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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Information system hazard analysis

Mason-Blakley, Fieran 29 January 2018 (has links)
We present Information System Hazard Analysis (ISHA), a novel systemic hazard analysis technique focused on Clinical Information System (CIS)s. The method is a synthesis of ideas from United States Department of Defense Standard Practice System Safety (MIL-STD-882E), System Theoretic Accidents Models and Processes (STAMP) and Functional Resonance Analysis Method (FRAM). The method was constructed to fill gaps in extant methods for hazard analysis and the specific needs of CIS. The requirements for the method were sourced from existing literature and from our experience in analysis of CIS related accidents and near misses, as well as prospective analysis of these systems. The method provides a series of iterative steps which are followed to complete the analysis. These steps include modelling phases that are based on a combination of STAMP and FRAM concepts. The method also prescribes the use of triangulation of hazard identification techniques which identify the effects of component and process failures, as well as failures of the System Under Investigation (SUI) to satisfy its safety requirements. Further to this new method, we also contribute a novel hazard analysis model for CIS as well as a safety factor taxonomy. These two artifacts can be used to support execution of the ISHA method. We verified the method composition against the identified requirements by inspection. We validated the method’s feasibility through a number of case studies. Our experience with the method, informed by extant safety literature, indicates that the method should be generalizable to information systems outside of the clinical domain with modification of the team selection phase. / Graduate
302

Seismic Hazard Assessment of Tripura and Mizoram States along with Microzonation of Agartala and Aizawl Cities

Sil, Arjun January 2013 (has links) (PDF)
Tee present research focuses on seismic hazard studies for the states of Tripura and Mizoram in the North-East India with taking into account the complex sesismotectonic characteristics of the region. This area is more prone to earthquake hazard due to complex subsurface geology, peculiar topographical distribution, continuous crustal deformation due to the under thrusting of Indian and the Eurasian plates, a possible seismic gap, and many active intraplate sources identified within this region. The study area encompasses major seismic source zones such as Indo Burmese Range (IBR), Shillong Plateau (SP), Eastern Himalayan arc (EH), Bengal Basin (BB), Mishmi Thrust (MT) and Naga Thrust (NT). Five historical earthquakes of magnitude Mw>8 have been listed in the study area and 15 events of magnitude Mw>7 have occurred in last 100 years. Indian seismic code BIS-1893-2002 places the study area with a high level of seismic hazard in the country (i.e. seismic zone V). More than 60% of the area is hilly steep-terrain in nature and the altitude varies from 0 to 3000 meters. Recent works have located a seismic gap, known as the Assam gap since 1950 between the EH, SP, and IBR with the Eurasian plate. Various researchers have estimated the return period, and a large size earthquake is expected in this region any time in future. The area is also highly prone to liquefaction, since rivers in Tripura (Gomati, Howrah, Dhalai, Manu, Bijay, Jeri, Feni) and the rivers in Mizoram (Chhimtuipui, Tlawng, Tut, Tuirial and Tuivawl etc.) are scattered throughout the study area where soil deposits are of sedimentary type. In 2011, both the states together have experienced 37 earthquakes (including foreshocks and aftershocks) with magnitudes ranging from 2.9 to 6.9. Of these events, there were 23 earthquakes (M>4) of magnitudes M6.4 (Feb 4th 2011), M6.7 (March 24th 2011), M6.9 (Sept.18th 2011), M6.4 (October 30th 2011), M6.9 (Dec 13th 2011), M5.8 (Nov 21st 2011), M5 (Aug 18th 2011), M4.9 (July 28th 2011), M4.6 (Dec 15th 2011), M4.6 (Jan 21st 2011), M4.5 (Dec 9th 2011), M4.5 (Oct 21th 2011), M4.5 (Oct 17th 2011), M4.5 (Sept 18th 2011), M4.3 (Oct 10th 2011), M4.3 (Sept 22nd 2011), M4.3 (April 4th 2011), M4.2 (Sept 9th 2011), M4.2 (Sept 18th 2011), M4.1 (April 29th 2011), M4.1 (Feb 22nd 2011), M4 (June 9th 2011), and M4 (Dec 2nd 2011) which occurred within this region [source: IMD (Indian Metrological Department), India]. The earthquake (M6.9) that occurred on Sept. 18th 2011 is known as the Sikkim earthquake, and it caused immense destruction including building collapse, landslides, causalities, disrupted connectivity by road damages and other infrastructural damages in Sikkim state as well as the entire North-East India. In the cities of Agartala and Aizawl of Tripura and Mizoram, construction of high rise building is highly restricted by the Government. Being the capital city, many modern infrastructures are still pending for growth of the city planning. Although many researchers have studied and reported about the status of seismicity in North-East Region of India, very few detailed studies have been carried out in this region except Guwahati, Sikkim and Manipur where almost the whole of the study area is highly vulnerable to severe shaking, amplification, liquefaction, and landslide. From the available literature, no specific study exists for Tripura and Mizoram till date. In the present research, seismic hazard assessment has been performed based on spatial-temporal distribution of seismicity and fault rupture characteristics of the region. The seismic events were collected from regions covering about 500 km from the political boundary of the study area. The earthquake data were collected from various national and international seismological agencies such as the IMD, Geological Survey of India (GSI), United State Geological Survey (USGS), and International Seismological Centre (ISC) etc. As the collected events were in different magnitude scales, all the events were homogenized to a unified moment magnitude scale using recent magnitude conversion relations (region specific) developed by the authors for North-East Region of India. The dependent events (foreshocks and aftershocks) were removed using declustering algorithm and in total 3251 declustered events (main shocks) were identified in the study area since 1731 to 2011. The data set contains 825 events of MW < 4, 1279 events of MW from 4 to 4.9, 996 events MW from 5 to 5.9, 131 events MW from 6 to 6.9, 15 events MW from 7 to 7.9 and 5 events MW ≥8. The statistical analysis was carried out for data completeness (Stepp, 1972). The whole region was divided into six seismic source zones based on the updated seismicity characteristics, fault rupture mechanism, size of earthquake magnitude and the epicentral depth. Separate catalogs were used for each zone, and seismicity parameters a and b were estimated for each source zone and other necessary parameters such as mean magnitude (Mmean), Mmax, Mmin, Mc and recurrence periods were also estimated. Toposheets/vector maps of the study area were collected and seismic sources were identified and characterized as line, point, and areal sources. Linear seismic sources were identified from the Seismotectonic atlas (SEISAT, 2000) published by the GSI, in addition to the source details collected from available literature and remote sensing images. The SEISAT map contains 43 maps presented in 42 sheets covering entire India and adjacent countries with 1:1million scale. Sheets representing the features of the study area were scanned, digitized and georeferenced using MapInfo 10.0 version. After this, tectonic features and seismicity events were superimposed on the map of the study area to prepare a Seismotectonic Map with a scale of 1:1million. In seismic hazard assessment, a state of art well known methodologies (deterministic and probabilistic) was used. In deterministic seismic hazard analysis (DSHA) procedure, hazard assessment is based on the minimum distance between sources to site considering the maximum magnitude occurred at each source. In hazard estimation procedure a lot of uncertainties are involved, which can be explained by probabilistic seismic hazard analysis (PSHA) procedure related to the source, magnitude, distance, and local site conditions. The attenuation relations proposed by Atkinson and Boore (2003), and Gupta (2010) are used in this analysis. Because in this region two type activities are mostly observed, regions such as SP, and EH are under plate boundary zone whereas IBR is under subduction process. These equations (GMPEs) were validated with the observed PGA (Peak ground acceleration) values before use in the hazard evaluation. The hazard curves for all six major sources were prepared and compiled to get the total hazard curve which represents the cumulative hazard of all sources. Evaluation of PGA, Sa (0.2s and 1.0s) parameters at bedrock level were estimated considering a grid size of 5 km x 5 km, and spectral acceleration values corresponding to a certain level of probability (2% and 10%) were done to develop uniform hazard spectrum (UHS) for both the cities (Agartala and Aizawl). To carry out the seismic microzonation of Agartala and Aizawl cities, a detailed study using geotechnical and geophysical data has been carried out for site characterization and evaluation of site response according to NEHRP (National Earthquake Hazard Response Program) soil classifications (A, B, C, D, and E-type). Seismic site characterization, which is the basic requirement for seismic microzonation and site response studies of an area. Site characterization helps to have the idea about the average dynamic behavior of soil deposits, and thus helps to evaluate the surface level response. A series of geophysical tests at selected locations have been conducted using multichannel analysis of surface waves (MASW) technique, which is an advanced method to obtain direct shear wave velocity profiles from in situ measurements for both the cities. Based on the present study a major part of Agartala city falls under site class D, very few portions come under site class E. On the other hand, Aizawl city comes under site class C. Next, a detailed site response analysis has been carried out for both the cities. This study addresses the influence of local geology and soil conditions on incoming ground motion. Subsurface geotechnical (SPT) and geophysical (MASW) data have been obtained and used to estimate surface level response. The vulnerable seismic source has been identified based on DSHA. Due to the lack of strong motion time history of the study area, synthetic ground motion time histories have been generated using point source seismological model (Boore 2003) at bedrock level based on fault rupture parameters such as stress drop, quality factor, frequency range, magnitude, hypocentral distance etc. Dynamic properties such as the shear modulus (G) and damping ratios (ζ) have been evaluated from the soil properties obtained from SPT bore log data collected from different agencies such as PWD (Public works Department), and Urban Development Dept. of the State Government, in situ shear wave velocity has been obtained from MASW survey in different locations, and following this, a site response analysis has been carried out using SHAKE-2000 to calculate the responses at the ground surface in combination of different magnitudes, distances and epicentral depth for a particular site class. An amplification factor was estimated as the ratio of the PGA at the ground surface to the PGA at bedrock level, a regression analysis was carried out to evaluate period dependant site coefficients, and hence, the period dependant hazard impact on the ground surface could be calculated to obtain the spatial variation of PGA over the study area. Further, liquefaction potential of the site (Agartala) was also evaluated using available SPT bore log data collected and using presently estimated surface level PGA. The results are presented in the form of liquefaction hazard map representing as a Factor of safety (FS) against liquefaction with various depths such as 1.5m, 10m, and 15m respectively. It has been seen that Agartala city shows highly prone to liquefaction even up to 15 m depth. Hence, site specific study is highly recommended for implementing any important project. The liquefaction hazard assessment could not be conducted for the Aizawl city because of non availability of the SPT-N data, however, the city stands on hills/mountains, and therefore, such a study is not applicable in this area. Further, seismic microzonation maps for both the cities have been prepared considering Analytical Hierarchy Process (AHP) which support to the Eigen value properties of the system. Two types of hazard maps have been developed, one using deterministic and another using the probabilistic seismic microzonation maps. These maps can be directly used as inputs for earthquake resistant design, and disaster mitigation planning of the study area. However, an investigation has also been made in forecasting a major earthquake (Mw>6) in North-East India using several probabilistic models such as Gamma, Weibull and lognormal models. IBR and EH show a high probability of occurrences in the next 5 years (i.e. 2013-2018) with >90% probability.
303

Essays in Organizational Economics

Livio, Luca 30 August 2016 (has links)
This thesis consists of three independent essays which contribute to the literatures on organizational and regulatory economics.In the first part of the dissertation, I address questions related to the optimal incentive provision in hierarchies. In particular, I investigate how the choice of the optimal compensation policy of an organization is affected by the workers' psychological preferences for reciprocity. This essay relates to a recent strand of theoretical and empirical research that studies how the presence of reciprocity concerns impacts on the optimal organizational design (See e.g. Dohmen et al. 2009, Englmaier and Leider, 2012, Englmaier et al. 2015).The second part of the dissertation concerns the optimal design and regulation of a hierarchical organization in the presence of capture concerns. In many organizations the task of evaluating an agent's performance is delegated to a third party, a supervisor, who can opportunistically misreport information. The question of how the provision of incentives in hierarchies is affected by the supervisor's opportunism has long been studied in economics. Addressing this research question is of great importance since it can improve our understanding of the internal organization of firms and can have broad applications to regulatory design. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished
304

SEISMIC PERFORMANCE AND DISASTER MANAGEMENT OF INTERDEPENDENT CRITICAL INFRASTRUCTURES / 相互依存性を有するクリティカルインフラストラクチャーの地震時性能と地震災害マネジメントに関する研究

Faraji, Mahdi 24 September 2012 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17142号 / 工博第3632号 / 新制||工||1551(附属図書館) / 29881 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 清野 純史, 教授 小池 武, 准教授 古川 愛子 / 学位規則第4条第1項該当
305

Moral hazard in active asset management

Brown, David C., Davies, Shaun William 08 1900 (has links)
We consider a model of active asset management in which mutual fund managers exert unobservable effort to earn excess returns. Investors allocate capital to actively managed funds and passively managed products. In equilibrium, investors are indifferent between investing an additional dollar with an active manager or with a passively managed product. As passively managed products become more attractive to investors, active managers’ revenues from portfolio-management services fall, reducing their effort incentives. More-severe decreasing-returns-to-scale are also associated with reduced incentives and increased moral hazard. Performance-based fees and holdings-based data are all unlikely to mitigate moral hazard.
306

The Geophysical Kitchen Sink Approach to Improving our Understanding of Volcano-Tectonic Interactions

George, Ophelia Ann 20 September 2016 (has links)
A multi-prong approach was taken in this dissertation to understand volcanic processes from both a long-term and more immediate hazard perspective. In the long-term, magma sources within the crust may produce measurable surficial response and long-wavelength gravity anomalies that provide information about the extent and depth of this magma. Long-term volcanic hazard forecasting is also improved by developing as complete a record as possible of past events. In the short-term, a long-standing question has been on the casting of precursory volcanic activity in terms of future volcanic hazards. Three studies are presented in this dissertation to address these issues. Inversion of high-resolution ground magnetic data in Amargosa Valley, NV indicates that anomaly B could be generated by a buried shield volcano. This new information changes the event count in this region which in turn affects the overall volcanic hazard estimation. Through the use of Finite Element Models (FEM) an in-depth characterization of the surficial response to magma underplating is provided for the Tohoku Volcanic Arc, Japan. These models indicate that surficial uplift was dominantly driven by mid-crustal intrusions and the magnitude and wavelength of this uplift was mainly controlled by the elastic layer thickness. In Dominica, seismic data were used as weights in spatial intensity maps to generate dynamic volcanic hazard maps influenced by changes in seismicity. These maps show an increasing trend in the north that may be indicative of an increase in earthquake and volcanic hazards.
307

Defining the characteristics of chemical allergens

Lalko, Jon January 2012 (has links)
A common characteristic of all chemical allergens, both respiratory and skin allergens, is the ability to form stable associations with proteins; the resulting hapten-protein complex being sufficient to provoke an immune response. There is evidence to suggest that selective binding of chemicals with proteins or peptides may impact on the quality of immune response that will develop. In the investigations described here, we have taken a reductionist approach to protein reactivity and evaluated the binding characteristics of 20 of the most commonly reported chemical respiratory allergens towards defined peptides with a single reactive amino acid of interest. The hypothesis is that it is possible to identify and characterize different forms of chemical allergens as a function of preferential peptide binding.Utilizing the standardized reaction conditions of a direct peptide reactivity assay (DPRA), the reactivity of respiratory allergens for cysteine and lysine peptides was evaluated. Activity in the DPRA is reported as the percent depletion of peptide following 24 h incubation. An important and intriguing observation was that, when compared with skin sensitizers, chemical respiratory allergens exhibited a preferential reactivity for lysine. This preference was characterized quantitatively as a ratio of the mean depletion of lysine compared with cysteine (Lys:Cys ratio). The Lys:Cys ratio was observed to be robust and reproducible over time.A limitation of many in chemico methods for hazard identification is the lack of a metabolic component that allows for the identification of pro-haptens. In order to address this limitation, reported here is the use of the peroxidase peptide reactivity assay (PPRA), which utilizes a horseradish peroxidase/hydrogen peroxide (HRP/P) enzymatic system as a proxy for oxidative metabolism. Additionally, reactivity in the PPRA is characterized after a 24 h reaction time utilizing a concentration-response model (thus, permitting consideration of dose-response relationships defined as an EC15 value). Unexpectedly, the preferences for lysine observed with chemical respiratory allergens in the DPRA were lost or blunted in PPRA. The EC15 values demonstrated that relative reactivity between chemical respiratory allergens varied by up to 4 orders of magnitude. The identification of quantitative differences in reactivity could prove useful as a guide to evaluate potency in the future, should reliable metrics become available.To characterize the selectivity of binding by chemical respiratory allergens, the DPRA was modified to allow for the evaluation of reactivity to histidine, tyrosine and arginine. Confirming our previous observations, each of the respiratory sensitizers was observed to react to both lysine and cysteine, with in most instances, a preference for the former. Reactive promiscuity was a function of the other peptides with histidine being the most reactive followed by arginine and tyrosine. To model more complex reactive conditions, a novel modification was made to the DPRA to allow competition for lysine and cysteine to be assessed in a single reaction mixture. The results of these competitive reactivity experiments identified a range of binding patterns to lysine and cysteine that in some cases resulted in different binding being expressed.At present, there are no methods available to reliably identify potential chemical respiratory allergens. The work presented here has demonstrated that respiratory allergens can be identified as potential sensitizers based on their ability to react with lysine and cysteine. More importantly, the balance of reactivity to these two peptides can provide a means of discriminating between respiratory and skin sensitizers.
308

Rhabdomyosarcoma Incidence and Survival in Whites, Blacks, and Hispanics from 1973-2013: Analysis from the Surveillance, Epidemiology, and End Results Program

Tinsley, Heather 03 November 2016 (has links)
Purpose Our objectives were to 1) determine the difference in Rhabdomyosarcoma (RMS) incidence and survival between different race/ethnicity groups, and 2) evaluate the difference in survival of RMS between children and adults of these race/ethnicity groups, using the Surveillance, Epidemiology, and End Results Program (SEER) database between 1973-2013. Patients and Methods We analyzed racial characteristic and incidence data from 4,280 patients diagnosed with RMS, between 1973-2013, that were reported to the SEER database. Survival and hazard analyses were conducted on 4,268 patients with known follow-up data, with end point being death from any cause. Results Over the 40-year study period overall RMS incidence rates have experienced a statistically significant decline (APC: -0.78, 95% CI: -1.28 – -0.28). Whites have experienced a significant decline in incidence rates (APC: -1.05, 95% CI: -1.60 – -0.50). Though not statistically significant, incidence rates in Blacks and Hispanics have trended upwards. While adjusted survival was not predicted by race, survival did significantly differ among racial/ethnic groups in children, with Hispanics and “Others” having the lowest 5- and 10-year survival rates (65% and 58% verses 58% and 56%, respectively). Black race/ethnicity was also shown to be a predictor for mortality for the time period 1990-2013. Conclusion Racial/ethnic minorities have worse RMS clinical presentation and incidence rates than Whites. While overall survival is not predicted by race, being an ethnic minority child diagnosed with RMS is predictive of survival. These disparities point towards a genetic component in RMS that has not yet been described.
309

Economic Aspects of Climate Change Adaptation and Natural Hazard Risk Mitigation

Meng, Sisi 16 June 2016 (has links)
According to Munich Re (2013), economic losses related to natural disasters have increased from an average of $50 billion in the 1980s to $200 billion over the last decade. The cost of natural disasters is accumulating rapidly and some claim that climate change is responsible. Others believe that human behaviors like population growth or land use should be blamed for these rising costs. The process of climate change has already taken place, and it is expected to continue to impact the future. As a result, people are more vulnerable today. Therefore, understanding the economic aspects of climate change and natural hazard risks should be considered as a major issue and addressed in greater detail. This dissertation aimed to explore household preferences of climate change adaptation and the economic impacts of natural hazards at both micro- and macro- levels. The dissertation consisted of three related empirical studies based on the two main changes that will occur with climate change predicted by scientific climate models: stronger hurricanes and rising sea levels. The first chapter examined the impact of a recent hurricane on household activities. The objective was to find out whether a more intensified hurricane caused greater damages, and whether such damages had a long-lasting impact on household recovery. If the impact of natural hazards is worse than before, people should avoid putting themselves in harm's way. However, evidence indicates that the population in coastal cities is still growing fast, as people tend to reside near the beaches and attractive landscapes. Concerns are thus prompted by the possible lack of perceptions for future risks caused by natural hazards. Therefore, the second chapter focused on household perceptions and preferences for adapting to sea level rise in Florida. Lastly, although a disaster strikes rich or poor nations indifferently, some small island nations are among the most vulnerable. In the third chapter, the macroeconomic implications of natural hazards in Central America and the Caribbean were investigated. A careful examination of the economic factors that can lead to smaller losses and higher abilities to cope with disasters is crucial in such countries.
310

Integrated field investigation, numerical analysis and hazard assessment of the Portillo Rock Avalanche site, Central Andes, Chile

Welkner, Daniela 05 1900 (has links)
This thesis reports a rock slope hazard investigation located in the Central Andes of Chile, where two significant rock mass wasting events were recognized. Dating using cosmogenic nuclide for ³⁶Cl showed that the deposits were post-glacial in age, corresponding to the Upper Pleistocene Portillo Rock Avalanche (PRA) and a Holocene rock slump and rockslide. The pre-historic landslide deposits underlie both a key transportation route between Chile and Argentina and an important ski resort. The purpose of this research was to investigate the likely failure mechanism and characterise the runout path and volume of the PRA. The insights gained on the back analysis of the slope were used in later stages to assess the hazard potential of a recurring major rockslide. The distinct element code UDEC was used to evaluate the failure mechanism. Elasto-plastic modelling results showed that sliding and shearing along the bedding planes together with brittle fracturing and shearing through the toe of the slope likely had occurred. Runout simulations were carried out using DAN3D. Combinations of rheologies were tested and ranked based on their ability to represent the current distribution of the debris by means of pre-failure topography reconstruction and volume estimates of the deposits. Results showed that the best basal rheological combination for the PRA was frictional during the rockslide and Voellmy when entrainment became important. In contrast, a constant frictional basal rheology best represented the Holocene rock slump. The performance of the present-day state of the slope was tested under different scenarios. Under static condition the slope proved to be stable indicating a stabilized geometrical profile with time. Also, the slope proved to be stable under increased pore water pressures at its toe. Finally the modelled slope was subjected to a seismic load (M=7.8) and its crest failed due to an outward rotation of blocks, probably aided by topographic amplification. The runout simulations showed that the leading edge of the flow could override part of the International Santiago-Mendoza Corridor with no direct impact to the Portillo Ski Resort. Overall, though, under this highly unlikely dynamic condition for the site, the hazard level is very low. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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