Deep Reinforcement Learning for Robust Control of 6-DOF Robotic Manipulators

In this thesis, we explore the performance of a Deep Reinforcement Learning (DRL) controller for robotic manipulators, focusing on a two-link manipulator and a more complex 6-DOF manipulator. The main objective of this study is to design an AI controller using DRL techniques and evaluate its performance, using the PID controller as a benchmark for comparison in both the two-link and 6-DOF manipulator cases. The DRL controller’s performance is compared to a model-free PID controller, which is tuned using H-infinity optimization. Results show that the DRL controller exhibits superior performance in terms of settling times, overshoots, and resilience to disturbances. This study highlights the potential of DRL controllers in controlling robotic manipulators, providing better adaptability and robustness compared to traditional PID controllers. The findings have important applications in various fields, including industrial automation, medical robotics, and aerospace engineering, indicating the promising future of AI-based control systems

Feedback Control of an Exoskeleton for Paraplegics: Toward Robustly Stable Hands-free Dynamic Walking

This manuscript presents control of a high-DOF fully actuated lower-limb exoskeleton for paraplegic individuals. The key novelty is the ability for the user to walk without the use of crutches or other external means of stabilization. We harness the power of modern optimization techniques and supervised machine learning to develop a smooth feedback control policy that provides robust velocity regulation and perturbation rejection. Preliminary evaluation of the stability and robustness of the proposed approach is demonstrated through the Gazebo simulation environment. In addition, preliminary experimental results with (complete) paraplegic individuals are included for the previous version of the controller.Comment: Submitted to IEEE Control System Magazine. This version addresses reviewers' concerns about the robustness of the algorithm and the motivation for using such exoskeleton

Assessment Of Specific T-Cell Receptor Engagement Without Necessity For Identification Of The Relevant Antigen

Individual cancers, even of the same cell type, express unique arrays of distinctive tumor antigens, requiring accurate laboratory measurement of induced immunity against them problematic. Fluorescently tagged reagents (dextramers) that selectively engage clonal T-cell receptors (TCR) can cytofluorographically quantify both frequency and avidity antigen-specific T-cells, but cannot be synthesized without prior identification of the relevant antigen. Since clinically evident tumors may contain as many as 300 unique point mutations capable of generating a large number of uniquely antigenic proteins, and since procurement of such information for each cancer is currently unrealistic, it is presently only possible to assess responses to anti-cancer immunotherapy by clinical determination of estimation of the tumor burden capacity. Therefore, there is a need to develop methodology that can quantify the collective anti-tumor T-cell response, without prior identification of the full array of expressed tumor antigens. We have developed a practical high-resolution method to measure antigen-specific CD8 T-cell responses, via T-cell proton extrusion, an immediate result of selective TCR engagement by antigen presenting cells. The fluorescent emission characteristics of hydroxypyrene trisulfonate (HPTS) correlate with solution-phase proton concentrations, manifesting as increased emission signals. We exploit this TCR characteristic within the context of T-cell activation and show that stimulation with anti-CD3 immunoglobulin stimulates measureable TCR to release protons to a significantly higher degree than unengaged TCR (

Food safety policy and management : a case study of implementing the HACCP system in the fish industry in the Sultanate of Oman

Oman is one of the most important countries engaged in fishing in the Middle East. Fishing and agriculture have been traditional Omani occupations and sources of food and employment for the people in Oman. Over the last 40 years, many major food-importing countries have established strict hygiene regulations and legislation, including definitive standards for fishery products. Many countries exporting fishery products, particularly developing ones, did not have the mechanisms in place to meet such requirements. This led to rejection of consignments and economic losses, a fate suffered by Oman in 1997.Since 1997 Oman, has adopted a preventive approach to food safety, inspired by Council Directive 91/493/EEC and Commission Decision 94/356/EC. The acronym HACCP (standing for Hazard Analysis Critical Control Point) denotes the management philosophy and family of techniques employed to implement the preventive approach.In the light of these factors, it was considered important in this study to examine, through case studies, the extent to which HACCP principles and associated practices were being applied within the fish industry. Thus the difficulties of their application in practice would be assessed, and their reception in the fish processing industry reviewed. To meet this gap in knowledge, a survey was designed and carried out in all Omani regions. Such a study would determine the problems, as seen by the industry, that obstruct the proper implementation of HACCP.The aim of this study is to explore the process of HACCP implementation in the Omani food sector, using the seafood processing sector as a case study. To carry out this study, a triangulation method was employed to collect and validate both qualitative and quantitative data. A questionnaire was employed as the main method of data collection supplemented by semi-structured interviews of key-informants together with the application of a checklist against existing practices in the plants.The analysis of the food safety policy and management in Oman, in relation to the food industry as a whole, reveals that most problems experienced are those related to: a poorly developed institutional and legal framework; weak technical regulations; ill-defined inspection and approval procedures; lack of skilled staff for inspection and laboratory testing; many sub-standard processing factories; and the absence of adequate infrastructure for fish marketing.At the level of individual businesses, fish processing strategies for HACCP system implementation were investigated. The findings of this study are that most Omani fish processors are focused primarily on the development of their HACCP plans. Although developing of the HACCP plan is a fundamental part of the HACCP process, it is not widely understood among managers that this is just the beginning. The implementation and sustaining of a HACCP system can be a difficult and time-consuming mission. The study attributes this weakness to three main elements: poor training of personnel; shortcomings in prerequisite programmes; and a lack of commitment to maintenance of HACCP

Genetic Variation of Human Leukocyte Antigen (Hla) Alleles among Rheumatiod Arthritis Patients in Fujairah

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation that affects the joints. It occurs when the immune system attacks the body\u27s own tissues and organs. The precise cause of RA is not fully understood but evidence suggests that genes, hormones and environmental factors could be involved. It has been established that human leukocyte antigen (HLA) loci is a strong risk factor of RA. Specifically, the shared epitope (SE) region of HLA-DRB1 and variations at position 11 and 13 of HLA-DRB1 and position 77 of HLA-A have shown strong association with RA. The hypothesis of this study was that these variations could be associated with RA patients in the UAE. To study this, regions of the HLA-DRB1 and HLA-A genes from RA and control samples from Fujairah Hospital were sequenced and analyzed. Results indicated that there was minimal incidence of high risk HLADRB1 SE or variations at position 11 and 13 of HLA-DRB1 in these samples. An asparagine at position 77 (Asn77) appeared to be a much strong biomarker for RA in this population (Odds ratio = 20.52, p-value = 0.0001985). Additionally, missense mutations Arg56 and Glu76 were also observed with significantly higher incidence in RA samples. The relevance of these variations warrant further investigation. In summary, HLA-A appears to be a stronger indicator of RA than HLA-DRB1 in the samples analyzed

Zadehian Paradigms for Knowledge Extraction in Intelligent Manufacturing

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Tutorials for Integrating CAD/CAM in Engineering Curricula

This article addresses the issue of educating engineering studentswith the knowledge and skills of Computer-Aided Design and Manufacturing (CAD/CAM). In particular, three carefully designed tutorials—cutting tool offsetting, tool-path generation for freeform surfaces, and the integration of advanced machine tools (e.g., hexapod-based machine tools) with solid modeling—are described. The tutorials help students gain an in-depth understanding of how the CAD/CAM-relevant hardware devices and software packages work in real-life settings. At the same time, the tutorials help students achieve the following educational outcomes: (1) an ability to apply the knowledge of mathematics, science, and engineering; (2) an ability to design a system, component, or process to meet the desired needs, (3) an ability to identify, formulate, and solve engineering problems; and (4) an ability to use the techniques, skills, and modern engineering tools that are necessary for engineering practice. The tutorials can be modified for incorporating other contemporary issues (e.g., additive manufacturing, reverse engineering, and sustainable manufacturing), which can be delved into as a natural extension of this study.journal articl