We present a systematic and efficient way of managing the path metric memory and simplifying its connection network to the add_compare_select unit (ACSU) for Viterbi decoder (VD) design. Using the derived equations for memory partition and add-compare-select (ACS) arrangement together with the extended in-place scheduling scheme proposed in this work, we can increase the memory bandwidth for conflict-free path metric accesses with hardwired interconnection between the path metric memory and ACSU. Compared with the existing work, the developed architecture possesses the following advantages: (1) Each partitioned memory bank can be treated as a local memory of a specific processing element, inside the ACSU, with hardwired interconnection, so that the interconnect complexity is reduced significantly. (2) The partitioned memory banks can be merged into only two pseudo-banks regardless of the number of adopted ACS processing elements. This not only greatly simplifies the design of address generation unit, but also makes smaller the physical size of required memory. (3) The implementation can be accomplished in a systematic way with regular and simple controlling circuitry. Experimental results demonstrate the effectiveness of the developed architecture and the benefit will be more apparent for convolutional codes with large memory order.

The Hajos calculus is a nondeterministic procedure which generates the class of non-3-colorable graphs. If all non-3-colorable graphs can be constructed in polynomial steps by the calculus, then NP = co-NP holds. Up to date, however, it remains open whether there exists a family of graphs that cannot be generated in polynomial steps. To attack this problem, we propose two graph calculi PHC and PHC* that generate non-3-colorable planar graphs, where intermediate graphs in the calculi are also restricted to be planar. Then we prove that PHC and PHC* are sound and complete. We also show that PHC* can polynomially simulate PHC.

In this paper, we consider a collision detection problem of spheres which asks to detect all pairs of colliding spheres in a set of n spheres located in d-dimensional space. We propose a collision detection algorithm for spheres based on slab partitioning technique and a plane sweep method. We derive a theoretical upper bound on the time complexity of the algorithm. Our bound tells that if both the dimension and the maximum ratio of radii of two spheres are bounded, then our algorithm runs in O(n log n + K) time with O(n + K) space, where K denotes the number of pairs of colliding spheres.

This paper describes the matrix order reduction method by the nodal analysis formulation and the application of relaxation-based simulation technique to interconnect and plane networks. First, the characteristics of the power/ground plane networks are considered. Next, the formulation of the plane network by nodal analysis (NA) method is suggested. Furthermore, application and estimation results of the relaxation-based numerical analyses are shown. Finally, it is confirmed that the relaxation-based methods improved by the suggested formulation are much more efficient than the conventional direct-based methods.

The cognitive radio system consists of multiple wireless access systems that cover overlapping areas and cognitive terminals that use one or more of the wireless access systems simultaneously. In this paper, we describe the system architecture of a platform for load balancing and throughput enhancement with cognitive radio system. In our platform, each terminal, which can access multiple radio systems, operates with a single local IP address. Based on our platform, we have developed both simulator and testbed system. Through the simulation of and the testing of a testbed system, we prove that systems load balance was achieved between WiMAX and wireless LAN, and total user throughput was increased with the proposed platform. Moreover, load balance to satisfy both real time service and best effort service. These results demonstrate the platform described in the paper can achieve a convergence with plural wireless systems.

Multiple supply voltage (MSV) is an effective scheme to achieve low power. Recent works in MSV are based on physical level and aim at reducing physical overheads, but all of them do not consider level converter, which is one of the most important issues in dual-vdd design. In this work, a logic and layout aware methodology and related algorithms combining voltage assignment and placement are proposed to minimize the number of level converters and to implement voltage islands with minimal physical overheads. Experimental results show that our approach uses much fewer level converters (reduced by 83.23% on average) and improves the power savings by 16% on average compared to the previous approach [1]. Furthermore, the methodology is able to produce feasible placement with a small impact to traditional placement goals.

Lightweight single-layer slotted waveguide array antennas are fabricated using plastic materials with metal-plating. A plastic material that has good heat-radiation properties is investigated. Three types of antennas are fabricated by milling, using ABS resin, heat-radiating plastic, and aluminum alloy. In measurements, all three types of antennas are confirmed to have almost the same VSWR and gain in the 25 GHz frequency band.

This paper focuses on the numerical and experimental investigations of the influence of two polymers (PA6 and POM) on the arc behavior during arc motion process. The mathematical model of 3-dimentional air arc plasma considering the ablation of lateral walls is built based on magnetic hydro-dynamics (MHD). By adopting the commercial computational fluid dynamics (CFD) package based on control-volume method, the above MHD model is solved and the distribution of temperature field, concentration field, flow field and electrical potential field in the arc chamber are calculated. The simulation results indicate that the vapor concentration behind the arc column is higher than that in front of the arc column because of the existence of "double vortices" in the arc chamber. The use of polymers causes the maximal arc voltage increase 16.2% with POM and 18.9% with PA6 in this case and causes the average arc velocity increase 15.8% with POM and 21.1% with PA6 in this case. The experiments are also carried out to study the influence of polymers on arc voltage and arc root position in the arc chamber during arc motion. The experimental results prove the validity of the numerical investigation.

Subjects' episodic memory performance is not simply reflected by eye movements. We use a 'theta phase coding' model of the hippocampus to predict subjects' memory performance from their eye movements. Results demonstrate the ability of the model to predict subjects' memory performance. These studies provide a novel approach to computational modeling in the human-machine interface.

We formulated the excitation rate of VUV and emitted visible light from rare gas on PDP by using the Boltzmann equation with electron-atom collision integral term and obtained the excitation rate as the function of Temperature and Mass. This form of excitation rate was firstly derived in PDP area. In addition we showed the Pressure dependence of intensity ratio of Ne/VUV as the application of our excitation rate formulae.

The number of broadband users is rapidly increasing worldwide. Japan already has over 10 million FTTH users. Another trend is the rapid digitalization of home electrical equipment e.g. digital cameras and hard disc recorders. These trends will encourage the emergence of the next generation home network. In this paper, we introduce the next generation home network image and describe the five domains into which home devices can be classified. We then clarify the optimum medium with which to configure the network given the requirements imposed by the home environment. Wiring cable lengths for three network topologies are calculated. The results gained from the next generation home network implemented on the first phase testbed are shown. Finally, our conclusions are given.

Techniques for patterned modification of substrate surfaces are important for forming microarrays on protein chips. A hexamethyldisiloxane plasma-polymerized film (HMDS PPF) was deposited on a glass substrate and the resulting surface was partially modified by subsequent nitrogen plasma treatment with a patterned shadow mask. When surface adsorption of an antibody protein (F(ab')2 fragment of anti-human immunoglobulin G) was visualized by fluorescence microscopy, distinct 8080 µm2 square spots were observed, surrounded by a non-fluorescent 80 µm-wide grid. This pattern could be attributed to proteins selectively adsorbed onto the nitrogen plasma-treated regions but not onto the surface of pristine HMDS PPF. This provided a simple fabrication method of protein patterning.

In this paper, the impact of display on quality assessment is addressed. Subjective quality assessment experiments have been performed on both LCD and CRT displays. Two sets of still images and two sets of moving pictures have been assessed using either an ACR or a SAMVIQ protocol. Altogether, eight experiments have been led. Results are presented and discussed, some differences are pointed out. Concerning moving pictures, these differences seem to be mainly due to LCD moving artefacts such as motion blur. LCD motion blur has been measured objectively and with psycho-physics experiments. A motion-blur metric based on the temporal characteristics of LCD can be defined. A prediction model have been then designed which predict the differences of perceived quality between CRT and LCD. This motion-blur-based model enables the estimation of perceived quality on LCD with respect to the perceived quality on CRT. Technical solutions to LCD motion blur can thus be evaluated on natural contents by this mean.

The TFT-LCD image has non-uniform brightness that is the major difficulty of finding the visible defect called Mura in the field. To facilitate Mura detection, background signal shading should level off and Mura signal must be amplified. In this paper, Mura signal amplification and background signal flattening method is proposed based on human visual system (HVS). The proposed DC normalized contrast sensitivity function (CSF) is used for the Mura signal amplification and polynomial regression (PR) is used to level off the background signal. In the enhanced image, tri-modal thresholding segmentation technique is used for finding Dark and White Mura at the same time. To select reliable defect, falsely detected invisible region is eliminated based on Weber's Law. By the experimental results of artificially generated 1-d signal and TFT-LCD image, proposed algorithm has novel enhancement results and can be applied to real automated inspection system.

The surface amino groups of plasma-polymerized films prepared from various nitrogen-containing monomers were quantitatively characterized for bioelectronic and biomedical applications. X-ray photoelectron spectroscopy (XPS) measurements were conducted on two kinds of surfaces: pristine surfaces of plasma-polymerized film prepared using various nitrogen-containing monomers, and theirs surfaces whose amino groups had been derivatized by a primary-amine-selective reagent carrying an XPS label. The XPS data showed that the maximum surface density of amino groups for this film was 8.41013 cm-2. Amino groups constituted 14-64% of all surface nitrogen atoms (NH/N), depending on the monomer used.

Auditory artifacts due to switching head-related transfer functions (HRTFs) are investigated, using a software-implemented dynamic virtual auditory display (DVAD) developed by the authors. The DVAD responds to a listener's head rotation using a head-tracking device and switching HRTFs to present a highly realistic 3D virtual auditory space to the listener. The DVAD operates on Windows XP and does not require high-performance computers. A total system latency (TSL), which is the delay between head motion and the corresponding change of the ear input signal, is a significant factor of DVADs. The measured TSL of our DVAD is about 50 ms, which is sufficient for practical applications and localization experiments. Another matter of concern is the auditory artifact in DVADs caused by switching HRTFs. Switching HRTFs gives rise to wave discontinuity of synthesized binaural signals, which can be perceived as click noises that degrade the quality of presented sound image. A subjective test and excitation patterns (EPNs) analysis using an auditory filter are performed with various source signals and HRTF spatial resolutions. The results of the subjective test reveal that click noise perception depends on the source signal and the HRTF spatial resolution. Furthermore, EPN analysis reveals that switching HRTFs significantly distorts the EPNs at the off signal frequencies. Such distortions, however, are masked perceptually by broad-bandwidth source signals, whereas they are not masked by narrow-bandwidth source signals, thereby making the click noise more detectable. A higher HRTF spatial resolution leads to smaller distortions. But, depending on the source signal, perceivable click noises still remain even with 0.5-degree spatial resolution, which is less than minimum audible angle (1 degree in front).

A stacked square microstrip antenna with shorting plates is proposed for wide band operation. The vswr 2 with gain at θ=0 0 dBi is achieved in the frequency range between the first and second resonant frequencies by loading the two shorting plates. The proposed antenna has bandwidth of approximately 60%.

We propose a low cost and stand-alone platform-based SoC for H.264/AVC decoder, whose target is practical mobile applications such as a handheld video player. Both low cost and stand-alone solutions are particularly emphasized. The SoC, consisting of RISC core and decoder core, has advantages in terms of flexibility, testability and various I/O interfaces. For decoder core design, the proposed H.264/AVC coprocessor in the SoC employs a new block pipelining scheme instead of a conventional macroblock or a hybrid one, which greatly contribute to reducing drastically the size of the core and its pipelining buffer. In addition, the decoder schedule is optimized to block level which is easy to be programmed. Actually, the core size is reduced to 138 KGate with 3.5 kbyte memory. In our practical development, a single external SDRAM is sufficient for both reference frame buffer and display buffer. Various peripheral interfaces such as a compact flash, a digital broadcast receiver and a LCD driver are also provided on a chip.

A floorplan is a subdivision of a rectangle into rectangular faces with horizontal and vertical line segments. We call a floorplan room-to-room when adjacencies between rooms are considered. Fujimaki and Takahashi showed that any room-to-room floorplan can be represented as a permutation. In this paper, we give an O(n)-time algorithm that constructs the vertical and the horizontal constraint graphs of a floorplan for a given permutation under this representation.

This letter proposes a motion information inferring scheme for multi-view video coding motivated by the idea that the aspect of motion vector between the corresponding positions in the neighboring view pair is quite similar. The proposed method infers the motion information from the corresponding macroblock in the neighboring view after RD optimization with the existing prediction modes. This letter presents evaluation showing that the method significantly enhances the efficiency especially at high bit rates.