Planning with Incomplete Information

Planning is a natural domain of application for frameworks of reasoning about actions and change. In this paper we study how one such framework, the Language E, can form the basis for planning under (possibly) incomplete information. We define two types of plans: weak and safe plans, and propose a planner, called the E-Planner, which is often able to extend an initial weak plan into a safe plan even though the (explicit) information available is incomplete, e.g. for cases where the initial state is not completely known. The E-Planner is based upon a reformulation of the Language E in argumentation terms and a natural proof theory resulting from the reformulation. It uses an extension of this proof theory by means of abduction for the generation of plans and adopts argumentation-based techniques for extending weak plans into safe plans. We provide representative examples illustrating the behaviour of the E-Planner, in particular for cases where the status of fluents is incompletely known.Comment: Proceedings of the 8th International Workshop on Non-Monotonic Reasoning, April 9-11, 2000, Breckenridge, Colorad

Attendee-Sourcing: Exploring The Design Space of Community-Informed Conference Scheduling

Constructing a good conference schedule for a large multi-track conference needs to take into account the preferences and constraints of organizers, authors, and attendees. Creating a schedule which has fewer conflicts for authors and attendees, and thematically coherent sessions is a challenging task. Cobi introduced an alternative approach to conference scheduling by engaging the community to play an active role in the planning process. The current Cobi pipeline consists of committee-sourcing and author-sourcing to plan a conference schedule. We further explore the design space of community-sourcing by introducing attendee-sourcing -- a process that collects input from conference attendees and encodes them as preferences and constraints for creating sessions and schedule. For CHI 2014, a large multi-track conference in human-computer interaction with more than 3,000 attendees and 1,000 authors, we collected attendees' preferences by making available all the accepted papers at the conference on a paper recommendation tool we built called Confer, for a period of 45 days before announcing the conference program (sessions and schedule). We compare the preferences marked on Confer with the preferences collected from Cobi's author-sourcing approach. We show that attendee-sourcing can provide insights beyond what can be discovered by author-sourcing. For CHI 2014, the results show value in the method and attendees' participation. It produces data that provides more alternatives in scheduling and complements data collected from other methods for creating coherent sessions and reducing conflicts.Comment: HCOMP 201

e-EVN radio detection of Aql X-1 in outburst

The neutron star X-ray binary Aql X-1 is currently in outburst. Using the European VLBI Network (e-EVN) we observed Aql X-1 at 5 GHz in two time-slots: 2013 June 18 between 19:48 - 20:36 UT (MJD 56461.825 - 56461.858), and 2013 June 19 between 02:53 - 05:54 UT (MJD 56462.120 - 56462.246). The two datasets were combined together and then calibrated

Developing an e-infrastructure for social science

We outline the aims and progress to date of the National Centre for e-Social Science e-Infrastructure project. We examine the challenges faced by the project, namely in ensuring outputs are appropriate to social scientists, managing the transition from research projects to service and embedding software and data within a wider infrastructural framework. We also provide pointers to related work where issues which have ramifications for this and similar initiatives are being addressed

Collaboration through Wiki and Paper Compositions in Foreign Language Classes

This study investigates the nature of collaboration on wikis as opposed tothe nature of collaboration resulting in a paper composition. In order tounderstand this phenomenon students were placed in groups of four andasked to write two essays during the semester. On one essay students wereasked to produce a composition in the target language on a wiki. Onanother they were asked to produce a composition that would be given tothe teacher in hard copy. Specific research questions includeddetermining to what extent students prefer collaborating to produce a wikior paper composition. Additionally, we attempted to determine, accordingto students, what the advantages and disadvantages of collaborating on awiki composition versus a paper composition are and what effect theseadvantages and disadvantages might have on collaboration. Data wascollected from over one hundred university students through likert-scaletype questions, open-ended written questions as well as face to faceinterviews. Findings indicate that the collaborative process on the wikireflected true collaboration where students had a hand in each part of thecomposition. On the other hand, while completing the paper composition,students generally handed their assigned portion to a single student in thegroup who was designated the compiler and would rarely see or commenton the other group members’ work. The authors also provide a discussionof specific advantages and disadvantages of wiki and paper-basedcompositions and important implications for practitioners

Understanding and Supporting Directed Content Sharing on the Web

To find interesting, personally relevant web content, we often rely on friends and colleagues to pass links along as they encounter them. In this paper, we study and augment link-sharing via e-mail, the most popular means of sharing web content today. Armed with survey data indicating that active sharers of novel web content are often those that actively seek it out, we present FeedMe, a plug-in for Google Reader that makes directed sharing of content a more salient part of the user experience. Our survey research indicates that sharing is moderated by concern about relevancy to the recipient, a desire to send only novel content to the recipient, and the effort required to share. FeedMe allays these concerns by recommending friends who may be interested in seeing the content, providing information on what the recipient has seen and how many emails they have received recently, and giving recipients the opportunity to provide lightweight feedback when they appreciate shared content. FeedMe introduces a novel design space for mixed-initiative social recommenders: friends who know the user voluntarily vet the material on the userâ s behalf. We present a two week field experiment (N=60) demonstrating that FeedMeâ s recommendations and social awareness features made it easier and more enjoyable to share content that recipients appreciated and would not have found otherwise

An outburst of SS 433 observed on milliarcsecond scale

SS 433 is a high-mass X-ray binary system (XRB) and one of the most persistent sources of relativistic jets in the Milky Way. The object has been intensively studied in radio at arcsecond scales, however the high-resolution observations (i.e. VLBI) are relatively scarce. In 2008 November the system was in outburst. Using the e-VLBI capabilities of the European VLBI Network (EVN) we observed SS 433 for three epochs during the active phase. The data offered a detailed view of the system’s behaviour in outburst at milliarcsecond scales. We used the “kinematic model" (which predicts the position along the jet of any knot ejected at some particular time in the past) to investigate the dynamic parameters of SS 433 and we examined the polarization properties of the ejected material. We report here the preliminary results