bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effectiveness of Lifestyle Educational Program in Health Promoting Behaviors and Menopausal Symptoms in 45-60-Year-Old Women in Marvdasht, Iran
Authors: Nazari Mahin , Farmani Samaneh , Kaveh Mohammad Hosein , Ghaem Haleh
Published: February 2016

Introduction: Health and lifestyle of women are of great importance in some periods of life, such as menopause. Since postmenopausal women are considered as a vulnerable group of the society, finding a strategy to improve their health seems necessary.

Methods: This experimental study with pretest-posttest design was carried out on 200 postmenopausal women between 45 and 60 years old in Ramjerd, Marvdasht, Iran, in 2014. The women who met the inclusion criteria of the study were selected by simple random sampling. The data were collected using demographic information questionnaire, Menopause Rating Scale (MRS), and Walker’s Health Promoting Lifestyle Profile (HPLPII). The data were entered into the SPSS statistical software (version 19) and were analyzed using descriptive statistics, paired t-test, independent t-test, and chi-square test. P-values less than 0.05 were considered as statistically significant.

Results: The results of paired t-test showed a significant difference in the mean scores of health promoting lifestyle and MRS in the experimental group (P<.05), but not in the control group (P>.05).

Conclusion: Lifestyle education was effective in health promoting behaviors and menopausal symptoms. After the educational intervention, health promoting behaviors increased and menopausal symptoms decreased in the postmenopausal women. Therefore, educational interventions based on health promoting lifestyles can be used as an appropriate strategy to reduce postmenopausal women’s menopausal symptoms and improve their health.
EFL Students’ and Teachers’ Attitudes toward Foreign Language Speaking Anxiety: A Look at NESTs and Non-NESTs
Authors: HAN Turgay , Tanriöver Ahmet Serkan , Sahan Özgür
Published: February 2016

Native English Speaking Teachers (NESTs) have been employed in various English language teaching (ELT) positions and departments at private and state universities in Turkey, particularly over the last three decades. However, undergraduate EFL students’ attitudes toward NESTs and Non-Native English Speaking Teachers (Non-NESTs) remain seriously under-investigated. The purpose of this study is to examine the impact of communication classes given by NESTs and Non-NESTs on students’ foreign language speaking anxiety (FLSA). Forty-eight undergraduate EFL students attending communication classes taught by (American) NESTs and (Turkish) Non-NESTs were given a questionnaire to examine their attitudes toward foreign language speaking anxiety (FLSA). Further, a sub-sample of students was interviewed to investigate their feelings, beliefs and opinions about the relationship between the FLSA they experienced and their communication classes given by NESTs and Non-NESTs. Similarly, the teachers were interviewed to examine their feelings about the FLSA their students experience in their communication classes. Quantitatively, the results showed no significant difference in attitude toward FLSA between the students who attended classes taught by NESTs and Non-NESTs, although a significant difference was observed between the two classes taught by Non-NESTs. Further, female and male students did not differ significantly in terms of attitudes toward FLSA in NESTs’ and Non-NESTs’ classes. The qualitative findings revealed that both teachers and students had positive attitudes toward mistakes made during the oral production of the foreign language (FL). Finally, the correction strategies employed by the teachers in the classroom are believed to have an impact on student attitudes toward FLSA.
Internally Generated Revenue (IGR) and Effectiveness of University Administration in Nigeria
Authors: Ofoegbu Felicia I. , Alonge Hezekiah O.
Published: February 2016

The purpose of the study was mainly to identify the major sources and utilization of internally generated financial revenue by Nigerian University administrators. The population of the study consisted of all the 102 university administrators from the seventeen Federal Universities in Southern Nigeria. Descriptive statistics and Pearson Product Moment Correlation were used to analyze the research questions and hypotheses formulated for the study. The analysis revealed that commercial ventures were among the main sources of IGR while the proceeds were used for services including staff welfare, maintenance of facilities and beautification of the university premises. A further analysis of data showed that there was a significant relationship between internally generated resources and the management and development of universities in Southern Nigeria. It is recommended that university administrators should be more transformative in their leadership style in order to strengthen their revenue base for effectiveness in University management.
Proposing Favorite Strategies to Produce Social and Political Documentaries for IRIB (Islamic Republic of Iran Broadcasting)—By Purpose of Promoting State Social Capital for Adult and University Students
Authors: Sarabi Said
Published: February 2016

Informing and providing awareness is a part of mass media’s significant responsibilities and social and political documentaries is one of the effective frames in performing this significant duty on adults and university students. Therefore, the main purpose of this study is proposing favorite strategies for IRIB in making social and political TV documentaries with the aim of promoting state social capital for university students and adults. The method is in-depth interview with experts and utilizing the findings of another research titled “an analysis of the views of Communication Sciences students regarding the IRIB’s political and documentaries with an emphasis on the utilitarian approach and gratification level” adopting the Rosengren approach. Results showed that aggressive strategies are the most proper policies for the IRIB. Finally, the formulated aggressive strategies were prioritized and the most important strategy for this research is “producing social and political documentaries with informational approach in an accurate, precise, and comprehensive manner and considering other needs of audiences such as amusement, personal identity, and personal relationships”.
Reindeer herding and environmental change in the Oymyakon District, Sakha Republic
Authors: Nakada Atsushi
Published: February 2016

The aim of this study is to assess the influence of environmental change on reindeer herding in the Oymyakon District in the eastern part of the Sakha Republic. To investigate environmental change and its influence on reindeer herding, semi-structured interviews were conducted at two villages in the Oymyakon District, from February 24th to March 8th, 2013. As a result of the interview, meteorological, topographical, and ecological changes and their influence on general livelihood were evaluated by local residents to a greater or lesser degree. Part of the climatic changes felt by local residents was supported meteorological data set. Generally speaking, local reindeer herders and a manager of reindeer herding enterprise did not think these climatic, topographical and biological impacts were serious problems for reindeer herding. More serious problems, in their consideration, were social and economic difficulties. Judging from these results and the fluctuation of the number of domestic reindeer, even though meteorological variables are gradually changing, serious environmental changes have not generally been noted by local residents as yet. It can be concluded that the environmental changes do not appear to have exerted intense harmful influences on reindeer herding in Oymyakon District so far.
Non-structural carbohydrate content in cryptogamic Antarctic species after two years of passive warming on the Fildes Peninsula
Authors: Casanova-Katny Angélica , Pizarro Marisol , Caballero Marta María , Cordero Raúl , Zúiga Gustavo E.
Published: February 2016

Cryptogamic vegetation dominates the ice-free areas of the maritime Antarctic. This particular flora grows slowly due to extreme environmental conditions, typically low temperature that may limit growth during a short summer. Over the last 50 years, the Antarctic Peninsula has undergone the highest registered temperature increases in Antarctica. As a consequence of higher temperatures, we hypothesized that lichens and mosses would produce more carbohydrates. To test this, open top chambers (OTCs) were installed in an Usnea-Himantormia community on Fildes Peninsula of King George Island. After two years, lichen thalli and plant tissues were collected to quantify non-structural carbohydrates in three lichens and two mosses. Responses contrasted between species. While non-structural carbohydrates were higher in the OTC for the lichen Himantormia lugubris, the values decreased in the moss Polytrichastrum alpinum. No marked responses to experimental warming were observed in the other three species. A significant species-specific increase in soluble sugar was observed inside the OTCs, while polyols content were not markedly different due to OTC treatment. In general, the obtained results indicate that warming does not increase carbohydrate content in all cryptogams, instead suggesting a strong species-specific response to a scenario of global warming. Further long-term warming experiments are needed to assess the responses of target species in the terrestrial Antarctic ecosystem.
A Semantic Algebra for Binding Constructs
Authors: Mosses Peter D.
Published: February 2016

This paper presents a semantic algebra, suitable for use in giving the denotational semantics of various forms of declarations and binding constructs in programming languages. The emphasis of the paper is on the development of semantic descriptions which are easy to understand at an intuitive level, being based on algebraic operators corresponding to fundamental concepts of programming languages. Some familiarity with denotational semantics and abstract data types is assumed.
A Cook's Tour of Countable Nondeterminism
Authors: Apt K. R. , Plotkin Gordon D.
Published: February 2016

We provide four semantics for a small programming language involving unbounded (but countable) nondeterminism. These comprise an operational one, two denotational ones based on the Egli-Milner and Smyth orders, respectively, and a weakest precondition semantics. Their equivalence is proved. We also introduce a Hoare-like proof system for total correctness and show its soundness and completeness in an appropriate sense. Admission of countable nondeterminism results in a lack of continuity of various semantic functions; moreover some of the partial orders considered are in general not cpo's and in proofs of total correctness one has to resort to the use of (countable) ordinals. Proofs will appear in the full version of the paper.
Specification and Design of Distributed Systems
Authors: Sørensen Ib Holm
Published: February 2016

This thesis presents a method for specifying, analysing and refining the designs of distributed systems in terms of the permissible activity across the interfaces between process components. Such a specification gives the rules for the behaviour of each process component and postpones decisions about its internal structure.

This specification method will be shown to allow important questions about the behaviour of a distributed system to be posed early in the design process: in particular, designs will be analysed with respect to termination and absence of deadlocks. The specification method can be employed to describe systems in different degrees of detail, and it is demonstrated that a specification can evolve to a stage close to realisation using a stepwise refinement method which ensures that the important properties are maintained.
Results on the Propositional µ-Calculus
Authors: Kozen Dexter
Published: February 2016

We define a propositional version of the µ-calculus, and give an exponential-time decision procedure, small model property, and complete deductive system. We also show that it is strictly more expressive than PDL. Finally we give an algebraic semantics and prove a representation theorem.
Mathematical Foundation of A Semantic Directed Compiler Generator
Authors: Christiansen Henning , Jones Neil D.
Published: February 2016

This paper describes technical details which were not included in the paper ''Control Flow Treatment in a Simple Semantics-Directed Compiler Generator'', presented at the IFIP working conference on Formal Description of Programming Concepts, Germany, 1982, due to lack of space. The present paper cannot be read separately.

We describe our method in full detail, including the iterate-operator in the S-algebra. Furthermore we give complete formal descriptions of the semantic algebra S and its models (Section 1), the compiler generation function d^c and the compile time interpretation J (Section 2), the target language semantics (Section 3), and in Section 4 the correctness proof.
EPSILON: A System Description Language
Authors: Jensen Kurt , Kyng Morten
Published: February 2016

This paper presents the Epsilon language and defines its formal syntax and semantics. Epsilon is a language for the description of systems, which contain concurrent components, some of these being edp-equipment or by other means representing highly structured information handling. The actions consist of continuous changes described by equations, of communication between the components and of normal algorithmic actions.

Epsilon may be used for the description of computer systems together with their environments, e.g. production equipment and human operators. Parts of such a description may serve as the system specification from which computer programs are developed. Epsilon is not itself an implementable language.

This paper defines the semantics of Epsilon by means of a model based on high-level Petri nets, i.e. a model founded on the notion of concurrency. The model also uses denotational semantics and equation systems.
High-Level Petri Nets
Authors: Jensen Kurt
Published: February 2016

This paper combines two closely related net models, predicate/transition nets and coloured Petri nets, into a new net model called high-level Petri nets. The new model is intended to combine the qualities of the two old models into a single formalism, and we propose in the future to use high-level Petri nets instead of both predicate/transition nets and coloured Petri nets.
Specification and Verification of Networks in a Petri Net based Language
Authors: Kyng Morten
Published: February 2016

In this paper we present a system description language and a technique of top-down specification and verification of distributed systems. Our language is called Epsilon, and it has been developed for the description and analysis of systems containing concurrent components.

We have used and developed concepts from the Simula and Delta languages and from Petri net theory. A system described in Epsilon consists of a number of concurrent objects. Each object has a set of attributes, e.g. variables and procedures, and executes a sequence of actions. Epsilon includes both normal algorithmic statements and first order predicate logic as description elements.

An abbreviated version of this paper has been presented at the third European Workshop on Applications and Theory of Petri Nets, Springer Informatik Fachberichte 66.
A Measure in Which Boolean Negation is Exponentially Powerful
Authors: Skyum Sven
Published: February 2016

The power of negation in combinatorial complexity theory has for a long time been an intriguing question. In this paper we demonstrate that in the more restricted setting of projections among families of Boolean functions, negation can be exponentially powerful.
Program Models: Meaning and Proof
Authors: Mayoh Brian H.
Published: February 2016

When does one understand a program P? One reasonable answer is: when one has a conceptually clear model M such that any relevant question about P can be reformulated as a logically equivalent question about M. This paper argues for diagram models of parallel programs as a simple generalization of the familiar flowchart, graph and equation-set models of sequential programs. Diagram models of Petri nets were introduced by Hinderer.
HSIM - a hardware simulator
Authors: Hagerup Torben
Published: February 2016

In this report a system capable of simulating hardware systems is presented. It is described from a user as well as from an implementation point of view. The intended reader has a broad knowledge of computer science and an interest in hardware.
On Contractive Linear Multistep and One-Leg Methods
Authors: Sand Jørgen
Published: February 2016

Contractive variable-formula methods for the integration of y'=lambda(t)y (lambda(t)) restricted to some region of interest) are formed by using polyhedral norms for showing the contractivity of several one-leg or linear multistep formulas. When possible the results are given for variable step-size.
Finite Precision Rational Arithmetic: Slash Number Systems
Authors: Matula David W. , Kornerup Peter
Published: February 2016

Fraction number systems described by fixed-slash and floating slash formats are specified. The structure of arithmetic over such systems is prescribed by the rounding obtained from ''best rational approximation''.

Multi-tiered precision hierarchies of both fixed-slash and floating-slash type are proposed and analyzed with regards to their support of both exact rational and approximative real computation.
Degrees of Non-determinism and Concurrency: A Petri Net View
Authors: Nielsen Mogens , Thiagarajan P. S.
Published: February 2016

The aim of this paper is to present an introduction to the theory of Petri nets. The subject matter of this theory is distributed systems and processes. In our presentation, we shall emphasise concepts at the expense of specific results and techniques. Applications of the theory, though many and varied, will not be dealt with here. Even in dealing with the concepts, we shall focus on those that we believe are relevant to the study of distributed systems in general (independent of the specific framework one might choose). In the concluding part, we will attempt a broader sketch of the scope and contents of net theory.
Learning Difficulties of Programmers: Faced With a New Programming Environment
Authors: Nielsen Jakob
Published: February 2016

When faced with a totally new environment composed of a new interaction paradigm and a new programming tool, programmers exhibited many of the same learning difficulties as novice users learning to use an ordinary word processor.
Experiments with a Multiprocessor
Authors: Møller-Nielsen Peter , Staunstrup Jørgen
Published: February 2016

In this report we summarize four years of experience with the Multi-Maren multiprocessor laboratory.

We have preferred to work with problems concerning software, in particular whether there are algorithms that can utilize the potentially very large processing power of a multiprocessor.

We have found that this is certainly the case and in the report we present a few of these fast multiprocessor algorithms.

On the other hand we have also found a number of examples where the gain in using a multiprocessor is very small. In all these examples the limiting factors are inherent in the algorithm, they are not hardware bottlenecks. We justify this somewhat surprising claim by showing that even in multiprocessors with an order of magnitude more processors than ours it is unlikely that hardware bottlenecks will limit the performance.
Logic Programming, Substitutions and Finite Computability
Authors: Frandsen Gudmund Skovbjerg
Published: February 2016

Apt and van Emden have studied the semantics of logic programming by means of fixed point methods. From a model theoretic point of view, their formalisation is very nice. Least and greatest fixed points correspond to least and greatest Herbrand-models respectively.

Viewed operationally, there is an ugly asymmetry. The least fixed point expresses finite computability, but the greatest fixed point denotes negation by trans-finite failure, i.e. the underlying operator is not omega-continuous for decreasing chains in general.

We use the notion of finite computability inherent in Scott domains to build a domainlike construction (the cd-domain) that offers omega-continuity for increasing and decreasing chains equally. On this basis negation by finite failure is expressed in terms of a fixed point.

The fixed point semantics of Apt and van Emden is very abstract concerning the concept of substitution, although it is fundamental for any implementation. Hence it becomes quite tedious to prove the correctness of a concrete resolution algorithm. The fixed point semantics of this paper offers an intermediate step in this respect. Any commitments to specific resolution strategies are avoided, and the semantics may be the basis of sequential and parallel implementations equally. Simultaneously the set of substitution dataobjects is structured by a Scott information theoretic partial order, namely the cd-domain.
On Proving Limited Completeness
Authors: Mosses Peter D. , Plotkin Gordon D.
Published: February 2016

We give proofs of Wadsworth's classic Approximation Theorem for the pure lambda-calculus. One of these illustrates a new method utilising a certain kind of intermediate semantics for proving correspondences between denotational and operational semantics. The other illustrates a direct technique of Milne, employing recursively-specified inclusive relations.
An Introduction to High-Level Petri Nets
Authors: Jensen Kurt
Published: February 2016

This paper describes a Petri net model, where information is attached to each token and when a transition fires, it can inspect and modify the information. The model is based on predicate/transitions (Genrich and Lautenbach) and on coloured Petri nets (Jensen).

This generalization of ordinary Petri nets allows, for many applications, more manageable descriptions, due to the fact that equal subnets can be folded into each other yielding a much smaller net. The paper investigates how to analyse high-level Petri nets, and it turns out that invariants and reachability trees, two of the most important methods for ordinary Petri nets, can be generalized to apply for high-level Petri Nets.
Four Different Perspectives on Human-Computer Interaction
Authors: Kammersgaard John
Published: February 2016

In this paper the value of a multiperspective view on the use of computers is stressed. It is argued that the ability to apply more than one perspective is valuable both to designers of computer applications, to researchers dealing with human-computer applications, and to users of a particular computer application. As a means for that the systems perspective, the dialogue partner perspective, the tool perspective, and the media perspective are represented. All four perspectives are primarily characterized in relation to human-computer interaction, and the characterizations are based on a common set of concepts presented at the start of the paper. In the final section the value of applying multiple perspectives is illustrated by means of a few examples.
Notions of Realizable Non-Sequential Processes
Authors: Fernandez C. , Nielsen Mogens , Thiagarajan P. S.
Published: February 2016

This paper presents some results on non-sequential processes using the language of net theory. The results are concerned with the relationship between various formalizations of the intuition that the causality relation enforced by a process should be in some sense ''finitely realizable''. The formalizations proposed are of very different flavours, based on notions of observability, approximability, state space covering and discreteness.
Multiple Inheritance, a Structuring Mechanism for Data, Processes and Procedures
Authors: Thomsen Kristine Stougård
Published: February 2016

A motivation is given for the use of multiple inheritance as a general mechanism for data, processes and procedures, and an object oriented programming language that incorporates such an inheritance mechanism is outlined. Objects in this language combine the notions of abstract data structures and processes. Classes and procedures are organized in multiple inheritance hierarchies. The main contribution of this paper is the introduction of a coroutine-like strategy for combining multiple action parts of objects. Coincidence of named properties from different classes are treated by combining all versions of the property. The inheritance mechanism on procedures offers an elegant way of combining a number of inherited operations with the same name.
Programmeringssprog: Begreber og undtagelser: (Resumé)
Authors: Knudsen Jørgen Lindskov
Published: February 2016

Dette notat indeholder en almen beskrivelse af den behandlede problemstilling, samt en motivation for angrebsvinklen på denne problemstilling. Herudover gives en redegørelse for de opnåede resultater, samt for relationerne til den øvrige forskning indenfor området.
Vurdering af systemudviklingsprojekter: - sammenfatning
Authors: Munk-Madsen Andreas
Published: February 2016

This report is a summary (in Danish) of the four reports:

Evaluation of System Development Projects, PB-218

Project Evaluation -- Setting the Problem, PB-216

Viden om systemudvikling, PB-213

Formalizations in Systems Development, PB-193 (also in Behaviour and Information Technology, Vol.5 (1986) pp 145-155

and constitutes together with these the author's Ph.D. dissertation.
Classification of Actions or Inheritance also for Methods
Authors: Kristensen Bent Bruun , Madsen Ole Lehrmann , Møller-Pedersen Birger , Nygaard Kristen
Published: February 2016

The main thing with the sub-class mechanism as found in languages like C++, SIMULA and Smalltalk is its possibility to express specializations. A general class, covering a wide range of objects, may be specialized to cover more specific objects. This is obtained by three properties of sub-classing: An object of a sub-class inherits the attributes of the super-class, virtual procedure/method attributes (of the super-class) may be specialized in the sub-class, and (in SIMULA only) it inherits the actions of the super-class.

In the languages mentioned above, virtual procedures/methods of a super-class are specialized in sub-classes in a very primitive manner: they are simply re-defined and need not bear any resemblance of the virtual in the super-class. In BETA, a new object-oriented language, classes and methods are unified into one concept, and by an extension of the virtual concept, virtual procedures/methods in sub-classes are defined as specializations of the virtuals in the super-class. The virtual procedures/methods of the sub-classes thus inherit the attributes (e.g. parameters) and actions from the ''super-procedure/method''.

In the languages mentioned above only procedures/methods may be virtual. As classes and procedures/methods are unified in BETA this gives also virtual classes. The paper demonstrates, how this may be used to parameterize types and enforce constraints on types.
Prototyping Revisited: - design with users in a cooperative setting
Authors: Bødker Susanne
Published: February 2016

In this paper, prototyping will be discussed from the point-of-view of user/designer cooperation in design. Active user participation in systems design is a way of improving the quality of the design process as well as the product - a computer application in use. To participate actively in design, users must be allowed to experience the future use situation in the design process. Various prototyping methods seem to offer valuable help in this process. Cooperation between users and designers, the mutual learning process, and hands-on experiences to reveal the triggering of proper operations is, however, only one side of the epistemological interests behind prototyping. At the same time, the practical solutions of different approaches are to some extent applicable but it is perhaps a good idea to reconsider the concept from the perspective of cooperation between users and professional designers.
Object Oriented Programming and Computerised Shared Material
Authors: Sørgaard Pål
Published: February 2016

Computer supported cooperative work currently receives much attention. There are many aspects of cooperative work. One of these is the use of shared material. Much cooperation is based on silent coordination mediated by the shared material used in the work process. The properties of the shared material are, however, often ignored when work is computerised. Instead the emphasis has been on automating frequent work procedures. This has resulted in very inflexible systems.

A fundamental idea in object oriented programming is to model the phenomena in the part of reality the system addresses. These modelling techniques can be used to implement shared material on computers. The result is a raw system providing the material and the essential primitive operations on this material. Such a system can be seen as a specialised programming environmeht which can be tailored to the needs of individual users or be modified for future needs.
Transaction Supporting Systems and Organisational Change
Authors: Sørgaard Pål
Published: February 2016

The transaction cost theory distinguishes between three types of organisation: the market,the bureaucracy, and the group. Transaction supporting systems are computer systems which support the constituent transactions of an organisation. There is an ongoing discussion about possible shifts on the scale from market to group induced by transaction supporting systems. Transaction supporting systems supporting market organisation can remove some of the reasons for shifts from market to more complex organisations. The set of transaction supporting systems at the disposal for bureaucracies and groups is, however, much larger than the set available to market organisation. Computer systems supporting cooperative work can only be fully exploited by a group. Therefore any prediction of a shift will depend on the kinds of computer systems taken into consideration. The conclusion is that although the transaction cost theory is useful in characterising the role of computer systems in organisations, we cannot use the theory to make general assertions about the impact of computer systems on the relative benefits of the different types of organisation.
From High-level Descriptions to VLSI Circuits
Authors: Greenstreet Mark R. , Staunstrup Jørgen
Published: February 2016

This paper presents a high-level language for describing VLSI circuits designed as a collection of asynchronous concurrent processes. This language is called ''Synchronized Transitions'' , and it can be used to describe designs from very high levels of abstraction down to the gate level design. Both synchronous and asynchronous/self-timed circuits can be described, and it is not necessary to choose a particular type of circuitry in the early phases of a design. ''Synchronized Transitions'' programs may be used for experimenting with (simulating) a design at several levels, e.g., to explore different high-level decisions or to verify the gate level. By observing certain constraints in a ''Synchronized Transitions'' program, it is possible to systematically transform the program into an efficient layout.
Five Easy Pieces: Reframing the Design of Office Systems
Authors: Greenbaum Joan , Madsen Kim Halskov
Published: February 2016

Problems with the use of computer systems may often be traced back to the designers' narrow view or understanding of office work. Neither office work nor design of office systems should be done strictly according to rules or procedures. Similar cases, examples and previous situations play just as important a role. In the spirit of this, we present, not a set of guidelines for design, but five pieces or exercises that stimulate seeing things in new ways. We use metaphors as a way to interpret computer system use. And by the dichotomous ideas of description versus  interpretation, similarity and differences, planned action versus situated action, group discussion against indiuidual problem-solving, and authoritative knowledge against shared knoweldge, we hope to set in motion a dialectical reframing process.
Some Behavioural Aspects of Net Theory
Authors: Thiagarajan P. S.
Published: February 2016

Net theory was initiated by C.A. Petri in the early 60's. We shall first convey the basic concerns of net theory by presenting a simple system model called elementary net systems. Then we shall give a brief sketch of some of the tools that have been proposed to describe the behaviour of elementary net systems.

Section 2 develops some notation and introduces a purely sequential mode of behavioural description called firing sequences. In the next section the theory of traces which have an independent existence is used to recover information concerning concurrency from the firing sequences. In section 4 the notion of non-sequential processes is introduced.

Both trace theory and the theory of non-sequential processes represent concurrency directly but handle information concerning conflict in an indirect fashion. One must work with the whole set of traces or non-sequential processes in order to talk about conflicts and that too in an indirect fashion. This disadvantage can be overcome with the help of behavioural tools called unfoldings and labelled event structures that are presented in section 5.
User Support: From Surface to Structure
Authors: Hellman Riitta
Published: February 2016

It is not unusual that a user gets lost when using a computer system. Supporting users in difficult situations is therefore very important independently of whether they are working with personal applications or with an integrated information system. User support can be approached in many ways. One possible way is to develop help systems for assisting the users. I claim, however, that most current approaches to help systems tend to focus on plain data and information processing issues leaving the organizational context in which the use takes place without attention. It is asserted in this paper that it is possible to reflect the context in a help system. An approach to representing the context in connection with a help system is made by introducing the idea of a context database. A context database is parallel to the actual database and it contains information about task flows, task-connected information objects, and the like. (The information objects themselves are stored in the actual database). In order to be able to realize a help system which takes the organizational context in account the analysis of work and information system has to focus on information processing tasks, information objects, and other entities which are needed for the context database. A proposal for how to perform such analysis enterprises is presented. The proposal introduces five groups of objects of analysis: tasks, organization of work, job design, computer applications, and information media.
Rapid Prototyping with Fourth Generation Systems: - An Empirical Study
Authors: Grønbæk Kaj
Published: February 2016

The focus of this paper is on design and evaluation techniques supporting active end-user involvement in Information System (IS) development based on rapid prototyping with Fourth Generation Systems. The paper discusses experiences on the development and use of mainly two sorts of prototypes denoted horisontal and vertical prototypes. The experiences result from an interview study, carried out by the author and two colleagues, in nine Danish development projects.

A central result from the study is that users did not give sufficient response on presented horisontal prototypes. Moreover, unexpected iterations became necessary in most of the projects studied although horisontal prototypes had been accepted by the users. In contrast vertical prototypes, which are capable of handling realistic data from the use domain, appeared to stimulate extensive and constructive response from users before the final system tests. These observations lead to the daim that the developers should be aware of the tacit knowledge which plays an important role in users' work practices. To utilise the users' tacit knowledge, the design techniques based on prototyping should involve the end-users more actively, and the evaluation techniques should support testing in a work-like setting early in the development process.

Three proposals on techniques to meet these requirements are given. The first proposal is aimed at having end-user representatives participating in certain design activities where Fourth Generation Systems are being used. The second proposal is aimed at utilising the potential of simulating functionality behind horisontal prototypes. The final proposal is aimed at performing ongoing evaluation activities in conjunction with design activities.
Unified Algebras and Institutions
Authors: Mosses Peter D.
Published: February 2016

A novel framework for algebraic specification of abstract data types is introduced. It involves so-called ''unified algebras'', where sorts are treated as values, so that operations may be applied to sorts as well as to the elements that they classify.

An institution for unified algebras is defined, and shown to be liberal. However, the ordinary ''forgetful'' functor does not forget any values in unified algebras, so the usual data constraints do not have any models. A ''more forgetful'' functor is introduced and used to define so-called ''bounded'' data constraints, which have the expected models.
A Note on the Jacobian Conjecture
Authors: Zhang Zhi-Li
Published: February 2016

We extend a corollary in H. Bass, et al.:  The Jacobian Conjecture: Reduction of Degree and Formal Expansion of the Inverse, yielding a sufficient and necessary condition for a polynomial map to have an inverse of the simplest form, and give a surprisingly simple proof for the Jacobian Conjecture in two variables of the case f_i = x_i-h_i, where h_i is homogeneous of degree >= 2, i = 1,2.
Some new thoughts on Neural Networks with complex connection matrices
Authors: Szilagyi Miklos , Mikkelsen Jens Christian , Mortensen Kjeld Høyer
Published: February 2016

In the literature neural networks are usually understood in the domain of real activation functions and connection weights. The concept of neural networks was generalized by M. Szilagyi to include complex connections between complex units. In the present note this idea is further developed. A mathematical model is presented, an expression for the network's energy as well as a complex learning rule are proposed.
Two analyses of CSCW and groupware
Authors: Grudin Jonathan
Published: February 2016

This report consists of two papers on the topics of computer supported cooperative work and groupware. The first examines the emergence of CSCW in the mid-1980s, finding that its timing and composition reflect changes within one context of systems development, product development. Many of the issues -- and some of the participants -- have a history in internal systems development; some confusion of identity in the field may be traced to the merging of these development paradigms. The second paper examines eight challenges in designing and evaluating groupware or CSCW applications, challenges that are new for product or application developers. One that is particularly problematic, due to the way software products are marketed, is the need to address a range of organizational factors on a site-by-site basis to obtain acceptance of systems developed to support groups.
Confusion in the Garden of Eden
Authors: Skyum Sven
Published: February 2016

The publication contains an examination of the connection between unambiguity of cellular systems and the existence of Garden of Eden configurations in cellular automata. The examination includes both finite and infinite configurations. A rewritten and corrected version has been accepted for publication in Proc. of the Amer. Math. Soc.
Bounds on Certain Multiplications of Affine Combinations
Authors: Boyar Joan , Fich Faith , Larsen Kim Skak
Published: February 2016

Let A and B be n x n matrices the entries of which are affine combinations of the variables a_1,... ,a_m,b_1,. .. ,b_m over GF(2). Suppose that, for each i, 1<= i <= m, the term a_i b_i is an element of the product matrix C = A € B. What is the maximum value that  m  can have as a function of  n ? This question arises from a recent technique for improving the communication complexity of zero-knowledge proofs.

The obvious upper bound of n^2 is improved to n^2 sqrt[3] 3 + O(n). Tighter bounds are obtained for smaller values of n. The bounds for n = 2, n = 3, and n = 4 are tight.
Efficient Rebalancing of Chromatic Search Trees
Authors: Boyar Joan , Larsen Kim Skak
Published: February 2016

In PODS'91, Nurmi and Soisalon-Soininen presented a new type of binary search tree for databases, which they call a chromatic tree. The aim is to improve runtime performance by allowing a greater degree of concurrency, which, in turn, is obtained by uncoupling updating from rebalancing. This also allows rebalancing to be postponed completely or partially until after peak working hours.

The advantages of the proposal of Nurmi and Soisalon-Soininen are quite significant, but there are definite problems with it. First, they give no explicit upper bound on the complexity of their algorithm. Second, some of their rebalancing operations can be applied many more times than necessary. Third, some of their operations, when removing one problem, create another.

We define a new set of rebalancing operations which we prove give rise to at most I_ log_2(N+1) _I - 1 $ rebalancing operations per insertion and at most I_ log_2 (N+1)_I - 2 rebalancing operations per deletion, where N is the maximum'size the tree could ever have, given its initial size and the number of insertions performed. Most of these rebalancing operations, in fact, do no restructuring; they simply move weights around. The number of operations which actually change the structure of the tree is at most one per update.
Using Artifacts as Triggers for Participatory Analysis
Authors: Mogensen Preben Holst , Trigg Randall H.
Published: February 2016

Based on a study of a three-day workshop between users and developers, we show how artifacts like computer prototypes can be used to trigger productive discussions. We demonstrate how clashes between contextualized artifacts and the practitioners' (users) conceptions and experiences of their work practices trigger new understandings of current practice as well as possible futures. In this way, artifacts support the work of participatory analysis as well as participatory design.
Strategies for Expression Evaluation Using Sort-Merge Algorithms
Authors: Larsen Kim Skak
Published: February 2016

The sort-merge technique for evaluating relational algebra and calculus expressions was advocated very early and is a very widely used implementation technique. We present an algorithm for query analysis prior to execution with the aim of determining sort orders for every subexpression in such a way that resorting can be avoided during the actual evaluation. We prove that our algorithm will find such a solution, if one exists. In that case, we get the additional benefit of perfect pipelining, which implies that we do not have to save temporary results of evaluating subexpressions. The algorithm's running time is quadratic in the size of the expression.

In case no assignment of sort orders to subexpressions exists such that resorting can be avoided entirely, the aim is to find a minimum number of places to resort. We also consider this problem.
The Correctness of an Optimized Code Generation
Authors: Lange Torben Poort
Published: February 2016

For a functional programming language with a lazy standard semantics, we define a strictness analysis by means of abstract interpretation. Using the information from the strictness analysis we are able to define a code generation which avoids delaying the evaluation of the argument to an application, provided that the corresponding function is strict.

To show the correctness of the code generation, we adopt the framework of logical relations and define a layer of predicates which finally will ensure that the code generation is correct with respect to the standard semantics.
Progress measures, immediate determinacy, and a subset construction for tree automata
Authors: Klarlund Nils
Published: February 2016

Using the concept of progress measure, we give a new proof of Rabin's fundamental result that the languages defined by tree automata are closed under complementation.

To do this we show that for certain infinite games based on tree automata, an immediate determinacy property holds for the player who is trying to win according to a Rabin acceptance condition. Immediate determinacy is stronger than the  forgetful determinacy of Gurevich and Harrington, which depends on more information about the past, but applies to another class of games.

Next, we show a graph theoretic duality theorem for winning conditions. Finally, we present an extended version of Safra's determinization construction. Together, these ingredients and the determinacy of Borel games yield a straightforward recipe for complementing tree automata.

Our construction is almost optimal, i.e. the state space blow-up is essentially exponential --- thus roughly the same as for automata on finite or infinite words.

To our knowledge, no prior constructions have been better than double exponential.
Re-framing Research in Human-Computer Interaction from the Point-of-View of Activity Theory?
Authors: Bødker Susanne
Published: February 2016

Within human-computer interaction cognitive science is today the leading approach. Yet its position is threaded philosophically as well as from within the field. Most attempts to re-frame human-computer interaction from within the field are minor revisions to the traditional theoretical basis, still without much to say about real-life computer applications. In this paper I shall present and discuss an alternative approach based on activity theory.

The following summarizes the theoretical anchor points:

Activity is mediated. That artifacts mediate use means that we are normally not aware of them as such in use, they are transparent to us. Artifacts are seen as historical devices.

Although collective, each activity is conducted through actions of individuals.

Activities are not taking place in isolation but interwoven with other activities. Artifacts may be the instruments of a web of activities. The concepts of breakdowns and focus shifts are used in the further analysis of specific computer applications in use, and a mapping technique for such analysis is developed. Based on an example I take the first steps towards a more contex\-tualized analysis of human-computer interaction. The human activity framework has provided a vehicle for bringing together an overall analysis of work and use of computer technology with a detailed analysis of human-computer interaction. It provides a way of understanding the relations between the overall socio-political conditions of work and the specific use of the specific computer application in a specific situation. What actually goes on may be analysed from many different levels of activity, where the actual actors are different, and maybe even different from those who conduct the specific actions.
A New Characterization of Graphs Based on Interpretation Relations
Authors: Paz Azaria , Pearl Judea , Ur Shmuel
Published: February 2016

While graphs are normally defined in terms of the 2-place relation of adjacency, we take the 3-place relation of interception as the basic primitive of the definition.
The paper views graphs as an economic scheme for encoding interception relations, and establishes as axiomatic characterization of relations that lend themselves to representation in terms of graph interception, thus providing a new characterization of graphs.