Compare Design Alternatives Research Articles

Engineering information format utilisation across building design stages: An exploration of BIM applicability in China

Building Information Modelling (BIM) has been extensively advocated in the construction industry for its potential to improve design efficiency and quality. However, its application continues to encounter considerable resistance from designers because BIM is less efficient than conventional 2D and 3D data formats in some design tasks. Consequently, a flexible approach that integrates BIM into existing workflows, instead of fully replacing traditional data formats, is believed to better enhance BIM application. Given this concern, this study conducts a questionnaire survey among Chinese designers to investigate the engineering information formats used in practice and to assess the potential and applicability of this flexible approach. Analysis of the survey responses using relevance analysis, logistic regression, and multiple correspondence analysis reveals that BIM is more frequently used for coordinating multi-disciplinary data in the later stages of project development than in early design phases. Conversely, conventional 2D and 3D formats are preferred for creating and comparing design alternatives during the concept and developed design stages. A practical application for BIM emerges in the technical design stage of prefabricated construction projects. These results suggest a promising approach for BIM application: allowing the use of conventional data format in the concept and developed design stages, integrating these designs into a shared BIM model in the technical design stage, and maintaining them in the BIM model thereafter. Besides offering an in-depth analysis of engineering information format utilisation, this study offers practical strategies for contractors, policymakers, and BIM developers to extend BIM application and promotion.

Digital-age Urbanism with Eddy3D for Grasshopper

Abstract The changing climate is a trigger for architects to reconsider the conventional design approach and possibly enrich it with novel approaches brought by the digital age. Sun analysis for urban planning with wind analysis too, proves inevitable for creating comfortable public spaces and built environment in general. When incorporating wind analysis into the process of architectural/urban design, several crucial pre-requisites determine the use of CFD (Computational Fluid Dynamics) simulations: (1) the demand from the client, (2) the time-space needed for the investigations, (3) the powerful enough hardware, and (4) software that enables a fast, user-friendly interface for parametric investigations. Among the benefits of investigating wind speed and flowlines in the digital environment is the possibility to compare design alternatives very quickly and with the same boundary conditions. Moreover, the popular algorithmic software Grasshopper currently enables wind investigation of the geometry directly in the modeling environment without the need to export the file to a standalone CFD software. This way, multiple design options can be investigated once the parametric geometry is prepared, and the digital wind tunnel is set.

Cost-benefit analysis in fire safety engineering: State-of-the-art and reference methodology

Cost-effectiveness is a key consideration within fire safety engineering. Currently, different approaches are being applied in literature. These approaches differ in how cost-effectiveness is evaluated, which costs are considered, and how the preferred design solution is defined. Recognizing this issue, the Fire Protection Research Foundation enrolled an international team of researchers, supported by a broad stakeholder panel, to develop a reference methodology. In this paper, this reference methodology for cost-benefit analysis in fire safety engineering is presented following an extensive literature review. The methodology clarifies the minimum requirements for assessing cost-effectiveness, and highlights that only a present net value evaluation can be used to compare design alternatives. Commonly used cost-benefit ratios should only be used when deciding on the effectiveness of a single package of fire safety measures. An illustrative case study demonstrates the application of the methodology and shows how designs based on cost-benefit ratios can be sub-optimal when evaluating multiple possible fire safety measures.

On measuring coupling between microservices

In software quality management, the selection strategy for proper metrics varies depending on the application scenarios and measurement objectives. MicroService Architecture (MSA), despite being commonly employed nowadays, still cannot be reliably measured and compared if the microservices in a system are independent. Software managers and architects need to understand whether their microservices are “decoupled enough”, if not, which ones are over-coupled, and by how much. In this paper, we contribute a novel set of metrics – Microservice Coupling Index (MCI) – derived from the relative measurement theory. Instead of measuring coupling evidence with simple counts, we measure how dependent and coupled the microservices are relative to the possible couplings between them. We measured the MCI metrics for 15 open source projects that involve 113 distinct microservices. Empirical investigation confirmed that MCIs differ quite significantly from existing coupling measures and that they are more discriminative than existing ones for separating high and low degrees of microservice couplings and thus more useful in comparing design alternatives. A series of experimental studies were conducted, showing that the larger the MCIs, the less likely the bugs and changes can be localized and separated, and the less likely that the individual microservices in a system can be independently developed and evolved.

Early Design Space Exploration Framework for Memristive Crossbar Arrays

For memristive crossbar arrays, currently, no high-level design validation and early space exploration tools exist in the literature. Such tools are essential to quickly verify the design functionality as well as compare design alternatives in terms of power and performance. In this work, we propose a VHDL-based framework that enables us to quickly perform behavioral simulation as well as estimate dynamic energy consumption and speed of any large memristive crossbar array. We propose a high-level (VHDL) model of a memristor based on which crossbar architectures can be modeled. The individual memristor model is embedded with power and delay numbers obtained from a detailed memristor model. We demonstrate the framework for MAGIC-style memristive crossbars. We validate the framework against detailed Verilog-A based model on fifteen combinational benchmarks. For the single row model, we obtained 153x simulation speedup over HSPICE, average estimation errors of 6.64% and 0% for dynamic energy consumption and cycle-time, respectively. For the transpose model, we obtained average estimation errors of 5.51% and 10.90% for dynamic energy consumption and cycle-time, respectively. We also extend our framework to support another prominent logic style and validate through a case study. The proposed framework can be easily extended to other emerging technologies.

Development of a Multi-Criteria Design Optimization Methodology for Automotive Plastics Parts.

The plastic industry is undergoing drastic changes, due to the customer sustainability perception of plastics, and the eruption of new processes (such 3D printing) and materials (such as renewably sourced resins). To enable a fast transition to high-quality, sustainable plastic applications, a specific methodology could be a key competitive advantage. This novel methodology is focused on improving the objectivity and efficiency of plastic production and the design review process. It is applicable to discrete optimization events in any product lifecycle milestone, from concept design to serial production stages. The methodology includes a natural way to capture plastic-related knowledge and trends, oriented towards building a dynamic “interaction matrix”, with a list of potential optimizations and their positive or negative impacts in a comprehensive set of multi-criteria evaluations. With an innovative approach, the matrix allows the possibility to incorporate a business strategy, which could be different at every lifecycle stage. The business strategy is translated from the common “verbal” definition into a quantitative set of “Target and Restrictions”, making it possible to detect and prioritize the best potential design optimization changes according to the strategy. This methodology helps to model and compare design alternatives, verify impacts in every evaluation criteria, and make robust and objective information-based decisions. The application of the methodology in real cases of plastic material design optimization in the automotive industry has provided remarkable results, accelerating the detection of improvement methods aligned with the strategy and maximizing the improvement in product competitiveness and sustainability. In comparison with the simultaneous application of existing mono-criteria optimization methodologies (such as “Design to Cost” or “Eco Design”) and subjective expert-based reviews, the novel methodology has a reduced workload and risks, confirming its potential for future application and further development in other polymer-based products, such as consumer goods or packaging.

Reliability Inversion: A Cautionary Tale

Reliability analysis is often based on worst-case assumptions to produce guaranteed lower bounds on system survival probability. Reliability engineers make lower bounds as tight as possible, but sometimes system structure is unfriendly to the derivation of tight bounds. Unfortunately, loose reliability lower bounds make it difficult to compare design alternatives or to select among competing systems.

An energetic profile for greener buildings

Reducing carbon emissions is one of the major challenges facing policy makers today. Cities need a better grasp of the effects of comprehensive energy retrofitting to deal with this crisis. In this study, an Energetic Profile for Existing Office Buildings concept and its features are presented. It consists of seven architectural parameters from macro to micro, including building environment, envelope, compactness, shape, floor plan flexibility and access to daylight, floor efficiency and space subdivision. The Energetic Profile identifies energy-saving opportunities and defines the key energetic-architectural typologies of office buildings that are rarely incorporated in environmentally conscious standards. For each parameter, a methodology is presented to calculate the total energy impact (cooling, heating, and lighting). This is illustrated by an assessment of a theoretical office building located in a hot and humid climate. The findings prove the effectiveness of the Energetic Profile in identifying energy savings, comparing design alternatives, and qualifying the influence of construction phases. Applications of the Energetic Profile to new office buildings are also discussed.

Evaluation of Intelligent Wells Performance in a Five-Spot Arrangement

The efficiency of water flooding processes can be improved by installing intelligent wells which are good candidates for control and optimization. Optimal control theory based on adjoint formulations was found to be efficient for reservoir optimization. However, this solution approach is local and may not be suitable for comparing design alternatives. In this work, an approach for determining an optimal starting point for optimal control theory procedure was developed to give near global optima. The performance in terms of net present value (NPV) of two forms of five-spot pattern was compared. The method results to similar performances of the two alternatives because it was formulated to give true optimal solution trajectories. It was found that regular five-spot pattern results to a NPV in excess of $4,900 over inverted design. Respective increase in oil and water productions of 0.23% and 0.22% were recorded for former design against the later.Keywords: intelligent wells; adjoint; optimal control theory; global optimum; water flooding.

New Methods for Sustainable Circular Buildings

Cities can and should be an open field to sustainable circular guidelines since its scale complexity becomes an impact (positive or negative) over the environment as deep as its dimension. On this scenario, construction industry aims to develop products that fulfil also functional requirements and at the same time safety and durability during all the life cycle phases, promoting reversible buildings to avoid constructions obsolescence and recourses’ waste. Most of the Building Sustainability Assessment methods require detail in the input data, hampering their usability at early design stages. So, the paper presents two complementary methods that are being developed to promote early stage sustainability through both sustainability design decision-making guidance and assessment of investment willingness and affordability. The first method enables project teams to compare design alternatives and verify which is the most sustainable choice and alerts them how sustainability concerns are linked to all design criteria, constraints and decisions. The second method is a cost-benefit analysis method to analyse and compare building solutions that consider the stakeholders’ investment willingness and market availability. These new approaches can lead to a more sustainable built environment and contribute to more circular economy since it allows thinking on reversible and transformable buildings since the early design stages choosing solutions closer to the building stakeholders’ investment willingness and the users’ affordability.

Intelligent Computational Schemes for Designing more Seismic Damage-Tolerant Structures

ABSTRACTA novel concept of multiple deterministic analyses is proposed to design safer and more damage-tolerant structures for seismic excitation. The underlying risk is estimated to compare design alternatives. The basic response surface method is significantly improved to approximately generate implicit performance functions explicitly. Using the advanced factorial design, moving least squares, and Kriging methods, nine alternatives are proposed and verified using Monte Carlo simulations. They correctly identified and correlated the damaged states of structural elements using only few hundreds of deterministic analyses. The authors believe that they proposed alternatives to the random vibration approach and Monte Carlo simulation.

Optimized preliminary structural design of steel composite buildings using the Sustainable Office Designer

AbstractDedicated to Prof. Dr. Akimitsu Kurita on his 70th birthdayPreliminary structural design is used for estimating and comparing design alternatives. It is mainly a manual procedure based on experience and documented in the form of design tables or charts. In an effort to automate this procedure for steel composite office buildings, the Sustainable Office Designer (SOD) has been developed as a SketchUp plug‐in. It can generate optimized preliminary structural designs for given rectangular boundary shapes and employs a rapid approximate calculation instead of an expensive structural analysis. Steel columns are used and verified according to DIN EN 1993‐1‐1, while beams are designed as composite members and verified to DIN EN 1994‐1‐1. Pre‐calculated design tables are used for slab systems. Optimization results are obtained and compared for different objectives, e.g. life cycle assessments (LCA) and costs.

Engineered Hours Per Product for Simultaneous Engineering

Modern Cooperative Engineering approaches suggest a transparent tracking of production costs during development stages. The traditional concept of Engineered Hours per Product, originally developed for the automotive industry, focusses on specific production and assembly times. Necessary but auxiliary tasks are ignored since their reduction is within the domain of production departments. Thereby this approach promotes the decrease of production time but does not give an adequate measure to compare design alternatives. This paper presents a complementary approach based on the assumption that the production system has reached a stable status and remains relatively constant for new variants. Based on existing products core time drivers based on features are successively identified until an adequate approximation of the time for the current product is achieved. Those time drivers thereby include the total time to perform the task, including auxiliary task and can be used during the development stage. The paper concludes with an industrial case study to illustrate the benefits.

Robotic Design Choice Overview Using Co-Simulation and Design Space Exploration

Rapid robotic system development has created a demand for multi-disciplinary methods and tools to explore and compare design alternatives. In this paper, we present a collaborative modeling technique that combines discrete-event models of controller software with continuous-time models of physical robot components. The proposed co-modeling method utilizes the Vienna development method (VDM) and MATLAB for discrete-event modeling and 20-sim for continuous-time modeling. The model-based development of a mobile robot mink feeding system is used to illustrate the collaborative modeling method. Simulations are used to evaluate the robot model output response in relation to operational demands. An example of a load-carrying challenge in relation to the feeding robot is presented, and a design space is defined with candidate solutions in both the mechanical and software domains. Simulation results are analyzed using design space exploration (DSE), which evaluates candidate solutions in relation to preselected optimization criteria. The result of the analysis provides developers with an overview of the impacts of each candidate solution in the chosen design space. Based on this overview of solution impacts, the developers can select viable candidates for deployment and testing with the actual robot.

Approach for parameter estimation in Markov model of software reliability for early prediction: a case study

Early prediction of software reliability may be used to evaluate design feasibility, compare design alternatives, identify potential failure areas, trade-off system design factors, track reliability improvements, identify the cost overrun at an early stage and to provide optimal development strategies. Many researchers have proposed different approaches to predict the software reliability based on Markov model but the uncertainty associated with these approaches is to find the transition probabilities in between the two states of the Markov chain. The authors propose an approach to address this problem by modelling the software system through Petri Net, converting it into Markov chain and solving the linear system mathematically. The validation of the proposed approach has also been shown by comparing the predicted reliability, based on predicted transition probability, with computed reliability, based on operational profile of safety critical software of Nuclear Power Plant.

Design of radiant floor heating panel in view of floor surface temperatures

The radiant floor heating panel should be designed to maintain the indoor condition within the comfort range, to prevent discomfort when contacting floor surfaces of uneven temperature distribution, and to prevent skin burn and unwanted deformation of materials. For these reasons, heat flux and floor surface temperature distribution should be examined at the design stage. However, the current design convention focuses mainly on securing enough heat flux and not much of attention is given to floor surface temperature distribution.In this study, design charts were developed that help designers to consider heat flux, difference between maximum and minimum floor surface temperature (DFST), and maximum floor surface temperature (MFST) at the design stage through investigating the relationships between heat flux and design parameters and conducting numerical simulations to analyze floor surface temperature distributions. These charts were validated through experiments. Then some applications and limitations were suggested for utilizing the design charts.The design charts can be applied to panels with no floor covering, linoleum and oak wood as floor coverings. Design alternatives for other floor coverings can also be developed by interpolating the values from the design charts, because there are linear relationships between the required average water temperature and heat flux.The results of this study can be used to examine the designed panel to verify whether it can provide enough heat flux and that DFST and MFST are appropriate. Additionally, the developed design charts help the designer to compare design alternatives, thus enhancing the flexibility of the panel design.

A reliability model for Service Component Architectures

Service-oriented applications are dynamically built by assembling existing, loosely coupled, distributed, and heterogeneous services. Predicting their reliability is very important to appropriately drive the selection and assembly of services, to evaluate design feasibility, to compare design alternatives, to identify potential failure areas and to maintain an acceptable reliability level under environmental extremes.This article presents a model for predicting reliability of a service-oriented application based on its architecture specification in the lightweight formal language SCA-ASM. The SCA-ASM component model is based on the OASIS standard Service Component Architecture for heterogeneous service assembly and on the formal method Abstract State Machines for modeling service behavior, interactions, and orchestration in an abstract but executable way.The proposed method provides an automatic and compositional means for predicting reliability both at system-level and component-level by combining a reliability model for an SCA assembly involving SCA-ASM components, and a reliability model of an SCA-ASM component. It exploits ideas from architecture-based and path-based reliability models. A set of experimental results shows the effectiveness of the proposed approach and its comparison with a state-of-the art BPEL-based approach.

An analytical procedure for strain response prediction of flexible pavement

The bottom-up fatigue damage in flexible pavements is typically assessed through the tensile strains at the bottom of the asphalt layer. The fatigue damage is then correlated using a calibration factor to the fatigue cracking. Therefore, the success of any pavement design depends on the accuracy and efficiency of employed mechanistic parameters, such as stress and strain. A procedure that can accurately and rapidly predict pavement strain response when traffic and environmental data are provided is desirable. In this study, an analytical procedure was developed to predict pavement response using a mixed pool of tensile strains from instrumentation and 3D FE simulation. Statistical features make the developed procedure powerful and efficient such that the strain responses due to every individual axle pass can be predicted. A demonstration example of predicting tensile strains under multiple-axle loading conditions is provided to facilitate application of the procedure to other data-sets. The maximum difference of 9 microstrain in response implies a reasonable accuracy of the analytical procedure. As demonstrated by using a full-depth flexible pavement section, the analytical procedure is effective and of immediate assistance to experimentally compare design alternatives.

Framework for hybrid performance prediction process model

The dynamic behavior of distributed systems requires that their performance characteristics be determined rigorously, preferably in the early stages of software engineering process. Evaluation of the performance at the end of software development leads to increase in the cost of design change. To compare design alternatives or to identify system bottlenecks, quantitative system analysis must be carried out from the early stages of the software development life cycle. In this paper we describe a process model, Hybrid Performance Prediction Process Model that allows modeling and evaluating distributed systems with the explicit goal of assessing performance of the software system during feasibility study. The use case performance engineering approach proposed in this paper exploits use case model and provides flexibility to integrate the software performance prediction process with software engineering process. We use an e-parking application to demonstrate various elements in our framework. The performance metrics are obtained and analyzed by considering two software architectures. Sensitivity analysis on the behavior of resources is carried out. This analysis helps to determine the capacity of the execution environment to obtain the defined performance objectives.

Analyzing User Costs In a Hospital: Methodological Implication of Space Syntax to Support Whole-life Target Value Design

Research Hypothesis: H1: Space Syntax analysis can be used to simulate a user’s experience and movement for investigating design alternatives in the design of healthcare facilities. H2: Space Syntax can efficiently be used to support Whole-life Target Value Design (TVD). Purpose: This paper investigates a methodological implication of Space Syntax to Whole- life TVD in the design of healthcare facilities. Research Design/Method: Three hypothetical hospital ward design alternatives are selected – shallow-plan, deep-plan, and courtyard-plan type – to analyze user costs in hospital design to determine which alternative is the most cost-efficient. These three hypothetical design alternatives are evaluated using a Space Syntax program, and then the findings are interpreted to determine user costs. Findings: The study finds that the deep-plan type has four “low” scores, the shallow-plan type has three “high” and one “medium” score, and the courtyard type has two “high” scores and two “medium” scores. Thus, the deep-plan type is determined to be the lowest user cost type, and the shallow-plan type is expected to have the highest user costs. Limitations: User costs are discussed in qualitative basis such as high, medium, or low with proportion to the simulation due to the lack of empirical evidence in financial value. Implications: Space Syntax assures valid results of spatial analysis in relation to users’ movement within the built environment. Value for practitioners: Space Syntax allows designers to visually compare design alternatives relating to space planning during set-based design using spatial analysis applications.