This paper treats mutual exclusion of a single shared-resource in distributed autonomous environments. The most important property of the autonomous network treated in this paper is its membership variability, that is, frequent occurrence of entries of new nodes and exits of old nodes. Thus, when the network is large-scale, it is not possible for each node to keet up the information of all other nodes. We in this paper design a mutual exclusion algorithm for distributed environments of autonomous nodes based on Chandy-Misra protocol for Dining Philosopher (diners) problems, which realizes a distributed implementation of the token ring method. We consider requirements of the communication topology that makes mutual exclusion possible, and propose entry and exit protocols for each node to perform them individualistically and autonomously.

In this paper, four simple nonlinear circuits with time-varying resistors are analyzed. These circuits consist of only four elements; a inductor, a capacitor, a diode and a time-varying resistor and are a kind of parametric excitation circuits whose dissipation factors vary with time. In order to analyze chaotic phenomena observed from these circuits a degeneration technique is used, that is, diodes in the circuits are assumed to operate as ideal switches. Thereby the Poincar maps are derived as one-dimensional maps and chaotic phenomena are well explained. Moreover, validity of the analyzing method is confirmed theoretically and experimentally.

This paper studies multidimensional linear periodically shift-variant digital filters (LPSV filters). The notion of a generalized multidimensional transfer function is presented for LPSV filters. The frequency characteristic of the filters is discussed in terms of this transfer function. Since LPSV filters can decompose the spectrum of an input signal into some spectral partitions and rearrange the spectrum, LPSV filters can serve as a frequency scrambler. To show the effect of multidimensional frequency scramble, 2-D LPSV filters are designed based on the 1-D Parks-McClellan algorithm. The resultant LPSV filters divide the input spectrum into some components that are permuted and possibly inverted with keeping the symmetric of the spectrum. Experimental results are presented to illustrate the effectiveness of frequency scramble for real images.

Asynchronous Transfer Mode (ATM) is an information transport technique that well supports Broadband ISDN (B-ISDN). One unsolved problem to the perfection of ATM networks is to provide a testing environment that conforms to some standardized network management scheme. From this point of view, remotely controlled virtual path testing is considered in this paper. Remotely controlled virtual path testing should be executed through the standardized Telecommunications Management Network (TMN) model, which employs the OSI systems management concept as the basis of information exchange. Thus, this paper addresses the two issues that arise when OSI systems management standards are applied to virtual path testing. One issue is to define relevant information models. The other issue is to provide test resources with a concurrency control mechanism that guarantees a consistent test environment without causing deadlocks. To resolve these issues, technical requirements are clarified for the remote control of test resources. Next, alternatives to the concurrency control mechanism are shown and compared through computer simulations. A method of defining information models is then proposed. The proposed method ensures the easy storage and retrieval of intermediate test results as well as permitting the effective provision of concurrency control for test resources. An application scenario is also derived. The scenario shows that tests can be executed by using standardized communication services. These results confirm that virtual path testing can be successfully achieved in conformance with the OSI systems management standards.

This paper proposes a new admission control strategy for ATM networks, which is based on the simulation approach and regression results. Instead of using many traffic descriptors, in our strategy only numbers of connections of different types are needed in performing admission control. The strategy is evaluated from different points of view, real-time, safety, policing and its efficiency which is referred as allowed utilized bandwidth. Since the admission criteria is developed in a form of regression model, the computation of performance for accepting a new connection is quick and easy. Using the confidence region in statistics to represent the admission criteria, a conservative estimation of performance can be achieved. Besides, this strategy is quite independent, thus can be compatible with most policing functions. Finally, its bandwidth utilization is found to be above 0.54. However, the success of this strategy still depends on the reality of input traffic model. Whenever the traffic can be clearly described, the proposed strategy can be easily and precisely applied. Therefore, we also build a traffic model for different type of traffic including constant-bit-rate (CBR), variable-bit-rate (VBR) and bursty traffic. The application of the proposed strategy to different multiplexing schemes, like priority queues and polling system, etc., should be further studied. Considering different level of performance requirement for different type of traffic, which should aid the bandwidth utilization of this strategy, is also an interesting research issue.

In this paper, a methodology for designing the architecture of the processor array for wide class of image processing algorithms is proposed. A concept of spatially expanding the SFG description which enables us to handle the problem as merely one-dimensional signal processing is used in constructing the methodology. Problem of I/O interface which is critical in real-time processing is also considered.

When we study time-domain electromagnetic fields, we frequently use the finite-difference time-domain (FD-TD) method. In this paper, we discuss errors of the FD-TD method and present the optimum mesh spacings in the FD-TD method when the three mesh spacings are different.

A multicarrier modulation is considered as an effective technique in high speed digital transmission under the multipath fading. In this paper, we theoretically analyze the bit error rate (BER) performance of the multicarrier modulation/differential detection scheme, and show the trade-offs between the BERs and the number of carriers or the guard period to clarify the optimum values to minimize the BER in the number of carriers and the guard period.

This paper describes a fiber-optic microcell radio system with a spectral delivery switch to meet traffic demands. Optical link performance is discussed from the view points of link loss and noise figure aimed at system design. The theoretical carrier-to-noise ratio (CNR) performance is shown as a function of the input electrical power of the laser and the received optical power. Improvement of dynamic range defined by both CNR and intermodulation distortion is proposed by using the frequency modulation (FM) technique. The experimental results using the proposed technique indicate that the performance is much better than that of conventional methods. Moreover, economical diversity planning delivery methods over fibers are presented. This strategy will provide more cost effective and flexible networks.

The inverted slot line (ISL) has been propoaed for millimeter-wave LiNbO3 optical modulator. It is simple in structure, and capable of achieving the perfect velocity matching between carrier and modulating waves. The excellent performance of the ISL optical modulator has been demonstrated at 100 GHz, and the extension into the 50 GHz range is being expected. This paper addresses the analysis of the ISL based on the spectral domain approach. The major results obtained here are the demonstration of the perfect velocity matching not only at 10 GHz but also at 50 GHz, and the characterization of the ISL in terms of effective refractive index, characteristic impedance, overlap integral factor and transmission loss. The depth of optical phase modulation is also estimated at 50 GHz to show a promising performance in the millimeter-wave frequency range. The effective refractive index and the characteristic impedance are found to be theoretically predictable, but the field profile, the overlap integral factor and the transmission loss are not necessarily in good agreement with measurements. As a result of analysis, it can be concluded that the Y-cut substrate is superior to the Z-cut substrate in the following respects: 1. Coupling with the surface wave mode hardly occurs near the operating frequency range. 2. The perfect velocity matching can be attained with a larger spacing between the electrode and the ground plane. 3. The transmission loss is smaller. 4. The field intensity and the voerlap integral factor do not seem to be much deteriorated in the actual ISL.

This paper proposes the laser diode receiving mixer which utilizes the laser diode nonlinearity. The laser diode receiving mixer can make the bidirectional fiber optic link simple and cost-effective. These laser diodes are applied to configure the LD-LD MIX link which consists of two laser diodes, two local oscillators, two microwave switches and one fiber cable. The LD-LD MIX link configuration is extended to introduce novel two fiber optic links, i.e. the local suppression link and the image cancellation link. These links utilize the combination of microwave circuits and optical devices. These configurations are experimentally investigated at microwave frequencies and the QPSK signal transmission is successfully demonstrated.

The erosion of contact metal, which determines the life of contacts in the telephone switching system, is proportional to the arc energy. The equations for arc voltage, arc current, arc duration time and number of arcs are expressed explicitly in terms of circuit parameters and contact properties, and the expression is derived for arc energy that accompanies a single operation of contact closure. Contact erosion is consistent with the calculated arc energy. The erosion rate at closure is estimated based on the measured contact-erosion volume and the calculated arc energy. Arc energy at contact closure becomes as large as that at contact break if the cable is long or the supply voltage is high. This expression in combination with the expression for contact break enabled us to perform contact life design, which is indispensable for maintenance administration of telephone switching systems.

Reactive gases such air pollution agents as H2S or SO2 usually corrode the electrical contact surfaces. Since corrosion products formed on the surface increase contact resistance, they harmfully degrades contact reliability. To prevent the corrosion of the surface, oil coating on it may be effective. The oil film acts basically as a barrier for reaction between the corrosive gas and the surface. For thin film coating, the corrosion inhibition can not be expected. However, effect of film thickness on the corrosion property has not been clarified. In the present study, in order to clarify the corrosion inhibition of the oil coating for the contacts, the stearic acid coating on Ag (silver) contact surface was studied from view-point of the relationship between the thickness of the coating film and the contact resistance. As results, the effect of the stearic acid coating on corrosion inhibition in the atmosphere contained with H2S 3 ppm was found. However, the corrosion of the surface coated with thin stearic acid film occurred at microscopically scattered thin patiches in the specific pattern of the film. Existing of the optimum thickness of the stearic acid coating which gives both minimum contact resistance and effective corrosion inhibition was found. In the intermediate film thickness, this optimum thickness was induced by the increased contact resistance due to corrosion of the thin film region and insulation property of the stearic acid in the thick film region. Moreovr,it was found that this optimum thickness was affected by corrosion time. At the early stage of corrosion, the optimum thickness was about 200 . However, the corrosion time becomes longer as 700 min, this optimum thickness changed to thick as 1000 . With this increase in the thickness, the contact resistance in the optimum thickness rised to high level. Furthermore, the contact resistance in the optimum thickness decreased with increase in the contact load. However, dependence of the contact load on the optimum thickness was not recognized under a certain corrosion time.

This paper reports the influence of optical reflection induced noise and distortion for optical fiber feeder systems for microcellular mobile communication systems. Since the optical feeder requires very wide dynamic range, noise and distortion must be suppressed to an extremely low level. From optical transmission experiments and theoretical analysis, the basic characteristics of the reflection induced noise and distortion were investigated. By using these results, it was estimated that, for currently used analog mobile telephone systems, the number of connectors with 35 dB reflectance must be limited to less than 17, in order to suppress the noise caused by the connector reflections. Moreover, it was confirmed that the reflection induced distortion drastically decreases according to the increase of the length between reflectors. Therefore, the distortion can be suppressed by expanding the connector spacing to more than 7 meters.

This paper presents an efficient multi-precision modular-multiplication algorithm which minimizes the calculation RAM space required when implementing public-key schemes with software on general-purpose computers including smart cards and personal computers. Many modular-multiplication algorithms cannot be efficiently realized on small systems due to their high RAM consumption. The Montgomery algorithm, which can rapidly perform modular multiplication, has received a lot of attention. Unfortunately, the Montgomery algorithm is difficult to implement, especially in smart cards which have extremely limited RAM space. Furthermore, when the modulus of modular multiplication is frequently changed, or when the number of permissible repeated modular multiplications is small, pre- and post-processing operations such as conversion from/to the Montgomery space become wasteful. The proposed algorithm avoids these problems because it requires only half the RAM space and no pre- and post-processing operations. The algorithm is a radical extension to the approximation methods that use the most significant bits and our newly proposed lookahead determination method. This paper gives a proof of the completeness of this method, describes implementation results using a smart card, introduces a theory supported by the results, and considers the optimal technique to enhance the speed of this method.

A new direct projection patterning technique of aluminum using synchrotron radiation (SR) is proposed. It is based on the thermal reaction control effect of SR excitation. In the case of the Si surface, pure thermal growth is possible at 200, however, this growth is suppressed perfectly by SR irradiation. On the other hand, Al growth on the SiO2 surface is impossible at the same temperature thermally, however, SR has an effect to initiate thermal reaction. Both new effects of SR, suppression and initiation, are clarified to be caused by atomic order level thin layers formed from CVD gases by SR excitation on the surfaces. By using these effects, the direct inverse and normal projection patterning of Al are successfully demonstrated.

Optical fiber transmission systems have advanced rapidly with the advent of highly advanced electronic and optical devices. This paper introduces several IC technologies required for ultra-high-speed optical transmission and overviews current IC technologies used for the existing and developing optical fiber trunk transmission systems. Future trends in device technologies are also discussed.

In this paper, we investigate the round complexity of zero-knowledge interactive proof systems of possession of knowledge, and mainly show that if a relation R has a three move blackbox simulation zero-knowledge interactive proof system of possession of knowledge, then there exists a probabilistic polynomial time algorithm that on input x{0,1}*, outputs y such that (x,y)R with overwhelming probability if xdom R, and outputs "" with probability 1 if x dom R. The result above can not be generalized to zero-knowledge interactive proof systems of possession of knowledge with more than four moves, because it is known that there exists a "four" move blackbox simulation perfect zero-knowledge interactive proof system of possession of knowledge for a nontrivial relation R.

A study of hot-carrier-induced photon emission in thin SOI/MOSFETs has been carried out both for bonded-SOI and SIMOX/SOI. The photon emission is observed not only in the drain region but also in the source region for SOI/MOSFETs, whereas only in the drain region for conventional bulk MOSFETs. From the emission spectrum, it can be concluded that the emission mechanism of the source region is probably a photon-assisted direct recombination of electrons and holes, while both the recombination and Bremsstrahlung are the possible mechanism for the drain region. The total photo intensity from SOI/MOSFETs increases as the SOI film thickness decreases, showing that strong impact ionization occurs near the drain region for thinner SOI devices. The relation between the lifetime and the photo intensity for SOI/MOSFETs is very similar to that between the lifetime and the substrate current for conventional bulk/MOSFETs, proving that photon emission is a good indicator of the hot carrier degradation in thin SOI/MOSFETs. The lifetime measurement using the photon emission both for SOI and bulk devices indicates that longer lifetime can be expected for thin film SOI/MOSFETs with a reduced drain bias which will be indispensable for future sub-half micron MOSFETs.

One model of a laser is a set of differential equations called the Maxwell-Bloch equations. Actually, in a physical system, causing a chaotic behavior is very difficult. However the chaotic behavior can be observed easily in the system which has a mirror to feedback the delayed output.