Predictive control,embedded cyberphysical systems and systems of systems – A perspective

Today’s world is changing rapidly due to advancements in information technology, computation and communication. Actuation, communication, sensing, and control are becoming ubiquitous. These technological advancements have led to the widespread availability of information and the possibility to connect systems in unforeseen manner. There is a strong desire for smart(er) cities, buildings, devices, factories, health monitoring – a smarter world. However, designing such a smarter world requires addressing also many challenges resulting from the emerging complex interactions and interoperation of systems. How is it possible to handle the increasing complexity during design and maintenance of such systems? How can one guarantee safety and performance of systems operating over networks which are subject to erroneous communication, delays, and failures of sensors and actuators? Is it possible to design control systems which allow for easy reconfiguration or even self-organization, for example by letting subsystems join and leave larger systems via plug and play strategies? Can one guarantee privacy of the controlled subsystems while exchanging information, which is necessary for maintaining overall system performance? We believe that predictive control is a well suited control approach to tackle some of these challenges due to its flexibility with respect to the formulation of the problem and the possibility to directly take constraints, preview information, as well as models of different complexity of the physical world into account. In this perspective we limit our attention to three areas we believe predictive control methods can provide a basis to tackle the appearing challenges: the efficient and easy implementation of predictive control on omnipresent embedded computation hardware, the question of resource and network aware control, as well as control on the network level of systems of systems. We briefly summarize results from these fields and outline some ideas on challenges, which arise.     

Human factors in a dynamic information society: where are we heading?

Society is becoming increasingly dynamic and integrated owing to the extensive use of information technology. This has several implications that pose new challenges to the human factors profession. In an integrated society, changes and disturbances propagate rapidly and widely and the increasing scale of operations requires also that rare events and circumstances are considered during systems design. In this situation, human factors contributions should be increasingly proactive, not only responding to observed problems, but also, they should be based on models of adaptive human behaviour in complex, dynamic systems. The paper suggests some methodological issues to consider for human factors analyses by designers, evaluators and teachers.     

On global controllability of affine nonlinear systems with a triangular-like structure

In this paper, we investigate a class of affine nonlinear systems with a triangular-like structure and present its necessary and sufficient condition for global controllability, by using the techniques developed by Sun Yimin and Guo Lei recently. Furthermore, we will give two examples to illustrate its application.     

A study of a technological development process: Human factors—the forgotten factors?

The aim of this study was to explore how human factors were taken into account in the development of a new type of drilling equipment. This study is part of a larger project on the understanding of human factors in the design and implementation of automated drilling technology. The principal study was a longitudinal study lasting 4 years that involved 43 interviews, offshore and onshore observations, and two surveys. The analysis in this paper is based on seven informants who were either part of the design team or the paramount project team developing new automated drilling technology for an offshore oil- and gas-producing installation in the same development project, in addition to project documents. The informants were interviewed using semi-structured interviews, and grounded theory based on the coding process of Strauss and Corbin (Basics of qualitative research: grounded theory procedures and techniques. Sage, Newbury Park, 1990) was used to analyse the data. The core category was found to be insufficient human factor analyses performed in the development phase due to the two main categories, namely (1) insufficient information coordination and (2) narrow focus in different phases of the project. This was found to contribute to increased costs, low user-friendliness, and end users’ insufficient knowledge of safe usage and potential risks. Our conclusion was that homogenous top competence involving technical aspects contributed to developers’ lack of understanding of the need for sufficient analyses of end user requirements and of the tasks that would be affected by the new technology. Hence, we argue that technological development could benefit from including human factors experts from the project’s outset to bridge the gap between the lack of relevant information and sufficient information on which to base development decisions. In addition, we contend that performing human factors analyses throughout the development of a project would be beneficial due to the potential of hindering cultural aspects such as a non-questioning culture, which is viewed as a hazard in high-risk organizations.     

Human factors/ergonomics as a systems discipline? “The human use of human beings” revisited

Discussions of the possible future of Human factors/ergonomics (HFE) usually take the past for granted in the sense that the future of HFE is assumed to be more of the same. This paper argues that the nature of work in the early 2010s is so different from the nature of work when HFE was formulated 60–70 years ago that a critical reassessment of the basis for HFE is needed. If HFE should be a systems discipline, it should be a soft systems rather than a hard systems discipline. It is not enough for HFE to seek to improve performance and well-being through systems design, since any change to the work environment in principle alters the very basis for the change. Instead HFE should try to anticipate how the nature of work will change so that it can both foresee what work will be and propose what work should be.     

Co-simulation for performance prediction of integrated building and HVAC systems – An analysis of solution characteristics using a two-body system

Integrated performance simulation of buildings and heating, ventilation and air-conditioning (HVAC) systems can help in reducing energy consumption and increasing occupant comfort. However, no single building performance simulation (BPS) tool offers sufficient capabilities and flexibilities to analyze integrated building systems and to enable rapid prototyping of innovative building and system technologies. One way to alleviate this problem is to use co-simulation to integrate different BPS tools. Co-simulation approach represents a particular case of simulation scenario where at least two simulators solve coupled differential-algebraic systems of equations and exchange data that couples these equations during the time integration.This article analyzes how co-simulation influences consistency, stability and accuracy of the numerical approximation to the solution. Consistency and zero-stability are studied for a general class of the problem, while a detailed consistency and absolute stability analysis is given for a simple two-body problem. Since the accuracy of the numerical approximation to the solution is reduced in co-simulation, the article concludes by discussing ways for how to improve accuracy.     

Optimizing a damped system – a case study

We consider a second-order damped-vibrational system described by the equation M ?+C(v) [xdot]+K x=0, where M, C(v), K are real, symmetric matrices of order n. We assume that the undamped eigenfrequencies (eigenvalues of (λ² M+K) x=0) ω₁, ω₂, …, ω _n , are multiple in the sense that ω₁=ω₂, ω₃=ω₄, …, ω _n?1=ω _n , or are given in close pairs ω₁ ≈ ω₂, ω₃ ≈ ω₄, …, ω _n?1 ≈ ω _n . We present a formula which gives the solution of the corresponding phase space Lyapunov equation, which then allows us to calculate the first and second derivatives of the trace of the solution, with no extra cost. It can serve for the efficient trace minimization.     

On small-controllability of a class of Hammerstein-nonlinear systems – an implicit function approach

In this paper, an implicit function approach is applied to controllability of a class of discrete-time Hammerstein-nonlinear systems. Based on this approach, the systems are shown to own a strong property, namely, small-controllability. As an immediate application, the obtained small-controllability results are generalised to the continuous-time Hammerstein-nonlinear systems and some continuous-time versions of small-controllability are presented.     

Top-down development of layered fault tolerant systems and its problems — a deontic perspective

Although the top-down development paradigm has successfully been applied to master the complexity of large systems, it has not yet been accepted as a useful paradigm for fault tolerant system design. This is mainly due to a problem that is sometimes referred to as the lazy programmers paradox. The lazy programmer paradox was already present and solved in top-down development methods for non-critical systems. However, the problem has re-appeared in an even more serious variant for critical systems. A few toy examples concerning exception handling in an Ada-like language are used to explain and illustrate the paradox. One possible solution to the problem is to use a specification language in which one can express that certain behaviours of a system are preferred over others. This paper proposes deontic logic as such a specification language. Therefore, a short and rather informal introduction to deontic logic is included. A non-trivial example is included to illustrate how deontic logic can be used to solve the lazy programmer paradox.Supported by NWO/SION Project 612-316-022: Fault Tolerance: Paradigms, Models, Logics, Construction.     

Optimisation of PM scheduling for multi-component systems – a simulated annealing approach

Proper planning of preventive maintenance (PM) is crucial in many industries such as oil transmission pipelines, automotive and food industries. A critical decision in the PM plans is to determine frequencies and types of maintenance actions in order to achieve a certain level of system availability with a minimum total cost. In this paper, we consider the problem of obtaining availability-based non-periodic optimal PM planning for systems with deteriorating components. The objective is to sustain a certain level of availability with the minimal total maintenance-related costs. In the proposed approach, the planning horizon is divided into some inspection periods of equal intervals. For any given interval, a decision must be made to perform one of the three actions on each component; inspection, preventive repair and preventive replacement. Any of these activities has different effects on the reliability of the components and the corresponding distinct costs based on the required recourses. The cost function includes the cost for repair, replacement, system downtime and random failures. System availability and PM resources are the main constraints considered. Since the proposed model is combinatorial in nature involving non-linear decision variables, a simulated annealing algorithm is employed to provide good solutions within a reasonable time.     

Specifying information systems for business process integration – A management perspective*

Supply chain management and customer relationship management are concepts for optimizing the provision of goods to customers. Information sharing and information estimation are key tools used to implement these two concepts. The reduction of delivery times and stock levels can be seen as the main managerial objectives of an integrative supply chain and customer relationship management. To achieve this objective, business processes need to be integrated along the entire supply chain including the end consumer. Information systems form the backbone of any business process integration. The relevant information system architectures are generally well-understood, but the conceptual specification of information systems for business process integration from a management perspective, remains an open methodological problem. To address this problem, we will show how customer relationship management and supply chain management information can be integrated at the conceptual level in order to provide supply chain managers with relevant information. We will further outline how the conceptual management perspective of business process integration can be supported by deriving specifications for enabling information system from business objectives. This work has been funded by the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung), record no. 01HW0196.     

The campfire storytelling system – automatic creation and modification of a narrative

This paper presents and evaluates a method for automatically generating a narrative that includes initial input from the listener, without forcing him/her to become an actual character in the story. More importantly, the story can be modified by the listener during the course of the story being narrated. This latter feature works without pre-defining alternative paths, thereby permitting the changes to take place at any time throughout the course of the story. This system, called the Campfire Storytelling System, employs a contextual approach to narrative generation called the Cooperating Context Method (CCM). Campfire STS was assessed for its functionality and its user acceptance. Thirty-eight human test subjects evaluated stories generated by Campfire STS. They responded to a survey stating their opinions about the generated stories, their entertainment value for adults, their creativity, and other similar issues. Furthermore, 20 of these subjects who self-reported non-trivial experience with children were additionally asked to evaluate the generated stories with respect to how much children would enjoy them. The results of these evaluations suggest that Campfire STS is able to create interesting and novel stories, as well as change them seamlessly in mid-stream while still maintaining interesting and entertaining stories.     

Innovation systems in Malaysia: a perspective of university—industry R&D collaboration

Collaborative research and development (R&D) activities between public universities and industry are of importance for the sustainable development of the innovation ecosystem. However, policymakers especially in developing countries show little knowledge on the issues. In this paper, we analyse the level of university–industry collaboration in Malaysia. We further examine the fundamental conditions that hinder university–industry collaboration despite the government’s initiatives to improve such linkages. We show that the low collaboration  is a result of an R&D gap between the entities. While the universities engage in basic and fundamental R&D, the private sectors involved in incremental innovation that requires less R&D investments. The different nature of the industries’ R&D requires closer cooperation between firms namely buyers, suppliers and technical service providers and not the universities. Among others, the lack of an intermediary role, absorptive capacity and collaborative initiative by the industry also contribute to the problem. The study suggests that the collaborative activities can benefit both if deliberate and effective efforts on reducing the R&D mismatch are made between the universities and industry. Likewise, proper institutional arrangements in coordinating these activities are required. This result seems to reflect the nature of many developing countries’ national innovation systems, and therefore, lessons from Malaysia may serve as a good case study.     

Accomplishing universal access through system reachability—a management perspective

The aim of this paper is to describe the need of a method by which we can estimate the return on accessibility investments in information technology (IT) systems. This paper reveals some of the reasons why accessibility still is a secondhand criterion when designing digital services. It also describes the authors experiences regarding the concept of accessibility and how it must develop in order to obtain the status of a basic business criterion for the benefit of disabled people who are currently excluded from public services and labour markets. The paper also questions the need of a separate accessibility standard. Additionally, we discuss some of the hindering in the market and limiting perspectives that are blocking further development. One of the problems in the market seems to be that accessibility as a concept has been more of an issue about creating equal opportunities and therefore probably does not have the quality of a business criterion. In order to bridge that gap, we argue for replacing accessibility with reachability, which is a concept based on a measure used by media when estimating the reached percentage of a population or target group.     

On the accuracy of the global positioning system—A test using a hand-held receiver

Abstract

This study aims to evaluate the accuracy of location (x, y and z) using a Magellan GPS NAV 1000 receiver. The position of a known reference point was compared with 50 fix points measured in two-dimensional (2D) mode (x, y) and with 50 fix points measured in three-dimensional (3D) mode (x, y and z).

The mean errors and the root mean square errors (RMSE) in the Euclidian distances between the reference point and the measured fix points were 17·9?m and 20·0?m respectively for the 2D measurements, and 25·7?m and 34·8?m respectively for the 3D measurements. The mean error in elevation was 0·2?m and the corresponding RMSE was 39·1?m. The study indicates a significant difference in the total error (Euclidian distance) between points obtained with different signal qualities and different geometric qualities. The error in the Euclidian distance never exceeded 44·0?m using 2D mode, which suggests that the Magellan GPS NAV 1000 receiver should be a useful supportive tool for many remote sensing applications.     

Inter-organizational information systems adoption – a configuration analysis approach

In this article we propose a new complementary approach to investigate Inter-Organizational Information Systems (IOIS) adoption called configuration analysis. We motivate the need for a new approach by the common observation that the structure and the strategy of an IOIS are interdependent and that the IOIS adoptions consequently cluster orderly. For example, an IOIS setup with a powerful customer as a hub and many suppliers as spokes frequently surfaces across diffusion studies. Yet, this fact has not been integrated into existing analyses, and its implications have not been fully developed. We propose that IOIS scholars need to look beyond the single adopting organization in IOIS adoption studies and in contrast consider adoption units what we call an adoption configuration. Each such configuration can be further characterized along the following dimensions: (1) vision, (2) key functionality, (3) mode of interaction, (4) structure and (5) mode of appropriation. In addition, these dimensions do not co-vary independently. For example, a particular organizing vision assumes a specific inter-organizational structure. A typology of IOIS configurations for adoption analysis is laid out consisting of dyadic, hub and spoke, industry and community configurations. Specific forms or adoption analysis are suggested for each type of configuration. Overall, configuration analysis redirects IOIS adoption studies both at the theoretical and the methodological level, and a corresponding research agenda is sketched.     

Exploring consumer preferences in cloud archiving – a student's perspective

Cloud storage has seen an increasing rise in demand and diffusion. Consequently, the cloud storage market is also becoming an increasingly commoditised market. That is, homogenous products are offered at equal prices, and this offer makes it more difficult for cloud storage providers to generate revenue and differentiate themselves from their competitors. Therefore, it is vital for providers to precisely understand customer preferences so that these can be targeted with appropriate services. To examine these preferences, we conduct a choice experiment and analyse choice decisions gathered from 340 German students by means of a conjoint analysis. We perform an individual-level analysis of preferences, which reveals significant differences and heterogeneity within the sample. By using a subsequent cluster analysis, we identify three distinct customer segments that also show significant differences in, for example, the perceptions of information privacy and risks. Our findings contribute to the literature by uncovering the preference structure and trade-offs that users make in their choice of storage services when employed for the purpose of archiving. We conclude the study with a discussion of practical implications that can aid cloud storage providers in service design decisions, and highlight the limitations associated with our research approach and drawn sample.