Engineering cybernetics: 60 years in the making

The landmark book of Hsue-Shen Tsien, ‘Engineering Cybernetics', gave birth 60 years ago to an engineering science of interrelations and synthetic behaviors. Clothing the bare bones of Norbert Wiener's conception of cybernetics, the book delineates for the new science the requirement(of having direct impacts on engineering applications), the aim(of encapsulating engineering principles and concepts), the problems(of analysis, design, and uncertainty), the tools(of basic and advanced mathematics), and the scope(systems that are single input and output or multiple input and output, linear or nonlinear, deterministic or stochastic).The book is a showcase of originality, critical thinking and foresights. In particular, the author calls into question the basic assumption that ‘the properties and characteristics of the system to be controlled were always assumed to be known' and points out that, in reality, ‘large unpredictable variations of the system properties may occur'. Sixty years later, the full spectrum of Tsien's prophetic ideas is yet to be fully grasped and engineering cybernetics, as Tsien envisioned, is still in the making.     

Natural,practical and social contexts of e‐learning: a critical realist account for learning and technology

Much of the research in educational technology with a primary concern over how technology enhances learning has been criticized as privileging the immediate learning settings over the other dimensions of learners’ social life and the wider social and economic contexts in which learning and technology are located. The ability to develop a rich understanding of learning and technology in various contexts requires careful use of theory that might enable ‘looking beyond learning’. To meet this need, this paper proposes the use of a critical realistic account of learning and technology, in particular Margaret Archer's ‘three orders of reality’ and ‘personal Identity’. Drawing on an empirical case study for illustration, the paper argues that such an approach offers a ‘way out’ to unpack the relationship between learning and technology through a deep exploration of the interrelationship between individual practices of learning, with or without technology, and the bigger picture of how learning intervenes in other dimensions of social life and how other contexts come into play in learning settings.     

Industrial Inspection Efficiency and the Probability of a Defect Occurring

Abstract

Following Colquhouu's more general result that in a vigilance task probability rather than frequency of occurrence determines an operator's efficiency, the effect of ‘ probability ’ has been tested on the shop floor for probabilities in the range 0·01 to 0·05 for paced and unpaced inspection.

A ‘ probability ’ effect was found for the ‘ unpaced condition ’. Raising the probability increased the level of detection of defects significantly

The practical and theoretical implications of the current study are discussed: particularly relating the relevance of laboratory studies to practical situations.     

汉字输入键盘设计方法的研究——兼论标准汉字双拼键盘的设计

本文提出了汉字‘权值’的概念, 并以汉字‘权值’做为衡量标准, 以汉字输入双拼键盘的设计为例, 对如何设计一个优秀的汉字输入键盘的方法进行了详细研究。 同时指出,‘权值’概念的提出同样适合其它类型汉字编码方案的键盘设计。     

Termination of High-Level Replacement Units with Application to Model Transformation

Visual rewriting techniques, in particular graph transformations, are increasingly used to model transformations of systems specified through diagrammatic sentences. Several rewriting models have been proposed, differing in the expressivity of the types of rules and in the complexity of the rewriting mechanism; yet basic results concerning the formal properties of these models are still missing for many of them. In this paper, we propose a contribution towards solving the termination problem for rewriting systems with external control mechanisms. In particular, we obtain results of more general validity by extending the concept of transformation unit to high-level replacement systems, a generalization of graph transformation systems. For high-level replacement units, we state and prove several abstract properties based on termination criteria. Then, we instantiate the high-level replacement systems by attributed graph transformation systems and present concrete termination criteria. These are used to show the termination of some replacement units needed to express model transformations as a consequence of software refactoring.     

Detection of Errors by Skilled Typists

Abstract

Skilled typists are able to detect and correct many errors which they make in copy text, even when they cannot see their copy; (Long 1976. West, 1967). The present investigation shows that they can also do this when they see neither their copy nor the keyboard they use; and that when they detect that they have made errors they arc usually also able to specify precisely what these have been. Typists sometimes make one, or even two additional correct keystrokes before pausing to signal that they have committed an error. They are nevertheless sometimes still able to report precisely what these errors were

When copy obtained from a typewriter using mechanical linkages is examined, the density of impressions of different characters may be taken to indicate how hard particular keys have been struck. A second experiment shows that errors, more frequently than correct responses, are executed with light keystrokes. This, in line with previous work by Megaw (1972). suggests that typists sometimes become aware that they are about to make an error before they complete the keystroke implementing it. They may then attempt to ‘pull back’ incorrect keystrokes, producing fainter impressions on copy

The probability that typists will subsequently signal detection of such ‘ faint’ (or‘ pulled’) errors was found to be significantly greater than the probability that they will subsequently signal their detection of other errors, made with ‘firm’ (i.e. ‘unpulled’) keystrokes

These data, related to earlier findings by Diehl and Seibel (1962), Klemmer (1971). Long (1975, 1976a,b) and Seibel (1972) offer little support for the assumption that skilled typists may monitor their emitted responses in ‘units’ of greater than one keystroke. They rather suggest that, even al very high response rates (e.g. 172ms or faster), typists read copy, programme and emit responses and evaluate each of their responses for accuracy as concurrent, or partially overlapping activities.     

Cost-benefit analysis of two-unit parallel system with administrative delay in repair

The analysis of parallel systems with two dissimilar units is examined. Each unit has two modes—‘normal’ or ‘total failure’. Whenever an operative unit fails, an administrative delay occurs in locating the repairman and making him available at the system location. A system is observed at suitable regenerative epochs in order to obtain various economic related reliability characteristics. The explicit results are obtained in few particular cases.     

Distributed improvisation: a systems perspective of improvisation ‘epics’ by led outdoor activity leaders

Improvisation represents the spontaneous and real-time conception and execution of a novel response to an unanticipated situation. In order to benefit from the positive safety potential of this phenomenon, it is necessary to understand what influences its appropriateness and effectiveness. This study has applied the system-based methodology Impromaps to analysing accounts of improvisation aimed at mitigating adverse safety outcomes. These accounts were obtained from led outdoor activity (LOA) leaders through critical decision method interviews. Influencing factors and interactions have been identified across all system levels. The factors most influential to leaders’ ability to improvise are ‘Policy, procedures and rules’, ‘Organisation culture’, ‘Training’, ‘Role responsibilities’, ‘Communication/instruction/demonstration’, ‘Situation awareness’, ‘Leader experience’, ‘Mental simulation’, ‘Equipment, clothing & PPE’ and ‘Terrain/physical environment’. To enhance the likelihood of effective, appropriate improvisation, LOA providers are recommended to focus on higher level factors over which they are able to exert greater control.

Practitioner Summary: To enhance resilience in safety-critical situations, organisations need to understand what influences appropriate, effective improvisation. To elucidate this, the Impromaps methodology is applied to in-depth interview data. The Impromap affords a graphical depiction of the influencing factors and interactions across the system, providing a basis for the development of interventions.     

Use of Computer Interview Data to Test Associations between Risk Factors and Pregnancy Outcomes

Computer interviews have been used in a variety of settings as a means of gathering data and providing health education information. The objective of this study was to determine whether data gathered from a computer interview have predictive validity in determining pregnancy outcomes. Pregnant women (N= 190) completed a computer-assisted interview to provide risk factor information. Medical records were reviewed to obtain prenatal and birth outcome information. Twenty-nine percent experienced prenatal complications and nearly half experienced problems related to labor and delivery. After known risk factors were controlled for, self-reported psychosocial problems, low social support, and substance abuse by the father were associated with pregnancy complications. An unbalanced diet and low social support were associated with lower infant birth weight. Findings suggest that data collected via computer interviews can provide useful risk factor screening information.     

Synaptic redistribution and variability of signal release probability of Hebbian neurons at low-firing frequencies in a dynamic stochastic neural network

This paper presents the finding of the research we conducted to evaluate the variability of signal release probability at Hebb’s presynaptic neuron under different firing frequencies in a dynamic stochastic neural network. A modeled neuron consisted of thousands of artificial units, called ‘transmitters’ or ‘receptors’ which formed dynamic stochastic synaptic connections between neurons. These artificial units were two-state stochastic computational units that updated their states according to the signal arriving time and their local excitation. An experiment was conducted with three stages by updating the firing frequency of Hebbian neuron at each stage. According to our results, synaptic redistribution has improved the signal transmission for the first few signals in the signal train by continuously increasing and decreasing the number of postsynaptic ‘active-receptors’ and presynaptic ‘active-transmitters’ within a short time period. In long-run, at low-firing frequency, it has increased the steady state efficacy of the synaptic connection between the Hebbian presynaptic and the postsynaptic neuron in terms of the signal release probability of ‘active-transmitters’ in the presynaptic neuron as observed in biology. This ‘low-firing’ frequency of the presynaptic neuron has been identified by the network by comparing it with the ongoing frequency oscillation of the network.     

The relative success of alternative approaches to strategic information systems planning: an empirical analysis

Strategic information systems planning (SISP) is an exercise or ongoing activity that enables organisations to develop priorities for information systems development. It has been suggested that the ‘SISP approach’, a combination of method, process and implementation, is the most complete way of describing SISP activity. Based upon questionnaire responses from 267 IT Directors, four distinct approaches to SISP have been derived using cluster analysis. A comparison of these four approaches with five approaches of Earl, M.J., 1993. Experiences in SISP, MIS Quarterly, (March), 1–24, indicates that three bear strong similarities to the ‘organisational’, ‘business-led’, and ‘administrative’ approaches, whilst the fourth cluster is related to both Earl's ‘method-driven’ and ‘technological’ approaches. An analysis of the relationship between SISP approach and SISP success demonstrates that the ‘organisational approach’ is significantly more successful than the other three approaches.     

High-level replacement units and their termination properties

Visual rewriting techniques, in particular graph transformations, are increasingly used to model transformations of systems specified through diagrammatic sentences. Several rewriting models have been proposed, differing in the expressivity of the types of rules and in the complexity of the rewriting mechanism; yet, for many of them, basic results concerning the formal properties of these models are still missing. In this paper, we give a contribution towards solving the termination problem for rewriting systems with external control mechanisms. In particular, we obtain results of more general validity by extending the concept of transformation unit to high-level replacement systems, a generalization of graph transformation systems. For high-level replacement units, we state and prove several abstract properties based on termination criteria. Then, we instantiate the high-level replacement systems by attributed graph transformation systems and present concrete termination criteria. We explore some types of rules and replacement units for which the criterion can be established. These are used to show the termination of some replacement units needed to express model transformations formalizing refactoring.     

EXTENDING THE CONCEPT OF INTERVAL

The relative variation in length found among the intervals between occurrences of characters in written text provides extremely valuable clues as to the identity of those characters. It is possible to obtain still more identity information by extending the definition of ‘interval’ so that intervals of various kinds can be distinguished. In addition, it is possible to make use of ‘complex’ or ‘multi-dimensional’ intervals by giving simultaneous consideration to a number of adjacent ‘simple’ intervals.     

‘Resisting Creativity,Creating the New’. A Deleuzian Perspective on Creativity

Create/Innovate or die. This is the taken‐for‐granted ‘truth’ in the social, political and economic context in which we currently live. In fact, so accepted is this mantra that criticism seems foolish; mere evidence of the entrenched conservatism that needs to be challenged. This article posits an alternative view of creativity, drawing in particular on the thinking of the philosopher Gilles Deleuze. The writing of Deleuze is used to explore our understanding of creativity, in terms of what ‘creativity’ is (and what it is not), and the destructive (and sometimes pointless) nature of creativity. In doing so it is hoped that this article challenges clichéd representations of ‘creativity’, the typical ‘creativity is wonderful and we need a lot more of it . . .’ type arguments and assist scholars to become more creative (or at least more reflective) in their own practice.     

On the security of open source software

Abstract With the rising popularity of so‐called ‘open source’ software there has been increasing interest in both its various benefits and disadvantages. In particular, despite its prominent use in providing many aspects of the Internet's basic infrastructure, many still question the suitability of such software for the commerce‐oriented Internet of the future. This paper evaluates the suitability of open source software with respect to one of the key attributes that tomorrow's Internet will require, namely security. It seeks to present a variety of arguments that have been made, both for and against open source security and analyses in relation to empirical evidence of system security from a previous study. The results represent preliminary quantitative evidence concerning the security issues surrounding the use and development of open source software, in particular relative to traditional proprietary software.     

Temporal Context of Organizational Learning in New Product Development Projects

Faced with the evolution of the competitive environment, firms have to find the delicate balance between two goals that are sometimes contradictory: accelerate the time spent on product development and leave time to the personnel implicated in these projects to develop collective learning. This research shows that the project ‘time’ has an important influence on the realization of collective learning during new product development projects. The commitment of the project team in activities like experimentation, detection and correction of errors, and research of new combinations which constitute organizational learning depends on the two conceptions of the project ‘time’. If the duration of the project and the time spent by the functional personnel on the project constitute the objective time of the project (first conception of time), the project ‘time’ is also a subjective time which corresponds to the project team’s shared vision of the project’s deadlines (second conception of time).     

Taking CSCW seriously

The topic of Computer Supported Cooperative Work (CSCW) has attracted much attention in the last few years. While the field is obviously still in the process of development, there is a marked ambiguity about the exact focus of the field. This lack of focus may hinder its further development and lead to its dissipation. In this paper we set out an approach to CSCW as a field of research which we believe provides a coherent conceptual framework for this area, suggesting that it should be concerned with thesupport requirements of cooperative work arrangements. This provides a more principled, comprehensive, and, in our opinion, more useful conception of the field than that provided by the conception of CSCW as being focused on computer support for groups. We then investigate the consequences of taking this alternative conception seriously, in terms of research directions for the field. As an indication of the fruits of this approach, we discuss the concept of ‘articulation work’ and its relevance to CSCW. This raises a host of interesting problems that are marginalized in the work on small group support but critical to the success of CSCW systems ‘in the large’, i. e., that are designed to meet current work requirements in the everyday world.     

Pedagogy embedded in educational software design: report of a case study

Most educational software is designed to foster students' learning outcomes but with little consideration of the teaching framework in which it will be used. This paper presents a significantly different model of educational software that was derived from a case study of two teachers participating in a software design process. It shows the relationship between particular elements of the teachers' pedagogy and the characteristics of the software design. In this model, the ‘classroom atmosphere’ is embedded in the human–computer interface scenarios and elements, the ‘teaching strategy’ in the design of the browsing strategies of the software, and the ‘learning strategy’ in the particular forms of interaction with the software. The model demonstrates significant links between the study of Pedagogy and the study of Information Technology in Education and has implications for the relationship between these two areas of research and consequently for teacher training. The model proposes a perspective on educational software design that takes into consideration not only learning theories, but also teaching theories and practice.     

DPPS: A novel dual privacy-preserving scheme for enhancing query privacy in continuous location-based services

Since smartphones embedded with positioning systems and digital maps are widely used, location-based services (LBSs) are rapidly growing in popularity and providing unprecedented convenience in people’s daily lives; however, they also cause great concern about privacy leakage. In particular, location queries can be used to infer users’ sensitive private information, such as home addresses, places of work and appointment locations. Hence, many schemes providing query anonymity have been proposed, but they typically ignore the fact that an adversary can infer real locations from the correlations between consecutive locations in a continuous LBS. To address this challenge, a novel dual privacy-preserving scheme (DPPS) is proposed that includes two privacy protection mechanisms. First, to prevent privacy disclosure caused by correlations between locations, a correlation model is proposed based on a hidden Markov model (HMM) to simulate users’ mobility and the adversary’s prediction probability. Second, to provide query probability anonymity of each single location, an advanced k-anonymity algorithm is proposed to construct cloaking regions, in which realistic and indistinguishable dummy locations are generated. To validate the effectiveness and efficiency of DPPS, theoretical analysis and experimental verification are further performed on a real-life dataset published by Microsoft, i.e., GeoLife dataset.     

Orderings for term-rewriting systems

Methods of proving that a term-rewriting system terminates are presented. They are based on the intuitive notion of ‘simplification orderings’, orderings in which any term that is syntactically simpler than another is smaller than the other. As a consequence of Kruskal's Tree Theorem, any nonterminating system must be self-embedding in the sense that it allows for the derivation of some term from a simpler one; thus termination is guaranteed if every rule in the system is a reduction in some simplification ordering.Most of the orderings that have been used for proving termination are indeed simplication orderings; using this notion often allows for much easier proofs. A particularly useful class of simplification orderings, the ‘recursive path orderings’, is defined. Examples of the use of simplication orderings in termination proofs are given.