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2020

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Articles 2731 - 2760 of 10642

Full-Text Articles in Engineering

Nonlinear H∞ Control For Marine Speed With Parameter Perturbation And Ambient Interference, Yupeng Yuan, Zhang Meng, Xinping Yan, Guo Bo, Jianglong Wan Aug 2020

Nonlinear H∞ Control For Marine Speed With Parameter Perturbation And Ambient Interference, Yupeng Yuan, Zhang Meng, Xinping Yan, Guo Bo, Jianglong Wan

Journal of System Simulation

Abstract: In order to improve the automation level and enhance the navigation safety of ships, stable control for ship speed is very important. Good control effect is difficult to obtain based on the conventional control method since the marine speed control system is a time-varying parameters and nonlinear complicated propulsion system. The uncertainty of the system parameters and the effect of environment such as winds, waves and currents were considered adequately in ship motion mathematical model with disturbing force. The mathematic model was linearized accurately with the differential geometry method. Then the nonlinear H∞ controller was designed according to …

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Simulation And Analysis Of Airborne Phase Array Weather Radar Reflectivity, Wang Lei, Chaopeng Yu, Liu Ping Aug 2020

Simulation And Analysis Of Airborne Phase Array Weather Radar Reflectivity, Wang Lei, Chaopeng Yu, Liu Ping

Journal of System Simulation

Abstract: The relation between radar parameters such as radar gain, beam width and impulse width and radar reflectivity based on the parameters of airborne phase array weather radar at X-band were proposed. Combined with weather radar equation correction and flight parameters, horizontal sector scanning and vertical sector scanning reflectivity data of airborne phased array weather radar were simulated based on new generation weather radar (CINRAD/SA) reflectivity. The results show that along the radial direction, the distance resolution of airborne phase array radar used impulse compress technology is higher than new generation weather radar and along the shear direction, because antenna …

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Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza Aug 2020

Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza

Faculty Publications

The electromagnetic characteristics of the soil are discussed in this chapter. The characteristics of porous bedrock, soil medium, and impacts of rain attenuations are also presented. The models of dielectric soil properties are studied with a rigorous focus on the constitutive parameters of subsurface soil medium. Moreover, the permittivity and wavenumber in soil are explained. In addition, the frequency-dependent dielectric properties such as dispersion in soil, absorption characteristic, and penetration depth versus frequency are reviewed. Furthermore, the effective permittivity of soil–water mixture for through-the soil-propagation mechanism is analyzed thoroughly.

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Wireless Underground Channel Modeling, Abdul Salam, Usman Raza Aug 2020

Wireless Underground Channel Modeling, Abdul Salam, Usman Raza

Faculty Publications

A comprehensive treatment of wireless underground channel modeling is presented in this chapter. The impacts of the soil on bandwidth and path loss are analyzed. A mechanism for the UG channel sounding and multipath characteristics analysis is discussed. Moreover, novel time-domain impulse response model for WUC is reviewed with the explanation of model parameters and statistics. Furthermore, different types of the through-the-soil wireless communications are surveyed. Finally, the chapter concludes with discussion of the UG wireless statistical model and path loss model for through-the-soil wireless communications in decision agriculture. The model presented in this chapter is also validated with empirical …

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Signals In The Soil: An Introduction To Wireless Underground Communications, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: An Introduction To Wireless Underground Communications, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well.

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Signals In The Soil: Underground Antennas, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: Underground Antennas, Abdul Salam, Usman Raza

Faculty Publications

Antenna is a major design component of Internet of Underground Things (IOUT) communication system. The use of antenna, in IOUT, differs from traditional communication in that it is buried in the soil. Therefore, one of the main challenges, in IOUT applications, is to establish a reliable communication. To that end, there is a need of designing an underground-specific antenna. Three major factors that can impact the performance of a buried antenna are: (1) effect of high soil permittivity changes the wavelength of EM waves, (2) variations in soil moisture with time affecting the permittivity of the soil, and (3) difference …

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Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza Aug 2020

Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza

Faculty Publications

This chapter presents a framework for adaptive beamforming in underground communication. The wireless propagation is thoroughly analyzed to develop a model using the soil moisture as an input parameter to provide feedback mechanism while enhancing the system performance. The working of array element in the soil is analyzed. Moreover, the effect of soil texture and soil moisture on the resonant frequency and return loss is studied in detail. The wave refraction from the soil–air interface highly degrades the performance of the system. Furthermore, to beam steering is done to achieve high gain for lateral component improving the UG communication. The …

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Current Advances In Internet Of Underground Things, Abdul Salam, Usman Raza Aug 2020

Current Advances In Internet Of Underground Things, Abdul Salam, Usman Raza

Faculty Publications

The latest developments in Internet of Underground Things are covered in this chapter. First, the IOUT Architecture is discussed followed by the explanation of the challenges being faced in this paradigm. Moreover, a comprehensive coverage of the different IOUT components is presented that includes communications, sensing, and system integration with the cloud. An in-depth coverage of the applications of the IOUT in various disciplines is also surveyed. These applications include areas such as decision agriculture, pipeline monitoring, border control, and oil wells.

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Soil Moisture And Permittivity Estimation, Abdul Salam, Usman Raza Aug 2020

Soil Moisture And Permittivity Estimation, Abdul Salam, Usman Raza

Faculty Publications

The soil moisture and permittivity estimation is vital for the success of the variable rate approaches in the field of the decision agriculture. In this chapter, the development of a novel permittivity estimation and soil moisture sensing approach is presented. The empirical setup and experimental methodology for the power delay measurements used in model are introduced. Moreover, the performance analysis is explained that includes the model validation and error analysis. The transfer functions are reported as well for soil moisture and permittivity estimation. Furthermore, the potential applications of the developed approach in different disciplines are also examined.

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Signals In The Soil: Subsurface Sensing, Abdul Salam, Usman Raza Aug 2020

Signals In The Soil: Subsurface Sensing, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, novel subsurface soil sensing approaches are presented for monitoring and real-time decision support system applications. The methods, materials, and operational feasibility aspects of soil sensors are explored. The soil sensing techniques covered in this chapter include aerial sensing, in-situ, proximal sensing, and remote sensing. The underlying mechanism used for sensing is also examined as well. The sensor selection and calibration techniques are described in detail. The chapter concludes with discussion of soil sensing challenges.

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Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the latest developments in the field of decision agriculture are discussed. The practice of management zones in digital agriculture is described for efficient and smart faming. Accordingly, the methodology for delineating management zones is presented. Modeling of decision support systems is explained along with discussion of the issues and challenges in this area. Moreover, the precision agriculture technology is also considered. Moreover, the chapter surveys the state of the decision agriculture technologies in the countries such as Bulgaria, Denmark, France, Israel, Malaysia, Pakistan, United Kingdom, Ukraine, and Sweden. Finally, different field factors such as GPS accuracy and …

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Autonomous Irrigation Management In Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Autonomous Irrigation Management In Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the important application of autonomous irrigation management in the field decision agriculture is discussed. The different types of sensor-guided irrigation systems are presented that includes center pivot systems and drip irrigation systems. Their sensing and actuator components are with detailed focus on real-time decision-making and integration to the cloud. This chapter also presents irrigation control systems which takes, as an input, soil moisture and temperature from IOUT and weather data from Internet and communicate with center pivot based irrigation systems. Moreover, the system architecture is explored where development of the nodes including sensing and actuators is presented. …

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Underground Wireless Channel Bandwidth And Capacity, Abdul Salam, Usman Raza Aug 2020

Underground Wireless Channel Bandwidth And Capacity, Abdul Salam, Usman Raza

Faculty Publications

The UG channel bandwidth and capacity are vital parameters in wireless underground communication system design. In this chapter, a comprehensive analysis of the wireless underground channel capacity is presented. The impact of soil on return loss, bandwidth, and path loss is discussed. The results of underground multi-carrier modulation capacity are also outlined. Moreover, the single user capacity and multi-carrier capacity are also introduced with an in-depth treatment of soil texture, soil moisture, and distance effects on channel capacity. Finally, the chapter is concluded with a discussion of challenges and open research issues.

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Modulation Schemes And Connectivity In Wireless Underground Channel, Abdul Salam, Usman Raza Aug 2020

Modulation Schemes And Connectivity In Wireless Underground Channel, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, a thorough treatment of the modulation schemes for UG Wireless is presented. The effects of soil texture and water content on the capacity of multi-carrier modulation in WUC are discussed. The multi-carrier capacity model results are analyzed. Moreover, the underground MIMO design for underground communications is explained thoroughly. An analysis of medium access in wireless underground is done as well. Furthermore, the soil properties are considered for cross-layer communications of UG wireless. The performance analysis of traditional modulation schemes is also considered. The soil moisture-based modulation approach is also explored in this chapter. The connectivity and diversity …

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Variable Rate Applications In Decision Agriculture, Abdul Salam, Usman Raza Aug 2020

Variable Rate Applications In Decision Agriculture, Abdul Salam, Usman Raza

Faculty Publications

In this chapter, the variable rate applications (VRA) are presented for the field of decision agriculture. The characteristics of VRA control systems are described along with control hardware. Different types of VRA systems are discussed (e.g., liquid VRA systems and dry VRA systems). A case study is also explored in this regard. Moreover, recent advances and future trends are also outlined. Accordingly, a sustainable variable-rate irrigation scheduling is studied where different hardware and software component of the cyber-physical system are considered. Finally, chapter is concluded with a novel sensor deployment methodology.

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Novel Material For Advanced Tissue Regeneration, Karrer Mahdi Kadum Alghazali Aug 2020

Novel Material For Advanced Tissue Regeneration, Karrer Mahdi Kadum Alghazali

Theses and Dissertations

Nerve tissue damage or failure can occur for various reasons, including infection, disease, aging, and trauma. The tissue microenvironment (extracellular matrix-ECM) plays a key role in regulating the self-renewal and recovery of damaged tissue. ECM-cell interactions govern cell migration and physiology, with biochemical and biophysical boundaries being the main factors that control ECM-cell interaction. Optimizing these boundaries for the recovering tissue will create a healthy microenvironment to support and enhance the recovery rate (1, 2). We have developed a novel, multidimensional nanocomposite system that incorporates gold nanorods (AuNRs) (aspect ratio of around 3) as an artificial ECM for cell adhesion, …

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Study Of Light Extraction Efficiency For Thin-Film-Flip-Chip Light-Emitting Diodes With Periodic Spheroids, Xiaojie Yu, Li Kang, Fanmin Kong, Qingyang Yue Aug 2020

Study Of Light Extraction Efficiency For Thin-Film-Flip-Chip Light-Emitting Diodes With Periodic Spheroids, Xiaojie Yu, Li Kang, Fanmin Kong, Qingyang Yue

Journal of System Simulation

Abstract: The enhancement of light extraction efficiency for thin-film-flip-chip light-emitting diodes (LED) based gallium nitride (GaN) with triangular lattice periodic ellipsoid was studied. Three dimensional finite difference time domain methods (3D-FDTD) were applied to analyze the structural parameters (the period and ellipsoid height) effects on thin-film-flip-chip LED light extraction efficiency. FDTD numerical results prove that ellipsoids structure can improve LED light extraction efficiency and impair guide mode. Method rigorous coupled wave (RCWA) is adopted to analyze diffraction characteristics. This research results show that optimization of the periodic ellipsoid can improve thin-film-flip-chip LED light extraction efficiency increased by 2.8 times.

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Prediction Of Energy Efficiency Of Nc Machine Tools Based On Recursive Method With Discounted Measurements, Cai Lei, Wang Yan, Zhicheng Ji Aug 2020

Prediction Of Energy Efficiency Of Nc Machine Tools Based On Recursive Method With Discounted Measurements, Cai Lei, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: Aiming at the problem that the energy efficiency of numerical control machine tool is difficult to obtain directly, a new method combined with the recursive method with discounted measurements was presented to predict the energy efficiency of machine tool. The estimation model of the cutting power was given in view of the power balance equation of the machine tool main drive system and the additional load loss function, further taking into account the additional load loss coefficients in model could not be directly measured, the recursive method with discounted measurements was adopted to identify the additional load loss coefficients …

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Invasive Weed Optimization Algorithm Combined With Chaotic Mutation And Analysis Of Its Property, Huang Xia, Chunming Ye, Cao Lei Aug 2020

Invasive Weed Optimization Algorithm Combined With Chaotic Mutation And Analysis Of Its Property, Huang Xia, Chunming Ye, Cao Lei

Journal of System Simulation

Abstract: Inspired by the reproductive aggressive behavior of weeds in nature, invasive weed optimization algorithm (IWO) was developed as a novel bionic swarm intelligence optimization algorithm. An improved IWO algorithm was proposed on the basis of analyzing bionic principle and limitations of basic IWO, which applied an initialization strategy based on chaotic opposition-based learning, increased the diversity of the population through the mutation operator, and enhanced its ability to jump out of local optimal value by chaotic search around current elites. Simulation results for benchmark functions show that the proposed algorithm has improved optimization property compared with IWO, as an …

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Stylization Rendering Algorithm Based On Interactive Graph Cuts Method For Image Segmentation, Zhao Yang, Guowu Yuan, Dangen Xie, Xu Dan Aug 2020

Stylization Rendering Algorithm Based On Interactive Graph Cuts Method For Image Segmentation, Zhao Yang, Guowu Yuan, Dangen Xie, Xu Dan

Journal of System Simulation

Abstract: The image is cut into two parts, the object and background, using the Graph Cuts interactive image segmentation algorithm. Through interactive image segmentation, user segmented image into a foreground region and a background region. For background area, a variety of non-photorealistic rendering algorithm was designed, which could render the original image into artistic images with other cartoon painting, pencil drawing or painting style. For foreground region, the algorithm maintained its feathers unchanged. By merging foreground and background areas, the artistic images were obtained with variety styles. Experiments show that the algorithm designed can get the desired result for processing …

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Cooperative Controller Design For Redundant Dual Arm Robot, Meiling Wang, Minzhou Luo Aug 2020

Cooperative Controller Design For Redundant Dual Arm Robot, Meiling Wang, Minzhou Luo

Journal of System Simulation

Abstract: Cooperative operation for a redundant dual arm robot can be divided into three modes, namely, independent mode, full constrained cooperative working mode and partly constrained cooperative working mode. The dynamic equations of both dual arms and the interactions between dual arms and the operating objects were established and derived based on the three modes, and a unified formulation was obtained. With focus on motion and force of the desired task being operated, a unified controller was designed which could be carried out based on two dynamic model based controllers, namely feedforward controller and computer torque controller. Simulations of dual …

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Multiresolution Scene Matching Algorithm For Infrared And Visible Images Based On Non-Subsampled Contourlet Transform, Liu Gang, Guangyu Wang, Zhou Heng, Mingjing Wang Aug 2020

Multiresolution Scene Matching Algorithm For Infrared And Visible Images Based On Non-Subsampled Contourlet Transform, Liu Gang, Guangyu Wang, Zhou Heng, Mingjing Wang

Journal of System Simulation

Abstract: Aiming at scene matching problem for taking infrared image as the actual data and the visible image as the referenced data, a multiresolution matching algorithm was proposed based on non-subsampled contourlet transform (NSCT). By using the transform of phase congruency transform, the difference of grayscale and contrast between infrared image and visible light image was weakened. Subsequently, the two types of images were separately transformed into non-subsampled contourlet domain and the proposed method took the Krawtchouk invariant moment as matching feature. The presented method, which used the improved genetic algorithm (GA) as searching strategy which conquered the precocious phenomenon, …

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Modeling And Motion Analysis Of Multi-Bodies Dynamic Of Unmaned Parafoil Vehicle, Zhang Hao, Zili Chen, Jingang Qiu Aug 2020

Modeling And Motion Analysis Of Multi-Bodies Dynamic Of Unmaned Parafoil Vehicle, Zhang Hao, Zili Chen, Jingang Qiu

Journal of System Simulation

Abstract: Unmanned Parafoil Vehicle (UPV) has gradually become a hotspot in the flexible wing vehicle research filed for its superior fight performance and advantages in application. An eight degrees of freedom (DOF) nonlinear dynamic model of UPV in mechanism law was proposed, aiming at the structure characteristics of the two flexible connections, and considering the added mass of canopy and the relative motion of two bodies. The response of model to different levels of thrust changes was simulated and analyzed, pulling a single steering line and pulling the left and right steering lines of canopy symmetrically on the steady state …

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Repairable K/N Voting System Life Situation Model Analysis And Simulation From Time Response, Yongfeng Fang, Jianjun Chen Aug 2020

Repairable K/N Voting System Life Situation Model Analysis And Simulation From Time Response, Yongfeng Fang, Jianjun Chen

Journal of System Simulation

Abstract: For the k of k/n system is given according to the one's experience in the current, the probability of the failure of the singular system components was given according to the stress-strength interference theory and the load distribution of the component withstand. The dynamic reliability prediction model of the repairable k/n system was established by using probabilistic differential equations and by the repairable system components moving in reliable and failure. The equation was solved and their answers were shown to give the precisely k when the k would be determined. The model shows accuracy and feasibility …

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Research On Cholecystectomy Virtual Surgery Simulation Training Platform, Wang Jun, Liu Dong Aug 2020

Research On Cholecystectomy Virtual Surgery Simulation Training Platform, Wang Jun, Liu Dong

Journal of System Simulation

Abstract: The main performance factors in virtual surgery system with immersion are real-time, realistic deformation and smooth feel handle. A kind of cholecystectomy simulation training platform with force feedback feel was built, putting forward a kind of collision detection method based on Capsule-Sphere mixture model of different model with different bounding box in the real-time and a kind of mass-spring deformation method based on mesh-skeleton model in the force-deformation, and being tested on the virtual surgery force feedback device in prophase research. The experimental results show that the two modes are applied to the virtual cholecystectomy simulation and the platform …

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Wood Structure Nondestructive Detection Based On Singular Spectrum Analysis And Svm, Guoxiong Zhou, Aibin Chen, Xianyan Zhou Aug 2020

Wood Structure Nondestructive Detection Based On Singular Spectrum Analysis And Svm, Guoxiong Zhou, Aibin Chen, Xianyan Zhou

Journal of System Simulation

Abstract: In view of unknown defect of wood component defect, a method of wood structure nondestructive recognition based on Singular spectrum analysis and SVM was proposed. The wood specimen was tested to obtain the test signal by ultrasonic testing instrument. In order to eliminate the testing effect of the tester gain control and defect size, angle variation on the test defect echo amplitude, the abnormal fluctuation was to filter and characteristic of the original signal was extracted by singular spectrum analysis, and SVM could train the parameters and distinguish the wood defects. Simulation results show that the proposed method …

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Analysis And Simulation Of A Class Of Time-Varying Wireless Networked Control Systems, Weihua Deng, Minrui Fei Aug 2020

Analysis And Simulation Of A Class Of Time-Varying Wireless Networked Control Systems, Weihua Deng, Minrui Fei

Journal of System Simulation

Abstract: The problem of stabilization was investigated for a class of discrete time-varying systems over a physical IEEE 802.11b wireless channel. The wireless network-induced delays were characterized by an inverse Gaussian distribution model (IGDM) and the time-varying nature was depicted by uncertain parameter model. The model-based state feedback controller was designed to compensate the influence of delays and time-varying nature. And the stochastic stabilisability of discrete time-varying networked control system was analyzed and the solution of controller was given in the form of linear matrix inequalities (LMIs). The effectiveness of the proposed methods was illustrated by numerical simulation examples.

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Segmentation And Recognition Of Hand-Drawn Situation Maps, Deng Wei, Lingda Wu, Yougen Zhang, Yang Chao Aug 2020

Segmentation And Recognition Of Hand-Drawn Situation Maps, Deng Wei, Lingda Wu, Yougen Zhang, Yang Chao

Journal of System Simulation

Abstract: Most of current research on online sketched military symbol recognition concerns the isolated samples. In pen-based situation marking systems, users prefer segmenting and recognizing the full sketched situation maps. However, it is a more difficult problem. The characteristics of hand-drawn situation maps and difficulties to segment them were analyzed, and a dynamic programming-based approach was proposed. A hand-drawn situation map was segmented coarsely by minimum spanning tree-based stroke clustering. The candidate segmentation path was evaluated by synthesizing geometric analysis and isolated symbol classifier together, using confidence transformation and fusion. The dynamic programming algorithm was used to search the …

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Robust Steerable Frequency Invariant Beamformer Design Based On Srv-Cls, Suting Chen, Zhang Wei Aug 2020

Robust Steerable Frequency Invariant Beamformer Design Based On Srv-Cls, Suting Chen, Zhang Wei

Journal of System Simulation

Abstract: The frequency invariant beamformer (FIB) has important applications in wideband array signal processing. Conventional FIB design approaches are usually proposed without considering the mismatches in microphone array characteristic, which leads to the performance of the FIBs degrading in practical applications. Therefore, a robust steerable frequency invariant beamformer design approach based on spatial response variation constrained least squares (SRV-CLS) was proposed. It combined the SRV-CLS FIB design approach with classical robust beamforming algorithm, and added the microphone characteristics as robust favor in the cost function. The proposed approach could work well in the presence of microphone mismatches, ensured the frequency …

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Virtual Reality Game For Head Rehabilitation Based On Kinect, Shutao Shen, Gao Fei, Xu Ning Aug 2020

Virtual Reality Game For Head Rehabilitation Based On Kinect, Shutao Shen, Gao Fei, Xu Ning

Journal of System Simulation

Abstract: The application of virtual reality in the rehabilitation has been extensively studied, which helps patients after a stroke independently perform daily living activities, while saving time, money and other costs. This study used Microsoft Kinect virtual reality game to assess the movement of the users. The game required movement outside of the head, torso and arms. In nine games exercise, the average and maximum amount of movement remained unchanged. However, with the increase of exercise, the frequency of head movement increased. The results show that by head movement, video games can be used to balance the posture rehabilitation, …

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