A formal approach to negotiating agents development

This paper presents a formal and executable approach to capture the behaviour of parties involved in a negotiation. A party is modeled as a negotiating agent composed of a communication module, a control module, a reasoning module, and a knowledge base. The control module is expressed as a statechart, and the reasoning module as a defeasible logic program. A strategy specification therefore consists of a statechart, a set of defeasible rules, and a set of initial facts. Such a specification can be dynamically plugged into an agent shell incorporating a statechart interpreter and a defeasible logic inference engine, in order to yield an agent capable of participating in a given type of negotiations. The choice of statecharts and defeasible logic with respect to other formalisms is justified against a set of desirable criteria, and their suitability is illustrated through concrete examples of bidding and multi-lateral bargaining scenarios.     

Bayesian recognition of local 3-d shape by approximating image intensity functions with quadric polynomials

The recognition in image data of viewed patches of spheres, cylinders, and planes in the 3-D world is discussed as a first step to complex object recognition or complex object location and orientation estimation. Accordingly, an image is partitioned into small square windows, each of which is a view of a piece of a sphere, or of a cylinder, or of a plane. Windows are processed in parallel for recognition of content. New concepts and techniques include approximations of the image within a window by 2-D quadric polynomials where each approximation is constrained by one of the hypotheses that the 3-D surface shape seen is either planar, cylindrical, or spherical; a recognizer based upon these approximations to determine whether the object patch viewed is a piece of a sphere, or a piece of a cylinder, or a piece of a plane; lowpass filtering of the image by the approximation. The shape recognition is computationally simple, and for large windows is approximately Bayesian minimum-probability-of-error recognition. These classifications are useful for many purposes. One such purpose is to enable a following processor to use an appropriate estimator to estimate shape, and orientation and location parameters for the 3-D surface seen within a window.     

Patchwork: A fast interpreter for a restricted dataflow language

We have built a system, Patchwork, that allows programs to be organized according to a dataflow model. In our implementation, application programs use Patchwork to assemble complex microcode programs for a graphics processor from a library of microcode modules. We describe a simple and efficient implementation, in which the only overhead incurred is a single extra level of indirection when invoking a module or when a module accesses inputs, outputs, or local storage. The implementation depends on being able to describe a distinct execution tree for the network, which obviates the need both for run-time monitoring of the execution and for movement of data. Thus, neither dataflow hardware nor a dataflow language is needed for the implementation. Patchwork supports flow-of-control constructs such as looping and branching, the assembly of complex modules from simpler ones, modules written in a variety of languages for a variety of different devices, the interleaved execution of several programs on a single processor, and the execution of a single program on a set of processors in parallel. An analysis showed that Patchwork contributed between 2 and 5% to the total running time of sample microcode programs.     

A superscalar simulation employing poisson distributed stalls

This paper presents a statistical approach to estimating the performance of a superscalar processor. Traditional trace-driven simulators can take a large amount time to conduct a performance evaluation of a machine, especially as the number of instructions increases. The result of this type of simulation is typically tied to the particular trace that was run. Elements such as dependencies, delays, and stalls are all a direct result of the particular trace being run, and can differ from trace to trace. This paper describes a model designed to separate simulation results from a specific trace. Rather than running a trace-driven simulation, a statistical model is employed, more specifically a Poisson distribution, to predict how these types of delay affects performance. Through the use of this statistical model, a performance evaluation can be conducted using a general code model, with specific stall rates, rather than a particular code trace. This model allows simulations to quickly run tens of millions of instructions and evaluate the performance of a particular micro-architecture while at the same time, allowing the flexibility to change the structure of the architecture.     

On the controllability of systems with a time-varying delay†

This paper is concerned with the controllability of a system with a time-varying delay. The system to be considered here is described by a linear differential-difference equation of a retarded type, where a time-varying delay is a certain class of a time-varying function. First, the concepts of controllability for linear differential-difference systems with a constant delay, introduced by Weiss (1987), are developed to the system with a time-varying delay. Second, necessary and sufficient conditions for controllability are obtained. Finally, the controllability of a stationary system with a constant delay is treated, including the results of Chyung and Lee (1966).     

Exact combinatorial bounds on the probability of overfitting for empirical risk minimization

Three general methods for obtaining exact bounds on the probability of overfitting are proposed within statistical learning theory: a method of generating and destroying sets, a recurrent method, and a blockwise method. Six particular cases are considered to illustrate the application of these methods. These are the following model sets of predictors: a pair of predictors, a layer of a Boolean cube, an interval of a Boolean cube, a monotonic chain, a unimodal chain, and a unit neighborhood of the best predictor. For the interval and the unimodal chain, the results of numerical experiments are presented that demonstrate the effects of splitting and similarity on the probability of overfitting.     

HelSweeper: Screw-sweeps of canal surfaces

A tube is a solid bounded by the union of a one-parameter family of circles that may be decomposed into canal-surfaces and planar disks or annuli. A screw-sweep is the region swept by a shape during a screw motion. HelSweeper computes the boundary of a screw-sweep of an arbitrary union of tubes and polyhedra. To do so, it generates a superset of faces, splits them at their intersections, and selects the face portions that form the desired boundary. The novelty of the proposed approach lies in the fact that the faces contributed to this superset by a tube are each a screw-sweeps of a rigid curve (generator), which is the locus of grazing points, and that each grazing point is formulated as the intersection of a circle of the tube with a corresponding screw-plane. Hence, each such face is a one-parameter family of helices, each being the screw-sweep of a grazing point.     

Stochastic colored Petri net models of flexible manufacturing systems: Material handling systems and machining

This paper presents an overview of SCPN theory, a set of three generic SCPN submodels, a behavior-preserving methodology for combining those submodels into a larger model, and a combined model. The three submodels include a machine with failures, repairs, and limited I/O buffers, and two types of conveyor submodels—a simple conveyor segment and a conveyor segment at a machine.     

Image Manifolds which are Isometric to Euclidean Space

Recently, the Isomap procedure [10] was proposed as a new way to recover a low-dimensional parametrization of data lying on a low-dimensional submanifold in high-dimensional space. The method assumes that the submanifold, viewed as a Riemannian submanifold of the ambient high-dimensional space, is isometric to a convex subset of Euclidean space. This naturally raises the question: what datasets can reasonably be modeled by this condition? In this paper, we consider a special kind of image data: families of images generated by articulation of one or several objects in a scene—for example, images of a black disk on a white background with center placed at a range of locations. The collection of all images in such an articulation family, as the parameters of the articulation vary, makes up an articulation manifold, a submanifold of L ². We study the properties of such articulation manifolds, in particular, their lack of differentiability when the images have edges. Under these conditions, we show that there exists a natural renormalization of geodesic distance which yields a well-defined metric. We exhibit a list of articulation models where the corresponding manifold equipped with this new metric is indeed isometric to a convex subset of Euclidean space. Examples include translations of a symmetric object, rotations of a closed set, articulations of a horizon, and expressions of a cartoon face. The theoretical predictions from our study are borne out by empirical experiments with published Isomap code. We also note that in the case where several components of the image articulate independently, isometry may fail; for example, with several disks in an image avoiding contact, the underlying Riemannian manifold is locally isometric to an open, connected, but not convex subset of Euclidean space. Such a situation matches the assumptions of our recently-proposed Hessian Eigenmaps procedure, but not the original Isomap procedure.     

Panoramic appearance-based recognition of video contents using matching graphs

This paper proposes a general scheme for recognizing the contents of a video using a set of panoramas recorded in a database. In essence, a panorama inherently records the appearances of an omni-directional scene from its central point to arbitrary viewing directions and, thus, can serve as a compact representation of an environment. In particular, this paper emphasizes the use of a sequence of successive frames in a video taken with a video camera, instead of a single frame, for visual recognition. The associated recognition task is formulated as a shortest-path searching problem, and a dynamic-programming technique is used to solve it. Experimental results show that our method can effectively recognize a video.     

A disruption recovery plan in a three-stage production-inventory system

This paper proposes a recovery plan for managing disruptions in a three-stage production-inventory system under a mixed production environment. First, a mathematical model is developed to deal with a disruption at any stage while maximizing total profit during the recovery-time window. The model is solved after the occurrence of a disruption event, with changed data used to generate a revised plan. We also propose a new and efficient heuristic for solving the developed mathematical model. Second, multiple disruptions are considered, where a new disruption may or may not affect the recovery plans of earlier disruptions. The heuristic, developed for a single disruption, is extended to deal with a series of disruptions so that it can be implemented for disruption recovery on a real-time basis. We compare the heuristic solutions with those obtained by a standard search algorithm for a set of randomly generated disruption test problems, and that show the consistent performance of our developed heuristic with lower computational times. Finally, some numerical examples and a real-world case study are presented to demonstrate the benefits and usefulness of our proposed approach.     

An experimental remote handling system

An experimental robotic remote handling system is described which has been constructed in order to investigate various engineering problems in advanced remote handling such as the man-machine interface, system control and communication. The device consists of a mobile and a control station. The mobile station comprises an electrical manipulator having seven degrees of freedom, a TV camera, a control sub-computer, a servo-control unit, radio transmitters and receivers, batteries, etc., which are mounted on a crawler-type vehicle. The control station is equipped with the master arm of the manipulator, radio transmitters and receivers, a TV monitor, a main control computer and its peripheral devices, etc. The manipulator can be operated in either a master-slave, a playback or a programmed control mode with the assistance of control computers. Communication between the mobile and the control stations is made using optical fibres or a radio link.     

A new deterministic approach in a decision support system for ship’s trajectory planning

The paper introduces a Decision Support System for ships, developed to solve a problem of collision avoidance with static and dynamic obstacles. The system maps the decision making capability of a human (navigation) expert to solve the path planning problem for a ship in a complex navigation environment. It can be further developed to provide automatic control of a ship. It utilizes a new, fast and effective, deterministic method, called the Trajectory Base Algorithm, to calculate a safe, optimal path for a ship. The system structure, a detailed explanation of a new method, followed by results of simulation tests are all presented in the paper. The results proof a successful application of the method to solve a path planning problem for ships with the consideration of both static and dynamic obstacles in the environment, marine traffic regulations and dynamic properties of a ship, what makes this approach applicable in commercial systems. The approach can also be adapted for application in mobile robots path planning. The experimental results and ability of the system to achieve a new functionality of full autonomy show significance of this contribution to the development of Expert and Intelligent Systems domain. The author believes that autonomous systems constitute the future of Expert and Intelligent Systems.     

Modeling interactive storytelling genres as application domains

In this paper, we introduce a formalism to specify interactive storytelling genres in the context of digital entertainment, adopting an information systems approach. We view a genre as a set of plots, where a plot is a partially ordered sequence of events, taken from a fixed repertoire. In general, the specification of a genre should allow to determine whether a plot is a legitimate representative of the genre, and also to generate all plots belonging to the genre. The formalism divides the specification of a genre into static, dynamic and behavioral schemas, that reflect a plan recognition/plan generation paradigm. It leads to executable specifications, supported by LOGTELL, a prototype tool that helps users generate, modify and reuse plots that follow a genre specification. To illustrate the use of the formalism, we specify a simple Swords & Dragons genre and show plots generated by the tool.     

A class of new transforms tailored for the hypergeometric series

A new class of transforms, tailored for the hypergeometric series, is proposed and tested on a number of series. From a knowledge of a given number of terms of a sequence, these transforms reproduce the functions with a better accuracy than the Levin-like transforms. Though there exists a correlation between the approximative power of a rational approximant and its ability to predict the leading terms of a series, there are exceptions to this, especially in the case of divergent series. The new transforms can, in most cases, predict a number of extra terms not used in the construction of the approximants.     

高压传感器在高静压下的动态校准方法

提出了一种校准高压传感器频响特性的方法,动态校准系统主要由甘油油腔、霍普金森杆、气枪、应变片、电荷放大器、活塞式压力计和数据采集系统等组成.校准时先利用活塞式压力计在封闭式油腔中产生高静压,高静压作用于被校准的压力传感器.气枪发射子弹,子弹撞击霍普金森杆产生近似于冲激函数的窄脉冲应力波,应力波通过甘油传播并激励传感器,...     

Another look at the “longest ascending subsequence” problem

Summary Dijkstra has given a derivation of an efficient algorithm for a problem concerning monotonic subsequences, and extracted a proof of a related theorem from the algorithm. Here it is shown that a careful separation of concerns can lead to a beautiful conventional proof, a very different derivation of Dijkstra's algorithm, a more elegant proof from the algorithm, and the discovery of a duality property.     

Simplifying Subtyping Constraints: A Theory

This paper offers a theoretical study of constraint simplification, a fundamental issue for the designer of a practical type inference system with subtyping. In the simpler case where constraints are equations, a simple isomorphism between constrained type schemes and finite state automata yields a complete constraint simplification method. Using it as a guide for the intuition, we move on to the case of subtyping, and describe several simplification algorithms. Although no longer complete, they are conceptually simple, efficient, and very effective in practice. Overall, this paper gives a concise theoretical account of the techniques found at the core of our type inference system. Our study is restricted to the case where constraints are interpreted in a non-structural lattice of regular terms. Nevertheless, we highlight a small number of general ideas, which explain our algorithms at a high level and may be applicable to a variety of other systems.     

Developing a vision-based auto-recharging system for mobile robots

This article describes a vision-based auto-recharging system that guides a mobile robot moving toward a docking station. The system contains a docking station and a mobile robot. The docking station contains a docking structure, a control device, a charger, a safety detection device, and a wireless RF interface. The mobile robot contains a power detection module (voltage and current), an auto-switch, a wireless RF interface, a controller, and a camera. The controller of the power detection module is a Holtek chip. The docking structure is designed with one active degree of freedom and two passive degrees of freedom. For image processing, the mobile robot uses a webcam to capture a real-time image. The image signal is transmitted to the controller of the mobile robot via a USB interface. We use an Otsu algorithm to calculate the distance and orientation of the docking station from the mobile robot. In the experiment, the proposed algorithm guided the mobile robot to the docking station.