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A Solution to the Modularity Problem for Programming Languages: 2023 Benjamin Franklin Medal in Computer and Cognitive Science presented to Barbara H. Liskov, Ph.D.

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JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS 2023年第18期360卷 A14189-A14194页

作者： Marcus, Mitchell P. Univ Penn Philadelphia PA USA

Early programming methodologies proved inadequate for the reliable implementation of the large programs enabled by rapidly growing computer memories, resulting in prohibitively long times for software development. Attempts to solve this problem by limiting control structure primitives within programming languages or by imposing external design methodologies to enforce ill-defined notions of modularity proved unsuccessful. Barbara Liskov's definition of abstract data types in 1973 and her embodiment of this notion in the programming language CLU provided a major step toward solving this problem. The key idea was to define the fundamental building blocks of programs as a set of abstractions, each of which resulted from the combination of a data type with all the operations that needed to be performed on the data type. Data abstraction is now fundamental to all modern programming languages. A second key innovation of Liskov's was what she called "behavioral subtyping" for object-oriented programming, now known as the Liskov Substitution Principle (LSP). The LSP formally defines when objects of subclasses can be safely substituted for the parent class, a crucial requirement of bug-free programming within this programming paradigm. In addition, Liskov has made several key contributions to distributed computer systems, including the first use of atomic actions for successful concurrency and providing a practical solution to the problem of Byzantine faults.

关键词： object oriented programming

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design Method for Building Automation Control Programs to Enable the Energetic Optimization of Industrial Supply systems 54

Design Method for Building Automation Control Programs to En...

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54th CIRP Conference on Manufacturing Ssystems, CMS 2021

作者： Fuhrländer-Völker, Daniel Lindner, Martin Weigold, Matthias Otto-Berndt-Str. 2 Darmstadt64287 Germany

Standard PLC programming language does not allow to use complex algorithms in building automation for the energetic optimization of industrial supply systems. This paper discusses how future building automation systems should be designed for this purpose. An adapted building automation control program is implemented on an industrial PC and evaluated in the real scale ETA Research Factory. The program ensures scalability and functional safety through object-oriented programming and implementation of a safety fallback system. The industrial PC is enabled to communicate via OPC UA. Finally we present a communication interface to connect the building automation to optimization programs using Python. © 2021 The Author(s).

关键词： object oriented programming

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Covariant conversions (coco): A design pattern for type-safe modular software evolution in object-oriented systems 35

Covariant conversions (coco): A design pattern for type-safe...

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35th European Conference on object-oriented Programming, ECOOP 2021

作者： Bessai, Jan Heineman, George T. Düdder, Boris Technische Universität Dortmund Germany Worcester Polytechnic Institute MA United States University of Copenhagen Denmark

ISBN: (纸本)9783959771900

Software evolution is an essential challenge for all software engineers, typically addressed solely using code versioning systems and language-specific code analysis tools. Most versioning systems view the evolution of a system as a directed acyclic graph of steps, with independent branches that could be merged. What these systems fail to provide is the ability to ensure stable APIs or that each subsequent evolution represents a cohesive extension yielding a valid system. Modular software evolution ensures that APIs remain stable, which is achieved by ensuring that only additional methods, fields, and data types are added, while treating existing modules through blackbox interfaces. Even with these restrictions, it must be possible to add new variations, fields, and methods without extensive duplication of prior module code. In contrast to most literature, our focus is on ensuring modular software evolution using mainstream object-oriented programming languages, instead of resorting to novel language extensions. We present a novel CoCo design pattern that supports type-safe covariantly overridden convert methods to transform earlier data type instances into their newest evolutionary representation to access operations that had been added later. CoCo supports both binary methods and producer methods. We validate and contrast our approach using a well-known compiler construction case study that other researchers have also investigated for modular evolution. Our resulting implementation relies on less boilerplate code, is completely type-safe, and allows clients to use normal object-oriented calling conventions. We also compare CoCo with existing approaches to the Expression Problem. We conclude by discussing how CoCo could change the direction of currently proposed Java language extensions to support closed-world assumptions about data types, as borrowed from functional programming. © 2021 Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing. All

关键词： Directed graphs

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Application oriented synthesis of mobile multi-robot systems for cooperative object transport

Application oriented synthesis of mobile multi-robot systems...

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作者： Toro Ramos, Juan Mauricio Technical University of Berlin

学位级别：博士

The flexibility and increasing autonomy of mobile robots have been making the automation of challenging use cases in the course of the last decades possible. In this way, their implementation has not been limited to isolated single robots, and the use of multiple agents working together to achieve a common goal has been shown to increase considerably the overall capabilities of the system, in terms, for example, of a better spatial distribution, exertion of forces in handling tasks and higher flexibility, allowing the robots to be used in a wider spectrum of applications. Nevertheless, although the implementation of cooperative multi-robot systems (MRSs) harbours great potential, the larger solution space and design freedoms which emerge from all possible combinations of different robots, structures and operational configurations increase the complexity and required effort for their planning and synthesis. All this often leading to over-dimensioned cooperative MRSs with redundancies that are not conceived for a specific purpose but rather result from the simplification of the synthesis process, and where the real potentials of MRSs are not fully exploited. This work presents a general framework that structures and supports the early stage of the synthesis process of MRSs for cooperative transport applications without reducing the potential solution space. It starts by analysing the use case from the customer perspective and proposes novel indices for the characterization of the system's performance. Building on this, main clusters of configuration parameters or settings that directly influence the behaviour of the MRS are proposed, and through the analysis of their interrelations, specific design measures are derived. The applicability and added value of the proposed framework is discussed on the example of an automatic car transport system, where the possibility of abstracting the synthesis process and simultaneously reaching new solutions not taken into account by

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Cyber-physical system modeling with Modelica using message passing communication

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SIMULATION MODELLING PRACTICE AND THEORY 2022年第0期117卷 102501-102501页

作者： Sanz, Victorino Urquia, Alfonso Univ Nacl Educ Distancia UNED ETSI Informat Dept Informat & Automat Juan del Rosal 16 Madrid 28040 Spain

Modelica is an object-oriented modeling language whose design and features facilitate the description of cyber-physical systems (CPS). Message passing communication (MPC), seen as the transmission of impulses of information between model components, eases the description of the discrete-event parts of CPS models. However, Modelica does not currently supports MPC. Modelica supports an equation-based component connection rationale, where Modelica tools automatically transform component connections into model equations, following a physical modeling approach. The differences between MPC and Modelica connections are analyzed. A proposal for supporting MPC in Modelica is presented, inspired by the coupled PDEVS model communication approach. The presented MPC proposal is based on the definition of structures to manage messages, named buffers, interface ports and communication channels. Also, an implementation of the proposed MPC mechanism in the form of a new free Modelica library, named MSGLib, is presented. MSGLib includes functionality to manage and dynamically store messages, and describe component communications. Two examples, a pick and place system and a robotic arm, are presented to demonstrate the use of the library, and its combination with other Modelica models.

关键词： Cyber-physical systems Hybrid systems Modelica object-oriented modeling Simulation

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Port-Based Modeling of Transport Phenomena in Thermofluid systems and object-oriented implementation with the Modelica Language

SSRN

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SSRN 2023年

作者： Márquez, Francisco M. Zufiria, Pedro J. Yebra, Luis José Alcalá de Henares28801 Spain Madrid28040 Spain Tabernas04200 Spain

In this paper we present the physical foundations and the development of a Modelica library with the fundamental components for modeling thermofluid systems, including the transport phenomena that appear in moving *** model the behavior of these systems, we have assumed the Equilibrium Thermodynamics postulates and the local equilibrium postulate of Classical Irreversible Thermodynamics adapted to the port-Hamiltonian formalism. To graphically represent components and connections that form complex systems, we have used the bond graph symbology with some modifications making diagrams easier to *** have chosen Modelica because it is an object-oriented modeling language that facilitates incremental library design. To this end, we start by modeling generic components from which we derive components to compose models of thermofluid systems. Modelica also allows the modeling of acausal components, where the input/output relation is not an intrinsic characteristic of the model, but it is defined by setting the excitation (or boundary conditions) under which models are *** these tools we formulate the equations of change for simple single-substance thermofluid systems transporting mass, momentum, and energy and then we obtain the integral balances in control volumes with moving boundaries. In both cases, special attention is paid to entropy generation since entropy is a state variable in bond graph and port-Hamiltonian *** the integral balance equations, the library has been expanded with components (bonds, flow sources, heat sources, flow sinks, control volumes) for the thermofluid domain, and some piping models have been built to compare simulation results with the Modelica Standard Library *** this article, we have also added the viscosity and thermal conductivity equations to the properties of water (IAPWS 95) and Syltherm 800 for their use as fluids in the above piping system examples. © 2023, The Authors. All rights reserved.

关键词： Entropy

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use of Structural Mutations in object-oriented Mathematical Models of Robot Manipulation systems

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Mathematical Models and Computer Simulations 2020年第1期12卷 90-98页

作者： Krakhmalev, O.N. Bryansk State Technical University Bryansk 241035 Russian Federation

Abstract: The use of the method of targeted structural mutations of mathematical models is considered. The method allows us to create approximate models of robot manipulation systems by modifying their object-oriented mathematical models. Manipulation systems are considered as continuously deterministic systems described by systems of algebraic and ordinary differential equations. The implementation of this method is based on the possibilities provided by the method of visually designing the object diagrams of mathematical models. object diagrams are modified by replacing the parts selected in them with alternative objects to these parts. The use of the structural mutation method makes it possible to compensate the influence of random factors that are not taken into account by the original mathematical model obtained by the analytical method. © 2020, Pleiades Publishing, Ltd.

关键词： genesis of targeted mutations mathematical models mutation method object-oriented approach simulation modeling visual design of models

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Analyzing co-design of agroecology-oriented cropping systems: lessons to build design-support tools

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AGRONOMY FOR SUSTAINABLE DEVELOPMENT 2022年第4期42卷 72-72页

作者： Quinio, Maude Jeuffroy, Marie-Helene Guichard, Laurence Salazar, Paola Detienne, Francoise Univ Paris Saclay AgroParisTech INRAE UMR Agron F-78850 Thiverval Grignon France Inst Polytech Paris CNRS Telecom Paris I3 SES Palaiseau France

If the challenges involved in agroecological transition are to be addressed, cropping systems (CS) need to be changed profoundly, which in turn requires innovative design adapted to local conditions. This is however by no means an easy task since such design activity requires extensive knowledge on objects and processes rarely studied until now, most of which is distributed among numerous stakeholders. Since the 2000s, research on design in agriculture has aimed at developing participatory methods to support on-farm design of new systems, but few studies have focused on the elaboration of design-support tools. With a view to defining the features of tools intended to support the design of agroecology-oriented cropping systems, ergonomists recommended an analysis of the activities of the future users of these tools in their real work situations. We started out by implementing a diagnosis of use situations, based on observations of real collective design activities. To this end, we took part in six design workshops, which differed in terms of goals and of designers participating (i.e., farmers, advisors, students, or scientists). We first identified the diversity of features of these design situations, and then analyzed three processes across the design workshops: (i) the reformulation of the design goal;(ii) the large exploration of candidate solutions;and (iii) the local adaptation of these solutions while anticipating the on-field implementation. Here, we show, for the first time, the type of reasonings and knowledge that designers and facilitators displayed and used throughout the agroecological cropping system design process. We identify the features that future design-support tools should have to guide co-designers of agroecological CS. Such tools should promote several types of design reasoning and allow the development of external representations of the object under design. Our results provide operational guidelines for the elaboration of new design-support to

关键词： use situation design process design workshop Agroecology Distributed knowledge design reasoning

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object oriented Mathematical Modeling of Electrical Machines 4

Object Oriented Mathematical Modeling of Electrical Machines

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4th IEEE International Conference on Intelligent Energy and Power systems (IEPS)

作者： Pliuhin, Vladyslav Sukhonos, Maria Bileckiy, Ihor OM Beketov Natl Univ Urban Econ Dept Elect Energy Supply & Lighting Kharkiv Ukraine OM Beketov Natl Univ Urban Econ Sci Res Dept Kharkiv Ukraine

ISBN: (纸本)9780738105680

This paper is concerned with the implementation of the concept of automated synthesis of electric machine mathematical models, depending on design and type of the latter. The proposed method of the mathematical model synthesis is based on the provisions of the object-oriented design theory, which is widely used in the field of information technology. A generalized electromechanical energy converter, a squirrel-cage induction motor, a synchronous motor, a DC motor and a transformer are considered as a reference. Due to the application of the object-oriented concept of hierarchy and inheritance, each individual electric machine is generated from a generalized electromechanical energy converter with the simultaneous synthesis of equations describing electrodynamic transients in the form of a product of parameters and currents matrix. It is proposed to use the practical application of the technique under consideration in the optimization of electrical machines in dynamic operating modes during the computer-aided design process.

关键词： electric machine mathematical model object oriented inheritance hierarchy structural synthesis

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Identifying and Visualizing Variability in object-oriented Variability-Rich systems 19

Identifying and Visualizing Variability in Object-Oriented V...

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23rd International systems and Software Product Line Conference (SPLC)

作者： Ternava, Xhevahire Mortara, Johann Collet, Philippe Sorbonne Univ UPMC LIP6 Paris France Univ Cote Azur CNRS I3S Sophia Antipolis France

ISBN: (纸本)9781450371384

In many variability-intensive systems, variability is implemented in code units provided by a host language, such as classes or functions, which do not align well with the domain features. Annotating or creating an orthogonal decomposition of code in terms of features implies extra effort, as well as massive and cumbersome refactoring activities. In this paper, we introduce an approach for identifying and visualizing the variability implementation places within the main decomposition structure of object-oriented code assets in a single variability-rich system. First, we propose to use symmetry, as a common property of some main implementation techniques, such as inheritance or overloading, to identify uniformly these places. We study symmetry in different constructs (e.g., classes), techniques (e.g., subtyping, overloading) and design patterns (e.g., strategy, factory), and we also show how we can use such symmetries to find variation points with variants. We then report on the implementation and application of a toolchain, symfinder, which automatically identifies and visualizes places with symmetry. The publicly available application to several large open-source systems shows that symfinder can help in characterizing code bases that are variability-rich or not, as well as in discerning zones of interest w.r.t. variability.

关键词： Identifying software variability visualizing software variability object-oriented variability-rich systems tool support for understanding software variability software product line engineering

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