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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.
21

Finding Blame for Environmental Outcomes: A Cognitive Style Approach to Understanding Stakeholder Attributions, Attitudes, and Values

Hawkins, Christopher Thomas 01 September 2011 (has links)
This study sought to connect two bodies of knowledge--integrative complexity and attribution theory. Integrative complexity is a term that indicates the simplicity vs. complexity of a person's mental frame and perceptual skill. A person who perceives nuance and subtle differences typically scores higher on an integrative complexity measure. Attribution theories are concerned with how individuals perceive causation for various events. The limited research into the linkages between perceived causation for an event and how complexly a person thinks about the domain of that event, coupled with the dearth of attribution research in the natural resource management literature, inspired this research. Florida Keys coral reef users were sent a mail questionnaire between July 2009 and March 2010. Integrative complexity level was determined using an index that was developed for this research. Based on attributional and cognitive complexity literature, it was hypothesized that people who score lower in integrative complexity would exhibit an "external" attribution pattern. Integrative complexity was also proposed to influence: attitude and value extremity; number of perceived problem causes; and use of mediated communication. Finally, it was hypothesized that individuals will assign more blame to other groups than to their own. Six of the study's seven null hypotheses were rejected: 1) a significant relationship was found between integrative complexity level and the number of causes that respondents recorded for the decline of the Florida Keys reef ecosystem, 2) significant differences were observed in attitude extremity according to integrative complexity, 3) significant differences were observed in value orientation according to integrative complexity, 4) significant differences were observed in value extremity according to integrative complexity level, 5) significant differences were observed in mediated communication according to integrative complexity level, and 6) significant differences were observed in blame pattern according to group affiliation. Only one null hypothesis was not rejected: no support was found for a connection between integrative complexity and attribution style. These results indicate support for the integrative complexity index, though work to refine the measure seems in order. Additional recommendations for future research include investigating new approaches to examining the relationship between integrative complexity and attribution style.
22

Key Management for Wireless Sensor Networks in Hostile Environments

Chorzempa, Michael William 09 June 2006 (has links)
Large-scale wireless sensor networks (WSNs) are highly vulnerable to attacks because they consist of numerous resource-constrained devices and communicate via wireless links. These vulnerabilities are exacerbated when WSNs have to operate unattended in a hostile environment, such as battlefields. In such an environment, an adversary poses a physical threat to all the sensor nodes. An adversary may capture any node, compromising critical security data including keys used for encryption and authentication. Consequently, it is necessary to provide security services to these networks to ensure their survival. We propose a novel, self-organizing key management scheme for large-scale and long-lived WSNs, called Survivable and Efficient Clustered Keying (SECK). SECK provides administrative services that ensures the survivability of the network. SECK is suitable for managing keys in a hierarchical WSN consisting of low-end sensor nodes clustered around more capable gateway nodes. Using cluster-based administrative keys, SECK provides five efficient security administration mechanisms: 1) clustering and key setup, 2) node addition, 3) key renewal, 4) recovery from multiple node captures, and 5) re-clustering. All of these mechanisms have been shown to localize the impact of attacks and considerably improve the efficiency of maintaining fresh session keys. Using simulation and analysis, we show that SECK is highly robust against node capture and key compromise while incurring low communication and storage overhead. / Master of Science
23

Do hurricanes and other severe weather events affect catch per unit effort of reef-fish in the Florida Keys?

Rios, Adyan Beatriz 05 June 2012 (has links)
Severe weather events frequently affect important marine fish stocks and fisheries along the United States Atlantic and Gulf of Mexico coasts. However, the effects of these events on fish and fisheries are not well understood. The availability of self-reported data from two fisheries in a region frequently affected by tropical cyclones provided a unique opportunity to investigate short-term responses to past events. This study involved selecting severe weather events, calculating changes in effort and catch-per-unit- effort (CPUE), and analyzing those changes across various temporal, spatial, and species-specific scenarios. Responses in each variable were analyzed within and across scenario factors and explored for correlations and linear multivariate relationships with hypothesized explanatory variables. A negative overall directional change was identified for logbook fishing effort. Based on both correlations and linear models, changes in logbook fishing effort were inversely related to changes in average maximum wind speed. Severe weather events are more likely to affect fishing effort than catch rates of reef-fish species. However, lack of responses in CPUE may also relate to the ability of this study to detect changes. The temporal and spatial scales analyzed in this study may not have been adequate for identifying changes in effort for the headboat fishery, or in CPUE for either fishery. Although there was no region-wide response in CPUE associated with severe weather events, further research on this topic is necessary to determine if storm-induced changes in fishery data are likely strong, long-lasting, or widespread enough to influence the outcome of stock-wide assessments. / Master of Science
24

Updated distribution and reintroduction of the Lower Keys marsh rabbit

Faulhaber, Craig Alan 17 February 2005 (has links)
Listed as federally-endangered in 1990, the Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri) exists as a metapopulation in patches of wetland habitat in Florida’s Lower Keys. This study sought to address 2 priority actions identified by the LKMR Recovery Team: (1) monitoring of populations and (2) reintroduction. Monitoring the distribution and status of LKMR populations is critical for targeting future management actions. Informal transects for rabbit fecal pellets were used to survey habitat patches documented in1988–1995 surveys and to identify additional patches of occupied and potential habitat. Next, a buffer was created around patches to help managers account for uncertainty in rabbit movements and to identify groups of patches that might function as local populations. Surveys included 228 patches of occupied and potential habitat, 102 of which were occupied by rabbits. Patches were arranged in 56 occupied and 88 potential populations. Surveys revealed new patches of both occupied and potential habitat. Considering only areas included in 1988–1995 surveys, however, revealed a net decrease in the number of occupied patches. Many of the recently extirpated populations, which tended to occupy the periphery of larger islands or small neighboring islands, were unlikely to be recolonized without human intervention. Reintroduction provides a means of artificially recolonizing potential habitat. Two pilot reintroductions were conducted to evaluate this conservation strategy for the species. The second reintroduction was postponed, but the first effort met all criteria for short-term success, including survival comparable to a control group, fidelity to release sites, and evidence of reproduction. There are a limited number of potential source populations for translocations. Future efforts should consider using in-situ captive breeding to prevent potential long-term impacts to these populations. Few potential release sites exhibited suitable habitat quality and landscape context. Thus, for reintroduction to be more widely-applied for this species, it must be part of a comprehensive management plan involving land acquisition, control of secondary impacts from development, and habitat restoration and enhancement.
25

Updated distribution and reintroduction of the Lower Keys marsh rabbit

Faulhaber, Craig Alan 17 February 2005 (has links)
Listed as federally-endangered in 1990, the Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri) exists as a metapopulation in patches of wetland habitat in Florida’s Lower Keys. This study sought to address 2 priority actions identified by the LKMR Recovery Team: (1) monitoring of populations and (2) reintroduction. Monitoring the distribution and status of LKMR populations is critical for targeting future management actions. Informal transects for rabbit fecal pellets were used to survey habitat patches documented in1988–1995 surveys and to identify additional patches of occupied and potential habitat. Next, a buffer was created around patches to help managers account for uncertainty in rabbit movements and to identify groups of patches that might function as local populations. Surveys included 228 patches of occupied and potential habitat, 102 of which were occupied by rabbits. Patches were arranged in 56 occupied and 88 potential populations. Surveys revealed new patches of both occupied and potential habitat. Considering only areas included in 1988–1995 surveys, however, revealed a net decrease in the number of occupied patches. Many of the recently extirpated populations, which tended to occupy the periphery of larger islands or small neighboring islands, were unlikely to be recolonized without human intervention. Reintroduction provides a means of artificially recolonizing potential habitat. Two pilot reintroductions were conducted to evaluate this conservation strategy for the species. The second reintroduction was postponed, but the first effort met all criteria for short-term success, including survival comparable to a control group, fidelity to release sites, and evidence of reproduction. There are a limited number of potential source populations for translocations. Future efforts should consider using in-situ captive breeding to prevent potential long-term impacts to these populations. Few potential release sites exhibited suitable habitat quality and landscape context. Thus, for reintroduction to be more widely-applied for this species, it must be part of a comprehensive management plan involving land acquisition, control of secondary impacts from development, and habitat restoration and enhancement.
26

Criando mensagens secretas na escola básica utilizando a criptografia – RSA

Castro Junior, Waldir Claudio de 21 August 2015 (has links)
Submitted by Daniele Amaral (daniee_ni@hotmail.com) on 2016-09-15T16:05:03Z No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:51:53Z (GMT) No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-16T19:51:57Z (GMT) No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) / Made available in DSpace on 2016-09-16T19:52:02Z (GMT). No. of bitstreams: 1 DissWCCJ.pdf: 1969639 bytes, checksum: cbe6746c0279668ba7ff3b8de72d8caf (MD5) Previous issue date: 2015-08-21 / Não recebi financiamento / Cryptography is a fascinating topic, concerning the practical point of view, and it is useful to access bank accounts, e-mails and social networks. According to this perspective, this study aimed to show how simple it may be to make use of cryptography. It was proved, through the work performed, that it is possible for students from elementary and high school to encrypt and decrypt messages using R.S.A. Cryptography, which involves the concept of creating public keys and private keys for the encryption of messages. A simple but powerful activity on the utility view was assigned to show students from the 9th grade of elementary school and from the 1st and 2nd years of high school from a private school in São Paulo State how interesting and pleasurable the use of Mathematics can be. Such activities are not usually present in the traditional didactic materials. The theoretical tools, containing theorem and corollaries, as well as their demonstrations, which mathematically justify the validity of techniques and the algorithm used on R.S.A. Cryptography will be presented. The activities do not assume sophisticated prerequisites and can be applied in the classroom, in real situations, so that the students can appreciate the beauty of Mathematics. / A criptografia é um assunto fascinante do ponto de vista prático; é útil para acessar contas bancárias, e-mails e redes sociais. Segundo esta perspectiva, esta dissertação baseou-se em mostrar o quão simples pode ser a utilização da criptografia. No trabalho realizado foi mostrado que é possível, para alunos do Ensino Fundamental e Médio, codificar e decifrar mensagens utilizando a criptografia - RSA, a qual envolve o conceito da criação de chaves públicas e chaves privadas para a codificação de mensagens. Uma atividade simples, porém importante do ponto de vista utilitário, foi aplicada para mostrar aos alunos do 9º ano do Ensino Fundamental, da 1ª e 2ª séries do Ensino Médio de uma escola particular do interior paulista para mostrar o quão interessante e prazerosa pode ser a utilização da Matemática. Tais atividades não constam usualmente nos materiais didáticos tradicionais. Nesta dissertação será apresentado o ferramental teórico, contendo teoremas e corolários, assim como suas demonstrações, os quais justificam, matematicamente, a validade das técnicas e do algoritmo utilizados na criptografia – RSA. As atividades não pressupõem pré-requisitos sofisticados, podendo ser aplicadas em sala de aula, em situações reais, para que os alunos apreciem a beleza da Matemática.
27

Perceptions and Preferences of Commercial Fishers in the Florida Keys for Alternative Management Frameworks

Pierce, Brett P 09 November 2011 (has links)
The decline of the world’s fisheries, and the inability of traditional management frameworks to maintain them, has led managers to adopt new, alternative management frameworks. Alternative management frameworks include marine protected areas (MPA) and dedicated access privileges (DAP). The use of such frameworks has often been shown to be quite unpopular, especially with commercial fishers. In this thesis, commercial fishers’ preference for alternative management frameworks is examined in the context of the unique multispecies fisheries of the Florida Keys. By surveying commercial fishers, it was found that the size of operation plays no role in affecting fisher perception of dedicated access privileges. Furthermore, fishers who are organized are less likely to support dedicated access privilege frameworks. Finally, the fishing industry does not support the implementation of dedicated access privileges in the Florida Keys. These findings can provide inputs for managers in developing effective management plans in the region.
28

Určovací klíče v procesu poznávání přírodnin / Identification Keys as a Way of Getting to Know the Nature

Novotný, Petr January 2013 (has links)
TITLE: Identification Keys as a Way of Getting to Know the Nature AUTHOR: Petr Novotný DEPARTMENT: Biology and Environmental Studies Department SUPERVISOR: doc. PhDr. Petr Dostál, CSc. ABSTRACT: This doctoral thesis deals with biological identification keys. It aims to unify and clarify the terminology used to describe the identification keys, to describe the evolution of the concept of these keys and their typology. It describes their role and importance in education from the perspective of current didactic overview as well as from the perspective of Czech historical botanical keys. The aim of the research part is to design and validate methods for assessing identification keys. This research has been divided into two themes - the analysis of a key and the testing of a key. As the result of this processing is a design of identification keys evaluation model. This model is validated on the current Czech botanical designation key Kubát (2002). Based on thesis outcomes, it is possible to better understand the theoretical basis of identification keys and their role in the process of getting to know the nature. KEYWORDS: Theory of Identification Keys; Identification Keys Evaluation; Biological Species Cognition;
29

Population Status and Evaluation of Landscape Change for the Lower Keys Marsh Rabbit

Schmidt, Jason Alan 2009 December 1900 (has links)
Wildlife biologists and land managers tasked with the recovery of the endangered Lower Keys marsh rabbit (LKMR; Sylvilagus palustris hefneri) were in need of a current population estimate as well as a method to estimate the LKMR population annually. Habitat loss and fragmentation from population growth and development have threatened the existence of the LKMR. Establishing and understanding long-term habitat availability for the LKMR is important for determining causes of historical population declines as well as designing and implementing successful recovery plans. I conducted a range-wide pellet survey and a mark-recapture study to estimate the LKMR population. I evaluated the fit of 5 models and considered the variation in behavioral response model the best model. I correlated (r2 = 0.913) this model's rabbit abundance estimates to pellet density in 11 patches and generated a range-wide population estimate of 317, a western clade population of 257, an eastern clade population of 25, and translocated LKMR populations of 35 and 0 on Little Pine and Water keys, respectively. This prediction equation provides managers a quick, efficient, and non-invasive method to estimate LKMR abundance from pellet counts. To quantify the amount of habitat loss and fragmentation that occurred over the last 50 years, I systematically delineated and compared potential LKMR habitat using 1959 and 2006 aerial photographs. Additionally, I investigated if other factors could have reduced the amount of suitable habitat available for the LKMR with a comparison of habitat loss and fragmentation on a developed island and an undeveloped island. Range-wide, I found that number of habitat patches increased by 38, total class area decreased by 49.0%, and mean patch size decreased by 44.3%. Mean shape index increased by 4.2% and mean proximity index decreased by 13%. Both the 1959 and 2006 connectance indices were low while the 2006 set decreased 12.1%. I observed the same patterns of habitat loss and fragmentation on both the developed and undeveloped islands as I did in the range-wide landscape analysis. I found that LKMR habitat has declined in area and become more fragmented over the last 50 years. Habitat loss and fragmentation by development have directly endangered the LKMR; however, sea level rise and woody encroachment also could have historically caused habitat loss and fragmentation. Although development in LKMR habitat was halted, sea-level rise and woody encroachment could continue to alter LKMR habitat.
30

Affordable Housing in the Florida Keys: Providing Affordable Units Within the Limits of Local Growth Management Regulations

Parrish, Bradley K. January 2007 (has links)
No description available.

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