60 research outputs found
CBE Clima Tool: a free and open-source web application for climate analysis tailored to sustainable building design
Buildings that are designed specifically to respond to the local climate can
be more comfortable, energy-efficient, and with a lower environmental impact.
However, there are many social, cultural, and economic obstacles that might
prevent the wide adoption of designing climate-adapted buildings. One of the
said obstacles can be removed by enabling practitioners to easily access and
analyse local climate data. The CBE Clima Tool (Clima) is a free and
open-source web application that offers easy access to publicly available
weather files (in EPW format) specifically created for building energy
simulation and design. It provides a series of interactive visualization of the
variables therein contained and several derived ones. It is aimed at students,
educators, and practitioners in the architecture and engineering fields. Since
its launch has been consistently recording over 3000 monthly unique users from
over 70 countries worldwide, both in professional and educational settings.Comment: Submitted to Software
Cozie Apple: An iOS mobile and smartwatch application for environmental quality satisfaction and physiological data collection
Collecting feedback from people in indoor and outdoor environments is
traditionally challenging and complex in a reliable, longitudinal, and
non-intrusive way. This paper introduces Cozie Apple, an open-source mobile and
smartwatch application for iOS devices. This platform allows people to complete
a watch-based micro-survey and provide real-time feedback about environmental
conditions via their Apple Watch. It leverages the inbuilt sensors of a
smartwatch to collect physiological (e.g., heart rate, activity) and
environmental (sound level) data. This paper outlines data collected from 48
research participants who used the platform to report perceptions of
urban-scale environmental comfort (noise and thermal) and contextual factors
such as who they were with and what activity they were doing. The results of
2,400 micro-surveys across various urban settings are illustrated in this paper
showing the variability of noise-related distractions, thermal comfort, and
associated context. The results show people experience at least a little noise
distraction 58% of the time, with people talking being the most common reason
(46%). This effort is novel due to its focus on spatial and temporal
scalability and collection of noise, distraction, and associated contextual
information. These data set the stage for larger deployments, deeper analysis,
and more helpful prediction models toward better understanding the occupants'
needs and perceptions. These innovations could result in real-time control
signals to building systems or nudges for people to change their behavior.Comment: Accepted at the CISBAT 2023 The Built Environment in Transition,
Hybrid International Conference, EPFL, Lausanne, Switzerland, 13-15 September
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Ventilation mode effect on thermal comfort in a mixed mode building
Between 2017 and 2018, we conducted a longitudinal field experiment in a mixed-mode ventilation building located in Wollongong Australia, with a particular focus on occupant thermal comfort and adaptive behaviour. This study investigated how different building operation modes i.e. air-conditioning (AC) and natural ventilation (NV), can have an impact on occupant perception of thermal comfort. Time-And-place matching of objective (physically measured indoor climate parameters, outdoor meteorological data, and building operational information) and subjective data (i.e. occupant survey questionnaires) enabled empirical investigation of the relationships between those parameters. The result of the analysis revealed that subjective perception of indoor thermal environment can be affected by different modes of building operation. Occupants were found to be more tolerant of, or adaptive to, the indoor thermal conditions when the building was in the NV mode of operation compared to the AC operational mode. The applicability of the adaptive comfort standard to the mixed-mode ventilation context was also discussed
Controlling Rayleigh-Backscattering-Induced Distortion in Radio over Fiber Systems for Radioastronomic Applications
Radio over Fiber (RoF) Systems exploiting a direct modulation of the laser
source are presently utilized within important Radioastronomic scenarios. Due
to the particular operating conditions of some of these realizations, the
phenomena which typically generate nonlinearities in RoF links for
telecommunications applications can be here regarded as substantially harmless.
However, these same operating conditions can make the RoF systems vulnerable to
different kinds of nonlinear effects, related to the influence of the Rayleigh
Backscattered signal on the transmitted one. A rigorous description of the
phenomenon is performed, and an effective countermeasure to the problem is
proposed and demonstrated, both theoretically and experimentally.Comment: Accepted for publication in IEEE/OSA Journal of Lightwave Technolog
Approaching sustainable development through energy management, the case of Fongo Tongo, Cameroon
This work is aimed at defining a possible solution for sustainable energy development in the Menoua Department, West Cameroon. The purpose of the cooperation between ALA Milano Onlus and the Biomass Energy Efficiency Laboratory of the University of Modena and Reggio Emilia was to analyze the case study in order to propose a solution for energy production capable of meeting the needs of the Cameroonian society while also heading towards a sustainable development. Primary researches suggested that the most viable solution was to integrate the corn food processing with the gasification of the cobs. The thermo-conversion process was modeled with a black-box approach; the results of the model were further compared with the energy required for corn processing, therefore demonstrating the sustainability and virtuosity of the chosen solution. A commercial 20 kWel gasifier was selected for supplying electrical power to three central buildings: the city hall, the Chaufferie and the school. This solution is a security measure assuring continue power supply to these vital buildings. Furthermore, it will bind the relation between the rural and the city areas through the energy exchange process
Optimal Dithering Configuration Mitigating Rayleigh-Backscattering-Induced Distortion in Radioastronomic Optical Fiber Systems
In the context of Radioastronomic applications where the Analog
Radio-over-Fiber technology is used for the antenna downlink, detrimental
nonlinearity effects arise because of the interference between the forward
signal generated by the laser and the Rayleigh backscattered one which is
re-forwarded by the laser itself toward the photodetector.
The adoption of the so called dithering technique, which involves the direct
modulation of the laser with a sinusoidal tone and takes advantage of the laser
chirping phenomenon, has been proved to reduce such Rayleigh Back Scattering -
induced nonlinearities. The frequency and the amplitude of the dithering tone
should both be as low as possible, in order to avoid undesired collateral
effects on the received spectrum as well as keep at low levels the global
energy consumption.
Through a comprehensive analysis of dithered Radio over Fiber systems, it is
demonstrated that a progressive reduction of the dithering tone frequency
affects in a peculiar fashion both the chirping characteristics of the field
emitted by the laser and the spectrum pattern of the received signal at the
fiber end.
Accounting for the concurrent effects caused by such phenomena, optimal
operating conditions are identified for the implementation of the dithering
tone technique in radioastronomic systems.Comment: 11 pages. Accepted for Journal of Lightwave Technolog
Radio frequency over fiber technology for SKA-low receiver
The signal reception chain is an essential element for achieving the square kilometer array-low (SKA-low) system requirements in terms of high sensitivity and dynamic range. The balance between gain, linearity, and low power consumption, as well as the cost, are fundamental parameters that influence the selection of the most suitable technology for SKA-low. Further factors, such as low self-generated radio frequency (RF) interference, high reliability, robustness under extreme environment, and last but not least, the distance between the antennas and the acquisition systems, have impacts on the selection for both architecture and receiver system design. The selected technology for the SKA-low RF signal transportation is RF-over-fiber systems, where the preamplified RF signal picked up by the antennas is carried via analogue modulation over optical fiber. The rationales behind the selection are reported, along with descriptions on the development of the receiver prototypes. The prototypes were deployed and installed on the demonstrator arrays at the selected SKA-low site in Western Australian. Particular attention has been put on the thermal characterization of the receiver system under the actual operating temperature on site, especially when both transmitting part and the optical medium are subjected to external ambient temperature variations. Performance issues encountered in the demonstrator arrays are also discussed along with some proposals for future activities
Power Over Fibre Systems for the Italian SKA-Low Demonstrators
The Power over Fibre technique allows to power remote electronics without using copper cables. Avoiding any interaction between the antenna and its power/signal cable is attractive in the case of testing systems where the evaluation of antenna and/or array performance are crucial parameters under investigation. This is the case of the Sardina Array Demonstrator, an Italian SKA testing platform. In this work is evaluated the applicability of this technology in order to power the electronics of the antennas which will form SAD. The results of an extensive measurement campaign, with respect to both temperature and fibre length, of commercial PoF receivers, is here presented
The colours of comfort:From thermal sensation to person-centric thermal zones for adaptive building strategies
Thermal comfort research has been traditionally based on cross-sectional studies and spatial aggregation of individual surveys at building level. This research design is susceptible to compositional effects and may lead to error in identifying predictors to thermal comfort indices, in particular in relation to adaptive mechanisms. A relationship between comfort and different predictors can be true at an individual level but not evident at the building level. In addition, cross-sectional studies overlook temporal changes in individual thermal perception due to contextual factors. To address these limitations, this study applied a longitudinal research design over 8 to 21 months in eight buildings located in six countries around the world. The dataset comprises of 5,567 individual thermal comfort surveys from 258 participants. The analysis aggregated survey responses at participant level and clustered participants according to their thermal sensation votes (TSV). Four TSV clusters were introduced, representing four different thermal sensation traits. Further analysis reviewed the probability of cluster membership in relation to demographic characteristics and behavioural adaptation. Finally, the analysis at individual level enabled the introduction of a new metric, the thermal zone (Zt), which in this study ranges from 21.5°C to 26.6°C. The thermal sensation traits and person-centric thermal zone (Zt) are a first step into the development of new metrics incorporating individual perceived comfort into dynamic building controls for adaptive buildings
Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?
International audienc
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