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A canonical neural circuit for cortical nonlinear operations

NEURAL COMPUTATION 2008年第6期20卷 1427-1451页

作者： Kouh, Minjoon Poggio, Tomaso Ctr Biol & Compuatat Learning Cambridge MA 02139 USA MIT McGovern Inst Cambridge MA 02139 USA

A few distinct cortical operations have been postulated over the past few years, suggested by experimental data on nonlinear neural response across different areas in the cortex. Among these, the energy model proposes the summation of quadrature pairs following a squaring nonlinearity in order to explain phase invariance of complex VI cells. The divisive normalization model assumes a gain-controlling, divisive inhibition to explain sigmoid-like response profiles within a pool of neurons. A gaussian-like operation hypothesizes a bell-shaped response tuned to a specific, optimal pattern of activation of the presynaptic inputs. A max-like operation assumes the selection and transmission of the most active response among a set of neural inputs. We propose that these distinct neural operations can be computed by the same canonical circuitry, involving divisive normalization and polynomial nonlinearities, for different parameter values within the circuit. Hence, this canonical circuit may provide a unifying framework for several circuit models, such as the divisive normalization and the energy models. As a case in point, we consider a feedforward hierarchical model of the ventral pathway of the primate visual cortex, which is built on a combination of the gaussian-like and max-like operations. We show that when the two operations are approximated by the circuit proposed here, the model is capable of generating selective and invariant neural responses and performing object recognition, in good agreement with neurophysiological data.

关键词： EVOKED potentials (Electrophysiology) NEURONS computer algorithms NONLINEAR models (Statistics) NEURAL networks (Neurobiology) NEURAL circuitry ARTIFICIAL intelligence

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PSAIA - Protein structure and interaction analyzer

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BMC STRUCTURAL BIOLOGY 2008年第1期8卷 21-21页

作者： Mihel, Josip Sikic, Mile Tomic, Sanja Jeren, Branko Vlahovicek, Kristian Univ Zagreb Fac Elect Engn & Comp Dept Elect Syst & Informat Proc Zagreb 10000 Croatia Rudjer Boskovic Inst HR-10000 Zagreb Croatia Univ Zagreb Fac Sci Div Biol Dept Mol BiolBioinformat Grp Zagreb 10000 Croatia

Background: PSAIA (Protein Structure and Interaction Analyzer) was developed to compute geometric parameters for large sets of protein structures in order to predict and investigate protein-protein interaction sites. Results: In addition to most relevant established algorithms, PSAIA offers a new method PIADA (Protein Interaction Atom Distance Algorithm) for the determination of residue interaction pairs. We found that PIADA produced more satisfactory results than comparable algorithms implemented in PSAIA. Particular advantages of PSAIA include its capacity to combine different methods to detect the locations and types of interactions between residues and its ability, without any further automation steps, to handle large numbers of protein structures and complexes. Generally, the integration of a variety of methods enables PSAIA to offer easier automation of analysis and greater reliability of results. PSAIA can be used either via a graphical user interface or from the command-line. Results are generated in either tabular or XML format. Conclusion: In a straightforward fashion and for large sets of protein structures, PSAIA enables the calculation of protein geometric parameters and the determination of location and type for protein-protein interaction sites. XML formatted output enables easy conversion of results to various formats suitable for statistic analysis. Results from smaller data sets demonstrated the influence of geometry on protein interaction sites. Comprehensive analysis of properties of large data sets lead to new information useful in the prediction of protein-protein interaction sites.

关键词： PROTEINS -- Analysis PROTEIN-protein interactions computer algorithms GRAPHICAL user interfaces (computer systems) XML (Document markup language)

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Approximation, Randomization and Combinatorial Optimization. algorithms and Techniques 2008

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丛书名： Lecture Notes in computer Science

2008年

作者： Ashish Goel Klaus Jansen José Rolim Ronitt Rubinfeld

ISBN: (数字)9783540853633

ISBN: (纸本)9783540853626

This book constitutes the joint refereed proceedings of the 11th International Workshop on Approximation algorithms for Combinatorial Optimization Problems, APPROX 2008 and the 12th International Workshop on Randomization and Computation, RANDOM 2008, held in Boston, MA, USA, in August 2008. The 20 revised full papers of the APPROX 2008 workshop were carefully reviewed and selected from 42 submissions and focus on algorithmic and complexity issues surrounding the development of efficient approximate solutions to computationally difficult problems. RANDOM 2008 is concerned with applications of randomness to computational and combinatorial problems and accounts for 27 revised full papers, also diligently reviewed and selected out of 52 workshop submissions.

关键词： computer science Statistical methods Congresses. computer algorithms Congresses. Approximation theory Data processing Congresses. Combinatorial optimization Data processing Congresses.

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Development of Force Control Device with High Power and High Resolution

Development of Force Control Device with High Power and High...

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2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, Pages 526-1042

作者： Hisashi Osumi Takahiro Tomiyama Faculty of Science and Engineering Chuo University Bunkyo Tokyo Japan Olympus Corporation Japan Graduate School of Chuo University Tokyo Japan

ISBN: (纸本)9781424420575

A force control device with high power and high resolution is developed. It consists of a spring and a small force actuator which are connected in parallel between the base plate and the output plate. By installing this device into a tip of a high power industrial robot, large forces with high resolution can be achieved under the existence of static friction. In this paper, the principle of force control device is verified by using a simple two d.o.f. experimental setup. From experimental results, the effectiveness of the developed control device and its control algorithm is verified.

关键词： High definition Control apparatus Force control HIGH POWER Base plates static friction computer algorithms Power (Psychology) Energy sources terminal interface processor

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Stability of swarm robot based on local forces of local swarms

Stability of swarm robot based on local forces of local swar...

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SICE Annual Conference

作者： Hiroshi Hashimoto Shinichi Aso Syo Yokota Akinori Sasaki Yasuhiro Ohyama Hiroyuki Kobayashi Advanced Institute of Industrial Technology Japan Tokyo University of Technology Japan Osaka Institute of Technology Japan

ISBN: (纸本)9784907764302

This paper proposes a control algorithm for a robotic swarm based on the center of gravity of the local swarm. In order to be compatible with maintaining a high stability of the whole swarm and advancing to the goal, virtual forces; local forces and an advancing force which are produced by the algorithm, are applied to multiple autonomous mobile robots. Local forces such as an attraction and a repulsion, are applied to each robot for increasing the stability of the local swarm. Overlapping each local swarm partially increases the stability of the whole swarm. The advancing force is applied to each robot for advancing to the goal while maintaining the stability of the local swarm. Since obstacles which prevent the robot advancing are considered as a disturbance from the viewpoint of the stability of the whole swarm, an effectiveness of the algorithm in obstacle space is evaluated using a dynamics simulation. As a result, it is found that the algorithm is able to maintain the high stability of the whole swarm advancing to the goal.

关键词： dike swarms kinetic simulation computer algorithms algorithms advance Force Robot Center of gravity Repulsion

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Distributed Formation Control of Multiple Aircraft Using Constraint Forces

Distributed Formation Control of Multiple Aircraft Using Con...

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2008 American Control Conference, Pages 441-879

作者： Yunfei Zou Prabhakar R. Pagilla Ryan T. Ratliff Mechanical and Aerospace Engineering Oklahoma State University Stillwater OK USA

ISBN: (纸本)9781424420780

A new approach for formation flight control of multiple aircraft is presented. Constraint forces are used to derive the dynamics of a constrained, multi-body system. A stable, distributed control algorithm is designed based on the information flow graph for a group of aircraft. The aircraft will achieve a particular formation while ensuring accurate navigation of the entire group. It is assumed that uncertainty exists in the drag coefficient of each aircraft. An adaptation algorithm is developed to compensate for the uncertainty and estimate the drag coefficient. The advantage of the proposed distributed control algorithm is that it allows the addition/removal of other aircraft into/from the formation seamlessly with simple modifications of the control input. Furthermore, the algorithm provides inherent scalability. Simulations were conducted to verify the proposed approach.

关键词： Aircraft Drag coefficient Flowcharts Constraint decentralised control computer algorithms Force algorithms

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Modular Robot Based on 3 Rotational DoF Modules

Modular Robot Based on 3 Rotational DoF Modules

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2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, Pages 526-1042

作者： Ariadna Yerpes Jose Baca Juan A. Escalera Manuel Ferre Rafael Aracil Group of Intelligent Machines Universidad Politecnica de Madrid Madrid Spain

ISBN: (纸本)9781424420575

This paper shows the advantages of having a modular system with 3-DoF spherical actuator in the base module to perform tasks that require displacement and object manipulation. Having 3-DoF actuator improves the complexity of coordination patterns and control algorithms of the modular system more relevantly as compared to having only 1 or 2DoF actuator in the module. Nevertheless, modules with actuators of only 1 or 2DoF require more modules to be assembled together in order to achieve complex tasks. Experiments performed with RobMAT modular system proves that a 3DoF actuator in the module is better, because tasks such as displacement, obstacle climbing and object manipulation, can be efficiently carried out with systems of 2 modules, 4 modules and 6 (maximum) modules connected together.

关键词： Modular robots Object Manipulation Modular systems actuators Religious Missions computer algorithms

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Impact of distributed generation units with power electronic converters on distribution network protection

Impact of distributed generation units with power electronic...

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2008 IET 9th International Conference on Developments in Power System Protection (DPSP 2008)

作者： J. Morren S.W.H. De Haan Essent Netwerk B.V. Hertogenbosch Netherlands

An increasing number of distributed generation units (DG units) are connected to the distribution network. These generators affect the operation and coordination of the distribution network protection. The influence from DG units that are coupled to the network with a power electronic converter (PEC) is different from that of conventional DG units with an electrical machine directly coupled to the network. This contribution shows that PEC-based DG units can be controlled in such a way that the negative influence on the distribution network protection is limited. A decision tree and a flow-chart are presented that show how a PEC-based DG should respond to network faults. The flow-chart can be used in real time to bring the proper control algorithm in operation during a fault.

关键词： Distributed Generation Power electronics Distribution network Protection Power grids distributed power generation Power electronics network protection Flowcharts DIESEL GENERATOR computer algorithms Converters Decision Trees Electronics

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A Car Transportation System by Multiple Mobile Robots - iCART

A Car Transportation System by Multiple Mobile Robots - iCAR...

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2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, Pages 2611-3132

作者： Mitsuru Endo Kenji Hirose Yasuhisa Hirata Kazuhiro Kosuge Takashi Kanbayashi Mitsukazu Oomoto Kei Akune Hiroyuki Arai Hiroyuki Shinoduka Kouki Suzuki Department of Bioengineering and Robotics Tohoku University Aoba 6-6-01 Aramaki Sendai 980-8579 JAPAN

ISBN: (纸本)9781424420575

In this paper, we propose a new car transportation system referred to as iCART(intelligent cooperative autonomous robot transporters). This system consists of two robots for the car transportation. Each robot is controlled by using a decentralized control algorithm for transporting the car in coordination. A trajectory for transporting the car is given to one of robots, and another robot estimates the trajectory through the interaction force between two robots. This car transportation system could transport any size of cars, and is available for any kinds of car transportation tasks such as parking, ballet parking, tow away service, and the transportation of cars at a factory, ferry, parking area, etc. The proposed car transportation system are developed and the control algorithm is experimentally applied to them. The experimental results illustrate the validity of the proposed system.

关键词： Cars transport system Robot Carina computer algorithms transport decentralized control algorithm trajectory

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Triple Tilting Rotor mini-UAV: Modeling and Embedded Control of the Attitude

Triple Tilting Rotor mini-UAV: Modeling and Embedded Control...

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2008 American Control Conference, Pages 3088-3529

作者： J. Escareno A. Sanchez O. Garcia R. Lozano Heudiasyc-UTC UMR 6599 Centre de Recherches de Royallieu B.P. 20529 60205 Compiegne France

ISBN: (纸本)9781424420780

The goal of this paper is to present a novel configuration for a three-rotor mini Unmanned Aerial Vehicle (UAV). The proposed design incorporates advantageous structural features which enhance the maneuverability of the rotorcraft. The detailed mathematical model of the vehicle's attitude is obtained through the Newton-Euler formulation. In terms of control, we propose a control law which is robust with respect to dynamical couplings and adverse torques. The vehicle tilts simultaneously the three rotors to stabilize the yaw dynamics. The resulting control algorithm is simple for embedded purposes. A customized low-cost embedded system was developed to test an autonomous stabilized-attitude flight, obtaining satisfactory results.

关键词： Three-rotor aircraft Coupled dynamics Collective tilting Homemade IMU Embedded architecture VTOL Attitude control law maneuverability Structural properties embedding computer algorithms Treble

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