Taking ARM as the hardware platform, the embedded system is built from both hardware and software aspects with the application as the center. In the hardware design, build the hardware platform scheme, design the sche...Taking ARM as the hardware platform, the embedded system is built from both hardware and software aspects with the application as the center. In the hardware design, build the hardware platform scheme, design the schematic diagram as well as PCB, complete the hardware debugging, and ensure the system hardware platform function;in the software design, optimize the three-stage pipeline structure of ARM instruction system, design the instruction set, install the embedded system on the virtual machine, build the cross-toolchain, and set up the correct NFS network file system. Finish the design of the ARM-based embedded system platform, combined with the hardware requirements of the experimental platform, transplant the powerful Uboot as the Bootloader of the system, and further transplant the Linux-2.6. 32 kernel to the system start the operation normally, and finally, build the root file to finish the study of its portability.展开更多
[Objective] The research aimed to study design and development of system platform of 'study on relationship between natural phenology and climate change' based on WEB and GIS. [Method] Relied on the technologi...[Objective] The research aimed to study design and development of system platform of 'study on relationship between natural phenology and climate change' based on WEB and GIS. [Method] Relied on the technologies of WEB and GIS, a set of system platform of 'study on relationship between natural phenology and climate change' was developed based on the hybrid architecture of C/S (Client/Server) and B/S (Browser/Server). Moreover, its establishing process and functional module were detailedly introduced. [Result] The natural phenology and climate change in Guangxi were research objects of system platform of 'study on relationship between natural phenology and climate change'. By combining WEB and GIS with database, the primary application of 'study on relationship between natural phenology and climate change' was realized. The system used hybrid architecture of C/S and B/S. The four-layer architectures were independent to improve security, stability and maintainability of system. The visual interface on the foreground was simply, clear and easy to use. The generating program of GIS three-dimensional graph on the background was real-time and high-efficiency, providing powerful guarantee for stable and safe operation of phenology research work process. The system had functions of inquiry, analysis, statistical diagram, GIS three-dimensional graph and data export. Through the analysis of natural phenology observation data, the system could find variation rule of natural phenology as three-dimensional space (longitude, latitude and altitude) and its relationship with climate change. [Conclusion] The research laid good foundation for further deeply carrying out application of 'study on relationship between natural phenology and climate change', and also provided reference basis for recognizing nature and using change rule of phenology to execute production scheduling and strategic decision (seed-introduction and regionalization).展开更多
The research aims to explore the transition from monolithic Digital Experience Platforms (DXPs) to Microservices-based DXPs, addressing scalability challenges. The study systematically decomposes monolithic structures...The research aims to explore the transition from monolithic Digital Experience Platforms (DXPs) to Microservices-based DXPs, addressing scalability challenges. The study systematically decomposes monolithic structures into Microservices, emphasizing business capability and subdomain decomposition. Concrete insights, challenges, and solutions encountered during this transformation process are presented. The research contributes valuable insights into the challenges and benefits of adopting Microservices in DXPs. Results highlight the importance of architectural patterns and strategic scaling dimensions for improved performance and scalability. The case study on Backbase’s Engagement Banking Platform showcases successful implementation, providing flexibility, integration, and efficient development in the evolving DXP landscape.展开更多
This article analyzes the design and integrates application of a mine integrated automation system platform based on PON. At the beginning, the paper analyzes the basic principle and structure of PON. The set of integ...This article analyzes the design and integrates application of a mine integrated automation system platform based on PON. At the beginning, the paper analyzes the basic principle and structure of PON. The set of integrated automation network platform according to the information transmission characteristics of mine based on access network and Ethernet of PON is designed. The paper descripes the platform in detail from aspacts of designs of system hardware, software and others. The results show that the system platform can improve the efficiency and reduce the cost.展开更多
The development of deepwater oil fields has reached a new stage with the dramatic increase in water depth and the recent increasing demands of the economic development in the filed. The use of a Tension Leg Platform ...The development of deepwater oil fields has reached a new stage with the dramatic increase in water depth and the recent increasing demands of the economic development in the filed. The use of a Tension Leg Platform (TIP) combined with other systems, such as Floating Production Storage and Offloading (FPSO) system, Floating Production Unit (FPU) system, Tender Assisted Drilling (TAD) system, etc., has drawn the industry attention and increased significantly in the past few years. For the areas lacking of pipeline system, the use of TIP(s) combined with FPSO has been chosen to efficiently develop the deepwater fields. The TIP with a Tender Assisted Drilling system significantly reduces the payload of the platform and reduces the investment in the TIP system substantially. This opens the door for many new deepwater field developments to use the tension leg platform. The advantage of the TIP combined with a TAD system is more significant when several TIPs are used for the continuous development of the field. One of the applications for the TIP with a tender assisted drilling system can be in the development of an offshore marginal field. Owing to the increase of water depth, the conventional fixed platform model for the exploration of those fields becomes uneconomical. It also would be too expensive to use a large TIP structure for those marginal fields due to the large amount of initial investment. The TIP system with tender assisted drilling can be used to develop those fields economically. There are many marginal fields in China offshore, especially in shelf areas. The application of this field developing model, combined with the existing field developing experience in China, will open the door for many marginal field developments. This paper will review the application of the combined TIP system through some examples of completed/ongoing projects, and major technical issues encountered in those practices. The potential application of this technology in China deepwater development will be discussed in the end.展开更多
In this paper, the impact analysis of air gap concerning the parameters of mooring system for the semi-submersible platform is conducted. It is challenging to simulate the wave, current and wind loads of a platform ba...In this paper, the impact analysis of air gap concerning the parameters of mooring system for the semi-submersible platform is conducted. It is challenging to simulate the wave, current and wind loads of a platform based on a model test simultaneously. Furthermore, the dynamic equivalence between the truncated and full-depth mooring system is still a tuff work. However, the wind and current loads can be tested accurately in wind tunnel model. Furthermore, the wave can be simulated accurately in wave tank test. The full-scale mooring system and the all environment loads can be simulated accurately by using the numerical model based on the model tests simultaneously. In this paper, the air gap response of a floating platform is calculated based on the results of tunnel test and wave tank. Meanwhile, full-scale mooring system, the wind, wave and current load can be considered simultaneously. In addition, a numerical model of the platform is tuned and validated by ANSYS AQWA according to the model test results. With the support of the tuned numerical model, seventeen simulation cases about the presented platform are considered to study the wave, wind, and current loads simultaneously. Then, the impact analysis studies of air gap motion regarding the length, elasticity, and type of the mooring line are performed in the time domain under the beam wave, head wave, and oblique wave conditions.展开更多
This study investigates strategies for solving the system reliability of large three-dimensional jacket structures.These structural systems normally fail as a result of a series of different components failures.The fa...This study investigates strategies for solving the system reliability of large three-dimensional jacket structures.These structural systems normally fail as a result of a series of different components failures.The failure characteristics are investigated under various environmental conditions and direction combinations.Theβ-unzipping technique is adopted to determine critical failure components,and the entire system is simplified as a series-parallel system to approximately evaluate the structural system reliability.However,this approach needs excessive computational effort for searching failure components and failure paths.Based on a trained artificial neural network(ANN),which can be used to approximate the implicit limit-state function of a complicated structure,a new alternative procedure is proposed to improve the efficiency of the system reliability analysis method.The failure probability is calculated through Monte Carlo simulation(MCS)with Latin hypercube sampling(LHS).The features and applicability of the above procedure are discussed and compared using an example jacket platform located in Chengdao Oilfield,Bohai Sea,China.This study provides a reference for the evaluation of the system reliability of jacket structures.展开更多
A design of semi-submersible platform is mainly based on the extreme response analysis due to the forces experienced by the components during lifetime. The external loads can induce the extreme air gap response and po...A design of semi-submersible platform is mainly based on the extreme response analysis due to the forces experienced by the components during lifetime. The external loads can induce the extreme air gap response and potential deck impact to the semi-submersible platform. It is important to predict air gap response of platforms accurately in order to check the strength of local structures which withstand the wave slamming due to negative air gap. The wind load cannot be simulated easily by model test in towing tank whereas it can be simulated accurately in wind tunnel test. Furthermore, full scale simulation of the mooring system in model test is still a tuffwork especially the stiffness of the mooring system. Owing to the above mentioned problem, the model test results are not accurate enough for air gap evaluation. The aim of this paper is to present sensitivity analysis results of air gap motion with respect to the mooring system and wind load for the design of semi-submersible platform. Though the model test results are not suitable for the direct evaluation of air gap, they can be used as a good basis for tuning the radiation damping and viscous drag in numerical simulation. In the presented design example, a numerical model is tuned and validated by ANSYS AQWA based on the model test results with a simple 4 line symmetrical horizontal soft mooring system. According to the tuned numerical model, sensitivity analysis studies of air gap motion with respect to the mooring system and wind load are performed in time domain. Three mooring systems and five simulation cases about the presented platform are simulated based on the results of wind tunnel tests and sea-keeping tests. The sensitivity analysis results are valuable for the floating platform design.展开更多
Floating platform system has been extensively used in ocean exploitation, particularly for a tension-leg platform (TLP) system in deep water. Most of the TLPs are multi-mooring systems, where multi-joints are connec...Floating platform system has been extensively used in ocean exploitation, particularly for a tension-leg platform (TLP) system in deep water. Most of the TLPs are multi-mooring systems, where multi-joints are connected to the tension-legs so that the platform is not allowed to twist freely and may subject to enormous force induced by large incident waves in the weak-direction of the structure. This study aims to exploit a single moored offshore platform system that may attract less force and can be operated with less effort. In our analysis, in addition to mechanical properties of the tether, two important properties are also taken into consideration for the single mooring tether with expanded cross sectional dimension and utilization of stronger material, namely, the sag-extensibility and the flexural rigidity. Finally, the dynamic structural behavior produced by the mechanical effects on the new system is investigated and compared with that of traditional design while the wave-structure interactions of large body are also accounted for. Our study finds that the neglect of sag-extensibility or the flexural rigidity of large, strong mooring cable may result in a conservative but not necessarily safe design.展开更多
A system reliability estimation method for spatial jacket platforms is developed in this paper. The jacket platform is modeled into three-dimensional assembly of spatial beam and plate elements in Finite Element Metho...A system reliability estimation method for spatial jacket platforms is developed in this paper. The jacket platform is modeled into three-dimensional assembly of spatial beam and plate elements in Finite Element Method (FEM). The limit failure states correspond to collapse of a series of structural members which are identified by engineering design criteria. In this paper the following aspects are taken into account: the punching shear and buckling failures in member failure modes for the tubular joints and tubular columns respectively; incremental loading approach for establishment of the safety margin equations of system failure; the algorithm of enumerating significant failure modes for the structural systems and other concepts, such as the false failure mode and the virtual limit state. The final work is devoted to the reliability analysis for a practical jacket platform presently put into operation on the Bohai Sea. The computed results shows that method suggested in this paper is feasible and effective for the evaluation of the system reliability of offshore platforms.展开更多
Steel jacket-type platforms are the common kind of the offshore structures and health monitoring is an important issue in their safety assessment. In the present study, a new damage detection method is adopted for thi...Steel jacket-type platforms are the common kind of the offshore structures and health monitoring is an important issue in their safety assessment. In the present study, a new damage detection method is adopted for this kind of structures and inspected experimentally by use of a laboratory model. The method is investigated for developing the robust damage detection technique which is less sensitive to both measurement and analytical model uncertainties. For this purpose, incorporation of the artificial immune system with weighted attributes (AISWA) method into finite element (FE) model updating is proposed and compared with other methods for exploring its effectiveness in damage identification. Based on mimicking immune recognition, noise simulation and attributes weighting, the method offers important advantages and has high success rates. Therefore, it is proposed as a suitable method for the detection of the failures in the large civil engineering structures with complicated structural geometry, such as the considered case study.展开更多
According to the known sequence of iron stress-induced gene (isiAB operon), wecloned its 1. 5 kb fragment by PCR, and used this Fragment as integration homologous fragment. Afterseveral steps of subcloning donor DNA i...According to the known sequence of iron stress-induced gene (isiAB operon), wecloned its 1. 5 kb fragment by PCR, and used this Fragment as integration homologous fragment. Afterseveral steps of subcloning donor DNA into the isiAB fragment, a donor plasmid pZL which could be inte-grated into the chromosomal DNA of Synechococcus sp. PCC7942 was constructed. In order to express theheterologous gene at a high level through the integration platform system, we constructed the donor DNAby the following steps. We cloned the strong promoter (240 bp) of heat shock gene groESL operon fromSynechococcus sp. PCC7942 by PCR. Then subcloned the multiple cloning sites (MCS), rbcS polyA intothe downstream of the groESL promoter. The kanamycin resistance gene, as the marker gene, was alsosubcloned into the donor DNA. Thus, in the donor plasmid pZL, the integration homologous fragment andseveral expression elements, such as groESL promoter, MCS, rbcS polyA teminator and kanamycin re-sistance gene, were all included.After naturally transformed and introduced the donor plasmid pZL into Synechococcus sp. PCC7942,as in the pZL, the donor DNA sequence is flanked by two DNA fragments (0.4 kb and 0.7 kb) homolo-gous to the isiAB fragment of Synechococcus sp. PCC7942, the homologous DNA can recombine with thechromosomal DNA. After screening by kanamycin, the transformants which integrated the heterologousDNA were selected. The efficiency of transformation is about 1×10-6. By southem blot analysis, it wasconfirmed that the donor DNA had been integrated into the chromosomal DNA of Synechococcus sp.PCC7942, located on the site of the isiAB gene, and can be replicated with the chromosomal DNA.展开更多
A control model of binocular vergence eye movements is presented. The control model can reduce blind areas caused by the double cameras in motion platform. In order to validate the model performance, an experimental p...A control model of binocular vergence eye movements is presented. The control model can reduce blind areas caused by the double cameras in motion platform. In order to validate the model performance, an experimental platform and its control system based on TMS320LF2407 are designed. The control system has its compacted configuration and high reliability. The simulation and experimental results show that the control system can realize binocular vergence movements. Compared with the conventional moving double cameras system, this new system can considerably reduce blind areas.展开更多
Organizations tend to use information systems (IS) applications that require data to be exchanged between different parties, while data exchange is restricted with information reach and range, which determines the org...Organizations tend to use information systems (IS) applications that require data to be exchanged between different parties, while data exchange is restricted with information reach and range, which determines the organizations’ IT platform. To determine the best platform, a comparison between electronic data interchange (EDI) and web services was conducted depending on certain criteria, and then we match the results with the information reach and range. The main findings show that the web services platform can take place when the range of information access is required by anyone and anywhere regardless of IT base. EDI can take place when the range of information access doesn’t exceed the organizations’ boundaries. But when the range of information access exceeds the organizations’ boundaries, still between certain partners, web services or EDI can take place, and thus the organization can select them from those platforms depending on other criteria such as security, and cost.展开更多
Expert System (ES) is considered effective and efficient in agricultural production, as agricultural informationization becomes a main trend in agricultural development. ES, however, is applied unsatisfactorily in m...Expert System (ES) is considered effective and efficient in agricultural production, as agricultural informationization becomes a main trend in agricultural development. ES, however, is applied unsatisfactorily in most rural areas of China and it has considerably affected and restricted the development of the agricultural informationization. This paper proposed a solution to voice service system of ES, which was suitable for the information transmission, and it especially could help the peasants in remote regions obtain knowledge from ES through the voice service system. As for the disadvantages of massive knowledge data and slow deduction, in this system the classification method could be adopted based on the decision tree. Designing pruning algorithm to "trim off" the unrelated knowledge to the users in query course would simplify the structure of the decision tree and accelerate the speed of deduction before the inference engine deduced the knowledge required by users.展开更多
文摘Taking ARM as the hardware platform, the embedded system is built from both hardware and software aspects with the application as the center. In the hardware design, build the hardware platform scheme, design the schematic diagram as well as PCB, complete the hardware debugging, and ensure the system hardware platform function;in the software design, optimize the three-stage pipeline structure of ARM instruction system, design the instruction set, install the embedded system on the virtual machine, build the cross-toolchain, and set up the correct NFS network file system. Finish the design of the ARM-based embedded system platform, combined with the hardware requirements of the experimental platform, transplant the powerful Uboot as the Bootloader of the system, and further transplant the Linux-2.6. 32 kernel to the system start the operation normally, and finally, build the root file to finish the study of its portability.
基金Supported by Guangxi Natural Science Fund Item in China ( Guikezi 0991023Z)
文摘[Objective] The research aimed to study design and development of system platform of 'study on relationship between natural phenology and climate change' based on WEB and GIS. [Method] Relied on the technologies of WEB and GIS, a set of system platform of 'study on relationship between natural phenology and climate change' was developed based on the hybrid architecture of C/S (Client/Server) and B/S (Browser/Server). Moreover, its establishing process and functional module were detailedly introduced. [Result] The natural phenology and climate change in Guangxi were research objects of system platform of 'study on relationship between natural phenology and climate change'. By combining WEB and GIS with database, the primary application of 'study on relationship between natural phenology and climate change' was realized. The system used hybrid architecture of C/S and B/S. The four-layer architectures were independent to improve security, stability and maintainability of system. The visual interface on the foreground was simply, clear and easy to use. The generating program of GIS three-dimensional graph on the background was real-time and high-efficiency, providing powerful guarantee for stable and safe operation of phenology research work process. The system had functions of inquiry, analysis, statistical diagram, GIS three-dimensional graph and data export. Through the analysis of natural phenology observation data, the system could find variation rule of natural phenology as three-dimensional space (longitude, latitude and altitude) and its relationship with climate change. [Conclusion] The research laid good foundation for further deeply carrying out application of 'study on relationship between natural phenology and climate change', and also provided reference basis for recognizing nature and using change rule of phenology to execute production scheduling and strategic decision (seed-introduction and regionalization).
文摘The research aims to explore the transition from monolithic Digital Experience Platforms (DXPs) to Microservices-based DXPs, addressing scalability challenges. The study systematically decomposes monolithic structures into Microservices, emphasizing business capability and subdomain decomposition. Concrete insights, challenges, and solutions encountered during this transformation process are presented. The research contributes valuable insights into the challenges and benefits of adopting Microservices in DXPs. Results highlight the importance of architectural patterns and strategic scaling dimensions for improved performance and scalability. The case study on Backbase’s Engagement Banking Platform showcases successful implementation, providing flexibility, integration, and efficient development in the evolving DXP landscape.
基金Key Program of National Natural Science of China(Grant No.U1261205)SDUST Research Fund(No.2010KYTD101)
文摘This article analyzes the design and integrates application of a mine integrated automation system platform based on PON. At the beginning, the paper analyzes the basic principle and structure of PON. The set of integrated automation network platform according to the information transmission characteristics of mine based on access network and Ethernet of PON is designed. The paper descripes the platform in detail from aspacts of designs of system hardware, software and others. The results show that the system platform can improve the efficiency and reduce the cost.
文摘The development of deepwater oil fields has reached a new stage with the dramatic increase in water depth and the recent increasing demands of the economic development in the filed. The use of a Tension Leg Platform (TIP) combined with other systems, such as Floating Production Storage and Offloading (FPSO) system, Floating Production Unit (FPU) system, Tender Assisted Drilling (TAD) system, etc., has drawn the industry attention and increased significantly in the past few years. For the areas lacking of pipeline system, the use of TIP(s) combined with FPSO has been chosen to efficiently develop the deepwater fields. The TIP with a Tender Assisted Drilling system significantly reduces the payload of the platform and reduces the investment in the TIP system substantially. This opens the door for many new deepwater field developments to use the tension leg platform. The advantage of the TIP combined with a TAD system is more significant when several TIPs are used for the continuous development of the field. One of the applications for the TIP with a tender assisted drilling system can be in the development of an offshore marginal field. Owing to the increase of water depth, the conventional fixed platform model for the exploration of those fields becomes uneconomical. It also would be too expensive to use a large TIP structure for those marginal fields due to the large amount of initial investment. The TIP system with tender assisted drilling can be used to develop those fields economically. There are many marginal fields in China offshore, especially in shelf areas. The application of this field developing model, combined with the existing field developing experience in China, will open the door for many marginal field developments. This paper will review the application of the combined TIP system through some examples of completed/ongoing projects, and major technical issues encountered in those practices. The potential application of this technology in China deepwater development will be discussed in the end.
文摘In this paper, the impact analysis of air gap concerning the parameters of mooring system for the semi-submersible platform is conducted. It is challenging to simulate the wave, current and wind loads of a platform based on a model test simultaneously. Furthermore, the dynamic equivalence between the truncated and full-depth mooring system is still a tuff work. However, the wind and current loads can be tested accurately in wind tunnel model. Furthermore, the wave can be simulated accurately in wave tank test. The full-scale mooring system and the all environment loads can be simulated accurately by using the numerical model based on the model tests simultaneously. In this paper, the air gap response of a floating platform is calculated based on the results of tunnel test and wave tank. Meanwhile, full-scale mooring system, the wind, wave and current load can be considered simultaneously. In addition, a numerical model of the platform is tuned and validated by ANSYS AQWA according to the model test results. With the support of the tuned numerical model, seventeen simulation cases about the presented platform are considered to study the wave, wind, and current loads simultaneously. Then, the impact analysis studies of air gap motion regarding the length, elasticity, and type of the mooring line are performed in the time domain under the beam wave, head wave, and oblique wave conditions.
基金supported by the National Natural Science Foundation of China (No. 51779236)the NSFC- Shandong Joint Fund Project (No. U1706226)the National Key Research and Development Program (No. 2016YFC 0303401)
文摘This study investigates strategies for solving the system reliability of large three-dimensional jacket structures.These structural systems normally fail as a result of a series of different components failures.The failure characteristics are investigated under various environmental conditions and direction combinations.Theβ-unzipping technique is adopted to determine critical failure components,and the entire system is simplified as a series-parallel system to approximately evaluate the structural system reliability.However,this approach needs excessive computational effort for searching failure components and failure paths.Based on a trained artificial neural network(ANN),which can be used to approximate the implicit limit-state function of a complicated structure,a new alternative procedure is proposed to improve the efficiency of the system reliability analysis method.The failure probability is calculated through Monte Carlo simulation(MCS)with Latin hypercube sampling(LHS).The features and applicability of the above procedure are discussed and compared using an example jacket platform located in Chengdao Oilfield,Bohai Sea,China.This study provides a reference for the evaluation of the system reliability of jacket structures.
基金financially supported by the National Natural Science Foundation of China(Grant No.11072149)
文摘A design of semi-submersible platform is mainly based on the extreme response analysis due to the forces experienced by the components during lifetime. The external loads can induce the extreme air gap response and potential deck impact to the semi-submersible platform. It is important to predict air gap response of platforms accurately in order to check the strength of local structures which withstand the wave slamming due to negative air gap. The wind load cannot be simulated easily by model test in towing tank whereas it can be simulated accurately in wind tunnel test. Furthermore, full scale simulation of the mooring system in model test is still a tuffwork especially the stiffness of the mooring system. Owing to the above mentioned problem, the model test results are not accurate enough for air gap evaluation. The aim of this paper is to present sensitivity analysis results of air gap motion with respect to the mooring system and wind load for the design of semi-submersible platform. Though the model test results are not suitable for the direct evaluation of air gap, they can be used as a good basis for tuning the radiation damping and viscous drag in numerical simulation. In the presented design example, a numerical model is tuned and validated by ANSYS AQWA based on the model test results with a simple 4 line symmetrical horizontal soft mooring system. According to the tuned numerical model, sensitivity analysis studies of air gap motion with respect to the mooring system and wind load are performed in time domain. Three mooring systems and five simulation cases about the presented platform are simulated based on the results of wind tunnel tests and sea-keeping tests. The sensitivity analysis results are valuable for the floating platform design.
基金financially supported by the Science Council of Taiwan (Grant No. NSC-97-2221-E-110-080)
文摘Floating platform system has been extensively used in ocean exploitation, particularly for a tension-leg platform (TLP) system in deep water. Most of the TLPs are multi-mooring systems, where multi-joints are connected to the tension-legs so that the platform is not allowed to twist freely and may subject to enormous force induced by large incident waves in the weak-direction of the structure. This study aims to exploit a single moored offshore platform system that may attract less force and can be operated with less effort. In our analysis, in addition to mechanical properties of the tether, two important properties are also taken into consideration for the single mooring tether with expanded cross sectional dimension and utilization of stronger material, namely, the sag-extensibility and the flexural rigidity. Finally, the dynamic structural behavior produced by the mechanical effects on the new system is investigated and compared with that of traditional design while the wave-structure interactions of large body are also accounted for. Our study finds that the neglect of sag-extensibility or the flexural rigidity of large, strong mooring cable may result in a conservative but not necessarily safe design.
文摘A system reliability estimation method for spatial jacket platforms is developed in this paper. The jacket platform is modeled into three-dimensional assembly of spatial beam and plate elements in Finite Element Method (FEM). The limit failure states correspond to collapse of a series of structural members which are identified by engineering design criteria. In this paper the following aspects are taken into account: the punching shear and buckling failures in member failure modes for the tubular joints and tubular columns respectively; incremental loading approach for establishment of the safety margin equations of system failure; the algorithm of enumerating significant failure modes for the structural systems and other concepts, such as the false failure mode and the virtual limit state. The final work is devoted to the reliability analysis for a practical jacket platform presently put into operation on the Bohai Sea. The computed results shows that method suggested in this paper is feasible and effective for the evaluation of the system reliability of offshore platforms.
文摘Steel jacket-type platforms are the common kind of the offshore structures and health monitoring is an important issue in their safety assessment. In the present study, a new damage detection method is adopted for this kind of structures and inspected experimentally by use of a laboratory model. The method is investigated for developing the robust damage detection technique which is less sensitive to both measurement and analytical model uncertainties. For this purpose, incorporation of the artificial immune system with weighted attributes (AISWA) method into finite element (FE) model updating is proposed and compared with other methods for exploring its effectiveness in damage identification. Based on mimicking immune recognition, noise simulation and attributes weighting, the method offers important advantages and has high success rates. Therefore, it is proposed as a suitable method for the detection of the failures in the large civil engineering structures with complicated structural geometry, such as the considered case study.
文摘According to the known sequence of iron stress-induced gene (isiAB operon), wecloned its 1. 5 kb fragment by PCR, and used this Fragment as integration homologous fragment. Afterseveral steps of subcloning donor DNA into the isiAB fragment, a donor plasmid pZL which could be inte-grated into the chromosomal DNA of Synechococcus sp. PCC7942 was constructed. In order to express theheterologous gene at a high level through the integration platform system, we constructed the donor DNAby the following steps. We cloned the strong promoter (240 bp) of heat shock gene groESL operon fromSynechococcus sp. PCC7942 by PCR. Then subcloned the multiple cloning sites (MCS), rbcS polyA intothe downstream of the groESL promoter. The kanamycin resistance gene, as the marker gene, was alsosubcloned into the donor DNA. Thus, in the donor plasmid pZL, the integration homologous fragment andseveral expression elements, such as groESL promoter, MCS, rbcS polyA teminator and kanamycin re-sistance gene, were all included.After naturally transformed and introduced the donor plasmid pZL into Synechococcus sp. PCC7942,as in the pZL, the donor DNA sequence is flanked by two DNA fragments (0.4 kb and 0.7 kb) homolo-gous to the isiAB fragment of Synechococcus sp. PCC7942, the homologous DNA can recombine with thechromosomal DNA. After screening by kanamycin, the transformants which integrated the heterologousDNA were selected. The efficiency of transformation is about 1×10-6. By southem blot analysis, it wasconfirmed that the donor DNA had been integrated into the chromosomal DNA of Synechococcus sp.PCC7942, located on the site of the isiAB gene, and can be replicated with the chromosomal DNA.
基金supported by the National Natural Science Foundation of China (Grant Nos.60605028, 50975168)National Hi-tech Research and Development Program of China (Grant Nos.2007AA04Z225, 2009AA04Z211)+1 种基金Program for Excellent Young Teachers of Shanghai (Grant Nos.07Q14024,07QH14006)Shuguang Program of Shanghai (Grant No.07SG47)
文摘A control model of binocular vergence eye movements is presented. The control model can reduce blind areas caused by the double cameras in motion platform. In order to validate the model performance, an experimental platform and its control system based on TMS320LF2407 are designed. The control system has its compacted configuration and high reliability. The simulation and experimental results show that the control system can realize binocular vergence movements. Compared with the conventional moving double cameras system, this new system can considerably reduce blind areas.
文摘Organizations tend to use information systems (IS) applications that require data to be exchanged between different parties, while data exchange is restricted with information reach and range, which determines the organizations’ IT platform. To determine the best platform, a comparison between electronic data interchange (EDI) and web services was conducted depending on certain criteria, and then we match the results with the information reach and range. The main findings show that the web services platform can take place when the range of information access is required by anyone and anywhere regardless of IT base. EDI can take place when the range of information access doesn’t exceed the organizations’ boundaries. But when the range of information access exceeds the organizations’ boundaries, still between certain partners, web services or EDI can take place, and thus the organization can select them from those platforms depending on other criteria such as security, and cost.
基金Supported by Northeast Agricultural University Doctoral Development FoundationChina Postdoctoral Science Foundation
文摘Expert System (ES) is considered effective and efficient in agricultural production, as agricultural informationization becomes a main trend in agricultural development. ES, however, is applied unsatisfactorily in most rural areas of China and it has considerably affected and restricted the development of the agricultural informationization. This paper proposed a solution to voice service system of ES, which was suitable for the information transmission, and it especially could help the peasants in remote regions obtain knowledge from ES through the voice service system. As for the disadvantages of massive knowledge data and slow deduction, in this system the classification method could be adopted based on the decision tree. Designing pruning algorithm to "trim off" the unrelated knowledge to the users in query course would simplify the structure of the decision tree and accelerate the speed of deduction before the inference engine deduced the knowledge required by users.