118,120 research outputs found

    Formal Reasoning Using an Iterative Approach with an Integrated Web IDE

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    This paper summarizes our experience in communicating the elements of reasoning about correctness, and the central role of formal specifications in reasoning about modular, component-based software using a language and an integrated Web IDE designed for the purpose. Our experience in using such an IDE, supported by a 'push-button' verifying compiler in a classroom setting, reveals the highly iterative process learners use to arrive at suitably specified, automatically provable code. We explain how the IDE facilitates reasoning at each step of this process by providing human readable verification conditions (VCs) and feedback from an integrated prover that clearly indicates unprovable VCs to help identify obstacles to completing proofs. The paper discusses the IDE's usage in verified software development using several examples drawn from actual classroom lectures and student assignments to illustrate principles of design-by-contract and the iterative process of creating and subsequently refining assertions, such as loop invariants in object-based code.Comment: In Proceedings F-IDE 2015, arXiv:1508.0338

    Strategic Design through Brand Contextualization

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    Providing meaningful customer experience is at the core of any successful business activity. Brands can function as vehicles to bundle the ingredients of experience together and give them structure by which consumers are able to understand and interpret products and services. To complement the technical and functional reality and experience, brands create particular narratives around products and services, within the realm of their use experience. This paper aims to contribute to understanding of strategic design and brand contextualization by looking thoroughly into a research-driven student project. The product-service design assignment given to seven teams of four to five post-graduate students was to design a new bike-sharing system, serving the sustainable urban mobility needs of the city of Gothenburg in Sweden. The task was accompanied by a request to create a fictive brand case and specific brand narrative, based on a thorough analysis of pre-selected existing brands. The paper discusses how the teams crafted their brand narratives and how different design and service elements were used to create specific and meaningful brand experiences. In addition to the contribution of the paper to design research and practice, we present a process that might be more widely useful for the education of strategic design and brand management

    Microelectromechanical Systems (MEMS) Resistive Heaters as Circuit Protection Devices

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    With increased opportunities for the exploitation (i.e., reverse engineering) of vulnerable electronic components and systems, circuit protection has become a critical issue. Circuit protection techniques are generally software-based and include cryptography (encryption/decryption), obfuscation of codes, and software guards. Examples of hardware-based circuit protection include protective coatings on integrated circuits, trusted foundries, and macro-sized components that self-destruct, thus destroying critical components. This paper is the first to investigate the use of microelectromechanical systems (MEMS) to provide hardware-based protection of critical electronic components to prevent reverse engineering or other exploitation attempts. Specifically, surface-micromachined polycrystalline silicon to be used as meandering resistive heaters were designed analytically and fabricated using a commercially available MEMS prototyping service (i.e., PolyMUMPs), and integrated with representative components potentially at risk for exploitation, in this case pseudomorphic high-electron mobility transistors (pHEMTs). The MEMS heaters were initiated to self-destruct, destroying a critical circuit component and thwart a reverse engineering attempt. Tests revealed reliable self-destruction of the MEMS heaters with approximately 25 V applied, resulting in either complete operational failure or severely altering the pHEMT device physics. The prevalent failure mechanism was metallurgical, in that the material on the surface of the device was changed, and the specific failure mode was the creation of a short-circuit. Another failure mode was degraded device operation due to permanently altered device physics related to either dopant diffusion or ohmic contact degradation. The results, in terms of the failure of a targeted electronic component, demonstrate the utility of using MEMS devices to protect critical components which are otherwise vulnerable to exploitation

    Simultaneous experimentation as an entrepreneurial strategy for emergent markets: Transcending the trade-off between flexibility and funding?.

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    The unpredictable nature of emergent markets implies that ventures entering such markets are confronted with technological and commercial uncertainty. Defining a viable business model under such circumstances is a complex and precarious endeavour. Previous research has either advanced the idea of focus – in order to attract resources and realize first mover advantages – or sequential experimentation financed through bootstrapping, implying limited resources during initial phases of the venture. As such, a trade-off between flexibility and resource acquisition has been introduced. Within this contribution we explore how ventures starting up in emergent industries can balance the attainment of financial resources with flexibility and business model adaptation. Based on a sequence analysis of six case studies, we identify two distinctive approaches to business development in emergent industries: focused commitment versus simultaneous experimentation. Our findings reveal that focused commitment is instrumental for acquiring resources but at the same time impedes flexibility, while simultaneous experimentation allows to attract resources while maintaining manoeuvring space for business model adaptation. An analytical comparison of both approaches suggests that simultaneous experimentation is indeed a more viable strategy when entering emergent industries.entrepreneurial opportunities; business model; uncertainty; commitment; experimentation;
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