Influence of whispering gallery modes on light focusing by dielectric circular cylinder

In this paper diffraction of a plane monochromatic TE-wave on an ideal homogeneous dielectric cylinder with several resonant wavelength scale radii is analyzed. Two subsequent near-surface maxima of intensity (two focuses) generated at the cylinder output were found on the optical axis. The first subwavelength focus is formed by one of the whispering gallery mode lobes. Its intensity is 50 times the incident light intensity and its full width at the half maximum of the intensity is equal to 0.155 of the incident wavelength. The second focus is two times less in intensity. Its focal spot known as a photonic nanojet is stretched toward the optical axis. The second focus is formed at a distance about the wavelength from the cylinder surface. Its width is equal to 0.44 of the wavelength and its length is two wavelengths. The abilities of light focusing by a two-layered cylinder and influence of materials absorption on the light focusing are also examined by numerical simulation.     

Numerical simulation of the whispering gallery modes in prolate spheroids

In this paper, we discuss the progress in the numerical simulation of the so-called ‘whispering gallery’ modes (WGMs) occurring inside a prolate spheroidal cavity. These modes are mainly concentrated in a narrow domain along the equatorial line of a spheroid and they are famous because of their extremely high quality factor. The scalar Helmholtz equation provides a sufficient accuracy for WGM simulation and (in a contrary to its vector version) is separable in spheroidal coordinates. However, the numerical simulation of ‘whispering gallery’ phenomena is not straightforward. The separation of variables yields two spheroidal wave ordinary differential equations (ODEs), first only depending on the angular, second on the radial coordinate. Though separated, these equations remain coupled through the separation constant and the eigenfrequency, so that together with the boundary conditions they form a singular self-adjoint two-parameter Sturm–Liouville problem.     

Micro-optical probe model using integrated triple microring resonators for vertical depth identification

Microsystem Technologies - The nonlinear microring resonator system is designed and the triple vertically Panda rings arranged for 3D imaging probe generation. The required whispering gallery modes...     

基于节点状态模型的传输模式自适应选择算法

针对现有的流媒体传输方法不能在高效分发数据的同时保证数据接收质量的问题, 提出了一种传输模式自适应选择算法。该算法首先根据节点状态模型, 将节点状态分为数据接收质量和综合状态值两部分, 对各节点本身稳定状态和节点重要性进行综合判定, 再结合现有数据缓冲模型进行传输模式自适应选择。仿真结果表明, 该算法有效地提高了数据在传输过程中的分发效率, 同时通过对服务器负载一定程度的控制, 在保证数据接收质量的同时, 提高了系统的可扩展性。     

Malicious node prevention and mitigation in MANETs using a hybrid security model

Mobile ad-hoc network (MANET) has got tremendous success and attention due to its self-maintenance and self-configuration properties or behavior. Based on wired and wireless networks, the network topology of MANETs changes rapidly by means of routing attacks. Hence, providing security to this infrastructure-less network is a major issue. The routing protocols for ad-hoc networks cope well with the dynamically changing topology but are not designed to accommodate defense against malicious attacker. Malicious nodes have opportunities to modify or discard routing information or advertise fake routes to attract user data to go through themselves. In this article, we discuss a hybrid technique using anonymity, one-way trapdoor protocol, hash functions, and elliptic curve cryptographic to mitigate attacks in the MANET. The simulation is carried on NS-2 and the simulation results are dissected on different system execution measurements, for example, packet send and received, packet dropped, average network throughput, end-to-end delay, and packet delivery ratio.     

On selecting a low-order model using the dominant mode concept

A technique for selecting a low-order system to approximate a high-order model has been suggested by Davison [2]. A critical component in this technique is the criterion used to select the most appropriate order and modes for the low-order approximation. Criteria have been discussed and analyzed by Mahapatra [5], [6], Rao, Lamba, and Rao [7], and Elrazaz and Sinha [3]. In this note we overcome deficiencies in the criteria that have been proposed and we introduce a new criterion which is rigorously justified. The criterion we suggest is also applicable when eigenvalues of the system are nonreal.     

利用置信规则库构建WSN节点故障检测模型

在无线传感器网络(wireless sensor network, WSN)节点故障检测领域的研究过程中,故障检测准确率会受节点数据的不确定性和专家知识模糊性的影响。针对这一问题,本文提出了一种基于置信规则库(belief rule base, BRB)的WSN节点故障检测方法。首先,根据WSN工作原理及节点工作特性描述WSN节点故障检测过程;然后,从空间和时间2个维度对节点数据提取特征,建立基于空间和时间相关性的WSN节点故障检测模型;最后,利用Intel Lab Data无线传感器数据集进行案例研究以验证模型的有效性。结果证明,本文方法能够统筹利用专家知识和节点数据实现WSN节点故障检测。     

Accurate reconstruction of 3D model of a human face using structured light

An automated system for the reconstruction of textured 3D models of human faces has been developed. 3D information is read using the structured lighting used in calibrated projector-camera system. The accuracy of 3D reconstruction is studied experimentally. De Wansa Wickramarante Viktor Klementovich. Born 1983. Graduated from the Moscow State Institute of Radioengineering, Electronics, and Automation (Technical University). Post graduate student of MSIREA. Scientific interests: pattern recognition, biometry, 3D scanners. Author of 5 papers. Awarded the 3 degree diploma at the All-Russian Conference MMRO-13; the incentive diploma at the International Conference ROAI-8-2007. Vladimir Vasilievich Ryazanov. Vladimir V. Ryazanov gratuated from the Moscow Institute of Physical Technology in 1973 and the post-graduate courses at the Computer Center, Academy of Sciences, USSR, in 1976. Received Ph.D. in 1977 (“Computer Science”) and Professor degree in 1994 (“Applications of Mathematical Methods, Mathematical Modeling and Computers in Scientific Investigations”). At the Dorodnicin Computer Center of the Russian Academy of Sciences since 1976. Head of the Situations Recognition Sector in the Department of Recognition Problems and Combinatorial Analysis. Author of approximately 150 papers. Scientific interests: data mining, mathematical models of pattern recognition, classification and forecasting, optimization of recognition and classification models, learning, synthesis of optimal collective solutions in the classification problem, creation of intelligent program systems for data analysis and recognition, and practical applications in technology, medicine, industry. Alexander Vinogradov. Born in 1951. Graduate from Moscow Institute of Physics and Technology in 1974. Kandidat degree in mathematical cybernetics, 1978. Spere of main interests—geometric and algebraic methods in data analysis and image processing. Author of about 50 scientific publications.     

Terrain surface classification with a control mode update rule using a 2D laser stripe-based structured light sensor

It is necessary for autonomous ground vehicles operating on outdoor terrains to identify and adapt to different terrains in order to improve their mobility and safety. This work presents a classification scheme to identify outdoor terrains and an update rule to reduce the possibility of implementing control modes based on classification inaccuracies. A laser stripe-based structured light sensor, which has a laser and infrared camera component, is used to sense terrains directly in front of the vehicle (). Use of this infrared vision system allows sensing at night, without external lighting, unlike many previous vision-based approaches that rely on stand-alone cameras. Also, unlike many previous results, the classification algorithm presented here does not rely on measures of color, which are subject to illumination and weather conditions. Instead, the method presented here relies on spatial relationships which are captured in two quantities: spatial frequency from range data and texture from camera data. The presented terrain classification scheme uses a probabilistic neural network classifier to exploit the spatial differences in four terrains: asphalt, grass, gravel and sand. This approach yields empirical results that report a greater than 97% classification accuracy when both spatial frequency and texture features are used. Color robustness and lighting robustness is then shown through additional experiments. Furthermore, instead of implementing control modes directly from the identified terrains, it is shown that the use of current and past terrain detections allows for the rejection of misclassifications with minimal effect on the rate at which a new control mode can be implemented.     

Electrostatic correction of structural imperfections present in a microring gyroscope

This paper describes a procedure for identifying mass and stiffness imperfections present in a microring gyroscope. In general mass and stiffness imperfections will be present as a result of fabrication variances and will contribute to mistuning of the gyroscope. Both mass and stiffness imperfections are treated as perturbations of the ideal isotropic mass and stiffness. The mass and stiffness perturbations are combined to form a structural imperfection, which is shown to be determinable from Nyquist plots of the frequency response functions. An analysis of electrostatic "tuning" is presented and demonstrates that the nonlinear negative spring component produced from a particular arrangement of capacitive electrodes is capable of removing such structural imperfections. If uncorrected the structural imperfections would otherwise result in anisoinertia and anisoelasticity. A comparison between the theoretically predicted tuning voltage and the experimentally derived value is made and shown to be in agreement. The major advantage of electrostatic tuning is that it may be implemented on-chip during operation thus providing active tuning. This is in contrast to the trimming techniques employing laser ablation or focussed ion beam, which may only be done prepackaging.     

Comment on "On selecting a low-order model using the dominant mode concept"

In the above-mentioned paper [1], the authors presented a criterion for selecting the order of a low-order system to approximate a high-order model. Their criterion is very similar to what has been presented before in [2] and [3]. The authors claimed that the extension to handle systems with complex eigenvalues [3] is incorrect. Also, they used examples to show the superiority of their criterion. In this comment, it will be demonstrated that their claims are not absolutely correct.     

Design of first- and second-order sliding mode observers for induction motors using a stator-flux model

We extend current research in the area of ‘sensorless’ control of induction motors by presenting two observers based on first- and second-order sliding mode control theories for the simultaneous estimation of flux and speed. We base the observers on the stator-flux model of the motor instead of the usual rotor-flux model mainly because of the uncertain rotor resistance that plays a significant role in the latter. By designing the observers as if they are sliding mode controllers, we lend the properties of parameter insensitive closed-loop dynamics and finite time convergence to the stator flux and speed estimation schemes. We also present simulation and experimental results to validate the operation of the observers.     

减小金属筒形谐振子振型偏移角的方法

金属筒形谐振子的频率裂解、阻尼不均匀会使谐振子的振型发生偏移,导致激励和检测偏离波腹波节点,影响陀螺的输出零位、零偏稳定性等性能,因而减小谐振子的振型偏移角是提高金属筒形谐振陀螺性能的关键。在分析了谐振子加工误差对振型偏移角的影响的基础上,提出了基于前馈和反馈控制的振型偏移角的校正方法,并分析了其优缺点。实验结果表明:前馈控制方案使谐振子振型的偏移角减小0. 8°～0. 9°,反馈控制方案使偏移角减小0. 6°～0. 7°,为谐振子的修调和测控电路的设计提供了参考。     

EEG-based classification of emotions using empirical mode decomposition and autoregressive model

Multimedia Tools and Applications - Emotion can be classified based on 2-dimensional valence-arousal model which includes four categories of emotional states, such as high arousal high valence, low...     

Independently controllable dual‐band filter using single quad‐mode silver‐loaded dielectric resonator

This article proposes a novel bandpass filter with two controllable passbands using a single quad‐mode silver‐loaded dielectric resonator (DR). The silver plane is inserted in the middle of the cubic DR and two degenerate pairs are used to build the two passbands. Because of the distinct E‐field distributions, the silver plane has significant effect on the degenerate pair (TE^x₁₁₂ and TE^y₁₁₂), whereas another one (TE^x₁₁₁ and TE^y₁₁₁) remains unchanged. With the aid of the silver plane, both center frequencies and bandwidths of the two bands can be controlled independently. To verify the proposed idea, a prototype dual‐band BPF is designed and fabricated. Good agreement between simulated and measured results can be observed.     

Independently controllable dual‐band microstrip bandpass filter using quadruple‐mode stub‐loaded resonator

In this article, a quadruple‐mode stub‐loaded resonator (QM‐SLR) is introduced and its four modes are excited using a simple approach, which can provide a dual‐band behavior. By changing the length of the loaded stubs, independently tunable transmission characteristics of the proposed quadruple‐mode stub‐loaded resonator were extensively described for filter design. Moreover, microwave varactors were adopted to represent the length variation of the loaded stubs for the dual‐band tunability. The equivalent circuit modeling of the open stub with microwave varactor was given and discussed. Then, adopting the compact quadruple‐mode stub‐loaded resonator with three varactors, an independently controllable dual‐band bandpass filter (BPF) was designed, analyzed, and fabricated. Its separated bandwidths and transmission zeros can be tuned independently by changing the applying voltage of the microwave varactors. A good agreement between simulated and measured results verified the design methodology. The proposed filter possesses compact size, simple structure, and excellent dual‐band performances. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:602–608, 2016.     

Green logistic vehicle routing problem: Routing light delivery vehicles in urban areas using a neuro-fuzzy model

Today’s growth in the level of traffic in cities is leading to both congestion and environmental pollution (exhaust emissions and noise), as well as increased costs. Traffic congestion makes cities less pleasant places to live in, a particular problem being the negative impact on health as a result of increased exhaust emissions. In addition to these emissions, another major effect of transport which can lead to serious health problems is noise (EEA, 2013a, 2013b). There is a strong tendency in the world towards the development of “clean” motor vehicles that do not pollute the environment, that is, that do not emit harmful substances in their exhaust fumes and which create less noise without causing other types of pollution. The growth in the influence of transport on the environment has resulted in planners formulating procedures which take into account the effect of traffic on the quality of life in urban areas. This paper presents a model for the routing of light delivery vehicles by logistics operators. The model presented takes into account the fact that logistics operators have a limited number of environmentally friendly vehicles (EFV) available to them. When defining a route, EFV vehicles and environmentally unfriendly vehicles (EUV) are considered separately. For solving the problem of routing in the model, an adaptive neural network was used which was trained by a simulated annealing algorithm. An adaptive neural network was used for assessing the performance of the network branches. The input parameters of the neural network were the logistics operating costs and environmental parameters (exhaust emissions and noise) for the given vehicle route. Each of the input parameters of the neural network was thoroughly examined. The input parameters were broken down into elements which further describe the state of the environment, noise and logistics operating costs. After obtaining the performance of the network links for calculating the route for EFV and EUV vehicles a modified Clark–Wright algorithm was used. The proposed model was tested on a network which simulates the conditions in the very centre of Belgrade. All of the input parameters of the model were obtained on the basis of 40 automatic measuring stations for monitoring the air quality (SEA, 2012).     

A compact UWB bandpass filter with a notched band using a multistubs loaded resonator

A novel multistubs loaded resonator (MSLR) is proposed in this article, which is constructed by several open‐ and short‐circuited stubs. The analysis shows that it is characterized by four resonant modes. Then, the MSLR is applied in the design of a compact ultra‐wideband (UWB) bandpass filter. The measured results show that its 3dB bandwidth can cover [3.0, 11.5] GHz, that is, 3 dB fractional bandwidth is 117%, and the return loss within the passband is greater than 15 dB. Especially, the roll‐off rate is higher than 33 dB/GHz and more than 40 dB harmonic suppression can be achieved up to 17 GHz. In order to suppress the interference of some undesired narrowband signal such as wireless local‐area network (WLAN) radio signal, a notched band is created for the UWB bandpass filter, which is realized by forming one stepped slot on each of the feedlines, respectively. The measured results show that a notched band with 2.01% fractional bandwidth at the center frequency of 5.85 GHz can be achieved and its suppression is about ?19 dB.     

Retraction Note: A selective excitation mode design for a wider high-to-low frequencies tunable capacitive MEMS resonator

Microsystem Technologies -