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101.
Real robots should be able to adapt autonomously to various environments in order to go on executing their tasks without breaking
down. They achieve this by learning how to abstract only useful information from a huge amount of information in the environment
while executing their tasks. This paper proposes a new architecture which performs categorical learning and behavioral learning
in parallel with task execution. We call the architectureSituation Transition Network System (STNS). In categorical learning, it makes a flexible state representation and modifies it according to the results of behaviors.
Behavioral learning is reinforcement learning on the state representation. Simulation results have shown that this architecture
is able to learn efficiently and adapt to unexpected changes of the environment autonomously.
Atsushi Ueno, Ph.D.: He is a research associate in the Artificial Intelligence Laboratory at the Graduate School of Information Science at the
Nara Institute of Science and Technology (NAIST). He received the B.E., the M.E., and the Ph.D. degrees in aeronautics and
astronautics from the University of Tokyo in 1991, 1993, and 1997 respectively. His research interest is robot learning and
autonomous systems. He is a member of Japan Association for Artificial Intelligence (JSAI).
Hideaki Takeda, Ph.D.: He is an associate professor in the Artificial Intelligence Laboratory at the Graduate School of Information Science at the
Nara Institute of Science and Technology (NAIST). He received his Ph.D. in precision machinery engineering from the University
of Tokyo in 1991. He has conducted research on a theory of intelligent computer-aided design systems, in particular experimental
study and logical formalization of engineering design. He is also interested in multiagent architectures and ontologies for
knowledge base systems. 相似文献
102.
103.
Tsuneaki Matsudaira Hideaki Itoh Shigeharu Naka Hiroshi Hamamoto Mikio Obayashi 《Journal of Materials Science》1988,23(1):288-292
TiB2 powder was synthesized by solid state reaction using amorphous boron and TiN as a source of titanium. The TiB2 formation did not occur at all in a nitrogen atmosphere even at 1400° C. TiB2 formed above 1100° C in argon and hydrogen atmospheres. The only crystalline phase of TiB2 powder was favourably synthesized at 1400° C for 360 min in an argon atmosphere from a starting powder with a composition containing excess boron (B/Ti = 2.2). The synthesized powder was well dispersed and had a particle size of 0.5 to 2 µm. The powder activity was evaluated by sintering at 4 G Pa and 1300 to 1600° C for 15 min. 相似文献
104.
The thermal conductivity of KNO3-NaNO3 mixtures was measured by a modified transient hot-wire method using liquid metal in a capillary as a heat source. The method was developed for measurements on electrically conducting liquids at high temperatures. Measurements were performed on pure NaNO3 and its three mixtures with KNO3 in the temperature range from 498 to 593 K. 相似文献
105.
Reliable and well-established methods to measure the thermal conductivity of gases are available only in the moderate temperature range, namely, up to about 1000 K. In the present study, a set of the most probable thermal conductivity values of components of gaseous combustion products in a wide range of temperatures has been obtained through an optimum combination of three procedures: critical assessment of available data in the moderate temperature range, experimental determination by the shock-tube method at high temperatures, and theoretacal estimation of temperature dependence in the intermediate temperature range. Among the components of combustion products, one monatomic gas and one diatomic gas, namely, argon and nitrogen, were studied in the present paper. The shock-tube measurements have been performed in the temperature ranges 1000–4500 K for argon and 500–2200 K for nitrogen. The results of the critical evaluation and the shock-tube measurements have been combined with the aid of theoretically assumed temperature dependence of the thermal conductivity.Invited paper presented at the Ninth Symposium on Thermophysical Properties, June 24–27, 1985, Boulder, Colorado, U.S.A. 相似文献
106.
Hideaki Itoh Shigeharu Naka Tsuneaki Matsudaira Hiroshi Hamamoto 《Journal of Materials Science》1990,25(1):533-536
A sintered compact of titanium diboride (TiB2) was prepared by hot pressing of the synthesized TiB2 powder, which was obtained by a solid-state reaction between TiN and amorphous boron. Densification of the sintered compact occurred at 20 MPa and 1800° C for 5 to 60 min with the aid of a reaction sintering, including the TiB2 formation reaction between excess 20 at % amorphous boron in the as-synthesized powder (TiB2 + 0.2B) and intentionally added 10 at % titanium metal. A homogeneous sintered compact of a single phase of TiB2, which was prepared by hot pressing for 30 min from the starting powder composition [(TiB2 + 0.2B) + 0.1 Ti], had a fine-grained microstructure composed of TiB2 grains with diameters of 2 to 3 m. The bulk density was 4.47 g cm–3, i.e. 98% of the theoretical density. The microhardness, transverse rupture strength and fracture toughness of the TiB2 sintered compact were 2850 kg mm–2, 48 kg mm–2 and 2.4 MN m–3/2, respectively. The thermal expansion coefficient increased with increasing temperature up to 400° C and had a constant value of 8.8 x 10–6 deg–1 above 500° C. 相似文献
107.
Kimikazu Sasa Tsutomu Takahashi Yuki Tosaki Yuki Matsushi Keisuke Sueki Michiko Tamari Takahiro Amano Toshiyuki Oki Shozo Mihara Yoshihiro Yamato Yasuo Nagashima Kotaro Bessho Norikazu Kinoshita Hiroshi Matsumura 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(7-8):871-875
We present the current status and research programs of a multinuclide accelerator mass spectrometry (AMS) system on the 12UD Pelletron tandem accelerator at the University of Tsukuba (Tsukuba AMS system), Japan. A maximum terminal voltage of 12 MV is available for the AMS system. The Tsukuba AMS system can measure environmental levels of long-lived radioisotopes of 14C, 26Al, 36Cl and 129I by employing a molecular pilot beam. Recently, enhancements in AMS techniques and equipment, including sample preparation, the ion source and the data acquisition system, have improved the performance of 36Cl-AMS. The standard deviation of fluctuations is typically ±2%, and the machine background level for the 36Cl/Cl ratio is lower than 1 × 10?15 with a halite sample. We have measured over 500 samples in 1 year, including samples for earth and environmental sciences and nuclear safety research. 相似文献
108.
Hideaki Yamashita 《IIE Transactions》2001,33(10):889-895
We study automated guided vehicle systems that contain multiple vehicles. Each vehicle transports an item from a certain point to its destination. The inter-arrival time of items to each node is assumed to be independently and geometrically distributed. Each node has an infinite buffer capacity, and thus no item is lost. The deadhead time of the empty vehicle and the transportation time of the loaded vehicle are assumed to be arbitrarily distributed. We propose two empty vehicle dispatching policies, and numerically calculate the waiting time distributions of the items for each policy using a state-space reduction technique for Markov chains. Several examples are given to demonstrate the advantages and disadvantages of each policy. 相似文献
109.
This paper deals with a dynamic voltage restorer (DVR) characterized by installing the shunt converter at the load side. The DVR can compensate for the load voltage when a voltage sag appears in the supply voltage. An existing DVR requires a large capacitor bank or other energy‐storage elements such as double‐layer capacitors or batteries. The DVR presented in this paper requires only a small DC capacitor intended for smoothing the DC‐link voltage. Moreover, three control methods for the series converter are compared and discussed to reduce the series‐converter rating, paying attention to the zero‐sequence voltages included in the supply voltage and the compensating voltage. Experimental results obtained from a 200‐V, 5‐kW laboratory system are shown to verify the viability of the system configuration and the control methods. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(3): 73–82, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20460 相似文献
110.
Zahrul Fuadi Koshi Adachi Hideaki Ikeda Hisataka Naito Koji Kato 《Tribology Letters》2009,33(3):169-178
In this paper, a fundamental mechanism for creep-groan generation is investigated by adopting a simple yet effective caliper-slider
experimental model. Contact condition, which is a function of three parameters, namely normal force, contact roughness, and
material combination, is connected with the creep-groan phenomenon in terms of contact stiffness. Creep-groan generation is
determined by analyzing the frequency characteristic of the generated vibration acceleration when the sliding commences due
to a simultaneous application and release of force in the tangential and normal directions, respectively. As per the obtained
results, creep-groan occurrence or absence in the employed experimental model may be classified into three regions based upon
the value of the contact stiffness, i.e., occurrence, non-occurrence, and mixed regions. The results also indicate that creep-groan
occurrence in this caliper-slider experimental model can be avoided by controlling the value of contact stiffness in an effective
manner. 相似文献