Institution Morphisms

Institutions formalise the intuitive notion of logical system, including syntax, semantics, and the relation of satisfaction between them. Our exposition emphasises the natural way that institutions can support deduction on sentences, and inclusions of signatures, theories, etc.; it also introduces terminology to clearly distinguish several levels of generality of the institution concept. A surprising number of different notions of morphism have been suggested for forming categories with institutions as objects, and an amazing variety of names have been proposed for them. One goal of this paper is to suggest a terminology that is uniform and informative to replace the current chaotic nomenclature; another goal is to investigate the properties and interrelations of these notions in a systematic way. Following brief expositions of indexed categories, diagram categories, twisted relations and Kan extensions, we demonstrate and then exploit the duality between institution morphisms in the original sense of Goguen and Burstall, and the ‘plain maps’ of Meseguer, obtaining simple uniform proofs of completeness and cocompleteness for both resulting categories. Because of this duality, we prefer the name ‘comorphism’ over ‘plain map’; moreover, we argue that morphisms are more natural than comorphisms in many cases. We also consider ‘theoroidal’ morphisms and comorphisms, which generalise signatures to theories, based on a theoroidal institution construction, finding that the ‘maps’ of Meseguer are theoroidal comorphisms, while theoroidal morphisms are a new concept. We introduce ‘forward’ and ‘semi-natural’ morphisms, and develop some of their properties. Appendices discuss institutions for partial algebra, a variant of order sorted algebra, two versions of hidden algebra, and a generalisation of universal algebra; these illustrate various points in the main text. A final appendix makes explicit a greater generality for the institution concept, clarifies certain details and proves some results that lift institution theory to this level. Received December 2000 / Accepted in revised form January 2002     

What the <0.70, 1.17, 0.99, 1.07> is a Symbol?

The notion of a ‘symbol’ plays an important role in the disciplines of Philosophy, Psychology, Computer Science, and Cognitive Science. However, there is comparatively little agreement on how this notion is to be understood, either between disciplines, or even within particular disciplines. This paper does not attempt to defend some putatively ‘correct’ version of the concept of a ‘symbol.’ Rather, some terminological conventions are suggested, some constraints are proposed and a taxonomy of the kinds of issue that give rise to disagreement is articulated. The goal here is to provide something like a ‘geography’ of the various notions of ‘symbol’ that have appeared in the various literatures, so as to highlight the key issues and to permit the focusing of attention upon the important dimensions. In particular, the relationship between ‘tokens’ and ‘symbols’ is addressed. The issue of designation is discussed in some detail. The distinction between simple and complex symbols is clarified and an apparently necessary condition for a system to be potentially symbol, or token bearing, is introduced.     

Geographic ‘Place’ and ‘Community Information’ Preferences

People dynamically structure social interactions and activities at various locations in their environments in specialized types of places such as the office, home, coffee shop, museum and school. They also imbue various locations with personal meaning, creating group ‘hangouts’ and personally meaningful ‘places’. Mobile location-aware community systems can potentially utilize the existence of such ‘places’ to support the management of social information and interaction. However, acting effectively on this potential requires an understanding of how: (1) places and place-types relate to people’s desire for place-related awareness of and communication with others; and (2) what information people are willing to provide about themselves to enable place-related communication and awareness. We present here the findings from two qualitative studies, a survey of 509 individuals in New York, and a study of how mobility traces can be used to find people’s important places in an exploration of these questions. These studies highlight how people value and are willing to routinely provide information such as ratings, comments, event records relevant to a place, and when appropriate their location to enable services. They also suggest how place and place-type data could be used in conjunction with other information regarding people and places so that systems can be deployed that respect users’ People-to-People-to-Places data sharing preferences. We conclude with a discussion on how ‘place’ data can best be utilized to enable services when the systems in question are supported by a sophisticated computerized user-community social-geographical model.     

The social acceptability of AI systems: Legitimacy,epistemology and marketing

The expression, ‘the culture of the artificial’ results from the confusion between nature and culture, when nature mingles with culture to produce the ‘artificial’ and science becomes ‘the science of the artificial’. Artificial intelligence can thus be defined as the ultimate expression of the crisis affecting the very foundation of the system of legitimacy in Western society, i.e. Reason, and more precisely, Scientific Reason. The discussion focuses on the emergence of the culture of the artificial and the radical forms of pragmatism, sophism and marketing from a French philosophical perspective. The paper suggests that in the postmodern age of the ‘the crisis of the systems of legitimacy’, the question of social acceptability of any action, especially actions arising out of the application of AI, cannot be avoided.     

The Use of a Formalised Risk Model in NHS Information System Development

Information systems (IS) and technology are used extensively throughout the National Health Service (NHS), and the 1998 national information strategy, ‘Information for Health’, sets out how the NHS will be developing and implementing IS to support patient care within the next decade. This new IS initiative is set against a mixed record of success of IS projects in the NHS, with a number of high-profile failures. This paper highlights the need to consider the ‘organisational issues’ involved in systems implementation to avoid failures. It goes on to advocate the use of a process-oriented and organisation studies-based model for risk analysis and management for use in NHS IS projects. Two famous NHS case studies are used to validate the model. It is concluded that there is a real need in the NHS for tools to better control the inherent risks involved in IS development and implementation. Ultimately, the success of IS projects in the NHS is crucial if they want to best utilise clinical and patient information, with the overall aim of improving the efficiency and standard of the nation’s health care.     

Efficient distribution-free population learning of simple concepts

We consider a variant of the ‘population learning model’ proposed by Kearns and Seung [8], in which the learner is required to be ‘distribution-free’ as well as computationally efficient. A population learner receives as input hypotheses from a large population of agents and produces as output its final hypothesis. Each agent is assumed to independently obtain labeled sample for the target concept and output a hypothesis. A polynomial time population learner is said to PAC-learn a concept class, if its hypothesis is probably approximately correct whenever the population size exceeds a certain bound which is polynomial, even if the sample size for each agent is fixed at some constant. We exhibit some general population learning strategies, and some simple concept classes that can be learned by them. These strategies include the ‘supremum hypothesis finder’, the ‘minimum superset finder’ (a special case of the ‘supremum hypothesis finder’), and various voting schemes. When coupled with appropriate agent algorithms, these strategies can learn a variety of simple concept classes, such as the ‘high–low game’, conjunctions, axis-parallel rectangles and others. We give upper bounds on the required population size for each of these cases, and show that these systems can be used to obtain a speed up from the ordinary PAC-learning model [11], with appropriate choices of sample and population sizes. With the population learner restricted to be a voting scheme, what we have is effectively a model of ‘population prediction’, in which the learner is to predict the value of the target concept at an arbitrarily drawn point, as a threshold function of the predictions made by its agents on the same point. We show that the population learning model is strictly more powerful than the population prediction model. Finally, we consider a variant of this model with classification noise, and exhibit a population learner for the class of conjunctions in this model. This revised version was published online in June 2006 with corrections to the Cover Date.     

The significant other: the value of jewellery in the conception,design and experience of body focused digital devices

In this paper, we demonstrate how craft practice in contemporary jewellery opens up conceptions of ‘digital jewellery’ to possibilities beyond merely embedding pre-existing behaviours of digital systems in objects, which follow shallow interpretations of jewellery. We argue that a design approach that understands jewellery only in terms of location on the body is likely to lead to a world of ‘gadgets’, rather than anything that deserves the moniker ‘jewellery’. In contrast, by adopting a craft approach, we demonstrate that the space of digital jewellery can include objects where the digital functionality is integrated as one facet of an object that can be personally meaningful for the holder or wearer.     

Scope control and grammatical dependencies

This paper develops a semantics with control over scope relations using Vermeulen’s stack valued assignments as information states. This makes available a limited form of scope reuse and name switching. The goal is to have a general system that fixes available scoping effects to those that are characteristic of natural language. The resulting system is called Scope Control Theory, since it provides a theory about what scope has to be like in natural language. The theory is shown to replicate a wide range of grammatical dependencies, including options for, and constraints on, ‘donkey’, ‘binding’, ‘movement’, ‘Control’ and ‘scope marking’ dependencies.     

Timing and causality in process algebra

 There has been considerable controversy in concurrency theory between the ‘interleaving’ and ‘true concurrency’ schools. The former school advocates associating a transition system with a process which captures concurrent execution via the interleaving of occurrences; the latter adopts more complex semantic structures to avoid reducing concurrency to interleaving. In this paper we show that the two approaches are not irreconcilable. We define a timed process algebra where occurrences are associated with intervals of time, and give it a transition system semantics. This semantics has many of the advantages of the interleaving approach; the algebra admits an expansion theorem, and bisimulation semantics can be used as usual. Our transition systems, however, incorporate timing information, and this enables us to express concurrency: merely adding timing appropriately generalises transition systems to asynchronous transition systems, showing that time gives a link between true concurrency and interleaving. Moreover, we can provide a complete axiomatisation of bisimulation for our algebra; a result that is often problematic in a timed setting. Another advantage of incorporating timing information into the calculus is that it allows a particularly simple definition of action refinement; this we present. The paper concludes with a comparison of the equivalence we present with those in the literature, and an example system specification in our formalism. Received December 20, 1993/February 23, 1995     

Language and Space: a two-level semantic approach based on principles of ontological engineering

An increasing number of applications for dialogue systems presuppose an ability to deal appropriately with space. Dialogues with assistance systems, intelligent mobility devices and navigation systems all commonly involve the use of spatial language. For smooth interaction, this spatial language cannot be interpreted ‘in the abstract’—it must instead be related directly to a user’s physical location, orientation, goals and needs and be embedded appropriately in a system’s interaction. This is far from straightforward. The situated interpretation of natural language concerning space, spatial relationships and spatial activities represents an unsolved challenge at this time. Despite extensive work on spatial language involving many disciplines, there are no generally accepted accounts that provide support for the kind of flexible language use observed in real human-human spatial dialogues. In this paper, I review some recent approaches to the semantics for natural language expressions concerning space in order to motivate a two-level semantic-based approach to the interpretation of spatial language. This draws on a new combination of natural language processing and principles of ontological engineering and stands as a foundation for more sophisticated and natural dialogue system behavior where spatial information is involved.     

Linguistic diversity and information poverty in South Asia and Sub-Saharan Africa

This communication starts with a fundamental question that drives the actions of most local and global policy-makers: out of two categories of people (not mutually exclusive), the ‘have nots’ and the ‘know nots’, which one is more difficult to eradicate (one may pose the question differently—solving which of these two problems is likely to solve the other). A lot of attention and resources have been deployed and are committed on the challenge of uplifting the ‘have nots’ to the section of bare minimum ‘haves’ category. A cause and effect study between these two sections of people essentially show a mutual dependency that eventually leads to a vicious cycle of poverty to information poverty to back again poverty which has historically been difficult to eradicate, and studies have often established education and access to timely information to be a long term sustainable remedy to both these perpetual problems. The role that the Internet can play in this background towards empowering the billions of impoverished across two of the most underdeveloped regions, namely South Asia (SA) and Sub-Saharan Africa (SSA), home to world’s largest number of illiterates and poor people (70% or even more together) is immense. With anywhere, anytime accessibility of rich Internet content, aided by its falling prices and increased connectivity and easy to use features, to parts of rural and even to inaccessible remote areas, online content can effectively act as a low-cost feasible solution not only to provide basic education, but also to deliver meaningful information and content to the millions of primary-level educated people within the underprivileged sections of SA & SSA, thereby enabling them to integrate and exploit various socio-economic opportunities arising from growth in global economies. However, rich linguistic diversity, both in SA and SSA, poses a challenge to that opportunity. Content development to information access to literacy, all leading to socio-economic developments, do face additional difficulties arising from linguistic diversity for SA and SSA, regions already plagued with low level of content generation and access in local languages. A closer examination of the ‘sea’ of online content reveals that SA scores poorly in local language content development, whereas English is primarily used for Internet usage, though nearly 90% of people of India do not use English as a 2nd or 3rd languages. For SSA, a study reported here qualitatively examines whether linguistic diversity indeed has any negative correlations with gross national income and Internet penetration, and finds that they indeed are inversely related in 80% or more cases. One case-effort is also examined to develop local language content, critical to reap benefits from content for development for SA and SSA, in South Asia, but it was found to be inadequate in proportion to the severity and scale of the problem. It is alarmingly concluded that unless war-footing action is adopted to generate relevant local language content (or effectively supported by software like Google Translation) in the linguistically diverse backward regions of the world, much of the benefits that could have been derived from increased reach of freely available online content would be lost, causing an escalation of information poverty to the ‘bottom of the pyramid’ section of people in South Asia and Sub-Saharan Africa. Ranjit Goswami is also a faculty member with Indian Institute of Foreign Trade, Kolkata, India.     

Socio-Technical and Soft Approaches to Information Requirements Elicitation in the Post-Methodology Era

The contributors to this special issue focus on socio-technical and soft approaches to information requirements elicitation and systems development. They represent a growing body of research and practice in this field. This review presents an overview and analysis of the salient themes within the papers encompassing their common underlying framework, the methodologies and tools and techniques presented, the organisational situations in which they are deployed and the issues they seek to address. It will be argued in the review that the contributions to this special edition exemplify the ‘post-methodological era’ and the ‘contingency approaches’ from which it is formed.     

A survey on the history of transaction management: from flat to grid transactions

Transactions have been around since the Seventies to provide reliable information processing in automated information systems. Originally developed for simple ‘debit-credit’ style database operations in centralized systems, they have moved into much more complex application domains including aspects like distribution, process-orientation and loose coupling. The amount of published research work on transactions is huge and a number of overview papers and books already exist. A concise historic analysis providing an overview of the various phases of development of transaction models and mechanisms in the context of growing complexity of application domains is still missing, however. To fill this gap, this paper presents a historic overview of transaction models organized in several ‘transaction management eras’, thereby investigating numerous transaction models ranging from the classical flat transactions, via advanced and workflow transactions to the Web Services and Grid transaction models. The key concepts and techniques with respect to transaction management are investigated. Placing well-known research efforts in historical perspective reveals specific trends and developments in the area of transaction management. As such, this paper provides a comprehensive, structured overview of developments in the area.     

An informational divergence geometry for stochastic matrices

Summary The informational divergence between stochastic matrices is not a metric. In this paper we show that, however, consistent definitions can be given of ‘spheres’, ‘segments’ and ‘straight lines’ using the divergence as a sort of ‘distance’ between stochastic matrices. The geometric nature of many ‘reliability functions’ of Information Theory and Mathematical Statistics is thus clarified. This work has been done within the GNIM-CNR research activity.     

Development of an Architecture for a Hybrid Manufacturing Information System

In a previous paper, the concept of a Generic Non Standard-specific Information Flow System (GNSIFS) was discussed [1]. The main feature of GNSIFS is that it can perform data exchange among a group of manufacturing systems, regardless of the operating systems or standards being used. Further research in this field shows that, to enhance the capability of GNSIFS, the database system of GNSIFS, which is considered to be the key constituent of the whole system, should consist of a relational data model that is to be complemented with a free format data model. In addition, the ‘reasoning’ capability of this information flow system can also be advanced if a Rule Knowledge DataBase (RKDB), together with the associated inference engine, can be included in the GNSIFS, resulting in the formation of a Hybrid Manufacturing Information System (HMIS) which manages the information flow from a combination of relational, free format and rule knowledge data models. This hybrid information management feature is favourable to the progressive advancement of the ‘reasoning’ nature of the system, and at the same time, has the benefit of relational data processing. This paper describes the architecture required for the formation of this Hybrid Manufacturing Information System (HMIS), and tests this system in a real company to evaluate its viability in an industrial environment.     

On the numerical solution of nonlinear systems of Volterra integro-differential equations with delay arguments

Particular cases of nonlinear systems of delay Volterra integro-differential equations (denoted by DVIDEs) with constant delay τ > 0, arise in mathematical modelling of ‘predator–prey’ dynamics in Ecology. In this paper, we give an analysis of the global convergence and local superconvergence properties of piecewise polynomial collocation for systems of this type. Then, from the perspective of applied mathematics, we consider the Volterra’s integro-differential system of ‘predator–prey’ dynamics arising in Ecology. We analyze the numerical issues of the introduced collocation method applied to the ‘predator–prey’ system and confirm that we can achieve the expected theoretical orders of convergence.      

Perceive this as that – Analogies, artificial perception, and category theory

This paper formalizes and analyzes cognitive transitions between artificial perceptions that consist of an analogical or metaphorical transference of perception. The formalization is performed within a mathematical framework that has been used before to formalize other aspects of artificial perception and cognition. The mathematical infrastructure consists of a basic category of ‘artificial perceptions’. Each ‘perception’ consists of a set of ‘world elements’, a set of ‘connotations’, and a three valued (true, false, undefined) predicative connection between the two sets. ‘Perception morphisms’ describe structure preserving paths between perceptions. Quite a few artificial cognitive processes can be viewed and formalized as perception morphisms or as other categorical constructs. We show here how analogical transitions can be formalized in a similar way. A factorization of every analogical transition is shown to formalize metaphorical perceptions that are inspired by the analogy. It is further shown how structural aspects of ‘better’ analogies and metaphors can be captured and evaluated by the same categorical setting, as well as generalizations that emerge from analogies. The results of this study are then embedded in the existing mathematical formalization of other artificial cognitive processes within the same premises. A fallout of the rigorous unified mathematical theory is that structured analogies and metaphors share common formal aspects with other perceptually acute cognitive processes. This revised version was published online in June 2006 with corrections to the Cover Date.     

Prices are macro-observables! Stylized facts from evolutionary finance

Prices are macro-observables of a financial market that result from the trading actions of a huge number of individual investors. Major stylized facts of empirical asset returns concern (i) non-Gaussian distribution of empirical asset returns and (ii) volatility clustering, i.e., the slow decay of auto- correlations of absolute returns. We propose a model for the aggregate dynamics of the market which is generated by the coupling of a ‘slow’ and a ‘fast’ dynamical component, where the ‘fast’ component can be seen as a perturbation of the ‘slow’ one. Statistical properties of price changes in this model are estimated by simulation; sample size is 4 × 10⁶. It is shown that increasing the decoupling of these two dynamical levels generates a crossover in the distribution of log returns from a concave Gaussian-like distribution to a convex, truncated Levy-like one. For a sufficiently large degree of dynamic decoupling, the return trails exhibit pronounced volatility clustering.     

‘Perfectly’ Scalable Data I/O

This paper describes and analyzes a new architecture for file systems in which ‘metadata’, lock control, etc., are distributed among diverse resources. The basic data structure is a segment, viz. a logical group of files, folders, or other objects. The file system requires only one root, and can be non-hierarchical without a complete tree structure within segments. For ‘embarrassingly parallel’ data distributions, scalability is trivially perfect for all N,where N is the number of servers. Even for random file access, a new extreme statistical mechanics is used to show that data I/O is ‘perfectly’ scalable with probability 1, with degradation from perfect scaling that is small and bounded by f ln N/ ln (ln N). Here f is the fraction of data that is metadata. In contrast, earlier solutions degrade much faster, like Nf. No structural changes in classical metadata are required.