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The paper proposes a modular functional modeling framework, which aims at integrating the different functional modeling perspectives, relevant to different disciplines. The results of two extensive literature studies on diverse functional modeling approaches proposed in a variety of disciplines are consolidated. These studies identified specific needs for an integrated functional modeling approach to support interdisciplinary conceptual design. The presented framework aims at fulfilling these needs. It consists of a variety of associated views, represented through different matrices. This matrix-based representation facilitates the analysis of different functional modeling perspectives and their interdependencies. Finally, the implications of the presented approach are discussed.

In this paper we present a tool to perform guided HAZOP studies using a functional modeling framework: D-higraphs. It is a formalism that gathers in a single model structural (ontological) and functional information about the process considered. In this paper it is applied to an industrial case showing that the proposed methodology fits its purposes and fulfills some of the gaps and drawbacks existing in previous reported HAZOP assistant tools.

The purpose of this paper is to introduce a new formalism to help in the aim of developing and integrating models for complex process systems. A new methodology to develop in a unique an integrated manner structural as well as functional models is presented. The methodology is based on a previous formalism named higraphs. In this paper the application of this approach will be mainly on risk analysis.

Qualitative modeling paradigm offers process systems engineering a potential for developing effective tools for handling issues related to Process Safety. A qualitative functional modeling environment can accommodate different levels of abstraction for capturing knowledge associated with the process system functionalities as required for the intended safety applications. To provide the scientific rigor and facilitate the acceptance of qualitative modelling, this contribution focuses on developing a scientifically based validation method for functional models. The Multilevel Flow Modeling (MFM) methodology is adopted in the paper as a formalized qualitative functional modeling methodology for dynamic process systems. A functional model validation procedure is proposed to assess whether the intended modeling purpose indeed represents a relevant proposal and whether the model represents the system behavior sufficiently well. With the reasoning capability provided by the MFM syntax and semantics, the validation procedure is illustrated on a three-phase separator system of an MFM model. The MFM model reasoning results successfully compares against analysis results from API RP. 14-C.

a new modeling approach for mode handling of Flexible Manufacturing Systems (FMS) is presented in this paper. At first the basic concepts of this modeling approach are introduced. Then the modeling steps of the FMS functional model are presented and illustrated through an example of a flexible manufacturing cell. The proposed method is modular, hierarchical and supports re-use concept. The established model is generic and well adapted to our control system context. Integration within this control system in particular within the supervision framework, is studied in the last paragraph.

In this paper, we propose to use functional modeling to extract physiological characteristics from dynamic gadolinium-enhanced MRI. The clinical objective is to independently compute the two vascular supplies of the liver, coming from hepatic artery and portal vein. These supplies are progressively modified in hepatocarcinogenesis, and their assessment can be useful for nodule characterization. A first physiological microscopic model of liver vascularization, allows simulating the evolution of the contrast material concentration. After comparison of simulated and real curves, a simplified version of this model is used to extract arterial and portal perfusion parameters, in normal case and in hepatic nodules. These values are in accordance with data obtained by invasive methods.

Multilevel Flow Modeling (MFM) is a well recognized methodology for functional modeling of complex systems which primarily focuses on the representation of their goals and functions. It has been successfully used in industrial process, e.g. nuclear power plant, chemical plants etc. to facilitate the operation on fault analysis and control. A significant improvement of the MFM methodology has been recently proposed, where the “role” concept was introduced to enable the representation of structural entities and the conveyance of important information for building up knowledge bases, with the purpose of complementing this reasoning methodology. Domestic heating systems, as the main resource to meet the thermal requirements of end-users, have different implementations in Europe in order to achieve various degrees of controllability and heating efficiencies. As all the heating systems serve the same basic needs i.e. supplying and transferring thermal energy, it is off interest to use MFM to investigate similarities and differences between different implementations. In this paper, three typical domestic European heating systems, which differ from each other in the number of temperature sensors and auxiliary components e.g. storage tanks, are modeled using the MFM methodology. Both the goals and functions of material and energy processes and the control functions of the heating systems are represented in the MFM models. It is found that varying the physical system setup results in only little differences among the MFM models. The ‘role’ concept is used to associate the relation between physical structures and functions in all MFM models. This study contributes to MFM library expansion and provides a significant test of the expressivity of MFM.

Multilevel Flow Modeling (MFM) is a methodology for functional modeling of industrial processes on several interconnected levels of means-end and part-whole abstractions. The basic idea of MFM is to represent an industrial plant as a system which provides the means required to serve purposes in its environment. MFM has a primary focus on plant goals and functions and provide a methodological way of using those concepts to represent complex industrial plant. The paper gives a brief introduction to the historical development, introduces the concepts of MFM and presents the application of the concepts in detail by a water mill example. The overall reasoning capabilities of MFM and its basis in cause-effect relations are also explained. The appendix contains an overview of MFM concepts and their definitions.

Traditionally alarms are designed on the basis of empirical guidelines rather than on a sound scientific framework rooted in a theoretical foundation for process and control system design. This paper proposes scientific principles and a methodology for design of alarms based on a functional modeling technique (MFM) which represents a process in terms of its goals, functions and operating requirements. The reasoning capabilities of MFM enable identification of operational situations which threaten to generate an alarm and derivation of potential response scenarios. The design methodology can be applied to any engineering system which can be modeled by MFM. The methodology provides a set of alarms which can facilitate event interpretation and operator support for abnormal situation management. The proposed design methodology provides the information content of the alarms, but does not deal with alarm presentation or display design issues. A hydraulically powered grinding process is employed as an industrially relevant system to show the applicability of the proposed design methodology with promising results.

The paper investigates application of functional modeling for independent protection layer analysis of risk assessment in complex industrial plant with special reference to nuclear power production. Layer of Protection Analysis （LOPA）is a simplified semi-quantitative risk assessment method that typically builds on the information developed during a qualitative hazard evaluation such as HAZOP. LOPA typically uses order of magnitude categories for initiating event frequency,consequence severity, and the likelihood of failure of independent protection layers (IPLs) to approximate the risk of a scenario. Identifying the IPLs systematically is a fundamental challenge as a basis for estimating the probability of failure on demand of each IPLs and for evaluating the risk to a decision concerning the scenario. Functional safety is the main focus of this study, which shows the modeling and reasoning capability of functional modeling, e.g. Multilevel Flow Modeling (MFM) and its application in IPLs analysis of a design based accident scenario, e.g. Loss of coolant accident (LOCA). Previously, MFM has showed its potential to be used for safety barrier analysis and Defense in Depth. The main contribution of the study is to explore a procedure using MFM to identify safeguards and then credit some of them as IPLs. Firstly, MFM modeling of the process system including control flow structures is presented. Secondly, the rule-based cause reasoning of MFM is used to identify initiating causes (chain of causes) of a specific consequence. Thirdly, safeguards are derived (safety functions in the system are designed represented by MFM functions) to prevent the consequence to happen. Fourth, judging the initiating causes and safeguards whether they can have common mode failure. If there is no common mode failure, then the safeguard is considered as an IPL. This procedure is demonstrated in a PWR LOCA accident scenario.

During the lifetime of the Acoustical Society of America, certain developments have led to an improved understanding of the physical and tonal properties of woodwind instruments. These developments include theoretical analysis, instrumentation for measuring acoustical properties, and high speed digital computing. This paper will review past work, summarize the present state of our knowledge. and offer some conjectures on the future. The content is restricted to a consideration of mechanical‐reed woodwinds, although comparable things could be said about “air‐reed” woodwinds. The following aspects will be discussed: (1) acceptable bore shapes; (2) theory of tone holes; (3) experimental measurement of input impedance: (4) numerical calculation of input impedance; (5) implications of input impedance: (6) reed and air‐column interaction: (7) small‐amplitude, steady‐state vibrations: (8) medium‐amplitude, nonbeating, steady‐state vibrations; (9) functional modeling of arbitrary amplitude transient and steady‐st...

A novel methodology is presented for the modeling and the simulation of wireless embedded systems. Tight interaction between the analog and the digital functionality makes the design and verification of such systems a real challenge. The applied methodology brings together the functional models of the baseband algorithms written in C language with the circuit descriptions at behavioral level in Verilog or Verilog-AMS for the system simulations in a single kernel environment. The physical layer of an ultrawideband system has been successfully modeled and simulated. The results confirm that this methodology provides a standardized framework in order to efficiently and accurately simulate complex mixed signal applications for embedded systems.