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41.
Robust DOA estimation and target docking for mobile robots 总被引:1,自引:1,他引:0
Direction of arrival (DOA) guided automated target acquisition and docking system is proposed for mobile robots employing
the dual-directional antenna system. The dual-directional antenna estimates the DOA of the signal of interest using the ratio
of the signal strengths between two adjacent antennas. In practice, DOA estimation poses a significant technical challenge,
since the RF signal is easily distorted by the environmental conditions. Therefore, the robot often loses its way in an electromagnetically
disturbed environment. To cope with this problem, a robust DOA estimation algorithm is developed based on Kalman filtering.
This algorithm allows the robot to reduce the potential error in the estimated DOA, and adjust the robot’s heading to the
target transponder without needing to know the positions of current and previous measurements in a global coordinate system.
The simulation and experiment results clearly demonstrate that the mobile robot equipped with the developed system is able
to dock to a target transponder in an indoor environment partially occupied by obstacles. 相似文献
42.
43.
44.
H Düppe P G?rdsell BS Hanson O Johnell BE Nilsson 《Canadian Metallurgical Quarterly》1996,50(2):170-173
OBJECTIVE: To study the effects of participation rate in sampling on "normative" bone mass data. DESIGN: This was a comparison between two randomly selected samples from the same population. The participation rates in the two samples were 61.9% and 83.6%. Measurements were made of bone mass at different skeletal sites and of muscle strength, as well as an assessment of physical activity. SETTING: Malm?, Sweden. SUBJECTS: There were 230 subjects (117 men, 113 women), aged 21 to 42 years. RESULTS: Many subjects participated in both studies (163). Those who took part only in the study with the higher participation rate (67) almost invariably had higher values for bone mass density at the sites measured (up to 7.6% for men) than participants in the study with the lower participation rate. No differences in muscle strength were recorded. CONCLUSION: A high degree of compliance is important to achieve a reliable result in determining normal values in population based studies. 相似文献
45.
Jun Wang Bormin Huang Jiaji Wu Jong‐Wha Chong 《Journal of the Society for Information Display》2011,19(8):551-560
Abstract— Overdrive is commonly used to reduce the liquid‐crystal response time and motion blur in liquid‐crystal displays (LCDs). However, overdrive requires a large frame memory in order to store the previous frame for reference. In this paper, a lapped transform‐based codec (LTC) is proposed to reduce the frame memory needed for LCD overdrive. In the latest literature, a directional prediction‐based codec (DPC) employs eight directional predictions, which takes up a large percentage of the computational complexity of the codec and does not consider the de‐correlation of the inter‐blocks. Therefore, the LTC first uses the lapped transform to decompose the correlation of the inter‐blocks in the YUV color space. A hadamard transform is then used for energy compaction. The reordered coefficients are pre‐quantized and encoded using the proposed adaptive bit‐plane coding (ABPC) method for a simple hardware implementation. The simulation results show that the proposed LTC significantly improves the DPC in both subjective and objective performance and outperforms the block truncation coding (BTC) and adaptive multi‐level BTC (AM‐BTC), which have been described in the literature. 相似文献
46.
1958(2)
Manifold-ranking based topic-focused multi-document summarization
2007
An Introduction to Kolmogorov Complexity and Its Applications
1997
The use of MMR,diversity-based reranking for reordering documents and producing summaries
1998
Centroid-based summarization of multiple documents
2004(6)
A trainable document summarizer
1995
Impact of linguistic analysis on the semantic graph coverage and learning of document extracts
2005
Document summarization using conditional random fields
2007
Adasum:An adaptive model for summarization
2008
Lexpagerank:Prestige in multidocument text summarization
2004
Mihalcea R.Taran P
Textrank-Bring order into texts
2004
Mihalcea R.Tarau P
A language independent algorithm for single and multiple document summarization
2005
Wan X.Yang J.Xiao J
Towards an iterative reinforcement approach for simultaneous document summarization and keyword extraction
2007
Wan X
An exploration of document impact on graph-based multi-document summarization
2008
Bennett C H.Gács P.Li M.Vitányi P M,Zurek W H
Information distance
1998(4)
Li M.Badger J H.Chen X.Kwong S,Kearney P,Zhang H
An information-based sequence distance and its application to whole mitochondrial genome phylogeny
2001(2)
Li M.Chen X.Li X.Ma B Vitányi P M
The similarity metric
2004(12)
Long C.Zhu X.Li M.Ma B
Information shared by many objects
2008
Benedetto D.Caglioti E.Loreto V
Language trees and zipping
2002(4)
Bennett C H.Li M.Ma B
Chain letters and evolutionary histories
2003(6)
Cilibrasi R L.Vitányi P M
The Google similarity distance
2007(3)
Zhang X.Hao Y.Zhu X.Li M
Information distance from a question to an answer
2007
Ziv J.Lempel A
A universal algorithm for sequential data compression
1977(3)
Lin C Y.Hovy E
Automatic evaluation of summaries using n-gram co-occurrence statistics
2003
Nenkova A.Passonneau R.Mckeown K
The pyramid method:Incorporating human content selection variation in summarization evaluation
2007(2)
47.
This paper presents a passive control scheme for a force reflecting bilateral teleoperation system with a varying time communication delay. To improve the stability and performance of the system, the master and slave must be coupled dynamically via a transmission network through which the force and velocity are communicated bilaterally. However, the time delay caused by various factors, such as the transmission distance, network congestion, and communication bandwidth, is a long-standing impediment to bilateral control that can destabilize the system. In this study, we investigated how a varying time delay affects the stability of a teleoperation system. A new optimal adaptive approach based on a passive control scheme was designed bilaterally for both the master and slave sites. Extra variables were transmitted together with the wave variables in the scattering system. The proposed scheme achieved both passive control, and an acceptable tracking performance. The tracking performance was demonstrated using a computer simulation of varying time delays in a bilateral teleoperation system. 相似文献
48.
Mingyuan Zhao Chong Fu Luping Ji Ke Tang Mingtian Zhou 《Expert systems with applications》2011,38(5):5197-5204
Support vector machines (SVM) are an emerging data classification technique with many diverse applications. The feature subset selection, along with the parameter setting in the SVM training procedure significantly influences the classification accuracy. In this paper, the asymptotic behaviors of support vector machines are fused with genetic algorithm (GA) and the feature chromosomes are generated, which thereby directs the search of genetic algorithm to the straight line of optimal generalization error in the superparameter space. On this basis, a new approach based on genetic algorithm with feature chromosomes, termed GA with feature chromosomes, is proposed to simultaneously optimize the feature subset and the parameters for SVM.To evaluate the proposed approach, the experiment adopts several real world datasets from the UCI database and from the Benchmark database. Compared with the GA without feature chromosomes, the grid search, and other approaches, the proposed approach not only has higher classification accuracy and smaller feature subsets, but also has fewer processing time. 相似文献
49.
In financial service industry, service improvement should be considered from process viewpoint and customer viewpoint because the value creation is ultimately linked with internal business processes on the back office and customers are involved as a co-producer of value. In this perspective, customer complaints through call centers are adequate to support the analysis for service improvement in financial service industry. In this study, we propose a web-based decision support system for business process management employing customer complaints, namely Voice of the Customer (VOC), and its handling data for service improvement. It involves VOC conversion for data enrichment and includes analysis of summarization, exception and comparison. The proposed system is evaluated on a major credit card company in South Korea. 相似文献
50.