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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

A Knowledge-Based Approach To Pattern Clustering

Shekar, B 07 1900 (has links)
The primary objective of this thesis is to develop a methodology for clustering of objects based on their functionality typified by the notion of concept. We begin by giving a formal definition of concept. By assigning a functional interpretation to the underlying concept, we demonstrate the applicability of the functionally interpreted concept for clustering objects. This functional interpretation leads us to identifying two classes of concepts, namely, the Necessary class and the Quality-Improvement class. Next, we categorize the functional cohesiveness among objects into three different classes. Further, we axiomatize the restrictions imposed, on the execution of functions of objects, by the non-availability of sufficient resources. To facilitate describing functional clusters in a succinct manner, we define connectives that capture the imposed restrictions. Also we justify the adequacy of these connectives for describing functional clusters. We then propose a suitable data structure to represent the functionally interpreted concept, and develop an algorithm to perform this axiomatic functional partitioning of objects. We illustrate the functional partitioning of objects through a real-world example. We formally establish the invariance of the resulting cluster descriptions, with respect to the order in which the given set of objects is examined. This invariance would facilitate parallel implementations of the proposed methodology. We then analyze different functional cluster configurations from a structural viewpoint. In doing so, we identify the presence of a specific property among certain cluster configurations. We also state a sufficient condition for the presence of this property in any cluster. A separate class of concepts, namely the Concept Transformer class, displaying certain properties, is identified and studied in detail. We also demonstrate its applicability to functional clustering. Finally, we examine a knowledge-based pattern synthesis problem from a functional angle as a significant application of the functional interpretation of concept and associated data structures. Here, we show that a concept, from the functional view-point, can be viewed as the synthesis of various other concepts; the synthesis is an outcome of a knowledge-based goal-directed pattern-matching activity. The proposed methodology has the potential to cluster objects that imply functions by virtue of their physical properties.
22

An Electroencephalogram (EEG) Based Biometrics Investigation for Authentication| A Human-Computer Interaction (HCI) Approach

Rodriguez, Ricardo J. 09 October 2015 (has links)
<p> Encephalogram (EEG) devices are one of the active research areas in human-computer interaction (HCI). They provide a unique brain-machine interface (BMI) for interacting with a growing number of applications. EEG devices interface with computational systems, including traditional desktop computers and more recently mobile devices. These computational systems can be targeted by malicious users. There is clearly an opportunity to leverage EEG capabilities for increasing the efficiency of access control mechanisms, which are the first line of defense in any computational system. </p><p> Access control mechanisms rely on a number of authenticators, including &ldquo;what you know&rdquo;, &ldquo;what you have&rdquo;, and &ldquo;what you are&rdquo;. The &ldquo;what you are&rdquo; authenticator, formally known as a biometrics authenticator, is increasingly gaining acceptance. It uses an individual&rsquo;s unique features such as fingerprints and facial images to properly authenticate users. An emerging approach in physiological biometrics is cognitive biometrics, which measures brain&rsquo;s response to stimuli. These stimuli can be measured by a number of devices, including EEG systems. </p><p> This work shows an approach to authenticate users interacting with their computational devices through the use of EEG devices. The results demonstrate the feasibility of using a unique hard-to-forge trait as an absolute biometrics authenticator by exploiting the signals generated by different areas of the brain when exposed to visual stimuli. The outcome of this research highlights the importance of the prefrontal cortex and temporal lobes to capture unique responses to images that trigger emotional responses. </p><p> Additionally, the utilization of logarithmic band power processing combined with LDA as the machine learning algorithm provides higher accuracy when compared against common spatial patterns or windowed means processing in combination with GMM and SVM machine learning algorithms. These results continue to validate the value of logarithmic band power processing and LDA when applied to oscillatory processes.</p>
23

Semantics-based language models for information retrieval and text mining /

Zhou, Xiaohua. Hu, Xiaohua. January 2008 (has links)
Thesis (Ph.D.)--Drexel University, 2008. / Includes abstract and vita. Includes bibliographical references (leaves 142-154).
24

Hastighetskamerors effekt på trafikolyckor

Frisk, Philip January 2018 (has links)
In 2006, a new ATK-system (Automated traffic enforcement system) was introduced in Sweden with the purpose to reduce average speed and number of accidents on the Swedish roads. In this study, road accidents that occurred close to the speed cameras in the new ATK-system are analyzed with GIS-tools. A total number of 1 104 ATK-cameras and 1 975 road accidents were included in the analysis. All of the included accidents occurred within three years before and three years after the installation of the nearby camera, and also within  a distance of 400 m before and 1 000 m after every camera. The amount of accidents that occurred before the installment date was compared to the amount that occurred after to give an understanding for the effect ATK-cameras have on road accidents. ATK-cameras were included in the analysis regardless of the associated roads road type, speed limit or any other road attribute. The analysis was done in six parts, each focusing on one of the six following attributes; accident type, injuries, vehicle type, road condition, speed limits at the ATK-spot and distance from ATK-camera. The results show that the total decrease of accidents within the camera-areas analyzed in this study (0–400 m in front of and 0–1 000 m behind speed cameras) is 18.5 %. Road exit collision is the accident type with the largest decrease of accidents and a large decrease of accidents with severe injuries and death is shown. On the contrary, an increase of overtake collisions and motorcycle accidents is shown. The largest decrease of accidents occurs in the distance interval of 0 – 500 m behind the cameras. In the intervals 0–400 in before and 500–1 000 m after, the decrease is lower. The analysis also shows that the cameras have a greater positive effect on roads with the speed limit 50 or 80 km/h as compared with other roads. In addition, the cameras have a greater positive effect when the road condition is bad. / År 2006 infördes ett nytt ATK-system (Automatisk trafikkontroll) i Sverige i syfte att sänka medelhastigheten och antalet olyckor på de svenska vägarna. I detta arbete analyseras trafikolyckor som skett i nära geografisk anslutning till ATK-kameror i det nya systemet med hjälp av GIS-verktyg. Totalt ingår 1 104 ATK-kameror och 1 975 trafikolyckor i analysen. Samtliga olyckor har skett under en tidsperiod tre år före eller tre år efter installation av närliggande kamera, samt inom en sträcka på 400 m före och 1 000 m efter varje kamera. Antalet olyckor som skett före installation av närliggande ATK-kamera jämförs med antalet olyckor som skett efter, för att ge en uppfattning om kamerornas effekt på trafikolyckorna. ATK-kameror inkluderades i analysen oavsett den samhörande vägens vägtyp, hastighetsbegränsning eller övriga vägattribut. Analysen genomfördes i sex delanalyser, var och en med avseende på ett av följande sex attribut; olyckstyp, personskador, fordonstyp, väglag, hastighetsbegränsning vid ATK och avstånd från ATK. Resultaten visar att den totala reduceringen av trafikolyckor inom de kameraområden som analyseras i detta arbete (0–400 m framför och 0–1000 m bakom hastighetskameror) är 18,5 %. Avsvängnings-olyckor är den olyckstyp som procentuellt reduceras mest och en stor reducering av olyckor med svårt skadade och avlidna påvisas. Däremot påvisas en ökning av omkörningsolyckor och motorcykelolyckor. Den största olycksreduceringen sker i avståndsintervallet 0–500 m bakom kamerorna. I avstånds-intervallen 0–400 m framför och 500–1 000 m bakom är reduceringen mindre. Analysen visar även att kamerorna har en större positiv effekt vid vägar med  hastighetsbegränsningen 50 eller 80 km/h, jämfört med övriga vägar. Dessutom har kamerorna en större positiv effekt vid dåligt väglag.
25

Industrial Control System (ICS) Network Asset Identification and Risk Management

Abdulrazzaq, Mohammed, Wei, Yuan January 2018 (has links)
Setting against the significant background of Industrial 4.0, the Industrial Control System (ICS) accelerates and enriches the upgrade the existing production infrastructure. To make the infrastructures “smart”, huge parts of manual operations have been automated in this upgrade and more importantly, the isolated controlled processes have been connected through ICS. This has also raised the issues in asset management and security concerns. Being the starting point of securing the ICS, the asset identification is, nevertheless, first dealt by exploring the definition of assets in the ICS domain due to insufficient documentation and followed by the introduction of ICS constituents and their statuses in the whole network. When the definition is clear, a well-received categorization of assets in the ICS domain is introduced, while mapping out their important attributes and their significance relating the core of service they perform. To effectively tackle the ever-increasing amount of assets, identification approaches are compared and a case study was performed to test the effectiveness of two open source software. Apart from the identification part, this thesis describes a framework for efficient asset management from CRR. The four cyclic modules proposed give an overview on how the asset management should be managed according the dynamics of the assets in the production environment.
26

Påverkande faktorer på internkommunikation : En fallstudie på en offentlig verksamhet

Ajvazaj, Albina January 2018 (has links)
No description available.
27

Computational modeling of avascular tumours using a hybrid on-lattice framework for cell-population dynamics

Viklund, Lina January 2018 (has links)
This master thesis consists of integrating an advanced model for avascular tumour growth into a multiscale computational framework for cell-population dynamics. In order to demonstrate this framework, the authors of the framework developed a simple model for avascular tumour growth, governed by the Laplace equation and a set of rules relating to the oxygen concentration, that they integrated with the framework. The realisation of this model closely followed previously established growth patterns of tumour cells up until the last phase, where predictions by some authors say the volume of the tumour should plateau. However, an additional phase was observed where asymmetric protrusions appear on the tumour's surface, causing the volume to continue to increase. The authors speculate that this could be due to their model lacking the inclusion of cell-cell adhesion, which restrains the migration of cells. The advanced tumour model implemented in this thesis include several additional mechanisms that the simple model lacks, and thus the driving research question for the thesis is whether integrating this advanced model into the framework will produce results that do not exhibit protrusions. Results suggest that despite this more advanced model, the outcome will still be an asymmetric tumour with unrestricted growth.
28

The Internationalization Process of Telenor: A Case Study of Telenor in Thailand

Chanmongkolpanich, Kittiya, Panthong, Supasana January 2009 (has links)
This thesis is to describe the internationalization process of Telenor in terms of entry modes and management of control. While reading this thesis, readers will be acknowledged more about the appropriate process that Telenor applied to Thailand. Moreover, the suitable control to manage Telenor’s international operation in Thailand is also shown herewith.
29

Stop starting, start finishing : En fallstudie om formell kompetensutveckling med fokus på utvärderingsfasen

Ingers, Åsa, Nilsson, Hanna January 2014 (has links)
Vi lever idag i ett samhälle i ständig utveckling vilket ställer krav på verksamma företag att konstant driva på den egna utvecklingen. I detta arbete är kompetenta och kunniga medarbetare viktigt, men det är enligt Rekryteringsenkäten 2012 (Svenskt Näringsliv, 2012) svårt för företagare att anställa den kompetens de behöver. Om inte kompetensen finns på arbetsmarknaden är intern kompetensutveckling ett möjligtalternativ för att ta fram den kompetens som efterfrågas och detta är något som det årligen investeras stora summor i. Vilken effekt dessa investeringar har på företagen är dock något som inte utvärderas i någon större utsträckning (Pineda, 2010) vilket leder till att pengar riskerar att upprepade gånger investeras i overksamma insatser. Hur kan detta åtgärdas? Det finns ett flertal teoretiska modeller för utvärdering av kompetensutveckling, men det saknas empirisk forskning som visar hur företag arbetar med området och det är denna lucka uppsatsen bidrar till att fylla. Undersökningen syftar till att genom en fallstudie beskriva de olika stegen i formell kompetensutveckling på organisationsnivå, med särskilt fokus på utvärdering, och undersöka den problematik som finns kring dessa aspekter utifrån existerande modeller för formell kompetensutveckling och utvärdering av kompetensutvecklande insatser. Följande forskningsfrågor besvaras: 1. Vilka nyckelaktiviteter utförs i det formella kompetensutvecklingsarbetet? 2. Saknas några nyckelaktiviteter i jämförelse med teoretiska modeller för formell kompetensutveckling och utvärdering av kompetensutvecklande insatser? 3. Vilka hinder finns i arbetet med utvärdering av kompetensutveckling och hur kan dessa överbryggas? Undersökningen har antagit en deduktiv ansats och en kvalitativ metod. En fallstudie har genomförts där sex aktörer på olika nivåer i fallföretaget genom personliga intervjuer fått beskriva kompetensutvecklingsprocessen och hur kompetensutveckling utvärderas. Resultatet har därefter analyserats med hjälp utav ADDIE-modellen och Kirkpatricks fyra-nivå modell. Resultatet ger en bild av kompetensutvecklingsarbetet som ostrukturerat och omedvetet där utvärderingsarbetet till stor del är personberoende. Alla faser i ADDIE går att finna i det arbete företaget gör och de hinder som identifierats är övergripande av en strukturell karaktär. Förbättringsmöjligheterna för utvärderingsarbetet består främst av att tydliggöra rutiner, ansvar och praktiska hjälpmedel.
30

Evaluation of Citizen Help Request (CHR) initiated by Bangladesh Police: A Case Study

Hasan, Mohammad Mahmudul January 2012 (has links)
No description available.

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