In order to improve the performance and simplify the structure of the conventional detectors in high density magnetic channels, a new equalizer based on bilinear recursive polynomial models, which uses the previously estimated sequence, is proposed. The performance is compared with the conventional equalizers and the maximum likelihood sequential detection bound. The simulation results show that as the normalized recording density becomes higher the proposed equalizer with much simpler structures shows the similar or better performances compared to the partial response maximum likelihood methods and the proposed equalizer is robust to the jitter noise.
The fixed dimension modified sinusoidal model (FDMSM) was recently proposed as an attractive candidate for compact representation of audio signals in adverse conditions. This paper aims to study the capability of the FDMSM signal representation for analysis and synthesis of speech mixtures as well as noisy audio signals corrupted by highly colored noise of babble and harmonic. Extensive simulation results verified that the FDMSM provides high perceptual quality of the synthesized output signal compared with the conventional harmonic plus noise model (HNM) for both speech mixtures as well as audio signals corrupted by various types of noise.
Based on the observation that dynamic occurrence of zeros in the cache access stream and cache-resident memory values of ordinary programs exhibit a strong bias towards zero, this paper presents a novel CMOS four-transistor (4T) SRAM cell for very high density and low power cache applications. This cell retains its data with leakage current and positive feedback without refresh cycle. The new cell size is 20% smaller than a conventional six-transistor cell using same design rules and delay access of a cache based on new 4T SRAM cell is 32% smaller than a cache based on 6T SRAM cell. Also the dynamic and static power consumption of new cell is 40% and 20% smaller than 6T SRAM cell, respectively.
March tests have been widely used for detecting functional faults during SRAM testing. Recent development has extended the March test for diagnostic purpose to locate and identify the fault types. This paper analyses March algorithms for detection and diagnosis of Stuck-At Faults (SAFs) and Transition Faults (TFs). Unfortunately, the algorithms under studied are not able to distinguish between the two faults. Therefore, this paper proposes a new March-based diagnostic algorithm that can differentiate SAFs from TFs.
A 9-bit ultra low-power successive approximation analog-to-digital converter (SA-ADC), which is able to operate at very low supply voltage, is presented. The low power consumption is achieved by using new switched-comparator architecture. In the proposed architecture the comparator, which is one of the most power hungry blocks of the SA-ADC, is switched off after the decision-making interval as well as during reset time to save power. The SA-ADC is simulated in the 0.18µm CMOS technology and the simulation results are provided. The switched-comparator SA-ADC consumes 412nW at 0.5V and as a result of the proposed switching scheme a power saving of 17.4% is obtained. It provides a signal-to-noise-and-distortion ratio (SNDR) of 50.36dB at the sampling rate of 12.5kS/s.
In this paper, a single-phase five-level PV inverter topology for grid-connected photovoltaic (PV) system with a novel PWM control scheme is presented. PWM signals were generated by comparing two reference signals identical to each other with an offset equivalent to the amplitude of the triangular carrier signal. A digital PI current control algorithm is implemented to keep the current injected into the grid sinusoidal and to have high dynamic performance with rapidly changing atmospheric conditions and low THD. This new configuration of the proposed inverter is implemented in a prototype.
This paper proposes an improvement to the Eigenphases method, in which the image is normalized to reduce the illumination and facial expression effects and the Principal Components Analysis (PCA) is used for feature extraction, while the Gaussian Mixture Model (GMM)is used to improve the performance of classification stage. An important advantage of GMM is that this system is trained without supervisor and constructs an independent model for each user. The proposed method is evaluated using the ”AR Face Database”, which includes the face images of 120 subjects (65 males and 55 females). Evaluation results show that the proposed method provides better performance than the original eigenphases method.
Amorphous selenium (a-Se) avalanche multiplication photoconductive film, HARP film, has been developed for the purpose of making a high sensitivity video camera. HARP film used for the red channel in a color camera is doped with tellurium (Te) to improve its red-light sensitivity. However, doping a-Se with Te causes impurity levels that trap electrons, and the built-in-field from the trapped electrons causes image defects when a camera using the film is shooting intense spotlights. A heat treatment to suppress the defect occurrence was found. We describe this treatment and discuss its mechanism.
To support healthcare organizations responses, many companies have started solutions to be satisfied the specific requirements of healthcare programs, and plans. This paper presents authentication scheme of RFID system based on GPS location in the U-health care services.