Correction to: Cloud-based vehicular networks: a taxonomy,survey, and conceptual hybrid architecture

Wireless Networks - The original version of this article unfortunately contained a mistake in the title. The correct title has been published with this erratum.     

Object-oriented intelligent computer-integrated design, processplanning, and inspection

The methodology for developing intelligent integrated computer-aided design and manufacturing systems based on object-oriented principles is discussed. The ways in which the application of these principles affects the nature of these systems are reviewed. The implementation of an automated, intelligent, and flexible computer-integrated-manufacturing (CIM) system prototype using an object-oriented programming environment (Smalltalk-80, Version 4.0) is detailed. A CIM system includes CAD, a process planner, and an inspection planner. Each of these components is discussed individually     

Experimental seismic evaluation of old concrete columns reinforced by plain bars

Concrete buildings reinforced by plain (smooth) bars are one of the special types of old reinforced concrete buildings that were generally built before the 1970s. As columns are generally the most important structural members of a framed structure, understanding their realistic seismic behavior is very helpful in estimating structural deformations, forces and energy dissipation capacities. Furthermore, in most of old‐framed building structures, columns play a key role in the final behavior because of strong beam–weak column conditions. This article reports the results of experimental monotonic and cyclic tests on four concrete column specimens reinforced by plain bars and with various types of splices. Through the experimental results, it tried to obtain more clarification on the complicated behavior of such old reinforced members as well as the differences compared with relevant results of columns reinforced by deformed bars. It was realized that slip (fixed‐end rotation) contribution is the major source of deformation in all specimens independent from type of splices. Moreover, general mode of behavior was restrained‐rocking action independent of type of splice detailing. A simple theory for the explanation of hysteresis force–displacement response was proposed. The theory assumes a concrete block rocking element that is restrained with plain bars at both ends. Copyright © 2010 John Wiley & Sons, Ltd.     

CBPOP: A Domain-Independent Multi-Case Reuse Planner

The reuse of multiple cases to solve a single planning problem presents a promise of better utilization of past experience over single-reuse planning, which can lead to better planning performance. In this paper, we present the theory and implementation of CBPOP, and show how it addresses the multi-reuse planning problems. In particular, we present novel approaches to retrieval and refitting. We also explore the difficult issue of when to retrieve in multi-reuse scenarios, and we empirically compare the results of several solutions we propose. Results from our experiments show that the best ranking function for pure generative planning is not necessarily the best ranking function for multi-reuse planning. The surprising result in the reuse scenarios is that the single-goal case library performed better than larger case libraries consisting of solutions to multi-goal problems.     

Could-based vehicular networks: a taxonomy,survey, and conceptual hybrid architecture

Wireless Networks - In recent times, vehicular network research has attracted the attention of both researchers and the industry partly due to its potential applications in efficient traffic...     

Enhancing robustness and perturbation tolerance of cognitive radio engines with metacognition

A cognitive radio engine (CE) is an intelligent agent which observes the radio environment and chooses the best communication settings that best meet the application’s goal. In this process, providing reliable performance is one of the major tasks in designing CEs for wireless communication systems. The main purpose of this work is providing predictable performance and controlling the cost of intelligent algorithms based on the CE’s experience and complexity analysis respectively. In this work, we extend our meta-CE design to control the cost of computations and provide more reliable performance for providing the minimum requirement of the radio applications in different scenarios. To achieve this, we use robust training algorithm (RoTA) in two different levels alongside of the individual CE algorithms. The RoTA, enables radio to guarantee some minimum output performance based on the learning stages. RoTA uses confidence interval approximation for standard normal distribution to calculate the lower and upper bounds of CE’s expected performance to analyze the reliability of decisions. Moreover, in the case of non-stationary environments, RoTA is facilitated by forgetfulness factor to provide minimum performance guarantees. The second level of RoTA operates in meta-level to control the amount of computation complexity of intelligent algorithms in all levels with respect to the obtained performance and complexity analysis.     

Integrated process planning using tool/process capabilities and heuristic search

CAD–CAM integration has involved either design with standard manufacturing features (feature-based design), or interpretation of a solid model based on a set of predetermined feature patterns (automatic feature recognition). Thus existing approaches are limited in application to predefined features, and also disregard the dynamic nature of the process and tool availability in the manufacturing shop floor. To overcome this problem, we develop a process oriented approach to design interpretation, and model the shape producing capabilities of the tools into tool classes. We then interpret the part by matching regions of it with the tool classes directly. In addition, there could be more than one way in which a part can be interpreted, and to obtain an optimal plan, it is necessary for an integrated computer aided process planning system to examine these alternatives. We develop a systematic search algorithm to generate the different interpretations, and a heuristic approach to sequence operations (set-ups/tools) for the features of the interpretations generated. The heuristic operation sequencing algorithm considers features and their manufacturing constraints (precedences) simultaneously, to optimally allocate set-ups and tools for the various features. The modules within the design interpretation and process planner are linked through an abstracted qualitative model of feature interactions. Such an abstract representation is convenient for geometric reasoning tasks associated with planning and design interpretation.     

A reliability-based methodology for considering corrosion effects on fatigue deterioration in steel bridges - Part I: Methodology -

It is known that the effects of corrosion on fatigue originate from two major sources: stress concentration due to corrosion discontinuities (CNF factor) and stress amplification due to loosing net section (NAF factor). In order to account for these effects, a performance function is developed which takes CNF and NAF factors into account and considers both random and time-dependent nature of the involved parameters. In order to consider real fatigue and environmental conditions, the available CNF-y and y-t functions are extended employing α and φ factors, respectively. In addition, some recommendations have been made to establish corrosion pattern of different steel sections. The final output of the methodology is development of a reliability-based procedure to establish time-dependent deterioration profile of a structural member, which assists in decision-making with regard to maintenance activities. The proposed methodology has been applied to Neka Bridge, a railway bridge in northern Iran, which is presented in Part II.     

Modeling errors for dimensional inspection using active vision

In active vision inspection, errors in dimensional measurements are often due to displacement of the sensor and image digitization effects. Using a model of error in linear measurements based on a normally distributed sensor displacement, uniform image digitization and geometric approximation, the accuracy of measurements from a particular sensor setting can be assessed. In comparison with experimental measurements, this error model demonstrates a high predictive ability. Related experiments demonstrate a procedure for assessing the accuracy of sensor settings providing insight into what sensor settings lead to lower measurement variances and thus higher measurement reliability.     

Purposeful gazing and vergence control for active vision

The purposeful-gazing capability of active vision offers advantages to many manufacturing tasks. This paper discusses the problems associated with purposeful gazing and fixation of attention for active vision. In binocular active vision, gazing at a selected target refers to directing the visual axes to capture the target in the (appropriate part of) the visual field by both sensors (cameras), and holding gaze refers to directing the visual axes of the sensors so as to maintain the target or point of interest in the visual field of both sensors. This paper proposes solutions to the important problems involved in gaze stabilization by developing techniques for vergence error extraction, and vergence servo control. Vergence is the tilt movement process of two visual sensors (in a binocular system) in opposite directions to fixate at a selected point. Binocular gazing is realized by decreasing the disparity which represents the vergence error. In order to obtain the disparity for extraction of vergence error, a phase-based approach that robustly and efficiently estimates vergence disparity is developed. To control vergence, we present a dual sampling-rate approach for vision-sensor-based dynamic servo control.