3,975 research outputs found
Sensitivity analysis and how to choose parameters to calibrate
No full textThe MULTITUDE Project (Methods and tools for supporting the Use, caLibration and validaTIon of Traffic simUlations moDEls) is an Action (TU0903) supported by the EU COST office (European Cooperation in Science and Technology) and focuses on the issue of uncertainty in traffic simulation, and of calibration and validation as tools to manage it. It is driven by the concern that, although modelling is now widespread, we are unsure how much we can trust our results and conclusions. Such issues force into question the trustworthiness of the results, and indeed how well we are using them.
The project consists of 4 Working Groups (WGs) which hold short, focussed, meetings on topics of interest and propose work items on key issues. Additionally the project holds an annual meeting, as well as training schools, where the latest thinking can be passed on to young researchers and practitioners.
This report covers much of the technical work performed by Working Group 4 ‘Synthesis, dissemination and training’, and has been contributed to by:
- Costas Antoniou, NTUA, GR
- Jaume Barcelo, UPC, ES
- Mark Brackstone, IOMI, UK
- Hilmi Berk Celikoglu, ITU, TR
- Biagio Ciuffo, JRC, IT
- Vincenzo Punzo, JRC/UNINA, IT
- Pete Sykes, PS-TTRM, UK
- Tomer Toledo, Technion, IL
Peter Vortisch, KIT, DE
Peter Wagner, DLR, DE
This document assesses the current situation regarding guidelines for traffic simulation model calibration and validation worldwide, discusses the problems currently faced, and suggests potential ways in which they can be addressed, both directly, and indirectly through the development of the overall field of traffic simulation as a whole
Exploiting Parallelism for Hard Problems in Abstract Argumentation
No full textAbstract argumentation framework (AF) is a unifying framework able to encompass a variety of nonmonotonic reasoning approaches, logic programming and computational argumentation. Yet, efficient approaches for most of the decision and enumeration problems associated to AF s are missing, thus potentially limiting the efficacy of argumentation-based approaches in real domains. In this paper, we present an algorithm for enumerating the preferred extensions of abstract argumentation frameworks which exploits parallel computation. To this purpose, the SCC-recursive semantics definition schema is adopted, where extensions are defined at the level of specific sub-frameworks. The algorithm shows significant performance improvements in large frameworks, in terms of number of solutions found and speedup
VGI in National Mapping Agencies: Experiences and Recommendations
No full textDespite the considerable growth in Volunteered Geographic Information (VGI) activities in citizen sensing and the evident opportunities for VGI use in map revision and updating, few European National Mapping Agencies (NMAs) or other types of government bodies have engaged significantly with VGI. Moreover, the level of engagement of NMAs with the VGI community varies greatly, and most of them have proposed their own tools for encouraging citizens and public partners to collect feedback or new data. There are numerous barriers limiting the participation of citizens and public partners in NMA data collection, including data quality issues, the motivation of the contributors and legal issues. The aim of this chapter is to give an overview of the experiences of some European NMAs in engaging with VGI. Guidelines and recommendations to support wider engagement with the VGI community are also proposed to help NMAs and interested government bodies exploit the potential of VGI for authoritative mapping.COST Action TD 1202 (Mapping and the Citizen Sensor
Passive multistatic SAR with GNSS transmitters and using joint bi/multi-static CLEAN technique
No full textThis paper explores the capability of GNSS as opportunity transmitters for passive multistatic SAR. The large number of navigation satellites illuminating the same area from multiple view angles enables a single ground-based stationary receiver to combine the individual bistatic images thus achieving multistatic imagery capability with improved spatial resolution. Nevertheless, such a technique introduces artifacts corrupting the quality of the image information space. In this paper, a joint bi/multi-static CLEAN algorithm is exploited in order to correctly recovering the information of the scene. An experimental study is therefore presented, demonstrating the potential of this technology to extract detailed information of an area for persistent monitoring purposes
Splicing- and cleavage-independent requirement of RNA polymerase II CTD for mRNA release from the transcription site
No full textEukaryotic cells have a surveillance mechanism that identifies aberrantly processed pre-mRNAs and prevents their flow to the cytoplasm by tethering them near the site of transcription. Here we provide evidence that mRNA release from the transcription site requires the heptad repeat structure of the C-terminal domain (CTD) of RNA polymerase II. The mammalian CTD, which is essential for normal co-transcriptional maturation of mRNA precursors, comprises 52 heptad repeats. We show that a truncated CTD containing 31 repeats (heptads 1-23, 36-38, and 48-52) is sufficient to support transcription, splicing, cleavage, and polyadenylation. Yet, the resulting mRNAs are mostly retained in the vicinity of the gene after transcriptional shutoff. The retained mRNAs maintain the ability to recruit components of the exon junction complex and the nuclear exosome subunit Rrp6p, suggesting that binding of these proteins is not sufficient for RNA release. We propose that the missing heptads in the truncated CTD mutant are required for binding of proteins implicated in a final co-transcriptional maturation of spliced and 3′ end cleaved and polyadenylated mRNAs into export-competent ribonucleoprotein particles. © The Rockefeller University Press
Performing Ancient Greek Tragedy in Twentieth-Century Greece: Dimitris Rontiris and Karolos Koun
No full textIn this article Michaela Antoniou gives an account of the two prevailing acting schools in ancient Greek tragedy in the twentieth century, as formed and developed by Dimitris Rontiris at the National Theatre and Karolos Koun at the Theatro Technis (Art Theatre). She discusses how these two great theatre masters directed, guided, and taught their actors to perform tragedy, arguing that Rontiris's approach stemmed from a text-based perspective that focused on reciting and pronunciation, while Koun's developed from a physical and emotional approach that prioritzed actors and their abilities. Her article summarizes each director's philosophy regarding the Greek tragedies, and discusses the position of the genre within modern Greek theatre, mapping the process employed by the actors, and analyzing their method in order to illustrate the different perspectives that the two great directors had with regards to approaching and performing a role. Michaela Antoniou completed her PhD at Goldsmiths, University of London, and is currently working as an external collaborator of the Department of Theatre Studies, National and Kapodistrian University of Athens. She has also worked on the stage as an actress and playwright, and is a published author
SPECIAL ISSUE ON EMERGING TECHNIQUES FOR THE MANAGEMENT OF UNCERTAINTY IN COMPUTATIONAL TRAFFIC MODELS
No full textCLEAN technique for passive bistatic and multistatic SAR with GNSS transmitters
No full textThis paper presents the description and some examples of application of the CLEAN technique to passive SAR based on GNSS emissions, in order to extract the scattering centers in the achieved images and to increase the understanding of the imaged scene. Two different operative scenarios are considered: the bistatic case, involving a single GNSS transmitter and a ground-based receiver, and the multistatic case, achieved by considering the non-coherent combination of the BSAR images obtained by multiple, spatially separated satellites. The effectiveness of the technique in extracting the point scatterers' returns in the bi/multi-static images is proved against simulated and real datasets. Moreover, the inherent capability of rejection of the ghost scatterers arising in the multistatic images from close scattering centers is shown. The application of the proposed technique allows the proper extraction of the amount of information of the observed area. © 2015 IEEE
Verification Conditions are Code
No full textThis paper presents a new theoretical result concerning Hoare Logic. It is shown here that the verification conditions which support a Hoare Logic program derivation are themselves sufficient to construct a correct implementation of the given pre-, post- condition specification. This property is mainly of theoretical interest, though it is possible that it may have some practical use, for example if predicative programming methodology is adopted. The result is shown to hold for both the original, partial correctness, Hoare logic, and also a variant for total correctness derivations
JNK3 as a therapeutic target for neurodegenerative diseases
No full textc-Jun N-terminal kinases (JNKs) and in particular JNK3 the neuronal specific isoform, have been recognized as
important enzymes in the pathology of diverse neurological disorders.
Indeed, several efforts have been made to design drugs that inhibit JNK signaling. The success that characterized the new
generation of cell permeable peptides rose the hope in the field of neurodegeneration. However, in order to design new and more efficient therapeutical approaches careful re-examination of current knowledge is required. Scaffold proteins are key endogenous regulators of JNK signaling: they can modulate spatial and temporal activation of the JNK signaling and can thus provide the basis for the design of more specific inhibitors.
This review focuses on delineating the role of scaffold proteins on the regulation of JNK signaling in neurons. Furthermore the possibility to design a new JNK3 cell permeable peptide inhibitor by targeting the -arrestin-JNK3 interaction is discussed
- …
