bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of in‐call buffer/window allocation schemes for short intermittent file transfers over broadband packet networks
Authors: Doshi Bharat
Published: July 2007

While static open loop rate controls may be adequate for handling continuous bit rate (CBR) traffic, relatively smooth data traffic, and relatively low speed bursty data traffic over broadband integrated networks, high speed bursty data sources need more dynamic controls. Burst level resource allocation is one such dynamic control. Potential benefits and other issues for burst level resource parameter negotiations for bursty data traffic over high speed wide area packet networks have been discussed earlier.1–6 A detailed analysis of an adaptive buffer/window negotiation scheme for long file transfers using these concepts is presented in Reference 1. In this paper we discuss two burst level buffer/window negotiation schemes for short intermittent file transfers, focusing on the specific needs of such traffic streams. We develop closed network of queues models to reflect the behaviour of the proposed schemes. These models, while being simple, capture essential details of the control schemes. Under fairly general assumptions, the resulting network of queues is of product form and can be analysed using the mean value analysis. We use such an analysis to compare the proposed schemes and to determine appropriate sizes of trunk buffers to achieve the desired balance between bandwidth utilization and file transfer delay. The effects of other parameters on the performance of these schemes as well as on the buffer sizing rules are also discussed.

Burst level (in‐call) parameter negotiation may be carried out by the end system with the network elements or by an interface system (access controller) with the broadband network elements. We discuss implications of this location as well as the needed protocol features. Finally, the service discrimination capabilities desired at the trunk controllers in switching nodes are briefly discussed.
Voiceband data speed discrimination
Authors: Benvenuto N.
Published: July 2007

Some results of research to discriminate voiceband data signals of different speeds are reported. A discrimination technique based upon the autocorrelation envelope and second order moment of the complex lowpass data signal is introduced. Under ideal channel conditions, the discriminator, within a window of 128 ms of PCM data samples, classifies whether the signal is at 9600 bit/s, 4800 bit/s, 2400 bit/s, 1200 bit/s or 300 bit/s. Performance of the discriminator for signals in the presence of various analog impairments shows that this method is quite robust.
PDM: A versatile digital transmission system for video
Authors: Burgess G. D.
Published: July 2007

This report discusses a pulse density modulation (PDM) video transmission system. PDM is a one‐bit digital coding scheme with advantages of transparency due to an inherently extended signal bandwidth and relatively simple decoding; these make it ideal for a variety of applications.

The system outlined is designed to carry a single analogue video channel, together with several sound channels, over a 140 or 280 Mbit/s digital transmission‐link. An alternative option to the sound channels will be to carry a 2.048 Mbit/s data channel. Since the analogue video input will be PDM coded, this will enable the system to carry video formats which have a flat base‐band frequency response requirement of in excess of 20 MHz (such as HDTV), allowing a large degree of flexibility in use.
Traffic modelling for packet communication networks
Authors: Stavrakakis Ioannis
Published: July 2007

A general model for the description of traffic processes in packet communication networks is presented in this paper. The packet traffic generated by a network component is described in terms of a generalized Bernoulli process whose intensity depends on the state of the component. When the state space of the component is large, an approximate traffic characterization is proposed based on the dominant states. The latter characterization is shown to be well performing for the considered examples of practical network components. Based on the proposed general model, an analysis approach for multi‐component communication networks is presented. Numerical results illustrate the inaccuracy of the widely adopted i.i.d. modelling, the effectiveness of the proposed general model and the significant complexity reduction through the adoption of the approximate one.
Splice‐induced impairments on very‐high‐speed digital data communications over copper telephone networks
Authors: Sistanizadeh Kamran
Published: July 2007

The effects of splice‐induced crosstalk, insertion loss and echo on very‐high‐speed digital data communications over copper telephone networks are analysed and evaluated. Sealing current is used to mitigate the adverse effects of the splices. The specifications of sealing current (i.e. magnitude, shape, frequency of application) have significant ramifications on the operations of the digital communication systems. For proper operation of echo‐cancellers (i.e. fast adaptation and tracking) on full‐duplex transceivers operating at 800 kbit/s, and to achieve a bit error ratio of 10−7, the magnitude and the rate of the change of splice fluctuations must be controlled.

It is shown that the effects of crosstalk and insertion loss are not as severe as the occurrence of echo due to rapid fluctuations of splice impedance. The admissible ranges of splice fluctuations for a series of worst‐case scenarios are computed, and their effects on the performance of the echo‐canceller are discussed.

If the splice fluctuation is restricted to 0·1 Ω on a 20 Ω splice, with the splice in the vicinity of the transceiver, the echo is —36 dB with respect to the far‐end received signal, which is an acceptable level on a 9 kft subscriber loop with an American Wire Gauge of 26. However, quantification of the dynamics (i.e. the rate of change) of splice fluctuations requires laboratory experiments and field measurements.
Contention protocols for ring networks with large bandwidth‐delay products
Authors: Feldmeier David C.
Published: July 2007

As the bandwidth‐delay product of ring networks increases, conventional access protocols, such as the gated token protocol, become less efficient. We propose overcoming this problem with contention‐based access protocols. We discuss the necessary properties of any contention ring access protocol and present two specific proposals. Some simple analysis and simulation is done to determine the performance of these protocols. Our protocols are shown to have better end‐to‐end delay than a gated token protocol. We also simulate another contention protocol called the hybrid protocol, proposed by Bhargava, et al. It is shown that the simple protocols described in this paper have performance comparable to that of the more complex hybrid protocol on networks with high bandwidth‐delay products.
Optical broadband access using ATM on a passive optical network
Authors: Keller H. , Glade M. , Hartl B. , Horbach C.
Published: July 2007

Within the framework of the ‘FITL (fibre in the loop) evolution’, Siemens is developing a prototype based on a passive optical network (PON) for the economic provision of BISDN services in the subscriber access area. It provides 32 subscribers with BISDN access up to a maximum user data rate of 45 Mbit/s per subscriber. The information is transferred via ATM cells and PON‐specific overhead in both directions on the PON at a data rate of 155.52 Mbit/s. For transmission to the subscribers, the time division multiplex procedure (TDM) is used. For transmission in the opposite direction, a highly flexible time division multiple access procedure (TDMA) controls the access to PON for the subscriber‐side line terminations.

In order to keep the transmission system inexpensive emphasis is placed on a digital calibration of the fibre loop delay, a burst transmitter at the subscriber side without amplitude recovery and a burst receiver at the exchange side with purely digital bit synchronization. However, to achieve these features a small part of data rate must be used as a PON specific overhead.
Dynamic expression patterns of leucine‐rich repeat containing protein 10 in the heart
Authors: Kim Ki‐Hyun , Kim Tae‐Gyun , Micales Bruce K. , Lyons Gary E. , Lee Youngsook
Published: July 2007

Leucine‐rich repeat containing protein 10 (LRRC10) is a heart‐specific factor whose function remains unknown. Examination of the intracellular location of the gene products is a critical step in determining the biological functions of the protein. Our expression analyses in mice indicate that LRRC10 is exclusively expressed from the precardiac region in early embryos to the adult heart. LRRC10 expression is markedly elevated upon birth, suggesting its role in the embryonic as well as adult hearts. Of interest, LRRC10 exhibits dynamic intracellular expression patterns in cardiomyocytes. Cardiomyocytes from embryos and newborns show diffuse cytoplasmic and nuclear staining of LRRC10. In contrast, striking striations are observed in adult cardiomyocytes, which are colocalized with the markers for the Z‐line, sarcoplasmic reticulum (SR), and transverse (T)‐tubule by double immunostaining. Further investigation by electron micrographs places LRRC10 in a diad region where the SR interacts with the T‐tubule that locates along the Z‐line. Developmental Dynamics 236:2225–2234, 2007. © 2007 Wiley‐Liss, Inc.
Bone development in the femoral epiphysis of mice: The role of cartilage canals and the fate of resting chondrocytes
Authors: Blumer Michael J.F. , Longato Stefano , Schwarzer Christoph , Fritsch Helga
Published: July 2007

In mammals, the exact role of cartilage canals is still under discussion. Therefore, we studied their development in the distal femoral epiphysis of mice to define the importance of these canals. Various approaches were performed to examine the histological, cellular, and molecular events leading to bone formation. Cartilage canals started off as invaginations of the perichondrium at day (D) 5 after birth. At D 10, several small ossification nuclei originated around the canal branched endings. Finally, these nuclei coalesced and at D 18 a large secondary ossification centre (SOC) occupied the whole epiphysis. Cartilage canal cells expressed type I collagen, a major bone‐relevant protein. During canal formation, several resting chondrocytes immediately around the canals were active caspase 3 positive but others were freed into the canal cavity and appeared to remain viable. We suggest that cartilage canal cells belong to the bone lineage and, hence, they contribute to the formation of the bony epiphysis. Several resting chondrocytes are assigned to die but others, after freeing into the canal cavity, may differentiate into osteoblasts. Developmental Dynamics 236:2077–2088, 2007. © 2007 Wiley‐Liss, Inc.
In vivo quantum dot labeling of mammalian stem and progenitor cells
Authors: Slotkin Jonathan R. , Chakrabarti Lina , Dai Hai Ning , Carney Rosalind S.E. , Hirata Tsutomu , Bregman Barbara S. , Gallicano G. Ian , Corbin Joshua G. , Haydar Tarik F.
Published: July 2007

Fluorescent semiconductor nanocrystal quantum dots (QDs) are a class of multifunctional inorganic fluorophores that hold great promise for clinical applications and biomedical research. Because no methods currently exist for directed QD‐labeling of mammalian cells in the nervous system in vivo, we developed novel in utero electroporation and ultrasound‐guided in vivo delivery techniques to efficiently and directly label neural stem and progenitor cells (NSPCs) of the developing mammalian central nervous system with QDs. Our initial safety and proof of concept studies of one and two‐cell QD‐labeled mouse embryos reveal that QDs are compatible with early mammalian embryonic development. Our in vivo experiments further show that in utero labeled NSPCs continue to develop in an apparent normal manner. These studies reveal that QDs can be effectively used to label mammalian NSPCs in vivo and will be useful for studies of in vivo fate mapping, cellular migration, and NSPC differentiation during mammalian development. Developmental Dynamics 236:3393–3401, 2007. © 2007 Wiley‐Liss, Inc.
A parallel automatic routing technique based on local current comparison method—application of associative silicon retina
Authors: Cheng Gui‐Xin , Tanaka Mamoru
Published: July 2007

This paper proposes a new local current comparison method to search for the routing path. In the proposed method, the routing plane is represented by a resistive network. A voltage is provided to the start and the end pins to be connected, and the routing path is determined from the current distribution in the equilibrium state. Thus, the local current of the edges connected to each node of the routing path is maximized. By this local current comparison method, the routing path is determined along the direction of the maximum current and several nets can be routed while avoiding the competition.

The routing method for the multipin net also is proposed based on the local current comparison method. Since the potential distribution of the nodes in the resistive network is an approximate solution of the equipotential line distribution of the static electric field, it is shown that the optimal or quasi‐optimal short routing path can be determined. Using the multilayer resistive network, the multilayer routing can also be realized. Then the automatic routing method is proposed where more than one net can be routed in parallel by modifying the specification of voltages according to the result of the previous current distribution obtained by the local current comparison method.

A method to locate the bottleneck (BN) of the net also is presented. The proposed local current comparison method is related closely to the node neighborhood analysis from the viewpoint of the cellular neural net, based on the energy minimization method. The method is especially suited to the dedicated hardware implementation by the mixed analog‐digital chip.
Proposal of median‐type fuzzy filter and its optimum design
Authors: Arakawa Kaoru , Arakawa Yasuhiko
Published: July 2007

This paper proposes a median‐type fuzzy filter, aiming at the signal estimation in the case where the impulse and white Gaussian noise are superposed on the signal with sudden changes, such as the image signal. The filter is realized by generalizing the fuzzy filter previously proposed by the authors. In the previously proposed fuzzy filter, the signal point to be estimated is taken as the reference point and the signal is estimated by determining the input signals relatively close to the reference point, using the fuzzy clustering; whereas the filter proposed in this paper uses the median value of the input signal sequence as the reference point and the signal is estimated by determining the input signals close to that reference point using the fuzzy clustering. The signal is estimated by determining the center of gravity of the cluster of the points close to the median. Furthermore, in the proposed filter, the optimum design is realized by learning with respect to appropriate training signals. It is in general not possible to decide definitely whether or not the input signal is close to the median, and thus the fuzzy clustering is effective since it takes into consideration the ambiguity of the signal. By introducing the fuzzy clustering, it is shown in particular that an effective signal estimation is realized for the signal with subtle changes.
A CAM‐based hardware implementation of the improved line‐search algorithm
Authors: Kubota Kazuto , Sato Masao , Ohtsuki Tatsuo , Suzuki Kei
Published: July 2007

In the routing process in VLSI and PCB, the “gridless router” has been considered where the routing is executed without using a grid. The improved line search algorithm is one of the gridless routers where the linesearch algorithm is extended so that the route search procedure is executed on a linear memory space in a polynomial time. The search of the route with the minimum bends is ensured. However, the algorithm has a problem in that the route is obtained by iterating the search of the two‐dimensional figures and the computational complexity ofO(nlog2n) at the minimum andO(n2) in the worst case is required for the layout area composed ofnvertices.

This paper notes that the complexity of solving the two‐dimensional figure search problem can be suppressed by using the associative memory and presents an algorithm for the improved line search using the associative memory where the time and space complexity isO(n). The proposed algorithm is implemented on the associative processor and the result is compared to the result of implementation on the general‐purpose computer.
Vector quantization with hypercolumnar clusters
Authors: Kohata Minora , Takagi Tasuku
Published: July 2007

This paper proposes a new vector quantization method which can reduce search complexity and code book memory size by reducing the number of code vectors without increasing quantization distortion. This method uses hypercolumnar clusters; and an input vector is quantized to a cluster, the center axis of which is nearest to the input vector. Thus, one vector and one scalar must be coded and transmitted. The proposed method was applied to four geometrically different distributions and LPC cepstra of speech signals. As a result, the number of code vectors was decreased compared with that in an ordinary vector quantizer, in all of the forementioned distributions. Then the reduction of memory size and search complexity were evaluated.

The excessive bits required for the scalar quantization in this method also were studied.
2‐D cutting‐stock algorithms based on local optimization
Authors: Sakamoto Toyokazu
Published: July 2007

This paper proposes the two‐dimensional (2‐D) cutting‐stock algorithm based on the local optimization. First, it is intended to eliminate the combinational process for the rectangular parts in the traditional system. The search operation is defined as the one‐to‐one mapping of the rectangular parts to the partial rectangular regions generated by the divide operation. A stack is used to store the data for the partial rectangular regions, and the merge operation is introduced as a new concept of operation in the stack. The algorithm is constructed recursively using the following four operations, i.e., search, divide, merge, and stack. Through an application example, it is verified that the proposed algorithm can realize nearly the same layout efficiency as the traditional method by the dynamic programming.
Inverse gaussian distribution and its application
Authors: Sato Shunsuke , Inoue Junko
Published: July 2007

The inverse Gaussian distribution is related closely to the Gaussian distribution as is suggested by its name. It is used not only in mathematical statistics but also in various fields such as engineering to describe various phenomena and to make quantitative analysis.

Schrödinger derived the cumulant generating function for the first‐passage time of the Brownian motion with a drift. Then Tweedie extended Schrödinger's result and found that the cumulant‐generating function for the time to travel for a unit distance and the cumulant‐generating function for the distance traveled in the unit time are in the relation of the inverse function. Tweedie found also that the same relations exist between the binomial distribution and the negative binomial distribution as well as between Poisson distribution and gamma distribution. He called one of those the inverse of the other. The study of the inverse Gaussian distribution was developed further by Wasan, Johnson and Kotz; Folks and Chhikara; et al.

This paper discusses the first‐passage time distribution of the Wiener process as the origin of the inverse Gaussian distribution, the inverse Gaussian distribution itself and its properties, the generalized inverse distribution, and the application of the inverse Gaussian distribution.
Synthesis of “narrow‐band” random moving image via computer
Authors: Takahashi Nobuyuki , Tanaka Tetsuya , Ogura Hisanao
Published: July 2007

This paper presents a simple generating algorithm for a moving random image by generalizing the algorithm for a stationary random image in a previous work. Although the algorithm is applicable to a more general case, special emphasis is placed on the “narrow‐band” random image with two or more spectral peaks which models a rough sea surface with strong periodic correlation. Such a “narrow‐band” image can be given as the real or imaginary part of a complex‐valued random image described by a noncausal model.

A moving random image which is a spatio‐temporal random field and a moving image drifting in a certain direction can be generated by a modified simple algorithm; and several examples are given. Generation of such a stationary or moving random image with given statistical properties is useful in the study of various image processing.
A parametric loudspeaker—applied examples
Authors: Aoki Kenichi , Kamakura Tomoo , Kumamoto Yoshiro
Published: July 2007

A parametric loudspeaker using the self‐demodulation of finite‐amplitude ultrasound has a sharper directivity than a conventional loudspeaker of the same aperture size. This is because of the formation of the end‐fire array with virtual sound sources which are generated in the ultrasound beam. In general, when the aperture becomes smaller, the difference in directivity appears clearly.

This article describes a theoretical prediction of the optimum frequency of primary ultrasound waves to develop a transmitter with small aperture and compares the theory and experiment using an 11‐cm diameter parametric loudspeaker. The possibility of practical use for guidance equipment such as an audible pedestrian signal also is discussed. Furthermore, using large‐aperture parametric loudspeakers, an experiment is carried out in a reverberant tunnel to confirm the effectiveness in the improvement of speech articulation.
Reduction of deviation of frequency characteristics of saw filters by mechanical polishing of zno film surface
Authors: Kadota Michio , Kondoh Chikashi , Chubachi Noriyoshi
Published: July 2007

It was found that the surface acoustic wave (SAW) amplitudes in SAW filters made of ZnO films vary from filter to filter even when the center frequencies are the same and the deviation of amplitudes must be reduced. It was found also that the frequency and amplitude characteristics could be improved by mirror polishing of the ZnO film surface.

In an SAW filter with a ZnO/interdigital transducer (IDT)/glass substrate structure, periodic convex areas due to the thickness of the finger electrode of IDT and fine roughness were present on the device surface. As a result of investigating the influence of the surface structure on the amplitude deviation, it was found that the convex areas did not influence the electromechanical coupling coefficient; but they reduced the acoustic velocity of SAW. In addition, it was clarified that the convex areas due to the finger electrode and fine roughness on the ZnO surface caused deviations in the acoustic velocity of SAW and reflections of SAW, causing a deviation in the amplitude characteristics.
Two‐dimensional line spectrum estimation by polar coordinate ar models
Authors: Sakurai Manabu , Hamada Nozomu
Published: July 2007

In this paper, a spectrum estimation method is proposed which is based on a two‐dimensional autoregressive (AR) model with polar coordinate coefficient arrangement. When the signal is given in terms of an orthogonal coordinate system, such a coordinate system is naturally used for linear prediction in a conventional AR estimation method. The support of the estimation coefficients and the peak shape of the corresponding estimation spectrum are known to be related by a certain rule.

By using an AR model in which the coordinate arrangement of the linear prediction is in a polar coordinate, the rotation of the coordinate region keeps an AR model in the same polar coordinate form. Hence, it is possible to determine the relative positional relationship between the estimated spectrum shape and the coefficient mask. It is shown that the present method can estimate the spectrum with a high resolution by using this relationship and avoiding the interference between the spectral peaks.
A method for analog circuit design that stores and reuses design procedures
Authors: Morie Takashi , Onodera Hidetoshi , Tamaru Keikichi
Published: July 2007

This paper proposes a new design methodology that improves the efficiency of analog circuit design. In the conventional design environment, designers try to enhance design productivity by storing designed circuits in a library for future reuse. However, a fixed circuit stored in a library is optimized to a particular set of performance specifications; and, hence, its reusability is low.

By contrast, the proposed methodology stores not only designed results but also design methods that show how to design circuits. When different sets of specifications are required, circuits are designed automatically based on the stored design methods, which improves design efficiency.

To evaluate the proposed design methodology, a method is devised that automatically stores a design procedure from the design process of a human designer and reuses it for circuit analysis. A prototype design system that realizes it is implemented. Experimental results on the design of an operational amplifier show the effectiveness of the proposed methodology.
Computer generation of lyapunov functions and estimation of a stability region
Authors: Ohta Yuzo , Nonomura Tsuyoshi , Imanishi Hiroshi , Haneda Hiromasa
Published: July 2007

The Lyapunov method is one of the most powerful methods for analysis of stability. However, from the practical viewpoint, there is no method to construct a Lyapunov function applicable to systems in general.

This paper presents the Lyapunov function that is determined by a polytope and which is suitable for computer generation of Lyapunov functions since neither a special form of function nor the number of parameters to be chosen need be given in advance. Moreover, the estimate of the stability region can easily be improved since the modification of Lyapunov function is that of the corresponding polytope.

In this paper, the notion of the traditional sector condition is generalized so that a given function is bounded by using the convex combination of a set of piecewise‐linear functions. Using this generalized sector condition, improved stability conditions are derived and it is applied to construct the Lyapunov function.
Design of digital allpass networks based on the eigenvalue problem
Authors: Zhang Xi , Iwakura Hiroshi
Published: July 2007

This paper presents a new method of the phase design for the digital allpass network utilizing the eigenvalue problem. The proposed design method considers the phase error between the phase response of the allpass network to be realized and the ideal phase response. The design problem is formulated as an eigenvalue problem based on the Remez algorithm. By calculating the eigenvector corresponding to the maximum eigenvalue, the filter coefficients are determined and the optimal approximate solution is obtained by iterative calculation.

In the design method, the eigenvector corresponding to the maximum eigenvalue is calculated to determine the filter coefficients so that the phase error is minimized. Consequently, the convergence of the design algorithm is guaranteed. Usually, the optimal approximate solution is obtained by several times of iterations. The error‐ratio of the phase characteristics can be set arbitrarily, and the stability of the filter is ensured.

Finally, the method is extended to the phase design for the digital allpass network with complex coefficients, several design examples are shown, and the usefulness of the proposed design method is demonstrated.
Synthesis of switched‐capacitor higher‐order immittance simulation circuits
Authors: Ono Toshio
Published: July 2007

Element level simulation using a switched capacitor (SC) have been employed mainly for inductance simulation and there have been quite a few reports on the higher‐order immittance simulation which is a current research topic of analog filters.

This paper proposes two types of SC circuits—ungrounded frequency‐dependent negative resistance (FDNR) and frequency‐dependent negative inductance (FDNL)—synthesized by bilinear transformation and the simulation results by the SC circuit analysis program (SWITCAP) are compared with the theoretical values. Moreover, the experimental results on the discrete components are shown which agree well with theoretical values.

The circuits use unity gain buffers (UGBs) as active devices due to their simple synthesis, and they are controlled by a two‐phase clock. Moreover, the parasitic capacitors which are derived from bottom plates of an integrated capacitor have no effect on the performance except for one capacitor which determines the element values.
Design of 3‐D separable‐denominator digital filters using minimal decomposition and balanced realization
Authors: Hinamoto Takao , Harada Ken‐Ichi
Published: July 2007

Based on a concept of minimal decomposition and balanced model reduction, a technique is developed for designing three‐dimensional (3‐D) separable‐denominator digital filters in the spatial domain. This is done by decomposing a desired 3‐D FIR filter into three parts and by representing it by a cascade connection of three 1‐D filters. The minimal decomposition treated here can be viewed as an extension of that in the 2‐D separable‐denominator case. A numerical example also is given to illustrate the utility of the proposed technique. The amount of calculation required here is relatively small and the stability of the resulting filter is always guaranteed.
Training method of the excitation codebooks for code‐excited linear prediction
Authors: Moriya Takehiro , Miki Satoshi , Ohmuro Hitoshi , Mano Kazunori
Published: July 2007

This paper considers the codebook for low bit‐rate speech coding by code‐excited linear prediction (CELP) and the mapping table for the channel code. It also proposes an optimization procedure for sequential training based on the structured excitation codebook. In the discussions of structurization of the codebook, the conjugate structure to represent the output by the sum of two vectors, the pitch synchronized processing, rotating use of the codebook, the time‐domain sloped gain, and the integrated mapping to the channel code are considered. The distortion measure used in the training is the same closed‐loop measure as is used in the coding. In other words, the distortion between the input speech and the synthesized speech at the perceptually weighted filter output is minimized. By training the codebook, the SNR of the coded speech is improved by approximately 1 dB. The improvement in speech quality is also verified. It is also verified that the robustness against bit error can be improved by the training of the mapping table to the channel code, as well as by training based on the distortion measure considering bit error.
Theory of cosine‐modulated two‐dimensional perfect reconstruction filter banks
Authors: Ikehara Masaaki
Published: July 2007

This paper considers a cosine‐modulated, two‐dimensional (2‐D) perfect reconstruction (PR) filter banks theory. First, a 2‐D digital filter with half‐pass‐band obtained by the sampling matrix had to be designed. Next, 2‐D analysis filter banks are realized by cosine‐modulating this prototype 2‐D digital filter so that 2‐D analyzed signals become real. It is shown that the modulation in the 2‐D frequency plane is equivalent to 1‐D modulation. A necessary and sufficient condition for 2‐D perfect reconstruction filter banks is derived. If the polyphase filter pairs of the prototype filter doubly complement, the resulting 2‐D filter bank satisfies the condition of perfect reconstruction.
A recursive orthogonal wavelet device
Authors: Yasuoka Hiromichi , Ikehara Masaaki , Isobe Hiroyuki
Published: July 2007

A design for a one‐dimensional (1‐D), 2‐D recursive orthogonal wavelet consisting of a parallel connection of a delay and allpass network is presented. There have been some methods to obtain wavelet functions from perfect reconstruction filter banks following an investigation by Mallat of the relation between wavelet transform and filter banks. These methods are based mostly on an FIR filter. A method based on IIR filters has never been investigated. IIR digital filter has fewer orders than FIR digital filters to realize the same specification and satisfies the orthogonal condition of the orthogonal wavelet by using both parallel connection of some delays and an allpass filter. Furthermore, a maximum number of zeros are placed at aliasing frequencies in the lowpass filter as a way of obtaining the regularity of the wavelet. Finally, some design samples of discrete scaling and wavelet functions are presented.
A new method for breaking the Lu‐Lee cryptosystem
Authors: Hayashi Akira , Shimizu Hideo
Published: July 2007

The authors present a method to break the Lu‐Lee (LL) cryptosystem, whose security is based on the difficulty of factoring the product of large primes. Previously, other methods of attacking the LL cryptosystem have been proposed, but the new method proposed here is different from them. In the present method, the computation required is polynomial‐time and computer experiments make it clear that all the cipher text can be broken with high speed. In this method, the authors construct simultaneous congruences from the encryption congruence and then transform these into simultaneous equations, whose solution gives the original plain text. The authors do require a condition for the transformation into equations, but it is satisfied in almost all cases; so the probability of success of the attack can be considered to be high.
The relation between neighboring type and equilibrium type in the natural observation theory
Authors: Iijima Taizo
Published: July 2007

The theory of natural observation, an approach analysis which replaces Fourier analysis, has been divided into two types: the neighboring type; and the equilibrium type. These types have theoretical systems that are derived from different starting points; theoretically, they have mutual close relations. The purpose of this paper is to elucidate the close relations between these two types. First, it is shown that the set of fundamental observed values defined for one side of types is uniquely derivable from the other, and also that the mathematical form of the derivation maintains duality.

Next, an infinite number of invariant determinants are constructed from the set of fundamental observed values, and they are proved to be independent of type.
Synthesis of low‐sensitivity leapfrog switched capacitor filters (SCFs)
Authors: Ishikawa Masayuki , Fujii Nobuo
Published: July 2007

This paper proposes multiinput switched capacitor (SC) integrators required for realization of leapfrog SC filters exhibiting zero sensitivity at matching points. the signal flow graph‐based simulation of an LC ladder filter built of proposed integrators shows that the filter exhibits zero sensitivity. Integrators are driven by a two‐phase clock and, under certain conditions, are insensitive to parasitic capacitance. Furthermore, total filter capacitance generally is kept small.

Computer simulation of lowpass and bandpass filters constructed of the proposed integrators illustrates their comparatively low sensitivity.
Global optimization method using chaos in dissipative system
Authors: Fujita Tokumitu , Yasuda Keiichiro , Yokoyama Ryuichi
Published: July 2007

Most of the actual optimization problems are nonlinear and have many peaks (nonconvex). With the widespread use of the high‐speed and large‐capacity computers as the background, it has recently been felt highly necessary to derive the global optimal solution for the optimization problem which is nonlinear and has multiple peaks. It is one of the most important topics of research in the field of optimization.

The major global optimization method developed until now can be divided into the trajectory method, the function transformation method, and the simulated annealing method.

This paper proposes a new approach which is totally different from the forementioned conventional methods, i.e., the global optimization method for the unconstrained nonlinear optimization problem where chaos is introduced. the proposed method is based on the dissipative system where the inertia term and the nonlinear damping term are added to the conventional gradient method.

By appropriately adjusting the characteristics of the nonlinear damping term, the generation of chaos can itself be controlled. Then, by overriding the barrier of the energy function between the local minima, the process converges to the global optimal solution.

Finally, the proposed method is applied to the typical multipeaked nonlinear optimization problem with two and ten variables and it is shown that the global optimal solution can be derived by adequately adjusting the parameter of the nonlinear damping term.
Features of a two‐dimensional random field: Number of degrees of freedom, correlation areas and correlation lengths
Authors: Kikkawa Sho , Sakamoto Masato , Kobayashi Naoya
Published: July 2007

One of the important features that characterize the physical random field or the image texture is Taylor's correlation length. However, there has not been presented a clear‐cut theory as to the foundation of the correlation length from the viewpoint of probability theory or statistical theory. Another aspect is that the feature is one‐dimensional, and, therefore, the application to the random field is limited to the isotropic random field.

This paper defines thenth order statistical number of degrees of freedom as the equivalent number of uncorrelated points in the square finite region in the homogeneous random field. From the definition, the correlation area and the correlation length are derived. the correlation area is referred to as the average area of the region statistically affected by an arbitrary point on a two‐dimensional field. the correlation length represents the effective distance between adjacent independent or uncorrelated points on the line parallel to thex‐ ory‐axis. the first‐order correlation length is the same as the conventional Taylor correlation length. the first‐order correlation area is a natural extension of Taylor's correlation length to the two‐dimensional random field. the correlation length along the principal axis, which is independent of the definition of the coordinate axis, is also derived. Those features are based on the theory of statistics and are expected to be useful for the analysis of the actual random physical field and the texture analysis of the image.
Design of two‐dimensional maximally flat diamond‐shaped half‐band finite impulse response filters with rectangular supports of impulse response
Authors: Inui Kiwamu , Yoshida Toshiyuki , Nishihara Akinori , Fujii Nobuo
Published: July 2007

Two‐dimensional (2‐D) diamond‐shaped filters are important filters with many applications and are known to be designed and implemented efficiently as 2‐D half‐band filters. On the other hand, filters with different number of taps in both directions are often suitable for a specific application rather than filters with equal number of taps.

This paper proposes a design method for 2‐D maximally flat diamond‐shaped filters with rectangular support of impulse response. First, the maximally flat conditions at the origin are considered together with equations which make the filter approximately diamond‐shaped. Then, by combining the derived conditions to form a system of linear equations with respect to the independent filter coefficients, designs for the difference in the number of taps 2, 4, and 6 are demonstrated. Finally, together with giving several design examples, comparison with other design methods are made and the usefulness of the suggested design method is verified.
Altitude prediction by natural spline tracker
Authors: Shirakawa Masayuki
Published: July 2007

In airborne collision avoidance system (ACAS) and air traffic control radar beacon system, altitude tracking filter is used for altitude prediction. These trackers are known to have large error when the data are lost. This paper presents the new prediction filter to improve the accuracy in this coast situation. the extrapolation of natural spline function is used for this purpose. the simulation shows this tracking filter has better performance than conventional filter.
Rotary ultrasonic motor utilizing contour and flexural vibrations of a rectangular thick plate
Authors: Iijima Tamotu , Nakagawa Yasuhiko , Ito Hiroshi
Published: July 2007

A method of vibration analysis for an ultrasonic motor using asymmetric flexural vibrations and symmetric contour vibrations of a thick rectangular plate is given. An investigation of the symmetricity of the flexural vibrations using the Rayleigh quotient is used to derive an expression for the resonant frequency of the same flexural mode and the similarity ratio of the vibration plate thickness and contour dimensions. The possibility of estimating the resonant frequency of a rectangular plate of different dimensions is then confirmed experimentally.

With the contour vibration mode with small displacements at the middle and large displacements at the ends, the middle side constrained is analyzed. The vibration plate was an SUS304 rectangular plate with a PZT plate attached; as in the case of the PZT rectangular plate, it is confirmed experimentally that shear stress can be neglected. When allowance is made for machined holes in the vibration plate (such as screw holes), a value close to the measurement value is still obtained.
Image reconstruction based on zero‐crossing representations of wavelet transform
Authors: Cheong Cha Keon , Aizawa Kiyoha , Hatori Mitsutoshi , Saito Takahiro
Published: July 2007

This paper discusses a reconstruction method of the image signal from the zero‐crossing representation. First, the one‐ and two‐dimensional multiscale wavelet transforms are described which have the completeness and the translation invariance. A new zero‐crossing representation is proposed in which the zero‐crossing points are extracted from the multiscale wavelet transform. the information concerning the maximum value (the minimum value when negative) between two consecutive zero‐crossing points as well as its position is combined. Then it is shown that the original signal can be reconstructed with a stable and fast convergence from the zero‐crossing representation of the signal through the iterated projections to the convex set.

The effect of the wavelet basis filter on the convergence in the reconstruction is investigated, and a necessary condition for the optimal basis filter is derived considering the convergence.

Finally, a new basis filter is designed using the B‐spline function and the usefulness of the proposed method is demonstrated for the one‐dimensional signal and the image signal. It is shown also that the signal reconstruction procedure converges with stability, even if there exists an error at the extracted zero‐crossing point.
Design of short tap perfect reconstruction filters for subband coding of images
Authors: Komatsu Kunitoshi , Sezaki Kaoru , Yasuda Yasuhiko
Published: July 2007

Short tap filters reduce the computational complexity of filtering processes and also reduce image degradations associated with ringing effects near edges in image subband coding. When the number of taps is reduced, however, coding performance generally deteriorates. In this paper, short tap filters that satisfy isolated perfect reconstruction constraints are designed so as to improve coding performance. For the sake of comparisons, linear phase‐ and orthogonal filters are also designed. Filters with coefficients determined by the values 2nare designed to reduce further the computational burden of the filter process. Assuming that the input can be modeled by an AR(1) process, the set of parameters which determine the tap coefficients are selected to maximize the coding gain. the relationship between signal‐to‐noise ratio and entropy is determined to evaluate coding performance. the superior coding performance of the perfect reconstruction filters shows no degradation when subjected to an integer coefficient constraint. Also, filters with coefficients determined by the values 2nand excellent coding performance are obtained.
Pseudodiagonalization of the autocorrelation of a stochastic process by an over‐complete wavelet system
Authors: Sakaguchi Fuminori
Published: July 2007

If a stochastic process can be regarded as a superposition of the wavelets which arise randomly and independently of one another, the random‐wavelet picture of a stochastic process is intuitive and convenient. This paper investigates theoretically in what case the picture can be used; i.e., in what case the autocorrelation of the stochastic process can be diagonalized by using the over‐complete wavelet system. A general method for calculating the pseudodiagonal form from an arbitrarily given autocorrelation function using the operator algebra is proposed. Next, some properties of stationary wavelet‐diagonal processes are investigated where it is shown that the power spectra of these processes are related to the spectral estimates under the circumstances in which the number of the time points are constrained to a constant finite number.
Evaluation of analog printed circuit board wiring routes by surface charge modeling method and applicatuion to the determination of wiring
Authors: Kasuga Masatoshi , Konta Isamu , Matsuda Jin‐Ichi
Published: July 2007

A surface charge modeling method is one of the routing methods based on strategies that minimize network energy. The relationship between potential energy and typical routing criteria is theoretically investigated first. It is concluded that the minimal energy state coincides with the minimal wire length in case of the sufficiently large printed circuit boards (PCBs). Then a procedure for improving wiring starting from an initial wiring which is a minimal route connecting terminal pairs in a straight line is described. This technique has the advantage of not requiring wiring specification priorities and obtaining the wiring routes of the shortest‐path topology.
Optimal design of infinite impulse response hilbert transformers
Authors: Shimizu Satoru , Yahagi Takashi , Henriques Marco A. A.
Published: July 2007

This paper proposes a new method for designing the optimal infinite impulse response (IIR) Hilbert transformer. Until now, finite impulse response (FIR) filters have mostly been used in the design of the digital filter for the circuit such as the Hilbert transformer, where the linear‐phase response is required. Several methods have been proposed for designing the IIR filter, which, however, had problems in the complexity of the algorithm or the accuracy of the designed Hilbert transformer.

This paper considers first the FIR Hilbert transformer as a model. the design of the tap coefficients for the IIR filter which gives the same output as that of the model, when the same input is given, is reduced to the parameter estimation problem when the Kalman filter is used for control. Then the IIR Hilbert transformer is designed in the time domain.

To obtain a better response, an evaluation funclion is defined that represents the error from the ideal frequency response. the tap coefficients are fine‐adjusted by the Fletcher‐Powell method so that the evaluation function is minimized. By this approach, it is possible to design the IIR Hilbert transformer while maintaining the stability and the phase linearity, which are the features of the FIR filter. the 16th‐order IIR Hilbert transformer actually is designed by the proposed method, and it is shown that a performance better than the 30th‐ and the 31st‐order reference FIR Hilbert transformers can be realized.