In this letter, we address geometry coding of 3-D mesh models. Using a joint prediction, the encoder predicts vertex positions in the layer traversal order. After we apply the joint prediction algorithm to eliminate redundancy among vertex positions using both position and angle values of neighboring triangles, we encode those prediction errors using a uniform quantizer and an entropy coder. The proposed scheme demonstrates improved coding efficiency for various VRML test data.
Kazutoshi SUGIMOTO Hiraku OKADA Takaya YAMAZATO Masaaki KATAYAMA
In narrow band power-line communication (PLC) systems, which use frequency band below a few hundred kHz, the noise on power-line is non-white and non-stationary. Under such environment, the performance of Orthogonal Frequency Division Multiplex (OFDM) modulation system is analyzed, and time and frequency dependence of bit error rate (BER) is clarified. In addition, the possibility of performance improvement with the symbol level repetition coding employing cyclo-stationary feature of power-line noise is presented.
Hirokazu HAYASHI Noriyuki MIURA Hirotaka KOMATSUBARA Marie MOCHIZUKI Koichi FUKUDA
This paper describes an effective model which reproduces the dependence on the source/drain (S/D) process of the reverse short channel effect (RSCE) of the MOSFET threshold voltage (Vth). It is useful for local modeling which is effective within the limited process conditions. The proposed model is based on the physics where the key factor of RSCE is the dopant pile-up in the Si/SiO2 interface. The purpose of the model is for TCAD to be put to actual use as a quick solution tool. The calculation cost is much lower than a pair diffusion model, because the model is implemented in a conventional process simulator that solves one equation for each impurity. The capability of the simplified model is investigated for the dependence of various process conditions on the RSCE. Using our model, we also report the application of both the actual n-channel and p-channel MOSFETs.
Robert MORELOS-ZARAGOZA Shinichiro HARUYAMA Masayoshi ABE Noboru SASHO Lachlan B. MICHAEL Ryuji KOHNO
This paper discusses a design methodology suitable for the development of software defined radio platforms. A flexible digital receiver was designed and implemented using a multi-port direct converter and an FPGA-based platform. The design starts with a hardware-oriented top-level system model. The model is built based on basic signal processing blocks connected together in a graphical tool. Carrier symbol timing recovery is implemented in the discrete-time (digital) domain with an interpolator-based synchronizer. Carrier phase and frequency are recovered using a feedback synchronization algorithm (a second-order type-II digital PLL). Experimental results of the platform and its simulation results demonstrate the effectiveness of the proposed design methodology.
Masami AKAIKE Takashi OHIRA Keizo INAGAKI Qing HAN
Higher-order harmonics and distortions generated by nonlinearity of capacitance-voltage characteristic of a single varactor and an anti-series-connected varactor pair are analyzed and compared. The effect of linear and parabolic terms of nonlinearity to harmonics outputs and distortions is discussed. It is shown that an anti-series-connected varactor pair has a completely suppressed linear term and reduced parabolic term. The advantage of an anti-series-connected varactor pair is theoretically explained.
Noritaka YAMAMOTO Takashi HIRAGA
We demonstrated apertureless scanning near-field optical microscopy using a small protrusion (a simple 500-nm-diameter polystyrene particle) on a flat glass substrate as a probe. We designed a small sample stage to operate with the particle probe. It is a 40-µm-diameter circular stage, fabricated from an optical fiber by Hydrofluoric acid (HF) etching. In this paper, we present the first atomic force microscope and scanning near-field optical microscope images obtained with such a probe. We also discuss schemes for probe-sample distance control in this novel form of apertureless scanning near-field optical microscopy.
Migyoung JUNG Gueesang LEE Sungju PARK Rolf DRECHSLER
OPKFDDs (Ordered Pseudo-Kronecker Functional Decision Diagrams) are a data structure that provides compact representation of Boolean functions. The size of OPKFDDs depends on a variable ordering and on decomposition type choices. Finding an optimal representation is very hard and the size of the search space is n! 32n-1, where n is the number of input variables. To overcome the huge search space of the problem, a genetic algorithm is proposed for the generation of OPKFDDs with minimal number of nodes.
Shinsuke KOBAYASHI Kentaro MITA Yoshinori TAKEUCHI Masaharu IMAI
This paper proposes a compiler generation method for PEAS-III (Practical Environment for ASIP development), which is a configurable processor development environment for application domain specific embedded systems. Using the PEAS-III system, not only the HDL description of a target processor but also its target compiler can be generated. Therefore, execution cycles and dynamic power consumption can be rapidly evaluated. Two processors and their derivatives were designed using the PEAS-III system in the experiment. Experimental results show that the trade-offs among area, performance and power consumption of processors were analyzed in about twelve hours and the optimal processor was selected under the design constraints by using generated compilers and processors.
Hiromitsu UCHIDA Masatoshi NII Norio TAKEUCHI Yoshihiro TSUKAHARA Moriyasu MIYAZAKI Yasushi ITOH
A novel compact T/R (Transmit/Receive) switching circuit for wideband T/R modules has been proposed. It employs quadrature couplers and gate-and-drain-driven HPAs to remove circulators or T/R switches from a conventional T/R module, and T/R switching is made with controlling biasing conditions of the FETs in HPAs. Furthermore, an optimum biasing condition and design of output matching circuit of the HPA have been studied to reduce loss in RX-mode, and the validity of the method has been confirmed by measurements.
A blind equalizer which uses the differential constant modulus algorithm (DCMA) is introduced. An anchored FIR equalizer applied to a first-order autoregressive channel and updated according to the DCMA is shown to converge to the inverse of that channel regardless of the initial tap-weights and the gain along the direct path.
The one-sample locally optimum rank detector test statistics for composite signals in multiplicative and signal-dependent noise are obtained. Since the one-sample locally optimum rank detector makes use of the sign statistics of observations as well as the rank statistics, both 'even' and 'odd' score functions have to be considered. Although the one-sample locally optimum rank detector requires two score functions while the two-sample detector requires only one score function, the one-sample detector requires fewer calculations since it has to rank fewer observations.
Short range communication between roadside equipment and on-board equipment is very important for ITS (Intelligent Transport System). In this paper, for reliable roadside communication, the radio multi-path propagation at 2.4 GHz at roadside was measured and analyzed.
In this letter, we propose a two-stage object-based error-concealment technique for MPEG-2 video transmitted in a burst-packet-loss environment. A burst packet loss typically destroys a large area of MPEG-2 coded video. In the first stage, the missing area is intra-picture estimated and concealed in terms of a region-based approach. In the second stage, irregular-moving objects with respect to the background are identified and compensated from the predictive picture. As compared with conventional concealment approaches, the proposed method achieves better PSNR performance and reduces the visual artifacts.
The two-sample locally optimum rank detector test statistics for composite signals in additive, multiplicative, and signal-dependent noise are obtained in this letter. Compared with the structure of the one-sample locally optimum rank detector, that of the two-sample locally optimum rank detector is shown to be simpler, although it needs more computations. It is known that there is a trade-off of computational complexity and structural simplicity between the one- and two-sample detectors.
Kiyotaka YAMAMURA Masaki SATO Osamu NAKAMURA Takayoshi KUMAKURA
An efficient algorithm is proposed for finding all dc solutions of piecewise-linear (PWL) circuits. This algorithm is based on a powerful test (termed the LP test) for nonexistence of a solution to a system of PWL equations in a given region using the dual simplex method. The proposed algorithm also uses a special technique that decreases the number of regions on which the LP test is performed. By numerical examples, it is shown that the proposed algorithm could find all solutions of large scale problems, including those where the number of variables is 500 and the number of linear regions is 10500, in practical computation time.
Se-Hyun PARK Jiro HIROKAWA Makoto ANDO
The authors propose a novel 3-way power divider named a planar cross-junction, which is used as the center feed for single-layer slotted waveguide arrays. A feeding waveguide consisting of a cascade connection of these dividers is placed at the middle of radiating waveguide in a single layer. The length of radiating waveguides is halved; the long line effect in traveling wave operation is halved and bandwidth is widened. One divider as a unit is designed by Galerkin's method of moments to suppress the reflection and to control the amplitude and the phase of the divided power into two radiating waveguides on both sides of a feed one. Two types of the cross-junction with a different divided power ratio are designed and tested by experiments in 4 GHz band. The mutual coupling effects between two adjacent cross-junctions as cascaded in a feeding waveguide of the array are predicted to be small enough; units designed here are directly applicable for a multiple-way power divider.
Yukihiko NAKATA Tetsuya OKAMOTO Toshimasa HAMADA Takashi ITOGA Yutaka ISHII
We report, in this paper, on a combined process of photo-oxidation and PECVD using TEOS and O2 gases to produce an SiO2 gate insulator for poly-Si TFTs. Light of 172 nm-wavelength from a Xe excimer lamp generates active oxygen radicals efficiently and selectively without producing ozone. These oxygen radicals efficiently oxidize silicon. In contrast to plasma oxidation, photo-oxidation offers the ability to produce gate oxides without ion bombardment. Oxide-silicon interfaces with interface trap densities of 2-3 1010 cm-2 eV-1 were obtained by photo-oxidation at 200-300. A stack structure was produced using 4.3-nm-thick photo-oxide topped with a 40-nm-thick PECVD oxide film deposited at 300. This stack structure without annealing exhibited excellent interface behavior and the same J-E characteristics as a 100-nm-thick PECVD film annealed at 600.
Yoshiki EBIKO Yasuyoshi MISHIMA
We present the effects of N2O plasma treatment for hot carrier reliability and gate oxide stability in excimer-laser annealed poly-Si TFTs. N2O plasma treatment between SiO2 and poly-Si suppresses both the reduction in mobility caused by hot carrier stress and the Vth shift caused by gate bias stress. The results of XPS spectra and the energy distribution of the trap state density of stressed TFTs show that the introduction of Si-N bonds plays an important role in poly-Si TFT reliability.
Ki-Yun KIM Hyung-Jin CHOI Ho KIM
This letter presents a new approximation algorithm suitable for Taylor series expansion. The algorithm can effectively reduce the approximation error by using only a small number of terms in series expansion. The proposed algorithm can be more easily implemented and has better performance than the conventional Euler approximation algorithm. Also, the approximation performance of the proposed algorithm is compared with direct approaches, such as least-squares and Chebyshev approximation algorithm to show the relative advantages of the proposed algorithm. This letter also presents an application example of the proposed approximation algorithm in carrier recovery of OFDM (Orthogonal Frequency Division Multiplexing) modem.
Emir Tufan AKMAN Koray KAYABOL
In this letter, our proposed approach exploits the use of original and simplest Cellular Neural Network (CNN) for 2D Doubly Complementary (DC) Infinite Impulse Response (IIR) filter banks design. The properties of feedback and feedforward templates are studied for this purpose. Through some examples it is shown how generalizations of these templates can be used for DC IIR filter banks design. We modify Lagrangian function which is used for optimizing a low-pass filter design considering the constraint for stability of CNN. The brief conclusions with design examples that illustrate the proposed method and an image enhancement and restoration applications of designed filter banks are presented.