With quick topology changes due to mobile node movement or signal fading in MANET environments, conventional routing restoration processes are costly to implement and may incur high flooding of network traffic overhead and long routing path latency. Adopting the traditional shortest path tree (SPT) recomputation and restoration schemes used in Internet routing protocols will not work effectively for MANET. An object of the next generation SPT restoration system is to provide a cost-effective solution using an adaptive learning control system, wherein the SPT restoration engine is able to skip over the heavy SPT computation. We proposed a novel SPT restoration scheme, called Cognitive Shortest Path Tree Restoration (CSPTR). CSPTR is designed based on the Network Simplex Method (NSM) and Sensitivity Analysis (SA) techniques to provide a comprehensive and low-cost link failure healing process. NSM is used to derive the shortest paths for each node, while the use of SA can greatly reduce the effort of unnecessary recomputation of the SPT when network topology changes. In practice, a SA range table is used to enable the learning capability of CSPTR. The performance of computing and communication overheads are compared with other two well-known schemes, such as Dijstra's algorithm and incremental OSPF. Results show that CSPTR can greatly eliminate unnecessary SPT recomputation and reduce large amounts of the flooding overheads.

We propose here a fully Spice-oriented design algorithm of op-amps for attaining the maximum gains under low power consumptions and assigned slew-rates. Our optimization algorithm is based on a well-known steepest descent method combining with nonlinear programming. The algorithm is realized by equivalent RC circuits with ABMs (analog behavior models) of Spice. The gradient direction is decided by the analysis of sensitivity circuits. The optimum parameters can be found at the equilibrium point in the transient response of the RC circuit. Although the optimization time is much faster than the other design tools, the results might be rough because of the simple transistor models. If much better parameter values are required, they can be improved with Spice simulator and/or other tools.

This paper proposes a closed form solution to L2-sensitivity minimization of second-order state-space digital filters subject to L2-scaling constraints. The proposed approach reduces the constrained optimization problem to an unconstrained optimization problem by appropriate variable transformation. Furthermore, restricting ourselves to the case of second-order state-space digital filters, we can express the L2-sensitivity by a simple linear combination of exponential functions and formulate the L2-sensitivity minimization problem by a simple polynomial equation. As a result, L2-sensitivity is expressed in closed form, and its minimization subject to L2-scaling constraints is achieved without iterative calculations.

The TFT-LCD image has non-uniform brightness that is the major difficulty of finding the visible defect called Mura in the field. To facilitate Mura detection, background signal shading should level off and Mura signal must be amplified. In this paper, Mura signal amplification and background signal flattening method is proposed based on human visual system (HVS). The proposed DC normalized contrast sensitivity function (CSF) is used for the Mura signal amplification and polynomial regression (PR) is used to level off the background signal. In the enhanced image, tri-modal thresholding segmentation technique is used for finding Dark and White Mura at the same time. To select reliable defect, falsely detected invisible region is eliminated based on Weber's Law. By the experimental results of artificially generated 1-d signal and TFT-LCD image, proposed algorithm has novel enhancement results and can be applied to real automated inspection system.

This paper proposes a closed form solution to L2-sensitivity minimization of second-order state-space digital filters. Restricting ourselves to the second-order case of state-space digital filters, we can express the L2-sensitivity by a simple linear combination of exponential functions and formulate the L2-sensitivity minimization problem by a simple polynomial equation. As a result, the L2-sensitivity minimization problem can be converted into a problem to find the solution to a fourth-degree polynomial equation of constant coefficients, which can be algebraically solved in closed form without iterative calculations.

Random variations in Id-Vg characteristics of MOS transistors in an LSI chip are shown to be concisely characterized by using only 3 transistor parameters (Vth, β0, vSAT) in the MOS level 3 SPICE model. Statistical analyses of the transistor parameters show that not only the threshold voltage variation, ΔVth, but also the current factor variation, Δβ0, independently induces Id-variation, and that Δβ0 is negatively correlated with the saturation velocity variation, ΔvSAT. Using these results, we have proposed a simple method that effectively takes the correlation between parameters into consideration when creating statistical model parameters for designing a circuit. Furthermore, we have proposed a sensitivity analysis methodology for estimating the process window of SRAM cell operation taking transistor variability into account. By applying the concise statistical model parameters to the sensitivity analysis, we are able to obtain valid process windows without the large volume of data-processing and long turnaround time associated with the Monte Carlo simulation. The process window was limited not only by ΔVth, but also by Δβ0 which enhanced the failure region in the process window by 20%.

The thin film transistor liquid crystal display (TFT-LCD) image has nonuniform brightness, which is a major difficulty in finding the Mura defect region. To facilitate Mura segmentation, globally widely varying background signal must be flattened and then Mura signal must be enhanced. In this paper, Mura signal enhancement and background-signal-flattening methods using wavelet coefficient processing are proposed. The wavelet approximation coefficients are used for background-signal flattening, while wavelet detail coefficients are employed to magnify the Mura signal on the basis of an adapted contrast sensitivity function (CSF). Then, for the enhanced image, trimodal thresholding segmentation technique and a false-region elimination method based on the human visual system (HVS) are employed for reliable Mura segmentation. The experimental results show that the proposed algorithms produce promising results and can be applied to automated inspection systems for finding Muras in a TFT-LCD image.

To design a controller with block-diagonal structure for trajectory sensitivity minimization, we propose a method based on LMI. In order to reduce the trajectory sensitivity, linear quadratic regulator theory is adopted, and this is solved using LMI optimization technique.

The minimization problem of an L2-sensitivity measure subject to L2-norm dynamic-range scaling constraints is formulated for a class of two-dimensional (2-D) state-space digital filters. First, the problem is converted into an unconstrained optimization problem by using linear-algebraic techniques. Next, the unconstrained optimization problem is solved by applying an efficient quasi-Newton algorithm with closed-form formula for gradient evaluation. The coordinate transformation matrix obtained is then used to synthesize the optimal 2-D state-space filter structure that minimizes the L2-sensitivity measure subject to L2-norm dynamic-range scaling constraints. Finally, a numerical example is presented to illustrate the utility of the proposed technique.

In recent works [1],[4], it has been shown that the damping of a linear time invariant system relates to the so-called characteristic ratios (αk, k=1,…, n-1) which are defined by coefficients of the denominator of the transfer function. However, the exact relations are not yet fully understood. For the purpose of exploring the issue, this paper presents the analysis of time response sensitivity to the characteristic ratio change. We begin with the sensitivity of output to the perturbations of coefficients of the system denominator and then the first order approximation of the αk perturbation effect is computed by an explicit transfer function. The results are extended to all-pole systems in order to investigate which characteristic ratios act dominantly on step response. The same analysis is also performed to a special class of systems whose denominator is composed of so called K-polynomial. Finally, some illustrative examples are given.

New service concepts involving mobile devices with a diverse range of embedded sensors are emerging that share contexts supporting communication on a wireless network infrastructure. To promote these services in mobile devices, we propose a method that can efficiently detect a context provider by partitioning the location, time, speed, and discovery sensitivities.

The conventional complete discrete wavelet transform (DWT) is shift-sensitive, so that the analysis often becomes unstable. In this paper, we define a measure of shift-sensitivity, based on which we propose a new DWT less sensitive than the complete DWT. The measure is derived from the normalized variation of the output waveform for a shifted signal. The measure indicates that a narrow-band high-pass filter is desirable for shift-insensitivity. Then we propose a new DWT which makes use of a complex filter with half bandwidth of a high-pass filter of an ordinary DWT. In two dimensions, the proposed DWT can decompose an image into either four or six directional components which include two separate diagonals, while the complete DWT decomposes the image into three directional components. We show the effectiveness of our method by evaluating the shift-sensitivity of our DWT and other DWTs. By our DWT a smooth continuing edge of an image can be detected, but by the complete DWT a discontinuous edge is produced.

This paper proposes a cell layout synthesis technique to minimize the sensitivity to wiring faults due to spot defects. We modeled the sensitivity to faults on intra-cell routings with consideration to the spot defects size distribution and the end effect of critical areas. The effect of the sensitivity reduction on the yield is also discussed. By using the model as a cost function, we comprehensively generate the minimum width layout of CMOS logic cells and select the optimal layouts. Experimental results show that our technique reduces about 15% of the fault sensitivities compared with the wire-length-minimum layouts for benchmark CMOS logic circuits which have up to 14 transistors.

We demonstrated a vertically coupled microring resonator (VCMRR) filter as an Add/Drop wavelength filter. However, the accuracy of center wavelength was not sufficiently high for dense wavelength division multiplexing (DWDM) systems. Thus, a UV trimming technique using a SiN (n=2.01 at λ=1.55 µm) ring core was previously developed. Although a wide center wavelength trimming range of -12.1 nm and the long-term stability of center wavelength were realized, the core size required for single-mode propagation was too small for fabrication using a photolithography process. Therefore in this study, we introduced SiON as the microring core to relax the single-mode condition of core size. We discovered a large UV sensitivity of SiON film formed by a PECVD method, and a wide range UV trimming of microring resonator of -10.5 nm was demonstrated using this phenomenon.

This paper studies a cellular system with mobile customers. The network system consists of cells, the tagged cell and the adjacent cells which surround the tagged one. Each cell has a finite number of channels that give calls to the mobile customers. The service (holding) time distribution of the calls is general. Customers in the adjacent cells inflow into the tagged cell according to a Poisson process. The sojourn time distribution of each customer in the tagged cell is general. Each customer without call in progress generates his call according to a Poisson process. It is proved that the steady state distribution in the tagged cell is the generalized Erlang loss formula which is the joint distribution of the number of customers with calls and the number of customers without calls. The distribution depends on the service time distribution and the sojourn time distribution only through their means.

We propose a new method to recover scene points from a single calibrated view using a subset of distances among the points. This paper first introduces the problem and its relationship with the perspective n point problem. Then the number of distances required to uniquely recover scene points are explored. The result is then developed into a practical vision algorithm to calculate the initial points' coordinates using distance constraints. Finally SQP (Sequential Quadratic Programming) is used to optimize the initial estimations. It can minimize a cost function defined as the sum of squared reprojection errors while keeping the specified distance constraints strictly satisfied. Both simulation data and real scene images have been used to test the proposed method, and good results have been obtained.

In this paper, a novel methodology for designing and analyzing high performance sigma-delta leapfrog modulators for ultra-high resolution analog-to-digital (A/D) converters is presented. The less sensitive topology, the leapfrog topology, in component variations is analyzed by considering the noise transfer function (NTF). By using theoretical analysis, the loop coefficients are constrained to a small, clear and definite range called the stable region (SR). With the output voltage limited within 2 V, an absolutely stable region (ASR) is obtained. A program that analyzes and generates the required coefficients is constructed for easily designing this topology. For a 256 over-sampling ratio (OSR) and the coefficients from ASR, the signal to noise ratio (SNR) and dynamic range (DR) are 105 dB and 100 dB, respectively. In accordance with the behavior simulation results, the system is not only stable and efficient but also suitable for high-resolution applications.

Schottky gas sensors of CO were fabricated using high quality AlGaN/GaN/Si heterostructures. The CO sensors show good sensitivity in the temperature range of 250 to 300 (530%, at 160 ppm CO in N2) and fast response comparable with SnO2 sensors. A two-region linear regime was observed for the dependence of sensitivity on CO concentration. GaN sensors on Si substrate offer the possibility of integration with Si based electronics. The gas sensors show slow response with time, the change of material properties possibly in the presence of large thermal stress.

We have developed an ultrahigh-sensitivity "New Super-HARP" handheld camera, which has a sensitivity that is about 100 times as great as that of a CCD camera. The sensitivity of TV cameras is determined by the performance of the imaging device. We developed the world's first imaging device that achieves high sensitivity and high picture quality by using the avalanche multiplication phenomenon in an amorphous selenium photoconductive target. This "Super-HARP" pickup tube, which has already been used in TV production, has a selenium target 8-µm thick. It is about 10 times as sensitive as CCDs. We have now developed a greatly improved version of the Super-HARP tube with a target 25-µm thick. This improved version, called the New Super-HARP pickup tube, is about 10 times as sensitive as the Super-HARP pickup tube. The New Super-HARP handheld camera equipped with the new tubes has a maximum sensitivity of 11 lx at F8. This camera is a powerful tool for reporting breaking news at night and other low-light conditions, the production of scientific programs, and numerous other applications.

An ultra-high-sensitivity HDTV color camcorder (camera with VTR) has been developed featuring image intensifiers with GaAsP photocathodes, which provide very high quantum efficiency. To achieve superior performance and a compact camera body, we combined three 1-inch image intensifiers with a 2/3-inch taking lens and three 2/3-inch CCDs by means of a new optical system capable of enlarging and reducing images. The camcorder provides excellent color reproducibility even under low light level conditions (0.2 lx) at an iris setting of f/2, with a signal-to-noise ratio of 55 dB at pedestal level. Its sensitivity is about 400 times greater than that of current HDTV CCD camcorders, making it particularly well suited for capturing images of faint objects in space, aurora, etc., filming the nocturnal activities of animals in their natural settings, and reporting breaking news at night.