In the early stage of hyperthermia, a large number of engineering efforts have been done in the development or the improvement of the heating and temperature measuring techniques. However, they were not always satisfactory clinically. Thus, even in this moment, various engineering researches as well as the electromagnetic techniques for hyperthermia should be build up rapidly. This paper describes some of the highlights of developed or ongoing electromagnetic heating techniques in hyperthermia and identities a trend of emerging electromagnetic heating. Furthermore, the author emphasizes that few medical engineering efforts have been done in the boundary field between pure physics and clinics, and the proper way to develop the hyperthermia equipment is the best use of successes in the three essential regions: Physics, Biology and Clinics.

In conventional word-spotting methods for automatic recognition of continuous speech, individual frames or segments of the input speech are assigned labels and local likelihood scores solely on the basis of their own acoustic characteristics. On the other hand, experiments on human speech perception conducted by the present authors and others show that human perception of words in connected speech is based, not only on the acoustic characteristics of individual segments, but also on the acoustic and linguistic contexts in which these segments occurs. In other words, individual segments are not correctly perceive by humans unless they are accompanied by their context. These findings on the process of human speech perception have to be applied in automatic speech recognition in order to improve the performance. From this point of view, the present paper proposes a new scheme for detecting words in continuous speech based on template matching where the likelihood of each segment of a word is determined not only by its own characteristics but also by the likelihood of its context within the framework of a word. This is accomplished by modifying the likelihood score of each segment by the likelihood score of its phonetic context, the latter representing the degree of similarity of the context to that of a candidate word in the lexicon. Higher enhancement is given to the segmental likelihood score if the likelihood score of its context is higher. The advantage of the proposed scheme over conventional schemes is demonstrated by an experiment on constructing a word lattice using connected speech of Japanese uttered by a male speaker. The result indicates that the scheme is especially effective in giving correct recognition in cases where there are two or more candidate words which are almost equal in raw segmental likelihood scores.

We discuss how to determine automatically the number of mixture components in continuous mixture density HMMs (CHMMs). A notable trend has been the use of CHMMs in recent years. One of the major problems with a CHMM is how to determine its structure, that is, how many mixture components and states it has and its optimal topology. The number of mixture components has been determined heuristically so far. To solve this problem, we first investigate the influence of the number of mixture components on model parameters and the output log likelihood value. As a result, in contrast to the mixture number uniformity" which is applied in conventional approaches to determine the number of mixture components, we propose the principle of distribution size uniformity". An algorithm is introduced for automatically determining the number of mixture components. The performance of this algorithm is shown through recognition experiments involving all Japanese phonemes. Two types of experiments are carried out. One assumes that the number of mixture components for each state is the same within a phonetic model but may vary between states belonging to different phonemes. The other assumes that each state has a variable number of mixture components. These two experiments give better results than the conventional method.

This paper proposes two algorithms for defining a routing domain in multiclass-of-service networks. One an off-line-based method, whose objective is to optimize dynamic routing performance by using precise knowledge on the traffic levels. The algorithm of the proposed method takes into account the random nature of the traffic flow, which is not considered in the network flow approach. The proposed method inherits the conceptual simplicity of the network flow approach and remains applicable to large and complex networks. In simulation experiments, the proposed off-line-based method performs better than the method based on the network flow approach, but has a similar the computation time requirement. The other method proposed here is an on-line-based method for application to B-ISDNs, where precise traffic data is not expected to be available. In this method, the routing domain is defined adaptively according to the network performance (call-blocking probability) measured in real-time. In simulation experiments, the performance of this method is comparable to that of the off-line-based method--especially when highly efficient dynamic routing is used. This paper also derives and describes methods for approximating the implied costs for multiclass-of-service networks. The approximations are very useful not only for off-line-based routing domain definition (RDD) methods but also for other kinds of network controls or optimal network dimensioning based on the concept of revenue optimization.

A Superconductor-Insulator-Superconductor (SIS) mixer using two junctions connected in parallel through a stripline inductance has been studied. The essential point of the two-junctions device is that the capacitance of the junctions was tuned out by the inductance to obtain a broadband operation without mechanical tuning elements. It has been shown by theoretical analysis that the performance of this type of device is excellent and nearly quantum-limited performance of the mixer can be obtained. It has been demonstrated that the double sideband (DSB) noise temperature of a receiver employing this type of device was less than 40 K over the bandwidth of 90-120 GHz and that the lowest receiver noise temperature of 18 K, which is only 3.2 times as large as the quantum limited photon noise was obtained around 118 GHz. Junctions used in the two-junctions device have significantly larger area, i.e. larger capacitance, and smaller normal resistance than conventional ones. In order to obtain a good impedance match between the source and the junctions, an impedance transformer made of a superconductiong stripline was integrated with the junctions. This type of two-junctions device can easily be scaled to submillimeter frequency without using submicron-sized SIS junctions.

This paper studies routing methods for the complete broadcast multipoint-to-multipoint communication. For a Z-node (Z-site) of the participants of the connection, each site transmits one signal and receives Z-1 signals. The routing method based on connecting each participant by multiple directed point-to-point circuits uses wasteful bandwidth that the source-to-destination data may be duplicated needlessly. We propose routing methods that the connection approach is based on setting multicast tree routes that each participant (site) has one own multicast tree connecting to the other participants under two constraints: the delay-bounded constraint of source-destination path and the available constrained bandwidth for the service of links. For this routing approach, we propose both heuristic algorithm finding approximate solution and search enumeration based algorithm finding optimal solution, and compare the approximate solution with the optimal solution. This approach can lower costs for the subscribers and conserves bandwidth resources for the network providers.

Cryocooler cooled superconducting magnets using Bismuth based high-Tc current leads have been successfully demonstrated. The magnets mainly consisted of a superconducting coil, current leads and a radiation shield which are cooled by a two stage Gifford-McMahon cryocooler without using liquid helium. Our first liquid helium-free 4.6 T (Nb, Ti)3Sn superconducting magnet with a room temperature bore of 38 mm operated at 11 K has recorded a continuous operation at 3.7 T for 1,200 hours and total cooling time over 10,000 hours without trouble. As a next step, we constructed a (Nb, Ti)3Sn liquid helium-free superconducting magnet with a wider room temperature bore of 60 mm. The coil temperature reached 8.3 K in 37 hours after starting the cryocooler. The magnet generated 5.0 T at the center of the 60 mm room temperature bore at an operating current of 140 A. An operation at a field of 5 T was confirmed to be stable even if the cryocooler has been stopped for 4 minutes. These results show that the liquid helium-free superconducting magnets can provide an excellent performance for a new application of the superconducting magnet.

The superconducting magnet on a maglev vehicle vibrate and heats up inside under the influence of various disturbances in running. We have investigated the characteristics of heating in the superconducting magnet vibrating under the electro-magnetic disturbance from the ground coils. This magnetic disturbance has a frequency component ranging widely from 0 Hz to several hundred Hz which is proportional to the speed of the maglev vehicle. It was revealed that an extreme increase of heat load on the inner vessel of the energized magnet occurred at a particular frequency and it surpassed the capacity of the refrigerator installed in the tank of the superconducting magnet. As a result of the investigation, we could identify broadly three factors of heating, and now we have good prospects of largely suppressing the heating by reducing the disturbance through the folded arrangement of the ground coils and a structural improvement of the magnet.

A graph G is said to be universal for a family F of graphs if G contains every graph in F as a subgraph. A minimum universal graph for F is a universal graph for F with the minimum number of edges. This paper considers a minimum universal graph for the family Fkn of graphs on n vertices with path-width at most k. We first show that the number of edges in a universal graph Fkn is at least Ω(kn log(n/k)). Next, we construct a universal graph for Fkn with O(kn log(n/k)) edges, and show that the number of edges in a minimum universal graph for Fkn is Θ(kn log(n/k)) .

A multiple instruction stream-multiple data stream (MIMD) computer is a parallel computer consisting of a large number of identical processing elements. The essential feature that distinguishes one MIMD computer family from another is the interconnection network. In this paper, we are concerned with a representative type of interconnection networks: the hypercube connected network. A family of regular graphs is presented as a possible candidate for the implementation of a distributed system and for fault-tolerant architectures. The symmetry of graphs makes it possible to determine message routing by using a simple distributed algorithm. A candidate having the same property is the hypercube connected network. Arbitrary data permutations are generally accomplished by sorting. For certain classes of permutations, however, this is, for many frequently used permutations in parallel processing such as bit reversal, bit shuffle, bit complement, matrix transpose, butterfly permutations used in FFT algorithms, and segment shuffles, there exist algorithms that are more efficient than the best sorting algorithm. One such class is the bit permute complement (BPC) class of permutations. In this paper, we, first, develop an algorithm to realize an arbitrary BPC permutation in hypercube connected networks. The developed algorithm in hypercube connected networks requires only 1 token memory register in each node. We next evaluate the ability to realize BPC permutations in these networks of an arbitrary size by estimating the number of required routing steps.

We extend the theorem of Gramlich on modular termination of term rewriting systems, by relaxing the disjointness condition and introducing the composability instead. More precisely, we prove that if R1, R-1 are composable, terminating term rewriting systems such that their union is nonterminating then for some a {1, -1}, Ra OR is nonterminating and R-aRa is Fa-lifting. Here, OR is defined to be the special system {or(x, y) x, or(x, y) y}, Fa is the set of function symbols associated with Ra, and an Fa-lifting system contains a rule which has either a variable or a symbol from Fa at the leftmost position of its right-hand side. The extended theorem is stronger than the original one in that it relaxed the disjointness and constructor-sharing conditions and allowed the two systems to share defined symbols in common under the restriction of composability. The corollaries of the theorem show several sufficient conditions for decomposability of termination, which are useful for proving termination of term rewriting systems defined by combination of several composable modules.

A Hierarchical Cubic Network (HCN) is a hierarchical hypercube network proposed by Ghose. The HCN is topologically superior to many other similar networks, in particular, the hypercube. It has a considerably lower diameter than a comparable hypercube and is realized using almost half the number of links per node as a comparable hypercube. In this paper, we propose the shortest routing algorithm in HCN(n, n) and show that the diameter of HCN(n, n) with 22n nodes is n(n1)/31 which is about 2/3 of that of a comparable hypercube. We also propose the optimal routing algorithm in HCN(m, n) where mn and obtain that its diameter is n(m1)/31. Typical parallel algorithms run in HCN(m, n) with the same time complexity as a hypercube and the hypercube topology can be emulated with O(1) time complexity in it.

We investigated performance of routing schemes in B-ISDN, for heterogeneous traffic flows under various bandwidths. In particular, we compared the simulated performance of these schemes by evaluating their blocking probabilities. To achieve high performance, these schemes use special kinds of routing algorithm, one which is pre-selection algorithm and one which is cyclic algorithm. We investigated the efficiency of the pre-selection algorithm and the robustness of the cyclic algorithm for nonuniform traffic and network resources. We found that these routing algorithm schemes can compensate for errors in resource design.

Voting is a general way of achieving mutual exclusion and synchronization in distributed systems with replicated data. In centralized voting protocols, a requesting node, which works as a central controller, exchanges messages in order to collect votes from other nodes. This paper proposes decentralized voting protocols, in which all nodes execute the same protocol and reach the same result in a decentralized and autonomous way. When a decentalized voting protocol is implemented by using one-round message exchange, it requires n(n1) messages, where n is the number of nodes. The number of messages can be reduced by using multiple-round message exchange. The paper describes the computation in each node in the form of the finite state automaton, and gives communication structures for it. It is shown that kn(n1/k1) messages are enough when messages are exchanged in k rounds.

The blazing effects of dielectric grating consisting of two adjacent sinusoidally modulated layers which lead to the asymmetric profiles on a substrate are analyzed by using improved Fourier series expansion method. This method can be applied to the wide range of grating structure and gave high accurate results by comparing with those obtained by previous method. In this paper, the efficient blazing effects can be achieved by varying normalized distance (w/p) and the normalized thickness (d1/D), where D is kept fixed. The results are greater than those of trapezoidal profiles and triangular profiles. The influences of the second order of modulation index on the radiation efficiencies and normalized leakage factor are also discussed.

In this paper, we describe a worst-case design optimization approach for statistical design of integrated circuits with a circuit performance model scheme. After formulating worst-case optimization to an unconstrained multi-objective function minimization problem, a new objective function is proposed to find an optimal point. Then, based on an interpolation model scheme of approximating circuit performance, realistic worst-case analysis can be easily done by Monte Carlo based method without increasing much the computational load. The effectiveness of the presented approach is demonstrated by a standard test function and a practical circuit design example.

The main aim of device-level global routing is to obtain high-performance detailed routing under various layout constraints. This paper deals with global routing for analog function blocks. For analog LSIs, especially for those operating at high frequency, various layout constraints are specified prior to routing. Those constrainsts must be completely satisfied to achieve the required circuit performance. However, they are sometimes too hard to be solved by any heuristic method even if a problem is small in size. Thus, we propose a method based on the branch-and-bound algorithm, which can generate all possible solutions to find the best one. Unfortunately, the method tends to take a large amount of processing time. In order to defeat the drawbacks by accelerating the process, constraints are classified into two groups: constraints on single nets and constraints between two nets. Therefore our method consists of two parts: in the first part only constraints on single nets are processed and in the second part only constraints between two nets are processed. The method is efficient because many possible routes that violate layout constraints are rejected immediately in each part. This makes it possible to construct a smaller search tree and to reduce processing time. Additionally this idea, all nets processed in the second phase are sorted in the proper order to reduce the number of edges in the search tree. This saves much processing time, too. Experimental results show that our method can find a good global route for hard layout constraints in practical processing time, and also show that it is superior to the well-known simulated annealing method both in quality of solutions and in processing time.

A radial line slot antenna (RLSA) is a high gain and high efficiency planar antenna proposed for DBS subscribers. Spirally arrayed slots are excited by a cylindrical wave with the rotational symmetry. In a small sized antenna where large slot coupling is adopted, aperture efficiency reduction due to rotational asymmetry associated with a spiral arrangement of the slots becomes notable. Authors proposed a RLSA with a concentric slot arrangement excited by a rotating mode in order to enhance the rotational symmetry. This is the first report of the normal operation of a rotating mode RLSA fed by a cavity resonator. The experiments confirm the basic operation of this novel antenna; the gain of 27.8dBi and the efficiency of 68% is measured at 11.85GHz for the RLSA with 0.24mφ.

There is a wide perception of the need for conformance and interoperability testing to ensure the interoperability of open systems. In the circumstances, we have been making efforts to establish a system for interconnectability testing, which is a type of the interoperability testing. In this paper, we discuss an interconnectability testing system, named AICTS (AIC's InterConnectability Testing System) that we have designed. We also discuss a conformance testing system, named ACTS (AIC Conformance Test System), which we developed as the first step toward building an interconnectability testing system. ACTS is capable of extensions for an interconnectability testing system.

We have done a computer search for solutions of the equation x3y3z3n in the range max (|x|, |y|, |z|) 3414387 and 0 n 1000. We have discovered 21 new integer solutions for n {39, 143, 180, 231, 312, 321, 367, 439, 462, 516, 542, 556, 660, 663, 754, 777, 870}. As a result, there are 52 values of n (except n 4 (mod9)) for which no solutions are found.