Alternative Design Decisions Research Articles

A PBPO+ Graph Rewriting Tutorial

We provide a tutorial introduction to the algebraic graph rewriting formalism PBPO+. We show how PBPO+ can be obtained by composing a few simple building blocks, and model the reduction rules for binary decision diagrams as an example. Along the way, we comment on how alternative design decisions lead to related formalisms in the literature, such as DPO. We close with a detailed comparison with Bauderon's double pullback approach.

Understanding variation in the results of real-world evidence studies that seem to address the same question

ObjectivesMultiple database studies on the same question, conducted by different investigators using different approaches or different data sources, can be considered sensitivity analyses for the same causal treatment effect question. We evaluated the contribution of alternative study design parameters and analysis choices to variation in estimates of the risk of major bleeding with dabigatran compared with warfarin. Study Design and SettingWe followed a 7-step process: (1) identify published studies asking the same question, (2) independently reproduce selected studies in the same data sources as the original authors, (3) contact original authors, (4) evaluate validity, (5) document critical study parameter specifications, (6) implement a designed matrix of variations in study parameters based on the original studies, and (7) evaluate contributors to variation in results. ResultsMost variation remained unexplained (60–88%). Of the explained variation, two-thirds were related to data and population differences, and one-third were related to the use of alternative study design and analysis parameters. Among these, the most prominent were differences in outcome algorithms and criteria used to define follow-up. ConclusionWhen making policy decisions based on database study findings, it is important to evaluate the validity, consistency, and robustness of results to alternative design and analysis decisions.

Human-centred and BIM-integrated automated value analysis of buildings

This paper presents a study on automated value analysis of buildings for supporting value-adding and human-centred decision making in building planning and design. The analysis was conducted using a proposed system for automatically analyzing the value of a building based on its properties and multidimensional stakeholder values. The system is integrated with building information modelling (BIM) and is composed of three modules: a stakeholder input capturing module, a building information extraction module, and a value analysis module. The value analysis relies on valuation models that are theoretically grounded in axiology (value theory) and integration theory. A set of experiments were conducted, using the proposed system, to analyze the impacts of alternative planning and design decisions on the value of buildings to the stakeholders. The results indicate that it is important that decision makers not only enhance a design’s ability in fulfilling individual stakeholder values, but also account for the stakeholders’ systems of value priorities and seek to create a high level of synergy between the value that the design fulfils and the personal value systems of the stakeholders. The research contributes to the body of knowledge by integrating the human element of value – the human values – into value analysis. It could promote improved information for making more value-adding and human-centred decisions, and it could provide a foundation for planning and designing buildings in a way that is synergistically aligned with human values. Since the current study is limited in scope, in the future, the authors will expand the analysis by studying different types and scales of buildings and considering additional stakeholder values.

On Memristors for Enabling Energy Efficient and Enhanced Cognitive Network Functions

The high performance requirements of nowadays computer networks are limiting their ability to support important requirements of the future. Two important properties essential in assuring cost-efficient computer networks and supporting new challenging network scenarios are operating energy efficient and supporting cognitive computational models. These requirements are hard to fulfill without challenging the current architecture behind network packet processing elements such as routers and switches. Notably, these are currently dominated by the use of traditional transistor-based components. In this article, we contribute with an in-depth analysis of alternative architectural design decisions to improve the energy footprint and computational capabilities of future network packet processors by shifting from transistor-based components to a novel component named <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Memristor</i> . A memristor is a computational component characterized by non-volatile operations on a physical state, mostly represented in form of (electrical) resistance. Its state can be read or altered by input signals, e.g. electrical pulses, where the future state always depends on the past state. Unlike in traditional von Neumann architectures, the principles behind memristors impose that memory operations and computations are inherently colocated. In combination with the non-volatility, this allows to build memristors at nanoscale size and significantly reduce the energy consumption. At the same time, memristors appear to be highly suitable to model cognitive functionality due to the state dependence transitions in the memristor. In cognitive architectures, our survey contributes to the study of memristor-based Ternary Content Addressable Memory (TCAM) used for storage of cognitive rules inside packet processors. Moreover, we analyze the memristor-based novel cognitive computational architectures built upon self-learning capabilities by harnessing from non-volatility and state-based response of memristors (including reconfigurable architectures, reservoir computation architectures, neural network architectures and neuromorphic computing architectures).

Quality measures for ETL processes: from goals to implementation

SummaryExtraction transformation loading (ETL) processes play an increasingly important role for the support of modern business operations. These business processes are centred around artifacts with high variability and diverse lifecycles, which correspond to key business entities. The apparent complexity of these activities has been examined through the prism of business process management, mainly focusing on functional requirements and performance optimization. However, the quality dimension has not yet been thoroughly investigated, and there is a need for a more human‐centric approach to bring them closer to business‐users requirements. In this paper, we take a first step towards this direction by defining a sound model for ETL process quality characteristics and quantitative measures for each characteristic, based on existing literature. Our model shows dependencies among quality characteristics and can provide the basis for subsequent analysis using goal modeling techniques. We showcase the use of goal modeling for ETL process design through a use case, where we employ the use of a goal model that includes quantitative components (i.e., indicators) for evaluation and analysis of alternative design decisions. Copyright © 2015 John Wiley &amp; Sons, Ltd.

On requirement verification for evolving Statecharts specifications

Software development processes have been evolving from rigid, pre-specified, and sequential to incremental, and iterative. This evolution has been dictated by the need to accommodate evolving user requirements and reduce the delay between design decision and feedback from users. Formal verification techniques, however, have largely ignored this evolution and even when they made enormous improvements and found significant uses in practice, like in the case of model checking, they remained confined into the niches of safety-critical systems. Model checking verifies if a system's model $$\mathcal{M}$$ M satisfies a set of requirements, formalized as a set of logic properties $$\Phi$$ ? . Current model-checking approaches, however, implicitly rely on the assumption that both the complete model $$\mathcal{M}$$ M and the whole set of properties $$\Phi$$ ? are fully specified when verification takes place. Very often, however, $$\mathcal{M}$$ M is subject to change because its development is iterative and its definition evolves through stages of incompleteness, where alternative design decisions are explored, typically to evaluate some quality trade-offs. Evolving systems specifications of this kind ask for novel verification approaches that tolerate incompleteness and support incremental analysis of alternative designs for certain functionalities. This is exactly the focus of this paper, which develops an incremental model-checking approach for evolving Statecharts. Statecharts have been chosen both because they are increasingly used in practice natively support model refinements.

Performance improvements for iterative electron tomography reconstruction using graphics processing units (GPUs)

Iterative reconstruction algorithms are becoming increasingly important in electron tomography of biological samples. These algorithms, however, impose major computational demands. Parallelization must be employed to maintain acceptable running times. Graphics Processing Units (GPUs) have been demonstrated to be highly cost-effective for carrying out these computations with a high degree of parallelism. In a recent paper by Xu et al. (2010), a GPU implementation strategy was presented that obtains a speedup of an order of magnitude over a previously proposed GPU-based electron tomography implementation. In this technical note, we demonstrate that by making alternative design decisions in the GPU implementation, an additional speedup can be obtained, again of an order of magnitude. By carefully considering memory access locality when dividing the workload among blocks of threads, the GPU's cache is used more efficiently, making more effective use of the available memory bandwidth.

Using disability data to estimate design exclusion

Exclusion auditing is a process that can quantitatively evaluate the inclusive merit of different products, or alternative design decisions. The results from such an audit can provide prioritised directions for product improvement and support the business case for reducing the capability levels required to use mainstream products. The 1996/1997 disability follow-up survey, conducted by the Office of National Statistics, is currently the most comprehensive data source for estimating design exclusion in the UK. In this paper, the data source is explained in detail, and a method is presented that uses this data to estimate the exclusion associated with several tasks that occur in series or in parallel, illustrated through worked examples. Having evaluated how many people are excluded, one can investigate why they were excluded, thus generating design insights into how they could be included. Data from the survey is also converted to a series of stylised graphs, which are intended to inspire designers to think about the relationship between the demands required to use a product and the resulting levels of population exclusion.

Design sensitivity of reactive absorption units for improved dynamic performance and cleaner production: the NO x removal process

The dynamic characteristics of reactive absorption processes are of great importance for the smooth operation of the unit and the overall performance of the implemented control system under the influence of process disturbances and the presence of tight environmental and safety constraints. In the present study, the effect of the major design parameters and column configurations on the dynamic behaviour of the environmentally sensitive NO x removal processes, through the use of rigorous rate-based dynamic models, is investigated. Static and dynamic disturbance rejection properties are evaluated for the screening and assessment of alternative design decisions.

ESTIMATION OF EXTERNAL WALLS DECISIONS OF MULTISTOREY RESIDENTIAL BUILDINGS APPLYING METHODS OF MULTICRITERIA ANALYSIS

This paper analyses the most widespread designs of external walls of the multi‐storey residential buildings now in use. Such 49 alternative designs of external walls of multi‐storey residential buildings are analyzed using multicriteria analysis program under uncertainty. Few ways of the decision are applied for the decision of the problem: the method of distance to an ideal point, Baye's rule and Wald's rule. To project and understand effective construction of a building, it is necessary to execute exhaustive analysis of all decisions (planimetric, prolongation of term and quality of buildings operation, improvement of architectural decisions, etc.). The level of a design of external walls efficiency of multi‐storey residential buildings depends on very many factors, including: cost of the construction work, used materials and building mechanisms, aesthetics, properties of service, thermal insulation properties, durability, etc. The offered decision of the choice of the effective decision problem using the system of the criteria having different dimensions takes into account the rational estimation of economic, climatic, social conditions and traditions and also allows better to satisfy architectural, functional, service, comfort and other requirements of the client. It also allows to reduce design, building and operational expenses. The choice of a variant mainly depends on needs and existing financial ability of the customer. The offered system of the effective decision choice using the principles of the multi‐criteria analysis is described in the presented paper. There is an opportunity on the basis of the offered system to compare alternative design decisions of external walls of multi‐storey residential buildings and the choice of the most effective variants.

Unified user interface design: designing universally accessible interactions

Designing universally accessible user interfaces means designing for diversity in end-users and contexts of use, and implies making alternative design decisions, at various levels of the interaction design, inherently leading to diversity in the final design outcomes. Towards this end, a design method leading to the construction of a single interface design instance is inappropriate, as it cannot accommodate for diversity of the resulting dialogue artifacts. Therefore, there is a need for a systematic process in which alternative design decisions for different design parameters may be supported. The outcome of such a design process realizes a design space populated with appropriate designed dialogue patterns, along with their associated design parameters (e.g. user- and usage-context-attribute values). This paper discusses the Unified Interface Design Method, a process-oriented design method enabling the organization of diversity-based design decisions around a single hierarchical structure, and encompassing a variety of techniques such as task analysis, abstract design, design polymorphism and design rationale.

Moving Forward, One Step at a Time

We reply to John Duffield's critique of the Rational Design project, a special issue ofInternational Organizationthat explains the features of international institutions from a game-theoretic perspective. The project was deliberately limited to the analysis of explicit and observable institutional arrangements, and focused on the specific institutional properties of centralization, membership, scope, control, and flexibility. Its empirical contribution relies on case studies, but it is significantly amplified by the tight connections provided by a common theoretical perspective that is oriented toward testing a set of specific conjectures about institutional design. The results raise further issues of measurement and cross-case comparisons that provide valuable lessons for future work on institutional design. Although all of these research design choices are worth revisiting and questioning, as Duffield does, the initial results of the Rational Design project show that it provides a good basis from which to explore alternative research design decisions.

Process Calculi à la Bird-Meertens

This paper is an attempt to apply the reasoning principles and calculational style underlying the so-called Bird-Meertens formalism to the design of process calculi, parametrized by a behaviour model. In particular, basically equational and pointfree proofs of process properties are given, relying on the universal characterisation of anamorphisms and therefore avoiding the explicit construction of bisimulations. The developed calculi can be directly implemented on a functional language supporting coinductive types, which provides a convenient way to prototype processes and assess alternative design decisions.

Urban bioclimatic design strategies for a tropical city

Some towns in the intertropical zone, such as the city of Belo Horizonte in Brazil, presented in this paper, have composed climates whose variations throughout the year require alternative design decisions, in order to make use of passive environmental resources. On the other hand, the great variation of urban settlements produces different kinds of microclimates inside the city. This paper shows the application of an urban design strategy that takes into account those climatic variations, using the city's available climatic data and physical simulations of the thermal field in urban areas, to analyze the influence of urban forms (land use, typology and building configurations) on climatic change. With the application of a thermal comfort index, it is possible to evaluate the local conditions of human bioclimatic stress. This kind of result can be applied to the city land-use legislation, bearing in mind the preservation of bioclimatic conditions in urban spaces.

An integrated knowledge-based system for alternative design and materials selection and cost estimating

Building design and material type used are the two main parameters that have a significant impact on the cost of a building. Therefore, it is important for a cost estimating tool to have a mechanism that allows the designer to perform a rapid `what if' analysis on design alternatives and materials selection at the early planning stage without the accompaniment of detailed design and drawings. However, the traditional design cost estimating procedures generally focus on assessing costs after design decisions are made and conveyed to the construction drawing as a quantity take off. On the other hand, comparative cost estimating (unit cost per square meter) uses historical data collected by averaging buildings of different designs, heights and materials. Even today's computer aided design (CAD) software incorporates a mechanism to take off quantities from completed designs and drawings. However, basically they are the same as the traditional quantity take off estimating because a single specified design still controls the resulting costs, and there is no alternative materials selection integrated to the cost system. This article presents an integrated knowledge-based system for alternative design decisions, materials selection and cost estimating mainly for pre-design analysis. The knowledge-based system also includes materials selection and cost estimating for after-detailed design by providing edit tables for inputting the dimensions of building elements from completed designs and drawings or by directly importing from CAD. The system generates activities quantities, costs and lists of materials selected and their respective quantities. An analysis of alternative design and materials selection for a residential building using the integrated system is presented.

The π-Calculus in Direct Style

We introduce a calculus which is a direct extension of both the λ and the π calculi. We give a simple type system for it, that encompasses both Curry‘s type inference for the λ-calculus, and Milner‘s sorting for the π-calculus as particular cases of typing. We observe that the various continuation passing style transformations for λ-terms, written in our calculus, actually correspond to encodings already given by Milner and others for evaluation strategies of λ-terms into the π-calculus. Furthermore, the associated sortings correspond to well-known double negation translations on types. Finally we provide an adequate CPS transform from our calculus to the π-calculus. This shows that the latter may be regarded as an “assembly language”, while our calculus seems to provide a better programming notation for higher-order concurrency. We conclude by discussing some alternative design decisions.

Supporting systems development by capturing deliberations during requirements engineering

Support for various stakeholders involved in software projects (designers, maintenance personnel, project managers and executives, end users) can be provided by capturing the history about design decisions in the early stages of the system's development life cycle in a structured manner. Much of this knowledge, which is called the process knowledge, involving the deliberation on alternative requirements and design decisions, is lost in the course of designing and changing such systems. Using an empirical study of problem-solving behavior of individual and groups of information systems professionals, a conceptual model called REMAP (representation and maintenance of process knowledge) that relates process knowledge to the objects that are created during the requirements engineering process has been developed. A prototype environment that provides assistance to the various stakeholders involved in the design and management of large systems has been implemented. >

A Computer Simulation Model Applied to Design Problems of a Petrochemical Complex

This paper describes a computer simulation model which was developed by BP Chemicals International and applied to some of the design problems of a petrochemical complex. The individual plants in this type of complex are closely interlinked in terms of input and output of raw materials, usage from common storage tanks and utilities requirements. Thus decisions taken within a particular area can have serious effects on overall site performance. The simulation model was constructed to assist management in evaluating the consequences of alternative design decisions.