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345 Uppsatser om Laser Cutting - Sida 14 av 23

Observatörer för skattning av verktygspositionen hos en industrirobot : Design, simulering och experimentell verifiering

This thesis approaches the problem of estimating the arm angles of an industrial robot with flexibilities in joints and links. Due to cost-cutting efforts in the industrial robots industry, weaker components and more cost-effective structures have been introduced which in turn has led to problems with flexibilities, nonlinearities and friction. In order to handle these challenging dynamic problems and achieve high accuracy this study introduces state observers to estimate the tool position.The observers use measurements of the motor angles and an accelerometer and the different evaluated observers are based on an Extended Kalman Filter and a deterministic variant. They have been evaluated in experiments on an industrial robot with two degrees of freedom. The experimental verification shows that the state estimates can be highly accurate for medium frequency motions, ranging from 3-30Hz.

Dubbskador på Alvestakubb

Mechanical harvesting may result in timber damages leading to reduced saw log quality. The initiator of this study was VIDA ? a privately owned concern operating in the value-adding process industry of forest raw materials. The aim of this study was to examine the type and amount of damages on Alvestakubb caused by the harvester head during the cutting process. The aim was also to compare the damages caused by different types of feed rollers and to evaluate the effects of temperature on damage occurrence.

Överföring av radiocesium till potatis vid olika nedfallstidpunkter :

Agricultural land could be polluted by radioactive substances after a fallout. We would then need information about the level of contamination to decide whether the crops could be utilized as food under these circumstances. In an experiment carried out during the 1990ies the retention of 134Cs in potato haulm and the transfer to the tubers were studied. The experiment was carried out during three consecutive years. The plants were cultivated in pots under field conditions and the artificial deposition was sprayed directly onto the potato haulm at different times during the growing season.

Kan markfuktighetskartor användas för att hitta skogsmark med hög bonitet? : ett gis-baserat försök med dtw-index och laserskannad övre höjd

The depth-to-water-index (DTW-index) is derived from digital elevation models (DEM) to map soil wetness, in terms of distance from soil surface to the ground water table. The aim of this GIS based study was to investigate the existence of a relationship between DTW-index and forest site productivity (SP). The belief of such an assumed relationship was based on knowledge that the ground water level is related to site properties that can either promote or impede tree growth. Data primarily comprised rasters of the Krycklan catchment in northern Sweden and depicted DTW-index and a laser scanned vegetation height. The 100th height percentile of each pixel in the vegetation raster was assumed to mirror the top-height, letting it act as a relative measure of SP within a delineated area of equal stand age.

Identifiering av konfliktbestånd med hjälp av laserskanning

The interest in harvesting wood fuel in conflict stands has grown in recent years as a consequence of the increased demand for biofuel. Conflict stands are young forests that have not been cleaned and have a large number of stems ha-1with a great height and diameter distribution. This means that traditional field measurements in conflict stands are difficult and very time consuming. Therefore, the forestry sector is in need of new, more efficient inventory methods. In this study, the Lidar data from Lantmäteriet?s (the Swedish mapping, cadastral and land registration authorities) new national height model was used in combination with plots from the Swedish national forest inventory from 2009 to create functions for; height, volume, diameter and number of stems.

Identitetssökande katalaner. En kvalitativ studie om katalaners flernivåidentifikation

The aim of this bachelor thesis is to study how Catalans´ identifications, with respect to their city (Barcelona), their region (Catalonia), their country (Spain) and Europe, are related to each other. Furthermore it deals with whether they use cultural or civic notations when they speak of their identification with the different territorial levels.The thesis is based on a qualitative method with interviews with ten Catalans living in Barcelona, aged from 18 to 58. The result showed that Catalans´ identifications with different territorial levels vary in how they relate to each other. This variation can be classified using three models, namely; ?The Russian doll model? which implies that the identities are ranked hierarchically, ?cross-cutting? that is people can identify themselves with the different levels depending on various situations, and also ?The marble cake model? which means that the different identities are so intertwined that they cannot be separated.

Implementing a receiver in a fast data transfer system : A feasibility study

This report is an outcome of a master degree project at Linköpings University in co-operation with Micronic Laser Systems AB. The purpose with this master degree project was to investigate how to implement a receiver in a data transfer system. The system consists of several data channels, where every channel consists of three parts: driver, transmission lines and receiver. The driver send low amplitude differential signals via the transmission lines to the receiver that amplifies and converts it to a single-ended signal. The receiver has to be fast and be able to feed an output signal with high voltage swing.

Eutanasi : en skonsam död

This work is about euthanasia and how to use it on horses, dogs and cats. A description for each animal is done, about when it is time, why, which methods can be used and who is allowed to use them, how and where it shall be done. The methods we have concentrated on are: - Chemical destruction and the most common drugs for euthanatize horses, dogs and cats. - Physical disruption of the brain activity by a captive bolt, only for horses. The captive bolt only makes the horse unconscious and must always be followed by cutting off the vena jugularis. Then the horse dies because of loss of blood. No matter which method used for euthanizing, the animal must be declared to be dead by the operator before other measures. The testing criteria for death: muscle relaxation and cyanosis, cessation of reflex activity and pupillary dilatation, cessation of respiratory activity and cessation of all cardiac activity.

Tillvaratagande av GROT i skärgårdsnära miljö :

The main aim of this study was to investigate and compare different methods for the extraction of forest fuel from environments close to an archipelago. The study was based on relevant literature and published reports as well as personal communications. Forestry has traditionally been characterized by intense efforts to rationalize and mechanize the cutting technique used for timber and pulpwood. In line with the increasing importance of forestry, more concentrated efforts can be expected in the area of techniques and methods, especially for the above-mentioned product lines. In Sweden, forestry is of major importance and the Swedish economy and standard of living have mainly been created based on the revenues generated from it. Thus, it is vital that Swedish forests are harvested in an efficient and responsible manner. The demand for biofuel is growing and today accounts for 15% of total Swedish energy production, a share that will probably increase. This study is based on three research questions, which are described under the heading of Aim. The results reveal that the most profitable method for handling forest fuel is the traditional one, which is also the most commonly used method in southern Sweden, namely the stockpiling of logs in a clearing by means of forwarders followed by splintering at the place from where they will be distributed. Today, the high cost of barge transport required for the extraction of forest fuel in an archipelago environment renders such operations unprofitable.

Histonmodifieringar och alternativ splicing

Alternativ splicing av pre-mRNA ger upphov till proteindiversitet. Histonmodifieringar kopplas till den alternativa splicingens reglering genom adaptorsystem som overfor den epigenetiska informationen direkt till splicingfaktorerna. De cis- agerande RNA- elementen pa exoner och introner med tillhorande trans- reglerande splicingfaktorer paverkas darfor direkt av specifika histonmodifieringar. En sammankopplande integrerad modell over en rad DNA- baserade processer foreslas. Denna komplexa modell ger en bild av interaktioner och paverkan mellan dessa delar.

Gormsson - En symaskin för nybörjare

We are getting smarter. Our knowledge of the world around us is increasing rapidly and our population spend a big portion of their time in school studying it. But art and craft are moving out to give room for more theoretical subjects. Today many of us can not even fix a torn shirt without help. We buy new ones, they are cheap enough.

SJUKGYMNASTIK SOM BEHANDLING VID LÄNDRYGGSDISKBRÅCK

ABSTRACTBackground: Most cases of lumbar disc herniation are asymptomatic. When symptomatic, LDH may cause a significant physical and mental distress. Initially, most patients are treated conservative but sometimes operations may be required.Aim: The aim of this study was to provide a review of the scientific basis of physiotherapy, including behavioural therapy, as a treatment to lumbar disc herniation regarding pain, function and the size of disc herniation in people suffering from lumbar disc herniation.Method: Four databases were used in the searches of literature. Assessment of the validity of the studies was done with the PEDro-scale and valuation of evidence rate was made according to guidelines made by the Swedish Council on Health Technology Assessment (SBU).Result: Nine RCT-studies were included with a total of 713 participants. The scientific basis is moderate to support a pain reduction and limited regarding improvement of physical function when it comes to physical exercises, including MDT.

Kapacitets- och produktivitetsanalys förflödesoptimering

This thesis describes possibilities for Metso Paper to lower their costs of spray pipes for their pulp wash press TRPE, with maintained good functionality and quality.Information that can be used by competitors has been censored in this version of the essay.To find solutions, alternative suppliers have been contacted and asked to quote. There has also been a new spray pipe designed. The manufacturing costs of the new design have been calculated.The thesis also contains a concept generation of an alternative product to the spray pipes in installations where a high pressure washer is used.To be able to ask other manufacturers of spray pipes to quote, a demand specification based on the currently used spray pipe was made. This was then sent to two alternative suppliers.An investigation of earlier used spray pipes, and the currently used, shows that the nozzles are a big part of the total costs of the spray pipes. To attempt to reduce the nozzles high cost an concept generation was made to find the best solution for a new design.There was a request that it should be possible to change the internal brushes in the spray pipe without cutting and welding.

Kvalitetsledningssystem för företag igolvbranschen

This thesis describes possibilities for Metso Paper to lower their costs of spray pipes for their pulp wash press TRPE, with maintained good functionality and quality.Information that can be used by competitors has been censored in this version of the essay.To find solutions, alternative suppliers have been contacted and asked to quote. There has also been a new spray pipe designed. The manufacturing costs of the new design have been calculated.The thesis also contains a concept generation of an alternative product to the spray pipes in installations where a high pressure washer is used.To be able to ask other manufacturers of spray pipes to quote, a demand specification based on the currently used spray pipe was made. This was then sent to two alternative suppliers.An investigation of earlier used spray pipes, and the currently used, shows that the nozzles are a big part of the total costs of the spray pipes. To attempt to reduce the nozzles high cost an concept generation was made to find the best solution for a new design.There was a request that it should be possible to change the internal brushes in the spray pipe without cutting and welding.

Socialdemokraterna, Miljöpartiet, Folkpartiet & Moderaterna i integrationsdebatten

Title: A study about conditions for leadership in knowledge-intensive firms.Authors: Cecilia Ekström and Niklas SandbergKeywords: Leadership, knowledge-intensive firm, hierarchies, followers.Background: Leadership is becoming one of our greatest social myths and is considered a total solution for many problems that occur in an organization. The view of leadership is usually from a top-down perspective, which contributes to an often underestimated view of the follower. Just as it is important to understand the leader's view of leadership, it is important to understand how employees view the structure from which the leader derives its legitimacy. The existing conditions in knowledge-intensive firms, such as autonomy, place special demands on the formal leadership.Purpose: The purpose of this study takes an employee perspective, to understand what the conditions are for formal leadership in knowledge-intensive firms.Method: A qualitative research method was used and empirical material was collected through interviews with employees in knowledge-intensive firms. The empirical material was analyzed by the respondents? mental images which were set against the theoretical framework of the thesis.Conclusions: The conditions for formal leadership in knowledge-intensive firms make it advantageous to have a leader with a withdrawn role.

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