed simulation codes based on effectively DOE, and then be linked to optimization routines for fast analysis, or serve as a bridge for integrating simulation software across different domains. A design optimization of composite material structure is used to demonstrate the newly introduced methodology.
文摘The present work makes the exhibition of a manfacturing cell for didactic pulposes, implemented as part of evaluation in the last cycle of mechatronics engineering formation within Technological University of North Aguascalientes. It includes the motivation that led to plnning and subsequent implementation of manufacturing system described, the characteristics of particular processing operations that it was decided to include, methodology to achieve joint work and synchronization of each operation performed, the results of operation obtained and their comparison with initial expectations, as well as the conclusions derived from process, which lead to considering such a project as an ideal model to verify the formation of the future mechatroonics engineers, when faced with applications of their area of exercise, reviewing operating principle of mechanical, electronic, control and computing systems to achieve their synergy in a mechatronic system.
基金the National Natural Science Foundation of China (Grant No. 60202005).
文摘To strike a tradeoff between the security and the consumption of energy,computing and communication resources in the nodes,this paper presents an efficient authentication scheme based on one-way key chain for sensor network. The scheme can provide immediate authentication to fulfill the latency and the storage requirements and defends against various attacks such as replay,impersonation and denial of service. Meanwhile,our scheme possesses low overhead and scalability to large networks. Furthermore,the simple related protocols or algorithms in the scheme and inexpensive public-key operation required in view of resource-starved sensor nodes minimize the storage,computation and communication overhead,and improve the efficiency of our scheme. In addition,the proposed scheme also supports source authentication without precluding in-network processing and passive participation.
文摘The development of computer information technology makes the information of the audited unit more and more high. The introduction of accounting computerization information system makes the processing of enterprise economic business more convenient and efficient. Here came the computer controlled environment audit new risks, of course, the computer technology applied to the audit work to improve the audit efficiency by a lot, but also increased the complex information technology environment audit risk. Starting from the concept of computer audit risk, this paper analyzes and discusses the new risks and causes of audit under the computer condition, and puts forward some constructive risk control measures.
文摘With the rapid development of animation design and other computer science techniques, the application of computer based design pattern is urgently appreciated. In this paper, we conduct research on the similarities and differences between Flash ActionScript based animation design technique and traditional design pattern. Current computer animation technology has developed rapidly at home and abroad, in the production of 2D and 3D animation, creating many new methods, new technology, using the computer aided animation in different degree to replace the manual animation technology, computerized gradually. We could significantly conclude from the user interface and the sample example of the pattern of computer based animation design. In the future, we plan to research more to touch the latest techniques related to flash technique.
文摘Developing nations, like Nigeria, whose financial systems and infrastructural base are not yet fully developed face data rendition challenges which may hamper the representativeness of their interest rate statistics.A critical component of any credible interest rate data compilation framework relates to the sampling procedure.In Nigeria, no work has been done with regards to employing alternatives sampling techniques in the computation of interest rate statistics largely because of the small number of deposit money banks in the country. Leveraging on existing literature and established statistical methods, the study examines two sampling techniques for generating credible and reliable interest rates in Nigeria. The current interest rate compilation framework in the country is presented and alternative sampling procedures were explored with a view to investigating their appropriateness for Nigeria＇s interest rate computation. The interest rates generated based on the current population-based compilation method is compared with those of the alternative approaches. This paper recommends the use of purposive sampling method that covers Deposit Money Banks （DMBs） which account for about 70.0 per cent of the banking sector total assets as an appropriatealternative.
