We briefly survey recent developments in the thin film synthesis and junction fabrication of MgB2 toward superconducting electronics. The most serious problem in the thin film synthesis of MgB2 is the high vapor pressure required for phase stability. This problem makes in-situ film growth difficult. However, there has been substantial progress in thin film technology for MgB2 in the past three years. The low-temperature thin-film process in a UHV chamber can produce high-quality MgB2 films with Tc 35 K. Furthermore, technology to produce single-crystal epitaxial MgB2 films has recently been developed by using hybrid physical-chemical vapor deposition. With regard to Josephson junctions, various types of junctions have been fabricated, all of which indicate that MgB2 has potential for superconducting devices that operate at 20-30 K, the temperature reached by current commercial cryocoolers.

This paper proposes a distributed adaptive routing algorithm that may be applied to inter-domain calls passing over any type of network topology, traffic management and switching techniques on the path, while carrying bidirectional traffic with multiple QoS requirements. The path is searched within a contour area restricted by the number of hops between source and destination while the end-to-end admission of calls is controlled at source node and each hop's admission at each node, reflecting the latest resources availability and network conditions for the given QoS requirements. Performance analysis in various conditions shows good applicability in real networks.

An audio signal level compressor is presented, which is based on the approximation algorithm using an interpolating polynomial. To implement a compression characteristic in a digital audio system, a power calculation with fractional numbers is required and it is difficult to be performed directly in digital circuits. We introduce a polynomial expression to approximate the power operation, then the gain calculation is easily performed with a number of additions, multiplications and a division. Newton's interpolation formula is used to calculate the compression characteristics in a very short time and the obtained compression characteristics are very close to the ideal ones.

The High Tc SQUID was used in an unshielded environment to make eddy current nondestructive testing measurement on a multi-layer aluminum structure. As a demonstration of their capabilities, subsurface defects in a multilayer aluminum structure have been located and mapped using phase shift with no magnetic shielding around the specimen.

This paper presents a new fast and robust circle extraction method that is capable of extracting circles from images with complicated backgrounds. It is not based on the Hough transform (HT) that requires a time-consuming voting process. The proposed method uses a least-squares circle fitting algorithm for extracting circles. The arcs are fitted by extended digital lines that are extracted by a fast line extraction method. The proposed method calculates accurate circle parameters using the fitted arcs instead of evidence histograms in the parameter space. Tests performed on various real-world images show that the proposed method quickly and accurately extracts circles from complicated and heavily corrupted images.

This paper describes a second-order continuous-time ΔΣ modulator for a W-CDMA receiver, which operates at a supply voltage of 0.9 V, the lowest so far reported for W-CDMA. Inverter-based balanced OTAs without using differential pair are proposed for a low-voltage operation. Circuit parameters are optimized by system simulations. The modulator was implemented in a 0.13-µm CMOS technology. It consumes only 1.5 mW. The measured SNDR is 50.9 dB over a bandwidth of 1.92 MHz.

In this paper, an efficient architecture for an adaptive Reed-Solomon decoder is presented, where the block length n and the message length k can be varied from their minimum allowable values up to their selected values. This eliminates the need of inserting zeros before decoding shortened RS codes. And the error-correcting capability t can be changed adaptively to channel state at every codeword block. The decoder allows efficient decoding in both burst mode and continuous mode, and it permits 3-step pipelined processing based on the modified Euclid's algorithm. Each step in decoding is designed to be clocked by a separate clock. Thus, each step can be efficiently pipelined with no help of multiplexing. Also, it makes it possible to employ no additional buffer even when the decoder input and output clocks are different. The adaptive RS decoder over GF(28) having the error-correcting capability of upto 10 has been designed in VHDL, and successfully synthesized in an FPGA chip. It can be used in a wide range of applications because of its versatility.

In this paper, we describe an accelerative current-programming method for active matrix OLED (AM-OLED) display. This new method uses common source configuration, "Acceleration Control" line and some mechanisms to prevent the programming current from flowing through OLED device. It would solve the basic problem of the current-programming pixel circuit: a long programming period, especially at the dark gray-level. The proposed method accelerates the current programming process at any gray levels, and it would be the solution for the problem.

In order to improve the quality of VoIP services, an adaptive routing method is proposed in the application layer of Internet gateways. This method determines routing paths based on the average one-way delays in a predetermined re-routing interval. In order to evaluate the performance of the method, five different routing policies are specifically designed and tested. Experimental results show that the method can improve the QoS of Internet phone services.

Three-dimensional (3D) wafer stacked implementation (WSI) has been proposed as a promising technology for massively parallel computers. A hierarchical 3D-torus (H3DT) network, which is a 3D-torus network of multiple basic modules in which the basic modules are 3D-mesh networks, has been proposed for efficient 3D-WSI. However, the restricted use of physical links between basic modules in the higher level networks reduces the dynamic communication performance of this network. A torus network has better dynamic communication performance than a mesh network. Therefore, we have modified the H3DT network by replacing the 3D-mesh modules by 3D-tori, calling it a Modified H3DT (MH3DT) network. This paper addresses the architectural details of the MH3DT network and explores aspects such as degree, diameter, cost, average distance, arc connectivity, bisection width, and wiring complexity. We also present a deadlock-free routing algorithm for the MH3DT network using two virtual channels and evaluate the network's dynamic communication performance under the uniform traffic pattern, using the proposed routing algorithm. It is shown that the MH3DT network possesses several attractive features including small diameter, small cost, small average distance, better bisection width, and better dynamic communication performance.

Over the past few years, there has been significant interest in content-aware routing that use the information found in the payload of packets to provide intelligent request distribution. As these content-aware routing mechanisms have become an increasingly important building block for Internet service providers, the network behavior and effectiveness of such mechanisms are unclear. In this paper we analyze the network dynamic of a busy Web site with the content-aware routing mechanism. We find that some unique characteristics of Web traffic may limit the effectiveness of the content-aware switching. Based on these observations, we also propose solutions to remedy these deficiencies.

Electronic voting is a prime application of cryptographic tools. Many researches are addressing election or confidence voting in this area. We address a new type of voting scheme "Divisible Voting Scheme," in which each voter has multiple ballots where the number of ballots can be different among the voters. This type of voting is popular. We first define the divisible voting scheme and show naive protocols based on existing voting schemes. Then we propose two efficient divisible voting schemes. The first scheme uses multisets, the second scheme uses L-adic representation of the number of ballots. The total cost for a voter is O(M 2 log (N)) in the first scheme and O(M log (N)) in the second scheme where M is the number of candidates to vote for and N is the number of ballots for a voter.

We consider the multicast routing problem for large-scale wavelength division multiplexing (WDM) optical networks where transmission requests are established by point-to-multipoint connections. To realize multicast routing in WDM optical networks, some nodes need to have light (optical) splitting capability. A node with splitting capability can forward an incoming message to more than one output link. We consider the problem of minimizing the number of split-capable nodes in the network for a given set of multicast requests. The number of wavelengths is fixed and given a priori. We propose a genetic algorithm that exploits the combination of alternative shortest paths for the given multicast requests in order to minimize the number of required split-capable nodes. This algorithm is examined for two realistic networks constructed based on the locations of major cities in Ibaraki Prefecture and those in Kanto District in Japan. Our experimental results show that the proposed algorithm can reduce more than 10% of split-capable nodes compared with other routing algorithms whereby the optimization for the split-capable node placement is not taken into account.

We discuss a typical profile of the k-error linear complexity for balanced binary exponent periodic sequences and the number of periodic distinct sequences by their profiles. A numerical example with period 16 is also shown.

Cowen gave a universal compact routing algorithm with a stretch factor of three and table-size of O(n2/3log4/3n) based on a simple and practical model. (The table-size is later improved to O(n1/2log3/2n).) This paper considers, using the same model, how the necessary table-size differs if the stretch factor must be less than three. It is shown that: (i) There is a routing algorithm with a stretch factor of two whose table-size is (n -+ 2)log n. (ii) There is a network for which any routing algorithm that follows the model and with a stretch factor of less than three needs a table-size of (n - 2)log n in at least one node. Thus, we can only reduce roughly an additive log n (i.e., table-entries) from the trivial table-size of n log n which obviously enables shortest-path routing. Furthermore it turns out that we can reduce only an additive log n (i.e., only one table-entry) from the trivial n log n if we have to achieve a stretch factor of less than two. Thus the algorithm (i) is (roughly) tight both in its stretch factor and in its table-size.

This paper proposes a scattered-pilot-OFDM reception scheme employing turbo inter-carrier interference (ICI) cancellation in the fast varying fading environments of mobile communications. In the OFDM transmission, the orthogonality among the subcarriers cannot hold due to large Doppler shift, and the OFDM signal suffers from severe degradation due to ICI. The proposed receiver carries out two modes: (i) a coherent detection (CD) mode, and (ii) a turbo ICI cancellation (TC) mode. Initially, the receiver performs the CD mode. When any decision errors are detected, it shifts from the CD mode to the TC one that carries out both the ICI cancellation and the channel estimation by using the decoder output (the log likelihood ratio). In addition, the iteration of the TC mode can improve the accuracy of the channel estimation and ICI cancellation ability. Computer simulations following specifications for the mobile reception mode in the digital terrestrial television broadcasting demonstrate that the receiver can effectively cancel ICI due to the fast varying fading, and that its average BER performance is much better than that of CD.

We present an efficient Hybrid Mix scheme that provides both routing flexibility and the optimal length of ciphertext. Although it is rather easy to embed routing information in the ciphertext, and a scheme that provides the optimal length of ciphertext is already known, it is not a trivial task to achieve both properties all at the same time. A critical obstacle for providing the optimal length of ciphertext is the session-key encapsulation header in a ciphertext that carries the encrypted session-key to each router, which linearly increases according to the number of intermediate routers. We solve this problem by improving the previously reported Hybrid Mix scheme such that the resulting scheme benefits from routing flexibility with a constant length of such headers. Our basic scheme is only secure against honest, but curious intermediate routers. Therefore, we further address the robustness issue to prevent malicious behavior by incorporating and improving an existing efficient approach based on the Message Authentication Code.

Fingerprinting is a technique to add identifying marks to each copy of digital contents in order to enhance traceability to a distribution system. Collusion attacks, in which the attackers collect two or more fingerprinted copies and try to generate an untraceable copy, are considered to be a threat for the fingerprinting system. With the aim of enhancing collusion security to the fingerprinting system, several collusion secure codes, such as c-frameproof code, c-secure frameproof code and c-identifiable parent property code, have been proposed. Here, c indicates the maximum number of colluding users. However, a practical construction of the above codes is still an issue because of the tight restrictions originated from their combinatorial properties. In this paper, we introduce an evaluation of frameproof, secure frameproof, and identifiable parent property by the probability that a code has the required property. Then, we focus on random codes. For frameproof and secure frameproof properties, we estimate the average probability that random codes have the required property where the probability is taken over the random construction of codes and random construction of coalitions. For the estimation, we assume the uniform distribution of symbols of random codes and the symbols that the coalitions hold. Therefore, we clarify the adequacy of the assumptions by comparison with numerical results. The estimates and numerical results resemble, which implies the adequacy of the assumption at least in the range of the experiment.

In this paper, we propose an efficient protocol for proving the correctness of shuffling and an efficient protocol for simultaneously proving the correctness of both shuffling and decryption. The former protocol is the most efficient in computational and communication complexity among 3-move honest verifier perfect zero-knowledge protocols for proving a shuffling of ElGamal cipher-texts. The latter protocol is the most efficient in computational, communication, and round complexity, as a whole, in proving the correctness of both shuffling and decryption of ElGamal cipher-texts. The proposed protocols will be a building block of an efficient, universally verifiable mix-net, whose application to voting systems is prominent.

The research communitiy has shown considerable interest in studying access control in single Trusted Operating Systems (TOS). However, interactions among multiple TOSs have attracted relatively little attention. In this paper, we propose a Collaborative Role-Based Access Control (C-RBAC) model for distributed systems in which accesses across system domain boundaries are allowed. Access entities in a TOS vary in time. The changes in the organizational structure of the access entities in one system may influence other cooperating systems. In addition, policy-freeness, domain and rule conflicts are possible. These problems restrict the flexibility and scalability of coordination. We propose drafting a meta-component to play the role of a coordinator in multi-domain role-based access control. It is then possible to impart flexibility and scalability in a secure fashion. Experimental studies of the proposed model with the Network File System and SELinux system support our conclusion.