Controlling Concurrent Change - A Multiview Approach Toward Updatable Vehicle Automation Systems

The development of SAE Level 3+ vehicles [{SAE}, 2014] poses new challenges not only for the functional development, but also for design and development processes. Such systems consist of a growing number of interconnected functional, as well as hardware and software components, making safety design increasingly difficult. In order to cope with emergent behavior at the vehicle level, thorough systems engineering becomes a key requirement, which enables traceability between different design viewpoints. Ensuring traceability is a key factor towards an efficient validation and verification of such systems. Formal models can in turn assist in keeping track of how the different viewpoints relate to each other and how the interplay of components affects the overall system behavior. Based on experience from the project Controlling Concurrent Change, this paper presents an approach towards model-based integration and verification of a cause effect chain for a component-based vehicle automation system. It reasons on a cross-layer model of the resulting system, which covers necessary aspects of a design in individual architectural views, e.g. safety and timing. In the synthesis stage of integration, our approach is capable of inserting enforcement mechanisms into the design to ensure adherence to the model. We present a use case description for an environment perception system, starting with a functional architecture, which is the basis for componentization of the cause effect chain. By tying the vehicle architecture to the cross-layer integration model, we are able to map the reasoning done during verification to vehicle behavior

Pattern-based software architecture for service-oriented software systems

Service-oriented architecture is a recent conceptual framework for service-oriented software platforms. Architectures are of great importance for the evolution of software systems. We present a modelling and transformation technique for service-centric distributed software systems. Architectural configurations, expressed through hierarchical architectural patterns, form the core of a specification and transformation technique. Patterns on different levels of abstraction form transformation invariants that structure and constrain the transformation process. We explore the role that patterns can play in architecture transformations in terms of functional properties, but also non-functional quality aspects

Structural expression and application in contemporary architecture

The development of structural technology has allowed the architect greater freedom in resolving problems related to the planning, aesthetics and construction of forms and spaces. As technology advances the range of structural solutions is increased to further enable the implementation of architectural ideas which develop independently from technology.Two fundamentally opposite philosophies embrace the structural integration of architecture:1. that although technology "frees" architecture, it does not determine architecture. Thus ideas on which architectural forms are based may be sourced outside architecture and structure; for e.g. movements in art and analogies drawn from nature have influenced the ideology of several modern architectural movements.2. that architectural form itself may be generated out of structural considerations and that the structural problem itself may serve as a rich source of architectural ideas from which forms and spaces may be generated.Both approaches operate in the contemporary context and are a reflection of the need to merge the design philosophies of architecture and structural technology.The thesis comprises three sections and is based on the assumption that structure is used to improve certain core aspects of architecture. This is related to allowing flexibility in architectural expression and planning, and the simplification of fabrication and construction processes.SECTION I of the thesis proceeds by investigating the background to the different design philosophies of the architect and the engineer in order to provide an understanding of the differences in their design priorities. Significant Modern Movement examples are studied in relation to the abstract ideologies which influence architectural form and structural integration in order to hypothesise on the core aspects previously mentioned.In SECTION II, these investigations are extended to case examples in the contemporary context and buildings are studied in relation to 4 main considerations: a) architectural b) structural c) utilitarian d) constructionInterviews with project architects and engineers were conducted to substantiate the information from publications in refereed Journals and reference texts and project design reports.In addition to relying on papers written on the architectural and structural design development of the selected buildings, interviews with the relevant project consultants were arranged to obtain further background information relevant to the thesis.SECTION III then further discusses the factors affecting the development and application of structure in the architectural context in order to arrive at conclusions based on the recurrent themes and approaches identified in Section II case studies. These conclusions are interpreted in relation to Section I ideologies on structural integration and architectural expression and establish the common design aims of both architect and engineer in order to attempt bridging the gaps in their professional understanding of building design.The conclusions may be summarised as follows:1) that there are three recurrent approaches to arranging structure in relation to architectural layout. Structure may occupy the a) periphery of the architectural plan b) the centre of the plan c) plan in intermittent fashion (as in the case of 2 -way modules) There are also examples where a combination of the three approaches is possible.2) that the recurrent approaches to using structure in articulating the external form may be summarised as follows: i) the form implied by an ideal structural model may be adapted as an architectural form (for eg. a portal frame shed) ii) that structural form is modified to suit functional and aesthetic requirements. Nervi's Small Sports Palace in Rome is an example where a structural dome is modified at its peripheral edges and supports for utilitarian and aesthetic reasons). iii) that non -load bearing elements may be articulated within a regular structural frame, (as exemplified by Corbusier's Dom -ino principle) iv) that structure may be detailed as architectural ornament whilst maintaining essential structural action, (as in the case of Horta's Art Nouveau creation). v) that an appropriate functional structural may be developed to maintain a 'sculptural form" initially conceived, without consideration of support, (as in the case of Utzon's Sydney Opera House). vi) that structural form is developed intuitively and simultaneously as an expression of architectural form, (as in the case of the Pantheon).These recurrent approaches (1) and (2) are perhaps related to the development and application of structural configurations which do not excessively constraint the design of architectural spaces and the expression of architectural forms.Structural application in building is moving towards systems which use increasingly less material to achieve the required strength and rigidity required to transfer loads in ways influenced by the shape of architectural forms and spaces. This is directed towards reducing structural dead weight which in long -span and high -rise structure is critical to both performance and cost efficiency. This may be achieved by avoiding the development of excessive bending moments in the structure and this may be part of the reason for the increasing number of applications of structural systems which transmit primarily axial loads, particular tension in steel construction. However, pure tension or compression structures do not exist and the necessity to accommodate useable space and the shapes of architectural forms could imply the development of some bending in a system which first set out to avoid its presence. Bending necessitates the use of deeper structural sections which makes the structure visually bulky and more expensive in terms of material quantity. In this respect, the experimentation of flexible structures which acquire a satisfactory degree of rigidity with stressed cables and rods is aimed at providing more aesthetic and economical solutions than with conventionally rigid systems.The engineering aims of developing increasingly slender structures could therefore be aimed at economy and elegance whilst the architectural implications could be:i) A structural system which assists the aesthetic considerations of formal and spatial composition, or one which does not necessarily restrict modes of aesthetic treatment in order to provide support.ii) A structural system which allows flexibility in the layout and use of floor space and in the interpretation of spatial character.iii) A structural system with the means to optimise fully, the commercial potential of prime sites with complex building constraints.iv) A structural system which effectively integrates mechanical service and electronic networks without compromising aesthetic themes.v) A structural system which provides the option of satisfactory levels of natural lighting and ventilation as well as enabling an energy efficient building.These ideals are related to the structural improvement to architectural form and space and could perhaps serve as the common design aims of both architect and engineer

Quality-aware model-driven service engineering

Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Quality aspects ranging from interoperability to maintainability to performance are of central importance for the integration of heterogeneous, distributed service-based systems. Architecture models can substantially influence quality attributes of the implemented software systems. Besides the benefits of explicit architectures on maintainability and reuse, architectural constraints such as styles, reference architectures and architectural patterns can influence observable software properties such as performance. Empirical performance evaluation is a process of measuring and evaluating the performance of implemented software. We present an approach for addressing the quality of services and service-based systems at the model-level in the context of model-driven service engineering. The focus on architecture-level models is a consequence of the black-box character of services

Resolving Architectural Mismatches of COTS Through Architectural Reconciliation

The integration of COTS components into a system under development entails architectural mismatches. These have been tackled, so far, at the component level, through component adaptation techniques, but they also must be tackled at an architectural level of abstraction. In this paper we propose an approach for resolving architectural mismatches, with the aid of architectural reconciliation. The approach consists of designing and subsequently reconciling two architectural models, one that is forward-engineered from the requirements and another that is reverse-engineered from the COTS-based implementation. The final reconciled model is optimally adapted both to the requirements and to the actual COTS-based implementation. The contribution of this paper lies in the application of architectural reconciliation in the context of COTS-based software development. Architectural modeling is based upon the UML 2.0 standard, while the reconciliation is performed by transforming the two models, with the help of architectural design decisions.

Mediating Cognitive Transformation with VR 3D Sketching during Conceptual Architectural Design Process

Communications for information synchronization during the conceptual design phase require designers to employ more intuitive digital design tools. This paper presents findings of a feasibility study for using VR 3D sketching interface in order to replace current non-intuitive CAD tools. We used a sequential mixed method research methodology including a qualitative case study and a cognitive-based quantitative protocol analysis experiment. Foremost, the case study research was conducted in order to understand how novice designers make intuitive decisions. The case study documented the failure of conventional sketching methods in articulating complicated design ideas and shortcomings of current CAD tools in intuitive ideation. The case study’s findings then became the theoretical foundations for testing the feasibility of using VR 3D sketching interface during design. The latter phase of study evaluated the designers’ spatial cognition and collaboration at six different levels: “physical-actions”, “perceptualac ons”, “functional-actions”, “conceptual-actions”, “cognitive synchronizations”, and “gestures”. The results and confirmed hypotheses showed that the utilized tangible 3D sketching interface improved novice designers’ cognitive and collaborative design activities. In summary this paper presents the influences of current external representation tools on designers’ cognition and collaboration as well as providing the necessary theoretical foundations for implementing VR 3D sketching interface. It contributes towards transforming conceptual architectural design phase from analogue to digital by proposing a new VR design interface. The paper proposes this transformation to fill in the existing gap between analogue conceptual architectural design process and remaining digital engineering parts of building design process hence expediting digital design process

The architectural and environmental retrofitting of public social housing as a resource for contemporary cities. The redesign of building envelopes

The current focus on the transformation of Western cities puts forward, in a shared and far-reaching manner, ‘degrowth’ as an opportunity to renew and update the perspective of sustainability, not only from an environmental point of view, but from a social and economic point of view as well. The most modern updated legislation is also headed in this direction: considering building stock as a resource for renovation, adopting policies and strategies aimed at reducing land and energy consumption, reusing and recycling building stock. Nowadays, the interpretation of the terms Reduce, Reuse, Recycle in relation to urban devel-opment offers the opportunity to create a new generation of spaces and architectures that sees buildings – dilapidated, neglected, worn out or abandoned – as a real resource and, hence, value. Renovations concern new programmes and projects for rethinking the uses, meanings and the values contained in existing construction (from individual buildings to whole neigh-bourhoods) and which can change. Within this scenario, suburbs are now considered part of the contemporary city and they are becoming the object of particular attention from those who are involved in urban planning and managing urban developments. Among the resources that have already been built, social hous-ing stock is a wide field of investigation, from different points of view. This built heritage can involve different levels of building and space transformation and defines various design approaches: the overall architectural quality is to be acknowledged. These design approaches reinterpret regeneration activities and are not just limited to the ‘technical’ renovation of buildings: they also take into account the consequent urban, social and economic implications