Work has been underway at the CSM on the development of autonomous (tele-managed) LHD mining machines. Previous work has shown that ultrasonic sensors exhibit several characteristics which make them a reasonable choic...
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Work has been underway at the CSM on the development of autonomous (tele-managed) LHD mining machines. Previous work has shown that ultrasonic sensors exhibit several characteristics which make them a reasonable choice for sensor based navigation in underground mining operations. This paper discusses recent work done to (1) develop control algorithms for use with these sensors, (2) experiments with a scale model of an LHD to verify the ultrasonic based control and modeling methods, and (3) approaches to developing real-time task level control models.
In this short note, adaptive and nonadaptive control algorithms, which make use of fundamental mathematical property concerning positive definite matrices and Lyapunov stability theory are proposed for the control of ...
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In this short note, adaptive and nonadaptive control algorithms, which make use of fundamental mathematical property concerning positive definite matrices and Lyapunov stability theory are proposed for the control of robot manipulators. Using the fact that matrix dD(q)/dt - 2C(q,q) is skew symmetric, nonadaptive controllers which have a simplified structure with less computational burden are proposed. Then based on the dynamic equations of robot manipulators, parameter adaptation rules are developed for updating the partially or totally unknown parameters in the proposed nonadaptive controllers, generalizing the nonadaptive controllers to model reference adaptive controllers. To further take the advantage of the simplified structure of the proposed adaptive controllers, the dynamic model of robot manipulators must be expressed linearly in terms of the parameters of links and payload inertias. So we also present a method on how to derive the dynamic model of robot manipulator which is linear in terms of its parameters. This dynamic model of robot manipulators is also suitable for the pure identification of the parameters of links and payload of the manipulator.
A comprehensive analysis of reported hepatitis C virus genomic sequences comprising 151 partial or complete nucleotide sequences and 159 partial or complete amino acid sequences revealed an irregular composition of co...
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A comprehensive analysis of reported hepatitis C virus genomic sequences comprising 151 partial or complete nucleotide sequences and 159 partial or complete amino acid sequences revealed an irregular composition of conserved and variable regions. There were but eight conserved nucleotide sequences, none outside the 5' noncoding and structural regions. A search among conserved amino acid sequences revealed 14 candidate B-cell epitopes, which were chosen mainly on the basis of their hydrophilicity profiles. Twenty five candidate T-cell epitopes were selected according to the criteria of absolute conservation of amino acid sequence, together with characteristic sequence motifs, amphipathic helical structure, or both. Conserved peptide sequences, with the characteristics of both B- and T-cell epitopes, were identified in the nonstructural 5 (NS5) region of the genome.
An important, yet seemingly unattainable, goal in structural molecular biology is to be able to predict the native three-dimensional structure of a protein entirely from its amino acid sequence. Prediction methods bas...
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An important, yet seemingly unattainable, goal in structural molecular biology is to be able to predict the native three-dimensional structure of a protein entirely from its amino acid sequence. Prediction methods based on rigorous energy calculations have not yet been successful, and best results have been obtained from homology modelling and statistical secondary structure prediction. Homology modelling is limited to cases where significant sequence similarity is shared between a protein of known structure and the unknown. Secondary structure prediction methods are not only unreliable, but also do not offer any obvious route to the full tertiary structure. Recently, methods have been developed whereby entire protein folds are recognized from sequence, even where little or no sequence similarity is shared between the proteins under consideration. In this paper we review the current methods, including our own, and in particular offer a historical background to their development. In addition, we also discuss the future of these methods and outline the developments under investigation in our laboratory.
This paper presents a new method of keeping one of the most suitable driving conditions for regulating the outflow volume from the ventricular-assist device (VAD). The experimental results from a mock circulatory syst...
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This paper presents a new method of keeping one of the most suitable driving conditions for regulating the outflow volume from the ventricular-assist device (VAD). The experimental results from a mock circulatory system have shown that the relationship between the stroke volume and the systolic duration of the VAD can be specified by the combination of characteristic curves of the positive and negative drive pressures. The optimal operating point on the characteristic curve have been defined as the point at which thrombosis on the blood-contacting surface and hemolysis due to mechanical damage can be avoided and at which the driving energy can be minimized. The present analysis has been revealed that the optimal operating point is the vertex of the triangular figure obtained from the characteristic curve. The algorithms for keeping the optimal operating point and for regulating the stroke volume have been also proposed.
This paper outlines basic antenna array theory with major emphasis on pattern analysis and synthesis for periodic linear and planar arrays, phased arrays, and conformal arrays. Extension is made to synthesis technique...
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This paper outlines basic antenna array theory with major emphasis on pattern analysis and synthesis for periodic linear and planar arrays, phased arrays, and conformal arrays. Extension is made to synthesis techniques which use computer algorithms. These include arbitrary side lobe control, shaped beams, and phase-only null steering. The subjects of random errors and phased array quantization errors are outlined.
This paper describes research at West Virginia University that develops an autonomous mobile robot for use in underground mines. The navigation scheme combines elements of both hierarchical control and reactive or sub...
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This paper describes research at West Virginia University that develops an autonomous mobile robot for use in underground mines. The navigation scheme combines elements of both hierarchical control and reactive or subsumptive-type control. The robot navigates by sensing the environment and selecting a navigational "mode" that is appropriate to the circumstances and to the robot's mission. Examples of navigational modes are wall following, collision avoidance, and homing. The modes are implemented in modules formed by combinations of neural network processors and conventional control algorithms. This paper describes the overall control system architecture and the navigational strategies of the experimental robot vehicle.
Application of partial-response (PR) signaling and maximum-likelihood sequence detection (MLSD) to digital magnetic recording has been shown in theory and practice to further increase the storage densities and reliabi...
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Application of partial-response (PR) signaling and maximum-likelihood sequence detection (MLSD) to digital magnetic recording has been shown in theory and practice to further increase the storage densities and reliability that systems using run-length limited (RLL) coding and peak detection (PD)-still the prevalent signal processing techniques today-can currently achieve. In this paper, the realization of a digital recording system using PR class-IV signaling with MLSD (PRML) is described. To perform MLSD at the high data rates encountered in recording systems, a simple implementation of the Viterbi detector is developed based on a difference-metric algorithm. We present decision-directed schemes for gain control and timing recovery, for tracking variations of the gain and timing phase during data readback, and for fast initial adjustment from a known preamble. The dynamic behavior of the control algorithms is studied by computer simulations. Coding is used to facilitate timing recovery and gain control, to limit the path memory length of the Viterbi detector, and to allow fast and reliable startup of the receiver. The design and properties of rate-8/9 constrained codes are examined. Finally, the problem of equalization is addressed, and analog and combined analog/digital filter implementations are developed. A simple adaptive equalizer capable of compensating variations of the recording channel characteristics with track radius and/or head-to-medium distance is described.
What is the current state of the art in protein design? This question was approached in a recent two-week protein design workshop sponsored by EMBO and held at the EMBL in Heidelberg. The goals were to test available ...
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What is the current state of the art in protein design? This question was approached in a recent two-week protein design workshop sponsored by EMBO and held at the EMBL in Heidelberg. The goals were to test available design tools and to explore new design strategies. Five novel proteins were designed: Shpilka, a sandwich of two four-stranded beta-sheets, a scaffold on which to explore variations in loop topology;Grendel, a four-helical membrane anchor, ready for fusion to water-soluble functional domains;Finger-clasp, a dimer of interdigitating beta-beta-alpha-units, the simplest variant of the "handshake" structural class;Aida, an antibody binding surface intended to be specific for flavodoxin;Leather-a minimal NAD binding domain, extracted from a larger protein. Each design is available as a set of three-dimensional coordinates, the corresponding amino acid sequence and a set of analytical results. The designs are placed in the public domain for scrutiny, improvement, and possible experimental verification.
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