A wideband design of the waveguide short-slot 2-plane coupler with 2×2 input/output ports is designed, fabricated, and evaluated. Using coupling coefficients of complementary propagating modes which are TE11, TE21, and TE30 modes, the flatness of the output amplitudes of 2-plane coupler is improved. The coupler operates from 4.96GHz to 5.27GHz (bandwidth 6.1%) which is wider than the former coupler without considering the complementary propagating mode from 5.04GHz to 5.17GHz (bandwidth 2.5%).

Association rule mining discovers relationships among variables in a data set, representing them as rules. These are expected to often have predictive abilities, that is, to be able to predict future events, but commonly used rule interestingness measures, such as support and confidence, do not directly assess their predictive power. This paper proposes a cross-validation -based metric that quantifies the predictive power of such rules for characterizing software defects. The results of evaluation this metric experimentally using four open-source data sets (Mylyn, NetBeans, Apache Ant and jEdit) show that it can improve rule prioritization performance over conventional metrics (support, confidence and odds ratio) by 72.8% for Mylyn, 15.0% for NetBeans, 10.5% for Apache Ant and 0 for jEdit in terms of SumNormPre(100) precision criterion. This suggests that the proposed metric can provide better rule prioritization performance than conventional metrics and can at least provide similar performance even in the worst case.

The micro-mechanism of molten pool and metal droplet sputtering are significant to the material erosion caused by breaking or making arcs especially for high-power switching devices. In this paper, based on Navier-Stokes equations for incompressible viscous fluid and potential equation for electric field, a 2D axially symmetric simplified hydrodynamic model was built to describe the formation of the molten metal droplet sputtering and molten pool under arc spot near electrode region. The melting process was considered by the relationship between melting metal volumetric percentage and temperature, a free surface of liquid metal deformation was solved by coupling moving mesh and the automatic re-meshing. The simulated metal droplet sputtering and molten pool behaviors are presented by the temperature and velocity distribution sequences. The influence mechanism of pressure distribution and heat flux on the formation of molten pool and metal droplet sputtering has been analyzed according to the temperature distribution and sputtering angles. Based on the simulation results, we can distinguish two different models of the molten metal droplet sputtering process: edge ejection and center ejection. Moreover, a new explanation is proposed based on calculated results with arc spot pressure distribution in the form of both unimodal and bimodal. It shows that the arc spot pressure distribution plays an important role in the metal droplet ejected from molten pool, the angle of the molten jet drop can be decreased along with the increment of the arc spot pressure.

Let Fpm be the field of pm elements where p is an odd prime. In this letter, binary sequence pairs of period N=pm-1 are presented, where sequences are generated from the polynomial x2-c for any c Fpm{0}. The cross-correlation values of sequence pairs are completely determined, our results show that those binary sequence pairs have optimal three-level correlation.

Interference in ad hoc WLANs is a common occurrence as there is no centralized access point controlling device access to the wireless channel. IEEE 802.11 WLANs use carrier sense multiple access with collision avoidance (CSMA/CA) which initiates the Request to Send/Clear to Send (RTS/CTS) handshaking mechanism to solve the hidden node problem. While it solves the hidden node problem, RTS/CTS triggers the exposed node problem. In this paper, we present an evaluation of a method for reducing exposed nodes in 802.11 ad hoc WLANs. Using asymmetric transmission ranges for RTS and CTS frames, a cross-layer design is implemented between Layer 2 and 3 of the OSI model. Information obtained by the AODV routing protocol is utilized in adjusting the RTS transmission range at the MAC Layer. The proposed method is evaluated with the NS-2 simulator and we observe significant throughput improvement, and confirm the effectiveness of the proposed method. Especially when the mobile nodes are randomly distributed, the throughput gain of the Asymmetric RTS/CTS method is up to 30% over the Standard RTS/CTS method.

This paper describes a top-down design methodology to optimize resonant capacitance in a wireless power transfer system with 3-D stacked two receivers. A 1:2 selective wireless power transfer is realized by a frequency/time division multiplexing scheme. The power transfer function is analytically formulated and the optimum tuning capacitance is derived, which is validated by comparing with system simulation results. By using the optimized values, power transfer efficiencies at 6.78MHz and 13.56MHz are simulated to be 80% and 84%, respectively, which are <3% worse than a conventional wireless power transfer system.

In this letter, we explored the usage of spatio-temporal information in one unified framework to improve the performance of multichannel speech recognition. Generalized cross correlation (GCC) is served as spatial feature compensation, and an attention mechanism across time is embedded within long short-term memory (LSTM) neural networks. Experiments on the AMI meeting corpus show that the proposed method provides a 8.2% relative improvement in word error rate (WER) over the model trained directly on the concatenation of multiple microphone outputs.

In this letter, we propose a solution for managing multiple adaptive streaming clients running on different devices in a wireless home network. Our solution consists of two main aspects: a manager that determines bandwidth allocated for each client and a client-based throughput control mechanism that regulates the video traffic throughput of each client. The experimental results using a real test-bed show that our solution is able to effectively improve the quality for concurrent streaming clients.

The microfabrication technique based on SR (Synchrotron Radiation) direct etching process has recently been applied to construct PTFE microstructures. This paper attempts to fabricate an integrated PTFE-filled waveguide Butler matrix for short millimeter-wave by SR direct etching. First, a cruciform 3-dB directional coupler and an intersection circuit (0-dB coupler) are designed at 180 GHz. Then, a 4×4 Butler matrix with horn antennas is designed and fabricated. Finally, the measured radiation patterns of the Butler matrix are shown.

The fifth generation (5G) system using millimeter waves is considered for application to high traffic areas with a dense population of pedestrians. In such an environment, the effects of shadowing and scattering of radio waves by human bodies (HBs) on propagation channels cannot be ignored. In this paper, we clarify based on measurement the characteristics of waves scattered by the HB for typical non-line-of-sight scenarios in street canyon environments. In these scenarios, there are street intersections with pedestrians, and the angles that are formed by the transmission point, HB, and reception point are nearly equal to 90 degrees. We use a wide-band channel sounder for the 67-GHz band with a 1-GHz bandwidth and horn antennas in the measurements. The distance parameter between antennas and the HB is changed in the measurements. Moreover, the direction of the HB is changed from 0 to 360 degrees. The evaluation results show that the radar cross section (RCS) of the HB fluctuates randomly over the range of approximately 20dB. Moreover, the distribution of the RCS of the HB is a Gaussian distribution with a mean value of -9.4dBsm and the standard deviation of 4.2dBsm.

We report room-temperature atomic layer deposition (ALD) of SnO2 using tetramethyltin (TMT) as a precursor and plasma-excited humidified argon as an oxidizing gas and investigate the saturation behaviors of these gases on SnO2-covered Si prisms by IR absorption spectroscopy to determine optimal precursor/oxidizer injection conditions. TMT is demonstrated to adsorb on the SnO2 surface by reacting with surface OH groups, which are regenerated by oxidizing the TMT-saturated surface by plasma-excited humidified argon. We provide a detailed discussion of the growth mechanism. We also report the RT ALD application to the RT TFT fabrication.

This work presents a hybrid formulation of the stochastic reduced order model (SROM) algorithm, which makes use of Gauss quadrature, a key ingredient of the stochastic collocation method, to avoid the cumbersome optimization process required by SROM for optimal extraction of the sample set. With respect to classic SROM algorithms, the proposed formulation allows a significant reduction in computation time and burden as well as a remarkable improvement in the accuracy and convergence rate in the estimation of statistical moments. The method is here applied to a specific case study, that is the prediction of crosstalk in a two-conductor wiring structure with electrical and geometrical parameters not perfectly known. Both univariate and multivariate analyses are carried out, with the final objective being to compare the performance of the two SROM formulations with respected to Monte Carlo simulations.

The recent switch from analog to digital TV broadcasting around the world has led to the development of communications standards that consider the use of TV White Spaces (TVWS). One such standard is the IEEE 802.22 wireless regional area network (WRAN), which considers the use of TVWS to provide broadband wireless services over long transmission links, and therefore presents an opportunity to bring connectivity and data-based services from urban to rural areas. Services that could greatly benefit from the deployment of wireless broadband data links between urban and rural areas are those related to telemedicine and m-health. To enable proper telemedicine service delivery from urban (e.g. an urban hospital) to rural locations (e.g. a rural clinic) it is of paramount importance to provide a certain quality of service (QoS) level. In this context, QoS provisioning for telemedicine applications over wireless networks presents a major challenge that must be addressed to fulfill the potential that rural wireless telemedicine has to offer. In this paper, a cross-layer approach combining medium access control (MAC) and application (APP) layers is proposed with the aim of reducing blocking probability in teleconsulting services operating over IEEE802.22/WRANs. At the APP layer, a teleconsulting traffic profile based on utilization rates is defined. On the other hand, at the MAC layer, an Adaptive Bandwidth Management (ABM) mechanism is used to perform a QoS-based classification of teleconsulting services and then dynamically allocate the bandwidth requirements. Three teleconsulting services with different bandwidth requirements are considered in order to evaluate the performance of the proposed approach: high-resolution teleconsulting, medium-resolution teleconsulting, and audio-only teleconsulting. Simulation results demonstrate that the proposed approach is able to reduce blocking probability by using different criteria for service modes within the admission control scheme.

Two wideband circularly polarized (CP) equilateral triangular slot (ETS) antennas are proposed for communication system and the Global Navigation Satellite System (GNSS) Radio Occultation (RO) sensor of the GAIA-I microsatellite. These wide slot antennas use the ring slot antenna CP generation method due to their shape. The compact antennas employ truncated corners, grounded equilateral triangular perturbation patch and branched feed line to create CP radiation. A 3-dB axial ratio bandwidth (ARBW) enhancement is achieved by inserting a pair of slits into the ETS. A parametric study on the influence of those shape modifications in reflection coefficient and axial ratio is presented. An ETS antenna for communication system of the GAIA-I is fabricated and measured, which is shown to agree well with its simulated performance by providing CP fractional bandwidth of 52%. An ETS antenna designed for the GNSS RO sensor of GAIA-I delivers 3-dB ARBW of 41.6%. The ETS antenna offers uni-directional radiation by mounting a 3D printed truncated cone reflector underneath which also enhances antenna gain.

The existing methods to estimate satellite attitude by using radar cross section (RCS) sequence suffer from problems such as low precision, computation complexity, etc. To overcome these problems, a novel model of satellite attitude estimation by the local maximum points of the RCS sequence is established and can reduce the computational time by downscaling the dimension of the feature vector. Moreover, a particle swarm optimization method is adopted to improve efficiency of computation. Numerical simulations show that the proposed method is robust and efficient.

In this study, the reference pure metal-oxide semiconductor field-effect transistors (MOSFETs) and low-voltage (LV) and high-voltage (HV) MOSFETs with a super-junction (SJ) structure in the drain side were experimentally compared. The results show that the drain-side engineering of SJs exerts negative effects on the electrostatic discharge (ESD) and latch-up (LU) immunities of LV n-channel MOSFETs, whereas for LV p-channel MOSFETs and HV n-channel laterally diffused MOSFETs (nLDMOSs), the effects are positive. Compared with the pure MOSFET, electrostatic discharge (ESD) robustness (It2) decreased by approximately 30.25% for the LV nMOS-SJ, whereas It2 increased by approximately 2.42% and 46.63% for the LV pMOS-SJ and HV nLDMOS-SJ, respectively; furthermore, LU immunity (Vh) decreased by approximately 5.45% for the LV nMOS-SJ, whereas Vh increased by approximately 0.44% and 35.5% for the LV pMOS-SJ and HV nLDMOS-SJ, respectively. Thus, nMOS-SJ (pMOS-SJ and nLDMOS-SJ) has lower (higher) It2 and Vh, and this drain-side SJ structure of MOSFETs is an inferior (superior) choice for improving the ESD/LU reliability of LV nMOSs (LV pMOS and HV nLDMOS).

A method is proposed for improving the accuracy of the characteristic basis function method (CBFM) using the multilevel approach. With this technique, CBFs taking into account multiple scattering calculated for each block (IP-CBFs; improved primary CBFs) are applied to CBFM using a multilevel approach. By using IP-CBFs, the interaction between blocks is taken into account, and thus it is possible to reduce the number of CBFs while maintaining accuracy, even if the multilevel approach is used. The radar cross section (RCS) of a cube, a cavity, and a dielectric sphere were analyzed using the proposed CBFs, and as a result it was found that accuracy is improved over the conventional method, despite no major change in the number of CBFs.

A component-oriented FPGA design platform is proposed for robot system integration. FPGAs are known to be a power-efficient hardware platform, but the development cost of FPGA-based systems is currently too high to integrate them into robot systems. To solve this problem, we propose an FPGA component that allows FPGA devices to be easily integrated into robot systems based on the Robot Operating System (ROS). ROS-compliant FPGA components offer a seamless interface between the FPGA hardware and software running on the CPU. Two experiments were conducted using the proposed components. For the first experiment, the results show that the execution time of an FPGA component for image processing was 1.7 times faster than that of the original software-based component and was 2.51 times more power efficient than an ordinary PC processor, despite substantial communication overhead. The second experiment showed that an FPGA component for sensor fusion was able to process multiple sensor inputs efficiently and with very low latency via parallel processing.

Japan Broadcasting Corporation (NHK) started test satellite broadcasting of ultra-high-definition television (UHDTV) on August 1st, 2016. The test broadcasting is being provided in the 12-GHz (11.7 to 12.75GHz) band with right-hand circular polarization. In 2018, left-hand circular polarization in the same frequency band will be used for satellite broadcasting of UHDTV. Because UHDTV satellite broadcasting uses the 16APSK modulation scheme, which requires a higher carrier-to-noise ratio than that used for HDTV in Japan, it is important to mitigate the cross-polarization interference. Therefore, we fabricated and tested a dual-circularly polarized offset parabolic reflector antenna that has a feed antenna composed of a 2×2 microstrip antenna array, which is sequentially rotated to enhance the polarization purity. Measured results showed that the fabricated antenna complied with our requirements, a voltage standing wave ratio of less than 1.4, antenna gain of 34.5dBi (i.e., the aperture efficiency was 69%), and cross-polarization discrimination of 28.7dB.

Transient scattering by a metal cylinder covered with inhomogeneous lossy material is analyzed for application of radar systems to nondestructive testing of reinforced concrete structures. First, inhomogeneous lossy material that is a model of corrosion by rust is approximated by a cylindrical multilayered medium, and analytic solution of a scattered field in frequency domain is derived. Next, time domain scattering response is calculated from the frequency domain data by using the inverse Fourier transform. Numerical results of pulse responses indicate that corrosion rate of the concrete can be evaluated by checking the waveform distortion of the pulse responses.