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With the highly demanded requirements for manipulating large scientific datasets, scientists are in need of flexible cluster-level software to execute fast scientific data analysis. In this paper, we discuss whether the Apache Spark framework is suitable for scientific data management. We present our system SparkArray, which extends Spark with a multidimensional array data model and a set of common...
This paper presents a millimeter-wave fully differential compact transformer-based passive reflective-type phase shifter (RTPS). The proposed RTPS design employs two transformer-based 90° couplers and two transformer-based multi-resonance reflective loads, offering low-loss and an ultra-compact chip size. A proof-of-concept design at 62GHz is implemented in a standard 130nm BiCMOS process with a core...
Presented is a novel half Gb DRAM device for 3D stacked systems utilizing TSV. It is designed through the use of a new computer-aided design methodology and which realizes 819 Gb/s bandwidth across 16 channels and <10ns read latency on a 45nm DRAM process. The architecture is based on small subarrays with short WL and BL to realize the low latency and energy efficiency. We also integrated several...
We consider the source number estimation problem in the presence of unknown spatially nonuniform noise and underdetermined mixtures. We develop a new attractive source number estimator by replacing the covariance with the Fourth-Order (FO) cumulant of the observations. Furthermore, a Modified Minimum Description Length (MMDL) principle is proposed to reduce the divergence of the singular values corresponding...
This paper presents a new method to estimate the direction of arrival (DOA), which is based on the reduced rank covariance matrix. The new method can reduce the computation complexity greatly and keep a good performance at the same time. For comparison purpose, we compare this new method with the classical multiple signal classification (MUSIC). The results of the root mean square error and the computation...
This paper presents a new methodology based on the reduced rank covariance matrix for direction of arrival (DOA) estimation, which can be have lower complexity compare to the classical Multiple Signal classification (MUSIC). Since the reduced rank covariance matrix contains all the information that the traditional covariance has, the performance of the proposed method is almost the same with the classical...
Sample covariance matrix (SCM) and its eigenvalue decomposition (EVD) are needed in the conventional subspace based algorithm. Under normal circumstances, the computation burden is really heavy, especially for the estimation of the coherent signals which also needs to use the spatial smooth technology. In this paper, we firstly use the Nyström-Based method to obtain the signal subspace, which results...
In this paper, the effect of radiation performance of antenna array in confined space on the field coverage is analyzed. In order to find the suitable radiation pattern that can give smoother wave coverage in confined space, a simple but efficient numerical method based on the parallel FDTD method and point source array approximation is presented. The current on each array element is obtained from...
New foreground digital calibration methods are proposed for successive approximation register (SAR) analog-to-digital converters (ADCs) to reduce the performance loss due to digital-to-analog converter (DAC) mismatch. A set of calibration coefficients which represent the actual weights of the specified patterns is obtained during foreground calibration, and then used during normal operation to correct...
To distributed sources, the usage of conventional point-source model will cause inaccuracy in the direction-of-arrival (DOA) estimation. Conventional methods for distributed sources usually estimate the DOAs and the distribution parameters with multi-dimensional peak search operations, which will lead to much higher computational complexity than that in the point source model. In this paper, a blind...
The design method of new planar waveguide-slot array antenna with a centre hole is presented in the paper. Throughout analyzing the effects on patterns sidelobes in the waveguide-slot array antenna with a centre hole, the array's patterns is optimized by Genetic Algorithm method. The results of design are good and compare very well with ones analyzed by the emulational software of the electromagnetic...
Tracking multiple objects under occlusion is one of the most challenging issues in computer vision. Occlusion results in mistaken match when finding the most similar candidate. Adapting to the change of objects is essential for tracking as objects often undergo intrinsic changes, but noise is unavoidably introduced during updating of the object, and this further confuses the tracker. In order to address...
A 5th-order Chebyshev active RC complex filter for wireless sensor networks with automatic frequency tuning is presented in this paper. This filter is synthesized from 5th-order low-pass LC prototype, and designed using leapfrog structure. An automatic frequency tuning is used to prevent the deviation of the RC constant of the filter. This filter is fabricated in TSMC 0.18μm CMOS process. The measurement...
A 10-Gb/s transimpedance amplifier (TIA) for the parallel optical receiver module is realized in 0.18-μm CMOS technology. The proposed TIA employs a regulated cascode (RGC) input structure and adopts active inductor peaking and feedback techniques to enhance the bandwidth. Besides, a noise optimization is processed. The TIA provides a conversion gain of 50 dBΩ and 3-dB bandwith of 7 GHz. The measured...
Three-dimensional (3D) supercapacitors have been demonstrated using vertically aligned carbon nanotubes (CNT) arrays and electroplated nickel nanoparticles. Two significant achievements have been demonstrated in this work: (1) a unique and reliable vacuum-assisted electroplating methodology for the uniform deposition of nickel nanoparticles on CNTs up to 150 ??m in length, and (2) usage of pseudo...
In this paper, a novel p-FFT method based on characteristic basis function method (CBFM) has been proposed and implemented to solve electromagnetic scattering by large scaled finite periodic arrays. The CBFs can be constructed by solving the integral equations associated with one unit cell at plane wave incidence from different incident angles and with different polarizations. Then, the unit cell...
All the quorum generation algorithms based on greedy algorithm before denotes that the number of nodes selected to insert the quorum should change from one to N0.5, and the time complexity should change from O (2N3.5) to O (N!). Based on this phenomenon, a reasonable supposition will be proposed as follow: When the number of nodes selected to insert in quorum once is belong with the natural number...
We present a USB-based, highly directional, and portable microphone array device that delivers a crisp, clear and noise-reduced speech signal. This device consists of four linearly distributed microphone sensors and a filter-and-sum beamformer designed using broadband beam-forming algorithm. The device has a narrow acoustic beam pattern and identical frequency responses for almost all speech bands...
The performance of the SAGE algorithm in channel parameter estimation could be severely degraded by the error accumulated from the interference cancellation (IC) stage as each path in the channel is estimated sequentially. This is a direct result of removing inaccurate estimate of the interfering paths, and errors occurring at the IC stage for the first few paths will be accumulated and influence...
In this paper, a novel robust adaptive beamformer based on principal component regression (PCR) is derived. Unlike many existing methods, the proposed method is completely automatic (or so-called parameter-free), which means, it do not need the choice of user parameters. The performance of our approach is illustrated by numerical simulations and compared to other robust adaptive beamformers. The simulation...
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