An optical fiber multi-function device consisting of a single gradient-index-rod lens and a multi-facet blazed reflection grating is proposed to simultaneously realize functions of wavelength demultiplexing and optica...
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An optical fiber multi-function device consisting of a single gradient-index-rod lens and a multi-facet blazed reflection grating is proposed to simultaneously realize functions of wavelength demultiplexing and optical signal distribution in a multimode optical fiber transmission system. We analyzed the demultiplexing characteristics and the tolerance of optical components using the ray trace method. This device can realize not only low loss optical signal distribution but also offers improved demultiplexing characteristics in comparison with the previously proposed demultiplexer-multiposition switch. The following characteristics are expected from the design using commercially available optical components: a working band of 0.64-0.88 mu m, channel separation of 34-36 nm, 3 dB bandwidth of 27-28 nm, channel cross-talk of less than -40 dB and minimum excess insertion loss of 0.9-2.1 dB.
This paper presents a new upper bound on overall bit error rate (BER) for a concatenated code which consists of an inner convolutional code and an outer interleaved Reed-Solomon code. The upper bound on BER is derived...
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This paper presents a new upper bound on overall bit error rate (BER) for a concatenated code which consists of an inner convolutional code and an outer interleaved Reed-Solomon code. The upper bound on BER is derived based on a lower bound on the effective minimum distance of the concatenated code. This upper bound can be used for the cases when the interleaver size is small such that the conventional upper bound is not applicable.
The dispersion characteristics of two nonidentical coupled microstrip lines and N identical coupled microstrip lines are analyzed using the coupled-mode theory combined with Galerkin's moment method in spectral do...
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The dispersion characteristics of two nonidentical coupled microstrip lines and N identical coupled microstrip lines are analyzed using the coupled-mode theory combined with Galerkin's moment method in spectral domain. In this approach, the solutions to the original coupled microstrips are approximated by a linear combination of eigenmode solutions associated with the isolated single microstrip, and the reciprocity relation is used ro derive the coupled-mode equations. The coupling coefficients are given by the simple overlap integrals in spectral domain between the eigenmode fields and currents of the individual microstrips. It is shown that the numerical results are in very good agreement with those obtained by the direct Galerkin's moment method over a broad range of weak to moderately strong coupling.
We propose and demonstrate a unique optical signal inverter using injection locking in coupled semiconductor lasers with a narrow-band Fabry-Perot (F-P) etalon. In this method, one laser diode is operated as a master ...
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We propose and demonstrate a unique optical signal inverter using injection locking in coupled semiconductor lasers with a narrow-band Fabry-Perot (F-P) etalon. In this method, one laser diode is operated as a master laser to control the injection locking and the other is operated as a slave laser. By setting of the F-P etalon inside the coupled cavity, the locking and unlocking states can be allocated to the lon and high levels for the output power respectively. Under direct modulation of the master laser, the inverted light signal is available from the output port. This optical inverter can be operated at an output power of similar to 7 mW.
The objective of this study was to identify a biologically inspired intelligent control process that can solved the robot dynamic hybrid control problem. This control problem was investigated as “blind-tracking” tas...
The objective of this study was to identify a biologically inspired intelligent control process that can solved the robot dynamic hybrid control problem. This control problem was investigated as “blind-tracking” tasks for a human operator considering as equivalent problem of force and position control for a robotic hand. To perform the blind-tracking task, three levels of coordination was required, namely; learning level, skill level and adaptation level. These levels are representing the human cognitive agents. From this light, a control model was presented for a robotic hand to perform hybrid (force/position) control. The proposed control process was justified through the different type of human operator’s performance. Naturally the human operators can be indexed from their past experiences, skills, and, guesses through their age and work habit. Thus the elements of the intelligent control model can be established.
Since the layout compaction problem is dual to the minimum cost flow problem, flow algorithms can be applicable to the layout compaction. In this paper, an existing flow algorithm is investigated in terms of the layou...
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Since the layout compaction problem is dual to the minimum cost flow problem, flow algorithms can be applicable to the layout compaction. In this paper, an existing flow algorithm is investigated in terms of the layout compaction, and a fast flow algorithm is devised on the basis of the primal-dual method. Experimental results show that the proposed algorithm is the fastest dedicatedly for the compaction problem.
A new type of optical actuator is proposed by using the bimetal( Ni-Cr-Fe/36Ni-Fe ), which is to be developed for a optical micro-mechatronics system. The paper describes fundamental characteristics on a larger actuat...
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A new type of optical actuator is proposed by using the bimetal( Ni-Cr-Fe/36Ni-Fe ), which is to be developed for a optical micro-mechatronics system. The paper describes fundamental characteristics on a larger actuator both theoretically and experimentally. In order to identify some unknown parameters of the actuator, the results simulated by FEM are presented, and are compared with the experimental data. Furthermore, a numerical experiment on the optical micro-actuator is carried out to analyze step characteristic by FEM. Finally, the development of helical actuator is also provided.
In this paper, we will pay attention to the spline wavelets which are real-type wavelets and have good characteristics such as compact support, the symmetric property and so on. We propose an RI-Spline wavelet which i...
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In this paper, we will pay attention to the spline wavelets which are real-type wavelets and have good characteristics such as compact support, the symmetric property and so on. We propose an RI-Spline wavelet which is complex-type wavelet and has the compact support, and we confirm the effectivity of this wavelet in the continuous case by a model signal. Next, for the application of the spline wavelets to control golf sound, we examine the relation between golf impact sound and vibration velocity of golf club. As a result, it is found that using the continuous and discrete wavelet transform together is effective for the analysis of the sound and the vibration. This technique will be useful for the unsteady signal analysis.
This paper presents a new technique to derive features for images that are translated, scaled equally/unequally and rotated. The problem is formulated using conventional regular moments. It is shown that the conventio...
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This paper presents a new technique to derive features for images that are translated, scaled equally/unequally and rotated. The problem is formulated using conventional regular moments. It is shown that the conventional regular moment-invariants remain no longer invariant when the image is scaled unequally in the x- and y-directions. A method is proposed to form moment-invariants that do not change under such unequal scaling. The newly formed moments are also invariant to translation and reflection. However, it is not invariant for images that are rotated. A neural network is trained to estimate the angle of rotation; it is then used to derive the invariant moments for images that are unequally scaled, translated and rotated. computer simulation results are also included to show the validity of the method proposed.
Usually, the subspace-based state-space system identification algorithms are focused on discrete-time models, which may cause some numerical problems when the sampling interval is small. This paper proposes an algorit...
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Usually, the subspace-based state-space system identification algorithms are focused on discrete-time models, which may cause some numerical problems when the sampling interval is small. This paper proposes an algorithm of subspace-based state-space system identification for continuous-time systems from sampled input-output data. The ω — operator ω = ( p - α)/( p + α) where p denotes a differential operator and α > 0, is introduced to avoid direct numerical differentiations. And the ω — operator state-space model identified by the 4SID method can be transformed back to the common continuous-time state-space model. The numerical superiority of the ω — operator approach compared to some other methods is verified through simulation study.
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