An analysis of ‘ industrial dynamics ’

In this paper a linearized version of an ‘ industrial dynamics ’ simulation mode discussed by Forrester (1061) is presented and analysed. It is shown that at least for the stop change in final demand treated by Forrester (19R1) the behaviour of the linearized model presented here is not dissimilar to the behaviour of Forrester's nonlinear model. Analysis of the linearized model shows that the poor transient behaviour of the system is due primarily to the modes associated with the exponential smoothing of the demand.     

A ‘complexity level’ analysis of immediate vision

This paper demonstrates how serious consideration of the deep complexity issues inherent in the design of a visual system can constrain the development of a theory of vision. We first show how the seemingly intractable problem of visual perception can be converted into a much simpler problem by the application of several physical and biological constraints. For this transformation, two guiding principles are used that are claimed to be critical in the development of any theory of perception. The first is that analysis at the complexity level is necessary to ensure that the basic space and performance constraints observed in human vision are satisfied by a proposed system architecture. Second, the maximum power/minimum cost principle ranks the many architectures that satisfy the complexity level and allows the choice of the best one. The best architecture chosen using this principle is completely compatible with the known architecture of the human visual system, and in addition, leads to several predictions. The analysis provides an argument for the computational necessity of attentive visual processes by exposing the computational limits of bottom-up early vision schemes. Further, this argues strongly for the validity of the computational approach to modeling the human visual system. Finally, a new explanation for the pop-out phenomenon so readily observed in visual search experiments, is proposed.     

Visualization of curvature plots and evaluation of fairness: an analysis of the effect of ‘scaling’

Changing the aspect-ratio (scale) of a graphical plot significantly affects the “messages” getting across to a viewer. This is true also for curvature plots and other graphs currently used in Curve & Surface Modeling to evaluate fairness. In particular, the sharp corners appearing in such graphs, employed as local fairness indicators by current practices, are significantly affected by nonuniform scaling. A detailed study of this phenomenon is presented offering specific guidelines for correctly “reading” curvature plots.     

Multi-parameter sensitivity analysis of linear dynamic systems through the second method of Liapunov †

Using the second method of Liapunov, a new procedure for performing sensitivity calculations in the stability analysis of linear dynamic systems is developed. Defining stability measure in terms of a Liapunov function and its time derivative, the paper formulates a method for the calculation of the sensitivity of stability measure to variations in system parameters. The method provides a basis for optimal stability design of linear dynamic systems, the criterion of optimality being that the sensitivity of the stability measure to parameter variations be zero. The feasibility and usefulness of the method are illustrated by numerical examples involving one and two variable parameters. Comparison of the time responses of the output variable obtained by using zero-sensitivity parameter settings with those resulting from the use of the minimum integral-square error criterion demonstrates the superiority of the proposed method. The procedure is simple and lends itself readily to programming on a digital computer.     

Systemic analysis of so-called ‘accidents on the level’ in a multi trade company

Slips, trips and falls on the level are considered commonplace and are rarely subjected to in-depth analysis. They occur in highly varied circumstances in an occupational situation. In-depth analysis of these accidents was conducted within a company with the aim of understanding them better, to be able to discuss prevention field possibilities and priorities for the company concerned. Firstly, available data on ‘accidents on the level’ occurring over the last 4 years were analysed and a typology for these accidents was derived, based on individual activity at the time of the accident and accident location. The three most serious accident-causing situations were analysed in-depth from interviews with injured persons, as well as from activity observation and activity-related verbal information obtained from operatives. These most serious situations involved accidents occurring when climbing down from trucks or when walking either in surroundings outside company premises or from (to) a vehicle to (from) a work location. In-depth accident analysis and characterization of accident-causing situations as a whole enhance our understanding of the accident process and allow us to envisage priorities for action in the prevention field, in operational terms. Each accident-causing situation reveals environmental factors that in fact constitute accident factors (obstacle, stone, etc.), when the individual walks or climbs down from a truck. Analysis shows that other events are necessary for accident occurrence. For example, the individual may be subjected to a time constraint or may be preoccupied. Results obtained here, in a company integrating different trades, are discussed and compared with those referred to in the literature. Generalization of some of these results is also considered.     

Organizational structure of Mazda’s Keiretsu: a graph theoretic analysis

According to Freeman, centrality indices, which include degree, closeness, and betweenness, are an effective way to measure organizational structure. However, Ito discussed the implications of centrality, and found that differences exist even when the centrality is the same. Using data on transactions and cross shareholdings that were drawn from Mazda’s Yokokai Keiretsu, a new method — the SNW model — is proposed to calculate structural importance. Therefore, this article provides a new perspective for discovering the structural importance of network organizations. Furthermore, implications based on statistical comparisons between the SNW model and corporate performance such as sales and profits are proffered.     

Just for the ‘F’ of it

当美国音乐电视台fuse想要提升自己的形象时，Juxt Interactive、一只法国雪貂和一个丑毙了的仙女就这么出现了，它们一起创造头韵式的魔法。[编者按]     

Studies of Work ‘in the Wild’

Computer Supported Cooperative Work (CSCW) -     

Global sensitivity analysis based on Gini’s mean difference

Global sensitivity analysis has been widely used to detect the relative contributions of input variables to the uncertainty of model output, and then more resources can be assigned to the important input variables to reduce the uncertainty of model output more efficiently. In this paper, a new kind of global sensitivity index based on Gini’s mean difference is proposed. The proposed sensitivity index is more robust than the variance-based first order sensitivity index for the cases with non-normal distributions. Through the decomposition of Gini’s mean difference, it shows that the proposed sensitivity index can be represented by the energy distance, which measures the difference between probability distributions. Therefore, the proposed sensitivity index also takes the probability distribution of model output into consideration. In order to estimate the proposed sensitivity index efficiently, an efficient Monte Carlo simulation method is also proposed, which avoids the nested sampling procedure. The test examples show that the proposed sensitivity index is more robust than the variance-based first order sensitivity index for the cases with non-normal distributions.     

The ‘transfer of skill’ and the ‘transfer of human relations’ to machine systems

The necessity and opportunity for face-to-face contact with other colleagues is being increasingly reduced as a result of factory automation (FA) or office automation (OA). This means that human functions which are a result of human contact and relationships are substituted for by the function of machine systems. This transfer of relations from the human system to the machine system causes isolation of the individual in the process of work. This chapter considers some reasons for isolation with particular reference to the computerisation of production systems. The paper addresses the serious consequences for the environmental situation in Japan and the fabric of Japanese society.     

Implementing the ‘Fool's model’ of combinatory logic

This paper studies Fool's models of combinatory logic, and relates them to Hindley's D-completeness problem. A fool's model is a family of sets of formulas, closed under condensed detachment. Alternatively, it is a model ofCL in naive set theory. We examine Resolution; and the P-W problem. A sequel shows T is D-complete; also, its extensions. We close with an implementation FMO of these ideas.     

Chaos emerged on the ‘edge of chaos’

Rule 110 is a complex cellular automaton (CA) in Wolfram's system of identification, capable of supporting universal computation. It has been suggested that a universal CA should be on the ‘edge of chaos’, which means that the dynamical behaviour of such a system is neither simple nor chaotic. There is no doubt that the dynamical property of Rule 110 is extremely complex and still not well understood. This paper proves the existence of subsystems on which this rule is chaotic in the sense of Devaney.     

Fractal analysis of the structure and dynamics of a satellite‐detected urban heat island

In this Letter, three fractal models—surface, profile and pixel models are developed to analyse the structure and dynamics of an urban heat island (UHI). These three models were tested using data from Shanghai taken in 1990, 1995 and 1998. The surface model is capable of capturing the fractal dimension of the entire study area. The profile model can be used to analyse the structural characteristics of the UHI along certain directions and is capable of revealing changes in the texture characteristics of UHI. The pixel model can describe the changes in thermal characteristics surrounding each pixel in a particular locale and is suitable for analysing the micro‐structure of the UHI.     

The cost structure of influencers’ posts: the risk of losing followers

Personal and Ubiquitous Computing - This paper presents an exploratory study of the posting behavior of digital influencers in social participation platforms. As there are different platforms of...     

Multi-parameter sensitivity analysis of power-system stability by Popov's method†

Popov's method of frequency-domain stability criteria is used to conduct the multiparameter sensitivity analysis of power system stability. The two-parameter parametric sensitivity mode] of a one-machine infinite-bus system is developed, This model involves stability measure ξ, defined in terms of Lur'o-type Liapunov functions constructed systematically. Based on the application of the model to a specific numerical example, results and conclusions are given. This type of sensitivity analysis is useful for optimum design and operation of the power system. The criterion of optimality is zero sensitivity. In general, this form of analysis is applicable to any dynamic engineering system.     

A ‘non-parametric’ version of the naive Bayes classifier

Many algorithms have been proposed for the machine learning task of classification. One of the simplest methods, the naive Bayes classifier, has often been found to give good performance despite the fact that its underlying assumptions (of independence and a normal distribution of the variables) are perhaps violated. In previous work, we applied naive Bayes and other standard algorithms to a breast cancer database from Nottingham City Hospital in which the variables are highly non-normal and found that the algorithm performed well when predicting a class that had been derived from the same data. However, when we then applied naive Bayes to predict an alternative clinical variable, it performed much worse than other techniques. This motivated us to propose an alternative method, based on naive Bayes, which removes the requirement for the variables to be normally distributed, but retains the essential structure and other underlying assumptions of the method. We tested our novel algorithm on our breast cancer data and on three UCI datasets which also exhibited strong violations of normality. We found our algorithm outperformed naive Bayes in all four cases and outperformed multinomial logistic regression (MLR) in two cases. We conclude that our method offers a competitive alternative to MLR and naive Bayes when dealing with data sets in which non-normal distributions are observed.     

Note on ‘ On the definition of transfer function ’

An algorithm for directly obtaining the canonical state-space model corresponding to the Cauer third form of continued fraction expansion (CFE) from a given general state-space model is presented. The algorithm can be used to determine the transfer function of linear time-invariant system from its state-space model as well as to obtain the reduced order models..Two new similarity matrices, one transforms a state-space equation from a general form to a Cauer third CFE canonical form, and the other transforms a state-space model in phase-variable form to a state-space model in a Cauer third CFE canonical form, are derived. Using these matrices an approximate relationship between the original state vector and the state-vector of reduced model obtained by the method of Cauer third CFE is established     

Interpreting the externalised images of pupils’ conceptions of ICT: methods for the analysis of concept maps

The ImpacT2 evaluation is using image based concept mapping as one method of exploring the impact of networked technologies on students' learning. In a pre-test administered in June 2000, students in three cohorts aged 10–11, 13–14 and 15–16, produced around 2000 ‘maps’. Entitled ‘Computers in My World’, these provide a means of students externalising mental representations of networked technologies. Using a phenomenographic approach, the study aims to identify qualitatively different patterns of thinking and trends in the development of pupils' concepts. Five quanititative measures emerged from heuristic analysis of the maps: nodes, links, connectivity, ‘Spheres of Thinking’ and ‘Zones of Use’. Analysis of the pre-test maps was carried out alongside analysis of pre-test questionnaires, using SPSS. The outcomes suggest correlations between pupils' experience and the constent of their maps. Phenomenographic interviewing of selected 11 year old pupils, which entailed handling control over to interviewees through the use of open-ended questions, enabled further exploration of their experiences and understandings of those experiences. A method for in-depth interviewing of young students is described. Data suggest that pupils have sophisticated ‘secondary artifacts’ or mental models of the nature of networked technologies and their role in today's world. This has implications for the way that ICT is used in schools and for its potential as a tool for students' learning.     

A comparative analysis of the EU GDPR to the US’s breach notifications

One component of the newly implemented European Union General Data Protection Regulation (GDPR), a revision of a 1995 directive, is mandatory breach notification. The US has no such federal law. This means companies must satisfy multiple US laws and that makes it more challenging to comply. This study is a comparison of the GDPR with the statutes of the 50 US states, highlights the challenges companies face and reveals the types of decisions companies must make to be in compliance with these statutes.