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  • 301.
    Alriksson, Stina
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Conjoint analysis as a tool for communication and corporate environmental decision-making2008Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Conjoint analysis has been used extensively in marketing, transportation and healthcare for the past 50 years. Since the mid-1990s, it has also been applied to an increasing number of environmental issues. In this thesis, conjoint analysis is applied to environmental objectives of the Swedish steel industry. The aim of the research project has been to develop a method for eliciting stakeholder preferences for environmental issues and to present the results to the stakeholders through the multivariate data analysis method of partial least squares regression.

    This licentiate thesis is based on three studies: a literature review of all conjoint studies conducted on environmental issues, a pilot study in which a new method was developed, and a main study where this method was tested on four environmental objectives of the Swedish steel industry. Up to the present, 109 environmental conjoint studies have been carried out. Recently, studies in environ¬mental economy have dominated, with investigators trying to estimate a mone¬tary value on environmental values or products. The problem selection has varied widely, from ecosystem management and green products to waste and risk management.

    One trend among environmental conjoint studies has been to use conjoint methods that report results at a group level. In the pilot study here, conjoint analysis was combined with partial least squares regression to enable presentation of results at individual level. The benefit of individual-level results is that they can be used to initiate a dialogue between an industry and its stakeholders, as well as between different stakeholder groups. The presentation mode also allows the researcher to find segments of respondents that think alike, although perhaps from different groups. In the pilot study, cluster analysis was used successfully to find hidden segments among the respondents.

    In the main study, the method from the pilot study was used to elicit preferences for four environmental objectives of the Swedish steel industry: reduced use of non-renewable energy, reduced use of non-renewable resources, decreased emission of carbon dioxide and weight reduction of products. Six stakeholder groups participated in the study, and the results showed that decreased emission of carbon dioxide was the environmental objective that most participants prioritised highest. Lowest priority was given to weight reduction of products.

    Conjoint analysis combined with multivariate data analysis methods such as partial least squares regression, principal component analysis and cluster analysis has been verified as an effective method for eliciting stake¬holder preferences on industry-wide environmental issues.

  • 302.
    Alriksson, Stina
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Grip, Carl-Erik
    Luleå Tekniska Universitet.
    Studies of preferences as an extra dimension in system studies2011In: World Renewable Energy Congress – Sweden, 8–13 May, 2011Linköping, Sweden: Volume 7, Industrial Energy Efficiency / [ed] Bahram Moshfegh, Linköping: Linköping University Electronic Press, 2011, p. 1732-1739Conference paper (Refereed)
    Abstract [en]

    Industrial energy systems are complicated networks where changes in one process influence itsneighboring processes. The network complexity increases if production/use of bio fuel is introduced in anexisting system. Process integration can be a useful tool to study such systems and thus avoid sub optimization.However, changes in an industrial complex do not only influence the technical values of energy and materialefficiency. The social impact is also important and sometimes is comparable to that of technical factors.A process integration project has recently been carried out for a paper mill in northern Sweden with a side viewon future expansion with a bio refinery. An activity to study the social impacts were included through a Conjointanalysis, a stated preference method that combines statistics and interviewing technique.The results indicate that the participants are divided in four groups, the largest group focusing on a change in theprocess towards a bio refinery, the second largest focusing on the local environment. The third and fourth groupboth look at the local forestry, one group wanting to increase local forest production, and one rejecting anincrease.

  • 303.
    Alriksson, Tobias
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Visualisering av byggprojekt i Revit2014Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [sv]

    Rapporten avhandlar visualiseringen i marknadsföringsstadiet av ett byggnadsprojekt med tillämpning på Trivselhus bostäder. För att få en grund till vad som ska ändras gällande företagets nuvarande visualisering har intervjuer genomförts med samtliga berörda parter. Dessa är säljare, kunder och husdesigners. Efter detta har två förslag till förändringar av nuvarande visualiseringar arbetats fram i Revit med intervjuerna som underlag.

  • 304.
    Alsouda, Yasser
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    An IoT Solution for Urban Noise Identification in Smart Cities: Noise Measurement and Classification2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Noise is defined as any undesired sound. Urban noise and its effect on citizens area significant environmental problem, and the increasing level of noise has become a critical problem in some cities. Fortunately, noise pollution can be mitigated by better planning of urban areas or controlled by administrative regulations. However, the execution of such actions requires well-established systems for noise monitoring. In this thesis, we present a solution for noise measurement and classification using a low-power and inexpensive IoT unit. To measure the noise level, we implement an algorithm for calculating the sound pressure level in dB. We achieve a measurement error of less than 1 dB. Our machine learning-based method for noise classification uses Mel-frequency cepstral coefficients for audio feature extraction and four supervised classification algorithms (that is, support vector machine, k-nearest neighbors, bootstrap aggregating, and random forest). We evaluate our approach experimentally with a dataset of about 3000 sound samples grouped in eight sound classes (such as car horn, jackhammer, or street music). We explore the parameter space of the four algorithms to estimate the optimal parameter values for the classification of sound samples in the dataset under study. We achieve noise classification accuracy in the range of 88% – 94%.

  • 305.
    Alsouda, Yasser
    et al.
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Pllana, Sabri
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Kurti, Arianit
    RISE Interactive, Sweden.
    A Machine Learning Driven IoT Solution for Noise Classification in Smart Cities2018In: Machine Learning Driven Technologies and Architectures for Intelligent Internet of Things (ML-IoT), August 28, 2018, Prague, Czech Republic, Euromicro , 2018, p. 1-6Conference paper (Refereed)
    Abstract [en]

    We present a machine learning based method for noise classification using a low-power and inexpensive IoT unit. We use Mel-frequency cepstral coefficients for audio feature extraction and supervised classification algorithms (that is, support vector machine and k-nearest neighbors) for noise classification. We evaluate our approach experimentally with a dataset of about 3000 sound samples grouped in eight sound classes (such as, car horn, jackhammer, or street music). We explore the parameter space of support vector machine and k-nearest neighbors algorithms to estimate the optimal parameter values for classification of sound samples in the dataset under study. We achieve a noise classification accuracy in the range 85% -- 100%. Training and testing of our k-nearest neighbors (k = 1) implementation on Raspberry Pi Zero W is less than a second for a dataset with features of more than 3000 sound samples.

  • 306.
    Alsouda, Yasser
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Pllana, Sabri
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Kurti, Arianit
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    IoT-based Urban Noise Identification Using Machine Learning: Performance of SVM, KNN, Bagging, and Random Forest2019In: Proceedings of the International Conference on Omni-Layer Intelligent Systems (COINS '19), New York: ACM Publications, 2019, p. 62-67Conference paper (Refereed)
    Abstract [en]

    Noise is any undesired environmental sound. A sound at the same dB level may be perceived as annoying noise or as pleasant music. Therefore, it is necessary to go beyond the state-of-the-art approaches that measure only the dB level and also identify the type of noise. In this paper, we present a machine learning based method for urban noise identification using an inexpensive IoT unit. We use Mel-frequency cepstral coefficients for audio feature extraction and supervised classification algorithms (that is, support vector machine, k-nearest neighbors, bootstrap aggregation, and random forest) for noise classification. We evaluate our approach experimentally with a data-set of about 3000 sound samples grouped in eight sound classes (such as car horn, jackhammer, or street music). We explore the parameter space of the four algorithms to estimate the optimal parameter values for classification of sound samples in the data-set under study. We achieve a noise classification accuracy in the range 88% - 94%.

  • 307.
    Alsterlind, Stina
    Linnaeus University, Faculty of Engineering and Technology, Kalmar Maritime Academy.
    Att leva med en sjöfarare: En kvalitativ studie ur partnerns perspektiv2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A profession at sea involves alternating away/home periods, which means a special situation for the seafarer in reconciling profession and family life. This rotation system can also be assumed to have consequences fot those who live with a seafarer. Against this backgrund, the purpose of this study was to illustrate how the rotation system may effect the partners´daily lives ande thier ralationship with the saefarer. A qualitaive approach was used because I wanted to understand and describe the respondents´personal experiences. The results showed that the perception among the respondents varied. The problematic aspects that emerged were above all the absence of acxact dates for the serfarer to sign on and off the vessel. Thay found it difficult to be proactive and make common plans when the dates often changed. The positive aspects that were highlighted included; quality time together, own time and natural breakes in the realtionship which could lead to positive emotions of renewal. The key to getting the relationship to work was seen as a positive attitude and a common compromise from both parties.

  • 308.
    Al-Sundook, Amaar
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Testkrets för lavingenombrott för högspännings diod2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    High frequency power converters are used for both consumer products and in industrial power plants. In some industrial applications, a very high output voltage can be obtained. A transformer gives a high voltage in the secondary, which is then rectified by diodes. High voltage diodes are important components in the rectifier to withstand tough work so that the transformer supplying the desired high voltage.

    Alstom in Växjö is working with Air Pollution Control Equipment. They develop marketing and executing projects with advanced systems and products for smoke gas cleaning to power plants and the industry. The objective is to minimize the risk of negative impact on the environment. In Växjö, Alstom also has a large unit for service, which also consists of several local offices covering all parts of the country.

    Another important facility in Växjö is Alstom's global research and development center, where new environmental solutions and technologies are tested in large scale format. The test center has a long tradition of environmental control systems, but during the past decade the center has been one important platform for the development of Alstom’s products for carbon particle separation (electrostatic filter). These electrostatic filters use diodes as the main component of a high frequency transformer. The diodes must be specially designed to withstand high voltages. The development of the Alstom invented a new type of power diode.  The idea is that the diode is withstand of 10kV in the reverse direction.

    The goal of this work is based on building a facility to test the new diode and see how the diode works with high voltage in the reverse direction condition.

  • 309.
    Alsyouf, Imad
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Cost Effective Maintenance for Competitve Advantages2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes the role of cost effective maintenance in achieving competitive advantages. It explores by means of a survey which maintenance practices are used, and how maintenance policies are selected in Swedish industries. Also, it suggests a model for selecting the most cost effective maintenance policy, and how to improve the effectiveness of condition based maintenance decision-making. Finally it discusses how to assess the impact of maintenance practices on business strategic objectives.

    The main results achieved in the thesis are 1) A better understanding of maintenance organisation, management, systems and maintenance status in Swedish industry. For example, it was found that about 70% of Swedish companies still consider maintenance as a cost centre. Preventive and predictive maintenance approaches are also emphasised. 2) Most Swedish firms, i.e. about 81%, use the accumulated knowledge and experience within the company as a method for maintenance selection. Besides, about 31% use a method based on modelling the time to failure and optimisation. About 10% use failure mode effect and criticality analysis (FMECA) and decision trees and only 2% use multiple criterion decision-making (MCDM). However, the most used maintenance selection method is not the one most satisfactory to its users. Furthermore, about 30% use a combination of at least two methods. 3) A practical model for selecting and improving the most cost effective maintenance policy was developed. It is characterised by incorporating all the strengths of the four methods used in industry. 4) A mechanistic model for predicting the value of vibration level was verified both at the lab and in a case study. 5) A model for identifying, assessing, monitoring and improving the economic impact of maintenance was developed and tested in a case study. Thus it was proved that maintenance is no longer a cost centre, but could be a profit-generating function.

    To achieve competitive advantages, companies should do the right thing, e.g. use the most cost effective maintenance policy, and they should do it right, e.g. ensure that they have the right competence. Furthermore, they should apply the never-ending improvement cycle, i.e. Plan-Do-Check-Act, which requires identifying problem areas by assessing the savings and profits generated by maintenance and monitoring the economic impact of the applied maintenance policy. Thus, they would know where investments should be allocated to eliminate the basic reasons for losses and increase savings.

    The major conclusion is that proper maintenance would improve the quality, efficiency and effectiveness of production systems, and hence enhances company competitiveness, i.e. productivity and value advantages, and long-term profitability.

  • 310.
    Alsyouf, Imad
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Maintenance practices in Swedish industries: Survey results2009In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 121, p. 212-223Article in journal (Refereed)
    Abstract [en]

    The purpose of this paper is to investigate the maintenance practices that are used in Swedish industry. The study was performed by conducting a cross-sectional survey within Swedish firms that have at least 100 employees. The main results achieved from the study show that the role of maintenance is not highly recognised. There is a need to spend and invest more in maintenance, which is considered by the majority of Swedish industries as a necessary expense. Although about 13% of the maintenance department time is spent on planning maintenance tasks, nevertheless, about one third of the time is spent on unplanned tasks. There is a need for more adoption of maintenance concepts such as total productive maintenance (TPM) and reliability-centred maintenance (RCM). The lack or ineffectiveness of planning and scheduling can significantly restrict the maintenance department in achieving its objectives and can thus prevent the company from maximising business profits and offering competitive advantages.

  • 311.
    Alsyouf, Imad
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    The Role of Maintenance in Improving Companies' Productivity and Profitability2002In: Proceedings IFRIMmmm: Maintenance mangagement & modelling conference, Växjö, 2002, Vol. 105, no 1Conference paper (Refereed)
  • 312.
    Alsyouf, Imad
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    The Role of Maintenance in Improving Companies' Productivity and Profitability2007In: International Journal of Production Economics, ISSN 0925-5273, Vol. 105, no 1, p. 70-78Article in journal (Refereed)
    Abstract [en]

    This paper illustrates how an effective maintenance policy could influence the productivity and profitability of a manufacturing process. It was possible to show how changes in the productivity affect profit, separately from the effects of changes in the uncontrollable factors, i.e. price recovery. The main results of the case study performed at a Swedish paper-mill showed that a paper-mill machine could, ideally, generate extra profit of at least 7.8 million Swedish kronor (SEK) (approximately US$ 0.975 million) per year, i.e. 12.5% of its yearly maintenance budget, if it avoids all unplanned stoppages and bad quality production due to maintenance-related causes. Thus, maintenance is not a cost centre, but a profit generating function.

  • 313.
    Alsyouf, Imad
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Wind energy system reliability and maintainability, and operation and maintenance strategies2010In: Wind energy systems: optimising design and construction for safe and reliable operation, Cambridge: Woodhead Publishing Limited, 2010, no 10, p. 303-328Chapter in book (Refereed)
    Abstract [en]

    This chapter discusses the reliability, operation and maintenance strategies for wind power systems. It examines the role of systems engineering in optimising the aspects of a system relating to reliability, supportability and maintainability. It considers various maintenance approaches and the role of proper maintenance practices in providing a secure and reliable energy supply at the right cost. It discusses the importance of identifying and understanding the relevant cost factors associated with wind power systems, based on lifecycle costing and using relevant performance measures to help select a cost-effective maintenance approach. It then reviews some efforts aimed at improving the design, production, construction, operation and maintenance of wind power systems. Finally, some future trends are discussed in the areas of operation and maintenance of wind power systems.

  • 314.
    Alsyouf, Imad
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Alzghoul, Ahmad
    Luleå University.
    Soft computing applications in wind power systems: a review and analysis2009In: European Offshore Wind 2009 Conference proceedings, 2009Conference paper (Other academic)
    Abstract [en]

    This paper reviews, analyses, discusses and summarises the recent research and development and trends in the applications of soft computing in the field of wind power systems. We show the usage and the influence of soft computing on the different aspects of wind power systems especially in the field of operation and maintenance. This work provides the state of the art in this area which will be a good guidance for future research work. The main results achieved from the study show that the soft computing techniques are adequate for solving the different challenges at the different phases of the life cycle processes of wind power systems.  Using the various soft computing techniques with wind power systems proved to be useful for the wind energy business. Using these tools contribute by improving the robustness of the decisions at different phases of the system's life cycle. Soft computing can enhance the efficiency and effectiveness of the operation and maintenance of offshore wind power systems through improving the availability levels. Thus, providing secure, sustainable and competitive energy supply for the future.

  • 315.
    Altergren, Andreé
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Förberedelse till modernisering av styrsystem för produktion av processvatten2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The heat and power station Allöverket in Kristianstad produced the process water in a plant called the total desalination. In this plant which consists out of two identical lines, they let the incoming water passing through ion exchangers to replace the undesired ions in the water to more desired ions. The reason for doing this is that the undesired ions in the water give coatings on the turbine. When the ion exchangers have been saturated, they must be restored to the original condition. This is done by starting a regeneration program, which consists of a number of steps such as back flushing, intake of chemicals and four different flushes. There are limits on the conductivity and the content of silicon in the water that will be delivered. But there is only measurement of the conductivity connected to the control system, and because of this they control the plant with different timers. To the control system there is connected a number of centrifugal pumps, solenoid valves and instrumentation for measurement of conductivity. In the total desalination sits a Siemens S5 control system that controls the plant after amount of water, conductivity and different times of the sequences. The control functions are now located on a control cabinet out of the factory. The Siemens S5 control system is old and outdated and will be changed to an ABB 800xA control system. This control system they already use to control other parts of the factory from the control room. With this study I have developed a new functional description of the plant and it consists of function diagrams which describes how the software controls the plant today. To the function description, I have also made a new technical description and revised the process scheme so that all documentation of the plant says the same thing.

  • 316.
    Altgen, Michael
    et al.
    Aalto Univ, Finland.
    Willems, Wim
    FirmoLin Technol BV, Netherlands.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rautkari, Lauri
    Aalto Univ, Finland.
    Hydroxyl accessibility and dimensional changes of Scots pine sapwood affected by alterations in the cell wall ultrastructure during heattreatment2018In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 152, p. 244-252Article in journal (Refereed)
    Abstract [en]

    There is a complex link between the water sorption behavior and the presence of accessible hydroxyl groups in the wood cell wall, which can be altered by heat-treatment (HT). This study analyses the effect of changes in the cell wall ultrastructure caused by two HT techniques on the hydroxyl accessibility, water vapor sorption and dimensional changes of Scots pine (Pinus sylvestris L.) sapwood. HT of wood in pressurized hot water at 120-170 °C was applied to cause the preferential bond cleavage, whereas HT of wood in oven-dry state in superheated steam at 180-240 °C was performed to create additional covalent cross-links within the cell wall matrix. Removal of cell wall polymers by HT and water leaching reduced the oven-dry dimensions of wood and enhanced the cellulose aggregation during drying. Cellulose aggregation restricted the cell wall shrinkage in circumferential direction, resulting in inhomogeneous shrinkage of the cell wall with only little changes in lumen volume by HT. Cellulose aggregation also reduced the water-saturated dimensions, but a decrease in swelling was only achieved when additional cross-links were formed by HT in dry state. Additional cross-links in the cell wall matrix also resulted in an additional reduction in water sorption at 25 °C and 93% RH. However, this was not caused by a further reduction in the hydroxyl accessibility. Instead, cross-linking was shown to reduce the amount of accessible OH groups that are simultaneously active in sorption, which was explained based on the concept of sorption of water dimers at hydroxyl group pairs at high RH levels.

  • 317.
    Altsäter, Erik
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Lagerstyrningssystem för ökad flexibilitet2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project has been performed at Production unit 1 (PV1) at Wexiödisk AB, where hood type washing machines is manufactured. The purpose of this project has been to investigate which inventory control models that could be suitable to control the section’s material supplies. The work has been accomplished in two steps. At first, items unique to products manufactured at PV1 were treated, followed by items common with other products. According models in relevant literature, suggestions were made to how the models could be applied practically. The suggestions was presented to and discussed with the parties concerned who chose Two-bin system 2. A trial was carried out according to the principle of “the Japanese river” which implied lowered inventory levels. The problems that occurred were noted. The result was that the number of items that was weekly picked and distributed was reduced which has created a basis to also reduce the administration of the systems picking lists. The item wagon has been removed which has cleared floor space at the assembly section. Conditions have been created to merge two picking lists into one and thereby simplify the work for the inventory staff.

  • 318.
    Alvarez, Claudio
    et al.
    University of Los Andes, Chile .
    Milrad, Marcelo
    Linnaeus University, Faculty of Technology, Department of Media Technology.
    Borie, Francisco
    University of Los Andes, Chile .
    Luna, Martín
    University of Los Andes, Chile .
    CollPhoto: A Paper + Smartphone Problem Solving Environment for Science and Engineering Lectures2014In: Collaboration Technologies and Social Computing: 7th International Conference, CollabTech 2014, Santiago, Chile, September 8-10, 2014. Proceedings / [ed] Takaya Yuizono; Gustavo Zurita ;Nelson Baloian ;Tomoo Inoue; Hiroaki Ogata et al. (Eds):, Springer, 2014, p. 1-15Conference paper (Refereed)
    Abstract [en]

    Recent studies in science and engineering education support that inductive learning activities encouraging active student involvement may improve students’ motivation, development of soft skills and academic performance, compared to traditional lectures. Until recently, several technology-enhanced learning environments have been proposed to facilitate such activities in classrooms. However, these commonly depend on dedicated hardware devices, such as clickers or tablet PCs. Contrastingly, smartphones are being massively adopted by society as these become increasingly powerful and inexpensive. Even so, the use of smartphones as learning tools in lecture halls has still not been widely adopted. In this paper we present CollPhoto, a paper-plus-smartphone environment that supports face-to-face problem solving activities in the classroom. CollPhoto provides the instructor with instant visibility of students’ work, and facilitates him/her conducting discussions, based on a selection of students’ responses. We report on the design and initial validation of CollPhoto in the context of two computer science courses.

  • 319.
    Alvarsson, Johan
    et al.
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Sjöström, Victor
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Konvertering av Kraftringens geotermianläggning: Undersökning av alternativ till köldmediet R134a2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the geothermal plant of 'Kraftringen' the refrigerant R134a, which is a fluorescent greenhouse gas with relatively high GWP (Global Warming Potential), circulates. When the new F-Gas regulation was introduced in 2015, it resulted in a significant price increase for high-pressure GWP refrigerants. 'Kraftringen' therefore wants to investigate which conversion options there are for R134a, partly to reduce costs, but also to minimize the climate impact of the business.

     

    Different refrigerants have been compared with regard as to how they affect the plants performance. Moreover, it has been investigated which refrigerants are in the correct pressure range with regard to what the plants compressor and pipes are designed for. The survey has been done by performing theoretical calculations based on measured values from when the heat pumps operate at maximum load. In the refrigerant selection process, the same evaporation and condensation temperature as during the measuring was used.

     

    In the study we found two refrigerants, R152a and R450A, which would serve as conversion options in terms of them being in the correct pressure and temperature range. Both options have lower GWP and a higher heat factor than the current refrigerant R134a. However, R152a is flammable and has a higher degree of safety than the other two refrigerants.

  • 320.
    Alvunger, Per-Olof
    Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
    Yrkeskunnandets problematik: En studie i yrkeskunnande2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna essä handlar bland annat om det dilemma som finns mellan rollen som yrkesarbetare och lärarrollen. Essän är ett försök av mig att titta på mitt eget yrkeskunnande och kika på några andras berättelser för att försöka hitta nyckelord, analogier och olika exempel som kanske kan leda till en fördjupad förståelse vad ett yrkeskunnande handlar om. Syftet med denna essä är att se om jag lyckas att hitta de nyckelord som jag förknippar med yrkeskunnande och om dessa ord kan återfinnas i andras berättelser. Jag berättar om olika möten jag har haft med människor och redogör för händelser i mitt liv som påverkat mitt eget kunnande. Jag har med några människors berättelser och de redogör för erfarenheter som har påverkat deras kunskap på något sätt.

  • 321.
    Al-Yakoubi, Murad
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Roham, Elias
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Underhåll och övervakning av distributionstransformatorer2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Följande projekt går i korthet ut på att avgöra om användning av kylsystemet i en transformatorstation är relevant, om det minimerar temperaturhöjningen orsakad av effektförlusterna som transformatorn avger. Arbetet ska resultera i förslag på val av transformatorer samt beskriva dess egenskaper. Vidare vill vi finna lösningar kring problemet med överhettning i transformatorstationerna och att de generella kraven såsom låg ljudnivå och tillräcklig ventilation (för att ta bort den värmeförlust som de inre komponenterna avger) skall uppfyllas.  För att kunna ge olika förslag på val av transformator i transformatorstationerna har vi på Holtab AB utfört olika beräkningar som visar skillnad för pris, kvalitet, livslängd och egenskaper (effektförluster, energiförluster).

  • 322.
    Amatya, Suyesh
    et al.
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Kurti, Arianit
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Cross-Platform Mobile Development: Challenges and Opportunities2013In: ICT Innovations 2013: ICT Innovations and Education / [ed] Vladimir Trajkovik and Misev Anastas, Springer, 2013, 1, p. 219-229Chapter in book (Refereed)
    Abstract [en]

    Mobile devices and mobile computing have made tremendous advances and become ubiquitous in the last few years. As a result, the landscape has become seriously fragmented which brings lots of challenges for the mobile development process. Whilst native approach of mobile development still is the predominant way to develop for a particular mobile platform, recently there is shifting towards cross-platform mobile development as well. In this paper, we have performed a survey of the literature to see the trends in cross-platform mobile development over the last few years. With the result of the survey, we argue that the web-based approach and in particular,hybrid approach, of mobile development serves the best for cross-platform development. The results of this work indicate that even though cross platform tools are not fully matured they show great potential. Thus we consider that cross-platform development offers great opportunities for rapid development of high-fidelity prototypes of the mobile application.

  • 323.
    Ambrosius, Robin
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Machine Learning Based Optimizations for Bot Aided Interviews: In the Field of Due Diligence2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Startups need investments in order to scale their business. The value of such startups, especially software-based startups, are difficult to evaluate because there is no physical value that can be judged.  The company DueDive built experience in due diligence by conducting many interviews in this area, which are the base for the due diligence. These interviews are time consuming and require a lot of domain knowledge in the field, which makes them very expensive. This thesis evaluated different machine learning algorithms to integrate into a software that supports such interviews process. The goal is to shorten the interview duration and lowering the required know know for the interviewer using suggestions by the AI. The software uses completed interview sessions to provide enhanced suggestions through artificial intelligence. The proposed solution uses basket analysis and imputation to analyze the collected data. The result is a topic-independent software that is used to administrate and carry out interviews with the help of AI. The results are validated and evaluated in a case study using a generic, self-defined interview.

  • 324.
    Amoateng, Eric
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    COMPUTATION OF THE ARC LENGTH FROM THE SHADOW BOUNDARY OF A CAD OBJECT2012Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    CAD objects are geometrical descriptions of physical scenes from the real world. Ray tracing is used to project the objects onto a pixel screen. A lit and a shadow zone are formed according to the direction of the incoming field (light) and the orientation of the pixel screen. The arc length along the surface of the object, from the shadow boundary to a point in the lit zone, is computed by means of numerical integration. The arclengths corresponding to two orthogonal directions that are aligned with the pixels on the pixel screen are computed and used for interpolation to obtain the arc length for all directions. A number of simulations for various CAD geometries are made using a ray-tracer implemented in FORTRAN 90.

  • 325.
    Anderchen, Silvia
    et al.
    Linnaeus University, Faculty of Technology, Department of Informatics.
    Charvát, Martin
    Linnaeus University, Faculty of Technology, Department of Informatics.
    User Perspective of Privacy Exposure on Facebook: An Examination of Risks Perception Among University Students in Sweden2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Social media become a powerful communication medium for effective online social interaction globally. The use of various social networking sites has integrated into people’s daily lives especially among young adults. Problem arises when personal information is used without individuals’ involvement and relevant privacy risks increased. The main focus for the thesis is to investigate privacy perception and risks knowledge of Facebook usage among university students in Sweden. Based on this focus, the research identifies the key reasons that students decide to use and still use Facebook despite of privacy risks. The study also explores how user perspective of privacy affects the utilization of Facebook. The adopted methodology is qualitative research through the methods of interview and Facebook data analysis among ten young adult students at Linnaeus University in Sweden. As result, the research has identified seven concepts and three special outcomes to answer the research questions. Through the analysis, we have recognized weak perception of privacy risks among university students. Although users claim they are privacy concerned yet large amount of private information is shared on Facebook. The findings have shown that users are somewhat willing to accept certain part of potential privacy risks and personal information usage by different parties, in exchange for benefits and needs of online interaction in today’s modern society. Users believe the shared personal information on Facebook is under control and they can prepare for possible consequences. However, we believe that people’s needs for popular online social interaction outweigh privacy concerns. We suggest that it is significantly important for social networking sites’ users to balance benefits and risks, in order to maintain balanced usage and positive effects of online personal privacy. In the end of the thesis, we have suggested two future research directions based on our research topic.

  • 326.
    Andersen, Henrik
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Speldesignsmönster bland populära sociala nätverksspel: En kartläggande studie över hur användningen av speldesignsmönster i sociala nätverksspel skiljer sig från andra digitala spel.2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Idenna uppsats granskades de fem populäraste sociala nätverksspelen på den sociala nätverkstjänsten Facebook. Syftet var att genom att studera speldesignsmönster urskiljaeventuella skillnader mellan sociala nätverksspel och andra digitala spel. Dessa skillnader analyserades för att kontrollera om de kunde vara bidragande faktorer till sociala nätverksspels popularitet. Avslutningsvis skapades och lanserades två spelprototyper där den ena utrustades med några av de spelmönster som uppmärksammats i undersökningen, medan den andra spelprototypen helt saknade dessa spelmönster. De båda spelprototyperna lanserades samtidigt på den sociala nätverkstjänsten Facebook.

  • 327.
    Andersen, Mattias
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Claeson, Martin
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Utvärdering av ett nyutvecklat samverkansbjälklag och dess utvecklingspotential2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I dagens byggnader ställs allt högre krav på stora rum och öppna ytor vilket ger efterfrågan på ökad spännvidd hos bjälklagen. Detta är svårt att klara av med traditionella träbjälklag. För att ändå få ett lätt bjälklag undersöks möjligheten att kunna fördela ut bjälklagets belastning i två riktningar. Bjälklaget ska alltså vara fyrsidigt upplagt. För att lösa detta har en idé uppkommit som går ut på ett samverkansbjälklag mellan trä och plåt. Detta bjälklag ska i bärriktning 1 bära genom fackverkan medan det i bärriktning 2 ska bära genom balkverkan. För att ett fyrsidigt upplagt bjälklag ska fungera krävs att sambandet mellan kraft och deformation är likvärdigt i båda riktningarna.

    Examensarbetets uppgift har varit att tillverka provkroppar för att undersöka sambandet mellan kraft och deformation i både bärriktning 1 och bärriktning 2. Provning utförs för att se om bjälklaget har förutsättningar att kunna användas i praktiken.

    Efter provning av bjälklagsprovkropparna konstaterades att det finns möjligheter att gå vidare med produkten och fortsätta utvecklingsarbetet. För de provkroppar som provades i bärriktning 1 och 2 var sambandet mellan kraft och deformation nära identisk upp till 7,5 kN då mittnedböjningen var ca 10 mm.

  • 328.
    Andersen, Michael Styrk
    et al.
    University of Southern Denmark, Denmark.
    Brandt, Anders
    University of Southern Denmark, Denmark.
    An alternative to the flutter derivatives2016In: BBAA VIII, 8th International Colloquium on Bluff Body Aerodynamics and Applications, Northeastern University, Boston, Massachusetts, USA, June 7-11, 2016: colloquium proceedings, Boston: Northeastern University, College of Engineering , 2016Conference paper (Refereed)
    Abstract [en]

    A new simplified framework to study flutter and assess the full scale flutter wind speed is suggested. The flutter instability problem is reduced from a problem involving 8 flutter derivatives to only 4 coefficients. With this method it is possible to estimate the self-excited forces with increased precision by using stability diagrams. Furthermore, the physical transparency of the aerodynamic damping and stiffness terms is increased because the development in vertical and torsional damping and stiffness is analysed instead of flutter derivatives.

  • 329.
    Andersen, Michael Styrk
    et al.
    University of Southern Denmark, Denmark.
    Johansson, Jens
    University of Southern Denmark, Denmark.
    Brandt, Anders
    University of Southern Denmark, Denmark.
    Hansen, Svend Ole
    University of Southern Denmark, Denmark ; Svend Ole Hansen ApS, Denmark.
    Aerodynamic stability of long span suspension bridges with low torsional natural frequencies2016In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 120, p. 82-91Article in journal (Refereed)
    Abstract [en]

    Classical flutter of suspended bridge decks can be avoided if the torsional frequencies are lower than the vertical. Wind tunnel tests of single boxes and twin box section models with torsional natural frequencies above and below the vertical frequency has been conducted. Flutter was avoided in all tests where the torsional frequency was lower than the vertical. But too low torsional stiffness caused large static displacements of the girder at medium–high wind speeds and steady state oscillations driven by a combination of torsional divergence and stalling behavior at the critical wind seed. In order to design aerodynamically stable suspension bridges with low torsional natural frequencies it is suggested to increase the mass moment of inertia and provide adequate torsional stiffness by the main cables spacing.

  • 330.
    Anderson, Helén
    et al.
    Jönköping University.
    Lindström, Göran
    Uppsala University.
    Blombäck, Anna
    Jönköping University.
    Dahlin, Peter
    Jönköping University.
    Janhager, Jenny
    KTH, Integrerad produktutveckling.
    Lage Hellman, Jens
    Chalmers.
    Olofsson, Christer
    Swedish University of Agricultural Sciences.
    Olsson, Annika
    Lund University.
    Olsson, Magnus
    Lund University.
    Svengren Holm, Lisbeth
    Lund University.
    Ölundh Sandström, Gunilla
    KTH, Integrerad produktutveckling.
    Skapa kundnärvaro i innovationsprocessen2008In: Innovationsförmåga / [ed] Annika Olsson, Malmö: Holmbergs i Malmö AB , 2008, p. 40-59Chapter in book (Other (popular science, discussion, etc.))
  • 331.
    Andersson, Adam
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Faaborg, Emil
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Philipsson, Peter
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Utveckling av insteg för dumper2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete är utfört i samarbete med dumpertillverkaren Volvo CE i Braås. Då dumpern framförs i hård terräng är det nedersta insteget fäst i två stålvajrar vilket gör det flexibelt. Då flexibiliteten in mot maskinen idag är större än företaget önskar undersöks det i detta arbete alternativ till dagens lösning. Detta görs med hjälp av ingenjörsverktyget ”Eight Steps to Getting Design Right” vilket är en produktutvecklingsmetod som gör det lätt för läsaren att följa utvecklingen från idé till färdig produkt. Arbetet resulterade i att två nya lösningar togs fram. En lik dagens, som bygger på att lösningen är flexibel i två led samt har en styvare vajer jämfört med den på dagens lösning. Den andra lösningen, tänkt som tillvalslösning bygger på leder som innanför ett robust skal är kopplat till en kraftkälla som gör det möjligt för steget att fällas upp och ned.

  • 332.
    Andersson, Alexander
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Bergman, Carl
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Underlag för fördelaktig upphängning av kylvattenledningar i en äldre byggnad2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Arbetet redovisar möjligheterna att hänga upp tyngre vattenledningar i en äldre industrilokal där en äldre byggnadsstandard användes vid uppförandet.

    Ett flertal alternativ har tagits fram och där de mest lämpade har arbetats vidare genom att jämföra fördelar och nackdelar.

  • 333.
    Andersson, Amanda
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Jönsson, Frida
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Effektivisering av produktion på producerande företag.: Fallstudie på Eksjöhus AB.2016Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Studien har utförts på Eksjöhus AB för att öka förståelsen för hur produktion kan effektiviseras med hjälp av produktionsteknik. Företaget står inför en snabbt ökad efterfrågan och behöver effektivisera sin produktion för att kunna möta kommande utmaningar. Vid studier av nuvarande läge konstaterades att produktionens väntetider är mycket långa, samtidigt som mycket material transporteras långa sträckor och hanteras på ett sätt som enligt Lean Production benämns som slösaktigt. Genom fyra förbättringsförslag har ledtiden på en teoretisk nivå kunnat reduceras med cirka 20 procent.

  • 334.
    Andersson, Anders
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Nilsson, Börje
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Acoustic Transmission in Ducts of Various Shapes with an Impedance Condition2008In: International Conference on Numerical Analysis and Applied Mathematics 2008, AIP, Melville, USA , 2008, p. 33-36Conference paper (Refereed)
    Abstract [en]

    Propagation of acoustic waves in a two-dimensional duct with an impedance condition at the boundary, is studied. The duct is assumed to have two ends at infinity being asymptotically straight, but otherwise to be arbitrarily shaped.The so called Building Block Method allows us to synthesize propagation properties for ducts with complicated geometries from results for simpler ducts. Conformal mappings can be used to transform these simple ducts to straight ducts with constant cross-sections.By using recently developed techniques for numerical conformal mappings, it is possible to construct a transformation between an infinite strip and an arbitrarily shaped duct with smooth or piecewise smooth boundary, keeping both smoothness and the well controlled boundary direction towards infinity that the above mentioned method requires.To accomplish a stable formulation of the problem, we express it in terms of scattering operators. The resulting differential equation is solved using wave splitting and invariant embedding techniques. We expand the involved functions in Fourier series, and hence, it is possible to give the operators a matrix representation. Numerical results are produced using truncated matrices.

  • 335.
    Andersson, Anders
    et al.
    Jönköping University.
    Nilsson, Börje
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Biro, Thomas
    Jönköping University.
    Fourier Methods for harmonic scalar waves in general waveguides2016In: Journal of Engineering Mathematics, ISSN 0022-0833, E-ISSN 1573-2703, Vol. 98, no 1, p. 21-38Article in journal (Refereed)
    Abstract [en]

    A set of semi-analytic techniques based on Fourier analysis is used to solve wave-scattering problems in variously shaped waveguides with varying normal admittance boundary conditions. Key components are the newly developed conformal mapping methods, wave splitting, Fourier series expansions in eigenfunctions to non-normal operators, the building block method or the cascade technique, Dirichlet-to-Neumann operators, and reformulation in terms of stable differential equations for reflection and transmission matrices. For an example, the results show good correspondence with a finite element method solution to the same problem in the low- and medium-frequency domains. The Fourier method complements finite element analysis as a waveguide simulation tool. For inverse engineering involving tuning of straight waveguide parts joining complicated waveguide elements, the Fourier method is an attractive alternative including time aspects. The prime motivation for the Fourier method is its added physical understanding primarily at low frequencies.

  • 336.
    Andersson, Andreas
    et al.
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Lindquist, Karin
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Fördjupning i skadestatistik inom sjöfarten: En analys av anmälda arbetsolyckor 2011 – 2013 utförd på uppdrag av Sjöfartens Arbetsmiljönämnd2015Independent thesis Basic level (degree of Bachelor), 10 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis was to analyse the reported work-related accidents in shipping by using frequency combined with consequence. Thereafter the purpose was to reach conclusions regarding which work-related accident was the most serious. The thesis also aimed to find if there were any connections between these accidents. Statistics were ordered from the Swedish Work Environment Authority. These statistics were processed in several ways, for instance demarcations regarding position onboard was made. Since the conditions of reporting workrelated accidents had changed during time, relevant years was chosen after consideration. The result of the study shows that when a person experiences an accident where he or she stumbles, trips, slips or treads heavily, the person is more likely to have a long sick-leave. These types of accidents are also the most common ones. To lose control of equipment or to lose control of equipment used to move material is also a common accident leading to a long sickleave. The only connection found is that the external factor hawser is present at several accidents with different consequences and cause.

  • 337.
    Andersson, Anneli
    et al.
    École Polytechnique of Montréal, Canada.
    Laurent, Patrick
    École Polytechnique of Montréal, Canada.
    Kihn, Anne
    Université Libre de Bruxelles, Belgium.
    Prévost, Michèle
    École Polytechnique of Montréal, Canada.
    Servais, Pierre
    Université Libre de Bruxelles, Belgium.
    Impact of temperature on nitrification in biological activated carbon (BAC) filters used for drinking water treatment2001In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 35, no 12, p. 2923-2934Article in journal (Refereed)
    Abstract [en]

    The impact of temperature on nitrification in biological granular activated carbon (GAC) filters was evaluated in order to improve the understanding of the nitrification process in drinking water treatment. The study was conducted in a northern climate where very cold water temperatures (below 2°C) prevail for extended periods and rapid shifts of temperature are frequent in the spring and fall. Ammonia removals were monitored and the fixed nitrifying biomass was measured using a method of potential nitrifying activity. The impact of temperature was evaluated on two different filter media: an opened superstructure wood-based activated carbon and a closed superstructure activated carbon-based on bituminous coal. The study was conducted at two levels: pilot scale (first-stage filters) and full-scale (second-stage filters) and the results indicate a strong temperature impact on nitrification activity. Ammonia removal capacities ranged from 40 to 90% in pilot filters, at temperatures above 10°C, while more than 90% ammonia was removed in the full-scale filters for the same temperature range. At moderate temperatures (4–10°C), the first stage pilot filters removed 10–40% of incoming ammonia for both media (opened and closed superstructure). In the full-scale filters, a difference between the two media in nitrification performances was observed at moderate temperatures: the ammonia removal rate in the opened superstructure support (more than 90%) was higher than in the closed superstructure support (45%). At low temperatures (below 4°C) both media performed poorly. Ammonia removal capacities were below 30% in both pilot- and full-scale filters.

  • 338.
    Andersson, Anton
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Persson, Johan
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Effektivisering av en produktionsprocess: Med hänsyn till materialförsörjningen2016Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Fallstudiens syfte är att studera ett fallföretags produktionsprocess samt deras materialförsörjning för att få en bättre uppfattning om vilka faktorer som påverkar effektiviteten. Målet är att leverera en layout som ska leda till att upplärningsprocessen blir kortare, att flexibiliteten ökar samt att man får en taktad produktion. Teori och insamlad empirisk data har analyserats noggrant för att komma fram till en slutsats och för att kunna ge rekommendationer på eventuella förbättringsmöjligheter till fallföretaget. Både för och nackdelar till rekommendationerna har diskuterats för att de skulle bli så relevanta som möjligt för fallföretaget.

  • 339. Andersson, B L
    et al.
    Carlsson, Bo
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Monitoring of climatic/environmental data at the Swedish National Testing Institute in Borås1989Report (Other academic)
  • 340.
    Andersson, Caroline
    et al.
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Eklund, Henrik
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Toxiska luftföroreningar ombord på fartyg: Riskbedömning av svensk ombordpersonals yrkesmässiga exponering för toxiska luftföroreningar2016Independent thesis Basic level (degree of Bachelor), 10 HE creditsStudent thesis
    Abstract [en]

    The main purpose of this study was to measure and evaluate the air quality onboard two Swedish ships, and compare the results with the exposure limits laid out by the Swedish Work Environment Authority (Arbetsmiljöverket) and the Swedish population’s exposure to various substances. The results of this study were also meant to be helpful to form new advice and recommendations to minimize exposure and also to provide material for future studies.

    During approximately one week onboard the two ships data were collected using passive samplers to register levels of benzene, nitrogen dioxide and polycyclic aromatic hydrocarbons.

    The results indicated that the air quality onboard the two ships were generally good. All measured concentrations were well below safety applications and it did not differ very much neither between ships nor compared with the Swedish population’s exposure. In conclusion, Swedish sailors onboard Swedish ships are not in greater danger of toxic air pollutants onboard compared to when they are at home.

  • 341. Andersson Chan, Anneli
    Biofiltration of Odorous Gas Emissions2006Doctoral thesis, comprehensive summary (Other academic)
  • 342.
    Andersson Chan, Anneli
    City of Växjö, Sweden.
    Experience with Anammox Sludge Liquor Treatment and up-coming Challenges with Thermal Hydrolysis Effluents at The Sundet Wastewater Treatment Plant, Vaxjo Sweden2015In: Water and Energy, Washington June 8-10 2015, 2015Conference paper (Refereed)
  • 343.
    Andersson Chan, Anneli
    Växjö kommun, Sweden.
    Increased nitrogen removal in existing volumes at the Sundet wastewater treatment plant, Växjö2013Conference paper (Refereed)
    Abstract [en]

    The HELCOM Baltic Sea Action Plan is an ambitious program to obtain good ecological status of the Baltic marine environment by 2021. Sweden has a preliminary commitment to reduce nitrogen by 21 000 ton, partly from the wastewater sector (3 000 ton nitrogen), and due to this many wastewater treatment plants need to improve their nitrogen removal. On top of that, the incoming load of nitrogen is increasing due to rising protein consumption. Co-digestion of external substrates (often rich in nitrogen) with wastewater sludge for increased biogas production further contributes to higher nitrogen loads. Increased nitrogen removal capacity often means more bioreactor volumes, which can be very expensive and sometimes impossible if space is limited. Therefore, there is a need for compact hybrid solutions that can increase capacity within existing volumes.

    The Sundet WWTP in Växjö received a new environmental permit in 2010 for 95 000 pe. Emission criteria for treated water are 10 mg BOD7/l, 0.2 mg P/l, and 60% nitrification. During a five year evaluation period (2012- 2016) assessments to ensure 15 mg N/l in the effluent should be conducted. To increase the nitrogen removal capacity within existing volumes, two processes using MBBR technology with plastic carriers were chosen:

    • Increased nitrification capacity in the existing activated sludge system through the Hybas™ combination process of MBBR and activated sludge (Integrated Fixed-Film Activated Sludge, IFAS).

    • Separate biological treatment of sludge liquor with the AnitaMox™ process, using autotrophic Nremoval through anaerobic ammonium oxidation (anammox) in a one-stage process with carriers.

    One of the six treatment trains was rebuilt to fit the integrated fixed-film activated sludge process for improved nitrification. The anoxic zone in this train was doubled for improved denitrification capacity. Data collected onsite from over a year (from October 2011 to present) are analyzed and compared with the performance of a conventional activated sludge train operated in parallel.

    The Hybas trained nitrified more consistently than the reference train, with effluent concentrations <1 mg NH4- N/l for most of the time. To keep the nitrification capacity in the reference train during the winter, a higher MLSS concentration was required, as well as larger aerated volumes. This lead to inadequate denitrification, while the capacity was substantially higher in the Hybas train, with emission concentrations well under the objective of 15 mg N/l. No additional carbon was added to the system. Practical experiences concerning operational requirements and challenges of the Hybas process (air flow and hydraulic loading, carrier management, and nutrient limitations) are discussed in the paper.

    The existing sludge liquor treatment (SBR, sequence batch reactor) was retrofitted in 2011 to an AnitaMox process. Thanks to a seeding start-up strategy, the process reached full capacity with more than 90% ammonia removal within two months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period. Full-scale experiences from more than a year has proven AnitaMox to be an energy- and cost efficient nitrogen removal process compared to the previous SBR process, and at the same time robust and relatively simple to operate. However, an increased process control and more on-line instruments require resources and qualified personnel.

    These two full-scale demonstration projects have been a successful learning experience in identifying and correcting both process and operational issues, which may not have arisen at pilot scale. The set objectives in terms of nitrogen removal were met for both processes and design modifications will improve the future operation at the Sundet WWTP.

  • 344.
    Andersson Chan, Anneli
    Växjö kommun, Sweden.
    Sustainable Biogas Production in the Greenest City in Europe2015In: IBIO 2015 - BIT's 8th World Congress of Industrial Biotechnology, Nanjing China April 25-28, 2015Conference paper (Other (popular science, discussion, etc.))
  • 345. Andersson Chan, Anneli
    et al.
    Johansson, N
    Christensson, Magnus
    Växjö - a holistic approach to increased biogas production2013In: Sludge Management and Anaerobic Digestion in a Broad Holistic System Perspective, 6-8 May 2013, Västerås, Sweden., 2013Conference paper (Refereed)
  • 346.
    Andersson Chan, Anneli
    et al.
    Växjö kommun, Tekniska förvaltningen, Sweden.
    Johansson, Niklas
    Växjö kommun, Tekniska förvaltningen, Sweden.
    Christensson, Magnus
    AnoxKaldnes, Lund, Sweden.
    Increased nitrogen removal in existing volumes at Sundet wastewater treatment plant, Växjö2014In: Water practice and technology, E-ISSN 1751-231X, Vol. 9, no 2, p. 215-224Article in journal (Refereed)
    Abstract [en]

    Many wastewater treatment plants need to improve their nitrogen removal due to stricter requirements and increasing loads. This often means larger bioreactor volumes, which can be very expensive and is sometimes impossible if space is limited. Therefore, there is a need for compact hybrid solutions that can increase capacity within existing volumes. Two full-scale demonstration projects using moving bed biofilm reactor (MBBR) technology has proven to be an efficient way to treat nitrogen in existing volumes at Sundet wastewater treatment plant in Växjö. Increased nitrification and denitrification capacity in parts of the main stream were demonstrated through the Hybas™ process, a combination of MBBR and activated sludge using the integrated fixed-film activated sludge technology. The ANITA™ Mox process, using autotrophic N-removal through anaerobic ammonium oxidation (anammox), provided high nitrogen removal for the sludge liquor. Data collected on-site for over a year are analyzed and compared with the performance of conventional treatment systems. These two full-scale demonstration projects have been a successful learning experience in identifying and correcting both process and operational issues, which may not have arisen at pilot scale. The set objectives in terms of nitrogen removal were met for both processes and design modifications have been identified that will improve future operation at Sundet WWTP.

  • 347.
    Andersson, Christopher
    et al.
    Linnaeus University, Faculty of Science and Engineering, Kalmar Maritime Academy.
    Karlsson, Emil
    Linnaeus University, Faculty of Science and Engineering, Kalmar Maritime Academy.
    Energieffektivisering till sjöss: Inom linjetrafik2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna studie handlade om att undersöka vilka energireducerande metoder som åtta svenska rederier inom linjetrafiken har valt att tillämpa ombord på sina fartyg. Detta för att kunna ge en bild om vilka eventuellt nya system och metoder framtida sjömän står inför. Metoden som användes var genom ett utskickat frågeformulär där berörda rederier kunde svara på frågor angående deras energibesparingar. Även rederiernas hemsidor undersöktes för att kunna få en djupare insikt om vilka energibesparande metoder rederierna använde sig av. Sedan söktes vidare information om dessa energibesparande metoder för att kunna ge en beskriva dem. Slutsatsen som drogs av studien visade att nästan alla undersökta rederier tillämpar någon form av energibesparande åtgärder, men endast fyra av de tillfrågade åtta nämnde att de hade visioner som de strävade efter att uppnå. Studien hade en låg svarsfrekvens vilket kan indikera på att rederierna antingen inte vill dela med sig av sin energipolicy, eller så är denna policy helt avsaknad.

  • 348.
    Andersson, Daniel
    et al.
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Petter, Andersson
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Frikyla: En möjlighet för Östersjöfarten att spara energi?2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To maintain a comfortable climate on board ships, cooling is necessary during the warm period of the year which requires energy. This thesis is a survey about whether so-called free cooling could reduce this energy consumption. The ROPAX-ferry Finntrader trafficking the route Malmö–Travemünde has been used as an example.

    This survey was carried out by creating a calculation model in which a brine system with a possibility of free cooling was connected to Finntrader’s current HVAC-system, alongside the current chillers. Statistics of air temperature, air humidity and sea water temperature was acquired for the period 2013-2015 and were inserted into the calculation model. These calculations showed that a certain amount ofenergy could be saved with free cooling, how much depending on the effectiveness of the heat exchangers.

    The amount of energy that could be saved was quite small compared to the cost of the components required by the model.

  • 349.
    Andersson, Fredrik
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Jönsson, Henrik
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Förbättrad precision vid ankomstkontroll2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Examensarbetet utfördes på Balco AB i Växjö, som tillverkar och erbjuder balkongsystem på

    totalentreprenad. Eftersom Balcos ökade omsättning har lett till att ankomstrollen inte längre kan utföras med

    tillräckligt hög precision, så har produktionsplaneringen blivit lidande. Syftet med projektet var därför att Balco

    ska kunna ankomstrapportera inkomna aluminiumprofiler från underleverantörer på ett smidigt sätt, samt med

    hög precision.

    För att lösa Balcos problem vid ankomstkontrollen, så att de enkelt kan rapportera in och få en god översikt

    av ankommit gods, har projektgruppen kommit fram till tre olika alternativa lösningar. Dessa lösningar är

    streckkodssystem, RFID-system och manuell identifiering. För bästa resultat, och användning av

    identifikationssystemen, är det troligtvis nödvändigt att ett MPS-system implementeras.

    Slutsatsen och rekommendationerna innefattas främst av en lösning med ett streckkodssystem, men där den

    primära nyckeln till ökad precision och kontroll av ankommande gods ligger i att införa ett väl fungerande

    datasystem.

  • 350.
    Andersson, Frida
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Karlsson, Joakim
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Utveckling av tätningskoncept till TeijoViverk ABs industritvättmaskiner2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Arbetet redovisar en utvecklingsprocess av TeijoViverk ABs tätningskoncept. Tätningskonceptet delas in i tre stycken konceptdelar; Infästningskoncept, Tätningsytakoncept och Tätningslistkoncept. Av de koncept som tagits fram till varje del har en utvärdering gjorts mellan de olika koncepten och ett gemensamt förslag för dessa har tagits fram.

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