Localized event-based reasoning for multiagent domain1

This paper presents the GEM concurrency model and GEMPLAN, a multiagent planner based on this model. Unlike standard state-based AI representations, GEM is unique in its explicit emphasis on events and domain structure. In particular, a world domain is modeled as a set of regions composed of interrelated events. Event-based temporal-logic constraints are then associated with each region to delimit legal domain behavior. The GEMPLAN planner directly reflects this emphasis on domain structure and constraints. It can be viewed as a general-purpose constraint satisfaction facility which constructs a network of interrelated events (a “plan”) that is subdivided into regions (“subplans”), satisfies all applicable regional constraints, and also achieves some stated goal. GEMPLAN extends and generalizes previous planning architectures in the range of constraint forms it handles and in the flexibility of its constraint satisfaction search strategy. One critical aspect of our work has been an emphasis on localized reasoning—techniques that make explicit use of domain structure. For example, GEM localizes the applicability of domain constraints and imposes additional “locality constraints” on the basis of domain structure. Together, constraint localization and locality constraints provide semantic information that can be used to alleviate several aspects of the frame problem for multiagent domains. The GEMPLAN planner reflects the use of locality by subdividing its constraint satisfaction search space into regional planning search spaces. Utilizing constraint and property localization, GEMPLAN can pinpoint and rectify interactions among these regional search spaces, thus reducing the burden of “interaction analysis” ubiquitous to most planning systems. Because GEMPLAN is specifically geared towards parallel, multiagent domains, we believe that its natural application areas will include scheduling and other forms of organizational coordination.     

Adjunct automation to the cellmate cell culture robot

The design and implementation of an automated tissue culture flask labeling, delivery, scraping, and retrieval system centered around the Cellmate^™ cell culture robot is presented. Three new custom subsystems named FlaskMaster, FlaskLabeler, and FlaskScraper were created and integrated into the Cellmate robotic system. FlaskMaster is a centralized multi-axis robot with a surrounding enclosure that houses racks of stacked tissue culture flasks (size T-175). The FlaskMaster system interfaces externally with the Cellmate's conveyor system to deliver and retrieve flasks. FlaskLabeler is a print and apply system that labels flasks prior to transfer between FlaskMaster and the Cellmate. FlaskScraper is a scraping rod and blade assembly that was specifically designed for automated scraping of T-175 flasks. The combination of these systems allows for large-scale, unattended cell seeding and harvesting of cells from flasks. The addition of these new capabilities significantly reduces the manpower needed to operate the Cellmate. Moreover, these changes greatly improve the performance and capability of the stand-alone Cellmate system.     

Almost global attraction in planar systems

In this work, we present a result relating the recent ideas of almost global stability and density functions with the classical Poincaré–Bendixson theory for planar systems.     

Discontinuous grammars1,2

This article ties together previously scattered research on discontinuous grammars—logic grammars in which non-explicit sequences of symbols can be alluded to in the rules and sometimes repositioned by them. After an introduction, we define them formally, present their background, and provide intuitive insight into their use. Next, we examine several motivating arguments, from both formal and natural language processing viewpoints, and we discuss the static discontinuity family of these grammars, in which (a) the nonexplicit strings are not allowed to move and (b) linguistic constraints specifically designed to suit, in particular, Government and Binding theory can be defined modularly and statically in terms of node domination in parse trees and are enforced dynamically. Finally, we discuss implementation issues, related work, and extensions.     

The foundational model of anatomy in OWL: Experience and perspectives

We present the method developed for migrating the Foundational Model of Anatomy (FMA) from its representation with frames in Protégé to its logical representation in OWL and our experience in reasoning with it. Despite the extensive use of metaclasses in Protégé, it proved possible to convert the FMA from Protégé into OWL DL, while capturing most of its original features. The conversion relies on a set of translation and enrichment rules implemented with flexible options. Unsurprisingly, reasoning with the FMA in OWL proved to be a real challenge, due to its sheer size and complexity, and raised significant inference problems in terms of time and memory requirements. However, various smaller versions have been successfully handled by Racer. Some inconsistencies were identified and several classes reclassified. The results obtained so far show the advantage of OWL DL over frames and, more generally, the usefulness of DLs reasoners for building and maintaining the large-scale biomedical ontologies of the future Semantic Web.     

A design procedure for the exact H∞ siso-robust performance problem

Presented in this paper is a loop-shaping solution to the H^∞ robust performance problem for a class of SISO systems. The key feature of this work is the explicit incorporation of phase information into the controller synthesis to facilitate loop-shaping over all frequencies. Consequently, a significant reduction in the required controller gain/bandwidth is achieved. It is also shown that the optimal solution, in the sense of controller gain/bandwidth minimization, to the robust performance problem is that which makes μ = 1 over all frequencies. This is different from the usual definition of optimality in the H^∞/μ literature. An example is included for completeness.     

Effect of the reaction time, reagent concentration and sample thickness on the thermal derivatisation of p porous silicon with α-undecene and ω-carboxy alkenes: A FTIR investigation

This paper presents a detailed study, based on Fourier transform infrared (FTIR) analysis, on the derivatisation of p⁺-type porous silicon (PS) via thermal activated hydrosilylation of α-undecene. The α-undecene was used as a model for alkene precursor to calculate the efficiency of the hydrosilylation reaction, determined by comparing the integrated intensity of the SiH_x peaks (2200–2000 cm⁻¹) of the as-prepared and modified sample, by varying three parameters: the reaction time, the reagent concentration and the sample thickness. This study aims to optimize the PS derivatisation as a function of the thickness, in order to consider the thermal activation as a useful process for modifying PS slab waveguide for sensing application. Moreover two methods using ω-carboxy alkenes (where the carboxylic moiety was an ester or an acid) to obtain a PS surface –COOH-terminated, to be exploited for bioconjugation protocols, were tested and the reactions efficiency compared with the alkene model, i.e. α-undecene. FTIR spectroscopy and contact angle measurements were used to characterize the modified PS samples.     

Debunking the ‘digital native’: beyond digital apartheid,towards digital democracy

This paper interrogates the currently pervasive discourse of the ‘net generation’ finding the concept of the ‘digital native’ especially problematic, both empirically and conceptually. We draw on a research project of South African higher education students' access to and use of Information and Communication Technologies (ICTs) to show that age is not a determining factor in students' digital lives; rather, their familiarity and experience using ICTs is more relevant. We also demonstrate that the notion of a generation of ‘digital natives’ is inaccurate: those with such attributes are effectively a digital elite. Instead of a new net generation growing up to replace an older analogue generation, there is a deepening digital divide in South Africa characterized not by age but by access and opportunity; indeed, digital apartheid is alive and well. We suggest that the possibility for digital democracy does exist in the form of a mobile society which is not age specific, and which is ubiquitous. Finally, we propose redefining the concepts ‘digital’, ‘net’, ‘native’, and ‘generation’ in favour of reclaiming the term ‘digitizen’.