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101.
Stephen G. McGill Seung‐Joon Yi Hak Yi Min Sung Ahn Sanghyun Cho Kevin Liu Daniel Sun Bhoram Lee Heejin Jeong Jinwook Huh Dennis Hong Daniel D. Lee 《野外机器人技术杂志》2017,34(4):775-801
This paper describes Team THOR's approach to human‐in‐the‐loop disaster response robotics for the 2015 DARPA Robotics Challenge (DRC) Finals. Under the duress of unpredictable networking and terrain, fluid operator interactions and dynamic disturbance rejection become major concerns for effective teleoperation. We present a humanoid robot designed to effectively traverse a disaster environment while allowing for a wide range of manipulation abilities. To complement the robot hardware, a hierarchical software foundation implements network strategies that provide real‐time feedback to an operator under restricted bandwidth using layered user interfaces. Our strategy for humanoid locomotion includes a backward‐facing knee configuration paired with specialized toe and heel lifting strategies that allow the robot to traverse difficult surfaces while rejecting external perturbations. With an upper body planner that encodes operator preferences, predictable motion plans are executed in unforeseen circumstances. These plans are critical for manipulation in unknown environments. Our approach was validated during the DRC Finals competition, where Team THOR scored three points in 18 min of operation time, and the results are presented along with an analysis of each task. 相似文献
102.
Distributed
filtering and synchronization of diffusively state‐coupled heterogeneous systems 下载免费PDF全文
This paper studies distributed filtering‐based ssynchronization of diffusively state‐coupled heterogeneous systems. For given heterogeneous subsystems and a network topology, sufficient conditions for the filtering‐based synchronization are developed with a guaranteed performance. The estimation and synchronization error dynamics are obtained in a decoupled form, and it is shown that the filter and the controller can be designed separately by LMIs. The feasibility of the proposed design method using LMIs is discussed, and the main results are validated through examples with various setup. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
103.
A rate-distortion (R-D) optimized progressive coding algorithm for three-dimensional (3D) meshes is proposed in this work. We propose the prioritized gate selection and the curvature prediction to improve the connectivity and geometry compression performance, respectively. Furthermore, based on the bit plane coding, we develop a progressive transmission method, which improves the qualities of intermediate meshes as well as that of the fully reconstructed mesh, and extend it to the view-dependent transmission method. Experiments on various 3D mesh models show that the proposed algorithm provides significantly better compression performance than the conventional algorithms, while supporting progressive reconstruction efficiently. 相似文献
104.
Chin-Gook Lhee Jae-Sam Park Hyun-Sik Ahn Do-Hyun Kim 《Fuzzy Systems, IEEE Transactions on》2001,9(2):343-348
In this paper, a fuzzy logic controller (FLC) is designed based on the similarity between the FLC and the sliding mode control (SMC). The proposed scheme provides the sliding mode-like FLC with fast self-tuning the dead-zone parameters (boundary layer thickness) under parameter variations of the controlled system. To show the validity and the effectiveness of the proposed control method, simulations are performed for the position control of a rotary inverted pendulum 相似文献
105.
The filtering problem for continuous‐time linear systems with unknown parameters is considered. A new suboptimal filter is herein proposed. It is based on the optimal mean‐square linear combination of the local Kalman filters. In contrast to the optimal weights, the suboptimal weights do not depend on current observations; thus, the proposed filter can easily be implemented in real‐time. Examples demonstrate high accuracy and efficiency of the suboptimal filter. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
106.
Ahn TS Al-Kaysi RO Müller AM Wentz KM Bardeen CJ 《The Review of scientific instruments》2007,78(8):086105
A new method is presented for analyzing the effects of self-absorption on photoluminescence integrating sphere quantum yield measurements. Both the observed quantum yield and luminescence spectrum are used to determine the self-absorption probability, taking into account both the initial emission and subsequent absorption and reemission processes. The analysis is experimentally validated using the model system of the laser dye perylene red dispersed in a polymer film. This approach represents an improvement over previous methods that tend to overestimate the true quantum yield, especially in cases with high sample absorbance or quantum yield values. 相似文献
107.
Capturing and reusing knowledge in engineering change management: A case of automobile development 总被引:2,自引:0,他引:2
Hong Joo Lee Hyung Jun Ahn Jong Woo Kim Sung Joo Park 《Information Systems Frontiers》2006,8(5):375-394
The development of complex products, such as automobiles, involves engineering changes that frequently require redesigning
or altering the products. Although it has been found that efficient management of knowledge and collaboration in engineering
changes is crucial for the success of new product development, extant systems for engineering changes focus mainly on storing
documents related to the engineering changes or simply automating the approval processes, while the knowledge that is generated
from collaboration and decision-making processes may not be captured and managed easily. This consequently limits the use
of the systems by the participants in engineering change processes. This paper describes a model for knowledge management
and collaboration in engineering change processes, and based on the model, builds a prototype system that demonstrates the
model’s strengths. We studied a major Korean automobile company to analyze the automobile industry’s unique requirements regarding
engineering changes. We also developed domain ontologies from the case to facilitate knowledge sharing in the design process.
For achieving efficient retrieval and reuse of past engineering changes, we used a case-based reasoning (CBR) with a concept-based
similarity measure.
相似文献
Hong Joo LeeEmail: |
108.
109.
M. C. Downer H. Ahn D. H. Reitze X. Y. Wang 《International Journal of Thermophysics》1993,14(3):361-370
Femtosecond pump-probe reflectance of graphite and diamond targets following intense laser irradiation is used to measure the optical properties of the pressurized liquid carbon phase while it retains an optically sharp surface before expanding hydrodynamically as a hot plasma. These measurements allow the historically elusive liquid phase of carbon to be characterized optically for the first time. A Drude dielectric model of the reflectance spectrum 1 ps after excitation just above the melting threshold reveals a poorly conducting liquid metal with a dc resistivity 625±75 · cm. The optically determined resistivity decreases with increasing sample excitation. The initial stages of hydrodynamic surface expansion of Al, W, and C targets are also quantitatively characterized by time-resolved reflectance, revealing the expansion speed as well as further dielectric properties of the high-temperature-pressure phase.Paper presented at the Third Workshop on Subsecond Thermophysics, September 17–18, 1992, Graz, Austria. 相似文献
110.
Artificial neural networks (ANNs) have been popularly applied for stock market prediction, since they offer superlative learning
ability. However, they often result in inconsistent and unpredictable performance in the prediction of noisy financial data
due to the problems of determining factors involved in design. Prior studies have suggested genetic algorithm (GA) to mitigate
the problems, but most of them are designed to optimize only one or two architectural factors of ANN. With this background,
the paper presents a global optimization approach of ANN to predict the stock price index. In this study, GA optimizes multiple
architectural factors and feature transformations of ANN to relieve the limitations of the conventional backpropagation algorithm
synergistically. Experiments show our proposed model outperforms conventional approaches in the prediction of the stock price
index. 相似文献