This paper proposes a block-based video encoder employing variable frame skipping (VFS) to improve the video quality in low bit rate channel. The basic idea of VFS mechanism is to decide and skip a suitable, non-fixed number of frames in temporal domain to reduce bit usage. The saved bits can be allocated to enhance the spatial quality of video. In literature, several methods of frame skipping decision have been proposed, but most of them only consider the similarities between neighboring coded frames as the decision criteria. Our proposed method takes into account the reconstruction of the skipped frames using motion-compensated frame interpolation at decoder. The proposed VFS models the reconstructed objective quality of the skipped frame and, therefore, can provide a fast estimate to the frame skipping at encoder. The proposed VFS can determine the suitable frame skipping in real time and provide the encoded video with better spatial-temporal bit allocation.
In this paper, a new algorithm for the optimal training sequence with respect to sequence length in 1-dimensional cluster-based sequence equalizers (1-D CBSE) is presented. The proposed method not only removes the step of random training sequence selection but also shortens the length of the selected training sequences. The superiority of the new method is demonstrated by presenting several simulation results of quadrature phase shift keying (QPSK) signaling schemes and related analyses.
Mitsutoshi YAHARA Kuniaki FUJIMOTO Hirofumi SASAKI
In this paper, we propose a voltage controlled oscillator (VCO) with up mode type Miller-integrator. The controlled voltage of this VCO can continuously change 0 V center in the positive and negative bidirection. Also, the relationship between control voltage and oscillating frequency shows the good linearity, and the calculated and the measured values agree well.
Masaji TOMITA Tomio SAKASHITA Yoshio KARASAWA
In this paper, a new method based on the mode-matching method in the sense of least squares is presented for analyzing the two dimensional scattering problem of TE plane wave incidence to the infinite plane surface with an arbitrary imperfection of finite extent. The semi-infinite upper and lower regions of that surface are a vacuum and a perfect conductor, respectively. Therefore the discussion of this paper is developed about the Dirichlet boundary value problem. In this method, the approximate scattered wave is represented by the integral transform with band-limited spectrum of plane waves. The boundary values of those scattered waves are described by only abscissa z and Fourier spectra are obtained by applying the ordinary Fourier transform. Moreover, new approximate functions are made by inverse Fourier transform of band-limited those spectra. Consequently, the integral equations of Fredholm type of second kind for spectra of approximate scattered wave functions are derived by matching those new functions to exact boundary value in the sense of least squares. Then it is shown analytically and numerically that the sequence of boundary values of approximate wave functions converges to the exact boundary value, namely, the boundary value of the exact scattered wave in the sense of least squares when the profile of imperfection part is described by continuous and piecewise smooth function at least. Moreover, it is shown that this sequence uniformly converges to exact boundary value in arbitrary finite region of the boundary and the sequence of approximate wave functions uniformly converges to the exact scattered field in arbitrary subdomain in the upper vacuum domain of the boundary in wider sense when the uniqueness of the solution of the Helmholtz equation is satisfied with regard to the profile of the imperfection parts of the boundary.
Yuan-Long JEANG Jer-Min JOU Win-Hsien HUANG
In this paper, a methodology based on a mix-mode interconnection architecture is proposed for constructing an application specific network on chip to minimize the total communication time. The proposed architecture uses a globally asynchronous communication network and a locally synchronous bus (or cross-bar or multistage interconnection network MIN). First, a local bus is given for a group of IP cores so that the communications within this local bus can be arranged to be exclusive in time. If the communications of some IP cores should be required to be completed within a given amount of time, then a non-blocking MIN or a crossbar switch should be made for those IP cores instead of a bus. Then, a communication ratio (CR) for each pair of local buses is provided by users, and based on the Huffman coding philosophy, a process is applied to construct a binary tree (BT) with switches on the internal nodes and buses on the leaves. Since the binary tree system is deadlock free (no cycle exists in any path), the router is just a relatively simple and cheap switch. Simulation results show that the proposed methodology and architecture of NOC is better on switching circuit cost and performance than the SPIN and the mesh architecture using our developed deadlock-free router.
Shinnosuke SEKI Satoshi KOBAYASHI
In this paper, we are concerned with a structural ambiguity problem of tree adjoining grammars (TAGs), which is an essential problem when we try to model consensus structures of given set of ribonucleic acid (RNA) secondary structures by TAGs. RNA secondary structures can be represented as strings with structural information, and TAGs have a descriptive capability of this kind of strings, what we call structure-annotated strings. Thus, we can model RNA secondary structures by TAGs. It is sufficient to use existing alignment methods for just computing the optimal alignment between RNA secondary structures. However, when we also want to model the resulting alignment by grammars, if we adopt these existing methods, then we may fail in modeling the alignment result by grammars. Therefore, it is important to introduce a new alignment method whose alignment results can be appropriately modeled by grammars. In this paper, we will propose an alignment method based on TAG's derivations each corresponding to a given RNA secondary structure. For an RNA secondary structure, there exist a number of derivations of TAGs which correspond to the structure. From the grammatical point of view, the property of TAGs drives us to the question how we should choose a derivation from these candidates in order to obtain an optimal alignment. This is the structural ambiguity problem of TAGs, which will be mainly discussed in this paper. For dealing with this problem appropriately, we will propose an edit distance between two structure-annotated strings, and then present an algorithm which computes an optimal alignment based on the edit distance.
This paper proposes a coordinator for workflow management systems (WFMSs). It is a basic module for developing WFMSs. It is also a coordinator to coordinate multiple WFMSs. The coordinator provides functions to facilitate executing workflows and to ensure secure access of workflow information. Facilitating workflow execution is well-known, but ensuring secure access of workflow information is identified as important only recently. Although many models ensure secure workflow information access, they fail to offer the features we need. We thus developed a new model for the control. This paper presents the coordinator its access control model.
Masayuki HASHIMOTO Kenji MATSUO Atsushi KOIKE
This paper proposes an effective JPEG 2000 encoding method for reducing tiling artifacts, which cause one of the biggest problems in JPEG 2000 encoders. Symmetric pixel extension is generally thought to be the main factor in causing artifacts. However this paper shows that differences in quantization accuracy between tiles are a more significant reason for tiling artifacts at middle or low bit rates. This paper also proposes an algorithm that predicts whether tiling artifacts will occur at a tile boundary in the rate control process and that locally improves quantization accuracy by the original post quantization control. This paper further proposes a method for reducing processing time which is yet another serious problem in the JPEG 2000 encoder. The method works by predicting truncation points using the entropy of wavelet transform coefficients prior to the arithmetic coding. These encoding methods require no additional processing in the decoder. The experiments confirmed that tiling artifacts were greatly reduced and that the coding process was considerably accelerated.
Eun-Gu JUNG Jeong-Gun LEE Sang-Hoon KWAK Kyoung-Son JHANG Jeong-A LEE Dong-Soo HAR
A multiple-issue on-chip bus of a layered architecture in a Globally Asynchronous Locally Synchronous (GALS) design style, supporting in-order/out-of-order completion, is proposed in this letter. The throughput of the proposed on-chip bus is increased by 31.3% and 34.3%, while power consumption overhead is only 6.76% and 3.98%, respectively, as compared to an asynchronous single-issue on-chip bus.
This paper presents a fuzzy optimization based scheduling method for the manufacturing systems with uncertain production capacities. To address the uncertainties efficiently, the fuzzy optimization technique is used in defining the scheduling problem. Based on the symmetric approach of fuzzy optimization and Lagrangian relaxation technique, a practical fuzzy-optimization based algorithm is developed. The computational experiments based on the real factory data demonstrate that the proposed method provides robust scheduling to hedge against uncertainties.
Vasily G. MOSHNYAGA Tomoyuki YAMANAKA
Design of portable battery operated multimedia devices requires energy-efficient multiplication circuits. This paper proposes a novel architectural technique to reduce power consumption of digital multipliers. Unlike related approaches which focus on multiplier transition activity reduction, we concentrate on dynamic reduction of supply voltage. Two implementation schemes capable of dynamically adjusting a double voltage supply to input data variation are presented. Simulations show that using these schemes we can reduce energy consumption of 1616-bit multiplier by 34% and 29% on peak and by 10% and 7% on average with area overhead of 15% and 4%, respectively, while maintaining the performance of traditional multiplier.
Tuan-Anh PHAN Chang-Wan KIM Yun-A SHIM Sang-Gug LEE
This paper presents a frequency-controllable image rejection mixer in heterodyne architecture for 2 GHz applications based on TSMC 0.18 µm CMOS technology. The designed mixer uses a notch filter to suppress the image signal and allows precise tuning the image frequencies. An image rejection of 20-70 dB is obtained in a 200 MHz of bandwidth. The simulation results show single-side band (SSB) NF is improved 3.7 dB, the voltage conversion gain of 14.7 dB, improved by more than 4 dB. The circuit operates at the supply voltage of 1.8 V, and dissipates 11.34 mW.
Although a proposed steganographic encoding scheme can reduce distortion caused by data hiding, it makes the system susceptible to active-warden attacks due to error spreading. Meanwhile, straightforward application of error correction encoding inevitably increases the required amount of bit alterations so that the risk of being detected will increase. To overcome the drawback in both cases, an integrated approach is introduced that combines the stego-encoding and error correction encoding to provide enhanced robustness against active attacks and channel noise while keeping good imperceptibility.
Toshiki KANAMOTO Tetsuya WATANABE Mitsutoshi SHIROTA Masayuki TERAI Tatsuya KUNIKIYO Kiyoshi ISHIKAWA Yoshihide AJIOKA Yasutaka HORIBA
This paper proposes a new non-destructive methodology to estimate physical parameters for LSIs. In order to resolve the estimation accuracy degradation issue for low-k dielectric films, we employ a parallel-plate capacitance measurement and a wire resistance measurement in our non-destructive method. Due to (1) the response surface functions corresponding to the parallel-plate capacitance measurement and the wire resistance measurement and (2) the searching of the physical parameter values using our cost function and simulated annealing, the proposed method attains higher precision than that of the existing method. We demonstrate the effectiveness of our method by application to our 90 nm SoC process using low-k materials.
Hiroyuki TSUJIKAWA Kenji SHIMAZAKI Shozo HIRANO Kazuhiro SATO Masanori HIROFUJI Junichi SHIMADA Mitsumi ITO Kiyohito MUKAI
In the move toward higher clock rates and advanced process technologies, designers of the latest electronic products are finding increasing silicon failure with respect to noise. On the other hand, the minimum dimension of patterns on LSIs is much smaller than the wavelength of exposure, making it difficult for LSI manufacturers to obtain high yield. In this paper, we present a solution to reduce power-supply noise in LSI microchips. The proposed design methodology also considers design for manufacturability (DFM) at the same time as power integrity. The method was successfully applied to the design of a system-on-chip (SOC), achieving a 13.1-13.2% noise reduction in power-supply voltage and uniformity of pattern density for chemical mechanical polishing (CMP).
We consider the chains of integrators with nonlinear terms which allow state and input delays. We provide an output feedback controller which globally asymptotically stabilizes the given system under certain sufficient conditions. It turns out that the obtained result includes several existing results as particular cases. This point is shown through two applications of the main result. Also, industrial processes are presented to illustrate the practicability of our result.
Takeshi MATSUMOTO Hiroshi SAITO Masahiro FUJITA
In this paper, an efficient equivalence checking method for two C descriptions is described. The equivalence of two C descriptions is proved by symbolic simulation. Symbolic simulation used in this paper can prove the equivalence of all of the variables in the descriptions. However, it takes long time to verify the equivalence of all of the variables if large descriptions are given. Therefore, in order to improve the verification, our method identifies textual differences between descriptions. The identified textual differences are used to reduce the number of equivalence checkings among variables. The proposed method has been implemented in C language and evaluated with several C descriptions.
Hiroki NAKAHARA Tsutomu SASAO Munehiro MATSUURA
This paper shows a design method for a sequential circuit by using a Look-Up Table (LUT) ring. The method consists of two steps: The first step partitions the outputs into groups. The second step realizes them by LUT cascades, and allocates the cells of the cascades into the memory. The system automatically finds a fast implementation by maximally utilizing available memory. With the presented algorithm, we can easily design sequential circuits satisfying given specifications. The paper also compares the LUT ring with logic simulator to realize sequential circuits: the LUT ring is 25 to 237 times faster than a logic simulator that uses the same amount of memory.
Chia-Chi CHU Ming-Hong LAI Wu-Shiung FENG
An order selection scheme for two-sided oblique projection-based interconnect reduction will be investigated. It will provide a guideline for terminating the conventional nonsymmetric Pade via Lanczos (PVL) iteration process. By exploring the relationship of the system Grammians of the original network and those of the reduced network, it can be shown that the system matrix of the reduced-order system generated by the two-sided oblique projection can also be expressed as those of the original interconnect model with some additive perturbations. The perturbation matrix only involves bi-orthogonal vectors at the previous step of the nonsymmetric Lanczos algorithm. This perturbation matrix will provide the stopping criteria in the order selection scheme and achieve the desired accuracy of the approximate transfer function.
Nam Hyun PARK Chang Wook AHN Rudrapatna S. RAMAKRISHNA
This paper proposes a genetically inspired adaptive clustering algorithm for numerical and categorical data sets. To this end, unique encoding method and fitness functions are developed. The algorithm automatically discovers the actual number of clusters and efficiently performs clustering without unduly compromising cluster-purity. Moreover, it outperforms existing clustering algorithms.