In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor （HEMT） with a U-type gate foot. The U-gate Al...In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor （HEMT） with a U-type gate foot. The U-gate AlGaN/GaN HEMT mainly features a gradually changed sidewall angle, which effectively mitigates the electric field in the channel, thus obtaining enhanced off-state breakdown characteristics. At the same time, only a small additional gate capacitance and decreased gate resistance ensure excellent RF characteristics for the U-gate device. U-gate AlGaN/GaN HEMTs are feasible through adjusting the etching conditions of an inductively coupled plasma system, without introducing any extra process steps. The simulation results are confirmed by experimental measurements. These features indicate that U-gate A1GaN/GaN HEMTs might be promising candidates for use in millimeter-wave power applications.展开更多
The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical ind...The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical industry, etc. In this paper, a new series of generalized partially balanced incomplete blocks PBIB designs with m associated classes (m = 4, 5 and 7) based on new generalized association schemes with number of treatments v arranged in w arrays of n rows and l columns (w ≥ 2, n ≥ 2, l ≥ 2) is defined. Some construction methods of these new PBIB are given and their parameters are specified using the Combinatory Method (s). For n or l even and s divisor of n or l, the obtained PBIB designs are resolvable PBIB designs. So the Fang RBIBD method is applied to obtain a series of particular U-type designs U (wnl;) (r is the repetition number of each treatment in our resolvable PBIB design).展开更多
Sandwich panel is commonly used in ship and marine engineering equipment,such as side structure and superstructure deck of a ship,which is of good anti-explosion performance.This paper addresses a study on the dynamic...Sandwich panel is commonly used in ship and marine engineering equipment,such as side structure and superstructure deck of a ship,which is of good anti-explosion performance.This paper addresses a study on the dynamic response of the U-typed sandwich panel under explosion load through the numerical simulation and theoretical methods.Based on the orthotropic plate theory,the U-typed sandwich panel is simplified and transformed into a single degree of freedom(SDOF)spring system,the equivalent motion equation of the SDOF system and the expression of triangular explosion load function are established based on the SDOF theory,and the maximum response spectrum of the SDOF system is obtained.Then,the response of the equivalent SDOF system of the U-typed sandwich panel under explosion load is analyzed,and the theoretical results match well with the numerical simulation results,which verifies the accuracy of the theoretical method proposed in this paper.The theoretical method proposed in this paper could have good engineering applications for the structural anti-explosion design,and provide a reference for the evaluation of the anti-explosion performance of ship and offshore platform structures.展开更多
We are examining the behavior of a composite made of ferroelectrics with strong dielectric properties and ferrites with magnetic properties due to the rising need for materials for multipurpose devices.Many applicatio...We are examining the behavior of a composite made of ferroelectrics with strong dielectric properties and ferrites with magnetic properties due to the rising need for materials for multipurpose devices.Many application avenues will be favored by the pairing of these materials’individual qualities with one another.Perovskite and U-type hexaferrite composite materials have been chosen for this study based on their magnetic and dielectric properties.The composites,(1−x)PLT−x(Ba1−3xNd2x)4Co2Fe36O60 where x=0.52,0.54,0.56,0.58 are prepared by solid state reaction method and phase formation was examined.Consideration has been given to the magnetic,dielectric,and magneto-dielectric properties.This work has established the link between the electric and magnetic domains while applying electric and magnetic forces to the materials.The magneto-dielectric research revealed magneto-electric coupling in all of the samples.However,the sample shows the maximum coupling for x=0.54 with MDR%values of 93.17%,which might be because this sample appears to have a high magneto-resistance(161%).展开更多
The objective of this paper is to study the issue of uniformity on three-level U-type designs in terms of the wrap-around L2-discrepancy.Based on the known formula,we present a new lower bound of wrap-around L2-discre...The objective of this paper is to study the issue of uniformity on three-level U-type designs in terms of the wrap-around L2-discrepancy.Based on the known formula,we present a new lower bound of wrap-around L2-discrepancy for three-level U-type designs and compare it with those existing ones through figures,numerical simulation and illustrative examples.展开更多
This paper aims to develop a new robust U-type test for high dimensional regression coefficients using the estimated U-statistic of order two and refitted cross-validation error variance estimation. It is proved that ...This paper aims to develop a new robust U-type test for high dimensional regression coefficients using the estimated U-statistic of order two and refitted cross-validation error variance estimation. It is proved that the limiting null distribution of the proposed new test is normal under two kinds of ordinary models.We further study the local power of the proposed test and compare with other competitive tests for high dimensional data. The idea of refitted cross-validation approach is utilized to reduce the bias of sample variance in the estimation of the test statistic. Our theoretical results indicate that the proposed test can have even more substantial power gain than the test by Zhong and Chen(2011) when testing a hypothesis with outlying observations and heavy tailed distributions. We assess the finite-sample performance of the proposed test by examining its size and power via Monte Carlo studies. We also illustrate the application of the proposed test by an empirical analysis of a real data example.展开更多
基金Project supported by the Major Program of the National Natural Science Foundation of China （Grant No. 60890191） and the National Key Basic Research Program of China （Grant No. 2010CB327503）.
文摘In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor （HEMT） with a U-type gate foot. The U-gate AlGaN/GaN HEMT mainly features a gradually changed sidewall angle, which effectively mitigates the electric field in the channel, thus obtaining enhanced off-state breakdown characteristics. At the same time, only a small additional gate capacitance and decreased gate resistance ensure excellent RF characteristics for the U-gate device. U-gate AlGaN/GaN HEMTs are feasible through adjusting the etching conditions of an inductively coupled plasma system, without introducing any extra process steps. The simulation results are confirmed by experimental measurements. These features indicate that U-gate A1GaN/GaN HEMTs might be promising candidates for use in millimeter-wave power applications.
文摘The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical industry, etc. In this paper, a new series of generalized partially balanced incomplete blocks PBIB designs with m associated classes (m = 4, 5 and 7) based on new generalized association schemes with number of treatments v arranged in w arrays of n rows and l columns (w ≥ 2, n ≥ 2, l ≥ 2) is defined. Some construction methods of these new PBIB are given and their parameters are specified using the Combinatory Method (s). For n or l even and s divisor of n or l, the obtained PBIB designs are resolvable PBIB designs. So the Fang RBIBD method is applied to obtain a series of particular U-type designs U (wnl;) (r is the repetition number of each treatment in our resolvable PBIB design).
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51779110 and 51809122)the Natural Science Foundation of Jiangsu Province(Grant No.BK20191461)the Six Talent Peaks Project in Jiangsu Province(Grant No.KTHY-064).
文摘Sandwich panel is commonly used in ship and marine engineering equipment,such as side structure and superstructure deck of a ship,which is of good anti-explosion performance.This paper addresses a study on the dynamic response of the U-typed sandwich panel under explosion load through the numerical simulation and theoretical methods.Based on the orthotropic plate theory,the U-typed sandwich panel is simplified and transformed into a single degree of freedom(SDOF)spring system,the equivalent motion equation of the SDOF system and the expression of triangular explosion load function are established based on the SDOF theory,and the maximum response spectrum of the SDOF system is obtained.Then,the response of the equivalent SDOF system of the U-typed sandwich panel under explosion load is analyzed,and the theoretical results match well with the numerical simulation results,which verifies the accuracy of the theoretical method proposed in this paper.The theoretical method proposed in this paper could have good engineering applications for the structural anti-explosion design,and provide a reference for the evaluation of the anti-explosion performance of ship and offshore platform structures.
文摘We are examining the behavior of a composite made of ferroelectrics with strong dielectric properties and ferrites with magnetic properties due to the rising need for materials for multipurpose devices.Many application avenues will be favored by the pairing of these materials’individual qualities with one another.Perovskite and U-type hexaferrite composite materials have been chosen for this study based on their magnetic and dielectric properties.The composites,(1−x)PLT−x(Ba1−3xNd2x)4Co2Fe36O60 where x=0.52,0.54,0.56,0.58 are prepared by solid state reaction method and phase formation was examined.Consideration has been given to the magnetic,dielectric,and magneto-dielectric properties.This work has established the link between the electric and magnetic domains while applying electric and magnetic forces to the materials.The magneto-dielectric research revealed magneto-electric coupling in all of the samples.However,the sample shows the maximum coupling for x=0.54 with MDR%values of 93.17%,which might be because this sample appears to have a high magneto-resistance(161%).
基金Supported in part by the National Natural Science Foundation of China(Nos.11871237,11801576,11271147,11401596)the Fundamental Research Funds for the Central Universities(South-Central University for Nationalities(Nos.CZQ18017,CZQ19010))
文摘The objective of this paper is to study the issue of uniformity on three-level U-type designs in terms of the wrap-around L2-discrepancy.Based on the known formula,we present a new lower bound of wrap-around L2-discrepancy for three-level U-type designs and compare it with those existing ones through figures,numerical simulation and illustrative examples.
基金supported by National Natural Science Foundation of China (Grant Nos. 11071022, 11231010 and 11471223)Beijing Center for Mathematics and Information Interdisciplinary ScienceKey Project of Beijing Municipal Educational Commission (Grant No. KZ201410028030)
文摘This paper aims to develop a new robust U-type test for high dimensional regression coefficients using the estimated U-statistic of order two and refitted cross-validation error variance estimation. It is proved that the limiting null distribution of the proposed new test is normal under two kinds of ordinary models.We further study the local power of the proposed test and compare with other competitive tests for high dimensional data. The idea of refitted cross-validation approach is utilized to reduce the bias of sample variance in the estimation of the test statistic. Our theoretical results indicate that the proposed test can have even more substantial power gain than the test by Zhong and Chen(2011) when testing a hypothesis with outlying observations and heavy tailed distributions. We assess the finite-sample performance of the proposed test by examining its size and power via Monte Carlo studies. We also illustrate the application of the proposed test by an empirical analysis of a real data example.
