991 resultados para polymer coil shrinking theory


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After decades of mergers and acquisitions and successive technology trends such as CRM, ERP and DW, the data in enterprise systems is scattered and inconsistent. Global organizations face the challenge of addressing local uses of shared business entities, such as customer and material, and at the same time have a consistent, unique, and consolidate view of financial indicators. In addition, current enterprise systems do not accommodate the pace of organizational changes and immense efforts are required to maintain data. When it comes to systems integration, ERPs are considered “closed” and expensive. Data structures are complex and the “out-of-the-box” integration options offered are not based on industry standards. Therefore expensive and time-consuming projects are undertaken in order to have required data flowing according to business processes needs. Master Data Management (MDM) emerges as one discipline focused on ensuring long-term data consistency. Presented as a technology-enabled business discipline, it emphasizes business process and governance to model and maintain the data related to key business entities. There are immense technical and organizational challenges to accomplish the “single version of the truth” MDM mantra. Adding one central repository of master data might prove unfeasible in a few scenarios, thus an incremental approach is recommended, starting from areas most critically affected by data issues. This research aims at understanding the current literature on MDM and contrasting it with views from professionals. The data collected from interviews revealed details on the complexities of data structures and data management practices in global organizations, reinforcing the call for more in-depth research on organizational aspects of MDM. The most difficult piece of master data to manage is the “local” part, the attributes related to the sourcing and storing of materials in one particular warehouse in The Netherlands or a complex set of pricing rules for a subsidiary of a customer in Brazil. From a practical perspective, this research evaluates one MDM solution under development at a Finnish IT solution-provider. By means of applying an existing assessment method, the research attempts at providing the company with one possible tool to evaluate its product from a vendor-agnostics perspective.

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Kirjallisuusarvostelu

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Tutkimuksen tarkoituksena on laadullisin menetelmin syventää tietoa työikäisten (28–60-vuotiaiden) suomalaisten kvantitatiivisesti mitatun koherenssin tunteen takana olevista tekijöistä. Tutkimuksella halutaan tuottaa aineistolähtöisesti tietoa siitä, mitkä käsitteet kuvaavat tutkittavien kerrottujen elämänkokemusten kautta selvitettyä koherenssin tunnetta ja samalla lisäämään ymmärrystä Antonovskyn salutogeenisesta teoreettisesta mallista. Tutkimukseen osallistuneet olivat Health and Social Support tutkimukseen vuosina 1998 ja 2003 osallistuneita. Koko kyseinen tutkimusotos edusti vuonna 1998 20–24, 30–34, 40–44 ja 50–54 -vuotiasta Suomen väestöä. Tutkimuksen metodina käytettiin glaserilaista grounded theory -metodologiaa. Tutkimuksen aineistonkeruu toteutettiin kolmessa eri vaiheessa. Ensimmäisessä vaiheessa haastateltiin 27 tutkittavaa. Toisessa vaiheessa haastateltavilta kerättiin lisäaineistoa kirjallisesti. Kahdeksan vastasi tähän pyyntöön. Kolmannessa vaiheessa haastateltiin seitsemää. Haastattelujen yhteydessä haastateltavat täyttivät koherenssin tunteen mittarin (13-osainen). Aineisto analysoitiin koherenssipisteiden mukaisesti kolmena eri aineistona. Tulokseksi saatiin substantiivinen teoria. Tutkimuksen tuloksena kuvattiin sosiaalinen perusprosessi, joka nimitettiin Elämän kokonaisuudeksi tässä hetkessä. Sosiaalisen perusprosessin sisällä on typologia. Jokaisesta koherenssipisteryhmästä muodostettiin oma typologia. Kukin typologia sisälsi neljä tyyppiä. Sosiaalisen perusprosessin vaiheet olivat: ehdot tämän hetken taustalla, eläminen ehtojen varassa ja uusia luoden (tietynlainen ihminen, eläminen tässä hetkessä, kokonaisnäkemys elämästä) sekä jatkaminen ehtojen varassa ja uusia luoden. Typologiat ovat nimeltään eheät, pärjäävät ja sinnittelijät. Haastateltavien kokemuksia ei analyysivaiheessa pyritty liittämään tiettyyn kontekstiin, vaan ne liittyivät toimintaan ja käyttäytymiseen. Tulosten tarkasteluvaiheessa tehtiin kuitenkin lyhyt kuvaus elämänkulkututkimuksesta sekä sosiaalisesta ja kulttuurisesta ympäristöstä. Tutkimustulokset ovat kuvailevia ja niiden perusteella saadaan viitteitä siitä, millaiset asiat ovat yhteydessä koherenssin tunteeseen ja millä tavalla yhteys rakentuu. Saatu substantiivinen teoria on pätevä tässä aineistossa. Tulokset noudattelevat Antonovskyn salutogeenista teoreettista mallia siltä osin, että mitä korkeammat koherenssipisteet olivat, sitä enemmän typologiassa oli eheyttä lisääviä tekijöitä. Eheys tuo elämään henkistä liikkumavaraa, jota typologian tyypit (rakentava, ilmavasti elävä, elämänmyönteinen, juureva realisti) ilmentävät. Typologioiden kuvauksista voidaan lukea, että kaikissa tyypeissä kuvataan vaikeita elämänkokemuksia. Olennaista on se, miten näihin vaikeuksiin suhtaudutaan. Eheillä on parhaat edellytykset käsitellä elämän haasteita. Voidaan kuitenkin todeta, että kaikki tähän tutkimukseen osallistuneet olivat selviytyjiä.

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This thesis attempts to fill gaps in both a theoretical basis and an operational and strategic understanding in the areas of social ventures, social entrepreneurship and nonprofit business models. This study also attempts to bridge the gap in strategic and economic theory between social and commercial ventures. More specifically, this thesis explores sustainable competitive advantage from a resource-based theory perspective and explores how it may be applied to the nonmarket situation of nonprofit organizations and social ventures. It is proposed that a social value-orientation of sustainable competitive advantage, called sustainable contributive advantage, provides a more realistic depiction of what is necessary in order for a social venture to perform better than its competitors over time. In addition to providing this realistic depiction, this research provides a substantial theoretical contribution in the area of economics, social ventures, and strategy research, specifically in regards to resource-based theory. The proposed model for sustainable contributive advantage uses resource-based theory and competitive advantage in order to be applicable to social ventures. This model proposes an explanation of a social venture’s ability to demonstrate consistently superior performance. In order to determine whether sustainable competitive advantage is in fact, appropriate to apply to both social and economic environments, quantitative analyses are conducted on a large sample of nonprofit organizations in a single industry and then compared to similar quantitative analyses conducted on commercial ventures. In comparing the trends and strategies between the two types of entities from a quantitative perspective, propositions are developed regarding a social venture’s resource utilization strategies and their possible impact on performance. Evidence is found to support the necessity of adjusting existing models in resource-based theory in order to apply them to social ventures. Additionally supported is the proposed theory of sustainable contributive advantage. The thesis concludes with recommendations for practitioners, researchers and policy makers as well as suggestions for future research paths.

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Insufficient understanding of entrepreneurial opportunities characterizes entrepreneurship research (Companys & McMullen 2006, 302). Subsequently, the purpose of this study was to analyze the concept of entrepreneurial opportunity and to explore and synthetize the integrated theory of entrepreneurial opportunity. A theoretical and concept analytical approach was adapted. Findings of this study was that entrepreneurial opportunity concept was used for variety of different phenomena. No commonly accepted definition existed. Altogether 24 attributes that described the concept were found. The most frequently attached attributes were agent and action, new goods and services, market, value, new means ends or both, and future. Further, the results implied that opportunity could be best understood as a part of a process. Opportunity emerges out of intervened factors. Changes in the environment together with factors related to knowledge, cognition and social ties are the most important drivers of opportunity. Preventing factors that impeded the emergence of opportunity were typically related to cognitive and organizational factors. This study found a tendency towards more integrated theory of entrepreneurial opportunity. The integrated theory acknowledged the usefulness of both discovery and creation theories of opportunity in explaining opportunity. Yet three argument types of integrating two different opportunity theories were identified. These were process category, contextual category and complementing category. Opportunity is at the same time cognitive, social and linguistic construct, although it is shaped by the objective environment. Opportunity requires linguistic endeavors to become explicit. Materialization of opportunity occurs in a social context. Moreover, it is always characterized by some extent of subjectivity, as opportunities cannot appear without the agent and their action. Due to these the concept remains always to some extent ambiguous. Tolerating and harnessing change and investing in human and social capital create the preeminent environment for the entrepreneurial opportunity to be identified.

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Papper kan anses vara ett av de mest använda materialen i det dagliga livet. Tidskrifter, tidningar, böcker och diverse förpackningar är några exempel på pappersbaserade produkter. Papperets egenskaper måste anpassas till användningsändamålet. En tidskrift kräver t.ex. hög ljushet, opacitet och en slät yta hos papperet, medan dessa egenskaper är mindre viktiga för en dagstidning. Allt tryckpapper behöver vissa mekaniska egenskaper för att tåla vidarebearbetning såsom kalandrering, tryckning och vikning. Man kan bestryka papper för att förbättra dess optiska egenskaper och tryckbarhetsegenskaper. Vid bestrykning appliceras en dispersion av mineralpigment och polymerbindemedel som ett tunt lager på papperets yta. Bestrykningsskiktet kan ses som ett komplext, poröst kompositmaterial som även bidrar till papperets mekaniska egenskaper och dess processerbarhet i diverse konverteringsoperationer. Kravet på framställning av förmånligt papper med tillräckliga styrkeegenskaper ställer allt högre krav på optimeringen av pappersbestrykningsskiktets egenskaper och produktionskostnader. Målet med detta arbete var att förstå sambandet mellan pigmentbestrykningsskiktets mikrostruktur och dess makroskopiska, mekaniska egenskaper. Resultaten visar att adhesionen i gränsytan mellan pigment och bindemedel är kritisk för bestrykningsskiktets förmåga att bära mekanisk belastning. Polära vätskor är vanliga i tryckfärger och kan, eftersom de påverkar syra/bas-interaktionerna mellan pigment och latexbindemedel, försvaga denna adhesion. Resultaten tyder på att ytstyrkan hos bestruket papper kan höjas genom användning av bifunktionella dispergeringsmedel för mineralpigment. Detta medför inbesparingar i pappersproduktionen eftersom mängden bindemedel, den dyraste komponenten i bestrykningsskiktet, kan minskas.

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Työn tavoitteena on selvittää mitä on grounded theory, miten se on sovellettavissa akateemisissa julkaisuissa ja miten eri julkaisujen grounded theory -tutkimukset eroavat toisistaan. Työ on toteutettu järjestelmällisesti analysoimalla neljän markkinointia käsittelevän lehden julkaisemat GT-tutkimukset vuosina 2000-2012. Tuloksina havaitaan lehdille tyypillisiä ominaispiirteitä. Tarkastelun kohteena ovat tutkimusotannat, tutkimusprosessit, tutkimusten aihealueet sekä tutkimuksissa esitetyt lopputulokset. Lisäksi työssä tarkastellaan havaittuja trendejä grounded theory tutkimuksissa sekä pohditaan tutkimusmenetelmän tulevaisuutta. Perinteinen GT-tutkimus on tietyissä akateemisissa lehdissä yhä yleisesti käytetty menetelmä, mutta sen soveltava käyttö, sekä monimenetelmäiset tutkimukset ovat selvässä kasvussa.

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In this paper, a systematic and quantitative view is presented for the application of the theory of constraints in manufacturing. This is done employing the operational research technique of mathematical programming. The potential of the theory of constraints in automated manufacturing is demonstrated.

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Fiber reinforced polymer composites have been used in many applications, such as in automobile, aerospace and naval industries, due basically to their high strength-to-weight and modulus-to-weight, among other properties. Even though particles are usually not able to lead to the level of reinforcement of fibers, particle reinforced polymer composites have been proposed for many new applications due to their low cost, easy fabrication and isotropic properties. In this work, polymer composites were prepared by incorporating glass particles of different morphologies on poly(aryl sulfones) matrices. Particles with aspect ratios equal to 1, 2.5 and 10 were used. The prepared composites were characterized using electron microscopy and thermal analysis. Mechanical properties of the composites were evaluated using a four-point bending test. The thermo-mechanical behavior of the obtained composites was also investigated. The results showed that the morphology of the particles alter significantly the mechanical properties of composites. Particles with larger values of aspect ratio led to large elastic modulus but low levels of strain at failure. This result was explained by modeling the thermo-mechanical behavior of the composites using a viscoelastic model. Parameters of the model, obtained from a Cole-Cole type of plot, demonstrated that interactions at the polymer-reinforcing agent interface were higher for composites with large aspect ratio particles. Higher levels of interactions at interfaces can lead to higher degrees of stress transfer and, consequently, to composites with large elastic modulus, as experimentally observed.

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This doctoral thesis presents a study on the design of tooth-coil permanent magnet synchronous machines. The electromagnetic properties of concentrated non-overlapping winding permanent magnet synchronous machines, or simply tooth-coil permanent magnet synchronous machines (TC-PMSMs), are studied in details. It is shown that current linkage harmonics play the deterministic role in the behavior of this type of machines. Important contributions are presented as regards of calculation of parameters of TC-PMSMs,particularly the estimation of inductances. The current linkage harmonics essentially define the air-gap harmonic leakage inductance, rotor losses and localized temporal inductance variation. It is proven by FEM analysis that inductance variation caused by the local temporal harmonic saturation results in considerable torque ripple, and can influence on sensorless control capabilities. Example case studies an integrated application of TC-IPMSMs in hybrid off-highway working vehicles. A methodology for increasing the efficiency of working vehicles is introduced. It comprises several approaches – hybridization, working operations optimization, component optimization and integration. As a result of component optimization and integration, a novel integrated electro-hydraulic energy converter (IEHEC) for off-highway working vehicles is designed. The IEHEC can considerably increase the operational efficiency of a hybrid working vehicle. The energy converter consists of an axial-piston hydraulic machine and an integrated TCIPMSM being built on the same shaft. The compact assembly of the electrical and hydraulic machines enhances the ability to find applications for such a device in the mobile environment of working vehicles.Usage of hydraulic fluid, typically used in working actuators, enables direct-immersion oil cooling of designed electrical machine, and further increases the torque- and power- densities of the whole device.

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In this paper is Analyzed the local dynamical behavior of a slewing flexible structure considering nonlinear curvature. The dynamics of the original (nonlinear) governing equations of motion are reduced to the center manifold in the neighborhood of an equilibrium solution with the purpose of locally study the stability of the system. In this critical point, a Hopf bifurcation occurs. In this region, one can find values for the control parameter (structural damping coefficient) where the system is unstable and values where the system stability is assured (periodic motion). This local analysis of the system reduced to the center manifold assures the stable / unstable behavior of the original system around a known solution.

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Kirjallisuusosassa tarkastellaan ligniiniä luonnon polymeerinä sekä sen kemiallisia perustietoja. Aiheena on myös sen tuotanto ja käyttö uusiutuvana raaka-ainelähteenä energian-, materiaali- ja kemikaalituotantoon sekä niiden mahdolliset tulevaisuudennäkymät. Mekaanisten prosessien osalta keskitytään kiintoaineen hienontamiseen. Lisäksi perehdytään planeettamyllyn toiminnan teoriaan sekä tuoreimpiin tutkimuksiin planeettamyllyjauhatukseen liittyen. Työn kokeellisen osan tarkoituksena oli tutkia ligniinin jauhautuvuutta, sillä partikkelien pienentämisellä voidaan kasvattaa ligniininijauheen ominaisalaa ja tasoittaa sen kokojakaumaa. Jauhautuvuuden avulla voidaan esimerkiksi arvioida ligniinille tehtävän hienojauhatuksen kannattavuutta jatkoprosesseja varten. Tutkimuskysymyksinä oli ”kuinka hyvin ligniini jauhautuu planeettamyllyllä?”, ”onko kylmäkäsittelyllä vaikutusta jauhatustulokseen?”, ”miten eri parametrit (jauhatusaika, kuulakoko ja kierrosnopeus) vaikuttavat jauhatustulokseen?” sekä ”muuttaako hienojauhatus ligniinin kemiallista koostumusta?”. Tutkittavana materiaalina oli kaupallinen kraft-ligniini ja koelaitteena käytettiin planeettamyllyä. Syötölle ja kaikille jauhatustuotteille suoritettiin partikkelikokoanalyysi, ja lisäksi syötölle ja erittäin hienoksi jauhetulle tuotteelle suoritettiin FTIR-analyysi. Kokeiden mukaan ligniini oli hyvin jauhautuvaa, eikä kylmäkäsittelyllä ollut merkittävää vaikutusta jauhatukseen. Kuulakoon pienentäminen sekä jauhatusajan ja kierrosnopeuden kasvattaminen alensivat ligniininjauheen partikkelikokoa. Lisäksi hienojauhatuksen ei todettu muuttaneen ligniinin kemiallista koostumusta.

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Fiber-reinforced composites (FRCs) are a new group of non-metallic biomaterials showing a growing popularity in many dental and medical applications. As an oral implant material, FRC is biocompatible in bone tissue environment. Soft tissue integration to FRC polymer material is unclear. This series of in vitro studies aimed at evaluating unidirectional E-glass FRC polymer in terms of mechanical, chemical, and biological properties in an attempt to develop a new non-metallic oral implant abutment alternative. Two different types of substrates were investigated: (a) Plain polymer (BisGMA 50%–TEGDMA 50%) and (b) Unidirectional FRC. The mechanical behavior of high fiber-density FRCs was assessed using a three-point bending test. Surface characterization was performed using scanning electron and spinning disk confocal microscopes. The surface wettability/energy was determined using sessile drop method. The blood response, including blood-clotting ability and platelet morphology was evaluated. Human gingival fibroblast cell responses - adhesion kinetics, adhesion strength, and proliferation activity - were studied in cell culture environment using routine test conditions. A novel tissue culture method was developed and used to evaluate porcine gingival tissue graft attachment and growth on the experimental composite implants. The analysis of the mechanical properties showed that there is a direct proportionality in the relationship between E-glass fiber volume fraction and toughness, modulus of elasticity, and load bearing capacity; however, flexural strength did not show significant improvement when high fiber-density FRC is used. FRCs showed moderate hydrophilic properties owing to the presence of exposed glass fibers on the polymer surface. Blood-clotting time was shorter on FRC substrates than on plain polymer. The FRC substrates also showed higher platelet activation state than plain polymer substrates. Fibroblast cell adhesion strength and proliferation rate were highly pronounced on FRCs. A tissue culture study revealed that gingival epithelium and connective tissue established an immediate close contact with both plain polymer and FRC implants. However, FRC seemed to guide epithelial migration outwards from the tissue/implant interface. Due to the anisotropic and hydrophilic nature of FRC, it can be concluded that this material enhances biological events related with soft tissue integration on oral implant surface.