Juan C. Granda

Temperature Measurement of Molten Pig Iron With Slag Characterization and Detection Using Infrared Computer Vision

Accurate temperature measurement in industrial environments is as important as it is challenging. Precise control over temperature measurement is crucial when processing metals, such as iron or steel, where temperature monitoring is critical to productivity and product quality. In the steel manufacturing process, temperature measurement of molten pig iron is particularly important, as it is a required parameter of the physical models used to control operations in steel furnaces. However, measuring the temperature of molten pig iron is not an easy task. Conventional methods using thermocouples or pyrometers present serious drawbacks which limit their applicability and do not provide accurate measurements. In this paper, an infrared computer vision system is proposed to measure the temperature of molten pig iron while it is being poured. The proposed system confronts two challenges: The stream must be detected in the infrared images, and the slag, which can partially cover the stream of molten pig iron, must be detected and removed from the stream. Fast, robust, and accurate methods are proposed. A calibration procedure for the emissivity of the molten pig iron and for the temperature level is also proposed and applied. This procedure makes it possible to differentiate molten pig iron from slag in the stream. Tests indicate that the results meet production needs.

An efficient networking technique for synchronous e-learning platforms in corporate environments

A synchronous e-learning platform is an effective way to implement training programs for human resources in large corporations. These organizations are usually dispersed in multiple sites very distant from each other, so transport of multimedia data within an e-learning activity is a true challenge. Usually, multimedia data is delivered using the RTP protocol. In this paper, an optimal transport technique based on a multicast overlay network is proposed. The overlay is made up of multiple servers that operate at the RTP level and combine unicast and multicast transport whenever possible. This technique has proved to be more efficient than a solution based exclusively on unicast delivery.

Autonomic Platform for Synchronous e-Training in Dispersed Organizations

Synchronous e-training of human resources uses conferencing services to support training at the workplace. Multimedia data is interchanged between participants in real-time in a synchronous e-training activity providing an enriched learning experience. Large organizations are usually widely dispersed in several sites, so synchronous e-training activities are especially difficult. Most of the sites constitute multicast islands, as IP multicast is available, so the data transport can use IP multicast within the sites of the organization in order to save bandwidth. In this paper, an autonomic synchronous e-training platform based on standard protocols implementing self-management features such as self-deployment, self-organization and self-healing is proposed. The platform deploys an overlay network composed of Real-time Transport Protocol relays acting as multicast/unicast reflectors. The overlay is automatically reorganized according to the joining and leaving of participants and network failures. The use of standard protocols and a modular design enable the interoperability, extensibility and portability of the platform.

Uncertainty Propagation Analysis in 3-D Shape Measurement Using Laser Range Finding

Quality evaluation of rolling processes in the metal industry involves an inspection of the shape of the outgoing products in real time during manufacturing. Shape measurement systems are usually based on 3-D reconstructions of the surface of rolled products. As surface properties are crucial, these systems favor contactless techniques. Using 3-D measurements of the surface of rolled products, several geometric properties can be analyzed. In this paper, we analyze how uncertainty is propagated in a contactless shape measurement system designed and developed by the authors and presented in previous published works. This measurement system is based on active triangulation, and it is able to provide inline width and flatness measurements of long, flat-rolled products in harsh industrial environments. The camera model used to calibrate the vision system is described, and it is used to estimate the uncertainty of the reprojected 3-D points on the scene. The system uses the reprojected 3-D points, and the speed of the product movement in the production line to reconstruct its surface. Thus, the uncertainty of the speed is also estimated. Finally, the propagation of both the uncertainty of the 3-D reprojection, and the uncertainty of the speed into the final width and flatness measurements is analyzed. This paper comprises a detailed uncertainty propagation analysis in 3-D shape measurements computed indirectly through functional relationships.

E-pSyLon: a synchronous e-learning platform for staff training in large corporations

Synchronous e-learning is becoming increasingly popular as a tool for developing human resource training plans in large corporations. A synchronous e-training platform has been designed and implemented to explore the possibilities of synchronous e-training in a large corporation. The client tool is used by learners and instructors to collaborate in real-time during e-training activities. It is based on standard protocols also used in voice over IP, which makes it inter-operable with other software and hardware devices. The functionalities offered by the client tool have been chosen based on those provided by commercial tools, but focusing on the specific characteristics of users and network conditions of corporate environments. This facilitates highly interactive synchronous e-training activities. Multimedia configuration of activities is flexible, so participants with different network link capabilities can join activities. The e-training platform has been tested in real e-training activities in ArcelorMittal Spain. The opinions of the users reflect an enhanced learning experience when using the client tool.

Assessing the QoE in Video Services Over Lossy Networks

Quality of experience is of critical importance in streaming video services, because the traditional quality of service cannot represent the quality perceived by viewers. This work evaluates several objective quality metrics under realistic bursty packet loss conditions in the network, with the support of a packet loss model. Alignment of reference and streamed video sequences (with different levels of spatial-temporal information) are also explored as a technique to prevent inaccurate computation of objective metrics due to frame loss. Finally, the correlation between subjective and objective metrics for each motion level and the computing time of metrics are analysed. The most suitable objective metrics to characterize the real degradation in the quality perceived by viewers, for both off-line and real-time assessment, are proposed. The integration of motion, busty packet loss, sequence alignment after frame loss and computing time of metrics are the main contributions of this research work.

Optimizing Steel Coil Production: An Enhanced Inspection System Based on Anomaly Detection Techniques

Endless strip generation is the key to productivity and quality in several types of steel coil production lines. Coil-tocoil joining by means of welding machines provides such a strip. Since the joint is the weakest area of the strip, its quality must be assessed for the production line to accept it. Therefore, it is necessary to inspect the quality of the weld in the welding-cycle time. Based on our knowledge acquired in the previous development of quality assessment prototypes for steel strips, we present in this article an improved inspection system to detect defective resistance seam welds based on anomaly detection techniques. This system does not rely on the weld classifications done in production lines based on welding control programs. Therefore, it is immune to the influence of both incorrectly configured welding control programs and chemical composition variations from coil to coil of the same steel grade. Tuning the inspection system required a fully experimental design, which would have taken several months using a conventional computer. For this reason, the high-performance computing (HPC) facilities at the Edinburgh Parallel Computing Center were used to cut down the tuning time.

A fast and robust decision support system for in-line quality assessment of resistance seam welds in the steelmaking industry

Assessing the quality of a weld in the steelmaking industry is a complex task. The level of complexity increases when the assessment is based on non-destructive tests. Skilled technicians are often required to make a decision based on automatic assessments of welds. Technicians consider the results of the automatic assessments and use their expert knowledge in order to make a final decision about the quality of the weld. In this paper we propose a decision support system to assess the quality of resistance seam welds of steel strips based on statistical analysis of both the mechanical and electrical variables involved in the welding process to be assessed as well as previously recorded historical data of similar welds. The proposed system is designed following component model based software architecture. The system consists of a set of orthogonal modules: welding variable measurement, welding variable processing and welding quality assessment, communicated by means of dedicated interfaces. The proposed system has been installed in three steel manufacturing lines. With the reduction in the time spent by technicians to make a decision about each weld, the productivity of the manufacturing line has greatly improved. Furthermore, production costs have been reduced since the number of defective welds assessed as non-defective was reduced, and thus the failures in the manufacturing lines due to weld breakages. The experimental results after two years of use in a steel strip galvanizing line are shown.

Design Issues in Remote Visualization of Information in Interactive Multimedia E Learning Systems

This work deals with the most relevant aspects of the visualization of information in interactive multimedia e-learning systems and the underlying design and implementation issues for a tool to support the functionality required in these systems properly. This paper is focused on synchronous e-learning systems, but the concepts presented can be applied to many other interactive systems, such as videoconferencing, collaborative work and e-meeting systems. In these systems a slide presentation is visualized by all users, who usually work collaboratively on the presentation integrating digital ink annotations.Although there are several tools that support the visualization and real-time annotation of electronic presentations, most of them have been designed to work in local visualization environments, typically within a classroom, and few details of their design and the technologies used in their implementation have been disclosed. The main contribution of this paper is to go a step beyond local environments, considering the functionality required in remote visualization environments and providing detailed aspects of their design and implementation.

Overlay network based on WebRTC for interactive multimedia communications

Real-time interactive communications have become critical for business, e-commerce, e-government and education. Teleconferencing systems have been usually deployed using proprietary and expensive systems. Overlay networks are often used to support multi-point teleconferencing and provide services unavailable in the underlying physical networks. With the advent of WebRTC, real-time communication applications can be implemented directly in the browser without installing custom applications or additional plugins. This paper proposes an overlay network based on WebRTC oriented to interactive multimedia communications. The overlay is organized in four planes for data delivery, signaling, control and floor control. The data distribution relies on a clustered organization of WebRTC clients interconnected through a reflector mesh, where a reflector mixes the streams coming from a single cluster. The overlay also includes self-organization techniques, re-organizing the clusters when clients leave or join. The signaling plane uses the Session Initiation Protocol (SIP) for the negotiation and establishment of media sessions between clients and reflectors. Signaling is centralized in a rendezvous point which is also responsible for re-organizing the data plane. Finally, the floor control plane is responsible for limiting the number of streams in the overlay by sharing the data channels between clients. Ubiquity of the communication services and interoperability with other WebRTC applications are the main advantages of our proposal.