71,895 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Open enough? Eight factors to consider when transitioning from closed to open resources and courses: A conceptual framework
No full textTransitioning from closed courses and educational resources to open educational resources (OER) and open courseware (OCW) requires considerations of many factors beyond simply the use of an open licence. This paper examines the pedagogical choices and trade-offs involved in creating OER and OCW. Eight factors are identified that influence openness (open licensing, accessibility and usability standards, language, cultural considerations, support costs, digital distribution, and file formats). These factors are examined under closed, mixed and most open scenarios to relatively compare the amount of effort, willingness, skill and knowledge required. The paper concludes by suggesting that maximizing openness is not practical and argues that open educators should strive for ‘open enough’ rather than maximal openness
Composing Event-B Specifications - Case-Study Experience
No full textEvent-B is a formal method, based on set theory and first-order logic, for specification and verification of reactive systems supported by the Rodin tool kit. Feature modelling is a well-known technique for managing variability and configuring products within software product lines (SPLs). Our objective is to explore whether we can use existing Event-B composition techniques and tooling for feature-based product line development. If case-study experiments reveal these mechanisms to be inadequate, then they also should suggest further research directions. The main objective is to maximise the amount of reuse. This includes avoiding as far as possible having to reprove a composed specification when the models being composed have already been proven. We have modelled two case-studies in Event-B using both horizontal and vertical refinements. This work contributes by analysing existing tools and techniques in Event-B for feature-based development, exploring composition related issues by modelling example case-studies and suggesting further tooling requirements
Diagnostic and statistical manual of mental disorders : DSM-IV, 4th Ed/ Edit. : Michael B. First
No full textxxbii, 886 hal.; 27 cm
Diagnostic and statistical manual of mental disorders : DSM-IV, 4th Ed/ Edit. : Michael B. First
No full textxxbii, 886 hal.; 27 cm
Formal Specifications and Verification of Message Ordering Properties in a Broadcasting System using Event B
No full textCausal and total order broadcast has been proposed as a mechanism to provide fault tolerance for constructing reliable distributed systems. The use of formal methods to develop a model of a system, specifying critical properties and the verification of them is a way of obtaining better design of dependable services. Event B is a formal technique which provides a framework for developing mathematical models of distributed systems by rigorous description of the problem, gradually introducing solutions in the refinement steps, and verification of solutions by discharge of proof obligations. In this paper, we present a formal development of a system in Event B where processes communicate by broadcast and the messages are delivered following a causal and a total order. We first present separate models of a broadcast system each for a causal order and a total order. Subsequently, we verify that the models of the system preserves the required ordering properties. Further, we develop a model of a system satisfying both causal and a total order on the messages. Later in the refinement, we outline how these ordering properties can correctly be implemented by the vector clocks. In this approach we discover some interesting invariant properties which describes the relationship of abstract causal and total order with the vector clocks and the sequence numbers
ProB: A Model Checker for B
No full textWe present ProB, an animation and model checking tool for the B method. ProB's animation facilities allow users to gain confidence in their specifications, and unlike the animator provided by the B-Toolkit, the user does not have to guess the right values for the operation arguments or choice variables. ProB contains a model checker and a constraint-based checker, both of which can be used to detect various errors in B specifications. We present our first experiences in using ProB on several case studies, highlighting that ProB enables users to uncover errors that are not easily discovered by existing tools
Tasking Event-B: An Extension to Event-B for Generating Concurrent Code
No full textThe Event-B method is a formal approach for modelling systems in safety-, and business-critical, domains. Initially, system specification takes place at a high level of abstraction; detail is added in refinement steps as the development proceeds toward implementation. Our aim has been to develop a novel approach for generating code, for concurrent programs, from Event-B. We formulated the approach so that it integrates well with the existing Event-B methodology and tools. In this paper we introduce a tasking extension for Event-B, with Tasking and Shared Machines. We make use of refinement, decomposition, and the extension, to structure projects for code generation for multitasking implementations. During the modelling phase decomposition is performed; decomposition reduces modelling complexity and makes proof more tractable. The decomposed models are then extended with sufficient information to enable generation of code. A task body describes a task’s behaviour, mainly using imperative, programming-like constructs. Task priority and life-cycle (periodic, triggered, etc.) are also specified, but timing aspects are not modelled formally. We provide tool support in order to validate the practical aspects of the approach
Diagnostic and statistical manual of mental disorders : text revision DSM-IV-TR, 4th Ed./ Edit.: Michael B. First
No full textxxxvii, p. 943; 27 c
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