11. |
|
|
12. |
- Karabiyik, Hande, et al.
(författare)
-
Panel data measures of price discovery
- 2022
-
Ingår i: Econometric Reviews. - : Informa UK Limited. - 0747-4938 .- 1532-4168. ; 41:3, s. 269-290
-
Tidskriftsartikel (refereegranskat)abstract
- This paper considers disaggregated price data that are observed not only for multiple markets over extended periods of time, but also for a large number of assets. The previous literature has argued that in such data rich environments, which arise frequently in applied work, the analysis of price discovery can be made more precise by accounting for the panel structure of the data. Moreover, since the individual assets are not that interesting anyways, little is lost by taking the overall panel perspective. These arguments are, however, mainly based on empirical observations, and there is little in terms of econometric support. The purpose of the present study is to fill this gap in the literature. This is done by offering a full-blown econometric analysis of panel analogs of the information share and permanent–transitory measures of price discovery, which are the workhorses of the time series literature. Both measures are shown to be consistent and they support standard normal inference, which is in contrast to the time series case, where such inference is only possible for the permanent–transitory measure.
|
|
13. |
- Kreuger, Per, et al.
(författare)
-
The TUFF train scheduler
- 1997. - 1
-
Ingår i: ILPS'97 Workshop on Tools and Environments for (Constraint) Logic Programmins.
-
Konferensbidrag (refereegranskat)
|
|
14. |
|
|
15. |
- Olofsson, Hans, 1952
(författare)
-
A circumstellar journey-physics and chemistry of AGB stellar winds
- 2008
-
Ingår i: Physica scripta. Topical Issues. - 0281-1847. ; T133:014028
-
Konferensbidrag (refereegranskat)abstract
- The physics and chemistry of the envelopes of gas and dust that surround stars on the asymptotic giant branch are the subjects of this review. Estimates of stellar mass-loss rates in this phase, as determined through observations and modelling of different circumstellar probes, are discussed. A particular phenomenon of highly episodic mass loss is described. Estimates of circumstellar molecular abundances are compared with expectations from chemical models.
|
|
16. |
- Olofsson, H, et al.
(författare)
-
A high-resolution study of episodic mass loss from the carbon star TT Cygni
- 2000
-
Ingår i: ASTRONOMY AND ASTROPHYSICS. - : SPRINGER VERLAG. - 0004-6361. ; 353:2, s. 583-597
-
Tidskriftsartikel (refereegranskat)abstract
- CO radio line observations with the IRAM Plateau de Bure interferometer show that the carbon star TT Cyg is surrounded by a large (radius similar to 35 " or 2.7 x 10(17) cm), geometrically thin (average width similar to 2." 5 or 1.9 x 10(16) cm) shell of
|
|
17. |
|
|
18. |
- Virta, Sari, et al.
(författare)
-
Managing Dependencies and Tensions in Value Networks Development : Case Mediapolis in Finland
- 2016
-
Konferensbidrag (refereegranskat)abstract
- Media organisations face growing demands for co-operation. Achieving innovation that is vital requires collaborative arrangements based on creative interaction. Collaboration is often realized in networked operations between media organisations (e.g. Baumann, 2013), media clusters as one example. At the same time, competition in the media field intensifies. It is here that the concept and theory of value networks becomes useful (e.g. de Man, Berends, Lammers, van Raaij & van Weele 2008; Bathelt, Malmberg & Maskell, 2004). Also, the intensity, i.e. the frequency and range of interactions in clusters of media companies becomes a central factor for consideration (Picard, 2008). In this reality, managerial challenges, especially, in relation to interaction, collaboration and co-opetition are considerable, and respective competences need to be developed and utilized for success.Collaborative production is typical for innovation-intensive industries (Nohria & Eccles, 1992), and media firms are no different in this respect. However, the configuration of collaborative relationships in and between media organisations in networks is a complex managerial task, especially in the rapidly changing environment of diminishing resources. Media managers must be competent in handling various dependencies in value networks for shared value creation (e.g. Bilton, 2007), and especially the related tensions. To be useful, co-operative relationships need to be created and built, and the network development happens in stages (Büchel & Raub, 2002).The empirical case of the paper is Mediapolis (http://mediapolis.fi/en/) in Tampere, Finland. It is a new media centre and a cluster, an ecosystem and a network for content production and digital industries with a vision ”Mediapolis is a centre for storytelling and digital industries, where interdisciplinary innovations are born”. The Mediapolis campus was launched in the autumn 2014, although the planning started some years before. It is an interesting case for analysis, because its viability depends on the creation and management of a creative value network.Mediapolis development illustrates challenges and tensions of simultaneous collaboration and competition, i.e. co-opetition in a value network aiming for innovation. Especially, the managerial challenges in creating and developing the Mediapolis operational model have been significant, and continue to be so. The paper explores the first years of Mediapolis, providing a unique access to the forming stage of a creative media cluster development and its management. Thus, the paper contributes directly to the conference theme by developing understanding about creative collaboration and coopetition aiming at achieving media innovation, especially focusing on the complexity of interactions and tensions between Mediapolis partners.The empirical research material consists of semi-structured interviews, including the main Mediapolis partners’ management representatives as interviewees. The interviews have been conducted in different stages of Mediapolis development, e.g. in the early stages of planning and after the campus launch. Also, Mediapolis documentation has been collected from open sources (e.g. websites) and acquired from partner organisations. The study utilizes a qualitative case study approach (Stake, 1995), suitable for analysing unique cases in detail to create understanding about a phenomenon. Document analysis (Bowen, 2009) and qualitative thematic coding with ‘factual’ approach (e.g. Patton, 2002; Alastalo & Åkerman, 2010) are used as methodological approaches, and Atlas.ti software is utilized for analysis.In conclusion, the purpose of the paper is to discuss and elaborate on the various managerial and organisational dependencies and tensions in creating Mediapolis. Further, a central focus will be on the managerial competences required to deal with the new realities of value networks successfully in the media industry. The methodological approach is qualitative, with the aim of creating new knowledge on the scholarly field of media management for both academic and practical purposes. In media management, value networks have been scarcely researched, but the topic is highly timely and worthy of scholarly attention.
|
|
19. |
- Zeng, Hong-Li, et al.
(författare)
-
Global analysis of more than 50,000 SARS-CoV-2 genomes reveals epistasis between eight viral genes
- 2020
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 117:49, s. 31519-31526
-
Tidskriftsartikel (refereegranskat)abstract
- Genome-wide epistasis analysis is a powerful tool to infer gene interactions, which can guide drug and vaccine development and lead to deeper understanding of microbial pathogenesis. We have considered all complete severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes deposited in the Global Initiative on Sharing All Influenza Data (GISAID) repository until four different cutoff dates, and used direct coupling analysis together with an assumption of quasi-linkage equilibrium to infer epistatic contributions to fitness from polymorphic loci. We find eight interactions, of which three are between pairs where one locus lies in gene ORF3a, both loci holding nonsynonymous mutations. We also find interactions between two loci in gene nsp13, both holding nonsynonymous mutations, and four interactions involving one locus holding a synonymous mutation. Altogether, we infer interactions between loci in viral genes ORF3a and nsp2, nsp12, and nsp6, between ORF8 and nsp4, and between loci in genes nsp2, nsp13, and nsp14. The paper opens the prospect to use prominent epistatically linked pairs as a starting point to search for combinatorial weaknesses of recombinant viral pathogens.
|
|
20. |
- Zholud, Dmitrii, 1984
(författare)
-
Extreme Value Analysis of Huge Datasets: Tail Estimation Methods in High-Throughput Screening and Bioinformatics
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents results in Extreme Value Theory with applications to High-Throughput Screening and Bioinformatics. The methods described here, however, are applicable to statistical analysis of huge datasets in general. The main results are covered in four papers. The first paper develops novel methods to handle false rejections in High-Throughput Screening experiments where testing is done at extreme significance levels, with low degrees of freedom, and when the true null distribution may differ from the theoretical one. We introduce efficient and accurate estimators of False Discovery Rate and related quantities, and provide methods of estimation of the true null distribution resulting from data preprocessing, as well as techniques to compare it with the theoretical null distribution. Extreme Value Statistics provides a natural analysis tool: a simple polynomial model for the tail of the distribution of p-values. We exhibit the properties of the estimators of the parameters of the model, and point to model checking tools, both for independent and dependent data. The methods are tried out on two large scale genomic studies and on an fMRI brain scan experiment. The second paper gives a strict mathematical basis for the above methods. We present asymptotic formulas for the distribution tails of probably the most commonly used statistical tests under non-normality, dependence, and non-homogeneity, and derive bounds on the absolute and relative errors of the approximations. In papers three and four we study high-level excursions of the Shepp statistic for the Wiener process and for a Gaussian random walk. The application areas include finance and insurance, and sequence alignment scoring and database searches in Bioinformatics.
|
|