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- Juslin, Patrik N, 1969-, et al.
(author)
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Emotional communication
- 2002
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In: The science and psychology of music performance. - New York : Oxford University Press. - 0195138104 ; , s. 219-236
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Book chapter (other academic/artistic)abstract
- We review research which shows that performers are able to communicate specific emotions to listeners, and that they use a large number of musical features in the performance to accomplish a particular expression. The findings are organized according to a theoretical framework, which describes the communicative process in terms of E. Brunswik's (1956) lens model. We also discuss traditional strategies for teaching expression, including the use of metaphors, aural modeling, and felt emotion, and conclude that these strategies rarely provide informative feedback to the performer. A new and empirically based approach to teaching expression called cognitive feedback is outlined, and its efficacy evaluated. The goal is to provide performers with the tools they need to develop their own personal expression.
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- Patrik, Gustavsson, et al.
(author)
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Geography, Cost-of-Living, and Determinants to Economic Growth : A Study of the Swedish Regions, 1911-1993
- 2003
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Reports (other academic/artistic)abstract
- This paper analyses determinants to economic growth with a spatial perspective using data on the Swedish counties for the period 1911-1993. We find that the county growth rate of income per capita is strongly related to the growth rate of income per capita in contiguous counties regardless of what explanatory variables are included in the regressions. We also find empirical evidence of geographical spillovers through the income per capita and market size in contiguous counties. In addition, we find that population density and population age structure impact the growth rate of income per capita only when incomes are not adjusted for regional differences in cost-of-living. When correctly adjusting for such differences, which rarely occur in the growth literature that uses regional data, the growth effects of these variables disappear. The regressions also show that the estimated growth effect of net in-migration is negative and statistically significant.
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- Persson, Mats, 1954-, et al.
(author)
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Development and maintenance of guideline-based decision support for pharmacological treatment of hypertension
- 2000
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In: Computer Methods and Programs in Biomedicine. - : Elsevier. - 0169-2607 .- 1872-7565. ; 61:3, s. 209-219
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Journal article (peer-reviewed)abstract
- The objective was to build a computer-based decision support system (DSS), which could apply the formal rules embedded in guidelines regarding pharmacological treatment of hypertension. The aim was also to test VISUAL BASIC as a development tool for DSS's in health care. From the Swedish guidelines for treatment of hypertension, the most widely accepted and scientifically best proved treatment strategies were chosen and implemented as rules. A DSS that is capable of applying the evidence-based rules extracted from guidelines regarding drug treatment of hypertension, to any patient's medical profile, was constructed. The output consists of a recommendation regarding preferred generic drug class and also a written report, reflecting decision steps provided by the rule-base and inference engine. We also provide methods for formalising an implementable language of guidelines. A mainstream programming language like VISUAL BASIC can be an alternative when building complicated decision support systems. A logic formal notation can facilitate communication between the expert and the programmer. The program is a stand-alone product independent of computerized medical records and thereby easy to install and maintain.
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- Persson, Patrik, et al.
(author)
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A methodology for estimation of mass transfer parameters in a detailed chromatography model based on frontal experiments
- 2004
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In: Chemical Engineering Research & Design. - : Elsevier BV. - 0263-8762. ; 82:A4, s. 517-526
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Journal article (peer-reviewed)abstract
- A methodology for estimation of the unknown physical parameters in a detailed model for chromatographic processes is proposed. The model describes the concentration of the solute in the mobile phase and considers external/internal mass transfer resistance. The external volume and its mixing effect are also considered. The unknown model parameters estimated are the bed void, the axial dispersion coefficient, the liquid film mass transfer coefficient, the effective diffusion coefficient and the apparent bead porosity. All the parameters in the model were subsequently determined in three classes of experiments, the external mixing behaviour, the mobile phase behaviour and the stationary phase behaviour. The estimates are based on the sum of the least squares of the residuals between the experimental breakthrough curves and the model response. The methodology is exemplified by frontal experiments with lysozyme, bovine serum albumin and immuno globulin gamma on a well-defined column set-up. When the mixing properties in the external volume had to be accounted for, to avoid adding broadening behaviour to the dispersion coefficient, the film mass transfer coefficient and the diffusion coefficient were also investigated. The results show that it is possible to estimate the unknown parameters using the proposed methodology.
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- Persson, Patrik, et al.
(author)
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An interactive environment for real-time software development
- 2000
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In: 33rd International Conference on Technology of Object-Oriented Languages , 2000. TOOLS 33. Proceedings. - 076950731X ; , s. 57-68
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Conference paper (peer-reviewed)abstract
- Object-oriented languages, in particular Java, are beginning to make their way into embedded real-time software development. This is not only for the safety and expressiveness of the source language; the mobility and dynamic loading of Java bytecode make it particularly useful in embedded real-time systems. However using such languages in real-time systems makes it more difficult to predict the worst-case execution time of tasks. Such predictions are necessary for predictable task scheduling in the developed system. Garbage collection, common in object-oriented languages, must be considered; to schedule garbage collection safely, we must know how much memory it has to handle. Dynamic binding in conjunction with dynamic loading of code also needs treatment. We show how techniques for predicting time and memory demands of object-oriented programs are integrated into the Skanerost development environment. The environment explicitly targets an iterative development process, which is particularly important in real-time software development since time and memory demands cannot be determined until the code is written. Design changes due to timing problems become more costly as development progresses, and Skanerost allows such problems to be detected early.
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- Persson, Patrik, 1973-
(author)
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Analysis and Design of Conformal Array Antennas
- 2002
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Doctoral thesis (other academic/artistic)abstract
- Today there is a great need for communication between people and even between things, using systems onboard e.g. aircraft, cars, ships and satellites. As a consequence, these communications needs require antennas mounted on or integrated in the surfaces of different vehicles or platforms, i.e. conformal antennas. In order to ensure proper operation of the communication systems it is important to be able to determine the characteristics of these antennas. This thesis is about the analysis and design of conformal antennas using high frequency asymptotic methods. Commonly used eigenfunction solutions or numerical methods such as FDTD, FEM or MoM are difficult to use for arbitrarily shaped electrically large surfaces. However, the high frequency approximation approach together with an accurate ray tracing procedure offers a convenient solution for these surfaces. The geodesics (ray paths) on the surfaces are key parameters in the analysis and they are discussed in detail. In the first part of the thesis singly and doubly curved perfectly electrical conducting (PEC) surfaces are studied, with respect to the mutual coupling among aperture type elements. A synthesis problem is also considered where the effect of the mutual coupling is taken into account. As expected, the mutual coupling must be included in the synthesis procedure to be able to realize the prescribed pattern, especially in the shaped main lobe. Furthermore, the polarization of the antenna elements is very important when considering antennas on generally shaped surfaces. For such antennas the polarization must most likely be controlled in some way for a proper function. For verification of the results two experimental antennas were built at Ericsson Microwave Systems AB, Mölndal, Sweden. The first antenna is a circular cylinder with an array of rectangular waveguide fed apertures and the second antenna is a doubly curved surface (paraboloid) with circular waveguide fed apertures. It is found that it is possible to obtain very accurate results with the asymptotic method when it is combined with the Method of Moments, i.e. a hybrid method is used. The agreement compared to measurements is good at levels as low as –80 dB in many cases. The second part of the thesis is about the development of a high frequency approximation for surface field calculations on a dielectric covered PEC circular cylinder. When using conformal antennas in practice they have to be covered with a radome for protection and with the method developed here this cover can be included in the analysis. The method is a combination of two different solutions, one valid in the non-paraxial region of the cylinder and the other is valid in the paraxial region. The method is verified against measurements and reference results obtained from a spectral domain moment method code.
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- Persson, Patrik, et al.
(author)
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Calculating the mutual coupling between apertures on a convex circular cylinder using a hybrid UTD-MoM method
- 2001
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In: IEEE Transactions on Antennas and Propagation. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-926X .- 1558-2221. ; 49:4, s. 672-677
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Journal article (peer-reviewed)abstract
- In this paper, the problem of calculating the mutual coupling between apertures on a perfectly conducting circular cylinder is considered. The mutual coupling is calculated by a combination of uniform theory of diffraction (UTD) and the method of moments (MoM). This hybrid method makes it possible to include higher order aperture modes in order to improve the accuracy. It is found that the UTD-MoM solution gives accurate results, even for small cylinders. The results are verified against results found in the literature, as well as against measurements performed at Ericsson Microwave System in Molndal, Sweden. For this purpose, a cylindrical test antenna with 54 apertures was built. Using a single-mode approximation, good agreement down to about -60 dB, comparisons to measured data has been obtained. If additional modes are added the results improve significantly both in amplitude and phase, Zn several cases, the agreement is good down to coupling levels about -80 dB. This requires that about six modes are included. However, the most important mode, besides the fundamental TE10 mode is the TM11 mode.
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- Persson, Patrik
(author)
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CALIBRATION OF CHROMATOGRAPHY MODELS
- 2004
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Doctoral thesis (other academic/artistic)abstract
- AbstractThis thesis is devoted to calibration of mathematical chromatography models. Chromatography models include unknown parameters that must be determined before the models can be applied to optimization or scale-up of a chromatography process. The aim of the work presented in the thesis was to develop methods for determining these unknown model parameters.The fundamental approach adopted to determine model parameters was fitting of the mathematical chromatography model in question to experimental data by estimating the parameters using regression methods.Several factors, as parameter dependencies, the order in which the parameters should be estimated, the generation of experimental data required, suitable fitting procedures, etc., must be taken into account in the methodology developed for the determination of the unknown model parameters.This thesis presents a methodology for calibration of a detailed chromatography model. Fitted empirical correlations for different band broadening behaviours taking the flow rate and bead size into account, have also been developed and presented. Model simplifications are discussed, and the use of simpler models to describe continuous monolithic beds.The methodology was applied to chromatography columns packed with different cross linked Sepharose gels and columns containing continuous supermacroporous monolithic beds, using acetone, latex particles, blue dextran, E. coli cells, lysozyme, immuno globulin g and bovine serum albumin, at different flow rates. This was done under both non-retained and sorption conditions. The results show that it is possible to determine unknown parameters included in chromatography models describing both packed beds and continuous monolithic beds using the methodology developed.
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