20 research outputs found
Daylight performance through different types of glazing in the tropics
Having glazing on buildings will allow natural daylighting in a room. There are four types of glazing which are commonly used in the market today: Clear, light green, bronze and black float glass where tinted glazing will provide shading to the interior. These four glass are being tested using Integrated Environmental Solutions Virtual Environment (IESVE) software with different proportion to investigate the influence of arrangements of glazing to permit daylight and to serve as shading device. There are 40 combinations of different glazing proportion tested in the simulation. The combination of 75 % clear float glass on a green float glass base gives the highest lux value at a point 90cm from the opening whereas the lowest value is exhibited through a 25% green float glass with a black float glass base of 75%. The finding shows that glazing with lower Visual Light Transmittance as the base will give a lower Daylight Factor compared to using it on top of the other glazing. Furthermore, although there is a large contrast of Daylight Factor between the 0.9m and 3.6m depth, several combination of glazing achieved the requirement of Malaysian Standard 1525 for daylighting in office
Calibrating Car-Following Models using Trajectory Data: Methodological Study
The car-following behavior of individual drivers in real city traffic is
studied on the basis of (publicly available) trajectory datasets recorded by a
vehicle equipped with an radar sensor. By means of a nonlinear optimization
procedure based on a genetic algorithm, we calibrate the Intelligent Driver
Model and the Velocity Difference Model by minimizing the deviations between
the observed driving dynamics and the simulated trajectory when following the
same leading vehicle. The reliability and robustness of the nonlinear fits are
assessed by applying different optimization criteria, i.e., different measures
for the deviations between two trajectories. The obtained errors are in the
range between~11% and~29% which is consistent with typical error ranges
obtained in previous studies. In addition, we found that the calibrated
parameter values of the Velocity Difference Model strongly depend on the
optimization criterion, while the Intelligent Driver Model is more robust in
this respect. By applying an explicit delay to the model input, we investigated
the influence of a reaction time. Remarkably, we found a negligible influence
of the reaction time indicating that drivers compensate for their reaction time
by anticipation. Furthermore, the parameter sets calibrated to a certain
trajectory are applied to the other trajectories allowing for model validation.
The results indicate that ``intra-driver variability'' rather than
``inter-driver variability'' accounts for a large part of the calibration
errors. The results are used to suggest some criteria towards a benchmarking of
car-following models
Bim and genetic algorithm optimisation for sustainable building envelope design
Decision-making (DM) at the early building design stages is essential to optimise sustainability performances. Nevertheless, the current methods of optimising building sustainability are complex as they involve multiple design variables and performance objectives. With the development of building information modelling (BIM), complicated buildings can be digitally constructed with precise geometry and accurate information for design optimisation in the early stages of project. Thus, this study explores the use of BIM and Genetic Algorithm (GA) to support DM and optimisation for sustainable building envelope design. To develop a BIM-GA optimisation method, Autodesk Revit template was created to extract data of building envelope from a Base Model (BM). Then, the data were employed to compute overall thermal transfer value (OTTV) and construction cost for BM evaluation and GA optimisation. A hypothetical building was modelled and then analysed using the proposed method as a test case. The BIM-GA optimisation method can address the difficulties of DM on building sustainability in the early design process
Importance of a view window in rating green office buildings
The essence of a view window (VW) in an office building is not only to bring an optimal balance between daylight and electric light, but also for psychological and health purpose. VW does not only allow the admittance of light and views, but indirectly affects the productivity and psychological wellbeing of office occupants; it has a link to the sustainability in both conventional and green buildings. This paper defines the function of a view window as it relates to green office building. Through literature review and an experiment conducted in room 432-01 located at B11 Faculty of Built Environment, Universiti Teknologi Malaysia. The function of VW in a green office building is highlighted; and the findings show that a VW would enhance sustainability in an office setting and has a dimension greater than 750mm above a finish floor level and less or equal to 2300mm above a finish floor level and with a wall to window ratio (WWR) of 25% to 40%