Tan-Hsu TAN San-Yuan HUANG Ching-Su CHANG Yung-Fa HUANG
A statistical model based on a partitioned Markov-chains model has previously been developed to represent time domain behavior of the asynchronous impulsive noise over a broadband power line communication (PLC) network. However, the estimation of its model parameters using the Simplex method can easily trap the final solution at a local optimum. This study proposes an estimation scheme based on the genetic algorithm (GA) to overcome this difficulty. Experimental results show that the proposed scheme yields estimates that more closely match the experimental data statistics.
With the development of COMPASS system, finding suitable and efficient multiplexing solutions have become important for the system signal design. In this paper, based on the alternative BOC (AltBOC) modulation technique, the multiplexing scheme for COMPASS Phase II B1 signals is proposed. Then, to combine all COMPASS Phase III (CP III) B1 components into a composite signal with constant envelope, the generalized majority voting (GMV) technique is employed based on the characteristics of CP III B1 signals. The proposed multiplexing schemes also provide potential opportunities for GNSS modernization and construction, such as GPS, Galileo, etc.
Te-Yuan HUANG Kuan-Ta CHEN Polly HUANG Chin-Laung LEI
Quantifying user satisfaction is essential, because the results can help service providers deliver better services. In this work, we propose a generalizable methodology, based on survival analysis, to quantify user satisfaction in terms of session times, i.e., the length of time users stay with an application. Unlike subjective human surveys, our methodology is based solely on passive measurement, which is more cost-efficient and better able to capture subconscious reactions. Furthermore, by using session times, rather than a specific performance indicator, such as the level of distortion of voice signals, the effects of other factors like loudness and sidetone, can also be captured by the developed models. Like survival analysis, our methodology is characterized by low complexity and a simple model-developing process. The feasibility of our methodology is demonstrated through case studies of ShenZhou Online, a commercial MMORPG in Taiwan, and the most prevalent VoIP application in the world, namely Skype. Through the model development process, we can also identify the most significant performance factors and their impacts on user satisfaction and discuss how they can be exploited to improve user experience and optimize resource allocation.
In this paper, we present an approach for 3D face recognition based on Multi-level Partition of Unity (MPU) Implicits under pose and expression variations. The MPU Implicits are used for reconstructing 3D face surface in a hierarchical way. Three landmarks, nose, left eyehole and right eyehole, can be automatically detected with the analysis of curvature features at lower levels of reconstruted face. Thus, the 3D faces are initially registered to a common coordinate system based on the three landmarks. A variant of Iterative Closest Point (ICP) algorithm is proposed for matching the point surface of a given probe face to the implicits face surface in the gallery. To evaluate the performance of our approach for 3D face recognition, we perform an experiment on GavabDB face database. The results of the experiment show that our method based on MPU Implicits and Adaptive ICP has great capability for 3D face recognition under pose and expression variations.
Shih-Yuan HUANG Chi-Wu MAO Kuo-Sheng CHENG
Pattern extraction is an indispensable step in bare printed circuit board (PCB) inspection and plays an important role in automatic inspection system design. A good approach for pattern definition and extraction will make the following PCB diagnosis easy and efficient. The window-based technique has great potential in PCB patterns extraction due to its simplicity. The conventional window-based pattern extraction methods, such as Small Seeds Window Extraction method (SSWE) and Large Seeds Window Extraction method (LSWE), have the problems of losing some useful copper traces and splitting slanted-lines into too many small similar windows. These methods introduce the difficulty and computation intensive in automatic inspection. In this paper, a novel method called Contour Based Window Extraction (CBWE) algorithm is proposed for improvement. In comparison with both SSWE and LSWE methods, the CBWE algorithm has several advantages in application. Firstly, all traces can be segmented and enclosed by a valid window. Secondly, the type of the entire horizontal or vertical line of copper trace is preserved. Thirdly, the number of the valid windows is less than that extracted by SSWE and LSWE. From the experimental results, the proposed CBWE algorithm is demonstrated to be very effective in basic pattern extraction from bare PCB image analysis.
Min-Hung WENG Cheng-Yuan HUNG Hung-Wei WU
The paper reports a compact and high performance dual-band bandpass filter (BPF) using two types of dual-mode resonators. The dual mode cross shaped resonator and the three dual mode ring resonators in the designed dual-band BPF are excited to control the first and second passband, respectively. It is shown that the designed and fabricated dual-band BPF has narrow bandwidths and very sharp attenuation rate due to the existence of the transmission zeros. The frequency response of the designed dual-band BPF shows good agreement between the simulations and experiments.
Min-Hung WENG Cheng-Yuan HUNG Hung-Wei WU
The investigation presents a low cost and low insertion loss X-band dual mode bandpass filter (BPF) based on inexpensive commercial FR4 substrate. The proposed filter at a central frequency f0 of 11.3 GHz has high filter performance filter with a fractional bandwidth of 14%, the insertion loss of -2.7 dB, and two transmission zeros. The designed procedures are presented in this letter and the fabricated filter verifies the proposed designed concept.
Shih-Bin JHONG Min-Hang WENG Sean WU Cheng-Yuan HUNG Maw-Shung LEE
A novel low insertion-loss and wideband microstrip bandpass filter has been designed and tested. The basic configuration of this novel dual-mode filter is a square ring resonator with direct-connected orthogonal feed lines, and dual-perturbation elements are introduced within the resonator at symmetrical location. The effects of the size of the perturbation element are studied. A new filter having wider bandwidth and transmission zeros are presented. The proposed filter responses are in good agreement with the simulations and experiments.
Cheng-Yuan HUNG Ru-Yuan YANG Min-Hang WENG Yan-Kuin SU
In this letter, the fabrication of a compact and high performance semi-lumped coplanar waveguide low-pass filter (CPW-LPF) on high resistivity silicon (HRS) substrate at millimeter wave is proposed. The design procedure and the equivalent circuit of the proposed semi-lumped CPW-LPF is discussed. The filter structure of is very simple but its performances is fairly good. This designed filter at cutoff frequency fc of 31 GHz has very good measured characteristics including the low insertion loss, sharp rejection and low group delay, due to the reduced substrate loss of HRS. Experimental results of the fabricated filter show a good agreement with the predicted results.
Shiann-Shiun JENG Chia-Yuan HUANG Chih-Yang LAI
In wireless communications, a smart antenna system utilizes an antenna array to acquire the spatial signatures of transmitted signals. This system uses the difference in the spatial signatures or the direction of arrival (DOA) of signals to correctly obtain the desired signal. This can reduce co-channel interference, mitigate the fading phenomenon caused by multipath transmissions, improve the communication quality and increase the system capacity. The purpose of this paper is to evaluate the performance of smart antennas using four beamforming algorithms applied to a wideband code division multiple access (W-CDMA) system. The simulation results show that, based on the same power consumption at the transceiver and using a Rake receiver, a W-CDMA system with a smart antenna can operate at a lower bit error rate at the specific signal to noise ratio (SNR). Moreover, the smart antenna system accommodates more users at the specific signal to interference ratio (SIR), even though a certain angle difference exists between the actual DOAs and the estimated DOAs.
Han-Yu CHEN Kun-Ming CHEN Guo-Wei HUANG Chun-Yen CHANG Tiao-Yuan HUANG
In this work, a simple method for extracting MOSFET threshold voltage, effective channel length and channel mobility by using S-parameter measurement is presented. In the new method, the dependence between the channel conductivity and applied gate voltage of the MOSFET device is cleverly utilized to extract the threshold voltage, while biasing the drain node of the device at zero voltage during measurement. Moreover, the effective channel length and channel mobility can also be obtained with the same measurement. Furthermore, all the physical parameters can be extracted directly on the modeling devices without relying on specifically designed test devices. Most important of all, only one S-parameter measurement is required for each device under test (DUT), making the proposed extraction method promising for automatic measurement applications.
Xueying WANG Yuan HUANG Xin LONG Ziji MA
In recent years, the increasing complexity of deep network structures has hindered their application in small resource constrained hardware. Therefore, we urgently need to compress and accelerate deep network models. Channel pruning is an effective method to compress deep neural networks. However, most existing channel pruning methods are prone to falling into local optima. In this paper, we propose a channel pruning method via Improved Grey Wolf Optimizer Pruner which called IGWO-Pruner to prune redundant channels of convolutional neural networks. It identifies pruning ratio of each layer by using Improved Grey Wolf algorithm, and then fine-tuning the new pruned network model. In experimental section, we evaluate the proposed method in CIFAR datasets and ILSVRC-2012 with several classical networks, including VGGNet, GoogLeNet and ResNet-18/34/56/152, and experimental results demonstrate the proposed method is able to prune a large number of redundant channels and parameters with rare performance loss.
Ayumu YAMADA Zhiyuan HUANG Naoko MISAWA Chihiro MATSUI Ken TAKEUCHI
In this work, fluctuation patterns of ReRAM current are classified automatically by proposed fluctuation pattern classifier (FPC). FPC is trained with artificially created dataset to overcome the difficulties of measured current signals, including the annotation cost and imbalanced data amount. Using FPC, fluctuation occurrence under different write conditions is analyzed for both HRS and LRS current. Based on the measurement and classification results, physical models of fluctuations are established.
Yuan HU Jingqi YAN Wei LI Pengfei SHI
A robust method is presented for 3D face landmarking with facial pose and expression variations. This method is based on Multi-level Partition of Unity (MPU) Implicits without relying on texture, pose, orientation and expression information. The MPU Implicits reconstruct 3D face surface in a hierarchical way. From lower to higher reconstruction levels, the local shapes can be reconstructed gradually according to their significance. For 3D faces, three landmarks, nose, left eyehole and right eyehole, can be detected uniquely with the analysis of curvature features at lower levels. Experimental results on GavabDB database show that this method is invariant to pose, holes, noise and expression. The overall performance of 98.59% is achieved under pose and expression variations.
Min-Hang WENG Chang-Sin YE Cheng-Yuan HUNG Chun-Yueh HUANG
A novel dual mode bandpass filter (BPF) with improved spurious response is presented in this letter. To obtain low insertion loss, the coupling structure using the dual mode resonator and the feeding scheme using coplanar-waveguide (CPW) are constructed on the two sides of a dielectric substrate. A defected ground structure (DGS) is designed on the ground plane of the CPW to achieve the goal of spurious suppression of the filter. The filter has been investigated numerically and experimentally. Measured results show a good agreement with the simulated analysis.
With the development of global navigation satellite systems (GNSS), the interference among global navigation satellite systems, known as the radio frequency compatibility problem, has become a matter of great concern to system providers and user communities. The acceptable compatibility threshold should be determined in the radio frequency compatibility assessment process. However, there is no common standard for the acceptable threshold in the radio frequency compatibility assessment. This paper firstly introduces the comprehensive radio frequency compatibility methodology combining the spectral separation coefficient (SSC) and code tracking spectral sensitivity coefficient (CT_SSC). Then, a method for determination of the acceptable compatibility threshold is proposed. The proposed method considers the receiver processing phase including acquisition, code and carrier tracking and data demodulation. Simulations accounting for the interference effects are carried out at each time step and every place on earth. The simulations mainly consider the signals of GPS, Galileo and BeiDou Navigation Satellite System (BDS) in the L1 band. Results show that all of the sole systems are compatible with other GNSS systems with respect to a special receiver configuration used in the simulations.
Jianzhang CHEN Jianping LI Yuanyuan HUANG
Nonprimitive non-narrow-sense BCH codes have been studied by many scholars. In this paper, we utilize nonprimitive non-narrow-sense BCH codes to construct a family of asymmetric quantum codes and two families of quantum convolutional codes. Most quantum codes constructed in this paper are different from the ones in the literature. Moreover, some quantum codes constructed in this paper have good parameters compared with the ones in the literature.
Yuan HU Li LU Jingqi YAN Zhi LIU Pengfei SHI
In this paper, we present the sexual dimorphism analysis in 3D human face and perform gender classification based on the result of sexual dimorphism analysis. Four types of features are extracted from a 3D human-face image. By using statistical methods, the existence of sexual dimorphism is demonstrated in 3D human face based on these features. The contributions of each feature to sexual dimorphism are quantified according to a novel criterion. The best gender classification rate is 94% by using SVMs and Matcher Weighting fusion method. This research adds to the knowledge of 3D faces in sexual dimorphism and affords a foundation that could be used to distinguish between male and female in 3D faces.
In the framework of the modernization plan of COMPASS system, the existing COMPASS signals should be transmitted along with the modernized signals to maintain backward compatibility. In this paper, an efficient multiplexing scheme based on the optimal aligning method for combining COMPASS Phase II B3 and Phase III B3 signals is proposed, which offers significantly higher efficiency than Interplex and Generalized Majority Voting (GMV) multiplexing methods. The proposed scheme can provide potential opportunities for COMPASS system and other global navigation satellite systems (GNSS) modernization and construction plans.