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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.
1

Hur utformar man framtidens transportsystem genom en användarcentrerad designprocess?

Gustafsson, Joakim January 2016 (has links)
Examensarbetet handlar om att utforska och utveckla det framtidsvisonära transportsystemet ”GTS Transportsystem” framtaget av GTS Stiftelsen. Detta med hjälp av frågeställningen: Hur ser framtidens GTS Transportsystem ut i ett användarcentrerat perspektiv? Inom en designprocess genomfördes ett omfattande researcharbete för att skapa en förståelse för vilka behov och krav som borde tillgodoses i det framtida transportsystemet. GTS studerades och analyserades för att få en djupare förståelse kring deras visioner, idéer, tekniska lösningar och hur väl genomtänkt de olika delarna var. Intervjuer med målgruppen människor med funktionsnedsättning, synliggjorde olika typer av problem som uppstår i dagens jämförbara transportsystem. Med hjälp av intervjudata och en analys kunde tre fiktiva personas skapas med tillhörande scenarier. En analys av ett framtida GTS scenario ledde till att problem kunde identifieras som sedan låg till grund för vidare arbete med framtagning av olika problemområden. Problemområdet som sedan valdes var stationer och hållplatser (i uppsatsen benämnd Terma). En idégenereringsfas ledde till nya idéer kring flöden, funktioner, gates och arkitektur. Det slutliga resultatet blev ett framtida Terma-koncept med en genomgående utformning för tillgänglighet, trygghet och innovation. I konceptet skapades en gate med fokus på säkerhet, en funktionell och öppen planlösning som förenklar resandet, samt en ny lösning kring kabinernas flöden runt och över byggnaden. Allt detta för att en framtida resa i GTS skall fungera säkert och smidigt. / The research was conducted in order to contribute to the general body of knowledge regarding the prospective transport system GTS Transport System developed by GTS Foundation. This dissertation will explore and further develop the GTS system. This was achieved with the research question: How does the future GTS Transport System look in a user-centered design perspective?   In a design process, a deep and comprehensive research laid the foundation in order to create an understanding of the needs and demands that would need to be fulfilled for the future transport system. The GTS Transport System was carefully studied and analyzed in order to reach a deeper understanding around its visions, ideas and technical solutions. Further it was studied in order to determine how well thought through the different feature where.   Interviews were conducted with a target group of people having a disability; this disclosed certain problems with today’s transport systems. With the support of the data gathered and an analysis, three fictive personas where created with associated scenarios.   An analysis of a future GTS scenario led to the discovery of certain problems and laid the foundation for further establishing areas in need of improvements. The areas that were chosen where stations and stopping places (in the dissertation called Terma).   An idea-generating phase led to new ideas about flow, functions, gates and architecture.   The results of the dissertation led to a concept about how the future transport Terma may be designed. With secure available and innovative gates, a well thought through layout that is available and safe for the people using the transport system. A new concept of flows where created which enabled the vessels to move around and over the building. This results in a smooth and safe travel experience.
2

Svenska producenter och skyddade beteckningar

Klasson, Adam, Petrov, Ilya January 2019 (has links)
No description available.
3

IEEE 802.15.4 MAC Protocol Study and Improvement

Cheng, Liang 27 November 2007 (has links)
IEEE 802.15.4 is a standard used for low rate personal area networks (PANs). It offers device level connectivity in applications with limited ower and relaxed throughput requirements. Devices with IEEE 802.15.4 technology can be used in many potential applications, such as home networking, industry/environments monitoring, healthcare equipments, etc, due to its extremely low power features. Although the superframe beacons play the key role in synchronizing channel access in IEEE 802.15.4, they are sources for energy inefficiency. This research focuses on exploring how to optimize the beacons, and designing novel schemes to distribute the information that are supposed to be delivered to a subset of PAN devices. In this work, an acknowledgement based scheme is proposed to reduce the energy consumption in the distribution of guaranteed time slot (GTS) descriptors. Based on the observation that the superframe beacon frame has global impact on all PAN devices, an energy-efficient channel reservation scheme is presented to deliver the information (GTS descriptors and pending addresses). In addition, the problem of channel underutilization is studied in the contention free period. To address the problem, a new GTS allocation scheme is proposed to improve the bandwidth utilization.
4

Efficient GTS Allocation Schemes for IEEE 802.15.4

Haque, Syed E 11 April 2012 (has links)
IEEE 802.15.4 is a standard defined for wireless sensor network applications with limited power and relaxed throughput needs. The devices transmit data during two periods: Contention Access Period (CAP) by accessing the channel using CSMA/CA and Contention Free Period (CFP), which consists of Guaranteed Time Slots (GTS) allocated to individual devices by the network coordinator. The GTS is used by devices for cyclic data transmission and the coordinator can allocate GTS to a maximum of only seven devices. In this work, we have proposed two algorithms for an efficient GTS allocation. The first algorithm is focused on improving the bandwidth utilization of devices, while the second algorithm uses traffic arrival information of devices to allow sharing of GTS slots between more than seven devices. The proposed schemes were tested through simulations and the results show that the new GTS allocation schemes perform better than the original IEEE 802.15.4 standard.
5

Modulace centrální cholinergní neurotransmise. / Modulation of central cholinergic neurotransmission

Valušková, Paulína January 2017 (has links)
Introduction: Central cholinergic system plays a key role in control of different brain functions such as learning, memory, attention, locomotion and rewards. Disrupted integrity, regulation or capacity of cholinergic signalling is closely connected with cognitive symptoms of several neurodegenerative and neuropsychiatric diseases, as Alzheimer disease, Parkinson disease, attention deficit hyperactivity disorder (ADHD), depression, schizophrenia and increased distractibility. The major neurotransmitter of cholinergic neurons is acetylcholine (ACh) and regulation of ACh levels is main pharmacotherapeutic approach to the treatment of diseases associated with central cholinergic system. The aim of the thesis was to study the changes of central cholinergic neurotransmission with respect to various aspects of modulation of ACh levels in the brain by controlling its release through M4 muscarinic receptors (MR), its hydrolysis by acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) and after hydrolysis in the synapse, regulation of the uptake of metabolite choline by high affinity choline transporter (CHT). Methods: Here we used telemetry to measure locomotor activity and body temperature in mice with selective deletion of M4 MR (M4KO) and their wild type (M4WT) controls under the basal conditions...
6

Ieee 802.15.4 Wireless Sensor Networks: Gts Scheduling and Service Differentiation

Na, Che Woo 22 September 2011 (has links)
Recently there has been a growing interest in the use of Low Rate Wireless Personal Area Networks (LR-WPAN) [1] driven by the large number of emerging applications such as home automation, health-care monitoring and environmental surveillance. To fulfill the needs for these emerging applications, IEEE has created a new standard called IEEE 802.15.4 for LR-WPAN, which has been widely accepted as the de facto standard for wireless sensor networks. Unlike IEEE 802.11 [2], which was designed for Wireless Local Area Networks (WLAN), it focuses on short range wireless communications. The goal of the IEEE 802.15.4 LR-WPAN is to support low data rate connectivity among wireless sensors with low complexity, cost and power consumption [3]. It specifies two types of network topologies, which are the beacon-enabled start network and the nonbeacon-enabled peer-to-peer network. For the beacon-enabled network, it defines the Guaranteed Time Slot (GTS) to provide real-time guaranteed service for delay-sensitive applications. In the nonbeacon-enabled network the GTS is reserved time slots such that it is requested, allocated and scheduled to wireless sensors that need guaranteed service for delay-sensitive applications. Existing GTS scheduling algorithms include First-Come-First-Served (FCFS) [1], priority-based [4] and Earliest Deadline First (EDF) [5] methods. Such FCFS and priority-based scheduling methods have critical drawbacks in achieving real-time guarantees. Namely, they fail to satisfy the delay constraints of delay-sensitive transactions. Further, they lead to GTS scarcity and GTS underutilization. On the other hand, the EDF-based scheduling method provides delay guarantee while it does not support delay-sensitive applications where arrival of the first packet has a critical impact on the performance. To solve these problems, we design the optimal work-conserving GTS Allocation and Scheduling (GAS) algorithm that provides guarantee service for delay-sensitive applications in beacon-enabled networks. Not only does the GAS satisfy the delay constraints of transactions, but also it reduces GTS scarcity and GTS underutilization. Further, it supports delay-sensitive applications where arrival of the first packet has a critical impact on the performance. Through the extensive simulation results, we show that the proposed algorithm outperforms the existing scheduling methods. Our algorithm differs from the existing ones in that it is an on-line scheduling and allocation algorithm and allows transmissions of bursty and periodic transactions with delay constraints even when the network is overloaded. In the nonbeacon-enabled peer-to-peer network some operating scenarios for rate-sensitive applications arise when one considers wireless video surveillance and target detection applications for wireless sensor networks. To support such rate-sensitive applications in wireless sensor networks, we present a Multirate-based Service Differentiation (MSD) operating in the nonbeacon-enabled peer-to-peer network. Unlike existing priority-based service differentiation models, the MSD defines the independent Virtual Medium Access Controls (VMACs), each of which consists of a transmission queue and the Adaptive Backoff Window Control (ABWC). Since the VMACs serve multiple rate-sensitive flows, it is possible that more than one data frame is collided with each other when their backoff times expire simultaneously. To solve such a virtual collision in the virtual collision domain, we design the Virtual Collision Avoidance Control (VCAC). The ABWC component adjusts the backoff window to reflect the local network state in the local collision domain. The VCAC component prevents virtual collisions and preempts packets with the minimal cost in the virtual collision domain. By analyzing these algorithms, we prove that the ABWC component enables the achieved data rate to converge to the rate requirement and the VCAC component produces a virtual-collision-free schedule to avoid degradation of the achieved data rate. Through the simulation, we validate our analysis and show the MSD outperforms existing algorithms. / Ph. D.
7

Structure and Function of Flavonoid Glucosyltransferases: Using a Specific Grapefruit Enzyme as a Model

McIntosh, Cecilia A. 10 August 2015 (has links)
Glucosyltransferases (GTs) are enzymes that enable transfer of glucose from an activated donor (UDP-glucose) to the acceptor substrates. A flavonol specific glucosyltransferase cloned from Citrus paradisi has strict substrate and regiospecificity (Cp3OGT). The amino acid sequence of Cp3OGT was aligned with a purported anthocyanin GT from Clitorea ternatea and a GT from Vitis vinifera that can glucosylate both flavonols and anthocyanidins. Using homology modeling to identify candidate regions followed by site directed mutagenesis, three double mutations of Cp3OGT were made. Biochemical analysis of the three mutant proteins was performed. S20G+T21S protein retained activity similar to the wildtype (WT- Kmapp-80 µM; Vmax = 16.5 pkat/µg, Mutant- Kmapp-83 µM; Vmax -11 pkat/µg) but the mutant was more thermostable compared to the WT and this mutation broadened its substrate acceptance to include the flavanone, naringenin. S290C+S319A mutant protein retained 40% activity relative to wildtype, had an optimum pH shift, but had no change in substrate specificity (Kmapp-18 µM; Vmax-0.5 pkat/µg). H154Y+Q87I protein was inactive with every class of flavonoid tested. Product identification revealed that the S20G+T21S mutant protein widened the substrate and regio-specificity of CP3OGT. Docking analysis revealed that H154 and Q87 could be involved in orienting the ligand molecules within the acceptor binding site. H363, S20, and S150 were also found to make close contact with the 7-OH, 4-OH and 3’-OH groups, respectively.
8

Structure and Function of Flavonoid Glucosyltransferases: Using a specific Grapefruit Enzyme as a Model

McIntosh, Cecilia A. 01 March 2016 (has links)
No description available.
9

Une perspective sémantique et dialogique sur l'activité de validation en mathématiques / A semantic and dialogical perspective on the mathematical activity of validation

Barrier, Thomas 07 December 2009 (has links)
La thèse s’intéresse aux situations de validation au sens de la Théorie des Situations Didactiques Mathématiques (TSDM). Son objectif est d’interroger la filiation revendiquée de cette théorie à la logique dialogique de Lorenzen. La thèse soutient la pertinence didactique de l’adoption d’une perspective sémantique et dialogique sur les processus de validation en mathématiques. Cette approche consiste à analyser les relations entre les assertions et les objets dénotés au sein des jeux de langage à travers les liens stratégiques de validation qui les relient. La méthodologie générale de la recherche s’appuie à la fois sur des ressources philosophiques et didactiques, l’hypothèse de travail est celle de la complémentarité des méthodes analytique et expérimentale en didactique des mathématiques. Au niveau du travail analytique, la référence principale est la sémantique selon la théorie des jeux de Hintikka et sa correction par Vernant. Elle est mobilisée pour reconsidérer les fondements de la TSDM. Sur le plan expérimental, j’ai analysé les pratiques de quantification d’étudiants en mathématiques lors de leur évaluation de deux preuves en Analyse réelle. Le choix de ces preuves repose sur une brève enquête épistémologique. / The thesis deals with situations of validation as understood in the Theory of Didactical Situations (TDS). It investigates the proclaimed lineage between TDS and Lorenzen’s dialogic logic. The thesis argues for the didactical relevance of adopting a semantic and dialogic perspective on the validation process in mathematics. This approach consists in analyzing the relationship between assertions and the denoted objects of the language gamesvia the strategic links of validation between them. The methodology adopted draws on both philosophical and didactical resources, and the thesis develops the hypothesis that analytic and experimental methods are complementary in the didactics of mathematics. For the analytic treatment, the leading reference is Hintikka’s Game Theoretical Semantics (GTS) and its correction by Vernant. GTS is mobilized to reconsider the foundations of TDS. On the side of the experimental method, I used epistemological criteria to select two proofs in real analysis and then analyzed the quantification practices used by mathematics students when evaluating the validity of these proofs.
10

Une perspective sémantique et dialogique sur l'activité de validation en mathématiques

Barrier, Thomas 07 December 2009 (has links) (PDF)
La thèse s'intéresse aux situations de validation au sens de la Théorie des Situations Didactiques Mathématiques (TSDM). Son objectif est d'interroger la filiation revendiquée de cette théorie à la logique dialogique de Lorenzen. La thèse soutient la pertinence didactique de l'adoption d'une perspective sémantique et dialogique sur les processus de validation en mathématiques. Cette approche consiste à analyser les relations entre les assertions et les objets dénotés au sein des jeux de langage à travers les liens stratégiques de validation qui les relient. La méthodologie générale de la recherche s'appuie à la fois sur des ressources philosophiques et didactiques, l'hypothèse de travail est celle de la complémentarité des méthodes analytique et expérimentale en didactique des mathématiques. Au niveau du travail analytique, la référence principale est la sémantique selon la théorie des jeux de Hintikka et sa correction par Vernant. Elle est mobilisée pour reconsidérer les fondements de la TSDM. Sur le plan expérimental, j'ai analysé les pratiques de quantification d'étudiants en mathématiques lors de leur évaluation de deux preuves en Analyse réelle. Le choix de ces preuves repose sur une brève enquête épistémologique.

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