Architectural reflection for software evolution

Software evolution is expensive. Lehman identifies several problems associated with it: Continuous adaptation, increasing complexity, continuing growth, and declining quality. This paper proposes that a reflective software engineering environment will address these problems by employing languages and techniques from the software architecture community. Creating a software system will involve manipulating a collection of views, including low-level code views and high-level architectural views which will be tied together using reflection. This coupling will allow the development environment to automatically identify inconsistencies between the views, and support software engineers in managing architectures during evolution. This paper proposes a research programme which will result in a software engineering environment which addresses problems of software evolution and the maintenance of consistency between architectural views of a software system

Using automated source code analysis for software evolution

Software maintenance is one of the most expensive and time-consuming phases in the software life-cycle. The size and complexity of commercial applications probably present the greatest difficulty that maintainers face when making changes to their applications. As a result of the corresponding loss of understanding, business knowledge encapsulated within the system becomes fragmented, and any changes made as a result of new business initiatives become difficult to implement and hence may mean a loss of business opportunities. This paper outlines an approach to regaining understanding of software which has been used in the Release project at Durham University. This approach involves determining the calling structure of a program in terms of a call-graph, and from this call-graph extracting a dominance tree. Various problems which have been encountered during the construction of tools to perform this task are described

Astronomical application of IR CID technology

A portable microcomputer data system was developed to test a 2 x 64-element Si:Bi charge injection device (CID) infrared detector array on the Lick Observatory Shane telescope. An existing 0.5 m spectrograph was used for the tests after modification, and a spectral resolution of 1000 was achieved. Slow device response, due to the low background conditions in the spectrograph were shown. Astronomical data were later obtained, and a device read noise on the order of a few hundred electrons was achieved. The signal to noise ratios of the resulting spectra were about a factor of five lower than what could have been achieved with discrete photoconductive detectors. It is concluded that the CID array is competitive for applications in backgrounds lower than those used in the tests

A Student-Centered Learning Approach to Design for Manufacturability: Meeting the Needs of an Often- Forgotten Customer

A hands-on learning module was implemented at Marquette University in 2012 to teach biomedical engineering students about basic manufacturing processes, lean manufacturing principles, and design for manufacturability. It incorporates active and student-centered learning as part of in-class assembly line simulations. Since then, it has evolved from three class periods to five. The module begins with two classroom presentations on manufacturing operations and electronics design, assembly, and testing. Students then participate in an in-class assembly line simulation exercise where they build and test an actual product per written work instructions. They reflect on this experience and suggest design and process changes to improve the assembly line process and quality, save time, and reduce cost and waste. At the end of the module students implement their suggested design and process improvements and repeat the exercise to determine the impact of their improvements. They learn of the importance of Design for Manufacturability, well-written work instructions, process design, and designing a product not only for the end user, but also for the assemblers and inspectors. Details of the module, and its implementation and assessment are presented along with student feedback and faculty observations

An open source collaboration infrastructure for Calibre

The study of Free and Open Source (Libre) software and the benefits provided by its processes and products to collaborative software development has been somewhat ad hoc. Each project wishing to use tools and techniques drawn from Libre software conducts its own research, thus duplicating effort, consequently there is a lack of established community practice on which new projects can draw. Long-standing intuitive theories of Libre development lack empirical validation. The long-term goal is to provide a resource to guide the evolution of Libre-software projects, from inception to maturity. The CALIBRE project is a co-ordination action aiming to address these issues through its research, its wider educational goals, and with an open invitation to the community to contribute. To succeed, the CALIBRE project needs an effective technological infrastructure which must support internal and external collaboration, communication and contribution to the project. The requirements of CALIBRE are similar to those of a Libre software project; this suggests that adopting a SourceForge-style environment which will be incrementally enhanced with further specialised tools as the requirements become better understood will be a sensible strategy

An artefact repository to support distributed software engineering

The Open Source Component Artefact Repository (OSCAR) system is a component of the GENESIS platform designed to non-invasively inter-operate with work-flow management systems, development tools and existing repository systems to support a distributed software engineering team working collaboratively. Every artefact possesses a collection of associated meta-data, both standard and domain-specific presented as an XML document. Within OSCAR, artefacts are made aware of changes to related artefacts using notifications, allowing them to modify their own meta-data actively in contrast to other software repositories where users must perform all and any modifications, however trivial. This recording of events, including user interactions provides a complete picture of an artefact's life from creation to (eventual) retirement with the intention of supporting collaboration both amongst the members of the software engineering team and agents acting on their behalf

A design recording framework to facilitate knowledge sharing in collaborative software engineering

This paper describes an environment that allows a development team to share knowledge about software artefacts by recording decisions and rationales as well as supporting the team in formulating and maintaining design constraints. It explores the use of multi-dimensional design spaces for capturing various issues arising during development and presenting this meta-information using a network of views. It describes a framework to underlie the collaborative environment and shows the supporting architecture and its implementation. It addresses how the artefacts and their meta-information are captured in a non-invasive way and shows how an artefact repository is embedded to store and manage the artefacts

A Hands-On, Active Learning Approach to Increasing Manufacturing Knowledge in Engineering Students

This paper describes a new learning module implemented as part of the senior capstone design course at Marquette University to teach engineering students about basic manufacturing processes, lean manufacturing principles, and design for manufacturability. The module includes several examples of active and student centered learning as part of an in-class assembly line simulation exercise. Students reflected on this experience, and suggested process improvements to save time, reduce cost and waste, and improve the assembly line process. They learned of the importance of manufacturing documentation, process design, and design for assembly. At the end of the module, students understood the importance of designing a product not only for the end user, but also for the assemblers and inspectors. Details of the module design and implementation will be presented along with comments from students

An evaluation framework to drive future evolution of a research prototype

The Open Source Component Artefact Repository (OSCAR) requires evaluation to confirm its suitability as a development environment for distributed software engineers. The evaluation will take note of several factors including usability of OSCAR as a stand-alone system, scalability and maintainability of the system and novel features not provided by existing artefact management systems. Additionally, the evaluation design attempts to address some of the omissions (due to time constraints) from the industrial partner evaluations. This evaluation is intended to be a prelude to the evaluation of the awareness support being added to OSCAR; thus establishing a baseline to which the effects of awareness support may be compared

Cooperative effects enhance the transport properties of molecular spider teams

Molecular spiders are synthetic molecular motors based on DNA nanotechnology. While natural molecular motors have evolved towards very high efficiency, it remains a major challenge to develop efficient designs for man-made molecular motors. Inspired by biological motor proteins such as kinesin and myosin, molecular spiders comprise a body and several legs. The legs walk on a lattice that is coated with substrate which can be cleaved catalytically. We propose a molecular spider design in which n spiders form a team. Our theoretical considerations show that coupling several spiders together alters the dynamics of the resulting team significantly. Although spiders operate at a scale where diffusion is dominant, spider teams can be tuned to behave nearly ballistic, which results in fast and predictable motion. Based on the separation of time scales of substrate and product dwell times, we develop a theory which utilizes equivalence classes to coarse-grain the microstate space. In addition, we calculate diffusion coefficients of the spider teams, employing a mapping of an n-spider team to an n-dimensional random walker on a confined lattice. We validate these results with Monte Carlo simulations and predict optimal parameters of the molecular spider team architecture which makes their motion most directed and maximally predictable