检索结果-南通市图书馆

Computer Modeling in Engineering & Sciences 2023年第6期135卷 2155-2172页

作者： Xiaojun Zhu heming huang School of Computer Science Qinghai Normal UniversityXining810008China The State Key Laboratory of Tibetan Intelligent Information Processing and Application Xining810008China School of Electronic and Information Engineering Lanzhou City UniversityLanzhou730000China

Recently,speech enhancement methods based on Generative Adversarial Networks have achieved good performance in time-domain noisy ***,the training of Generative Adversarial Networks has such problems as convergence difficulty,model collapse,*** this work,an end-to-end speech enhancement model based on Wasserstein Generative Adversarial Networks is proposed,and some improvements have been made in order to get faster convergence speed and better generated speech ***,in the generator coding part,each convolution layer adopts different convolution kernel sizes to conduct convolution operations for obtaining speech coding information from multiple scales;a gated linear unit is introduced to alleviate the vanishing gradient problem with the increase of network depth;the gradient penalty of the discriminator is replaced with spectral normalization to accelerate the convergence rate of themodel;a hybrid penalty termcomposed of L1 regularization and a scale-invariant signal-to-distortion ratio is introduced into the loss function of the generator to improve the quality of generated *** experimental results on both TIMIT corpus and Tibetan corpus show that the proposed model improves the speech quality significantly and accelerates the convergence speed of the model.

关键词： Speech enhancement generative adversarial networks hybrid penalty gated linear units multi-scale convolution

Uncovering recent progress in nanostructured light-emitters for information and communication technologies

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2021年第9期10卷 1571-1587页

作者： Frédéric Grillot Jianan Duan Bozhang Dong heming huang LTCI Institut Polytechnique de ParisTélécom Paris19 place Marguerite Perey91120PalaiseauFrance Center for High Technology Materials University of New-Mexico1313 Goddard St SEAlbuquerqueNM87106USA State Key Laboratory on Tunable Laser Technology School of Electronic and Information EngineeringHarbin Institute of TechnologyShenzhen518055China

Semiconductor nanostructures with low dimensionality like quantum dots and quantum dashes are one of the best attractive and heuristic solutions for achieving high performance photonic *** one or more spatial dimensions of the nanocrystal approach the de Broglie wavelength,nanoscale size effects create a spatial quantization of carriers leading to a complete discretization of energy levels along with additional quantum phenomena like entangled-photon generation or squeezed states of light among *** article reviews our recent findings and prospects on nanostructure based light emitters where active region is made with quantum-dot and quantum-dash *** applications ranging from silicon-based integrated technologies to quantum information systems rely on the utilization of such laser ***,we link the material and fundamental properties with the device *** this purpose,spectral linewidth,polarization anisotropy,optical nonlinearities as well as microwave,dynamic and nonlinear properties are closely *** paper focuses on photonic devices grown on native substrates(InP and GaAs)as well as those heterogeneously and epitaxially grown on silicon *** research pipelines the most exciting recent innovation developed around light emitters using nanostructures as gain media and highlights the importance of nanotechnologies on industry and society especially for shaping the future information and communication society.

关键词： emitter communication polarization

PDMS microchannel fabrication technique based on microwire-molding

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第24期53卷 3928-3936页

作者： JIA YueFei JIANG JiaHuan MA XiaoDong LI Yuan huang heming CAI KunBao CAI ShaoXi WU YunPeng Bioengineering College Chongqing University Chongqing 400044 China Communication Engineering College Chongqing University Chongqing 400044 China

Micro-flow channel is basic functional component of microfluidic chip,and every step-forward of its construction technique has been receiving concern all over the *** article presents a not-complicated but flexible method for fabrication of micro-flow *** method mainly utilizes the conventional molding capability of polydimethylsiloxane(PDMS) and widespread commercial microwires as *** have fabricated out some conventional types of microchannels with different topological shapes,as examples for the demonstration of this flexible fabrication route which was not dependent on the stringent demands of photolithographical or microelectromechanical system(MEMS) *** smooth surface,high-intensity,and high flexibility of the wires made it possible to create many types of topological structures of the two-dimensional or three-dimensional microchannel or channel *** geometric shape of the cross-section of thus forming microchannel in PDMS was the negative of that of embedded-in microwire,in high-fidelity if suitable measures were ***-over,such a microchannel fabrication process can easily integrate the conductivity and low resistivity of the metal wire to create micro-flow devices that are suitable for the electromagnetic control of liquid or the temperature regulation in the *** some preliminary optical analysis was provided for the observation of thus forming rounded *** on this molding strategy,we even made some prototypes for functional microflow application,such as microsolenoids chip and temperature control *** an experiment of forming a droplet in the cross channel further confirmed the feasibility and applicability of this flexible microchannel forming technique.

关键词：微丝软平版印刷术 PDMS 制模方法

How could imperfect device properties influence the performances of spiking neural networks?

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年

作者： Jingyang CHEN Zhihao WANG Tong WANG heming huang Zheyuan SHAO Zhe WANG Xin GUO State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology

Spiking neural networks (SNNs) provide an efficient way to apply artificial intelligence systems on edge devices. Memristive devices with tunable conductance states can be used to emulate the functions of biological neurons and synapses and to build SNNs. In this work, fully-connected SNNs based on various memristive devices are constructed, and a hardware-compatible spike-timing-dependent plasticity (STDP)learning rule is applied to train the SNNs. Strategies are designed to suppress the overfitting problem and improve the performance of the SNNs in the case of a small training set. However, the properties of memristive devices are never perfect. The effects of imperfect device properties, e.g., asymmetric weight update, insufficient number of conductance states, and low on/off ratio, on the performance of the SNNs are elaborated.

关键词：

Inhibiting p38 mitogen-activated protein kinase attenuates cerebral ischemic injury in Swedish mutant amyloid precursor protein transgenic mice

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2012年第14期7卷 1088-1094页

作者： Liangyu Zou Haiyan Qin Yitao He heming huang Yi Lu Xiaofan Chu Department of Neurology Shenzhen People's HospitalSecond Clinical CollegeJinan UniversityShenzhen 518020Guangdong ProvinceChina

Cerebral ischemia was induced using photothrombosis 1 hour after intraperitoneal injection of the p38 mitogen-activated protein kinase （MAPK） inhibitor $B239063 into Swedish mutant amyloid precursor protein （APP/SWE） transgenic and non-transgenic mice. The number of surviving neurons in the penumbra was quantified using Nissl staining, and the activity of p38 MAPKs was measured by western blotting. The number of surviving neurons in the penumbra was significantly reduced in APP/SWE transgenic mice compared with non-transgenic controls 7 days after cerebral ischemia, but the activity of p38 MAPKs was significantly elevated compared with the non-ischemic hemisphere in the APP/SWE transgenic mice. SB239063 prevented these changes. The APP/SWE mutation exacerbated ischemic brain injury, and this could be alleviated by inhibiting p38 MAPK activity.

关键词： cerebral ischemia amyloid precursor protein transgenic Alzheimer's disease p38mitogen-activated protein kinase SB239063 neural regeneration

Dynamic and nonlinear properties of epitaxial quantum dot lasers on silicon for isolator-free integration

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2019年第11期7卷 1222-1228页

作者： Jianan Duan heming huang Bozhang Dong Justin C.Norman Zeyu Zhang John E.Bowers Frederic Grillot LTCI Telecom ParisInstitut Polytechnique de Paris46 rue Barrault75013 ParisFrance Materials Department University of CaliforniaSanta BarbaraCalifornia 93106USA Department of Electrical and Computer Engineering University of CaliforniaSanta BarbaraCalifornia 93106USA Institute for Energy Efficiency University of CaliforniaSanta BarbaraCalifornia 93106USA Center for High Technology Materials University of New MexicoAlbuquerqueNew Mexico 87106USA

This work investigates the dynamic and nonlinear properties of quantum dot(QD) lasers directly grown on silicon with a view to isolator-free applications. Among them, the chirp parameter, also named the αHfactor,is featured through a thermally insensitive method analyzing the residual side-mode dynamics under optical injection locking. The αHat threshold is found as low as 0.32. Then, the nonlinear gain is investigated from the gain compression factor viewpoint. The latter is found higher for epitaxial QD lasers on silicon than that in heterogeneously integrated quantum well(QW) devices on silicon. Despite that, the power dependence of the αHdoes not lead to a large increase of the chirp coefficient above the laser’s threshold at higher bias. This effect is confirmed from an analytical model and attributed to the strong lasing emission of the ground-state transition, which transforms into a critical feedback level as high as-6.5 d B, which is ~19 d B higher than a comparable QW ***, the intensity noise analysis confirms that QD lasers are overdamped oscillators with damping frequencies as large as 33 GHz. Altogether, these features contribute to fundamentally enhancing the reflection insensitivity of the epitaxial QD lasers. This last feature is unveiled by the 10 Gbit/s error-free high-speed transmission experiments. Overall, we believe that this work is of paramount importance for future isolator-free photonics technologies and cost-efficient high-speed transmission systems.

关键词： quantum nonlinear epitaxial

Reflection sensitivity of dual-state quantum dot lasers

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2023年第10期11卷 1713-1722页

作者： ZHIYONG JIN heming huang YUEGUANG ZHOU SHIYUAN ZHAO SHIHAO DING CHENG WANG YONG YAO XIAOCHUAN XU FRÉDÉRIC GRILLOT JIANAN DUAN State Key Laboratory on Tunable Laser Technology School of Electronic and Information EngineeringHarbin Institute of TechnologyShenzhen 518055China LTCI Telecom ParisInstitut Polytechnique de Paris91120 PalaiseauFrance DTU Electro Department of Electrical and Photonics EngineeringTechnical University of Denmark2800 LyngbyDenmark School of Information Science and Technology ShanghaiTech UniversityShanghai 201210China Center for High Technology Materials The University of New-MexicoAlbuquerqueNew Mexico 87106USA

This work experimentally and theoretically demonstrates the effect of excited state lasing on the reflection sensitivity of dual-state quantum dot lasers,showing that the laser exhibits higher sensitivity to external optical feedback when reaching the excited state lasing *** sensitivity can be degraded by increasing the excited-to-ground-state energy separation,which results in a high excited-to-ground-state threshold *** addition,the occurrence of excited state lasing decreases the damping factor and increases the linewidth enhancement factor,which leads to a low critical feedback *** findings illuminate a path to fabricate reflectioninsensitive quantum dot lasers for isolator-free photonic integrated circuits.

关键词： state excited quantum

Dynamic performance and reflection sensitivity of quantum dot distributed feedback lasers with large optical mismatch

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2021年第8期9卷 1550-1558页

作者： BOZHANG DONG JIANAN DUAN heming huang JUSTIN CNORMAN KENICHI NISHI KEIZO TAKEMASA MITSURU SUGAWARA JOHN EBOWERS FRéDéRIC GRILLOT LTCI Telecom ParisInstitut Polytechnique de Paris19 Place Marguerite Perey91120 PalaiseauFrance Institute for Energy Efficiency University of CaliforniaSanta BarbaraCalifornia 93106USA Materials Department University of CaliforniaSanta BarbaraCalifornia 93106USA QD Laser Inc.KawasakiKanagawa 210-0855Japan Department of Electrical and Computer Engineering University of CaliforniaSanta BarbaraCalifornia 93106USA Center for High Technology Materials University of New-MexicoAlbuquerqueNew Mexico 87106USA Current address:State Key Laboratory on Tunable Laser Technology School of Electronic and Information EngineeringHarbin Institute of TechnologyShenzhen 518055China

This work reports on a high-efficiency In As/Ga As distributed feedback quantum dot *** large optical wavelength detuning at room temperature between the lasing peak and the gain peak causes the static,dynamic,and nonlinear intrinsic properties to all improve with temperature,including the lasing efficiency,the modulation dynamics,the linewidth enhancement factor,and consequently the reflection *** reported show an optimum operating temperature at 75°C,highlighting the potential of the large optical mismatch assisted single-frequency laser for the development of uncooled and isolator-free high-speed photonic integrated circuits.

关键词： mismatch optical tuning

Four-wave mixing in 1.3 μm epitaxial quantum dot lasers directly grown on silicon

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2022年第5期10卷 1264-1270页

作者： JIANAN DUAN BOZHANG DONG WENG W.CHOW heming huang SHIHAO DING SONGTAO LIU JUSTIN C.NORMAN JOHN E.BOWERS FREDEIC GRILLOT LTCI Telecom ParisInstitut Polytechnique de Pahs91120 PalaiseauFrance Sandia National Laboratories AlbuquerqueNew Mexico 87185USA Institute for Energy Efficiency University of California Santa BarbaraSanta BarbaraCalifornia 93106USA Center for High Technology Materials University of New-MexicoAlbuquerqueNew Mexico 87106USA State Key Laboratory on Tunable Laser Technology School of Electronic and Information EngineeringHarbin Institute of TechnologyShenzhen 518055China Ayar Labs Santa ClaraCalifornia 95054USA Quintessent Inc.GoletaCalifornia 93117USA

This work compares the four-wave mixing(FWM)effect in epitaxial quantum dot(QD)lasers grown on silicon with quantum well(QW)lasers.A comparison of theory and experiment results shows that the measured FWM coefficient is in good agreement with theoretical *** gain in signal power is higher for p-doped QD lasers than for undoped lasers,despite the same FWM *** to the near-zero linewidth enhancement factor,QD lasers exhibit FWM coefficients and conversion efficiency that are more than one order of magnitude higher than those of QW ***,this leads to self-mode locking in QD *** findings are useful for developing on-chip sources for photonic integrated circuits on silicon.

关键词： lasers quantum mixing

在线全文

学校读者我要写书评

暂无评论

面向不平衡数据集的语音情感识别研究

计算机工程与应用 2024年第4期60卷 122-132页

作者：张会云黄鹤鸣青海师范大学计算机学院西宁810008 藏语智能语音信息处理及应用国家重点实验室西宁810008

样本平衡对机器学习至关重要,在不平衡数据集中,虽然某些类别的样本数量可能很少,但其重要性可能更高。研究了基于不平衡数据集的语音情感识别技术。在不同信噪比下采用不同噪声对不平衡基线数据集EMODB和IEMOCAP进行扩充,构建含噪数据... 详细信息

样本平衡对机器学习至关重要,在不平衡数据集中,虽然某些类别的样本数量可能很少,但其重要性可能更高。研究了基于不平衡数据集的语音情感识别技术。在不同信噪比下采用不同噪声对不平衡基线数据集EMODB和IEMOCAP进行扩充,构建含噪数据集EMODBM和IEMOCAPM;采用SMOTE、RandomOverSampler、SMOTEENN、ADASYN、TomekLinks以及SMOTETomek等6种技术对基线数据集和含噪数据集进行重采样,实现类别样本平衡;在基线数据集和扩充数据集上分别提取21维的低级描述符特征;采用新提出的模型MA-CapsNet验证重采样技术的有效性。实验表明,重采样后各类情感样本基本平衡,使模型的学习更公平、更客观,并且模型在重采样数据集上的鲁棒性更好。

关键词：语音情感识别重采样胶囊网络数据扩充