bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hollow Thermoresponsive Microgels
Authors: Nayak Satish , Gan Daoji , Serpe Michael J. , Lyon L. Andrew 
Published: February 2005

AbstractThermoresponsive poly(N‐isopropyl acrylamide) (pNIPAm) microgels possessing a hollow structure have been synthesized from core–shell nanoparticles upon oxidation of the particle core, followed by removal of the produced polymer segments by centrifugation. N,N′‐(1,2‐dihydroxyethylene)bisacrylamide (DHEA) is used as a cross‐linker for preparing the degradable core, whereas N,N′‐methylenebis(acrylamide) (BIS) is used as a cross‐linker to add a nondegradable pNIPAm shell. Addition of NaIO4 to a suspension of these particles in water leads to controlled degradation of the particle core by cleavage of the 1,2‐glycol bond in DHEA. Fluorescence spectroscopy, UV/Vis spectroscopy, and photon correlation spectroscopy are used to characterize the hollow particles produced.
Sonographic measurement of cervical length in threatened preterm labor in singleton pregnancies with intact membranes
Authors: Tsoi E. , Fuchs I. B. , Rane S. , Geerts L. , Nicolaides K. H. 
Published: February 2005

AbstractObjectivesTo predict when delivery will occur, within 48 h and 7 days of presentation and before 35 weeks' gestation in women presenting with threatened preterm labor.MethodsSonographic measurement of cervical length was carried out in 510 women with singleton pregnancies presenting with threatened preterm labor and intact membranes at 24 to 33 + 6 weeks of gestation. The measurement was not taken into account in the subsequent management of the pregnancies. The outcome measures were delivery within 48 h and 7 days of presentation and delivery before 35 weeks.ResultsThe median gestation at presentation was 30 + 1 (range, 24 to 33 + 6) weeks and the median cervical length was 25 (range, 1–51) mm. Delivery within 48 h of presentation occurred in 21 (4.1%) cases, delivery within 7 days occurred in 43 (8.4%) and delivery before 35 weeks occurred in 76 (14.9%). Logistic regression analysis demonstrated that the only significant independent predictor of delivery within 48 h was cervical length (odds ratio (OR), 0.73; 95% CI, 0.65–0.81) and for delivery within 7 days the independent predictors were cervical length (OR, 0.69; 95% CI, 0.63–0.76) and vaginal bleeding (OR, 19.42; 95% CI, 3.87–97.4). In the subgroup of women who did not deliver within 7 days of presentation, the incidence of delivery before 35 weeks was 7.1% (33 of 467) and the only significant independent predictor of such delivery was cervical length (OR, 0.92; 95% CI, 0.88–0.96, P < 0.0001). There was no significant independent contribution to any of the outcome measures from ethnic group, maternal age, gestational age, body mass index, parity, cigarette smoking or use of tocolytics.ConclusionsIn women with threatened preterm labor sonographic measurement of cervical length helps to distinguish between true and false labor and to predict early preterm delivery. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
A theory of Orwellian specifications with NewThink
Authors: Mukherjee Paul , Stavridou Victoria 
Published: February 2005

Abstract
We introduce NewThink, a specification language designed specifically for real-time safety-critical systems. NewThink is a component of an overall Orwellian development method for safety-critical systems which consists of a specification language, a programming language and a set of sound decomposition rules. In this paper, we present the syntax and semantics of NewThink. We demonstrate a relationship between timed and static specifications, which potentially allows us to continue using techniques from the static case in the timed case. We also prove that our extension for real-time is conservative, which is very much in keeping with our Orwellian philosophy.
Real space process algebra
Authors: Baeten J. C. M. , Bergstra J. A. 
Published: February 2005

Abstract

The real time process algebra of Baeten and Bergstra [
Formal Aspects of Computing
,
3
, 142–188 (1991)] is extended to real space by requiring the presence of spatial coordinates for each atomic action, in addition to the required temporal attribute. It is found that asynchronous communication cannot easily be avoided. Based on the state operators of Baeten and Bergstra [
Information and Computation
,
78
, 205–245 (1988)] and following Bergstra et al. [
Proc. Seminar on Concurrency
, LNCS 197, Springer, 1985, pp. 76–95], asychronous communication mechanisms are introduced as an additional feature of real space process algebra. The overall emphasis is on the introductory explanation of the features of real space process algebra, and characteristic examples are given for each of these.
An “executable” impredicative semantics for the Ada configuration
Authors: Bucci A. , Inverardi P. , Martini S. 
Published: February 2005

Abstract
We present a translation of Ada configuration constructs, in a higher order, impredicatively typed, functional language (HOTFUL) with subtypes. The aim of this work is to provide an expressive executable semantics for Ada configuration constructs, and to verify the suitability of the chosen HOTFUL for such a task. In particular, we address the practicability of the approach when dealing with the development of a whole complex system, as well as the description of single modular units. After giving the detailed rules for the translation, we compare our approach with what could be obtained selecting a different typed language as “target”, namely the predicative type system of Standard ML.
Testing equivalence as a bisimulation equivalence
Authors: Cleaveland Rance , Hennessy Matthew 
Published: February 2005

Abstract
In this paper we show how the testing equivalences and preorders on transition systems may be interpreted as instances of generalized bisimulation equivalences and prebisimulation preorders. The characterization relies on defining transformations on the transition systems in such a way that the testing relations on the original systems correspond to (pre)bisimulation relations on the altered systems. On the basis of these results, it is possible to use algorithms for determining the (pre)bisimulation relations in the case of finite-state transition systems to compute the testing relations.
Paramorphisms
Authors: Meertens Lambert 
Published: February 2005

Abstract
“Catamorphisms” are functions on an initial data type (an inductively defined domain) whose inductive definitional pattern mimics that of the type. These functions have powerful calculation properties by which inductive reasoning can be replaced by equational reasoning. This paper introduces a generalisation of catamorphisms, dubbed “paramorphisms”. Paramorphisms correspond to a larger class of inductive definition patterns; in fact, we show that any function defined on an initial type can be expressed as a paramorphism. In spite of this generality, it turns out that paramorphisms have calculation properties very similar to those of catamorphisms. In particular, we prove a Unique Extension Property and a Promotion Theorem for paramorphisms.
Sequential to parallel buffer refinement
Authors: Kay Andrew , Lupton Peter 
Published: February 2005

Abstract
This paper is intended to solve a particular problem related to the refinement of a shared sequential buffer into a parallel collection of buffers arising from a study on the IBM CICS project. Using the notion of cooperating refinement we show that the two systems are equivalent from the users' points of view (except with respect to efficiency). This is achieved by constructing an interleaving for each possible sequence of commands which access the buffer. The induction used in the proof is non-standard, and makes the problem harder than it would at first seem. Further we show that the interleaving cannot be done ‘on the fly’, showing that in some other sense, the parallel collection is indeed superior, as intuition suggests.
Generator induction in order sorted algebras
Authors: Owe Olaf , Dahl Ole-Johan 
Published: February 2005

Abstract
Linguistic and semantic consequences of combining the ideas of order sorted algebras (as in OBJ) and generator induction (as in Larch) are investigated. It is found that one can gain the advantages of both, in addition to increased flexibility in defining signatures and generator bases. Our treatment also gives rise to typing control stronger in a certain sense than that of OBJ, as well as the detection of inherently inconsistent signatures.
Compositional generation of home states in free choice nets
Authors: Best Eike , Cherkasova Ludmila , Desel Jörg 
Published: February 2005

Abstract
Free choice nets are a class of Petri nets which allow the modelling of concurrency and nondeterministic choice, but with the restriction that choices cannot be influenced externally. Home states are initial states which lead to a strongly connected state graph, that is, a home state can be reached from any of its successor states. The main result of this paper characterises the home states of a well-formed free choice net compositionally by recourse to its decomposition into T-components.
LOTOS extended with probabilistic behaviours
Authors: Miguel Carlos , Fernández Angel , Vidaller Leon 
Published: February 2005

Abstract
A common characteristic of process algebras is that they permit us the partial description of concurrent systems by including non-deterministic behaviours. These non-deterministic components are abstractions of the actual ones, and they can be detailed in successive refinements. This paper proposes an enrichment of the above abstraction. It defines a formal description technique which is able to characterize the non-determinism in a probabilistic way. The proposed technique, called LOTOS-P is an upward compatible extension of LOTOS. The compatibility includes also the possibility of specifying non-deterministic behaviours; that is, without probabilistic characterization.
The contents of the paper are mainly related to the definition of probabilistic models based on process algebras, and the study of the observable behaviour of systems by using testing relations. The advantage of the proposed model with respect to previous works is twofold. First, the model is simpler, and second, the compatibility with LOTOS is achieved. The simplicity does not make the model useless because its expressive power permits us to express random behaviours in the same way they are being expressed with classical techniques of discrete systems modeling.

The probabilistic evaluation of the properties of the system can be done by applying the defined calculus, but also by
simulation
. Simulation means that we are able to obtain the desired results with a given confidence level.
Two implementation relations and the correctness of communicating replicated processes
Authors: Koutny Maciej , Mancini Luigi V. , Pappalardo Giuseppe 
Published: February 2005

Abstract
This paper studies the correctness of distributed systems made up of replicated processes that communicate by message passing. Processes are described within the divergence model of CSP. The notion of correctness introduced is based on a relation that formally expresses the conformance of an implementation process with the target process it is intended to implement. A weak and a strong version of the relation are introduced, aimed at treating acyclic and cyclic process networks respectively. Both allow the study of (total) correctness and may cope with non-deterministic targets and implementations.
We then show how a target process may be implemented (in the formal sense introduced) by replicating it in a set of copies, a majority of which is non-faulty.
The rely-guarantee method for verifying shared variable concurrent programs
Authors: Xu Qiwen , de Roever Willem -Paul , He Jifeng 
Published: February 2005

Abstract

Compositional proof systems for shared variable concurrent programs can be devised by including the interference information in the specifications. The formalism falls into a category called
rely-guarantee
(or
assumption-commitment)
, in which a specification is explicitly (syntactically) split into two corresponding parts. This paper summarises existing work on the rely-guarantee method and gives a systematic presentation. A proof system for partial correctness is given first, thereafter it is demonstrated how the relevant rules can be adapted to verify deadlock freedom and convergence. Soundness and completeness, of which the completeness proof is new, are studied with respect to an operational model. We observe that the rely-guarantee method is in a sense a reformulation of the classical non-compositional Owicki & Gries method, and we discuss throughout the paper the connection between these two methods.
The rest stays unchanged (concurrency and state-based specification)
Authors: Pitt David , Byers Paddy 
Published: February 2005

Abstract
Pre-/postconditions have been extensively used in program specification, e.g. Z [Spi89], VDM [Jon86], and proof, e.g. Hoare logic, Dijkstra's guarded commands [DiF88]. In [ScP86, SPB90] the authors introduced neutral and central relations to formalise the concept of “the rest stays the same”. In this paper we abstract away from the specific definition of neutral relation given in [SPB90], through the mechanism of relational boolean algebras. This leads to the definition of implicitly central relations which are easier for the user in practical examples and facilitate the use of pre-/postcondition reasoning about truly concurrent behaviour.
Richer types for Z
Authors: Spivey Michael 
Published: February 2005

Abstract
The formal specification language Z is strongly typed, but has a rather inexpressive type system in which essentially the only type constructors are power set and Cartesian product. This paper explores the possibility of using a richer type system for extracting information about a Z specification, so that properties like being a function or a sequence become part of the type of an expression. This richer type system adds further type constructors to the sparse set contained in the language definition, and uses properties of Z's library functions to infer information about complex expressions from information about their simpler parts.
Definition and basic properties of the deva meta-calculus
Authors: Weber Matthias 
Published: February 2005

AbstractThis article presents the definition and some basic properties of the Deva meta-calculus, a generic logical framework whose design was driven by the needs arising from the instantiation to software development methods. As a result, Deva contains structures that do not occur in comparable logical frameworks. There now exist a number of case studies about the formalization of software development methods in Deva. In this article, a structured definition of Deva is presented and basic parts of its language theory, viz Church-Rosser, closure, and strong normalization, are summarized.
Formalizing process algebraic verifications in the calculus of constructions
Authors: Bezem Marc , Bol Roland , Groote Jan Friso 
Published: February 2005

AbstractThis paper reports on the first steps towards the formal verification of correctness proofs of real-life protocols in process algebra. We show that such proofs can be verified, and partly constructed, by a general purpose proof checker. The process algebra we use isμCRL, ACPτaugmented with data, which is expressive enough for the specification of real-life protocols. The proof checker we use is Coq, which is based on the Calculus of Constructions, an extension of simply typed lambda calculus. The focus is on the translation of the proof theory ofμCRL andμCRL-specifications to Coq. As a case study, we verified the Alternating Bit Protocol.
Action systems, unbounded nondeterminism, and infinite traces
Authors: Butler Michael , Morgan Carroll 
Published: February 2005

Abstract

Morgan [Mor90a] has described a correspondence between Back's action systems [BKS83] and the conventional
failures-divergences
model of Hoare's
communicating sequential processes
(CSP) formalism [Hoa85]. However, the CSP failures-divergences model does not treat unbounded nondeterminism, although unbounded nondeterminism arises quite naturally in action systems; to that extent, the correspondence between the two approaches is inadequate.

Fortunately there is an extended
infinite traces
model of CSP [RoB89] which treats unbounded nondeterminism. We extend the CSP-action system correspondence, using that model instead, to take the unbounded nondeterminism of action systems properly into account.

In passing, we develop a definition of the weakest precondition under which an infinite heterogeneous trace of actions is enabled.
Exits in the refinement calculus
Authors: King Steve , Morgan Carroll 
Published: February 2005

Abstract

Although many programming languages contain exception handling mechanisms, their formal treatment — necessary for rigorous development — can be complex. Nevertheless, this paper presents a simple incorporation of
exit
commands and exception blocks into a rigorous program development method. The refinement calculus, chosen for the exercise, is a method of developing imperative programs. It is based on weakest preconditions, although they are not used explicitly during program construction; they merely justify the general method. In the style of the refinement calculus, program development laws are given that introduce and allow the manipulation of
exit
s. The soundness of the new laws is shown using weakest preconditions (as for the existing refinement calculus laws). The extension of weakest preconditions needed to handle
exit
s is a variation on earlier work of Cristian; the variation is necessary to handle nondeterminism.
Peirce algebras
Authors: Brink Chris , Britz Katarina , Schmidt Renate A. 
Published: February 2005

Abstract

We present a two-sorted algebra, called a
Peirce algebra
, of relations and sets interacting with each other. In a Peirce algebra, sets can combine with each other as in a Boolean algebra, relations can combine with each other as in a relation algebra, and in addition we have both a set-forming operator on relations (the Peirce product of Boolean modules) and a relation-forming operator on sets (a cylindrification operation). Two applications of Peirce algebras are given. The first points out that Peirce algebras provide a natural algebraic framework for modelling certain programming constructs. The second shows that the so-called
terminological logics
arising in knowledge representation have evolved a semantics best described as a calculus of relations interacting with sets.
Process algebra with guards: Combining Hoare logic with process algebra
Authors: Groote Jan Friso , Ponse Alban 
Published: February 2005

Abstract
We extend process algebra with guards, comparable to the guards in guarded commands or conditions in common programming constructs such as ‘if — then — else — fi’ and ‘while — do — od’.
The extended language is provided with an operational semantics based on transitions between pairs of a process and a (data-)state. The data-states are given by a data environment that also defines in which data-states guards hold and how atomic actions (non-deterministically) transform these states. The operational semantics is studied modulo strong bisimulation equivalence. For basic process algebra (without operators for parallelism) we present a small axiom system that is complete with respect to a general class of data environments. Given a particular data environmentL we add three axioms to this system, which is then again complete, provided weakest preconditions are expressible andL is sufficiently deterministic.
Then we study process algebra with parallelism and guards. A two phase-calculus is provided that makes it possible to prove identities between parallel processes. Also this calculus is complete. In the last section we show that partial correctness formulas can easily be expressed in this setting. We use process algebra with guards to prove the soundness of a Hoare logic for linear processes by translating proofs in Hoare logic into proofs in process algebra.
Brief cognitive behavioural interventions for regular amphetamine users: a step in the right direction
Authors: Baker Amanda , Lee Nicole K. , Claire Melissa , Lewin Terry J. , Grant Tanya , Pohlman Sonja , Saunders John B. , Kay‐Lambkin Frances , Constable Paul , Jenner Linda , Carr Vaughan J. 
Published: February 2005

ABSTRACTAims  The present study sought to replicate and extend a small pilot study conducted by Baker, Boggs & Lewin (2001) which demonstrated that brief interventions consisting of motivational interviewing and cognitive‐behaviour therapy (CBT) were feasible and associated with better outcomes compared with a control condition.Design  Randomized controlled trial (RCT).Setting  Greater Brisbane Region of Queensland and Newcastle, NSW, Australia.Participants  The study was conducted among 214 regular amphetamine users.Measurements  Demographic characteristics, past and present alcohol and other drug use and mental health, treatment, amphetamine‐related harms and severity of dependence.Findings  The main finding of this study was that there was a significant increase in the likelihood of abstinence from amphetamines among those receiving two or more treatment sessions. In addition, the number of treatment sessions attended had a significant short‐term beneficial effect on level of depression. There were no intervention effects on any other variables (HIV risk‐taking, crime, social functioning and health). Overall, there was a marked reduction in amphetamine use among this sample over time and, apart from abstinence rates and short‐term effects on depression level, this was not differential by treatment group. Reduction in amphetamine use was accompanied by significant improvements in stage of change, benzodiazepine use, tobacco smoking, polydrug use, injecting risk‐taking behaviour, criminal activity level, and psychiatric distress and depression level.Conclusions  A stepped‐care approach is recommended. The first step in providing an effective intervention among many regular amphetamine users, particularly those attending non‐treatment settings, may include provision of: a structured assessment of amphetamine use and related problems; self‐help material; and regular monitoring of amphetamine use and related harms. Regular amphetamine users who present to treatment settings could be offered two sessions of CBT, while people with moderate to severe levels of depression may best be offered four sessions of CBT for amphetamine use from the outset, with further treatment for amphetamine use and/or depression depending on response. Pharmacotherapy and/or longer‐term psychotherapy may be suitable for non‐responders. An RCT of a stepped‐care approach among regular amphetamine users is suggested.