Effects of variety reduction and amplification in circular feedback systems

Kybernetes ◽  
2014 ◽  
Vol 43 (9/10) ◽  
pp. 1330-1337 ◽  
Author(s):  
Thomas Fischer
Keyword(s):  
Optical Feedback ◽  
Computational Modelling ◽  
Feedback System ◽  
Output Channel ◽  
Feedback Systems ◽  
Content Type ◽  
Theoretical Concepts ◽  
Input And Output ◽  
Photo Camera ◽  
Recursive System

Purpose – The purpose of this paper is to present the result of an experiment examining the effects of changing input and output channel variety in an optical feedback system and their potential to give rise to novelty, as some non-trivial systems do. Design/methodology/approach – The experimental design is based on a digital computer connected to a digital photo camera (input channel), and to a monitor screen (output channel). The camera is pointed at the monitor to form a circular feedback system. Monitor and camera resolutions constitute the variable input and output variety of the system, allowing the visual investigation of effects of variety reduction and variety amplification in circular feedback systems. Findings – Results suggest that variety amplification in input and/or output channels promotes the emergence of discernible novelty in the apparent absence of a creative/generative capability or agenda within the recursive system. Research limitations/implications – An analogy between an optical feedback system and human novelty generation is shown, while generalisability of observations made beyond the described experiment remains to be established. Originality/value – A new approach to the computational modelling of aspects of human creativity is presented. Photographic investigation of variety reduction and variety amplification is new, and hoped to be of value to those wishing to examine these theoretical concepts in concrete terms.

Optimal Model Reference Control Scheme Design for Nonlinear Strict-Feedback Systems

2020 ◽  
Vol 38 (9A) ◽  
pp. 1342-1351
Author(s):  
Musadaq A. Hadi ◽  
Hazem I. Ali
Keyword(s):  
Reference Model ◽  
Feedback System ◽  
Optimization Method ◽  
Feedback Systems ◽  
Model Reference ◽  
Scheme Design ◽  
Model Reference Control ◽  
Control Scheme ◽  
Lyapunov Stability Analysis ◽  
Strict Feedback

In this paper, a new design of the model reference control scheme is proposed in a class of nonlinear strict-feedback system. First, the system is analyzed using Lyapunov stability analysis. Next, a model reference is used to improve system performance. Then, the Integral Square Error (ISE) is considered as a cost function to drive the error between the reference model and the system to zero. After that, a powerful metaheuristic optimization method is used to optimize the parameters of the proposed controller. Finally, the results show that the proposed controller can effectively compensate for the strictly-feedback nonlinear system with more desirable performance.

Spontaneous spatial symmetry breaking in passive nonlinear optical feedback systems

1988 ◽  
Vol 38 (4) ◽  
pp. 2005-2010 ◽  
Author(s):  
A. Ouarzeddini ◽  
H. Adachihara ◽  
J. V. Moloney
Keyword(s):  
Symmetry Breaking ◽  
Nonlinear Optical ◽  
Optical Feedback ◽  
Feedback Systems ◽  
Spatial Symmetry

Determining the factors affecting the technical efficiency scores of public hospitals using different regression methods

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bayram Şahin ◽  
Gülnur İlgün ◽  
Seda Sönmez
Keyword(s):  
Public Hospitals ◽  
Regression Analyses ◽  
Tobit Regression ◽  
Control Variables ◽  
Content Type ◽  
Factors Affecting ◽  
Provincial Level ◽  
Regression Methods ◽  
Input And Output ◽  
Dea Method

PurposeThis study aims to identify the efficiency scores of hospitals affiliated to the Ministry of Health in Turkey between the years of 2010–2015 at provincial level and to reveal the factors that affect the efficiency scores.Design/methodology/approachThe two-stage data envelopment analysis (DEA) method was used to achieve the study purpose. In the first stage, DEA method based on input-oriented Charnes–Cooper–Rhodes (CCR) model was performed to calculate the efficiency scores of public hospitals at the provincial level between 2010 and 2015, and in the second stage, Tobit regression and linear regression analyses were used to identify whether the efficiency scores of provinces are affected by the input, output and control variables.FindingsUpon the analysis, the average efficiency scores of 81 provinces by years were found to vary between 0.79 and 0.89. According to both regression analyses, all of the input and output variables were found to have significant effects on the efficiency scores of provinces while only the population of province among the control variables was identified as the factor with an effect on the efficiency scores of provinces (p < 0.05).Practical implicationsThe results of this study are thought to guide health policymakers and managers in terms of both determining efficient and inefficient hospitals at the provincial level and revealing which variables should be taken into account in order to increase efficiency.Originality/valueThe study differs from previous studies on the efficiency of hospitals. First, although previous studies were generally descriptive studies to determine the efficiency level of hospitals, this study is an analytical study that tries also to show the factors affecting the efficiency of hospitals. In addition, while examining the effect of input and output variables on efficiency scores, control variables were also included in the study.

Criteria for Recovery of Zero Initial Condition Responses of Unstable Plants Under Input Saturation

2000 ◽  
Author(s):  
Wei Wu ◽  
Suhada Jayasuriya
Keyword(s):  
Initial Conditions ◽  
Input Saturation ◽  
Input Sequence ◽  
Feedback System ◽  
Open Loop ◽  
Feedback Systems ◽  
Bounded Control ◽  
Analysis And Design ◽  
Study Results ◽  
Unstable Plant

Abstract In this paper, we consider the sufficient and/or necessary conditions under which responses of unstable plants with zero initial conditions would be bounded under step inputs. Several possible unstable pole patterns are examined, and corresponding criteria are derived. It is shown that an unstable plant can be stabilized to have bounded responses using an alternate step input sequence. Step inputs simulate the saturated inputs in a feedback system with bounded control, where the closed-loop stability of an unstable plant is really difficult to study. Results from this open-loop study may lend some insight into the analysis and design of such feedback systems under input saturation nonlinearities.

Fuzzy overall equipment effectiveness and line performance measurement using artificial neural network

2019 ◽  
Vol 25 (2) ◽  
pp. 340-354 ◽  
Author(s):  
Mahsa Fekri Sari ◽  
Soroush Avakh Darestani
Keyword(s):  
Fuzzy Inference ◽  
Intelligent System ◽  
Data Gathering ◽  
Linguistic Terms ◽  
Automatic Data ◽  
Content Type ◽  
Smart Systems ◽  
Input And Output ◽  
Artificial Neural ◽  
Uncertain Input

Purpose The overall equipment effectiveness (OEE) is a powerful metric in production as well as one of the methods in evaluating function for measuring productivity in the production process. In the existing method, measuring OEE is based on three main elements consisting availability, performance and quality. The purpose of this paper is to evaluate the recognized metrics of production: OEE and overall line effectiveness (OLE) by using smart systems techniques. Design/methodology/approach In this paper, to improve the calculative methods and productivity with three methods: measuring OEE using Mamdani fuzzy inference systems (FIS), measuring OEE using Sugeno FIS, and measuring OLE using FIS and artificial neural networks (ANNs) are proposed. Findings The proposed methodologies aim to decrease some weaknesses of OEE and OLE methods by exploiting intelligent system techniques, such as FIS and ANNs. In particular, this research will solve the following issues that occur in manual and automatic data gathering. This technique is an effective way of measuring OEE and OLE with regard to different weights of losses as well as difference in the weight of the machines. In addition, it allows the operator’s knowledge to take a part in the measurement using uncertain input and output with implementation of linguistic terms. The presented method is the details and capabilities of those methods in various tested scenarios, and the results have been fully analyzed. Originality/value In relation to other methodologies, it allows the operator’s knowledge to take part in the measurement using uncertain input and output with implementation of linguistic terms. The presented method is the details and capabilities of those methods in various tested scenarios, and the results have been fully analyzed.

Two-sided form, differentiation and second-order observation in Escher’s artworks and Calvino’s stories

Kybernetes ◽  
2019 ◽  
Vol 48 (5) ◽  
pp. 1060-1077
Author(s):  
Laura Appignanesi
Keyword(s):  
Twentieth Century ◽  
Systems Theory ◽  
Second Order ◽  
Order System ◽  
Literary Works ◽  
Content Type ◽  
Theoretical Concepts ◽  
Art And Literature ◽  
Second Order Systems ◽  
Late Works

Purpose The purpose of this paper is to find a leading idea of the mid-twentieth century, demonstrating the pervasive nature of some concepts belonging to second-order systems theory. To achieve this objective, the paper looks at the art and literature of this era, to identify the principles developed by Luhmann in his late works. In particular, Escher’s drawings, Calvino’s stories and Luhmann’s concepts seem to express, in different ways, the same functioning mechanism of the complex social system. Design/methodology/approach With reference to theoretical approach and methodology, this paper carries out an interdisciplinary demonstration by alternative modes of logos and mythos. Some of the pillars of general systems theory are examined through the logical articulation of concepts developed by Spencer-Brown, von Foerster, and first of all through the late works of Luhmann, as well as through the analysis of Escher’s artworks and Calvino’s literary works. This paper interprets these artistic and literary works using cybernetic principles and systemic concepts, in particular, “two-sided forms,” “system–environment differentiation” and “second-order observation.” Findings In general, the main finding is the similarity of fascination with paradoxes and forms, with post-ontological reasoning, in twentieth century. The result of the cross-reading of Escher, Calvino and Luhmann reveals the presence of what Simmel called the “hidden king”: a philosophical paradigm of an era. In mid-1900s, this leading idea seems to express itself in the discoveries of biology and cybernetics, such as in Luhmann’s theory, art and literature. Escher’s drawings, Calvino’s stories and the concepts of Luhmann are projections of second-order system theory, in its constructivist value. Originality/value The originality of this paper lies mainly in the demonstration of theoretical concepts through the alternative modes of logos and mythos. These reflections can provide a new perspective to investigate social sciences from a cultural angle. This particular approach allows a deep awareness of the theory. The concrete value is to provide a better understanding to manage complexity.

Language at work in the Big Four: global aspirations and local segmentation

2018 ◽  
Vol 31 (7) ◽  
pp. 2031-2054 ◽  
Author(s):  
Dominic Detzen ◽  
Lukas Loehlein
Keyword(s):  
Corporate Culture ◽  
Professional Service ◽  
Service Firms ◽  
Professional Service Firms ◽  
Organizational Relationships ◽  
Native Languages ◽  
Content Type ◽  
Theoretical Concepts ◽  
Big Four

Purpose The purpose of this paper is to examine how professional service firms (PSFs) manage the linguistic tensions between global Englishization and local multilingualism. It achieves this by analysing the work of Big Four audit firms in Luxembourg, where three official languages co-exist: Luxembourgish, French, and German. In addition, expatriates bring with them their native languages in a corporate environment that uses English as its lingua franca. Design/methodology/approach The paper combines the institutionalist sociology of the professions with theoretical concepts from sociolinguistics to study the multifaceted role of language in PSFs. Empirically, the paper draws from 25 interviews with current and former audit professionals. Findings The client orientation of the Big Four segments each firm into language teams based on the client’s language. It is thus the client languages, rather than English as the corporate language, that mediate, define, and structure intra- and inter-organizational relationships. While the firms emphasize the benefits of their linguistic adaptability, the paper reveals tensions along language lines, suggesting that language can be a means of creating cohesion and division within the firms. Originality/value This paper connects research on PSFs with that on the role of language in multinational organizations. In light of the Big Four’s increasingly global workforce, it draws attention to the linguistic divisions within the firms that question the existence of a singular corporate culture. While prior literature has centred on firms’ global–local divide, the paper shows that even single branches of such firm networks are not monolithic constructs, as conflicts and clashes unfold amid a series of “local–local” divides.

Modeling head tracking of visual targets

2002 ◽  
Vol 12 (1) ◽  
pp. 25-33
Author(s):  
K.J. Chen ◽  
E.A. Keshner ◽  
B.W. Peterson ◽  
T.C. Hain
Keyword(s):  
Control System ◽  
Visual Feedback ◽  
Human Head ◽  
Feedback System ◽  
Optimization Methods ◽  
Head Tracking ◽  
Feedback Systems ◽  
Control Gain ◽  
Head Control ◽  
Visual Targets

Control of the head involves somatosensory, vestibular, and visual feedback. The dynamics of these three feedback systems must be identified in order to gain a greater understanding of the head control system. We have completed one step in the development of a head control model by identifying the dynamics of the visual feedback system. A mathematical model of human head tracking of visual targets in the horizontal plane was fit to experimental data from seven subjects performing a visual head tracking task. The model incorporates components based on the underlying physiology of the head control system. Using optimization methods, we were able to identify neural processing delay, visual control gain, and neck viscosity parameters in each experimental subject.

Building resilience for food service businesses in times of crisis: a Four-F action plan

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ananya Bhattacharya ◽  
Ambika Zutshi ◽  
Ali Bavik
Keyword(s):  
Crisis Management ◽  
Dynamic Capabilities ◽  
Planning Process ◽  
Action Plan ◽  
Food Service ◽  
Decision Makers ◽  
Theoretical Frameworks ◽  
Content Type ◽  
Theoretical Concepts ◽  
Service Businesses

Purpose This paper aims to propose a “Four-F (finding facts, fostering alternates, fulfilling implementation and feasibility testing)” action plan to global food service businesses (FSB) such as restaurants (dine-in/take away) to build resilience during times of global crises. The 2019 Coronavirus disease and FSBs apply as working examples elaborating the proposed Four-F action plan with several managerial implications for the internal and external stakeholders of FSBs. Design/methodology/approach The method involves reviewing and coding 108 articles using the PRISMA approach, then applying findings to develop the Four-F action plan integrating multiple theoretical concepts (such as stakeholder, crisis management and dynamic capabilities). Findings There are two key findings. First, though all four crisis phases should be considered by decision-makers as part of their contingency planning process, the pre and post-crisis stages need higher attention. Second, the Four-F action plan provides specific recommendations to FSBs stakeholders (consumers, suppliers and government) for each crisis phase (pre-crisis, crisis emergence, crisis occurrence and post-crisis). Originality/value To the best of the authors’ knowledge, this is the first paper that has incorporated multiple theoretical frameworks (stakeholder theory, crisis management and dynamic capabilities) within the FSBs context and provided the Four-F action plan for decision-makers to understand and manage crisis phases.

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