| 1. |
- Strömbäck, Filip, et al.
(författare)
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The Progression of Students’ Ability to Work With Scope, Parameter Passing and Aliasing
- 2023
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Ingår i: ACE '23. - New York, NY, USA : Association for Computing Machinery. - 9781450399418 ; , s. 39-48
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Konferensbidrag (refereegranskat)abstract
- Students need the ability to reason about the behavior of programs when working with advanced concepts like concurrency and abstraction. To achieve this, students require core programming skills that allow them to trace and predict the outcome of a program. While previous research indicates that teachers cannot expect students to acquire all core programming skills after their introductory CS course, less is known of students’ progression in later years. In this study, we investigate 397 students’ ability to predict the outcome of short computer programs. The participants are from different programs and progressions in their studies. We find that students, regardless of program and year, struggle with predicting the outcome of short programs that require an accurate mental model of some less readily apparent concepts, such as references. Further, we discover that there is no significant improvement in the first three years. Finally, we propose further avenues of research to improve these learning outcomes.
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| 2. |
- Badger, J., et al.
(författare)
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Fortschrittliche Technologie zum Schleifen von Nockenwellen
- 2016
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Ingår i: Schleifen und Polieren. ; 20:1, s. 42-49
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Die komplexe Kinematik und die sich ständig ändernden Eingriffsverhältnisse des Schleifprozesses wurden bestimmt und dann mit dem Jaeger-Modell im KTS angewendet. Anhand eines schnellen Schleifexperiments an zylindrischen Werkstücken wurde der Kennliniengraph (spezifische Energie aufgetragen über die Spandicken) bestimmt. Nun konnten die Energieanteile, die die Körner in Reibung und Spanbildung umsetzen an jedem Punkt entlang der Kontaktfläche zwischen Schleifscheibe und Werkstück gegenübergestellt werden. Infolgedessen konnte die erzeugte Wärmemenge bestimmt werden. Diese Kurve lieferte die Eingangsdaten für das Model zur Suche nach den optimalen Bedingungen.
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| 3. |
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| 4. |
- Berglund, Aseel, et al.
(författare)
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Using speech and dialogue for interactive TV navigation
- 2004
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Ingår i: Universal Access in the Information Society. - : Springer. - 1615-5289 .- 1615-5297. ; 3:3-4, s. 224-238
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Tidskriftsartikel (refereegranskat)abstract
- Interaction techniques for interactive television (iTV) are currently complex and difficult to use for a wide-range of viewers. Few previous studies have dealt with the potential benefits of multimodal dialogue interaction in the context of iTV for the purpose of flexibility, usability, efficiency, and accessibility. This paper investigates the benefits of introducing speech and connected dialogue for iTV interaction, and presents a case study in which a prototype system was built allowing users to navigate the information space and control the operation of the TV by a speech-based natural language interface. The system was evaluated by analysing the user experience in five categories capturing essential aspects of iTV interaction: interaction style, information load, data access, effectiveness and initiative. Design considerations relevant for speech and dialogue information systems for TV interfaces also emerged from the analysis.
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| 5. |
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| 6. |
- Berglund, Erik, 1993-
(författare)
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Novel Hessian approximations in optimization algorithms
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There are several benefits of taking the Hessian of the objective function into account when designing optimization algorithms. Compared to using strictly gradient-based algorithms, Hessian-based algorithms usually require fewer iterations to converge. They are generally less sensitive to tuning of parameters and can better handle ill-conditioned problems. Yet, they are not universally used, due to there being several challenges associated with adapting them to various challenging settings. This thesis deals with Hessian-based optimization algorithms for large-scale, distributed and zeroth-order problems. For the large-scale setting, we contribute with a new way of deriving limited memory quasi-Newton methods, which we show can achieve better results than traditional limited memory quasi-Newton methods with less memory for some logistic and linear regression problems. For the distributed setting, we perform an analysis of how the error of a Newton-step is affected by the condition number and the number of iterations of a consensus-algorithm based on averaging, We show that the number of iterations needed to solve a quadratic problem with relative error less than ε grows logarithmically with 1/ε and also with the condition number of the Hessian of the centralized problem. For the zeroth order setting, we exploit the fact that a finite difference estimate of the directional derivative works as an approximate sketching technique, and use this to propose a zeroth order extension of a sketched Newton method that has been developed to solve large-scale problems. With the extension of this method to the zeroth order setting, we address the combined challenge of large-scale and zeroth order problems.
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| 7. |
- Berglund, Lisa, et al.
(författare)
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Glucose-Dependent Insulinotropic Polypeptide (GIP) Stimulates Osteopontin Expression in the Vasculature via Endothelin-1 and CREB.
- 2016
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 65:1, s. 239-254
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Tidskriftsartikel (refereegranskat)abstract
- Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone with extrapancreatic effects beyond glycemic control. Here we demonstrate unexpected effects of GIP signaling in the vasculature. GIP induces the expression of the pro-atherogenic cytokine osteopontin (OPN) in mouse arteries, via local release of endothelin-1 (ET-1) and activation of cAMP response element binding protein (CREB). Infusion of GIP increases plasma OPN levels in healthy individuals. Plasma ET-1 and OPN levels are positively correlated in patients with critical limb ischemia. Fasting GIP levels are higher in individuals with a history of cardiovascular disease (myocardial infarction, stroke) when compared to controls. GIP receptor (GIPR) and OPN mRNA levels are higher in carotid endarterectomies from patients with symptoms (stroke, transient ischemic attacks, amaurosis fugax) than in asymptomatic patients; and expression associates to parameters characteristic of unstable and inflammatory plaques (increased lipid accumulation, macrophage infiltration and reduced smooth muscle cell content). While GIPR expression is predominantly endothelial in healthy arteries from human, mouse, rat and pig; remarkable up-regulation is observed in endothelial and smooth muscle cells upon culture conditions yielding a "vascular disease-like" phenotype. Moreover, a common variant rs10423928 in the GIPR gene associated with increased risk of stroke in type 2 diabetes patients.
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| 8. |
- Berglund, Pontus
(författare)
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Cell cycle perspectives on breast cancer cell behaviour
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Uncontrolled proliferation and the capacity to infiltrate surrounding tissues are two important characteristics of aggressive tumour cells. Previous observations in both colorectal cancer and basal cell carcinoma indicated that infiltrative tumour cell behaviour might be counteracted by a high proliferative activity, suggesting a coordination of these two activities at the cellular level. Here we studied the potential relation between proliferative activity and migratory behaviour in breast cancer, by focusing on the cell cycle regulatory proteins cyclin E and cyclin D1. By expressing cyclin E in a breast cancer cell line we obtained experimental results indicating that increased proliferative activity obstructed migratory and invasive capacity. When validating these results in a large set of primary breast cancers, we observed that increasing cyclin E levels correlated with a less infiltrative tumour growth appearance – a finding in line with our experimental results. Several studies have proposed that cyclin E is strongly associated with poorer disease outcome in breast cancer. Therefore, we continued to investigate the potential prognostic relevance of the inverse relation between cyclin E and infiltrative tumour growth. We revealed a distinct subgroup of less infiltrative, cyclin E high breast cancers with a relatively favourable prognosis. This subgroup was an important exception compared to the majority of tumours where cyclin E indeed correlated to a poorer outcome. We also tried to delineate in detail how the migratory capacities of tumour cells related to cell cycle activities. Synchronised G0/early G1 cells displayed an increased migratory potential compared to both late G1/S-phase cells as well as unsynchronised, actively cycling cells. Further, silencing of cyclin D1 in two cell lines indicated a novel CDK- and cell cycle independent function of cyclin D1 in restraining migratory capacity. This novel role of cyclin D1 seemed to influence the behaviour of ER positive breast tumours, where cyclin D1 high tumours were in general of smaller size and, further, exhibited a somewhat less infiltrative growth pattern. In addition, increased cyclin D1 levels correlated to a more favourable prognosis.
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| 9. |
- Berglund, Pontus, et al.
(författare)
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Cyclin E confers a prognostic value in premenopausal breast cancer patients with tumours exhibiting an infiltrative growth pattern
- 2008
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Ingår i: Journal of Clinical Pathology. - : BMJ. - 0021-9746 .- 1472-4146. ; 61:2, s. 184-191
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To investigate the prognostic value of cyclin E in relation to tumour growth pattern by analysing stage II primary breast cancers from premenopausal women not subjected to any further adjuvant treatment. To analyse the value of cyclin E as a predictor of tamoxifen response, by comparing untreated and treated patients with oestrogen receptor positive tumours. Methods: Breast cancer samples, assembled in tissue microarrays, were immunohistochemically stained for cyclin E and evaluated regarding the presence of nuclear staining. The overall growth characteristics of each tumour were assessed using whole tissue sections. Results: Tumours displaying a pushing margin phenotype were strongly associated with high cyclin E levels, lymph node negative disease, a high histological grade and oestrogen receptor negativity, and exhibited a better prognosis compared to tumours with an infiltrative growth pattern. In the total cohort of non-treated patients (n = 187), cyclin E was not associated with recurrence free survival (RFS). However, when analysing the subgroup of tumours lacking a pushing growth pattern (n = 141), cyclin E was significantly associated with RFS, independent of histological grade and node status. There was no significant difference in tamoxifen response with regard to different cyclin E levels. Conclusion: The prognostic value of cyclin E in premenopausal breast cancer is limited to patients with breast carcinomas exhibiting an exclusively infiltrative growth pattern. This limitation could be explained by the presence of a small but distinct subgroup of cyclin E-high breast cancers with a pushing margin phenotype and a more favourable outcome.
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| 10. |
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