Terahertz imaging and spectroscopy : application to defense and security

The aim of this work is to demonstrate the potential and capabilities of terahertz technology for parcels screening and inspection to detect threats such as weapons and explosives, without the need to open the parcel.In this study, we first present terahertz time-domain spectroscopy and spectral imaging for explosives detection. Two types of explosives as well as their binary mixture is analyzed. Due to the complexity of extracting information when facing such mixtures of samples, three chemometric tools are used: principal component analysis (PCA), partial least square analysis (PLS) and partial least squares-discriminant analysis (PLS-DA). The analyses are applied to terahertz spectral data and to spectral-images in order to: (i) describe a set of unknown data and identify similarities between samples by PCA; (ii) create a classification model and predict the belonging of unknown samples to each of the classes, by PLS-DA; (iii) create a model able to quantify and predict the explosive concentrations in a pure state or in mixtures, by PLS.The second part of this work focuses on millimeter wave imaging for weapon detection in parcels. Three different imaging techniques are studied: passive imaging, continuous wave (CW) active imaging and frequency modulated continuous wave (FMCW) active imaging. The performances, the advantages and the limitations of each of the three techniques, for parcel inspection, are exhibited. Moreover, computed tomography is applied to each of the three techniques to visualize data in 3D and inspect parcels in volume. Thus, a special tomography algorithm is developed by taking in consideration the Gaussian propagation of the wave.Le but de ce travail est de quantifier le potentiel et les capacités de la technologie térahertz à contrôler des colis afin de détecter les menaces telles que les armes et les explosifs, sans avoir besoin d'ouvrir le colis.Dans cette étude, nous présentons la spectroscopie térahertz résolue en temps et l'imagerie multi-spectrale pour la détection des explosifs. Deux types d’explosifs, ainsi que leurs mélanges binaires sont analysés. En raison de la complexité de l'extraction des informations face à tels échantillons, trois outils de chimiométrie sont utilisés: l’analyse en composantes principales (ACP), l'analyse des moindres carrés partiels (PLS) et l'analyse des moindres carrés partiels discriminante (PLS-DA). Les méthodes sont appliquées sur des données spectrales térahertz et sur des images spectrales pour : (i) décrire un ensemble de données inconnues et identifier des similitudes entre les échantillons par l'ACP ; (ii) créer des classes, ensuite classer les échantillons inconnus par PLS-DA ; (iii) créer un modèle capable de prédire les concentrations d’un explosif, à l'état pur ou dans des mélanges, par PLS.Dans la deuxième partie de ce travail, nous présentons l'imagerie par les ondes millimétriques pour la détection d'armes dans les colis. Trois techniques d'imagerie différentes sont étudiées : l'imagerie passive, l’imagerie active par des ondes continues (CW) et l’imagerie active par modulation de fréquence (FMCW). Les performances, les avantages et les limitations de chacune de ces techniques, pour l’inspection de colis, sont présentés. En outre, la technique de reconstruction tomographique est appliquée à chacune de ces trois techniques, pour visualiser en 3D et inspecter les colis en volume. Dans cet ordre, un algorithme de tomographie spécial est développé en prenant en considération la propagation gaussienne de l'onde

Mitigating Crime Risks in the International Logistics Network:the Case of Swiss Post

The terrorist attacks of September 11, 2001 raised major concerns about the vulnerability of global transportation systems to transnational crime and terrorism. Although the attacks occurred in the context of passenger transport, they spurred unprecedented academic research on supply chain security (SCS). Alas, today, more than a decade later, theoretical underpinnings of the SCS discipline remain weak. First, the extant SCS literature offers only a cursory and ambiguous view on the risks that SCS management addresses. Second, the academic research offers little evidence of how security solutions affect security and logistics performance. Due to the scarce and conflicting scientific evidence, managers and authorities are having a difficult time securing the supply chain without disrupting trade and logistics operations. This thesis comprises three research phases that seek to address the two crucial weaknesses of the current academic knowledge. The first phase intends to identify and characterize risks that the SCS management addresses and capture them under a unified theoretical frame â a taxonomy of supply chain crimes. The taxonomy results from a study of managerial descriptions of crime problems that occur or could occur in the supply chain context. The second phase aims at producing a research agenda and at isolating principles for logistics-friendly design of security systems through a synthesis of peer-reviewed academic SCS literature. The synthesis is done using the so-called systematic literature review technique, which follows a prescribed and transparent protocol devised to reduce researcher bias and increase transparency of the review process. The third research phase describes the international postal service from the perspective of Swiss Post, putting a special emphasis on postal security management and law enforcement. The later case study analysis tests validity of the supply chain crime taxonomy and aims to generate evidence-based concepts for improving the postal security management. Research findings imply that supply chain crime problems are numerous and diverse, most important being cargo theft, smuggling, and cyber crime. Despite the variety, however, the crime problems collapse into three main taxonomic classes when categorized by the way criminals interact with the supply chain: 1) by taking assets out of the supply chain, 2) by introducing unauthorized goods into the supply chain, and 3) by directly attacking the supply chain. Besides, the criminals commonly resort to a range of facilitating crimes to carry out crimes of the main taxonomic classes. The literature synthesis found that the SCS discipline has attracted cross-disciplinary and steadily growing academic interest over the past decade. The synthesis also suggested that although there are no universal optimal rules for the SCS management, there are certain design principles that should be considered when SCS management decisions are made. The case study evidence revealed that postal security management comprises multiple domains, each having distinctive goals and employing different security solutions. Except for the airmail domain, the number and stringency of existing postal security controls seem low, though proportional to the current terrorist and crime threats. Application of the design principles into the case study context identified a set of promising concepts for improving the postal security management. [...

Development of an automated robot vision component handling system

Thesis (M. Tech. (Engineering: Electrical)) -- Central University of technology, Free State, 2013In the industry, automation is used to optimize production, improve product quality and increase profitability. By properly implementing automation systems, the risk of injury to workers can be minimized. Robots are used in many low-level tasks to perform repetitive, undesirable or dangerous work. Robots can perform a task with higher precision and accuracy to lower errors and waste of material. Machine Vision makes use of cameras, lighting and software to do visual inspections that a human would normally do. Machine Vision is useful in application where repeatability, high speed and accuracy are important. This study concentrates on the development of a dedicated robot vision system to automatically place components exiting from a conveyor system onto Automatic Guided Vehicles (AGV). A personal computer (PC) controls the automated system. Software modules were developed to do image processing for the Machine Vision system as well as software to control a Cartesian robot. These modules were integrated to work in a real-time system. The vision system is used to determine the parts‟ position and orientation. The orientation data are used to rotate a gripper and the position data are used by the Cartesian robot to position the gripper over the part. Hardware for the control of the gripper, pneumatics and safety systems were developed. The automated system‟s hardware was integrated by the use of the different communication protocols, namely DeviceNet (Cartesian robot), RS-232 (gripper) and Firewire (camera)

Non-destructive Testing in Civil Engineering

This Special Issue, entitled “Non-Destructive Testing in Civil Engineering”, aims to present to interested researchers and engineers the latest achievements in the field of new research methods, as well as the original results of scientific research carried out with their use—not only in laboratory conditions but also in selected case studies. The articles published in this Special Issue are theoretical–experimental and experimental, and also show the practical nature of the research. They are grouped by topic, and the main content of each article is briefly discussed for your convenience. These articles extend the knowledge in the field of non-destructive testing in civil engineering with regard to new and improved non-destructive testing (NDT) methods, their complementary application, and also the analysis of their results—including the use of sophisticated mathematical algorithms and artificial intelligence, as well as the diagnostics of materials, components, structures, entire buildings, and interesting case studies

Big Earth Data and Machine Learning for Sustainable and Resilient Agriculture

Big streams of Earth images from satellites or other platforms (e.g., drones and mobile phones) are becoming increasingly available at low or no cost and with enhanced spatial and temporal resolution. This thesis recognizes the unprecedented opportunities offered by the high quality and open access Earth observation data of our times and introduces novel machine learning and big data methods to properly exploit them towards developing applications for sustainable and resilient agriculture. The thesis addresses three distinct thematic areas, i.e., the monitoring of the Common Agricultural Policy (CAP), the monitoring of food security and applications for smart and resilient agriculture. The methodological innovations of the developments related to the three thematic areas address the following issues: i) the processing of big Earth Observation (EO) data, ii) the scarcity of annotated data for machine learning model training and iii) the gap between machine learning outputs and actionable advice. This thesis demonstrated how big data technologies such as data cubes, distributed learning, linked open data and semantic enrichment can be used to exploit the data deluge and extract knowledge to address real user needs. Furthermore, this thesis argues for the importance of semi-supervised and unsupervised machine learning models that circumvent the ever-present challenge of scarce annotations and thus allow for model generalization in space and time. Specifically, it is shown how merely few ground truth data are needed to generate high quality crop type maps and crop phenology estimations. Finally, this thesis argues there is considerable distance in value between model inferences and decision making in real-world scenarios and thereby showcases the power of causal and interpretable machine learning in bridging this gap.Comment: Phd thesi

Development of spatial inspection methods to support building inspections and compliance

The use of spatial information is important to performing building inspections and determining compliance according to regulations. This research identifies the current issues relating to lack of access to spatial information, poor integration of data sources and lack of quality information in the inspection process. A spatially-enabled framework to support building inspections was designed and proposed. A prototype was developed for a case study in a district of Riyadh, Saudi Arabia, and used to evaluate the framework. The prototype utilised a range of data and imagery of various quality to identify and compare instances of violations with calculated certainties. Results indicate substantial benefits to building inspectors for integrating a spatially-enabled process into a building inspection workflow

Developing a traffic control device maintenance management system interfacing with Gis

Roadway systems contain a wide variety of spatially distributed physical features which require installation, maintenance and replacement. These features include traffic control devices such as signs, signals, pavement markings and streetlights. Several technologies exist that can be utilized by the transportation sector to improve program management of a number of these features. Geographic Information Systems (GIS) technology provides a powerful environment for the capture, storage, retrieval, analysis, and display of spatial (locationally defined) data. A need exists to provide an inventory of the transportation physical plant to interface with a work management system. Information pertaining to the number and condition of such features is required for planning, operating, maintaining, managing and budgeting needs. This thesis summarizes the development of a user-friendly, computerized process to establish a graphical interface between a roadway inventory database and GIS; Evaluation of existing technologies and a survey of current literature will provide a basis for the design of a Traffic Control Device Maintenance Management System. This system will provide a consistent form of technology transfer on a common platform. This system will manage resources by integrating work-orders and the database. The system will utilize GIS technology to integrate a work-order system and a database reporting system for resource management. The work order interface capabilities will include maintenance work-order management, project cost and progress tracking, and program planning and policy analysis; The key is to develop a user-friendly system useful to both the field-level installation crews and planning-level management. A case study in Clark County, Nevada, will be used to evaluate alternative methods of collecting and data on traffic control devices and to illustrate the development of a GIS-based management system. This system is intended to improve the efficiency and effectiveness of operational practices as well as serve as a vital decision support tool for planning and management

Developing a methodology for reducing diamond breakage within processing plant

Diamond breakage has been a problem experienced by diamond operations. Material breakage characterisation methods has been used to determine the hardness or resistance to breakage of diamond host rock, ceramic diamond simulants and simulants embedded in the concrete blocks. This establishes a relationship between specific input energy and degree of breakage that can be used for size reduction to minimise diamond breakage. Ceramic diamond simulants have been used in the process to identify areas that are more prevalent to diamond breakage. It was found that sections of high impact such as the cone crushers and drop height in the surge bins had the highest risk of diamond breakage. Kimberlite ore and ceramic diamond simulants were subjected to compressive breakage in drop weight test. The progeny particle size distribution and degree of breakage were compared. Standard breakage characterisation models were fitted to the breakage data of tested material and relative hardness parameters determined to establish the energy threshold. The breakage tests results showed that the ceramic diamond simulants were very hard while the kimberlite ore and concrete blocks were medium to soft. The material hardness parameters were determined from fitting the breakage data to the standard impact breakage characterisation models (t10-Ecs breakage model and Size dependent breakage model). Concrete blocks and Kimberlite ore showed less resistance to compressive breakage as demonstrated by higher A values compared to the ceramic diamond simulants. Applying material hardness categories presented by Napier-Munn et al (1999), Kimberlite ore was soft, concrete blocks ranged medium to soft and ceramic diamond simulants very hard. The remedial measures implemented in the process were to rubber line the concentrate bins in the recovery to minimise the impact forces, as well the surge bins in the process plant were controlled in such a way that reduces the drop height. Finally, the cone crushers and pan feeders operating philosophy has been improved to start at high speed to achieve choke feed conditions faster and to promote interparticle crushing. The close side settings were also optimized to reduce liner to liner interaction rather enhance particle-to-particle interaction. Through the optimised process, it had been observed that the diamond breakage had dropped below 5% level of the total stones recovered at +5cts. The methodology developed proved to be working after being tested in the chosen flowsheet

Condition monitoring of belt based motion transmission systems

A key asset of Royal Mail Group consists of a nationwide network of sorting offices that forms a constituent component of the means through which the organisation provides an efficient nationwide postal service within the United Kingdom. It may be argued that the efficiency currently possessed by modem sorting offices is due to the utilisation of machines that automate the process of sorting items of mail. The modem letter-sorting machine possessed by Royal Mail can sort up to 30,000 letters per hour; such machines serve as an example of an achievement of the application of Mechatronics. The maintenance of letter sorting machines constitutes a large overhead for the organisation. In the face of competition from pervasive electronic media within the personal communications market and the prospect of deregulation, Royal Mail seeks to streamline its operation in part by the reduction of the overheads incurred through maintenance of letter sorting machinery. The adoption of condition based maintenance techniques and predictive maintenance, for letter sorting machine components such as belts and bearings, forms part of the strategy through which Royal Mail seeks to reduce this overhead. Utilisation of flat belts and timing belts for the implementation of key functions in letter sorting machinery, such as the transportation of items of mail within the mail sorting process, results in the use of many such components within letter sorting machinery. A direct link exists between the maintenance of peak performance of a sorting machine and the maintenance of belt drives; as such the maintenance of belt drives forms a substantial component of the maintenance overhead. The focus of this thesis consists of the condition monitoring of belt based motion transmission systems and in particular, flat belts. The research that forms the basis of this thesis consists of three elements. Firstly, consideration of current knowledge of belt based power transmission such as knowledge of the mechanics of the belt based power transmission process within the context of condition monitoring... [cont'd