In this paper we examine the architectural and operational design issues of a practical network management system using the Simple Network Management Protocol (SNMP) in the context of a large-scale OSI-based campus-network TAINS. Various design aspects are examined and the importance of time-management is elicited. In the proposed design, intelligent, time-synchronised agents are deployed to collect information about the network segments to which they are attached. The manager talks to the agents and gathers relevant network information. This information is used by the expert network manager, in conjunction with a network knowledge base (NKB) and a management information knowledge base (MIKB) , to reconstruct the overall network-traffic characteristic, to evaluate the status of the network and to take/suggest some action. This model is particularly useful in networks where some global control, monitoring and management is desired and installing agents on all elements, connected to the network, is impossible. The use of time labels and narrow time windows enables the manager to obtain a reasonably accurate picture of the network status. The introduction of time-labelled composite objects in the Management Information Base (MIB) provides a means of reducing the load of management-related traffic on the network. The MIKB containing a logical description of the behaviour of the managed objects defined in the MIB, drives the expert system and provides the knowledge of general nature that a human expert has about networks. The proposed MIKB concept provides a very convenient schema for building the knowledge base in an expert network management system. Further since the MIKB is MIB-specific, it can be used in network management systems for managing similar MIB's.

This paper describes the properties of non-dispersive and dispersive delay lines fabricated using EuBaCuO superconducting films. The 24 cm long stripline non-dispersive delay line showed a very low loss of 0.3 dB/nsec at 77 K and 10 GHz, and no dispersion at a delay time of 2.3 nsec at frequencies below 20 GHz. The 14 cm long microstrip dispersive delay line with modal dispersion exhibited a relative delay time of approximately 120 psec in the 118 GHz frequency range. The 26 cm long stripline dispersive delay line with structural dispersion due to coupling provided a relative delay time of 230 psec in the above frequency range and roughly the same loss as a non-dispersive delay line.

A ner trial of statistical evaluation for a nonstationary traffic flow and its traffic noise is proposed as a prediction method of its probability distribution function by considering the temporal change of distribution parameters especially from a structural viewpoint. First, a headway distribution of the nonstationary traffic flow passing through within a road segment is proposed on the basis of an Erlang distribution by reflecting a temporal change of its distribution parameters. Then, an initial phase density concerning with asynchronous counting method and the probability of counting n cars over a long time interval are derived from the above nonstationary expression of headway distribution. Thus, the statistics of noise intensity at an observation point has been predicted by combining the above probabilistic factors and deterministic factors related to noise propagation environment with use of a compound stochastic process model. Finally, te effectivenss of the proposed theory has been confirmed experimentally by applying it to the actual traffic flow on a highway.

This study is concerned with modeling and analyzing a nonlinear elastomer impact phenomenon when a mass experiences a collision with the contact pad mounted on the underlying linear dynamic structure. The contact pad which consists of the viscoelastic elastomer is modeled here by a nonlinear contact stiffness and nonlinear contact damper. The underlying dynamic structure is measured by a Fourier spectral analyzer and its analytical form is utilized in modeling and analyzing the whole dynamic impact problem. The impact force profiles are predicted and analyzed in terms of pulse duration, time-to-peak force, and peak force. Finally, the damping mechanism and its hysteresis phenomena are also discussed.

In this letter, a generalized syndrome polynomial is proposed from which several decoding key-equations for Reed-Solomon codes can be derived systematically. These equations are always solved by the extended Euclidean algorithm.

This paper proposes a high resolution and fast frequency settling PLL synthesizer for frequency hopping radio communication equipment. The proposed synthesizer enables the carrier frequency to be changed within the duration of a burst signal and yields higher frequency resolution than the reference signal frequency. To reduce frequency settling time without degradation of frequency resolution and phase noise, this paper proposes a new phase and frequency preset (PEP) PLL synthesizer which employs a digital phase accumulator to generate high resolution reference signal. Experimental results show that the settling time of a prototype synthesizer is less than 300µs while spurious signals are suppressed by more than 55 dB. In comparison with conventional PLL synthesizers, the frequency settling time is reduced by 80%. Furthermore, the higher frequency resolution than the reference signal is successfully demonstrated. Therefore, the proposed PFP PLL synthesizer with the digital reference signal can achieve the output signal with high frequency resolution less than 1Hz.

Telecommunication services are accomplished by cooperative networks of widely distributed communication processes and service users. Those specifications are often modeled by a set of possible message sequences among cooperating processes and users. The distributed and cooperative nature of telecommunication services results in a wide variety of message sequences and makes it more difficult for service designers to design such telecommunication services. To mitigate the difficulty, we propose a design support system with MSRs (message sequence rules) as design knowledge. The system supports the following two design activities: (1) specification of a typical message sequence that corresponds to a service behavior in a successful case, and (2) specification of incidentally possible message sequences that involve service behaviors in successful and unsuccessful cases. For the former activity, the system interacts with designers and identifies the messages they give with MSRs to understand the context of the message sequence and suggest possible subsequent messages. For the latter activity, the system applies MSRs to the typical message sequence and reasons possible messages from/to relevant processes and users under every state to suggest incidentally possible message sequences. Accordingly, designers may be relieved of investigating a wide variety of service behaviors in successful and unsuccessful cases. The system capability is based on MSRs equivalent to reusable message sequence components. MSRs can be obtained through abstraction of implementation-dependent messages and decomposition of those sequences into temporal relations among messages. The rule acquisition method provides MSRs with the potential to generate a wide variety of message sequences. In order to verify rule applicability, we have experimentally designed three kinds of services and conducted an experimental rule application to those specifications. The experimental evaluation results indicate that applicability is fairly high.

Thin-film YBCO Josephson junctions were successfully fabricated by a pulsed excimer laser ablation, and the mixing experiments in the microwave region (820 GHz) were carried out at the temperature of 77 K. The IF output maximum was obtained at the bias voltage midway between the zero and the first Shapiro steps for the fundamental mixing. For the 2nd harmocic mixing, the IF output maximum was obtained at a zero bias voltage, and the conversion efficiency was -14 dB at the microwave frequency of 18 GHz. These results strongly suggest that the fabricated thin-film Josephson junctions work well at the temperature of 77 K as detectors and mixers in the microwave regions (820 GHz).

This letter proposes an active reflector for calibrating a synthetic aperture radar (SAR), in which the frequency of a received SAR signal is shifted by a certain amount and then it is retransmitted to the SAR. The frequency shift causes a shift of the reflector SAR image in an azimuth direction relative to its background. This function would allow to enhance a signal-to-clutter ratio of the reflector image by moving it onto a radiometrically dark background, and hence it would be of value for SAR calibration even in a narrow test site. The theory, design and development are described briefly.

Among the many fabrication methods for oxide superconductor films, metal organic chemical vapor deposition (MOCVD) is particularly suitable for industrial application because of its mass productivity and the low growth temperature. Therefore we have studied this technique using the horizontal cold wall furnace type MOCVD method to obtain high quality superconducting films. As the result, we have succeeded in fabricating YBa2Cu3Oy films which have high critical temperatures (over 80 K) under substrate temperatures as low as 700 without post-annealing. But, in the course of our experiments, it was found that the thicknesses of YBa2Cu3Oy films fabricated by MOCVD were not uniform. The cause of this non-uniformity is believed to be that the deposition rate exponentially falls off along the flow direction because of the decrease of the source gas concentration through the reaction. In this paper, this non-uniformity is analytically studied. It is shown that the deposition rate decrease can be controlled with a tapered inner tube, and that these theoretical results are in good agreement with the results of experiment. In addition, it is indicated that the superconducting property of the films has less dependence on substrate position as a result of the tapered inner tube.

This paper proposes a next-generation narrow-band ISDN (N-ISDN), including a suitable network and network node architecture. The proposed N-ISDN allows every subscriber to use H0/HI-class calls as easily as present telephone calls, and could rapidly expand ISDN services to all the subscribers of a public network. The present status of ISDN is first analyzed then the need for popularization of H0/HI-call services is discussed. The proposed key technologies to popularize HO/HI services are (1) on-chip integration of ISDN switching systems, (2) distribution of small on-chip switching systems over the subscriber switching area, (3) H0-based trunk circuit networks using H0 on-chip switching systems and (4) efficient and flexible call management for 64-kb/s basic-class calls. An estimation of hardware volume of switching nodes is used to show that the proposed architecture is more economical than other possible alternatives, i.e. conventional ISDN and B-ISDN.

As the size and complexity of network increases, the distributed systems management (DSM) will be vital in order to improve the availability of network management, to reduce the complexity of network operations, and to provide the high reliability. In this paper, we (1) describe general requirements required for systems management in distributed environment, (2) introduce the basic structure of distributed network management system (DNMS) for efficient network management, and also especially illustrate the concrete design of system management application process which is an important element among them, (3) propose the connectionless CMIP to accomplish for effectively managing the distributed management system, and indicate its efficiency; this protocol is available to manage dynamically changing DSM environment, to negotiate among the managing systems, to handle the dynamic informations etc. Finally, (4) the behavior and software structure of a suggested management system during negotiation to execute the received request for implementation are presented.

This paper analyzes the performance of an ATM cell multiplexer with a two level MMPP input on a discrete-time basis. We approximated the input process as a simple MMPP model. We developed an MMPP/D/1/K queueing model for the ATM cell multiplexer, and employed an analytic approach for the evaluation of cell loss probability. We verified the accuracy of the results using computer simulation. We applied the above analytic method to connection admission control (CAC) of the ATM network. The resulting connection admission control scheme employs the concept of the "effective bandwidth" and table-look-up procedure. We confirmed through a computer simulation that the proposed connection admission control scheme outperforms the peak bandwidth allocation scheme with respect to link utilization.

This letter describes damages of piezoelectric polymer using in hydrophones to measure high acoustic pressures at the focal point of Extracorporeal Shockwave Lithotripter (ESWL).

This paper discusses a computer-aided network planning support system called PIGEON that has been developed primarily for advancing countries implementing the applicability to various types of networks and the supportability to the sensitivity analysis. For the implementation of the applicability, the customization by reflecting existing network facilities and their accompanying restrictive conditions into a design result is focused. A case study on the customization shows the effectiveness of the reflection. The procedures are given of the sensitivity analysis in order to examine and to evaluate the effect of the uncertain factors in network planning. In particular, a method called "network modification" is proposed for the sensitivity analysis for uncertain factors associated with a partial network. The network modification efficiently integrates network planner's judgments into a design result by the interactive method. In addition, this paper describes the importance of streamlining the data input and the evaluation of design results, showing the operating time required for each work phase in network planning.

The motion of particles in low-pressure chemical vapor deposition (LPCVD) (0.4 Torr) equipment has been investigated by a numerical simulation. The effects of wafer orientation, electrostatic forces, and thermophoresis were evaluated. Horizontal surface-down processing and vertical processing can reduce particulate contamination remarkably compared with horizontal surface-up processing. Static electricity control is essential. Weakly charged wafers (several V to several 10 V) can significantly increase submicron particle deposition. In the absence of electrical forces, thermophoresis prevents deposition of particles in the size range 0.03 µmDp0.6 µm, when the temperature difference between the wafer surface and the gas inlet temperature exceeds 100. Deposition of particles smaller than 0.03 µm still occurs by diffusion.

Lexical-Functional Grammars (LFG's) were introduced to define the syntax of natural languages. In LFG's, each node of a derivation tree has some attributes. An LFG G consists of a context-free grammar (cfg) G0 called the underlying cfg of G and a description Pfs of constraints between the values of the attributes. Pfs can specify (1) constraints between the value of an attribute of a node and those of its children, and (2) constraints between the value of an attribute of a node called a controller and that of a node called its controllee. RLFG's were introduced as a subclass of LFG's. In RLFG's, only constraints between the value of an attribute of a node and those of its children can be specified. It is shown in this paper that the class of languages generated by RLFG's is equal to the class of recursively enumerable languages. Some restrictions on LFG's were proposed for the purpose of efficient parsing. Among them are (1) the condition called a valid derivation, and (2) the condition that the underlying cfg is cycle-free. For an RLFG G, if the production rules of the underlying cfg of G are of the form AaB or Aa for nonterminal symbols A, B and a terminal symbol a, then G is called an R-RLFG. Every R-RLFG satisfies the above restriction (1) and (2). It is also shown in this paper that the class of languages generated by R-RLFG's contains an NP-hard language, which means that parsing in deterministic polynomial time of LFG's is impossible in general (unless PNP) even if the above restrictions (1) and (2) are satisfied.

A new timing driven placement method based on the fuzzy theory is proposed. In this method, the longest path delay, the chip area and the wire length can be simultaneously minimized. Introducing the probability measures of fuzzy events, falling down into the optimal solutions can be avoided.

This letter describes one neuron's dynamics. This neuron provides its own feedback input. We call this neuron the recurrent neuron and investigate its nonlinear dynamics.

Based on the Fornasini-Marchesini second local state-space (LSS) model, the coefficient sensitivities of two-dimensional (2-D) digital filters are analyzed in conjunction with frequency weighting functions. The overall sensitivity called the frequency-weighting sensitivity is then evaluated using the 2-D generalized Gramians that are newly introduced for the Fornasini-Marchesini second LSS model. Next, the 2-D filter structures that minimize the frequency-weighting sensitivity are synthesized for two cases of no constraint and scaling constraints on the state variables. Finally, an example is given to illustrate the utility of the proposed technique.