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排序方式: 共有983条查询结果,搜索用时 15 毫秒
1.
Takeshi Shiofuku Norihiro Abe Yoshihiro Tabuchi Hirokazu Taki Shoujie He 《Artificial Life and Robotics》2008,13(1):290-293
This paper presents an approach of measuring in real-time the vector of finger that is pointing to an object. DSP is used
in the operation processing unit in order to do the real-time processing. The steps include the extraction of flesh-colored
regions from an image, the labeling of the flesh-colored regions, and the detection of two characteristic positions on the
finger so that the direction that the finger is pointing at will be calculated. The entire process takes about 29 msec, which
makes it possible to have the frame rate of 34 fps. With this frame rate, this measurement approach is considered real-time
and promising to be merged into other application systems.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
2.
A serious problem in motion control is the occurrence of torque ripple. Since a direct drive (DD) motor with a magnet rotor uses a rare-earth magnet, the torque ripple is more serious than that of conventional servomotors. This paper presents an auto-compensation of torque ripple using a software-implemented torque observer. The frequency and amplitude of torque ripple can be obtained in the controller by using the estimated torque from an observer, and the autonomous generation of a compensating current component for a torque ripple is possible. The proposed algorithm has been verified by experiments. 相似文献
3.
Tada Y. Kobayashi Y. Yamabayashi Y. Matsuoka S. Hagimoto K. 《Selected Areas in Communications, IEEE Journal on》1996,14(5):914-922
Photonic networks based on wavelength division multiplexing (WDM) and optical path technologies are expected to realize flexible, transparent, and cost-effective transport networks with a large transmission capacity. This paper explores the design framework of photonic transport networks taking into consideration the operation administration and maintenance (OA&M) functions required for the successful introduction of WDM systems based on the optical path concept. From the view point of network maintenance, clear distinction is made between the optical path layer and the optical section layer to facilitate accurate and smooth failure localization. The digital multiplexing span between physical multiplexing interfaces at the end-to-end digital nodes should have the same maintenance span as the corresponding optical path. We argue that cooperative maintenance by OA&M functions at both the digital and optical layers can be a practical way of network supervision. A supervisory (SV) signal transfer method and a configuration that is suitable for the terrestrial trunk network are also indicated. As an example, a practical SV system design methodology and an actual procedure developed for a single channel optical transmission system based on optical in-line amplifiers are introduced. Furthermore, application of the developed SV system and network restoration schemes is discussed for future WDM-based photonic networks. The OA&M aspects introduced will be valuable for creating future photonic network systems 相似文献
4.
We propose to redesign a neural network used as a motion generator with bimanual coordination for upper limb prosthesis in
order to improve its learning capability. We assumed that the wearer of the prosthesis was a unilateral amputee. In our previous
work, we proposed a prosthesis control system using a neural network that learned bimanual coordination in order to implement
smooth motion with both hands. However, the previously proposed system has the problem that a neural network cannot generate
the desired motion of the prosthesis in special cases. The reason is that the motion generator calculates the desired posture
of the prosthesis from the current posture of the healthy arm only, regardless of the current posture of the prosthesis. We
propose to use the current posture of both the healthy arm and the prosthesis as neural network inputs in order to solve this
problem. In this article, we show that a single neural network whose input was the current posture of both arms could learn
the relationships of the coordinated motions of holding boxes of different sizes, and the newly proposed system can calculate
the desired motion of the prosthesis in special cases through computer simulations. 相似文献
5.
Susumu Fujii Masato Yoshiya Akuto Yumura Yohei Miyauchi Masahiro Tada Hideyuki Yasuda 《Journal of Electronic Materials》2014,43(6):1905-1915
The phonon thermal conductivity of misfit-layered Ca3Co4O9 has been calculated by perturbed molecular dynamics using a classical force field. Detailed numerical analyses reveal that, in spite of its smaller cross-sectional area, the CoO2 layer transports more heat than the thicker rock salt (RS) layer, although its local thermal conduction is more suppressed than in another layered cobaltite, Na x CoO2. The origins of these differences have been elucidated through careful examination of the atomic arrangements in each layer. Since thermal conduction in the RS layer can be reduced without deteriorating electronic properties for which the CoO2 layer is responsible, it is suggested that the RS layer should be modified to further suppress the overall in-plane thermal conductivity. Computational experiments with increasing number of Ca–O planes in the RS layer showed the opposite trend to what can be predicted based on the misfit between two dissimilar layers. Further analyses to reveal the origin of these unexpected results provide yet another strategy to further decrease the thermal conductivity, namely to control the dynamic interference between atoms across the interface between two layers. 相似文献
6.
Cao H.L. Luo Y. Nakano Y. Tada K. Dobashi M. Hosomatsu H. 《Photonics Technology Letters, IEEE》1992,4(10):1099-1102
Grating duty factor strongly affects the performance of gain-coupled (GC) distributed feedback (DFB) laser diodes with an absorptive grating. Through numerical analysis the authors have found an optimum value in the duty factor for their low threshold operation. The minimum threshold gain achievable at this optimum duty factor is found to be almost independent of the order of the grating. According to this prediction, the authors have fabricated GaAlAs/GaAs GC DFB lasers with a third-order absorptive grating where the grating duty factor has been made close to the theoretical optimum value. In 200-μm-long devices with both facets as-cleaved, low CW threshold current of 25 mA, external efficiency of 0.5 mW/mA, and SMSR as high as 45 dB have been obtained, which is qualitatively consistent with the analysis. High yield of single mode oscillation seems to be the result of the gain coupling 相似文献
7.
M. Kato K. Tada Y. Nakano 《Photonics Technology Letters, IEEE》1996,8(6):785-787
We have fabricated a multiple-quantum-well (MQW) waveguide optical modulator incorporating tensile strain and quantum well with mass-dependent width (QWMDW) for the first time. The structure was built on a strain relief InAlGaAs buffer layer grown on a GaAs substrate. Polarization-independent modulation with more than -10 dB extinction (at 8 V reverse voltage) was achieved over a very wide operating range, from 858 to 886 nm wavelength. 相似文献
8.
9.
Noda M. Hosogi K. Sumitani K. Nakano H. Nishitani K. Otsubo M. Makino H. Tada A. 《Electron Devices, IEEE Transactions on》1991,38(12):2590-2598
A GaAs MESFET with a partially depleted p layer that has a specific application to SRAMs has been developed. The short-channel effect is well suppressed for gate lengths down to 0.5 μm by a rather dense p layer buried under the channel. Its acceptor ion dose is as high as 2×1012 cm-2, which corresponds to a partially depleted condition. As for applications for SRAMs, it is possible to attain fully functional 7-ns 4-kb SRAMs that are operative at 75°C by using the FET with a 1-μm gate. A chip yield of 22% has been achieved in a 3-in wafer 相似文献
10.
Murakami M. Matsuda T. Maeda H. Tada Y. Imai T. 《Lightwave Technology, Journal of》2001,19(11):1665-1674
This paper describes the WDM upgrading of a submarine optical amplifier system installed for single-channel transmission in commercial use. The key technologies used include 10-Gb/s high-speed forward error correction, preemphasis to overcome the optical passband-width constraint, optimized signal pulse format that leads to partial return-to-zero (PRZ) signaling, and dispersion compensation to suppress the degradation caused by fiber nonlinearity and dispersion. It also reports field experimental results on upgraded system performance. The results confirm that simply upgrading the terminal equipment allows the transmission capacity of a submersed line consisting of submarine repeaters and cables to be flexibly increased from 10 Gb/s to 40 Gb/s per fiber pair 相似文献