This paper presents a new kind of macromodel of OTA,which can be used to solve the problem in which the two port macromodel couldnt reflect some functions of the OTA.The new model also opens up a new way for the simu...This paper presents a new kind of macromodel of OTA,which can be used to solve the problem in which the two port macromodel couldnt reflect some functions of the OTA.The new model also opens up a new way for the simulation of the OTA circuit.This paper discusses the way of designing this model and simulating it in SPICE.The result proves its reasonable design and its simplicity in structure.In the application of this model,we design a complete symmetric double differential quarter square OTA multiplying unit by using four three port OTA macromodels.It successfully solved the problem of the unsymmetry of two input ports in an OTA multiplying unit.This result fully agrees with the experiment.展开更多
The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that ope...The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.展开更多
Small water-plane area twin-hull(SWATH) has drawn the attention of many researchers due to its good sea-keeping ability.In this paper,MMG's idea of separation was used to perform SWATH movement modeling and simulat...Small water-plane area twin-hull(SWATH) has drawn the attention of many researchers due to its good sea-keeping ability.In this paper,MMG's idea of separation was used to perform SWATH movement modeling and simulation;respectively the forces and moment of SWATH were divided into bare hull,propeller,rudder at the fluid hydrodynamics,etc.Wake coefficient at the propellers which reduces thrust coefficient,and rudder mutual interference forces among the hull and propeller,for the calculation of SWATH,were all considered.The fourth-order Runge-Kutta method of integration was used by solving differential equations,in order to get SWATH's movement states.As an example,a turning test at full speed and full starboard rudder of ‘Seagull' craft is shown.The simulation results show the SWATH's regular pattern and trend of motion.It verifies the correctness of the mathematical model of the turning movement.The SWATH's mathematical model is applied to marine simulator in order to train the pilots or seamen,or safety assessment for ocean engineering project.Lastly,the full mission navigation simulating system(FMNSS) was determined to be a successful virtual reality technology application sample in the field of navigation simulation.展开更多
In this paper,the structure of 'double juts' soil sampler and a series of new soil samplers are introduced.The internal diameter of auger tip the sampler is less than that of sampling tube, but the external di...In this paper,the structure of 'double juts' soil sampler and a series of new soil samplers are introduced.The internal diameter of auger tip the sampler is less than that of sampling tube, but the external diameterof auger tip is larger than that of sampling tube. Therefore, adhesion and cutting resistance can be reducedby limiting connection areas between sampler and the soil. Such a new structure makes it possible to bewidely used for the production of a series of special soil samplers.展开更多
Locality preserving projection (LPP) is a newly emerging fault detection method which can discover local manifold structure of a data set to be analyzed, but its linear assumption may lead to monitoring performance de...Locality preserving projection (LPP) is a newly emerging fault detection method which can discover local manifold structure of a data set to be analyzed, but its linear assumption may lead to monitoring performance degradation for complicated nonlinear industrial processes. In this paper, an improved LPP method, referred to as sparse kernel locality preserving projection (SKLPP) is proposed for nonlinear process fault detection. Based on the LPP model, kernel trick is applied to construct nonlinear kernel model. Furthermore, for reducing the computational complexity of kernel model, feature samples selection technique is adopted to make the kernel LPP model sparse. Lastly, two monitoring statistics of SKLPP model are built to detect process faults. Simulations on a continuous stirred tank reactor (CSTR) system show that SKLPP is more effective than LPP in terms of fault detection performance.展开更多
OBJECTIVE To evaluate the results and complications associated with nasopharyngeal carcinoma (NPC) treated with combined external-beam radiotherapy (EBR) and intracavitary brachytherapy (IB) using a new-type app...OBJECTIVE To evaluate the results and complications associated with nasopharyngeal carcinoma (NPC) treated with combined external-beam radiotherapy (EBR) and intracavitary brachytherapy (IB) using a new-type applicator. METHODS Eighty patients with untreated NPC were divided into two groups based on therapy methods. An experimental group was treated with EBR plus IB and a control group was treated only with EBR. IB was given to the patients of the experimental group when the external radiotherapy dose amounted to more than 60~65 Gy. The total dose of IB was 6~20 Gy and the total dose of EBR of the control group was 70~75 Gy. RESULTS Follow-up was conducted for 97.5% of the patients with re- suits as follows: the overall response rates (ORR) for the experimental and the control groups were 92.5% and 75.3% respectively (P〈0.05); the 3 and 5-year survival rates for the experimental group were 87.5% and 74.2% and for the control group, 65.0% and 55.6% (P〈0.05); for the experimental group, the 3 and 5-year disease-free survival rates were 72.5% and 64.5% and for the control group, 60.0% and 52.8% (P〉0.05).Some complications following radiotherapy showed a significant difference. CONCLUSION External irradiation plus intracavitary brachytherapy using a new-type applicator may improve the ORR and survival rates, reduce radiation complications and increase the quality of life. 展开更多
Investigation was focussed to application of waste POX (partial oxidation), e.g., meal rape in form of suspension in high boiling hydrocarbons from crude oil distillation. There is an opportunity for utilization of ...Investigation was focussed to application of waste POX (partial oxidation), e.g., meal rape in form of suspension in high boiling hydrocarbons from crude oil distillation. There is an opportunity for utilization of biomass waste resulted from fuels bio-components production. A decrease of oxygen and water steam demand in feed for POX process was observed in this variant. Catalytic effect of iron nanoparticles or nickel nitrate as catalysts in improvement of the pilot plant biomass/oil partial oxidation was investigated as well. Presence of catalyst in the feed supports formation of carbon monoxide and suppression content of methane in the gas product. Experimental data were well compared with process simulation based on eauilibrium reactor model.展开更多
The mass transfer process in a perforated rotating disk contactor(PRDC) using a toluene-acetone-water system was investigated.The volumetric overall mass transfer coefficients are calculated in a PRDC column.Both mass...The mass transfer process in a perforated rotating disk contactor(PRDC) using a toluene-acetone-water system was investigated.The volumetric overall mass transfer coefficients are calculated in a PRDC column.Both mass transfer directions are considered in experiments.The influences of operating variables containing agitation rate,dispersed and continuous phase flow rates and mass transfer in the extraction column are studied.According to obtained results,mass transfer is significantly dependent on agitation rate,while the dispersed and continuous phase flow rates have a minor effect on mass transfer in the extraction column.Furthermore,a novel empirical correlation is developed for prediction of overall continuous phase Sherwood number based on dispersed phase holdup,Reynolds number and mass transfer direction.There has been great agreement between experimental data and predicted values using a proposed correlation for all operating conditions.展开更多
Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In mos...Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In most cases, these measurements are not suitable for detecting defects that appear as a result of failures of certain elements of the assembly lines. These so called self-recovering failures very often remain unnoticed, because they do not cause a suspension of the assembly process and if not taken into consideration, they can seriously menace the final product quality. In this paper, the authors use PFMEA to identify and evaluate the risk of the self-recovering failures. They also propose a simple Simulink model, which could be useful when trying to estimate the effect of installing new control devices at an existing assembly line upon its overall reliability and productivity.展开更多
In this paper, an evolutionary recursive Bayesian estimation algorithm is presented, which incorporates the latest observation with a new proposal distribution, and the posterior state density is represented by a Gaus...In this paper, an evolutionary recursive Bayesian estimation algorithm is presented, which incorporates the latest observation with a new proposal distribution, and the posterior state density is represented by a Gaussian mixture model that is recovered from the weighted particle set of the measurement update step by means of a weighted expectation-maximization algorithm. This step replaces the resampling stage needed by most particle filters and relieves the effect caused by sample impoverishment. A nonlinear tracking problem shows that this new approach outperforms other related particle filters.展开更多
This paper introduces a powerful design and analysis tool named SIMCAT, that is developed to support applications to license a CANDU nuclear reactor, refurbish projects, and support the existing CANDU stations. It con...This paper introduces a powerful design and analysis tool named SIMCAT, that is developed to support applications to license a CANDU nuclear reactor, refurbish projects, and support the existing CANDU stations. It consists of the CATHENA (Canadian Algorithm for Thermo-Hydraulic Network Analysis), the control logics from C6SIM (CANDU 6 Analytical Simulator), and a communication protocol, PVM (parallel virtual machine). This is the first time that CATHENA has been successfully coupled directly with a program written in another language. The independence of CATHENA and the C6SIM controllers allows the development of both CATHENA and C6SIM controller to proceed independently.展开更多
The high efficiency hydrogen fiber Bragg grating (FBG) sensor is presented. The sensitive film was a new alliance of palladium-silver (Pd-Ag). In addition, the titanium (Ti) layer was used as the adhesive layer....The high efficiency hydrogen fiber Bragg grating (FBG) sensor is presented. The sensitive film was a new alliance of palladium-silver (Pd-Ag). In addition, the titanium (Ti) layer was used as the adhesive layer. The presented sensor showed the resolution of more than 60pm/1%H2, and a fast response time of4s - 5s was guaranteed in the 0.1%H2 - 4%H2 range. Moreover, the life time of the sensor was investigated. The obtained results showed that the sensor had an enhanced life time. Furthermore, the sensor was applied in the propulsion system fuel tank model of the aerospace vehicle. The obtained results indicated that it is a prevention system against the disaster aerospace due to hydrogen leakage.展开更多
Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation...Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation, air conditioning and refrigeration systems. A novel finless bare tube heat exchanger was studied using a validated heat exchanger modeling tool. The capacity based optimization and entransy dissipation based thermal resistance were used and compared. The applicability of using entransy dissipation based thermal resistance in this type of heat exchanger optimization has been discussed. It has been demonstrated that minimizing entransy dissipation and maximizing capacity are equivalent to optimizing evaporators with fixed flow rates and different when optimizing evaporators with variable flow rates and the deviation is negligible when heat exchanger capacity is small(~1 k W) and more obvious as heat exchanger capacity increases. Thus entransy dissipation based thermal resistance could be used as an alternative optimization index to capacity for evaporators with fixed flow rate and small capacity evaporators with variable flow rates and should be used individually with capacity as an optimization index for evaporators with large capacity and variable flow rates.展开更多
文摘This paper presents a new kind of macromodel of OTA,which can be used to solve the problem in which the two port macromodel couldnt reflect some functions of the OTA.The new model also opens up a new way for the simulation of the OTA circuit.This paper discusses the way of designing this model and simulating it in SPICE.The result proves its reasonable design and its simplicity in structure.In the application of this model,we design a complete symmetric double differential quarter square OTA multiplying unit by using four three port OTA macromodels.It successfully solved the problem of the unsymmetry of two input ports in an OTA multiplying unit.This result fully agrees with the experiment.
基金Research Fund from Science and Technology on Underwater Vehicle Laboratory
文摘The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.
基金Supported by the National Nature Science Foundation of China under Grant No.51109020 the National Key Project for Basic Research“973”(2009CB320805)
文摘Small water-plane area twin-hull(SWATH) has drawn the attention of many researchers due to its good sea-keeping ability.In this paper,MMG's idea of separation was used to perform SWATH movement modeling and simulation;respectively the forces and moment of SWATH were divided into bare hull,propeller,rudder at the fluid hydrodynamics,etc.Wake coefficient at the propellers which reduces thrust coefficient,and rudder mutual interference forces among the hull and propeller,for the calculation of SWATH,were all considered.The fourth-order Runge-Kutta method of integration was used by solving differential equations,in order to get SWATH's movement states.As an example,a turning test at full speed and full starboard rudder of ‘Seagull' craft is shown.The simulation results show the SWATH's regular pattern and trend of motion.It verifies the correctness of the mathematical model of the turning movement.The SWATH's mathematical model is applied to marine simulator in order to train the pilots or seamen,or safety assessment for ocean engineering project.Lastly,the full mission navigation simulating system(FMNSS) was determined to be a successful virtual reality technology application sample in the field of navigation simulation.
文摘In this paper,the structure of 'double juts' soil sampler and a series of new soil samplers are introduced.The internal diameter of auger tip the sampler is less than that of sampling tube, but the external diameterof auger tip is larger than that of sampling tube. Therefore, adhesion and cutting resistance can be reducedby limiting connection areas between sampler and the soil. Such a new structure makes it possible to bewidely used for the production of a series of special soil samplers.
基金Supported by the National Natural Science Foundation of China (61273160), the Natural Science Foundation of Shandong Province of China (ZR2011FM014) and the Fundamental Research Funds for the Central Universities (10CX04046A).
文摘Locality preserving projection (LPP) is a newly emerging fault detection method which can discover local manifold structure of a data set to be analyzed, but its linear assumption may lead to monitoring performance degradation for complicated nonlinear industrial processes. In this paper, an improved LPP method, referred to as sparse kernel locality preserving projection (SKLPP) is proposed for nonlinear process fault detection. Based on the LPP model, kernel trick is applied to construct nonlinear kernel model. Furthermore, for reducing the computational complexity of kernel model, feature samples selection technique is adopted to make the kernel LPP model sparse. Lastly, two monitoring statistics of SKLPP model are built to detect process faults. Simulations on a continuous stirred tank reactor (CSTR) system show that SKLPP is more effective than LPP in terms of fault detection performance.
文摘OBJECTIVE To evaluate the results and complications associated with nasopharyngeal carcinoma (NPC) treated with combined external-beam radiotherapy (EBR) and intracavitary brachytherapy (IB) using a new-type applicator. METHODS Eighty patients with untreated NPC were divided into two groups based on therapy methods. An experimental group was treated with EBR plus IB and a control group was treated only with EBR. IB was given to the patients of the experimental group when the external radiotherapy dose amounted to more than 60~65 Gy. The total dose of IB was 6~20 Gy and the total dose of EBR of the control group was 70~75 Gy. RESULTS Follow-up was conducted for 97.5% of the patients with re- suits as follows: the overall response rates (ORR) for the experimental and the control groups were 92.5% and 75.3% respectively (P〈0.05); the 3 and 5-year survival rates for the experimental group were 87.5% and 74.2% and for the control group, 65.0% and 55.6% (P〈0.05); for the experimental group, the 3 and 5-year disease-free survival rates were 72.5% and 64.5% and for the control group, 60.0% and 52.8% (P〉0.05).Some complications following radiotherapy showed a significant difference. CONCLUSION External irradiation plus intracavitary brachytherapy using a new-type applicator may improve the ORR and survival rates, reduce radiation complications and increase the quality of life.
文摘Investigation was focussed to application of waste POX (partial oxidation), e.g., meal rape in form of suspension in high boiling hydrocarbons from crude oil distillation. There is an opportunity for utilization of biomass waste resulted from fuels bio-components production. A decrease of oxygen and water steam demand in feed for POX process was observed in this variant. Catalytic effect of iron nanoparticles or nickel nitrate as catalysts in improvement of the pilot plant biomass/oil partial oxidation was investigated as well. Presence of catalyst in the feed supports formation of carbon monoxide and suppression content of methane in the gas product. Experimental data were well compared with process simulation based on eauilibrium reactor model.
文摘The mass transfer process in a perforated rotating disk contactor(PRDC) using a toluene-acetone-water system was investigated.The volumetric overall mass transfer coefficients are calculated in a PRDC column.Both mass transfer directions are considered in experiments.The influences of operating variables containing agitation rate,dispersed and continuous phase flow rates and mass transfer in the extraction column are studied.According to obtained results,mass transfer is significantly dependent on agitation rate,while the dispersed and continuous phase flow rates have a minor effect on mass transfer in the extraction column.Furthermore,a novel empirical correlation is developed for prediction of overall continuous phase Sherwood number based on dispersed phase holdup,Reynolds number and mass transfer direction.There has been great agreement between experimental data and predicted values using a proposed correlation for all operating conditions.
文摘Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In most cases, these measurements are not suitable for detecting defects that appear as a result of failures of certain elements of the assembly lines. These so called self-recovering failures very often remain unnoticed, because they do not cause a suspension of the assembly process and if not taken into consideration, they can seriously menace the final product quality. In this paper, the authors use PFMEA to identify and evaluate the risk of the self-recovering failures. They also propose a simple Simulink model, which could be useful when trying to estimate the effect of installing new control devices at an existing assembly line upon its overall reliability and productivity.
基金Sponsored by the National Security Major Basic Research Project of China(Grant No.973 -61334)
文摘In this paper, an evolutionary recursive Bayesian estimation algorithm is presented, which incorporates the latest observation with a new proposal distribution, and the posterior state density is represented by a Gaussian mixture model that is recovered from the weighted particle set of the measurement update step by means of a weighted expectation-maximization algorithm. This step replaces the resampling stage needed by most particle filters and relieves the effect caused by sample impoverishment. A nonlinear tracking problem shows that this new approach outperforms other related particle filters.
文摘This paper introduces a powerful design and analysis tool named SIMCAT, that is developed to support applications to license a CANDU nuclear reactor, refurbish projects, and support the existing CANDU stations. It consists of the CATHENA (Canadian Algorithm for Thermo-Hydraulic Network Analysis), the control logics from C6SIM (CANDU 6 Analytical Simulator), and a communication protocol, PVM (parallel virtual machine). This is the first time that CATHENA has been successfully coupled directly with a program written in another language. The independence of CATHENA and the C6SIM controllers allows the development of both CATHENA and C6SIM controller to proceed independently.
文摘The high efficiency hydrogen fiber Bragg grating (FBG) sensor is presented. The sensitive film was a new alliance of palladium-silver (Pd-Ag). In addition, the titanium (Ti) layer was used as the adhesive layer. The presented sensor showed the resolution of more than 60pm/1%H2, and a fast response time of4s - 5s was guaranteed in the 0.1%H2 - 4%H2 range. Moreover, the life time of the sensor was investigated. The obtained results showed that the sensor had an enhanced life time. Furthermore, the sensor was applied in the propulsion system fuel tank model of the aerospace vehicle. The obtained results indicated that it is a prevention system against the disaster aerospace due to hydrogen leakage.
基金supported by the sponsors of the Energy Efficiency and Heat Pumps Consortium and Modeling and Optimization Consortium at the Center for Environmental Energy Engineering(CEEE)of the University of Maryland and Heat Transfer Technologies LLC for manufacturing the heat exchanger prototype
文摘Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation, air conditioning and refrigeration systems. A novel finless bare tube heat exchanger was studied using a validated heat exchanger modeling tool. The capacity based optimization and entransy dissipation based thermal resistance were used and compared. The applicability of using entransy dissipation based thermal resistance in this type of heat exchanger optimization has been discussed. It has been demonstrated that minimizing entransy dissipation and maximizing capacity are equivalent to optimizing evaporators with fixed flow rates and different when optimizing evaporators with variable flow rates and the deviation is negligible when heat exchanger capacity is small(~1 k W) and more obvious as heat exchanger capacity increases. Thus entransy dissipation based thermal resistance could be used as an alternative optimization index to capacity for evaporators with fixed flow rate and small capacity evaporators with variable flow rates and should be used individually with capacity as an optimization index for evaporators with large capacity and variable flow rates.