Det svenska elpriset har de senaste åren stigit kraftigt och förutspås öka ytterliggare under kommande år. Huvudorsaken är avregleringen av den europeiska elmarknaden som påbörjats. Detta har medfört att svenska företag börjat intressera sig för att minska sin elanvändning och på så sätt bevara sin konkurrenskraft gentemot företag på kontinenten. Ett vanligt sätt för att spara energi är att installera en luftridå vid en dörr eller port mot angränsande lokal eller omgivning med annan temperatur. Genom att rikta plana luft¬strömmar med hög hastighet vid porten reduceras möjligheten för de olika luftvolymerna att blandas. Luftridån skyddar därmed mot drag och bevarar lokalens ursprungliga temperatur vilket förbättrar den termiska komforten. En väl fungerande luftridå fyller därmed dubbla funktioner. Den här rapporten är ett examensarbete utförts för Boxholm Stål i samarbete med avdelningen Energisystem, IKP, Linköpings tekniska högskola. Uppgiften är att undersöka flödet och effektiviteten hos en luftridå på en industriell port vid Boxholm Stål. Genom att konstruera en simuleringsmodell baserad på luftridån och validera den ska effektiviteten beräknas. Vidare kommer modellen modifieras för att skapa alternativa konfigurationer vilkas effektivitet kan jämföras med den ursprungliga modellen. Arbetet ska även ge kunskap om hur ett framtida elpris kommer att påverka energikostnaden för driften av luftridån. För att utföra dessa beräkningar användes ett verktyg för matematisk modellering av strömning, CFD. Programvarorna Gambit och Fluent har använts för att skapa modellerna samt utföra och presentera de numeriska beräkningarna. Resultaten visar att en väl konfigurerad luftridå kan både förbättra arbetsklimatet och minska driftkostnader för uppvärmning av lokalen. Jämförelser mellan modellerna visar på stor skillnad i effektivitet beroende på luftridåns placering i förhållande till porten samt den vinkel som luften blåses från inloppet. Enbart genom att modifiera vinkeln för det befintliga inloppet kan driftkostnaderna reduceras med över 60 % jämfört med en oskyddad port utan luftridå. Elprisets påverkan av driftskostnaderna är mycket stor då en dåligt konfigurerad luftridå drar ut stora mängder luft ur lokalen som måste ersättas med uppvärmd luft. En modifierad vinkel på luftridån kan minska driftkostnaderna trots ett framtida ökat elpris. För en luftridå placerad ovanför porten är inloppets vinkel av större betydelse än lufthastigheten. Den optimala vinkeln för inloppet ligger mellan 20 och 30 grader oberoende av en lufthastighet. / The Swedish electricity price has rapidly increased during the last years and is predicted to further increase in the coming years. The main reason is the deregulation of the European electricity market which has begun. As a result Swedish companies have become interested in decreasing their use of electricity to maintain their competitiveness towards foreign companies. A common way to save electricity is to install an air curtain at a door or gate between an adjacent premises or surroundings with different temperature. By aiming plane jets with high velocity at the gate, the different air volumes possibility to mix is reduced. The air curtain therefore protects against draft and maintains the temperature of the premises which improves the thermal comfort. An air curtain working properly can both improve working environment and save energy. This report is a final thesis performed for Boxholm Stål in cooperations with the department of energy systems, IKP, Linköping University. The main goal is to examine the flow and efficiency of an air curtain for an industrial gate at Boxholm Stål. By developing and validating a simulation model based on a real air curtain, the efficiency can be estimated. Furthermore, the model will be modified to create alternative configurations which will be compared with the original model. The thesis will also bring knowledge of how a future electricity price will affect the energy costs for operating the air curtain. To perform these calculations, CFD, a tool for mathematical modeling of fluids was used. The computer programs Gambit and Fluent were used to create the models, perform and present the numerical calculations. The result shows that an air curtain working correctly can both improve the working conditions and reduce the operating costs for heating the premises. Comparisons between the models show large differences in efficiency depending of the positions of the air curtain relative to the gate and the angle at which the air is ejected from the inlet. Solely by modifying the angle for the existing inlet, the operating costs can be reduced by over 60 % compared to a gate without an air curtain. The electricity price’s influence on the operating costs is very large since a poorly operating air curtain is pulling large quantities of air, from the premises to the surroundings, which has to be replaced by heated outdoor air. A modified angle on the air curtain can reduce the operating costs even for a higher electricity price in the future. For an air curtain placed above the gate, the angle of the inlet is of greater importance than the air velocity. The optimal angle for the inlet is between 20 and 30 degrees independent of the air velocity.

Detta examensarbete inom lean produktion anpassar, tillämpar och utvecklar metoden för värdeflödeskartläggning på Siemens Industrial Turbomachinery AB:s tillverkning av mellanväggar. Företaget ser en ökad efterfrågan på ångturbiner, där mellanväggar är ingående komponenter. Produktionen av mellanväggar sker idag i funktionell verkstad där mellanväggen genomgår drygt 20 operationer. Värdeflödeskartläggningen ska presentera ett förbättrat produktionssystem för mellanväggar som kan möta den prognostiseradeefterfrågan. Metoden för värdeflödeskartläggning har sitt ursprung hos Toyota och bilindustrin. Examensarbetet utvecklar metoden för kundorderstyrd lågvolymproduktion och presenterar en metodhandbok för leanimplementatörer. Den föreslagna datainsamlingsmetoden förutsätter att en tvärfunktionell grupp från värdeflödet sätts samman. Vid utbildning av gruppen är det viktigt med exempel från den egna branschen, helst den egna verksamheten för att skapa en positiv identifiering. Utifrån givna förutsättningar resulterade värdeflödeskartläggningen i en flödesgrupperad, U‐formad layout för mellanväggstillverkning. Flödesgruppen är i sin tur indelad i tre celler där produktionen styrs genom CONWIP. Vid den dimensionerande efterfrågan beräknas de föreslagna förändringarna resultera i en ledtidsreduktion på 70 % och kapitalbindningen i mellanväggar minska med 28,5 miljoner kr. För att nå dit måste fokus i organisationen flyttas till flöde och takttider, dagens system där ekonomistyrningen riktar in sig på beläggningstimmar i maskiner suboptimerar systemet. Utbildning är en förutsättning för att skapa den kulturförändring som krävs för att skapa en lärande organisation med ett snabbt materialflöde med få störningar. Den genomförda kartläggningen ger också riktade rekommendationer om var i värdeflödet vissa typer av insatser vore till stor nytta, dels kortsiktigt men även långsiktigt. / This master’s thesis in the area of Lean Production adjust, apply and develop the method for Value Stream Mapping at Siemens Industrial Turbomachinery AB:s production of diaphragms. The company stands to an increased demand of steam turbines, in which diaphragms are components. Today the manufacturing of diaphragms is carried out in a conventional workshop divided into functional departments. The production process consists of more than 20 operations. The aim for the Value Stream Mapping of the production process of diaphragms is to present an improved production system with ability to reach the future demand of diaphragms to steam turbines. The method for Value Stream Mapping origins from Toyota and the automobile industry and this master’s thesis develops the method for low volume make‐to‐order production and presents a methodology guide for lean implementers. The suggested methodology recommends that a cross‐functional team is gathered to map and develop the operations. When educating the team it is important to show examples from the same kind of industry, preferably from the own company, to create a positive feeling of identification. By the given presumptions the value stream mapping resulted in a product oriented layout with a u‐shaped material flow. The layout is divided into the three production cells in which each work in process is controlled by CONWIP. At the dimensioning demand the suggested improvements are calculated to result in a lead time reduction by 70 % and the capitalization in work in process is reduced by 2.7 million euros. To reach this target the focus in the organization needs to be changed into flow of material and takt time. Today’s capacity oriented focus sub‐optimizes the system – the goal is to deliver products at the right time, amount and quality to the customer at a low cost, not activate machines. Education is a key in the cultural change that is needed to create a learning organization with few disturbances and a fast material flow. The Value Stream Mapping of diaphragms resulted in directed suggestions where in the production flow certain lean production tools will generate most advantages for the Value Stream.

<p>Network-on-Chip (NoC) is proposed as a systematic approach to address future System-on-Chip (SoC) design difficulties. Due to its good performance and small buffering requirement, wormhole switching is being considered as a main network flow control mechanism for on-chip networks. Wormhole switching for NoCs is challenging from NoC application design and switch complexity reduction.</p><p>In a NoC design flow, mapping an application onto the network should conduct a feasibility analysis in order to determine whether the messages’ timing constraints can be satisfied, and whether the network can be efficiently utilized. This is necessary because network contentions lead to nondeterministic behavior in message delivery. For wormhole-switched networks, we have formulated a contention tree model to accurately capture network contentions and reflect the concurrent use of links. Based on this model, the timing bounds of real-time messages can be derived. Furthermore, we have developed an algorithm to test the feasibility of real-time messages in the networks.</p><p>From the wormhole switch micro-architecture level, switch complexity should be minimized to reduce cost but with reasonable performance penalty. We have investigated the flit admission and flit ejection problems that concern how the flits of packets are admitted into and ejected from the network, respectively. For flit admission, we propose a novel coupling scheme which binds a flit-admission queue with an output physical channel. Our results show that this scheme achieves a reduction of up to 8% in switch area and up to 35% in switch power over other comparable solutions. For flit ejection, we propose a p-sink model which differs from a typical ideal ejection model in that it uses only p flit sinks to eject flits instead of p • v flit sinks as required by the ideal model, where p is the number of physical channels of a switch and v is the number of virtual channels per physical channel. With this model, the buffering cost of flit sinks only depends on p, i.e., is irrespective of v. We have evaluated the coupled flit-admission technique and p-sink model in a 2D 4 x 4 mesh network. In our experiments, they exhibit only limited performance penalties in some cases. We believe that these cost-effective models are promising candidates to be used in wormhole-switched on-chip networks.</p> / QC 20100524

<p>This thesis work has been performed on request by SWT (Scandinavia WeldTech AB). SWT manufactures, develop and sell ready to assemble building systems for concrete rafter beam applications. The beams in this system consist of a u-beam that is welded to a flange. To be able to fill the beams with concrete there is holes in the beams top end. The holes are made in a “punching machine”.  These holes are cut out and the remaining steel piece is bent down in the u-beam. The problem today is that the machine only can make holes in beams with a height up to 340 mm. Now SWT wants a machine that can handle beams up to 500 mm high.</p><p>Our task in this work was to make a feasibility study on what needs to be done to rebuild the machine. Besides the demand with higher beams we also looked at things to improve. Another task was to investigate the needs for cutting in beams made by thicker steel plates.</p><p>In this work we used some of the theories described by David G. Ullman for the concept generation and evaluation. When generating the concepts we choose to make a concept of each subpart of the machine. Then we put the winning concepts together to form a final solution for the whole machine. When looking at the wear on the tools we could see that much could be done by making the control of the cutting column easier when adjusting the tool. To see what demands there were for cutting in thicker plates we had to come up with a theory for calculation off cutting and bending. Then we had to compare our theory with the reality, and that was done by measuring the pressure on the working cylinder when the machine was operating. Those results showed that our theory was working for 5 mm thickness but not for 4 mm thickness. There is however some uncertainness that makes our measured results not quite reliable for 4 mm steel.</p><p>When it comes to the demand to manage higher beams we came to the conclusion that the best alternative is to manufacture a new frame. This is also suggested for the plates in the feeding unit. But we recommend that the existing cylinders and roof is used.</p><p>For the problem on how to make the tool adjustments easier we came up with two solutions. The alternative with manual adjusting and assembly demands a reconstruction of the hydraulic system so that its functions meets the demands that are needed to realize the proposed solution. The advantage with this proposition is that the operator always has the possibility to affect the position of the tools so that the right cutting column is received. Our other suggestion is to install permanent steering guiding so the lower die gets in right position when mounting it. This proposal does not mean any bigger reconstruction but it does not make it possible to adjust the position of the cutting tool. To work proper both our solutions demands that the lower dies is modified.</p><p>To make the mounting of the upper die easier we came up with two solutions that in short terms means that the die is held up before mounting. This means that the operator can have both his hands free when tighten the bolts.</p><p>If thicker plate should be cut it will lead to large reconstructions of the hydraulic system with new cylinders and more. This due to the maximum pressing force that the machine is capable of is too small. But for a small change in thickness it might be enough to lower the force by reducing the friction in terms of better lubrication and modified tools.</p>

<p>In the ATLAS experiment now being finished at CERN in Geneva, bunches ofprotons will collide at a rate of 40 million times per second. Over 40 TB of datawill be generated every second. In order to reduce the amount of data to a moremanageable level, a system of triggers is put in place. The trigger system mustquickly evaluate if the data from a collision indicates that an interesting physicalprocess took place, in which case the data are to be stored for further analysis.    ATLAS uses a trigger system with three steps. The first step, the First LevelTrigger, is responsible of reducing the rate from 40MHz to 75KHz, and is donecompletely in hardware. It receives a new event every 25 ns, and must decidewithin 2.5 μs whether the event should be passed on to the next trigger level.    In this document is the redesign of two subsystems of the First Level Triggerdescribed. When prototypes were made 5-10 years ago, both subsystems used 7PLDs. Today, the same logic could be fitted in one FPGA, and because of theflexibility gained by having all logic in a single FPGA, both subsystems could berealized with the same PCB design.</p>

Modern imaging modalities can generate three-dimensional datasets with a very high detail level. To transfer all the information to the user in an efficient way there is a need for three-dimensional visualization. In order to enhance the diagnostic capabilities the utilized methods must supply the user with fast renderings that are easy to interpret correctly. It can thus be a challenge to visualize a three-dimensional dataset in a way that allows the user to perceive depth and shapes. A number of stereoscopic solutions are available on the market but it is in many situations more practical and less expensive to use ordinary two-dimensional displays. Incorporation of advanced illumination can, however, improve the perception of depth in a rendering of a volume. Cast shadows provide the user with clues of distances and object hierarchy. Simulating realistic light conditions is, however, complex and it can be difficult to reach interactive frame rates. Approximations and clever implementations are consequently required. This thesis presents efficient methods for calculation of illumination with the objective of providing the user with high spatial and shape perception. Two main types of light conditions, a single point light source and omni-directional illumination, are considered. Global transport of light is efficiently estimated using local piecewise integration which allows a graceful speed up compared to brute force techniques. Ambient light conditions are calculated by integrating the incident light along rays within a local neighborhood around each point in the volume. Furthermore, an approach that allows the user to highlight different tissues, using luminous materials, is also available in this thesis. A multiresolution data structure is employed in all the presented methods in order to support evaluation of illumination for large scale data at interactive frame rates.

This work deals with innovative energy efficient fluid power systems for mobile applications. The subjects taken up concern to what extent and how energy losses can be reduced in mobile working hydraulics systems. Various measures are available for increasing energy efficiency in these kinds of systems. Examples include: Flow controlled systems The pump controller is switched from a load sensing toa displacement controlled one. The displacement is controlled in an open loopfashion directly from the operator’s demand signals. This reduces energy consumptionat the same time as dynamic issues that are attached to LS systemscan be avoided. Individual metering valve systems Flexibility is increased by removing the mechanicalcoupling between the meter-in and meter-out orifices in directionalvalves. An overview of this kind of system is given in the thesis. A designproposal that has been implemented is also presented. Initial test results areshown. Patents for this particular system have been applied for. Displacement control Metering losses are reduced by removing the directional valves.One pump is used for each load in such systems. This hardware layout involvesconsiderable changes compared to conventional systems. Displacementcontrolled systems are not studied in this work. In mobile applications, overall efficiency is often poor and losses are substantial. The measures listed above can help improve this significantly in such applications. A flow dividing system can decrease energy consumption by about 10% and an individual metering system by about 20%. Losses in pump controlled systems are difficult to give a figure for; the losses are rather attached to the pumps and motors and not to the system layout. However, the losses for these systems are presumably even lower than for individual metering systems. The main focus in this work is on individual metering systems but questions about which components and so on are also treated. For example, the Valvistor valve concept has been studied as part of this work.

This thesis explored and visualized the relationships of documents data, based on the technique of self-organizing maps (SOM), a subtype of artificial neural network for visualizing high-dimensional data in low-dimensional views. The source data for this thesis are the full Extensible Markup Language (XML) texts of A Standard Corpus of Present Day Edited American English. The first step is transforming these XML files to produce a term-document matrix, including stop word removal, stemming, tf-idf (term frequency–inverse document frequency) weighting, global filtering; here rows of this matrix represent documents as n-dimensional vectors. Secondly, these vectors are clustered and visualized by SOM consisting of neurons, each neuron relatives to a set of documents with a certain number of same terms. Then a network has been constructed from SOM, with vertices set of neurons and documents, lines set of linkages between neurons and documents. Finally this network exports to the Pajek for analysis and final visualization.

ESAB is a world leader in production of welding consumables and equipment. The company manufactures, among other things, welding electrodes. A roller straightening unit is used in the cutting process to straighten the wire, which the welding electrode consists of, by adjusting some of the rollers during operation. According to ESAB’s standard and the European machinery directives, moving parts of machinery, such as rollers of the roller straightening unit, must be out of the operator’s reach. Guards and protective devices should achieve their safety function with minimal downtime and the least reduction in productivity. The main purpose with this project is to draw up protection device proposals for roller straightening units and based on drawings implement one suitable concept.

Rapid development in Information technology are creating learning and teaching more interactive and efficient through innovative technology. The potential use of Internet and computer technology in the education has been widely recognized globally. Bhutan although with its limited ICT (Information and communication Technology) infrastructure shares the same view and wishes to yield the benefits of the technology into their education curriculum. The aim of the project is to demonstrate the capability of web technology in developing web portal with low-end technology to teach school children the basic skills of mapping and GIS. The basic skills on map reading and application of simple query related to GIS forms the core component of this application which will help children learn map reading. The application is created with low-end technology and is simple and easy to use. The project is not a complete portal and will not cover all aspect of mapping but will supplement the conventional classroom curriculum and can be developed into a full cross-curriculum portal with further contribution.