DISCRETE EVENT-DYNAMIC SYSTEMS FOR MODELING DYNAMIC VALUED NETS

The last few years have seen the development of Discrete Event-Dynamic Net Systems^1,2 as instruments for modeling complex systems. They are able to achieve the following objectives:

—formality of the modeling methodology

—ability to model static and dynamic aspects

—ability to pass between levels of differently rich structures by morphisms

—uniform representation of the communication process as

—an information process

—a decision process and

—a control process

—homogeneity of the representation and modeling methods

—ability to derive qualitative and quantitative statements.

The foundation is provided by a Discrete Event-Dynamic Net System which includes the axiomatic declaration of general Petri nets. In order to calculate the structural and dynamic aspects, so-called Petri net machines are developed. It is shown that this approach can even be used to treat the following aspects:

—use of time during the process

—increase of costs during the generation and transportation of information

—augmentation, evaluation and transformation of information objects.

Recursive formulas are derived and some examples calculated.     

THEORY OF CYBERNETIC AND INTELLIGENT MACHINE BASED ON LIE COMMUTATORS

Many attempts^{1, 7, 8, 35} have been made to overcome the limit imposed by the Turing Machine³⁴ to realise general mathematical functions and models of (physical) phenomena.

They center around the notion of computability.

In this paper we propose a new definition of computability which lays the foundations for a theory of cybernetic and intelligent machines in which the classical limits imposed by discrete algorithmic procedures are offset by the use of continuous operators on unlimited data. This data is supplied to the machine in a totally parallel mode, as a field or wave.

This theory of machines draws its concepts from category theory, Lie algebras, and general systems theory. It permits the incorporation of intelligent control into the design of the machine as a virtual element. The incorporated control can be realized in many (machine) configurations of which we give three:

a) a quantum mechanical realization appropriate to a possible understanding of the quantum computer and other models of the physical microworld,

b) a stochastic realization based on Kolmogorov-Gabor theory leading to a possible understanding of generalised models of the physical or thermodynamic macroworld, and lastly

c) a classical mechanical realization appropriate lo the study of a new class of robots.

Particular applications at a fundamental level are cited in geometry, mathematics, biology, acoustics, aeronautics, quantum mechanics, general relativity and. Markov chains. The proposed theory therefore opens a new way towards understanding the processes that underlie intelligence.     

A THEORETICAL STUDY ON ADAPTIVE QUALITY CONTROL SYSTEMS

This paper is a study of an adaptive quality control system from a viewpoint of quality goal. The main purpose is to introduce a conceptual framework for setting up quality goals which are in accordance with the external environment and internal capacity of quality control systems. We apply a mathematical general systems approach.

The results of our paper are summarized as follows:

1)As important decision-making in adaptive QCS, the decision-making for estimalion of fitness and examination of attainability are proposed and formalized mathematically.

2)A refinement process is formalized in which models are revised according to the changes of market.

3)Basic steps for setting quality goals are obtained which are based on the above formalization.     

The Proactive and Preventive Privacy (3P) Framework for IoT Privacy by Design

The Problem

Internet of Things (IoT) is providing new services and insights by sensing contextual data but there are growing concerns of privacy risks from users that need immediate attention.

The Reason

The IoT devices and smart services can capture Personally Identifiable Information (PII) without user knowledge or consent. The IoT technology has not reached the desired level of maturity to standardize security and privacy requirements.

The Solution

IoT Privacy by Design is a user-centric approach for enabling privacy with security and safety as a ‘win-win’ positive outcome of IoT offerings, irrespective of business domain. The Proactive and Preventive Privacy (3P) Framework proposed in this paper should be adopted by the IoT stakeholders for building trust and confidence in end users about IoT devices and smart services.     

Book reviews

Computer Software: legal protection in the United Kingdom Henry Carr & Richard Arnold, 1992 London: Sweet & Maxwell, 2nd ed, xv + 312 pp., £45.00 (hardback)

Advanced Information Systems for Lawyers V. Mital & L. Johnson, 1992 London: Chapman & Hall. pp. 306, £35.00

Law of Contract Laurence Koffman & Elizabeth MacDonald, 1992 London: Fourmat Publishing, 430 pp., paperback £22.50

The Electronic Media and the Transformation of Law M. Ethan Katsh, 1991 Oxford: Oxford University Press. £13.95     

Book reviews

Crime and the Computer, Martin Wasik, 1991, Oxford: Clarendon Press. £35.00.

Yearbook of Law, Computers and Technology, Volume 5. K.V. Russell (Ed.), 1991. London: Butterworths. £29.50.

Computers, Artificial Intelligence and the Law. Mervyn E. Bennun (Ed.), 1991. London: Ellis Horwood. xx +132 (including bibliography & index), £26.50

Modelling Legal Argument: reasoning with cases and hypotheticals. Kevin D. Ashley, 1990. Cambridge: MIT Press. 329 pp.     

DEVELOPMENT OF AN AUTOMATIC OBJECT-ORIENTED CONTINUOUS SIMULATION ENVIRONMENT

The construction of automatic control and modelling environments has been attempted using shallow reasoning expert systems. The inadequacy of this approach for real-life systems has become apparent, and the need for deeper knowledge—which can only be obtained by extensive simulation—is now acknowledged.

The simulation process, which consists of model building and model selection, followed by the generation and execution of a software simulator, can be partially automated if an Object-Oriented methodology is adopted. In this article, a methodology is presented, which is presently under investigation in the DESiRE (Dynamic Expert Systems in Robotic Experimentation)project

In the modelling phase, a hierarchical, uniform way of describing and manipulating continuous and discrete models is needed, if the highly desirable reusability of submodels is to be achieved. This is only possible if a clear distinction is made between bare models (and information about their intrinsic coupling) and causal simulation experiment-related data.

In the simulation phase, before generating numerical simulation code, a symbolic reduction of the continuous parts of the model is performed, thus eliminating inaccuracy introduced by the untimely application of possibly unstable numerical algorithms.

Finally, from the reduced representation, executable simulator-objects are produced for use in a distributed environment.     

Book reviews

Electronic Finance Law Chris Reed, 1993 Hemel Hempstead: Woodhead‐Faulkner. 450 pp. £50.00

Introduction to Computer Law, 2nd Edn David I. Bainbridge, 1993 London: Pitman £18.99

Deontic Logic in Computer Science: normative system specification John‐Jules CH. Meyer & Roel J. Wieringa, 1993 London: John Wiley £34.95, xiv + 317pp.     

A comfort assessment of existing cervical orthoses

Purpose: Identify location and intensity of discomfort experienced by healthy participants wearing cervical orthoses.

Method: Convenience sample of 34 healthy participants wore Stro II, Philadelphia, Headmaster, and AspenVista^® cervical orthoses for four-hour periods. Participants reported discomfort level (scale 0–6) and location.

Results: Participants reported mean discomfort for all orthoses over the four-hour test between ‘a little discomfort’ and ‘very uncomfortable’ (mean discomfort score = 1.64, SD = 1.50). Seven participants prematurely stopped tests due to pain and six reported maximum discomfort scores. Significant linear increase in discomfort with duration of wear was found for all orthoses. Significantly less discomfort was reported with Stro II than Headmaster and Philadelphia. Age correlated with greater perceived discomfort. Orthoses differed in the location discomfort was experienced.

Conclusion: Existing cervical orthoses cause discomfort influenced by design and duration of wear with orthoses’ design the more significant factor. This work informed the design of a new orthosis and future orthoses developments.

Practitioner Summary: The purpose of this study was to gain greater knowledge about the discomfort caused by wearing of existing neck orthoses in order to inform the design and development of a new neck orthosis. This study gathers empirical data from a surrogate population and concludes that orthosis design is more influential than the duration of wear.     

Push Notifications in Diet Apps: Influencing Engagement Times and Tasks

Background: Smartphones have reached levels of popularity and penetration where they are now suitable for use in population health interventions. A key feature of smartphones is push notification or in app messaging service, which can be used to alert users to messages or instructions pertaining to an installed app. Little evidence exists as to the persuasive power of these messages.

Method: We conducted a 24-week live user evaluation of push notifications used in a behavior-based mobile app for a meal replacement program to understand the role of push notifications in persuading users to engage with self-monitoring tasks.

Results: User perception of the prompts were verified through questionnaires, which in conjunction with the interaction logs show that users were tolerant of multiple daily prompts. The decline in compliance to the tasks set, however, shows that while the participants did not object to receiving prompts, they were less likely to respond to them as the study progressed.

Conclusions: Push notifications and user tasks are appropriate mechanisms to engage users with mobile technology in the short term.     

The Observer-Generated Information Process: Composite Stages,Cooperative “Logical” Structure,and Self-Organization

Conventional information science generally considers an information process, but traditionally uses the probability measure for random events, and Shannon’s entropy measure as an uncertainty function of the states. The cutting process on separated states decreases quantity information concealed in the states correlation, holding hidden process information.

Up to now, “information process” has not had a scientifically conclusive definition nor its implicit structure.

The presenting information process performs logical operations with discrete information units (Bits) to achieve a goal, integrating the discrete mutually connected sequence of symbols and the extracting process’ hidden information in the structure of an information Observer. The probing time-space observation develops the unit of space-time geometry-memorizing logic.

The defined information process starts generating observations of a random process via the logic of probing impulses, sequentially cutting the process entropy measure and creating the discrete information units whose integration enfolds the information geometrical structure of an Observer. Found composite stages of the information process and the synthesized optimal process trajectory minimize observation time in an artificially designed information Observer with intellectual searching logic. The analytical modeling, computer simulations, and experimental applications validate the results.     

Book reviews

Patent Harmonization Harold C. Wegner London, Sweet & Maxwell, 1993 xx + 376 pp., £70.00 (hardback)

Of Authors and Origins: essays on copyright law Brad Sherman & Alain Strowel (Eds) Oxford, Clarendon Press, 1994 xiv + 313 pp., £30.00 (hardback)

Future Air Navigation Systems Werner Guldimann & Stefan Kaiser Dordrecht, Martinus Nijhoff, 1993 Utrecht Studies in Air and Space Law, Vol. 13 viii + 281 pp., £76.50 (hardback)

The Law of Copyright Terence Prime London, Fourmat Publishing, 1992, xxiv + 313 pp., £30.00 (paperback)     

Fast detection of significantly transformed areas due to illegal waste burial with a procedure applicable to Landsat images

The problem of illegal waste burial is a serious threat to human health and ecosystems. These illegal activities occur most often in areas which have been heavily modified and considered degraded, mainly quarry areas and landfills, even if it is licensed.

To identify the areas where there is suspicion of illegal waste burial, a great amount of time is often necessary. As a matter of fact, the detection of suspicious areas is often based on a comparison of available airborne images with high temporal and spatial resolution, and surveys. This is also done to gather significant aspect of change as deep soil reshuffle in small excavation areas. These methods however, take a long time to be applied because large areas have to be analysed within sub-areas. Consequently, there is loss of understanding related to a wider and complete phenomenon that allows us to have information of all the territory that has undergone heavy transformations, especially if due to illegal conduct of waste disposal. As a result, there are no enough data to strategically evaluate how to counteract such illegal activities.

Since these areas have already been heavily disturbed and subjected to continuous changes over time, one or more detection techniques in a standardized procedure might only be applicable in some contexts. The above method comparison and survey is certainly a useful tool for detecting areas affected by excavation activities or waste illegal disposal. It also provides information where significant transformations have occurred in a short time.

The purpose of this work is the development of a processing procedure with Landsat images applicable to agro-ecosystems that can produce results in heavily transformed areas where suspicion of illegal waste burial is high.     

ON THE REPRESENTATION OF ACTIVITY ARRAYS†

A general methodology for empirical investigaiion is described which consists of: (i) the selection of a system on the object of investigation with respect to the purpose and constraints of investigation, (ii) the gathering of data for the system and organizing them in the form of activity arrays, (iii) the processing of the data through which certain time-invariant properties representing the data are determined, (iv) the interpretation of these time-invariant data representations from the standpoint of the purpose of investigation.

It is shown that each activity array yields many different representations. A procedure through which the various representations can be obtained is described that consists of: (1) the selection of a mask specifying a pattern for sampling the data, (2) the sampling procedure through which certain types of time-invariant relations are determined for the given mask, (3) the simplification of the time-invariant relations, if necessary or desirable.

A basis for the objective comparison of possible representations and ascertainment of the representation with the highest possible degree of determinism, subject to given constraints, is developed.

The procedure is applicable to both well defined and fuzzy variables of any scale. No classification into input and output variables is required, although it is not prohibited.     

Hand anthropometry survey of rural farm workers in south-eastern Nigeria

The importance of hand anthropometry as it relates to design of hand tools particularly for farm workers have been established; however, anthropometric data for this group of agricultural workers have continued to remain scarce. A survey of hand anthropometry relevant in design of agricultural hand tools was carried out on 200 male and 100 female adult farm workers in south-eastern Nigeria. Comparison of the male and female data obtained showed that male dimensions were higher than that recorded for the females. The hand anthropometric data of the male and female farm workers were compared with that of other populations but no clear distinction was observed. It was however clear that the following hand dimensions, 2nd Joint to root digit 3 and width at tip digit 3 recorded for Nigerian farm workers were highest and lowest, respectively, compared to other populations.

Practitioner Summary:

Hand anthropometric data relevant in design of hand tools have continued to remain scarce particularly for farm workers. Hand anthropometry survey of farm workers carried out in south-eastern Nigeria revealed higher dimensions for males than females; however, no clear distinction was observed in comparison with other populations.     

Dissemination and use of a participatory ergonomics guide for workplaces

Musculoskeletal disorders (MSDs) result in lost-time injury claims and lost productivity worldwide, placing a substantial burden on workers and workplaces. Participatory ergonomics (PE) is a popular approach to reducing MSDs; however, there are challenges to implementing PE programmes. Using evidence to overcome challenges may be helpful but the impacts of doing so are unknown. We sought to disseminate an evidence-based PE tool and to describe its use. An easy-to-use, evidence-based PE Guide was disseminated to workplace parties, who were surveyed about using the tool. The greatest barrier to using the tool was a lack of time. Reported tool use included for training purposes, sharing and integrating the tool into existing programmes. New actions related to tool use included training, defining team responsibilities and suggesting programme implementation steps. Evidence-based tools could help ergonomists overcome some challenges involved in implementing injury reduction programmes such as PE.

Practitioner Summary

Practitioners experience challenges implementing programmes to reduce the burden of MSDs in workplaces. Implementing participatory interventions requires multiple workplace parties to be ‘on-board’. Disseminating and using evidence-based guides may help to overcome these challenges. Using evidence-based tools may help ergonomics practitioners implement PE programmes.     

The Importance of Auditing Your Company’s Strategic Plan

A company’s strategic plan is its long-term outlook that sets out the plans, goals, objectives and actions for the next three to ten years. The board needs an objective assurance that the plan was properly developed. The internal audit function is best positioned to provide this assurance. The reason: it is one of the board’s most powerful mechanisms for understanding the full spectrum of key governance, risk, and control issues facing the company embodied in the strategic plan.

Auditing a strategic plan begins with a review of what it constitutes (its elements) and the methodology (its process) used in developing the plan. It thus becomes much easier to focus the audit effort in determining whether the output for each step along the way in these two broad streams has been achieved.

If not carefully planned and executed, a strategic plan audit could do irreparable damage to the reputation of the audit effort throughout the organization. As a result, it requires a multi-talented team with a high-powered leader, preferably the chief audit executive.

Although a strategic plan fails due to such common factors as planning teams lacking an understanding of the business, lack of commitment, not having the right people, or not adapting to a changing environment to take full advantage of technological developments, there is a key reason often overlooked: lack of an audit of the plan itself which, if done properly, could uncover these reasons for failure long before they happen.     

Home is where the head is: a distributed cognition account of personal health information management in the home among those with chronic illness

Managing chronic illness requires personal health information management (PHIM) to be performed by lay individuals. Paramount to understanding the PHIM process is understanding the sociotechnical system in which it frequently occurs: the home environment. We combined distributed cognition theory and the patient work system model to investigate how characteristics of the home interact with the cognitive work of PHIM. We used a 3D virtual reality CAVE that enabled participants who had been diagnosed with diabetes (N = 20) to describe how they would perform PHIM in the home context. We found that PHIM is distinctly cognitive work, and rarely performed ‘in the head’. Rather, features of the physical environment, tasks, people, and tools and technologies present, continuously shape and are shaped by the PHIM process. We suggest that approaches in which the individual (sans context) is considered the relevant unit of analysis overlook the pivotal role of the environment in shaping PHIM.

Practitioner Summary:

We examined how Personal Health Information Management (PHIM) is performed in the homes of diabetic patients. We found that approaches to studying cognition that focus on the individual, to the exclusion of their context, overlook the pivotal role of environmental, social, and technological features in shaping PHIM.     

MEASUREMENT THEORY AND SIGNAL THEORY PART I—Investigations on the Foundations

The concept of a sensor with finite resolution is chosen as the cornerstone of a physical measurement theory. It is concluded that the concept of a band-limited channel is less appropriate for this purpose because it is defined with help of specific mathematical operators on functions that are defined on an infinite interval.

It is shown that measurement in continuum physics requires transfer, transformation and transport of energy to, by, and through a sensor: a non-equilibrium process. As theory requires equilibrium for any measurement, a paradox arises. It is indicated that experimental physics avoids this paradox with help of a hierarchy of space and time scales. The definitions and propositions are formulated in a similar way in order to avoid this equilibrium/non-equilibrium paradox.

The equivalence of the various forms of energy, as stated by the first law of thermodynamics and verified by experimental physics, renders interpretation of physical measurement relatively easy.

Signals are defined to be products of measurement. They are carriers of a finite amount of information. As the class of continuous functions generate an infinite amount of information, discrete functions are selected to represent sampled and digitized signals. If the sampling interval is of the order of the largest characteristic time scale of the total system, then little information is lost by digitization. The number of significant digits is related to the resolution of the sensor and of the other parts of the measuring instrument. A measuring instrument is shown to be composed of a chain or a set of chains of sensors.     

Fighter pilots’ heart rate,heart rate variation and performance during instrument approaches

Fighter pilots’ heart rate (HR), heart rate variation (HRV) and performance during instrument approaches were examined. The subjects were required to fly instrument approaches in a high-fidelity simulator under various levels of task demand. The task demand was manipulated by increasing the load on the subjects by reducing the range at which they commenced the approach. HR and the time domain components of HRV were used as measures of pilot mental workload (PMWL). The findings of this study indicate that HR and HRV are sensitive to varying task demands. HR and HRV were able to distinguish the level of PMWL after which the subjects were no longer able to cope with the increasing task demands and their instrument landing system performance fell to a sub-standard level. The major finding was the HR/HRV’s ability to differentiate the sub-standard performance approaches from the high-performance approaches.

Practitioner Summary:

This paper examined if HR and HRV were sensitive to varying task demands in a fighter aviation environment and if these measures were related to variations in pilot’s performance.