Recent Advance in Synaptic Plasticity Modulation Techniques for Neuromorphic Applications

Manipulating the expression of synaptic plasticity of neuromorphic devices provides fascinating opportunities to develop hardware platforms for artifi-cial intelligence.However,great efforts have been devoted to exploring biomimetic mechanisms of plasticity simulation in the last few years.Recent progress in various plasticity modulation techniques has pushed the research of synaptic electronics from static plasticity simulation to dynamic plasticity modulation,improving the accuracy of neuromorphic computing and providing strategies for implementing neuromorphic sensing functions.Herein,several fascinating strategies for synap-tic plasticity modulation through chemical techniques,device structure design,and physical signal sensing are reviewed.For chemical techniques,the underly-ing mechanisms for the modification of functional materials were clarified and its effect on the expression of synaptic plasticity was also highlighted.Based on device structure design,the reconfigurable operation of neuromorphic devices was well demonstrated to achieve programmable neuromorphic functions.Besides,integrating the sensory units with neuromorphic processing circuits paved a new way to achieve human-like intelligent perception under the modulation of physical signals such as light,strain,and temperature.Finally,considering that the relevant technology is still in the basic exploration stage,some prospects or development suggestions are put forward to promote the development of neuromorphic devices.

Study on Temperature Modulation Techniques for Micro Gas Sensors

The sensitivity and selectivity of gas sensors are related with not only sensing material,but also their operating temperatures.Applying this property,temperature modulation technique has been proposed to improve the selectivity of gas sensors.With a newly developed alumina based micro gas sensor,the sensitivity to CO and CH_4 at different operating temperatures was investigated.By modulating the temperature of the sensor at pulse and sine wave modes with different frequencies and amplitudes,the dynamic responses of the sensor were measured and processed.Results show that the modulating waveshape plays an important role in the improvement of selectivity,while the influence of frequency is small at the suitable sampling frequency in the range of 25 mHz～200 mHz.

Classification of Multi-User Chirp Modulation Signals Using Wavelet Higher-Order-Statistics Features and Artificial Intelligence Techniques

Higher order statistical features have been recently proved to be very efficient in the classification of wideband communications and radar signals with great accuracy. On the other hand, the denoising properties of the wavelet transform make WT an efficient signal processing tool in noisy environments. A novel technique for the classification of multi-user chirp modulation signals is presented in this paper. A combination of the higher order moments and cumulants of the wavelet coefficients as well as the peaks of the bispectrum and its bi-frequencies are proposed as effective features. Different types of artificial intelligence based classifiers and clustering techniques are used to identify the chirp signals of the different users. In particular, neural networks (NN), maximum likelihood (ML), k-nearest neighbor (KNN) and support vector machine (SVMs) classifiers as well as fuzzy c-means (FCM) and fuzzy k-means (FKM) clustering techniques are tested. The Simulation results show that the proposed technique is able to efficiently classify the different chirp signals in additive white Gaussian noise (AWGN) channels with high accuracy. It is shown that the NN classifier outperforms other classifiers. Also, the simulations prove that the classification based on features extracted from wavelet transform results in more accurate results than that using features directly extracted from the chirp signals, especially at low values of signal-to-noise ratios.

Spatial Modulation-Based Ambient Backscatter: Bringing Energy Self-Sustainability to Massive Internet of Everything in 6G

Ambient backscatter communications(AmBC)is a new ultra-low-power communication paradigm,which holds great promise for enabling energy self-sustainability(ESS)to massive data-intensive Internet of Everything(IoE)devices in 6G.Recent advances improve throughput and reliability by adopting multiple-antenna techniques in conventional backscatter communications(CoBC),but they cannot be directly applied to AmBC devices for high spectral and energy efficiency due to the unknown RF source and minimalist design in backscatter tag.To fill this gap,we propose SM-backscatter,an AmBC-compatible system that greatly improves spectral efficiency while maintaining ultra-low-power consumption.Specifically,the SM-backscatter consists of two novel components:i)a multiple-antenna backscatter tag that adopts spatial modulation(SM),and ii)a joint detection algorithm that detects both backscatter and source signals.To this end,we theoretically obtain an optimal detector and propose two suboptimal detectors with low complexity.Subsequently,we derive the BERs of both the backscatter and source signals to analyze the communication performance by introducing a two-step algorithm.Our simulation results verify the correctness of the theoretical analysis and indicate that our system can significantly outperform existing solutions.

Feasibility of the partial-single arc technique in RapidArc planning for prostate cancer treatment

The volumetric modulated arc therapy(VMAT)technique,in the form of RapidArc,is widely used to treat prostate cancer.The full-single arc(f-SA)technique in RapidArc planning for prostate cancer treatment provides efficient treatment,but it also delivers a higher radiation dose to the rectum.This study aimed to compare the dosimetric results from the new partial-single arc(p-SA)technique with those from the f-SA technique in RapidArc planning for prostate cancer treatment.In this study,10 patients with lowrisk prostate cancer were selected.For each patient,two sets of RapidArc plans(f-SA and p-SA)were created in the Eclipse treatment planning system.The f-SA plan was created using one full arc,and the p-SA plan was created using planning parameters identical to those of the f-SA plan but with anterior and posterior avoidance sectors.Various dosimetric parameters of the f-SA and p-SA plans were evaluated and compared for the same target coverage and identical plan optimization parameters.The f-SA and p-SA plans showed an average difference of±1%for the doses to the planning target volume(PTV),and there were no clear differences in dose homogeneity or plan conformity.In comparison to the f-SA technique,the p-SA technique reduced the doses to the rectum by approximately 6.1%to 21.2%,to the bladder by approximately 10.3%to 29.5%,and to the penile bulb by approximately 2.2%.In contrast,the dose to the femoral heads,the integral dose,and the number of monitor units were higher in the p-SA plans by approximately 34.4%,7.7%,and 9.2%,respectively.In conclusion,it is feasible to use the p-SA technique for RapidArc planning for prostate cancer treatment.For the same PTV coverage and identical plan optimization parameters,the p-SA technique is better in sparing the rectum and bladder without compromising plan conformity or target homogeneity when compared to the f-SA technique.

Performance Evaluation of Diversity Techniques in IDMA Scheme for Next Generation (4G) in Underwater Wireless Communication

This paper provides a review on the diversity techniques of IDMA (Interleave Division Multiple Access) technology in underwater wireless IDMA employs interleavers as the only means in order to distinguish the users. This paper provides a comprehensive study of diversity techniques in IDMA scheme to mitigate the fading issue. In this paper, we compare the different generation diversity techniques in IDMA scheme on computational complexity, bit error rate and memory requirement. Recent advancement in underwater communication is modulation techniques, multiplexing techniques and multiple access techniques. Underwater communication channel is characterized.

A study on coupling technique and implementation of the wave-circulation coupled model

The coupler is fundamental for a coupled model to realize complex interactions among component models.This paper focuses on the coupling process of Wave-Circulation(W-C) coupled model which consists of MASNUM(key laboratory of marine science and numerical modeling wave model)and POM(Princeton Ocean Model).The current coupling module of this coupled model is based on the inefficient I/O file,which has already become a performance bottleneck especially when the coupled model utilizes a large number of processes.To improve the performance of the W-C model,a flexible coupling module based on the model coupling toolkit(MCT) is designed and implemented to replace the current I/O file coupling module in the coupled model.Empirical studies that we have carried out demonstrate that our online coupling module can dramatically improve the parallel performance of the coupled model.The online coupling module outperforms the I/O file coupling module.When processes increase to 96,the whole process of EXP-C takes only 695.8 seconds,which is only 58.8%of the execution time of EXP-F.Based on our experiments under 2D Parallel Decomposition(2DPD),we suggest setting parallel decomposition strategies automatically to component models in order to achieve high parallel efficiency.

High-speed directly modulated distributed feedback laser based on detuned loading and photon-photon resonance effect

A monolithic integrated two-section distributed feedback(TS-DFB)semiconductor laser for high-speed direct modulation is proposed and analyzed theoretically.The grating structure of the TS-DFB laser is designed by the reconstructionequivalent-chirp(REC)technique,which can reduce the manufacturing cost and difficulty,and achieve high wavelength controlling accuracy.The detuned loading effect and the photon-photon resonance(PPR)effect are utilized to enhance the modulation bandwidth of the TS-DFB laser,exceeding 37 GHz,while that of the conventional one-section DFB laser is only 16 GHz.When the bit rate of the non-return-to-zero(NRZ)signal reaches 55 Gb/s,a clear eye diagram with large opening can still be obtained.These results show that the proposed method can enhance the modulation bandwidth of DFB laser significantly.

水下控制系统测试台设计及试验研究

针对水下控制模块测试需求,文中设计了一种多功能水下控制模块测试台。水下控制模块(SCM)作为水下生产系统的核心部分,其安装成本高、难度大,且不便于在水下维护,因此,在其入水前必须对其进行严格的功能测试,确保在水下工作的可靠性。首先,对关于水下控制模块测试的相关技术和标准进行研究,得出水下控制模块在测试台上进行的测试主要包括内部静水压力测试、液压内部泄漏测试和液压系统功能测试;然后,基于被测水下控制模块的性能指标对测试台的机械结构和液压系统进行了设计,并对上述测试内容的测试方法进行了研究;最后,通过试验对测试台的测试功能进行验证。文中研究为我国设计和研制国产水下生产系统测试设备提供了宝贵经验。

45°双驱动弹光调制高速椭偏测量方法

为解决传统机械旋转补偿器型椭偏仪测量速度较慢问题,提出一种电驱动的双弹光调制的高速椭偏测量方法。通过理论分析并仿真研究45°双驱动弹光调制器工作在纯行波模式下的调制方式。结果发现,当双驱动弹光调制器工作在纯行波模式可实现快轴方向的高速周期性旋转,且相位延迟量为常量。结合椭偏原理,详细研究一种基于双驱动弹光调制的高速椭偏测量理论模型,结果表明,该模型光学周期<10μs,用于实际可真正实现超高速偏光调制。通过研究,有望解决半导体集成电路,微电子和光伏电池等生产过程中薄膜超高速检测难题,对薄膜在线检测、瞬态变化测量具有重要意义和学术价值。

煤矿井下钻探远程支持技术及其应用前瞻

为提升钻探工艺技术信息化程度,进一步提高业务水平、服务效率和企业管理水平,提出以煤矿井下钻探技术为理论支撑,基于网络有线、无线传输等建构煤矿井下钻探技术远程支持服务体系,开发出基于该远程支持服务体系的煤矿井下钻探技术远程服务平台系统。平台的功能实现由5个模块组成,包括慕课视频点播模块、远程故障维修模块、远程技术支持模块、消息推送模块、信息安全模块。通过基于“端对端”的钻探技术标准化培训平台和基于浏览器/B/S架构的钻探技术装备远程指导系统,为施工现场提供了故障诊断、技术查询、可视化维修等技术支持,使煤矿井下钻探技术服务更高效、更及时,有力提高了服务效率,降低了人工成本,更有效地提升了钻探工艺服务信息化程度,为钻探设备的智能化发展赋能。

基于信息管理系统为基础的中医护理方案实施与管理模块的构建和应用

目的:基于信息管理系统为基础,开发“中医护理方案实施与管理模块”,促进中医护理质量的提升。方法:基于行动研究法,开发“中医护理方案实施与管理模块”。以脑梗死病人为例,选取模块应用前后各85例病人的护理表单数据进行分析,比较应用前后的中医护理成效及中医护理质量。结果:基于信息化的中医护理方案模块应用后在中医护理操作次数、中医操作例数方面高于应用前,护士录入病历的工作时间短于应用前,护士的满意度高于应用前,病人的护理满意度高于应用前(P<0.05)。在护理文书合格率、护理查房合格率、护理技术开展率、健康教育覆盖率等方面均高于应用前(P<0.05)。结论:基于信息化的中医护理方案模块能够明显提升临床中医护理操作项目数量,提高护士的工作效率以及对病人的护理质量,改善病人的护理满意度,创新护理管理模式。

不同扫描体位和定位像方向对单髋关节CT图像及辐射剂量影响

在自动管电流调制(ATCM)技术下,探讨不同扫描体位及定位像方向在单髋关节CT中对图像和辐射剂量的影响。将120例进行单髋关节CT检查患者随机分为4组。A组常规扫描以身体正中线作矢状垂直定位线,定位像前后位+左侧位,扫描视野选择大体型,其余三组以患侧髋关节为中心的等中心扫描,扫描视野均选择小体型,其中B组定位像采用前后位+X线管靠近身体长轴的侧位像;C组采用前后位+X线管远离身体长轴的侧位像;D组仅采用前后位。比较4组患者的容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP),同时测量并计算图像客观噪声、信噪比(SNR)、对比信噪比(CNR),评估图像主观噪声、条纹伪影及诊断信心度。结果显示4组间客观噪声、SNR、CNR、CTDIvol、DLP的差异具有统计学意义(P<0.01),组间比较显示,C与D组各项的差异无统计学意义(均P>0.05),其余组间比较各项的差异具有统计学意义(P<0.01),C、D组辐射剂量整体降低16%~35%;4组图像在主观噪声、条纹伪影及诊断信心度上的差异无统计学意义(P>0.05)。在基于最后一次采集定位像信息的ATCM系统中进行单髋关节CT扫描时,推荐等中心扫描方案同时选择小体型扫描视野,将前后定位像或选择X线管远离身体长轴的侧位定位像作为最后一次执行计划,能保证图像质量同时进一步优化辐射剂量。

A Hybrid Cybersecurity Algorithm for Digital Image Transmission over Advanced Communication Channel Models

The efficient transmission of images,which plays a large role inwireless communication systems,poses a significant challenge in the growth of multimedia technology.High-quality images require well-tuned communication standards.The Single Carrier Frequency Division Multiple Access(SC-FDMA)is adopted for broadband wireless communications,because of its low sensitivity to carrier frequency offsets and low Peak-to-Average Power Ratio(PAPR).Data transmission through open-channel networks requires much concentration on security,reliability,and integrity.The data need a space away fromunauthorized access,modification,or deletion.These requirements are to be fulfilled by digital image watermarking and encryption.This paper ismainly concerned with secure image communication over the wireless SC-FDMA systemas an adopted communication standard.It introduces a robust image communication framework over SC-FDMA that comprises digital image watermarking and encryption to improve image security,while maintaining a high-quality reconstruction of images at the receiver side.The proposed framework allows image watermarking based on the Discrete Cosine Transform(DCT)merged with the Singular Value Decomposition(SVD)in the so-called DCT-SVD watermarking.In addition,image encryption is implemented based on chaos and DNA encoding.The encrypted watermarked images are then transmitted through the wireless SC-FDMA system.The linearMinimumMean Square Error(MMSE)equalizer is investigated in this paper to mitigate the effect of channel fading and noise on the transmitted images.Two subcarrier mapping schemes,namely localized and interleaved schemes,are compared in this paper.The study depends on different channelmodels,namely PedestrianAandVehicularA,with a modulation technique namedQuadratureAmplitude Modulation(QAM).Extensive simulation experiments are conducted and introduced in this paper for efficient transmission of encrypted watermarked images.In addition,different variants of SC-FDMA based on the Discrete Wavelet Transform(DWT),Discrete Cosine Transform(DCT),and Fast Fourier Transform(FFT)are considered and compared for the image communication task.The simulation results and comparison demonstrate clearly that DWT-SC-FDMAis better suited to the transmission of the digital images in the case of PedestrianAchannels,while the DCT-SC-FDMA is better suited to the transmission of the digital images in the case of Vehicular A channels.

光通信中几何成形的高阶调制技术研究

从信息论诞生以来,如何减小系统容量和香农极限之间的差距一直是通信领域的一个焦点。几何成形技术作为一种典型的调制格式优化技术,在不引入任何冗余的情况下,通过把均匀分布发射功率相等的星座图设置为概率相等、间距不均匀的星座图,使得信号符合服从于目标信道的最佳分布,从而使系统传输速率更接近香农极限,从而提升系统的信道容量。回顾了近年来几何成形的高阶调制技术在光纤通信领域的发展历程,梳理了近年来几何成形技术在光纤通信领域的相关研究。最后,结合当前的研究现状,对未来几何成形的调制技术提出了研究方向和建议。

高可信度音爆预测平台设计研究

分析了高可信度音爆数值预测平台在超音速民机低音爆设计中的应用现状及需求,重点阐述了某高可信度音爆预测平台的集成框架、应用流程、数据存储和交换、以及数据可视化等方面的设计策略,并提出了构建方案,为工程一线设计人员研制了友好易用的音爆预测软件。软件以音爆预测问题的可视化交互定义为基础,采用混合程序策略,可实现音爆信号的近场预测、远场预测及主观响应评价。同时,软件具有良好的开放性及兼容性,可灵活集成先进的音爆预测程序,快速完成音爆数值预测的最新研究成果的应用转化,为超音速民机低音爆设计研制提供技术和工具支撑。

基于四开关升降压变换器的三模式设计

四开关升降压(four-switch buck-boost,FSBB)变换器具有宽范围电压输入的优势。由于开关频率高,变换器工作在降压(Buck)模式或者升压(Boost)模式下效率最高,但是在输入电压改变时,两种模式之间的切换会产生转换盲区。文中采用脉宽调制(pulse width modulation,PWM)技术,对传统的两模式控制方法加以改进,设计加入了第三种升降压(Buck-Boost)模式进行平滑过渡。实验结果表明,瞬时改变输入电压时,输出电压波形波动小,证明新的控制方法有效地解决了转换盲区问题,保证了输出电压的稳定。

A Novel Technique of Measuring SOA Differential Carrier Lifetime and a -Factor Using SOA Optical Modulation Response

We demonstrate a new technique of measuring differential carrier lifetime and linewidth enhancement factor in a semiconductor optical amplifier. In our method, the optical responses and fiber transfer functions of a self-gain modulated SOA are measured and, from these, values of carrier lifetimes and linewidth enhancement factors are determined for various SOA input optical powers.

铅门跟随技术和铅门固定技术在宫颈癌调强放射治疗中的剂量学比较

目的探究铅门跟随技术(Jaw Tracking Technique,JTT)和铅门固定技术(Static Jaw Technique,SJT)在宫颈癌调强放疗中剂量学的差异。方法选取25例宫颈癌患者,对每例患者分别在3种治疗模式[动态调强适形放射治疗(Dynamic IntensityModulatedRadiotherapy,dIMRT)、静态IMRT(StaticIMRT,sIMRT)、容积旋转调强放疗(Volumetric Modulated Arc Therapy,VMAT)]下采用两种铅门技术共设计出75组治疗计划,在满足靶区处方总剂量为50Gy下,比较两组治疗计划靶区及危及器官(Organs at Risk,OAR)的剂量分布、机器跳数、出束时间。结果3种治疗技术的治疗计划靶区剂量均能满足临床处方剂量要求,3种治疗模式中JTT计划与SJT计划的计划靶区(Planning Target Volume,PTV)适形度指数和均匀度指数比较,差异均无统计学意义。dIMRT组JTT计划的OAR剂量除膀胱V_(50)其他参数均显著低于SJT计划(P<0.05)。sIMRT组的JTT计划的OAR剂量除小肠V_(50)其他参数均显著低于SJT计划(P<0.05)。VMAT组OAR剂量两种计划比较差异均无统计学意义(P>0.05)。dIMRT组和sIMRT组JTT计划的机器跳数显著高于SJT计划,当剂量率相同时dIMRT组JTT计划的出束时间较SJT计划显著增加(P<0.05),而sIMRT组JTT计划的出束时间显著短于SJT(P<0.05),VMAT组JTT计划和SJT计划的机器跳数比较差异无统计学意义(P>0.05),但JTT计划的出束时间显著高于SJT计划(P<0.05)。结论宫颈癌患者调强放疗中运用JTT和SJT对靶区和OAR受量均能满足临床要求,但dIMRT和sIMRT组JTT能更好地降低OAR受量,减少并发症的发生。VMAT组JTT技术则无明显优势。