Sensor data-based decision making

Increasing globalization and growing industrial system complexity has amplified the interest in the use of information provided by sensors as a means of improving overall manufacturing system performance and maintainability. However, utilization of sensors can only be effective if the real-time data can be integrated into the necessary business processes, such as production planning, scheduling and execution systems. This integration requires the development of intelligent decision making models that can effectively process the sensor data into information and suggest appropriate actions. To be able to improve the performance of a system, the health of the system also needs to be maintained. In many cases a single sensor type cannot provide sufficient information for complex decision making including diagnostics and prognostics of a system. Therefore, a combination of sensors should be used in an integrated manner in order to achieve desired performance levels. Sensor generated data need to be processed into information through the use of appropriate decision making models in order to improve overall performance. In this dissertation, which is presented as a collection of five journal papers, several reactive and proactive decision making models that utilize data from single and multi-sensor environments are developed. The first paper presents a testbed architecture for Auto-ID systems. An adaptive inventory management model which utilizes real-time RFID data is developed in the second paper. In the third paper, a complete hardware and inventory management solution, which involves the integration of RFID sensors into an extremely low temperature industrial freezer, is presented. The last two papers in the dissertation deal with diagnostic and prognostic decision making models in order to assure the healthy operation of a manufacturing system and its components. In the fourth paper a Mahalanobis-Taguchi System (MTS) based prognostics tool is developed and it is used to estimate the remaining useful life of rolling element bearings using data acquired from vibration sensors. In the final paper, an MTS based prognostics tool is developed for a centrifugal water pump, which fuses information from multiple types of sensors in order to take diagnostic and prognostics decisions for the pump and its components --Abstract, page iv

Trade finance in crisis : should developing countries establish export credit agencies ?

New data on export insurance and guarantees suggest that publicly backed export credit agencies have played a role to prevent a complete drying up of trade finance markets during the current financial crisis. Given that export credit agencies are mainly located in advanced and emerging economies, the question arises whether developing countries that are not equipped with these agencies should establish their own agencies to support exporting firms and avoid trade finance shortages in times of crisis. This paper highlights a number of issues requiring attention in the decision whether to establish such specialized financial institutions. It concludes that developing countries should consider export credit agencies only when certain pre-requirements in terms of financial capacity, institutional capability, and governance are met.Debt Markets,Emerging Markets,Access to Finance,Banks&Banking Reform,Financial Intermediation

RFID-Based Smart Freezer

This paper presents a novel radio-frequency identification (RFID)-based smart freezer using a new inventory-management scheme for extremely low temperature environments. The proposed solution utilizes backpressure inventory control, systematic selection of antenna configuration, and antenna power control. The proposed distributed-inventory-control (DIC) scheme dictates the amount of items transferred through the supply chain. when a high item visibility is ensured, the control scheme maintains the desired level of inventory at each supply-chain echelon. The performance of the DIC scheme is guaranteed using a Lyapunov-based analysis. The proposed RFID antenna-configuration design methodology coupled with locally asymptotically stable distributed power control ensures a 99% read rate of items while minimizing the required number of RFID antennas in the confined cold chain environments with non-RF-friendly materials. The proposed RFID-based smart-freezer performance is verified through simulations of supply chain and experiments on an industrial freezer testbed operating at -100degF

In Situ Soil Property Estimation for Autonomous Earthmoving Using Physics-Infused Neural Networks

A novel, learning-based method for in situ estimation of soil properties using a physics-infused neural network (PINN) is presented. The network is trained to produce estimates of soil cohesion, angle of internal friction, soil-tool friction, soil failure angle, and residual depth of cut which are then passed through an earthmoving model based on the fundamental equation of earthmoving (FEE) to produce an estimated force. The network ingests a short history of kinematic observations along with past control commands and predicts interaction forces accurately with average error of less than 2kN, 13% of the measured force. To validate the approach, an earthmoving simulation of a bladed vehicle is developed using Vortex Studio, enabling comparison of the estimated parameters to pseudo-ground-truth values which is challenging in real-world experiments. The proposed approach is shown to enable accurate estimation of interaction forces and produces meaningful parameter estimates even when the model and the environmental physics deviate substantially.Comment: 10 pages, 6 figures, to be published in proceedings of 16th European-African Regional Conference of the International Society for Terrain-Vehicle Systems (ISTVS

A Robust Localization Solution for an Uncrewed Ground Vehicle in Unstructured Outdoor GNSS-Denied Environments

This work addresses the challenge of developing a localization system for an uncrewed ground vehicle (UGV) operating autonomously in unstructured outdoor Global Navigation Satellite System (GNSS)-denied environments. The goal is to enable accurate mapping and long-range navigation with practical applications in domains such as autonomous construction, military engineering missions, and exploration of non-Earth planets. The proposed system - Terrain-Referenced Assured Engineer Localization System (TRAELS) - integrates pose estimates produced by two complementary terrain referenced navigation (TRN) methods with wheel odometry and inertial measurement unit (IMU) measurements using an Extended Kalman Filter (EKF). Unlike simultaneous localization and mapping (SLAM) systems that require loop closures, the described approach maintains accuracy over long distances and one-way missions without the need to revisit previous positions. Evaluation of TRAELS is performed across a range of environments. In regions where a combination of distinctive geometric and ground surface features are present, the developed TRN methods are leveraged by TRAELS to consistently achieve an absolute trajectory error of less than 3.0 m. The approach is also shown to be capable of recovering from large accumulated drift when traversing feature-sparse areas, which is essential in ensuring robust performance of the system across a wide variety of challenging GNSS-denied environments. Overall, the effectiveness of the system in providing precise localization and mapping capabilities in challenging GNSS-denied environments is demonstrated and an analysis is performed leading to insights for improving TRN approaches for UGVs.Comment: 15 pages, 9 figures, 2 tables, to be published in The Proceedings of the Institute of Navigation GNSS+ 2023 conference (ION GNSS+ 23

Tool management in flexible manufacturing systems

In this study, impact of cutting tool life and tool slot size on tool management in Flexible Manufacturing Systems (FMS) is investigated. --Abstract, page iii

Developing Resiliency and Scalability Metrics as Part of Contingency Basing Supply Chain Design

This research focuses on scalability and resiliency in conjunction with providing safe, secure, and self-sustaining contingency basing and supply chain operations. The infrastructure for basic needs such as energy, fuel, water, food, and waste management is critical and needs to be flexible. The methodology concentrates on the scalability and resiliency of 40 functional contingency base blocks with 12 different coefficients. Two types of scalability are used - scaling out, which adds more infrastructure; and scaling up, which adds more resources to the contingency base design. Resiliency is measured by how the system reacts to rapid change, such as an interrupted supply chain network or a surge in soldiers. Strategic planning and clear metrics for resiliency and scalability will increase the effectiveness and efficiency of the current basing standards and the supply chain network. This work fills a critical gap in the literature and will provide the Contingency Basing engineering manager with strategic decision tools and metrics

The Effect of Intravenous L-Carnitine on the Vasospasm Process in the Experimental Subarachnoid Hemorrhage Model

AIM: Cerebral vasospasm after subarachnoid hemorrhage (SAH) is an important cause of morbidity and mortality. In this study, we examined the effects of L-carnitine on the cerebral vasospasm process. MATERIAL and METHODS: Twenty male New Zealand white rabbits were randomly divided into 4 groups. Group 1 served as control; group 2 was not subjected to SAH and received intravenous L-carnitine 3 times; group 3 was subjected to SAH and group 4 was subjected to SAH and treated with 100 mg/kg intravenous L-carnitine at 0, 24, and 48 hours after SAH. All animals were euthanized by perfusion-fixation 72 hours after SAH induction. The brains were then removed and stored in fixative +4 degrees C overnight. The subjects' basilar arteries were sectioned from four separate zones. Basilar artery cross-sectional areas and thicknesses of vessels were measured by using the SPOT for Windows Version 4.1 computer programme. Statistical comparisons were performed by using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: Basilar artery wall thicknesses in group 4 were significantly lower than in group 3 (p=0.009). Basilar artery cross-sectional areas in group 4 were higher than in group 3 and the difference was statistically significant (p=0.008). CONCLUSION: L-carnitine was shown to be potentially beneficial on the resolution of cerebral vasospasm following SAH.WoSScopu

A SysML Framework for Modeling Contingency Basing

Contingency basing presents a planner with numerous design decisions driven by multiple design criteria such as the number of soldiers, base permanency, base location, and other factors. The operational environment of the base is not static either; design requirements change as the mission changes. In this work, we introduce a model-based systems engineering approach to elicit design and operational needs while dealing with the design complexity of constructing a contingency base. The model includes the key facility types that can make a contingency base, interactions between facility types, and required utilities for each facility type. The model elements are kept at an abstract level so the details can be altered as required by the customer needs. Pairing the model with an external analysis tool allows for quick development and testing. Properties of the facility types can be altered either in the model or the analysis tool, and reflected in both. Using the model- based systems engineering concepts of reusability, these elements can be saved and re-used in future base designs allowing for a rapid and adaptable design process. In addition, the sharing of information visually with Object Management Group\u27s Systems Modeling Language™ diagrams enhances the ability to collaborate with nonengineering subject matter experts within the design domain. By graphically showing the conditions and layout of the proposed contingency base, Department of Defense personnel not trained in modeling and simulation were able to interact with the engineering designs and identify gaps in the proposed architecture