Wireless Sensor System for Prediction of Carbon Monoxide Concentration using Fuzzy Time Series

Carbon monoxide (CO) concentration produced from incomplete material burning affects both work health and safety. A smart system capable of early detection of carbon monoxide (CO) concentration is therefore required. This research develops a carbon monoxide sensor detection capability using a wireless sensor system that transmits data to the web server via internet connection. A semiconductor CO sensor is installed in a remote terminal unit. A computer application is developed for data acquisition and sending  via online and in real time to a web server using an internet modem. For a web-based prediction of CO concentration, a Fuzzy Time Series algorithm induced by Pritpal Sing matrix is used. This research uses CO concentration data for two months. The resulting carbon monoxide concentration   prediction   is  displayed   in  real  time  on  a dashboard. This prediction is for the next day’s forecast. Results show that the Fuzzy Time Series that is induced by Pritpal Sing matrix has an average error of 2.67 %, calculated  with its average forecasting error rate (AFER). This error value varies, depending on the number of data and data characteristics

An experimental study on timely activation of smoke alarms and their effective notification in typical residential buildings

The volume of smoke alarm sound in rooms (other than room of sound origin) in real houses and smoke alarm activation time in rooms in full-scale model houses using ionization, photoelectric and dual detector smoke alarms were determined in this study. The alarm sound level measurements indicated that the sound level in many locations is likely to be too low to provide reliable notification, particularly for sleeping people, if smoke alarms are not installed in every room. In addition, changing to a lower frequency (520 Hz square wave) alarm would further aid effective notification of building occupants. The smoke alarm activation measurements showed that the time to detection (given a particular smoke source) was influenced by door position (open versus closed), the room in which the fire occurs, the location (room or hallway) of the detector, the type of detector and the smoke alarm manufacturer. Furthermore time to detection is also influenced by the type and form of the material that is burning. It was observed that photoelectric smoke alarms had the highest incidence of non-activation and when they did activate they, on average, took longer to activate than ionization and dual (ionization and photoelectric) smoke alarms over all smoke sources considered in this study. It is concluded that to achieve early detection and provide adequate notification, smoke alarms are necessary in every room and should be interconnected

A Search for Rapid Photometric Variability in Symbiotic Binaries

We report on our survey for rapid (time scale of minutes) photometric variability in symbiotic binaries. These binaries are becoming an increasingly important place to study accretion onto white dwarfs since they are candidate Type Ia supernovae progenitors. Unlike in most cataclysmic variables, the white dwarfs in symbiotics typically accrete from a wind, at rates greater than or equal to 10^{-9} solar masses per year. In order to elucidate the differences between symbiotics and other white dwarf accretors, as well as search for magnetism in symbiotic white dwarfs, we have studied 35 primarily northern symbiotic binaries via differential optical photometry. Our study is the most comprehensive to date of rapid variability in symbiotic binaries. We have found one magnetic accretor, Z And, previously reported by Sokoloski & Bildsten (1999). In four systems (EG And, BX Mon, CM Aql, and BF Cyg), some evidence for flickering at a low level (roughly 10 mmag) is seen for the first time. These detections are, however, marginal. For 25 systems, we place tight upper limits (order of mmag) on both aperiodic and periodic variability, highlighting a major difference between symbiotics and cataclysmic variables. The remaining five of the objects included in our sample (the 2 recurrent novae RS Oph and T CrB, plus CH Cyg, o Ceti, and MWC 560) had previous detections of large-amplitude optical flickering, and we present our extensive observations of these systems in a separate paper. We discuss the impact of our results on the ``standard'' picture of wind-fed accretion, and speculate on the possibility that in most symbiotics, light from quasi-steady nuclear burning on the surface of the white dwarf hides the fluctuating emission from accretion.Comment: 24 pages, 17 figures. Submitted to MNRAS (12/21/00), and revised in response to referee comments (3/30/01

The Real-Time Evolution of Sakurai's Star (V4334 Sgr) and other (V)LTP Objects

We report on the progress of our on-going campaign to monitor the evolution of the VLTP objects V4334 Sgr and V605 Aql, as well as the suspected (V)LTP object CK Vul. V4334 Sgr does not show signs of increased ionization compared to our previous observations in 2004. We obtained the first radio detection of V605 Aql, indicating a strong increase in radio flux since 1987. We also present the first radio detection of CK Vul and discuss the expansion of the material ejected during the 1670 event.Comment: 4 pages, 2 figures in eps format, IAU symp. 234: `Planetary Nebulae in our Galaxy and Beyond', eds. M. J. Barlow & R. H. Mende

State-of-the art of acousto-optic sensing and imaging of turbid media

Acousto-optic (AO) is an emerging hybrid technique for measuring optical contrast in turbid media using coherent light and ultrasound (US). A turbid object is illuminated with a coherent light source leading to speckle formation in the remitted light. With the use of US, a small volume is selected,which is commonly referred to as the “tagging” volume. This volume acts as a source of modulated light, where modulation might involve phase and intensity change. The tagging volume is created by focusing ultrasound for good lateral resolution; the axial resolution is accomplished by making either the US frequency, amplitude, or phase time-dependent. Typical resolutions are in the order of 1 mm. We will concentrate on the progress in the field since 2003. Different schemes will be discussed to detect the modulated photons based on speckle detection, heterodyne detection, photorefractive crystal (PRC) assisted detection, and spectral hole burning (SHB) as well as Fabry-Perot interferometers. The SHB and Fabry-Perot interferometer techniques are insensitive to speckle decorrelation and therefore suitable for in vivo imaging. However, heterodyne and PRC methods also have potential for in vivo measurements. Besides measuring optical properties such as scattering and absorption, AO can be applied in fluorescence and elastography applications

Low Carbon Abundance in Type Ia Supernovae

We investigate the quantity and composition of unburned material in the outer layers of three normal Type Ia supernovae (SNe Ia): 2000dn, 2002cr and 20 04bw. Pristine matter from a white dwarf progenitor is expected to be a mixture of oxygen and carbon in approximately equal abundance. Using near-infrared (NIR, 0.7-2.5 microns) spectra, we find that oxygen is abundant while carbon is severely depleted with low upper limits in the outer third of the ejected mass. Strong features from the OI line at rest wavelength = 0.7773 microns are observed through a wide range of expansion velocities approx. 9,000 - 18,000 km/s. This large velocity domain corresponds to a physical region of the supernova with a large radial depth. We show that the ionization of C and O will be substantially the same in this region. CI lines in the NIR are expected to be 7-50 times stronger than those from OI but there is only marginal evidence of CI in the spectra and none of CII. We deduce that for these three normal SNe Ia, oxygen is more abundant than carbon by factors of 100 - 1,000. MgII is also detected in a velocity range similar to that of OI. The presence of O and Mg combined with the absence of C indicates that for these SNe Ia, nuclear burning has reached all but the extreme outer layers; any unburned material must have expansion velocities greater than 18,000 km/s. This result favors deflagration to detonation transition (DD) models over pure deflagration models for SNe Ia.Comment: accepted for publication in Ap

Fireground location understanding by semantic linking of visual objects and building information models

This paper presents an outline for improved localization and situational awareness in fire emergency situations based on semantic technology and computer vision techniques. The novelty of our methodology lies in the semantic linking of video object recognition results from visual and thermal cameras with Building Information Models (BIM). The current limitations and possibilities of certain building information streams in the context of fire safety or fire incident management are addressed in this paper. Furthermore, our data management tools match higher-level semantic metadata descriptors of BIM and deep-learning based visual object recognition and classification networks. Based on these matches, estimations can be generated of camera, objects and event positions in the BIM model, transforming it from a static source of information into a rich, dynamic data provider. Previous work has already investigated the possibilities to link BIM and low-cost point sensors for fireground understanding, but these approaches did not take into account the benefits of video analysis and recent developments in semantics and feature learning research. Finally, the strengths of the proposed approach compared to the state-of-the-art is its (semi -)automatic workflow, generic and modular setup and multi-modal strategy, which allows to automatically create situational awareness, to improve localization and to facilitate the overall fire understanding

Fire debris analysis by Raman spectroscopy and chemometrics

A paper reporting the use of Raman Spectroscopy in fire debris analysis is presented. Five polymer based samples, namely carpet (polypropylene), nylon stockings (nylon), foam packaging (polystyrene), CD cases (polystyrene) and DVD cases (polypropylene) were burnt with each one of the following ignitable liquids: petrol, diesel, kerosene and ethanol. Raman shifts were obtained and, in some cases, peaks were identified to correspond to pyrolysis products in the form of alkanes, aromatic or polyaromatic compounds. All pyrolysis peaks were used to produce a Principal Component Analysis (PCA) of the burned samples with the different ignitable liquids. The change in the Raman spectra made it possible to identify some of the pyrolysis products produced in the combustion and also to identify the different plastic materials in fire debris, even when different fuels have been used and the chemical and structural identity of the plastic has been altered in the fire