995 resultados para 3D problems


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Additive manufacturing, or 3D printing, is globally one of most interesting area in developing of manufacturing technologies. This technology is suitable for fabrication off industrial products and it interests actors in fields of computer sciences, economics, medical sciences and design&arts. Additive manufacturing is often referred as third industrial revolution: first revolution was invention of steam engines in 18th century and second was industrial revolution started by Henry Ford in 1920s. Companies should be able to test suitability of their products for additive manufacturing and 3D printing but also how much better products could be when products are totally re-designed so that all potential of this new technology can be utilized. This is where education has its importance; new generations who enter working life should be educated to know of additive manufacturing and 3D printing, its advantages but also of it limits. There has to be also possibility to educate industry and people already working there, so that industrial implementation could be done successfully. This is especially very valid for Finland. Education is strongly needed so that Finnish industry can maintain its competence in global markets. Role of education is extremely important when a new technology is industrially implemented. Additive manufacturing and 3D printing offers freedom to design new products, production and generally ways of doing things. Development, planning and execution of education for additive manufacturing and 3D printing is challenging as this area develops very fast. New innovations are coming almost every month. Planning of education for additive manufacturing and 3D printing requires collection pieces of data from various of sources. Additive manufacturing and 3D printing industry and its development has to be followed frequently, and material for additive manufacturing and 3D printing has to be renewed frequently.

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In this doctoral thesis, a tomographic STED microscopy technique for 3D super-resolution imaging was developed and utilized to observebone remodeling processes. To improve upon existing methods, wehave used a tomographic approach using a commercially available stimulated emission depletion (STED) microscope. A certain region of interest (ROI) was observed at two oblique angles: one at a standard inverted configuration from below (bottom view) and another from the side (side view) via a micro-mirror positioned close to the ROI. The two viewing angles were reconstructed into a final tomogram. The technique, named as tomographic STED microscopy, was able to achieve an axial resolution of approximately 70 nm on microtubule structures in a fixed biological specimen. High resolution imaging of osteoclasts (OCs) that are actively resorbing bone was achieved by creating an optically transparent coating on a microscope coverglass that imitates a fractured bone surface. 2D super-resolution STED microscopy on the bone layer showed approximately 60 nm of lateral resolution on a resorption associated organelle allowing these structures to be imaged with super-resolution microscopy for the first time. The developed tomographic STED microscopy technique was further applied to study resorption mechanisms of OCs cultured on the bone coating. The technique revealed actin cytoskeleton with specific structures, comet-tails, some of which were facing upwards and some others were facing downwards. This, in our opinion, indicated that during bone resorption, an involvement of the actin cytoskeleton in vesicular exocytosis and endocytosis is present. The application of tomographic STED microscopy in bone biology demonstrated that 3D super-resolution techniques can provide new insights into biological 3D nano-structures that are beyond the diffraction-limit when the optical constraints of super-resolution imaging are carefully taken into account.

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Tämä diplomityö tehtiin Valmet Technologies Oy:n Järvenpään toimipisteelle. Työn tavoitteena oli tutkia miten pituusleikkureiden 3D-suunnittelua voidaan tehostaa hyödyntämällä uuden 3D-CAD -järjestelmän ominaisuuksia optimaalisesti. Työ koostuu teoriaosuudesta, haastattelututkimuksesta sekä käytännön osuudesta. Teoriaosuudessa perehdytään pituusleikkurin toimintaan ja rakenteeseen, 3D-suunnittelun teoriaan sekä CATIA-järjestelmään. Teoriaosuudessa etsitään myös uusia näkökulmia 3D-suunnitteluun. Haastattelututkimuksessa kartoitetaan nykyinen suunnitteluprosessi, suunnittelun kehitettäviä kohteita, sekä käytössä olevia suunnittelumenetelmiä, jotka ovat todettu toimiviksi. Haastattelututkimuksessa haastatellaan Valmet Technologies Oy:n Järvenpään toimipisteessä työskenteleviä pituusleikkureiden pääsuunnittelijoita sekä heidän esimiehiään. Lisäksi erillisten haastattelujen avulla kerätään kokemuksia CATIA V6 -ohjelmiston käytöstä sekä suunnitteluohjelmiston vaihtumisesta. Käytännön osuuden tavoitteena on arvioida pituusleikkurin parametroitujen mallirakenteiden siirtämiseen sekä korjauksiin kuluvia aikamääriä kyseisiin toimenpiteisiin tarvittavien resurssien määrittämiseksi. Käytännön osuudessa siirretään kaksi Valmet OptiWin Drum Compact -pituusleikkurin parametroitua osakokonaisuutta uuteen CAD-järjestelmään ja niille suoritetaan tarvittavat korjaustoimenpiteet Tutkimuksen tulosten perusteella yhteisen mallinnusmetodologian puuttuminen on merkittävin kehityskohde suunnittelun kehittämisessä. Lopuksi luotiin kehitysehdotukset sekä implementointisuunnitelma, joiden avulla pituusleikkureiden 3D-suunnittelua voidaan kehittää ja CATIA V6 -ohjelmisto voidaan ottaa käyttöön tehokkaasti.

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Additive manufacturing (shortened as AM), or more commonly 3D printing, consists of wide variety of different modern manufacturing technologies. AM is based on direct printing of a digital 3D model to a final product which is fabricated adding material layer by layer. This is from where term additive manufacturing has its origin. It is not only material what is added, but it is also value, properties etc. which are added. AM enables production of different and even better products compared to conventional manufacturing technologies. An estimation of potential of additive manufacturing can be gathered by considering the potential of laser cutting, which is one of the most widely used modern manufacturing technologies. This technique has been used over 40 years, and whole market around this technology is at the moment c. four billion euros and yearly growth is around 10 %. One factor affecting this success of laser cutting is that laser cutting enables radical improvements to products made of flat sheet. AM and 3D printing will do the same for three dimensional parts. Laser devices, which are at the moment used in 3D printing, are globally at the moment only around 1% of all laser devices used in any fabrication technology, so even with a cautious estimate the potential growth of at least 100 % is coming in next few years. Role of education is very important, when this kind of modern technology is industrially implemented. When both generation entering to work life and also generation who has been a while in work life understands new technology, its potential and limitations, this is the point when also product design can be rethought Potential of product design is driving force for wide use of additive manufacturing and 3D printing. Utilization of additive manufacturing and 3D printing is also opportunity for Finland and Finnish industry. This technology can save Finnish manufacturing industry. This technique has stron potential, as Finland has traditionally strong industrial know-how and good ICT knowledge.

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The increasing performance of computers has made it possible to solve algorithmically problems for which manual and possibly inaccurate methods have been previously used. Nevertheless, one must still pay attention to the performance of an algorithm if huge datasets are used or if the problem iscomputationally difficult. Two geographic problems are studied in the articles included in this thesis. In the first problem the goal is to determine distances from points, called study points, to shorelines in predefined directions. Together with other in-formation, mainly related to wind, these distances can be used to estimate wave exposure at different areas. In the second problem the input consists of a set of sites where water quality observations have been made and of the results of the measurements at the different sites. The goal is to select a subset of the observational sites in such a manner that water quality is still measured in a sufficient accuracy when monitoring at the other sites is stopped to reduce economic cost. Most of the thesis concentrates on the first problem, known as the fetch length problem. The main challenge is that the two-dimensional map is represented as a set of polygons with millions of vertices in total and the distances may also be computed for millions of study points in several directions. Efficient algorithms are developed for the problem, one of them approximate and the others exact except for rounding errors. The solutions also differ in that three of them are targeted for serial operation or for a small number of CPU cores whereas one, together with its further developments, is suitable also for parallel machines such as GPUs.

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Solving the water crisis in the developing world is a critical issue. Four billion people in the globe, so called the Base of the Pyramid (BoP) population suffer from inadequate access to safe drinking water, while millions die daily from waterborne diseases and lack of clean water. The BoP people desperately need to obtain a satisfactory access to safe water sources. In order to address the issue, this research has been carried out. To provide holistic consideration to the matter, comprehensive exploration of various causes of the water crisis and its impacts in developing countries were discussed. Then, various viable and relevant solutions to the problem have been thoroughly scrutinized, including scientific, rational, practical and speculative approaches, examination of existing methods, technologies and products at the BoP water market. The role of clean water to the sustainable development was specifically featured. The paper also has studied social and economic factors, actors and circumstances which affect the market development of clean water technologies in the BoP. Possibilities and potentials of successful business between foreign water enterprises and BoP consumers were considered, while primary obstacles are deliberated on, with suggestion of the ways to tackle them. Technologies and products which are needed by the poor must be affordable, sustainable and of an appropriate quality. The crucial question of technology transfer was soundly discussed with pointing out main hindrances on the way of its implementation between the developed and developing world. The means to overcome these barriers were properly observed as well. To explore to some extent the possibility and feasibility of technology transfer from Finland to the BoP sector, 3 case study analyses have been implemented. Personal discussions in form of interviews were conducted at Kemira, Outotec and Fenno Water, Finnish water treatment and supply enterprises. The results of the interviews shed light on the specific practical matters, actual obstacles and potential solutions of the technology transfer from Finland to low-income countries.

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Fluid handling systems account for a significant share of the global consumption of electrical energy. They also suffer from problems, which reduce their energy efficiency and increase life-cycle costs. Detecting or predicting these problems in time can make fluid handling systems more environmentally and economically sustainable to operate. In this Master’s Thesis, significant problems in fluid systems were studied and possibilities to develop variable-speed-drive-based detection methods for them was discussed. A literature review was conducted to find significant problems occurring in fluid handling systems containing pumps, fans and compressors. To find case examples for evaluating the feasibility of variable-speed-drive-based methods, queries were sent to industrial companies. As a result of this, the possibility to detect heat exchanger fouling with a variable-speed drive was analysed with data from three industrial cases. It was found that a mass flow rate estimate, which can be generated with a variable speed drive, can be used together with temperature measurements to monitor a heat exchanger’s thermal performance. Secondly, it was found that the fouling-related increase in the pressure drop of a heat exchanger can be monitored with a variable speed drive. Lastly, for systems where the flow device is speed controlled with by a pressure measurement, it was concluded that increasing rotational speed can be interpreted as progressing fouling in the heat exchanger.

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This research attempted to address the question of the role of explicit algorithms and episodic contexts in the acquisition of computational procedures for regrouping in subtraction. Three groups of students having difficulty learning to subtract with regrouping were taught procedures for doing so through either an explicit algorithm, an episodic content or an examples approach. It was hypothesized that the use of an explicit algorithm represented in a flow chart format would facilitate the acquisition and retention of specific procedural steps relative to the other two conditions. On the other hand, the use of paragraph stories to create episodic content was expected to facilitate the retrieval of algorithms, particularly in a mixed presentation format. The subjects were tested on similar, near, and far transfer questions over a four-day period. Near and far transfer algorithms were also introduced on Day Two. The results suggested that both explicit and episodic context facilitate performance on questions requiring subtraction with regrouping. However, the differential effects of these two approaches on near and far transfer questions were not as easy to identify. Explicit algorithms may facilitate the acquisition of specific procedural steps while at the same time inhibiting the application of such steps to transfer questions. Similarly, the value of episodic context in cuing the retrieval of an algorithm may be limited by the ability of a subject to identify and classify a new question as an exemplar of a particular episodically deflned problem type or category. The implications of these findings in relation to the procedures employed in the teaching of Mathematics to students with learning problems are discussed in detail.