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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Optical Sensor Tasking Optimization for Space Situational Awareness

Bryan David Little (6372689) 02 August 2019 (has links)
In this work, sensor tasking refers to assigning the times and pointing directions for a sensor to collect observations of cataloged objects, in order to maintain the accuracy of the orbit estimates. Sensor tasking must consider the dynamics of the objects and uncertainty in their positions, the coordinate frame in which the sensor tasking is defined, the timing requirements for observations, the sensor capabilities, the local visibility, and constraints on the information processing and communication. This research focuses on finding efficient ways to solve the sensor tasking optimization problem. First, different coordinate frames are investigated, and it is shown that the observer fixed Local Meridian Equatorial (ground-based) and Satellite Meridian Equatorial (space-based) coordinate frames provide consistent sets of pointing directions and accurate representations of orbit uncertainty for use by the optimizers in solving the sensor tasking problem. Next, two classical optimizers (greedy and Weapon-Target Assignment) which rely on convexity are compared with two Machine Learning optimizers (Ant Colony Optimization and Distributed Q-learning) which attempt to learn about the solution space in order to approximate a global optimal solution. It is shown that the learning optimizers are able to generate better solutions, while the classical optimizers are more efficient to run and require less tuning to implement. Finally, the realistic scenario where the optimization algorithm receives no feedback before it must make the next decision is introduced. The Predicted Measurement Probability (PMP) is developed, and employed in a two sensor optimization framework. The PMP is shown to provide effective feedback to the optimization algorithm regarding the observations of each sensor.<br>
52

Dynamic Cyber-Incident Response

Mepham, Kevin Douglas January 2018 (has links)
Cyber-Incident Response (or, as it was initially called, Computer Incident response) has traditionally followed cyclic models such as the SEI Incident Response Cycle and SANS models, which aim to detect and identify incidents, stop, contain and eradicate them. Using the knowledge gained from the incidents, these models then advocate improving the capabilities to defend against subsequent attacks of the same nature. Although some later versions of these models, including the NIST model proposed in 2012, have nested the cycles to provide a more reactive response, they are neither demonstrably empirically founded nor do they represent the interests of all stakeholders within an organisation. This research addresses cyber-incident response from a broader perspective, looking from the viewpoint of a cross-functional set of stakeholders and ensures that incident response decisions are sensitive to temporal priorities, taken from an organisation-wide perspective and provide a range of responses rather than only containing and eradicating an incident. During this research, principal component analysis and structural equation modelling were used to develop the Dynamic Cyber Incident Response Model (DCIRM) which resulted in the development of a fielded prototype tool, the Cyber Operations Support Tool (COST). COST was then subjected to both controlled experimentation and operational validation. Empirical analysis of both of these activities confirmed the utility and effectiveness of the COST and the underlying DCIRM. The COST has since been used to train military cyber operational planners. The novel areas of this research are the dynamic nature of DCIRM which takes account of the changing asset values based on the point in the business/mission cycle, the trade-off between risk to the organisation and gathering intelligence during an incident, the flexibility in response options within organisational constraints and the abstraction of the information to allow a non-cyber specialist to make an appropriate incident response decision.
53

Danger prediction by modern technology : The role of wearable technology in improving workers’ situational awareness in hazardous industries

Larsson, Simon Lars Johan January 2019 (has links)
The health and safety of workers is critically important to all companies, especially those operating in hazardous environments.  Companies typically rely on an array of personal protective equipment to help ensure the safety of their workers, however as technology evolves, a new generation of devices are helping revolutionize the industry.  Wearable technology is now becoming commonplace in both our personal and professional lives.    This study focused on understanding the use of, and attitude towards, various wearable technologies by workers in hazardous environments.  It also explored the change in perception within the workers as these technologies were leveraged and made recommendations for improvement in the future.   A qualitive methodology was applied to understand the people, social, and cultural context.  Participants from industry were interviewed in an inductive and iterative manner, extracting data with an emphasis on the narrative.  Thematic analysis was then utilized to distill the data into Codes, Categories, and ultimately Concepts.   While it became evident that workers had limited personal experience with wearable technology outside of the workplace, they all used it in some manner during their work.  The use of wearable technology was largely motivated by policies and procedures imposed by the companies.  Interestingly, the workers did have an expectation that the user of these devices had a positive impact on their overall safety.  Somewhat surprisingly, the outlook on the future of the technology was not very positive.  There are several opportunities for improvement both to design and implementation of safety related wearable technology, as well as a desire to better leverage artificial intelligence and augmented reality.   Most companies utilize some level of wearable technology to assist in keeping their workers safe.  How workers utilize wearable technology to identify dangerous locations and situations varies greatly from organization to organization, but also between individual workers within any organization.  Although the use of wearable technology within the workplace has been demonstrated to improve safety, the primary motivator for its use is the fact that organization mandate their staff to compliance through policies and standard operating processes. Despite the fact that personal safety should be of utmost importance to any worker, they appear to be so unmotivated to actually utilize the technology available to them that it must be made mandatory through policy.  Within this environment, it becomes very difficult for workers to consider how wearable technology capabilities can be improved in regard to safety-related situational awareness.
54

Eye tracking metrics for workload estimation in flight deck operations

Ellis, Kyle Kent Edward 01 July 2009 (has links)
Flight decks of the future are being enhanced through improved avionics that adapt to both aircraft and operator state. Eye tracking allows for non-invasive analysis of pilot eye movements, from which a set of metrics can be derived to effectively and reliably characterize workload, this research will generate quantitative algorithms to classify pilot state through eye tracking metrics. Through various metrics within the realm of eye tracking, flight deck operation research is used to determine metric correlations between a pilot's workload and eye tracking metric patterns. The basic metrics within eye tracking, such as saccadic movement, fixations and link analysis provide clear measurable elements that experimenters analyzed to create a quantitative algorithm that reliably classifies operator workload. The study conducted at the University of Iowa's Operator Performance Lab 737-800 simulator was outfit with a Smarteye remote eye-tracking system that yielded gaze vector resolution down to 1 degree across the flight deck. Three levels of automation and 2 levels of outside visual conditions were changed on a KORD ILS approach between CAT II and CAT III visual conditions, and varying from full autopilot controlled by the pre-programmed flight management system, flight director guidance, and full manual approach with localizer and glide slope guidance. Initial subjective results indicated a successful variation in driving pilot workload across all 12 IFR pilots that were run through the 7 run testing sequence.
55

Monitoring and Use of Social Media In Emergncy Management In Florida

Martini, Leila 23 October 2014 (has links)
The emergence of mobile technologies and social media applications has led to a shift in the emergency/disaster related communication environment. Citizens are playing an increasingly important role in providing real time information to emergency organizations. This shift has resulted in an expectation by the public that emergency management (EM) organizations monitor and respond to calls for help disseminated via these applications. The purpose of this study is to explore the extent to which Florida EM agencies have incorporated the monitoring of social media into their organizational processes. The state of social media use in Florida is under researched. In this explanatory sequential design study, Florida EM personnel was surveyed using the CNA Analyst/National Emergency Management Association (NEMA) survey (Su et. al, 2012) on the use of social media in EM. Subsequently, a subset of respondents was interviewed to determine to what extent they have incorporated the monitoring of social media into their organizational processes. Several recommendations can be made related to the use of social media in emergency management in Florida. Each of these is discussed in detail: 1.) Reverse mentoring programs; 2.) Development of social media policies; 3.) Continue to attend trainings and conferences; 4.) Explore promising practices; and 5.) Social marketing campaigns for citizens. Overall, it appears that Florida has an immature yet evolving system for use of social media in emergency management. While Florida EM agencies are knowledgeable about social media in general, they lack policies, systems, and staff to take full advantage of social media as a tool in emergency management. As more training is offered, and promising practices are shared, systems will likely continue to evolve. The evolution of systems within agencies will depend largely on leadership attitudes, organizational policies, and staffing resources.
56

Modeling situated health information seeking and use in context the use of two approaches to grounded theorizing as applied to 81 sense-making methodology derived narrative interviews of health situation facing /

Song, Mei. January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 292-306).
57

Differences in Situational Awareness and How to Manage Them in Development of Complex Systems

Alfredson, Jens January 2007 (has links)
Situationsmedvetenhet (Eng. Situational Awareness), (SA), handlar om att ha koll på läget och vara medveten om vad som händer. Redan då ett komplext system utvecklas får vi en möjlighet att påverka vilken SA en framtida användare av systemet kan komma att få. Det gäller att ta tillvara på detta tillfälle! Ibland uppträder skillnader i SA, beroende på en rad olika orsaker. Denna avhandling handlar om SA och hur man kan använda de skillnaderna vid utveckling av komplexa system. Detta är relevant vid utveckling av en rad olika typer av komplexa system, även om de flesta exempel i denna avhandling kommer från flygdomänen. Avhandlingen innehåller beskrivningar hämtade från litteratur inom området och förslag på utveckling av SA-teori utifrån fokus på just skillnader. Skillnaden mellan vad du behöver vara medveten om och vad du verkligen är medveten om föreslås ge en indikation om individens SA. Vidare föreslås skillnaden mellan vad du är medveten om och vad du tror dig vara medveten om också ge en indikation om individens SA. SA kan skattas för en grupp av människor som arbetar tillsammans, genom variationerna i hur samstämmiga deras uppfattningar är. Termen situationshantering (Eng. Situation Management), (SM), föreslås med en vidare mening än SA, inkluderande SA, men också varje del av perceptionscykeln, hantering av mentala resurser och hantering av situationen genom extern påverkan. SM är en väl lämpad term vid utveckling av komplexa system då fokus här är på situationen och hur den kan hanteras, snarare än fokus på vad en individ eller en grupp uppfattar. Att skatta skillnader i SA och att kunna särskilja olika typer av skillnader är viktiga förutsättningar för att kunna hantera skillnader i SA vid utveckling av komplexa system på ett bra sätt. I avhandlingen gås flera sätt att skatta sådana skillnader igenom och speciellt tas för- och nackdelar med ögonrörelsemätning upp. Med referens till litteraturen och till de bilagda artiklarna beskrivs skillnader i SA beroende på a) designalternativ, b) roller i processen från utveckling till användning c) kontext och d) analysnivå. Skillnaderna i SA föreslås ses som både kvantitativa (dvs. hög eller låg SA) och kvalitativa (tex. olika aspekter av en situation). Ansatser såsom SM, realtidsvärdering, mätning och analys av SA på flera nivåer samtidigt samt simulatorbaserad design föreslås för att hantera skillnader i SA vid utveckling av komplexa system. / What’s up, Doc? Situational awareness (SA) is about being aware of what is going on. Already when a complex system is developed there is an opportunity to help a future user of the system to form a better SA. Let us make the best out of this opportunity! When assessing SA, differences in SA will sometimes appear. This dissertation is about SA, and how to manage differences in SA in development of complex systems. This topic is highly valid for development of a variety of complex systems, although most examples in this dissertation are from the aviation domain. Framed by state of the art literature, suggestions are made on theoretical improvements of SA theory, with a focus on differences. The difference between what you are required to be aware of and what you are aware of is suggested as a SA-indicator. Also, the difference between what you are aware of and what you think you are aware of is suggested as another SA-indicator. Further, differences within a team such as variations in degree of agreement could be used for team SA assessment. Also, the term situation management (SM) is suggested, with a proposed wider meaning than SA, including SA and every part of the perception action cycle, the management of mental resources, and external means of managing the situation. SM is a suitable term when developing complex systems due to the focus on the situation and how that could be managed, instead of only focusing on what is perceived by an individual or team. Assessing differences in SA and to differentiate between various types of differences are recognised as important prerequisites to effectively manage differences in SA in development of complex systems. Several assessment techniques are reviewed and especially advantages and disadvantages of the use of eye movements for SA assessment are described. With reference to the literature as well as to the appended papers differences in SA due to a) design alternatives, b) roles in the design-use process, c) context, and d) level of analysis, are described. Differences in SA are suggested to be regarded as both quantitative (i.e. high or low SA) and qualitative (e.g. various aspects of a situation are regarded). Approaches such as, SM, on-line evaluation of SA, simulator based design, as well as measuring and analysing SA on multiple levels simultaneously, are suggested as means to manage differences in SA in the development of complex systems.
58

An Evaluation of the Convergent Validity of Situational Assessment of Leadership-Student Assessment (SALSA© ) with Multi-Source Feedback in MBA and Ed.D. in Educational Leadership Students

Tucker, Justin 01 May 2011 (has links)
The current study assessed the convergent validity of the Situational Assessment of Leadership – Student Assessment (SALSA©), a situational judgment test (SJT), with multi-source ratings. The SALSA© was administered to MBA and Ed.D. in Educational Leadership students via Blackboard; multi-source ratings, which paralleled the leadership dimensions of the SALSA©, were administered online. Each student completed the SALSA© and was rated by his or her supervisor, 3-5 peers, 1-5 subordinates, and him/herself. SALSA© scores were not correlated with any of the corresponding dimensions on multi-source ratings. This finding may suggest that the multi-source ratings and SALSA© are not measuring the same leadership construct; or these results may be due to low variance in SALSA scores and low variance in the ratings. Self ratings were not significantly higher than other ratings, with three exceptions. Also, no difference was found between SALSA scores for MBA and Ed.D. students. This study was limited by the small sample size.
59

Analytical approach to the design of optimal satellite constellations for space-based space situational awareness applications

Biria, Ashley Darius 15 February 2012 (has links)
In recent years, the accumulation of space debris has become an increasingly pressing issue, and adequately monitoring it is a formidable task for designated ground-based sensors. Supplementing the capabilities of these ground-based networks with orbiting sensing platforms would dramatically enhance the ability of such systems to detect, track, identify, and characterize resident space objects -- the primary goals of modern space situational awareness (SSA). Space-based space situational awareness (SBSSA), then, is concerned with achieving the stated SSA goals through coordinated orbiting sensing platforms. To facilitate the design of satellite constellations that promote SSA goals, an optimization approach is selected, which inherently requires a pre-defined mathematical representation of a cost index or measure of merit. Such representations are often analytically available, but when considering optimal constellation design for SBSSA applications, a closed-form expression for the cost index is only available under certain assumptions. The present study focuses on a subset of cases that admit exact representations. In this case, geometrical arguments are employed to establish an analytical formulation for the coverage area provided as well as for the coverage multiplicity. These analytical results are essential in validating numerical approximations that are able to simulate more complex configurations. / text
60

The dynamics of deployment and observation of a rigid body spacecraft system in the linear and non-linear two-body problem

Ottesen, David Ryan 04 March 2013 (has links)
Modern space situational awareness entails the detection, tracking, identification, and characterization of resident space objects. Characterization is typically accomplished through the use of ground and space based sensors that are able to identify some specific physical feature, monitor unique dynamical behaviors, or deduce some information about the material properties of the object. The present investigation considers the characterizaiton aspects of situational awareness from the perspective of a close-proximity formation reconnaissance mission. The present study explores both relative translational and relative rotational motion for deployment of a spacecraft and observation of a resident space object. This investigation is motivated by specific situations in which characterization with ground or fixed space based sensors is insufficient. Instead, one or more vehicles are deployed in the vicinity of the object of interest. These could be, for instance, nano-satellites with imaging sensors. Nano-satellites offer a low-cost and effective technological platform, which makes consideration of the proposed scenario more feasible. Although the motivating application is rooted in space situational awareness, the techniques explored are generally applicable to flight in the vicinity of asteroids, and both cooperative vs. non-cooperative resident space objects. The investigation is initially focused on identifying the key features of the relative dynamics that are relevant to space situational awareness applications. Subsequently, effective spacecraft control techniques are considered to achieve the reconnaissance goals. / text

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