The view of the author presented in this dissertation is that the integration of modern railway technologies and information technology systems establishes effective maintenance management and ensures continuous asset management improvement. In conjunction with the integration of different technologies is the requirement to implement these technologies and strategies in a systematic process according to a prioritised order of value adding, to improve the required service objectives (Mitchell et al., 2007; Woodhouse, 2001). The dissertation describes the planning of maintenance activities on railway assets. It involves various aspects through the asset management life cycle from asset inventory and condition data acquisitioning methods and the utilization of maintenance history to assist in the work identification, planning and work execution of maintenance activities. The challenge in the railways includes a large geographic area resulting in challenges to minimize maintenance visits and resulting costs. It further provides details on the integration and efficient utilisation of information and presents the value it adds to ensure maintenance effectiveness. The study focuses on methods for data collection and a systematic process for decision-making analysis with the ultimate aim of producing an effective maintenance plan (specifically for mechanised tamping) based on all available infrastructure management data including operational requirements. Lastly the effect of condition-based maintenance is illustrated, demonstrating that this strategy increases maintenance effectiveness (doing the right things), resulting in a decrease in maintenance cost and an increase in capacity. / Dissertation (MEng)--University of Pretoria, 2012. / Civil Engineering / unrestricted

Bakgrunden till arbetet är att EKS 11 och Eurokod ger möjlighet till egen tolkning vid dimensionering av olyckslaster. Dimensioneringen varierar därmed med den aktuella konstruktörens tolkning. Detta kan medföra en överdimensionering som är ekonomiskt och miljömässigt onödig.   Syftet med arbetet var att utreda byggnadsdelars dimensioneringsprocess för brand och påkörning enligt EKS11 och Eurokod. Målet var att skapa arbetsgångar för dimensionering av en loftgångspelare utifrån brand eller påkörning. Som underlag för dimensioneringsgången användes ett projekt som Sweco tidigare hade arbetet med. Projektet bestod av dimensionering av pelare till loftgångar. Loftgångarna hör till ett bostadshus med tre våningar och stöds av utvändiga pelare.   Branddimensionering gjordes för en oskyddad stålpelare, limträpelare och brandskyddsmålad stålpelare. Utifrån byggnadens förutsättningar kunde den brandtekniska klassen bestämmas till R60 för samtliga pelare. Brandlasten för loftgångspelaren utifrån egentyngder och variabla laster var 68 kN och det antogs att pelaren utsattes för en 4-sidig brand. Utnyttjandegraden för en oskyddad stålpelare med en VKR-profil 120x120x6,3 och hållfastheten S355 var 90 %. Den utvändiga brandkurvan användes vid dimensionering.   Den brandskyddsmålade pelaren med en VKR-profil 80x80x6,3 och hållfastheten S355 krävde 2250 g/m2 av brandskyddsfärg för att klara av brandlasten.   Utnyttjandegraden för en oskyddad limträpelare, i furu, med profilen 215x270 och hållfastheten GL30c var 77 %. Efter 60 minuters brand hade tvärsnittet för limträet minskat från 215x270 till 98x178.   Loftgångspelaren var placerade 2,5 meter från ytterkanten på en cykel/gångbanan, vilket medförde att dimensionering mot påkörning erfordras. Den statiska påkörningskraften för loftgångspelaren var 82 kN. Kraftens storlek baserades på att cykel/gångbanan kräver underhåll, vilket medför att fordon kommer vid upprepade tillfällen bruka vägen. Loftgångspelaren dimensionerades för en horisontal kraft på 82 kN och en vertikal kraft på 53 kN. För stålpelaren med en VKR-profil 120x120x6,3 och hållfastheten S355 var utnyttjandegraden vid böjknäckning 90 %. Utnyttjandegraden vid böjknäckning var 86 % för en limträpelare med tvärsnittet 215x270 mm och hållfastheten GL30c.   Utifrån beräkningarna av brand och påkörning för loftgångspelare upprättades fyra arbetsgångar som redovisas i flödesscheman. Två för brand vid användning av stål eller limträ. Två för påkörning vid användning av stål eller limträ. / The background for the work is that the EKS 11 and Eurocode each are open for interpretation when sizing accidental loads. Therefore, sizing varies according to each constructor’s interpretation. This may result in oversizing which leads to increased economic costs and climate impact.   The purpose of this investigation was to examine the uncertainties of EKS 11 and Eurocode regarding fire and collision. The goal was to create a workflow for designing exterior corridors columns for fire or collision. An earlier project from Sweco Structures were used as the basis for the workflow and design. The project designed columns of glulam or steel for exterior corridors belonging to a residential building with three floors.   The fire design was performed for an unprotected steel column, a fire painted steel column and a glulam column. The fire resistance class was determined to be R60 for all exterior columns based on the building conditions. The fire load for the column was 68 kN based on the self-weight and imposed load. It was assumed that the column was exposed to a 4-sided fire. The utilization rate for the unprotected steel column with a VKR profile 120x120x6,3 mm and the strength S355 was 90%. The external fire curve was used for the design.   The fire painted column with a VKR profile 80x80x6,3 mm and the strength S355 required 2250 g/m2 of fireproof paint to sustain the fire load.   The utilization rate for an unprotected glulam column with a profile of 215x270 mm and the strength GL30c after 60 minutes of fire exposure was 77 %. The remaining area after the fire was 98x178 mm.   The column for the exterior corridor was situated 2,5 meters from the outer rim of a bike and a walkway which means that a collision force needs to be considered. The static collision force was 82 kN. The size of the force is based on the fact that a walkway needs maintenance which means that vehicles will repeatedly use the road. The column was designed for a horizontal force of 82 kN and a vertical force of 53 kN. The steel column with a VKR profile 120x120x6,3 mm and the strength S355 had a utilization rate of 90 % with regards to flexural buckling. The utilization rate for the glulam column with a profile 215x270 mm and the strength GL30c regarding flexural strength was 86 %.   Four workflows were created based on the fire and collision calculations and is reported in flow charts. Two for fire design when using steel or glulam. Two for collision when using steel or glulam.

Water-related diseases are a major issue of public health worldwide. Raw drinking water retrieved from surface and groundwater undergoes treatment at water treatment plants in order to disable certain microorganisms that if were to be released in drinking water, would cause a variety of unwanted gastrointestinal symptoms. As such, it is imperative that research goes in the direction of preventing the entry of such microorganisms in drinking water by identifying potential risk situations involving high concentrations in raw water.   The objective of this thesis research is to examine variations and peaks in concentrations of notable pathogens found in raw water samples retrieved from the influx of five different water treatment facilities in Sweden, along with visualisations of related health symptoms that might have been the result of pathogen contamination in areas that were supplied by those waterworks. The primary source for the raw water data is Folkhälsomyndigheten (Public Health Agency of Sweden) and covers the period of March 2014 to 2015 in an ongoing project, however data from before this project started have also been retrieved from Vattentäktsarkivet covering the period of 2009-2013 for the representative waterworks. The data used to visualise the related health symptoms were retrieved from Healthcare Guide 1177, based on telephone triage. Along with that data, SCB data on population were used along with a shapefile of postal areas of Sweden, provided by Postnummerservice.   In order to visualise symptoms across time and to examine possible rises of symptoms related to gastrointestinal diseases across the period of analysis, Excel and Geographical Information System (GIS) toolboxes Spatial Analyst and Data Management were used in order to process the data from 1177, create time-animated outputs that depicted the symptoms monthly for every area and to identify areas that reported the most symptoms using density maps and hot-spot analysis. Statistical analysis and graphs for the data regarding the raw water dataset were performed in Excel.   The results implied minor correlations between high concentrations of notable pathogens in raw water and a rise of symptoms reported to 1177 in some months and areas during the period of analysis. The suspect months and areas were identified through a visualisation of clusters of symptoms and increases in comparison to normal seasonal effects. The winter months along with March and April generally showed the highest number of reported symptoms in all counties and a comparison of incidence rates revealed that the municipalities of Östersund and Trollhättan had the highest incidence rates in regards to their population.   A large source of error in the analysis is the raw water dataset itself. Since raw water always undergoes treatment, it is typically assumed that pathogens are removed prior to entering drinking water. It is possible that pathogens might elude this process, though it is difficult to exclude other sources of infection, such as contaminated food or seasonal contagious effects like winter-vomiting disease without access to patient records.

This report is aim to compared building standard of Chengdu city and Stockholm, as well as find out the suitable energy-saving scenario for two places. To simulate the total energy consumption of logistics building, energy software named design builder will be introduce to calculate. Some of other analysis will be implemented at the same time, including economic analysis, environment analysis and thermal comfort analysis.

Industrialization of construction is by some considered to be a solution to the building industry's problems about the lack of quality, high production costs, low productivity and poor environmental adaptation. Meanwhile, industrialized construction partly earned a bad reputation after the million housing program. As large-scale projects where promoted during this period, it worked very well to use the technique of construction elements. In the mid seventies though, criticism arose which claimed that the aesthetic qualities had been deprived in the corporates effort to make housing production as efficient as possible. Tyréns, Derome and CBBT (centre for building and housing in wood) cooperates in a development project to develop a building system for 4-8-storey buildings, consisting of three platforms: a technology platform, an IT platform and a processing platform. The technology platform consists of flexible, industrially built flat modules of wood and from this platform the subsystem stairwells, is broken out. The purpose of this thesis is to find an approach to analyze the demands and requirements in the development of stairwells and the goal is then to develop and construct a modular stairwell that meet current requirements and standards, and which solution can be easily integrated with existing building systems. The requirements and wishes have been compiled through literature studies, through the study of the building system, and through interviews with the developers of the building system and suppliers of stairs and elevators. The requirements are then compiled with the help of a simplified variant of the QFD method. The requirements have also been grouped according to whether they apply layout, all modules, walls or ceilings. After the compilation of requirements, new modules for the stairwell was developed. This work has been carried out by developing the existing modules of the construction system. It has brought several advantages. Among other things, as follows: • The number of modules in the build system has been brought down. • It has been easy to see to, that there are functional interface to other modules in the build system. • The new modules have the same manufacturing processes and the same fitting as the other modules in the build system. Calculations have also been made to verify allowable loads in terms of deflections and joints and to check that the fire requirements are met.

This is a study of partial composite action in timber constructions. The aim was to determine a method for calculating the flexural rigidity also known as bending stiffness in CLT-constructions made of CLT and wooden latches with screw connectors. The chosen method became a combination of Eurocode 5 and mathematical models. The goal was to try to show how partial composite action between CLT and wooden latches can improve the flexural rigidity of the construction to allow a longer span in floors and higher loads in walls.   The results show a significant increase in flexural rigidity to the extent that the total rigidity in some cases is almost as high as with full composite action. The addition in rigidity is highly dependent on the angle of the screws as well as the span of the construction. This makes easy assembly of the screw connection an important question as screws mounted at an angle gives a significantly higher capacity but is more difficult to assemble compared to screws at right angle. The calculations show that constructions with no composite action, where the latches’ rigidity is added to the CLT´s can be a first step towards higher utilization of the material, especially in walls. The advantage with no composite action is that the demands on the connection are lower which makes for easy assembly. In conclusion partial composite action can be an interesting topic for further studies but with more focus on the connection design with respect to the assembly on site. Also, areas as cost and building acoustics are relevant for further studies.

QC 20110630

In recent years, there has been a growing research interest in throughput optimization problems in a multi-hop wireless network. MIMO (multiple-input multiple-output), as an advanced physical layer technology, has been employed in multi-hop wireless networks to increase throughput with a given bandwidth or transmit power. It exploits the use of multiple antennas at the transmitter and receiver to increase spectral efficiency by leveraging its spatial multiplexing (SM) and interference cancellation (IC) capabilities. Instead of carrying complex manipulations on matrices, degree-of-freedom(DoF) based MIMO models, which require only simple computations, are widely used in networking research to exploit MIMO's SM and IC capabilities. In this thesis, we employ a new DoF model, which can ensure feasible solution and achieve a higher DoF region than previous DoF-based models. Based on this model, we study the DoF scheduling for a multi-hop MIMO network. Specifically, we aim to maximize the minimum rate among all sessions in the network. Some researches have been done based on this model to solve throughput optimization problems with the assumption that the route of each session is given priori. Although the fixed routing decreases the size of the problem, it also limits the performance of the network to a great extent. The goal of this thesis is to employ this new model to solve the throughput maximization problem by jointly considering flow routing, scheduling, and DoF allocation for SM and IC. We formulate it as a mixed integer linear program (MILP), which cannot be solved efficiently by commercial softwares even for moderate sized networks. Thus, we develop an efficient polynomial time algorithm by customizing the sequential fixing framework. Through simulation results, we show that this algorithm can efficiently provide near-optimal solutions for networks with different sizes. / Master of Science

In 1964, the then Swedish government decided that one million new homes would be erected within a decade to tackle the then housing shortage. This decision was characterized as the “million program”. Just over five decades later, many of the million program's buildings needrenovation. After many years of use, structural engineering measures are required to satisfytoday's standards regarding thermal comfort. One or more deficiencies mentioned about the buildings of the million programs can have a direct or indirect impact on the thermal comfort. Poor or excessive ventilation, windows that are leaky or have high heat permeability and poor insulation are factors that can adversely affect thermal comfort. Thermal comfort is a key issue today as it affects us all. According to The Public Health Agency of Sweden, thermal comfort can have several different effects on our health, where too high temperature can result in headaches, nausea, and fatigue, while too cold indoor climate can lead to more dramatic health effects such as lung-related diseases, vascular diseases and affected blood pressure. We Swedes spend about 90 % of our lives indoors.In this case study, a two-story slat was examined on Regnbågsgatan in Gävle with the aim of identifying deficiencies and developing a model in IDA-ICE and then investigating various improvement measures. Data to produce the model was collected through an ocular inspection with IR thermography for identification of thermal bridges, drawings, user data from Sveby and data from the Gavlegårdarna which were then supplemented with a literature study. The model was created with four different programs: Revit, where a basic geometric model was created, Simplebim for validation of model before IDA-ICE, COMSOL Multiphysics for modeling thermal bridges and finally IDA-ICE for energy and climate simulations.Potential improvement measures were discovered through literature study and analysis of deficiencies that could be identified in simulation of current cases for the slat building. The measures were carried out by changing different input data for the different components of the slat housing in the IDA-ICE program. A survey study was conducted to investigate how users experienced the thermal climate; however, the outcome of this study did not lead to anything as there were too few respondents.Deficiencies that could be detected during the first simulation were that rooms located at the gables had poor thermal comfort because the gables were not sufficiently insulated. Rooms with the worst thermal comfort could be identified at the northern end and a trend that floor 2 had poorer thermal comfort compared to floor 1. A combination of additional insulation of the gables, replacement of windows and balcony doors to those with a lower U-value, as well as a temperature-controlled FTX system had the best effect on thermal comfort. After this action, the building meets the requirement for bronze in terms of the thermal climate summer and winter according to Sweden Green Building Council.

In the beginning stage when a building is to be constructed it can be difficult to choose the material for the supporting frame. Today there is a lot of different materials with different properties, each material often has good properties while at the same time there is a worse property, heavy weight for example. The growing debate about climate change has led to an increased use of building with wood, as it is positive from a climate perspective. Structor Byggteknik Umeå AB has in their work as construction consultants received questions from customers who want to know more about the differences between cross-laminated wood (CL-wood) and light beams. These questions are the foundation to this project, in which the differences between how the chosen material affects the living area will be compared. The project will also include a comparison to see which material that consumes the most amount of wood. The aspect of climate impact will also be compared in the unit CO2-equivalents, which is a topical question today. To produce the data that will be used to compare the material two buildings where dimensioned, one with CL- wood and one with light beams. To perform the dimensioning a reference building made with concrete was used, from which a section of the building was retrieved as well as loads. In consultations with Structor, requirements were set for sound, U-value, and fire for the buildings that were dimensioned. The load countdown was performed with the program Statcon structure where the most loaded walls and floor slabs were checked in both serviceability limit state (SLS) and ultimate limit state (ULS). From the structure of the floor slabs and walls the amount of wood per 1 m2 were calculated for every building component. With known wall thickness two 3D-modells were produced, one for each material. From the 3D-modells the living area was compared. For the comparison of climate impact two climate declarations including module A1-A5 was created with the construction sector’s environmental calculating program (BM). The comparison of the living area resulted in a difference of 0,8 m2 per floor where the CL-wood was the larger one, despite that the exterior walls and the dividing walls were thicker for the building with CL-wood. This might be because the load-bearing inner walls in the light beam building were a lot thicker than the inner walls in the CL-building. The material consumption was compared by calculating the volume of wood for 1 m2 for every building component. The result showed a difference of 327 % where the light beam building consumed a smaller amount of wood. Most likely this is because the CL-slabs are homogeneous wood elements which increase the amount of wood per m2, while the light beam in the construction is placed with a center distance of 600 mm. One climate declaration was made for each building, the climate impact was compared both component against component and with a total of 1 m2 of every building component. The result showed that when all the building components is compared the CL-building generated a higher climate impact. A closer comparison between component against component shows that the floor slabs in the CL-building has a lower climate impact than the floor with light beams. The conclusion of the project is that both CL-wood and light beams have its advantage, but it can be difficult to say exactly which material is the better one. Despite this, light beams have two advantages in this project while CL-wood only has one. To facilitate the choice a check should be done where all the conditions and requirements are listed. With that list it’s possible to compare which material suits for the specific project. / I den initierande fasen för en byggnad kan det vara svårt att välja material för den bärande stommen. Idag finns det många olika material med olika egenskaper, varje material har någon eller några fördelar samtidigt som de också har en eller flera sämre egenskaper. I och med den växande klimatdebatten har allt fler valt att bygga med trä, då det är positivt ur ett klimatperspektiv. Structor Byggteknik Umeå AB (hädanefter Structor) har i sitt arbete som byggnadskonsulter fått frågor från kunder som vill veta mer om skillnaden mellan KL-trä och lättbalkar. Structor vill ha ett underlag för att kunna visa sina kunder vilket av de två alternativen som lämpar sig bäst för deras projekt. Detta är de som låg till grund för det här projektet där KL-trä och lättbalkar jämfördes med aspekter på hur materialvalet påverkar boarean samt materialåtgången av volymen trä. Även en jämförelse av klimatpåverkan i CO2-ekvivalenter utfördes för att belysa skillnader i ett dagsaktuellt ämne. För att ta fram det underlag som senare användes för att bedöma materialens för- och nackdelar dimensionerades två byggnader, en byggnad med KL-trä samt en byggnad med lättbalkar. Dimensioneringen utgick från en betongbyggnad som Structor dimensionerat under 2021, från den hämtades en sektion av byggnaden som gav bestämda mått samt laster. I samråd med Structor sattes krav på ljud, U-värde och brand för byggnaderna som dimensionerades. Lastnedräkningen utfördes med hjälp av programmet Statcon där de mest belastade väggarna och bjälklagen sedan kontrollerades i både bruksgränstillstånd samt i brottgränstillstånd. Den färdiga uppbyggnaden av bjälklag och väggar användes för att sammanställa mängden trä för 1 m2 av respektive byggdel. Med kända väggtjocklekar 3D-modellerades en våning av varje byggnad, 3D-modellerna användes därefter för att jämföra boarean. För jämförelsen av klimatpåverkan skapades en klimatdeklaration för modul A1-A5 med byggsektorns miljöberäkningsprogram (BM). Boarean som jämfördes utifrån 3D-modellerna resulterade i en skillnad på 0,8 m2 vilket blev cirka 0,47 % per våning där KL-byggnaden var den större, trots att ytterväggarna och de lägenhetsavskiljandeväggarna var tjockare i KL-byggnaden. Detta kan bero på att de bärande innerväggarna var tjockare för lättbalks-byggnaden, vilket var den avgörande faktorn för boarean. Materialåtgången jämfördes genom att beräkna volymen trä för 1 m2 av varje byggdel för respektive byggnad. Resultatet visade en skillnad på 327 % där lättbalksbyggnaden förbrukade mindre trä. Detta beror mest sannolikt på att KL-skivorna är homogena träelement som ökar mängden trä / m2, medan väggar med lättreglar endast placeras med centrumavstånd på 600 mm. En klimatdeklaration för varje byggnad gjordes i BM, klimatpåverkan jämfördes både byggdel mot byggdel och totalt där 1 m2 av varje byggdel sammanställdes. Resultatet visade här att KL-byggnaden genererade en högre klimatpåverkan när alla byggdelar jämförs. Granskas i stället varje byggdel för sig så har bjälklagen i KL-byggnaden en lägre klimatpåverkan än bjälklagen i lättbalksbyggnaden. Slutsatsen från projektet är att KL-trä och lättbalkar har sina fördelar och att det är svårt att dra en tydlig slutsats och säga vilket av dem som är det bättre. Dock så har lättbalkar två fördelar i detta projekt och KL-trä har endast en. Kontroll av förutsättningar och krav bör göras för varje projekt där materialet sedan jämförs för att ta reda på vilket som lämpar sig bäst för just det projektet.