Electrical and Computer Engineering Commons^™

Directional Patch Antenna Array Design For Desktop Wireless Internet, Noah Snyder

Electrical Engineering

To improve desktop wireless internet access, two patch antenna configurations were investigated in order to find an alternative for a dipole antenna, which is commonly used for Wi-Fi access. A Linksys WMP54G pci-card wireless adapter was used to test three antennas for 802.11g communications. The standard WMP54G dipole antenna and two patch antenna configurations were tested for Wi-Fi signal strength. The antennas were also tested in Cal Poly’s anechoic chamber to obtain resonant frequency and gain measurements. A 2.437 GHz center frequency, 72 MHz bandwidth antenna consisting of a single microstrip patch was constructed. After the patch antenna was determined …

Toward Automated Detection And Diagnosis Of Mammographic Microcalcifications, Imad Mohammad Zyout

Dissertations

Mammographie diagnosis is the most effective technique to detect breast cancer in its infancy when it is most responsive to treatment. An early and a significant indicator of breast cancer is the presence of clustered microcalcifications (MCs). Mammographie MCs greatly vary in their appearance and shape, and become indistinguishable when surrounded by dense breast tissue. This makes radiologist's interpretation of mammograms a tedious and an error prone task.

Although computer aided diagnosis (CAD) methods are being developed to aid radiologist in detecting and analyzing the malignancy of MCs, existing systems have not achieved a satisfactory performance. The specificity of existing …

Robust Neural Network Rise Observer Based Fault Diagnostics And Prediction, James W. Fonda, S. (Sarangapani) Jagannathan, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

A novel fault diagnostics and prediction scheme in continuous time is introduced for a class of nonlinear systems. The proposed method uses a novel neural network (NN) based robust integral sign of the error (RISE) observer, or estimator, allowing for semi-global asymptotic stability in the presence of NN approximation errors, disturbances and unmodeled dynamics. This is in comparison to typical results presented in the literature that show only boundedness in the presence of uncertainties. The output of the observer/estimator is compared with that of the nonlinear system and a residual is used for declaring the presence of a fault when …

A Mean-Variance Optimization Algorithm, Istvan Erlich, Ganesh K. Venayagamoorthy, Nakawiro Worawat

Electrical and Computer Engineering Faculty Research & Creative Works

A new stochastic optimization algorithm referred to by the authors as the 'Mean-Variance Optimization' (MVO) algorithm is presented in this paper. MVO falls into the category of the so-called "population-Based stochastic optimization technique." the uniqueness of the MVO algorithm is based on the strategic transformation used for mutating the offspring based on mean-variance of the n-best dynamic population. the mapping function used transforms the uniformly distributed random variation into a new one characterized by the variance and mean of the n-best population attained so far. the searching space within the algorithm is restricted to the range - zero to one …

Applying Feature Selective Validation (Fsv) As An Objective Function For Data Optimization, Siming Pan, Hanfeng Wang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Feature Select Validation (FSV) is a widely used validation method for data comparison. FSV provides a quantitative standard to describe the similarity between two sets of data. in this paper, the application of the FSV technique is extended to data optimization. the raw data obtained from simulations or measurements are often non-ideal for further processing. Several techniques, such as data perturbation, can be used to improve the data quality in certain aspects. However, after modifications the new data could be very different to the original one. using FSV as an objective function for the optimization process is discussed in this …

Hybrid Method Used To Model Via Transitions, Hanfeng Wang, Albert E. Ruehli, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid approach to solve via impedance and model via transitions is presented in the paper. the method is a combination of via-plane capacitance extraction and the impedance matrices calculation of parallel plane pair. a new formulation of the integral equation method for axially symmetric geometry is used for the capacitance extraction. the method is validated with other model results. ©2010 IEEE.

Efficient Mid-Frequency Plane Inductance Computation, Fan Zhou, Albert E. Ruehli, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

In power distribution networks (PDN), the modelling of the mid-frequency inductance for Zpp type plane pairs is very important. It is a key step for the placement of the decoupling capacitors. This paper gives an efficient approach for the calculation of the inductance for different capacitor placements. the PEEC based formulations takes advantage of the opposite currents in the planes. This leads to compute time reductions and memory savings for both the element calculation and the matrix solve step. We also use a formulation where placement of capacitors leads to only small changes in the circuit matrix. Comparisons with other …

A Novel Impedance Definition Of A Parallel Plate Pair For An Intrinsic Via Circuit Model, Yaojiang Zhang, Gang Feng, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Rigorous analysis of via-plate-pair interactions requires the impedance of a plate pair to be defined in terms of radial transmission lines on perfect magnetic conductor (PMC) ports. the plate domain is not a solid plate pair but one with multiple PMC holes where conventional impedance definitions are not suitable. a new impedance definition is proposed where port voltages and currents are expressed in terms of the inward and outward zero-order modes of a radial transmission line. Radial scattering parameters among multiple radial ports are then introduced and the transforms between the radial scattering and impedance matrices are given. an analytical …

Analyzing Via Impedance Variations With A Stochastic Collation Method, Jianxiang Shen, Hanfeng Wang, Ji Chen, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we describe a systematic approach to optimize and analyze the equivalent characteristic impedance of practical via structures. the procedure consists of (a) optimizing via structures for impedance matching using a Genetic algorithm, and (b) numerically characterize, by stochastic collocation method, the sensitivity of the equivalent characteristic impedance to the manufacturing uncertainties in the various geometrical parameters of a via structure. Such procedure naturally leads to a rigorous methodology for EM design/control in the presence of multiple sources of uncertainty. ©2010 IEEE.

Equivalent Transmission-Line Model For Vias Connected To Striplines In Multilayer Print Circuit Boards, Siming Pan, Jianmin Zhang, Qinghua B. Chen, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Vias are typical discontinuities for high-speed signal transmission in printed circuit boards. Previous work has studied the through-hole via connections from the top layer to the bottom between microstrip traces and proposed an equivalent transmission-line model for impedance matching between traces and vias. in this paper, the equivalent transmission-line model is extended for the via structures connected to strip lines based on modal decomposition. Both single-ended and differential cases are discussed, and the effects of the model parameters on the performance of signal transition are also investigated. the extended equivalent transmission-line model is accurate and fast to be embedded in …

Enhanced Mimo Lmmse Turbo Equalization, Jun Tao, Jingxian Wu, Yahong Rosa Zheng, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

We propose an enhanced linear minimum mean square error (LMMSE) turbo equalization scheme for multiple-input multiple-output (MIMO) communication systems. the turbo equalizer employs soft interference cancelation (SIC), where tentative soft decisions of the interfering symbols are subtracted from the received samples before the LMMSE filtering. the enhanced LMMSE turbo equalization with SIC introduces two improvements over existing methods. First, unlike existing methods that completely rely on the a priori soft decisions at the equalizer input for SIC, the new scheme performs SIC by continuously updating the soft decisions with the a posteriori information of the symbols that have just been …

Review Of Multi-Scale Electromagnetic Modeling, W. C. Chew, Lijun Jiang, H. Y. Chao, A. J. Hesford, M. K. Li, Z. G. Qian, Y. G. Liu, Y. P. Chen, Z. H. Ma, L. E. Sun, M. S. Tong, C. Davis, W. E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reviews various methods to solve multiscale problems ranging from low-frequency methods to very high-frequency methods. ©2010 IEEE.

Extracting Physical Ic Models Using Near-Field Scanning, Zhenwei Yu, Jayong Koo, Jason A. Mix, Kevin Slattery, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Accurate modeling of chip and chip-package is critical for EMI (Electromagnetic Interference) and RFI (RF Interference) analysis and prediction. in this paper, a model based on an array of dipoles from near-field measurement is proposed. a simple active circuit is simulated in a 3-D full-wave simulation tool, and the dipole model is calculated from the near-field data in the simulation using inverse method with regularization technique. This model has clear physical meaning, and it is validated using field at another place. ©2010 IEEE.

An Equivalent Three-Dipole Model For Ic Radiated Emissions Based On Tem Cell Measurements, Siming Pan, Jingook Kim, Sungnam Kim, Jaesu Park, Heoncheol Oh, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

An equivalent dipole model is proposed in this paper to represent the source of radiated electromagnetic emissions from an integrated circuit (IC). the height of an IC is usually much smaller than its length and width, so only three dipole moments are sufficient to characterize an IC in terms of its electromagnetic emissions. the dipole moments can be extracted from three TEM cell measurements. the radiated fields from the IC can then be calculated based on the extracted dipole sources. This IC emission model with three dipole moments is validated using the far-field measurements in a semi anechoic chamber for …

Decentralized State Feedback And Near Optimal Adaptive Neural Network Control Of Interconnected Nonlinear Discrete-Time Systems, Shahab Mehraeen, Jagannathan Sarangapani, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, first a novel decentralized state feedback stabilization controller is introduced for a class of nonlinear interconnected discrete-time systems in affine form with unknown subsystem dynamics, control gain matrix, and interconnection dynamics by employing neural networks (NNs). Subsequently, the optimal control problem of decentralized nonlinear discrete-time system is considered with unknown internal subsystem and interconnection dynamics while assuming that the control gain matrix is known. For the near optimal controller development, the direct neural dynamic programming technique is utilized to solve the Hamilton-Jacobi-Bellman (HJB) equation forward-in-time. The decentralized optimal controller design for each subsystem utilizes the critic-actor structure …

Improved Target Impedance And Ic Transient Current Measurement For Power Distribution Network Design, Jingook Kim, Songping Wu, Hanfeng Wang, Yuzou Takita, Hayato Takeuchi, Kenji Araki, Gang Feng, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

An improved definition of target impedance is proposed in this paper, which is derived from the time-domain waveforms of the IC transient current and the allowable voltage fluctuation. the proposed target impedance removes the unnecessary constraint in the original definition and allows for more cost-effective power distribution network (PDN) designs for consumer electronic products. a measurement procedure to obtain IC transient current waveforms is also developed for the PDN designs utilizing power traces. the proposed target impedance and the measurement procedure have been validated using practical functioning designs. ©2010 IEEE.

Incorporating Correlation Matrices Into Hardware Triply Selective Fading Channel Emulators Using Kronecker Product, Fei Ren, Yahong R. Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposes a hardware triply selective Rayleigh fading channel emulator which is implemented by incorporating spatial and inter-tap correlation matrices into uncorrelated frequency-flat Rayleigh fading waveforms with a Kronecker product method. the Kronecker product of square roots of three correlation matrices are computed in real time via serial, parallel, or mixed serial-parallel computational methods and then combined with uncorrelated flat fading waveforms. a 4x4 multiple-input multiple-output (MIMO) triply selective channel with 4 correlated delay-taps per subchannel is implemented on a Stratix III FPGA DSP development kit. We show that the three methods provide flexibility for designs in speed and …

Guest Editorial Special Section On The 2009 International Conference On Electromagnetic Near-Field Characterization And Imaging (Iconic'09), Jean Fu Kiang, Sergey Kharkovsky

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Recent Development Of Via Models: Hybrid Circuit And Field Analysis, Yaojiang Zhang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Via-plate interaction can be modeled as lumped circuits for vias and a two-dimensional field problem for the plate domain. the accuracy of the improved intrinsic via model and the conventional physics-Based via model is investigated by comparing them with either analytical formula or numerical simulations for a via in a circular plate pair with various edge boundary conditions. It is found that the intrinsic via model matches very well with both the analytical formula and numerical solutions in all the examples studied. However, the physics-Based via model is only an acceptable approximation at low frequencies and its accuracy is not …

Data Routing In Multicore Processors Using Dimension Increment Method, Arpita H. Kadakia

UNLV Theses, Dissertations, Professional Papers, and Capstones

A Deadlock-free routing algorithm can be generated for arbitrary interconnection network using the concept of virtual channels but the virtual channels will lead to more complex algorithms and more demands of NOC resource.

In this thesis, we study a Torus topology for NOC application, design its structure and propose a routing algorithm exploiting the characteristics of NOC. We have chosen a typical 16 (4 by 4) routers Torus and propose the corresponding route algorithm. In our algorithm, all the channels are assigned 4 different dimensions (n0,n1,n2 & n3). By following the dimension increment method, we break the dependent route circles, …