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Mätsystemanalys för kontrollmätning av stiftshåldiameter på en borrkronaGallego, Julio January 2016 (has links)
Detta examensarbete har utförts på Sandvik Mining and Construction Tools AB (SMC) och hade som uppdrag att införa arbete med statistisk processtyrning (SPS) vid en produktionscell. Innan implementering av SPS tekniker krävs det en säkerställning av mätsystemets tillförlitlighet. Målet med arbetet är att genom en mätsystemanalys (MSA) utvärdera den befintliga mätmetodens duglighet och erbjuda berörd personal vid SMC en ny mätmetodsmodell om den befintliga mätmetoden fallerar. Metoden som användes för att utföra MSA var en fallstudie. Analysen genomfördes med hjälp av olika förbättringsarbetssätt inom Sex sigmas metodik som till exempel DMAIC-förbättringscykel och fiskbensdiagram. Underlagen för studien baserades på kvantitativa- och kvalitativa data. Insamling av kvantitativa data utfördes med hjälp av strukturerade observationer medan kvalitativa data samlades in med hjälp av en nulägesanalys, individuella intervjuer, benchmarking och litteraturstudie. Arbetet består av 3 analyser utförda på två olika mätsystem. Resultatet pekade på att de befintliga mätsystemen inte var tillförlitliga nog för att kunna användas i produktionen hos SMC. Mätsystem 1 (mätmaskinen) exkluderades från vidare analyser på grund av tidsbrist för att kunna genomföra förbättringar på det. Mätsystem 2 gick igenom en förbättringsfas där flera grundorsaker till variationer i processen analyserades och förbättrades. Dessvärre blev mätsystemet fortfarande odugligt för att användning i produktionen. Med hjälp av matematiska och statistiska beräkningar fastställdes det att mätmaskinen är det lämpligaste mätsystem att använda inom produktionen hos SMC. Det kan betyda att mätsystemets acceptans är beroende av mätinstrumentet. / This essay has been carried out at Sandvik Mining and Construction Tools AB (SMC). The purpose of study was to introduce the statistical process control methodology (SPC) at the actual production cell. Before the implementation of SPC-techniques, it is required an analysis to ensure the measurement systems reliability. The objective of the work is that through a measurement system analysis (MSA) evaluate the existing measurement method capability and provide the relevant personnel at SMC with a new measurement model if the existing measurements methods fails. The method used to perform the MSA was a case study. The analysis was performed using various improvement works within Six-Sigma methods such as DMAIC improvement cycle and fishbone diagram. The study was based on quantitative and qualitative data. Collection of quantitative data was performed using structured observations while qualitative data was assembled by means of a situation analysis, individual interviews, benchmarking and a literature review. The work consists of three studies performed on two different measurement systems. The results indicated that the existing measurement systems were not reliable enough to be used in the SMC production. Measuring system 1 (measuring machine) were excluded from further analysis because of insufficient time to carry out improvements on it. Measuring system 2 went through a development phase where several causes of variations in the process were analyzed and improved. Unfortunately, the measurement system was still unfit for use in production. With the help of mathematical and statistics calculations, it was determined that the measuring machine is the most appropriate measurement system to use in the SMC production process. This could mean that the measurement system acceptance is dependent on the measuring instrument
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Statistický monitoring pevnostních vlastností hliníkuTymová, Jana January 2019 (has links)
This diploma thesis deals with statistical monitoring of strength properties of aluminium. The theoretical part is focused on the description of mechanical properties of aluminium, the influence of corrosion on aluminium and its alloys, the use of aluminium in various industries. Furthermore, the theoretical part presents statistical monitoring with a focus on the Minitab program. In the practical part there is experimental measurment which includes the comparison of results, in which the tensile properties of aluminium not influenced by corrosion are compared with effects of the corrosion bath,with impacted samples that were in the corrosion chamber for 300, 500 and 700 hours. Furthermore, there are presented various statistical methods for evaluation of tensile test results.
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Neparametrické testy v statistickém software / Nonparametric tests in statistical softwareSkolil, Lukáš January 2007 (has links)
Cílem této diplomové práce je praktické i teoretické seznámení uživatelů neparametrických metod s několika vybranými statistickými programy, v nichž je možné neparametrické analýzy provádět. Nedílnou součástí cíle je i porovnání těchto programů. V teoretické části jsou stručně popsány základy testování statistických hypotéz a teorie neparametrických testů. V praktické části jsou prozkoumány programy NCSS 2007, Statistica 7, SPSS 15, Systat 12, Stagraphics Centurion XV, Minitab 15, S-Plus 6.2, SAS 9.1 a StatXact 7. U každého software jsou popsány neparametrické testy, které obsahuje, a zjednodušeně i vkládání dat a výstupy. Nakonec jsou vybrané programy porovnány z několika hledisek. Všechny vybrané programy obsahují značné množství neparametrických testů a liší se většinou jen v detailech. Pro většinu analýz není potřeba hledat speciální programy a dají se použít všechny vybrané, pouze pro porovnávání rozptylů je nutné použít buď SAS nebo StatXact, protože v jiných programech ve výběru tyto testy nenalezneme.
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A Study of Solder Ball Deformation for Ball Grid Array Package Under Burn-In StressHsiao, Chia-ping 16 January 2007 (has links)
ABSTRACT
This thesis gathered the actual Burn-In (BI) data from one of the leading cooperation in the semiconductor industry, and analyzed the major factors¡¦ impact on BGA package solder ball deformation. The Taguchi Method was used for these analyses, and the commercial statistic software MiniTab14 was widely used on this thesis. The solder ball stress was analized by using the commercial FEM software Ansys 8.1.
Some electrical characters (such as device power) can be only observed from Burn-In process, but not static acceleration tests. These effects were fully discussed in this thesis. The analyses got the result that the smaller solder ball pitch/solder ball diameter causes the more serious solder ball deformation under the specific socket vendor precondition. Burn-In time are also a significant factor for solder deformation. Basically the longer BI time cause the more serious solder deformation. The device power effect is not significant within the power sampling range of this thesis.
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Svavelhaltsmätning av bränd kalk från RättvikMakhmour, Salim, Thunström, Robert January 2016 (has links)
This thesis project was carried out by two students on behalf of SMA Mineral AB, which owns the lime plant in Rättvik, where there was need to establish a sampling method for the local quick lime product. The aim was to ensure a maximum concentration of impurities in the product—primarily carbon and sulphur. The mean value of sulphur found in the input material varied over time. Consequently, a suitable statistical method was needed to ensure product quality for the prospective customer as they required that the sulphur content of the proposed product never exceed 500 ppm.The aim was, on the one hand, to process and compile the sampling results in accordance with a suitable statistical method which enabled reasonable conclusions about the product quality and, on the other hand, to answer three key queries that SMA Mineral AB posed:• to investigate whether the product’s sulphur content was affected during conveyance through the lime plant;• to investigate whether sampling at various time intervals may have been a factor which affected the product’s sulphur content;• to investigate whether there was, or were, any particular times of day at which the sulphur content always maintained the correct level.A number of phases were required to find answers to these questions. The planning phase was initiated by a visit to Rättvik, with the purpose of gaining an overall picture of how work at the plant was conducted as well as which guidelines and regulations were in effect. After this visit, a project plan was drawn up in order to serve as support for further work.The sampling campaign took place during the period of 13–16 April 2015 and analysis of the collected material was carried out the following week at the company’s laboratory in Persberg, Sweden. However, the results from the sampling campaign did not provide sufficient basis for answering the company’s questions, which is why data from SMA Mineral AB’s own data collection was used. Data collected during the sampling campaign proved to follow normal distribution. Subsequently, the statistical analysis of variance method, ANOVA, was applied in order to investigate whether the sulphur content changed with respect to the time interval and the sampling site. The test results demonstrated p-values under 0.005, which meant that neither the sampling site nor the sampling time intervals had an effect on the product’s sulphur content. The company’s question, whether there were daily time intervals of acceptable sulphur content in the product, was answered with the assistance of the company’s own data collection, which demonstrated that it did not follow normal distribution. For that reason, the bootstrap method was used to create confidence intervals for the different points in time. The result showed that there were no points in time during which acceptable material was produced. One reason for this is the occurrence of a set of deviating values that were observed to have a sulphur content that exceeded 1,000 ppm. This report presents recommendations for various measures independently of any opinions SMA Mineral AB may have concerning the source of these values and whether they can possibly be avoided. / <p>Validerat; 20160612 (global_studentproject_submitter)</p>
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Plánovaný experiment / Design of ExperimentHolec, Tomáš January 2016 (has links)
In this thesis, the design of experiment is studied. Firstly, a theoretic background in mathematical statistics necessary for understanding is built (chapter 2). The design of experiment is then presented in chapters 3 and 4. Chapter 3 is divided into several subchapters in which its brief history is provided as well as its complex theoretic description (basic principles, steps for planning, etc.). Chapter 4 deals with particular types of the design of experiment (Factorial experiments or Response surface design). Simple examples are provided to illustrate the theory in chapters 3 and 4. Last part of the thesis is strictly practical and focuses on an application of the theory for particular data sets and its evaluation (chapter 5).
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Propuesta de mejora para incrementar el nivel de servicio mediante la aplicación de herramientas Lean Service y BPM en una empresa comercializadora de repuestos mecánicosDelgadillo Obregón, Josué Nieri 20 November 2018 (has links)
Las empresas del mercado actual, como las familiares crecen mientras pasan los años, donde aprovechan muy bien la coyuntura del mercado. Sin embargo, con la globalización y el crecimiento de otras empresas, muchas de las empresas familiares comienzan a disminuir su índice de crecimiento, esto por no tener una buena organización interna que permita una mejor administración de los recursos.
Esta propuesta comprende mejorar la estructura interna de la empresa, la cual es una importadora de repuestos mecánicos para los sectores industriales y mineros. Esta mejora se basará desde la recopilación bibliográfica y revisión de casos de estudio, elaboración de mapas, análisis estadísticos y análisis de los resultados que permiten integrar todas las variables que determinara una nueva estructura y nuevos procesos para el crecimiento de la empresa.
Se realizo un análisis de la situación actual que atravesaba la empresa, con diagrama de procesos, análisis del problema, causas, consecuencias e impactos económicos. Donde posteriormente se realizaron análisis cualitativos a las causas raíces y posteriormente un análisis cuantitativo usando el software estadístico MINITAB que corroboraron la inestabilidad e incapacidad de los procesos actuales de la compañía.
Lo antes mencionado se realizó de una manera eficaz, al contar con la data real de la empresa, lo que aporto mucho al análisis.
Posteriormente se definieron las mejoras en los procesos como las estandarizaciones y nuevas estructuras de las áreas en la cadena de valor de la empresa. Esto se corroborará por medio de las simulaciones de los nuevos procesos, los cuales se compararon con los actuales, resultando disminuciones de tiempos en espera. / Companies in the current market, such as families, grow as the years go by, where the market conjuncture takes advantage very well. However, with the globalization and growth of other companies, many of the family businesses decrease their growth rate, this does not have a good organization that allows a better administration of resources.
This proposal includes improving the internal structure of the company, which is an importer of mechanical spare parts for the industrial and mining sectors. This improvement is based on the bibliographic compilation and review of case studies, mapping, statistical analysis and results analysis.
An analysis is made of the current situation that the company went through, the process diagram, the analysis of the problem, the causes, the consequences and the economic impacts. Where a qualitative analysis has been carried out, the causes, the roots, and the quantitative analysis, through the statistical software MINITAB that corroborate the instability and the incapacity of the current processes of the company.
What has been published in an effective way, as well as with the real data of the company, which contributed a lot to the analysis.
Subsequently, improvements in processes such as standardizations and new structures of the areas in the company's value chain will be defined. This will be corroborated by means of the simulations of the new processes, which are compared with the current ones, resulting in the reduction of waiting times. / Tesis
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On Occurrence Of Plagiarism In Published Computer Science Thesis Reports At Swedish UniversitiesAnbalagan, Sindhuja January 2010 (has links)
In recent years, it has been observed that software clones and plagiarism are becoming an increased threat for one?s creativity. Clones are the results of copying and using other?s work. According to the Merriam – Webster dictionary, “A clone is one that appears to be a copy of an original form”. It is synonym to duplicate. Clones lead to redundancy of codes, but not all redundant code is a clone.On basis of this background knowledge ,in order to safeguard one?s idea and to avoid intentional code duplication for pretending other?s work as if their owns, software clone detection should be emphasized more. The objective of this paper is to review the methods for clone detection and to apply those methods for finding the extent of plagiarism occurrence among the Swedish Universities in Master level computer science department and to analyze the results.The rest part of the paper, discuss about software plagiarism detection which employs data analysis technique and then statistical analysis of the results.Plagiarism is an act of stealing and passing off the idea?s and words of another person?s as one?s own. Using data analysis technique, samples(Master level computer Science thesis report) were taken from various Swedish universities and processed in Ephorus anti plagiarism software detection. Ephorus gives the percentage of plagiarism for each thesis document, from this results statistical analysis were carried out using Minitab Software.The results gives a very low percentage of Plagiarism extent among the Swedish universities, which concludes that Plagiarism is not a threat to Sweden?s standard of education in computer science.This paper is based on data analysis, intelligence techniques, EPHORUS software plagiarism detection tool and MINITAB statistical software analysis.
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Matematické modely spolehlivosti v technické praxi / Mathematical Models of Reliability in Technical ApplicationsSchwarzenegger, Rafael January 2017 (has links)
Tato práce popisuje a aplikuje parametrické a neparametrické modely spolehlivosti na cenzorovaná data. Ukazuje implementaci spolehlivosti v metodologii Six Sigma. Metody jsou využity pro přežití/spolehlivost reálných technických dat.
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Statistická podpora procesu řízení firmy / Statistical support of the company management processKubíček, Jan January 2021 (has links)
Master’s thesis describes statistical process control as a support for company management. Statistical process control methods and tools are introduced. Requirements for automotive industry are stated specifically for IATF 16949 standard and VDA 6.3 process audit method. Thesis presents current state in company Sanmina-SCI Czech Republic s.r.o regarding statistical regulation. Applies statistical process controls into the new process considering automotive requirements. It is all happening together with a new business introduction of automotive customer.
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