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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.
121

Development of an automotive steering-wheel mounted audio user Interface

Edwards, Matthew Ryan 08 June 2015 (has links)
A tier 1 automotive components supplier has developed a virtual user interface system for the purpose of replacing currently existing physical buttons mounted on automotive steering wheels. The system is capable of generating acoustic and vibratory feedback to the user for the purpose of mimicking the sound and feel of mechanical buttons. The work performed in this thesis served to investigate what the input waveform should be to the system in order to generate a desired audio output signal. Additionally, subjective testing in the form of a sound jury was conducted in order to identify which types of sounds should be associated with which command functions in order to indicate successful initiation of the intended function. A model for grouping command functions into banks, where each bank is assigned a single sound, was then developed for the purpose of reducing the total number of button sounds used in an automotive environment.
122

Energy-efficient steering systems for heavy-duty commercial vehicles

Winkler, Torsten, de Zaaijer, Rik, Schwab, Christian 28 April 2016 (has links) (PDF)
Besides the braking system the steering system is one of the most important systems on vehicles. The reliability and the performance of a steering system decides on the controllability of the vehicle under normal conditions as well as emergency situations. In everyday use the characteristics, the connectivity to assistance systems and the energy efficiency of the steering system become more and more important to fulfill the increasing demands regarding fuel consumption, carbon dioxide emissions and comfort. To meet these demands, new steering systems must be implemented and new technologies have to be developed. This contribution compares different approaches regarding functionality and energy efficiency to give an indication which system is the most promising solution for future front axle steering systems as well as rear steered axles (tag- or pusher axle) on trucks.
123

Test Bench for Experimental Research and Identification of Electrohydraulic Steering Units

Angelov, Ilcho, Mitov, Alexander 03 May 2016 (has links) (PDF)
The paper presents design solution and physical implementation of a system for examination of electro hydraulic steering based on OSPE 200 components. The implementation is based on synthesis of required hydraulic and structure parameters, presented in a previous paper. Now we present the interconnection of the digital control system and the closed-loop flow diagram. A formal description of embedded software is presented too, which supports operation of PI control algorithm in real-time. Identification is performed based on experimentally reported the transitional process by developing mathematical models. Presents the structure and capabilities of the models for identification, as well as procedures for their validation.
124

Skolan och den politiska offentligheten - öppning eller tillslutning? : Styrning och skolutveckling utifrån "försöket utan timplan"

Kristiansson, Martin January 2006 (has links)
<p>This study concerns school-development and the political public sphere in a Swedish context. It draws on an earlier study in which school-leaders expressed political signals in relation to school-development as being ambiguous and contradictive. On one hand they saw a political support for openness and dialogue in school. On the other hand they perceived control and competition. Another point of departure for the study is what tentatively was suggested as a shift in focus for the state government of schools during the 1990:s, from decentralization as such to an increased emphasis on control of its consequences. The overriding aim of the study was to illuminate how this shift could be understood regarding the relation between school-development and the political public sphere.</p><p>The study was conducted within a larger, national project where almost 900 schools worked without the national time table. Policy texts behind the governments’ decision on starting the project were used in order to describe and analyse school policy. School-leaders´ accounts on school-work and school-development in the project was used for analysis and description of school practice.</p><p>Habermas’ theory of communicative action, particularly his notions on “the welfare-state crisis” as an opening for a revitalized political public sphere grounded upon communicative action, was used as a theoretical frame for the study.</p><p>The results support the assumption that school policy, as formulated in the studied documents, did shift over time from a focus on decentralization to an emphasis on control of its consequences. The school-leaders, however, gave voice to a school practice where the importance of a communicative direction was emphasized. The overall conclusion is that while a vital political public sphere in Habermas´ terms is supported in school practice, school policy seems to direct school development in the opposite direction, thereby closing the opportunity for school to support a revitalized public sphere.</p>
125

Utveckling av rattstång med övre teleskopfunktion / Development of steering column with upper telescopic function

Josefsson, Johannes, Lundberg, Marcus January 2009 (has links)
<p>I denna rapport redogör projektgruppen för resultatet i kursen examensarbete 15hp (C-nivå) utfört på maskiningenjörsprogrammet, inriktning produktutveckling och design, vid Jönköpings Tekniska Högskola.</p><p>Examensarbetet har utförts i samarbete med Kongsberg Power Product Systems AB i Ljungsarp. Syftet var att utveckla en ny typ av övre teleskopfunktion till Kongsbergs modulsystem för ställbara rattstänger.</p><p>Utgångspunkten i projektet var att skapa en mer ergonomisk förarmiljö, något som Kongsbergs kunder och marknaden för långsamtgående fordon allt mer efterfrågar. Kraven som ställts på projektet bestod i största del av axiella och radiella krafter som konstruktionen skulle klara av, samt den axiella förlängningen av rattstången.</p><p>För att strukturera arbetet har en produktutvecklingsmetod från boken The Mechanical Design Process av David G. Ullman använts. Dessa metoder har använts i genomförandefasen för att leda fram till resultatet.</p><p>Projektet har resulterat i ett koncept som löser Kongsbergs krav på förbättrad förarergonomi.</p> / <p>In this report the project team describes the outcome of the course degree project 15 ECTS (C level) performed at the program of mechanical engineering, targeted product development and design, at Jönköping University.</p><p>The degree project has been carried out in cooperation with Kongsberg Power Products Systems AB in Ljungsarp. The aim was to develop a new type of upper telescopic function to the Kongsberg modular system for adjustable steering columns.</p><p>The starting point of the project was to create a more ergonomic driver's environment, as Kongsberg’s customers and the market for slow vehicles are increasingly demanding.</p><p>The requirements placed on the project consisted in the main part of the forces that construction would meet, and the axial extension of the steering column.</p><p>To structure the work a product development methodology from the book The Mechanical Design Process by David G. Ullman has been used.</p><p>The project has resulted in a concept that solves Kongsberg's demands for improved driver ergonomics.</p>
126

TELEOPERATED MRI‐GUIDED PROSTATE NEEDLE PLACEMENT

Seifabadi, REZA 30 May 2013 (has links)
Most robotic systems reported for MRI-guided prostate interventions use manual needle insertion, based on a previously acquired image, which requires withdrawing the patient from the scanner multiple times during the procedure. This makes the intervention longer, more expensive and elongating the discomfort to patient and, most importantly, less accurate due to the virtually inevitable motion of the target. As a remedy, automated needle placement methods were proposed, putting human supervision out of the control loop. This thesis presents the development of enabling technologies for human-operated in-room master-slave needle placement under real-time MRI guidance, while the patient is kept in the scanner and having the process of needle placement under continuos control of the physician. The feasibility of teleoperated needle insertion was demonstrated by developing a 1-DOF (degree of freedom) MRI-compatible master-slave system, which was integrated with a 4-DOF robot for transperineal prostate biopsy and brachytherapy. An accuracy study was conducted on a robotic system for MRI-guided prostate needle placement. Different error sources were identified and quantified. This study concluded that errors occurring during needle insertion have the most significant contribution to needle placement error. In order to compensate for these errors, teleoperated needle steering under real-time MRI guidance was proposed. A 2-DOF piezo-actuated MRI-compatible needle steering module was developed and integrated with the aforementioned 4-DOF transperineal robot, yielding a fully actuated 6-DOF (x, y, z, yaw, pitch, roll) robotic platform for MRI-guided prostate interventions. A novel MRI-compatible master robot was also developed to enable teleoperated needle steering inside the MRI room. MRI-compatible controller hardware and software were developed. A novel MRI-compatible force/torque sensor was devised using Fiber Bragg Grating for force measurement in MRI room. Phantom experiments proved the feasibility iii of teleoperated needle steering under real-time MRI guidance. A system was also developed for real-time 3D shape tracking of a bevel-tip needle with Fiber Bragg Grating sensors embedded along the needle shaft. The needle profile was overlaid on the real-time MR image, yielding real time navigation with accuracy better than 0.5 mm. The experimental system is presently being refitted for clinical safety and feasibility trials on real patients. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2013-05-30 12:26:18.732
127

Real-Time Calibration of the Steering Wheel Angle Sensor

Larsén, Nils January 2017 (has links)
A stationary or temporary offset in the steering system of a vehicle can result in functions, relying on the steering wheel angle, performing poorly. Due to the wide range of different vehicle configurations at Scania CV, all sensors with relevant information regarding vehicle direction are not available on all vehicles. By using a statistical approach, including common sensors installed on the vehicle, a conceptual algorithm calibrating the Steering Wheel Angle Sensor offset in real- time has been developed. The algorithm is simple and relies on the assumption that a vehicle is driving straight ahead most of the time above a certain minimum vehicle speed, thus the most frequent steering wheel angle is the straight ahead angle. The algorithm is only active above the certain minimum vehicle speed and consists of two moving windows comprising steering wheel angle samples in which the calculations are performed. The results show that the algorithm is able to detect offsets with a short calibration time. Storage of samples is required but no vehicle specific parameters are needed.
128

Digitalization and Big Data from the John Deere Perspective

Engel, Thomas 15 November 2016 (has links) (PDF)
No description available.
129

Risk management in developing countries

Memari, Mashan January 2016 (has links)
My thesis will focus on risk management practically in developing countries. In this research study, first a literature review about the concept of risk management and its concerns is provided which is the output of extensive review of resources such as journal papers, books and research studies. Then a case study will be reviewed in Iran which is considered as a developing country. In this step, the researcher attempts to extract needed information for her research based on the theory of frames. After gathering needed information the findings which are extracted from practical environment are compared to the academics material to answer the questions which are defined in the primary steps. Meanwhile, the main purpose of this study is reviewing the conditions of work environment in developing countries and extract main concerns and compare them to the standards, methodologies and tools and techniques of risk management to improve the efficiency and effectiveness of using these tools in performing risk management in developing countries.
130

Towards efficient vehicle dynamics development : From subjective assessments to objective metrics, from physical to virtual testing

Gil Gómez, Gaspar January 2017 (has links)
Vehicle dynamics development is strongly based on subjective assessments (SA) of vehicle prototypes, which is expensive and time consuming. Consequently, in the age of computer- aided engineering (CAE), there is a drive towards reducing this dependency on physical test- ing. However, computers are known for their remarkable processing capacity, not for their feelings. Therefore, before SA can be computed, it is required to properly understand the cor- relation between SA and objective metrics (OM), which can be calculated by simulations, and to understand how this knowledge can enable a more efficient and effective development process. The approach to this research was firstly to identify key OM and SA in vehicle dynamics, based on the multicollinearity of OM and of SA, and on interviews with expert drivers. Sec- ondly, linear regressions and artificial neural network (ANN) were used to identify the ranges of preferred OM that lead to good SA-ratings. This result is the base for objective require- ments, a must in effective vehicle dynamics development and verification. The main result of this doctoral thesis is the development of a method capable of predicting SA from combinations of key OM. Firstly, this method generates a classification map of ve- hicles solely based on their OM, which allows for a qualitative prediction of the steering feel of a new vehicle based on its position, and that of its neighbours, in the map. This prediction is enhanced with descriptive word-clouds, which summarizes in a few words the comments of expert test drivers to each vehicle in the map. Then, a second superimposed ANN displays the evolution of SA-ratings in the map, and therefore, allows one to forecast the SA-rating for the new vehicle. Moreover, this method has been used to analyse the effect of the tolerances of OM requirements, as well as to verify the previously identified preferred range of OM. This thesis focused on OM-SA correlations in summer conditions, but it also aimed to in- crease the effectiveness of vehicle dynamics development in general. For winter conditions, where objective testing is not yet mature, this research initiates the definition and identifica- tion of robust objective manoeuvres and OM. Experimental data were used together with CAE optimisations and ANOVA-analysis to optimise the manoeuvres, which were verified in a second experiment. To improve the quality and efficiency of SA, Volvo’s Moving Base Driving Simulator (MBDS) was validated for vehicle dynamics SA-ratings. Furthermore, a tablet-app to aid vehicle dynamics SA was developed and validated. Combined this research encompasses a comprehensive method for a more effective and ob- jective development process for vehicle dynamics. This has been done by increasing the un- derstanding of OM, SA and their relations, which enables more effective SA (key SA, MBDS, SA-app), facilitates objective requirements and therefore CAE development, identi- fies key OM and their preferred ranges, and which allow to predict SA solely based on OM. / <p>QC 20170223</p> / iCOMSA

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