摘要:

AbstractThis paper describes the synchronous oscillation in a multimode oscillator composed of an active element and several resonators with rational ratio frequencies. Using the concept of the averaged potential we proposed previously, we show that the ideal waveform minimizing the loss of the active element is generally the square wave or the stair‐step wave switching the minimal voltages of the active element voltage potential. Then, we can predict that the system has rational frequencies, the approximate square waves composed of these frequency components are excited stably by the synchronization. This synchronization phenomenon is confirmed by the simulation. An efficient algorithm for obtaining all of the stable synchronous oscillations is presented. The algorithm is performed by expressing all the synchronous oscillation waveforms by symbol trains according to their peculiar waveforms and calculating the initial values from the symbol trains. This method is applied successfully to the simulation of the oscillator where the active element is expressed by the cubic‐ or fifth‐power nonline

ISSN:8756-6621    

DOI:10.1002/ecja.4410700201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper presents a polynomial‐time algorithm for finding multicommodity flows in planar graphs. Suppose thatGis an undirected planar graph and that some of the source‐sink pairs are located on the boundary of the outer face and all the other pairs share a common sink located on that boundary. The algorithm determines whetherGhas multicommodity flows each from a source to a sink and of a given demand, and if it does, actually finds them.Letnbe the number of vertices inGandbbe the number of edges on the boundary of the outer face. Then the time complexity of the algorithm isO(n(b2+ T+(n)), whereT+(n)is the time required to find the shortest paths from a vertex to the others in a planar‐directed graph withnvertices and nonnegative real weighted edges. In the class of planar networks treated in this paper, it is known that the so‐called “Max Flow ‐ Min Cut the

ISSN:8756-6621    

DOI:10.1002/ecja.4410700202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper proposes a simple synthesis method of impedance matching and transforming filter. This method is based on the use of a multistage ladder network simulating a nonuniform transmission line. When the filter charactersitic functions defined in this paper satisfy the distortionless conditions of the voltage and current waveforms the artificial transmission line mentioned above almost operates as an ideal lowpass filter. As an example the characteristics of 1 ‐ 2ω transformable type lowpass filter are evaluated and the obtained results almost satisfy the conditions for the ideal filt

ISSN:8756-6621    

DOI:10.1002/ecja.4410700203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe fuzziness induced in the decision making in the actual system in general, comprises fuzziness in the formulation of the problem and that in the judgments of the decision maker (DM) as a human being. This paper proposes an interactive fuzzy satisficing method, which takes into consideration the fuzziness in problem formulation as well as that in the judgments of DM. The multiobjective nonlinear programming problem containing fuzzy parameters is transformed into the α ‐multiobjective nonlinear programming problem. After determining the fuzzy goal of DM for each objective function by eliciting the membership function, the following reference values are set: the fuzziness index α of DM for the fuzzy parameter; and the reference membership values, which are reference for the membership functions. For the specified α and the reference membership values, the corresponding augmented minimax problem is solved, and DM is supplied with the α‐Pareto optimal, together with the trade‐off ratios among membership functions and the trade‐off ratios between α and the membership functions. Obtaining the result, the DM takes the information concerning current α‐Pareto optimal solution and the trade‐off ratios into consideration, and respond by updating the reference membership values and the value of α if necessary. In this way the satisficing solution finally is derived for DM, thereby ensuring the α‐Pareto optimality. This is the proposed interactive fuzzy satisficing method. The interactive process is demonstrated for a numerical example by the interac

ISSN:8756-6621    

DOI:10.1002/ecja.4410700204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThen‐phase switched‐capacitor (SC) circuit operates by taking successively connection configurations. Consequently, even if the same edge voltage is considered, it takesndifferent kinds of voltages in general in a period. This makes it difficult to describe the operation of the SC circuit. Although several methods have already been proposed for representing the operation of the SC circuit, the representation by equivalent active RC circuit, which is presently used most widely, cannot provide a clear‐cut description of this essential point. From such a viewpoint, this paper first derives the primitive signal‐flow graph (SFG) representation for adequate representation of the SC circuit, which is formulated based on the common tree in the SC circuit. Then the simplified SFG representation is derived which is obtained by simplifying the representation, eliminating the cotree‐edge variables from the primitive SFG representation. The simplified SFG representation is a network representation, in which only the tree‐edge voltage and the tree‐edge stored‐charge in each phase are used as the variable‐node. It can adequately provide an intuitively clear representation of the relation between the variables in each phase and the relation between the timing of the switch connection and the operation of the circuit. The condition for the structure of SFG is derived, which corresponds to Hasler's structure condition in order that the stray capacitance does not affect the operation. By this method, the problem of constructing an SC circuit insensitive to the stray capacitance is reduced to the problem of constructing an SFG satisfying a

ISSN:8756-6621    

DOI:10.1002/ecja.4410700205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper describes the numerical results and derivation of the partial reflected waves from a square‐law medium in which a Gaussian beam is incident. First the WKB solution for the wave equation in the square‐law medium is presented along with approximate solution for the first, second and third reflected waves. The investigated partial reflected waves can not be found by means of the WKB solution. An approximate expression for the partial reflected waves between two reflected beams is derived by Bremmer series. It is found that the partial reflected waves do not depend on the spot size of the beam and are basically proportional to the gradient of the permittivity. The theoretical results are in good agreement with the experimental resu

ISSN:8756-6621    

DOI:10.1002/ecja.4410700206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThe CSMA/CD DCR (CDMA/CD with Deterministic Contention Resolution) is a multiaccess protocol for local area networks. With this protocol a packet collides with another only once at most, so that high throughput and small delay characteristics are achieved. This paper presents a method of analyzing this protocol using a slotted model. First, for the equal arrival rate case, numerical results are obtained and the performance is evaluated on a throughput‐delay characteristic basis. As for the delay characteristic, not only its average but also its variance and distribution are evaluated. Also, the delay characteristics for right‐ and leftmost stations are clarified. Next, the unequal arrival rate case is analyzed and the delay characteristic is studied. Finally, the performance of CSMA/CD DCR is compared with those of CSMA/CD and token scheme, and the application field of CSMA/CD DCR is clarif

ISSN:8756-6621    

DOI:10.1002/ecja.4410700207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractMultipacket transmission achieves higher channel utilization efficiency than single‐packet transmission, and also improves packet delay. Some multipacket transmission systems have been proposed. However, none has been proposed yet which takes account of priority level. This paper proposes a Priority Exhaustive‐Service‐Type Multipacket Transmission (PESMPT) method. This method is modeled as an exhaustive‐service‐type queueing system having traffic sources with different priority levels. We analyze PESMPT for the case of two priority levels and derive channel utilization efficiency, number of packets in a frame, packet transmission delay, etc. Also, from numerical examples, the performance of PESMPT is clarified and is compared with those of non‐priority exhaustive‐service‐type multipacket transmission method and HOL priority method which is the most general single‐packet transmission metho

ISSN:8756-6621    

DOI:10.1002/ecja.4410700208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper describes the traffic analysis of TSTST type building block speech paths. The main component of this configuration is the switch module. It consists of a small‐sized T‐switch and part of an S‐switch. TSTST configuration is used to make a large capacity switching system with these switch modules. Conventionally, TST configuration was used mainly for speech paths. However, the number of stages must be increased in order to make a large capacity switching system using switch networks with small channel multiplicity. The traffic handling characteristics of TSTST are almost the same as those of TST with the same size T‐switch and the same total number of channels, and this configuration can be applied to a wide range of speech path sizes. Furthermore, flexibility and reliability can be improved by adding alternative links to the fundamental TSTST configuration, and thereby link efficiency can be improved by a few percent compared with the configuration without alternativ

ISSN:8756-6621    

DOI:10.1002/ecja.4410700209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractPresented in this paper is a discussion of the output power combining capability and the stable operation of the desired mode in a cylindrical cavity multiple‐device oscillator, in which several devices are placed inside a cylindrical cavity to combine the output of all devices by way of coupling with the TM020 mode of the cavity. A lumped element equivalent circuit is first derived that has the fundamental characteristic of the oscillator structure. From the modal analysis based on this equivalent circuit, it is found that the oscillation output as the sum of the available powers of individual devices can be obtained in principle at TM010 and TM020 modes. It is also noted that the TM020 mode cannot be a stable mode when it is chosen as the desired mode and the TMm10 mode (m≧ 1) is generated as a stable rotational or standing wave mode. Then we discuss the method of loading the resistor for suppressing unwanted modes in which only the desired output combining mode is stable. Finally, an eight‐device oscillator with a simple structure fabricated for trial is used in experiments of power combining and unwanted mode suppression and the results of the analysis of the modal analysis are qualitatively conf

ISSN:8756-6621    

DOI:10.1002/ecja.4410700210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY