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The Relative Importance of Input Encoding and Learning Methodology on Protein Secondary Structure PredictionClayton, Arnshea 09 June 2006 (has links)
In this thesis the relative importance of input encoding and learning algorithm on protein secondary structure prediction is explored. A novel input encoding, based on multidimensional scaling applied to a recently published amino acid substitution matrix, is developed and shown to be superior to an arbitrary input encoding. Both decimal valued and binary input encodings are compared. Two neural network learning algorithms, Resilient Propagation and Learning Vector Quantization, which have not previously been applied to the problem of protein secondary structure prediction, are examined. Input encoding is shown to have a greater impact on prediction accuracy than learning methodology with a binary input encoding providing the highest training and test set prediction accuracy.
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Food and the City: An Examination of the Role of Food in Local Neighbourhood RevitalizationBeaulieu, Nadine January 2010 (has links)
The majority of people in North America have lost not only the knowledge of how to successfully sustain themselves from the land but, even more troubling, the basic knowledge of where the food comes from, what real food is, or even what to do with it. It is not only basic knowledge of food that is being lost in the consumer culture; many of the private and public spaces that were central to the social fabric of the city, street, and family are changing and losing their significance. The mass marketing of the consumer lifestyle has led to the disappearance of home gardens, local restaurants, neighbourhood coffee shops, and farmers’ markets. It has altered the fine grain of our city, streets, and homes, thereby reducing the social interactions that once created lively streets in the past.
This thesis examines both the historical and current relationship and influence of food in cities, streets and homes in relation to the growing issues of access to fresh whole food and the dispersed city form. In addition, it will investigate how food orientated developments such as Community Food Centres can act as a catalyst for urban revitalization in failing urban cores and provide a resiliency to the economies of the city. The analysis of the influence of food, challenges that midsized cites are facing, and a series of precedents will provide a set guidelines for architects and planners developing urban projects. Three main themes are explored as a means to revitalization of urban neighbourhood through food: reuse of under used or abandoned land, our cultural connection to food, and the activities and culture that the two create together. These themes will explore the use and cultural significance of kitchens, markets, and restaurants and public space as architectural spaces that create community as a means to better understand what mechanisms of these aspects are the keys to the building of vibrant communities. This concept will be explored through the design of a community food centre in St. Patrick’s Ward in Guelph, Ontario.
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Maskrosbarn : En biografisk studieHammar, Minna January 2012 (has links)
Syfte med uppsatsen var att redogöra för hur individer som vuxit upp i familjer där en förälder missbrukat och/eller varit psykisk sjuk, beskriver sig själva i då och nutid, hemförhållanden och uppväxtförhållanden samt deras överlevnadsstrategier. Uppsatsen är av kvalitativ karaktär och utgörs av en innehållsanalys av tre biografier inom detta område. Genom att läsa tre biografier som belyser denna problematik samt med KASAM begreppen begriplighet, hanterbarhet, meningsfullhet och den dramaturgiska teorin har uppsatsen kunnat svara på frågeställningarna om hur individerna begriper sin barndom, hur har individerna hanterat sin barndomssituation samt om individerna kan se sin barndom som något bra. Uppsatsen har resulterat i förståelse för hur viktiga vuxna individer är för barn med sådan här problematik, samt hur viktigt det är att ha fritidsintressen. / The main purpose of this paper is to describe how individuals, who has grown up with parents who abused drugs or been mentally ill, describes themselves in the past as well as in the present, concerning their upbringing, home life, and their strategies of survival. The paper is qualitative in nature and consists of a content analysis of three biographies concerning this area. By reading these biographies that illustrates this problem and the concepts of KASAM; comprehensibility, manageability, meaningfulness and the dramaturgical theory, the paper has been able to explain how the individuals look back at their childhood, how they've been able to cope with it, and if they can see their childhood as a positive experience. The conclusions drawn from the paper are how important adult figures are in the life of these children and the importance of leisure activities.
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De vuxna maskrosbarnen : en kvalitativ intervjustudieFrost, Laila, Löfqvist, Marie January 2012 (has links)
Syftet med denna kvalitativa intervjustudie var att med hjälp av sociologiska teorier undersöka orsakerna till att maskrosbarn trots en destruktiv uppväxtmiljö kan utvecklas till socialt fungerande människor. Maskrosbarnen i denna studie har vuxit upp med missbruk och/eller psykisk sjukdom hos föräldrar i barndomen. Data samlades in via semistrukturerade intervjuer med fyra olika teman: det sociala arvet, skola och arbete, socialt nätverk samt hälsa och välmående. Vilket vi sedan analyserade med hjälp av de teoretiska tolkningsramarna, Antonovskys teori KASAM och Bourdieus teori om Klassreproduktion. Resultaten visade att förekomsten av trygghetspersoner i barndomen samt möjligheten att uppleva en annan familjedynamik och miljö än deras egen hemmiljö har påverkat dem positivt. Även deras avhållsamma inställning till alkohol och droger samt deras starka ansvarskänsla har påverkat deras totala sociala kapital positivt. / The purpose of this qualitative interview study was to research with the help of sociological theories the reasons why resilient children despite a destructive childhood can evolve to social functioning humans. Resilient children in this study have grown up with addiction and/or mental illness among parents in childhood. Data was collected by semi structured interviews with four different themes: the social heritage, education and work, social network and health and well-being. Which we analyzed with the help of the theoreticalframeworks, Antonovskys theory Salutogenesis and Bourdieus Reproduction theory. The results showed that the presence of safety figures in childhood as well as the opportunity to experience a different family dynamic and another environment than their own home environment has affected them positively. Even their abstinence approach to alcohol and drugs, and that they have a strong sense of responsibility has affected their overall social capital positively.
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Toward Attack-Resistant Distributed Information Systems by Means of Social TrustSirivianos, Michael January 2010 (has links)
<p>Trust has played a central role in the design of open distributed systems that span distinct administrative domains. When components of a distributed system can assess the trustworthiness of their peers, they are in a better position to interact with them. There are numerous examples of distributed systems that employ trust inference techniques to regulate the interactions of their components including peer-to-peer file sharing systems, web site and email server reputation services and web search engines.</p>
<p>The recent rise in popularity of Online Social Networking (OSN) services has made an additional dimension of trust readily available to system designers: social trust. By social trust, we refer to the trust information embedded in social links as annotated by users of an OSN. This thesis' overarching contribution is methods for employing social trust embedded in OSNs to solve two distinct and significant problems in distributed information systems. </p>
<p>The first system proposed in this thesis assesses the ability of OSN users to correctly classify online identity assertions. The second system assesses the ability of OSN users to correctly configure devices that classify spamming hosts. In both systems, an OSN user explicitly ascribes to his friends a value that reflects how trustworthy he considers their classifications. In addition, both solutions compare the classification input of friends to obtain a more accurate measure of their pairwise trust. Our solutions also exploit trust transitivity over the social network to assign trust values to the OSN users. These values are used to weigh the classification input by each user in order to derive an aggregate trust score for the identity assertions or the hosts.</p>
<p>In particular, the first problem involves the assessment of the veracity of assertions on identity attributes made by online users. Anonymity is one of the main virtues of the Internet. It protects privacy and freedom of speech, but makes it hard to assess the veracity of assertions made by online users concerning their identity attributes (e.g, age or profession.) We propose FaceTrust, the first system that uses OSN services to provide lightweight identity credentials while preserving a user's anonymity. FaceTrust employs a ``game with a purpose'' design to elicit the</p>
<p>opinions of the friends of a user about the user's self-claimed identity attributes, and uses attack-resistant trust inference to compute veracity scores for the attributes. FaceTrust then provides credentials, which a user can use to corroborate his online identity assertions. </p>
<p>We evaluated FaceTrust using a crawled social network graph as well as a real-world deployment. The results show that our veracity scores strongly correlate with the ground truth, even when a large fraction of the social network users are dishonest. For example, in our simulation over the sample social graph, when 50% of users were dishonest and each user employed 1000 Sybils, the false assertions obtained approximately only 10% of the veracity score of the true assertions. We have derived the following lessons from the design and deployment of FaceTrust: a) it is plausible to obtain a relatively reliable measure of the veracity of identity assertions by relying on the friends of the user that made the assertion to classify them, and by employing social trust to determine the trustworthiness of the classifications; b) it is plausible to employ trust inference over the social graph to effectively mitigate Sybil attacks; c) users tend to mostly correctly classify their friends' identity assertions.</p>
<p>The second problem in which we apply social trust involves assessing the trustworthiness of reporters (detectors) of spamming hosts in a collaborative spam mitigation system. Spam mitigation can be broadly classified into two main approaches: a) centralized security infrastructures that rely on a limited number of trusted monitors (reporters) to detect and report malicious traffic; and b) highly distributed systems that leverage the experiences of multiple nodes within distinct trust domains. The first approach offers limited threat coverage and slow response times, and it is often proprietary. The second approach is not widely adopted, partly due to the </p>
<p>lack of assurances regarding the trustworthiness of the reporters. </p>
<p>Our proposal, SocialFilter, aims to achieve the trustworthiness of centralized security services and the wide coverage, responsiveness, and inexpensiveness of large-scale collaborative spam mitigation. It enables nodes with no email classification functionality to query the network on whether a host is a spammer. SocialFilter employs trust inference to weigh the reports concerning spamming hosts that collaborating reporters submit to the system. To the best of our knowledge, </p>
<p>it is the first collaborative threat mitigation system that assesses the trustworthiness of the reporters by both auditing their reports and by leveraging the social network of the reporters' human administrators. Subsequently, SocialFilter weighs the spam reports according to the trustworthiness of their reporters to derive a measure of the system's belief that a host is a spammer. </p>
<p>We performed a simulation-based evaluation of SocialFilter, which indicates its potential: </p>
<p>during a simulated spam campaign, SocialFilter classified correctly 99% of spam, while yielding no false positives. The design and evaluation of SocialFilter offered us the following lessons: a) it is plausible to introduce Sybil-resilient OSN-based trust inference mechanisms to improve the reliability and the attack-resilience of collaborative spam mitigation; b) using social links to obtain the trustworthiness of reports concerning spammers (spammer reports) can result in comparable spam-blocking effectiveness with approaches that use social links to rate-limit spam (e.g., Ostra); c) unlike Ostra, SocialFilter yields no false positives. We believe that the design lessons from SocialFilter are applicable to other collaborative entity classification systems.</p> / Dissertation
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Evaluation Of Resilient Modulus Estimation Methods For Asphalt Mixtures Based On Laboratory MeasurementsDemirci, Canser 01 May 2010 (has links) (PDF)
Resilient modulus is a property for bound and unbound pavement materials characterizing the elastic behavior of materials under dynamic repeated loading. Resilient modulus is an important design parameter for pavement structures because it represents the structural strength of pavement layers through which the thickness design is based on. In Turkey, the layer thickness design is performed using resilient modulus determined empirically from various published sources. Determining a layer modulus using empirical methods causes inaccurate design solutions, which directly affects the structural performance and the overall cost of pavement construction. In this study, the resilient moduli of bituminous mixtures are measured in the laboratory by the indirect tensile test procedure for eight asphalt concrete samples according to NCHRP and ASTM procedures. The measured moduli of samples based on the two procedures are compared with the predicted values calculated from various empirical methods using aggregate and binder properties. An evaluation of each estimation method is presented on the basis of its accuracy level. The results show that the Witczak predictive equation produces the closest estimation to the modulus of samples for both laboratory measurement methods.
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Resilient modulus and permanent deformation testing of unbound granular materialsKancherla, Anuroopa 01 November 2005 (has links)
Numerous research efforts have been devoted to characterizing the behavior of granular materials, which is one of the main concerns of pavement engineers. For better understanding of this behavior, laboratory tests where in-situ stress conditions and traffic loads are adequately simulated are needed. This study makes use of an expanded test protocol called a performance test that includes resilient modulus as well as permanent deformation testing. This test protocol determines three nonlinear resilient modulus parameters (k1, k2, k3) and two permanent deformation parameters (?,??). The resilient modulus test results are required inputs in the Level 1 analysis of the proposed American Association of State Highway and Transportation Officials (AASHTO) Pavement Design Guide. In addition, both resilient modulus and permanent deformation test results provide material property inputs to pavement performance prediction models.
This study also evaluated the within laboratory repeatability of the performance test and developed a within laboratory precision statement. Further, a statistical analysis was conducted on the test results to estimate the number of test specimens required for testing for specific reliability levels. Two test specimens are required for a reliability level of 15%. A within laboratory study was also conducted to investigate the influence of specimen size on test results. The specimen height was reduced from 12 in. (304 mm) to 8 in. (203 mm), and there was no difference in test results at a confidence level of 95%.
The performance test was further used successfully in subsequent studies to evaluate the behavior of granular materials and the influence of various factors on their behavior. As fines content increased, the resilient modulus values decreased and permanent deformation increased. As the moisture content increased, the resilient modulus value decreased and the resistance to permanent deformation decreased.
A simplified laboratory measurement tool that is repeatable, relatively cheap and easy to perform might prompt the use of laboratory measured values of resilient modulus in pavement design and facilitate correlation of these values to field measured values on a large scale. Use of measured data for the base properties rather than estimates would insure improved pavement designs and, in many cases, would save money in construction costs.
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Risk and protective factors related to resilience in adolescents in an alternative education programCrawford, Kelly M 01 June 2006 (has links)
Using a multivariate correlational design, this study was designed to determine the degree to which selected risk and protective factors were related to resilience in an at-risk student population. A total of 12 individual, family and external risk and protective factors were identified and data were collected from 142 6th through 11th grade students in an alternative education program for individuals who had committed severe behavioral infractions. A series of multiple regression analyses were conducted using three outcome variables: a rating of students' resilient behavior, number of behavior referrals in the students' records, and standardized reading achievement scores. Five percent of the sample then was selected for semi-structured interviews to glean additional information about the relationships between the identified variables and student resilience.The combination of individual, family and external risk variables explained a significant amount of the variance in
student behavior referrals and reading achievement, but not in overall resilient status. With regard to behavior referrals, the largest contributors to the model were age, severity of sending offense and neighborhood crime. Reading achievement was related to special education status, as predicted, and negatively related to community violence. Parental structure was positively correlated with resilient status but the percentage of variance explained by the overall model was not significant.The combination of selected protective factors explained a significant amount of variance when resilient status and reading achievement were the measured outcomes, but not for the model addressing behavior referrals. Being a male and having strong cohesion as a family unit were the variables most highly related to resilient status, while special education eligibility and perceptions of school belongingness accounted for the largest variance in reading scores. School belongingness was negatively relate
d to reading achievement in this sample.An examination of qualitative data revealed that teacher characteristics were important to students' motivation to succeed, and information collected reiterated the importance of family structure and cohesion in students' resilient status. Other emerging themes were apparent when mentoring and friendship were discussed, as well as when students' self-perceived strengths, weaknesses and future aspirations were identified.
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Food and the City: An Examination of the Role of Food in Local Neighbourhood RevitalizationBeaulieu, Nadine January 2010 (has links)
The majority of people in North America have lost not only the knowledge of how to successfully sustain themselves from the land but, even more troubling, the basic knowledge of where the food comes from, what real food is, or even what to do with it. It is not only basic knowledge of food that is being lost in the consumer culture; many of the private and public spaces that were central to the social fabric of the city, street, and family are changing and losing their significance. The mass marketing of the consumer lifestyle has led to the disappearance of home gardens, local restaurants, neighbourhood coffee shops, and farmers’ markets. It has altered the fine grain of our city, streets, and homes, thereby reducing the social interactions that once created lively streets in the past.
This thesis examines both the historical and current relationship and influence of food in cities, streets and homes in relation to the growing issues of access to fresh whole food and the dispersed city form. In addition, it will investigate how food orientated developments such as Community Food Centres can act as a catalyst for urban revitalization in failing urban cores and provide a resiliency to the economies of the city. The analysis of the influence of food, challenges that midsized cites are facing, and a series of precedents will provide a set guidelines for architects and planners developing urban projects. Three main themes are explored as a means to revitalization of urban neighbourhood through food: reuse of under used or abandoned land, our cultural connection to food, and the activities and culture that the two create together. These themes will explore the use and cultural significance of kitchens, markets, and restaurants and public space as architectural spaces that create community as a means to better understand what mechanisms of these aspects are the keys to the building of vibrant communities. This concept will be explored through the design of a community food centre in St. Patrick’s Ward in Guelph, Ontario.
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Characterising the Deformation Behaviour of Unbound Granular Materials in Pavement StructuresRahman, Mohammad Shafiqur January 2015 (has links)
Unbound granular materials (UGMs) used in the base and sub-base layers of flexible pavements play a significant role in the overall performance of the structure. Proper understanding and characterization of the deformation behaviour of UGMs in pavement structures are, therefore, vital for the design and maintenance of flexible pavements. In this study, the resilient deformation (RD) and the permanent deformation (PD) behaviour of UGMs were investigated for the better understanding and improved modelling of these deformation characteristics. The study is based on a series of repeated-load triaxial (RLT) tests carried out on several UGMs commonly used in pavement structures. Here, the influences of stress level and moisture content - two of the most significant factors affecting the deformation behaviour of UGMs - were analysed. The effects of the grain size distribution and the degree of compaction were also considered. The study on the RD behaviour indicated that the resilient stiffness (MR)of UGMs increases with the increased bulk stress level, which can be satisfactorily described by the k-θ model. Moisture was found to negatively impact the MR as long as the deformation was mostly resilient with a negligible amount of accumulated PD. Analysis of the influence of moisture on the parameters k1 and k2 of the k-θ model showed that k1 decreases with increased moisture and k2 is relatively insensitive to moisture. Based on these observations, a simple model was developed for the impact of moisture on MR. The performance of this model was comparable to an existing moisture dependent MR model. In contrast, it was further observed that at the later stages of the RLT tests, after a relatively large number of load applications, the MR increased with increased moisture up to the optimum moisture content. This occurred when the RD was accompanied by a significant amount of PD. Further investigation suggested that moisture aided the post-compaction (PC) and possible particle rearrangement that resulted in the increased PD and increased MR. In this case k1 decreased, whereas k2 increased, with increased moisture. The existing MR-moisture model did not work for this behaviour. This suggests that the effect of PC on MRshould be considered in modelling. However, although not explored in this study, it may be possible to simulate this effect of increase in MR with increased moisture due to PC using the proposed model if k2 is expressed as a function of moisture. The PD characteristics of UGMs were investigated based on the multistage (MS) RLT test. In contrast with the single stage (SS) RLT test, the MS RLT test accounts for the effect of stress history and enables a comprehensive study of the material behaviour under cyclic stresses of various magnitudes. Since the existing PD models cannot be directly applied for the MS loading procedure, a general formulation based on the time hardening concept was derived that can be used to extend the models for the MS loading conditions. Based on this formulation, some of the current models were calibrated and their performance in predicting the PD behaviour in MS RLT tests was compared. The investigation regarding the impact of moisture on PD showed that moisture significantly increases the accumulation of PD. Generally, materials with finer grading showed more sensitivity to moisture with regards to both PD and RD. To characterize the impact of moisture, moisture sensitivity of different grain size distributions and the impact of the degree of compaction on PD with reduced effort, a simple model was proposed. Unlike some of the well-performing existing models, this model can be calibrated using a single MS RLT test without requiring any separate static failure triaxial tests. This model was validated using the MS RLT test data with satisfactory results. The sensitivity of the parameters of this model was studied with respect to moisture content, degree of compaction and grain size distribution. Some reasonable trends for the sensitivity of the parameters to these influential factors were obtained, which suggests that these may be further developed to incorporate into the model. / <p>QC 20150325</p>
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