Natural language processing

Beginning with the basic issues of NLP, this chapter aims to chart the major research activities in this area since the last ARIST Chapter in 1996 (Haas, 1996), including: (i) natural language text processing systems - text summarization, information extraction, information retrieval, etc., including domain-specific applications; (ii) natural language interfaces; (iii) NLP in the context of www and digital libraries ; and (iv) evaluation of NLP systems

Estimation of forest variables using airborne laser scanning

Airborne laser scanning can provide three-dimensional measurements of the forest canopy with high efficiency and precision. There are presently a large number of airborne laser scanning instruments in operation. The aims of the studies reported in this thesis were, to develop and validate methods for estimation of forest variables using laser data, and to investigate the influence of laser system parameters on the estimates. All studies were carried out in hemi-boreal forest at a test area in southwestern Sweden (lat. 58°30’N, long. 13°40’ E). Forest variables were estimated using regression models. On plot level, the Root Mean Square Error (RMSE) for mean tree height estimations ranged between 6% and 11% of the average value for different datasets and methods. The RMSE for stem volume estimations ranged between 19% and 26% of the average value for different datasets and methods. On stand level (area 0.64 ha), the RMSE was 3% and 11% of the average value for mean tree height and stem volume estimations, respectively. A simulation model was used to investigate the effect of different scanning angles on laser measurement of tree height and canopy closure. The effect of different scanning angles was different within different simulated forest types, e.g., different tree species. High resolution laser data were used for detection of individual trees. In total, 71% of the field measurements were detected representing 91% of the total stem volume. Height and crown diameter of the detected trees could be estimated with a RMSE of 0.63 m and 0.61 m, respectively. The magnitude of the height estimation errors was similar to what is usually achieved using field inventory. Using different laser footprint diameters (0.26 to 3.68 m) gave similar estimation accuracies. The tree species Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) were discriminated at individual tree level with an accuracy of 95%. The results in this thesis show that airborne laser scanners are useful as forest inventory tools. Forest variables can be estimated on tree level, plot level and stand level with similar accuracies as traditional field inventories

Organized equity markets in Germany

The German financial system is the archetype of a bank-dominated system. This implies that organized equity markets are, in some sense, underdeveloped. The purpose of this paper is, first, to describe the German equity markets and, second, to analyze whether it is underdeveloped in any meaningful sense. In the descriptive part we provide a detailed account of the microstructure of the German equity markets, putting special emphasis on recent developments. When comparing the German market with its peers, we find that it is indeed underdeveloped with respect to market capitalization. In terms of liquidity, on the other hand, the German equity market is not generally underdeveloped. It does, however, lack a liquid market for block trading. Klassifikation: G 51 . Revised version forthcoming in "The German Financial System", edited by Jan P. Krahnen and Reinhard H. Schmidt, Oxford University Press

Research Agenda for Studying Open Source II: View Through the Lens of Referent Discipline Theories

In a companion paper [Niederman et al., 2006] we presented a multi-level research agenda for studying information systems using open source software. This paper examines open source in terms of MIS and referent discipline theories that are the base needed for rigorous study of the research agenda

Generating indicative-informative summaries with SumUM

We present and evaluate SumUM, a text summarization system that takes a raw technical text as input and produces an indicative informative summary. The indicative part of the summary identifies the topics of the document, and the informative part elaborates on some of these topics according to the reader's interest. SumUM motivates the topics, describes entities, and defines concepts. It is a first step for exploring the issue of dynamic summarization. This is accomplished through a process of shallow syntactic and semantic analysis, concept identification, and text regeneration. Our method was developed through the study of a corpus of abstracts written by professional abstractors. Relying on human judgment, we have evaluated indicativeness, informativeness, and text acceptability of the automatic summaries. The results thus far indicate good performance when compared with other summarization technologies

Recreating Daily life in Pompeii

[EN] We propose an integrated Mixed Reality methodology for recreating ancient daily life that features realistic simulations of animated virtual human actors (clothes, body, skin, face) who augment real environments and re-enact staged storytelling dramas. We aim to go further from traditional concepts of static cultural artifacts or rigid geometrical and 2D textual augmentations and allow for 3D, interactive, augmented historical character-based event representations in a mobile and wearable setup. This is the main contribution of the described work as well as the proposed extensions to AR Enabling technologies: a VR/AR character simulation kernel framework with real-time, clothed virtual humans that are dynamically superimposed on live camera input, animated and acting based on a predefined, historically correct scenario. We demonstrate such a real-time case study on the actual site of ancient Pompeii.The work presented has been supported by the Swiss Federal Office for Education and Science and the EU IST programme, in frame of the EU IST LIFEPLUS 34545 and EU ICT INTERMEDIA 38417 projects.Magnenat-Thalmann, N.; Papagiannakis, G. (2010). Recreating Daily life in Pompeii. Virtual Archaeology Review. 1(2):19-23. https://doi.org/10.4995/var.2010.4679OJS192312P. MILGRAM, F. KISHINO, (1994) "A Taxonomy of Mixed Reality Visual Displays", IEICE Trans. Information Systems, vol. E77-D, no. 12, pp. 1321-1329R. AZUMA, Y. BAILLOT, R. BEHRINGER, S. FEINER, S. JULIER, B. MACINTYRE, (2001) "Recent Advances in Augmented Reality", IEEE Computer Graphics and Applications, November/December http://dx.doi.org/10.1109/38.963459D. STRICKER, P. DÄHNE, F. SEIBERT, I. CHRISTOU, L. ALMEIDA, N. IOANNIDIS, (2001) "Design and Development Issues for ARCHEOGUIDE: An Augmented Reality-based Cultural Heritage On-site Guide", EuroImage ICAV 3D Conference in Augmented Virtual Environments and Three-dimensional Imaging, Mykonos, Greece, 30 May-01 JuneW. WOHLGEMUTH, G. TRIEBFÜRST, (2000)"ARVIKA: augmented reality for development, production and service", DARE 2000 on Designing augmented reality environments, Elsinore, Denmark http://dx.doi.org/10.1145/354666.354688H. TAMURA, H. YAMAMOTO, A. KATAYAMA, (2001) "Mixed reality: Future dreams seen at the border between real and virtual worlds", Computer Graphics and Applications, vol.21, no.6, pp.64-70 http://dx.doi.org/10.1109/38.963462M. PONDER, G. PAPAGIANNAKIS, T. MOLET, N. MAGNENAT-THALMANN, D. THALMANN, (2003) "VHD++ Development Framework: Towards Extendible, Component Based VR/AR Simulation Engine Featuring Advanced Virtual Character Technologies", IEEE Computer Society Press, CGI Proceedings, pp. 96-104 http://dx.doi.org/10.1109/cgi.2003.1214453Archaeological Superintendence of Pompeii (2009), http://www.pompeiisites.orgG. PAPAGIANNAKIS, S. SCHERTENLEIB, B. O'KENNEDY , M. POIZAT, N.MAGNENAT-THALMANN, A. STODDART, D.THALMANN, (2005) "Mixing Virtual and Real scenes in the site of ancient Pompeii",Journal of CAVW, p 11-24, Volume 16, Issue 1, John Wiley and Sons Ltd, FebruaryEGGES, A., PAPAGIANNAKIS, G., MAGNENAT-THALMANN, N., (2007) "Presence and Interaction in Mixed Reality", The Visual Computer, Springer-Verlag Volume 23, Number 5, MaySEO H., MAGNENAT-THALMANN N. (2003), An Automatic Modeling of Human Bodies from Sizing Parameters. In ACM SIGGRAPH, Symposium on Interactive 3D Graphics, pp19-26, pp234. http://dx.doi.org/10.1145/641480.641487VOLINO P., MAGNENAT-THALMANN N. (2006), Resolving Surface Collisions through Intersection Contour Minimization. In ACM Transactions on Graphics (Siggraph 2006 proceedings), 25(3), pp 1154-1159. http://dx.doi.org/10.1145/1179352.1142007http://dx.doi.org/10.1145/1141911.1142007PAPAGIANNAKIS, G., SINGH, G., MAGNENAT-THALMANN, N., (2008) "A survey of mobile and wireless technologies for augmented reality systems", Journal of Computer Animation and Virtual Worlds, John Wiley and Sons Ltd, 19, 1, pp. 3-22, February http://dx.doi.org/10.1002/cav.22

Information transfer in signaling pathways : a study using coupled simulated and experimental data

Background: The topology of signaling cascades has been studied in quite some detail. However, how information is processed exactly is still relatively unknown. Since quite diverse information has to be transported by one and the same signaling cascade (e.g. in case of different agonists), it is clear that the underlying mechanism is more complex than a simple binary switch which relies on the mere presence or absence of a particular species. Therefore, finding means to analyze the information transferred will help in deciphering how information is processed exactly in the cell. Using the information-theoretic measure transfer entropy, we studied the properties of information transfer in an example case, namely calcium signaling under different cellular conditions. Transfer entropy is an asymmetric and dynamic measure of the dependence of two (nonlinear) stochastic processes. We used calcium signaling since it is a well-studied example of complex cellular signaling. It has been suggested that specific information is encoded in the amplitude, frequency and waveform of the oscillatory Ca2+-signal. Results: We set up a computational framework to study information transfer, e.g. for calcium signaling at different levels of activation and different particle numbers in the system. We stochastically coupled simulated and experimentally measured calcium signals to simulated target proteins and used kernel density methods to estimate the transfer entropy from these bivariate time series. We found that, most of the time, the transfer entropy increases with increasing particle numbers. In systems with only few particles, faithful information transfer is hampered by random fluctuations. The transfer entropy also seems to be slightly correlated to the complexity (spiking, bursting or irregular oscillations) of the signal. Finally, we discuss a number of peculiarities of our approach in detail. Conclusion: This study presents the first application of transfer entropy to biochemical signaling pathways. We could quantify the information transferred from simulated/experimentally measured calcium signals to a target enzyme under different cellular conditions. Our approach, comprising stochastic coupling and using the information-theoretic measure transfer entropy, could also be a valuable tool for the analysis of other signaling pathways

Perceptions of gender balance of IS journal editorial positions

An analysis of 18,854 editorial positions on IS journals was undertaken to examine the perceived gender balance of those positions as an indication of their contribution towards a positive role model for females considering an IS academic career. The nature and extent of perceived gender balance is examined in terms of overall composition of editorial positions, journal prestige and the specific area within IS covered by a journal. The results indicate that perceived gender balance of editorial positions reflects that of ICT academia generally, and that female representation appears to be concentrated in journals covering areas that are traditionally seen as female occupations, e.g., health, education, librarianship. As such, little or no encouragement is given to females considering an IS academic career.<br /

Evolving collective behavior in an artificial ecology

Collective behavior refers to coordinated group motion, common to many animals. The dynamics of a group can be seen as a distributed model, each “animal” applying the same rule set. This study investigates the use of evolved sensory controllers to produce schooling behavior. A set of artificial creatures “live” in an artificial world with hazards and food. Each creature has a simple artificial neural network brain that controls movement in different situations. A chromosome encodes the network structure and weights, which may be combined using artificial evolution with another chromosome, if a creature should choose to mate. Prey and predators coevolve without an explicit fitness function for schooling to produce sophisticated, nondeterministic, behavior. The work highlights the role of species’ physiology in understanding behavior and the role of the environment in encouraging the development of sensory systems