| 1. |
- Andersson, Håkan, 1970-
(författare)
-
A Co-Simulation Approach for Hydraulic Percussion Units
- 2018
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This Licentiate of Engineering thesis concerns modelling and simulation of hydraulic percussion units. These units are often found in equipment for breaking or drilling in rock and concrete, and are also often driven by oil hydraulics, in which complex fluid-structure couplings are essential for their operation.Current methodologies used today when developing hydraulic percussion units are based on decoupled analyses, which are not correctly capturing the important coupled mechanisms. Hence, an efficient method for coupled simulations is of high importance, since these mechanisms are critical for the function of these units. Therefore, a co-simulation approach between a 1D system simulation model representing the fluid system and a structural 3D FE-model is proposed.This approach is presented in detail, implemented for two well-known simulation tools and evaluated for a simple but relevant model. The Hopsan simulation tool was used for the fluid system and the FE-simulation software LS-DYNA was used for the structural mechanics simulation. The co-simulation interface was implemented using the Functional Mock-up Interface-standard.The approach was further developed to also incorporate multiple components for coupled simulations. This was considered necessary when models for the real application are to be developed. The use of two components for co-simulation was successfully evaluated for two models, one using the simple rigid body representation, and a second where linear elastic representations of the structural material were implemented.An experimental validation of the co-simulation approach applied to an existing hydraulic hammer was performed. Experiments on the hydraulic hammer were performed using an in-house test rig, and responses were registered at four different running conditions. The co-simulation model was developed using the same approach as before. The corresponding running conditions were simulated and the responses were successfully validated against the experiments. A parameter study was also performed involving two design parameters with the objective to evaluate the effects of a parameter change.This thesis consists of two parts, where Part I gives an introduction to the application, the simulation method and the implementation, while Part II consists of three papers from this project.
|
|
| 2. |
- Biel, Anders, 1948, et al.
(författare)
-
Fair and actual degrees of cooperation: Effects of others behavior and temporal separation of responses
- 2005
-
Ingår i: Paper presented at The 11th international conference on social dilemmas, Krakow, Poland..
-
Konferensbidrag (refereegranskat)abstract
- The aims of the present experiment were to investigate what information people in a public good dilemma base their ratings of fair cooperation rates on, and whether they tailor their ratings of fairness and their behavior to fit each other. Results indicate that the high correlations between fair and actual cooperation rates observed in previous research are misleading. When asked about fair de-grees of cooperation prior to making the own decision, people tailor their re-sponses. When the measures are separated in time, the correlations become more modest. Results also demonstrate that people use others behavior to determine what a fair degree of cooperation is
|
|
| 3. |
- Butler, Stephen, et al.
(författare)
-
The utility/futility of medications for neuropathic pain : an observational study
- 2019
-
Ingår i: Scandinavian Journal of Pain. - : Walter de Gruyter GmbH. - 1877-8860 .- 1877-8879. ; 19:2, s. 327-335
-
Tidskriftsartikel (refereegranskat)abstract
- Background and aimsThe RELIEF (Real Life) study by AstraZeneca was designed as an observational study to validate a series of Patient Reported Outcome (PRO) questionnaires in a mixed population of subjects with neuropathic pain (NP) coming from diabetes, neurology and primary care clinics. This article is an analysis of a subset of the information to include the medications used and the effects of pharmacological treatment over 6 months. The RELIEF study was performed during 2010–2013.MethodsSubjects were recruited from various specialty clinics and one general practice clinic across Canada. The subjects were followed for a total of 2 years with repeated documentation of their status using 10 PROs. A total of 210 of the recruited subjects were entered into the data base and analyzed. Of these, 123 had examination-verified painful diabetic neuropathy (PDN) and 87 had examination-verified post-traumatic neuropathy (PTN). To evaluate the responsiveness of the PROs to change, several time points were included and this study focusses primarily on the first 6 months. Subjects also maintained a diary to document all medications, both for pain and other medical conditions, including all doses, start dates and stop dates, that could be correlated to changes in the PRO parameters.ResultsRELIEF was successful in being able to correlate the validity of the PROs and this data was used for further AstraZeneca Phase 1, 2, and 3 clinical trials of NP. To our surprise, there was very little change in pain and low levels of patient satisfaction with treatment during the trial. Approximately 15% of the subjects reported improvement, 8% worsening of pain, the remainder reported pain unchanged despite the use of multiple medications at multiple doses, alone or in combination with frequent changes of medications and doses over the study. Those taking predominantly NSAIDs (COX-inhibitors) did no worse than those taking the standard recommended medications against NP.ConclusionsSince this is a real-life study, it reflects the clinical utility of a variety of internationally recommended medications for the treatment of NP. In positive clinical trials of these medications in selected "ideal" subjects, the effects are not overwhelming – 30% are 50% improved on average. This study shows that in the real world the results are not nearly as positive and reflects information from non-published negative clinical trials.ImplicationsWe still do not have very successful medications for NP. Patients probably differ in many respects from those subjects in clinical trials. This is not to negate the use of recommended medications for NP but an indication that success rates of treatment are likely to be worse than the data coming from those trials published by the pharmaceutical industry.
|
|
| 4. |
- Eek, Daniel, 1968, et al.
(författare)
-
A new look at the theory of social value orientations: Do prosocials maximize joint outcome or equal outcomes?
- 2004
-
Ingår i: Paper presented at The 10th conference of the international society for justice research (ISJR), Regina, Canada.
-
Konferensbidrag (refereegranskat)abstract
- Existing theories of social value orientations posit that prosocials maximize joint outcomes whereas proselfs maximize outcomes to themselves. Three studies were conducted to test the alternative hypothesis that prosocials prefer equal outcomes to maximizing joint outcome. In accordance with the hypothesis, Study 1 showed that prosocials preferred equal outcomes to maximize the joint outcome. Study 2 confirmed and extended these results by demonstrating that prosocials preferred equal outcomes to larger joint outcomes that were unequally distributed but provided both with larger outcomes. Study 3 demonstrated that in a modified prisoners dilemma game, a preference for equal outcomes to a larger joint outcome resulted in that prosocials cooperated when they believed or knew that the other cooperated, and defected when they believed or knew that the other defected
|
|
| 5. |
- Eek, Daniel, 1968, et al.
(författare)
-
A new look at the theory of social value orientations: Prosocials neither maximize joint outcome nor minimize outcome differences but prefer equality
- 2008
-
Ingår i: Biel, A., Eek, D., Gärling, T., & Gustafsson, M. (Eds.) (2008). New issues and paradigms in research on social dilemmas. New York: Springer. - New York : Springer. - 9780387725963
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter presents empirical evidence that casts doubt on current theories of social value orientations assuming that prosocials maximize joint outcome in preferences for allocating resources to themselves and others. It is instead argued and shown that a desire for equal outcomes dominates prosocials’ preferences.
|
|
| 6. |
- Eek, Daniel, et al.
(författare)
-
Effects of distributive goals on choices of allocation principles in a public-good dilemma
- 2004
-
Ingår i: Paper presented at The 10th conference of the international society for justice research (ISJR), Regina, Canada.
-
Konferensbidrag (refereegranskat)abstract
- Extending previous research on the role of fairness in social dilemmas, two experiments investigated allocation preferences in public good dilemmas. In Experiment 1, fairness conceptions were a significant predictor of how participants allocated the public good to their group. Experiment 2 aimed at studying the impact of distributive goals on allocation preferences. Participants were assigned to one of three conditions in which the different goals were induced. As hypothesized, the different goals affected which allocation principle the groups used to allocate the resource. These findings suggest that people in a public good dilemma apply the allocation principle that serves a particular group goal, even though this may interfere with their perceptions of fair allocations
|
|
| 7. |
- Eek, Daniel, 1968, et al.
(författare)
-
Effects of evaluation dimension and social comparison on choices of allocation principles.
- 2004
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A group of 49 undergraduate business school and 46 undergraduate psychology students and a group of 95 employees at different companies responded to a number of case-based organizational allocation tasks. Imagining themselves as employees in the organizations described, participants chose the fairest and the best out of four allocations in either a collectively or an individually framed organizational culture. Furthermore, social comparisons between different groups in the organizations were salient for half of the participants. It was predicted that evaluations on the fairness dimension, social comparison, and a collectively oriented organizational culture would increase choices of an equal allocation. It was also predicted that evaluations on the preference dimension, non-social comparison, and an individually oriented organizational culture would increase choices of non-equality distributions (i.e., maximization, pro-self, or pro-other). Results supported all predictions except those for organizational culture.
|
|
| 8. |
- Eek, Daniel, 1968, et al.
(författare)
-
Exploring a causal relationship between vertical and horizontal trust
- 2005
-
Ingår i: Trust and democracy: A multidisciplinary perspective. Göteborg, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- Three experiments tested how a possible causal relationship works between ver-tical trust (trust in authorities) and horizontal trust (trust in others). In Experi-ment 1, scenarios that increased or decreased the two forms of trust were created and used in subsequent experiments. Experiment 2 supported the hypothesized causal relationship from vertical to horizontal trust when trust levels were de-creased, but not when trust levels were increased. Experiment 3 verified that the strength of the causal effect of vertical trust on horizontal trust depends on whether trust is increased or decreased. In conclusion, increased vertical trust has positive effects on horizontal trust, decreased vertical trust has smaller nega-tive effects on horizontal trust, and horizontal trust has no effects on vertical trust.
|
|
| 9. |
- Eek, Daniel, et al.
(författare)
-
Is there a pro-self component behind the prominence effect? : Individual resource allocation decisions with communities as potential beneficiaries
- 2005
-
Ingår i: International Journal of Psychology. - : Wiley-Blackwell Publishing Ltd.. - 0020-7594 .- 1464-066X. ; 40:6, s. 429-440
-
Tidskriftsartikel (refereegranskat)abstract
- An important problem for decision-makers in society deals with the efficient and equitable allocation of scarce resources to individuals and groups. The significance of this problem is rapidly growing since there is a rising demand for scarce resources all over the world. Such resource dilemmas belong to a conceptually broader class of situations known as social dilemmas. In this type of dilemma, individual choices that appear "rational" often result in suboptimal group outcomes. In this article we study how people make monetary allocation decisions between the community where they live and a neighbouring community, with the aim of finding out to what extent these decisions are subject to biased over-weighting. The manuscript reports four experiments that deal with the way individuals make such allocation decisions when the potential beneficiaries are such communities. The specific goal of these experiments is to gauge the amount of bias in the weights that people assign to the various beneficiaries. Taken together, the results from all the four experiments suggest that making the gain of the neighbouring community prominent to a higher extent de-biases the outcomes (the prominence effect) compared to when own community gain is made prominent. Place identity is discussed as a potentially important factor in this connection. Hence, it may be argued that there seems to be some kind of a pro-self component that is able to explain a large part of the variance observed for the prominence effect. Connections between such a factor and in-group favouritism are discussed. A strength of the study was that these major results appeared to be quite robust when considered as task effects, as the salience of the manipulated context factors in the studies (in terms of reliable main or interaction effects) did not distort them.
|
|
| 10. |
- Eek, Daniel, 1968, et al.
(författare)
-
Only equality matters: Prosocials dont minimize outcome differences that cannot be eliminated
- 2005
-
Ingår i: Paper presented at The 11th international conference on social dilemmas, Krakow, Poland.
-
Konferensbidrag (refereegranskat)abstract
- Social value orientation theory makes two propositions about the motive of proso-cials; one that prosocials maximize the joint outcome between self and another person, another that prosocials minimize the difference in outcomes. Eek and Gärling (2005) showed that the first of these propositions was false. The present experiment aimed at testing the validity of the second proposition. Based on re-search showing that equality is considered a fair division of outcomes, it was ar-gued and found that prosocials strive to obtain equal outcomes. If their choices only minimize the difference in outcomes without achieving equal outcomes, pro-socials and proselfs choices dont differ
|
|
