This paper introduces evolutionary generation method of robust corner detectors for rotated images. Previous Harris, SUSAN and FAST corner detectors are highly efficient for well-defined corners, but frequently mis-detect as corners the corner-like edges which are often generated in rotated images. In this paper, we have focused on this challenging problem and proposed using Genetic Programming to do automated generation of corner detectors that work robustly on rotated images. Especially, a well-devised terminal set is proposed based on intensity-related information, several mask sizes, and amount of contiguity of neighboring pixels of similar intensity. This method is then compared to three existing corner detectors on test images and shows superior results.
This paper presents a new Multiple Description Lattice Vector Quantization (MDLVQ) based on A4 lattice quantizers for multiple description coding abbreviated as MDLVQ-A4. The Coinciding similar A4 sublattices are used to quantize the input stream for multiple description coding system. The use of multiple coinciding quantizers eliminates the labeling function of the traditional schemes. Experimental results of MDLVQ-A4 scheme for image coding show a higher performance in terms of PSNR of the side decoders as compared to the renowned techniques of image coding for several test images.
Radio frequency identification systems which use radio frequency for object identification are widely developed nowadays. Security problems such as privacy and untraceability had lead to propose numerous protocols for RFID systems. However most of these attempts have not been successful. In this paper we present a desynchronization attack against a recently proposed RFID protocol called Anonymous Forward-Secure Mutual Authentication or in short AFMAP. The complexity of attack is a few runs of the protocol and the success probability is 1. To the best of our knowledge, this is the first attack on AFMAP.
The static current-voltage (I-V) characteristics of a diamond Schottky barrier diode (SBD) have been previously studied. This paper experimentally studies the switching characteristics of a diamond SBD in comparison with the characteristics of a silicon carbide (SiC) SBD. The forward conduction current and the reverse bias voltage dependency of the reverse recovery phenomenon during the fast-switching operation of an SBD are evaluated. The experimental results validate the majority carrier device characteristics of the diamond SBD under study. The results indicate the feasibility of using a diamond device in a power conversion circuit.
we have proposed an open stubs loaded tapered compact microstrip resonator cell (OSL-TCMRC) for designing of the lowpass filter with wide stopband and low insertion loss. By optimization of this structure and insertion of open stubs, undesirable response and harmonics will be suppressed. In order to validate the proposed design, a lowpass filter with low insertion loss in passband and wide stopband is designed, fabricated and measured. Simulation results are compared to the experimental results and good agreement between them was achieved.
We proposed a fuzzy approach for MOS transistor model determination. We used TSMC CMOS 0.35um library that is used for circuit simulation in HSPICE. Because process variation is a fuzzy phenomenon so our calculations will be more real and close to the process variations and with using this fuzzy algorithm, the simulation results will be more near to the real world.
A high-power three-antenna measurement system is successfully developed for calibrating the complex antenna factor of low-sensitivity sensors. First, the system is compared with a conventional three-antenna measurement system using double-ridged guide horn antennas, and the validity of the high-power system is confirmed. Then, the low-sensitivity optical electric field sensor is calibrated by this system and this result is compared with the standard field method. A good agreement between these results is obtained. The high-power three-antenna measurement system is therefore found effective for calibrating the complex antenna factor of low-sensitivity sensors.
This paper presents a new method to design microstrip array antennas. In this method, non-regular polygonal patches are used and their shapes are determined by genetic algorithm (GA) depending on the design needs. The positions of patch vertexes are optimized by GA. Connecting the vertexes with an incorrect order yields to an invalid patch which its edges intersect themselves. So, ant colony optimization (ACO) is used to find correct connection order of vertexes. This method is used to design an array antenna with low amount of return loss and mutual coupling. Finally, design procedure is verified by simulation.
One of the most challenging issues in Random Early Detection (RED) algorithm is how to set its parameters to achieve high performance for the dynamic conditions of the network. While original RED uses fixed values for its parameters, this paper proposes a novel algorithm, in which particle swarm optimization (PSO) technique is used to dynamic tuning of RED's parameters. For this purpose, we formulate the active queue management issue as an optimization problem to be solved by PSO algorithm. Then, we employ PSO technique to direct the system to its optimum point. Simulation results show that the proposed algorithm behaves remarkably better than RED in terms of queue size, number of dropped packets, bottleneck utilization and global stability.
In this paper, a novel self-adjustable offset min-sum LDPC decoding algorithm is proposed for ISDB-S2 application. We present for the first time a uniform approximation of the check node operation through mathematical induction on Jacobian logarithm and theoretically shows that the offset value is mainly dependent on the difference of the two most unreliable inputs from the bit nodes, which makes the offset value adjustable during the iterative decoding procedure. Simulation results for all 11 code rates of ISDB-S2 demonstrate that the proposed method can achieve an average of 0.15dB gain compared to the Min-sum based algorithms, and consumes only 1.21% computation complexity compared to BP-based algorithms in the best case.
In this paper, a simple method to obtain a notch in the ultra-wideband (UWB) bandpass filter is presented. UWB bandpass filter is designed using ground plane aperture technique. To reject the undesired wireless local area network (WLAN) signals, a complementary single split ring resonator (CSSRR) is placed under the coupled lines of the bandpass filter. The CSSRR has flat insertion loss and good roll off rate than the conventional complementary split ring resonator (CSRR). The proposed filter offers an ultra wide bandwidth bandpass filter characteristics with a steep notch function around 5.5GHz. Hence the interference from the devices operated in the IEEE 802.11a spectrum can be avoided properly. IE3D simulation results of the notched UWB bandpass filter is in good agreement with the measurement results.
A new multi-functional vehicle antenna, consisting of LNA-integrated non-uniform helical antenna for both FM and terrestrial digital multimedia broadcasting (TDMB) operation, and a monopole antenna for the PCS operation is proposed. The proposed architecture combines the three antennas in such a way as to maximum the reuse of the antenna structure and, thereby, reduces the overall antenna size. To realize a single-port excitation of three different band antennas, the PCS antenna and FM antenna is simultaneously excited with the help of steel stud while the TDMB antenna is magnetically coupled from a portion of the FM antenna body.
In this paper, we present a graph-based fingerprint classification algorithm that deals with ones collected from touch scanners. A relational graph, which reflects distribution of ridge directions in an orientation field, is constructed with additional emphasis on the distribution of the ridges inside the core area that is defined to minimize external influences. For classification, a general edit distance scheme is employed to measure the similarity between the constructed graph and pre-trained graph models. Experimental results using a database in FVC2004 show that the proposed algorithm has higher classification accuracy than other structural approaches.
In this paper, we propose a new tuning method of threshold, which is a parameter of a switching median filter, by using the distribution distance. The switching median filter detects noise-corrupted pixels based on a threshold, and restores only the detected pixels. The present switching median filter deals with the random-valued impulse noises, whose distribution is ideally assumed as a uniform. In the present method, the threshold is tuned by evaluating a distribution distance between the assumed and the detected noises. L1-norm is used here as the distribution distance. The effectiveness of the proposed method is verified by some experiments.
This paper discusses an optical access system that enables emergency voice communication when a power failure occurs in a user's house, and we also propose a super low power consumption detector that consists entirely of passive devices. And we present applied techniques that comprise sub-carrier multiplexing for user multiplexing/demultiplexing and a new passive detector for signal regeneration driven solely by the transmitted optical signal power. Then we confirm the feasibility of the system experimentally by using a prototype detector that has 8-channel selectivity. We report the realization of the intended detector functions that we achieved by back-to-back simulated voice signal regeneration.
This paper presents an analytical-empirical method for the design of continuous-time ΔΣ modulators. For this purpose, both the Schreier and SISO toolboxes are employed. This method improves the robustness of the modulator against imperfections such as excess loop delay and unity-gain bandwidth of the opamps.