Current Notations Research Articles

SAM-SoS: A Stochastic Software Architecture Modeling and Verification Approach for Complex System-of-Systems

A System-of-Systems (SoS) is a complex, dynamic system whose Constituent Systems (CSs) are not known precisely at design time, and the environment in which they operate is uncertain. SoS behavior is unpredictable due to underlying architectural characteristics such as autonomy and independence. Although the stochastic composition of CSs is vital to achieving SoS missions, their unknown behaviors and impact on system properties are unavoidable. Moreover, unknown conditions and volatility have significant effects on crucial Quality Attributes (QAs) such as performance, reliability and security. Hence, the structure and behavior of a SoS must be modeled and validated quantitatively to foresee any potential impact on the properties critical for achieving the missions. Current modeling approaches lack the essential syntax and semantics required to model and verify SoS behaviors at design time and cannot offer alternative design choices for better design decisions. Therefore, the majority of existing techniques fail to provide qualitative and quantitative verification of SoS architecture models. Consequently, we have proposed an approach to model and verify Non-Deterministic (ND) SoS in advance by extending the current algebraic notations for the formal models as a hybrid stochastic formalism to specify and reason architectural elements with the required semantics. A formal stochastic model is developed using a hybrid approach for architectural descriptions of SoS with behavioral constraints. Through a model-driven approach, stochastic models are then translated into PRISM using formal verification rules. The effectiveness of the approach has been tested with an end-to-end case study design of an emergency response SoS for dealing with a fire situation. Architectural analysis is conducted on the stochastic model, using various qualitative and quantitative measures for SoS missions. Experimental results reveal critical aspects of SoS architecture model that facilitate better achievement of missions and QAs with improved design, using the proposed approach.

Leveraging Circular Economy through a Methodology for Smart Service Systems Engineering

Product Service Systems (PSS) and Smart Services are powerful means for deploying Circular Economy (CE) goals in industrial practices, through dematerialization, extension of product lifetime and efficiency increase by digitization. Within this article, approaches from PSS design, Smart Service design and Model-based Systems Engineering (MBSE) are combined to form a Methodology for Smart Service Architecture Definition (MESSIAH). First, analyses of present system modelling procedures and systems modelling notations in terms of their suitability for Smart Service development are presented. The results indicate that current notations and tools do not entirely fit the requirements of Smart Service development, but that they can be adapted in order to do so. The developed methodology includes a modelling language system, the MESSIAH Blueprinting framework, a systematic procedure and MESSIAH CE, which is specifically designed for addressing CE strategies and practices. The methodology was validated on the example of a Smart Sustainable Street Light System for Cycling Security (SHEILA). MESSIAH proved useful to help Smart Service design teams develop service-driven and robust Smart Services. By applying MESSIAH CE, a sustainable Smart Service, which addresses CE goals, has been developed.

Decoding Gentzen's Notation

In this note we consider Gentzen's first ordinal notation, used in his first published proof of the consistency of Peano Arithmetic (1936). It is a decimal notation, quite different from our current notations. We give a rule to translate this notation into our usual set-theoretic notation and we show some of its peculiarities. Then we indicate how to decode Gentzen's assignment of ordinal notations to derivations and give some examples. Finally, we go through his proof of their decrease after the application of his reduction procedure, giving further examples.

Responding to Ongoing Change

As modern organizations increasingly need to operate in uncertain and fast-paced business environments, pressures increase on information systems (IS) to support these enterprises in a dynamically changing world. Consequently, systems need to deliver results given incompletely known and constantly changing requirements and contexts and other uncertainties. Their development is no longer a progression from clear and stable requirements to solutions meeting them. Rather, it is a continuous process involving multiple iterations of analysis and exploration, design, and development taking into consideration changing organizational needs, available resources, and feedback from previous iterations. Since current modeling and analysis notations generally assume stable and predictable settings for IS development, this paper explores the difficulties in applying several such techniques for modeling continuously evolving systems in uncertain and rapidly changing socio-technical domains and identifies requirements for a comprehensive modeling notation suitable for these environments. Business intelligence capability implementation in enterprises is used as an illustration.

Understanding healthcare processes

Process models are powerful tools that facilitate workflow assessment. Stakeholders in healthcare technology projects use process models, but little is known about how current modeling notations support domain-specific challenges of understanding healthcare workflow. The aim of this study was to evaluate how well members of two healthcare stakeholder groups understand clinical processes modeled with Business Process Modeling Notation (BPMN) vs. a novel Health Process Notation (HPN). Engineers and healthcare-trained professionals were presented with process models and were tested for comprehension of processes and their perception of both notations. Participants showed a better understanding of relationships within the process and performed more efficiently with HPN. Nonetheless, BPMN was effective for representing sequences and task allocations. Professional background influenced certain aspects of stakeholders’ performance. The usefulness and ease of use of both notations were rated highly, suggesting that workflow models might help stakeholders assess the impact of technological change.

A Notation for the Task-Oriented Modeling of Business Processes

Current notations for business processes are mainly technological tools and lack strong links with the ontological items, i.e., the tasks and the business entities that information systems consist of. In particular, the information flow is missing from process models and human decisions are not adequately represented. In order to overcome those drawbacks, this paper proposes a notation, called TOMP (Task-Oriented Modeling of business Processes), which considers tasks and decisions as first-class constructs in process models and provides the explicit representation of the information flow in connection with an information model. It also illustrates the structure of to-do lists, which are the major interface between the participants and their tasks.

Spanish Sign Language synthesis system

This work presents a new approach to the synthesis of Spanish Sign Language (LSE). Its main contributions are the use of a centralized relational database for storing sign descriptions, the proposal of a new input notation and a new avatar design, the skeleton structure of which improves the synthesis process.The relational database facilitates a highly detailed phonologic description of the signs that include parameter synchronization and timing. The centralized database approach has been introduced to allow the representation of each sign to be validated by the LSE National Institution, FCNSE.The input notation, designated HLSML, presents multiple levels of abstraction compared with current input notations. Redesigned input notation is used to simplify the description and the manual definition of LSE messages.Synthetic messages obtained using our approach have been evaluated by deaf users; in this evaluation a maximum recognition rate of 98.5% was obtained for isolated signs and a recognition rate of 95% was achieved for signed sentences.

Principles for constructing notation in unit systems and their application to the SI

The SI is the world’s premier scientific instrument and, like all instruments, must be updated as science and technology advance. The CIPM is planning to redefine four SI base units in terms of invariants of nature and has already dubbed this revision the ‘New SI’. This title will confuse most SI users, who are impacted only by the structure and notation of the SI, and neither of these has changed. A truly ‘New SI’, to be practical in the information age, would have at minimum an unambiguous, and preferably a machine- and user-friendly, notation. These and other principles for constructing a notation are proposed, and the SI historical and current notations are examined against these. Several levels of remediation are suggested.

Feature selection for brain activity data on cortex–time–frequency space

This work presents a new approach to the synthesis of Spanish Sign Language (LSE). Its main contributions are the use of a centralized relational database for storing sign descriptions, the proposal of a new input notation and a new avatar design, the skeleton structure of which improves the synthesis process.The relational database facilitates a highly detailed phonologic description of the signs that include parameter synchronization and timing. The centralized database approach has been introduced to allow the representation of each sign to be validated by the LSE National Institution, FCNSE.The input notation, designated HLSML, presents multiple levels of abstraction compared with current input notations. Redesigned input notation is used to simplify the description and the manual definition of LSE messages.Synthetic messages obtained using our approach have been evaluated by deaf users; in this evaluation a maximum recognition rate of 98.5% was obtained for isolated signs and a recognition rate of 95% was achieved for signed sentences.

People-Oriented Enterprise Information Systems

Current notations and languages do not emphasize the participation of users in business processes and consider them essentially as service providers. Moreover, they follow a centralized approach as all the interactions originate from or end in a business process; direct interactions between users cannot be represented. What is missing from this approach is that human work is cooperative and cooperation takes place through structured interactions called conversations; the notion of conversation is at the center of the language/action perspective. However, the problem of effectively integrating conversations and business processes is still open and this chapter proposes a notation called POBPN (People-Oriented Business Process Notation) and a perspective, referred to as conversation-oriented perspective, for its solution.

Comparison of Indices Proposed as Criteria for Assigning Skin Notation

Skin notations are used as a hazard identification tool to flag chemicals associated with a potential risk related to transdermal penetration. The transparency and rigorousness of the skin notation assignment process have recently been questioned. We compared different approaches proposed as criteria for these notations as a starting point for improving and systematizing current practice. In this study, skin notations, dermal acute lethal dose 50 in mammals (LD(50)s) and two dermal risk indices derived from previously published work were compared using the lists of Swiss maximum allowable concentrations (MACs) and threshold limit values (TLVs) from the American Conference of Governmental Industrial Hygienists (ACGIH). The indices were both based on quantitative structure-activity relationship (QSAR) estimation of transdermal fluxes. One index compared the cumulative dose received through skin given specific exposure surface and duration to that received through lungs following inhalation 8 h at the MAC or TLV. The other index estimated the blood level increase caused by adding skin exposure to the inhalation route at kinetic steady state. Dermal-to-other route ratios of LD(50) were calculated as secondary indices of dermal penetrability. The working data set included 364 substances. Depending on the subdataset, agreement between the Swiss and ACGIH skin notations varied between 82 and 87%. Chemicals with a skin notation were more likely to have higher dermal risk indices and lower dermal LD(50) than chemicals without a notation (probabilities between 60 and 70%). The risk indices, based on cumulative dose and kinetic steady state, respectively, appeared proportional up to a constant independent of chemical-specific properties. They agreed well with dermal LD(50)s (Spearman correlation coefficients -0.42 to -0.43). Dermal-to-other routes LD(50) ratios were moderately associated with QSAR-based transdermal fluxes (Spearman correlation coefficients -0.2 to -0.3). The plausible but variable relationship between current skin notations and the different approaches tested confirm the need to improve current skin notations. QSAR-based risk indices and dermal toxicity data might be successfully integrated in a systematic alternative to current skin notations for detecting chemicals associated with potential dermal risk in the workplace.

The OO-method approach for information systems modeling: from object-oriented conceptual modeling to automated programming

Current and future (conventional) notations used in Conceptual Modeling Techniques should have a precise (formal) semantics to provide a well-defined software development process, in order to go from specification to implementation in an automated way. To achieve this objective, the OO-method approach to Information Systems Modeling presented in this paper attempts to overcome the conventional (informal)/formal dichotomy by selecting the best ideas from both approaches. The OO-method makes a clear distinction between the problem space (centered on what the system is) and the solution space (centered on how it is implemented as a software product). It provides a precise, conventional graphical notation to obtain a system description at the problem space level, however this notation is strictly based on a formal OO specification language that determines the conceptual modeling constructs needed to obtain the system specification. An abstract execution model determines how to obtain the software representations corresponding to these conceptual modeling constructs. In this way, the final software product can be obtained in an automated way.

Parallel object-oriented descriptions of graph reduction machines

Abstract machine descriptions of parallel computer architectures must capture communications and concurrency characteristics at a high level. Current design techniques and notations are weak in this respect. We present a layered method for refinement of a requirements specification through to a detailed systems architecture design. This paper concentrates on the two highest layers, the logical model, which is a requirements statement, and the systems architecture, which specifies logical processes and explicit communications. While requirements are expressed in a language that matches the problem domain, we suggest that a parallel object-oriented notation is most appropriate for the systems architecture layer. Refinements within this layer reflect implementation details (e.g. structure sharing and distribution of work among processing elements). We introduce a parallel object-oriented notation based on rewriting concepts and use it to refine the design of a parallel graph reduction machine to execute functional programs. The Paragon notation used is a natural extension of a graph rewriting language and the work forms the basis for a structured explication of parallel graph rewriting in which all communications are made explicit.

Modular Attribute Grammars

Attribute grammars provide a formal declarative notation for describing the semantics and translation of programming languages. Describing any real programming language is a significant software engineering challenge. From a software engineering viewpoint, current notations for attribute grammars have two flaws: tedious repetition of essentially the same attribute computations is inevitable, and the various components of the description cannot be decomposed into modules.… — From the Authors' Abstract

Computer graphics in music performance research

Theories of skilled music performance must account for variations on what is written in traditional musical notation. Some variations are intentional and reflect structural features of the music that are chosen for emphasis by the performer. Current music notations are inadequate to reflect these variations. Computer applications are described that allow graphical and statistical examination of performance variations on traditional musical notation. An integrated set of visual and sound tools is provided that allows music to be recorded, edited, analyzed, and played back on electronic and acoustic musical instruments. The graphical format allows flexibility through the use of windows, compression, expansion, and scrolling of multiple sources of information, mapping of acoustic to visual dimensions, and scaling of different performance parameters without normalization. Experimental evidence from piano performances is used to demonstrate how graphical formats can aid research on human performance.

A new notion of encapsulation

Generally speaking, a “module” is used as an “encapsulation mechanism” to tie together a set of declarations of variables and operations upon them. Although there is no standard way to instantiate or use a module, the general idea is that a module describes the implementation of all the values of a given type. We believe that this is too inflexible to provide enough control: one should be able to use different implementations (given by different modules) for variables (and values) of the same type. When incorporated properly into the notation, this finer grain of control allows one to program at a high level of abstraction and then to indicate how various pieces of the program should be implemented. It provides simple, effective access to earlier-written modules, so that they are useable in a more flexible manner than is possible in current notations. It generalizes to provide the ability to indicate structural transformations, in a disciplined fashion, in order to achieve efficiency with respect to time or space. However, the program will still be understood at the abstract level and the transformations or implementations will be looked at only to deal with efficiency concerns. Finally, some so-called “data types” (e.g. stack and subranges of the integers) can more properly be looked upon simply as restricted implementations of more general types (e.g. sequence and integer ). Thus, the notion of subtype becomes less important.

Fibered categories and the foundations of naive category theory

Any attempt to give “foundations”, for category theory or any domain in mathematics, could have two objectives, of course related.(0.1)Noncontradiction: Namely, to provide a formal frame rich enough so that all the actual activity in the domain can be carried out within this frame, and consistent, or at least relatively consistent with a well-established and “safe” theory, e.g. Zermelo-Frankel (ZF).(0.2)Adequacy, in the following, nontechnical sense:(i) The basic notions must be simple enough to make transparent the syntactic structures involved.(ii) The translation between the formal language and the usual language must be, or very quickly become, obvious. This implies in particular that the terminology and notations in the formal system should be identical, or very similar, to the current ones. Although this may seem minor, it is in fact very important.(iii) “Foundations” can only be “foundations of a given domain at a given moment”, therefore the frame should be easily adaptable to extensions or generalizations of the domain, and, even better, in view of (i), it should suggest how to find meaningful generalizations.(iv) Sometimes (ii) and (iii) can be incompatible because the current notations are not adapted to a more general situation. A compromise is then necessary. Usually when the tradition is very strong (ii) is predominant, but this causes some incoherence for the notations in the more general case (e.g. the notationf(x) for the value of a functionfatxobliges one, in category theory, to denote the composition of arrows (f, g) →g∘f, and all attempts to change this notation have, so far, failed).

Some remarks on simple tournaments

In this paper we shall prove some results about tournaments which we believe to be interesting both from an algebraic and a set theoretic point of view . The definition of a simple tournament, the subject of our title, was motivated by questions in algebra, but the results and the proofs we give are essentially set theoretical . We assume that the reader is familiar with the current notations of set theory . A tournament T = is a relational structure, where T is a non-empty set and -4 is a trichotomous binary relation on T, i .e . for every pair x, yET exactly one of the three relations

Circuit duality and polarity conventions

By indicating how, but for chance, the present confusion in electric-potential notation conventions also could have arisen in electric current notations, the author seeks to show that our troubles with potentials are man-made. He suggests that the cure of potential-definition ills is to define potential independently of any connected circuit, as is done with current.