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2007
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| |  | Cao, F. | On the Relation Between PDA and MMSE-ISDIC read moreAbstract: The probabilistic data association (PDA) and the minimum-mean-square-error filtering based iterative soft decision interference cancellation (MMSE-ISDIC) are two popular detectors for systems with co-channel interference. In this letter, the relation between the two detectors is analytically derived for the V-BLAST systems. The two detectors perform in a similar manner, whereas differ in the metric calculation. It is proved that for both original signal model and decorrelated signal model, the PDA and the MMSE-ISDIC detectors are equivalent in terms of performance for both uncoded and coded systems.  This article is not yet tagged | 2007 |
| | | Li, J. | Low-Complexity Algorithm for Near-Optimum Detection of V-BLAST Systems read moreAbstract: For the Vertical Bell Laboratories Layered Space-Time systems, the optimum a posteriori probability detector encounters the problem of calculating Gaussian mixtures with large numbers of components. In this letter, a new detector is proposed, which consists of an minimum-mean-square-error generalized decision feedback equalization-based dominant symbol combinations selection algorithm for mixture components reduction, and a Cholesky factorization-based efficient algorithm for likelihood function calculation. The new detector can obtain near optimum performance with a complexity much lower than that of a previous sequential algorithm with Gaussian approximation. This article is not yet tagged | 2007 |
| | | Lu, J. | An Epipolar Geometry-Based Fast Disparity Estimation Algorithm for Multiview Image and Video Coding read moreAbstract: Effectively coding multiview visual content is an indispensable research topic because multiview image and video that provide greatly enhanced viewing experiences often contain huge amounts of data. Generally, conventional hybrid predictive-coding methodologies are adopted to address the compression by exploiting the temporal and interviewpoint redundancy existing in a multiview image or video sequences. However, their key yet time-consuming component, motion estimation (ME), is usually not efficient in interviewpoint prediction or disparity estimation (DE), because interviewpoint disparity is completely different from temporal motion existing in the conventional video. Targeting a generic fast DE framework for interviewpoint prediction, we propose a novel DE technique in this paper to accelerate the disparity search by employing epipolar geometry. Theoretical analysis, optimal disparity vector distribution histograms, and experimental results show that the proposed epipolar geometry-based DE can greatly reduce search region and effectively track large and irregular disparity, which is typical in convergent multiview camera setups. Compared with the existing state-of-the-art fast ME approaches, our proposed DE can obtain a similar coding efficiency while achieving a significant speedup for interviewpoint prediction and coding. Moreover, a robustness study shows that the proposed DE algorithm is insensitive to the epipolar geometry estimation noise. Hence, its wide application for multiview image and video coding is promising. This article is not yet tagged | 2007 |
| | | Wang, X. | Fingerprint matching using OrientationCodes and PolyLines read moreAbstract: Sorry no abstract available for this article This article is not yet tagged | 2007 |
| | | Wang, Y. | A CMOS Image Sensor Utilizing Opacity of Nanometallic Particles for DNA Detection read moreAbstract: This paper reports a DNA detection protocol utilizing the opacity of self-assembled nanometallic particles and the optical response of a CMOS image sensor. Due to the complementary nature of the DNA hybridization process, the DNA fragments attached to the nanoparticles precipitate them only at locations where complementary DNA strands exist. The opacity of the chip surface change due to the accumulation of nanometallic particles can be used to detect the existence of some targeted DNA fragments. Ordinary light sources can be used in this approach rather than special ultraviolet light sources in the most popular fluorescence-based detection method. DNA detection has been carried out on a CMOS image sensor chip fabricated using a standard 0.5-$mu hbox{m}$ CMOS process. It has been demonstrated that the approach is very sensitive, detecting even single-base mismatched DNA targets with extremely low concentration DNA samples down to 10 pM. This article is not yet tagged | 2007 |
| | | Tian, D. | Joint Source and Channel Coding for 3-D Scene Databases Using Vector Quantization and Embedded Parity Objects read moreAbstract: Three-dimensional graphic scenes contain various mesh objects in one geometric space where different objects have potentially unequal importance regarding display. This paper proposes an object-oriented system for efficiently coding and streaming 3-D scene databases in lossy and rate-constrained environments. Vector quantization (VQ) is exploited to code 3-D scene databases into multiresolution hierarchies. For the best distortion-rate performance, adaptive quantization precisions are allocated to different objects and different layers of each object based on a weighted distortion model. Upon transmission, scalably coded objects are delivered in respective packet sequences to preserve their manipulation independency. For packet loss resilience, a plurality of FEC codes are generated as "parity objects" parallel to graphic objects, which protect the graphic objects concurrently and also preferentially in regard to their unequal decoding importance. A rate-distortion optimization framework is then developed, which performs rate allocation between graphic objects and parity objects and generates the parity data properly. We show that, by treating graphic objects jointly and preferentially in source and channel coding while preserving their independencies in transport, the proposed system reduces the receiving distortion of the 3-D database significantly compared to conventional methods This article is not yet tagged | 2007 |
| | | Ruffert, C. | Development and Evaluation of an Active Magnetic Guide for Microsystems With an Integrated Air Gap Measurement System read moreAbstract: An active magnetic levitation system based on repulsive magnetic forces was developed as a guide for a linear hybrid microstep motor. With this levitation system, the vertical force, which is typically an order of magnitude greater than the driving force, can be compensated. A capacitive measurement system provides measurement data to maintaining a constant air gap. This paper presents the design, fabrication, and first measurement results of the magnetic guide and the air gap measurement sensor. This article is not yet tagged | 2007 |
| | | Ju, S. | N-Type Field-Effect Transistors Using Multiple Mg-Doped ZnO Nanorods read moreAbstract: Nanorod field-effect transistors (FETs) that use multiple Mg-doped ZnO nanorods and a ${hbox{SiO}}_{2}$ gate insulator were fabricated and characterized. The use of multiple nanorods provides higher on-currents without significant degradation in threshold voltage shift and subthreshold slopes. It has been observed that the on-currents of the multiple ZnO nanorod FETs increase approximately linearly with the number of nanorods, with on-currents of $sim {hbox{1}}~mu{hbox{A}}$ per nanorod and little change in off-current $(sim hbox{4}times hbox{10} ^{-12})$. The subthreshold slopes and on–off ratios typically improve as the number of nanorods within the device channel is increased, reflecting good uniformity of properties from nanorod to nanorod. It is expected that Mg dopants contribute to high n-type semiconductor characteristics during ZnO nanorod growth. For comparison, nonintentionally doped ZnO nanorod FETs are fabricated, and show low conductivity to compare with Mg-doped ZnO nanorods. In addition, temperature-dependent current–voltage characteristics of single ZnO nanorod FETs indicate that the activation energy of the drain current is very low (0.05–0.16 eV) at gate voltages both above and below threshold. This article is not yet tagged | 2007 |
| | | Xu, L. | Iterative Generalized-Likelihood Ratio Test for MIMO Radar read moreAbstract: We consider a multiple-input multiple-output (MIMO) radar system where both the transmitter and receiver have multiple well-separated subarrays with each subarray containing closely spaced antennas. Because of this general antenna configuration, both the coherent processing gain and the spatial diversity gain can be simultaneously achieved. We compare several spatial spectral estimators, including Capon and APES, for target detection and parameter estimation. We introduce a generalized- likelihood ratio test (GLRT) and a conditional generalized- likelihood ratio test (cGLRT) for the general antenna configuration. Based on GLRT and cGLRT, we then propose an iterative GLRT (iGLRT) procedure for target detection and parameter estimation. Via several numerical examples, we show that iGLRT can provide excellent detection and estimation performance at a low computational cost. This article is not yet tagged | 2007 |
| | | Li, J. | Optical Communication Using Subcarrier PSK Intensity Modulation Through Atmospheric Turbulence Channels read moreAbstract: This paper studies optical communications using subcarrier phase-shift keying (PSK) intensity modulation through atmospheric turbulence channels. The bit error rate (BER) is derived for optical communication systems employing with 00K or subcarrier PSK intensity modulation. It is shown that a ${rm BER}=10^{-6}$ and a scintillion level $sigma=0.1$, an optical communication system employing subcarrier BPSK is 3 dB better than a comparable system using fixed threshold 00K. When $sigma=0.2$, an optical communication system employing subcarrier BPSK achieves a ${rm BER}=10^{-6}$ at SNR 13.7 dB, while the BER of a comparable system employing 00K can never be less than ${hbox{10}}^{-4}$ . Convolutional codes are discussed for optical communication through atmospheric turbulence channels. Interleaving is employed to overcome memory effect in atmospheric turbulence channels. An upper bound on BER is derived for optical communication systems employing convolution codes and subcarrier BPSK modulation. This article is not yet tagged | 2007 |
| | | Hu, H. | Study on Production of Inhaled Nitric Oxide for Medical Applications by Pulsed Discharge read moreAbstract: Nitric oxide (NO) is increasingly being used in the medical treatments of high blood pressure, acute respiratory distress syndrome, and some illnesses related to the lung. A convenient and safe production and operation system of NO is of interest to the medical circle. In this paper, NO was produced using pulsed discharge between needle-plate electrodes made of different materials in dry air under 1atm.The effects of varying the distance between electrodes, the pulsed discharge repetition frequency, the flow rate of clean air and the reactor operation time on the concentrations of NO and $hbox{NO}_{2}$, and the ratio of $hbox{NO}_{2}/hbox{NO}$ are presented. The method of removing $hbox{NO}_{2}$ is also introduced in detail. The results of the experiment show that on the cure of $hbox{NO}_{2}/hbox{NO}$ versus the distance between electrodes, a minimum ratio of about 7.8% has appeared at the distance of 3.5 mm. The concentrations of NO and $hbox{NO}_{2}$ are increased with increasing the pulsed discharge repetition frequency and decreased with an increase in the air flow rate. The small quantity of toxic $hbox{NO}_{2}$ could be deoxidized through catalytic process to NO which can be used in treatment. The ratio of $hbox{NO}_{2}/hbox{NO}$ decreased to a value below 3% when the gas temperature for deoxidization reached 790 K. Concurrently, the stable concentration of NO could be acquired through a pulsed arc discharge in dry air. This article is not yet tagged | 2007 |
| | | Zhang, W. -. | Identification of a diagnostic antibody-binding region on the immunogenic protein EpC1 from Echinococcus granulosus and its application in population screening for cystic echinococcosis read moreAbstract: Sorry no abstract available for this article This article is not yet tagged | 2007 |
| | | Lu, Z. | Further Results on the Maximum-Likelihood IFO Estimation for OFDM Systems read moreAbstract: Sorry no abstract available for this article This article is not yet tagged | 2007 |
| | | Pan, X. | Format-Independent Motion Content Description based on Spatiotemporal Visual Sensitivity read moreAbstract: Sorry no abstract available for this article This article is not yet tagged | 2007 |
| | | Li, J. | Optimal Search-Based Gene Subset Selection for Gene Array Cancer Classification read moreAbstract: High dimensionality has been a major problem for gene array-based cancer classification. It is critical to identify marker genes for cancer diagnoses. We developed a framework of gene selection methods based on previous studies. This paper focuses on optimal search-based subset selection methods because they evaluate the group performance of genes and help to pinpoint global optimal set of marker genes. Notably, this paper is the first to introduce tabu search (TS) to gene selection from high-dimensional gene array data. Our comparative study of gene selection methods demonstrated the effectiveness of optimal search-based gene subset selection to identify cancer marker genes. TS was shown to be a promising tool for gene subset selection. This article is not yet tagged | 2007 |
| | | Li, J. | Mobile Terminal Location for MIMO Communication Systems read moreAbstract: We propose a novel approach in the context of multiple-input multiple-output communication systems to determine the position of mobile terminals based on estimated multipath signal parameters such as angle-of-arrival, angle-of-departure and delay-of-arrival using only one Base Station. This approach minimizes the errors occurring from the estimation of multipath parameters and gives the position of the mobile terminal by simultaneously resolving a set of algebraic location equations. The root-mean-square (RMS) errors are measured and compared with the Cramer-Rao Lower Bound to demonstrate the performance of the proposed method. This article is not yet tagged | 2007 |
| | | Wu, Y. | Passive Localization of Near-Field Sources With a Polarization Sensitive Array read moreAbstract: The least squares-virtual ESPRIT algorithm (LS-VESPA) is extended to jointly estimate the direction-of-arrival (DOA) and ranges of multiple near-field sources impinging on an array of crossed dipoles. The algorithm utilizes fourth-order cumulants for direct estimation of the arrival angle and range parameters via the eigenvalues of certain constructed matrices. Compared with several existing algorithms, the loss of array aperture is effectively avoided. As a result, the proposed method can estimate DOAs and ranges of $(N-1)$ polarized near-field sources using $N$ dual-polarization sensors. Simulation results show that the proposed method outperforms a fourth-order statistics based ESPRIT-like method. This article is not yet tagged | 2007 |
2006
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| | | Datta, R. | Studying Aesthetics in Photographic Images Using a Computational Approach read moreAbstract: Sorry no abstract available for this article This article is not yet tagged | 2006 |
| | | Li, J. | Fingerprint indexing based on symmetrical measurement read moreAbstract: Sorry no abstract available for this article This article is not yet tagged | 2006 |
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