Reduced order observer based identification of base isolated buildings

The objective of this study is to identify system parameters from the recorded response of base isolated buildings,such as USC hospital building,during the 1994 Northridge earthquake.Full state measurements are not available for identification.Additionally,the response is nonlinear due to the yielding of the lead-rubber bearings.Two new approaches are presented in this paper to solve the aforementioned problems.First,a reduced order observer is used to estimate the unmeasured states.Second,a least squares technique with time segments is developed to identify the piece-wise linear system properties.The observer is used to estimate the initial conditions needed for the time segmented identification.A series of equivalent linear system parameters are identified in different time segments.It is shown that the change in system parameters,such as frequencies and damping ratios,due to nonlinear behavior of the lead-rubber bearings,are reliably estimated using the presented technique.It is shown that the response was reduced due to yielding of the lead-rubber bearings and period lengthening.

The Use of Self-cleaning Materials and Study Their Impact on the Quality of the Visual Appearance of Large Industrial Cities

One of the capabilities of the architecture is to respond to growing and,in some cases,varied needs of users.However,architecture and construction industry,in comparison with other sciences,have been very slow and inadequate to implement this technology despite very suitable ground for improvement.At the moment,one of the most essential discussions in this field is how to achieve qualitative understanding of construction materials.Accordingly,one of the key sections of a construction which plays a significant role in optimizing performance is shell of the building.In this article,in addition to the utilization technique of selfcleaning materials in construction industry which will result in embellishment of urban design,an attempt has also been made to present a suitable model on how to utilize these materials in order to improve the visual appearance quality of megalopolises.The technology of self-cleaning surfaces in order to increase durability and reduce costs and required time for equipment maintenance has currently become the focal point in construction industry.Now providing one answer to the question of whether will selfcleaning,purifying facades change the future of urban architecture?The main panorama of this research is to find and establish a dynamic and sustainable balance in embellishment of urban design.The necessity of research in this field as well as finding the best and most practical solution seem.To achieve all this,an analytical and descriptive research has been utilized,data has been collected by various books and national and international websites.

Islands of misfit buildings: Detecting uncharacteristic electricity use behavior using load shape clustering

Many energy performance analysis methodologies assign buildings a descriptive label that represents their main activity,often known as the primary space usage(PSU).This attribute comes from the intent of the design team based on assumptions of how the majority of the spaces in the building will be used.In reality,the way a building’s occupants use the spaces can be different than what was intended.With the recent growth of hourly electricity meter data from the built environment,there is the opportunity to create unsupervised methods to analyze electricity consumption behavior to understand whether the PSU assigned is accurate.Misclassification or oversimplification of the use of the building is possible using these labels when applied to simulation inputs or benchmarking processes.To work towards accurate characterization of a building’s utilization,we propose a modular methodology for identifying potentially mislabeled buildings using distance-based clustering analysis based on hourly electricity consumption data.This method seeks to segment buildings according to their daily behavior and predict which ones are misfits according to their assigned PSU label.This process finds potentially uncharacteristic behavior that could be an indication of mixed-use or a misclassified PSU.Our results on two public data sets,from the Building Data Genome(BDG)Project and Washington DC(DGS),with 507 and 322 buildings respectively,show that 26%and 33%of these buildings are potentially mislabelled based on their load shape behavior.Such information provides a more realistic insight into their true consumption characteristics,enabling more accurate simulation scenarios.Applications of this process and a discussion of limitations and reproducibility are included.

Impact of window and air-conditioner operation behaviour on cooling load in high-rise residential buildings

Space cooling is an important building energy end-use that was found in recent years to be significantly impacted by occupant behaviours.However,the majority of previous studies ignored the interplay between the operation of windows and air conditioners(ACs)on cooling load,particularly in building energy modelling.In addition,studies on the analysis of cooling load characteristics regarding high-rise buildings are insufficient.The vertical effect of high-rise buildings on cooling load remains vague.This study thus aims to examine how window and AC operation behaviours impact the cooling load of high-rise buildings in an urban context demonstrated by a real-life typical 40-floor residential building in Hong Kong.This study investigates window and AC operation behaviours jointly and examines the vertical effect on cooling load by using agent-based building energy modelling(BEM)techniques and initiating stochastic and diverse behaviour modes.A carefully designed questionnaire survey was conducted to help build behaviour modes and validate energy models.Ninety building energy models were established integrating meteorological parameters generated by the computational fluid dynamics(CFD)programme for ten typical floors and nine combinations of window and AC behaviour modes.The results show that comfort-based AC modes and schedule-based window modes yielded the lowest cooling load.Considering the combined effect of AC and window uses,the maximum difference in cooling loads could be 26.8%.Behaviour modes and building height induce up to 32.4%differences in cooling loads.Besides,a deviation between the behaviour modes and height on the cooling load was found.The findings will help develop a thorough energy model inferring occupants’window and AC behaviour modes along with the building height in high-rise residential buildings.The findings indicate that the interaction impact of window and AC behaviour modes and height should be jointly considered in future high-rise building energy modelling,building energy standards,and policymaking.

Nanoscale 3D Printing Technique Uses Micro-Pyramids to Build Better Biochips

This nanoprinting process allows researchers to 3D print more material on a biochip than ever before,making it easier to study biomedical issues.Making biochips,a key technology in studying disease,just got a little easier.This new nanoprinting process?uses gold-plated pyramids,an LED light,and photochemical reactions to print more organic material on the surface of one single biochip than ever before.The technique uses an array of polymer pyramids that are covered in gold and mounted onto an atomic force mi-