This letter proposes a high-performance single-sided horn-shaped tapered bowtie antenna which is compact and covers more than the whole UWB frequency band. This design implements a bowtie radiating element and tapered strip-line feeder element on a single-sided dielectric substrate, which offers a measured return loss of less than -10 dB over the whole UWB frequency band of 3.0-10.8 GHz. The measured radiation pattern is bi-directional with consistent gain over the above frequency band. This compact-size design shows much enhanced performance, compared to the previously reported antenna, which is useful for UWB radar and communication applications.

This paper presents a planar monopole antenna with slits and a stub for multi-band operation in vehicles. The proposed antenna is at least 55% smaller than the regular rectangular monopole antenna and covers eight wireless application bands. Slits cut into the rectangular monopole alter the surface current paths so that the band coverage is expanded. A long bent-stub is also added to cover the lowest service band.

We have proposed a terahertz (THz) emitter utilizing two-dimensional plasmons (2DPs) in a super-grating dual-gate (SGG) high electron mobility transistor (HEMT). The plasmon under each grating gate has a unique feature that its resonant frequency is determined by the plasma-wave velocity over the gate length. Since the drain bias voltage causes a linear potential slope from the source to drain area, the sheet electron densities in periodically distributed 2DP cavities are dispersed. As a result, all the resonant frequencies are dispersed and undesirable spectral broadening occurs. A SGG structure can compensate for the sheet electron density distribution by modulating the grating dimension. The finite difference time domain simulation confirms its spectral narrowing effect. Within a wide detuning range for the gate and drain bias voltages giving a frequency shifting of 0.5 THz from an optimum condition, the SGG structure can preserve the spectral narrowing effect.

We analyze the carrier dynamics in MOSFETs under low-voltage operation. For this purpose the displacement (charging/discharging) current, induced during switching operations is studied experimentally and theoretically for a 90 nm CMOS technology. It is found that the experimental transient characteristics can only be well reproduced in the circuit simulation of low voltage applications by considering the carrier-transit delay in the compact MOSFET model. Long carrier transit delay under the low voltage switching-on operation results in long duration of the displacement current flow. On the other hand, the switching-off characteristics are independent of the bias condition.

We have studied the formation of Pd-nanodots on SiO2 from ultrathin Pd films being exposed to remote hydrogen plasma at room temperature, in which parameters such as the gas pressure and input power to generate H2 plasma and the Pd film thickness were selected to get some insights into surface migration of Pd atoms induced with atomic hydrogen irradiation and resultant agglomeration with cohesive action. The areal dot density was controlled in the range from 3.4 to 6.51011 cm - 2 while the dot size distribution was changed from 7 to 1.5 in average dot height with 40% variation in full-width at half maximum. We also fabricated MOS capacitors with a Pd-nanodots floating gate and confirmed the flat-band voltage shift in capacitance-voltage characteristic due to electron injection to and emission from the dots floating gate.

In recent years, with the rapid growth of the Internet as well as the increasing demand for broadband services, live pay-television broadcasting via the Internet has become a promising business. To get this implemented, it is necessary to protect distributed contents from illegal copying and redistributing after they are accessed. Fingerprinting system is a useful tool for it. This paper shows that the anti-collusion code has advantages over other existing fingerprinting codes in terms of efficiency and effectivity for live pay-television broadcasting. Next, this paper presents how to achieve efficient and effective anti-collusion codes based on unital and affine plane, which are two known examples of balanced incomplete block design (BIBD). Meanwhile, performance evaluations of anti-collusion codes generated from unital and affine plane are conducted. Their practical explicit constructions are given last.

We fabricated a high-speed wavelength tunable arrayed-waveguide grating (AWG) and an AWG integrated with optical switches using (Pb,La)(Zr,Ti)O3-(PLZT). PLZT has a high electro-optic (EO) coefficient, which means these devices have considerable potential for use in reconfigurable optical add drop multiplexers (ROADMs). The PLZT waveguides in this work have a rib waveguide structure with an effective relative index difference (Δ) of 0.65%. Both AWGs have 8 channels with a frequency spacing of 500 GHz. The fabricated wavelength tunable AWGs allows us to freely shift the output at a particular wavelength to an arbitrary port by applying voltages to 3 mm long electrodes formed on each of the waveguides. We confirmed that the maximum tuning range with driving voltage of 22 V was approximately 32 nm at 1.55 µm. With the integrated 8-ch PLZT waveguide switch array, we could also select the output port by setting the drive voltage applied to the switch array. 2 2 directional coupler switches were used for the switch array. The two devices exhibited insertion losses of 17 dB and 19 dB, adjacent crosstalk of -18.5 dB and -19.7 dB, and a maximum extinction ratio of 19.6 dB and 12.6 dB, respectively. The tuning speed of both devices was 15 ns and their physical sizes were 9.0 23.0 mm and 8.0 29.5 mm, respectively.

A subdivision of a rectangle into rectangular faces with horizontal and vertical line segments is called a rectangular drawing or floorplan. It has been an open problem to determine whether there exist a polynomial time algorithm for computing R(n). We affirmatively solve the problem, that is, we introduce an O(n4)-time and O(n3)-space algorithm for R(n). The algorithm is based on a recurrence for R(n), which is the main result of the paper. We also implement our algorithm and computed R(n) for n 3000.

Interpretations by physicians of capsule endoscopy image sequences captured over periods of 7-8 hours usually require 45 to 120 minutes of extreme concentration. This paper describes a novel method to reduce diagnostic time by automatically controlling the display frame rate. Unlike existing techniques, this method displays original images with no skipping of frames. The sequence can be played at a high frame rate in stable regions to save time. Then, in regions with rough changes, the speed is decreased to more conveniently ascertain suspicious findings. To realize such a system, cue information about the disparity of consecutive frames, including color similarity and motion displacements is extracted. A decision tree utilizes these features to classify the states of the image acquisitions. For each classified state, the delay time between frames is calculated by parametric functions. A scheme selecting the optimal parameters set determined from assessments by physicians is deployed. Experiments involved clinical evaluations to investigate the effectiveness of this method compared to a standard-view using an existing system. Results from logged action based analysis show that compared with an existing system the proposed method reduced diagnostic time to around 32.5 7 minutes per full sequence while the number of abnormalities found was similar. As well, physicians needed less effort because of the systems efficient operability. The results of the evaluations should convince physicians that they can safely use this method and obtain reduced diagnostic times.

We present a recovery scheme based on Self-protected Spanning Tree (SST), which recovers from failure all by itself. In the recovery scheme, the links are assigned birthdays to denote the order in which they are to be considered for adding to the SST. The recovery mechanism, named Birthday-based Link Replacing Mechanism (BLRM), is able to transform a SST into a new spanning tree by replacing some tree links with some non-tree links of the same birthday, which ensures the network connectivity after any single link or node failure. First, we theoretically prove that the SST-based recovery scheme can be applied to arbitrary two-edge connected or two connected networks. Then, the recovery time of BLRM is analyzed and evaluated using Ethernet, and the simulation results demonstrate the effectiveness of BLRM in achieving fast recovery. Also, we point out that BLRM provides a novel load balancing mechanism by fast changing the topology of the SST.

The proposed built-in Power-Cut scheme intended for a wide range of dynamically data retaining memories including embedded SoC memories enables the system-level power management to handle SoC on which the several high density and low voltage scalable memory macros are embedded. This scheme handles the deep standby mode in which the SoC memories keep the stored data in the ultra low standby current, and quick recovery to the normal operation mode and precise power management are realized, in addition to the conventional full power-off mode in which the SoC memories stay in the negligibly low standby current but allow the stored data to disappear. The unique feature of the statically or dynamically changeable internal voltages of memory in the deep standby mode brings about much further reduction of the standby current. This scheme will contribute to the further lowering power of the mobile applications requiring larger memory capacity embedded SoC memories.

This paper reviews our recent progress on arrayed waveguide gratings (AWGs) using super-high-Δ silica-based planar lightwave circuit (PLC) technology and their application to integrated optical devices. Factors affecting the chip size of AWGs and the impact of increasing relative index difference Δ on the chip size are investigated, and the fabrication result of a compact athermal AWG using 2.5%-Δ silica-based waveguides is presented. As an application of super-high-Δ AWGs to integrated devices, a flat-passband multi/demultiplexer consisting of an AWG and cascaded MZIs is presented.

The medical care day by day and more and more is associated with and reliant upon concepts and advances of electronics and electromagnetics. Numerous medical devices are implanted in the body for medical use. Tissue implanted devices are of great interest for wireless medical applications due to the promising of different clinical usage to promote a patient independence. It can be used in hospitals, health care facilities and home to transmit patient measurement data, such as pulse and respiration rates to a nearby receiver, permitting greater patient mobility and increased comfort. As this service permits remote monitoring of several patients simultaneously it could also potentially decrease health care costs. Advancement in radio frequency communications and miniaturization of bioelectronics are supporting medical implant applications. A central component of wireless implanted device is an antenna and there are several issues to consider when designing an in-body antenna, including power consumption, size, frequency, biocompatibility and the unique RF transmission challenges posed by the human body. The radiation characteristics of such devices are important in terms of both safety and performance. The implanted antenna and human body as a medium for wireless communication are discussed over Medical Implant Communications Service (MICS) band in the frequency range of 402-405 MHz.

This letter proposes a neurobiological approach for action recognition. In this approach, actions are represented by a visual-neuron feature (VNF) based on a quantitative model of object representation in the primate visual cortex. A supervised classification technique is then used to classify the actions. The proposed VNF is invariant to affine translation and scaling of moving objects while maintaining action specificity. Moreover, it is robust to the deformation of actors. Experiments on publicly available action datasets demonstrate the proposed approach outperforms conventional action recognition models based on computer-vision features.

Symmetry constrains are the constraints that the given cells should be placed symmetrically in design of analog ICs. We use O-tree to represent placements and propose a decoding algorithm which can obtain one of the minimum placements satisfying the constraints. The decoding algorithm uses linear programming, which is too much time consuming. Therefore we propose a graph based method to recognize if there exists no placement satisfying both the given symmetry and O-tree constraints, and use the method before application of linear programming. The effectiveness of the proposed method was shown by computational experiments.

Wireless communication devices in the field of medical implant, such as cardiac pacemakers and capsule endoscopes, have been studied and developed to improve healthcare systems. Especially it is very important to know the range and position of each device because it will contribute to an optimization of the transmission power. We adopt the time-based approach of position estimation using ultra wideband signals. However, the propagation velocity inside the human body differs in each tissue and each frequency. Furthermore, the human body is formed of various tissues with complex structures. For this reason, propagation velocity is different at a different point inside human body and the received signal so distorted through the channel inside human body. In this paper, we apply an adaptive template synthesis method in multipath channel for calculate the propagation time accurately based on the output of the correlator between the transmitter and the receiver. Furthermore, we propose a position estimation method using an estimation of the propagation velocity inside the human body. In addition, we show by computer simulation that the proposal method can perform accurate positioning with a size of medical implanted devices such as a medicine capsule.

Body Area Networks (BAN) can provide a wide range of applications including medical support, healthcare monitoring, and consumer electronics with increased convenience or comfort. To harmonize with the strong demands from both medical and healthcare societies, and information and communications technology (ICT) industries, IEEE 802.15.6 task group (TG6) was set up to develop an IEEE wireless standard on BAN. This paper presents a general guidance to TG6. Some pre-works to set up TG6 are reviewed. The objectives, main topics, current status are described in details.

An AuSn reflow process using hydrogen radicals as a way to avert the cleaning of flux residues was investigated for its application to solder bumping. AuSn particles (manufactured by a gas atomizer) smaller than 5 µm, which are difficult to reflow by conventional methods that use rosin mildly activated (RMA) flux, were used for the experiments. In this process, the reduction effect by the hydrogen radicals removes the surface oxides of the AuSn particles. Excellent wetting between 1-µm-diameter AuSn particles and Ni metallization occurred in hydrogen plasma. Using hydrogen radicals, 100 µm-diameter AuSn bumps without voids were successfully formed at a peak temperature of 300. The average bump shear strength was approximately 73 gf/bump. Bump inspection after shear testing showed that a fracture had occurred between the Au/Ni/Cr under bump metallurgy (UBM) and Si substrate, suggesting sufficient wetting between the AuSn bump and the UBM.

The Green's function of free space for the fast inhomogeneous plane wave algorithm is represented by an integration in the complex plane. The error in the computational process is determined by the number of sampling points, the truncation of the integration path, and the extrapolation. Therefore, the error control method is different from that for the fast multipole method. We will discuss the worst-case interactions of the fast inhomogeneous plane wave algorithm for the box implementation and define the upper and lower bounds of the computational error.

In this paper, we have obtained the integral representation for the ground wave propagation over land-to-sea mixed-paths which uses the equivalent current source on an aperture plane. By extending the integral to the complex plane and deforming the integration path into the steepest descent path, we have derived a simple integral representation for the mixed-path ground wave propagation. We have also derived the hybrid numerical and asymptotic representation for an efficient calculation of the ground wave and for easy understanding of the diffraction phenomena. By using the method of the stationary phase applicable uniformly as the stationary phase point approaches the endpoint, we have derived the high-frequency asymptotic solution for the ground wave propagation over the mixed-path. We have confirmed the validity of the various representations by comparing both with the conventional mixed-path theory and with the experimental results performed in Kanto areas including the sea near Tokyo bay. By examining the asymptotic solution in detail, we have found out the cause or the mechanism of the recovery effect occurring on the portion of the sea over the land-to-sea mixed-path.