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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.
81

Visual Package for Control System Design Using a Java Infrastructure

Huitger, Catherine Ann January 2000 (has links)
No description available.
82

Development and Evaluation of the Ethernet Interface(s) for the Monitoring and Control System of a New Beamforming Radio Telescope

Srinivasan, Abirami 09 September 2010 (has links)
The Long Wavelength Array (LWA) is a large multi-purpose radio telescope, operating in frequencies between 10 and 88 MHz, designed for both long-wavelength astrophysics and ionospheric science. The LWA will eventually consist of 53 "stations", each consisting of 256 pairs of crossed-dipole antennas whose signals are formed into beams. The Monitoring and Control System (MCS), a subsystem of each LWA station, controls the station's subsystems and also monitors their status. This thesis addresses the interface-related features of MCS. The physical interface of the MCS with each subsystem is a Gigabit Ethernet connection and the interface protocol is User Datagram Protocol (UDP). An analysis of the throughput obtained through the interface using UDP is compared to that achieved using Transmission Control Protocol (TCP). It is seen that the throughput with UDP is 15\% better than with TCP, and that UDP is a better choice for the given requirements. Implementation of a new ionospheric calibration scheme requires that the MCS be capable of repointing between astronomical sources on a 5 ms time scale. The rate at which beams can be repointed is analyzed. It is confirmed that MCS is at least 2 orders of magnitude faster than necessary, and is limited by the ethernet network throughput. Python software that facilitates the development and testing of MCS and other subsystems have been developed, and are described. / Master of Science
83

How Initial Public Offerings Change Management Control System Packages

Sander, Christopher, Laidlaw, Clara January 2016 (has links)
This study aims to further develop research, from a management approach, by studying how MCS packages change when an organization undergoes an initial public offering. Furthermore, it aims to use Malmi and Brown’s (2008) management control system package in order to categorize and analyze the complexity of organizational change brought on by an initial public offering. This study draws on interviews with top managers in a high technological firm, which has recently been listed on the stock exchange. The results of this study imply that an initial public offering can change the MCS package in a number of different ways. Public companies do not necessarily become short-term, an initial public offering can affect a company’s external focus and measurements without affecting its internal measurements, in order for companies to become suitable for the stock market they formalize policies and appoint an independent board and listed companies can experience changes to their culture.
84

Organisational Change and Accounting Control Systems at an Australian University A Longitudinal Case Study

Moll, Jodie, j.moll@griffith.edu.au January 2003 (has links)
This thesis provides an attempt to better understand the design and operation of accounting control systems as part of an interrelated control package in an Australian higher education institution subject to an increasingly competitive environment. The study was designed: (1) to understand how and why the accounting control systems changed; (2) to understand how accounting shapes and can be shaped by other institutional processes; and (3) to understand the roles accounting control systems play in higher education institutions. The research aims and objectives lend to a longitudinal case study approach. The data collection consisted of two phases: (1) a pilot study to determine issues for the intensive study and to identify or develop a suitable theoretical framework; and (2) an intensive field study of the subject organisation to develop and explain the observations. Data collection involved a triangulation approach that mixes three sources: interview, observation, and document evidence over a two-year period between 2000 and 2002. The interviewees were selected from different hierarchical levels: Vice-Chancellor, Pro-Vice-Chancellor, Deans, Heads of School, general staff, and Education Queensland. This thesis draws on multiple theoretical perspectives to understand the complexities of accounting control systems change. These perspectives are: institutional theory, leadership theories, political and power theories, and resistance theories. Such an emergent research strategy was deemed pertinent to build a more holistic analysis and to offer alternative explanations of the phenomena under scrutiny. The case highlights a number of findings. First, despite the suggestion that universities operate as autonomous institutions, the University studied still succumbed to external pressures, especially from the Federal Government, for a more managerialist approach. In this study Federal Government pressures were the primary source of change identified. Second, the design and operation of the accounting control systems was found to be contingent on the related control systems and vice versa. Third, the accounting control systems played several roles in the organisation. In particular, they provided visibility to external constituents giving the impression that rational techniques had been employed consistent with Government prescriptions. This was the case for both the budget system and the performance management system. In addition to this, from an internal perspective, the budget was used to promote a sense of equity and fairness, at the same time reducing conflict in the organisation. Finally, the budget system was found to be a source of power in the organisation; it determined the level of control used to direct organisational activity. Implications for future research are presented in the concluding section.
85

Datorbaserat kontrollrum inom processindustrin : erfarenheter i ett tidsperspektiv

Holmgren, Mette January 1997 (has links)
Diss. Stockholm : Handelshögsk.
86

Choosing between Git and Subversion : How does the choice affect software developers?

Spandel, Daniel, Kjellgren, Johannes January 2014 (has links)
Today a lot of software projects are using version control systems for maintaining their software source code. There are a lot of version control systems, and the choice of which one to choose is far from simple. Today the two biggest version control systems are Git and Subversion. In this paper we have found the main differences between the two, and investigated how the choice between them affects software developers. Although software developers in many aspects are unaffected by the choice, we did find some interesting findings. When using Git, our empirical study shows that software developers seem to check in their code to the main repository more frequently than they do when using Subversion. We also found indications that software developers tend to use Subversion with a graphical interface, whereas the preferred interface for working with Git seems to be command-line. We were also surprised of how insignificant the learning aspect of the systems seems to be for the developers. Our goal with this paper is to provide a foundation to stand upon when choosing what version control system to use for a software project.
87

Řízení pohonů průmyslového robotu pomocí systémů KEBA / Control of industrial robot drives by KEBA systems

Opluštil, Aleš January 2014 (has links)
This thesis deals with the evaluation of the use of original drive on the older industrial robot KUKA KR 15/2 with a new control system from KEBA. An original control system is removed from robot controller KR C1 and replaced by KeMotion system, which is in this thesis completely described. It is necessary to choose an appropriate way of connection between electric drives of industrial robot and KeMotion control system and finally realize it by practical way. Based on communication with the control system, these engines had been assessed as appropriate. There is also a section created to the description of the control software and its implementation on KUKA robot and to creating of visualization of model.
88

Data Rate Upgrade of the DFCS Waveform

Walthall, David 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / New tracking/control system requirements demand that the present DFCS/GRDCUS/MTACS data link bit rate be increased. A possible method for achieving this increase is to select two additional 31-bit chip code patterns that are orthogonal to the present chip codes, and to each other. This method will not require any more bandwidth than the present 10 MHZ used. This method suggest that each of the four chip code patterns are assigned a two bit value ie: 00, 01, 10, 11. At present, the two correlated chip codes represent data in a pulse position method. No data is contained in which of the two chip codes actually correlated. This new method suggest each of the four chip code patterns will still perform the pulse position modulation and provide two additional bits of data. These additional two bits of data will up the data rate of the link by 100 percent.
89

Low cost integration of Electric Power-Assisted Steering (EPAS) with Enhanced Stability Program (ESP)

Soltani, Amirmasoud January 2014 (has links)
Vehicle Dynamics Control (VDC) systems (also known as Active Chassis systems) are mechatronic systems developed for improving vehicle comfort, handling and/or stability. Traditionally, most of these systems have been individually developed and manufactured by various suppliers and utilised by automotive manufacturers. These decentralised control systems usually improve one aspect of vehicle performance and in some cases even worsen some other features of the vehicle. Although the benefit of the stand-alone VDC systems has been proven, however, by increasing the number of the active systems in vehicles, the importance of controlling them in a coordinated and integrated manner to reduce the system complexity, eliminate the possible conflicts as well as expand the system operational envelope, has become predominant. The subject of Integrated Vehicle Dynamics Control (IVDC) for improving the overall vehicle performance in the existence of several VDC active systems has recently become the topic of many research and development activities in both academia and industries Several approaches have been proposed for integration of vehicle control systems, which range from the simple and obvious solution of networking the sensors, actuators and processors signals through different protocols like CAN or FlexRay, to some sort of complicated multi-layered, multi-variable control architectures. In fact, development of an integrated control system is a challenging multidisciplinary task and should be able to reduce the complexity, increase the flexibility and improve the overall performance of the vehicle. The aim of this thesis is to develop a low-cost control scheme for integration of Electric Power-Assisted Steering (EPAS) system with Enhanced Stability Program (ESP) system to improve driver comfort as well as vehicle safety. In this dissertation, a systematic approach toward a modular, flexible and reconfigurable control architecture for integrated vehicle dynamics control systems is proposed which can be implemented in real time environment with low computational cost. The proposed control architecture, so named “Integrated Vehicle Control System (IVCS)”, is customised for integration of EPAS and ESP control systems. IVCS architecture consists of three cascade control loops, including high-level vehicle control, low-level (steering torque and brake slip) control and smart actuator (EPAS and EHB) control systems. The controllers are designed based on Youla parameterisation (closed-loop shaping) method. A fast, adaptive and reconfigurable control allocation scheme is proposed to coordinate the control of EPAS and ESP systems. An integrated ESP & ESP HiL/RCP system including the real EPAS and Electro Hydraulic Brake (EHB) smart actuators integrated with a virtual vehicle model (using CarMaker/HiL®) with driver in the loop capability is designed and utilised as a rapid control development platform to verify and validate the developed control systems in real time environment. Integrated Vehicle Dynamic Control is one of the most promising and challenging research and development topics. A general architecture and control logic of the IVDC system based on a modular and reconfigurable control allocation scheme for redundant systems is presented in this research. The proposed fault tolerant configuration is applicable for not only integrated control of EPAS and ESP system but also for integration of other types of the vehicle active systems which could be the subject of future works.
90

Statistical analysis of deterministic textures in steel sheet production

Porrino, Alessandre January 2004 (has links)
Textured surfaces are universally adopted in the steel sheet production industry, and manufacturers are continuously improving the quality of the finished products through intense research in the surface characterisation field. Deterministic Surfaces are textured with specifically designed rolls in order to present a certain degree of regularity, which allows better control over the functional behaviour of the metal sheets. The regularity of the texture impressed on the steel sheets also allows unconventional approaches to surface characterisation and to the assessment of the texture's structure. Statistical analysis is the most effective way to target the isolation of the deterministic part of the surface, which represents the desired product, from the stochastic part, called ‘noise’ and associated with the inaccuracies of production and measurement. This work addresses the problem of characterisation of deterministic textures through statistical analysis, proposing innovative filtering techniques aimed at the realisation of an On-line Process Control System. Firstly the techniques proposed are theoretically formulated and studied, addressing in particular the physical meaning of the geometrical parameters extracted through statistical analysis of highly correlated portions of the textures. A method for isolating the deterministic textures present on a surface, called the Statistical Surface Filter, is presented and discussed in detail, and tested on existing laboratory samples. Secondly the filter is applied to preliminary measurements acquired by an innovative on-line measurement system currently under development, and evidence is shown that the technique is effective in separating the information regarding the regular patterns from the stochastic noise. The possible applications to on-line Statistical Process Control are discussed. Thirdly, the Statistical Surface Filter is tested on a set of measurements representing texturing rolls and textured sheets with different characteristics; statistical analysis of the surface parameters extracted from the filtered surfaces show that the technique allows the assessment of the different contributions of the various stages of the texturing process to the final product. Finally, a software package is implemented for the practical application of the filtering techniques and the parameters extraction; the algorithms that perform the statistical filtering are described and discussed, concluding with the operations of optimisation and fine-tuning for production-line implementation.

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