Donor and acceptor levels of organic photovoltaic compounds from first principles

Accurate and efficient approaches to predict the optical properties of organic semiconducting compounds could accelerate the search for efficient organic photovoltaic materials. Nevertheless, predicting the optical properties of organic semiconductors has been plagued by the inaccuracy or computational cost of conventional first-principles calculations. In this work, we demonstrate that orbital-dependent density-functional theory based upon Koopmans' condition [Phys. Rev. B 82, 115121 (2010)] is apt at describing donor and acceptor levels for a wide variety of organic molecules, clusters, and oligomers within a few tenths of an electron-volt relative to experiment, which is comparable to the predictive performance of many-body perturbation theory methods at a fraction of the computational cost.Comment: 13 pages, 11 figure

Classification of hyperspectral imagery with neural networks: comparison to conventional tools

Efficient exploitation of hyperspectral imagery is of great importance in remote sensing. Artificial intelligence approaches have been receiving favorable reviews for classification of hyperspectral data because the complexity of such data challenges the limitations of many conventional methods. Artificial neural networks (ANNs) were shown to outperform traditional classifiers in many situations. However, studies that use the full spectral dimensionality of hyperspectral images to classify a large number of surface covers are scarce if non-existent. We advocate the need for methods that can handle the full dimensionality and a large number of classes to retain the discovery potential and the ability to discriminate classes with subtle spectral differences. We demonstrate that such a method exists in the family of ANNs. We compare the maximum likelihood, Mahalonobis distance, minimum distance, spectral angle mapper, and a hybrid ANN classifier for real hyperspectral AVIRIS data, using the full spectral resolution to map 23 cover types and using a small training set. Rigorous evaluation of the classification accuracies shows that the ANN outperforms the other methods and achieves ?90% accuracy on test data

Elements of a Theory of Design Artefacts: a contribution to critical systems development research. PhD Thesis.

The thesis emphasises material mediation in design, use and research by introducing the concept of design artefacts as a unifying perspective. This concept is based on a dialectical materialist approach comprising activity theory as a general perspective (mainly Engestrøm), and specifically the notion of primary, secondary and tertiary artefacts (Wartofsky). This background is complemented with the notion of boundary objects (Star), as mediators in boundary zones. Systems development is understood as a zone where heterogeneous praxes meet to change a given praxis through the construction and introduction of new (computer) artefacts; this zone is mediated by design artefacts, which make different sense to the various praxes (boundary objects). Four main themes are addressed by the thesis: Firstly, the notion of design artefacts as an integrating perspective on systems development research and praxis, is introduced and developed. Secondly, a uniform notion of development tying use and design together, is discussed in relation to designing for development in use, and in relation to the notion of design as the transformation of artefacts. Thirdly, a pragmatic philosophy of science based on the understanding of theories as design artefacts, is proposed. Fourthly, the issue of innovation and creativity, together with the role of the individual is programmatically pointed to

The Doctrine of Separability and the Interaction between the Main Agreement and the Arbitration Clause

The basis for an arbitral proceeding is usually an arbitration agreement. In most situations, the arbitration agreement is included as an arbitration clause in the main agreement. Even if the arbitration clause seems to be a part of the main agreement, it has in accordance with the doctrine of separability to be regarded as a separate agreement from the main agreement. Without the doctrine of separability, the arbitral tribunal would lose its competence by ruling the main agreement, of which the arbitration clause would be a part invalid, terminated or non-existent. Consequently, the alleged invalidity of the main agreement does not automatically affect the arbitration clause and a separate assessment of the validity of the arbitration clause has to be done. The doctrine of separability has been justified with both the intent of the parties to solve all disputes regarding the main agreement by arbitration and with efficiency arguments, as for instance protection of the competence of the arbitral tribunal. In most jurisdictions, the doctrine of separability is accepted, but the exact scope and applicability of the doctrine varies from one jurisdiction to another. This thesis aims to determine the scope of the doctrine of separability and in addition, to create general rules for assessing the scope of the doctrine. The thesis aspires to clarify the legal state regarding the scope and applicability of the doctrine of separability in Finland. However, there is not much case law and legal doctrine concerning the doctrine of separability in Finland. Therefore, in addition to the legal dogmatic method, also a comparative method is used. The comparison is done with both international arbitration practice and as a Nordic comparison, focusing mainly on Sweden. The doctrine has been more thoroughly studied in both Sweden and internationally than in Finland. By clarifying the scope of the doctrine of separability, many conflicts regarding the competence of the arbitral tribunal could be avoided. The thesis is structured to first assess specific situations of applicability of the doctrine of separability and then assess if any general rules for the scope and applicability of the doctrine can be made. Regarding the specific situations of applicability, the doctrine is in Finland applied for at least separating the arbitration clause from a main agreement that is allegedly invalid or terminated. When it comes to a main agreement alleged to be non-existent, there is no consensus regarding if the doctrine should be applied. In the thesis, I have argued that the doctrine of separability should be applied even if the main agreement is allegedly non-existent. Otherwise, for instance a concluded arbitration clause in a draft agreement would be regarded as non-existent, if the main agreement is not concluded. When it comes to the applicability of the doctrine of separability to choice of law clauses in the main agreement, Finnish doctrine seems to have taken the standpoint that a separate assessment of the law applicable to the arbitration clause has to be done. Consequently, a choice of law clause in the main agreement does not automatically reach to the arbitration clause. However according to Finnish case law and literature, the doctrine of separability cannot reach to the interpretation and adjustment of arbitration clauses. In accordance with general contract law principles, arbitration clauses have to be interpreted and adjusted in the light of the main agreement. The second part of the research regards if any general rules can be applied to determine the scope and applicability of the doctrine of separability. I suggest that the doctrine of separability should be applied to all situations where the main agreement and the arbitration clause interconnects. The arbitration clause is a procedural agreement that is auxiliary to the substantive main agreement and thus has certain tasks and features that have to be protected by evaluating the arbitration clause separately. The doctrine of separability is a tool for contractual construction, which enables the courts and tribunals to give proper effect to the arbitration clause and the will of the parties. It does in no other way prevent the interaction between the agreements. When separately assessing and interpreting the arbitration clause, the general contract law rules determine the outcome of the assessment

Curriculum Making for Social Learning : Exploring Policy and Practice in Norwegian Lower Secondary Education

This thesis explores the concept of social learning in international policy and research, and curriculum making for social learning in Norwegian policy and practice. The main purpose of the study is to investigate how students social learning is influenced by curriculum making at the national policy level and by curriculum making in subjects at the classroom level in Norwegian lower secondary education. The study has a theoretical grounding in critical realism (Bhaskar, 2008a; Danermark, Ekström, Jakobsen, & Karlsson, 2011) that emphasizes social phenomena as complex and emergent from the interactions of agents, structures and mechanisms at multiple layers of reality. Wenger’s social theory of learning (Wenger, 1999) is used to analyse collective outcomes of students and teachers’ social interactions. Curriculum theory (Deng, 2017; Englund, 2015; Reid, 2016) is used to analyse teachers practices of curriculum making in subjects as instructional events in the classroom, and to analyse curriculum making at the national policy level (Chan, 2012; Hopmann, 2003; Lundgren, 2012) as negotiated practices of educational governance and control. The study has a qualitative design building on data from policy, research and classroom interaction. Policy and literature reviews have been conducted using critical research review methodology (Suri, 2013), and methods of contents and bibliometric analysis (Bowen, 2009; Weber, 1990) to generate data on curriculum making at the national and international levels. Qualitative interviews (Brinkmann & Kvale, 2015) with students and teachers and participant observation (Heath, Brooks, Cleaver, & Ireland, 2009; Okely, 2013) of their interactions has been used to generate data on curriculum making at the classroom level. The study identifies two main understandings of social learning as; the development of skills, and the development of community, in international policy and research. The study finds that Norwegian policymakers draw on both understandings in a compromised concept of social learning in the newly revised core curriculum. The study also identifies how students’ social learning is influenced by mechanism of personalization, peering, grouping and identification in subject teaching. Overall, these findings indicate that students’ social learning is influenced by a dual dialectic of curriculum making in policy and practice, and of social structures and students’ and teachers’ agency in the classroom