A fault-tolerant and congestion-aware architecture for wireless networks-on-chip

Wireless Networks - The combination of traditional wired links for regular transmissions and express wireless paths for long distance communications is a promising solution to prevent multi-hop...     

Thermoelectric Effect Spectroscopy and Photoluminescence of High-Resistivity CdTe:In

Thermoelectric effect spectroscopy and photoluminescence techniques were used to study the defect levels in samples from three crystals of CdTe:In grown by the vertical gradient freeze method. The main goal of the investigation was to study defects, which strongly trap charge carriers or act as recombination centers in order to eliminate them from the technological process. The main difference among detecting and non-detecting samples was the absence of electron traps with a very high capture cross-section and energy 0.6 eV to 0.7 eV, which act as lifetime killers even at low concentrations. Recently published ab initio calculations show a complex of Te antisite and Cd vacancy within this energy range.     

Personal identification using feature and score level fusion of palm- and fingerprints

The ever increasing demand of security has resulted in wide use of Biometric systems. Despite overcoming the traditional verification problems, the unimodal systems suffer from various challenges like intra class variation, noise in the sensor data etc, affecting the system performance. These problems are effectively handled by multimodal systems. In this paper, we present multimodal approach for palm- and fingerprints by feature level and score level fusions (sum and product rules). The proposed multi-modal systems are tested on a developed database consisting of 440 palm- and fingerprints each of 55 individuals. In feature level fusion, directional energy-based feature vectors of palm- and fingerprint identifiers are combined to form joint feature vector that is subsequently used to identify the individual using a distance classifier. In score level fusion, the matching scores of individual classifiers are fused by sum and product rules. Receiver operating characteristics curves are formed for unimodal and multimodal systems. Equal Error Rate (EER) of 0.538% for feature level fusion shows best performance compared to score level fusion of 0.6141 and 0.5482% of sum and product rules, respectively. Multimodal systems, however, significantly outperform unimodal palm- and fingerprints identifiers with EER of 2.822 and 2.553%, respectively.     

Development and Simulation of Sulfur‐doped Graphene Supported Platinum with Exemplary Stability and Activity Towards Oxygen Reduction

Sulfur‐doped graphene (SG) is prepared by a thermal shock/quench anneal process and investigated as a unique Pt nanoparticle support (Pt/SG) for the oxygen reduction reaction (ORR). Particularly, SG is found to induce highly favorable catalyst‐support interactions, resulting in excellent half‐cell based ORR activity of 139 mA mg_Pt ^?1 at 0.9 V vs RHE, significant improvements over commercial Pt/C (121 mA mg_Pt ^?1) and Pt‐graphene (Pt/G, 101 mA mg_Pt ^?1). Pt/SG also demonstrates unprecedented stability, maintaining 87% of its electrochemically active surface area following accelerated degradation testing. Furthermore, a majority of ORR activity is maintained, providing 108 mA mg_Pt ^?1, a remarkable 171% improvement over Pt/C (39.8 mA mg_Pt ^?1) and an 89% improvement over Pt/G (57.0 mA mg_Pt ^?1). Computational simulations highlight that the interactions between Pt and graphene are enhanced significantly by sulfur doping, leading to a tethering effect that can explain the outstanding electrochemical stability. Furthermore, sulfur dopants result in a downshift of the platinum d‐band center, explaining the excellent ORR activity and rendering SG as a new and highly promising class of catalyst supports for electrochemical energy technologies such as fuel cells.     

A universal low-noise analog receiver baseband in 65-nm CMOS

In this paper, a novel universal receiver baseband approach is introduced. The chain includes a post-mixer noise shaping blocker pre-filter, a programmable-gain post mixer amplifier (PMA) with blocker suppression, a differential ramp-based novel linear-in-dB variable gain amplifier and a Sallen–Key output buffer. The 1.2-V chain is implemented in a 65-nm CMOS process, occupying a die area of 0.45 mm². The total power consumption of the baseband chain is 11.5 mW. The device can be tuned across a bandwidth of 700-KHz to 5.2-MHz with 20 kHz resolution and is tested for two distinct mobile-TV applications; integrated services digital broadcasting-terrestrial ISDB-T (3-segment f _c = 700 kHz) and digital video broadcasting-terrestrial/handheld (DVB-T/H f _c = 3.8 MHz). The measured IIP3 of the whole chain for the adjacent blocker channel is 24.2 and 24 dBm for the ISDB-T and DVB-T/H modes, respectively. The measured input-referred noise density is 10.5 nV/sqrtHz in DVB-T/H mode and 14.5 nV/sqrtHz in ISDB-T mode.     

Rainfall propagation impairments for medium elevation angle satellite‐to‐earth 12 GHz in the tropics

Rain attenuation is the dominant propagation impairment for satellite communication systems operating at frequencies above about 10 GHz. The rainfall path attenuation at 12.255 GHz measured at Universiti Sains Malaysia (USM) for 4 years (2 January to 5 December) is presented. This paper presents an empirical analysis of rain rate and rain attenuation cumulative distribution functions obtained using 1‐min integrated rainfall data and comparison of the measured data with data obtained from well‐established rain model attenuation predictions. Copyright © 2008 John Wiley & Sons, Ltd.     

Camera calibration using symmetric objects.

This paper proposes a novel method for camera calibration using images of a mirror symmetric object. Assuming unit aspect ratio and zero skew, we show that interimage homographies can be expressed as a function of only the principal point. By minimizing symmetric transfer errors, we thus obtain an accurate solution for the camera parameters. We also extend our approach to a calibration technique using images of a 1-D object with a fixed pivoting point. Unlike existing methods that rely on orthogonality or pole-polar relationship, our approach utilizes new inter-image constraints and does not require knowledge of the 3-D coordinates of feature points. To demonstrate the effectiveness of the approach, we present results for both synthetic and real images.     

Transient detection in COTS processors using software approach

This paper presents a software-based error detection scheme called enhanced committed instructions counting (ECIC) for embedded and real-time systems using commercial off-the-shelf (COTS) processors. The scheme uses the internal performance monitoring features of a processor, which provides the ability to count the number of committed instructions in a program. To evaluate the ECIC scheme, 6000 software induced faults are injected into a 32-bit Pentium® processor. The results show that the error detection coverage varies between 90.52% and 98.18%, for different workloads.     

On Time-Frequency Resource Leasing in Cognitive Radio Networks

In this work, we introduce a new spectrum leasing based cognitive radio for OFDM-based primary/secondary networks. More precisely, we propose a new leasing scheme both in time and frequency domains in a network composed of a primary transmission and some secondary (cognitive) users forming a cooperative relay network. In the proposed scheme, the primary user decides to lease a part of its available resources (time and frequency) to a selected set of relays, with the aim of increasing its link reliability. The selected relays use a part of the leased resources for relaying the primary signal, and in counterpart, they are allowed to exploit the rest of the frame for their own data transmission. By defining appropriate cost functions, the proposed algorithm decides whether it is of advantage for the primary user to cooperate with the relay network or not. Moreover, if cooperation is advantageous for the primary network, the algorithm selects the optimal amount of the time-frequency resources (number of OFDM symbols and subcarriers) that are involved in the cooperation process. Simulation results show that by using the proposed relaying scheme, both primary and secondary (relay) networks can take advantage in terms of achievable data rates compared to classical leasing systems.     

Body controlled threshold voltage shifting variable gain current mirror

A programmable high-speed source-series-terminated driver with signal boost capability is presented. The driver uses only one main input data tap and is divided into main units and auxiliary units. A passive high pass filter is utilized to detect data transitions and control the inputs of the auxiliary units to enable a programmable amplitude boost for the output signal. The corner frequency of the high pass filter is adjusted depending on the data rate. Further, the amount of the high frequency signal boost can be adjusted depending on the loss of the channel. HSPICE simulations are used to demonstrate the performance of the driver at 10, 20 and 40 Gbps data rates. At 40 Gbps, the driver is capable of equalizing a PRBS9 data pattern signal through a channel that has a loss of 9 dB. At worst case conditions and 40 Gbps date rate, the driver achieves a differential eye-opening amplitude of 201 mVppd and an eye-opening of 0.952 UI. The driver is designed using 28 nm CMOS process and uses a nominal 1 V supply voltage. It consumes a maximum of 12 mW of at-speed power.