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With the growth of system scale, it has become very difficult problem that how to ensure the security of service in grid. In order to resolve this problem, we propose an auditing mechanism for the security of service in grid. In the auditing mechanism, we first define and analyze some atomic services for grid application which are based on the service processes of task. Then, we propose some detecting...
This paper reviews our recently developed fast and efficient algorithms for multiscale structure modeling. Low-frequency electromagnetic analysis becomes indispensable for multi-scale structures because of the involved minute length-scale compared to wavelength and mid length-scale on the order of wavelength or larger, where wave physics meets circuit physics. We are currently investigating stable...
In this paper, a miniaturised Butler matrix using 3-dB cross-slotted patch hybrids is presented. By asymmetrically loading the inductive cross-slotted slots on four patches, compact patch hybrid couplers can be achieved. After properly installing two quarter-wavelength short-circuited stubs as phase shifters, the overall size of the resultant Butler matrix is largely reduced. In comparison with traditional...
In this work, a Calderón multiplicative preconditioner (CMP) is proposed for the augmented electric field integral equation (A-EFIE) to improve the convergence. To avoid the imbalance between the vector potential and the scalar potential in the traditional EFIE, A-EFIE considers both the charge and the current as unknowns. After implementing the appropriate frequency scaling and the enforcement of...
In this paper, a simplified form of electric field integral equation with Calderón multiplicative preconditioner (CMP-EFIE) is presented for solving capacitive problems in the low-frequency regime. The decomposed three-term CMP-EFIE, though very stable, cannot capture the current accurately for a capacitor at low frequencies. By omitting the part of the hypersingular preconditioned term, the electric...
This paper presents a brief review and recent development of surface integral equation solvers for multiscale interconnects and circuits modeling. As the future production processes down to 5 nm and the operating frequency increases, both multi-scale and large-scale natures should be taken into account in the electromagnetic simulations. Fast, efficient, stable, and broadband integral equation based...
In this paper, a novel type of frequency responses of ultra-wideband (UWB) bandpass filter is presented. Different from the traditional Chebyshev transfer function filters, the inband reflection lobes can be theoretically controlled and realized to be a dome-shaped envelope filtering responses. The amplitude of reflection coefficients near the band edge can be easily assigned to be lower than those...
In this paper, a compact dual-band bandpass filter using the half-wavelength (λ/2) spiral-resonators and loaded open-stubs is proposed. First, the dual-resonances are employed by the λ/2 spiral-resonators. Secondly, the loaded open-stubs can not only adjust the second resonance for the designed limit, but also suppress the spurious for the upper stopband bandwidth extension. Thirdly, based on the...
As the population of space debris in orbit around the Earth grows, the probability for catastrophic collisions increases. Many agencies such as the IADC, FCC, and UN have proposed space debris mitigation guidelines or recommendations. For example, a minimum increase in perigee altitude of 235km + (1000 Cr A / m) where Cr is the solar radiation pressure coefficient, A/m is the aspect area to dry mass...
Microwave rectifiers have been developed in various forms since the microwave power transmission (MPT) began to attract researchers' attention. A hybrid simulation method is implemented by the combination of IE3D and ADS simulation to realize a fast and accurate rectifier design in this paper. A 5.8 GHz microstrip rectifier based on HSMS 286 Schottky diode is realized and fabricated based on the proposed...
In this paper, we propose a compact dual-band planar 3-dB hybrid patch coupler with embedded spiral open stubs. In order to install stubs on the hybrid for dual-band application, four equally circular holes are firstly etched on the cross-slotted patch, where the performance of the single-band hybrid coupler is almost maintained because of the slightly influence on the current distribution along the...
In this paper, a wireless power transfer (WPT) system based on two spiral magnetic-coupled resonators is studied and realized on the printed circuit board (PCB). For the mid-range energy transfer, the microwave filter design theory can be employed to explain the basic principle of magnetic induction in WPT system. Based on the filtering transfer function, the power transfer efficiency is defined by...
We use Candela CS20 optical surface analyzer to detect micropipe and downfall defects of 4H-SiC epilayers grown on 3-inch 4H-SiC substrates. Although both micropipes and downfalls appear as growth pits with different sizes in the topographic image, the micropipes are found to have a signature of bright elongated streaks in the scattered light image. Using this unique feature, the micropipes are distinguished...
In this paper, a compact hybrid-integrated microstrip rectangular ring antenna with circular polarization is proposed for RFID reader. By integrating a cross-slotted patch hybrid with a rectangular ring antenna in the same plane, the proposed antenna has the features of circular polarization, compact size, low cost, light weight and unique flexibility for RFID applications. A prototype operating at...
This paper addresses the low-frequency problems for open capacitive problems in the electric field integral equation using Calderón multiplicative preconditioner (CMP-EFIE). At low frequencies, the CMP-EFIE fails to extract accurate high-order current for a capacitor problem. By representing the electric current at different frequency orders as a power series, we successfully apply the perturbation...
In this paper, a miniaturized dual-band bandpass filter using the half-wavelength (λ/2) spiral-resonators and loaded open-stubs with a spiral-coupled scheme is proposed. The mechanism of the dual-band operation is shown as follows. The first passband resonance is employed by the fundamental resonant-mode (i.e., f1) of the λ/2 spiral-resonator. Meanwhile, the loading effect introduced by the loaded...
This paper presents miniaturized microstrip bandpass filters based on the quarter-wavelength (λ/4) spiral-coupled scheme (SCS). By introducing the mutual electric and magnetic coupling between two SCS, two resonant modes can be well adjusted to form a passband and four transmission zeros can be generated to obtain a good out-of-band rejection. Without modifying the initial design parameters, another...
This paper deals with the proposal, design and implementation of a class of compact dual- and triple-band bandpass filters with two transmission poles in each passband using a single microstrip ring resonator. Two methods are first presented to design two types of dual-mode dual-band bandpass filters using a single resonator. One is to synchronously excite the two pairs of the first and third-order...
The individual body formed by the many body effects of factors, there has been complex nonlinear relationship between them. This paper applies the neural network to train simulation between impact factor and individual constitution of the relationship, influence factor and physical fitness between “super quantization” relationship, this paper proposes a new algorithm of association rules data mining...
IPTV multicasting is an important service for residential users. In this paper, we explore how to allocate resources to different layer-encoded IPTV programs using multicast services in relay-assisted centralized wireless access networks. We consider the scenario of two-hop relay stations, and the MAC protocol is OFDMA-based, as in IEEE 802.16m or Long Term Evolution-Advanced (LTE-A). We formulate...
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