3,402 research outputs found
Formalizing Adaptation On-the-Fly
AbstractParadigm models specify coordination of collaborating components via constraint control. Component McPal allows for later addition of new constraints and new control in view of unforeseen adaptation. After addition McPal starts coordinating migration accordingly, adapting the system towards to-be collaboration. Once done, McPal removes obsolete control and constraints. All coordination remains ongoing while migrating on-the-fly, being deflected without any quiescence. Through translation into process algebra, supporting formal analysis is arranged carefully, showing that as-is and to-be processes are proper abstractions of the migrating process. A canonical critical section problem illustrates the approach
Discovering Blind Spots in Reinforcement Learning
Agents trained in simulation may make errors in the real world due to
mismatches between training and execution environments. These mistakes can be
dangerous and difficult to discover because the agent cannot predict them a
priori. We propose using oracle feedback to learn a predictive model of these
blind spots to reduce costly errors in real-world applications. We focus on
blind spots in reinforcement learning (RL) that occur due to incomplete state
representation: The agent does not have the appropriate features to represent
the true state of the world and thus cannot distinguish among numerous states.
We formalize the problem of discovering blind spots in RL as a noisy supervised
learning problem with class imbalance. We learn models to predict blind spots
in unseen regions of the state space by combining techniques for label
aggregation, calibration, and supervised learning. The models take into
consideration noise emerging from different forms of oracle feedback, including
demonstrations and corrections. We evaluate our approach on two domains and
show that it achieves higher predictive performance than baseline methods, and
that the learned model can be used to selectively query an oracle at execution
time to prevent errors. We also empirically analyze the biases of various
feedback types and how they influence the discovery of blind spots.Comment: To appear at AAMAS 201
Requirements for Information Extraction for Knowledge Management
Knowledge Management (KM) systems inherently suffer from the knowledge acquisition bottleneck - the difficulty of modeling and formalizing knowledge relevant for specific domains. A potential solution to this problem is Information Extraction (IE) technology. However, IE was originally developed for database population and there is a mismatch between what is required to successfully perform KM and what current IE technology provides. In this paper we begin to address this issue by outlining requirements for IE based KM
Challenges in Bridging Social Semantics and Formal Semantics on the Web
This paper describes several results of Wimmics, a research lab which names
stands for: web-instrumented man-machine interactions, communities, and
semantics. The approaches introduced here rely on graph-oriented knowledge
representation, reasoning and operationalization to model and support actors,
actions and interactions in web-based epistemic communities. The re-search
results are applied to support and foster interactions in online communities
and manage their resources
Agile in Public Administration: Oxymoron or reality? An experience report
In the last 10 years, Agile methods and practices have emerged as an
alternative for software development. Different "flavors" of Agile have
appeared ranging from project management to tests organization. These
approaches have being gaining popularity and involve now a solid option for
organizations developing software, but what about Public Administrations? Is
Agile a suitable option for developing software in Public Administrations?
Even if Public Administrations have been traditionally regarded as changeresistant,
Agile approach can also provide them with the benefits of quick
adaptation and frequent value delivery.
This paper presents the results of two different projects, which use an Agile
framework based on Scrum, developed by a Spanish Public Administration.
Additionally, after considering the obtained results, it takes out some relevant
learned lessons on the suitability of applying Agile approaches to Public
Administration environments.Ministerio de Ciencia e Innovación TIN2010-20057-C03-02Junta de Andalucía TIC-578
Automatic Generation of Minimal Cut Sets
A cut set is a collection of component failure modes that could lead to a
system failure. Cut Set Analysis (CSA) is applied to critical systems to
identify and rank system vulnerabilities at design time. Model checking tools
have been used to automate the generation of minimal cut sets but are generally
based on checking reachability of system failure states. This paper describes a
new approach to CSA using a Linear Temporal Logic (LTL) model checker called BT
Analyser that supports the generation of multiple counterexamples. The approach
enables a broader class of system failures to be analysed, by generalising from
failure state formulae to failure behaviours expressed in LTL. The traditional
approach to CSA using model checking requires the model or system failure to be
modified, usually by hand, to eliminate already-discovered cut sets, and the
model checker to be rerun, at each step. By contrast, the new approach works
incrementally and fully automatically, thereby removing the tedious and
error-prone manual process and resulting in significantly reduced computation
time. This in turn enables larger models to be checked. Two different
strategies for using BT Analyser for CSA are presented. There is generally no
single best strategy for model checking: their relative efficiency depends on
the model and property being analysed. Comparative results are given for the
A320 hydraulics case study in the Behavior Tree modelling language.Comment: In Proceedings ESSS 2015, arXiv:1506.0325
Change Support in Process-Aware Information Systems - A Pattern-Based Analysis
In today's dynamic business world the economic success of an enterprise increasingly depends on its ability to react to changes in its environment in a quick and flexible way. Process-aware information systems (PAIS) offer promising perspectives in this respect and are increasingly employed for operationally supporting business processes. To provide effective business process support, flexible PAIS are needed
which do not freeze existing business processes, but allow for loosely specified processes, which can be detailed during run-time. In addition, PAIS should enable authorized users to flexibly deviate from the predefined processes if required (e.g., by allowing them to dynamically add, delete, or move process activities) and to evolve business processes over time. At the same time PAIS must ensure consistency and robustness. The emergence of different process support paradigms and the lack of methods for comparing existing change approaches have made it difficult for PAIS engineers to choose the adequate technology. In this paper we suggest a set of changes patterns and change support features to foster the systematic comparison of existing process management technology with respect to process change support. Based on these change patterns and features, we provide a detailed analysis and evaluation of selected systems from both academia and industry. The identified change patterns and change support features facilitate the comparison of change support frameworks, and consequently will support PAIS engineers in selecting the right technology for realizing flexible PAIS. In addition, this work can be used as a reference for implementing more
flexible PAIS
Towards Activity Context using Software Sensors
Service-Oriented Computing delivers the promise of configuring and
reconfiguring software systems to address user's needs in a dynamic way.
Context-aware computing promises to capture the user's needs and hence the
requirements they have on systems. The marriage of both can deliver ad-hoc
software solutions relevant to the user in the most current fashion. However,
here it is a key to gather information on the users' activity (that is what
they are doing). Traditionally any context sensing was conducted with hardware
sensors. However, software can also play the same role and in some situations
will be more useful to sense the activity of the user. Furthermore they can
make use of the fact that Service-oriented systems exchange information through
standard protocols. In this paper we discuss our proposed approach to sense the
activity of the user making use of software
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