This paper discusses a generalized concept of multiple-symbol differential detection (MDD) and analytically derives weight parameters based on channel prediction for MDD on fast time-varying channels. At first, this paper shows that adaptive maximum-likelihood sequence estimation employing per-survivor processing (PSP-MLSE) with a single channel tap is similar concept to MDD. Next, the weight parameters for MDD are derived according to the channel estimation of PSP-MLSE based on a high order channel prediction. Finally, computer simulation confirms that MDD with the analytically derived parameters mitigates floor of bit error rate (BER) on fast time-varying fading channels without channel state information.

In this paper, dosimetry of an in vitro exposure apparatus based on a cylindrical waveguide is performed. The SAR distributions are first obtained numerically by using FDTD method. The thermal fields in the medium are then estimated by numerical calculations of the equation of heat conduction. The maximum temperature rise for 17.9 W/kg average SAR during 3000 s exposure is about 2 on the bottom of the medium where cells are located. The thermal distribution is relatively uniform near the center of the dish and the temperature in this region is around 38.7. The results of the numerical calculation are experimentally supported. The results provide the electromagnetic and thermal characteristics of the exposure apparatus, which will define the exposure conditions of the planned experiments using this apparatus.

A timing-driven placement algorithm based on path topology analysis is presented. The optimization for path delay is transformed into cell location optimization. The algorithm pays much attention on path topologies and applies an effective force directed method to find cell target locations. Total wire length optimization is combined with the timing-driven placement algorithm. MCNC (Microelectronics Centre of North-Carolina) standard cell benchmarks are experimented and results show that our timing-driven placement algorithm can make the longest path delay improve up to 13% compared with wirelength driven placement.

The four-septum transverse electromagnetic (TEM) cell is like the traditional TEM cell but has four plate-like septa in the internal space. A slowly rotating field can be easily generated in the four-septum TEM cell, thus radiated immunity/susceptibility characteristics of an EUT under arbitrary specific polarizations can be measured without rearranging the test setup. A design approach for the four-septum TEM cell is discussed in this paper. The characteristics of the cell are analyzed based on the telegrapher's equation and decomposition of the transmission mode into four independent modes. Then a design approach is given based on the analytical results. A prototype of the four-septum TEM cell based on the design is constructed and the characteristics of the prototype cell are experimentally evaluated. The validity and effectiveness of the design approach are confirmed.

This paper presents a color demosaicing method by introducing iterative asymmetric average interpolation. Missing primary colors on a Bayer pattern color filter array (CFA) are estimated by an asymmetric average interpolation where less intensity variation is assumed to be of stronger significance, before sharpness of an initial estimate is further improved by an iterative procedure. The iteration is implemented by an observation process followed by a restoration process. The former is modeled by blurring followed by CFA sampling and the latter is completely as same as the color demosaicing method initially applied. Experimental results have shown a favorable performance in terms of PSNR and visual appearance, in particular, in sharpness recovery.

This paper presents two novel blind set-theoretic adaptive filtering algorithms for suppressing "Multiple Access Interference (MAI)," which is one of the central burdens in DS/CDMA systems. We naturally formulate the problem of MAI suppression as an asymptotic minimization of a sequence of cost functions under some linear constraint defined by the desired user's signature. The proposed algorithms embed the constraint into the direction of update, and thus the adaptive filter moves toward the optimal filter without stepping away from the constraint set. In addition, using parallel processors, the proposed algorithms attain excellent performance with linear computational complexity. Geometric interpretation clarifies an advantage of the proposed methods over existing methods. Simulation results demonstrate that the proposed algorithms achieve (i) much higher speed of convergence with rather better bit error rate performance than other blind methods and (ii) much higher speed of convergence than the non-blind NLMS algorithm (indeed, the speed of convergence of the proposed algorithms is comparable to the non-blind RLS algorithm).

This paper presents the results of an investigation on the effect of a thin low-dielectric material (phantom shell) on measuring the Specific Absorption Rate (SAR) in the frequency range of 3 to 6 GHz. The International Electrotechnical Commission (IEC) has started to develop a SAR measurement procedure in order to cover such frequencies. In the procedure, the SAR is measured in a liquid phantom, which is a shell filled with tissue-equivalent liquid. Although the shell is thin and has low-dielectric properties, the influence of the phantom shell is thought to increase at higher frequencies. Therefore, an investigation using the transmission line model and the Finite-Difference Time-Domain (FD-TD) method was conducted. To verify the FD-TD results, measurements were also carried out. The calculation results using the FD-TD method agree well with the measurement results. If the frequency is higher, the SAR is affected by the shell even though the shell is thinner and has much lower dielectric properties than those of the tissue-equivalent liquid. Specifically, the SAR with the shell is approximately 1.3 times higher than without the shell at 5.2 GHz for the maximum case. The deviations in the loss and the thickness for the shell do not affect the SAR more than the relative permittivity.

Information transmission among biological neurons is carried out by a complex series of spike signals. The input inter-spike arrival times at a neuron are believed to carry information which the neurons utilize to carry out a task. In this paper, a new scheme which utilizes the input inter-spike intervals (ISI) for decoding an input spike train is proposed. A spike train consists of a sequence on input spikes with various inter-spike times. This decoding scheme can also be used for neurons which have multiple synaptic inputs but for which each synapse receives a single spike within one input time window. The ISI decoding neural network requires only a few neurons. Example applications show the usefulness of the decoding scheme.

In this letter, we propose a simplified step-by-step decoding algorithm for t-error-correcting binary Bose-Chaudhuri- Hocquenghem (BCH) codes based on logical analysis. Compared to the conventional step-by-step decoding algorithm, the computation complexity of this decoder is much less, since it significantly reduces the matrix calculation and the operations of multiplication.

This paper describes a distributed video transcoding system that can simultaneously transcode an MPEG-2 video file into various video coding formats with different rates. The transcoder divides the MPEG-2 file into small segments along the time axis and transcodes them in parallel. Efficient video segment handling methods are proposed that minimize the inter-processor communication overhead and eliminate temporal discontinuities from the re-encoded video. We investigate how segment transcoding should be distributed to obtain the shortest total transcoding time. Experimental results show that implementing distributed transcoding on 10 PCs can decrease the total transcoding time by a factor of about 7 for single transcoding and by a factor of 9.5 for simultaneous three kinds of transcoding rates.

We propose and demonstrate a novel ladder interferometric filter that exhibits flat-topped spectral response for use in wavelength-division-multiplexing (WDM) based photonic networks. We numerically analyze the flattened spectral response in a ladder-type filter by modifying the transfer matrix of ladder interferometer. Conventional parabolic-shaped and flat-topped-designed ladder interferometric filters are fabricated, and characterized. We demonstrate a flat-topped filter response in the fabricated device. The shape factor, which is defined by the ratio of -1 dB bandwidth to -10 dB bandwidth, is improved from 0.32 to 0.54. The tunability and the increase in filter extinction ratio of the proposed device are also discussed.

Electromagnetic field probes inevitably disturb the original distribution of the field when they are positioned close to a device. This disturbance in turn affects measurement accuracy and device operation. We developed an optical magnetic field probe, comprising a loop antenna element and an electro-optic crystal, for highly accurate magnetic near-field measurement in the GHz frequency range. We analyzed the invasiveness of the optical magnetic field probe quantitatively both experimentally and using finite difference time domain simulation. We found that eliminating the metal cable reduced the disturbance of the surrounding field that was to be measured. In addition, we investigated the magnetic field detection characteristics of the probe and its influence on the operation of a microstrip line. The optical magnetic field probe was less invasive and provided more accurate measurement.

In this letter, we propose an efficient closed-loop transmit (Tx) diversity scheme that works well for high mobility as well as low mobility. The proposed scheme exploits a quantized weight vector codebook designed by separating it into gain and phase codebooks. Simulation results reveal that the proposed scheme can provide a significant advantage in both complexity and flexibility over conventional methods.

Since WLAN (wireless LAN) systems share the 2.4-GHz frequency band with microwave ovens, interference caused by radiated oven noise is a serious problem in practical WLAN application. To mitigate the oven noise interference in DS-SS (direct-sequence spread spectrum) WLAN systems, the use of adaptive filters is proposed. This method is based on the fact that oven noise behaves like CW (continuous wave) interference within a short duration. In contrast to previous reduction techniques for oven noise, this method can be implemented without changing any specifications of current WLAN systems. The results of numerical and experimental analyses clearly demonstrate the effectiveness of adaptive filters for improving the bit error rates of WLAN links subject to oven noise interference.

2.4 GHz-band wireless LAN system based on a new standard, IEEE 802.11g, has been taking a great attention as it provides the attractive features such as low cost, unlicensed spectrum use, and high speed transmission rate up to 54 Mbps. However, 2.4 GHz radio frequency band is also used for Industrial, Scientific and Medical (ISM) devices such as microwave ovens, and the man-made noise leaked from ISM devices is known to be one of the major causes of the degradation in the performance of wireless communications systems using 2.4 GHz radio frequency band. In this paper, we evaluate the bit error rate (BER) and the throughput performances of WLAN system based on IEEE 802.11g standard (IEEE 802.11g WLAN system) under man-made noise environment, and discuss the effect of man-made noise on the performance of IEEE 802.11g WLAN system. Numerical results show that the BER and the throughput performances of IEEE 802.11g WLAN system are much degraded by the influence of man-made noise.

We study radiated RF (radio-frequency) electromagnetic field immunity test system for wireless LAN system by using opened PW (Parallel Wired) cell, in which metal cover is removed. Leakage electric field at distance of 160 cm from the opened PW cell decreases until 30 dB, and then does not affect to operation of the AP (Access Point) composed of the wireless LAN system that communicates EUT (Equipment Under Test) installed in the PW cell. NSA (Normalized Site Attenuation) between EUT and AP changes only several dB by inserting the PW cell, and then it can be concluded that the effect of PW cell for radio wave property of wireless communication system is negligible small. In addition, we try to measure dependencies of impressing level of disturbance wave on a throughput of wireless LAN systems IEEE802.11b and IEEE802.11g. As a result, it is confirmed that the radiated RF electromagnetic field immunity test system for wireless LAN system can be composed by using the opened PW cell without affecting from impressing disturbance wave.

This paper proposes resource management in Layer 1 Virtual Private Networks (VPNs). We have been proposing Layer 1 VPNs that provide layer 1 services to multiple customers over the single optical network with per VPN control and management capabilities. We have proposed two resource management models for Layer 1 VPNs, which constitute different class of services. One is the shared model, where resources are shared among VPNs. The other is the dedicated model, where resources are explicitly pre-assigned to each VPN. In this paper, after introducing an overview of Layer 1 VPNs, we evaluate several path computation algorithms for these two models focusing on the multi layer network scenario. In the shared model, there are several existing studies for non-VPN cases, but considerations for VPN cases are not investigated. This paper evaluates algorithms originally proposed for non-VPN cases for use in VPN cases. Simulation results show that the path computation algorithm that works as saving layer 1 resources achieves better resource sharing effect. In the dedicated model, the problem is identical to non-VPN cases. There is one conventional algorithm, but amount of available resources is not well considered. We propose a novel path computation algorithm. Simulation results show effectiveness of our proposed algorithm against the conventional algorithm. Furthermore, resource usage efficiency of two resource management models is compared. We analyze and propose applicability of resource management models.

This paper describes a digital impedance controller (DIC) [1] for high-speed signal interface. The proposed DIC provides the wide range impedance control covering from 23 Ω to 140 Ω with 3.29% maximum quantization error. The maximum quantization error of the proposed DIC is 2.26% with RQ ranging from 23 Ω to 53 Ω, the same range covered by conventional scheme. The high resolution and wide range impedance control is implemented by using automatic gate voltage optimization. The amount of jitter caused by quantization error is 6.9 ps while 13.8 ps in conventional scheme. The data input valid window is 623 ps at 0.75200 mV and maximum eye open is 641 mV meaning about 10% improvement at 1.5 Gbps/pin DDR3 SRAM interface.

The author prepared new composition of Cu-Sn based composite materials containing lamellar solid lubricants, and measured their performance with focus on contact resistance and the coefficient of friction using a low-speed tribo-meter. Among three kinds of composite materials, the composite material containing 26wt.% of total solid lubricants was lower in both of contact resistance and the coefficient of friction and showed stable characteristics compared with those containing 25wt.% and 35wt.% respectively. The author analyzed the characteristics of these materials using several techniques including BSE image, element analysis through EPMA, and mapping analysis, and examined why the composite material containing 26wt.% of total solid lubricants showed higher performance.

A method is proposed to investigate the dynamic characteristics of a magnet release in molded case circuit breaker. With the static field assumption, two grids of the magnetic torque and flux linkage are calculated with the variation of the current and air gap, firstly. Considering the influence of tripping torque, coupled with circuit equation and mechanism motion equation, the dynamic characteristics may be obtained with Runge-Kutta 4 method. Experiments have been done to verify the method, and the difference between the calculated results and the experimental results is below 10%. In addition, the influence of the reaction spring on the protection characteristics is analyzed using this method. It demonstrates that the setting current varies with the initial angle and the stiffness of the reaction spring, and the variation with the initial angle of the reaction spring is closely linear but the stiffness nonlinear.