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

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

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