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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.
501

The Use of an On-Board MV Imager for Plan Verification of Intensity Modulated Radiation Therapy and Volumetrically Modulated Arc Therapy.

Walker, Justin A. 20 August 2013 (has links)
No description available.
502

Simulerad nivåreglering av vattenkraftverk

Azizi, Hadi January 2022 (has links)
Vattenkraften är en viktig del av den svenska elförsörjningen och tillgodoser cirka 45 % av det årliga elbehovet i landet. Vattenkraften utnyttjar höjdskillnaden mellan inflödet och utflödet för att driva turbiner och producera el. I Sverige finns omkring 200 dammar med en fallhöjd större än 15 m och för höga nivåer vid någon av dessa skulle leda till ett dammbrott med omfattande konsekvenser. Ett viktigt område som det investeras mycket i idag är dammsäkerhet vilket går ut på att undvika okontrollerade översvämningar av dammen. Kännedom av fallhöjd och flöde är nödvändiga inom vattenkraft för att kunna beräkna producerad effekt och även vid dimensionering av dammar, vattenvägar och generatorer. Mättningar på inflödet till ett vattendrag anses vara mycket komplicerat och tidskrävande däremot kan utflödet genom utskoven beräknas med matematiska samband. Utskov avser öppningar i dammen som används för att avbörda vatten. Det finns således olika typer av utskov och det som påverkar valen är aspekter som kostnad, väderförhållanden, avbördningsförmåga, etc. För att undvika en möjlig överströmning av en damm dimensioneras ofta utskoven med avseende på vilken mängd vatten de bör avbörda. Ett krav som ofta ställs är att det ska vara möjligt att avbörda en vattendrags högsta vattennivå (HHQ). Några av de mest förekommande varianter av kontrollerade utskov i Sverige är valsdammar, luckdammar och bottenutskov.   Nivån i vattenmagasinet mäts upp med hjälp av sensorer som är placerade på olika platser vid dammen och uppmätta höga nivåer leder till att olika larmfunktioner löser ut. Regleringen av vattennivån sker då genom att avbörda vatten på ett kontrollerat sätt genom utskoven.  Genom att simulera regleringsprocessen av vattennivån i en virtuell miljö kan olika scenarier som kan uppstå vid magasinhantering testas på ett ekonomiskt sätt och hitta lämpliga reglerstrategier. Simuleringar är också en av de verktyg lyft fram inom industri 4.0 vilket kan bidra till framtidens lösningar inom automatiseringsprojekt. I arbetet studeras de olika beståndsdelar i ett vattenkraftverk och en tilltänkt metod presenteras för skapning av en virtuell modell av nivåregleringsprocessen i Siemens SIMIT, styrning av modellen via en virtuell PLC-enhet och visualisering av processen på en HMI-skärm. / Hydropower is an important part of the Swedish electricity supply and meets about 45% of the annual electricity needs in the country. Hydropower uses the height difference between inflow and outflow to power turbines and produces electricity. In Sweden, there are about 200 dams with a drop height greater than 15 m, and too high levels at any of these dams would lead to a dam break with extensive consequences. An important area in which a lot is invested today is dam safety, which is about avoiding uncontrolled flooding of the dam. Knowledge of drop height and water flow is necessary for hydropower to calculate the power produced and when dimensioning dams, waterways, and generators. Saturations on the inflow to a watercourse are very complicated and time-consuming, however, the outflow through the spillway can be calculated with mathematical correlations. Spillways refer to openings in the dam that are used to carry away water volumes. Thus, there are different types of spillways, and what influences the choices are aspects such as cost, weather conditions, etc. To avoid possible flooding of a dam, the spillways are often dimensioned with respect to the amount of water they should carry away. A requirement that is often made is that it must be able to carry away the highest water level (HHQ) of a watercourse.  The level in the water reservoir is measured with the help of sensors that are in different places by the dam and measured high levels lead to different alarm functions being triggered. The regulation of the water level then takes place by carrying away water in a controlled manner through the spillway. By simulating the regulation process of the water level in a virtual environment, different scenarios that can arise during reservoir management can be tested in an economical way and find suitable control strategies. Simulations are also one of the tools highlighted in industry 4.0, which can contribute to future solutions in automation projects. In the work, the various components of a hydropower plant are studied, and an intended method is presented for creating a virtual model of the level control process in Siemens SIMIT, controlling the model via a virtual PLC unit and visualizing the process on an HMI screen.
503

Berättande i spelmiljöer : Miljö- och indexikalt berättande i Portal / Narration in game environments : Environmental and indexical storytelling in Portal

Olsson, Linnéa January 2023 (has links)
I detta arbete har spelet Portal (2007) undersökts för det miljö- och indexikaltberättande som finns i spelet och svarat på frågan om vilka lärdomar det finns att ta ur ett spelutvecklarperspektiv. Arbetet är utformat som en teorikonsumerad fallstudie där Portal (2007) jämförs med redan satta definitioner på olika sorters rumsligt berättande. I undersökningen framkommer det att spelet alltid innehåller någon form av miljö- och indexikalt berättande, men det är inte jämnt fördelat utan det mesta sker i den senare delen av spelet. Lärdomarna som går att dra från undersökningen är att det sker en hel del miljö- och indexikalt berättande i enkla linjära spel fastän spelmekaniken kan ha varit fokusen under utvecklingen av spelet. Portal (2007) visar också på att det inte krävs ett stort utrymme för att miljön kan berätta sagor, det krävs bara ett litet gömställe.
504

Future liver remnant hypertrophy rate in portal vein embolization before left trisectionectomy: a retrospective cohort study / 左3区域切除術前の門脈塞栓術による残肝肥大率の検討:後ろ向きコホート研究

Onishi, Yasuyuki 23 March 2023 (has links)
京都大学 / 新制・論文博士 / 博士(医学) / 乙第13540号 / 論医博第2280号 / 新制||医||1066(附属図書館) / (主査)教授 小濱 和貴, 教授 近藤 尚己, 教授 妹尾 浩 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM
505

Floating Thresholds – On the Idea of the Portal in Architecture

Grelz, Ivan January 2023 (has links)
This project investigates a specific concept within architecture: the portal. Divided into eight independent chapters, all possible to read as stand-alone parts, the thesis – a hybrid essay consisting of text, images, drawings and models – uses the portal as a springboard, or tool, for approaching existing theories on the invisible forces that shape the world and our built environment.    The chapter Nature approaches the portal and architecture as separator from "nature", the chapter Ritual as a ritual device for transition, the chapter Myth as a mythological archetype, the chapter Liminal as interstitial space and recursion, the chapter Depth as an enhancer of depth, the chapter Speed as a technological machine, and finally, the epilogue concludes that architectural practice in large can be interpreted as the creation of different types of portals.   Architecture, both as a subject and as a practice, has the potential to manifest and mediate between various supplementary relationships, such as interior and exterior, nature and culture, sacred and profane, heaven and earth, past and future, between sign and signified, us and them, between order and chaos, between subject and object, thought and action, private and public, rationality and imagination, flat and three-dimensional, flesh and matter (the list can go on forever).    The portal works both as an analogy for this and as an actual tool; partly by changing the character of adjacent spaces by such basic things as placing a door in a wall or placing a building in a landscape, but partly by finding new ways to bridge between extremities, without necessarily dissolving them completely.
506

An Open Framework for Developing Distributed Computing Environments for Multidisciplinary Computational Simulations

Bangalore, Purushotham Venkataramaiah 10 May 2003 (has links)
Multidisciplinary computational simulations involve interactions between distributed applications, datasets, products, resources, and users. Because the very nature of the simulation software emphasizes a single-computer, small-usership and audience, the kinds of applications that have been developed often are unfriendly to incorporation into a distributed model. However, advances in networking infrastructure, and the natural tendency for information to be geographically distributed place strong requirements on integration of single-computer codes with distributed information sources, as well as multiple computer codes that are geographically distributed in their execution. The hypothesis of this dissertation is that it is possible, via novel integration of Internet, Distributed Computing, and Grid technologies, to create a distributed computational simulation systems that satisfies the requirements of modern multidisciplinary computational simulation systems without compromising functionality, performance, or security of existing applications. Furthermore, such a system would integrate disparate applications, resources, and users and would improve the productivity of users by providing new functionality not currently available. The hypothesis is proved constructively by first prototyping the Enterprise Computational Services framework based on a multi-tier architecture using the Java 2 Enterprise Edition platform and Web Services and then two distributed systems, the Distributed Marine Environment Forecast System and Distributed Simulation System for Seismic Performance of Urban Regions, are prototyped using this enabling framework. Several interfaces to the framework are prototyped to illustrate that the same framework can be used to develop multiple front-end clients required to support different types of users within a given computational domain. The two domain specific distributed environments prototyped using the framework illustrate that the framework provides a reusable common infrastructure irrespective of the computational domain. The effectiveness and utility of the distributed system and the framework are demonstrated by using a representative collection of computational simulations. Additional benefits provided by the distributed systems in terms of new functionality provided are evaluated to determine the impact on user productivity. The key contribution of this dissertation is a reusable infrastructure that could evolve to meet the requirements of next-generation hardware and software architectures while supporting interaction between a diverse set of users and distributed computational resources and multidisciplinary applications.
507

BEST PRACTICES OF WEB-BASED HUMAN RESOURCE COMPONENTS IN NOT-FOR-PROFIT ORGANIZATIONS

Rogers, Christian Bryan 28 March 2006 (has links)
No description available.
508

Effect of Slit Scan Imaging Techniques on Image Quality in Radiotherapy Electronic Portal Imaging

Walton, Dean R. 12 November 2008 (has links)
No description available.
509

Commissioning and Implementation of an EPID Based IMRT QA System “Dosimetry Check” for 3D Absolute Dose Measurements and Quantitative Comparisons to MapCheck

Patel, Jalpa A. 28 December 2010 (has links)
No description available.
510

Membrane embedded channel of bacteriophage phi29 DNA packaging motor for single molecule sensing and nanomedicine

Geng, Jia 01 October 2012 (has links)
No description available.

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