11,240 research outputs found
Building need-based systems for complex hostile situations
The concept of need-based systems is that they are not instantiated until they are brought to use. Such systems are either designed, assembled and instantiated for very concrete needs, alternatively built on speculation. They are used for evaluation, training or for real. In most cases they are not instantiated, though possibly brought into use as needed. How should needs be expressed? Needs are expressed in terms of results and effects. They may be simple or complex, where complex needs can be seen as structured compositions of more basic needs. When facing a hostile situation, it is critical to have predicted all needs necessary for resolving the given assignment. The complexity of needs, and of their interdependencies may appear to be overwhelming, and it is important to find optimal solutions to the problem at hand. What is needed is a knowledge-based conceptual model that describes the inter-relation of needs, predictions and effects. This paper proposes a number of viewpoints and tools to be applied to the construction of need-based systems -- viewing needs as a resource economy, as a non-linear dynamical system, making use of game theory, decision theory, and risk management. Models for needs and predictions, and the ways they are utilized, extends current systems engineering methods
Abstraction and registration: conceptual innovations and supply effects in Prussian and British Copyright (1820-50)
It is one of the orthodoxies of modern copyright law that the enjoyment and the exercise of the rights granted “shall not be subject to any formality” (Berne Convention 1886, Berlin revision 1908, Art.4), such as a registration requirement. In this article, we trace the origins of this provision to a conceptual shift that took place during the early 1800s. Specific regulations of the book trade were superseded by the protection of all instantiations (such as performances, translations and adaptations) of abstract authored work. For two seminal copyright acts of the period, the Prussian Act of 1837 and the UK Act of 1842, we show there was considerable concern about the economic implications of this new justificatory paradigm, reflected in a period of experimentation with sophisticated registration requirements. We indicate market responses to these requirements and plea for a reconsideration of “formalities” as redressing justificatory problems of copyright in the digital environment
CrossFlow: Cross-Organizational Workflow Management for Service Outsourcing in Dynamic Virtual Enterprises
In this report, we present the approach to cross-organizational workflow management of the CrossFlow project. CrossFlow is a European research project aiming at the support of cross-organizational workflows in dynamic virtual enterprises. The cooperation in these virtual enterprises is based on dynamic service outsourcing specified in electronic contracts. Service enactment is performed by dynamically linking the workflow management infrastructures of the involved organizations. Extended service enactment support is provided in the form of cross-organizational transaction management and process control, advanced quality of service monitoring, and support for high-level flexibility in service enactment. CrossFlow technology is realized on top of a commercial workflow management platform and applied in two real-world scenarios in the contexts of a logistics and an insurance company
Parallel scheduling of recursively defined arrays
A new method of automatic generation of concurrent programs which constructs arrays defined by sets of recursive equations is described. It is assumed that the time of computation of an array element is a linear combination of its indices, and integer programming is used to seek a succession of hyperplanes along which array elements can be computed concurrently. The method can be used to schedule equations involving variable length dependency vectors and mutually recursive arrays. Portions of the work reported here have been implemented in the PS automatic program generation system
Metadata Augmentation for Semantic- and Context- Based Retrieval of Digital Cultural Objects
Cultural objects are increasingly stored and generated in digital form, yet effective methods for their indexing and retrieval still remain an open area of research. The main problem arises from the disconnection between the content-based indexing approach used by computer scientists and the description-based approach used by information scientists. There is also a lack of representational schemes that allow the alignment of the semantics and context with keywords and low-level features that can be automatically extracted from the content of these cultural objects. This paper presents an integrated approach to address these problems, taking advantage of both computer science and information science approaches. The focus is on the rationale and conceptual design of the system and its various components. In particular, we discuss techniques for augmenting commonly used metadata with visual features and domain knowledge to generate high-level abstract metadata which in turn can be used for semantic and context-based indexing and retrieval. We use a sample collection of Vietnamese traditional woodcuts to demonstrate the usefulness of this approach
Analysis of rolling group therapy data using conditionally autoregressive priors
Group therapy is a central treatment modality for behavioral health disorders
such as alcohol and other drug use (AOD) and depression. Group therapy is often
delivered under a rolling (or open) admissions policy, where new clients are
continuously enrolled into a group as space permits. Rolling admissions
policies result in a complex correlation structure among client outcomes.
Despite the ubiquity of rolling admissions in practice, little guidance on the
analysis of such data is available. We discuss the limitations of previously
proposed approaches in the context of a study that delivered group cognitive
behavioral therapy for depression to clients in residential substance abuse
treatment. We improve upon previous rolling group analytic approaches by fully
modeling the interrelatedness of client depressive symptom scores using a
hierarchical Bayesian model that assumes a conditionally autoregressive prior
for session-level random effects. We demonstrate improved performance using our
method for estimating the variance of model parameters and the enhanced ability
to learn about the complex correlation structure among participants in rolling
therapy groups. Our approach broadly applies to any group therapy setting where
groups have changing client composition. It will lead to more efficient
analyses of client-level data and improve the group therapy research
community's ability to understand how the dynamics of rolling groups lead to
client outcomes.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS434 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Expert Elicitation for Reliable System Design
This paper reviews the role of expert judgement to support reliability
assessments within the systems engineering design process. Generic design
processes are described to give the context and a discussion is given about the
nature of the reliability assessments required in the different systems
engineering phases. It is argued that, as far as meeting reliability
requirements is concerned, the whole design process is more akin to a
statistical control process than to a straightforward statistical problem of
assessing an unknown distribution. This leads to features of the expert
judgement problem in the design context which are substantially different from
those seen, for example, in risk assessment. In particular, the role of experts
in problem structuring and in developing failure mitigation options is much
more prominent, and there is a need to take into account the reliability
potential for future mitigation measures downstream in the system life cycle.
An overview is given of the stakeholders typically involved in large scale
systems engineering design projects, and this is used to argue the need for
methods that expose potential judgemental biases in order to generate analyses
that can be said to provide rational consensus about uncertainties. Finally, a
number of key points are developed with the aim of moving toward a framework
that provides a holistic method for tracking reliability assessment through the
design process.Comment: This paper commented in: [arXiv:0708.0285], [arXiv:0708.0287],
[arXiv:0708.0288]. Rejoinder in [arXiv:0708.0293]. Published at
http://dx.doi.org/10.1214/088342306000000510 in the Statistical Science
(http://www.imstat.org/sts/) by the Institute of Mathematical Statistics
(http://www.imstat.org
Applied statistics: A review
The main phases of applied statistical work are discussed in general terms.
The account starts with the clarification of objectives and proceeds through
study design, measurement and analysis to interpretation. An attempt is made to
extract some general notions.Comment: Published at http://dx.doi.org/10.1214/07-AOAS113 in the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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