Novel 2×2 torsion-mirror optical switch arrays are fabricated by using the mixed micromachining based on the surface and bulk silicon microelectronics,then are investigated electromechanically in applied direct a...Novel 2×2 torsion-mirror optical switch arrays are fabricated by using the mixed micromachining based on the surface and bulk silicon microelectronics,then are investigated electromechanically in applied direct and alternating electric fields.When the thickness of the elastic torsion beams suspending the aluminum coated polysilicon micro-mirrors of the switches in the arrays is about 1μm,the electrostatic yielding voltages for driving the mirrors to achieve their ON-state are in the range of 270~290V,and the minimum holding voltages for mirrors ON-state are found as 55V or so.Theoretical analysis manifests that the yielding voltage is more sensitive to beam thickness than other design parameters do about the torsion-mirror switch structures.The lifetime can reach 10 8 times.The estimated shortest switching time of the switches at least lasts for less than 2ms.The force analysis on the two kinds of new fiber self-holding structures integrated monolithically in the chip of the optical switch arrays indicates that the structures can feature self-fixing and self-aligning of optical fibers.展开更多
Conventional jar tests and on-line size monitoring were used to investigate the effects of slow-mixing intensity and duration on residual turbidity and floc size during charge neutralization coagulation and sweep floc...Conventional jar tests and on-line size monitoring were used to investigate the effects of slow-mixing intensity and duration on residual turbidity and floc size during charge neutralization coagulation and sweep floc- culation with polyaluminum chloride. The compensatory effect of slow-mixing on coagulation performance fol- low!ng inadequate_or excessive rapid-mi_xing was also examined. It is found that slowTmixing intensity has a more marked positive ettect on charge neutralization coas;ulatlon tlaan on sweep tlocculatlon. llle optimal root-mean- square velocity gradient, G, for slow-mixing is 15 s-' for both coagulation mechanisms, and charge neutralization coagulation requires a longer slow-mixing duration. The optimal slow-mixing duration, based on residual turbidity,is longer than the time to tbrm the largest mean Ilocs. The optimal product of G and mixing duration, GT, lbr slow-mixing during charge neutralization coagulation (13500) are higher than that during sweep flocculation (4500) and both are less than the range of values recommended by the American Water Works Association (24000-84000).The optimal GT value under various slow-mixing conditions increases with G. Appropriate extension'of slow-mixing duration during charge neutralization coagulation can improve coagulation performance after an inadequate or excessive rapid-mixing duration, but during sweep flocculation, appropriate shortening of slow-mixing duration after an excessive rapid-mixing or appropriate extension of slow-mixing duration after an inadequate rapid-mixing is favorable.展开更多
This paper presents the development of ultra high strength concrete (UHSC) using local materials. UHSC mixture proportions were developed using local materials so that UHSC may be made more affordable to a wider var...This paper presents the development of ultra high strength concrete (UHSC) using local materials. UHSC mixture proportions were developed using local materials so that UHSC may be made more affordable to a wider variety of applications. Specifically, local sand with a top size of 600 um, and locally available Type I/II cement and silica fume were used in this research. Each of these material selections is seen as an improvement in sustainability for UHSC. Two mixtures (one with and one without fibers) were recommended as the UHSC mixtures. The greatest compressive strengths obtained in this study were 165.6 MPa for UHSC with steel fibers and 161.9 MPa for UHSC without fibers. The compressive and flexural strengths obtained from the UHSC mixtures developed in this work are comparable to UHSC strengths presented in the literature. Producing this innovative material with local materials reduces the cost of the material, improves sustainability, and produces mechanical performance similar to prepackaged, commercially available products.展开更多
Support Vector Machines (SVM) is a new general machine-learning tool based on structural risk minimization principle. This characteristic is very signific ant for the fault diagnostics when the number of fault sampl...Support Vector Machines (SVM) is a new general machine-learning tool based on structural risk minimization principle. This characteristic is very signific ant for the fault diagnostics when the number of fault samples is limited. Considering that SVM theory is originally designed for a two-class classification, a hybrid SVM scheme is proposed for multi-fault classification of rotating machinery in our paper. Two SVM strategies, 1-v-1 (one versus one) and 1-v-r (one versus rest), are respectively adopted at different classification levels. At the parallel classification level, using l-v-1 strategy, the fault features extracted by various signal analysis methods are transferred into the multiple parallel SVM and the local classification results are obtained. At the serial classification level, these local results values are fused by one serial SVM based on 1-v-r strategy. The hybrid SVM scheme introduced in our paper not only generalizes the performance of signal binary SVMs but improves the precision and reliability of the fault classification results. The actually testing results show the availability suitability of this new method.展开更多
The development of 5-aminosalicylic acid (5-ASA) therapy as a life long treatment for ulcerative colitis is reviewed from its origins in the 1940s to the present day. The drug was designed to treat rheumatoid arthriti...The development of 5-aminosalicylic acid (5-ASA) therapy as a life long treatment for ulcerative colitis is reviewed from its origins in the 1940s to the present day. The drug was designed to treat rheumatoid arthritis,but was found helpful in the management of nine patients with ulcerative colitis. This discovery preceded the emergence of the clinical trial as a tool for assessing a new drug's efficacy; as a result it lacked scientific rigour and was selective in its presentation of results. Nevertheless it identified the future cornerstone of therapy in ulcerative colitis. In 1962,the first double blind controlled trial of sulphasalazine was conducted on 40 patients. Outcome measures were subjective and included symptoms and an assessment of the rectal mucosa. In 1973,the first two papers on the role of sulphasalazine in maintenance of remission were published. Both used placebo controls and had a stratified design. Outcomes were measured using "an intention to treat" approach. The British study of 64 patients used both subjective and objective criteria to assess outcomes. Patients on placebo had a relapse rate four times patients on active treatment and this founded the basis for a life long approach to therapy with 5-ASA compounds in ulcerative colitis. However,in 1985,a small "on demand" study of 32 patients suggested this approach might be as effective as continuous treatment. Some support for this view came from an Italian study which showed no benefit to continued treatment for those in remission for two years or more. The central problem these studies identify is that of adherence to treatment in the long-term. Few studies have considered patients' attitudes to continuous therapy and it is an area that needs further investigation.展开更多
This paper introduces, for applications in the mining industry, an innovative hybrid column form which consists of an inner steel tube, an outer fibre-reinforced polymer(FRP) tube and an annular concrete infill betwee...This paper introduces, for applications in the mining industry, an innovative hybrid column form which consists of an inner steel tube, an outer fibre-reinforced polymer(FRP) tube and an annular concrete infill between them. The two tubes may be concentrically placed to produce a section form more suitable for columns, or eccentrically placed to produce a section form more suitable for beams. The FRP is combined with steel and concrete in these hybrid structural members in such a way that the advantages of FRP are appropriately exploited while its disadvantages are minimized. As a result, these hybrid members possess excellent corrosion resistance as well as excellent ductility and seismic resistance. This paper summarizes existing research on this new form of structural members, and discusses their potential applications in mining infrastructure before presenting a summary of the recent and current studies at University of Wollongong(UOW) on their structural behaviour and design.展开更多
This paper studied a supervisory control system for a hybrid off-highway electric vehicle under the chargesustaining(CS)condition.A new predictive double Q-learning with backup models(PDQL)scheme is proposed to optimi...This paper studied a supervisory control system for a hybrid off-highway electric vehicle under the chargesustaining(CS)condition.A new predictive double Q-learning with backup models(PDQL)scheme is proposed to optimize the engine fuel in real-world driving and improve energy efficiency with a faster and more robust learning process.Unlike the existing“model-free”methods,which solely follow on-policy and off-policy to update knowledge bases(Q-tables),the PDQL is developed with the capability to merge both on-policy and off-policy learning by introducing a backup model(Q-table).Experimental evaluations are conducted based on software-in-the-loop(SiL)and hardware-in-the-loop(HiL)test platforms based on real-time modelling of the studied vehicle.Compared to the standard double Q-learning(SDQL),the PDQL only needs half of the learning iterations to achieve better energy efficiency than the SDQL at the end learning process.In the SiL under 35 rounds of learning,the results show that the PDQL can improve the vehicle energy efficiency by 1.75%higher than SDQL.By implementing the PDQL in HiL under four predefined real-world conditions,the PDQL can robustly save more than 5.03%energy than the SDQL scheme.展开更多
This research proposes and implements an Arabic Sub-Words Recognition System (ASWR). The system focuses on employing a combination of statistical and structural features to provide complete pattern's description an...This research proposes and implements an Arabic Sub-Words Recognition System (ASWR). The system focuses on employing a combination of statistical and structural features to provide complete pattern's description and enhances the recognition rate. Support Vector Machines (SVMs) is utilized as a promising pattern recognition tool. In addition to that, the problems of dots and holes are solved in a completely different way from the ones previously employed. The proposed system proceeds in several phases as follows: (1) image acquisition, (2) binarisation, (3) morphological processing, (4) feature extraction, which includes statistical features, i.e., moment invariants, and structural features, i.e., dot number, dot position, and number of holes, features, and (5) classification, using multi-class SVMs and applying a one-against-all technique. The proposed system has been tested using different sets of words and subwords and has achieved a nearly 98.90% recogiaition rate. Comparative results with NNs are also presented.展开更多
Nowadays, urban design faces complex demands. It has become a necessity to negotiate between stakeholder objectives, the expectations of citizens and the demands of planning. It is desirable to involve the stakeholder...Nowadays, urban design faces complex demands. It has become a necessity to negotiate between stakeholder objectives, the expectations of citizens and the demands of planning. It is desirable to involve the stakeholders and citizens from an early stage in the planning process to enable their different viewpoints to be successfully expressed and comprehended. Therefore, the basic aim of the study was how the MR (mixed reality) application is designed to encourage and improve communication on urban design among stakeholders and citizens? In this paper, we discuss new approaches to visualize urban building and environment alternatives to different stakeholders and provide them with tools to explore different approaches to urban planning in order to support citizen's participation in urban planning with augmented and mixed reality. The major finding of the study is that learning "how these participatory technologies may help build a community of practice around an urban project". And throughout the different experiences, we can learn to assist towards development of a methodology to use the mixed reality as a simulation tool in the enhancement of collaborative interaction in real-Egyptian project. So, we can determine a number of recommendations to deal with new participatory design tools for urban planning projects.展开更多
An expert decision support system (EDSS) for multi-bins balance and contro1 of orequality in production ore bins of some large-scale open pit iron mine in China has been developed byexpert svitem tool software VP-EXPE...An expert decision support system (EDSS) for multi-bins balance and contro1 of orequality in production ore bins of some large-scale open pit iron mine in China has been developed byexpert svitem tool software VP-EXPERT and integration software LOTUS 1-2-3 in this paper. Itis known by practicing that a medium-scale EDSS constructed on microcomputer is completcly, feaasible by means of VP-EXEPERT to construct knowledge base system (KBS), LOTUS 1-2-3 tomake decision support system (DSS) and link them with BAT.展开更多
Automatic image annotation(AIA)has become an important and challenging problem in computer vision due to the existence of semantic gap.In this paper,a novel support vector machine with mixture of kernels(SVM-MK)for au...Automatic image annotation(AIA)has become an important and challenging problem in computer vision due to the existence of semantic gap.In this paper,a novel support vector machine with mixture of kernels(SVM-MK)for automatic image annotation is proposed.On one hand,the combined global and local block-based image features are extracted in order to reflect the intrinsic content of images as complete as possible.On the other hand,SVM-MK is constructed to shoot for better annotating performance.Experimental results on Corel dataset show that the proposed image feature representation method as well as automatic image annotation classifier,SVM-MK,can achieve higher annotating accuracy than SVM with any single kernel and mi-SVM for semantic image annotation.展开更多
Time and cost are two of the most important factors to consider in each construction project. In order to maximize performance, both the client and the contractor will work to optimize both the duration of the project...Time and cost are two of the most important factors to consider in each construction project. In order to maximize performance, both the client and the contractor will work to optimize both the duration of the project and its cost. We show a model of linear entire mixed programming to solve the considered problem. The aim is to minimize the project total time, by means of the assignment of equipments of work to the different production lines of the activities to realizing. The fundamental beginning is to support the same production (rate of production in meters/day of the activity in view of the equipment of work) for tbe different equipments to achieve the maximum efficiency in each period of time. With the limited availability of resources, the work must be continuous and the period of time between operations and final must be kept. However, this paper also presents the bibliographical study on methodologies of the optimization of construction processes in response to the two objectives: time and cost. This will consider the use of recta-heuristic techniques, such as population based algorithms.展开更多
Targeting the mode-mixing problem of intrinsic time-scale decomposition (ITD) and the parameter optimization problem of least-square support vector machine (LSSVM), we propose a novel approach based on complete en...Targeting the mode-mixing problem of intrinsic time-scale decomposition (ITD) and the parameter optimization problem of least-square support vector machine (LSSVM), we propose a novel approach based on complete ensemble intrinsic time-scale decomposition (CEITD) and LSSVM optimized by the hybrid differential evolution and particle swarm optimization (HDEPSO) algorithm for the identification of the fault in a diesel engine. The approach consists mainly of three stages. First, to solve the mode-mixing problem of ITD, a novel CEITD method is proposed. Then the CEITD method is used to decompose the nonstationary vibration signal into a set of stationary proper rotation components (PRCs) and a residual signal. Second, three typical types of time-frequency features, namely singular values, PRCs energy and energy entropy, and AR model parameters, are extracted from the first several PRCs and used as the fault feature vectors. Finally, a HDEPSO algorithm is proposed for the parameter optimization of LSSVM, and the fault diagnosis results can be obtained by inputting the fault feature vectors into the HDEPSO-LSSVM classifier. Simulation and experimental results demonstrate that the proposed fault diagnosis approach can overcome the mode-mixing problem of ITD and accurately identify the fault patterns of diesel engines.展开更多
For the low-earth-orbit (LEO) long-duration multi-spacecraft rendezvous mission, a mixed integer nonlinear programming (MINLP) model is built with consideration of the , perturbation and the time window constraint...For the low-earth-orbit (LEO) long-duration multi-spacecraft rendezvous mission, a mixed integer nonlinear programming (MINLP) model is built with consideration of the , perturbation and the time window constraints based on lighting condition. A two-level hybrid optimization approach is proposed. The up-level problem uses the visiting sequence, the orbital transfer duration and the service time after each rendezvous as design variables, and employs the mix-coded genetic algorithm to search the optimal solution; the low-level problem uses the maneuver time and impulses in each rendezvous as design vari- ables, and employs the downhill simplex method to search the optimal solution. To improve the solving efficiency of the low-level problem, a linear dynamic model with J~ perturbation is derived, and the approximate strategy of the low-level prob- lem is then proposed. The proposed method has been applied to several numerical problems. The results lead to three major conclusions: (1) The MINLP model for LEO long-duration multi-spacecraft rendezvous mission is effective, and the proposed hybrid optimization strategy can obtain good solutions that satisfy time window constraints; (2) The derived linear dynamic equations are good first-order approximation to the long-duration rendezvous trajectory under ,J2 perturbation; (3) Under J2 perturbation, the long-duration rendezvous problem has multiple local minimums either in the duration of multiple orbits or in a single orbit, and it agrees with the problem's characteristic to use the mix-coded genetic algorithm.展开更多
文摘Novel 2×2 torsion-mirror optical switch arrays are fabricated by using the mixed micromachining based on the surface and bulk silicon microelectronics,then are investigated electromechanically in applied direct and alternating electric fields.When the thickness of the elastic torsion beams suspending the aluminum coated polysilicon micro-mirrors of the switches in the arrays is about 1μm,the electrostatic yielding voltages for driving the mirrors to achieve their ON-state are in the range of 270~290V,and the minimum holding voltages for mirrors ON-state are found as 55V or so.Theoretical analysis manifests that the yielding voltage is more sensitive to beam thickness than other design parameters do about the torsion-mirror switch structures.The lifetime can reach 10 8 times.The estimated shortest switching time of the switches at least lasts for less than 2ms.The force analysis on the two kinds of new fiber self-holding structures integrated monolithically in the chip of the optical switch arrays indicates that the structures can feature self-fixing and self-aligning of optical fibers.
基金Supported by the National High Technology Research and Development Program of China (2009AA063901)the Special Funds for Technological Development of Research Institutes from the Ministry of Science and Technology of China(2010EG111022, 2011EG111307)+1 种基金the Budding Program (2011A-12-L)the Program for Innovative Research Team(IG201204N) of Beijing Academy of Science and Technology
文摘Conventional jar tests and on-line size monitoring were used to investigate the effects of slow-mixing intensity and duration on residual turbidity and floc size during charge neutralization coagulation and sweep floc- culation with polyaluminum chloride. The compensatory effect of slow-mixing on coagulation performance fol- low!ng inadequate_or excessive rapid-mi_xing was also examined. It is found that slowTmixing intensity has a more marked positive ettect on charge neutralization coas;ulatlon tlaan on sweep tlocculatlon. llle optimal root-mean- square velocity gradient, G, for slow-mixing is 15 s-' for both coagulation mechanisms, and charge neutralization coagulation requires a longer slow-mixing duration. The optimal slow-mixing duration, based on residual turbidity,is longer than the time to tbrm the largest mean Ilocs. The optimal product of G and mixing duration, GT, lbr slow-mixing during charge neutralization coagulation (13500) are higher than that during sweep flocculation (4500) and both are less than the range of values recommended by the American Water Works Association (24000-84000).The optimal GT value under various slow-mixing conditions increases with G. Appropriate extension'of slow-mixing duration during charge neutralization coagulation can improve coagulation performance after an inadequate or excessive rapid-mixing duration, but during sweep flocculation, appropriate shortening of slow-mixing duration after an excessive rapid-mixing or appropriate extension of slow-mixing duration after an inadequate rapid-mixing is favorable.
文摘This paper presents the development of ultra high strength concrete (UHSC) using local materials. UHSC mixture proportions were developed using local materials so that UHSC may be made more affordable to a wider variety of applications. Specifically, local sand with a top size of 600 um, and locally available Type I/II cement and silica fume were used in this research. Each of these material selections is seen as an improvement in sustainability for UHSC. Two mixtures (one with and one without fibers) were recommended as the UHSC mixtures. The greatest compressive strengths obtained in this study were 165.6 MPa for UHSC with steel fibers and 161.9 MPa for UHSC without fibers. The compressive and flexural strengths obtained from the UHSC mixtures developed in this work are comparable to UHSC strengths presented in the literature. Producing this innovative material with local materials reduces the cost of the material, improves sustainability, and produces mechanical performance similar to prepackaged, commercially available products.
文摘Support Vector Machines (SVM) is a new general machine-learning tool based on structural risk minimization principle. This characteristic is very signific ant for the fault diagnostics when the number of fault samples is limited. Considering that SVM theory is originally designed for a two-class classification, a hybrid SVM scheme is proposed for multi-fault classification of rotating machinery in our paper. Two SVM strategies, 1-v-1 (one versus one) and 1-v-r (one versus rest), are respectively adopted at different classification levels. At the parallel classification level, using l-v-1 strategy, the fault features extracted by various signal analysis methods are transferred into the multiple parallel SVM and the local classification results are obtained. At the serial classification level, these local results values are fused by one serial SVM based on 1-v-r strategy. The hybrid SVM scheme introduced in our paper not only generalizes the performance of signal binary SVMs but improves the precision and reliability of the fault classification results. The actually testing results show the availability suitability of this new method.
文摘The development of 5-aminosalicylic acid (5-ASA) therapy as a life long treatment for ulcerative colitis is reviewed from its origins in the 1940s to the present day. The drug was designed to treat rheumatoid arthritis,but was found helpful in the management of nine patients with ulcerative colitis. This discovery preceded the emergence of the clinical trial as a tool for assessing a new drug's efficacy; as a result it lacked scientific rigour and was selective in its presentation of results. Nevertheless it identified the future cornerstone of therapy in ulcerative colitis. In 1962,the first double blind controlled trial of sulphasalazine was conducted on 40 patients. Outcome measures were subjective and included symptoms and an assessment of the rectal mucosa. In 1973,the first two papers on the role of sulphasalazine in maintenance of remission were published. Both used placebo controls and had a stratified design. Outcomes were measured using "an intention to treat" approach. The British study of 64 patients used both subjective and objective criteria to assess outcomes. Patients on placebo had a relapse rate four times patients on active treatment and this founded the basis for a life long approach to therapy with 5-ASA compounds in ulcerative colitis. However,in 1985,a small "on demand" study of 32 patients suggested this approach might be as effective as continuous treatment. Some support for this view came from an Italian study which showed no benefit to continued treatment for those in remission for two years or more. The central problem these studies identify is that of adherence to treatment in the long-term. Few studies have considered patients' attitudes to continuous therapy and it is an area that needs further investigation.
基金the University of Wollongong through the 2013 URC Small Grants Scheme
文摘This paper introduces, for applications in the mining industry, an innovative hybrid column form which consists of an inner steel tube, an outer fibre-reinforced polymer(FRP) tube and an annular concrete infill between them. The two tubes may be concentrically placed to produce a section form more suitable for columns, or eccentrically placed to produce a section form more suitable for beams. The FRP is combined with steel and concrete in these hybrid structural members in such a way that the advantages of FRP are appropriately exploited while its disadvantages are minimized. As a result, these hybrid members possess excellent corrosion resistance as well as excellent ductility and seismic resistance. This paper summarizes existing research on this new form of structural members, and discusses their potential applications in mining infrastructure before presenting a summary of the recent and current studies at University of Wollongong(UOW) on their structural behaviour and design.
基金Project(KF2029)supported by the State Key Laboratory of Automotive Safety and Energy(Tsinghua University),ChinaProject(102253)supported partially by the Innovate UK。
文摘This paper studied a supervisory control system for a hybrid off-highway electric vehicle under the chargesustaining(CS)condition.A new predictive double Q-learning with backup models(PDQL)scheme is proposed to optimize the engine fuel in real-world driving and improve energy efficiency with a faster and more robust learning process.Unlike the existing“model-free”methods,which solely follow on-policy and off-policy to update knowledge bases(Q-tables),the PDQL is developed with the capability to merge both on-policy and off-policy learning by introducing a backup model(Q-table).Experimental evaluations are conducted based on software-in-the-loop(SiL)and hardware-in-the-loop(HiL)test platforms based on real-time modelling of the studied vehicle.Compared to the standard double Q-learning(SDQL),the PDQL only needs half of the learning iterations to achieve better energy efficiency than the SDQL at the end learning process.In the SiL under 35 rounds of learning,the results show that the PDQL can improve the vehicle energy efficiency by 1.75%higher than SDQL.By implementing the PDQL in HiL under four predefined real-world conditions,the PDQL can robustly save more than 5.03%energy than the SDQL scheme.
文摘This research proposes and implements an Arabic Sub-Words Recognition System (ASWR). The system focuses on employing a combination of statistical and structural features to provide complete pattern's description and enhances the recognition rate. Support Vector Machines (SVMs) is utilized as a promising pattern recognition tool. In addition to that, the problems of dots and holes are solved in a completely different way from the ones previously employed. The proposed system proceeds in several phases as follows: (1) image acquisition, (2) binarisation, (3) morphological processing, (4) feature extraction, which includes statistical features, i.e., moment invariants, and structural features, i.e., dot number, dot position, and number of holes, features, and (5) classification, using multi-class SVMs and applying a one-against-all technique. The proposed system has been tested using different sets of words and subwords and has achieved a nearly 98.90% recogiaition rate. Comparative results with NNs are also presented.
文摘Nowadays, urban design faces complex demands. It has become a necessity to negotiate between stakeholder objectives, the expectations of citizens and the demands of planning. It is desirable to involve the stakeholders and citizens from an early stage in the planning process to enable their different viewpoints to be successfully expressed and comprehended. Therefore, the basic aim of the study was how the MR (mixed reality) application is designed to encourage and improve communication on urban design among stakeholders and citizens? In this paper, we discuss new approaches to visualize urban building and environment alternatives to different stakeholders and provide them with tools to explore different approaches to urban planning in order to support citizen's participation in urban planning with augmented and mixed reality. The major finding of the study is that learning "how these participatory technologies may help build a community of practice around an urban project". And throughout the different experiences, we can learn to assist towards development of a methodology to use the mixed reality as a simulation tool in the enhancement of collaborative interaction in real-Egyptian project. So, we can determine a number of recommendations to deal with new participatory design tools for urban planning projects.
文摘An expert decision support system (EDSS) for multi-bins balance and contro1 of orequality in production ore bins of some large-scale open pit iron mine in China has been developed byexpert svitem tool software VP-EXPERT and integration software LOTUS 1-2-3 in this paper. Itis known by practicing that a medium-scale EDSS constructed on microcomputer is completcly, feaasible by means of VP-EXEPERT to construct knowledge base system (KBS), LOTUS 1-2-3 tomake decision support system (DSS) and link them with BAT.
基金Supported by the National Basic Research Priorities Programme(No.2007CB311004)the National Natural Science Foundation of China(No.61035003,60933004,60903141,60970088,61072085)
文摘Automatic image annotation(AIA)has become an important and challenging problem in computer vision due to the existence of semantic gap.In this paper,a novel support vector machine with mixture of kernels(SVM-MK)for automatic image annotation is proposed.On one hand,the combined global and local block-based image features are extracted in order to reflect the intrinsic content of images as complete as possible.On the other hand,SVM-MK is constructed to shoot for better annotating performance.Experimental results on Corel dataset show that the proposed image feature representation method as well as automatic image annotation classifier,SVM-MK,can achieve higher annotating accuracy than SVM with any single kernel and mi-SVM for semantic image annotation.
文摘Time and cost are two of the most important factors to consider in each construction project. In order to maximize performance, both the client and the contractor will work to optimize both the duration of the project and its cost. We show a model of linear entire mixed programming to solve the considered problem. The aim is to minimize the project total time, by means of the assignment of equipments of work to the different production lines of the activities to realizing. The fundamental beginning is to support the same production (rate of production in meters/day of the activity in view of the equipment of work) for tbe different equipments to achieve the maximum efficiency in each period of time. With the limited availability of resources, the work must be continuous and the period of time between operations and final must be kept. However, this paper also presents the bibliographical study on methodologies of the optimization of construction processes in response to the two objectives: time and cost. This will consider the use of recta-heuristic techniques, such as population based algorithms.
基金Project supported by the National High-Tech R&D Program(863)of China(No.2014AA041501)
文摘Targeting the mode-mixing problem of intrinsic time-scale decomposition (ITD) and the parameter optimization problem of least-square support vector machine (LSSVM), we propose a novel approach based on complete ensemble intrinsic time-scale decomposition (CEITD) and LSSVM optimized by the hybrid differential evolution and particle swarm optimization (HDEPSO) algorithm for the identification of the fault in a diesel engine. The approach consists mainly of three stages. First, to solve the mode-mixing problem of ITD, a novel CEITD method is proposed. Then the CEITD method is used to decompose the nonstationary vibration signal into a set of stationary proper rotation components (PRCs) and a residual signal. Second, three typical types of time-frequency features, namely singular values, PRCs energy and energy entropy, and AR model parameters, are extracted from the first several PRCs and used as the fault feature vectors. Finally, a HDEPSO algorithm is proposed for the parameter optimization of LSSVM, and the fault diagnosis results can be obtained by inputting the fault feature vectors into the HDEPSO-LSSVM classifier. Simulation and experimental results demonstrate that the proposed fault diagnosis approach can overcome the mode-mixing problem of ITD and accurately identify the fault patterns of diesel engines.
基金supported by the National Natural Science Foundation of China (Grant No. 10902121)the Foundation of State Key Laboratory of Astronautic Dynamics (Grant No. 2011ADL-DW0203)the Science Project of National University and Defense Technology (Grant No. JC09-01-01)
文摘For the low-earth-orbit (LEO) long-duration multi-spacecraft rendezvous mission, a mixed integer nonlinear programming (MINLP) model is built with consideration of the , perturbation and the time window constraints based on lighting condition. A two-level hybrid optimization approach is proposed. The up-level problem uses the visiting sequence, the orbital transfer duration and the service time after each rendezvous as design variables, and employs the mix-coded genetic algorithm to search the optimal solution; the low-level problem uses the maneuver time and impulses in each rendezvous as design vari- ables, and employs the downhill simplex method to search the optimal solution. To improve the solving efficiency of the low-level problem, a linear dynamic model with J~ perturbation is derived, and the approximate strategy of the low-level prob- lem is then proposed. The proposed method has been applied to several numerical problems. The results lead to three major conclusions: (1) The MINLP model for LEO long-duration multi-spacecraft rendezvous mission is effective, and the proposed hybrid optimization strategy can obtain good solutions that satisfy time window constraints; (2) The derived linear dynamic equations are good first-order approximation to the long-duration rendezvous trajectory under ,J2 perturbation; (3) Under J2 perturbation, the long-duration rendezvous problem has multiple local minimums either in the duration of multiple orbits or in a single orbit, and it agrees with the problem's characteristic to use the mix-coded genetic algorithm.