This paper proposes a multi-fisheye distortion method which can show a large-scale telecommunication network in a single window on the display of a workstation or personal computer. This distortion method has three advantages over the conventional single-fisheye distortion method. First, the focus area is magnified smoothly by the fisheye distortion method, and the peripheral area coordinates are calculated linearly to avoid unnecessary distortion. Second, multiple focus areas are magnified smoothly by using an average of the coordinates calculated for the individual focuses. Third, the scale of unnecessary areas is reduced to provide sufficient space for magnification. The effectiveness of this method is demonstrated by applying to the display of large-scale networks. The effect of the resulting network map distortion on the user is tested by a subjective evaluation experiment.

Managed Objects (MOs) can be specified by the combination of a static information model and a dynamic process model. First, this paper presents a mapping of attributes from a process model diagram to an information model diagram. Then, it introduces a concept of topology into these two models and proposes a hypothesis about the relationship of topology in these two models. To explicitly explain the hypothesis, it can be stated that all attributes of incoming or outgoing data related to a process in a process model are mapped to an information model where these attributes are interconnected by an explicit relationship which corresponds to a specific meaning, such as physical containment or logical connection. From an intuitive perspective, it can be said that if two attributes have a close topological relationship in a process model, the mapped attributes also have a close topological relationship in an information model. This hypothesis provides clues for determining whether there is an error in an attribute either in the process model or in the information model. By examining the way attributes of incoming or outgoing data related to a process are mapped to an information model, we can detect whether there is an error with respect to the process. The error correction is performed with the assistance of probability analysis. The method of error detection and correction can be implemented in a computer aided tool. Then, error detection on the attribute level becomes automatic, and error correction on the attribute level becomes interactive through the computer aided tool. Finally, the validity of the hypothesis is confirmed by analyzing ITU-T Recommendation M.3100. The specification of the fabric object class defined in M.3 100 is transformed into these two models and the hypothesis is validated for the analysis of the mapping between these two models.

Telecommunications management is essentially an aggregation of a wide range of activities, including operations and management (O & M) of telecommunications services and customers as well as the network and network elements. During the period of rapid growth in telecommunications, the highest priority was to meet increasing market demand and to construct a telecommunications network infrastructure. Therefore, research and development in telecommunications management were subordinated to the evolution of telecommunications services and systems. Recently, customers have been demanding higher quality services, as a variety of new, advanced services have been introduced. This has led to the need to integrate telecommunications services and O & M services. This paper first reviews the history of the development of telecommunications O & M in parallel with the progress of telecommunications in Japan and clarifies specific features in each step of this progress. This analysis identifies urgent problems and their solutions. The results suggests that telecommunications O & M and O & M services should be considered as a key to making future services possible and to the value of those services in a multi-media telecommunications services environment. Based on these studies, the future direction of O & M is then shown, focusing on cooperative O & M involving the customer in the multi-media, multidomain telecommunications environment.

Wavelength-division multiplexing (WDM) optical switching networks are one of most attractive technologies in optical interconnections. By combining with time-division multiplexing (TDM) and space-division multiplexing (SDM) technologies, remarkably high-throughput interconnections may be accomplished. In this paper, we propose WDM switching networks with time-division multiplexed optical signals by using free-space optics. We also propose novel WDM interconnections, including multiple-wavelength light-sources, optical fibers and wavelength-selectable detectors. We successfully confirmed basic principles for the WDM interconnections.

A novel total harmonic distortion (THD) measuring technique is proposed. A modified Volterra series using harmonics in place of powers of the sinusoidal input is used to identify the nonlinear models of the source and the device under test (DUT). The least-mean square (LMS) adaptive algorithm is applied for identification. While maintaining comparable speed and accuracy this technique provides a more flexible test procedure than conventional methods, in terms of the frequency resolution, the number of samples, and the sampling rate. It outperforms conventional methods when there is a bin energy leakage, which occurs in a non-coherent system. In addition, it is real-time computing while other conventional methods post process blocks of data. Simulation results collaborate the analytical results.

In this paper a method of recognizing waveform based on the Discrete Wavelet Transform (DWT) presented by us is applied to detecting the K-complex in human's EEG which is a slow wave overridden by fast rhythms (called as spindle). The features of K-complex are extracted in terms of three parameters: the local maxima of the wavelet transform modulus, average slope and the number of DWT coefficients in a wave. The 4th order B-spline wavelet is selected as the wavelet basis. Two channels at different resolutions are used to detect slow wave and sleep spindle contained in the K-complex. According to the principle of the minimum distance classification the classifiers are designed in order to decide the thresholds of recognition criteria. The EEG signal containing K-complexes elicited by sound stimuli is used as pattern to train the classifiers. Compared with traditional method of waveform recognition in time domain, this method has the advantage of automatically classifying duration ranks of various waves with different frequencies. Hence, it specially is suitable to recognition of signals which are the superimposition of waves with different frequencies. The experimental results of detection of K-complexes indicate that the method is effective.

An efficient algorithm is presented for finding all solutions of piecewise-linear resistive circuits containing sophisticated transistor models such as the Gummel-Poon model or the Shichman-Hodges model. When a circuit contains these nonseparable models, the hybrid equation describing the circuit takes a special structure termed pairwise-separability (or tuplewise-separability). This structure is effectively exploited in the new algorithm. A numerical example is given, and it is shown that all solutions are computed very rapidly.

A new Hybrid-ARQ scheme with a convolutional code and the Viterbi decoding is proposed, which uses the packet combining technique and a retransmission criterion based on an estimated decoding error rate. The throughput and bit error rate are evaluated by theoretical bounds and computer simulations. It is shown that a given error rate tolerance can be attained with good throughput for any signal to noise ratio, i.e. for the slow time-varying channels. Furthermore, the throughput performance can be improved by retransmitting not all but a part of packet.

Coding scheme is discussed for M-Choose-T communication in which at most T active users out of M potential users simultaneously transmit their messages over a common channel. The multiple-access channel considered in this paper is assumed to be a time-discrete noiseless adder channel without feedback with T binary inputs and one real-valued output, and is used on the assumption of perfect block and bit synchronization among users. In this paper a new class of uniquely decodable codes is proposed in order to realize error-free M-Choose-T communication over the adder channel described above. These codes are uniquely decodable in the sense that not only the set of active users can be specified but also their transmitted messages can be recovered uniquely as long as T or fewer users are active simultaneously. It is shown that these codes have a simple decoding algorithm and can achieve a very high sum rate arbitrarily close to unity if exactly T users are active.

We developed a parallel bordered-block-diagonal (BBD) matrix solution for parallel circuit simulation. In parallel circuit sumulation on a MIMD parallel computer, a circuit is partitioned into as many subcircuits as the processors of a parallel computer. Circuit partition produce a BBD matrix. In parallel BBD matrix solution, diagonal blocks are easily solved separately in each processor. It is difficult, however, to solve the interconnection (IC) submatrix of a BBD matrix effectively in parallel. To make matters worse, the more a circuit is partitioned into subcircuits for highly parallel circuit simulation, the larger the size of an IC submatrix becomes. From an examination, we found that an IC submatrix is more dense (about 30% of all entries are non-zeros) than a normal circuit matrix, and the non-zeros per row in an IC submatrix are almost constant with the number of subcircuits. To attain high-speed circuit simulation, we devised a data structure for BBD matrix processing and an approach to parallel BBD matrix solution. Our approach solves the IC submatrix in a BBD matrix as well as the diagonal blocks in parallel using all processors. In this approach, we allocate an IC submatrix in block-wise order rather than in dot-wise order onto all processors. Thus, we balance the processor perfomance with the communication capacity of a parallel computer system. When we changed the block size of IC submatrix allocation from dot-wise order to 88 block-wise order, the 88 block-wise order allocation almost halved the matrix solution time. The parallel simulation of a sample circuit with 3277 transistors was 16.6 times faster than a single processor when we used 49 processors.

We propose an RSA-type scheme over the nonsingular part of a singular cubic curve En (0,b) : y2x3+bx2 (mod n), where n is a product of form-free primes p and q. Our new scheme encrypts/decrypts messages of 2 log n bits by operations of the x and y coordinates. The decryption is carried out over Fp or a subgroup of a quadratic extension of Fp, depending on quadratic residuosity of message-dependent parameter b. The decryption speed in our new scheme is about 4.6 and 5.8 times faster than that in the KMOV scheme and the Demytko scheme, respectively. We prove that if b is a quadratic residue in Zn, breaking our new scheme over En(0,b) is not easier than breaking the RSA scheme.

This paper discusses Boolean functions satisfying the propagation criterion (PC) and their balancedness. Firstly, we discuss Boolean functions with n variables that satisfy the PC with respect to all but three elements in {0,1}n-{(0,...,0)}. For even n4, a necessary and sufficient condition is presented for Boolean functions with n variables to satisfy the PC with respect to all but three elements in {0,1}n-{(0,...,0)}. From this condition, it is proved that all of these Boolean functions are constructed from all perfectly nonlinear Boolean functions with n-2 variables. For odd n3, it is shown that Boolean functions with n variables satisfying the PC with respect to all but three elements in {0,1}n-{(0,...,0)} satisfy the PC with respect to all but one elements in it. Secondly, Boolean functions satisfying the PC of degree n-2 and their balancedness are considered. For even n4, it is proved that an upper bound on the degree of the PC is n-3 for balanced Boolean functions with n variables. This bound is optimal for n=4,6. It is also proved that, for odd n3, balanced Boolean functions with n variables satisfying the PC of degree n-2 satisfy the PC with respect to all but one elements in {0,1}n-{(0,...,0)}.

A filter-type coplanar parallel electrode with periodically loaded reactances is introduced to construct guided-wave light modulators of limited bandwidth. The device was built by using a Ti:LiNbO3 optical waveguide and was operated successfully at 633 nm. Measured 3 dB bandwidth was 1 GHz centered at 14.8 GHz. Required modulating power for 1 rad phase modulation was 67.6 mW.

The polarization dependence of femtosecond soliton-soliton interactions is investigated in detail. When the polarization direction of two solitons is orthogonal, the soliton interaction can be reduced in comparison to that for parallel polarization. The soliton self-frequency shift (SSFS) is still observed even in the orthogonal condition, but the quantity of the SSFS is much smaller than in the parallel condition. A stronger soliton interaction is observed between two solitons in an in-phase condition, than in an out-of-phase condition. The largest SSFS occurs in-phase with parallel polarization. The polarization dependence of femtosecond soliton interaction in a distributed erbium-doped fiber amplifier (DEDFA) is also investigated. It is shown that when the optical gain of the DEDFA is given adiabatically, the input pulse separation at which the first soliton occurs is less with orthogonal polarization. This is because the soliton pulse width is reduced due to the adiabatic soliton narrowing caused by the optical amplification.

Feasibility of 20 Gbit/s single channel transoceanic soliton transmission systems with a simple EDFA repeaters configuration has been studied. Both a simple and versatile soliton pulse generator and a polarization insensitive optical demultiplexer, which can provide a almost square shape optical gate with duration of full bit time period, have been proposed and demonstrated by using sinusoidally modulated electroabsorption modulators. The optical time-division multiplexing/demultiplexing scheme using the optical demultiplexer results in drastic improvement of bit error rate characteristics. We have experimentally confirmed that the use of alternating-amplitude solitons is an efficient way to mitigate not only soliton-soliton interaction but also Gordon-Haus timing jitter constraints in multi-ten Gbit/s soliton transmission. Timing jitter reduction using relatively wide band optical filter bas been investigated in 20 Gbit/s loop experiments and single-carrier, single-polarization 20 Gbit/s soliton data transmission over 11500 km with bit error rate of below 10-9 has been experimentally demonstrated, using the modulator-based soliton source, the optical demultiplexer, the alternation-amplitude solitons, and wide-band optical filters. Obtained 230 Tbit/skm transmission capacity shows the feasibility of 20 Gbit/s single channel soliton transoceanic systems using fully practical technologies.

Telecommunications management activities have mostly been supported by operators; however, machines are gradually playing more important roles in the management arena by utilizing computing technology. Additionally, management systems can now be networked by using standard interface specifications. The study of human and machine integration is thus essential for achieving the sophisticated management objectives of telecommunications. This paper proposes the principles for a telecommunications management integration network (TMIN), which integrates human and machine management networks, and proposes a source text description method for transferring management communication knowledge from human to machine. First, reference models are proposed for the management process and management communication. These models cover network management activities of both humans and machines. Second, the contents of the source text are clarified. Source text presents human management knowledge in a form suitable for machine-machine communication. Third, an efficient source text description method is proposed that reduces redundancy and proliferation. Finally, a means of harmonizing management information definitions with TMIN is suggested to facilitate human-machine cooperation.

Memory type polymer dispersed liquid crystal (PDLC) can be applied to a thermal addressing display device cell. Making use of its easy fabrication of large area display using flexible film substrate, the PDLC film can be used as reusable paper for direct-view mode display. In this study, memory type PDLC cells are prepared with an aluminum reflector deposited onto one side of the substrate and the reflection property in the PDLC cell with the reflector is clarified and compared to that without the reflector in the off-, on- and memory-states. The increase of contrast ratio and the decrease of driving voltage can be concurrently realized by decreasing the cell thickness by attaching the reflector. In addition, the reflected light in the off-state is bright and colorless due to the reflector, as compared with the weak, bluish reflected light in the cell without the reflector. Reflected light in the on-state and the memory-state are tinged with blue.

For two finite disjoint sets P and Q of strings over an alphabet Σ, an alphabet indexing for P, Q by an indexing alphabet Γ with |Γ||Σ| is a mapping :ΣΓ satisfying (P)(Q), where :Σ*Γ* is the homomorphism derived from . We defined this notion through experiments of knowledge acquisition from amino acid sequences of proteins by learning algorithms. This paper analyzes the complexity of finding an alphabet indexing. We first show that the problem is NP-complete. Then we give a local search algorithm for this problem and show a result on PLS-completeness.

We describe an application of InGaAs/AlGaAs VCSELs to multiple wavelength light source for optical interconnection. A flip-chip bonding technique is used to integrate the VCSELs lasing at different wavelengths. The integrated VCSELs of different wavelengths are individually grown and processed, so that one can optimize the device characteristics and the wavelength separation or distribution for multiple wavelength interconnection systems. A 9-wavelength VCSEL array with a wavelength separation of 5 nm has been successfully fabricated.

In formal specification languages for parallel processes, such as CSP and LOTOS, algebraic laws for basic operators are provided that can be used to transform process expressions, and in particular, composition of processes can be calculated using these laws. Process composition can be used to simplify and improve the specification, and also to prove properties of the specification such as deadlock absence. We here test the practicality of process composition using CSP and suggest useful techniques, working in an example with nontrivial size and complexity. We emphasize that the size explosion of composed processes, caused by interleaving of the events of component processes, is a serious problem. Then we propose a technique, which we name two-way pipe, that can be used to reduce the size of the composed process, regarded as a program optimization at specification level.