| 1. |
- Andersson, Maria L.E., et al.
(författare)
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Autoantibodies to Disease-Related Proteins in Joints as Novel Biomarkers for the Diagnosis of Rheumatoid Arthritis
- 2023
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 75:7, s. 1110-1119
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Tidskriftsartikel (refereegranskat)abstract
- Objective. This study was undertaken to develop and characterize a multiplex immunoassay for detection of autoantibodies against peptides derived from proteins known to play a role in development of arthritis and that are also expressed in joints.Methods. We selected peptides from the human counterpart of proteins expressed in the joints, based on mouse models that showed these to be targeted by pathogenic or regulatory antibodies in vivo. Using bead-based flow immunoassays measuring IgG antibodies, we selected triple helical or cyclic peptides, containing the epitopes, to avoid collinear reactivity. We characterized the analytical performance of the immunoassay and then validated it in 3 independent rheumatoid arthritis (RA) cohorts (n = 2,110), Swedish age- and sex-matched healthy controls, and patients with osteoarthritis (OA), patients with psoriatic arthritis (PsA), and patients with systemic lupus erythematosus (SLE).Results. Screening assays showed 5 peptide antigens that discriminated RA patients from healthy controls with 99% specificity (95% confidence interval [CI] 98-100%). In our validation studies, we reproduced the discriminatory capacity of the autoantibodies in 2 other RA cohorts, showing that the autoantibodies had high discriminatory capacity for RA versus OA, PsA, and SLE. The novel biomarkers identified 22.5% (95% CI 19-26%) of early RA patients seronegative for anti-cyclic citrullinated peptide and rheumatoid factor. The usefulness of the biomarkers in identifying seronegative RA patients was confirmed in validation studies using 2 independent cohorts of RA patients and cohorts of patients with OA, PsA, and SLE.Conclusion. A multiplex immunoassay with peptides from disease-related proteins in joints was found to be useful for detection of specific autoantibodies in RA serum. Of note, this immunoassay had high discriminatory capacity for early seronegative RA.
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| 2. |
- Andersson, Peter, 1981-, et al.
(författare)
-
Coincidence spectroscopy for increased sensitivity in radionuclide monitoring
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The majority of the energy in a nuclear explosion is released in the immediate blast and the initial radiation accounts. The remaining fraction is released through radioactive decay of the explosion's fission products and neutron activation products over a longer time span. This allows for the detection of a nuclear explosion by detecting the presence of residual decay. Radionuclide monitoring stations for detection of radioactive emissions to the atmosphere is thereby an important tool in the verification of compliance with nuclear disarmament treaties. In particular, the globally spanning radionuclide station network of the International Monitoring System (IMS) has been implemented for verification of the Comprehensive Nuclear-Test-Ban Treaty.High Purity Germanium (HPGe) detectors are workhorses in radionuclide monitoring. The detection of characteristic gamma rays can be used to disclose the presence of signature nuclides produced innuclear weapon tests. A particular development that has potential to improve the sensitivity of radionuclide monitoring is the coincidence technique where decaying nuclides that emit several coincident gamma rays can be detected at much smaller activity concentrations than with conventional gamma spectroscopy.In this project, dedicated gamma-gamma coincidence detectors are being developed, utilizing electronically segmented HPGe detectors. These detectors are expected to be highly sensitive to low-activity samples of nuclides that present coincident emissions of gamma rays. In this paper we present the concept, define performance parameters, and explore the performance of such detectors to a subset of radionuclides of particular CTBT relevance. In addition, we discuss the path forward in developing a next generation gamma-gamma coincidence spectroscopy system of segmented HPGe.
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| 3. |
- Magnusson, Alf, 1958, et al.
(författare)
-
A Comparison of Spray Properties for Model Fuel and Diesel Using Several Optical Methods
- 2004
-
Ingår i: 19th Ilass Europe.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Many experiments are carried out using a model fuel, for instance for measurement technique reasons. These data are usually transferred to situations where standard diesel fuel is used. The objective of this work is to characterize the liquid and vapour phase penetration of two different diesel fuels, one two-component model fuel, IDEA (70% n-decane and 30% α-methylnaphthalene) and one standard diesel fuel (Swedish Environmental Class I), when injected into air with density corresponding to early injections up to self ignition conditions in diesel engines. The experimental study was carried out in the high-pressure, high-temperature (HP/HT) spray rig at Chalmers, which was pressurized in the range of 4 to 85 bar and with temperature ranging from 400 to 800 K.A common-rail injection system with a single hole nozzle was used. Several optical methods (Schlieren, Shadowgraph, LIF (Laser Induced Fluorescence) and Mie-scattering) were used together or separately which allow a comparison of the output. Phase Doppler Anemometry (PDA) was used for the two fuels as a complement to the planar methods. Results from measurements show that there are differences in liquid penetration, fuel vaporization and droplet distribution in between the fuels and relatively good agreement between the methods
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| 4. |
- Adman, Per, et al.
(författare)
-
171 forskare: ”Vi vuxna bör också klimatprotestera”
- 2019
-
Ingår i: Dagens nyheter (DN debatt). - Stockholm. - 1101-2447.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 26/9. Vuxna bör följa uppmaningen från ungdomarna i Fridays for future-rörelsen och protestera eftersom det politiska ledarskapet är otillräckligt. Omfattande och långvariga påtryckningar från hela samhället behövs för att få de politiskt ansvariga att utöva det ledarskap som klimatkrisen kräver, skriver 171 forskare i samhällsvetenskap och humaniora.
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| 5. |
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| 6. |
- Andersson, Alf, et al.
(författare)
-
Characteristics of the Defense Mechanism Technique modified (DMTm) as Related to Age and Gender of Adolescent Inpatients at a Psychiatric Clinic
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A cross-sectional developmental study of 326 non-psychotic inpatients at a child and adolescent psychiatric clinic was carried out making use of the Defense Mechanism Technique modified (DMTm). The 139 girls and 187 boys were divided into three age groups: 12-13, 14-15 and 16-17 year olds. It was predicted on the basis of previous research that the younger boys would exhibit the defense of inclusive affect isolation more frequently than the older ones. This was found to be the case, this same age-related difference being found for the girls and for the group as a whole. The sign of disappearance of hero/heroine (H) was found more frequently in the younger than the older subjects, and the sign of H sad more frequently in the 14-15 year olds. As expected, the girls were scored for the identity defense of denial through reversal III more often than the boys. Other characteristics found more frequently in the girls than the boys were repression at the site of the attribute (A-repression) and the signs of H sad and A a child. The identity defense of denial through reversal I and the sign of splitting (split H) were characteristics more often observed in the boys than the girls. The findings were interpreted in terms of the Andersson developmental and psychodynamic model of the mind.
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| 7. |
- Andersson, Alf
(författare)
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Comparison of sheet-metal-forming simulation and try-out tools in the design of a forming tool
- 2004
-
Ingår i: Journal of Engineering Design. - : Informa UK Limited. - 1466-1837 .- 0954-4828. ; 15:6, s. 551-561
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Tidskriftsartikel (refereegranskat)abstract
- Today, sheet-metal-forming simulation is a powerful technique for predicting the formability of automotive parts. Compared with traditional methods such as the use of try-out tools, sheet-metal-forming simulation enables a significant increase in the number of tool designs that can be tested before hard tools are manufactured. Another advantage of sheet-metal-forming simulation is the possibility to use it at an early stage of the design process, for example in the preliminary design phase. Today, the accuracy of the results in sheet-metal-forming simulation is high enough to replace the use of try-out tools to a great extent. At Volvo Car Corporation, Body Components, where this study has been carried out, sheet-metal-forming simulation is used as an integrated part in the process of tool design and tool production.
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| 8. |
- Andersson, Alf, et al.
(författare)
-
Drug of choice as related to percept-genetic reconstruction of personality in terms of the Spiral Aftereffect Technique (SAT) and the Defense Mechanism Technique modified (DMTm).
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This study concerns whether the personality of drug addicts is related to their drug of choice. A group of 112 heavy drug addicts participated, each selected for either heroin (29 women, 52 men) or amphetamine (31 men) being their basic drug. Their personality was assessed by means of two percept-genetic techniques, the Spiral Aftereffect Technique (SAT) and the Defense Mechanism Technique modified (DMTm). The data was examined by use of Multidimensional Scaling. The most typical signs for the male heroin abusers were LLs on SAT and denial 1 and repression 3 but not repression 6 on DMTm. Both the female heroin and the male amphetamine abusers were characterized by L- on SAT and denial through reversal III and repression 6 on DMTm. It is suggested that male abusers for whom heroin is the drug of choice reconstruct the very first position of the Andersson developmental and psychodynamic model of the mind, linked in particular with primary dependency. This contrasts with both the male and the female abusers, for whom amphetamine and heroin, respectively, are the basic drugs, and who reconstruct positions in the Andersson model linked with hystero-phobia.
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| 9. |
- Andersson, Alf, et al.
(författare)
-
Enhanced denial or the emergence of affect isolation of an inclusive kind were uncommon in the Defense Mechanism Technique modified (DMTm) after successful psychodynamic therapy.
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A group of 74 psychiatric patients who had undergone psychodynamic therapy (PDT; 24 women, 10 men), cognitive psychotherapy (CPT; 9 women, 2 men) or cognitive behavioral therapy (CBT; 17 women, 12 men) were given the Defense Mechanism Technique modified (DMTm), a percept-genetic technique, both prior to therapy and four months after completing it, at which time they evaluated by questionnaire the therapeutic outcome in terms of their degree of satisfaction, change in personality, symptoms, and handling of problems and the therapy’s usefulness. As hypothesized, either an increase in denial or the emergence of inclusive affect isolation following therapy in DMTm occurred less frequently in PDT patients who rated their therapy as successful than in the remaining PDT patients and in both of the other two patient groups (CPT and CBT), irrespective in the latter case of how the therapeutic outcome was rated. The findings were interpreted in terms of the Andersson developmental and psychodynamic model of the mind.
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| 10. |
- Andersson, Alf, et al.
(författare)
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Evaluation and comparison of surface defects on a simplified model for the area around the fuel filler lid by simulation and experiments
- 2001
-
Ingår i: Simulation of Material Processing: Theory, Methods and Application: Proceedings of the 7th International Conference Numiform 2001. - 9026518226
-
Konferensbidrag (refereegranskat)abstract
- There is a serious need in the automotive industry to predict surface defects in outer panels. Measures to prevent these defects can not be taken until a test part has been manufactured. This costs a lot in time and money. Within the present project stamping tools for a model part resembling the area around the fuel filler lid was developed. This is an area of the outer surface of a car, which is particularly sensitive for surface defects. Based on this model both experiments and sheet-metal-forming simulations were performed and the results were compared. The result showed that the simulations were able to predict the location of the defects but the magnitudes of the defects were not sufficiently accurate. The defects that occurred were more like waves than small localised defects at the corners, “teddy bear ears”. These defects could be seen in both the experiments and the simulations.
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| 11. |
- Andersson, Alf
(författare)
-
Evaluation and Visualisation of Surface Defects – - a Numerical and Experimental Study on Sheet-Metal Parts
- 2005
-
Ingår i: NUMISHEET 2005: Proceedings of the 6th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Process (AIP Conf. Proc). - : AIP. - 0735402655 ; 778, s. 113-118
-
Konferensbidrag (refereegranskat)abstract
- The ability to predict surface defects in outer panels is of vital importance in the automotive industry, especially for brands in the premium car segment. Today, measures to prevent these defects can not be taken until a test part has been manufactured, which requires a great deal of time and expense. The decision as to whether a certain surface is of acceptable quality or not is based on subjective evaluation. It is quite possible to detect a defect by measurement, but it is not possible to correlate measured defects and the subjective evaluation. If all results could be based on the same criteria, it would be possible to compare a surface by both FE simulations, experiments and subjective evaluation with the same result.In order to find a solution concerning the prediction of surface defects, a laboratory tool was manufactured and analysed both experimentally and numerically. The tool represents the area around a fuel filler lid and the aim was to recreate surface defects, so-called "teddy bear ears". A major problem with the evaluation of such defects is that the panels are evaluated manually and to a great extent subjectivity is involved in the classification and judgement of the defects. In this study the same computer software was used for the evaluation of both the experimental and the numerical results. In this software the surface defects were indicated by a change in the curvature of the panel. The results showed good agreement between numerical and experimental results. Furthermore, the evaluation software gave a good indication of the appearance of the surface defects compared to an analysis done in existing tools for surface quality measurements. Since the agreement between numerical and experimental results was good, this indicates that these tools can be used for an early verification of surface defects in outer panels. ©2005 American Institute of Physics
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| 12. |
- Andersson, Alf
(författare)
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Evaluation and visualisation of surface defects on auto-body panels
- 2009
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Ingår i: Journal of Materials Processing Technology. - : Elsevier BV. - 0924-0136. ; 209:2, s. 821-837
-
Tidskriftsartikel (refereegranskat)abstract
- The ability to predict surface defects in outer panels is of vital importance in the automotive industry, especially for brands in the premium car segment. Today, measures to prevent these defects cannot be taken until a test part has been manufactured, which requires a great deal of time and expense. The decision as to whether a certain surface is of acceptable quality or not is based on subjective evaluation. it is quite possible to detect a defect by measurement, but it is not possible to correlate measured defects and the subjective evaluation. If all results could be based on the same criteria, it would be possible to compare a surface by both FE simulations, experiments and subjective evaluation with the same result. In order to find a solution concerning the prediction of surface defects, a laboratory tool was manufactured and analysed both experimentally and numerically. The tool represents the area around a fuel filler lid and the aim was to recreate surface defects, so-called "teddy bear ears". Several different sheet materials were analysed in order to evaluate their sensitivity to surface defects, and to investigate the possibility to predict defects in different materials. A major problem with the evaluation of such defects is that the panels are evaluated manually and to a great extent subjectivity is involved in the classification and judgement of the defects. In this study the same computer software was used for the evaluation of both the experimental and the numerical results. in this software the surface defects were indicated by a change in the curvature of the panel. The results showed good agreement between numerical and experimental results. Furthermore, the evaluation software gave a good indication of the appearance of the surface defects compared to an analysis done with the existing tools for surface quality measurements, e.g. D-Sight [D-Sight, 2007. http://www.lmint.com] results. Since the agreement between numerical and experimental results was good, this indicates that these tools can be used for an early verification of surface defects in outer panels. (C) 2008 Published by Elsevier B.V.
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| 13. |
- Andersson, Alf, et al.
(författare)
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Experimental evaluation of strains in the tension-compression using a new tool geometry, X-Die
- 2008
-
Ingår i: Journal of Materials Processing Technology. - : Elsevier BV. - 0924-0136. ; 200:1-3, s. 1-11
-
Forskningsöversikt (refereegranskat)abstract
- Sheet-metal forming involves a complex distribution of strains throughout the part. The strains occur due to tension, compression and a mix of both. A geometry has been developed, the X-Die, in order to gain insight into the strain behavior of different materials. The X-Die enables strain paths far into the tension-compression region, thus creating the possibility to extend the experimental base both for definition and for further extrapolation of the forming limit curve (FLC) in the tension-compression region, as well as to evaluate FE-simulation results for the same region. The experimental results show that the strain signature is impacted by material quality. In qualities such as extra high strength steel (EHSS) and aluminum the strains do not reach as far into the tension-compression region as the strains do in e.g. mild steel. This is due to failure in plane strain tension. Strain paths in materials such as mild steel and high strength steel (HSS) reach far into the tension-compression region before failure. Use of the X-Die provides possibilities to reach farther into the tension-compression region compared with traditional test methods for creating a forming limit diagram (FLD). Use of the X-Die yields well-defined strain signatures. These clearly defined strain signatures are favorable for comparison with numerical simulations, especially for strain signatures in the tension-compression region. Furthermore, the experiments using the X-Die indicate that a possible additional forming limit curve, which intersects the original forming limit curve (shear failure), exists so far into the tension-compression region that it is not applicable. Even though the experiments indicate compression strains > 100% (material DX56D), the experiments show potential for an experimentally determined extrapolation of the FLC up to similar to 75% compression strain. The results of the experiments indicate that the X-Die geometry is suitable as a supplementary tool in identifying the strain behavior of different materials far into the tension-compression region and is also a good tool for verification of numerical results in the tension-compression region. (c) 2007 Elsevier B.V. All rights reserved.
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| 14. |
- Andersson, Alf, et al.
(författare)
-
Failure Analysis With a New Tool Geometry, X-Die, in Areas With High Tension/Compression Strains
- 2007
-
Ingår i: MATERIALS PROCESSING AND DESIGN; Modeling, Simulation and Applications; NUMIFORM '07; Proceedings of the 9th International Conference on Numerical Methods in Industrial Forming Processes (AIP Conference Proceedings). - : AIP. - 1551-7616 .- 0094-243X. - 9780735404151 ; 908, s. 1445-1450
-
Konferensbidrag (refereegranskat)abstract
- Sheet-metal forming involves a complex strain distribution over the part. The strains consist of tension, compression, and a mix of both. A geometry has been developed, the X-Die, in order to gain insight into the strain behavior of different materials. The X-Die enables strain paths far into the tension/compression region, thus creating the possibility to extend the experimental base both for definition and for further extrapolation of the Forming Limit Curve (FLC) in the tension/compression region, as well as to evaluate FE-simulation results for the same region.Today, evaluation of cracks is made by using FLC. In the conventional test methods, the strains only reach 40% compression (true strain) and often much lower percentages. In conventional test methods, the FLC for any region beyond these levels is extrapolated from existing data.The experimental test proposed in this work consists of a geometry, the X-die, which has shown that rates of 70% tension/compression can be reached (point 0.7/−0.7 in the FLC). Thereby, the region for prediction of cracks on the compression side can be extended in the Forming Limit Diagram (FLD). Furthermore, the strain paths are easy to follow and the limits when cracks appear can be evaluated. Furthermore, the experimental results show that the behavior depends on the material quality. Qualities such as Extreme High Strength Steel (EHSS) and Aluminum have a limited tension/compression rate due to failure in plane strain tension. Material qualities with high r-values, e.g. Mild steel and High Strength Steel (HSS), reach high tension/compression rates before failure and have regions with clearly defined strain signatures. This will be favorable for comparison with numerical simulations, especially for strain signatures in the tension/compression region. Furthermore, the experiments did not indicate any limitation in the compression region besides the one defined in the normal procedure in creation of an FLC.This geometry is favorable to calibrate simulation results, in order to analyze prediction of strains located on the left side in an FLD. ©2007 American Institute of Physics
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| 15. |
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| 16. |
- Andersson, Alf
(författare)
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Information Exchange within the area of tool design and sheet-metal-forming simulations
- 2001
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Ingår i: Journal of Engineering Design. - : Informa UK Limited. - 1466-1837 .- 0954-4828. ; 12:4, s. 283-291
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Tidskriftsartikel (refereegranskat)abstract
- Today, shortened lead-times in the automotive industry have raised requirements on rapid information exchange. The increased use and access to the Internet have created possibilities to transfer information to people independent of location. This development, together with the increased speed in the portable computer technology, has opened possibilities for bringing results from sheet-metal-forming simulations directly to the customer. Previously, the results were presented with pictures; now it is possible to use animations. The only requirement is to have access to a post-processor or a viewer that is powerful enough to handle the results. The advantage with animated results is the improved possibilities to follow the sheet-metal-forming process. In this project, the methodology for reporting results from sheet-metal-forming simulations at Volvo Cars Body Components is studied. A potential for improvement would be possible if the reporting procedure is changed from paper copies to a database structure. In the database the results should be stored as files with animated results that the user is able to rotate and zoom. This methodology will contribute to faster and more accurate decisions because it will be based on current information and the user could easily analyse the results without access to special programs.
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| 17. |
- Andersson, Alf, et al.
(författare)
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Inline Process Control – a concept study of efficient in-line process control and process adjustment with respect to product geometry
- 2016
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Ingår i: Swedish Production Symposium 2016 SPS 2016. - Lund, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- All manufacturing processes have variation which may violate the fulfillment of assembly, functional, geometrical or esthetical requirements and difficulties to reach desired form in all areas. The cost for geometry defects rises downstream in the process chain. Therefore, it is vital to discover these defects as soon as they appear. Then adjustments can be done in the process without losing products or time. In order to find a solution for this, a project with the overall scope “development of an intelligent process control system” has been initiated. This project consists of five different work packages: Inline measurement, Process Evaluation, Corrective actions, Flexible tooling and demonstrator cell. These work packages address different areas which are necessary to fulfill the overall scope of the project. The system shall both be able to detect geometrical defects, propose adjustments and adjust simple process parameters. The results are demonstrated in a demo cell located at Chalmers University of Technology. In the demonstrator all the different areas have been verified in an industrial case study – assembly of GOR Volvo S80. Efficient offline programming for robot based measurement, efficient process evaluation based on case base reasoning (CBR) methodology, flexible fixtures and process adjustments based on corrective actions regarding in going part positioning.
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| 18. |
- Andersson, Alf, et al.
(författare)
-
Lack of affect defenses, affekt isolation of an inclusive kind or affect inhibition were uncommon in the Defense Mechanism Technique modified (DMTm) when psychodynamic therapy was recommended by the clinical staff.
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A group of 200 psychiatric patients, 129 women and 71 men, were given recommendations by a four-person staff of their receiving psychodynamic therapy (PDT; 47 women, 17 men), cognitive psychotherapy (CPT; 19 women, 5 men) or cognitive behavioral therapy (CBT; 34 women, 20 men), or of their having no psychotherapy (NPT; 29 women, 29 men). The staff knew the ICD-10 diagnoses but made its judgments primarily on the basis of information obtained from a clinical interview performed with each of the patients by some one of the members of the staff. All of the patients were given the Defense Mechanism Technique modified (DMTm), a percept-genetic technique, although the results of it had not yet been scored and were thus not used by the staff in making their recommendations. The question of the characteristics that could be expected to appear in the DMTm less frequently when PDT is recommended than when CPT, CBT or NPT is recommended was considered. The following three DMTm characteristics were predicted to appear less frequently in the PDT patients than in the other three groups: a lack of affect defenses, the presence of affect isolation of an inclusive kind and affect inhibition. This was found to hold, both for the male and for the female patients. The occurrence of inclusive affect isolation was found to be the most decisive characteristic.
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| 19. |
- Andersson, Alf, et al.
(författare)
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Leadership style and managerial type as related to working climate, gender and personality in terms of the Spiral Aftereffect Technique (SAT)
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The study considers relations in a group of 95 managers, 41 women and 54 men, between working climate of their units, their leadership styles in terms of their subordinates’ ratings of employee-centeredness, change-centeredness and production-centeredness, and their personality patterns according to the Spiral Aftereffect Technique (SAT). Eight managerial types were distinguished, based on low and high ratings on the three leadership style dimensions. Women were rated as being high on change-centeredness more often than men. The working climate of the unit of a ”vague manager” or of a ”bureaucrat” was rated as being low, that of a ”gardener”, of a ”buddy manager” and to some extent of an ”all-round manager” as being high. Managers classified as M on the SAT were frequently low or very low on employee-centeredness and change-centeredness, those classified as Mo frequently high or very high on these dimensions. Mo was typical for an ”all-round manager” and for a manager at a unit with high ratings of working climate. Low ratings of working climate were often found for managers classified as LLs or H. Interpretations of SAT personality patterns were based on the Andersson model of the mind.
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| 20. |
- Andersson, Alf
(författare)
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Macro-Geometric Defects, A numerical and experimental study of springback and surface defects
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today, shortened lead-times in the automotive industry have dramatically increased the need for more efficient development methods at every stage of the process development chain. In order to decrease the long lead-time for producing a forming tool, sheet-metal-forming simulation was introduced. Even though sheet-metal-forming simulation is widely used in the automotive industry today, there are still challenges to be overcome. Two important examples are the prediction of springback and surface defects. If reliable predictions of these phenomena could be achieved, much money could be saved in reduced lead-times and adjustment costs. These areas, together with drawbeads, were also highlighted as areas of significant interest when the use of FE simulation was compared to the use of try-out tools. In this evaluation the Production Performance Matrix (PSM) and the Process Correspondence Matrix (PCM) were used. In order to use the achieved information efficiently, a method for efficient information exchange for the FE simulation results was proposed. The main goal with this project was to find a method for analysis of macro-geometric defects (such as surface defects and springback). Analysis of surface defects involves difficulties in both experimental and numerical assessment. Since the defects are very small and also depend on both position and shape in the classification procedure, it is difficult to find an evaluation system which can detect both small variance in the shape of the surface and classify the defects. Furthermore, the numerical results depend both on the accuracy in the prediction of the forming behavior and the springback. In order to compare the results of the same classification procedure, a method has been developed whereby the surface can be analysed both numerically and experimentally in the same evaluation software. In this way, the classification will be the same and the results will be directly comparable. Regarding springback, a study of the parameters resulted in the conclusion that the important factors to consider in FE simulations of springback are, among others, to have small elements, low tool speed and good material models. The results were applied to an automotive part, a front side member. The simulations exaggerated the twist but the error was moderate for mild steel and Rephos steel. However, a TRIP steel was also examined and there the deviation was much larger. In the forming process the flow of material is controlled among other things by drawbeads. The material flow is very important in order to have a correct stress distribution in the formed part, which in turn affects both springback and surface defects. In this work a method for optimising the restraining force (which represents drawbeads in FE simulations) with a small number of iterations has been developed.
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| 21. |
- Andersson, Alf, et al.
(författare)
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Managerial type as related to percept-genetic signs of anxiety and defense in the Defense Mechanism Technique modified (DMTm)
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The study considers relations in a group of 95 managers, 41 women and 54 men, between managerial type and signs of anxiety and defense in the Defense Mechanism Technique modified (DMTm). Eight managerial types were distinguished, based on ratings of the managers by their subordinates in terms of the Ekvall and Arvonen (1991) leadership style dimensions of employee-centeredness, change-centeredness and production-centeredness. As expected, those classified as “bureaucrats” differed from the other managerial types in less often showing affect anxiety, identity anxiety and separation anxiety. Other findings related to predictions made were that a marked degree of introaggression 1 was typical of “idea-makers”, marked repression 3 typical of “idea-makers” and ”gardeners”, and marked denial through reversal IV typical of ”gardeners”. Various defenses were also found to be more common in the managers studied here than in a group of university teachers investigated earlier. The Andersson (1991) model of the mind served as a tool for interpreting the results.
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| 22. |
- Andersson, Alf
(författare)
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Numerical and experimental evaluation of springback in a front side member
- 2005
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Ingår i: Journal of Materials Processing Technology. - : Elsevier BV. - 0924-0136. ; 169:3, s. 352-356
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, a part of an automotive side front section (front side member inner) was studied and a comparison both regarding material behaviour and of accuracy of the FE simulations was made. Mild steel, Rephos steel and TRIP700 were compared both experimentally and numerically. The results showed that TRIP steel has a significantly larger springback than the other materials. Furthermore, the FE simulations overestimate the twisting in this part for all materials, with the TRIP material showing the largest deviation between the experiments and the simulations. The prediction of punch forces was, however, accurate for all materials.
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| 23. |
- Andersson, Alf
(författare)
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Numerical and Experimental Evaluation of Springback in Advanced High Strength Steel
- 2007
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Ingår i: Journal of Materials Engineering and Performance. - : Springer Science and Business Media LLC. - 1059-9495 .- 1544-1024. ; 16:3, s. 301-307
-
Tidskriftsartikel (refereegranskat)abstract
- The automotive industry is using more and more of Advanced High Strength Steel in order to reduce the weight of the car. Since this will generate more springback, it is of vital importance to be able to predict the amount of springback in the parts. Otherwise, many late changes have to be made in order to fit the parts in their position. In order to increase the ability to understand and test the behavior of the springback in sheet-metal parts, a new semi-industrial experimental tool, the flex-rail, has been developed. This is a very flexible tool, which can be used for various kinds of materials, from mild steel and aluminum to advanced high strength steel such as TRIP-steel and CP-steel by using different insert. The tool is designed for experimental analysis of 3D-springback, which is the case in the more complicated automotive parts, such as b-pillars and side members. The scope of this work is to analyze the springback behavior and prediction for Advanced High Strength Steel both numerically and experimentally. Sheet-metal-forming simulations were made in LS-DYNA. The results proved that the new geometry, flex-rail, gave a complex springback behavior for all tested materials. Furthermore, the prediction of springback showed good correlation in sections with small amounts of twist but that LS-DYNA under-predicts the springback for sections with large amounts of twist for all materials except DP600.
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| 24. |
- Andersson, Alf, et al.
(författare)
-
Personality of university teachers according to the Defense Mechanism Technique modified (DMTm) as related to their assessment of their university as an organizational setting
- 1999
-
Ingår i: Social Behavior and Personality. - : Scientific Journal Publishers Ltd. - 0301-2212. ; 27:6, s. 575-585
-
Tidskriftsartikel (refereegranskat)abstract
- The present study considers possible relations between personality and orgnizational-assessment variables. Subjects in a stratified sample of 114 university teachers, 36 women and 78 men, were examined using the Defense Mechanism Technique modified (DMTm), a percept-genetic technique. They also made assessment of their university as an organization. Two data sets were formed initially, the one considering of 18 DMTm variables and the other of these variables together with gender. In total 34 factor analyses were performed, each involving the inclusion, together with the data set in question, of a different one of the 17 organizational variables which were employed. Affect anxiety (DMTm) was found in factors together with ratings of organizational variables of openness/diversity, developmental orientation, planning/clarity, workload pressure (negative sign), personal attitude toward the superior, change-centeredness of the superior and organizational climate. Identity anxiety (DMTm) was found in a factor together with organizational climate (negative sign); repression 3 (DMTm) in a factor together with academic values, human orientation and formalization/centralization (negative sign); projected introaggression (DMTm) in a factor together with employee-centeredness of the superior (negative sign); and denial through reversal III (DMTm) in a factor together with structural orientation, formalization/centralization and sufficiency of resources (negative sign). The results were found to be interpretable in terms of the Andersson model of the mind and to support the usefulness of the type of data treatment employed.
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| 25. |
- Andersson, Alf, et al.
(författare)
-
Psychoanalytic models of the mind, creative functioning, and percept-genetic reconstruction
- 1998
-
Ingår i: Psychoanalysis and Contemporary Thought. ; 21:3, s. 359-382
-
Tidskriftsartikel (refereegranskat)abstract
- Creative functioning,as shown in the Creative Functioning Technique (CFT) of Smith and Carlsson, fits well with what one of us (Andersson)in his model of the mind refers to as dialectical construction, a mode of functioning associated with (pre)adolescence, with Freud's topographic model, and with the creativity principle. It is possible by use of two percept-genetic techniques, the Defense Mechanism Technique modified (DMTm) and the Spiral Aftereffect Technique (SAT), both of them interpreted within the framework of the Andersson model, to extend the theoretical perspective, allowing creative functioning to be understood in relation to two other psychoanalytic models, Melanie Klein's affect positions model and Heinz Kohut's model of self and selfobject. A demonstration of this was presented by one of us (Ryhammar) in a study of 132 university teachers, published recently in Swedish. Certain results of that study are presented here, together with the theoretical background. One finding was that introaggression as assessed in the DMTm is strongly related to creativity in terms of CFT. The implications of the results for the model are discussed.
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| 26. |
- Andersson, Alf, et al.
(författare)
-
Simulation and verification of different parameters effect on springback results
- 2002
-
Ingår i: Proceedings of the 5th International Conference and Workshop on Numerical Simulation of 3D Sheet Forming Processes (NUMISHEET 2002). ; , s. 201-210
-
Konferensbidrag (refereegranskat)abstract
- Today, simulation of springback has still not reached enough accuracy for acceptance as a production tool in the automotive industry. Further investigations need to be done in order to understand how to improve the results in an efficient way. In order to investigate which parameters that are important for the accuracy in a springback simulation, a parameter study of a U-shaped rail was performed. In the literature several similar studies can be found, but few of them have been analysing the effect of the stress variation. In our investigation these were studied together with the geometrical springback. In order to see the effect of different restraining conditions, five different blank holder forces were applied. Three different materials were studied both experimentally and numerically. The analysed materials were: a mild steel, an extra high strength steel and an aluminium grade. It can be concluded that several of the studied parameters show small effect on the springback results whereas other parameters show significant influence, such as element size in blank and tool and choice of hardening law. The result showed good agreement for the case, which were tuned in to experimental results. The materials showed that different settings were needed for the different materials.
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| 27. |
- Andersson, Alf
(författare)
-
Simulation of springback in TRIP- and stainless steel
- 2006
-
Ingår i: Materials Science and Technology 2006 conference and exhibition (Proceedings of a meeting held 15-19 October 2006, Cincinnati, Ohio). - 9781605601328
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
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| 28. |
- Andersson, Alf
(författare)
-
Springback analysis in Advanced High Strength Steel using a new flexible semi-industrial tool geometry
- 2007
-
Ingår i: 6th European LS-DYNA users´ Conference.
-
Konferensbidrag (refereegranskat)abstract
- The automotive industry is using more and more of Advanced High Strength Steel in order to reduce the weight of the car. Since this will generate more springback, it is of vital importance to be able to predict the amount of springback in the parts. Otherwise, many late changes have to be made in order to fit the parts in their position. In order to increase the ability to understand and test the behavior of the springback in sheet-metal parts, a new semi-industrial experimental tool, the flex-rail, has been developed. This is a very flexible tool, which can be used for various kinds of materials, from mild steel and aluminum to advanced high strength steel such as TRIP-steel and CP-steel by using different inserts. The tool is designed for experimental analysis of 3D-springback, which is the case in the more complicated automotive parts, such as b-pillars and side members. The scope of this work is to analyze the springback behavior and prediction for Advanced High Strength Steel both numerically and experimentally. Sheet-metal-forming simulations were made in LS-DYNA. The results proved that the new geometry, flex-rail, gave a complex springback behavior for all tested materials. Furthermore, the prediction of springback showed good correlation in sections with small amounts of twist but that LS-DYNA under-predicts the springback for sections with large amounts of twist for all materials.
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| 29. |
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| 30. |
- Andersson, Alf
(författare)
-
Use of FE-analysis for predicting and verifying the design of an automotive component forming process with special regard to macro geometric defects
- 2002
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis includes four appended papers. The thesis describes the challenges and advantages of the use of FE-analysis in the design of a component forming process in the automotive industry. Today, shortened lead-times in the automotive industry have dramatically increased the need for more efficient development methods in each stage of the process development chain. In order to decrease the long lead-time for producing a forming tool, sheet-metal-forming simulation was introduced. To successfully implement sheet-metal-forming simulation it is important to establish an efficient exchange of information. Efficient information handling will also generate a more accurate basis for decisions aimed at reducing the number of changes in the development phase to achieve the specified automotive part or process. Efficient information exchange can be established by using a database where animations from the sheet-metal-forming simulations are stored. The database should be accessible from the Internet in order to enable direct investigation and analysis by authorised persons. Today, sheet-metal-forming simulations are able to predict e.g. thinning, cracks and forces with high accuracy. The investigation showed that sheet-metal-forming simulation is superior in reducing lead-time and costs compared with the use of try-out tools. The Karafillis-Boyce (1993) material model has been implemented in the explicit, dynamic software LS- DYNA A special optimisation program, written in the programming language C, was developed to find proper parameters for the above-mentioned material model. The results showed that the model by Karafilli and Boyce provided superior results compared with the models by Barlat and Uan (1989), and Hill (1948), respectively. There are two important phenomena that sheet-metal-forming simulation cannot yet adequate predict, namely surface defects and springback. The accuracy regarding the prediction of surface defects and springback was evaluated by analysing a double curved sheet-metal part. This part resembled the area around the fuel filler lid. Based on this model, experiments and sheet-metal-forming simulations were performed and the results were compared. The results showed that, while sheet-metal-forming simulation could not adequately predict the magnitudes of the defects, it could successfully predict the location of the defects.
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| 31. |
- Andersson, Daniel, 1989-
(författare)
-
Artificial Earth : On the Genealogy of Planetary Technicity
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As technology transforms the conditions by which we come understand and interact with the world around us, it is relevant to ask questions about the historicalontological aspects of these patterns of change. The widespread adoption of the term “Anthropocene” during the last twenty years indicates the wide acceptance of the view that human activities have become such a powerful driving force for global environmental change that our destructive legacy will be recorded in geological history. Man, it is argued, has come to alter his terrestrial environment on such a global scale that the ontological difference between natural and technological patterns of change has lost its salience. Addressing our contemporary environmental problems, then, requires knowledge of how physical processes in the natural world operate. But it also necessitates a critical self-consciousness that pertains to the understanding of “the natural” vis-à-vis “the artificial” that underlies this kind of knowledge production. The latter forms the basis of this thesis, which treats the disclosure of technology as a “global” or “planetary” phenomenon – what, herein, is called “planetary technicity” – in earth system science and within the prevailing Anthropocene discourse, and argues that this disclosure gives rise to a research problem that necessitates the present study: insofar as natural and technological patterns of change are made ontologically equivalent, we are faced with a situation wherein technology is increasingly portrayed as beyond human control – just like the products of nature, artifice is depicted as self-organizing. Proceeding from an intellectual-historical point of departure, and within the framework of modern earth science, the methodological ambition of the thesis is to investigate the so-called “genealogical” provenance behind this particular disclosure of technology, with the intention of exposing its historical conditions. The thesis seeks to accomplish this by answering three main questions: how did the question of the nature of technology intersect with epistemological and methodological concerns in earth science; how were such concerns treated or resolved; and last but not least, what is the intellectualhistorical provenance of planetary technicity? In view of the genealogical examination, the thesis concludes that planetary technicity is a product of a certain intellectual-historical tradition in modern earth science that opposed itself toward mechanistic philosophy by taking up a holistic approach in order to study the earth, which meant that technology ontologically came to be attributed organic rather than mechanical features. In addition, the thesis highlights the historical coincidence – as opposed to the necessity – of this particular understanding of technology.
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| 32. |
- Andersson, Eva A, et al.
(författare)
-
Abdominal and hip flexor muscle activation during various training exercises.
- 1997
-
Ingår i: European Journal of Applied Physiology and Occupational Physiology. - : Springer Science and Business Media LLC. - 0301-5548 .- 1432-1025 .- 1439-6319 .- 1439-6327. ; 75:2, s. 115-23
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to provide objective information on the involvement of different abdominal and hip flexor muscles during various types of common training exercises used in rehabilitation and sport. Six healthy male subjects performed altogether 38 different static and dynamic training exercises trunk and hip flexion sit-ups, with various combinations of leg position and support, and bi- and unilateral leg lifts. Myoelectric activity was recorded with surface electrodes from the rectus abdominis, obliquus externus, obliquus internus, rectus femoris, and sartorius muscles and with indwelling fine-wire electrodes from the iliacus muscle. The mean electromyogram amplitude, normalised to the highest observed value, was compared between static and dynamic exercises separately. The hip flexors were highly activated only in exercises involving hip flexion, either lifting the whole upper body or the legs. In contrast, the abdominal muscles showed marked activation both during trunk and hip flexion sit-ups. In hip flexion sit-ups, flexed and supported legs increased hip flexor activation, whereas such modifications did not generally alter the activation level of the abdominals. Bilateral, but not unilateral, leg lifts required activation of abdominal muscles. In trunk flexion sit-ups an increased activation of the abdominal muscles was observed with increased flexion angle, whereas the opposite was true for hip flexion sit-ups. Bilateral leg lifts resulted in higher activity levels than hip flexion sit-ups for the iliacus and sartorius muscles, while the opposite was true for rectus femoris muscles. These data could serve as a basis for improving the design and specificity of test and training exercises.
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| 33. |
- Andersson, Eva A, et al.
(författare)
-
Diverging intramuscular activity patterns in back and abdominal muscles during trunk rotation.
- 2002
-
Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 1528-1159 .- 0362-2436. ; 27:6, s. E152-60
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: An intramuscular electromyographic study was performed on trunk rotations during sitting and standing. OBJECTIVE: The aim was to provide new information on activation levels for deep trunk muscles in various unresisted and resisted trunk rotations. SUMMARY AND BACKGROUND DATA: Frequent daily trunk twisting and decreased maximal strength during trunk rotation have been associated with low back pain or sciatic pain. However, the involvement of deep trunk muscles during different trunk rotations is relatively unknown. METHODS: Ten healthy subjects participated. Fine-wire electrodes were inserted, under ultrasound guidance, into psoas, quadratus lumborum, the superficial medial lumbar erector spinae (ES-s, multifidus) and its deep lateral portion (ES-d, iliocostalis), iliacus, rectus abdominis, obliquus externus, and obliquus internus. RESULTS: The highest involvement for all muscles was observed on the ipsilateral side, in maximal trunk twists with shoulder resistance, except obliquus externus, which showed a dominant contralateral side, and rectus abdominis, which was little activated in all rotations. In contrast, maximal trunk twist without shoulder resistance, i.e., freely performed, resulted generally in lower levels for all muscles involved and in a shift of side dominance for the lumbar muscles quadratus lumborum, psoas, and ES-s. CONCLUSIONS: During trunk rotations the activity patterns for various trunk muscles could drastically change, and even be the opposite, between the two body sides, within the same type of task, depending on several factors such as initial position, effort level, sitting or standing, and external shoulder resistance.
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| 34. |
- Andersson, Eva A
(författare)
-
EMG and strength in trunk and hip muscles
- 1997
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis was to study the myouelectric activity of all major muscles involved in the movements and stabilization of the trunk, pelvis and hips during training exercises, postures, motor tasks, maximal strength performance and locomotion. By use of ultra-sound, EMG electrodes could be guided safely and accurately into muscles situated even close to the spinal column, such as psoas, quadratus lumborum and deep parts of erector spinae. A task specific variation in activation levels were seen between muscle synergies, as well as between individual muscles within a synergy. Selective engagement of the abdominal muscles could be achieved in trunk flexion sit-ups, that is lifting only the upper trunk from the floor. An even higher activation of abdominal muscles was needed for static stabilization of the trunk and pelvis during hip flexion sit-ups, whereas single leg lifts were performed without involvement of the abdominal muscles. A selective activation of either the iliacus or psoas muscle was observed, for example in certain types of training exercises and in walking and running. Applying bending moments to the spine, resulted in a grading of the muscle activation response according to mechanical advantage, that is highest in the quadratus lumborum in lateral loading and in the superficial erector spinae in ventral loading. An exception was the most forward flexed position in standing where the superficial erector spinae "relaxed" but quadratus lumborum remained active. In general, the level of EMG in maximal efforts was maintained at the same high level irrespective of position in the range of motion, despite a marked variation in strength output. This position-dependency, as well as the strength values as such, varied in a specific way in groups of athletes, related to previous background. These data contribute to the understanding of muscle function and motor control of the trunk , pelvis and hips. They are also of relevance when evaluating and designing tests and training programs in rehabilitation and sport contexts as well as for improving biomechanical models of spinal loading.
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| 35. |
- Andersson, Eva A, et al.
(författare)
-
Intramuscular EMG from the hip flexor muscles during human locomotion.
- 1997
-
Ingår i: Acta Physiologica Scandinavica. - 0001-6772 .- 1365-201X. ; 161:3, s. 361-70
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose was to investigate the activation pattern of five major hip flexor muscles and its adaptation to changing speed and mode of progression. A total of 11 healthy subjects performed walking and running on a motor-driven treadmill at speeds ranging from 1.0 to 6.0 m s-1. Intramuscular fine-wire electrodes were used to record myoelectric signals from the iliacus, psoas, sartorius, rectus femoris and tensor fascia latae muscles. The basic pattern, with respect to number of activation periods, remained the same irrespective of speed and mode of progression. However, differences in the relative duration and timing of onset of activation occurred between individual muscles. Over the speed range in walking, a progressively earlier onset was generally seen for the activation period related to hip flexion. Changes in EMG amplitude were measured in the iliacus and psoas muscles and showed a marked increase and difference between walking and running at speeds above 2.0 m s-1. Thus, the alternating flexion-extension movements at the hip during locomotion appear to be governed by a rather fixed 'neural program' which normally only needs minor modulations to accomplish the adjustments accompanying an increase in speed of progression as well as a change from walking to running.
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| 36. |
- Andersson, Eva A, et al.
(författare)
-
Relative EMG levels in training exercises for abdominal and hip flexor muscles.
- 1998
-
Ingår i: Scandinavian Journal of Rehabilitation Medicine. - : Informa UK Limited. - 0036-5505 .- 1940-2228. ; 30:3, s. 175-83
-
Tidskriftsartikel (refereegranskat)abstract
- The main purpose of our study was to compare systematically EMG levels in sub-maximal training exercises for the trunk and hip flexor muscles with those voluntarily attainable in corresponding situations. Six healthy subjects performed three types of standardized training exercises, whose static positions, movement velocity and range of motion were reproduced during maximal voluntary isokinetic strength tests. EMG was recorded with wire electrodes from the iliacus muscle and with surface electrodes from the rectus femoris, sartorius, rectus abdominis, obliquus externus and internus muscles. The relative EMG values demonstrated a task dependency which could differ between individual muscles. The maximal voluntary activation levels were relatively constant across conditions. Exceptions were present, particularly for the rectus femoris and iliacus muscles. These findings highlight the consequences of using different methods of normalizing EMG. The relative EMG values presented may serve as guidelines when selecting training exercises for specific trunk and hip flexor muscles in sports and rehabilitation.
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| 37. |
|
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| 38. |
- Andersson, Eva, et al.
(författare)
-
EMG activities of the quadratus lumborum and erector spinae muscles during flexion-relaxation and other motor tasks.
- 1996
-
Ingår i: Clinical biomechanics (Bristol, Avon). - : Elsevier BV. - 1879-1271 .- 0268-0033. ; 11:7, s. 392-400
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to provide new information on the myoelectrical activation of the quadratus lumborum, the deep lateral and the superficial medial lumbar erector spinae, the psoas, and the iliacus muscles in various motor tasks. DESIGN: An intramuscular electromyographic study was performed. BACKGROUND: The contribution of individual deep trunk muscles to the stability of the lumbar spine is relatively unknown in different tasks, including the flexion-relaxation phenomenon. METHODS: Seven healthy subjects participated. Fine-wire electrodes were inserted with a needle guided by ultrasound. RESULTS: The highest activity observed for quadratus lumborum and deep lateral erector spinae occurred in ipsilateral trunk flexion in a side-lying position and for superficial medial erector spinae during bilateral leg lift in a prone position. Quadratus lumborum and deep lateral erector spinae were activated when the flexion-relaxation phenomenon was present for superficial medial erector spinae, i.e. when its activity ceased in the latter part of full forward flexion of the trunk, held relaxed and kyphotic. CONCLUSIONS: In general, the activation of the investigated muscles showed a high degree of task specificity, where activation of a certain muscle was not always predictable from its anatomical arrangement and mechanical advantage.
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| 39. |
- Andersson, Eva, et al.
(författare)
-
The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip.
- 1995
-
Ingår i: Scandinavian Journal of Medicine and Science in Sports. - 0905-7188 .- 1600-0838. ; 5:1, s. 10-6
-
Tidskriftsartikel (refereegranskat)abstract
- The activation patterns of the psoas and iliacus muscles were investigated in 7 healthy adult subjects (4 men and 3 women) during a variety of motor tasks in standing, sitting and lying. Myoelectric activity was recorded simultaneously from the 2 muscles using thin wire electrodes inserted under guidance of high-resolution ultrasound. In general, both muscles were coactivated, albeit to different relative levels, particularly when hip flexor torque was required. Selective activation of the iliacus could, however, be seen to stabilize the pelvis in contralateral hip extension during standing. Psoas was found to be selectively involved in sitting with a straight back and in contralateral loading situations requiring stabilization of the spine in the frontal plane. During training exercises from a supine position, such as sit-ups, the contribution of the psoas and iliacus muscles could be varied by changing the range of motion as well as the position and support for the legs. Thus, the 2 anatomically different muscles of the iliopsoas complex were shown to have individual and task-specific activation patterns depending on the particular demands for stability and movement at the lumbar spine, pelvis and hip.
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| 40. |
- Andersson, Eva, et al.
(författare)
-
Trunk muscle strength in athletes.
- 1988
-
Ingår i: Medicine & Science in Sports & Exercise. - 0195-9131 .- 1530-0315. ; 20:6, s. 587-93
-
Tidskriftsartikel (refereegranskat)abstract
- Maximal voluntary strength of the trunk muscles was measured in 57 male elite athletes (soccer players, wrestlers, tennis players, and gymnasts), 14 female elite gymnasts, and in a normal group of 87 conscripts. Mean ages in the different groups ranged from 18-22 yr. An isokinetic (constant velocity) technique was used to record maximal torque produced by trunk and hip muscles during flexion, extension, and lateral flexion over the range of motion. The constant angular velocities used were 15 deg.s-1 and 30 deg.s-1, respectively. Isometric strength was measured in a straight body position (0 deg. of flexion). The measurements were made with the subjects in a horizontal position with the pivot point at the hip and at the lumbar (L2-L3) level. All male athlete groups showed higher peak torque values than the normals. The differences were largest in hip extension and trunk flexion. The male gymnasts also showed significantly higher peak values in hip flexion as compared to all other categories. There was no difference in strength per kg body weight between female gymnasts and untrained males, except in trunk extension. The position for peak torque occurred earlier in the movements for the athletes, especially for the gymnasts in extension movements and for the tennis players in flexion movements. In isometric contractions essentially the same strength differences were present as in the slow isokinetic contractions. In lateral flexion wrestlers and tennis players showed significantly higher strength in movements toward the nondominant side. Thus, differences were present between the athletes and the normals, some of which appeared to be sport specific and related to long-term systematic training.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 41. |
- Andersson, Greger, et al.
(författare)
-
Adligt musicerande i 1700-talets Skåne
- 2005
-
Ingår i: Frispel : festskrift till Olle Edström. - 9185974781 ; , s. 3-13
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 42. |
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| 43. |
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| 44. |
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| 45. |
|
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| 46. |
- Bergström, Per, 1981-, et al.
(författare)
-
Automatic in-line inspection of shape based on photogrammetry
- 2016
-
Ingår i: The 7th International Swedish Production Symposium, SPS16, Conference Proceedings. - Lund : Swedish Production Academy. ; , s. 1-9
-
Konferensbidrag (refereegranskat)abstract
- We are describing a fully automatic in-line shape inspection system for controlling the shape of moving objects on a conveyor belt. The shapes of the objects are measured using a full-field optical shape measurement method based on photogrammetry. The photogrammetry system consists of four cameras, a flash, and a triggering device. When an object to be measured arrives at a given position relative to the system, the flash and cameras are synchronously triggered to capture images of the moving object.From the captured images a point-cloud representing the measured shape is created. The point-cloud is then aligned to a CAD-model, which defines the nominal shape of the measured object, using a best-fit method and a feature-based alignment method. Deviations between the point-cloud and the CAD-model are computed giving the output of the inspection process. The computational time to create a point-cloud from the captured images is about 30 seconds and the computational time for the comparison with the CAD-model is about ten milliseconds. We report on recent progress with the shape inspection system.
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| 47. |
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| 48. |
- Erdem, Ilker, 1987, et al.
(författare)
-
Development of Affordable Reconfigurable Tooling in Car Manufacturing Cells – A Case Study
- 2015
-
Ingår i: 23rd International Conference for Production Research, ICPR 2015, Manila, Philippines, 2-6 August 2015.
-
Konferensbidrag (refereegranskat)abstract
- Assembly fixtures are one of the cost driving factors in automotive industry. Previous research have shown that the utilization of affordable reconfigurable tooling (ART) can be a key-enabling technology to reduce the cost and lead times. Inspired by the research results, Volvo Cars Corporation initiated an automated process control project, the aim of which is the automatic inspection and correction of the defects in Body in White (BIW). The project comprises of three stages – the first of which is the in-line measurement of BIW. Then, the results of measurements are transferred to a common database where process evaluation through case-based reasoning suggests corrective actions on the fixture. The last stage involves the development of flexible tooling to meet these changes in a cost and time effective way. Hence, the aim of this paper is to present preliminary results on the development and implementation of ART as flexible tooling.
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| 49. |
- Eriksson, Bengt, et al.
(författare)
-
A PC based system for maintenance management of buildings : Description of the damage atlases
- 2001
-
Ingår i: CIB World Building Congress.
-
Konferensbidrag (populärvet., debatt m.m.)abstract
- The EU-project ENV4-CT98-0796 MMWood has the following objective: To develop and validate for the SMEs an integrated Maintenance and management system for historic (wooden) buildings, adapted to the needs and purposes of various user group levels. The system will specifically contain - A documentation system for outer and inner parts of historic (wooden) building parts and components. - Soft- and hardware tools for the building inspection in the course of maintenance tasks, - an environmental risk factor assessment module, - a standardized maintenance assessment module based on complementation of the Wood-Assess process of assessing the symptoms, causes, effects, consequences, risks and remedial actions for environmental damages to the historic buildings and - a cost and maintenance planning module. In the project Damage Atlases for the following materials are given: Wood (including Surface Treatment), Adjoining Materials in Wood Constructions, Rendering, Brick and Natural Stone. These Damage Atlases use the same general layout, following closely the guidelines and protocol developed in a previous EU-project with the acronym "Wood-Assess". The general layout given for these damages is built up with the following questions: - Type of material; - Description of the symptom; - Investigation methods; - Condition degrees referred to pictures; - Extent of the symptom; - Possible causes/degradation agents; - Total condition degree; - Consequences and risks; - Recommended actions. In this paper the general layout of these Damage Atlases is extensively described and included are also some examples of the treated damages. These Damage Atlases are also put into the PC-based maintenance and management system developed in the same project (a first version was developed in the Wood-Assess project ENV4-CT95-0110, which was reported in some detail in the previous CIB congress in Gavle).
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| 50. |
- Eriksson, Fredrik
(författare)
-
Det reglerade undantaget : högerns jordbrukspolitik 1904-2004
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Agricultural policy and protectionism were major forces behind the foundation of the Swedish Conservative Party (AVF, later Högerpartiet and now Moderata samlingspartiet). Agriculture was seen as a traditional way of life and as such agriculture was deemed important enough to be protected by tariffs. The party also had a strong agrarian phalange in its ranks. The thesis deals with the agricultural policy of the party and its predecessors during the 20th century. The main focus is to explain how the party has dealt with agricultural policy during the period. Due to the reasons mentioned above agricultural policy became a regulated exception of the party. This meant that the party accepted protectionism and other exceptions when it came to agriculture. Things that would not have been accepted in other areas. The main reason for this agricultural exceptionalism was the power of the farmers within the party structure. This, in combination with the Swedish neutrality and preparedness for war, lay behind this view on agriculture . Through neutrality agriculture became a factor in Swedish defense policy and as such ruled by consensus. For the conservatives agriculture and the farmers were seen as an important group within the electorate. Agriculture was also ideologically important through its traditionalism. In combination with strong groups of farmers within the party and the issue of preparedness led to a party policy where agriculture was something particular and an exception from normal policy. The agricultural policy of the party is studied on the ideological level, the internal party level and on the level of non-socialist party cooperation. The party policy during the century showed a remarkable continuity and the party in general defended agriculture from all threats of deregulation up until 1990 when a broad political decision was taken and agriculture was deregulated. The question of Swedish membership in the European Union is also adressed since it meant that agriculture had to be regulated once more.
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