Applying acceptance requirements to requirements modeling tools via gamification: a case study on privacy and security.

Requirements elicitation, analysis and modeling are critical activities for software success. However, software systems are increasingly complex, harder to develop due to an ever-growing number of requirements from numerous and heterogeneous stakeholders, concerning dozens of requirements types, from functional to qualitative, including adaptation, security and privacy, ethical, acceptance and more. In such settings, requirements engineers need support concerning such increasingly complex activities, and Requirements Engineering (RE) modeling tools have been developed for this. However, such tools, although effective, are complex, time-consuming and requiring steep learning curves. The consequent lack of acceptance and abandonment in using such tools, by engineers, paves the way to the application of RE techniques in a more error-prone, low-quality way, increasing the possibility to have failures in software systems delivered. In this paper, we identify main areas of lack of acceptance, affecting RE engineers, for such tools, and propose an approach for making modeling tools more effective in engaging the engineer in performing RE in a tool-based way, receiving adequate feedback and staying motivated to use modeling tools. This is accomplished by performing acceptance requirements analysis (through the Agon Framework) and using gamification to increase the engagement of engineers during the usage of RE modeling tools. Towards this end, we performed a case study, within the VisiOn European Project, for enhancing a tool for modeling privacy and security requirements. Our case study provides preliminary evidence that our approach supports in making RE modeling tools more engaging from the engineer perspective

Technical-economic feasibility analysis of micro grids integrating fuel cells in non-interconnected zones in Colombia

La necesidad de proveer soluciones energéticas sostenibles para las zonas no interconectadas de Colombia, dependiendo de los recursos renovables disponibles en cada zona, supone un desafío respecto al análisis de viabilidad técnico-económica de las alternativas de solución a través de las microrredes. Este documento tiene como objetivo analizar el impacto técnico-económico de introducir celdas de combustible en la reducción de costos a lo largo del tiempo de vida de una microrred para zonas no interconectadas, empleando el software HOMER. Dicho impacto se evalúa tanto en el diseño técnico de la microrred como en el Valor Presente Neto y en el Costo nivelado de Energía ($/kWh). El análisis se realiza a partir de la cuantificación de la demanda de un poblado prototipo, el dimensionamiento y costo de las tecnologías que conforman la microrred para atender la demanda, y la disponibilidad de los recursos renovables solar y eólico de dos zonas localizadas en diferentes latitudes no interconectadas de Colombia. Adicionalmente, se analiza el efecto de introducir las celdas de combustible en el mix energético, resaltando las ventajas obtenidas al comparar cada caso frente a una generación tradicional basada en consumo de Diésel.The sustainable power solutions provided to non-interconnected zones should be based on the renewable energy resources available in each area. This presents a challenge for the techno-economic feasibility of alternative solutions through micro grids. The objective of this work is to analyze, using HOMER software, the techno-economic impact of introducing fuel cells on cost reduction during the lifetime of micro grids in non-interconnected zones. Such impact is evaluated in the technical design of the micro grid as Present Value and Levelized Cost of Electricity ($/kWh). The analysis considers the calculation of the demand of a generic village, the size and cost of the technologies that constitute the micro grid to satisfy the demand, and the availability of solar and wind power in two areas located at different latitudes in Colombia. In addition, the effect of introducing fuel cells into the energy mix was examined. Finally, the advantages were highlighted by comparing each case with traditional generation alternatives based on diesel consumption

From Secure Business Process Models to Secure Artifact-Centric Specifications

Making today's systems secure is an extremely difficult and challenging problem. Socio and technical issues interplay and contribute in creating vulnerabilities that cannot be easily prevented without a comprehensive engineering method. This paper presents a novel approach to support process-aware secure systems modeling and automated generation of secure artifact-centric implementations. It combines social and technical perspectives in developing secure complex systems. This work is the result of an academic and industrial collaboration, where SecBPMN2, a research prototype, has been integrated with SAP River, an industrial artifact-centric language

Mathematical model of photovoltaic systems for distributed maximum power point tracking

Este articulo presenta un modelo para sistemas de generación fotovoltaica orientado a evaluar el desempeño de algoritmos distribuidos de búsqueda del punto de máxima potencia. El modelo considera la conexión en serie de n conjuntos módulo-convertidor que pueden ser dimensionados dependiendo de la aplicación en particular. Dicho modelo está compuesto por un conjunto de ecuaciones que pueden ser implementadas en cualquier software de cálculo matemático o en un lenguaje de programación que soluciones este tipo de ecuaciones. El modelo incluye el comportamiento estático del módulo fotovoltaico a partir de una ecuación que estima su relación voltaje-corriente, además, incluye el modelo del convertidor elevador de potencia con pérdidas en el inductor, esto con el fin de aproximar el modelo general a una solución realística de la aplicación. El modelo final es validado mediante simulaciones y comparado con una implementación del mismo en un software de simulación electrónica tradicional.This paper presents a model of photovoltaic generation systems oriented to evaluate the performance of distributed maximum power point tracking algorithms. The model considers the series connection of n module-converter sets, which can be dimensioned depending on the particular application. This model is composed of an equation set that can be implemented in any mathematical analysis software or programming language that allows to solve this kind of equations. The proposed model also includes the static behavior of the photovoltaic module, described by one equation that estimates the current-voltage relation. Additionally, it includes a model of the Boost power electronic converter with inductor lost, which allows an approximation to realistic applications. The final model is validated using simulations, and it is compared with a traditional electronic simulation software implementation

Pregled znanstvenih napredaka u učinskoj elektronici usmjerenih ka osiguravanju efikasnog rada i dužeg životnog vijeka PEMgorivih ćelija

This article focuses on the main issues that affect the lifetime and performance of proton-exchange membrane fuel cells. The short lifespans of these fuel cells represent a barrier to their massive commercialization and usage in mobile and stationary applications. As fuel cell is a very complex system, a lot of knowledge of different areas is required, such as chemistry, electricity and mechanics, in order to completely understand its operation and all the problems that can occur during it. It is for this reason that an interdisciplinary approach needs to be taken when designing fuel-cell energy systems. This paper focuses on identifying and solving those issues that negatively affect the lifetime and performance of fuel cells. It is hoped that this article would be a valuable aid for power electronics’ researchers and engineers for better understanding the presented issues and a useful guide for solving them with the use of proper power electronic-devices. Initially, the basic operation and structure of a proton-exchange membrane fuel cell is explained. Three main issues that can occur during operation of a mobile or stationary fuel cell energy system are pointed out and discussed in details, on the basis of the state-of-the-art on fuel cell technology. These issues are poor water management, reactant gas starvation and fuel cell current ripple. This article provides answers as to why they occur, how they affect the fuel cell, how they can be mitigated, and what are the future trends within this research field.Članak se osvrće na ključna pitanja koja utječu na vrijeme rada i performanse gorivih ćelija s polimernom membranom kao elektrolitom. Kratak životni vijek gorivih ćelija takve vrste prepreka je njihovoj komercijalizaciji i masovnoj upotrebi u mobilnim i stacionarnim stanicama. Budući da su gorive ćelije komplicirani sustavi potrebno je znanje iz raznih područja kemije, elektrotehnike i mehanike da bi se u potpunosti mogao razumjeti njihov način rada i problemi koji se događaju. Upravo je zbog toga multidisciplinarni pristup nužnost pri razvoju sustava koji koriste gorive ćelije. Ovaj je članak usmjeren prema identifikaciji i rješavanju onih problema koji negativno utječu na životni vijek i performanse gorivih ćelija. Autori se nadaju da će se članak pokazati kao korisna pomoć i vodič istraživačima i inženjerima u domeni učinske elektronike pri susretu s navedenim problemima. Objašnjen je način rada i struktura gorive ćelije s polimernom membranom kao elektrolitom. Izložena su, i diskutirana do u detalje, tri glavna problema sa stajališta trenutačnih spoznaja u području učinske elektronike. Ti problemi su: loše upravljanje vodom, nestanak reaktantnog plina i strujni trzaji u gorivim ćelijama. Objašnjeno je zašto se ovi problemi događaju, kako utječu na gorivu ćeliju, kako ih se može spriječiti i koje su buduće perspektive istraživanja

Specifying and Reasoning over Socio-Technical Security Requirements with STS-Tool

Abstract. STS-Tool is the modelling and analysis support tool for STS-ml, our proposed actor- and goal-oriented security requirements mod-elling language for Socio-Technical Systems (STSs). STS-Tool allows de-signers to model an STS through high-level primitives, to express security constraints over the interactions between the actors in the STS, as well as to derive security requirements once the modelling is completed. The tool features a set of automated reasoning techniques for (i) checking if a given STS-ml model is well-formed, and (ii) determining if the specifica-tion of security requirements is consistent, that is, there are no conflicts among security requirements. We have implemented these techniques us-ing disjuntive datalog programs. 1 The Socio-Technical Security modelling language The Socio-Technical Security modelling language (STS-ml) [1] is an i * based security requirements modelling language. STS-ml includes high-level organisa-tional primivites such as actor, goal, delegation, etc. A distinguishing featur

2010 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC'10

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