Reliability, Safety and Error Recovery for Advanced Control Software

For long-duration automated operation of regenerative life support systems in space environments, there is a need for advanced integration and control systems that are significantly more reliable and safe, and that support error recovery and minimization of operational failures. This presentation outlines some challenges of hazardous space environments and complex system interactions that can lead to system accidents. It discusses approaches to hazard analysis and error recovery for control software and challenges of supporting effective intervention by safety software and the crew

The effect upon UK energy supply schedules of the use of combined heat and power with district heating

The widescale use of combined heat and power with district heating will have a significant effect upon the quantities of primary and secondary fuels used in the United Kingdom. A new methodology for investigating the complex technological interactions between supplies and demands for fuels is developed, and the effect of sample CHP/dh scenarios calculated. Particular attention is paid to electricity generation to determine the impact of CHP/dh upon the operation of the merit order

Design Recovery and Data Mining: A Methodology That Identifies Data-Cohesive Subsystems Based on Mining Association Rules.

Software maintenance is both a technical and an economic concern for organizations. Large software systems are difficult to maintain due to their intrinsic complexity, and their maintenance consumes between 50% and 90% of the cost of their complete life-cycle. An essential step in maintenance is reverse engineering, which focuses on understanding the system. This system understanding is critical to avoid the generation of undesired side effects during maintenance. The objective of this research is to investigate the potential of applying data mining to reverse engineering. This research was motivated by the following: (1) data mining can process large volumes of information, (2) data mining can elicit meaningful information without previous knowledge of the domain, (3) data mining can extract novel non-trivial relationships from a data set, and (4) data mining is automatable. These data mining features are used to help address the problem of understanding large legacy systems. This research produced a general method to apply data mining to reverse engineering, and a methodology for design recovery, called Identification of Subsystems based on Associations (ISA). ISA uses mined association rules from a database view of the subject system to guide a clustering process that produces a data-cohesive hierarchical subsystem decomposition of the system. ISA promotes object-oriented principles because each identified subsystem consists of a set of data repositories and the code (i.e., programs) that manipulates them. ISA is an automatic multi-step process, which uses the source code of the subject system and multiple parameters as its input. ISA includes two representation models (i.e., text-based and graphic-based representation models) to present the resulting subsystem decomposition. The automated environment RE-ISA implements the ISA methodology. RE-ISA was used to produce the subsystem decomposition of real-word software systems. Results show that ISA can automatically produce data-cohesive subsystem decompositions without previous knowledge of the subject system, and that ISA always generates the same results if the same parameters are utilized. This research provides evidence that data mining is a beneficial tool for reverse engineering and provides the foundation for defining methodologies that combine data mining and software maintenance

Protection of Future Electricity Systems

The electrical energy industry is undergoing dramatic changes: massive deployment of renewables, increasing share of DC networks at transmission and distribution levels, and at the same time, a continuing reduction in conventional synchronous generation, all contribute to a situation where a variety of technical and economic challenges emerge. As the society’s reliance on electrical power continues to increase as a result of international decarbonisation commitments, the need for secure and uninterrupted delivery of electrical energy to all customers has never been greater. Power system protection plays an important enabling role in future decarbonized energy systems. This book includes ten papers covering a wide range of topics related to protection system problems and solutions, such as adaptive protection, protection of HVDC and LVDC systems, unconventional or enhanced protection methods, protection of superconducting transmission cables, and high voltage lightning protection. This volume has been edited by Adam Dyśko, Senior Lecturer at the University of Strathclyde, UK, and Dimitrios Tzelepis, Research Fellow at the University of Strathclyde

Monroe Urbanized Area MTP 2035

237 pages. Developed by Alliance Transportation Group, Inc. in association with Neel-Schaffer, Inc. Developed for The Monroe Urbanized Area Metropolitan Planning Organization

An operational system for subject switching between controlled vocabularies: A computational linguistics approach

The NASA Lexical Dictionary (NLD), a system that automatically translates input subject terms to those of NASA, was developed in four phases. Phase One provided Phrase Matching, a context sensitive word-matching process that matches input phrase words with any NASA Thesaurus posting (i.e., index) term or Use reference. Other Use references have been added to enable the matching of synonyms, variant spellings, and some words with the same root. Phase Two provided the capability of translating any individual DTIC term to one or more NASA terms having the same meaning. Phase Three provided NASA terms having equivalent concepts for two or more DTIC terms, i.e., coordinations of DTIC terms. Phase Four was concerned with indexer feedback and maintenance. Although the original NLD construction involved much manual data entry, ways were found to automate nearly all but the intellectual decision-making processes. In addition to finding improved ways to construct a lexical dictionary, applications for the NLD have been found and are being developed

MS

thesisThe relationships between stress and pregnancy outcomes in hospital nurses were examined retrospectively. Nurses who had singleton pregnancies completed a questionnaire on perceived role strain, life changes, and perinatal complications. Role strain was significantly correlated to complications during antepartum and marginally related to postpartal problems. Nurses who experienced increased role strain were noted to engender many life changes. If the life changes they experienced were undesirable and only moderately controllable, regardless of role strain, they correlated with intrapartal complications. If problems were noted antepartally, they correlated highly with adverse intrapartal and postpartal outcomes. Complications, intrapartum to postpartum and intrapartum to newborn, were significantly related. Stress did not correlate significantly to newborn complications; nevertheless, the incidence of birth defects was high. No significant differences existed between intensive care and transitional care nurses in terms of role strain or pregnancy complications

Ecosystem Level Effects of Climate Change on Northern Peatlands

Northern peatlands are the world’s most efficient terrestrial ecosystems at storing carbon. The effects of global climate change are expected to be intensified in high latitude regions of the northern hemisphere, where peatlands are a dominant landscape feature. Accordingly, there is concern that climate change will change peatlands from carbon sinks into carbon sources. In order to better understand the impacts of climate change on peatland ecosystems, the research presented in this dissertation focuses on several mesocosm experiments conducted to develop a better understanding of the interactive effects of three key climate change stressors (increased atmospheric CO2, increased temperature, decreased water table elevation) on northern peatland vegetation structure and carbon cycling functions. Experimental findings include observations that temperatures between 4 and 8°C above ambient conditions triggered a plant community restructuring event, supporting the expansion of graminoids at the expense of Sphagnum mosses. This change in plant community was associated with an increase in dissolved organic carbon (DOC) concentration and lability, characteristics that indicate enhanced carbon release and a threat to northern peatland carbon stores. These findings were extended through further analysis to determine that differences in plant community structure were mechanistically linked to changes in carbon cycling functions through the introduction of microbial priming-like effects. Specifically, rooting growth forms increased belowground DOC lability, stimulating microbial activity and increasing respired CO2 rates — likely through the introduction of simple root exudates. These findings were then placed into the broader context of northern peatland climate change research using stable state theory as a framework to clarify the key factors that threaten peatland stability, point towards disturbance thresholds, and provide insights on the short- and long-term impacts of state shifts on northern peatland carbon uptake and storage

Electrokinetically-Enhanced Emplacement of Lactate in a Chlorinated Solvent Contaminated Clay Site to Promote Bioremediation

Bioremediation through the injection of electron donors and bacterial cultures is effective at treating chlorinated solvent contamination but faces limitations in low permeability zones where the injected amendments cannot be delivered successfully. Using electrokinetics in combination with bioremediation to enhance the delivery of amendments was tested at a chlorinated solvent contaminated field site, where lactate was injected into clay under a direct current. Advection at locations with higher hydraulic conductivities contributed to lactate transport and dilution of aqueous chlorinated solvents. There was evidence of successful delivery of lactate by electromigration (EM) in all monitoring locations with EM lactate transport rates between 1.3 to 3.0 cm/day. Lactate emplacement resulted in the stimulation of bacterial populations and evidence suggests some biodegradation of chlorinated solvents was observed on site. This research provides evidence that with further field investigation, electrokinetically-enhanced bioremediation has potential as a treatment strategy for contaminated low permeability strata