On the definition of quantum programming modules

There are no doubts that quantum programming and, in general, quantum computing, is one of the most promising areas within computer science and one of the areas where most expectations are being placed in recent years. Although the days when reliable and affordable quantum computers will be available is still a long way off, the explosion of programming languages for quantum programming has grown exponentially in recent years. The software engineering community has been quick to react to the need to adopt and adapt well-known tools and methods for software development, and for the design of new ones tailored to this new programming paradigm. However, many key aspects for its success depend on the establishment of an appropriate conceptual framework for the conception and design of quantum programs. This article discusses the concept of module, key in the software engineering discipline, and establishes initial criteria for determining the cohesion and coupling levels of a module in the field of quantum programming as a first step towards a sound quantum software engineering. As detailed in the article, the conceptual differences between classical and quantum computing are so pronounced that the translation of classical concepts to the new programming approach is not straightforward.This research was funded by Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia under the ‘Excelence Group Program 19895/GERM/15’

Engineering the development of quantum programs: Application to the Boolean satisfiability problem

The development of quantum programs is becoming a reality due to the rapid advancement of quantum computing. Over the past few years, a multitude of hardware platforms, algorithms, and programming languages have emerged to support this paradigm. By the very nature of Quantum Mechanics principles, there is an enormous change of philosophy when building quantum programs, which operate in a probabilistic space, unlike the deterministic behaviour shown by classical programming languages. These conceptual differences can be overcome by using techniques and tools of Software Engineering. In this paper, we apply Model-Driven Engineering techniques in a systematic way to ease the generation of quantum programs and we apply it to solve the satisfiability problem, very important in many engineering domains like verification of discrete systems and test of integrated circuits. To that aim, we contribute with a metamodel for representing quantum circuits and a model-to-text transformation to generate working IBM Qiskit code. This model-driven infrastructure is employed to automatically generate quantum programs from SAT equations through a model-to-model transformation that embeds Grover’s algorithm. Besides, we provide formulas for calculating the number of required quantum elements from SAT equations, crucial in the current context of limited quantum resources. The interoperability with other tools and the extensibility to target additional quantum platforms is guaranteed thanks to the use of a model-based toolchain. We cover several usage scenarios to validate the approach, providing exemplary SAT equations, the generated Qiskit code and the results of executing this code in IBM Quantum infrastructure.We acknowledge the use of IBM Quantum services for this work. The views expressed in this paper are those of the authors, and do not reflect the official policy or position of IBM or the IBM Quantum team

Tunable Optical Filters Using Compound Ring Resonators for DWDM

The device is based on a loop mirror in a ring resonator. The loop mirror allows tuning by changing the coupling coefficient of a directional coupler. The loop mirror is implemented using a Sagnac configuration to have the same optical path between the signals to be interfered (copropagating and counterpropagating ones). The filter structure allows optical integration for having higher free-spectral ranges. Simple design equations for the filter parameters and the tuning are reported. Measurements on a passive optical fiber tunable filter are presented. There is a good agreement between measurements and theory.Publicad

Measurements On Passive Tunable Optical Filters For DWDM

WFOPC 2002 IEEE/LEOS Workshop on Fibre and Optical Passive Components, University of Glasgow, Scotland, on 5th-6th June 2002.Measurements on a passive optical fibre tunable filter are presented. The device is based on a loop mirror in a ring resonator. The loop mirror allows tuning by changing the coupling coefficient of a coupler. The novel filter structure allows planar optical integration for having higher free spectral ranges. Novel and simple design equations for the filter parameters and the tuning process are reported. There is a good agreement between measurements and theory.Universidad Carlos III de MadridPublicad

Determination of the number of shots for Grover’s search algorithm

This paper focuses on Grover’s quantum search algorithm, which is of paramount importance as a masterpiece of Quantum Computing software. Given the inherent probabilistic nature of quantum computers, quantum programs based on Grover’s algorithm need to be run a number of times in order to generate a histogram of candidate values for solutions, which are then checked to identify the valid ones. In this paper, the distribution of the required number of shots to find all or a fraction of all the solutions to the Grover’s search problem is studied. Firstly, considering the similarity of the probability problem with the well-known coupon collector’s problem, two formulae are obtained from asymptotic results on the distribution of the required number of shots, as the number of problem solutions grows. These expressions allow to compute the number of shots required to ensure that, with probability p, all or a fraction of all the solutions are found. Secondly, the probability mass function of the required number of shots is derived, which serves as a benchmark to assess the validity of the asymptotic approximations derived previously. A comparison between the two approaches is presented and, as a result, a rule of thumb to decide under which circumstances employ one or the other is proposed.Mathieu Kessler acknowlegdes the support of Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (Grant 20911/PI/18)

Constructs for prototyping information systems using object petri nets

OASIS (Open and Active System Information Specification) is a language for the specification of object-oriented conceptual models. Object Petri nets (OPNs) support a full integration of object-oriented concepts into Petri nets. We propose a way to represent the object-oriented concepts used in the OASIS language with OPNs as a suitable semantic model for validating software specifications. We have developed a basic execution model for OASIS specifications, including its main features. Communication aspects between objects are taken into account in our proposal (triggering mechanism and shared events). We consider: event preconditions reducing the worlds to be reached, attribute valuations changing the states of objects, the creation and deletion of objects, and life-cycles of objects. OPNs are an appropriate semantic foundation for building a concurrent software engineering environment for distributed computation because they allow a natural representation of concurrence. We show how the object-oriented concepts of an OASIS specification are represented in OPN

A graph-based approach for modelling quantum circuits

A crucial task for the systematic application of model-driven engineering techniques in the development of quantum software is the definition of metamodels, as a first step towards automatic code generation and integration with other tools. The importance is even greater when considering recent work where the first extensions to UML for modelling quantum circuits are emerging and the characterisation of these extensions in terms of their suitability for a model-driven approach becomes unavoidable. After reviewing the related work, this article proposes a unified metamodel for modelling quantum circuits, together with five strategies for its use and some examples of its application. The article also provides a set of constraints for using the identified strategies, a set of procedures for transforming the models between the strategies, and an analysis of the suitability of each strategy for performing common tasks in a model-driven quantum software development environment. All of these resources will enable the quantum software community to speak the same language and use the same set of abstractions, which are key to furthering the development of tools to be built as part of future model-driven quantum software development frameworks

A family of experiments to evaluate the understandability of TRiStar and i* for modeling Teleo-Reactive systems

The Teleo-Reactive approach facilitates reactive system development without losing sight of the system goals. Objective: To introduce TRiStar as an extension of i* notation to specify Teleo-Reactive systems. To evaluate whether the notational extension is an improvement in terms of effectiveness and efficiency over the original language when it is used to specify Teleo-Reactive systems. Method: A family of experiments was carried out with final-year engineering students and experienced software development professionals in which the participants were asked to fill in a form designed to evaluate the efficiency and effectiveness of each of the languages. Results: Both the statistical results of the experiments, analyzed separately, and the meta-analysis of the experiments as a whole, allow us to conclude that TRiStar notation is more effective and efficient than i* as a requirements specification language for modeling Teleo-Reactive systems. Conclusion: The extensions made on i* have led to TRiStar definition, a more effective and efficient goal-oriented notation than the original i* language.This work was partially supported by the insPIre (ref. TIN2012-34003), cDrone (ref. TIN2013- 45920-R) and ViSelTR (ref. TIN2012-39279) projects of the Spanish Government. Also Spanish Ministerio de Educación, Cultura y Deporte, Subprograma Estatal de Movilidad, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016 for grant CAS14/0023

European Entrepreneurial Learning in Information and Communication Technologies. The EU-xCEL Experience in Spain

This paper describes the experience of the Cartagena node in the 2015 edition of the EU-xCEL project, which was funded by the European Union's Horizon 2020 Research and Innovation Programme. EU-xCEL aims at fostering entrepreneurship awareness and training among young graduates, in Information and Communication Technologies as well as to strengthen the European entrepreneurship ecosystem. This paper outlines the development of the training week and the posterior virtual incubation phase, as well as the experience of running the program in Cartagena. Finally, we outline some conclusions drawn from the experience.This work has been developed in the context of the EUxCEL project, funded by European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No 644801. It has been partially supported by the “Research Programme for Groups of Scientific Excellence at Region of Murcia" of the Seneca Foundation (Agency for Science and Technology of the Region of Murcia – 19895/GERM/15). Diego Alonso thanks the Spanish Ministerio de Educación, Cultura y Deporte, Subprograma Estatal de Movilidad, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016 for grant CAS14/00238

A systematic approach to developing safe tele-operated robots

Tele–operated service robots are used for extending human capabilities in hazardous and/or inaccessible environments. Their use is undergoing an exponential increase in our society, reason why it is of vital importance that their design, installation and operation follow the strictest possible process, so that the risk of accident could be minimised. However, there is no such process or methodology that guides the full process from identification, evaluation, proposal of solutions and reuse of safety requirements, although a hard work is being done, specially by the standardisation committees. It’s also very difficult to even find in the literature examples of safety requirements identification and use. This paper presents the engineering process we have followed to obtain the safety requirements in one of the robots of the EFTCoR1 project and the way this requirements have affected the architecture of the system, with a practical example: a crane robot for ship hull blasting.Financiado parcialmente por los programas programs CICYT, ANCLA (TIC2003-07804-C05-02), y parte de DYNAMICA (DYNamic and Aspect-Oriented Modeling for Integrated Component-based Architectures