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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.
11

Real-time control approaches to deadlock management in automated manufacturing systems

Bodner, Douglas Anthony 08 1900 (has links)
No description available.
12

A study of using information technology governance as a tool for achieving business objectives: a case study.

Jokonya, Osden. January 2006 (has links)
The objective of this research is to establish how Information Technology (IT) Governance supports business objectives in an organization. The relationship between IT Governance and organization business objectives continues to interest academics and practitioners (IT Governance Institute, 2003). Like governance generally, IT governance is about the decision rights and accountabilities that encourage desirable behavior in the use of IT. A major challenge of IT governance is resolving boundaries and scope between the organization and its business units. Investment in IT has in recent years become a strategic organizational choice, yet there exists little understanding of IT governance's contribution to business objectives (IT Governance Institute, 2003). A case study research approach was used to get an in-depth understanding of IT governance in a single organization with many business units. The organization that was selected for this purpose is RioZim Limited (formerly Rio Tinto Zimbabwe), a mining company situated in Zimbabwe. Using a field survey of business and IT executives, this study examined how IT governance is contributing towards business objectives. Data was collected from all business units on various IT issues and business objectives. The questions that were asked centered on IT governance practices based on responsibility and authority for IT decision making. Some IT governance issues explored in the study include stakeholder involvement in decision making on major IT domains. The research examined how IT Governance is supporting the business objectives. The results suggest that RioZim's IT governance does not adequately support business objectives. The study revealed that business objectives should drive IT governance. IT governance should be the responsibility of executives and all business units. The results of the study wi II add to the literature in demonstrating the importance of IT governance in supporting business objectives. It provides an assessment tool to business executives for evaluating their IT governance and it also provides guidelines for developing effective IT governance that supports business objectives. / Thesis (MBA)-University of KwaZulu-Natal, Durban, 2006.
13

The impact of the convergence of information technology and industrial automation on operational excellence in the manufacturing environment.

Marimuthu, Thanesh. January 2007 (has links)
The need to increase productivity, improve quality and increase flexibility whist continuously reducing costs is driving manufacturers to search for alternative means of converting the product idea into a manufactured product. Plant automation systems which are the nervous system and increasingly the intelligence of the plant have an integral role to play in this regard. This study investigates the convergence between traditional IT and Industrial Automation with a view to understanding how this phenomenon will affect operational excellence within the manufacturing environment. The study further investigates the key determinants of success for automation systems within the broader business context and how this can lead to an advantage over competitors. The study is limited to manufacturing operations within the greater Durban area. The results revealed that there is a clear relationship between industrial automation and information technology in manufacturing organisations. However, of interest is the fact that in the majority of the organisations surveyed the two functions operate as separate entities within the organisation resulting in overlaps of responsibility and accountability for key equipment and processes. Factory efficiency was found to be the key determinant of success in the majority of the organisations surveyed whilst the provisioning of production data when used strategically was found to have a positive effect in allowing the organisation to gain an advantage over its competitors. Due to the limitation of the short time frame allocated to this research, the study could not go in detail into the drivers of these findings consequently recommendations for further research is made. / Thesis (MBA)-University of KwaZulu-Natal, 2007.
14

An automated apparatus for non-contact inspecting of mass produced custom products.

Davrajh, Shaniel. January 2009 (has links)
The evolution of the manufacturing industry may be viewed as proceeding from Dedicated Manufacturing Systems (DMS) to Reconfigurable Manufacturing Systems (RMS). Customer requirements change unpredictably, and so DMS are no longer able to meet modern manufacturing requirements. RMS are designed with the focus of providing rapid response to a change in product design, within specified part families. The movement from DMS to RMS facilitates mass-production of custom products. Custom parts require inspection routines that can facilitate variations in product parameters such as dimensions, shape, and throughputs. Quality control and part inspection are key processes in the lifecycle of a product. These processes are able to verify product quality; and can provide essential feedback for enhancing other processes. Mass-producing custom parts requires more complex and frequent quality control and inspection routines, than were implemented previously. Complex, and higher frequencies of inspection negatively impact inspection times, and inherently, production rates. For manufacturers to successfully mass-produce custom parts, processes which can perform complex and varying quality control operations need to be employed. Furthermore, such processes should perform inspections without significantly impacting production rates. A method of reducing the impact of high frequency inspection of customized parts on production rates is needed. This dissertation focuses on the research, design, construction, assembly, and testing of a Non- Contact Automated Inspection System (NCAIS). The NCAIS was focused on performing quality control operations whilst maintaining the maximum production rate of a particular Computer Integrated Manufacturing (CIM) cell. The CIM cell formed part of a research project in the School of Mechanical Engineering, University of KwaZulu-Natal; and was used to simulate mass-production of custom parts. Two methods of maintaining the maximum production rate were explored. The first method was the automated visual inspection of moving custom parts. The second method was to inspect only specified Regions of Interest (ROIs). Mechatronic engineering principles were used to integrate sensor articulation, image acquisition, and image processing systems. A specified maximum production rate was maintained during inspection, without stoppage of parts along the production line occurring. The results obtained may be expanded to specific manufacturing industries. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2009.
15

Simulation in apparel manufacturing

Zhou, Yin January 1992 (has links)
No description available.
16

Material and information flow in an advanced automated manufacturing system

January 1982 (has links)
Stanley B. Gershwin. / Bibliography: leaves [9-10] / "May, 1982." "DAR78-17826"
17

Hybrid additive manufacturing platform for the production of composite wind turbine blade moulds

Momsen, Timothy Benjamin January 2017 (has links)
This dissertation discusses the application of additive manufacturing technologies for production of a large-scale rapid prototyping machine, which will be used to produce moulds for prototype composite turbine blades for the emerging renewables energy industry within the Eastern Cape region in South Africa. The conceptualization and design of three complete printer builds resulted in the amalgamation of a final system, following stringent theoretical design, simulation, and feasibility analysis. Following the initial product design cycle stage, construction and performance testing of a large-scale additive manufacturing platform were performed. In-depth statistical analysis of the mechatronic system was undertaken, particularly related to print-head locational accuracy, repeatability, and effects of parameter variation on printer performance. The machine was analysed to assess feasibility for use in the mould-making industry with accuracy and repeatability metrics of 0.121 mm and 0.156 mm rivalling those produced by some of the more accurate fused deposition modellers commercially available. The research data gathered serves to confirm that rapid prototyping is a good alternative manufacturing method for wind turbine blade plug and mould production.
18

Analysis of profibus communication using process automation and decentralised periphery against conventional (4-20MA)

Ntshangase, Blessing Zithulele Tefsa 10 1900 (has links)
The research Analyses, PROFIBUS Communication using Process Automation and Decentralized Periphery against Conventional (4-20mA) was based on the process plant constructed in 2012 by staff and students in the Department of Instrumentation and control at Mangosuthu University of Technology. Further work was not done including configuring the entire process plant, testing all devices and display the image of the process plant on human machine interface. The process plant operation was never tested and the research topic has not been attempted before. The research was conducted to improve the existing plant to full operation or functional project. The research study was conducted in March 2013 by BZT Ntshangase, it was established that both DP flowmeter and PA flowmeter were not tested before, not calibrated correctly and both drives which are (MM440 and MM420) were not setup to control both pump1 and pump 2 in manual or auto mode. The Programmable Logic Controller (PLC) was not configured to communicate with all devices on the network. PROFIBUS-DP and PROFIBUS-PA devices were not set up; input measurements were not scaled to read within certain limits. All devices used in the process plant were not assigned unique addresses for the network and DSG files were not installed so that Programmable logic controller (PLC) would identify all devices on the PROFIBUS network. The research was based on analysis of PROFIBUS communication using process automation and decentralized periphery against conventional (4-20mA), where one flowmeter was communicating with a PLC via PROFIBUS-DP and the other flowmeter was communicating through PLC via ET-200M to a DP/PA coupler. Research objective was to examine the time response between the two signals, data transmission, network configurations and their communication protocols and including transmission rate for both networks. Process plant components used in the research were tested for linear scaling, reliability, generalizability and validity. The reason for performing these tests was to produce consistent results and to checks how similar results are if the research was repeated under similar circumstances. During testing, respectable results were achieved. All simulated results were compared with the real-time results and then a conclusion drawn based on the obtained information and facts. Project design, implementation, test procedures and test results were achieved because prototype performed as per design and research objectives were achieved. Simulation tests were conducted and the obtained results analysed. The achieved results showed that the proposed solution or the prototype system performed as per design. The experimental results could be useful to other researchers in the future. At the end of the study conclusion and some recommendations for further studies are discussed efficiently to utilize resources in the process plant verification and validation. / Electrical Engineering / M. Tech. (Electrical Engineering)
19

Combined effect of job and AGV dispatching rules on a flexible manufacturing system

Dalal, Malay A. 04 August 2009 (has links)
In a Flexible Manufacturing System (FMS) jobs are moved between work-centers by an Automated Guided Vehicle System (AGVS). The operation of the AGVS is governed by two kinds of AGV dispatching rules: Workcenter Initiated Rules (WI), and Vehicle Initiated Rules (VI). At work-centers. jobs are prioritized for processing by Job Dispatching (JD) Rules. The objective of the study is to characterize system behavior when dispatching rules from each of the three categories are used concurrently -- an issue which has received very little attention in published research. In addition to common measures of system performance such as job flowtime and shop throughput, measures specifically directed at AGVS effectiveness such as waiting times and queue lengths for AGVs, and empty AGV travel are used. Combinations of rules from the three categories are studied under conditions of high and low AGV utilization. The simulation model of the FMS was developed using SLAM II - Material Handling Extension. The hypothetical FMS consists of four non-identical workcenters which process multiple part types. A fleet of four AGVs move the jobs between workcenters. Results indicate that for the system analyzed, WI rules (for vehicle selection) do not play a significant role in determining system performance even when the AGV fleet is under-utilized. For the system analyzed, V1 rules (for selecting jobs to picked up by AGVs) were found to have a significant effect on all measures of performance, only under conditions of constrained AGV fleet size. Good results were obtained with the Shortest Travel Distance rule. The relative performance of VI rules was found to be independent of job dispatching rules. However, some combinations of these rules interacted to produce inexplicable results. A notable observation of this research was that job dispatching rules have a significant effect on measures of AGVS performance. The effectiveness of AGV dispatching rules appears to be dependent on the system being analyzed. / Master of Science
20

GIBSS: a framework for the multi-level simulation of manufacturing systems

De Meter, Edward Christopher January 1989 (has links)
A systems approach for manufacturing system design calls for the division of a system design into sub-designs, and their specification over multiple levels of detail. Through an iterative design and evaluation process, a system design progresses from an abstraction to an implemental specification. To facilitate the evaluation process, models of sub-designs must be applicable to modular assembly, even if the sub-designs are heterogeneously specified. Computer simulation modeling is currently the most flexible method of manufacturing system analysis. When used in the multi-level design process, two forms of simulation models are encountered, uni-level and multi-level. A simulation model of a manufacturing system is considered uni-level if objects of equivalent type within the system are modeled at the same level of detail. On the other hand, a model is considered multi-level if objects of equivalent type are not modeled at the same level of detail. Unfortunately, current simulation frameworks do not integrate modular construction with the various discrete event and continuous simulation techniques needed to support multi-level modeling. This dissertation describes GIBSS (Generalized Interaction Based Simulation Specification), a simulation framework which supports the modular construction of uni-level and multi-level simulation models. Under GIBSS, the mechanisms and attributes of a manufacturing system simulation are distributed among various classes of independent sub-models. These classes are passive, internal interaction, external interaction, and master simulation. GIBSS describes the mechanics of each of these classes, as well as their method of synchronization. Using GIBSS, sub-models are created, executed, and validated independently, and then brought together to execute in parallel or near parallel fashion. As a result, uni-level and multi-level system simulation models are assembled from multiple sub-models. GIBSS eliminates a barrier to the rapid evaluation of manufacturing system designs. It facilitates the multi-level design process, and is the basis of a research effort, dedicated to the development of a new generation of computer-aided manufacturing system design environments. / Ph. D.

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