| 1. |
- Fernstad, Sara Johansson, et al.
(författare)
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To Explore What Isnt There-Glyph-Based Visualization for Analysis of Missing Values
- 2022
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : IEEE COMPUTER SOC. - 1077-2626 .- 1941-0506. ; 28:10, s. 3513-3529
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Tidskriftsartikel (refereegranskat)abstract
- This article contributes a novel visualization method, Missingness Glyph, for analysis and exploration of missing values in data. Missing values are a common challenge in most data generating domains and may cause a range of analysis issues. Missingness in data may indicate potential problems in data collection and pre-processing, or highlight important data characteristics. While the development and improvement of statistical methods for dealing with missing data is a research area in its own right, mainly focussing on replacing missing values with estimated values, considerably less focus has been put on visualization of missing values. Nonetheless, visualization and explorative analysis has great potential to support understanding of missingness in data, and to enable gaining of novel insights into patterns of missingness in a way that statistical methods are unable to. The Missingness Glyph supports identification of relevant missingness patterns in data, and is evaluated and compared to two other visualization methods in context of the missingness patterns. The results are promising and confirms that the Missingness Glyph in several cases perform better than the alternative visualization methods.
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| 2. |
- Jalilzadehazhari, Elaheh, 1985-
(författare)
-
A decision-making framework for enhancing client well-being : When designing windows and blinds
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The current state of window and blind design moves beyond evaluating a single function, such as energy consumption, to include a human perspective in architectural design approach to create value. A current thought among architects and design professionals is that the highest value outcomes can be obtained when any architectural design contributes to enhanced well-being. Previous studies show that an individual’s well-being is determined by five main life domain factors: health, economy, personality, demographic variables and behavior variables. However, the life domain factors health and economy show stronger and more positive correlations to well-being. At this point, value creation within architectural design context, including window and blind design, can be seen as an attempt to enhance well-being by improving health and providing economic benefits for clients. Clients can represent i) owners who own a built asset, ii) investors who commit capital and expect to obtain financial return, or iii) occupants who live or work in the building every day. In the context of owner-occupied buildings, the value creation process is mainly seen as an attempt to enhance well-being for one entity by improving health and providing economic benefits. When considering investment properties or assets held for sale, the value creation process is mainly translated into an attempt to enhance well-being for several entities by improving health for occupants and providing economic benefits for owners and/or investors.Selecting a window and blind design to enhance client well-being remains a challenging task due to three main difficulties. The first difficulty relates to the contradictory effects of windows and blinds on visual and thermal comfort, energy consumption and life cycle cost. The second difficulty is the availability of a variety of window and blind designs in different sizes, positions and forms, making the selection of windows and blinds an intricate decision challenge for architects and designers. The third difficulty involves decisions about the selection of windows and blinds that should include all criteria and their interactions simultaneously.To resolve the abovementioned difficulties, this research applied the analytical hierarchy process (AHP) as a multi-criteria decision-making method to select a window and blind design based on a trade-off between visual comfort, thermal comfort, energy consumption and life cycle cost. The analyses of results show the capability of AHP in resolving difficulties, however its application is mainly limited to a small number of designs. To overcome this limitation, a decision-making framework was developed based on integration between non-dominated sorting genetic algorithm-II (NSGA-II) as an optimization algorithm and AHP. The strength and limitations of the decision-making framework were later tested by employing it in window and blind design practice. To investigate further benefits from the implementation of the framework, it was expanded by evaluating additional building envelopes, i.e. windows as well as external walls, roof and floor constructions, which made it possible to select a trade-off construction solution. The analyses of results show the framework’s ability to resolve difficulties and locate a trade-off design in a relatively short period of time. However, the decision-making framework only allows the analysis of the objective criteria for evaluating visual comfort, thermal comfort, energy consumption and life cycle cost. This is because it is necessary to rely on the creativity of the architects and designers when designing windows and blinds in order to consider subjective issues. The decision-making framework can be used either by design teams or customer service experts in window manufacturing companies. A literature study was therefore conducted to extend the technology acceptance model and thereby investigate the determinants of framework user acceptance of the decision-making framework. The results showed that organizational, individual, technological and environmental characteristics were the most influential external variables when investigating determinants of framework user acceptance of the framework. Organizational characteristics included top management support, training, organizational culture, and organizational size, while individual characteristics included the users’ previous knowledge and experience. Technological characteristics embraced information quality and system quality, meanwhile environmental characteristics comprised fulfillment of regulations and competitiveness.
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| 3. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
-
Application of analytical hierarchy process for selecting an interior window blind
- 2017
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Ingår i: Architectural Engineering and Design Management. - : Taylor & Francis. - 1745-2007 .- 1752-7589. ; 13:4, s. 308-324
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Tidskriftsartikel (refereegranskat)abstract
- Window blinds have a substantial role in shaping the energy consumption and improving thermal comfort and visual comfort. However, difficulties in selecting a window blind remain, due to existence of potential conflicts between visual, thermal, energy and life cycle cost. To overcome this problem, this study evaluates the performance of interior blinds, including venetian with slat of 0° and 45°, roller and double pleated blinds with respect to visual, thermal, energy and life cycle cost. Later, the Analytical hierarchy method (AHP) is used for selecting the best blind based on trade-off among the visual, thermal, energy and life cycle cost. In using AHP, visual comfort is determined as most important objective with a weight of 52%. The results show that venetian blind with slat of 0° drawn 100% is the trade-off blind. Accomplishing the sensitivity analysis on blinds’ global weight shows that venetian blind with slat of 0° drawn 100% remains the trade-off blind until the weight of energy and life cycle cost is below 37% and 57% respectively and the weight of visual comfort is above 4%. However, changing thermal comfort weight has no impact on ranking of the blinds. This study shows the capability of AHP in managing the conflicts.
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| 4. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
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Application of multi-objective optimization for resolving conflicts when selecting windows
- 2019
-
Ingår i: The 9<sup>th</sup> International Conference on Sustainable Development in the Building and Environment（SuDBE2019）& the International Forum of Green and Healthy Buildings.. - Reading and Cambridge, UK.
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Konferensbidrag (refereegranskat)abstract
- Sweden passed legislation to achieve a target of net zero greenhouse gas emissions by the end of 2045. The Energy Performance of Building Directive further obliged European countries to ensure zero-energy building codes and improve the quality of indoor environments when buildings are renovated, as approximately 40% of total greenhouse gas emissions in Sweden are produced while heating buildings. Windows currently play a significant role in improving the quality of indoor environments and cutting total energy consumption, thereby reducing greenhouse gas emissions and mitigating environmental impact. Selecting a suitable window design is a complicated task compounded by two main difficulties: i) the availability of multiple window designs, each with a different glazing system, size, form and position; and ii) conflict between visual comfort, thermal comfort and energy consumption. Previous studies have primarily analysed a limited selection of window designs; however, analysing a wide variety of glazing systems, sizes, forms and positions will help resolve the abovementioned difficulties, thereby ensuring zero-energy building codes while improving the quality of an indoor environment. A multi-objective optimization was therefore completed to analyse the performance of a wide variety of window design variables and select suitable designs for an office room in Sweden. The results show the potential of multi-objective optimisation to resolve the difficulties of selecting suitable window designs.
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| 5. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
-
Determinants of users’ acceptance of a computer-based system
- 2019
-
Ingår i: 36th CIB W78 2019 Conference ICT in Design, Construction and Management in Architecture, Engineering, Construction and Operations (AECO), 18-20 September, 2019. - Newcastle, United Kingdom : University of Northumbria. ; , s. 786-797
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Konferensbidrag (refereegranskat)abstract
- Sweden has an ambitious target to attain 50% more efficient energy use by 2030. Improving the energy performance of buildings provides a great opportunity to achieve the above-mentioned target. At this point, windows play a substantial role in improving indoor environmental quality and reducing energy consumption and cost. A computer-based system was therefore developed, which allows selecting a suitable window design. The computer-based system was intended to be used in a large-sized window and door manufacturing company in Sweden. However, the benefits of implementing the computer-based system cannot be realized until users accept using it. Former literature employed the technology acceptance model to investigate the influence of external variables on cognitive beliefs and trace their effects on users’ intention and actual system use. A successful application of TAM relies on the specification of the external variable. Accordingly, this paper conducted a systematic literature review to determine the external variable, affecting users' acceptance, thereby extended TAM. The analyses of results showed that organizational, individual, technological and environmental characteristics were the most influential external variables when investigating determinants of users' acceptance toward a computer-based system. Organizational characteristics contained mainly top management support, training, organizational culture, and organizational size, while individual characteristics embraced users’ previous knowledge and experience. Technological characteristics comprised information quality and system quality, meanwhile environmental characteristics included fulfillment of regulations and competitiveness. The extended TAM overcomes limitations attributed to the unified theory of acceptance and use of technology model since it considers attitude as direct determinants of intentions. In addition, the extended TAM is advantageous when compared with technology, organization, environment framework, because it has clear constructs, which allows tracing the influence of external variables on cognitive beliefs, and thereby their effects on users’ intention and actual system use. The extended TAM will be used to investigate determinants of users’ acceptance of the computer-based system in the manufacturing company in Sweden and compare the effect of external variables on users' acceptance.
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| 6. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
-
Developing a decision-making framework for resolving conflicts when selecting windows and blinds
- 2019
-
Ingår i: Architectural Engineering and Design Management. - : Taylor & Francis. - 1745-2007 .- 1752-7589. ; 15:5, s. 357-381
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Tidskriftsartikel (refereegranskat)abstract
- Windows and blinds play a significant role in both shaping energy consumption and enhancing indoor comfort. But there are still difficulties with selecting windows and blinds due to the existence of potential conflicts between visual comfort, thermal comfort, energy consumption and life-cycle cost. A literature review was conducted with the purpose of developing a decision-making framework that resolves the conflicts, and allows selecting a window and blind design based on trade-off between visual comfort, thermal comfort, energy consumption and life-cycle cost. The decision-making framework was developed by integrating non-dominated sorting genetic algorithm-II as an optimization algorithm with analytical hierarchy process as a multi-criteria decision-making method. The optimization algorithm considers different window and blind design variables and analyses multiple designs, while the multi-criteria decision-making method ranks the optimization results and selects a trade-off design. An operating package enabled the decision-making framework to be automated. The operating package was obtained by coupling EnergyPlus as a simulation tool and modeFRONTIER as an integration platform. The decision-making framework was developed to select a trade-off window and blind design through intelligent use of simulation in analysing big-data in built environment, energy and cost sectors. Application of the framework ensures the minimum visual and thermal comfort thresholds with the lowest energy demand and cost. Architects and designers can use the framework during the design or renovation phase of residential and commercial buildings.
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| 7. |
- Jalilzadehazhari, Elaheh, 1985-
(författare)
-
Windows and blinds selection for enhancing subjective well-being
- 2017
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Earlier studies in the context of windows and blinds selection have mostly tried to increase the awareness regarding various effects of windows and blinds selection on subjective well-being, including their effect on visual comfort, thermal comfort, energy consumption and life cycle cost. However, the main problem is the potential conflicts between visual comfort, thermal comfort, energy consumption and life cycle cost. Increased awareness about the contradictory effect of windows and blinds selection on subjective well-being on one hand and lack of a feasible method in managing the conflicts on the other hand may bind individuals, as decision-makers, in a situation where they follow the immediate economic benefits rather than the long-term visual and thermal benefits. To solve the mentioned problem, this study analysed first the degree of the conflicts between average daylight illuminance and total energy consumption in Sweden. This decision was made due to large variation in solar elevation angle and solar intensity between summer and winter in Sweden, which has significant effects on daylight illuminance and total energy consumption. Analysing the conflicts was accomplished by developing two multivariate linear regression models for calculating average daylight illuminance and total energy consumption. Comparison and analysis of the multivariate linear regression models showed the existence of a high degree of conflicts, which makes window and blind selection a rather complex multidimensional problem. Specifying the degree of the conflicts formed a hypothesis as: “A multi criteria decision-making method increases the controllability and manages the conflicts in selecting windows and blinds”. The developed hypothesis was later tested by employing analytical hierarchy process, as widely used multi criteria decisionmaking method. The analytical hierarchy process prioritizes decision-maker’ preferences and introduces a desired trade-off solution. The results of employing analytical hierarchy process showed the capability of it in managing the conflicts among visual comfort, thermal comfort, energy consumption and life cycle cost. Finally, the application of the analytical hierarchy process was expanded by integrating it with nondominated sorting genetic algorithm-II, as an optimization algorithm. Through this integration, optimization algorithm combines windows’ and blinds’ design variables and analyses a large number of solutions, while analytical hierarchy process ranks the solutions based on decision-makers’ preferences and introduces a desired trade-off solution. The integration between analytical hierarchy process and the nondominated sorting genetic algorithm-II was presented later as a conceptual framework. The developed conceptual framework can be used for selecting windows and blinds II in both residential and commercial buildings. In selecting windows and blinds, the conceptual framework is a novel solution to the lack of a feasible method for increasing the controllability for decision-makers and obtaining a desired trade-off solution.
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| 8. |
- Jern, Mikael, 1946-, et al.
(författare)
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The GAV Toolkit for Multiple Linked Views
- 2007
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Ingår i: Fifth International Conference on Coordinated and Multiple Views in Exploratory Visualization, 2007. CMV '07.. - Los Alamitos, CA, USA : IEEE Computer Society. - 0769529038 ; , s. 85-97
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Konferensbidrag (refereegranskat)abstract
- Implementing InfoVis multivariate data tools, timelinked coordinated views and visual dynamic queries with conditioning from scratch is not a simple programming task. Our research objective is to develop a generic GeoAnalytics visualization (GAV) component toolkit, based on the principles behind visual analytics (VA), for dynamically exploring time-varying, geographically referenced and multivariate attributes simultaneously. GAV includes components based on a synergy of technologies from information visualization, geovisualization and scientific visualization. Our research concentrates on improving visual user interfaces (VUI) methods and trying to extend existing visual representation techniques. The effectiveness of our proposed component toolkit and framework is demonstrated in two customized applications GeoWizard analysing multivariate energy usage data for Swedish municipalities and MD-Explorer exploring multivariate data using novel interactive ternary diagrams. We use parallel coordinates with embedded visual inquiry methods that serves as a visual control panel for dynamically linked and coordinated views. Finally, discoveries made during the visual exploration process can be captured and organized in a format for later recall and communication to others.
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| 9. |
- Johansson Fernstad, Sara, et al.
(författare)
-
A Task Based Performance Evaluation of Visualization Approaches for Categorical Data Analysis.
- 2011
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Ingår i: Proceedings - 15th International Conferenceon Information Visualisation. - Los Alamitos, CA, USA : IEEE Computer Society. - 9781457708688 ; , s. 80-89
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Categorical data is common within many areas and efficient methods for analysis are needed. It is, however, often difficult to analyse categorical data since no general measure of similarity exists. One approach is to represent the categories with numerical values (quantification) prior to visualization using methods for numerical data. Another is to use visual representations specifically designed for categorical data. Although commonly used, very little guidance is available as to which method may be most useful for different analysis tasks. This paper presents an evaluation comparing the performance of employing quantification prior to visualization and visualization using a method designed for categorical data. It also provides a guidance as to which visualization approach is most useful in the context of two basic data analysis tasks: one related to similarity structures and one related to category frequency. The results strongly indicate that the quantification approach is most efficient for the similarity related task, whereas the visual representation designed for categorical data is most efficient for the task related to category frequency.
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| 10. |
- Johansson Fernstad, Sara, 1980-
(författare)
-
Algorithmically Guided Information Visualization : Explorative Approaches for High Dimensional, Mixed and Categorical Data
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Facilitated by the technological advances of the last decades, increasing amounts of complex data are being collected within fields such as biology, chemistry and social sciences. The major challenge today is not to gather data, but to extract useful information and gain insights from it. Information visualization provides methods for visual analysis of complex data but, as the amounts of gathered data increase, the challenges of visual analysis become more complex.This thesis presents work utilizing algorithmically extracted patterns as guidance during interactive data exploration processes, employing information visualization techniques. It provides efficient analysis by taking advantage of fast pattern identification techniques as well as making use of the domain expertise of the analyst. In particular, the presented research is concerned with the issues of analysing categorical data, where the values are names without any inherent order or distance; mixed data, including a combination of categorical and numerical data; and high dimensional data, including hundreds or even thousands of variables.The contributions of the thesis include a quantification method, assigning numerical values to categorical data, which utilizes an automated method to define category similarities based on underlying data structures, and integrates relationships within numerical variables into the quantification when dealing with mixed data sets. The quantification is incorporated in an interactive analysis pipeline where it provides suggestions for numerical representations, which may interactively be adjusted by the analyst. The interactive quantification enables exploration using commonly available visualization methods for numerical data. Within the context of categorical data analysis, this thesis also contributes the first user study evaluating the performance of what are currently the two main visualization approaches for categorical data analysis.Furthermore, this thesis contributes two dimensionality reduction approaches, which aim at preserving structure while reducing dimensionality, and provide flexible and user-controlled dimensionality reduction. Through algorithmic quality metric analysis, where each metric represents a structure of interest, potentially interesting variables are extracted from the high dimensional data. The automatically identified structures are visually displayed, using various visualization methods, and act as guidance in the selection of interesting variable subsets for further analysis. The visual representations furthermore provide overview of structures within the high dimensional data set and may, through this, aid in focusing subsequent analysis, as well as enabling interactive exploration of the full high dimensional data set and selected variable subsets. The thesis also contributes the application of algorithmically guided approaches for high dimensional data exploration in the rapidly growing field of microbiology, through the design and development of a quality-guided interactive system in collaboration with microbiologists.
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| 11. |
- Johansson Fernstad, Sara, et al.
(författare)
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Quality Based Guidance for Exploratory Dimensionality Reduction
- 2013
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Ingår i: Information Visualization. - : Palgrave Macmillan / SAGE Publications (UK and US). - 1473-8716 .- 1473-8724. ; 12:1, s. 44-64
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Tidskriftsartikel (refereegranskat)abstract
- High dimensional data sets containing hundreds of variables are difficult to explore, since traditional visualization methods often are unable to represent such data effectively. Dimensionality reduction is commonly employed prior to visualization to address this difficulty, and numerous dimensionality reduction methods are available. However, few dimensionality reduction approaches take the importance of several structures into account and few provide an overview of structures existing in the full high dimensional data set. For exploratory analysis, as well as for many other tasks, several structures may be of interest and exploration of the full high dimensional data set without reduction may also be desirable.This paper presents methods for exploratory analysis and interactive dimensionality reduction, where automated methods are employed to analyse and rank the variables using a range of quality metrics, providing one or more measures of ‘interestingness’ for individual variables. Through ranking, a single value of interestingness is obtained based on several quality metrics which is usable as a threshold for the most interesting variables. An interactive environment is presented where the user is provided many possibilities to explore and gain understanding of the structures within the high dimensional data set, all based on quality metrics and ranking. Guided by this, the analyst can explore the high dimensional data set and select interactively a subset of the potentially most interesting variables, employing various interactive methods for dimensionality reduction. The effectiveness and usefulness of the system is demonstrated through a use-case analysing data from a DNA sequence-based study of bacterial populations.
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| 12. |
- Johansson Fernstad, Sara, et al.
(författare)
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Visual Exploration of Microbial Populations
- 2011
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Ingår i: IEEE Symposium on Biological Data Visualization. - 9781467300032 ; , s. 127-134
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Studies of the ecology of microbial populations are increasingly common within many research areas as the field of microbiomics develops rapidly. The study of the ecology in sampled microbial populations generates high dimensional data sets. Although many analysis methods are available for examination of such data, a tailored tool was required to fulfill the need of interactivity and flexibility for microbiologists. In this paper, MicrobiVis is presented. It is a tool for visual exploration and interactive analysis of microbiomic populations. MicrobiVis has been designed in close collaboration with end users. It extends previous interactive systems for explorative dimensionality reduction by including a range of domain relevant features. It contributes a flexible and explorative dimensionality reduction as well as a visual and interactive environment for examination of data subsets. By combining information visualization and methods based on analytic tasks common in microbiology as a means for gaining new and relevant insights. The utility of MicrobiVis is demonstrated through a use case describinghow a microbiologist may use the system for a visual analysis of amicrobial data set. Its usability and potential is indicated throughpositive feedback from the current end users.
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| 13. |
- Johansson, Sara, et al.
(författare)
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Interactive Dimensionality Reduction Through User-defined Combinations of Quality Metrics
- 2009
-
Ingår i: IEEE Transactions on Visualization and Computer Graphics. - 1077-2626 .- 1941-0506. ; 15:6, s. 993-1000
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Tidskriftsartikel (refereegranskat)abstract
- Multivariate data sets including hundreds of variables are increasingly common in many application areas. Most multivariate visualization techniques are unable to display such data effectively, and a common approach is to employ dimensionality reduction prior to visualization. Most existing dimensionality reduction systems focus on preserving one or a few significant structures in data. For many analysis tasks, however, several types of structures can be of high significance and the importance of a certain structure compared to the importance of another is often task-dependent. This paper introduces a system for dimensionality reduction by combining user-defined quality metrics using weight functions to preserve as many important structures as possible. The system aims at effective visualization and exploration of structures within large multivariate data sets and provides enhancement of diverse structures by supplying a range of automatic variable orderings. Furthermore it enables a quality-guided reduction of variables through an interactive display facilitating investigation of trade-offs between loss of structure and the number of variables to keep. The generality and interactivity of the system is demonstrated through a case scenario.
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| 14. |
- Johansson, Sara, 1980-, et al.
(författare)
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Interactive Exploration of Ingredient Mixtures Using Multiple Coordinated Views
- 2009
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Ingår i: Proceedings Information Visualization, IV 2009. - Los Alamitos, CA, USA : IEEE Computer Society. - 9780769537337 ; , s. 210-218
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Konferensbidrag (refereegranskat)abstract
- The complex nature of multivariate data sets calls forhigh interactive performance and intuitive metaphors. Aspecific type of multivariate data is where the variables sum up to a constant, here defined as multicomponent data.This application paper presents an interactive applicationfor analysis of modelled multicomponent data. The aim isto find high performance variable combinations that fulfil some requested properties. The application is basedon coordinated views that include parallel coordinates, a ternary diagram, a 2D scatter plot and a line plot. It supports numerous interaction techniques enabling fast analysisof complex patterns in multicomponent data sets. The application is developed in collaboration with researchers within the fields of statistics and chemistry. An informal usability evaluation indicates that the interactive nature ofthe application clearly facilitates the analysis process.
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| 15. |
- Johansson, Sara, et al.
(författare)
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Interactive Quantification of Categorical Variables in Mixed Data Sets
- 2008
-
Ingår i: Information Visualisation, 2008. IV '08. 12th International Conference. - Los Alamitos, California : IEEE Computer Society. - 9780769532684 ; , s. 3-10
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Konferensbidrag (refereegranskat)abstract
- Data sets containing a combination of categorical and continuous variables (mixed data sets) are difficult to analyse since no generalized similarity measure exists for categorical variables. Quantification of categorical variables makes it possible to represent this type of data using techniques designed for numerical data. This paper presents a quantification process of categorical variables in mixed data sets that incorporates information on relationships among the continuous variables into the process, as well as utilizing the domain knowledge of a user. An interactive visualization environment using parallel coordinates as a visual interface is provided, where the user is able to control the quantification process and analyse the result. The efficiency of the approach is demonstrated using two mixed data sets.
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| 16. |
- Johansson, Sara, et al.
(författare)
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Visual Analysis of Mixed Data Sets Using Interactive Quantification
- 2009
-
Ingår i: ACM SIGKDD Explorations Newsletter. - New York : ACM. - 1931-0145 .- 1931-0153. ; 11:2, s. 29-38
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Tidskriftsartikel (refereegranskat)abstract
- It is often diffcult to analyse data sets including a combi-nation of categorical and numerical variables (mixed datasets) since there does not exist any similarity measure whichis as straight forward and general as the numerical distancebetween numerical items. Quantication of categorical vari-ables enables analysis using commonly used visual represen-tations and analysis techniques for numerical data. Thispaper presents a tool for exploratory analysis of categoricaland mixed data which uses a quantication process intro-duced in [Johansson2008]. The application enables analysis of mixeddata sets by providing an environment for exploratory anal-ysis using common visual representations in multiple coordi-nated views and algorithmic analysis that facilitates detec-tion of potentially interesting patterns within combinationsof categorical and numerical variables. The generality andusefulness of the quantication process and of the featuresof the application is demonstrated through a case scenariousing a data set from the IEEE VAST 2008 Challenge.
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| 17. |
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| 18. |
- Aguirre Rivera, Javier, 1989-, et al.
(författare)
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Real-time measurements of aminoglycoside effects on protein synthesis in live cells
- 2021
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 0027-8424 .- 1091-6490. ; 118:9
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Tidskriftsartikel (refereegranskat)abstract
- The spread of antibiotic resistance is turning many of the currently used antibiotics less effective against common infections. To address this public health challenge, it is critical to enhance our understanding of the mechanisms of action of these compounds. Aminoglycoside drugs bind the bacterial ribosome, and decades of results from in vitro biochemical and structural approaches suggest that these drugs disrupt protein synthesis by inhibiting the ribosome's translocation on the messenger RNA, as well as by inducing miscoding errors. So far, however, we have sparse information about the dynamic effects of these compounds on protein synthesis inside the cell. In the present study, we measured the effect of the aminoglycosides apramycin, gentamicin, and paromomycin on ongoing protein synthesis directly in live Escherichia coli cells by tracking the binding of dye-labeled transfer RNAs to ribosomes. Our results suggest that the drugs slow down translation elongation two- to fourfold in general, and the number of elongation cycles per initiation event seems to decrease to the same extent. Hence, our results imply that none of the drugs used in this study cause severe inhibition of translocation.
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| 19. |
- Akram Hassan, Kahin, 1990-, et al.
(författare)
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On the Performance of Stereoscopic Versus Monoscopic 3D Parallel Coordinates
- 2016
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Konferensbidrag (refereegranskat)abstract
- This work presents the results from an evaluation of stereoscopic versus monoscopic 3D parallel coordinates. The objective of the evaluation was to investigate if stereopsis increases user performance. The results show that stereoscopy has no effect at all on user performance compared to monoscopy. This result is important when it comes to the potential use of stereopsis within the information visualization community.
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| 20. |
- Albrecht, Inka, et al.
(författare)
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Development of autoantibodies against muscle-specific FHL1 in severe inflammatory myopathies
- 2015
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Ingår i: Journal of Clinical Investigation. - : AMER SOC CLINICAL INVESTIGATION INC. - 0021-9738 .- 1558-8238. ; 125:12, s. 4612-4624
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Tidskriftsartikel (refereegranskat)abstract
- Mutations of the gene encoding four-and-a-half LIM domain 1 (FHL1) are the causative factor of several X-linked hereditary myopathies that are collectively termed FHL1-related myopathies. These disorders are characterized by severe muscle dysfunction and damage. Here, we have shown that patients with idiopathic inflammatory myopathies (IIMs) develop autoimmunity to FHL1, which is a muscle-specific protein. Anti-FHL1 autoantibodies were detected in 25% of IIM patients, while patients with other autoimmune diseases or muscular dystrophies were largely anti-FHL1 negative. Anti-FHL1 reactivity was predictive for muscle atrophy, dysphagia, pronounced muscle fiber damage, and vasculitis. FHL1 showed an altered expression pattern, with focal accumulation in the muscle fibers of autoantibody-positive patients compared with a homogeneous expression in anti-FHL1-negative patients and healthy controls. We determined that FHL1 is a target of the cytotoxic protease granzyme B, indicating that the generation of FHL1 fragments may initiate FHL1 autoimmunity. Moreover, immunization of myositis-prone mice with FHL1 aggravated muscle weakness and increased mortality, suggesting a direct link between anti-FHL1 responses and muscle damage. Together, our findings provide evidence that FHL1 may be involved in the pathogenesis not only of genetic FHL1-related myopathies but also of autoimmune IIM. Importantly, these results indicate that anti-FHL1 autoantibodies in peripheral blood have promising potential as a biomarker to identify a subset of severe IIM.
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| 21. |
- Baeuerle, A., et al.
(författare)
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Where did my Lines go? Visualizing Missing Data in Parallel Coordinates
- 2022
-
Ingår i: Computer graphics forum (Print). - : Wiley. - 0167-7055 .- 1467-8659. ; 41:3, s. 235-246
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Tidskriftsartikel (refereegranskat)abstract
- We evaluate visualization concepts to represent missing values in parallel coordinates. We focus on the trade-off between the ability to perceive missing values and the concepts impact on common tasks. For this purpose, we identified three missing value representation concepts: removing line segments where values are missing, adding a separate, horizontal axis onto which missing values are projected, and using imputed values as a replacement for missing values. For the missing values axis and imputed values concepts, we additionally add downplay and highlight variations. We performed a crowd-sourced, quantitative user study with 732 participants comparing the concepts and their variations using five real-world datasets. Based on our findings, we provide suggestions regarding which visual encoding to employ depending on the task at focus.
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| 22. |
- Blom, Åsa, 1977-, et al.
(författare)
-
Some factors influencing susceptibility to discoloring fungi and water uptake of Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and Oriental spruce (Picea orientalis)
- 2013
-
Ingår i: Wood Material Science & Engineering. - : Informa UK Limited. - 1748-0272 .- 1748-0280. ; 8:2, s. 139-144
-
Tidskriftsartikel (refereegranskat)abstract
- The heartwood and sapwood from Scots pine (PS), Norway spruce (PA), and Oriental spruce (PO) were tested for susceptibility to discoloring fungi and water uptake. In addition, annual ring width and density were measured. The methods used were Mycologg for testing growth of fungi and a modified version of EN 927-5 to investigate water uptake. For pine, the heartwood showed a lower water uptake and no discoloring fungi growing in the tests. The heartwood had a significantly higher density and smaller annual ring width than the sapwood. In PA the heartwood had significantly lower discoloration than sapwood. The total water uptake in g/m2 was significantly higher in sapwood, but not the calculated moisture content. As for wood properties, the density was significantly higher in sapwood compared to heartwood, although there were no differences in annual ring width. Regarding PO, differences in water uptake could be seen between sapwood and heartwood although the densities were similar. These results show that susceptibility to discoloring fungi and water uptake is hard to correlate to a single inherent property when looking at different wood species.
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| 23. |
- Blom, Åsa, 1977-, et al.
(författare)
-
Utomhuskonstruktioner i trä : några erfarenheter från byggnation i trä av flerbostadshus
- 2017
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Användandet av materialet trä i produkter är ett lån från naturen som förr eller senare genom nedbrytning av vedsubstansen ska återföras till det naturliga kretsloppet. Avseende användningen av solitt trä i produkter bestäms tidsperioden innan återföringen till naturen av produktens konstruktion och trämaterialet i sig självt i relation till den omgivande miljön samt användningen och hanteringen av produkten. En produkts förmåga att motstå, eller behålla sina egenskaper trots dessa yttre påfrestningar benämns dess beständighet.
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| 24. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Basic knowledge of wood properties for improved performance of laminated Veneer products
- 2013
-
Ingår i: Pro Ligno. - Brasov : Publishing House of Transilvania University of Brasov. - 1841-4737 .- 2069-7430. ; 9:4, s. 549-556
-
Tidskriftsartikel (refereegranskat)abstract
- To ensure success in the production of laminated veneer products, it is necessary to acquire a sound basic understanding of the behaviour of the wood, and to understand the inherent reactions of wood to adhesive, heat, moisture, strain and stress. This can ensure an efficient wood utilization and promote the development of new processes and products that take advantage of the visco-elastic nature of wood. A shortcoming of the laminated bending process is that the products may become distorted after moulding and during use. In this study, we have examined how the performance of laminated veneer products can be improved through the implementation of basic knowledge of wood in the design and production process. The results show that the material and process parameters and storage in a changing relative humidity have a clear impact on distortion. Fibre orientation of the veneers in the moulded assembly was the most critical parameter to control. Fibre deviations mainly resulted in twist of the product. A moisture content in one veneer deviating from that of the rest of the veneers in the assembly before moulding resulted in distortion of the laminated veneer products both after moulding and during use. To decrease the negative effect of fibre orientation and moisture content on shape stability, the veneer should be straight-grained and well-conditioned to a moisture level adapted to the use of the final product. Special care should also be taken to orientate the veneers during assembly before moulding.
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| 25. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Contact free measurement of complex shapes in the wood industry
- 2011
-
Ingår i: Mechano-chemical transformations of wood during THM processing. - Biel, Switzerland : Bern University of Applied Sciencs, Architecture, Wood and Civil Engineering. - 9783952378700 ; , s. 143-144
-
Konferensbidrag (refereegranskat)abstract
- There is an increasing need to update and correct information about product geometry in the wood manufacturing industry. Changes in machinery or personnel can be the cause of that need. Manual measurement takes time and diff erent ways of digitizing the geometry of the products have therefore been developed.In this study, two methods (3D-coordinate measurement and optical scanning) have been tested together in order to determine the position of a product in relation to the processing machine, and to optically scan the product geometry. The aim was to identify and evaluate methods to digitize product geometry into a CAD-model for the wood industry. Th e seat shell measured was fitted in the CNC-machine where the processing later would be performed.The methodology used has made it possible to create a CAD-model from the physical model. Based on the experience from this methodology, it would be recommended to continue by creating of a tool that minimizes the need for after processing, i.e. the adjustment of certain coordinates manually.
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| 26. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Downtime causes in a production cell for laminated veneer products
- 2017
-
Ingår i: 23<sup>rd</sup> International Wood Machining Seminar Proceedings. - Warsaw, Poland : The Polish Chamber of Commerce of Furniture Manufacturers. - 9788394804602 ; , s. 28-35
-
Konferensbidrag (refereegranskat)abstract
- Productivity is often used to determine how well resources are used for an operation. Most often, the ratio of what is produced to what is required to produce it determines productivity. Laminated veneer products are considered complicated products often with complex shapes, a raw material with high variation, and machining processes that create scrap materials that need to be handled. Therefore, keeping a high productivity in the industries producing such products may become challenging. This study reports productivity measurements in a production cell consisting of an adhesive, pressing and processing station. The study seeks to increase understanding of production-related problems in this industry. The research has been using productivity measurement as well as interactive discussions between researchers and workers.Measurement of downtime causes were made for 20 days, for a total of approximately 300 hours. The production cell had 1,299 minutes of stops. Of those, 450 minutes were one-time events. The rest were intermittent disturbances. Many of them could be explained by the dust-laden air and processing residues but were also related to veneer and adhesive. There is a need for determining material and processing parameters; however, the first priority is cleaning the factory.From a social perspective, some other issues must be added to the discussion of this paper. First and foremost, the business has gone through a transformation from a family business to a privately held firm. From the non-family employee’s view, this is a huge change. This has resulted in unclear roles and responsibilities within the company, which has also affected the productivity of the company.
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| 27. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Improving the performance of bended laminated veneer products
- 2011
-
Ingår i: Mechano-chemical transformations of wood during THM processing. - Biel, Switzerland : Bern University of Applied Sciencs, Architecture, Wood and Civil Engineering. - 9783952378700 ; , s. 147-148
-
Konferensbidrag (refereegranskat)abstract
- Laminated bending of veneers mean that dried, thin veneers or thin wood sheets are glued together under influence of pressure and eventually increased temperature. At the same time the product is given its desired shape, most often curved. This thermo hydro mechanical process offers several benefits. For example thick bends of small radiuses of any species of wood may be formed and poor quality wood containing knots, splits and other defects may be utilised. Laminated bends can usually be set more readily and made to conform better to the shape of the form than similar bends of solid wood. Further no softening treatment is generally required before the pieces are bent. However, there are also disadvantages e.g. more technical skill and better equipment are usually required than for solid wood bending. The presence of glue may be somewhat detrimental to the machines used for the final cleaning up of the bent pieces. Further the glue lines which are usually visible on the sides may be an aesthetical unappreciated effect [1],[2].The quality of the laminated bended veneer products are obtained as an interaction between the process, the veneers and the glue [3]. In industries designing and producing these products it is of interest to obtain better understanding of how processing- and material parameters affect the product quality. With an improved understanding of the material and processing parameters it may be possible to increase the efficiency of wood utilisation and promote the development of new processes and products that manipulate the viscoelastic nature of wood. In particular the possibilities to obtain narrower radius of curvature and better possibilities of bending in more than one plane would be advantageous.This study has focused on the moisture content (MC) and the grain angle orientation in the veneers. These two specific aspects were assumed to have a great influence on spring-back and distortions of the laminated bended veneer products. Spring-back and distortions were therefore studied in separate tests where MC and the grain angle orientation was varied separately in manufactured laminated bended wood products. After manufacturing the products were exposed to variations in humidity and temperature whereupon the spring-back and distortions were measuredThree tests were performed. For the first and the second test a seat shell was selected as test product, figure 1a. To the third test another product was selected, figure 1b. This product was a small bookshelf. The company producing this shelf had experienced large problems considering distortions of this product. Further the product was very simple in shape with only one bend and therefore suitable for measurements.In the first test the influence of MC of the veneers was investigated. In the second and third test the influence of grain angle of the veneers was studied.For the study veneers of birch and beech were selected in the production. For the first and third study only birch veneers were used. The veneers were initially conditioned to equilibrium moisture contents (EMC) according to setups in different test groups. For the first study a test group was also built up from veneers taken directly out of production to study the industrial conditions. The seat shells in this test group contained veneers conditioned to EMC 4 %, except for the surface veneers that had been stored in the production hall. The humidity and temperature conditions in this room corresponded to MC 7 %.The manufacturing of the products were performed in industrial conditions. In the tests the products were built up from a number of veneers and the studied factors were varied between the veneers in a controlled manner.The results from the first test showed that the MC of the veneers influenced the spring-back and the distortions. A large moisture gradient between veneers and especially unsymmetrical placements of these in the construction were especially critical. The results from the second and third tests showed that grain angle deviation has large effect on the distortions of the products. Even a small grain angle deviation as in study two (5°) resulted in large problems with distortions. The study also showed that when crossing two or more veneers with deviating grain angles there were cases when these faults interacted and multiplied the distortions. In production grain angle deviations can be a result of inaccurate placement of the veneers during pressing, incorrect cutting of the veneers, inherent from the growth of the tree or a combination of these factors. Deviations of the grain angle were, however, shown to have only small effects on spring-back.
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| 28. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Influence of veneer orientation on shape stability of plane laminated veneer products
- 2014
-
Ingår i: Wood Material Science & Engineering. - : Informa UK Limited. - 1748-0272 .- 1748-0280. ; 9:4, s. 224-232
-
Tidskriftsartikel (refereegranskat)abstract
- One of the most important quality aspects of a laminated veneer product is its shape stability under changing relative humidity (RH). This study aimed to establish an understanding of how the orientation of individual veneers in the laminate, i.e., orientation according to fibre orientation and orientation of the loose (the side with ‘lathe checks’) or tight side of the veneer, affects the shape stability. Three-ply laminates from peeled veneers of beech (Fagus sylvatica L.) were studied. The four types of laminate were the following: loose sides of all veneers in the same direction (cross and parallel centre ply) and loose sides of the outer veneers facing inward (cross and parallel centre ply). Four replicates of each type yielded 16 samples. The samples were exposed to RH cycling at 20% and 85% RH at 20°C, and the shapes of the samples were determined. The shape stability was influenced by the veneer orientation. Laminations with the middle veneer perpendicular to the top and bottom veneer (cross-laminated) showed the best shape stability, especially when the loose sides of the veneers were oriented the same direction. In parallel-laminated veneers, the laminates with opposite directions of the loose sides in the two outermost veneers showed the best shape stability. The major explanation of the behaviour of the laminates is that the loose side expanded more than the tight side from the dry to the humid climate, which was shown by optical 3D deformation analysis (ARAMISTM). After RH cycling, the laminates with cross plies showed visible surface checks only when the tight side was facing outwards.
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| 29. |
- Blomqvist, Lars, 1962-
(författare)
-
Laminated Veneer Products : Shape Stability and Effect of Enhanced Formability on Bond-Line Strength
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis concerns two aspects of the manufacture of laminated veneer products (LVPs). The first aspect is related to the possible improvement of the shape stability of LVPs, and the second has its starting point in the modification of the veneer for enhanced formability as well as the question of whether and how these modifications affect the bond-line strength.LVPs are veneers bonded with adhesive into predetermined shapes, mostly for the production of furniture and interior fittings. Since any deviation from the intended shape is a problem for both manufacturer and customer, various studies have sought to evaluate the influence of different materials and process parameters on shape stability. Parameters studied have included wood species (beech and birch), an adhesive system based on urea formaldehyde, the adhesive distribution on the veneer, climate, moisture content and fibre orientations of the veneers, as well as the orientation of the individual veneers in a multiply.Manufacturers of LVPs must consider some basic facts about wood in orders adequately to provide shape-stable LVPs to customers. Wood emits and absorbs moisture in relation to the surrounding climate, and this can lead to shrinkage and swelling. Such moisture induced movements differ in the wood’s different directions, and the magnitude is specific for the species. A thorough understanding of this is the basis for achieving shape-stable LVPs.Symmetry is defined in this thesis such that the veneer properties are balanced in the laminate. This means that opposite veneers on either side of the centre veneer have similar characteristic. An LVP will become distorted if the veneers are asymmetrically oriented before the press. Deviation from the desired shape can be small immediately after the pressing, but it may increase significantly with moisture content (MC) variations. Asymmetry may result when veneers with different fibre orientations are included in the laminate or when the veneers are placed asymmetrically. It may also occur if veneers with different MCs are bonded together asymmetrically. One aggravating factor is that the lathe checks that are introduced when the veneers are peeled or sliced from the log affect the shape stability. In 3-ply crosswise-oriented plywood, the veneer surfaces on which the lathe checks occur should be oriented in the same way for high shape stability.Based on existing knowledge, the production of shape-stable LVPs requires that the veneers are conditioned to a uniform MC and sorted with regard to fibre orientation and the side with lathe checks before bonding. End-user climates should govern the MC of the veneers and the moisture added with the adhesive during the process. Straight-grain veneers and symmetry should always be the goal.Moulding can cause stretching, i.e. strain, of the veneers depending on the curvature of the mould. To prevent the veneers from rupture, there are various ways to strengthen the veneers particularly in the transverse direction in which the veneer is weakest. However, tests have shown that these pre-treatments of veneers for enhanced formability can prevent the adhesive from penetrating the wood surface. It is therefore important to confirm that the pre-treatment does not affect the bond-line strength.
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| 30. |
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| 31. |
|
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| 32. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Moisture-induced distortion of laminated veneer products
- 2013
-
Ingår i: Proceedings of the 9<sup>th</sup> meeting of the Northern European network for wood science and engineering (WSE). - Hannover, Germany. ; , s. 178-183
-
Konferensbidrag (refereegranskat)abstract
- Laminated veneer products consist of veneers bonded together with adhesive into a predetermined shape. Since wood is a hygroscopic material and also anisotropic by nature, laminated veneer products are especially shape-sensitive to changes in moisture content. A deviation from the intended shape is a problem for both the manufacturers and users of the final products and annually such deviations cause great economic losses in the manufacturing industry. To illustrate the influence of moisture on distortion and shape stability, studies have been performed in industrial conditions and in a laboratory environment. Veneers of beech and birch and a seat shell moulded from these veneers were used in the study. Distortion, i.e. spring-back, position and twist, has been determined directly after moulding and during subsequent moisture and drying cycles. The distortion follows more or less slavishly the changes in relative humidity around the product. The distortion is generally small directly after moulding but, after the laminates have been exposed to a variation in relative humidity, the distortion increases. Some of the problems of poor shape stability that may arise later in the bending process can be reduced if attention is paid to moisture content and fibre orientation already in the production of the veneer. To achieve good shape stability of laminated veneer products in practice, the following should be followed by the manufacture industry:develop cooperation with suppliers of veneer and set requirements of veneer with regard to deviation of the fibre orientation, and require that the veneer be dried and conditioned to a moisture content consistent with production,control incoming veneers with respect to fibre orientation and moisture content,plan warehousing of veneers and ensure adequate conditioning, andconsider the orientation of the veneers and the species.
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| 33. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Resource utilization in a production cell for laminated veneer products
- 2017
-
Ingår i: Pro Ligno. - Brasov, Romania : PRO LIGNO Foundation. - 1841-4737 .- 2069-7430. ; 13:4, s. 142-147
-
Tidskriftsartikel (refereegranskat)abstract
- The concept of productivity is often used to determine how well resources are used in an operation, and it is usually determined as the ratio of what is consumed in the production. Laminated veneer products are considered complicated products often taking complex shapes, using a raw material with high variation, and requiring machining processes that create scrap material that needs to be handled. Therefore, maintaining high productivity in industries producing such products may become challenging. This study reports on productivity measurements in a production cell consisting of an adhesive, pressing and a processing station. The study seeks to increase the understanding of production-related problems in this industry. This research has been based on productivity measurement as well as on interactive discussions between researchers and workers. Measurement of cycle times indicated bottlenecks in the processing cell. The discussion led via cycle times, processing residues and chatter marks to an examination of the foundation and rigidity of the CNC-machine in the processing cell. The study indicated that the performance of the CNC machine did not correspond to expectations. The machine was too weak to handle the required output in an efficient manner. Thus, there is a need to determine the performance expected before a machine or machine group is purchased. An update of the existing purchasing literature and its dissemination will support the crystallization of the purchasing process as a way forward to support the industry.
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| 34. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Shape stability of laminated veneer products : How to decrease the negative effects of fibre deviation?
- 2013
-
Ingår i: Forest Products Society (FPS) 67th International Convention. - Madison : Forest Products Society.
-
Konferensbidrag (refereegranskat)abstract
- A shortcoming of the laminated bending process is that the products may become distorted after moulding and during use. Annually, significant financial losses have incurred in the furniture and interior design industries as a result of distorted products. In this study, we have examined the influence of deviation of fibre orientation of individual veneers on distortion of a moulded shell to find ways to improve shape stability of laminated veneer products.Ninety cross-laminated shells, consisting of 7 veneers of Birch (Betula pubescens Ehrh.) with a total thickness of 3.6 mm, were studied. The in-plane dimensions of the veneer were 400x660 mm. All the veneers were straight-grained, but to simulate deviation in fibre orientation some of the individual veneers were oriented 7 degrees relative to the main orientation of the other veneers in the laminate. Distortion was determined directly after moulding and after storage in a changing relative humidity.The results show the well-known fact that deviation of fibre orientation of the veneers in the laminate influences the shape stability of the product. The results from this study, however, also show how the placement of the abnormal veneers in the laminated veneer products influences the degree of distortions. From this basic knowledge some improvements for production of laminated veneer products were suggested.
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| 35. |
- Blomqvist, Lars, 1962-
(författare)
-
Shape stability of laminated veneer products
- 2013
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is about the shape stability of laminated veneer products.Laminated veneer products consist of veneers bonded together with adhesive into a predetermined shape. Such products are used in several contexts but especially in furniture manufacture. Deviation from the intended shape is a problem for both manufacturers and customers of the final products. The shape stability of laminated veneer products depends on a variety of material and process parameters, and this thesis identifies several important factors that influence shape stability. The purpose of this thesis is to find ways to decrease distortion and improve shape stability so that product quality can be improved.Different ways of measuring shape stability, both in an industrial environment and in a more research-based context, are presented in this thesis. Various studies have been conducted to evaluate the influence of different material and process parameters on shape stability. The parameters studied were species (beech and birch), adhesive system (bio-based adhesives, adhesive systems based on urea formaldehyde), adhesive distribution on the veneer, climate, moisture content and fibre orientations of the veneers, as well as orientation of the individual veneers in an assembly.The results clearly show that the fibre orientation of the veneer strongly influences the shape stability of a laminated veneer product. This means that products can show considerable distortion (particularly twist) if the fibre orientation of the veneer is orientated in an unsuitable way in the assembly before moulding. The effect of fibre orientation on shape stability can be very small directly after moulding, but it increases considerably when the moulded product is subjected to a change in moisture content. In general, a change in moisture content leads to distortion. Moisture change alone, however, results in a controlled distortion.An asymmetrical construction coupled with different moisture contents of the veneers in an assembly before moulding will result in poor shape stability of the product. Other studied parameters had a low impact on shape stability, although beech resulted in more distortion and poorer shape stability than birch.In order to produce shape-stable laminated veneer products, the veneers should be conditioned to a uniform moisture content and sorted with regard to fibre orientation before bonding. The orientation of the veneers is highly important regarding both fibre orientation and the loose or tight side of the veneer. If shape stability is the main target, the loose sides of peeled and sliced veneers should be oriented in the same manner.
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| 36. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Shape stability of laminated veneer products : an experimental study of the influence on distortion of some material and process parameters
- 2013
-
Ingår i: Wood Material Science & Engineering. - : Taylor & Francis Group. - 1748-0272 .- 1748-0280. ; 8:3, s. 198-211
-
Tidskriftsartikel (refereegranskat)abstract
- Laminated bending of veneers is a common used and important process for manufacture of components primarily for furniture and interior purposes. According to the use, such products are in general very sensitive to variations in the intended shape, i.e. distortion can be of great problem and more or less destroy the use of the final product. The most critical mode of distortion is twist, but also other changes in shape may be of interest to keep low. The causes to distortion of laminated bended veneer products can be of material (veneer, adhesive and the combination of these), design, processes and climate nature and there is a challenge to know which parameters which are of major importance for distortion, both directly after moulding and when the products are in use.In this study, the influence of type of UF-adhesive hardener, i.e. liquid or powder, water content of adhesive, adhesive distribution, variation of moisture content of glued veneers, and fibre orientation of veneers, on twist and position for a 3D-veneer construction (a chair seat shell) has been studied. Distortion, i.e. twist and position, has been determined directly after moulding and after moisture cycling. The moisture cycling was to simulate and accelerate conditions that the shells are subjected in use. The aim of the work is to study how the above mentioned material and process parameters influence the shape stability of the products.The results show that the climate, i.e. how a certain level of temperature and relative humidity influence the moisture content of the moulded product, has a clear impact on the distortion of the product in use. An increase in moisture content results in a significant increase in distortion and vice versa. The level to which the moulded products distort during climate variation can be controlled through controlling material, design and process parameter during moulding. Of the studied parameter mentioned above, a deviation in fibre orientation of the veneers in the moulded assembly is the most critical parameter to have under control to minimize distortion. The fibre deviation mainly results in an increase in twist. A high moisture content of a veneer vis-à-vis the rest of the veneers in the assembly before moulding, will result in increased position and twist of the moulded product in use. The difference of moisture content between veneers and the position of veneers with high moisture content in the assembly will influence the level of distortion. Other studied parameter also influences the distortion to a lesser extent and can in these cases be related to the moisture distribution in the mouldings.
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| 37. |
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| 38. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
Temporary buildings in reusable lightweight material design
- 2016
-
Ingår i: Proceedings of the 2016 World Conference on Timber Engineering (WCTE). - Vienna : Vienna University of Technology.
-
Konferensbidrag (refereegranskat)abstract
- There is a growing need and market for temporary buildings for various purposes, including largeconstruction projects in the tourism and events sectors or in civil protection. This paper gives an overview about the useof reusable lightweight materials in temporary buildings. Based on a project proposal submitted to the 7th framework, anew concept of temporary buildings is proposed. This concept combines the advantages of the premanufacturing of asmall number of parts and wooden components and a flexible and modular erection of the temporary building. Thefocus is on fast establishment with a maximum of three persons. A flexible and modular extension is possible.Assembling and disassembling the individual components with novel connect systems, adapted from the furnitureindustry, is proposed.This project aims to bring these concepts into new temporary buildings with new, reusable, and flexible lightweightdesign.
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| 39. |
- Blomqvist, Lars, et al.
(författare)
-
The effect of veneer-modifcation on the bond-strength in laminated veneer products
- 2015
-
Ingår i: Pro Ligno. - 1841-4737 .- 2069-7430. ; 11:4, s. 43-49
-
Tidskriftsartikel (refereegranskat)abstract
- A major problem in the manufacture of three-dimensional laminated veneer products (LVP) is damage due to stretching and/or buckling of the veneer. To reduce or eliminate this problem, veneer densification or adding a strengthening layer to the veneer can be an alternative. To study how veneer modification influences the veneer-to-adhesive bond strength, three methods of modification were studied in relation to an unmodified reference veneer: (1) densified veneer, (2) veneer pre-bonded with paper and hot melt adhesive (HMA), (3) veneer pre-bonded with non-woven polypropylene (NW) fabric glued to the veneer (a) with a urea formaldehyde (UF) adhesive, (b) with a mixture of UF and polyvinyl acetate (PVAc) adhesive, and (c) with a PVAc adhesive. Densification, pre-bonding with paper, and NW with UF/PVAc adhesive mixture resulted in no or only a slight decrease in strength of the bond-line compared to the reference. NW glued with UF or PVAc adhesive showed a considerable reduction in the strength of the bond-line. The climatic cycling had no significant influence on the bond strength.
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| 40. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
The effect of veneer modification on the bond-line strength in laminated veneer products
- 2015
-
Ingår i: Pro Ligno. - Brasov, Romania : Transilvania University. - 1841-4737 .- 2069-7430. ; 11:4, s. 43-49
-
Tidskriftsartikel (refereegranskat)abstract
- A major problem in the manufacture of three-dimensional laminated veneer products (LVP) is damage due to stretching and/or buckling of the veneer. To reduce or eliminate this problem, veneer densification or adding a strengthening layer to the veneer can be an alternative. To study how veneer modification influences the veneer-to-adhesive bond strength, three methods of modification were studied in relation to an unmodified reference veneer: (1) densified veneer, (2) veneer pre-bonded with paper and hot melt adhesive (HMA), (3) veneer pre-bonded with non-woven polypropylene (NW) fabric glued to the veneer (a) with a urea formaldehyde (UF) adhesive, (b) with a mixture of UF and polyvinyl acetate (PVAc) adhesive, and (c) with a PVAc adhesive. Densification, pre-bonding with paper, and NW with UF/PVAc adhesive mixture resulted in no or only a slight decrease in strength of the bond-line compared to the reference. NW glued with UF or PVAc adhesive showed a considerable reduction in the strength of the bond-line. The climatic cycling had no significant influence on the bond strength.
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| 41. |
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| 42. |
- Blomqvist, Lars, 1962-, et al.
(författare)
-
The influence of veneer modification on adhesive bond strength
- 2014
-
Ingår i: Proceedings of 10th Meeting of the Northern European Network for Wood Science & Engineering (WSE). - Edinburgh : Edinburgh Napier University.. ; , s. 150-155
-
Konferensbidrag (refereegranskat)
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| 43. |
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| 44. |
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| 45. |
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| 46. |
- Borenäs, Marcus, et al.
(författare)
-
ALK ligand ALKAL2 potentiates MYCN-driven neuroblastoma in the absence of ALK mutation
- 2021
-
Ingår i: EMBO Journal. - : John Wiley & Sons. - 0261-4189 .- 1460-2075. ; 40:3
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Tidskriftsartikel (refereegranskat)abstract
- High‐risk neuroblastoma (NB) is responsible for a disproportionate number of childhood deaths due to cancer. One indicator of high‐risk NB is amplification of the neural MYC (MYCN) oncogene, which is currently therapeutically intractable. Identification of anaplastic lymphoma kinase (ALK) as an NB oncogene raised the possibility of using ALK tyrosine kinase inhibitors (TKIs) in treatment of patients with activating ALK mutations. 8–10% of primary NB patients are ALK‐positive, a figure that increases in the relapsed population. ALK is activated by the ALKAL2 ligand located on chromosome 2p, along with ALK and MYCN, in the “2p‐gain” region associated with NB. Dysregulation of ALK ligand in NB has not been addressed, although one of the first oncogenes described was v‐sis that shares > 90% homology with PDGF. Therefore, we tested whether ALKAL2 ligand could potentiate NB progression in the absence of ALK mutation. We show that ALKAL2 overexpression in mice drives ALK TKI‐sensitive NB in the absence of ALK mutation, suggesting that additional NB patients, such as those exhibiting 2p‐gain, may benefit from ALK TKI‐based therapeutic intervention.
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| 47. |
- Borenäs, Marcus, et al.
(författare)
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ALK signaling primes the DNA damage response sensitizing ALK-driven neuroblastoma to therapeutic ATR inhibition
- 2024
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 1091-6490. ; 121:1
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Tidskriftsartikel (refereegranskat)abstract
- High-risk neuroblastoma (NB) is a significant clinical challenge. MYCN and Anaplastic Lymphoma Kinase (ALK), which are often involved in high-risk NB, lead to increased replication stress in cancer cells, suggesting therapeutic strategies. We previously identified an ATR (ataxia telangiectasia and Rad3-related)/ALK inhibitor (ATRi/ALKi) combination as such a strategy in two independent genetically modified mouse NB models. Here, we identify an underlying molecular mechanism, in which ALK signaling leads to phosphorylation of ATR and CHK1, supporting an effective DNA damage response. The importance of ALK inhibition is supported by mouse data, in which ATRi monotreatment resulted in a robust initial response, but subsequent relapse, in contrast to a 14-d ALKi/ATRi combination treatment that resulted in a robust and sustained response. Finally, we show that the remarkable response to the 14-d combined ATR/ALK inhibition protocol reflects a robust differentiation response, reprogramming tumor cells to a neuronal/Schwann cell lineage identity. Our results identify an ability of ATR inhibition to promote NB differentiation and underscore the importance of further exploring combined ALK/ATR inhibition in NB, particularly in high-risk patient groups with oncogene-induced replication stress.
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| 48. |
- Choquet, Isabelle, 1965-, et al.
(författare)
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Clogging and lump formation during atmospheric plasma spraying with powder injection downstream the plasma gun
- 2007
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Ingår i: Journal of thermal spray technology (Print). - : Springer Science and Business Media LLC. - 1059-9630 .- 1544-1016. ; 16:4, s. 512-523
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to numerically and experimentally investigate lump formation during atmospheric plasma spraying with powder injection downstream the plasma gun exit. A first set of investigations was focused on the location and orientation of the powder port injector. It turned out impossible to keep the coating quality while avoiding lumps by simply moving the powder injector. A new geometry of the powder port ring holder was designed and optimized to prevent nozzle clogging, and lump formation using a gas screen. This solution was successfully tested for applications with Ni-5wt.%Al and ZrO2-7wt.%Y2O3 powders used in production. The possible secondary effect of plasma jet shrouding by the gas screen, and its consequence on powder particles prior to impact was also studied.
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| 49. |
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| 50. |
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