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In wideband digital array radars (DARs), channel equalization and fractional delay (FD) are needed for digital beamforming (DBF) since they can compensate the amplitude and phase imbalance between each channel as well as the aperture effect. Traditionally, the compensations were usually implemented separately via different finite impulse response (FIR) filters based on different design criterions...
As we move into many-core era fueled by Moore's Law, it has become unprecedentedly challenging to provide the shared memory abstraction through directory-based cache coherence. The main difficulty is the high area and power overhead of the directory in tracking the presence of a memory block in all the private caches. Sparse directory offers relatively better design trade-offs by decoupling the coherence...
A novel optically transparent RFID reader antenna using Indium tin oxide (ITO) film which can operate in the ultrahigh frequency (UHF) band is proposed in this paper. The proposed antenna is presented for a feasibility study for integration into the mirror surface of fitting rooms in clothing stores. The interactive information of clothing can be automatically provided for the client through RFID...
A multiband compact planar terminal antenna is designed and proposed in this paper, which is suitable for multi-functional wireless communication systems. The proposed antenna consists of a patch with two slots on it and a meandered strip loaded on the top. Two parasitic stubs are etched at the back of the antenna to widen the operating frequency band. The operating bandwidths of the antenna cover...
In this paper, a competitive three-phase buck-type PFC converter named SWISS Rectifier is comprehensively researched to inhibit mains current distortion. The control structure which would realize PFC function but also introduce harmonic components to mains current is illustrated and improved to achieve better performance. The origin of the mains current distortion occurred at the sector boundaries...
Space object image enhancement is an important problem in computer vision, which is also a fundamental issue for space observation. Instead of single image enhancement methods, we introduce a method based on intrinsic image de-composition by using an image sequence to solve the problem of space object image enhancement. We first capture several space object image sequences via ground simulation and...
We address the problem of vision-based pose estimation for space objects, which is to estimate the relative pose of a target spacecraft using imaging sensors. We develop a novel monocular vision-based method by employing Gaussian process regression (GPR) to solve pose estimation for space objects. GPR is a powerful regression model for predicting continuous quantities, and can easily obtain and express...
The paper presents a rapid analysis method of THz double elliptical mirror system based on the Gaussian beam (GB) expansion and tracking, working frequency at 119 GHz. Gaussian far-field pattern is firstly expanded into a series of sub-GBs making use of point matching (PM), then tracking GBs successively with specular reflection is to obtain near field and far field pattern. Synthesis results of mirror...
A novel tanh-profile corrugated feedhorn application in quasi-optical system is proposed in this paper. The simulation results of the corrugated feedhorn are carried out via CHAMP. The simulated bandwidth is from 300GHz to 350GHz and the center frequency is 324GHz. The proposed tanh-profile corrugated feedhorn application can achieve very low return loss, sidelobe and cross polarization levels around...
With the extensive use of sensor-embedded smart phones, Location-Based Social Networks (LBSN) become more and more popular among online social networks in recent years. In social networks, constructing the shortest path with minimum cost between any two nodes efficiently is vital for both graph analysis and implementation of applications. This is well known as the routing problem in social networks...
With the growing popularity of smart phones and the rapid development of Internet, the traditional network management system cannot adapt itself to the requirement intelligently. If we can use historic data to predict the trend of network traffic accurately, a better planning of network is more likely to be made and limited resource can be allocated and scheduled reasonably. However, massive amounts...
We propose stochastic performance analysis in order to provide probabilistic quality-of-service guarantees in on-chip packet-switching networks. In contrast to deterministic analysis which gives per-flow absolute delay bound, stochastic analysis derives per-flow probabilistic delay bounding function, which can be used to avoid over-dimensioning network resources. Based on stochastic network calculus,...
This paper proposes an image green enhancement method based on luminance and hue. In the current algorithm, there are two main issues, i.e., the presence of over-saturation and color deviation, which can not satisfy people's demands for stronger green enhancement. To solve these problems, the correct mathematical model about luminance on chrominance constraint relations is proposed and an appropriate...
Constant current control is a difficult issue for LLC resonant converter due to its variable frequency operation. After detailed analysis on the short circuit operation of conventional LLC DC-DC converter, a novel current-limiting method with the help of diode clamping is proposed. Against the conventional wisdom, the switching frequency is reduced toward zero to control the output current under over-load...
Community Question Answering (CQA) sites have become valuable repositories that host a massive volume of human knowledge. How can we detect a high-value answer which clears the doubts of many users? Can we tell the user if the question s/he is posting would attract a good answer? In this paper, we aim to answer these questions from the perspective of the voting outcome by the site users. Our key observation...
A novel THz Ultra Gaussian corrugated feed horn is proposed in this paper, which combines a sine-squared and a straight parallel profile to excite and couple the HE11 and HE12 modes at the optimum range of inputs. The center frequency is 0.34THz and the bandwidth is larger than 10%. The maximum fundamental mode Gaussian power coupling efficiency increases to approximately 99.8% in this design. Typically,...
This paper proposes a novel demosaicing algorithm based on improved gradients with color correlation. Compared to conventional method, especially on region with dense lines and textures, the proposed method may reduce the probability on the edge direction judgment, which may lead to obvious artifacts. The improved adaptive gradients calculation uses color correlation information. The proposed method...
Currently, the evaluation of placental maturity has mainly focused on subjective measure, which highly depends on the observation and experiences of the clinicians and not reliable. This paper proposes a new method for grading placenta maturity in B-mod ultrasound (US) images automatically based on local intensity order pattern (LIOP) and fisher vector (FV). After extracting invariant LIOP feature...
This paper presents the analysis of the focal region field of the proposed tri-reflector for Compact Antenna Test Range and the matched aperture field for a multimode corrugated horn. The analysis has been carried out by commercial software GRASP and the developed MATLAB program. Numerical results are presented, showing a good match between the two fields. This field can be used to design a matched...
This paper proposed a wideband antenna for global navigation satellite systems (GNSSs). The antenna has a −10 dB impedance bandwidth of 62.40% from 0.86 GHz to 1.64 GHz, 3 dB axial ratio (AR) bandwidth of 51.30% from 1.00 GHz to 1.69 GHz. Its circularly polarized (CP) bandwidth of 48.48% from 1.00 to 1.64 GHz covers the full band of four GNSSs (GPS, GLONASS, Compass and Galileo). In addition to utilizing...
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