We propose binary-quantized and spatio-temporally discretized network models of linear diffusion systems and investigate their filtering effect on single-bit sigma-delta (ΣΔ) modulated signals. The network consists of only one kind of elements that add ΣΔ modulated signals and quantize the sum in the form of single-bit signal. A basic one-dimensional network is constructed first. Then, the network is extended into two dimensions. These networks have characteristics equivalent to those of linear diffusion systems in both time and frequency domains. In addition, network noise caused by the quantization in the elements contains low-level low-frequency components and high-level high-frequency components. Therefore, the proposed networks have possibility to be used as signal propagation and diffusion media of ΣΔ domain filters.

Simply-typed term rewriting systems (STRSs) are an extension of term rewriting systems. STRSs can be naturally handle higher order functions, which are widely used in existing functional programming languages. In this paper we design recursive and lexicographic path orders, which can efficiently prove the termination of STRSs. Moreover we discuss an application to the dependency pair and the argument filtering methods, which are very effective and efficient support methods for proving termination.

In order to transport an ever-increasing amount of IP traffic effectively, Photonic IP networks that employ wavelength routing and Layer 3 cut-through are very important. This paper proposes a new network design algorithm that minimizes the network cost considering IP traffic growth for multi-layered photonic IP networks that comprise electrical label switched paths (LSPs) and optical LSPs. We evaluate the network cost obtained from the developed network design algorithm that considers IP traffic growth and compare it to the results obtained from a static zero-based algorithm. The static zero-based algorithm does not take into account the history of progressive past IP traffic changes/growth until that time. The results show that our proposed algorithm is very effective; the cost increase from the cost obtained using the zero-based algorithm is marginal. The algorithm developed herein enables effective multi-layered photonic IP network design that can be applied to practical networks where IP traffic changes/increases progressively and that can be used for long term network provisioning.

We develop a non-concurrent single-failure occurring model, a restoration scheme based on adaptively-decided sub-lightpath rerouting algorithm is then proposed, which aims to achieve better service guaranty with less network status information.

This paper presents an efficient and generic solution in the following scenario: There are n independent people using variety of signature schemes such as DSS, RSA, Schnorr, and so on, and a subset of them attempts to sign a document without being identified which subset they are. This is a generalized scenario of the Ring Signatures by Rivest, Shamir and Tauman, whose original scenario limits the subset to be a single person and the base signature scheme to be RSA/Rabin schemes. Our scheme allows any signature schemes based on sigma-protocols and claw-free permutations. It also offers shorter signatures and less computation compared to known generic construction. The security is argued in the random oracle model as well as previous schemes and shows that our scheme achieves reduction cost linear in the number of hash queries while it is square for previous generic constructions.

Marginal reliability importance (MRI) of a component in a system is defined as the rate at which the system reliability changes over changes of the component reliability. MRI helps network designers to construct a reliable network layout. We consider a problem to compute MRI of all components in a network system considering all-terminal reliability in order to rank the components with respect to MRI. The problem is time-consuming since computing network reliability is #P-complete. This paper improves the traditional approach for the problem to proposes an efficient algorithm. The algorithm applies some network transformations, three network reductions and one network decomposition. We have proved lemmas with respect to the relationship between the transformations and MRI, which compute MRI for an original network by using MRI and reliability for transformed networks. Additionally, we have derived a deformed formula to compute MRI, which can also reduce computational task. Numerical experiments revealed that the proposed algorithm reduced computational time considerably compared to the traditional approach.

A device structure for polymer Schottky diode, which has the glass chimney as a dopant reservoir enabling the reduction of series resistance without cathode corrosion, has been proposed. Doping with the acetonitrile solution of FeCl3 in the device resulted in the increase in the forward-bias current by one order of magnitude without notable increase in reverse-bias current, suggesting that the doping reduced the series resistance. It is found that the penetration speed depends on the solvents. Short time doping with the nitromethane solution of FeCl3 resulted in the increase by three orders of magnitude. However, doping for a long period yielded the considerable increase in the reverse-bias current due to the complete penetration of dopatn solution. When the upper opening of glass chimney of device is left opened and the sample after doping stored in air, the forward-bias current of the device reduced rapidly due to the undoping and/or degradation of polymer. It is possible to protect the degradation of device characteristics after doping, by sealing the chimney and storing the device in vacuum.

In-plane-aligned a-axis-oriented YBa2Cu3O7-δ (YBCO) thin films are attractive for the formation of planar intrinsic Josephson devices. In this study, these films were deposited by dc sputtering on LaSrGaO4 (LSGO) (100) substrates and the dependence of the characteristics on the deposition conditions was investigated. In-plane-aligned a-axis-oriented YBCO thin films were successfully grown in the substrate temperature range of 555-615. With the temperature gradient method, it was seen that the critical temperature of the film increased to 81 K. The current-voltage characteristic along the c-axis exhibited clear multibranch structures. These results indicate that ion-cleaning of the substrate surface broadens the growth temperature range of these films and planar intrinsic Josephson devices can be fabricated from these films.

We propose a new approach associated with the use of some selected sets of Walsh Hadamard codes for joint estimation of channels and the number of transmit antennas by employing only one OFDM pilot symbol. This allows transmit antenna diversity to be applied in systems which have a limited number of training symbols (preambles), e.g. HIPERLAN/2. The proposed approach does not require any a priori knowledge about the number of transmit antennas, providing flexibility in the number of antennas to be used. In addition, adaptive scheme associated with the proposed approach provides more accurate estimations of the channels. The effectiveness of the proposed approach is evaluated through simulation. Results show that the proposed scheme provides significant improvement over previous channel estimation schemes and has almost the same performance as the ideal system with the full knowledge of the channel state information.

The matrix inequality condition has been considered as the main condition for the stability of RHC. But it is difficult to apply the matrix inequality condition for guaranteeing the stability of any physical system because of the high gain problem brought about the high value of the final state weighting matrix. Therefore, in this study, a new stability condition for RHC is proposed and it extends the range of the final state weighting matrix guaranteeing the stability of RHC in comparison with the case of the matrix inequality condition. The proposed stability condition is based not only on a final state weighting matrix but also on a horizon size and guarantees the stability for other forms of model predictive control just like the matrix inequality condition.

A neural-signal sensing system with multi-input-channels was designed utilizing a new chopper amplifier with direct connected to a multiplexer. The proposed system consists of multiplexers, chopper amplifiers, a multi-mode analog-to-digital converter (ADC), and a wireless transmitter. It enables to measure 50-channel signals at the same time, which are selected out of 100 channels to detect useful information. The test chip including 10-channel-inputs chopper-amplifier and multi-mode ADC, that was designed and fabricated with a mixed signal 0.35-µm CMOS technology. Utilizing the proposed direct chopper input scheme and the shared chopper amplifier, the circuits was designed with a small area of 9.4 mm2. High accuracy channel selecting and multiplexing operations were confirmed, and an equivalent input noise of 10-nV/root-Hz was obtained with test chip measurements. Power dissipation of the chopper amplifier and the ADC were 6.0-mW and 2.5-mW at a 3-V supply voltage, respectively.

A simple and efficient context modeling technique (CM-WDR) is proposed to improve the performance of the wavelet difference reduction (WDR) algorithm for image compression. The CM-WDR employs an adaptive scanning order by context modeling. The PSNR improvement over WDR ranges from 0.1 to 1.5 dB at various bitrates.

In 1983, Chaum first introduced the concept of blind signature. In 2003, Hwang, Lee and Lai pointed out that the Chaum scheme cannot meet the untraceability property of the blind signature scheme. This letter will demonstrate that Hwang et al.'s claim is incorrect and the Chaum blind signature scheme still keeps the untraceability property.

As power consumption becoming a critical concern for System-On-a-Chip (SOC) design, accurate and efficient power analysis and estimation during the design phase at all levels of abstraction are becoming increasingly pressing in order to achieve low power without a costly redesign process. This paper surveys analysis and estimation techniques of dynamic power and leakage power for SOC design covering multiple design levels, which have been recently proposed, aiming to present a cohesive view of the power estimation techniques at all design levels of abstraction.

In order to improve the critical current density (Jc) of c-axis-oriented EuBa2Cu3O7 (c-EBCO) thin films deposited on R-plane sapphires (R-Al2O3) with a CeO2 buffer layer, insertion of an Sm2O3 buffer layer and optimization of its deposition condition were attempted. The effects of substrate temperature and film thickness of an Sm2O3 buffer layer on the orientation, crystallinity, surface morphology and superconducting properties of EBCO thin films were examined. As a result, EBCO thin films with Jc = 5.7 MA/cm2 at 77.3 K were obtained on a sapphire with a CeO2(80 )Sm2O3(200 ) buffer layer. Epitaxial relations of sputter-deposited films were clarified.

The sputter-deposition process of TiO2 thin films was investigated. When an oxide target is used, high-rate deposition above 57 nm/min can be realized by sputtering under a condition of low oxygen gas content. Under this sputtering condition, a Ti rich surface layer is formed by selective sputtering of oxygen atoms, and a large amount of Ti atoms are sputtered from this layer. The deposition rate, however, decreases steeply as the oxygen gas content increases. This decrease can be explained as follows. When a sufficient amount of oxygen gas is supplied into the chamber during sputtering, the oxygen atoms which are missing from the target surface by selective sputtering are filled up immediately. This leads to a very low deposition rate of the film, because only oxygen atoms are sputtered from the target. Therefore, the suppression of the incidence of oxygen gas to the target surface and a sufficient of oxygen supply to the substrate are necessary to realize the high-rate deposition of stoichiometric TiO2 films. From this point of view, using an oxide target instead of a metal target is useful for realizing a stable high-rate deposition of the film, since the amount of oxygen gas introduced in to the sputtering chamber can be reduced significantly. In addition, it was confirmed that pulse sputtering method is a useful technique for the deposition of TiO2 thin films. Meanwhile, low-voltage sputtering technique was difficult to use for the film deposition because of its low deposition rate.

Non-repudiation is a basic security requirement for electronic business applications to protect against a sender's false denial of having created and sent a message. Typically non-repudiation protocols are constructed based on digital signatures. However, there has been no theoretical treatment of such non-repudiation protocols. In this paper, we provide a formal security definition of non-repudiation protocols and analyze the security of a signature-based protocol. Our security definition and analysis are based on Canetti's framework of universally composable security.

We present a learning algorithm of the Hopfield neural network for minimizing edge crossings in linear drawings of nonplanar graphs. The proposed algorithm uses the Hopfield neural network to get a local optimal number of edge crossings, and adjusts the balance between terms of the energy function to make the network escape from the local optimal number of edge crossings. The proposed algorithm is tested on a variety of graphs including some "real word" instances of interconnection networks. The proposed learning algorithm is compared with some existing algorithms. The experimental results indicate that the proposed algorithm yields optimal or near-optimal solutions and outperforms the compared algorithms.

Indium tin oxide (ITO) films were deposited at a temperature below 50 by a low-voltage sputtering system. The sputtering voltage was fixed at 100 V and Ar, Kr, and Xe were used as the sputtering gases. Compared with the sputtering in Ar gas, the sputtering in Kr or Xe gas caused a significant suppression of crystallization of the deposited film and resulted in the formation of amorphous films. These films had much lower resistivities than the films deposited using Ar gas, since the Hall mobility of the films had a larger value. Typical Hall mobility and carrier density are 50 cm2/Vsec, and 51020 cm-3, respectively. This improvement was attributable to the reduction of high-energy particle bombardment to the film surface in the sputtering. These films are stable at a temperature below 150, and crystallization occurs at a temperature above 150.

To increase the spectral utilization efficiency of a wireless link, multiple-input multiple-output (MIMO) systems can be employed to transmit several data streams in parallel at the same time and on the same frequency but from different transmit antennas. However, at the receiver side multi-stream detection is needed. In this paper, ordered successive MMSE detection (OSD) is considered as a low-complexity detection scheme. OSD's main computational cost lies in computing the nulling weights that correspond to each stage of successive detection. In this paper, we develop an efficient semi-adaptive approach to generate MMSE weights. This semi-adaptive approach efficiently combines two approaches: channel estimates-based direct matrix inversion weights generation (direct approach) and Recursive Least Squares (RLS) algorithm-based weights generation (adaptive approach). Although the direct approach alone performs better than the adaptive approach, it is more complex for updating weights within the tracking mode. On the other hand, the adaptive approach alone is less complex in updating weights within the tracking mode, but converges slowly within the training mode. Our combined semi-adaptive approach effectively offsets these disadvantages. We demonstrate, through computer simulations, that the semi-adaptive approach can achieve the BER of the direct approach in slow time-varying MIMO channels, while its computational complexity is less than or comparable to that of the adaptive approach.