A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using...A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using this new sampler. Based on ANSYS10, the temperature finite element model of the sample cylinder was established. According to the law of conservation of energy, the unsteady heat transmit equation of the sampler under solid-liquid coupling condition was derived, then the mathematical model calculation was carried out by using a mixed finite-element finite-difference method, and two thermal insulation methods were used. The simulation was carried out by using the thickness of the thermal insulation layer and heat conductivity as the variable parameters and the temperature distribution of the sampler and related influencing factors were obtained. Optimization analysis was conducted using the simulation data and related parameters and the magnitude ranges of the parameters were obtained that could meet the design temperature requirements. The experimental data and simulation results indicated that the results were in good agreement with the realities, and this sampler might be of value for seabed sediment sampler design and manufacture.展开更多
Web services have gained popularity m recent years anu prowue a new moue, u~ w^u, w,,,~,, ,^- cilitates interaction of scientific and business applications through the Internet. More often, several services with simil...Web services have gained popularity m recent years anu prowue a new moue, u~ w^u, w,,,~,, ,^- cilitates interaction of scientific and business applications through the Internet. More often, several services with similar functionality are available from a large and changing number of service provid- ers. Quality of Service （QoS） is the dominant factor in service selection and is of great importance to users. In this paper, we propose a model for QoS measurement and web services selection. The model consists of QoS model, QoS monitoring, QoS comparison and service selection with a QoS feedback mechanism. The most suitable service is to take into account the agreed QoS, monitoring is done during invocation phase and if any deviation is recorded, next suitable service is selected. Fi- nally the model is proved to be feasible and effective by simulation experiments.展开更多
The application of normal distribution for quality characteristics has its limits on the condition that specification interval is asymmetric. In this paper, the compound normal distribution N(L,σ12,σ22) was proposed...The application of normal distribution for quality characteristics has its limits on the condition that specification interval is asymmetric. In this paper, the compound normal distribution N(L,σ12,σ22) was proposed and simulated, the property of the parameters Lσ1 and σ2 was studied. The distribution was further applied toangle quality process control.展开更多
Based on the Chinese National Standards involving heat pump water heater and space heating system, performances of the R744/R290 subcritical heat pump system have been discussed and compared with those of the R22 syst...Based on the Chinese National Standards involving heat pump water heater and space heating system, performances of the R744/R290 subcritical heat pump system have been discussed and compared with those of the R22 system, which is widely used in heat pump systems in China nowadays. It can be indicated that R744/R290 mixture can work efficiently as a refrigerant for heat pumps with a large heat-sink temperature rise. When mass fraction of R290 is increased, discharge pressure is reduced. Under the nominal working condition, there is an optimum mixture mass fraction of 20/80 for R744/R290 under conventional condensation pressure. Both the heating COPhs （coefficient of performance） and volumetric heating capacity are increased by about 12.62% and 34.24% respectively compared with those of R22 based system. But for the heat sink with a small temperature rise, R744/R290 system has poorer performances than R22 system. When heat transfer pinch point in evaporator and condensation processes is considered, the degree of superheat has a negative influence upon system performances under the given conditions.展开更多
Routing algorithms capable of providing quality of service （QoS） will play an important role in future communication networks. For the trajectory-based routing （ TBR）, An effective method of en- coding trajectorie...Routing algorithms capable of providing quality of service （QoS） will play an important role in future communication networks. For the trajectory-based routing （ TBR）, An effective method of en- coding trajectories into packets is proposed. The method uses a B-spline curve, which provides a lot of flexibility. The simulation results show that the performance of the proposed algorithms is im- proved significantly compared with the existing algorithm.展开更多
The numerical simulation on drawing process of automotive B-pillar was carried out on AutoForm software,and dangerous forming areas were discovered.The processing parameters,such as the layout of drawbeads,blank holdi...The numerical simulation on drawing process of automotive B-pillar was carried out on AutoForm software,and dangerous forming areas were discovered.The processing parameters,such as the layout of drawbeads,blank holding force and the shape of blank,were adjusted and optimized according to the simulation results.Results indicate that the quality defects can be forecast and removed,which improves the stability of forming process.The cost of design is decreased and the research cycle is shortened.It is proved that the drawing process and die design of B-pillar forming are feasible in actual production.展开更多
Mining machineries are generally exposed to intensive vibrations in harsh mining environment. If vibrations are beyond the tolerable limit, the machine and its operator health will be under the risk. In this work, the...Mining machineries are generally exposed to intensive vibrations in harsh mining environment. If vibrations are beyond the tolerable limit, the machine and its operator health will be under the risk. In this work, the vibration of a mining truck at different operational conditions are simulated and discussed. To achieve this aim, three haul roads with low, medium and poor qualities are considered based on the ISO standard. Accordingly, the vibration of a mining truck in different speeds, payload and distribution qualities of materials in the dump body are evaluated in each haul road quality using Trucksim software. The simulation results with statistical discussions indicate that the truck speed and the materials distribution quality have significant effects on the root mean square(RMS) of vertical vibrations. However, the effect of the payload is not considerable on the RMS. Moreover, the accumulation of materials on the rear side of the truck dump body is efficient on the vibrational health risk.展开更多
A work on soot emission control simulation in stoker-fired boiler by secondary air has been done. Some models such as k-e, combustion, radiation, and soot Khan-Greeves have been adopted. Soot production and emission h...A work on soot emission control simulation in stoker-fired boiler by secondary air has been done. Some models such as k-e, combustion, radiation, and soot Khan-Greeves have been adopted. Soot production and emission has been reduced by secondary air; the highest mass concentration is reduced from 7.46 × 10^-14 to 6.94 × 10^15; mass concentration of soot is decreased from 1.12 ×10^-15 to 9.25 ×10^-32 in the upper areas.展开更多
This paper presents an analysis of the electric power flows in a hot rolling mill plant using a power quality analyzer and developing simulation models with Matlab-Simulink. The model inputs have been taken from proce...This paper presents an analysis of the electric power flows in a hot rolling mill plant using a power quality analyzer and developing simulation models with Matlab-Simulink. The model inputs have been taken from process data by the process computer of the plant. Data from different rolling campaigns have been analysed. A STATCOM （static synchronous compensator） with a control strategy based on voltage oriented control with d-q coordinates is used as solution to improve the reactive compensation as well as to minimize the voltage fluctuations and sags effect. The overall electric model has been simulated with the STATCOM to check the improvement in the voltage stability and the consumption.展开更多
To provide a realistic simulation environment for users,intelligent models have become key components in military simulations. After the analysis of modeling nature of intelligent models,the validation criteria for de...To provide a realistic simulation environment for users,intelligent models have become key components in military simulations. After the analysis of modeling nature of intelligent models,the validation criteria for defining the validation points and validation metrics for measuring the agreements between human experts and intelligent models were presented. Further,such methods as graphical comparison,feature analysis and face validation were discussed according to the characteristics of intelligent models. Based on the validation criteria,validation metrics and validation methods,the intelligent models can be effectively validated,which has been proved in current developed intelligent models.展开更多
Virtual reality system has low cost and high efficiency advantages by many virtual reality research units and individuals. Virtual reality technology will be used in the machining process, and can demonstrate the mach...Virtual reality system has low cost and high efficiency advantages by many virtual reality research units and individuals. Virtual reality technology will be used in the machining process, and can demonstrate the machining process, discussed the processing scheme, to improve the quality of products. At the same time, the combination of modem education technology and virtual reality technology in the teaching, establishment of virtual machine and virtual machining simulation environment, that can improve the quality of teaching.展开更多
基金supported by The Key Technologies Research and Development Program of Shandong Province (Grant No.2006GG2206013)Foundation Sciences Funds of Qingdao (2007-2-3-15-jch)State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University (Grant No. XXXX0701)
文摘A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using this new sampler. Based on ANSYS10, the temperature finite element model of the sample cylinder was established. According to the law of conservation of energy, the unsteady heat transmit equation of the sampler under solid-liquid coupling condition was derived, then the mathematical model calculation was carried out by using a mixed finite-element finite-difference method, and two thermal insulation methods were used. The simulation was carried out by using the thickness of the thermal insulation layer and heat conductivity as the variable parameters and the temperature distribution of the sampler and related influencing factors were obtained. Optimization analysis was conducted using the simulation data and related parameters and the magnitude ranges of the parameters were obtained that could meet the design temperature requirements. The experimental data and simulation results indicated that the results were in good agreement with the realities, and this sampler might be of value for seabed sediment sampler design and manufacture.
基金Supported by the National Natural Science Foundation of China(No.60903003)the Beijing Natural Science Foundation of China(No.4112037)the Research Fund for the Doctoral Program of Higher Education of China(No.2008000401051)
文摘Web services have gained popularity m recent years anu prowue a new moue, u~ w^u, w,,,~,, ,^- cilitates interaction of scientific and business applications through the Internet. More often, several services with similar functionality are available from a large and changing number of service provid- ers. Quality of Service （QoS） is the dominant factor in service selection and is of great importance to users. In this paper, we propose a model for QoS measurement and web services selection. The model consists of QoS model, QoS monitoring, QoS comparison and service selection with a QoS feedback mechanism. The most suitable service is to take into account the agreed QoS, monitoring is done during invocation phase and if any deviation is recorded, next suitable service is selected. Fi- nally the model is proved to be feasible and effective by simulation experiments.
基金National Natural Science Foundation of China(7007203370372064).
文摘The application of normal distribution for quality characteristics has its limits on the condition that specification interval is asymmetric. In this paper, the compound normal distribution N(L,σ12,σ22) was proposed and simulated, the property of the parameters Lσ1 and σ2 was studied. The distribution was further applied toangle quality process control.
文摘Based on the Chinese National Standards involving heat pump water heater and space heating system, performances of the R744/R290 subcritical heat pump system have been discussed and compared with those of the R22 system, which is widely used in heat pump systems in China nowadays. It can be indicated that R744/R290 mixture can work efficiently as a refrigerant for heat pumps with a large heat-sink temperature rise. When mass fraction of R290 is increased, discharge pressure is reduced. Under the nominal working condition, there is an optimum mixture mass fraction of 20/80 for R744/R290 under conventional condensation pressure. Both the heating COPhs （coefficient of performance） and volumetric heating capacity are increased by about 12.62% and 34.24% respectively compared with those of R22 based system. But for the heat sink with a small temperature rise, R744/R290 system has poorer performances than R22 system. When heat transfer pinch point in evaporator and condensation processes is considered, the degree of superheat has a negative influence upon system performances under the given conditions.
基金Supported by the National Natural Science Foundation of China （11171316）, and the Zhejiang Provincial Natural Science Foundation of China （No. Y6090472）.
文摘Routing algorithms capable of providing quality of service （QoS） will play an important role in future communication networks. For the trajectory-based routing （ TBR）, An effective method of en- coding trajectories into packets is proposed. The method uses a B-spline curve, which provides a lot of flexibility. The simulation results show that the performance of the proposed algorithms is im- proved significantly compared with the existing algorithm.
文摘The numerical simulation on drawing process of automotive B-pillar was carried out on AutoForm software,and dangerous forming areas were discovered.The processing parameters,such as the layout of drawbeads,blank holding force and the shape of blank,were adjusted and optimized according to the simulation results.Results indicate that the quality defects can be forecast and removed,which improves the stability of forming process.The cost of design is decreased and the research cycle is shortened.It is proved that the drawing process and die design of B-pillar forming are feasible in actual production.
文摘Mining machineries are generally exposed to intensive vibrations in harsh mining environment. If vibrations are beyond the tolerable limit, the machine and its operator health will be under the risk. In this work, the vibration of a mining truck at different operational conditions are simulated and discussed. To achieve this aim, three haul roads with low, medium and poor qualities are considered based on the ISO standard. Accordingly, the vibration of a mining truck in different speeds, payload and distribution qualities of materials in the dump body are evaluated in each haul road quality using Trucksim software. The simulation results with statistical discussions indicate that the truck speed and the materials distribution quality have significant effects on the root mean square(RMS) of vertical vibrations. However, the effect of the payload is not considerable on the RMS. Moreover, the accumulation of materials on the rear side of the truck dump body is efficient on the vibrational health risk.
文摘A work on soot emission control simulation in stoker-fired boiler by secondary air has been done. Some models such as k-e, combustion, radiation, and soot Khan-Greeves have been adopted. Soot production and emission has been reduced by secondary air; the highest mass concentration is reduced from 7.46 × 10^-14 to 6.94 × 10^15; mass concentration of soot is decreased from 1.12 ×10^-15 to 9.25 ×10^-32 in the upper areas.
文摘This paper presents an analysis of the electric power flows in a hot rolling mill plant using a power quality analyzer and developing simulation models with Matlab-Simulink. The model inputs have been taken from process data by the process computer of the plant. Data from different rolling campaigns have been analysed. A STATCOM （static synchronous compensator） with a control strategy based on voltage oriented control with d-q coordinates is used as solution to improve the reactive compensation as well as to minimize the voltage fluctuations and sags effect. The overall electric model has been simulated with the STATCOM to check the improvement in the voltage stability and the consumption.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 60434010)the Foundation of the Outstanding Youth of Heilongjiang Province ( Grant No. JC200606)
文摘To provide a realistic simulation environment for users,intelligent models have become key components in military simulations. After the analysis of modeling nature of intelligent models,the validation criteria for defining the validation points and validation metrics for measuring the agreements between human experts and intelligent models were presented. Further,such methods as graphical comparison,feature analysis and face validation were discussed according to the characteristics of intelligent models. Based on the validation criteria,validation metrics and validation methods,the intelligent models can be effectively validated,which has been proved in current developed intelligent models.
文摘Virtual reality system has low cost and high efficiency advantages by many virtual reality research units and individuals. Virtual reality technology will be used in the machining process, and can demonstrate the machining process, discussed the processing scheme, to improve the quality of products. At the same time, the combination of modem education technology and virtual reality technology in the teaching, establishment of virtual machine and virtual machining simulation environment, that can improve the quality of teaching.
