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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.
61

Robotizované pracoviště pro plnění meziproduktu „Valve cartridge“ silikonem / Robotic workstation for silicon filling of part of “Valve cartridge”

Černý, Jiří January 2015 (has links)
This diploma thesis is focused on robotized technological workstation (RTW) for production of “Valve cartridge” product. The production workstation, studied in the diploma thesis, is located at IMI Precision Engineering company and is focused on silicon filling. In the introduction a present workstation is evaluated and a present status of industrial robots and robotized workstation is analyzed. In main part of the thesis two solutions for robotic automation are designed, with respect of assigned parameters. The final solution is chosen by method of multicriteria decisional analysis. Project documentation is created for chosen variant including manipulation work cycle and block diagram of RTW control. The thesis includes calculation of capital return. At the final part of the thesis ergonomics and safety of workstation is analyzed; the risks of robotized technological workstation components are also evaluated. Technologists and quality engineer requirements are taken into account during working on the thesis.
62

Mitteilungen des URZ 4/1993

Anders, Brose, Grunewald, Mueller, Riedel, Wolf, Ziegler 30 August 1995 (has links)
Neue Server - neue Dienste Backup-Dienst Workstation-Pool Software-Dienste Gopher+ - Informationsdienst Aktuelles zum Netzausbau
63

Flexible Engineering Software: An Integrated Workstation Approach to Finite Element Analysis

Ross, Brant Arnold 01 April 1985 (has links) (PDF)
One obstacle preventing more engineers from using finite element analysis (FEA) is the difficulty of transferring data between steps in the modeling process. A Fortran computer program, Rosetta.BYU, has been developed to open data paths between finite element preprocessors (mesh generators) and finite element analysis programs, using a custom data structure. It accepts neutral data files, Version 2.0 IGES data files, and Movie.BYU files for input/output. An application of Rosetta is described. A general workstation manager program, Davinci.BYU, is reviewed that provides a support layer between the engineer and the operating system, organizes software and data files, and facilitates on-line documentation and demonstrations. Requirements of a good user interface are discussed and supporting software, Squire.BYU, is described. An application of this software in an industrial setting is described.
64

A visualization approach for improved interpretation and evaluation of assembly line balancing solutions

Azamfirei, Victor January 2018 (has links)
Future manufacturing will be characterized by the complementarity between humans and automation (human-robot collaboration). This requires new methods and tools for the design and operation of optimized manufacturing workplaces in terms of ergonomics, safety, efficiency, complexity management and work satisfaction. There have been some efforts in the recent years to propose a tool for determining optimal human-automation levels for load balancing. Although the topic is quite new, it shares some similarities with some of the existing research in the area of robotic assembly line balancing. Therefore, it is crucial to review the existing literature and find the most similar models and methods to facilitate the development of new optimization models and algorithms. One of the two contributions that this thesis gives to the research world in the RALBP context is a literature review that involves high quality articles from 1993 to beginning 2018. This literature review includes visual and comprehensive tables—and a label system— where previous research patterns and trends are highlighted. Visualization of data and results obtained by assembly line optimization tools is a very important topic that has rarely been studied. Data visualization would provide a: 1. better comprehension of patterns, trends and qualitative data 2. more constructive information absorption 3. better visualization of relationships and patterns between operations, and 4. better contribution to data manipulation and interaction. The second contribution to research found in this thesis is the use of a human modelling (DHM) tool (called IPS), which is proposed as an assessment to the ergonomic risk that a robotic assembly line may involve. This kind of studies are necessary in order to reduce one of the most frequent reasons of work absence in our today society i.e. musculoskeletal disorders (MSDs). MSDs are often the result of poor work environments and they lead to reduced productivity and quality losses at companies. In view of the above, IPS was used in order to resolve the load handling problem between human and robot, depending on their skills and availability, while fulfilling essential ISO standards i.e. 15066 and 10218:1 and :2. The literature review made it possible to select highly useful documents in developing assumptions for the experiment and contributed to consider real features detected in the industry. Results show that even though IPS is not capable of calculating an entire robotic assembly with human-robot collaboration, it is able to simulate a workstation constituted of one robot and one human. Finite and assembly motions for both human and robot are expected to be implemented in future versions of the software. Finally, the main advantages of using DHM tools in assessing ergonomic risks in RALB can be extracted from the results of this thesis. This advantages include 1. ergonomic evaluation for assembly motions 2. ergonomic evaluation for a full working day (available in future version) and 3. essential ISO standard testing (available in future version).
65

Utbyte av styrsystem : Projektering, implementering och verifiering / Exchange of PLC control systems : Projection, implementation and authentication

Johansson, Anton, Bigeat, Régis, Kerr, Michael January 2020 (has links)
Sjöfartshögskolan i Kalmar behövde förnya sin programvara för programmerbara styrsystem (PLC), detta ledde till att två styrsystem blev påverkade. Det ena är för att styra och reglera en ångprocess medan den andra används för att styra en simulatortank. Det har tidigare varit relativt svårt för lärare att få studenter att komma igång med programmeringen då det förra systemet var komplext. Linnéuniversitet bestämde sig därför att ett utbyte av styrsystemet för ångprocessen och arbetsstationer var att föredra. Ett viktigt mål var att få arbetsstationerna mindre eftersom antalet stationer kommer utökas. Det framkom under arbetets gång att uppdatering av dokumentation av systemen behövde göras samt en förenkling av växling mellan PLC och regulator. Resultatet är ett system som är kompakt och lättare att hantera. / Kalmar Maritime Academy needed to renew the software for programmable logic controller (PLC). There are two systems that are involved, one is for controlling a steam process and the other a simulation of a cistern. Previously it has been relatively difficult for the teachers to get the students to begin with the programming because the prior system was to complex. Linnaeus University therefore decided that a change of control system for the steam system and workstation was preferable. An important task was to minimize the workstation size because the number of stations are increasing. While performing the work it became apparent that the documentation for the system needed to be updated, and to simplify the switch between PLC and regulator control. The result was a compact and easier system to use.
66

Návrh robotické buňky pro obsluhu vstřikolisů / Design of a Robotic Cell for Injection Molding Machines Operations

Franc, Vladimír January 2019 (has links)
The aim of this thesis is to design a robotic cell for automated injection molding operation. At the beginning of this paper, the input parameters and the assignment are analyzed. This is then followed up by the layout of the workplace, design of its equipment, selection of robots and the design of their end effectors and peripherals with regard to the specified boundary conditions and operator’s safety. The output of this work is a 3D cell model and its simulation model in PLM software Siemens Process Simulate, which verifies the production cycle time.
67

Zvýšení efektivity při svařování pecních konstrukcí / The effectiveness of welding on furnace structures.

Rousová, Michaela January 2010 (has links)
This diploma thesis is resolving all the possibilities of enhancing the efficiency of furnace structures welding. Small batch production does not offer many possibilities for implementing mechanization or automation. On the other hand, when using a big batch production, efficiency can be enhanced by means of a robotic workstation. When the production batch is big enough, we will see a costs save after a short time, mainly in labor costs. This means the return of investments will be in short time period. In the LAC company there are three types of products made. At laboratory furnaces the efficiency can be enhance by using fixtures. At other standard and atypical furnaces is very difficult to design fixtures or positioners because of their different sizes. Big complication can be also a company location on second floor. The most suitable product regarding to welding efficiency enhancement is big batch production of heaters. For this type the welding time can be shortened by means of a robotic workstation.
68

Rediseño de Puesto de Trabajo Utilizando Técnicas Ergonómicas para Reducir los Trastornos Musculoesqueléticos en una Empresa de Confección de Prendas de Vestir / Redesign of Workstation Using Ergonomic Techniques to Reduce Musculoskeletal Disorders in a Textile Company

Miranda Rodríguez, Brenda Ximena, Sáenz Julcamoro, Luis Antonio 14 December 2020 (has links)
La industria de confección textil tiene gran relevancia, particularmente en los países en desarrollo como Perú, ya que ocupa el segundo lugar con respecto al sector que más aporta al PBI en el ámbito manufacturero. En el 2019 los problemas del sector textil representaron el 19% del sector manufacturero, de los cuales el 25.4 % eran problemas de trastornos musculo esqueléticos (TME), esto debido a las malas prácticas y un inadecuado diseño de estaciones de trabajo. La importancia de trabajar en un adecuado ambiente laboral está relacionada directamente a la prevención de Desórdenes Músculo Esqueléticos (DME) y a las Ausencias Laborales. En varios estudios se señala la importancia de un adecuado diseño, así como el correcto uso de metodologías ergonómicas, para poder evaluarlos y validarlos; sin embargo, estos se enfocan en la validación de la metodología y no del proceso que abarca desde la formulación de propuestas hasta la validación de estas. Es por ello, que el presente estudio está enfocado en un modelo de rediseño de estación de trabajo que abarca desde las propuestas de diseño hasta la validación del mismo; utilizando técnicas ergonómicas observacionales como REBA, RULA, NIOSH y SNOOK Y CIRIELLO, y herramientas de ingeniería como Sistema de Manipulación de Materiales (SMM), Estudio de Métodos, Técnica de Interrogatorio Sistemático (TIS) y Economía de Movimientos. Como resultados se obtuvieron un 51.68 % de reducción de los TME en los puestos de trabajo de Tendido, Remalle y en el proceso de Abastecimiento de Rollo; asimismo, una reducción de 364 horas de ausentismo y un ahorro de 6,000 soles por año aproximadamente. / The textile industry is highly relevant, particularly in developing countries such as Peru, as it ranks second place with respect to the sector that contributes the most to GDP in the manufacturing field. In 2019, textile sector problems represented 19% of the manufacturing sector, of which 25.4% were problems of Musculoskeletal Disorders (MSD), this due to bad practices and an inadequate design of workstations. The importance of working in a suitable work environment is directly related to the prevention of Musculoskeletal Disorders (MSD) and Work Absences. Several studies point out the importance of an adequate design, as well as the correct use of ergonomic methodologies, to be able to evaluate and validate them; however, these focus on the validation of the methodology and not on the process that ranges from formulating proposals to validating it. For this reason, this study focuses on a model of redesign of the workstation that ranges from design proposals to validation of the same; using observational ergonomic techniques such as REBA, RULA, NIOSH and SNOOK AND CIRIELLO, and engineering tools such as Materials Handling System (MHS), Method Study, Systematic Interrogation Technique (SIT) and Movement Economics. As a result, a 51.68% reduction of the MSD was obtained in the jobs of “Tendido”, “Remalle” and in the process of “Abastecimiento de Rollo”; likewise, a reduction of 364 hours of absenteeism and a saving of 6,000 soles per year approximately. / Trabajo de Suficiencia Profesional
69

Empirical Evaluation of a Technology-rich Learning Environment

McCreary, Faith 02 November 2001 (has links)
In the fall of 1996, the Computer Science Department at Virginia Tech initiated a joint project with a local school district, to determine how ready access to networked computing in the fifth grade would affect students. Called the PCs for Families (PCF) project, its goal was to learn what could be achieved if technology access, support, and curriculum integration could be eliminated as obstacles or constraints in the classroom and at home. A technology-rich classroom was created, with the classroom teacher trained in constructivist teaching practices and technology integration by a master teacher. Network computers were found on every desktop, with scanners, digital cameras, and other technologies scattered throughout the room. A computer was sent home with each child and teacher, and as much support as necessary was provided to all program participants, including parents. As part of this research, a yearlong field experiment was undertaken to explore the effects of the PCF intervention on the third cohort of students participating in the project. Macroergonomics served as the theoretical framework for the experiment, which focused on the in-depth, systematic assessment of those quantitative changes that resulted from exposure to the PCF fifth-grade network classroom. Students participating in the field research were randomly selected from the larger pool of students eligible for the PCF project at the school. Selected students were randomly assigned to either to the PCF fifth-grade classroom or the standard fifth-grade classroom, which served as a control group. To first-time visitors walking into the PCF network classroom, the classroom bore little resemblance to its more traditional counterparts. However, the functioning of the PCF classroom was in many ways indistinguishable from that of its traditional counterparts. The yearly average for computer use in the PCF classroom was 4.275 hours, with computer use in the PCF classroom exceeding the three hours of computer laboratory time allotted to the control class only during the last 12 weeks of school. When used, the technology functioned as an electronic replacement for materials commonly found in traditional settings. Observers reported the pedagogy remained steadfastly teacher-centered and didactic. Despite limited utilization of the computer during classroom hours, analysis of individual, academic measures indicated PCF students made significantly greater gains than control students only on standardized writing tests. PCF students also performed significantly better than control students on measures related to technology skills. Boys in the PCF classroom also made greater improvements in their attitudes towards school than boys in the control classroom. At home, PCF students were found to interact with computer technology more often than their control counterparts. Despite lower overall home use, control students reported spending more time playing computer games than PCF students. Correlational analyses indicated significant linear relationships between changes in student performance, student entry characteristics, and home computer use variables. Student previous achievement was by far the strongest predictor of student SOL test performance, with computer use only linked to student standardized test performance on the writing and mathematics sections. As the number of email messages sent by the student increased, their writing performance increased with email usage accounting for almost ten percent of the total variance in the writing score. The only other computer use measure significantly associated with test performance was student self-reports of computer use, which accounted for less than four percent of the total variance in mathematics test performance. Computer use was associated more strongly with changes in student motivation. Student self-reports of home computer use accounted for fully 30 percent of the variance in changes on the school motivation survey. Analyses of data from the PCF proxy server suggest that student web browsing overshadows other home Internet activities, with email taking precedence over chat. Further, unlike chat or email, family web usage was sustained long after students left the PCF classroom. Over 68 percent of family web usage each week was attributable to student, not family, characteristics suggesting students play a large role in determining family usage. Academic information finding provides a plausible explanation for these results, with family web usage declining somewhat during summer months when students were not in school. Stability of both web and email use was relatively high among students. In keeping with critical mass theory, student email use increased when other students used email. However, social variables were not found to have a significant effect on web usage. Girls were found to make greater use of email than boys, with this research suggesting highly visual students used email more often. The field research also found a significant increase in student self-reports of musculoskeletal problems among the PCF students. A year-end examination of workstation fit found seat and monitor heights an average of two inches higher than the corresponding student dimensions. A participatory design study was used to elicit conceptions of computer workstations from PCF students, teachers, and parents. Children were interested in gaining greater control over the workstation, both in terms of individual technology and adjustability of furniture. Parents, however, focused on improving the richness of an individual student's workspace and de-emphasized collaborative work. Teacher opinions diverged more than other groups with designs strongly influenced by pedagogic beliefs. Results from the field study provide evidence that macroergonomic methodologies for analysis and design of work systems are extensible to classroom systems, and provide a systematic framework for examining issues related to the introduction of classroom computing technology. A critical element of any successful effort to integrate technology into the curriculum is access to adequate classroom technology and support; however, as this research illustrates, they are not sufficient to ensure successful integration. This research demonstrates other forces are at work, and in keeping with macroergonomic theory, key to the success of such an effort is the "fit" between the new technology and the characteristics of the classroom system, especially those of the teacher who effectively functions as the gatekeeper for the technology. / Ph. D.
70

Radiologisten kuvien katselussa käytettävien näyttöjen laatu:näyttöjen laitekanta, suorituskyky ja laadunvalvonta sekä kuvankatseluolosuhteet radiologisissa yksiköissä ja terveyskeskuksissa

Liukkonen, E. (Esa) 08 June 2010 (has links)
Abstract The purpose of this study was to investigate the quality of displays at radiology departments and healthcare centers, viewing conditions, quality control practices and user experiences of viewing radiological images from displays during 2007. The study aimed to provide guidelines to improving the quality of image viewing from displays and viewing conditions in healthcare. The data was gathered from radiology departments at university hospitals in Finland and healthcare centers in the treatment area of responsibility of the Oulu University Hospital. Display technology, quality control practices and users experiences of viewing were determined using questionnaires. Technical measurements were performed in order to acquire information on displays performance and viewing conditions. In addition, observation was used to evaluate viewing conditions. Almost all displays at radiological departments were applicable for diagnostics. At healthcare centers all displays were inapplicable for diagnostics. Both organization groups had displays using obsolete cathode ray tube technology and these displays did not pass current acceptance criteria. Most radiology departments had viewing conditions which were compatible with existing guidelines, whereas at healthcare centers lighting conditions were too bright for viewing radiological images from displays. Acceptance testing was done only for few of the displays and quality control was not performed regularly. Personnel responsible for quality assurance felt they were provided with inadequate resources for performing display quality control. Clinicians at healthcare centers did not identify the poor performance of displays. Radiologists and clinicians at healthcare centers rarely performed quality assurance for displays. The quality of displays, viewing conditions and the assessment of display performance at healthcare organizations was not at the level required by the existing guidelines. Both the cathode ray tube displays and uncalibrated liquid crystal displays should either be replaced with new ones or calibrated. Lighting and positioning of displays ought to be rearranged in order to diminish reflections. Furthermore, doctors ought to be able to rearrange lighting conditions with ease. More resources ought to be directed to display quality control and different quality control practices should be unified. Both the users and the quality control personnel should also be provided with more training in display quality control. Regular display quality control should be extended to all healthcare organizations. Clinicians working at healthcare centers should be provided with adequate training in the use of image viewing software. / Tiivistelmä Tämän tutkimuksen tarkoituksena oli selvittää vuoden 2007 aikana radiologisten yksiköiden ja terveyskeskusten radiologisten kuvien katseluun tarkoitettujen näyttöjen laatu, kuvankatseluolosuhteet ja laadunvalvontakäytännöt sekä käyttäjien kokemuksia röntgenkuvien katselusta näytöiltä. Tutkimuksen tavoitteena oli antaa toimenpide-ehdotuksia kuvankatselun ja kuvankatseluolosuhteiden kehittämiseksi terveydenhuollossa. Aineisto muodostui otoksesta viiden yliopistollisen sairaalan radiologisista yksiköistä ja Oulun yliopistollisen sairaalan erityisvastuualueen terveyskeskuksista. Näyttöjen laitekanta, laadunvalvontakäytännöt ja lääkäreiden kokemuksia näyttötyöskentelystä selvitettiin kyselyllä. Mittausten ja havainnoinnin avulla saatiin tietoa näyttöjen suorituskyvystä ja kuvankatselutilojen valaistusolosuhteista. Radiologisten yksiköiden näytöt olivat teknisesti pääosin radiologisista kuvista tehtävään diagnostiikkaan soveltuvia. Terveyskeskuksissa käytettiin näyttöjä, jotka eivät soveltuneet diagnostiikkaan. Molemmissa ryhmissä poistuvaan katodisadeputkitekniikkaan perustuvia näyttöjä oli vielä käytössä, eikä yksikään mitatuista näytöistä saavuttanut hyväksyttävyyskriteereitä kaikkien suorituskyvyn mittaustulosten osalta. Suurimmassa osassa radiologisten yksiköiden työpisteissä huoneen valaistus oli suositusten mukainen, kun taas terveyskeskuksissa huoneiden valaistus oli liian voimakas radiologisten kuvien katseluun käytetyillä näytöillä. Vastaanottotarkastus oli tehty vain pienelle osalle näytöistä ja säännöllistä laadunvalvontaa tehtiin näytöille vähän. Laadunvalvojat kokivat resurssit riittämättömiksi näyttöjen laadunvalvontaan. Terveyskeskuslääkärit eivät itse tunnistaneet näytön huonoa suorituskykyä. Radiologit ja terveyskeskuslääkärit tekivät laadunvalvontaa käyttämilleen näytöille hyvin vähän. Tutkimuksen kohteena olleissa radiologisissa yksiköissä ja terveyskeskuksissa röntgenkuvien katseluun tarkoitettujen näyttöjen laatu, valaistusolosuhteet ja laadunvalvonta eivät vastanneet suosituksia. Katodisädeputkinäytöt ja kalibroimattomat nestekidenäytöt tulisi vaihtaa uusiin tai kalibroida. Valaistusta ja näyttöjen sijoittelua tulisi muuttaa heijastusten vähentämiseksi. Lisäksi lääkärillä tulisi olla mahdollisuus muuttaa valaistusta helposti. Näyttöjen laadunvalvontaan tulisi saada enemmän resursseja, laadunvalvontakäytännöt tulisi yhtenäistää ja käyttäjille sekä laadunvalvojille tulisi antaa lisää koulutusta näyttöjen laadunvalvontaan. Säännöllinen näyttöjen laadunvalvonta tulisi ulottaa kaikkiin terveydenhuollon organisaatioihin. Terveyskeskuslääkäreille tulisi antaa koulutusta kuvankatseluohjelmien käyttöön.

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