This thesis establishes the evidential value of thumbnail cache file fragments identified in unallocated space. A set of criteria to evaluate the evidential value of thumbnail cache artefacts were created by researching the evidential constraints present in Forensic Computing. The criteria were used to evaluate the evidential value of live system thumbnail caches and thumbnail cache file fragments identified in unallocated space. Thumbnail caches can contain visual thumbnails and associated metadata which may be useful to an analyst during an investigation; the information stored in the cache may provide information on the contents of files and any user or system behaviour which interacted with the file. There is a standard definition of the purpose of a thumbnail cache, but not the structure or implementation; this research has shown that this has led to some thumbnail caches storing a variety of other artefacts such as network place names. The growing interest in privacy and security has led to an increase in user’s attempting to remove evidence of their activities; information removed by the user may still be available in unallocated space. This research adapted popular methods for the identification of contiguous files to enable the identification of single cluster sized fragments in Windows 7, Ubuntu, and Kubuntu. Of the four methods tested, none were able to identify each of the classifications with no false positive results; this result led to the creation of a new approach which improved the identification of thumbnail cache file fragments. After the identification phase, further research was conducted into the reassembly of file fragments; this reassembly was based solely on the potential thumbnail cache file fragments and structural and syntactical information. In both the identification and reassembly phases of this research image only file fragments proved the most challenging resulting in a potential area of continued future research. Finally this research compared the evidential value of live system thumbnail caches with identified and reassembled fragments. It was determined that both types of thumbnail cache artefacts can provide unique information which may assist with a digital investigation. ii This research has produced a set of criteria for determining the evidential value of thumbnail cache artefacts; it has also identified the structure and related user and system behaviour of popular operating system thumbnail cache implementations. This research has also adapted contiguous file identification techniques to single fragment identification and has developed an improved method for thumbnail cache file fragment identification. Finally this research has produced a proof of concept software tool for the automated identification and reassembly of thumbnail cache file fragments.

The context-workflow relationship is often poorly defined or forgotten entirely. In workflow systems and applications context is either omitted, defined by the workflow or defined based on a single aspect of a contextual dimension. In complex environments this can be problematic as the definition of context is useful in determining the set of possible workflows. Context provides the envelope that surrounds the workflow and determines what is or is not possible. The relationship between workflow and context is also poorly defined. That context can exist independently of workflow is often ignored, and workflow does not exist independently of context. Workflow representations void of context violate this stipulation. In order for a workflow representation to exist in a contextual dimension it must possess the same dimensions as the context. In this thesis we selected one contextual dimension to study, in this case the spatial dimension, and developed a comprehensive definition using building data models. Building data models are an advanced form of representation that build geometric data models into an ob ject-oriented representation consisting of common building elements. The building data model used was the Industry Foundation Classes (IFC) as it is the leading standard in this emerging field. IFC was created for the construction of facilities and not the use of facilities at a later time. In order to incorporate workflows into IFC models, a zoning technique was developed in order to represent the workflow in IFC. The zoning concept was derived from multi-criteria layout for facilities layout and was adapted for IFC and workflow. Based on the above work a zoning extension was created to explore the combination of IFC, workflow and simulation. The extension is a proof of concept and is not intended to represent a robust formalized system. The results indicate that the use of a comprehensive definition of a contextual dimension may prove valuable to future expert systems.

The context-workflow relationship is often poorly defined or forgotten entirely. In workflow systems and applications context is either omitted, defined by the workflow or defined based on a single aspect of a contextual dimension. In complex environments this can be problematic as the definition of context is useful in determining the set of possible workflows. Context provides the envelope that surrounds the workflow and determines what is or is not possible. The relationship between workflow and context is also poorly defined. That context can exist independently of workflow is often ignored, and workflow does not exist independently of context. Workflow representations void of context violate this stipulation. In order for a workflow representation to exist in a contextual dimension it must possess the same dimensions as the context. In this thesis we selected one contextual dimension to study, in this case the spatial dimension, and developed a comprehensive definition using building data models. Building data models are an advanced form of representation that build geometric data models into an ob ject-oriented representation consisting of common building elements. The building data model used was the Industry Foundation Classes (IFC) as it is the leading standard in this emerging field. IFC was created for the construction of facilities and not the use of facilities at a later time. In order to incorporate workflows into IFC models, a zoning technique was developed in order to represent the workflow in IFC. The zoning concept was derived from multi-criteria layout for facilities layout and was adapted for IFC and workflow. Based on the above work a zoning extension was created to explore the combination of IFC, workflow and simulation. The extension is a proof of concept and is not intended to represent a robust formalized system. The results indicate that the use of a comprehensive definition of a contextual dimension may prove valuable to future expert systems.

©Cranfield University / This thesis establishes the evidential value of thumbnail cache file fragments identified in unallocated space. A set of criteria to evaluate the evidential value of thumbnail cache artefacts were created by researching the evidential constraints present in Forensic Computing. The criteria were used to evaluate the evidential value of live system thumbnail caches and thumbnail cache file fragments identified in unallocated space. Thumbnail caches can contain visual thumbnails and associated metadata which may be useful to an analyst during an investigation; the information stored in the cache may provide information on the contents of files and any user or system behaviour which interacted with the file. There is a standard definition of the purpose of a thumbnail cache, but not the structure or implementation; this research has shown that this has led to some thumbnail caches storing a variety of other artefacts such as network place names. The growing interest in privacy and security has led to an increase in user’s attempting to remove evidence of their activities; information removed by the user may still be available in unallocated space. This research adapted popular methods for the identification of contiguous files to enable the identification of single cluster sized fragments in Windows 7, Ubuntu, and Kubuntu. Of the four methods tested, none were able to identify each of the classifications with no false positive results; this result led to the creation of a new approach which improved the identification of thumbnail cache file fragments. After the identification phase, further research was conducted into the reassembly of file fragments; this reassembly was based solely on the potential thumbnail cache file fragments and structural and syntactical information. In both the identification and reassembly phases of this research image only file fragments proved the most challenging resulting in a potential area of continued future research. Finally this research compared the evidential value of live system thumbnail caches with identified and reassembled fragments. It was determined that both types of thumbnail cache artefacts can provide unique information which may assist with a digital investigation. ii This research has produced a set of criteria for determining the evidential value of thumbnail cache artefacts; it has also identified the structure and related user and system behaviour of popular operating system thumbnail cache implementations. This research has also adapted contiguous file identification techniques to single fragment identification and has developed an improved method for thumbnail cache file fragment identification. Finally this research has produced a proof of concept software tool for the automated identification and reassembly of thumbnail cache file fragments.

This thesis documents the fieldwork component of the archaeological survey, testing, and data recovery efforts associated with 41BX1753, a historic-age site located in downtown San Antonio, Texas. This paper details the project’s activities and results and provides feature and artifact descriptions. Furthermore, this work provides a contextual analysis of 41BX1753 based on the artifacts recovered and the archival record. In the report, I explore the social, political and economic relationships in San Antonio’s past through the study of the material and archival records associated with a single property and its residents. Examined within a greater historical context, these records are indicative of choices made by some of San Antonio’s most influential residents indicating a sense of identity and status, as well as strategies of adaptation and accommodation to ensure stability in the face of constant change. / text

The growing need for designing and implementing reliable voice-based human-machine interfaces has inspired intensive research work in the field of voice-enabled systems, and greater robustness and reliability are being sought for those systems. Speech recognition has become ubiquitous. Automated call centers, smart phones, dictation and transcription software are among the many systems currently being designed and involving speech recognition. The need for highly accurate and optimized recognizers has never been more crucial. The research community is very actively involved in developing powerful techniques to combine the existing feature extraction methods for a better and more reliable information capture from the analog signal, as well as enhancing the language and acoustic modeling procedures to better adapt for unseen or distorted speech signal patterns. Most researchers agree that one of the most promising approaches for the problem of reducing the Word Error Rate (WER) in large vocabulary speech transcription, is to combine two or more speech recognizers and then generate a new output, in the expectation that it provides a lower error rate. The research work proposed here aims at enhancing and boosting even further the performance of the well-known Recognizer Output Voting Error Reduction (ROVER) combination technique. This is done through its integration with an error filtering approach. The proposed system is referred to as cROVER, for context-augmented ROVER. The principal idea is to flag erroneous words following the combination of the word transition networks through a scanning process at each slot of the resulting network. This step aims at eliminating some transcription errors and thus facilitating the voting process within ROVER. The error detection technique consists of spotting semantic outliers in a given decoder's transcription output. Due to the fact that most error detection techniques suffer from a high false positive rate, we propose to combine the error filtering techniques to compensate for the poor performance of each of the individual error classifiers. Experimental results, have shown that the proposed cROVER approach is able to reduce the relative WER by almost 10% through adequate combination of speech decoders. The approaches proposed here are generic enough to be used by any number of speech decoders and with any type of error filtering technique. A novel voting mechanism has also been proposed. The new confidence-based voting scheme has been inspired from the cROVER approach. The main idea consists of using the confidence scores collected from the contextual analysis, during the scoring of each word in the transition network. The new voting scheme outperformed ROVER's original voting, by up to 16% in terms of relative WER reduction.

Syften för denna studie har varit: ”att beskriva en variation av uppfattningar hos gymnasieelever på teoretiska gymnasieprogram vad gäller hur de uppfattar och resonerar omkring sitt eget skolfusk i förhållande till fenomen som eleverna själva uppfattar som betydelsefulla för det egna skolfusket” och ”att belysa elevers uppfattningar om sitt eget skolfusk genom fyra allmänt kända teoretiska perspektiv som kan antas tangera den förförståelse av elevers skolfusk som antas vanligt förekommande hos lärare på motsvarande gymnasieprogram.” Begreppet skolfusk har definierats och data har därefter samlats in genom kvalitativt utformade enkäter som besvarats av 36 gymnasielever från det studieförberedande samhällsvetenskapsprogrammet. Forskningsansatsen har varit fenomengrafisk och analysmetoden kontextuell analys. Huvudresultatet utgörs av fem kategorier som på kvalitativt skilda sätt beskriver elevernas uppfattningar kring skolfusk. Kategorierna har rubricerats efter det totala materialets mest meningsbärande aspekt, nämligen elevernas uppsåt/avsikt/intention med sitt skolfusk som utgörs av variationerna ”att klara av en tillfälligt besvärlig situation”, ”att utmana/provocera/protestera emot (skol)systemet”, ”att överleva i en skolsituation som upplevs för svår”, ”att höja betyg” och ”att slippa anstränga sig”. Empirin har också tolkats genom fyra teoretiska perspektiv som i studien ansetts representativa för lärares förförståelse kring elevers skolfusk. Av resultatet framgår att ett flertal elever i sina uppfattningar om eget skolfusk ensidigt orienterar sig åt prestationspsykologiska, sociologiska eller mikroekonomiska perspektiv. / The aims of this study have been: “to describe a variation of conceptions among upper secondary pupils in theoretical education programs concerning how they apprehend and reason about their own school cheating in relations to phenomena that the pupils themselves judge as meaningful for their own school cheating” and “to illustrate pupils conceptions of their own school cheating through four common known theoretical perspectives which can be considered to touch upon the precomprehension of pupils school cheating that is considered as frequent among teachers in corresponding education.” The conception school cheating has been defined and data have been collected through qualitatively designed questionnaires which have been answered by 36 upper secondary pupils in social science education preparing for ensuing studies. The research approach has been phenomenografical and the method of analyzing contextual analysis. The main result is constituted by five categories which in qualitative different ways describe the pupils conceptions of school cheating. The categories have been classified on the basis of the most meaningful aspect of the total data, “the pupils intentions of their school cheating” which is constituted by the variations “to manage a temporary troublesome situation”, “to challenge/provoke/protest upon the (school)system”, “to survive in a school situation which is experienced as to difficult”, “to raise grades” and “to avoid effort”. Empirical data have also been interpreted through four theoretical perspectives which in the study have been considered representative for teachers precomprehension of pupils school cheating. The result shows that a majority of pupils is one-sided orientated in their conceptions of their own school cheating towards perspectives of either achievement-psychology, sociology or micro-economics.

<p>Syften för denna studie har varit: ”att beskriva en variation av uppfattningar hos gymnasieelever på teoretiska gymnasieprogram vad gäller hur de uppfattar och resonerar omkring sitt eget skolfusk i förhållande till fenomen som eleverna själva uppfattar som betydelsefulla för det egna skolfusket” och ”att belysa elevers uppfattningar om sitt eget skolfusk genom fyra allmänt kända teoretiska perspektiv som kan antas tangera den förförståelse av elevers skolfusk som antas vanligt förekommande hos lärare på motsvarande gymnasieprogram.”</p><p>Begreppet skolfusk har definierats och data har därefter samlats in genom kvalitativt utformade enkäter som besvarats av 36 gymnasielever från det studieförberedande samhällsvetenskapsprogrammet. Forskningsansatsen har varit fenomengrafisk och analysmetoden kontextuell analys.</p><p>Huvudresultatet utgörs av fem kategorier som på kvalitativt skilda sätt beskriver elevernas uppfattningar kring skolfusk. Kategorierna har rubricerats efter det totala materialets mest meningsbärande aspekt, nämligen elevernas uppsåt/avsikt/intention med sitt skolfusk som utgörs av variationerna ”att klara av en tillfälligt besvärlig situation”, ”att utmana/provocera/protestera emot (skol)systemet”, ”att överleva i en skolsituation som upplevs för svår”, ”att höja betyg” och ”att slippa anstränga sig”.</p><p>Empirin har också tolkats genom fyra teoretiska perspektiv som i studien ansetts representativa för lärares förförståelse kring elevers skolfusk. Av resultatet framgår att ett flertal elever i sina uppfattningar om eget skolfusk ensidigt orienterar sig åt prestationspsykologiska, sociologiska eller mikroekonomiska perspektiv.</p> / <p>The aims of this study have been: “to describe a variation of conceptions among upper secondary pupils in theoretical education programs concerning how they apprehend and reason about their own school cheating in relations to phenomena that the pupils themselves judge as meaningful for their own school cheating” and “to illustrate pupils conceptions of their own school cheating through four common known theoretical perspectives which can be considered to touch upon the precomprehension of pupils school cheating that is considered as frequent among teachers in corresponding education.”</p><p>The conception school cheating has been defined and data have been collected through qualitatively designed questionnaires which have been answered by 36 upper secondary pupils in social science education preparing for ensuing studies. The research approach has been phenomenografical and the method of analyzing contextual analysis.</p><p>The main result is constituted by five categories which in qualitative different ways describe the pupils conceptions of school cheating. The categories have been classified on the basis of the most meaningful aspect of the total data, “the pupils intentions of their school cheating” which is constituted by the variations “to manage a temporary troublesome situation”, “to challenge/provoke/protest upon the (school)system”, “to survive in a school situation which is experienced as to difficult”, “to raise grades” and “to avoid effort”.</p><p>Empirical data have also been interpreted through four theoretical perspectives which in the study have been considered representative for teachers precomprehension of pupils school cheating. The result shows that a majority of pupils is one-sided orientated in their conceptions of their own school cheating towards perspectives of either achievement-psychology, sociology or micro-economics.</p>

The growing need for designing and implementing reliable voice-based human-machine interfaces has inspired intensive research work in the field of voice-enabled systems, and greater robustness and reliability are being sought for those systems. Speech recognition has become ubiquitous. Automated call centers, smart phones, dictation and transcription software are among the many systems currently being designed and involving speech recognition. The need for highly accurate and optimized recognizers has never been more crucial. The research community is very actively involved in developing powerful techniques to combine the existing feature extraction methods for a better and more reliable information capture from the analog signal, as well as enhancing the language and acoustic modeling procedures to better adapt for unseen or distorted speech signal patterns. Most researchers agree that one of the most promising approaches for the problem of reducing the Word Error Rate (WER) in large vocabulary speech transcription, is to combine two or more speech recognizers and then generate a new output, in the expectation that it provides a lower error rate. The research work proposed here aims at enhancing and boosting even further the performance of the well-known Recognizer Output Voting Error Reduction (ROVER) combination technique. This is done through its integration with an error filtering approach. The proposed system is referred to as cROVER, for context-augmented ROVER. The principal idea is to flag erroneous words following the combination of the word transition networks through a scanning process at each slot of the resulting network. This step aims at eliminating some transcription errors and thus facilitating the voting process within ROVER. The error detection technique consists of spotting semantic outliers in a given decoder's transcription output. Due to the fact that most error detection techniques suffer from a high false positive rate, we propose to combine the error filtering techniques to compensate for the poor performance of each of the individual error classifiers. Experimental results, have shown that the proposed cROVER approach is able to reduce the relative WER by almost 10% through adequate combination of speech decoders. The approaches proposed here are generic enough to be used by any number of speech decoders and with any type of error filtering technique. A novel voting mechanism has also been proposed. The new confidence-based voting scheme has been inspired from the cROVER approach. The main idea consists of using the confidence scores collected from the contextual analysis, during the scoring of each word in the transition network. The new voting scheme outperformed ROVER's original voting, by up to 16% in terms of relative WER reduction.

This research is concerned with how in/security is understood and the implications of contested meanings of in/security. The basic premise of this thesis is that in/security in itself has no meaning and thus cannot exist in isolation. Instead, in/security is always defined in relation to something or someone. How we understand in/security derives from the contexts we navigate and the identities we construct. An inquiry into in/security therefore demands incorporating a multiplicity of narratives and discussing these in relation to each other. While scholars have called for a greater emphasis on exploring in/security in marginal sites, I argue that accounts from the margins must not be at the exclusion of other more dominant narratives. Such analysis – placing the elite/margin, included/excluded, powerful/weak – in the same framework in order to produce a relational account of in/security is largely missing. This thesis sets out to provide a rich and detailed understanding of the everyday complexities of in/security. I propose a framework for capturing relational and contextual dimensions of in/security, and the implication of contested meanings of in/security understandings. Through an in-depth case study in the context of the transitions towards a post-conflict period in Colombia, following five decades of armed conflict, I inquired into in/security understandings at the margins in relation to the centre. The margins were represented by conflict-affected communities whereas the centre was represented by the Colombian government and key security sector institutions. The research found several relational dimensions of in/security understandings between the state- and the marginalized community-levels. Moreover, contextual and identity factors had a significant impact on how in/security was spoken about and what was spoken of. Through the framework, it was possible to see in continuum the way deeply ingrained understandings of in/security reproduce violence as the government seeks to transition the country into a post-conflict period following five decades of armed conflict. The research, through a detailed empirical case study, supports the view that in/security is relational and derivative of context and with ties to identity. It contributes to further our understandings of in/security at three distinct levels. At the theoretical level, the research builds upon existing literature in the field of security studies to advance an enhanced understanding of the relational and contextual dimensions of in/security, the contested meanings of in/security and the implications thereof. Methodologically, it proposes an alternative framework to capture the relational dimensions through shifting the problem formulation from a traditional focus on who is to be secured from what threats to how in/security is understood by different people/communities in different contexts. Empirically, it contributes to an off-centred understanding of in/security dynamics in the official transitions into the post-conflict period in Colombia. Through its empirical evidence it has the potential to offer an important contribution to the analysis of post-conflict transitions more generally.