This paper presents a converter that allows the operation as rectifier or inverter, with high power factor, which the voltage output can be lower, equal or higher than the peak of the input voltage, beyond working with only a cell of conventional commutation. The operation stages, equations, control strategy and design of the converter are presented. Finally, simulation re- sult are shown for rectifier and inverter operation.

This paper concerns the problem of actively searching for and localizing ground features by a coordinated team of air and ground robotic sensor platforms. The approach taken builds on well known Decentralized Data Fusion (DDF) methodology. In particular, it brings together established representations developed for identification and linearized estimation problems to jointly address feature detection and localization. This provides transparent and scalable integration of sensor information from air and ground platforms. As in previous studies, an Informationtheoretic utility measure and local control strategy drive the robots to uncertainty reducing team configurations. Complementary characteristics in terms of coverage and accuracy are revealed through analysis of the observation uncertainty for air and ground on-board cameras. Implementation results for a detection and localization example indicate the ability of this approach to scalably and efficiently realize such collaborative potential.

Databases and online systems have dramatically changed the way businesses transact and maintain records. The database-supported transaction systems enable businesses to conduct their businesses electronically, leading to quicker exchange of information on products and sales. With databases supplying information and online systems providing processing capabilities, businesses can input and process transactions as they occur. In turn, this facilitates quicker retrieval, classification, and reporting of activities. Unlike in the past where reports were generated several months after events

The problem of minimising losses in distribution networks has traditionally been investigated using a single, deterministic demand level. This has proved to be effective since most approaches are generally able to also result in minimum overall energy losses. However, the increasing penetration of (firm and variable) Distributed Generation (DG) raises concerns on the actual benefits of loss minimisation studies that are limited to a single demand/generation scenario. Here, a multi-period AC Optimal Power Flow (OPF) is used to determine the optimal accommodation of (renewable) DG in a way that minimises the system energy losses. In addition, control schemes expected to be part of the future Smart Grid, such as coordinated voltage control and dispatchable DG power factor, are embedded in the OPF formulation to explore the extra loss reduction benefits that can be harnessed with such technologies. The trade-off between energy losses and more generation capacity is also investigated. The methodology is applied to a generic UK distribution network and results demonstrate the significant impact that considering time-varying characteristics has on the energy loss minimisation problem and highlight the gains that the flexibility provided by innovative control strategies can have on both loss minimisation and generation capacity.

Since Þrst discovered in the New York City area in 1999, West Nile virus (WNV) has become established over much of the continental United States and has been responsible for Ͼ10,000 cases of severe disease and 400 human fatalities, as well as thousands of fatal infections in horses. To develop appropriate surveillance and control strategies, the identiÞcation of which mosquito species are competent vectors and how various factors inßuence their ability to transmit this virus must be determined. Therefore, we evaluated numerous mosquito species for their ability to transmit WNV under laboratory conditions. This report contains data for several mosquito species not reported previously, as well as a summary of transmission data compiled from previously reported studies.

This paper describes how to optimize the energy performance of single-story multiple-skin facades (MSF) by changing the settings of the facades and HVAC-system according to the net energy demand of the building. The annual energy performance is analyzed for typical Belgian climatic conditions using a whole building simulation tool. Three MSF are scrutinised: a mechanically ventilated airflow window, a naturally ventilated double-skin facade and a mechanically ventilated supply window. Their performance is compared against the performance of two traditional facades: a traditional window with exterior and interior shading device. It is shown that both the heating and cooling demand may significantly be improved by implementing control strategies such as controlling the airflow rate and the recovery of air returning from the multiple-skin facades.

This work addresses the real time control of the Khepera mobile robot [1] navigation in a maze with reflector walls. Boolean Neural Networks such as RAM [2] and GSN [3] models are applied to drive the vehicle, following a light source, while avoiding obstacles. Both neural networks are implemented with simple logic and arithmetic functions (NOT, AND, OR, Addition, and Comparison), aiming to improve system speed. The results obtained are compared with two other control strategies: Multi-layer Perceptron (MLP) [4] and Fuzzy Logic [5].

In this paper we illustrate the properties and the morphology of a human like neural reflex controller, used to set the stiness and joint positions of an anthropomorphic artificial hand. In particular we explain, by simulations results, its ability to emulate the myotatic human reflex, and its capacity to learn in real time the best control strategy. We also present

The automated material handling system (AMHS) is a highly automated transport solution of actual 300mm semiconductor waferfabs. The big logistic challenge in such a running system is the just-in-time delivery of lots (carriers). Therefore, beside tracks and vehicles, there are different storages (stocker) and buffers (under track storages and load ports) integrated in such a transport system. To conquer the

It has been veri"ed that a controllable series capacitor with a suitable control scheme can improve transient stability and help to damp electromechanical oscillations. A question of great importance is the selection of the input signals and a control strategy for this device in order to damp power oscillations in an e!ective and robust manner. Based on Lyapunov theory a control strategy for damping of electromechanical power oscillations in a multi-machine power system is derived. Lyapunov theory deals with dynamical systems without inputs. For this reason, it has traditionally been applied only to closed-loop control systems, that is, systems for which the input has been eliminated through the substitution of a predetermined feedback control. However, in this paper, we use Lyapunov function candidates in feedback design itself by making the Lyapunov derivative negative when choosing the control. This control strategy is called control Lyapunov function for systems with control inputs. Also, two input signals for this control strategy are used. The "rst one is based on local information and the second one on remote information derived by the single machine equivalent method. : S 0 0 0 5 -1 0 9 8 ( 0 1 ) 0 0 0 9 9 -1

The plant disease Apple Scab, caused by the ascomycete fungus Venturia inaequalis (Cke.) Wint. (anamorph Spilocea pomi Fr.), is the single most important disease of cultivated apple (Malus domestica Borkh.) worldwide. Severe apple crop losses can result when appropriate control measures are not taken, especially when the spring and early summer seasons are moist and cool. The fungal pathogen has a pronounced low temperature requirement for the initiation of the sexual or pseudothecial stage. In temperate apple growing regions of the world, this temperature requirement is met only after leaf fall, on the orchard floor, where, in winter months, low temperatures trigger the development of pseudothecia. In the spring, overwintered pseudothecia time their production of ascospores to precisely coincide with the emergence of new leaves, thus initiating a new cycle of disease.

The migratory nature of nuisance wildlife populations creates a special management problem by imposing a negative diffusion externality on landowners undertaking control efforts. This paper reviews three cost-minimizing wildlife-control models, each internalizing the diffusion externality under different management scenarios, namely, unilateral management, bilateral management, and centralized management. The three management scenarios lead to different optimal behaviors. Property owners exerting unilateral control must leave some wildlife untrapped to generate sufficient population pressure against the flow of continual immigration from neighboring populations. Analysis of the bilateral model indicates that noncooperating neighboring landowners having varying pay-off functions will end up with leaving all wildlife untrapped in their parcels. Under the centralized management scenario, landowners find it most profitable to collectively delegate the control responsibility of an entire watershed to a single manager. * Corresponding author property owners who suffer damage from untrapped furbearing populations. In the absence of a fur market, furbearing populations can transform from profit-earning economic 'goods' to nuisance-causing economic 'bads.'

The paper presents a new approach to the quantification of simulation fidelity based on an analysis of pilot guidance strategy. The manoeuvre guidance portrait is conceived as the solution to a low order equivalent system, and to properly allow for pilot adaptation to changing cues and task demands, the model parameters are allowed to vary. Thus the concept of the Adaptive Pilot Model is proposed and developed. The theoretical foundation to the concept is developed using the familiar spatial variables in flight control, such as distance and speed. Motion is then transformed into temporal variables and drawing on the theory of τ(t)-coupling from visual flow theory, (τ(t) is the instantaneous time to stop) the ADP model is shown to simplify into a much simpler algebraic relationship when the pilot maintains constant τ& during a deceleration. If we make assumptions about the separation of guidance and stabilisation control strategy, pilot guidance feedback gains are then simply related to frequency and damping of the ADP structure. Results are presented from the analysis of simulation trials with pilots flying an acceleration-deceleration manoeuvre that show strong correlation with the τ(t)-based guidance strategy. The interpretation of the theory in terms of simulation fidelity criteria is discussed.

The paper presents the results of research aimed at developing a risk assessment process that can be used to more thoroughly characterise risks associated with loader-and dozer-related fatal incidents in US mining. The assessment is based on historical data obtained from the US Mine Safety and Health Administration investigation reports, which includes 77 fatal incidents that occurred from 1995 to 2006. The Preliminary Hazard Assessment method is used in identifying and quantifying risks. Risk levels are then developed using a pre-established risk matrix that ranks them according to probability and severity. The resulting assigned risk value can then be used to prioritise risk control strategies. A total of 10 hazards were identified for loaders. The hazards 'failure to follow adequate maintenance procedure' and 'failure of mechanical/electrical/hydraulic components' were the most severe and frequent hazards and they fell into the category of 'high' risk. The same number of hazards was identified for dozers. The hazard 'failure to identify adverse site/geological conditions' was the most severe and frequent hazard and it fell into the category of 'high' risk.

This study describes the spatial distribution pattern of Lu. longipalpis abundance in Posadas-Garupá, Argentina, where four cases of human Visceral Leishmaniasis had been recorded. A total of 2428 Lu. longipalpis were captured in 42% of the 305 sites sampled with CDC light traps, its abundance shows spatial autocorrelation ranging up to 590 m (semivariogram model), with six downtown 'islands' of vector highest abundance (≥60 individuals). A significant association between Lu. longipalpis and the presence of chickens was observed (odds ratio 3.26). The best stepwise multiple regression using Generalized Linear Models explained 31% of the deviance for Lu. longipalpis abundance, including as explanatory variables: (a) negatively: households with 'lack of building material and with economic deprivation', (b) positively: surface covered by trees and bushes at 50 meters of the house, and households without electrical lighting. In conclusion, Lu. longipalpis in a recent settled focus of visceral leishmaniasis was urbanized with a highly heterogeneous spatial distribution within the cities, with the vectors concentrated in limited 'islands' of high abundance, in the downtown relatively more affluent and dense populated areas, but also more heterogeneous with patches that had higher tree coverage and poor urban services. These results once validated will contribute to the control strategy design through risk maps, in order to prioritize areas for prevention and control, and setting the appropriate scale for intervention.

In recent years, much attention has been focused upon predictive control of nonlinear systems. The implementation of such a control strategy for real processes has greatly improved their performance. This paper deals with a model-based predictive control (MBPC) strategy using a generalised Hammerstein model and its application to the temperature control of a semibatch reactor. Both unconstrained and constrained adaptive control problems are considered. A simple identification method based on the weighted recursive least squares method (WRLS) is used to estimate the model parameters on-line. An indirect adaptive nonlinear controller is designed by combining the predictive controller with an indirect parameter estimation algorithm. This adaptive scheme has been applied for the control of a semi-batch chemical reactor. Experimental results show that the performance of the generalised Hammerstein MBPC (NLMBPC) was significantly better than that of a linear model predictive controller (LMBPC).

This paper studies the grasp stability of two classes of threephalanx underactuated fingers with transmission mechanisms based on either linkages or tendons and pulleys. The concept of underactuation in robotic fingers-with fewer actuators than degrees of freedom (DOF)-allows the hand to adjust itself to an irregularly shaped object without complex control strategy and sensors. With a n-phalanx finger, n contacts (one for each phalanx) are normally required to statically constrain the finger. However, some contact forces may be lacking due to either the transmission mechanism, or simply the object size and position. Thus, one may define an i th order equilibrium, when the finger is in static equilibrium with i missing contacts. In this paper, the case for which n = 3 is studied with a particular emphasis on the cases for which i = 1 and i = 2. The fact that some contact forces do not appear or are negative, can lead in some cases to the ejection of the object from the hand, when no equilibrium configuration is achieved.

This paper presents a control strategy for the coordination of multiple mobile robots. A combination of the virtual structure and path following approaches is used to derive the formation architecture. A formation controller is proposed for the kinematic model of two-degree-of-freedom unicycle-type mobile robots. The approach is then extended to consider the formation controller by taking into account the physical

To solve problems of traffic saturation in cities, new alternative "Urban Transportation Systems" are based on electric vehicles in free-access. One necessary functionality of such systems is their ability to move in a platoon fashion. Platooning of these automatic guided vehicles, relying on RTK-GPS sensors and inter-vehicles communication, is addressed in this paper. The developed control law is based on a global control strategy; actually, it can take into account all the platoon state, and not only the immediate previous vehicle state. Distance here is understood as difference of curvilinear abscissa along a reference trajectory. Relying on nonlinear control theory, lateral and longitudinal control are fully decoupled, and therefore addressed independently. To ensure passengers comfort, additional monitoring functions supervise our control system. Then, experiment, carried out with urban vehicles, and simulations of long platoon, are presented.

This paper describes an integrated boost-full bridge rectEfier power factor corrector driven by a sliding-mode control. Due to the sliding-mode control, fast regulation of the output voltage is achieved. In addition, with this scheme, the major power goes through a single stage to the output, while both unity power factor and fast dynamic response is obtained, and the eficiency as well as the power density can be higher than in a conventional two cascade stage scheme. A prototype circuit has been built to verijj this approach. The control strategy and experimental results will be presented.

Page 1. ORIGINAL ARTICLE Design of an advanced incremental fuzzy logic controller for laser surface heat treatments José Antonio Pérez & José Luis Ocaña & Carlos Molpeceres Received: 5 July 2006 /Accepted: 7 November ...

The power control of wireless networks is formulated using a stochastic optimal control framework, in which the evolution of the channel is described by stochastic differential equations. Under this scenario, average and probabilistic Quality of Service (QoS) measures are introduced to evaluate the performance of any control strategy, while a solution of the stochastic optimal power control is obtained through

Caregiver interactions with young autistic children were contrasted with those involving caregivers and developmentally matched mentally retarded and normal infants. Caregivers of autistic children were similar to other caregivers in their responsiveness to child nonverbal communication bids and in their engagement in mutually sustained play. Caregivers of autistic children were similar to caregivers of mentally retarded children in their greater

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Air quality crisis in cities is mainly due to vehicular emissions. Transportation systems are increasing everywhere and the improvements in technology are insufficient to counteract growth. This paper examines the effect of vehicular emission on urban air quality and human health, and focuses on the unique features of an Indian mega city regarding its air pollution. A fact-finding survey was conducted to evaluate the status of air pollution at traffic intersections and the problem arising out of vehicular emissions in the study area. All the key pollutants are in excess of permitted levels. The severe detrimental effects of this pollution are reviewed. The problems have reached threatening dimensions. Vulnerable analysis (VA) has been carried out to evaluate the air pollution stress at different locations within the study area. Options for controlling mobile sources emissions are discussed and a strategic motor vehicle control strategy has been proposed to mitigate the air pollution in the city. Replacement of old vehicles, reformulating diesel fuel, introduction of liquid petroleum gas (LPG) and compressed natural gas (CNG), massive improvements in infrastructure and radical traffic management measures are among the actions that will need to be brought together to achieve this objective.

The BDFM shows economic promise as a variable speed drive or generator. One practical obstacle to commercial exploitation is the presence of operating speeds at which BDFM synchronous action cannot be maintained under open loop conditions. In [7] the authors proposed a control strategy using feedback linearization, requiring full state feedback. In this paper we present a simple rotor current observer with an arbitrary rate of convergence. Simulation results are given to validate the performance.

Despite the ability of matrix converters (MCs) to generate a higher number of voltage vectors compared with standard voltage-source inverters, most of the applications reported in the literature utilize only those having larger amplitudes. This paper investigates the use of MC input voltages with different amplitudes in order to reduce the inherent torque ripple that appears when direct torque control (DTC) is used to drive ac machines, particularly permanent-magnet synchronous motors, as its stator inductance is typically half of that of an induction machine of similar ratings. Utilizing a wider range of input voltage vectors for the MC, but not using the rotating vectors, a new lookup table that distinguishes between small and large torque errors is developed, leading to an enhanced MC-fed DTC. The enhancement enables a reduction in the electromagnetic torque ripple and outputcurrent total harmonic distortion. Furthermore, the proposed control strategy improves the MC voltage transfer ratio up to 86.6% compared with 50% achieved by the conventional DTC using MCs at the expense, however, of slightly decreasing the input power factor control capability. The proposed enhanced MC DTC was tested experimentally, and results comparing its performance with MC DTC using an adapted lookup table are shown.

The EU project "Screening and identification methods for official control of banned antibiotics and growth promoters in feedingstuffs", SIMBAG-FEED, is sponsored by the European Commission, DG Research, 5th Framework Programme, specific programme "Competitive and Sustainable Growth", generic activity "Measurements & Testing.

In the paper, the performances of a rule-based (RB) control strategy for a series Hybrid Solar Vehicle (HSV) are assessed via comparison with a batch genetic algorithm-based (GA) optimization. The RB strategy relies on heuristic rules defined by optimizing ICE start&stop strategy as function of average traction power and current solar irradiation. The comparison with the reference GA benchmark confirms the suitability of the proposed RB strategy for HSV on-board energy management. Extensive simulations were performed to test the influence of driving cycle features, power-prediction time-horizon and solar irradiation on HSV fuel economy. Such simulation analysis, beyond providing useful indications about correct implementation of the RB strategy, also demonstrates the potentialities offered by HSV powertrains in both urban and highway driving conditions.

This paper describes the visual control of a parallel robot called "RoboTenis". The system has been designed and built in order to carry out tasks in three dimensions and dynamical environments; the system is capable to interact with objects which move up to 1m/s. The control strategy is composed by two intertwined control loops: The internal loop is faster and considers the information from the joints, its sample time is 0.5 ms. Second loop represents the visual servoing system, is external to the first mentioned and represents our study purpose, it is based on predicting the object velocity which is obtained form visual information, its sample time is 8.3 ms. Lyapunov stability analysis, system delays and saturation components has been taken into account.

This document provides a market assessment of existing building sensors and controls and presents a range of technology pathways (R&D options) for pursuing advanced sensors and building control strategies. This report is a synthesis of five white papers, each devoted to either the market assessment or
the identification of R&D options to expand the market, and resultant energy savings, from advanced building controls and sensors.

The ideas presented in these white papers were purposefully unconstrained by budget to attempt to capture the full range of potential options. As such, choosing and summarizing highlights from each of these papers, and in turn highlighting this in an Executive Summary, is quite challenging. Instead, what is contained in this Executive Summary is an overview of each chapter.

Market Assessment
The market assessment includes estimates of market potential and energy savings for sensors and control strategies currently on the market as well as a discussion of market barriers to these technologies. Contributors to this report believe that significant energy savings and increased comfort and control for occupants can be achieved with advanced technologies. An estimation of the potential market and energy savings from these advanced technologies is the subject of a follow-on market assessment by TIAX, which should be available in 2005.

Technology Pathways
The Technology Pathway is organized into four chapters:
• Current Applications and Strategies for New Applications
• Sensors and Controls
• Networking, Security, and Protocols and Standards
• Automated Diagnostics, Performance Monitoring, Commissioning, Optimal Control, and Tools.

These chapters can roughly be characterized as follows:
1. Applications to building sub-systems (e.g., lighting) and potential new applications (e.g. disaster mitigation).
2. Sensor and controls hardware including wireless devices and actuators.
3. Issues relating to the inter networking of sensors, controls, and actuators and standards and protocols required for full interoperability.
4. Tools and applications for whole building system integration, monitoring, and controls.

Each technology pathway chapter gives an overview of the technology or application. This is followed by a discussion of needs and the current status of the technology. Finally, a series of research topics is proposed.

With the continuous development, in the last decades, of analytical techniques providing complex information at single cell level, the study of cell heterogeneity has been the focus of several research projects within analytical biotechnology. Nonetheless, the complex interplay between environmental changes and cellular responses is yet not fully understood, and the integration of this new knowledge into the strategies for design, operation and control of bioprocesses is far from being an established reality. Indeed, the impact of cell heterogeneity on productivity of large scale cultivations is acknowledged but seldom accounted for. In order to include population heterogeneity mechanisms in the development of novel bioprocess control strategies, a reliable mathematical description of such phenomena has to be developed. With this review, we search to summarize the potential of currently available methods for monitoring cell population heterogeneity as well as model frameworks suitable for describing dynamic heterogeneous cell populations. We will furthermore underline the highly important coordination between experimental and modeling efforts necessary to attain a reliable quantitative description of cell heterogeneity, which is a necessity if such models are to contribute to the development of improved control of bioprocesses.

The operation of two 60 m2 solar air heaters serving a large studio teaching space has been monitored for a twelve month period. The solar contribution of the heaters was found to be less than 5%, and in some instances the heaters actually contributed to the space heating load. A validated mathematical model of the studio and it's heating, ventilation and air conditioning system was used to investigate performance improvement strategies. It was found a different control strategy and recommissioned control sensors would substantially improve the solar air heater performance. This paper reports the performance of a large solar air heater (SAH) installed on a university building in southern Victoria. The paper begins with a description of the building and the solar air heating system. The methodology used to assess the performance of the solar heating system is described, followed by the results. A validated mathematical model was used to investigate performance improvement strate...

By "reverse engineering" the functions of a specific biological system, habituating control strategies are developed for process control applications. A habituating control system has the distinguishing property of more manipulated inputs than controlled outputs; with the inputs differing significantly in their dynamic effect on the outputs and in the relative costs of manipulating each one. A habituating controller coordinates the use of all the available inputs to achieve high-performance output objectives while simultaneously minimizing the cost of taking control action.

This paper presents an application of Neural Networks to the control of a real system with measurement noise. The system is a kiln and the steps taken to arrive at direct and inverse models are described. The results of controlling the kiln with a Direct Inverse Control strategy are presented.

The Global Pertussis Initiative (GPI) was established in 2001 to assess the global extent of the ongoing problem of pertussis and to evaluate and prioritize pertussis control strategies. Exchange of data, knowledge, and experience, facilitated by discussion and debate, resulted in the formulation, in 2002, of the following recommendation: all countries should consider expanding existing vaccination strategies to include adding pertussis booster doses to pre-school children (4-6 years old), to adolescents, and to those specific adults that have the highest risk of transmitting Bordetella pertussis infection to vulnerable infants. The GPI met again in 2005, where it reinforced its previous recommendation for universal adolescent immunization. Additionally, the GPI recommended implementation of the cocoon strategy (immunization of family members and close contacts of the newborn) in countries where it is economically feasible, and encouraged efforts toward global standardization of pertussis disease clinical definitions and diagnostics. Universal adult vaccination is a logical goal for the ultimate elimination of pertussis disease, but feasibility issues remain obstacles to implementation.

This paper describes an experiment on the "linguistic" synthesis of a controller for a model industrial plant (a steam engine). Fuzzy logic is used to convert heuristic control rules stated by a human operator into an automatic control strategy. The experiment was initiated to investigate the possibility of human interaction with a learning controller. However, the control strategy set up linguistically proved to be far better than expected in its own right, and the basic experiment of linguistic control synthesis in a non-learning controller is reported here.

This paper describes an experiment on the "linguistic" synthesis of a controller for a model industrial plant (a steam engine). Fuzzy logic is used to convert heuristic control rules stated by a human operator into an automatic control strategy. The experiment was initiated to investigate the possibility of human interaction with a learning controller. However, the control strategy set up linguistically proved to be far better than expected in its own right, and the basic experiment of linguistic control synthesis in a non-learning controller is reported here.

The decision on which strategy to use in the control of contagious animal diseases involves complex trade-offs between multiple objectives. This paper describes a Multi Criteria Decision Making (MCDM) application to illustrate its potential support to policy makers in choosing the control strategy that best meets all of the conflicting interests. The presented application focused on the evaluation of alternative strategies to control Classical Swine Fever (CSF) epidemics within the European Union (EU) according to the preferences of the European Chief Veterinary Officers (CVO). The performed analysis was centred on the three high-level objectives of epidemiology, economics and social ethics. The appraised control alternatives consisted of the EU compulsory control strategy, a pre-emptive slaughter strategy, a protective vaccination strategy and a suppressive vaccination strategy. Using averaged preference weights of the elicited CVOs, the preference ranking of the control alternatives was determined for six EU regions. The obtained results emphasized the need for EU region-specific control. Individual CVOs differed in their views on the relative importance of the various (sub)criteria by which the performance of the alternatives were judged. Nevertheless, the individual rankings of the control alternatives within a region appeared surprisingly similar. Based on the results of the described application it was concluded that the structuring feature of the MCDM technique provides a suitable tool in assisting the complex decision making process of controlling contagious animal diseases.

This paper surveys the current research literature on the stochastic lot scheduling problem which deals with scheduling production of multiple products with random demand on a single facility with limited production capacity and signi"cant change-overs between products. The deterministic version of this problem has received signi"cant coverage in the literature; however, the stochastic problem has been addressed only recently. Furthermore, a range of distinctly di!erent analytical methods have been applied to this problem. This paper provides a unifying framework for discussing these approaches and o!ers some explanation and clari"cation of the di!erent analytical methods for this problem. After discussing some of the modeling and managerial implications of this problem, a detailed review of both continuous and discrete time control strategies is given, and areas for further research are outlined.

As automated controllers supplant human intervention in controlling complex systems, the operators' role often changes from that of an active controller to that of a supervisory controller. Acting as supervisors, operators can choose between automatic and manual control. Improperly allocating function between automatic and manual control can have negative consequences for the performance of a system. Previous research suggests that the decision to perform the job manually or automatically depends, in part, upon the trust the operators invest in the automatic controllers. This paper reports an experiment to characterize the changes in operators' trust during an interaction with a semi-automatic pasteurization plant, and investigates the relationship between changes in operators' control strategies and trust. A regression model identifies the causes of changes in trust, and a ‘trust transfer function’ is developed using lime series analysis to describe the dynamics of trust. Based on a detailed analysis of operators' strategies in response to system faults we suggest a model for the choice between manual and automatic control, based on trust in automatic controllers and self-confidence in the ability to control the system manually.

This paper proposes a wheel-assembly automation system, which assembles a wheel into a hub of a vehicle hung to a moving hanger in a car manufacturing line. A macro-micro manipulator control strategy is introduced to increase the system bandwidth and tracking accuracy to ensure insertion tolerance. A camera is equipped at the newly designed wheel gripper, which is attached at the center of the end-effector of the macro-micro manipulator and is used to measure position error of the hub of the vehicle in real time. The redundancy problem in the macro-micro manipulator is solved without complicated calculation by assigning proper functions to each part so that the macro part tracks the velocity error while the micro part regulates the fine position error. Experimental results indicate that tracking error satisfies the insertion tolerance of assembly (±1mm), and thus it is verified that the proposed system can be applied to the wheel assembly task on a moving hanger in the manufacturing line.

SUMMARY Grapevine fanleaf virus (GFLV) is responsible for fan- leaf degeneration, which is one of the most severe virus diseases of grapevines worldwide. GFLV causes substan- tial crop losses, reduces fruit quality and shortens the longevity of grapevines in the vineyard. GFLV is trans- mitted specifically from grapevine to grapevine by the ectoparasitic nematode Xiphinema index, and belongs to the

Today, in Western Europe, Canada and the USA, more than half of all new active tuberculosis (TB) cases occur among foreign-born migrants. This article examines the impact of migration from high TB-incidence to low TB-incidence countries, and compares the costeffectiveness of different TB control strategies. A Medline search was conducted to identify relevant English language publications prior to December 2003. Additional articles were identified from the reference lists from these publications. Despite the high proportion of active cases in low-incidence countries attributable to foreignborn residents, the public health impact is relatively low. Current chest radiograph screening programmes have little impact and are not cost-effective. Screening with sputum culture would improve cost-effectiveness marginally. Treatment of latent infection detected through screening with tuberculin skin testing or chest radiographs may require coercive measures to maximise impact and cost-effectiveness. In contrast, contact tracing, particularly within ethnic communities, appears to be more cost-efficient and less intrusive. In low-incidence countries, screening of migrants at entry has little overall impact and is not a very cost-effective tuberculosis control strategy. More effective alternatives include contact tracing delivered through primary care and increased investment in global tuberculosis control.