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System Control (system + control)
Selected AbstractsThe virtual interaction panel: an easy control tool in augmented reality systemsCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2004M. L. Yuan Abstract In this paper, we propose and develop an easy control tool called Virtual Interaction Panel (VirIP) for Augmented Reality (AR) systems, which can be used to control AR systems. This tool is composed of two parts: the design of the VirIPs and the tracking of an interaction pen using a Restricted Coulomb Energy (RCE) neural network. The VirIP is composed of some virtual buttons, which have meaningful information that can be activated by an interaction pen during the augmentation process. The interaction pen is a general pen-like object with a certain color distribution. It is tracked using a RCE network in real-time and used to trigger the VirIPs for AR systems. In our system, only one camera is used for capturing the real world. Therefore, 2D information is used to trigger the virtual buttons to control the AR systems. The proposed method is real-time because the RCE-based image segmentation for a small region is fast. It can be used to control AR systems quite easily without any annoying sensors attached to entangling cables. This proposed method has good potential in many AR applications in manufacturing, such as assembly without the need for object recognition, collaborative product design, system control, etc. Copyright © 2004 John Wiley & Sons, Ltd. [source] Planning and controlling cooperating robots through distributed impedanceJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 6 2002Jérôme Szewczyk This article presents distributed impedance as a new approach for multiple robot system control. In this approach, each cooperating manipulator is controlled by an independent impedance controller. In addition, along selected degrees of freedom, force control is achieved through an external loop, to improve control of the object's internal loading. Extensive stability analysis is performed, based on a realistic model that includes robot impedance and object dynamics. Experiments are performed using two cooperating industrial robots holding an object through point contacts. Force and position control actions are suitably dispatched to achieve both internal loading control and object position control. Individual impedance parameters are specified according to the theoritical stability criterion. The performance of the system is demonstrated for transportation and contact tasks. © 2002 Wiley Periodicals, Inc. [source] Robust Isolation Of Sensor FailuresASIAN JOURNAL OF CONTROL, Issue 1 2003R. Xu ABSTRACT Sensor self-validity check is a critical step in system control and fault diagnostics. In this paper, a robust approach to isolate sensor failures is proposed. First, a residual model for a given system is built off-line and directly based on input-output measurement data. The residual model outputs are called "primary residuals" and are zero when there is no fault. Most conventional approaches to residual model generation are indirect, as they first require the determination of state-space or other models using standard system identification algorithms. Second, a new max-min design of structured residuals, which can maximize the sensitivity of structured residuals with respect to sensor failures, is proposed. Based on the structured residuals, one can then isolate the sensor failures. This design can also be done in an off-line manner. It is an optimization procedure that avoids local optimal solutions. Simulation and experimental results demonstrated the effectiveness of the proposed method. [source] Neural control of the urethra and development of pharmacotherapy for stress urinary incontinenceBJU INTERNATIONAL, Issue 8 2003M.O. Fraser SUMMARY This review discusses the control of the urethra by the central nervous system, emphasizing the importance of nervous system control and the role of serotonin and noradrenaline in storage, micturition and sphincter reflexes. The concept of pharmacological neuromodulation and the use of pharmacological therapy as first-line therapy for stress urinary incontinence (SUI) is presented. Coordination between the urinary bladder and urethra is mediated by many reflex pathways organized in the brain and spinal cord. During bladder filling, activation of mechanoreceptor afferent nerves in the bladder wall triggers firing in the cholinergic efferent pathways to the external urethral sphincter and in sympathetic adrenergic pathways to the urethral smooth muscle. These storage reflexes depend on interneuronal circuitry in the spinal cord and are modulated by descending pathways. It would therefore seem that neurotransmission in the central nervous system and periphery may be important in SUI, and moreover that pharmacological agents affecting these neurotransmitter pathways may be used to treat SUI. The central and peripheral mechanisms of action of duloxetine affect serotonin and noradrenaline neurotransmission in ways that may ameliorate the symptoms of SUI. [source] Modelling Operational Losses: A Bayesian ApproachQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 5 2004Paolo Giudici Abstract The exposure of banks to operational risk has increased in recent years. The Basel Committee on Banking Supervision (known as Basel II) has established a capital charge to cover operational risks other than credit and market risk. According to the advanced methods defined in ,The New Basel Capital Accord' to quantify the capital charge, in this paper we present an advanced measurement approach based on a Bayesian network model that estimates an internal measure of risk of the bank. One of the main problems faced when measuring the operational risk is the scarcity of loss data. The methodology proposed solves this critical point because it allows a coherent integration, via Bayes' theorem, of different sources of information, such as internal and external data, and the opinions of ,experts' (process owners) about the frequency and the severity of each loss event. Furthermore, the model corrects the losses distribution by considering the eventual relations between different nodes of the network that represent the losses of each combination of business line/event type/bank/process and the effectiveness of the corresponding internal and external controls. The operational risk capital charge is quantified by multiplying the value at risk (VaR) per event, a percentile of the losses distribution determined, by an estimate of the number of losses that may occur in a given period. Furthermore, it becomes possible to monitor the effectiveness of the internal and external system controls in place at the bank. The methodology we present has been experimented as a pilot project in one of the most important Italian banking groups, Monte dei Paschi di Siena. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||