Marine structures operating in natural ocean environment are subjected to various stochastic loads. For design of the marine structures, the most important task is to determine environmental load design criterion. Thi...Marine structures operating in natural ocean environment are subjected to various stochastic loads. For design of the marine structures, the most important task is to determine environmental load design criterion. This paper presents a method to determine the optimum environmental load design criterion for marine structures. This method is based on the investment and benefit analysis and it can reach the design purpose of decreasing total costs during the service life of the structures and increasing economic benefits.展开更多
This paper presents a sequential optimum algorithm for vehicle schedulingproblem, which includes obtaining initial theoretical solution, adjustingsolution, forming initial routes and adjustins routes. This method can ...This paper presents a sequential optimum algorithm for vehicle schedulingproblem, which includes obtaining initial theoretical solution, adjustingsolution, forming initial routes and adjustins routes. This method can beapplied to general transportation problems with multiple depots and multiplevehicle types on complex network. In comparison with manual scheduling ofChengdu Transportation Company II, the result shows that this method isreasonable, feasible and applicable.展开更多
DC I-V output,small signal and an extensive large signal characterization（load-pull measurements） of a GaN HEMT on a SiC substrate with different gate widths of 100μm and 1 mm have been carried out.From the small s...DC I-V output,small signal and an extensive large signal characterization（load-pull measurements） of a GaN HEMT on a SiC substrate with different gate widths of 100μm and 1 mm have been carried out.From the small signal data,it has been found that the cutoff frequencies increase with gate width varying from 100μm to 1 mm,owing to the reduced contribution of the parasitic effect.The devices investigated with different gate widths are enough to work in the C band and X band.The large signal measurements include the load-pull measurements and power sweep measurements at the C band（5.5 GHz） and X band（8 GHz）.When biasing the gate voltage in class AB and selecting the source impedance,the optimum load impedances seen from the device for output power and PAE were localized in the load-pull map.The results of a power sweep at an 8 GHz biased various drain voltage demonstrate that a GaN HEMT on a SiC substrate has good thermal conductivity and a high breakdown voltage,and the CW power density of 10.16 W/mm was obtained.From the results of the power sweep measurement at 5.5 GHz with different gate widths, the actual scaling rules and heat effect on the large periphery device were analyzed,although the effects are not serious. The measurement results and analyses prove that a GaN HEMT on a SiC substrate is an ideal candidate for high-power amplifier design.展开更多
文摘Marine structures operating in natural ocean environment are subjected to various stochastic loads. For design of the marine structures, the most important task is to determine environmental load design criterion. This paper presents a method to determine the optimum environmental load design criterion for marine structures. This method is based on the investment and benefit analysis and it can reach the design purpose of decreasing total costs during the service life of the structures and increasing economic benefits.
文摘This paper presents a sequential optimum algorithm for vehicle schedulingproblem, which includes obtaining initial theoretical solution, adjustingsolution, forming initial routes and adjustins routes. This method can beapplied to general transportation problems with multiple depots and multiplevehicle types on complex network. In comparison with manual scheduling ofChengdu Transportation Company II, the result shows that this method isreasonable, feasible and applicable.
基金Project supported by the Major Program and State Key Program of the National Natural Science Foundation of China(No.60736033)
文摘DC I-V output,small signal and an extensive large signal characterization（load-pull measurements） of a GaN HEMT on a SiC substrate with different gate widths of 100μm and 1 mm have been carried out.From the small signal data,it has been found that the cutoff frequencies increase with gate width varying from 100μm to 1 mm,owing to the reduced contribution of the parasitic effect.The devices investigated with different gate widths are enough to work in the C band and X band.The large signal measurements include the load-pull measurements and power sweep measurements at the C band（5.5 GHz） and X band（8 GHz）.When biasing the gate voltage in class AB and selecting the source impedance,the optimum load impedances seen from the device for output power and PAE were localized in the load-pull map.The results of a power sweep at an 8 GHz biased various drain voltage demonstrate that a GaN HEMT on a SiC substrate has good thermal conductivity and a high breakdown voltage,and the CW power density of 10.16 W/mm was obtained.From the results of the power sweep measurement at 5.5 GHz with different gate widths, the actual scaling rules and heat effect on the large periphery device were analyzed,although the effects are not serious. The measurement results and analyses prove that a GaN HEMT on a SiC substrate is an ideal candidate for high-power amplifier design.
