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Jun, Hyewon. "Power Management in Disruption Tolerant Networks." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19879.
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Disruption Tolerant Networks (DTNs) are mobile wireless networks that are designed to work in highly-challenged environments where the density of nodes is insufficient to support direct end-to-end communication. Recent efforts in DTNs have shown that mobility provides a powerful means for delivering messages in such highly-challenging environments. Unfortunately, many mobility scenarios depend on untethered devices with limited energy supplies. Without careful management, depleted energy supplies will degrade network connectivity and counteract the robustness gained by mobility. A primary concern is the energy consumed by wireless communications because the wireless interface is one of the largest energy consumers in mobile devices whether they are actively communicating or just listening. However, mobile devices exhibit a tension between saving energy and providing connectivity through opportunistic encounters. In order to pass messages, the device must discover communication opportunities with other nodes. At the same time, energy can be conserved by ``sleeping,' i.e., turning off or disabling the wireless interfaces. However, if the wireless interface is asleep, the node cannot discover other nodes for communication. Thus, power management in DTNs must balance the discovery of other nodes while aggressively sleeping the radio during the remaining periods.
In this thesis, we first develop a power management framework for a single radio architecture that allows a node to save energy while discovering communication opportunities. The framework is tailored to the available knowledge about network connectivity over time. Further, the framework supports explicit trade-offs between energy savings and connectivity, so network operators can choose, for example, to conserve energy at the cost of reduced message delivery performance. We next examine the possibility of using a hierarchical radio architecture in which nodes are equipped with two complementary radios: a long-range, high-power radio and a short-range, low-power radio. In this architecture, energy can be conserved by using the low-power radio to discover communication opportunities with other nodes and waking the high-power radio to undertake the data transmission. However, the short range of the low-power radio may result in missing communication opportunities. Thus, we develop a generalized power management framework in which both radios support the discovery. In addition, we incorporate the knowledge of traffic load and network dynamics and devise approximation algorithms to control the sleep/wake-up cycling of the radios to provide maximum energy conservation while discovering enough communication opportunities to handle the expected traffic load. Finally, we investigate the Message Ferrying (MF) routing paradigm as a means to save energy while trading off data delivery delay. In MF, special nodes called ferries move around the deployment area to deliver messages for nodes. While this routing paradigm has been developed mainly to deliver messages in partitioned networks, here we explore its use in a connected MANET. The reliance on the movement of the ferries to deliver messages increases the delivery delay if a network is not partitioned. However, delegating message delivery to the ferries provides the opportunity for nodes to save energy by aggressively putting their radios to sleep when ferries are far away. To exploit this feature, we present a power management framework, in which nodes switch their power management modes based on the knowledge of ferry location.
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Mistak, Daniel. "Disruption an interrogation of the foundations of ethical systems /." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Spring2010/d_mistak_041910.pdf.
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Pagani, Linda. "Children's coping with marital disruption : a family systems perspective." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41234.
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Adaptive processes were comparatively examined in elementary school children experiencing the postdivorce process and their peers from intact homes using a developmental conceptualization of coping with a family systems perspective. Children's psycho-social coping resources were assessed using the Self Perception Profile for Children, Coping Inventory, Children's Beliefs About Parental Divorce Scale, and Family Environment Scale. Children's global and specific coping efforts were measured using the Child Behavior Checklist and the Schoolagers' Coping Strategies Inventory, respectively. Parental coping efforts were examined using the Ways of Coping Questionnaire. Children from disrupted families were found to have diminished psycho-social coping resources (self-efficacy, self-esteem, coping styles, and social support). Between group differences were found in children's global coping efforts with the frequency and effectiveness of specific coping efforts being influenced by the time since marital disruption. Relationships between children's coping resources and efforts were also observed. In disrupted family systems, parental coping efforts characterized by escape-avoidant and social support seeking behaviors were found to be associated with children's global coping efforts.
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Hellström, Carolina. "Disruption i managementkonsultindustrin : Är det nu det händer?" Thesis, Linnéuniversitetet, Institutionen för informatik (IK), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-98396.
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The Swedish authority ”Tillväxtverket” concludes in the study ”Företagens villkor och verklighet 2020” that the number one obstacle for growth for the SME segment is the lack of the right workforce and right competencies. At a third place, the lack of time for core business and strategic topics are judged the most severe obstacle for growth. Competency, business development and strategic topics are classical areas for management consulting. The academia has predicted that the industry of management consulting will be disrupted since almost ten years. Disruption of the management consulting industry could make management consultancy available to the SME market and, thus contribute to the growth of SMEs. Purpose: The purpose of this study is to identify if small operations consider digital management consulting as relevant and, by this, give an answer on whether the time is now for disruption in the management consulting industry by entering this new segment with digitalized services. Methodology: A quantitative approach is used in this study and the empirical basis is a questionnaire. The respondent-group is based on the smaller segment in the IT-industry. Participants in this study are CEOs and COOs in the industry. Conclusion: Existing research point towards a disruption in the management consulting industry. The basis for disruption is fulfilled; an existing new segment exists, services that can be digitalized exist, the digitalization will enable lower prizing and reduced time-leakage will improve profits, there is also a need for the type of services that can be provided. The quantitative study conducted in this paper to support the above points towards that there is already a usage of external and internal resources for business development amongst small firms in the industry of Professional Services. The conducted survey also contains indications of that previous experience from management consulting will make the decision maker more 4(53) inclined to further explore consulting services. There are also results in the group showing that the experienced group is more positive in relation to “Digital Management Consulting”. The results are not significant for the population and no general conclusions could be drawn from the conducted study. It is suggested to conduct a study over a period of time with a joint approach (both clients and suppliers) to further explore the foundation for disruption in the management consulting industry through a digitalization of services for small and medium sized businesses.
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Giles, Hamilton. "Biotransformation potential of phytosterols in biological treatment systems under various redox conditions." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/48993.
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Phytosterols are naturally occurring compounds which regulate membrane fluidity and serve as hormone precursors in plants. They also have the potential to cause endocrine disturbances in aquatic animals at concentrations as low as 10 µg/L. Wastewaters from several industries which process plant matter can contain phytosterols at concentrations in excess of the above-stated level. Despite their endocrine disruption potential, very little is known about phytosterol physical properties and their biotransformation potential in biological treatment systems. Aerated stabilization basins (ASBs) are common biological treatment systems in North American pulp and paper mills. ASBs are large open lagoons which use tapered surface aeration to remove COD and prevent sulfate reduction in the water column. Phytosterols are released from wood during the pulping process and a small fraction enters the wastewater stream during washing of the pulp. Therefore, phytosterols may be exposed to aerobic or anaerobic environments depending on their solubility and solid-liquid partitioning behavior. The overall objective of this research was to systematically and quantitatively assess the biotransformation potential of phytosterols in biological treatment systems and to examine conditions leading to reduction of these compounds in wastewater effluent streams. The results of this research showed that phytosterols are sparingly soluble with aqueous solubility below 1 µg/L when present as a mixture. Phytosterols have a strong affinity to adsorb to solids and dissolved organic matter. The affinity for aerobic biomass was greater than for wastewater solids. The stigmasterol desorption rate and extent from wastewater solids increased with an increase in pH from 5 or 7 to 9. Phytosterols were biotransformed under aerobic conditions but not under sulfate-reducing or methanogenic conditions by stock cultures developed in this study. Biotransformation under nitrate-reducing conditions could not be confirmed conclusively. The continuous-flow system was successful in removing 72 to 96% of phytosterols. Biotransformation accounted for 23, 14 and 41 % of campesterol, stigmasterol and β-sitosterol removal, respectively. Phytosterols accumulated in the reactor sediment and accounted for 97 % of the total phytosterols remaining in the system. Phytosterols can be removed from wastewater streams during biological treatment by a combination of biotransformation and solids partitioning and control of system pH, DO and available carbon and energy sources can increase the degree of phytosterols removal. The results of this research can be used to engineer effective biological treatment systems for the removal of phytosterols from pulp mill wastewaters and other phytosterol-bearing wastewater streams.
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Lensing, Reshma P. (Reshma Pradhan) 1972. "Historical events and supply chain disruption : chemical, biological, radiological and cyber events." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/28561.
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Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2003.Includes bibliographical references (leaves 98-113).
In the wake of the attacks of September 11, 2001, terrorism emerged as a legitimate threat not just to society, but to corporations as well. This new threat has challenged old business rules and prompted companies to rethink their supply chain operations. However, the events of September 11th were not the first or the only disruptions that the business world had experienced. This thesis reviews past historical events that simulate the effects of a terrorist attack and extracts lessons that can be applied by today's corporations to prepare for future attacks or disruptions. The types of events studied include Biological, Chemical, Radiological and Cyber disruptions. Through the analysis and synthesis of each event's impact, the following generalized recommendations emerged: Prior warnings and events should be acknowledged, studied and utilized. Government intervention may strain operations under disruptive stress. Alternate sourcing should be considered to ease supply issues. Disruptions should be approached in a comprehensive and forthright manner. A security and safety culture should be fostered to prevent disruptions and control their spread. Systems should be prepared to quickly operate in isolation during a disruption. Finally, impact is frequently less severe then initially predicted. Through the events described and these recommendations, this thesis aims to provide lessons for firms to manage their supply chains through future disruptions.
by Reshma P. Lensing.
M.Eng.in Logistics
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Shefali, Shweta. "Disruption of the group health insurance in light of the Affordable Care Act - system approach." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90725.
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Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (page 127) and index.
Our current Healthcare system has multiple problems and it is widely perceived that it is not able to provide quality affordable healthcare to all Americans; millions of Americans are without Health Insurance. The Affordable Care Act (ACA) was signed into law to achieve goal of 'quality affordable care for all American'. The ACA has focus on Individual Health Insurance and the provision of Health Exchange Marketplaces to find and purchase Health Insurance. Disruptive Innovation is a phenomenon in which a new entrant company disrupts the existing established company. As ACA and Health Exchanges have provided level playing field for all companies - new entrants and established - will this lead to disruption of Healthcare? Disruptive Innovations is analyzed from System Approach point of view. Disruption is not limited to two companies; Disruptor System disrupts the existing system including incumbent company. Disruption will be spearheaded by new entrant Disruptor Company and disruption will take place at system level. The existing Healthcare System and Possible Disruptor Systems are defined and investigated. Relative advantage and disadvantages to these two systems with regard to ACA regulations are analyzed. Elements of the healthcare disruptor system are analyzed and information present in the public domain about Health Exchange enrolment after the end of first enrollment seasons is studied to find out who could be possible disruptor and whether disruptor system formation has started.
by Shweta Shefali.
S.M. in Engineering and Management
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Fialkoff, Marc Richard. "Assessment of the Jones Act Waiver Process on Freight Transportation Networks Experiencing Disruption." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/89069.
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In October 2012, Hurricane Sandy caused massive disruption and destruction to the Mid-Atlantic region of the United States. The intensity of the storm forced the Port of New York and New Jersey to close, forcing cargo diversion to the Port of Norfolk in Virginia. Because of the Jones Act restriction on foreign vessels moving between U.S. ports, the restriction on short sea shipping was viewed as a barrier to recovery.
Much of the critical infrastructure resilience and security literature focuses on the "hardening" of physical infrastructure, but not the relationship between law, policy, and critical infrastructure. Traditional views of transportation systems do not adequately address questions of governance and behaviors that contribute to resilience. In contrast, recent development of a System of Systems framework provides a conceptual framework to study the relationship of law and policy systems to the transportation systems they govern.
Applying a System of Systems framework, this research analyzed the effect of relaxing the Jones Act on freight transportation networks experiencing a disruptive event. Using WebTRAGIS (Transportation Routing Analysis GIS), the results of the research demonstrate that relaxing the Jones Act had a marginal reduction on highway truck traffic and no change in rail traffic volume in the aftermath of a disruption. The research also analyzed the Jones Act waiver process and the barriers posed by the legal process involved in administration and review for Jones Act waivers. Recommendations on improving the waiver process include greater agency coordination and formal rulemaking to ensure certainty with the waiver process.
This research is the first in studying the impact of the Jones Act on a multimodal freight transportation network. Likewise, the use of the System of Systems framework to conceptualize the law and a critical infrastructure system such as transportation provides future opportunities for studying different sets of laws and policies on infrastructure. This research externalizes law and policy systems from the transportation systems they govern. This can provide policymakers and planners with an opportunity to understand the impact of law and policy on the infrastructure systems they govern.PHD
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Kollmeier, Juna Ariele. "The intergalactic medium absorption, emission, disruption /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1153856075.
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Shen, Su 1973. "Integrated real-time disruption recovery strategies : a model for rail transit systems." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9127.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000.Includes bibliographical references (leaves 125-126).
Rail transit systems are subject to frequent disruptions caused by a variety of random disturbances, signal problems and door problems, for example. Such disruptions usually last for 10 to 20 minutes, which degrades the level of service significantly. To improve service reliability, transit agencies employ various real time control strategies, such as holding, expressing and short turning, to deal with these disruptions. The effectiveness of these control strategies relies upon the bird's-eye-view of the whole system. Unfortunately, it is difficult for human dispatchers to assess the situation and make good decisions in real time, even with the aid of advanced information technologies such as automatic vehicle location systems. This thesis focuses upon the development of a real-time disruption control model for rail transit systems during disruptions. A deterministic model to representing the rail transit system is first introduced. In the model, the passenger flow rates and running time between stations are constant but station-specific. Assuming that the disruption duration is known, a formulation is developed that makes use of real time vehicle location information and considers holding, expressing and short turning strategies to reduce the impact of the disruption. The objective is to minimize the sum of total platform waiting time and weighted in-vehicle delay. The original formulation is transformed into a linear mixed integer problem, which can be solved by any linear optimizer. The formulation is applied to a disruption scenario on a simplified system based on the Massachusetts Bay Transportation Authority Red Line. The sensitivity of different control strategies to the disruption duration assumption is investigated. The results showed that holding strategies combined with short turning strategies can reduce the weighted waiting time (the sum of platform waiting time and weighted in vehicle delay) by about 10-60%, compared with not applying any control strategies. Expressing only provided modest additional benefits. For the deterministic disruption duration assumption, sensitivity analysis showed that holding and expressing strategies are fairly robust, but the effectiveness of short turning strategies is quite sensitive to the accuracy of the disruption duration estimate. Most problem instances of the formulation can be solved in real-time with the proposed branching sequence used in the branch-and bound algorithm to solve this mixed integer problem.
by Su Shen.
S.M.
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Ogallo, Godfrey G. "Development of Remote Water Quality Monitoring System Using Disruption Tolerant Networking (DTN)." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1452255796.
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Doering, Michael [Verfasser], and L. [Akademischer Betreuer] Wolf. "Disruption Tolerant Vehicular Communication in Public Transportation Systems / Michael Doering ; Betreuer: L. Wolf." Braunschweig : Technische Universität Braunschweig, 2012. http://d-nb.info/1175822663/34.
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Metzler, Florian. "Firms, industries, and technological change : a patent-based approach to studying disruption and disruptors." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122729.
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Thesis: Ph. D. in Engineering Systems, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, 2019Cataloged from PDF version of thesis.
Includes bibliographical references.
This thesis presents a new empirical approach as well as a new patent-based dataset for studying disruption and technology transition cases. At the core of this approach lies a novel engineering systems framework of technological change. The framework focuses on the relationship between changes in technological competencies and changes in product designs, and encompasses both firm-level and industry-level dynamics. The new framework and dataset are applied to the study of three cases of technology transition during the 1993- 2012 period. The cases include (1) disruption in the mobile phone industry with a focus on Apple, BlackBerry, and Nokia; (2) disruption in the photography industry with a focus on Fujifilm, Canon, and Kodak; and (3) technology transition in the automotive industry with a focus on Toyota, Volkswagen, and GM.
The former two industries comprise widely discussed disruption cases, allowing me to demonstrate advantages of the presented approach and develop novel insights into these cases. The third case, on the automotive industry, generates complementary insights by considering an industry with products comprising more integrated product architectures. The case selection allows for cross-case comparisons to begin endogenizing industry-specific factors. The thesis' main contributions are methodological and theoretical: First, I present a new dataset - and corresponding data assembly methods - of comprehensive corporate patent portfolios. The portfolios take into account each firm's corporate family tree structure as well as acquisitions. As such, the dataset reflects the actual range of firms' codified technological activities more closely than previous efforts and enables a more accurate view on how technological change manifests in firms and industries.
To connect the data to theory, I develop a set of novel metrics to operationalize semantic concepts such as technological diversification and concentration of portfolios as well as firms' technological core and growth competencies. These metrics are based on a newly developed variance measure for hierarchically structured networks. I define growth competencies as competencies that undergo rapid year-to-year growth outside of a firm's core competencies. By identifying incumbents' growth competencies from historical data before major transitions, I am able to successfully hindcast future new entrants in the cases presented. Further, I introduce the concepts of technology space and product space as mappings of compositions of technological competencies and of technological competencies required by compositions of products. Second, the thesis makes theoretical contributions to resource-based view (RBV) and disruption literatures.
Specifically, it presents a dynamic extension to the RBV, endogenizing technological change as well as firm-industry interconnections with regard to the emergence of technology convergences and the evolution of product designs. My findings suggest that a firm's relative position and movement in technology space needs to be considered separately from its position and movement in product space, i.e. its changing composition of competencies and its changing composition of products. Specifically, whereas firms' movements in product space can appear abrupt and even surprising - such as the sudden entry into new markets - my analysis shows that changes in technology space tend to be slower, more continuous, and more predictable.
I find that in disruption cases such as with Apple's sudden "entry" into the mobile phone industry, the new framework reveals that it was in fact the mobile phone industry that gradually "entered" Apple's position in technology space - as the technological requirements of phone industry products became more and more similar to Apple's preexisting, and highly stable, competencies. Moreover, I extend the concept of technology-product connections, as put forth statically by RBV theorists, by adding a time-dependent dimension. I argue that incumbent failure - such as Nokia's and Kodak's - can be explained by incumbents' inability to diagnose and respond to the gradual weakening of their technology-product connections; in other words, by neglecting to either adjust their technological competencies or to adjust their product offerings in response to technological change.
In turn, a firm with greater awareness of its own composition of technological competencies relative to its competitors as well as the changing technological requirements of prevalent product designs can deliberately incorporate such insights into strategic decision-making. In the empirical cases, I observe the ability to sense dynamics in technology and product spaces relative to the firm, and the ability to time the firm's actions accordingly, to be more present in some firms than in others. I term the existence of such abilities timing and sensing capabilities and propose them to be a concrete and operationalizable subset of Dynamic Capabilities.
by Florian Metzler.
Ph. D. in Engineering Systems
Ph.D.inEngineeringSystems Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society
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Dehghani, Sanij Mohammad Saied. "Characterizing the Dynamics of Vulnerability for Roadway Infrastructure Systems." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/53507.
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Critical infrastructure systems, such as transportation, energy, water and communication, are the backbones of sustainable economic and social development. The tragedies and catastrophic events in the past few years have motivated researchers to study the vulnerability of infrastructure systems to disastrous events. A number of existing studies address roadway networks where researchers have characterized the robustness and vulnerability of roadways to earthquakes, floods, and targeted attacks.
However, extreme events with infrequent return periods are not very likely to occur in a 50-60 year analysis period of roadways, while many roadways are located in areas that are not even exposed to floods or earthquakes at all. On the other hand, roadway network endogenous characteristics such the condition and degradation over time not only increases the vulnerability of roadways to disastrous events, but also makes the roadway network vulnerable to disruptions that are caused by maintenance and repair activities on the roadways system. Nevertheless, the impacts of these endogenous network characteristics on roadway vulnerability have not been explicitly addressed in the existing studies.
This dissertation introduces the concept of condition-based vulnerability assessment (CBVA) to capture the effect of roadway endogenous characteristics such as condition and condition uncertainties, roadway network deterioration over time, topological properties of roadways, and travel rate and travel pattern on the dynamics of roadway network vulnerably. First a methodological framework is developed and the method is applied to an illustrative roadway system. The results show that the vulnerability of roadway system is more affected by the average condition of the roadway network than by the condition of individual roads in the system. Moreover, the findings show that small uncertainties associated with the condition of individual roads can significantly increase the variance of the predicated vulnerability.
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This initial methodological framework is then enhanced to account for physical degradation of the network over time and network equilibrium, and is applied to a real highway system. For the network studied network degradation increases roadway system vulnerability in a nonlinear mode. The result also suggest that the network vulnerability pattern is not very sensitive to travel pattern and link topological properties when the average network disruption probability (representing average network condition) is less than about 0.5. In other words, at low values of average disruption probability, it does not matter what link has what disruption probability level or how the travelers move across the network. However with further network degradation and as the average network disruption probability increases, the dynamics of network vulnerability depends on travel pattern on the network as well as on the link topological properties.Ph. D.
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Clarke, Neil. "Seasonal effects of treated sewage effluents upon the reproduction and development of European freshwater molluscs." Thesis, Brunel University, 2009. http://bura.brunel.ac.uk/handle/2438/4458.
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The most widespread evidence of environmental endocrine disruption in aquatic wildlife is from the feminising effects of oestrogenic endocrine disrupting compounds. However, very little is known of the effects of these chemicals (and others) upon freshwater molluscs found in our river and lakes. This thesis aimed at evaluating the effects of treated sewage effluent upon the reproductive and developmental cycle of a range of commonly found European freshwater gastropod molluscs. Initial mesocosm experiments were undertaken to test a range of mollusc species for their the suitability to the experimental system, and to test adult snails for their reproductive and developmental responses during spring to summer time. With suitable species chosen, P.corneus, a pulmonate species (sequential hermaphrodite), and V. Viviparus a prosobranch species (dioeious; separate sexes), full reproductive output was assessed over summertime and into autumn, along with developmental responses amongst the F1 generation of snails. My results suggest that the affects of effluent upon the reproductive and developmental cycle of P. corneus are strongly mitigated by both day length and water temperature (day length is most important with V. viviparus); results are sensitive to seasonal effects. However, at the peak of reproduction mid summer, P. corneus produced significantly more egg masses in effluent (100% effluent particularly), and more than one parameter of reproduction was affected. Egg masses were significantly smaller in effluent and contained significantly fewer eggs per mass. Further, there were indications that total reproductive output was increased (100% effluent significantly) in effluent compared to the river water control. In the prosobranch species V. viviparus results were less convincing, however, in 100% effluent a second reproductive peak occurred that was not seen in river water. Further, in both species there was a failure of certain reproductive parameters to observe the normal seasonal decline towards winter. In P. corneus there was a failure to stop producing egg masses in effluent, in V. viviparus the second reproductive peak in effluent could also threaten their survival with winter approaching. Developmental effects in the F1 generation were the subject of preliminary investigations, however, F1 V. viviparus demonstrated a higher than normal incidence of intersex (male and female developmental features) in effluent, and P. corneus appeared to have disturbed reproductive function (disturbance of both male and female reproductive function in the ovotestis). Therefore, both of these species of molluscs demonstrated that they are sensitive to the effects of effluent in mesocosm studies. However, we need to understand much more about their responses to effluent; in particular whether these effects could have repercussions for wild mollusc populations, and whether these effects could occur over more than one generation of snail threatening the survival of wild populations of molluscs.
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Nordin, Syarifah Zyurina. "Task scheduling in parallel processor systems." Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/2510.
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Task scheduling in parallel processing systems is one of the most challenging industrial problems. This problem typically arises in the manufacturing and service industries. The task scheduling problem is to determine a set of task assignments to a set of parallel processors for execution so as to optimize a specified performance measure. The difficulty of the problem is that the scheduling needs to satisfy a set of requirements as well as a range of environmental constraints. The problem is known to be NP-complete.In this study, we consider a non-preemtive task scheduling problem on iden- tical and unrelated parallel processor systems. We are interested in the objective function that minimizes the maximum of the completion time of the entire set of tasks (i.e makespan) so as to ensure a good load balance on the parallel proces- sors. We consider three different task characteristics to the classical task scheduling problem that has a set of n independent tasks to be assigned to m parallel processors.The first task characteristic that we consider is an on-line scheduling with release date specifications on an identical parallel processing system with a centralized queue and no splitting structure. We focus on developing simple and efficient heuristics for this problem. Three heuristic algorithms are proposed to solve this non-deterministic problem with scheduling over time where the availability of each task is restricted by release date. Our approach uses a multi-step method in the task selection phase and a greedy search algorithm in the processor selection phase. The multi-step method is used to reduce the non-determinism in on-line scheduling by partitioning the scheduling process into several procedures. We introduce two procedures in the priority rule loop which we refer to as Cluster Insertion and Local Cluster Interchange.Computational testing on randomly generated data is conducted using Microsoft Visual C++ 6.0 to examine the effectiveness of the proposed multi-step method against the optimal solution. Different size of problems are tested in the experiment involving 3 processors by 200 tasks up to 5 processors by 1000 tasks with five clusters ranging from 10 to 50. The computational results show that all the three heuristics performed very well with the value of the average gaps are improved as the number of the tasks in the system is increases. The average gap for all the three heuristics are less than 1.04% for the largest tested cases (i.e for 1000 tasks run on 5 processors).In the second problem, we address priority consideration as an added feature to the basic task characteristics of unrelated parallel processors scheduling. The priority consideration is defined by a list of ordered independent tasks with priority. A task requires to start processing after another task is finished on the same processor based on priority but may require to start earlier if processed on other machine. Our aim is to develop Mixed Integer Linear Programming models to obtain optimal solutions for three type of priority lists which are ascending order, descending order and general priority list. We validate the model using a case study taken from the literature. Then, computational testing is implemented on the general priority list using AIMMS 3.10 package and CPLEX 12.1 as the solver. Computational results show that the proposed MILP model is effective and produces optimal results for all tested cases. The model is very efficient as 95% of all the instances, which are problem up to 80 tasks assigned on 5 processors, have been solved within 5 minutes of CPU time.In the final problem, we address a further problem for the task scheduling with a disruption problem that occurs on the parallel processor system. The disruption is causes by the unavailability of the processor during a certain time and it is called resource disruption. Our recovery solution for the disruption problem is a rescheduling approach. A MILP model is developed for the rescheduling model for the case of non-resumable tasks. Recovery model for the disrupted initial schedule with dummy insertion is proposed for predictive disruption management and match up schedule for post-disruption management. To evaluate the model, computational testing is performed with different sets of data.Different levels of disruptions are considered with different weights in the objective function to observe the stability of the model. The optimum initial schedule and the rescheduling model is performed using CPLEX 12.1 solver in AIMMS 3.10 package. In our computational results we measure the stability rate which is to observe the stability condition of the current schedule compared to the initial schedule in term of the task migration. From the results, the stability is improved when the number of tasks in the system increases within a reasonable amount of time. Another interesting observation is that our model yields small average gaps that are less than 7.99% within 300 seconds of the CPU time for a large data set that reach 200 tasks by 10 processors. The average gaps are considerably small for the disruption problem since the rescheduling model have to match up with the optimum initial schedule.
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Hofmann, Christopher Michael. "Peptide-Based Systems for the Targeted Disruption and Treatment of Staphylococcus epidermidis Biofilms." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1333559337.
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Torgerson, Leigh, Joseph Hutcherson, and James McKelvey. "TCP PERFORMANCE ENHANCEMENT OVER IRIDIUM." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604499.
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ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, NevadaIn support of iNET maturation, NASA-JPL has collaborated with NASA-Dryden to develop, test and demonstrate an over-the-horizon vehicle-to-ground networking capability, using Iridium as the vehicle-to-ground communications link for relaying critical vehicle telemetry. To ensure reliability concerns are met, the Space Communications Protocol Standards (SCPS) transport protocol was investigated for its performance characteristics in this environment. In particular, the SCPS-TP software performance was compared to that of the standard Transmission Control Protocol (TCP) over the Internet Protocol (IP). This paper will report on the results of this work.
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Simon, Samantha Mea. "Technological Disruption in Entertainment: Navigating the Film Industry's Dynamic Relationship to the Consumer." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/scripps_theses/1028.
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The following thesis acts as a critical cultural progression report surrounding the current technological disruption in the entertainment industry and its impact on consumers. This begins with a study of the history starting in 1910 and covers the urbanization of America during the Industrial Revolution, the developing fan experience, a history of consumer demands in relation to oligopolistic principles and the blockbuster method, the invention and influence of the television, and the current effect of technological advancement in the entertainment industry. Following this historical overview, four chapters will study different methods of analysis covering the intricacies of the current technological disruption using four theories: population ecology, media systems dependency, the mainstream cult, and convergence and participatory culture. The culmination of this work will consist of drawing together the history, the theories, and the contemporary examples into a conclusion about the fate of the media oligopoly in which this researcher points to the importance of seamless integration between the media industry and the consumer by way of three possible outcomes.
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Schipper, Danny, and Lasse Gerrits. "Differences and similarities in European railway disruptionmanagement practices." Elsevier, 2018. https://publish.fid-move.qucosa.de/id/qucosa%3A72188.
Full textAbstract:
Disruptions severely undermine the reliability of railway systems. Consequently, a lot of investments are made to improve disruption management. Much has already been written about disruption management, often with the purpose of supporting operators in their decision making. However, to the best of our knowledge, this literature doesn't consider the structural differences of disruption management in different countries. An overview of the various ways in which disruptions are solved and conditions under which that happens could help rail infrastructure managers and train operating companies to reconsider the ways in which they operate. This paper takes stock of the similarities and differences in how disruptions are managed in Austria, Belgium, Denmark, Germany and the Netherlands. Of importance is not only how these systems work on paper, but above all what happens in practice, i.e. the habits and routines that operators have developed for solving disruptions.
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Campbell, Melissa English. "Structure and Disruption: A Detailed Study of Combining the Mechanics of Weaving with the Fluidity of Organic Forms." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1385041550.
Full text
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Hallin, Erik, and Mikael Fehrm. "Störningsinformation i tågtrafiken : Attityder bland resenärer och tågbolag till störningsinformation och tjänster för sådan information." Thesis, Högskolan Dalarna, Informatik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:du-22601.
Full textAbstract:
When booking a trip along the railway through several train operators it is not uncommon that information about possible disruptions along the railway (that can change or cancel the booked trip) are not relayed to the passengers. Today, research on rail traffic in Sweden is limited. It is unclear how satisfied customers are with the quality of the information they receive during their trip (if they get it at all), including with respect to disruptions. Our partners have identified what they believe is a need among train operators, which is a service for disruption information to travelers. In addition to confirming that there is a need for such a service, we have an interest to investigate how such a service might look like and what the users want. Our research has shown that passengers are not satisfied with either the amount of information about disturbances or how often they get it. Along with KnowitBorlänge, we have come up with a proposed solution that uses already existing technologies to create a portal for an efficient way to get the interference information to travelers.Vid bokandet av en resa längs med järnvägen via flera tågbolag så finns (i dagens läge) inte alltid information kring eventuella störningar längs med järnvägen som kan förändra eller ställa in den bokade resan. I dag är forskning kring bantrafiken i Sverige begränsad. Det är oklart hur nöjda resenärer är med kvalitén på den information de får kring sin resa (om de får den överhuvudtaget), bland annat med avseende på störningar. Vår samarbetspartner har identifierat vad de tror är ett behov hos tågbolag, vilket är en tjänst för information om tågtrafiken för resenärer. Utöver att bekräfta att det här behovet finns har vi även ett intresse att undersöka hur en sådan här tjänst skulle kunna se ut och vad användarna vill ha. Vår forskning har visat att resenärerna inte är nöjda med varken mängden information om störningar eller hur ofta de får den. Tillsammans med Knowit Borlänge har vi kommit fram till ett lösningsförslag som använder befintliga tekniker för att skapa en portal som på ett effektivt sätt levererar störningsinformation till resenärer.
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Krikos, Alexis Christopher. "Disruptive technology business models in cloud computing." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59255.
Full textAbstract:
Thesis (S.M. in System Design and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references.
Cloud computing, a term whose origins have been in existence for more than a decade, has come into fruition due to technological capabilities and marketplace demands. Cloud computing can be defined as a scalable and flexible shared computing solution in which third-party suppliers use virtualization technologies to create and distribute computing resources to customers on-demand, via the Internet browser. Cloud computing is steadily replacing more rigid software and services licensing models in both small/medium business (SMB) and in the enterprise. This analysis poses a twofold examination of cloud computing as a disruptive technology. First, cloud computing has replaced existing software and services licensing business models, owing to its scalability, flexibility, and utility-based pricing. Second, as cloud computing takes hold as the prominent computing services business paradigm, other disruptive forces will surface to further integrate and differentiate the cloud computing landscape. These forces include the customer-driven need to create hybrid clouds between private and public cloud domains, vendor-agnostic solutions in the cloud, along with open standards to make cloud computing ubiquitous. Three criteria are assessed in characterizing cloud computing as a disruptive technology (Christensen, 2002).1 First, cloud computing as an innovation, must enable less-skilled and/or less-wealthy individuals to receive the same utility as only the more-skilled and/or more-wealthy intermediaries could formerly attain. Second, cloud computing must target customers at the low end of a market with modest demands on performance, but with a performance trajectory capable of exceeding those demands and thus taking over markets, tier by tier. As a corollary to this second criterion, the cloud computing business model allows the disruptive innovator to achieve attractive returns at prices that are unattractive to the incumbents. Third, an ecosystem in the form of a fully integrated single entity or a set of modular entities is required to successfully support the disruptive innovation. The analysis has shown that cloud computing is replacing traditional outsourcing and premise-based data centers for software applications and services delivery. Scalability, flexibility, virtualization, and cost are essential business drivers. However, current cloud computing solutions, especially in the enterprise, lack sufficient security and customer control. This gives rise to numerous subordinate disruptive business solutions which enable the enterprise and emerging demographics to develop and deploy their applications and services in a secure, controlled, profitable, and ubiquitous environment.
by Alexis Krikos.
S.M.in System Design and Management
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Kean, Van Alexander. "The Petroleum Disruption Response System." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/41502.
Full textAbstract:
The petroleum disruptions experienced in 1973 and 1979
demonstrated to the Department of Defense (DoD) that, for
numerous reasons, the normal support for DoD requirements
could rapidly deteriorate. Crude oil shortages caused DoD's
historical supplier to prorate or completely cease deliveries
under existing contracts, and it became difficult for the
Defense Fuel Supply Center (DFSC) to secure replacement or
follow-on contracts for fuels. In order to sustain necessary
peacetime activities, the services were forced to dip into the
war reserves. The effect was a decrease in the wartime
sustainability of our forces until the war reserves were
reconstituted.
As a result of DoD "Supply Assurance" initiatives prompted by the 1979 disruption, numerous policy options have been developed to help the Office of the Secretary of Defense (OSD) more effectively deal with future shortage situations. The key to avoiding the problems of 1973 and 1979 is early identification of shortage situations and selection of appropriate policy options designed to ensure a steady supply of military fuels during energy emergencies.
The Petroleum Disruption Response System (PDRS) is a decision support system designed to assist DFSC energy analysts and planners in preparing recommendations for the Office of the Assistant Secretary of Defense (OASD) energy policy staff on appropriate policy options to ensure adequate petroleum supplies for the national defense.
This paper contains a conceptual model of PDRS that is
based on a network optimization distribution model. The model would optimize the resupply distribution network in terms of
minimum cost solution.
Master of Science
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Ashworth, Geoffrey (Geoffrey John). "Architectural disruption in aerospace." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/55202.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 70-71).
Distinctive technology and customer / supplier relationships are currently the primary sources of competitive advantage in the Aerospace industry. Modular Open System Architecture (MOSA) requirements represent a significant disruption to this mode of competition. The United States Department of Defense intends to accelerate the rate of aerospace innovation and inject additional competitiveness into the procurement process through the modularization of its products and effective intellectual property management. This combination of architectural disruption and new customer capabilities has the potential to reduce the industry's opportunity to capture value from innovative technologies or a position as first supplier. Historical examples such as Polaroid and IBM demonstrate the organizational paralysis that often results from disruptions in product architecture. The competitive formula becomes ingrained in the processes, resources, and culture of mature companies and is no longer explicit knowledge, which limits the company's ability to develop the capabilities required to compete in its new environment. Competing in a MOSA environment will require the development of new organizational capabilities such as rapid experimentation, fighting standards wars, and protecting system-level knowledge. Defining the disruptive threat and the foundations of current core competencies will enable firms to develop the organizational capabilities essential for this shift in competitive context.
(cont.) The author will present several historical examples of architectural disruption, a framework for evaluating the disruptive change, and an identification of organizational anchors that may hinder a particular competitor's ability to respond to MOSA. The goal of the thesis is to start a dialogue within an identified incumbent with in hopes of beginning the organizational transformation required to effectively compete in this new era.
by Geoffrey Ashworth.
S.M.
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Kijewski, Richard Joseph. "The impact of disruptive technology trends on networking hardware vendors." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/105310.
Full textAbstract:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 78-80).
The creation of the Internet has enabled the modern day technology economy. A critical component of the Internet is the routing and switching products that enable and support the movement of data through the Internet. These routing and switching products have enabled a networking market dominated by vendors of proprietary networking equipment. However, the Internet continues to grow rapidly, and this is putting pressure on the current architecture of these router and switch products. Alternative technologies and business models are being introduced to customers, changing the value proposition of proprietary networking equipment. This thesis provides a holistic analysis of the impact of the changing technology and business environment on the architecture of the current router and switch products, and the business implications for the vendors of these products. Academic frameworks and scholarly articles are used to analyze the value of the current architecture, and its ability to maintain the dominance of the incumbent vendors of proprietary networking equipment in the new environment. This analysis found that the current router and switch architecture is not flexible enough to support the growing demands of the Internet and corporate intranets. The value components of the proprietary architecture will be replaced by open and common versions of the same components, and then reconfigured to provide a novel and flexible architecture. As a result, the existing proprietary solutions will decrease in significance and a larger open ecosystem of software and hardware vendors will share the profits of the networking market. The vendors of proprietary networking equipment will be forced to adopt less lucrative business strategies to compete effectively in the new environment. A once dominant architecture and a source of tremendous value for these networking equipment vendors and their stakeholders will be replaced by an open architecture, resulting in the networking equipment vendors losing dominance in the market they created.
by Richard Joseph Kijewski.
S.M. in Engineering and Management
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Valente, João Filipe Torres. "Servo-system for controlled postural balance disruption." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/19139.
Full textAbstract:
Mestrado em Engenharia MecânicaO estudo do equilíbrio postural é uma preocupação que se aplica igualmente a seres humanos e robôs com pernas. Em relação a Humanos este problema foca-se na deteção de patologias, avaliação da capacidade de manter o equilíbrio e recolher dados acerca da forma como o equilíbrio é mantido. Por outro lado, o estudo da postura de um robô tem como objetivo avaliar e melhorar o seu controlo. Dada a necessidade de testar o equilíbrio do Projeto Humanóide da Universidade de Aveiro - PHUA, surgiu a ideia de criar um sistema de distúrbio do equilíbrio. A ideia é o sistema perturbar o equilíbrio utilizando forças de tração que poderão ser aplicadas em todas as direções do plano horizontal. Como primeira abordagem, o conceito é testado num pêndulo assistido por elásticos, com o objetivo de perceber qual a melhor forma de controlar o sistema e encontrar possíveis problemas para o seu controlo. Numa primeira fase, é desenhado um controlador para criar um estado de balanço em que as forças são iguais fazendo com que o pêndulo fique imóvel. Numa segunda fase, depois de atingir o estado descrito anteriormente, o pêndulo é brevemente puxado num sentido e são medidas as forças e o ângulo do pêndulo para se analisarem os efeitos do estímulo. Desta maneira, várias formas de aplicar estímulos são testadas assim como diferentes estímulos. Percebeu-se que: é possível aplicar estímulos repetíveis com este conceito; o facto de o sistema ser acoplado e não-linear causa dificuldades para o controlo, sendo necessário adoptar novas estratégias. Esta dissertação vai servir como suporte para o trabalho futuro, (que será construir o sistema à escala do PHUA) oferecendo um conjunto de informações e guias.
Postural balance is a concern that applies to both humans and bipedal robots. For Humans, this issue is focused on detecting some pathologies, evaluating individual balance capability, and gather data on how equilibrium is maintained. On the other hand the robot’s postural study aims to evaluate the machine’s control and help tune it. Given the need to test the equilibrium of University of Aveiro Humanoid Project - PHUA, the idea of creating a balance disruption system came up. The idea is that the system disrupts the balance using pull forces that can be applied in every direction of the horizontal plane. As a first approach, the concept is tested on a pendulum assisted by elastics, with the objective of understanding which is the best way to control the system and find possible problems to its control. On an initial phase, a controller is designed to create a state of balance where the pull forces are equal making the pendulum stand still. On a second phase, after achieving the state of balance described previously, the pendulum is briefly pulled in a direction and tensile forces and the pendulum’s angle are measured, with the purpose of analysing the effects of the stimulus. This way, different manners of applying stimuli and different types of stimuli are tested. It was realised that: it is possible to apply repeatable stimuli with this concept; the fact that the system is coupled and non-linear brings obstacles to its control, being necessary to adopt new control strategies. This dissertation will serve as a support for future work, (which is building the system at PHUA scale) offering a set of informations and guidelines.
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Nilsson, Karin. "The Future of Print Subscribers : A Stable Resource or just Wishful Thinking?" Thesis, Linnéuniversitetet, Institutionen för informatik (IK), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-97979.
Full textAbstract:
The same digital forces that are changing the Communications, Information, Media and Entertainment industries in general are radically changing newspaper companies in particular by changing their value chain. Newspapers are seeing their dominance erode when Internet and digitization are fundamentally changing and disrupting their traditional business models. There is a clear collectively decline in news consumption, and with that the news organizations’ roles in society are changing. Moreover, the reduced consumption of news puts pressure on the newspaper’s economy with shrinking revenues and increasing costs. The transformation of the newspaper into a purely digital business has been in progress under the past decade and it is rapidly accelerating. The subscribers of the printed morning newspaper have historically been characterized by a high degree of loyalty and engagement as well as a low price sensitivity. They constitute an attractive group for the newspaper to keep as digital subscribers in a possible future situation where the printed newspaper no longer can be provided. Thus, the purpose of this study is to find out to what extent the studied newspaper company can rely on the existing print subscribers to stay as digital subscribers and count them as a stable resource, that is as a part of the future digital subscription revenues.
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Kiper, Halil 1976. "Disruptions in the sports content delivery value chain due to consuming sports content over the Internet." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/105299.
Full textAbstract:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, February 2014.Cataloged from PDF version of thesis. "November 2013."
Includes bibliographical references (pages 81-83).
A major component of the highly lucrative sports business is the content delivery value chain consisting of a number of players including the content creators - sports leagues; content aggregators - TV networks; content distributors - pay TV providers; advertisers - one of the main financiers in the value chain; and consumers. The relationships between the value chain players have been both cooperative and competitive, especially when the borders separating them became less defined due to backward and forward integration efforts of players. With the advancements in Internet content delivery and electronic devices, a new form of sports content consumption has emerged that has the potential to re-define the borders between the value chain players and to disrupt the industry. This new form of sports content consumption is Sports over IP (SpoIP, sports content consumption over the Internet). This thesis lays out four different scenarios about how the SpoIP disruption could play out in the value chain. It uses information from similar disruption in other industries and system dynamics modeling to present the ramification and likelihood of each scenario. This work predicts that the consumers will be the winner of SpoIP disruption because they will have access to good quality and cheaper sports content going forward.
by Halil Kiper.
S.M. in Engineering and Management
30
Lee, Garrett J. (Garrett James), and Chang Zen-Lee M. "Supply chain disruptions : managing risks vs. managing crises." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40096.
Full textAbstract:
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (leaves 74-76).
This thesis looks at two back-to-back disruptive supply chain events, one due to a sole-supplier's bankruptcy and the other caused by Hurricane Rita, that occurred at a specialty chemical company, and uses these examples to demonstrate how managing crises is more costly than managing risks. In examining the events surrounding the sole-supplier bankruptcy, managing a crisis cost this specialty chemical company 45% more money than managing a risk. Through the findings of these two disruptive events, a framework, the Eye of Providence, is created to manage supply chain risks. First, an organization must determine how developed its risk-management protocol is. Next, by studying past disruptive events and determining the key impact factors, an organization could calculate and learn about the opportunity cost of managing crisis. Then, by continuously evaluating its suppliers and rigorously applying those key impact factors to the analysis of its supply chain practice, an organization could evaluate and identify its current vulnerabilities.
(cont.) Finally, by proactively monitoring event-based warning signals, or disruption indicators, an organization could assess its potential supply chain risks, and plan accordingly. Whether a company is low on the risk-maturity level or has already integrated risk management into its corporate culture, the process developed in this thesis serves as a versatile tool that can help businesses structure a more dynamic, resilient supply chain.
by Garrett J. Lee [and] Zen-Lee M. Chang.
M.Eng.in Logistics
31
Ruby, Christina L. "Ethanol Disruption of the Mammalian Circadian Timing System." Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1270053064.
Full text
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Saavedra, Román Jóse Guillermo. "Disruptive adaptability : a case study in a product development organization." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106265.
Full textAbstract:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, School of Engineering, System Design and Management Program, Engineering and Management Program, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 94-100).
Enhancing the practice of Product Development has been addressed in multiple works and published in documents of all kind ranging from theses and consultancy studies to papers in specialized journals. Regardless of the focus, either on processes, tools, methods or organizational design what is common is a reactive -"gapflling"-approach. In this work I propose that enhancing the practice of product development is better achieved when it is addressed from a holistic perspective in which either the improvement, optimization or enhancement of the product development practice is in essence an adaptation of the product development organization. Seeing the practice of product development from the adaptability lens, allows us to create enhancements that go beyond the traditional "gap-filling" approach of fixing issues using information from the past, and opens up a broader -yet richer-set of alternatives to design improvements that not only prevent issues to occur but that also are meant to change the game. The main focus of this work is the design of a disruptive adaptation for Ford Motor Company Product Development Organization focused on its capabilities for the development of in-vehicle features which are instrumental in the customer experience that is delivered by Ford automobiles. This design was developed following a systems thinking approach for large complex systems and is aligned to Ford Motor Company objective of changing the way the world moves. The design concept for this disruptive adaptation focuses on elaborating a desired future state of the capabilities to develop an unparalleled customer experience in Ford vehicles. It also considers the future context of a platform-based business model where the automobile is the platform. As starting point, I researched the current state of Ford capabilities for the development of in-vehicle features and realized that the Electronic Control Units (ECUs) of the vehicle play a fundamental role. Then, I used systems modeling tools such as Domain Mapping Matrix (DMM) and Design Structure Matrix (DSM) to understand and quantify the patterns of interaction among vehicle features that occur across all Electronic Component Units (ECUs) of an automobile. Finally I developed a holistic proposal to adapt the strategy, methods, tools and organizational structure that is meant to support Ford Motor Company in its pursuit to disrupt the mobility paradigm.
by Jóse Guillermo Saavedra Román.
S.M. in Engineering and Management
33
Welton, Thomas. "Imaging markers of brain network disruption in multiple sclerosis." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/43634/.
Full textAbstract:
Cognitive impairment and fatigue are prevalent and impactful symptoms of multiple sclerosis (MS). Effective markers are required by clinical studies to accurately test the efficacy of treatments for these symptoms. Graph analysis of brain networks based on magnetic resonance imaging (MRI) data can feasibly provide useful candidate markers of cognitive impairment and fatigability in MS which may be more objective, reliable and specific than existing markers. My original contribution to knowledge is therefore an exposition of the following hypothesis: “summary graph-theoretic descriptors of brain network organisation are good candidate markers of cognition or fatigue in MS”. To achieve this, network metrics were assessed based on three main criteria: reliability (“are the measurements the same across time and settings?”), validity (“do they measure what they are supposed to measure?”) and responsiveness (“are they altered when a change in cognitive state is induced?”). The applicability of the graph-theoretic approach was first established with a spatial meta-analysis of tract integrity and its relevance to cognition and disability. Reliability over time in healthy subjects was assessed by systematic review and reliability between different scanners and between MS and control groups was assessed in two longitudinal datasets by measuring intra-class correlation (ICC) of graph metrics. The validity criterion was assessed in an analysis of covariance and linear regression of cognitive and fatigue measures with brain network metrics in people with MS. Finally, an exploration of network dynamics during a sustained attention task with a sliding-window approach was performed to test the immediate responsiveness of the measures to alterations in cognitive state. Spatial meta-analysis of white matter tract degradation was performed using the Signed Differential Mapping method. Statistical maps were gathered from the original authors of studies which performed voxelwise correlations between fractional anisotropy (a measure of white matter integrity based on diffusion tensor imaging data) and measures of either cognitive impairment or physical disability. The combined sample included 495 people with MS and 253 controls from 12 studies. MS diagnosis was significantly associated with widespread lower tract fractional anisotropy. Distributions of voxels with significantly lower fractional anisotropy in relation to cognition and physical disability were only minimally overlapping. The number of and effect sizes for significant clusters in the cognition comparison were greater than those for the physical disability comparison, suggesting a greater relevance of cerebral white matter damage to cognition. The main results remained significant when using a stringent p-value threshold of 0.00001 to control for false positives. The next analysis was a systematic review of the reproducibility of graph metrics over time in healthy people. Online databases were searched for articles reporting ICCs for graph metrics based on imaging data and information was recorded on the sample size, acquisition method, inter-scan interval and reported ICCs. Twenty-six articles were included, with a combined sample size of 676. Overall, reproducibility over time was rated as “good”, but heterogeneity of methods precluded in-depth quantitative analysis. A qualitative synthesis of results highlighted the main methodologic factors affecting reproducibility, which included: ICC type, retest interval, fibre tracking algorithm, graph metric type, image processing strategy, region of interest size, graph threshold and acquisition method. Reliability of brain network metrics between scanners was tested using a travelling-subjects dataset in which 5 subjects each underwent a resting-state functional MRI scan at 10 sites. Graph metrics were calculated for each scan and then tested for ICC across sites. Reproducibility was “poor” for most metrics (characteristic path length ICC=0.23, global efficiency ICC=0.18, modularity ICC=0.24) and “fair” for two (clustering coefficient ICC=0.43, small-worldness ICC=0.42). There was limited evidence that some subjects tended to produce less reliable results and that magnets with higher field strengths did not produce more reliable results. The main implication is that multi-site studies using graph analysis of brain MRI data should investigate inter-site reproducibility beforehand. To investigate the validity of graph metrics as markers of cognitive impairment and fatigue, MRI and neurocognitive data were first gathered from 37 people with MS and 23 matched controls. The sample was characterised in detail and comprised a range of cognitive abilities. Data quality was investigated and the small-world structure of the data was confirmed by comparison to random and lattice graphs. Analysis of covariance controlling for age, sex and education showed significant group differences for all but one graph metric. Linear regression models predicted the main measures of cognitive impairment in the MS group, but not in the control group. Measures of fatigue were not well-explained by graph metrics. The direction of the relationships indicated that greater levels of cognitive impairment were related to increased network clustering and modularity, longer average path lengths, lower small-worldness, lower levels of education, old age and sleep disturbance. Finally, responsiveness of graph metrics was investigated in an analysis of functional network dynamics during performance of a sustained attention task. A “sliding-window” approach was taken, in which network metrics were calculated for 84 100-second windows at increments along the fMRI timeseries. Reaction times in the task showed a learning effect for both groups, but were consistently slower for the MS group. Plots of graph metrics over time showed differing responses to the task and to the transition between task and rest periods between groups. The small-worldness and clustering coefficient metrics were correlated with reaction times for both MS (small-worldness: r=0.623, < 0.001; clustering coefficient: r=0.554, p= < 0.001) and control (small-worldness: r=0.586, < 0.001; clustering coefficient: r=0.627, p= < 0.001) groups, but the characteristic path length metric was not (MS: r=-0.154, p=0.313; control: r=0.343, p=0.021). Disconnection of cortical areas by degradation of white matter is a viable explanation for cognitive symptoms in MS. There is some evidence that increased network segregation and decreased network integration may explain cognitive symptomatology. Graph theoretic summary brain network metrics do have potential for use as complimentary information to existing markers of cognitive impairment in clinical studies.
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Wilson, Bryan K. (Bryan Keith). "Risk from network disruptions in an aerospace supply chain." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61189.
Full textAbstract:
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 76-77).
This thesis presents methods for determining the effects of risk from disruptions using an aerospace supply chain as the example, primarily through the use of a computer simulation model. Uncertainty in the current marketplace requires managers to be cognizant of the adverse impact of risk on their company's performance. However, managers who lack formal procedures for dealing with the potential impact of risk often are caught not knowing how much to invest in risk mitigation strategies. A computer simulation model representing a supply chain for a space vehicle was used to test different disruption scenarios to determine their impact on total production duration time. Scenarios ranging from suppliers not providing parts on time to quality test failures to disease pandemics were all considered. Randomness was incorporated through use of a stochasticity factor that was applied uniformly throughout the model. Output of the model was used to develop confidence percentiles for the complete duration times. Through testing of the various scenarios using the model we learned that most disruptions will add a deterministic time to the total estimated duration time of the system, regardless of the location of the disruption in the supply chain. In addition, we showed that a thorough review must be performed when choosing the stochasticity factor due to its large influence in determining total duration times and performance percentiles. The creation of the confidence percentiles allows the aerospace company to use the model throughout the entire 3 to 4 year production process to continually update and evaluate their buffer times and likelihood of meeting target completion dates. This buffer time can then be turned into a key performance index to better manage this supply chain. This model was created for a real supply chain, and it is currently being used by the aerospace company to help them plan and make appropriate decisions in regards to risk mitigation strategies in preparation for production of the space vehicle. They hope to expand the use of computer simulation models throughout the rest of their division to help drive down costs by increasing efficiencies in their planning.
by Bryan K. Wilson.
M.Eng.in Logistics
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Flaherty, Matthew (Matthew W. ). "A strategic framework using open innovation and platforms to embrace disruptive "Software as a Service" technology." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59242.
Full textAbstract:
Thesis (S.M. in System Design and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 114-116).
Over the past several decades, technology has become fundamental to the facilitation of communication, collaboration and productivity inside and between enterprises. Enterprises use numerous tools to reach their customers, manage increasingly decentralized and mobile workforces and to create digital assets critical to their daily operations. In the last several years, changes in the availability of internet access and the compatibility of internet browsers has resulted in massively scalable services available on the internet - delivered by models termed "Software as a Service" and "Cloud Computing". This delivery mechanism is vastly different from traditional models of enterprise software delivery where enterprise purchase, install and manage their own enterprise software packages. This thesis will evaluate a strategy for one of the market leaders in messaging, IBM Lotus, in the face of the disruptive forces of new internet enabled delivery mechanisms like Software as a Service and Cloud Computing. In doing so, it will integrate the topics of several researchers in the field of strategy and innovation. After a treatment of background topics and themes, it will present an evaluation of the enterprise software market in the face of the disruptive forces created by the internet. A framework for evaluating market strategies for established players will be developed using concepts of software platforms and open innovation. Finally, a case study of the established player will be viewed through the lens of this framework.
by Matthew Flaherty.
S.M.in System Design and Management
36
Warshawsky, David. "A system of systems flexibility framework: A method for evaluating designs that are subjected to disruptions." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54277.
Full textAbstract:
As systems become more interconnected, the focus of engineering design must shift
to include consideration for systems of systems (SoS) e ects. As the focus shifts from
singular systems to systems of systems, so too must the focus shift from performance
based analysis to an evaluation method that accounts for the tendency of such large
scale systems to far outlive their original operational environments and continually
evolve in order to adapt to the changes. It is nearly impossible to predict the nature
of these changes, therefore the rst focus of this thesis is the measurement of
the
exibility of the SoS and its ability to evolve and adapt. Flexibility is measured
using a combination of network theory and a discrete event simulation, therefore,
the second focus is the development of a simulation environment that can also measure
the system's performance for baseline comparisons. The results indicate that
simulated
exibility is related to the performance and cost of the SoS and is worth
measuring during the design process. The third focus of this thesis is to reduce the
computational costs of SoS design evaluation by developing heuristics for
exibility.
This was done by developing a network model to correspond with the discrete event
simulation and evaluating network properties using graph theory. It was shown that
the network properties can correlate with simulated
exibility. In such cases it was
shown that the heuristics could be used in connection with an evolutionary algorithm
to rapidly search the design space for good solutions. The entire methodology was
demonstrated on a multi-platform maintenance planning problem in connection with
the Navy Hardware Open System Technologies initiative.
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Doucakis, Theodore. "Study of supply chain disruptions at a high tech corporation." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40097.
Full textAbstract:
Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 61).
Although supply chain disruptions are inevitable, frameworks have been developed for addressing supply chain risks. These frameworks present methods on mitigating, reducing or managing the risks through different approaches such as multiple sourcing. The research presented here identified two factors that contribute to successful recovery from supply chain disruptions. One factor is efficient communication between stakeholders in a supply chain. The communication needs to be present before a disruption occurs to enable fast detection. After a disruption occurs efficient communications will help minimize confusion and provide clear understanding of the recovery effort between stakeholders. The other factor is the inventory position downstream of the disruption. In particular, the available days of supply downstream from the disruption relative to the length of the disruption are crucial to the ability of a supply chain to recover from the disruption without disturbing the continuity of supply. In response to the effect of the days of supply compared to the recovery time a simple model is developed for assessing supply chain risk for an enterprise that sells products defined through a bill-of-materials.
(cont.) The model takes into consideration the complexity of a product as more parts and more levels are added to the bill of material. The supply chain risk score metric permits comparison across products, companies and industries. The model is simple to apply by analyzing each part in bill-of-materials by a ranking system comparing the recovery time to the days of supply downstream from the disruption. The supply chain risk score is to be used in parallel with other supply chain metrics in order to determine the best approach in reducing risks to an enterprise.
by Theodore Doucakis.
M.Eng.in Logistics
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Yip, Jennifer J. (Jennifer Jaclyn). "Evaluating upstream supply chain disruptions with partial availability." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98606.
Full textAbstract:
Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2015.Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 138-140).
Globalization, outsourcing, and the emphasis on lean supply chains continue to shape the supply chain industry. These trends have increased the prevalence and severity of disruptions to upstream supply. Disruptions to upstream supply can delay and potentially halt the flow of necessary materials and/or services to purchasing firms, often resulting in severe operational and financial losses. This has created a growing need for effective risk assessment techniques to evaluate the impact of disruptions and inform risk mitigation policies. As a result, many methodologies have been developed to assess risk by estimating the likelihood and impact of disruptions. Given the inherent difficulty in estimating the likelihood of disruptions, this thesis focuses on assessing the risk of supply shortfall independent of the causes and likelihoods of such disruptions. This thesis presents an optimization-based framework to assess the risk of both complete and partial supply disruptions and comments on inventory and procurement mitigation strategies. The framework is used to compare two allocation policies (fair allocation and preferential product allocation) for the distribution of scarce inventory in times of disruption. The framework is then applied to data from a food products manufacturer to determine the impacts of a disruption in the supply of two components feeding dozens of products.
by Jennifer J. Yip.
S.M. in Technology and Policy
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Tubilla, Kuri Fernando. "Dynamic scheduling of manufacturing systems with setups and random disruptions." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67606.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 249-256).
Manufacturing systems are often composed of machines that can produce a variety of items but that most undergo time-consuming (and possibly costly) setups when switching between product types. Scheduling these setups efficiently can have important economic effects on the performance of the plant and involves a tradeoff between throughput, inventory, and operating costs. In addition, the schedule must be robust to random disruptions such as failures or raw material shortages, which are common in production environments. In this thesis, we study policies that address the setup scheduling problem dynamically, in response to current conditions in the system. A new heuristic, called the Hedging Zone Policy (HZP), is introduced and developed. It is a dynamic-sequence policy that always produces the current part type at its maximum production rate until a fixed base stock level is reached. Then, before switching setups, the policy might produce the current part type at its demand rate for some additional time. When selecting changeovers, the HZP implements two types of decision rules. If the difference between base stock and surplus level is small for all part types, the item with the largest weighted difference is selected. Otherwise, the policy uses a fixed priority ranking to select between items that are far from their base stock value. In order to demonstrate the benefits of our policy, we also adapt and implement several other heuristics that have been proposed in the literature for related models. The policies are first analyzed in a purely deterministic setting. The stability of the HZP is addressed and it is shown that a poor selection of its parameters leads to a condition in which some low-priority parts are ignored, resulting in an unstable system. Using Lyapunov's direct method, we obtain an easy-to-evaluate and not-too-conservative condition that ensures production of all part types with bounded surplus. We then compare, through a series of extensive numerical experiments with three-part-type systems, the deterministic performance of the policies in both make-to-order and make-to-stock settings. We show that the HZP outperforms other policies within its class in both cases, a fact that is mainly attributed to its priority-based decisions. When compared to the approximate optimal cost of the problem, our policy performs very well in the make-to-order case, while the simplicity of its base stock structure makes it less competitive in the deterministic make-to-stock problem. The results are then leveraged for the study of a stochastic model, where we consider the effect of random disruptions in the form of machine failures. We prove that our model converges to a fluid limit under an appropriate scaling. This fact allows us to employ our deterministic stability conditions to verify the stochastic (rate) stability of the failure-prone system. We also extend our previous numerical experiments by characterizing the performance of the policies in the stochastic setting. The results show that the HZP still outperforms other policies in the same class. Furthermore, we find that except for cases where failures occur much less or much more frequently than changeovers, the HZP outperforms a fixed-sequence policy that is designed to track a pre-determined, near-optimal deterministic schedule.
by Fernando Tubilla.
Ph.D.
40
MELLO, JOSÉ ROBERTO de. "Regulamentação do sistema elétrico do reator IEA-R1." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26928.
Full textAbstract:
Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2016-12-21T12:55:48Z
No. of bitstreams: 0Made available in DSpace on 2016-12-21T12:55:48Z (GMT). No. of bitstreams: 0
O reator IEA-R1 do Instituto de Pesquisas Energéticas e Nucleares (IPENCNEN/ SP) é um reator de pesquisa tipo piscina aberta, projetado e construído pela empresa norte-americana \"Babcock & Wilcox\", tendo, como refrigerante e moderador, água leve deionizada e berílio e grafite como refletores. Até cerca de 1988, os sistemas de segurança do reator recebiam alimentação de uma única fonte de energia. Nos anos de 1989 e 1990, uma reforma de modernização do sistema elétrico para aumentar a potência do reator e, também, para atender às normas técnicas da Comissão Nacional de Energia Nuclear (CNEN) e da Associação Brasileira de Normas Técnicas (ABNT) foi realizada. Este trabalho tem o objetivo de mostrar a relação entre o sistema de energia elétrica e a segurança do reator IEA-R1. Além disso, ele demonstra que, caso ocorra alguma interrupção de energia elétrica durante a operação do reator, esta ocorrência não irá começar um evento de acidente.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Belshaw, Simon. "Generative systems and disruptive processes in musical composition." Thesis, University of Hertfordshire, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421281.
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Li, Jingquan. "Models and Algorithms of Real-Time Vehicle Rescheduling Problems under Schedule Disruptions." Diss., Tucson, Arizona : University of Arizona, 2006. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1652%5F1%5Fm.pdf&type=application/pdf.
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Duenas-Osorio, Leonardo Augusto. "Interdependent Response of Networked Systems to Natural Hazards and Intentional Disruptions." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7546.
Full textAbstract:
Critical infrastructure systems are essential for the continuous functionality of modern global societies. Some examples of these systems include electric energy, potable water, oil and gas, telecommunications, and the internet. Different topologies underline the structure of these networked systems. Each topology (i.e., physical layout) conditions the way in which networks transmit and distribute their flow. Also, their ability to absorb unforeseen natural or intentional disruptions depends on complex relations between network topology and optimal flow patterns. Most of the current research on large networks is focused on understanding their properties using statistical physics, or on developing advanced models to capture network dynamics.
Despite these important research efforts, almost all studies concentrate on specific networks. This network-specific approach rules out a fundamental phenomenon that may jeopardize the performance predictions of current sophisticated models: network response is in general interdependent, and its performance is conditioned on the performance of additional interacting networks. Although there are recent conceptual advances in network interdependencies, current studies address the problem from a high-level point of view. For instance, they discuss the problem at the macro-level of interacting industries, or utilize economic input-output models to capture entire infrastructure interactions.
This study approaches the problem of network interdependence from a more fundamental level. It focuses on network topology, flow patterns within the networks, and optimal interdependent system performance. This approach also allows for probabilistic response characterization of interdependent networked systems when subjected to disturbances of internal nature (e.g., aging, malfunctioning) or disruptions of external nature (e.g., coordinated attacks, seismic hazards). The methods proposed in this study can identify the role that each network element has in maintaining interdependent network connectivity and optimal flow. This information is used in the selection of effective pre-disaster mitigation and post-disaster recovery actions. Results of this research also provide guides for growth of interacting infrastructure networks and reveal new areas for research on interdependent dynamics. Finally, the algorithmic structure of the proposed methods suggests straightforward implementation of interdependent analysis in advanced computer software applications for multi-hazard loss estimation.
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McKinlay, Rebecca. "Risk assessment of endocrine disrupting pesticides in biological systems." Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/5585.
Full textAbstract:
Endocrine Disrupting Chemicals (EDCs) are a diverse array of natural and manmade substances capable of interfering with hormonally mediated processes. They are particularly harmful to cells that are differentiating and dividing rapidly, can stimulate unwanted cell growth, and can interfere with normal epigenetic imprinting causing changes that in some instances are heritable. Due to their epigenetic effects and effects on tissue growth and development, organisms at certain life stages are more vulnerable than others and effects may manifest a long time after exposure. The risks posed to human and environmental health by these compounds are currently unknown, but there is a growing scientific consensus that precautionary measures and further research to understand and quantify these risks are needed. Endocrine Disrupting pesticides represent a subset of EDC capable of reaching humans from a diverse range of sources via many different exposure routes. No definitive lists or screening methodologies exist to identify them. In the UK, exposure routes involving occupational pesticide use for agricultural purposes or the residues of these pesticides in food and water are well quantified but other sources of exposure are not. If risk management measures are to be enacted to protect the population, these exposures will have to be quantified and the risks they pose assessed. This project aims to identify the hazards posed by ED pesticides to humans living in the UK, prepare a framework for the assessment and management of risks they pose, identify the tasks that remain to be completed before such a framework could be implemented, and to investigate poorly documented ED pesticide exposure sources. Current toxicological testing of pesticides was found to be inadequate. Properties frequently exhibited by EDCs, such as non-monotonic (j-type) dose responses and the additive and synergistic actions of compounds were not taken into account. Only active ingredients are legally required to be tested even although adjuvants used to improve formulation effectiveness are not always inert and formulations can be more toxic or have greater ED potential than their active ingredients alone. Adjuvants are assessed on a reactive basis, which is not adequate to protect public health. A tiered risk assessment and management framework capable of screening potential ED pesticides and making recommendations for risk management can be created using existing deterministic and probabilistic models of human pesticide exposure. The identification of critical groups that are more vulnerable than the general population to the effects of EDCs allows risk assessment and management to be tailored to protect these groups, allowing the risk to both these groups and the general population to be minimised, in keeping with the precautionary principle. Further work is required, however, to collect appropriate datasets to model non agricultural exposure routes and model the exposure of rural residents and bystanders. Assumptions made in the creation of foreign models would need to be checked to ensure they were compatible with UK conditions. Appropriate ADIs for EDCs showing non-monotonic dose responses would also need to be determined, and exposure profile differences between people living in urban, periurban and rural environments would also have to be taken into account. A number of ED pesticides used for medicinal, veterinary and domestic purposes and the municipal and commercial maintenance of infrastructure and recreational areas were identified. Unfortunately little could be determined about the factors influencing their use by the public. The number of years spent in secondary education correlated positively with non ED medicinal pesticide use and both ED and non ED veterinary and domestic use. It was unclear why this should be. Golf courses were the most heavily treated publicly accessible areas studied and used the most ED pesticides. Large parks received least, with pesticide use concentrated on hard surfaces and high maintenance ornamental areas. Pesticide use in parks is dominated by herbicides. Applications to pavements and other publicly accessible hard surfaces consisted almost entirely of glyphosate based herbicides. Herbicide applications on pavements and in parks mostly take place in the spring and early summer. The bulk of pesticide applications on golf courses were applied in the autumn. Contractors carrying out maintenance work for local authorities were found to use more pesticides than local authority employees. Non chemical methods of ectoparasite, pest and weed prevention and control have the potential to reduce pesticide use. Some of the methods currently in use, however, were found to be more costly and challenging to implement than chemical methods. The integration of these into parasite, pest and weed prevention and control strategies where possible and their further should be encouraged.
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Mummery, Catherine Jane. "Neuroimaging studies of the distributed semantic system and its disruption in disease." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343897.
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Hensler, Philipp A. "The Belief System and Behavior of Financial Advisors After a Market Disruption." Case Western Reserve University Doctor of Management / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=casedm1568710731430581.
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Murthy, Niren. "The design and synthesis of endosomal disruptive polymers /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/8113.
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Romine, Jessica D. "Business Continuity and Resilience Engineering: How Organizations Prepare to Survive Disruptions to Vital Digital Infrastructure." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1330986438.
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Vaishnav, Chintan. "The end of core : should disruptive innovation in telecommunication invoke discontinuous regulation?" Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62869.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2010.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis. Page 247 blank.
Includes bibliographical references (p. 239-246).
This research analyzes how a telecommunications regulator can balance regulation with innovation, at a reasonable cost. This question has gained critical importance for telecom regulators as the unregulated Internet technologies such as voice and video over Internet disrupt the regulated traditional technologies such as telephony and television and the historical paradigm of the regulator. The existing U.S. telecommunications regulations were created in the integral age. In that paradigm, functional components that constitute a service compliant with regulation resided inside the network core; each operator was vertically integrated and controlled the total functionality necessary to deliver a service; a few such operators controlled the industry; they faced low competition and were under limited pressure to adopt innovation; and consumers had limited choice. The Internet has introduced a polar opposite paradigm-the modular age. In this paradigm, functional components that constitute a service are dispersed across the network core and edges; each firm controls only a subset of the total functionality necessary to constitute a service; many modular firms interoperate to deliver a service; firms compete fiercely and are under great pressure to innovate; and consumers enjoy far greater choice due to the multi-modal competition among multiple technologies. Although transitioning from an integral to a modular age dramatically flips the environment, the current regulatory response to this dramatic shift has been hesitant to shift its intellectual roots. Consequently, this thesis describes and analyzes the new telecommunications paradigm and explores its implications for an appropriate regulatory paradigm. The research uses the regulation of voice communications in the United States as a representative case. We analyze the new telecommunications paradigm as a dynamic complex system. Our research approach rests upon four principles of systems: two organizational principles (hierarchy and feedback) and two behavioral principles (emergent behavior and strategic and statistical behavior).The telecommunications system is viewed as one of the many subsystems that together fulfill the objectives of a society. The dynamics of the telecommunications system itself are conceptualized as those resulting from the interactions of four subsystems: regulatory dynamics, corporate strategy dynamics, consumer dynamics, and technology dynamics. The regulatory objectives to be fulfilled are conceived as an emergent property of such a system of systems. To carry out this research, we have developed a system-level dynamic feedback model and two case studies. As modular entrants of Internet-based technology disrupt integrated incumbents of traditional technology, bewildering dynamic complexity complicates decision-making by policymakers, managers, consumers, and technologists alike. Our model makes understandable the emergent behavior amidst the uncertainty that surrounds such a disruption phenomenon. The model formulations are behavioral. They are derived from the existing theories of technology and industry disruption, where possible. Alternatively, where theories have a gap, the decision processes of stakeholders, gleaned from unstructured interviews, are mathematised as the basis for the model formulations. The resulting structure is a fully endogenous systems model of regulation, competition, and innovation in telecommunications. In the first case study we analyze the regulatory environment of pre vs. post-Internet periods, both quantitatively and qualitatively. For the analysis, public comments in response to the Telecommunications Act of 1996 Notice for Proposed Rulemaking (NPRM) are compared with those in response to the IP-Enabled Services NPRM published in 2004. The analysis demonstrates how the differences in the integral and modular age are reflected in the regulatory record. The second case study analyzes how market, technology, organizational, and regulatory uncertainties affect technology and industry disruption. For this case, we use a combination of industrial statistics and content analysis of media publications. The analysis demonstrates the limits to technology and industry disruption. The case studies complement the model in two ways: first, they facilitate further refinement of the systems model; second, they empirically validate the arguments deduced from model analysis. Through this research we answer three questions: (1) Can the regulatory structure designed in an integral age-in its objectives, obligations (requirements), and enforcement mechanisms-work for a modular age? (2) How can regulators and managers improve decision making amidst the uncertainty surrounding the disruption of an integrated technology and industry by a modular one? (3) What is the new role of the telecommunications regulator and how can it be fulfilled in the modular age of the Internet? Our analysis shows that the current regulatory structure is inadequate for responding to the challenges the modular age poses. Firstly, the current objectives are appropriate but cannot be met unless regulators discontinue the merely efficiencycentered thinking and begin to address objectives at the societal level. Secondly, the current obligations may attain short-term goals, but have undesirable long-term consequences. Devising obligations that are appropriate in the long-term requires regulators to discontinue myopic measures such as incremental regulation of new technologies. Finally, the current enforcement mechanisms are blunted by the dynamic complexity of the modular age. Enforcing regulations effectively in the modular age necessitates adding to the regulatory quiver new mechanisms that are more versatile than the merely adversarial command-and-control mechanisms. Through model analysis, we demonstrate how a lack of understanding of the various uncertainties, and misperceptions of feedback in a complex system where regulators, firms, consumers, and technologists constantly interact, could lead to decisions that are costly for regulators as well as managers. Yet, as we demonstrate, with better grasp of the dynamic complexity involved, they can significantly improve decision-making to meet the challenges of the modular age. We argue that the most critical role for the telecommunications regulator in the new telecommunications paradigm is to sustain a balance between regulation and innovation, at a reasonable cost. Achieving such a balance in a modular structure is not trivial because of several natural tendencies. First, achieving high compliance at low cost is difficult because in highly modular architectures and industries, coordination costs, such as the time to build consensus, can be inordinately large. Second, keeping the innovationlevel high is difficult because it requires fighting the natural tendency of modular firms to gain and abuse market power. We propose a combination of two policy levers-Limiting Significant Market Power (SMP) Accumulation and Building Broad-based Consensus around Regulatory Issues-that most effectively achieve the desired balance and remain inadequately explored in the United States. We contend that implementing these policy levers will require, first, a more broadly construed antitrust regulation in the United States that will ensure higher modularity, and, second, a telecommunications regulatory agency that is empowered and organized to pursue objectives at the societal level and to build broad-based consensus among divergent interests in a highly modular structure.
by Chintan Vaishnav.
Ph.D.
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Marshall, Curtis J. "Autonomous & Resilient Countermeasures for Emergent System Disruptions with Application to Air Traffic Management." Thesis, The George Washington University, 2020. http://pqdtopen.proquest.com/#viewpdf?dispub=27664716.
Full textAbstract:
Engineered systems are susceptible to the disruption of intended functionality when unanticipated operating environments and constraints emerge during mission execution. To safeguard intended system functionality, resilient systems which integrate disruption avoidance and mitigation measures are needed. System automation methods have been successfully adopted for disruption avoidance and performance optimization based on anticipated needs and risks. However, given the development of unpredicted or emergent issues, human intervention is often relied on as an operational contingency to system failure or degraded performance. The purpose of this research was to develop and analyze a model for evaluating and selecting system responses to mitigate emergent disruptions without human intervention. The scope of this research addresses risk management within the system lifecycle with focus on system adaptation to unpredictable changes in the operational environment or functional constraints. The Disruption Resilience and Adaptation Model (DREAM) was formulated as an autonomous decision-making and performance evaluation process for mitigating unforeseen or unavoidable system disruptions. Evaluating the system as a whole, the model integrates diagnostic and prognostic heuristics for performance feedback and regulating system responses to actual or potential disruptions. The suitability of rule and utility-based automation methods as system adaptation techniques was also investigated. Via modeling and simulation, the DREAM and existing system automation methods were applied to an Air Traffic Management (ATM) problem and compared based on: (i) mission reliability; (ii) incident rate; (iii) system efficiency; (iv) standard deviation of efficiency; (v) and system stability. Simulation results demonstrate the DREAM yielded statistically significant reductions in the frequency and severity of ATM system disruptions in comparison to the existing rule-based standard and the leading utility-based method. As demonstrated in the ATM case study performed in this research, the DREAM can reduce the frequency and severity of system disruptions that are unanticipated or unpredictable. Furthermore, the DREAM can autonomously enable preventive and corrective action in response to unexpected system disruptions, increasing the likelihood of achieving intended system objectives without the need for human intervention. In practical terms, use of the DREAM could increase the operational availability of safety- and security-critical systems, such as ATM systems, for which disruptions can be catastrophic in nature. Beyond the ATM application in this research, the DREAM is targeted towards engineered systems which are susceptible to inevitable, yet unavoidable disruptions, such as natural disasters, intentional attacks, and human errors.