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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.
131

Communications with 1-Bit Quantization and Oversampling at the Receiver: Benefiting from Inter-Symbol-Interference

Krone, Stefan, Fettweis, Gerhard 25 January 2013 (has links) (PDF)
1-bit analog-to-digital conversion is very attractive for low-complexity communications receivers. A major drawback is, however, the small spectral efficiency when sampling at symbol rate. This can be improved through oversampling by exploiting the signal distortion caused by the transmission channel. This paper analyzes the achievable data rate of band-limited communications channels that are subject to additive noise and inter-symbol-interference with 1-bit quantization and oversampling at the receiver. It is shown that not only the channel noise but also the inter-symbol-interference can be exploited to benefit from oversampling.
132

Static Partial Order Reduction for Probabilistic Concurrent Systems

Fernández-Díaz, Álvaro, Baier, Christel, Benac-Earle, Clara, Fredlund, Lars-Åke 10 September 2013 (has links) (PDF)
Sound criteria for partial order reduction for probabilistic concurrent systems have been presented in the literature. Their realization relies on a depth-first search-based approach for generating the reduced model. The drawback of this dynamic approach is that it can hardly be combined with other techniques to tackle the state explosion problem, e.g., symbolic probabilistic model checking with multi-terminal variants of binary decision diagrams. Following the approach presented by Kurshan et al. for non-probabilistic systems, we study partial order reduction techniques for probabilistic concurrent systems that can be realized by a static analysis. The idea is to inject the reduction criteria into the control flow graphs of the processes of the system to be analyzed. We provide the theoretical foundations of static partial order reduction for probabilistic concurrent systems and present algorithms to realize them. Finally, we report on some experimental results.
133

Efficient information leakage neutralization on a relay-assisted multi-carrier interference channel

Ho, Zuleita K.-M., Jorswieck, Eduard A., Engelmann, Sabrina 22 November 2013 (has links) (PDF)
In heterogeneous dense networks where spectrum is shared, users privacy remains one of the major challenges. When the receivers are not only interested in their own signals but also in eavesdropping other users' signals, the cross talk becomes information leakage.We propose a novel and efficient secrecy rate enhancing relay strategy EFFIN for information leakage neutralization. The relay matrix is chosen such that the effective leakage channel (spectral and spatial) is zero. Thus, it ensures secrecy regardless of receive processing employed at eavesdroppers and does not rely on wiretaps codes to ensure secrecy, unlike other physical layer security techniques such as artificial noise. EFFIN achieves a higher sum secrecy rate over several state-of-the-art baseline methods.
134

Information Leakage Neutralization for the Multi-Antenna Non-Regenerative Relay-Assisted Multi-Carrier Interference Channel

Ho, Zuleita, Jorswieck, Eduard, Engelmann, Sabrina 21 October 2013 (has links) (PDF)
In heterogeneous dense networks where spectrum is shared, users' privacy remains one of the major challenges. On a multi-antenna relay-assisted multi-carrier interference channel, each user shares the spectral and spatial resources with all other users. When the receivers are not only interested in their own signals but also in eavesdropping other users' signals, the cross talk on the spectral and spatial channels becomes information leakage. In this paper, we propose a novel secrecy rate enhancing relay strategy that utilizes both spectral and spatial resources, termed as information leakage neutralization. To this end, the relay matrix is chosen such that the effective channel from the transmitter to the colluding eavesdropper is equal to the negative of the effective channel over the relay to the colluding eavesdropper and thus the information leakage to zero. Interestingly, the optimal relay matrix in general is not block-diagonal which encourages users' encoding over the frequency channels. We proposed two information leakage neutralization strategies, namely efficient information leakage neutralization (EFFIN) and local-optimized information leakage neutralization (LOPTIN). EFFIN provides a simple and efficient design of relay processing matrix and precoding matrices at the transmitters in the scenario of limited power and computational resources. LOPTIN, despite its higher complexity, provides a better sum secrecy rate performance by optimizing the relay processing matrix and the precoding matrices jointly. The proposed methods are shown to improve the sum secrecy rates over several state-of-the-art baseline methods.
135

Façons de faire l’évaluation formative d’enseignants de français sénégalais : une analyse de leurs savoirs pratiques en contexte d’effectifs pléthoriques au Lycée.

Diedhiou, Serigne Ben Moustapha (S.B.M.) 12 1900 (has links)
Cette recherche documente les façons de faire l’évaluation formative d’enseignants de français du Lycée exerçant en contexte de classes pléthoriques au Sénégal. Le choix récent dans ce pays de l’approche par compétences invite à privilégier cette fonction de l’évaluation, au regard de son potentiel pour la progression des apprentissages des élèves (Allal & Mottier Lopez, 2005; Black & Wiliam, 2009; Morrissette, 2010). Cependant, les orientations ministérielles concernant sa mise en œuvre sont très générales, et jusqu’ici, la recherche a laissé dans l’ombre son application en contexte de classes pléthoriques. Puisant au domaine des savoirs pratiques (Schön, 1983) et à une vision interactive et située de l’évaluation formative (Mottier Lopez, 2007; Morrissette, 2010), j’ai conduit une démarche de recherche collaborative auprès de 14 enseignants de français exerçant dans le même Lycée, ponctuée par 6 entretiens de groupe. Un premier registre d’analyse a décrit des façons de faire rattachées à trois dimensions de la pratique de l’évaluation formative: l’analyse du contexte de la pratique, la construction négociée du savoir et la gestion de l’effectif. Un second registre d’analyse de leurs façons de faire en contexte d’«étrangeté culturelle» (Douville, 2002) a permis de conceptualiser leur savoir-évaluer en relation avec leur façon d’interpréter les problèmes qui se posent aux élèves, leur conception de l’erreur et leurs manières de réinventer les modes d’accomplissement traditionnels de l’évaluation ancrés dans la culture scolaire. / This research documents the ways formative assessment is operationalized by French teachers working in the context of overcrowded classrooms in a Senegalese High School. The recent choice for implementing the competency-based approach in this country invites teachers to promote the use of formative assessment which is geared towards the provision of high quality learning (Allal & Mottier Lopez, 2005, Black & Wiliam, 2009 Morrissette, 2010). However, Ministerial guidelines for its implementation are very general, and so far, research has not been carried out as regards its application in overcrowded classes. Building on the field of reflective practice (Schön, 1983) and an interactive situated vision of formative assessment (Mottier Lopez, 2007; Morrissette, 2010), I led a collaborative research with 14 French teachers working in the same High School. Six focus groups discussions were carried out which shed light on three dimensions related to formative assessment practices: contextual analysis of teacher practices, the negotiated construction of knowledge and the management of the overcrowded classrooms. Analysis of formative assessment practices in the context of « cultural strangeness » (free translation) (Douville, 2002) helped to conceptualize their know-how on evaluation in light of how they interpret the problems faced by students, their conception of what error constitutes and the ways they reinvent the traditional performance evaluation methods rooted in the school culture.
136

Thermo-Energetische Gestaltung von Werkzeugmaschinen: Experimentelle Methodik

19 June 2014 (has links) (PDF)
Im Mittelpunkt der 3. Tagung des Sonderforschungsbereichs Transregio 96 am 29. und 30.Oktober 2013 am Werkzeugmaschinenlabor der RWTH Aachen standen die verschiedenen Lösungsansätze der einzelnen Teilprojekte bei der Durchführung der experimentellen Untersuchungen zur Verifizierung von Simulationsergebnissen bzw. zur Ableitung von Modellparametern. Es wurden vier Themenblöcke behandelt: • Ermittlung von thermisch relevanten Prozessparametern • Experimentelle Methodik zur Analyse von Teilsystemen in Werkzeugmaschinen • Methodische Rahmenbedingungen bei der Ermittlung von thermisch relevanten Parametern • Verfahren zur Verformungs- und Verlagerungsmessung
137

Coconstruction des composantes d'un programme d'intervention en soutien à la résilience de familles dont un adolescent est atteint d'un traumatisme craniocérébral

Gauvin-Lepage, Jérôme 08 1900 (has links)
La vie de famille avec un adolescent comporte son lot de défis. Les émotions de l’adolescent qui se présentent parfois comme des montagnes russes peuvent rendre les relations tendues et difficiles au sein de la cellule familiale, voire même au-delà de celle-ci. Par son caractère inattendu, l’avènement d’un traumatisme craniocérébral (TCC) chez l’adolescent vient fragiliser encore davantage la dynamique familiale. En outre, la myriade d’impacts engendrés par le TCC contraint la famille à modifier son projet de vie en s’investissant ensemble pour le reconstruire. La résilience devant une situation de traumatisme ne se manifeste pas de la même façon pour toutes les familles qui y sont confrontées. Certaines d’entre elles réussissent à se transformer positivement, tandis que d’autres n’y parviennent pas ou manifestent plus de difficultés. Il convient alors d’actualiser des approches de soins interdisciplinaires centrées sur la famille qui favoriseraient la reconnaissance des éléments pouvant soutenir son processus de résilience à travers cette épreuve et, enfin, aider à transformer son projet de vie. Avec comme perspective disciplinaire le modèle humaniste des soins infirmiers (Cara, 2012; Cara & Girard, 2013; Girard & Cara, 2011), cette étude qualitative et inductive (LoBiondo-Wood, Haber, Cameron, & Singh, 2009), soutenue par une approche collaborative de recherche (Desgagné, 1997), a permis la coconstruction des composantes d’un programme d’intervention en soutien à la résilience familiale, avec des familles dont un adolescent est atteint d’un TCC modéré ou sévère et des professionnels de la réadaptation. Le modèle de développement et de validation d’interventions complexes (Van Meijel, Gamel, Van Swieten-Duijfjes, & Grypdonck, 2004) a structuré la collecte des données en trois volets. Le premier volet consistait à identifier les composantes du programme d’intervention selon les familles (n=6) et les professionnels de la réadaptation (n=5). La priorisation et la validation des composantes du programme d’intervention, soit respectivement le deuxième et troisième volets, se sont réalisées auprès de ces mêmes familles (n=6 au volet 2 et n=4 au volet 3) et professionnels de la réadaptation (n=5 aux volets 2 et 3). Le processus d’analyse des données (Miles & Huberman, 2003) a repéré cinq thèmes intégrateurs, considérés comme les composantes du programme d’intervention en soutien à la résilience familiale à la suite du TCC modéré ou sévère d’un adolescent. Ce sont : 1) les caractéristiques de la famille et ses influences; 2) les stratégies familiales positives; 3) le soutien familial et social; 4) la prise en charge de l’aspect occupationnel et; 5) l’apport de la communauté et des professionnels de la santé. Les résultats issus de ce processus de coconstruction ont produit une matrice solide, suffisamment flexible pour pouvoir s’adapter aux différents contextes dans lesquels évoluent les familles et les professionnels de la réadaptation. Cette étude offre en outre des avenues intéressantes tant pour les praticiens que pour les gestionnaires et les chercheurs en sciences infirmières et dans d’autres disciplines quant à la mise en place de stratégies concrètes visant à soutenir le processus de résilience des familles dans des situations particulièrement difficiles de leur vie. / Family life with an adolescent has its share of challenges. The adolescent’s emotional rollercoasters can make relationships tense and difficult within the family unit, and even outside of it. By virtue of its unexpected character, the occurrence of traumatic brain injury (TBI) in an adolescent can undermine the family dynamics even further. Additionally, the myriad of impacts caused by a TBI forces the family to alter its plans for the future by committing themselves together to rebuild them. Resilience to trauma does not manifest itself in the same way for all families. Some manage to effect positive changes, while others are unable to do so, or experience more difficulties. In light of this, it appears relevant to develop family-centred care approaches fostering the recognition of elements that can support the family’s resilience process through hardships and, ultimately, help reconstruct its plans for the future. Using the humanist model of nursing care (Cara, 2012; Cara & Girard, 2013; Girard & Cara, 2011) as a disciplinary perspective, this qualitative and inductive study (LoBiondo-Wood, Haber, Cameron, & Singh, 2009), supported by a collaborative research approach (Desgagné, 1997), led to the co-construction of the building blocks for an intervention program to support family resilience in conjunction with families with an adolescent suffering from moderate or severe TBI and rehabilitation professionals. The complex intervention design and validation model (Van Meijel, Gamel, Van Swieten-Duijfjes, & Grypdonck, 2004) inspired a three-stage data collection process. The first stage consisted in identifying the building blocks of the intervention program in the eyes of families (n=6) and rehabilitation professionals (n=5). The prioritization and validation of these building blocks, respectively the second and third stages, were conducted with the same families (n=6 for stage 2 and n=4 for stage 3) and rehabilitation professionals (n=5 for stages 2 and 3). The data analysis process (Miles & Huberman, 2003) identified five encompassing themes, considered to be the building blocks of an intervention program to support family resilience following moderate to severe TBI in adolescents. They are: 1) family characteristics and its influences; 2) positive family strategies; 3) family and social support; 4) management of occupational aspects; 5) contribution of the community and health professionals. The results of this co-construction process established a strong matrix that is flexible enough to adapt to the various contexts in which families and rehabilitation professionals live and work. This study also offers promising avenues for practitioners, administrators and researchers in nursing and other fields with respect to the implementation of concrete strategies to support the resilience process of families facing particularly difficult times in their lives.
138

Ein Funken Wahrheit

Fraunholz, Uwe, Beese, Sebastian, Pulla, Ralf 01 April 2014 (has links) (PDF)
No description available.
139

Inverting the lens: insider photography by the Manaja’a family, Humayma, Jordan

Gordon Lanning, Robbyn Ellen Lorraine 22 December 2009 (has links)
In this thesis, I assert that photographs of Jordanian Bedouin produced by cultural insiders disrupt and challenge pan-Bedouin and romantic photographic constructions of Bedouin made by cultural outsiders. These outsiders, Western ethno-photographers and members of the Jordanian Hashemite monarchy, use photographs featuring visual symbols of Bedouin identity in order to legitimise claims to land, resources, and cultural capital. Data produced from collaborative action research (the creation of photography with a self-identifying Bedouin family from Humayma, Jordan) demonstrates an increasingly complex version of Jordanian Bedouin identity absent from outsider representations. This nuanced picture of Bedouin identity, while limited by its focus on a single family, may help contribute to further collaborative investigations of Bedouin identity in Jordan. This research has the potential to assist in the better understanding of the diverse social practices and concerns of Bedouin living in Jordan today.
140

As We Move Ahead Together: Foregrounding Reconciliating and Renewed First Nation/ Non-Aboriginal Relations in Environmental Management and Research

Dalton, Zoe 15 February 2011 (has links)
The research project upon which this dissertation is based focused on enhancing understandings of the nature of current First Nations/non-Aboriginal relations in environmental management. The project was undertaken as a collaborative initiative by the author, a non-Aboriginal doctoral researcher, in partnership with Walpole Island First Nation. The research served as an opportunity for co-producing knowledge on this subject across cultures and worldviews, and as an effort to build towards our shared aspiration of learning how distinct, yet inextricably linked, First Nations/non-Aboriginal understandings, approaches and worldviews can come together within a context of mutual respect and mutual benefit. The purpose of the research was to investigate the existence and types of issues leading to First Nations/non-Aboriginal tensions in environmental management, to analyze and unpack underlying causes of challenges identified via the research, and to construct avenues for relationship improvement. The research project was grounded in a specific investigation into relations in species at risk conservation and recovery in southern Ontario, Canada. The resulting dissertation is structured around three primary focal areas: 1) investigating and exposing colonial influences at play in Canada’s Species at Risk Act, and offering a new model for co-governance in this arena and beyond; 2) investigating relations surrounding efforts towards traditional ecological knowledge (TEK) transfer in species at risk work, with a focus on exploring issues identified in relation to intellectual imperialism; and 3) introducing and characterizing an original, reconceptualized approach to First Nations/non-Aboriginal relationships in academic research; this approach focused on ways in which investigatory practice can become a means of working towards broader reconciliation goals. Research findings from this dissertation indicate that colonial factors, often unevenly visible to actors involved in environmental management and research, continue to strongly affect the potential for positive, productive First Nations/non-Aboriginal relations in these spheres - including within the species at risk conservation and recovery arena examined here. Project results provide insight into the nature of the factors influencing relationships, as well as potential avenues for addressing the vitality of colonialism in contemporary relations and overcoming the influences on First Nations and on First Nations/non-Aboriginal relationships.

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