Past, present and future mathematical models for buildings (i)

This is the first of two articles presenting a detailed review of the historical evolution of mathematical models applied in the development of building technology, including conventional buildings and intelligent buildings. After presenting the technical differences between conventional and intelligent buildings, this article reviews the existing mathematical models, the abstract levels of these models, and their links to the literature for intelligent buildings. The advantages and limitations of the applied mathematical models are identified and the models are classified in terms of their application range and goal. We then describe how the early mathematical models, mainly physical models applied to conventional buildings, have faced new challenges for the design and management of intelligent buildings and led to the use of models which offer more flexibility to better cope with various uncertainties. In contrast with the early modelling techniques, model approaches adopted in neural networks, expert systems, fuzzy logic and genetic models provide a promising method to accommodate these complications as intelligent buildings now need integrated technologies which involve solving complex, multi-objective and integrated decision problems

Past, present and future mathematical models for buildings (ii)

This article is the second part of a review of the historical evolution of mathematical models applied in the development of building technology. The first part described the current state of the art and contrasted various models with regard to the applications to conventional buildings and intelligent buildings. It concluded that mathematical techniques adopted in neural networks, expert systems, fuzzy logic and genetic models, that can be used to address model uncertainty, are well suited for modelling intelligent buildings. Despite the progress, the possible future development of intelligent buildings based on the current trends implies some potential limitations of these models. This paper attempts to uncover the fundamental limitations inherent in these models and provides some insights into future modelling directions, with special focus on the techniques of semiotics and chaos. Finally, by demonstrating an example of an intelligent building system with the mathematical models that have been developed for such a system, this review addresses the influences of mathematical models as a potential aid in developing intelligent buildings and perhaps even more advanced buildings for the future

Simulation of a centralized cooling plant under different control strategies

peer reviewedThe simulated cooling plant equips an office building whose maximum cooling demand is about 5 MW. To meet this load, the cooling plant uses five cooling towers, four twin-screw chillers and four encapsulated ice storage tanks. The simulation of the cooling plant is carried out with the software TRNSYS. To perform the simulation, the system components are first modeled and identified on the basis of the information given by the equipment manufacturers and the installers. Once the parameter identification of the components is done, TRNSYS is used to simulate the cooling plant in each operating mode. This paper focuses on two operating modes : the pure discharging and the direct production with possible discharging. For these modes, a control strategy was developed during the cooling plant design phase. This paper discusses the impact on the plant performance of changes brought to the designed control strategie

IEA Annex 30 : "Bringing simulation to application". Presentation of Subtask 1 : "Model qualification"

peer reviewe

IEA Annex 30 : bringing simulation to application. Conclusions of subtask 1 : model qualification

peer reviewedFrom 1995 to 1998, IEA Annex 30 "Bringing Simulation to Application" has been adressing the problem of improving the conditions aiming at a more effective use of building and HVAC simulation among consulting engineers and building practitioners. Therefore, the project gathered both academic research teams and several consulting offices representatives in order to demonstrate, on real Case Studies, what should be done to achieve this goal. The first Subtask of the IEA Annex 30 was dealing with the most fundamental step appearing in the process of simulation use: qualification of the models implemented in the available simulation tools. The objective of the Subtask was to establish a framework allowing any simulation models developper to provide the necessary information making any simulation model user more confident when using such tools. To achieve this objective, Subtask 1 was divided in two parts: - a first part dealing with a survey of the available models and data resources useful for building and HVAC simulation; - a second part dealing with the development and the application on several examples of "model qualification procedures", which provides the required framework. The survey action was mainly focussing on the following items: models, meteorological data, internal gains, HVAC and material databases. The model qualification procedure was first defined as a sequence of operations involving several steps: model documentation, parameters identification, examples of use and sample results, validation (or verification of the models), integration in a data exchange process. This procedure was applied to several building and HVAC models: building thermal zones, cooling coil, chiller and cooling tower

Simulation d'un bâtiment et de son système de ventilation grâce à un solveur d'équations: Application au benchmarking

The today - availability of powerful engineering equation solvers is opening very new possibilities in technical component modelling and in system simulation. The simulation models, the “user guide” and the “reference guide” are all included in a same file. Reliable “reference” and “simplified” models are currently available for the building zone and for most HVAC components. Focus is given here on “simplified” models and on a simulation tool, called “Benchmark”. This tool should help an auditor to make the best use of the limited information usually available about actual fuel and electricity consumptions and to get a very first evaluation of the actual performances of a given HVAC system. An example of such use is presented. Another simulation tools and more information about the modelling of HVAC components will be presented in a further paper.HarmonA

Controlled comparison of milnacipran (F2207) 200 mg and amitriptyline in endogenous depressive inpatients

A multicentre study compared the antidepressant efficacy and the tolerance of milnacipran (200 mg/d) and amitriptyline (150 mg/d) in two parallel groups of 43 major depressive inpatients, endogenous subtype, as defined by Research Diagnostic Criteria. The duration of the study was 4 weeks, with weekly assessments by means of the Montgomery and Asberg depression scale (MADS), the Hamilton depression scale, the Clinical Global Impressions (CGI) and a checklist of symptoms and side‐effects. Results showed similar improvement in both groups but better tolerance with milnacipran (less drowsiness and anticholinergic side‐effects), reflected in the better scores on the therapeutic index of the CGI. The clinical profile of the two drugs was somewhat different with more transitory sedation with amitriptyline and more improvement in concentration difficulties with milnacipran during the first weeks of the study associated with more effect on retardation with milnacipran at the end of the study. Copyright © 1989 John Wiley & Sons, Ltd

BASS 4: a software system for ergonomic design and evaluation of working hours

OBJECTIVE: To extend an existing computer programme for the evaluation and design of shift schedules (BASS 3) by integrating workload as well as economic aspects. METHODS: The redesigned prototype BASS 4 includes a new module with a suitable and easily applicable screening method (EBA) for the assessment of the intensity of physical, emotional and cognitive workload components and their temporal patterns. Specified criterion functions based on these ratings allow for an adjustment of shift and rest duration according to the intensity of physical and mental workload. Furthermore, with regard to interactive effects both workload and temporal conditions, e.g. time of day, are taken into account. In a second new module, important economic aspects and criteria have been implemented. Different ergonomic solutions for scheduling problems can now also be evaluated with regard to their economic costs. RESULTS: The new version of the computer programme (BASS 4) can now simultaneously take into account numerous ergonomic, legal, agreed and economic criteria for the design and evaluation of working hours. CONCLUSIONS: BASS 4 can now be used as an instrument for the design and the evaluation of working hours with regard to legal, ergonomic and economic aspects at the shop floor as well as in administrative (e.g. health and safety inspection) and research problems.<br>OBJETIVOS: Expandir um programa computacional existente para planejamento e avaliação dos horários de turnos (BASS 3) por meio da incorporação da carga de trabalho e características econômicas. MÉTODOS: O protótipo BASS 4 contém um novo módulo com um método de triagem (EBA) conveniente e de fácil aplicação para a avaliação da intensidade dos componentes físico, emocional e cognitivo da carga de trabalho e seus padrões temporais. O uso de critérios específicos com base nestas avaliações possibilita ajustar a duração do turno e do descanso de acordo com a intensidade da carga de trabalho física e mental. Além disso, quanto aos efeitos interativos, tanto a carga de trabalho como os aspectos temporais, p. e., hora do dia, são considerados. Foram introduzidos em um outro módulo características e critérios econômicos de relevância. O novo programa permite também que sejam avaliadas diferentes soluções ergonômicas para problemas de planejamento segundo os custos financeiros. RESULTADOS: A nova versão do programa (BASS 4) tem a capacidade agora de processar simultaneamente vários critérios econômicos, ergonômicos, legais e acordados para o planejamento e avaliação do horário de trabalho. CONCLUSÕES: O BASS 4 pode ser usado agora como um instrumento para planejamento e avaliação dos horários de trabalho, incluindo-se características econômicas, ergonômicas e legais, no setor de produção e em questões administrativas (p.e. fiscalização da saúde e segurança) e relacionados à pesquisa