A nonrecursive algorithm for address generating during the Hilbert scan of image buffer is presented. The technique is based on two level look-up tables. For large images, the additional storage is less than one percent of image buffer size. The present implementation of the algorithm is only about two times slower than the raster scan. Three level lool-up tables are generated if image data array is too big to fit image buffer and it is accessed from a mass storage. Software tools were developed for look-up tables generating and for the convenient use of the algorithm from C programs.

This letter presents an automatic repeat request/adaptive forward error correction (ARQ/AFEC) hybrid system which adaptively alters the error-correcting capability according to channel state using a nonsystematic Reed-Solomon code. Frame efficiency is also presented.

This article briefly reviews the elementary concepts of the quantum communication theory. Specific topics on some of the optical communications by utilizing quantum nature of light wave will be discussed, especially for applications to information transmission of classes of squeezed state exceeding the present limitations, and for quantum coding theory relevant the photon communications.

A polynomial for automatic contour vector coding of the binary picture pattern is proposed. The proposed polynomial is the expansion of the Bezier polynomial to have the more flexibility. It is easy to be implemented and the generated curve is easy to be estimated from the given control points. This advantage is confirmed by the automatic contour coding of both English and Japanese fonts.

An iterative numerical method is used to synthesize a given non-series-parallel minimal LC network with a prescribed driving-point function. Converting the given network to a series-parallel network by a certain reduction method produces the initial element values. The concept of sensitivities of a network's evaluating equations with respect to the element values is used to achieve a convergent solution. The procedure is applicable to canonic and non-canonic networks alike. The element values can be determined to any degree of accuracy desired.

An influence of a waveguide facet reflection on hybrid-integrated LD gate characteristics was studied. The gate gain is sensitive to a change in the waveguide-gate gap width. An AR coating of the waveguide facet is essential for suppressing the gain-ripple due to a change in the gap width.

To study lower sideband enhancement, three kinds of modulation methods are applied to recording. Compared with results of experiments using a VCR and simulations, it is concluded that the order of magnitude of lower sideband enhancement is AM, Dual-frequency, FM with lower modulation index.

2.4 Gbit/s 4 WDM transmission experiment using a traveling-wave laser amplifier has been demonstrated. The result indicated that there exists the appropriate optical input power to the laser amplifier in order to minimize both interchannel crosstalk penalty and beat noise induced penalty.

The propagation constant, the effective index, the effective guide thickness and the refractive index has been measured by using the method of a variable spacing of a high-index film and the waveguide surface. The spacing can be varied by the electrostrictive element.

We have pressented here, for the Control Unit (CU) of Benes Interconnection Network (IN), a new fast parallel computational model named as; Cyclic Cube Engine (CCE), which depends on the Cyclic Cube topology, where the total number of processing elements is φ such that φN(11/h), h is an arbitrary integer, such that 2hlog N. N is number of the data items consisting the permutation. We have presented on this model parallel algorithm for parallel settings of Benes IN in order to realize arbitrary permutation with a setting time of O(h log2 N); (assuming N is base 2) using φN(11/h) processors (i.e., φN). This bound could be achieved by accelerating the parallel setting algorithm by function call of another very fast algorithm named as the accelerator. We have also, proven in the appendix of this paper, that our construction is within the lower bound of setting Benes IN for arbitrary permutation for general nonshared model when φN. Using these algorithms we have constracted a fast parallel setting algorithm to set the switches of Benes IN for arbitrary permutation in parallel time of O(h log2 N) where is hlog2 N. The parallel setting algorithm has been constructed depending on the CCE as the main computational structure suitable for setting Benes IN in parallel.

Two new segmentation methods for Japanese syllable recognition were proposed and were experimentally compared. In one of these methods, the adaptive power envelope template was compared with the logarithmic power envelope of input speech, and the most suitable position was searched. The second difference of the clipped power envelope was calculated and the point where is gave the maximum value was detected as the segment boundary in another method. A segmentation rate improvement of 2.1%, and the accurate syllable recognition rate of 90.5% in average for 10 speakers were obtained by the later method.

An intersectional optical switch structure based on the field induced refractive index variation was fabricated by the use of LPE grown GaInAsP/InP MQW wafer. The first switching operation in a MQW intersectional switch structure was achieved. The field induced refractive index variation in quantum well was estimated to be around 0.45% at the applied field of 13 V/µm from the experimentally obtained switching ratio. Finally a small X-type modulator with low chirp, low power saturation is proposed which make use of the reflection phenomenon caused by field induced rafractive index variation instead of absorption phenomenon as in conventional absorption type modulators.

In our previous paper, we had proved that the non-closure properties of the class of sets accepted by three-way two-dimensional alternating finite automata (L[TR2-AFA]) under several operations, i.e., row catenation, row closure, row cyclic closure, and projection operations. This letter investigates the remaining closure properties of L[TR2-AFA], especially under column-directional operations, showing that this class L[TR2-AFA] is not closed under column catenation, column closure, or column cyclic closure operations, too. Thus, we have settled the almost closure properties of L[TR2-AFA].

We consider the computation of an upper bound to error probability in Trellis-Coded Modulation (TCM) schemes in sequence dependent channnels. In its most common form, the pairwise-state" technique is applicable to this class of channels. However, it entails a degree of complexity that may not acceptable, because the dimension of the matrices involved in pairwise-state calculations is the square of the number of states, and the number of states, say N, equals the product of the code states and of the channel states. In this paper, we derive an error probability bound based on a computational technique which avoids the consideration of N2N2 matrices. It is based on the computaion of the transfer function of a graph with N1 nodes, and whose branch labels are NN matrices rather than scalars. we also describe some looser bounds which simplify the computation of error probability over intersymbol interference (ISI) channels, and show numerical results of the methods applied to trellis coded 16-QAM with 2-symbol ISI.

There exists a method to simultaneously obtain test paths and test data in conformity with the structure and path conditions of objective program. This paper discusses a method to simultaneously obtain a set of test paths of satisfying a desired coverage rate and test data of testing the test paths.

Described is FM modulation distortion in the light output of a semiconductor laser frequency-modulated with a triangular wave current. The variation of instantaneous FM modulation efficiency is caused by both the thermal effect of FM modulation and the optical feedback from a focusing lens.

To improve picture quality of a color-under VCR, chrominance bandwidth expansion is studied using subsampling technique. It is concluded that line offset subsampling and field offset subsampling are effective methods of improving reproduced picture quality.

This letter describes the potential attenuation mechanism of the charged human body due to walking on the polymer floor. A model is proposed for analyzing the human body potential. The validity is verified by measuring the potentials of the charged acrylic sheet.

Quadrature amplitude modulation (QAM) was found to suitable for the bandpass type frequency characteristic of magnetic recording/reproducing channels. A method of 20 Mbps signal recording using 32 QAM coded modulation is described.