Predicting thermal and energy performance of mixed-mode ventilation using an integrated simulation approach

Mixed-mode ventilation can effectively reduce energy consumption in buildings, as well as improve thermal comfort and productivity of occupants. This study predicts thermal and energy performance of mixed-mode ventilation by integrating computational fluid dynamics (CFD) with energy simulation. In the simulation of change-over mixed-mode ventilation, it is critical to determine whether outdoor conditions are suitable for natural ventilation at each time step. This study uses CFD simulations to search for the outdoor temperature thresholds when natural ventilation alone is adequate for thermal comfort. The temperature thresholds for wind-driven natural ventilation are identified by a heat balance model, in which air change rate (ACH) is explicitly computed by CFD considering the influence of the surrounding buildings. In buoyancy-driven natural ventilation, the outdoor temperature thresholds are obtained directly from CFD-based parametric analysis. The integrated approach takes advantage of both the CFD algorithm and energy simulation while maintaining low levels of complexity, enabling building designers to utilize this method for early-stage decisionmaking. This paper first describes the workflow of the proposed integrated approach, followed by two case studies, which are presented using a three-floor office building in an urban context. The results are compared with those using an energy simulation program with built-in multizone modules for natural ventilation. Additionally, adaptive thermal comfort models are applied in these case studies, which shows the possibility of further reducing the electricity used for cooling.     

Regeneration of informal areas: An integrated approach

Living conditions in informal areas present a severe problem to the development of society, particularly to public health and the respective socioeconomic context. People in these areas have no viable alternative to solve this problem themselves. In this study, several successful approaches are surveyed and new methods are developed to design a holistic process capable of not only tackling the issue of informal settlements, but doing so in a way that is cognizant of the current global economic reality and that integrates all the dimensions of sustainable development. In this study, an integrated regeneration strategy for Luanda's metropolitan plan in Angola is developed. The methodology is supported by a social context analysis and highly participative design process. The informal settlements vary in type and structure, urban patterns, and their social and economic structure. These factors have been taken into consideration in the approach advanced in this study, as they are deemed key aspects for the fine-tuning of the final approach. Hence, a partnership model is presented, where the public sector provides development conditions for the private sector. The model is supported by regeneration mechanisms that establish the roles and procedures of each stakeholder within the process. Multiple criteria for rehousing as well as guidelines for social and affordable housing are used to create an integrated approach.     

Construction contractor's claims analysis: An integrated system approach

In practice, attempts have been made to identify the cause of delays and to modify schedules, to incorporate revised durations and determine new project times. Professor of Construction Studies at Wolverhampton Polytechnic, UK, Frank Harris, and Sabah Alkass, Assistant Professor at Concordia University, Quebec, present an integrated computerized system that aids in the analysis of claims resulting from delays.     

Evaluating landscape changes using vegetation and land-use maps: an integrated approach

Over the past 60 years, European mountain landscapes have been affected by land abandonment coupled with urbanisation through tourist exploitation. The Bormio surroundings (southern-central Alps, Italy) are an exemplary case study for these phenomena. To evaluate their landscape changes of the last 50 years, a sequence of two vegetation maps (1959, 1975) and a land-use map (2009) were harmonised in terms of spatial scale and thematic contents. The cartographic units were reclassified as Landscape Elements (LE) on the basis of their dominant species. Change at landscape and LE level were analysed by a set of non-redundant metrics. The loss and fragmentation of meadows, as well as an increasing recovery of woodlands and a doubling of urbanised areas, characterised landscape changes.

Meadows and subalpine shrublands were highlighted as being the most threatened landscape elements. The advisability of landscape monitoring for the conservation of the endangered habitats is briefly discussed.     

An integrated approach for fire and explosion consequence modelling

Fire and explosion are accidents which potentially can occur in oil and gas processing facilities. While fire and explosion could occur as a consequence of each other, most published work has assessed fire and explosion separately, ignoring interactions between the two phenomena.The current study proposes a novel approach to model the entire sequences involved in a potential accident using liquid and gas release incidents as two test cases. The integrated scenario is modelled using Computational Fluid Dynamics (CFD) codes FLACS and FDS. An integrated approach is adopted to analyse and represent the effects (injuries/death) of the accident. The proposed approach can be used in designing safety measures to minimize the adverse impacts of such accidents. It can also serve as an important tool to develop safety training to improve emergency preparedness plans.     

An object-oriented framework for dynamic ecosystem modeling: application for integrated risk assessment.

Ecological risk assessment requires the integration of a wide range of data on anthropogenic processes, ecological processes and on processes related to environmental fate and transport. It is a major challenge to assemble a simulation system that can successfully capture the dynamics of complex ecological systems and an even more serious challenge to be able to adapt such a simulation to shifting and expanding analytical requirements and contexts. The dynamic information architecture system (DIAS) is a flexible, extensible, object-based framework for developing and maintaining complex simulations. DIAS supports simulations in which the real-world entities that make up ecological systems are represented as software 'entity objects'. The object-oriented integrated dynamic landscape analysis and modeling system (OO-IDLAMS) provides a good example of how DIAS has been used to build a suite of models for the purpose of assessing the ecological impacts of military land use and land management practices. OO-IDLAMS is a prototype conservation modeling suite that provides military environmental managers and decision-makers with a strategic, integrated and adaptive approach to natural resources planning and ecosystem management. The OO-IDLAMS prototype used Fort Riley, Kansas as a case study to demonstrate DIAS' capabilities to offer flexibility, interprocess dynamics and cost-effective reuse of code for ecosystem modeling and simulation. DIAS can also readily lend itself to other applications in ecological risk assessment. It has great potential for the integration of ecological models (associated with biological uptake and effects) with environmental fate and transport models. A DIAS ecological risk assessment application could be used to predict the magnitude and extent of ecological risks and evaluate remedy effectiveness in a timely and cost-effective manner.     

Sources of regional inefficiencyAn integrated shift-share, data envelopment analysis and input-output approach

This paper develops and tests an integrated set of models to investigate sources of (in)efficiencies in regional industry sectors. First, following the Haynes and Dinc (1997) extension of the shift-share model, leading regional industrial sectors are identified for analysis based on their scale, productivity and sources of productivity change. Second, by employing Data Envelopment Analysis (DEA), the efficiency of these lead sectors is investigated and the future competitiveness of these sectors is evaluated. Finally, by incorporating input-output analysis into the model the impact of intersectoral transactions on sectoral efficiency is assessed. Received: November 1997/Accepted: May 1998     

An integrated approach to BIM competency assessment,acquisition and application

Professional, organisational and educational institutions have started to adopt BIM software tools and adapt their existing delivery systems to satisfy evolving market requirements. To enable individuals within these organisations to develop their BIM abilities, it is important to identify the BIM competencies that need to be learned, applied on the job, and measured for the purposes of performance improvement. Expanding upon previous research, this paper focuses on individual BIM competencies, the building blocks of organisational capability. The paper first introduces several taxonomies and conceptual models to clarify how individual competencies may be filtered, classified, and aggregated into a seed competency inventory. Competency items are then fed into a specialised knowledge engine to generate flexible assessment tools, learning modules and process workflows. Finally, the paper discusses the many benefits this competency-based approach brings to industry and academia, and explores future conceptual and tool development efforts to enable industry-wide BIM performance assessment and improvement.     

Overhanging rock slope by design: An integrated approach using rock mass strength characterisation,large-scale numerical modelling and limit equilibrium methods

Overhanging rock slopes(steeper than 90°) are typically avoided in rock engineering design, particularly where the scale of the slope exceeds the scale of fracturing present in the rock mass. This paper highlights an integrated approach of designing overhanging rock slopes where the relative dimensions of the slope exceed the scale of fracturing and the rock mass failure needs to be considered rather than kinematic release of individual blocks. The key to the method is a simplified limit equilibrium(LE) tool that was used for the support design and analysis of a multi-faceted overhanging rock slope. The overhanging slopes required complex geometries with constantly changing orientations. The overhanging rock varied in height from 30 m to 66 m. Geomechanical modelling combined with discrete fracture network(DFN)representation of the rock mass was used to validate the rock mass strength assumptions and the failure mechanism assumed in the LE model. The advantage of the simplified LE method is that buttress and support design iterations(along with sensitivity analysis of design parameters) can be completed for various cross-sections along the proposed overhanging rock sections in an efficient manner, compared to the more time-intensive, sophisticated methods that were used for the initial validation. The method described presents the development of this design tool and assumptions made for a specific overhanging rock slope design. Other locations will have different geological conditions that can control the potential behaviour of rock slopes, however, the approach presented can be applied as a general guiding design principle for overhanging rock cut slope.     

Predicting integrated thermal and acoustic performance in naturally ventilated high-rise buildings using CFD and FEM simulation

The study of ventilation windows for both natural ventilation and noise mitigation has drawn significant attention recently. This paper presents the numerical approaches to analyse the integrated thermal and acoustical performance of ventilation windows, for a residential building in tropical climate which employs double-layer noise mitigation window for natural ventilation. Given a set of outdoor wind conditions, the distributions of indoor flow and temperature fields are simulated using Computational Fluid Dynamics (CFD) model. The thermal comfort is evaluated using statistical Predicted Mean Vote (PMV) method. For the acoustic performance, noise radiation from road traffic is assumed as the noise source, and the sound insulation of building façade is simulated using Finite Element Method (FEM). From the simulation results, it is found that the thermal satisfaction response is closely related to the inlet wind temperature and speed, and the window opening size greatly affects the ventilation performance. From the case study in Singapore, during certain season, day/night time and with sufficient wind flow, the ventilation window can provide enough fresh air, maintain adequate thermal comfort and quiet acoustic environment for the occupants. The numerical approaches presented in this paper are applicable to general window design studies, and the simulation findings can be incorporated into green building planning. The advantages of using simulation approaches are highlighted and their limitations are discussed.     

Predicting construction cost overruns using text mining,numerical data and ensemble classifiers

This paper discusses how text describing a construction project can be combined with numerical data to produce a prediction of the level of cost overrun using data mining classification algorithms. Modeling results found that a stacking model that combined the results from several classifiers produced the best results. The stacking ensemble model had an average accuracy of 43.72% for five model runs. The model performed best in predicting projects completed with large cost overruns and projects near the original low bid amount. It was found that a stacking model that used only numerical data produced predictions with lower precision and recall. A potential application of this research is as an aid in budgeting sufficient funds to complete a construction project. Additionally, during the planning stages of a project the research can be used to identify a project that requires increased scrutiny during construction to avoid cost overruns.     

An integrated approach to the layout and design of water distribution networks

A model for the least cost layout and design of looped water distribution networks has been developed. The model consists of two linked linear programming formulations. One linear program determines the least cost layout of a looped distribution network given an initial pressure distribution. The other model determines the least cost component design given an initial flow pattern or pipe layout. The linkage between the two linear programs is provided by the use of output from one linear program as input to the other. Since the constraints in the layout model may provide looping without ensuring true redundancy in the system, a layout review is necessary after solutions of the layout model. If true redundancy is not present a set of ‘optional’ constraints can be applied and the layout model solved again. The procedure is demonstrated by application to a sample network.     

An integrated approach for tactical monitoring and data-driven spread forecasting of wildfires

In recent times there have been increasing efforts to integrate technology into wildfire management, especially in the fields of tactical monitoring and simulation. On the one hand, thermal infrared imaging (TIR) systems have been installed aboard surveillance aircraft including unmanned systems (UAS). On the other, there exists a variety of models and simulators able to forecast the fire spread. However, both fields currently present significant limitations. While relevant information is still extracted manually from aerial thermal imagery and is most times merely qualitative, simulators’ accuracy on fire spread prediction has proved insufficient. To solve these issues, this article presents a twofold methodology to couple meaningful automated wildfire monitoring with accurate fire spread forecasting. The main goals are to, firstly, automatically process aerial TIR imagery so that valuable information can be produced in real time during the event and, secondly, use this information to adjust a Rothermel-based simulator in order to improve its accuracy on-line. The fire perimeter location is tracked automatically through an unsupervised edge detector. Afterwards, an assimilation module uses the remotely sensed data to optimise the simulator's fuel and wind parameters, which are assumed to remain constant for a certain period of time. Subsequently, the optimum parameters’ values are used to issue a fire evolution forecast. All outputs are projected onto the corresponding Digital Terrain Model (DTM) and integrated into a Geographic Information System (GIS) for visualization. The global system was validated using two large-scale experiments. If these algorithms can be applied to a sufficiently rich and varied set of experimental data and further developed to cope with more complex scenarios, they could eventually be incorporated into a fire management decision support system.     

An integrated construction planning system using object-oriented product and process modelling

An interactive planning system approach poses challenges to the efficient integration of the design and construction planning process. Current research is focused on organizational knowledge processing in building design and construction, such as the representation of object-oriented planning models and constraint management incorporating design, engineering and construction planning through several planning stages. Since building construction involves cooperation among designers, engineers and project managers, comprehensive organizational planning and management tools are relevant. The integrated construction planning system (ICPS) aims to cover a wide range of knowledge processing based on formalization and representation of building and construction systems. To realize the integrated construction planning system, appropriate modelling techniques need to be introduced. This paper presents the results of research on several issues such as formalization and representation of interactive design and construction planning processes, methods for incorporating project information, knowledge and constraints and the concept of applying an object-oriented paradigm to interactive building and construction system planning. A prototype system is also presented which integrates building space planning, building system planning, construction system planning, construction activity planning and construction site layout planning.     

An integrated approach to electric power system planning and cost of service allocation

Many methods have been proposed to allocate capacity related costs to the various customer classes in an electric power system. These methods are mainly deterministic. Deterministic techniques do not consider the stochastic nature of system components which actually affect the cost behaviour of the system. An important consideration in the process of cost allocation is to ensure that the method used follows the cost behaviour of the system studied. The cost behaviour is basically dependent on the methods and criteria used in system planning and operation. The criteria and planning methods used drives the development of the system which further drives the cost of future investment in the system. It is therefore highly desirable to use similar methods and criteria and to include the same variables which are considered in the system adequacy evaluation. Most large electric power utilities now use probabilistic techniques in their generation system planning. The most commonly used planning techniques are the Loss of Load Expectation (LOLE) and the Loss of Energy Expectation (LOEE) methods. Probabilistic techniques should also be used in the cost of service allocation process as these techniques are capable of incorporating the important factors which actually affect the system cost behaviour.     

An integrated empirical and modeling methodology for analyzing solar reflective roof technologies on commercial buildings

Buildings impact the environment in many ways as a result of both their energy use and material consumption. In urban areas, the emission of greenhouse gases and the creation of microclimates are among their most prominent impacts so the adoption of building design strategies and materials that address both these issues will lead to significant reductions in a building's overall environmental impact. This report documents the energy savings and surface temperature reduction achieved by replacing an existing commercial building's flat roof with a more reflective ‘cool roof’ surface material. The research methodology gathered data on-site (surface temperatures and reflectivity) and used this in conjunction with the as-built drawings to construct a building energy simulation model. A 20-year cost benefit analysis (CBA) was conducted to determine the return on investment (ROI) for the new cool roof construction based on the energy simulation results. The results of the EnergyPlus™ simulation modeling revealed that reductions of 1.3–1.9% and 2.6–3.8% of the total monthly electricity consumption can be achieved from the 50% cool roof replacement already implemented and a future 100% roof replacement, respectively.This corresponds to a saving of approximately $22,000 per year in energy costs at current prices and a consequent 9-year payback period for the added cost of installing the 100% cool roof. The environmental benefits associated with these electricity savings, particularly the reductions in environmental damage and peak-time electricity demand, represent the indirect benefits of the cool roof system.     

An integrated modelling and multicriteria analysis approach to managing nitrate diffuse pollution: 1. Framework and methodology

As trade-off relationships between the agronomy and the environment are common over land uses within a catchment, one of major concerns of catchment management plans is how to balance the trade-offs over land uses at the catchment-scale. In this two-part paper, an integrated modelling and multicriteria analysis (MCA) methodology is presented which can be used to evaluate a set of land use alternatives and to identify an 'ideal' compromise between economic return and environmental pollution. This 'ideal' compromise here is achieved by land use optimisation of which the objective is to minimise the environmental pollution (nitrate leaching rate) and to maximise the economic return (agronomic gross margin), considering both environmental and economic potential across the catchment in a site-specific manner. The suggested methodology can be used to produce a site-specifically optimised land use scenario that is an 'ideal' compromise between nitrate diffuse pollution and agronomy at the catchment-scales. Some issues on the actual application of the methodology are also discussed.     

An efficient two-stage approach for structural damage detection using meta-heuristic algorithms and group method of data handling surrogate model

In this study, the performance of an efficient two-stage methodology which is applied in a damage detection system using a surrogate model of the structure has been investigated. In the first stage, in order to locate the damage accurately, the performance of the modal strain energy based index for using different numbers of natural mode shapes has been evaluated using the confusion matrix. In the second stage, to estimate the damage extent, the sensitivity of most used modal properties due to damage, such as natural frequency and flexibility matrix is compared with the mean normalized modal strain energy (MNMSE) of suspected damaged elements. Moreover, a modal property change vector is evaluated using the group method of data handling (GMDH) network as a surrogate model during damage extent estimation by optimization algorithm; in this part of methodology, the performance of the three popular optimization algorithms including particle swarm optimization (PSO), bat algorithm (BA), and colliding bodies optimization (CBO) is examined and in this regard, root mean square deviation (RMSD) based on the modal property change vector has been proposed as an objective function. Furthermore, the effect of noise in the measurement of structural responses by the sensors has also been studied. Finally, in order to achieve the most generalized neural network as a surrogate model, GMDH performance is compared with a properly trained cascade feed-forward neural network (CFNN) with log-sigmoid hidden layer transfer function. The results indicate that the accuracy of damage extent estimation is acceptable in the case of integration of PSO and MNMSE. Moreover, the GMDH model is also more efficient and mimics the behavior of the structure slightly better than CFNN model.     

An integrated IO and CGE approach to analysing changes in environmental trade balances*

Input‐output (IO) tables and demand‐driven multiplier techniques are absolutely appropriate for conventional pollution attribution (accounting) analyses as they provide all the required information on pollution embodied in intersectoral interactions and interregional trade flows. However, as a model of how the economy adjusts in response to a marginal change in activity, IO is unlikely to be appropriate as it is only a very special case of general equilibrium models. We propose an integrated IO and computable general equilibrium (CGE) approach, with CGE analysis of the impacts of a change in activity and model results used to inform an IO attribution analysis of pollution embodied in interregional trade flows before and after the change is introduced. Resumen. Las tablas input‐output (IO) y las técnicas multiplicadoras en función de la demanda son totalmente apropiadas para los análisis (contables) convencionales de atribución de la contaminación ya que proporcionan toda la información requerida acerca de la contaminación que acompaña a las interacciones intersectoriales y flujos comerciales interregionales Sin embargo, como modelo acerca de cómo la economía se ajusta en respuesta a cambios marginales de la actividad, es poco probable que IO sea apropiado ya que es solamente un caso muy especial de modelos de equilibrio general. Proponemos un enfoque integrado de IO con equilibrio general computable (EGC), con un análisis EGC de los impactos de un cambio en la actividad y siendo los resultados del modelo utilizados para instruir un análisis de atribución IO de la contaminación presente en flujos comerciales interregionales, antes y después de la introducción del cambio.