The application of transformer networks and feature fusion models in medical image segmentation has aroused considerable attention within the academic circle.Nevertheless,two main obstacles persist:(1)the restrictions...The application of transformer networks and feature fusion models in medical image segmentation has aroused considerable attention within the academic circle.Nevertheless,two main obstacles persist:(1)the restrictions of the Transformer network in dealing with locally detailed features,and(2)the considerable loss of feature information in current feature fusion modules.To solve these issues,this study initially presents a refined feature extraction approach,employing a double-branch feature extraction network to capture complex multi-scale local and global information from images.Subsequently,we proposed a low-loss feature fusion method-Multi-branch Feature Fusion Enhancement Module(MFFEM),which realizes effective feature fusion with minimal loss.Simultaneously,the cross-layer cross-attention fusion module(CLCA)is adopted to further achieve adequate feature fusion by enhancing the interaction between encoders and decoders of various scales.Finally,the feasibility of our method was verified using the Synapse and ACDC datasets,demonstrating its competitiveness.The average DSC(%)was 83.62 and 91.99 respectively,and the average HD95(mm)was reduced to 19.55 and 1.15 respectively.展开更多
The loss mechanisms of different passive devices （on-chip inductors and capacitors） on different substrates are analyzed and compared. OPS （oxidized porous silicon） and HR （high-resistivity） substrates are used ...The loss mechanisms of different passive devices （on-chip inductors and capacitors） on different substrates are analyzed and compared. OPS （oxidized porous silicon） and HR （high-resistivity） substrates are used as low-loss substrates for on-chip planar LPF （low pass filter） fabrication. For the study of substrate loss, a planar coil inductor is also designed. Simulation results show that Q （the quality factor） of the inductor on both substrates is over 20. Measurements of the LPF on OPS substrate give a - 3dB bandwidth of 2.9GHz and a midband insertion loss of 0.87dB at 500MHz. The LPF on HR substrate gives a - 3dB bandwidth of 2.3GHz and a midband insertion loss of 0.42dB at 500MHz.展开更多
This paper proposes a novel super junction （S J） SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained ...This paper proposes a novel super junction （S J） SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained SiGe p＋ layer to overcome the drawbacks of existing Si switching power diode. The SJ SiGe diode can achieve low specific on-resistance, high breakdown voltages and fast switching speed. The results indicate that the forward voltage drop of SJ SiGe diode is much lower than that of conventional Si power diode when the operating current densities do not exceed 1000 A/cm^2, which is very good for getting lower operating loss. The forward voltage drop of the Si diode is 0.66V whereas that of the SJ SiGe diode is only 0.52V voltages are 203 V for the former and 235 V for the latter. at operating current density of 10A/cm^2. The breakdown Compared with the conventional Si power diode, the reverse recovery time of SJ SiGe diode with 20 per cent Ge content is shortened by above a half and the peak reverse current is reduced by over 15%. The SJ SiGe diode can remarkably improve the characteristics of power diode by combining the merits of both SJ structure and SiGe material.展开更多
We demonstrate a low-loss terahertz waveguide based on the InAs-graphene-SiC structure. By analyzing the terahertz waveguide proposed in this paper, we can obtain that it is the characteristic of a low transmission lo...We demonstrate a low-loss terahertz waveguide based on the InAs-graphene-SiC structure. By analyzing the terahertz waveguide proposed in this paper, we can obtain that it is the characteristic of a low transmission loss coefficient （αloss 0.55 dB/m） for fundamental mode （LP01） when the incident frequency is larger than 3.0 THz. The critical radii of the inside and outside cylinders have been found for the high-quality transmission. The large inside radius and the high transmission frequency result in a fiat transmission loss coefficient curve. As a strictly two-dimensional material, the double graphene surface rings perform better to improve the quality of transmission mode. These results provide a new idea for the research of the long-distance THz waveguide.展开更多
Trapping light in a photonic integrated circuit can findmany applications, such as optical storage, optical-packetswitching, optical sensing and microwave photonics. Althoughthere are many ways to implement an integra...Trapping light in a photonic integrated circuit can findmany applications, such as optical storage, optical-packetswitching, optical sensing and microwave photonics. Althoughthere are many ways to implement an integrated opticalbuffer, such as the use of ring resonators, photonic crystals,Bragg gratings and spiral waveguides, it is still challenging torealize optical buffers with long storage time and low loss.Photonic integrated circuits with small size are of interest forimplementing optical buffers. In general, three materials systemsare employed to implement integrated optical buffers, silicon,silicon nitride and indium phosphide. However, it is hardto implement optical buffers with a storage time over tens ofnanoseconds due to the intrinsic high loss of these materials.展开更多
This work presents a compact lowpass-bandpass microstrip diplexer with a novel configuration.It consists of a lowpass filter integrated with a bandpass filter via a simple compact junction.The proposed bandpass filter...This work presents a compact lowpass-bandpass microstrip diplexer with a novel configuration.It consists of a lowpass filter integrated with a bandpass filter via a simple compact junction.The proposed bandpass filter consists of four rectangular patch cells and some thin strips.The step impedance structures,with a radial cell,are applied to achieve a lowpass frequency response.The lowpass channel of the introduced diplexer has 2.64 GHz cut-off frequency,whereas,the bandpass channel center frequency is 3.73 GHz for WiMAX applications and covers the frequencies3.31 GHz to 4 GHz.In addition to having novel structures,both filters have other advantages in terms of high return loss,low insertion loss and high selectivity.The presented microstrip diplexer has the compact size of 29 mm×13.8 mm×0.762 mm,calculated at 2.64 GHz.The obtained insertion losses are 0.20 dB(for the first channel)and 0.25 dB(for the second channel),which make the proposed diplexer suitable for energy harvesting.The stopband properties of both bandpass and lowpass filters are improved by creating several transmission zeros.The comparison results show that the lowest insertion losses,the minimum gap between channels,good return losses,and good isolation are obtained.展开更多
This paper report on a low-loss, broadband, and tunable negative refractive index metamaterial (NRIM) consisting of yttrium iron garnet (YIG) slabs and printed circuit boards (PCBs). The YIG slabs under an applied mag...This paper report on a low-loss, broadband, and tunable negative refractive index metamaterial (NRIM) consisting of yttrium iron garnet (YIG) slabs and printed circuit boards (PCBs). The YIG slabs under an applied magnetic field provide a negative permeability and the PCBs provide a negative permittivity. The substrates of the PCBs decuple the interactions between the YIG slabs and wire array deposed on such substrates. The effective electromagnetic parameters of the NRIM and the conditions of exhibiting the negative refractive index character are analyzed theoretically. Then the negative transmission and negative refraction characters are investigated numerically and experimentally. The results indicate that the NRIM exhibits negative pass band within the X-band with a bandwidth of about 1 GHz and a peak transmission power of about - 2.5 dB. While changing the applied magnetic field from 2300 Oe to 2700 Oe, the measured pass band of NRIM shift from 8.42 GHz to 9.50 GHz with a 2.7 MHz/Oe step. The results open a sample way to fabricate the NRIM, further, the metamaterial cloak and absorber.展开更多
The sintering characteristics of hexagonal Co2-Y-type ferrite, Ba2Co2Fe12O22, with the addition of 0.6 wt% CuO, were studied in order to allow for preparation in air, as opposed to the conventionally recommended O2, f...The sintering characteristics of hexagonal Co2-Y-type ferrite, Ba2Co2Fe12O22, with the addition of 0.6 wt% CuO, were studied in order to allow for preparation in air, as opposed to the conventionally recommended O2, for industrial production. The dependence of the resistivity, ρ magnetic loss, tanδ, and the permeability, μ, at 1 GHz on the sintering temperature was investigated. A low tanδ of 0.05 with a m of 2.7 at a frequency of 1 GHz, along with a high ρ (up to 7 × 104 μm), were attained under sintering at 1170°C in air, which were the same features as those of samples sintered at 1200°C in O2. The dependence of tanδ on grain diameter was also examined, and it was determined that a small grain size (less than 2 μm) is preferable for low tanδ.展开更多
在探讨正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的优化中,一个显著挑战在于其信号检测性能的相对不足。同时,针对基于深度神经网络的索引调制(Deep Neural Network Based Index Modulation,DNN-IM)检测算法...在探讨正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的优化中,一个显著挑战在于其信号检测性能的相对不足。同时,针对基于深度神经网络的索引调制(Deep Neural Network Based Index Modulation,DNN-IM)检测算法,普遍存在着误码率及损失值偏高的问题。为了弥补上述难题,文中提出一种基于多层感知机(Multilayer Perceptron,MLP)的索引调制检测算法,即MLP-IM算法。该算法采用融合两个连接层与一个输出层的架构设计,通过挑选的激活函数实现对OFDM索引调制系统中数据比特的精准还原。首先将OFDM索引调制系统的基础理论巧妙应用于数据的预处理阶段,随后利用仿真数据集对MLP神经网络模型进行全面而深入的离线训练,确保模型的稳健性与准确性。在检测阶段,通过MLP-IM检测算法实现了对OFDM索引调制系统的高效检测。仿真结果表明,所提出的MLP-IM算法在误码率控制和损失值两个方面的性能表现与最大似然检测算法相媲美,甚至在某些场景下超越了现有DNN-IM算法的性能,其性能改善幅度在0.2~6 dB的区间内。展开更多
基金funded by the Henan Science and Technology research project(222103810042)Support by the open project of scientific research platform of grain information processing center of Henan University of Technology(KFJJ-2021-108)+1 种基金Support by the innovative funds plan of Henan University of Technology(2021ZKCJ14)Henan University of Technology Youth Backbone Teacher Program.
文摘The application of transformer networks and feature fusion models in medical image segmentation has aroused considerable attention within the academic circle.Nevertheless,two main obstacles persist:(1)the restrictions of the Transformer network in dealing with locally detailed features,and(2)the considerable loss of feature information in current feature fusion modules.To solve these issues,this study initially presents a refined feature extraction approach,employing a double-branch feature extraction network to capture complex multi-scale local and global information from images.Subsequently,we proposed a low-loss feature fusion method-Multi-branch Feature Fusion Enhancement Module(MFFEM),which realizes effective feature fusion with minimal loss.Simultaneously,the cross-layer cross-attention fusion module(CLCA)is adopted to further achieve adequate feature fusion by enhancing the interaction between encoders and decoders of various scales.Finally,the feasibility of our method was verified using the Synapse and ACDC datasets,demonstrating its competitiveness.The average DSC(%)was 83.62 and 91.99 respectively,and the average HD95(mm)was reduced to 19.55 and 1.15 respectively.
文摘The loss mechanisms of different passive devices （on-chip inductors and capacitors） on different substrates are analyzed and compared. OPS （oxidized porous silicon） and HR （high-resistivity） substrates are used as low-loss substrates for on-chip planar LPF （low pass filter） fabrication. For the study of substrate loss, a planar coil inductor is also designed. Simulation results show that Q （the quality factor） of the inductor on both substrates is over 20. Measurements of the LPF on OPS substrate give a - 3dB bandwidth of 2.9GHz and a midband insertion loss of 0.87dB at 500MHz. The LPF on HR substrate gives a - 3dB bandwidth of 2.3GHz and a midband insertion loss of 0.42dB at 500MHz.
基金Project supported by the National Natural Science Foundation of China (Grant No 50477012)the Doctoral Program Foundation of Institutes of Higher Education of China (Grant No 20050700006)the Special Scientific Research Program of the Education Bureau of Shaanxi Province,China (Grant No 05JK268)
文摘This paper proposes a novel super junction （S J） SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained SiGe p＋ layer to overcome the drawbacks of existing Si switching power diode. The SJ SiGe diode can achieve low specific on-resistance, high breakdown voltages and fast switching speed. The results indicate that the forward voltage drop of SJ SiGe diode is much lower than that of conventional Si power diode when the operating current densities do not exceed 1000 A/cm^2, which is very good for getting lower operating loss. The forward voltage drop of the Si diode is 0.66V whereas that of the SJ SiGe diode is only 0.52V voltages are 203 V for the former and 235 V for the latter. at operating current density of 10A/cm^2. The breakdown Compared with the conventional Si power diode, the reverse recovery time of SJ SiGe diode with 20 per cent Ge content is shortened by above a half and the peak reverse current is reduced by over 15%. The SJ SiGe diode can remarkably improve the characteristics of power diode by combining the merits of both SJ structure and SiGe material.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB339802)the National High Technology Research and Development Program of China(Grant No.2011AA010205)+3 种基金the National Natural Science Foundation of China(Grant Nos.61107086 and 61172010)the Natural ScienceFoundation of Tianjin,China(Grant Nos.11JCYBJC01100 and 13ZCZDSF02300)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120032110053)the THz Science and Technology Foundation of China Academy of Engineering Physics(Grant Nos.CAEPTHZ201201 and CAEPTHZ201304)
文摘We demonstrate a low-loss terahertz waveguide based on the InAs-graphene-SiC structure. By analyzing the terahertz waveguide proposed in this paper, we can obtain that it is the characteristic of a low transmission loss coefficient （αloss 0.55 dB/m） for fundamental mode （LP01） when the incident frequency is larger than 3.0 THz. The critical radii of the inside and outside cylinders have been found for the high-quality transmission. The large inside radius and the high transmission frequency result in a fiat transmission loss coefficient curve. As a strictly two-dimensional material, the double graphene surface rings perform better to improve the quality of transmission mode. These results provide a new idea for the research of the long-distance THz waveguide.
文摘Trapping light in a photonic integrated circuit can findmany applications, such as optical storage, optical-packetswitching, optical sensing and microwave photonics. Althoughthere are many ways to implement an integrated opticalbuffer, such as the use of ring resonators, photonic crystals,Bragg gratings and spiral waveguides, it is still challenging torealize optical buffers with long storage time and low loss.Photonic integrated circuits with small size are of interest forimplementing optical buffers. In general, three materials systemsare employed to implement integrated optical buffers, silicon,silicon nitride and indium phosphide. However, it is hardto implement optical buffers with a storage time over tens ofnanoseconds due to the intrinsic high loss of these materials.
文摘This work presents a compact lowpass-bandpass microstrip diplexer with a novel configuration.It consists of a lowpass filter integrated with a bandpass filter via a simple compact junction.The proposed bandpass filter consists of four rectangular patch cells and some thin strips.The step impedance structures,with a radial cell,are applied to achieve a lowpass frequency response.The lowpass channel of the introduced diplexer has 2.64 GHz cut-off frequency,whereas,the bandpass channel center frequency is 3.73 GHz for WiMAX applications and covers the frequencies3.31 GHz to 4 GHz.In addition to having novel structures,both filters have other advantages in terms of high return loss,low insertion loss and high selectivity.The presented microstrip diplexer has the compact size of 29 mm×13.8 mm×0.762 mm,calculated at 2.64 GHz.The obtained insertion losses are 0.20 dB(for the first channel)and 0.25 dB(for the second channel),which make the proposed diplexer suitable for energy harvesting.The stopband properties of both bandpass and lowpass filters are improved by creating several transmission zeros.The comparison results show that the lowest insertion losses,the minimum gap between channels,good return losses,and good isolation are obtained.
文摘This paper report on a low-loss, broadband, and tunable negative refractive index metamaterial (NRIM) consisting of yttrium iron garnet (YIG) slabs and printed circuit boards (PCBs). The YIG slabs under an applied magnetic field provide a negative permeability and the PCBs provide a negative permittivity. The substrates of the PCBs decuple the interactions between the YIG slabs and wire array deposed on such substrates. The effective electromagnetic parameters of the NRIM and the conditions of exhibiting the negative refractive index character are analyzed theoretically. Then the negative transmission and negative refraction characters are investigated numerically and experimentally. The results indicate that the NRIM exhibits negative pass band within the X-band with a bandwidth of about 1 GHz and a peak transmission power of about - 2.5 dB. While changing the applied magnetic field from 2300 Oe to 2700 Oe, the measured pass band of NRIM shift from 8.42 GHz to 9.50 GHz with a 2.7 MHz/Oe step. The results open a sample way to fabricate the NRIM, further, the metamaterial cloak and absorber.
文摘The sintering characteristics of hexagonal Co2-Y-type ferrite, Ba2Co2Fe12O22, with the addition of 0.6 wt% CuO, were studied in order to allow for preparation in air, as opposed to the conventionally recommended O2, for industrial production. The dependence of the resistivity, ρ magnetic loss, tanδ, and the permeability, μ, at 1 GHz on the sintering temperature was investigated. A low tanδ of 0.05 with a m of 2.7 at a frequency of 1 GHz, along with a high ρ (up to 7 × 104 μm), were attained under sintering at 1170°C in air, which were the same features as those of samples sintered at 1200°C in O2. The dependence of tanδ on grain diameter was also examined, and it was determined that a small grain size (less than 2 μm) is preferable for low tanδ.
文摘在探讨正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的优化中,一个显著挑战在于其信号检测性能的相对不足。同时,针对基于深度神经网络的索引调制(Deep Neural Network Based Index Modulation,DNN-IM)检测算法,普遍存在着误码率及损失值偏高的问题。为了弥补上述难题,文中提出一种基于多层感知机(Multilayer Perceptron,MLP)的索引调制检测算法,即MLP-IM算法。该算法采用融合两个连接层与一个输出层的架构设计,通过挑选的激活函数实现对OFDM索引调制系统中数据比特的精准还原。首先将OFDM索引调制系统的基础理论巧妙应用于数据的预处理阶段,随后利用仿真数据集对MLP神经网络模型进行全面而深入的离线训练,确保模型的稳健性与准确性。在检测阶段,通过MLP-IM检测算法实现了对OFDM索引调制系统的高效检测。仿真结果表明,所提出的MLP-IM算法在误码率控制和损失值两个方面的性能表现与最大似然检测算法相媲美,甚至在某些场景下超越了现有DNN-IM算法的性能,其性能改善幅度在0.2~6 dB的区间内。
