Extensive Indoor Research Articles

Locally-referenced ultrasonic--LPS for localization and navigation.

This paper presents a flexible deployment of ultrasonic position sensors and a novel positioning algorithm suitable for the navigation of mobile robots (MRs) in extensive indoor environments. Our proposal uses several independently-referenced local positioning systems (LPS), which means that each one of them operates within its own local reference system. In a typical layout, an indoor extensive area can be covered using just a reduced set of globally-referenced LPS (GRLPS), whose beacon positions are known to the global reference system, while the rest of the space can be covered using locally-referenced LPSs (LRLPS) that can be distributed arbitrarily. The number of LRLPS and their position can be also changed at any moment. The algorithm is composed of several Bayesian filters running in parallel, so that when an MR is under the GRLPS coverage area, its position is updated by a global filter, whereas when the MR is inside the LRLPS area, its position is updated using position increments within a local filter. The navigation algorithm has been tested by simulation and with actual data obtained using a real set of ultrasonic LPSs.

Multiband channel characteristics for indoor visible light communications

We present a multiband ray tracing (MRT) algorithm to analyze the indoor multiband channel characteristics for visible light communications (VLC). As visible light spans a wide spectrum from 380 to 780 nm, spectral reflectivities of walls are wavelength dependent. This model is able to analyze the multiband channel in VLC and provide the channel information for implementing the wavelength division multiplexing VLC system. To validate the effectiveness of the MRT model, an extensive indoor measurement of the multipath channel characteristics has been presented. Effects of relative angles from lighting emitting diodes (LEDs) to receivers and the variation of receiver locations have been taken into consideration. Theoretical results from the MRT model are validated against the measurement results on the channel path loss of the typical wavelength at 420 nm. Furthermore, channel characteristics like the root mean square delay spread and the spectral response of the three typical wavelengths based on the red green blue (RGB) LEDs are analyzed by the MRT model simulation. Finally, comparisons of receiver positions, relative angle as well as field-of-view angles, for three wavelengths are considered.

Human shadowing effect on indoor visible light communications channel characteristics

The shadowing effect caused by the human body can have a considerable influence on indoor visible light communications (VLC) channel characteristics. A shadowing ray tracing (SRT) algorithm to investigate the human shadowing channel characteristics is proposed. To validate the effectiveness of the SRT model, an extensive indoor human shadowing channel measurement has been presented. Both scenarios, the line-of-sight (LOS) and the non-line-of-sight (NLOS), have been measured. Theoretical results from the SRT model are validated against the measurement results for channel path loss. The results from measurements and simulations show that receiver rotations can mitigate human shadowing effect under the LOS scenario. Under the NLOS scenario, the VLC system becomes more sensitive to human shadowing when the distance between the LED and the receiver is large. Finally, more simulation results on the channel root mean square delay spread are also presented to analyze its relation with human shadowing distance to the receiver.

Antimicrobial resistance among Campylobacter spp. strains isolated from different poultry production systems at slaughterhouse level

The aim of the current work was to evaluate the prevalence and antimicrobial susceptibility of Campylobact er spp. isolated from different chicken production systems at the slaughterhouse level. Chicken sampling at slaughterhouse was performed for cecum, carcass, and breast meat from flocks of organic (n = 6), extensive indoor (n = 14), and intensive production (n = 14), totaling 34 ceca pools, 64 neck skin pools, and 132 breasts, representing 96,386 chickens. A collection of 167 strains were identified as Campylobacter coli (n = 85) and Campylobacter jejuni (n = 82) and were tested for susceptibility to 11 antimicrobial agents by the disk diffusion method. The frequency of Campylobacter in chicken samples from different production systems was between 79 and 100%. Campylobacter isolated from all origins were resistant to the fluoroquinolones studied (80–98%). However, for ciprofloxacin and ofloxacin, the Campylobacter isolates from extensive indoor chicken were significantly (P < 0.05) less resistant (77 and 58%) than that from organic (97 and 91%) and intensive production (96 and 95%). A high probability of tetracycline resistance occurrence was also found for the Campylobacter spp. tested (58% for C. jejuni and 76% for C. coli). A more frequent profile of multidrug resistance was noticed for isolates from intensive and organic production than for extensive indoor production. These results reinforce the need of efficient strategy implementation to control and reduce Campylobacter in chickens at production and slaughter levels, and the necessity to reduce the use of antimicrobials in poultry sector.

Rider Trunk and Bicycle Pose Estimation With Fusion of Force/Inertial Sensors

Estimation of human pose in physical human-machine interactions such as bicycling is challenging because of highly-dimensional human motion and lack of inexpensive, effective motion sensors. In this paper, we present a computational scheme to estimate both the rider trunk pose and the bicycle roll angle using only inertial and force sensors. The estimation scheme is built on a rider-bicycle dynamic model and the fusion of the wearable inertial sensors and the bicycle force sensors. We take advantages of the attractive properties of the robust force measurements and the motion-sensitive inertial measurements. The rider-bicycle dynamic model provides the underlying relationship between the force and the inertial measurements. The extended Kalman filter-based sensor fusion design fully incorporates the dynamic effects of the force measurements. The performance of the estimation scheme is demonstrated through extensive indoor and outdoor riding experiments.

Carcass morphology and meat quality from roosters slaughtered at eight months affected by genotype and finishing feeding

The aim of this study was to describe the carcass characteristics and the meat quality of the roosters from the autochthonous Mos breed slaughtered at 8 months. With comparative purpose roosters from hybrid line Sasso T44 were used in this study. Birds were reared on their typical production system (extensive indoor or barns and finishing diet whit corn). Both live and carcass weight were higher for commercial breed (p&lt;0.001). Drumstick, thigh and wing percentages were greater in Mos breed than in Sasso T-44, while breast was similar for both genotypes. Only significant differences in cholesterol and alpha-tocopherol content between genotypes have been found, whereas finishing feeding treatment had effect on moisture, intramuscular fat content, cholesterol, tocopherol isomers and meat yellowness. Unsaturated fatty acids constituted the main contribution to total amount of fatty acid (FA), where monounsaturated oleic acid was the major compound, and found higher concentrations in commercial breed. Mos breed showed higher amounts of polyunsaturated fatty acids (PUFA) and lower amounts of monounsaturated fatty acids (MUFA) than Sasso T-44. The relation PUFA/SFA was above 0.68 for Mos breed and was slightly lower for the other genotype. In conclusion, the carcass morphology and meat quality was influenced by breed and finishing feeding with corn.

Radio Wave Diffusion Indoors and Throughput Scaling with Cell Density

Diffusion theory is found to provide a simple yet accurate expression for the average received radio power loss indoors in non-line-of-sight propagation. Effective specific absorption is the sole parameter. Agreement with extensive indoor power measurements is found at all ranges. Use of the standard power-law to describe the data is found to lead to power exponents that vary from near 2 at short ranges to around 11 at 100 m. Extending the diffusion model to account for variation in scatterer density provides a stochastic mechanism explaining the log-normal nature of observed average power variations, usually termed "shadow fading". The standard deviation of power variation is found to increase with range (as r <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> at short ranges), in agreement with measurements and unlike accepted models. Exponential absorption in diffusion is determined to have a large impact on the signal-to-interference-and noise behavior, materially affecting conclusions on the value of increasing cell density as a method of increasing wireless network capacity.

A Machine Learning Approach to Ranging Error Mitigation for UWB Localization

Location-awareness is becoming increasingly important in wireless networks. Indoor localization can be enabled through wideband or ultra-wide bandwidth (UWB) transmission, due to its fine delay resolution and obstacle-penetration capabilities. A major hurdle is the presence of obstacles that block the line-of-sight (LOS) path between devices, affecting ranging performance and, in turn, localization accuracy. Many techniques have been proposed to address this issue, most of which make modifications to the localization algorithm. Since many localization algorithms work with distance or angle estimates, rather than received waveforms, information inherent in the wideband waveform is lost, leading to sub-optimal ranging error mitigation. To avoid this information loss, we present a novel approach to mitigate ranging errors directly in the physical layer. In contrast to existing techniques, which detect the non-line-of-sight (NLOS) condition, our approach directly mitigates the bias incurred in both LOS and non-LOS conditions. In particular, we apply two classes of non-parametric regressors to form an estimate of the ranging error. Our work is based on, and validated by, an extensive indoor measurement campaign with FCC-compliant UWB radios. The results show that the proposed regressors provide significant performance improvements in various practical localization scenarios, compared to conventional approaches.

Experimental characterisation of a Fresnel lens photovoltaic concentrating system

Abstract An extensive indoor experimental characterisation program to investigate the heat loss from a point focus Fresnel lens PV Concentrator (FPVC) with a concentration ratio of 100× was performed for a range of simulated solar radiation intensities between 200 and 1000 W/m 2 , different ambient air temperatures, and natural and forced convection. From the experimental program it was found that the solar cell temperature increased proportionally with the increase in simulated solar radiation for all experimental tests, indicating that conductive and convective heat transfer were significantly larger than the long wave radiative heat transfer within and from the FPVC system. For the simulated worst case scenario, in which the FPVC system was tested under a simulated solar radiation intensity of 1000 W/m 2 and ambient air temperature of 50 °C with no forced convection, the predicted silicon solar cell efficiency in the FPVC system was reduced to approximately half that at standard test conditions.

Broiler meat quality: The effect of rearing system and length of fattening period

Broiler meat production in recent years has been oriented towards the implementation of non-commercial rearing systems aimed at improving broiler rearing conditions, enhancing meat quality and improving the environment. This study presents productive and slaughter results of broilers reared under two non-commercial systems, including extensive indoor and free-range systems. Length of fattening period was 63 days. On days 49 and 63 of the experiment, male and female broilers were randomly selected from both rearing systems and slaughtered thereafter to be evaluated and compared for the following traits: dressing percentage and percentage yield of primal carcass cuts, as dependent upon rearing system, length of fattening period and broiler sex. The results showed a higher dressing percentage in broilers slaughtered on day 49, regardless of the higher carcass weight of broilers slaughtered on day 63. Broiler sex had a highly significant effect on the percentage yield of breast, thigh and drumstick in the dressed carcass (P&lt;0.01), whereas the percentage yield of thighs was also statistically highly significantly affected by rearing system (P&lt;0.01). Rearing system, length of fattening period and the interaction of these factors had no significant effect (P&gt;0.05) on the percentage yield of primal cuts (breast, thigh, drumstick, wing, back and pelvis), excepting that of pelvis which was significantly affected by rearing system (P&lt;0.05).

Chemical composition of chicken meat produced in extensive indoor and free range rearing systems

The present study involves the analysis of the chemical composition of white meat (breast muscles) and dark meat (leg muscles) of broilers in extensive indoor and free range systems. The length of fattening period was 56 days. At 56 days of age, 6 male and 6 female broilers were randomly selected from each rearing system and slaughtered. Cooled carcasses were dissected into primal cuts. Breast and leg muscle (thigh and drumstick) samples were used for chemical analyses. The obtained results suggested that free range rearing system was more favourable than extensive indoor system, as it resulted in a significantly higher protein content and a lower fat content of white and dark chicken meat. Female broilers produced a higher fat content and a somewhat lower protein content as compared to males. Keywords: Chemical composition, chicken meat, rearing system, sex

NLOS identification and mitigation for localization based on UWB experimental data

Sensor networks can benefit greatly from location-awareness, since it allows information gathered by the sensors to be tied to their physical locations. Ultra-wide bandwidth (UWB) transmission is a promising technology for location-aware sensor networks, due to its power efficiency, fine delay resolution, and robust operation in harsh environments. However, the presence of walls and other obstacles presents a significant challenge in terms of localization, as they can result in positively biased distance estimates. We have performed an extensive indoor measurement campaign with FCC-compliant UWB radios to quantify the effect of non-line-of-sight (NLOS) propagation. From these channel pulse responses, we extract features that are representative of the propagation conditions. We then develop classification and regression algorithms based on machine learning techniques, which are capable of: (i) assessing whether a signal was transmitted in LOS or NLOS conditions; and (ii) reducing ranging error caused by NLOS conditions. We evaluate the resulting performance through Monte Carlo simulations and compare with existing techniques. In contrast to common probabilistic approaches that require statistical models of the features, the proposed optimization-based approach is more robust against modeling errors.

Joint Control of Transmit Power and Frame Size for Energy-Optimized Data Transfer in Wireless Sensor Networks

Energy efficiency is one of the most important attributes in sensor network protocols. In sensor nodes, communication related activities consume the major share of battery energy. Therefore, judicious choice of transmit power and frame size are very important to maximize the energy efficiency and hence the lifetime of nodes. While there have been a few recent studies on transmit power control implementation in sensor nodes, no report has thoroughly investigated transmit power control and the effect of its interplay with frame size on nodal energy saving. In this paper, we report our implementation of automatic transmit power control in wireless sensor nodes based on open loop parameters — namely, link layer frame size, and close loop parameters — namely, number of consecutive positive acknowledgments and receive signal strength. Our extensive indoor and outdoor experimental results show that, for low to moderate transmission distances, transmit power control has the energy saving benefit, and the larger the frame size the more the energy saving. At a higher transmission distance or at a more error-prone communication scenario, transmit power control as well as a large frame size are detrimental to energy saving performance. The results from this study could be useful in deciding power control strategies and optimum frame length. key words: implementation studies, automatic transmit power control, frame size control, open loop power control, close loop power control, minimum energy transmission

Welfare assessment of broilers through examination of haematomas, foot-pad dermatitis, scratches and breast blisters at processing

AbstractAnalysis of post mortem lesions is a common means for assessing poultry welfare during rearing and pre-slaughter handling. The aim of this study was to determine the influence of: age, sex, rearing system, total number of birds on-farm, period between catch and slaughter and distance from poultry house to processing plant on the incidence of: foot-pad dermatitis (FPD), breast blisters (BB), bruises and scratches. Rearing systems consisted of extensive indoor (EI) and traditional free-range (TFR). Accordingly, birds were reared under non-intensive conditions (&lt; 12 broilers m−2). In TFR, the maximum flock size was 4,800, birds had continuous daytime access to open-air runs from at least the age of six weeks, and the minimum slaughter age was 81 days; whereas EI rearing was exclusively indoor and birds were slaughtered at 56 days or later. Observations occurred daily after plucking and each bird was examined for: haematomas, scratches, FPD and BB. Logistic regressions were applied to study the relationship between variables. Farms holding between 10,000-20,000 birds were the most affected with FPD, BB and scratches. The oldest birds (91-100 days) showed the greatest incidence of FPD and scratches. TFR birds exhibited the highest prevalence of bruises and lowest of FPD. BB were most common among birds travelling between 31-60 km from poultry farm to processing plant while scratches were more frequent at greater distances (91-120 km). Male broilers were more predisposed to BB than females. Scratching increased relative to the number of hours that birds awaited slaughter. Despite the fact that only a relatively small number of broiler flocks were examined, these findings may have implications for the draft of future European legislation regarding poultry welfare.

Indoor channel characteristics based on wideband MIMO measurements at 5.25 GHz

Extensive indoor channel measurements were conducted in Beijing with wideband multiple-input multiple-output (MIMO) sounder at 5.25 GHz. Both line-of-sight (LOS) and non-line-of-sight (NLOS) propagation were measured in the indoor office and hotspot scenarios. On the basis of measured data, statistical channel characteristics are presented in this article, including the empirical path loss (PL) models, three excess delay parameters, circular azimuth spread (CAS), and circular elevation spread (CES). Comparative analysis of different propagation mechanisms in two scenarios is conducted. These values are significant for indoor coverage and technical research of MIMO and orthogonal frequency division multiplexing (OFDM) for the international mobile telecommunications-advanced (IMT-Advanced) system.

Non-line-of-sight identification in ultra-wideband systems based on received signal statistics

Non-line-of-sight (NLOS) propagation can severely degrade the reliability of communication and localisation accuracy in indoor ultra-wideband (UWB) ‘location-aware’ networks. Link adaptation and NLOS bias mitigation techniques have respectively been proposed to alleviate these effects, but implicitly rely on the ability to accurately distinguish between LOS and NLOS propagation scenarios. A statistical NLOS identification technique based on the hypothesis-testing of received signal parameters in UWB propagation channels is discussed. In contrast to narrowband and wideband signals, UWB signals possess higher temporal resolution and robustness to multipath fading. We show that these characteristics result in differences in the statistics of (a) the time-of-arrival (TOA), (b) the received signal strength (RSS) and (c) the root-mean-squared delay spread (RDS) of the received signals, between LOS and NLOS propagation scenarios, which can be exploited for accurate channel identification. We statistically characterise the ability of TOA, RSS and RDS estimates to distinguish between LOS and NLOS propagation based on an extensive indoor measurement campaign. Our measurement results suggest that the RDS of UWB signals can, even in isolation and without complete statistical information, serve as a robust and computationally efficient indicator of the LOS/NLOS nature of propagation. Finally, we demonstrate the efficacy of the discussed NLOS identification method in a location-tracking application based on indoor UWB measurements.

The effect of sex and rearing system on carcass composition and cut yields of broiler chickens

The objective of this study is an analysis of meat quality in broilers of standard fast-growing hybrid Hybro G, reared in two different non-industrial systems (extensive rearing in a poultry house or &amp;ldquo;extensive indoor&amp;rdquo; system and rearing in a poultry house using a free range or &amp;ldquo;free-range&amp;rdquo; system). Quality parameters, i.e. proportions of basic carcass parts (breasts, drumsticks and thighs), abdominal fat, and proportions of basic tissues (muscles, bones and skin) in more valuable carcass parts, were investigated. The aim of the investigation was to analyse the effect of the two non-industrial rearing systems and broiler sex on the above-mentioned traits of broiler meat quality. The used rearing systems (free-range and extensive indoor ones) did not have a statistically significant effect on the proportions of major basic carcass parts and of abdominal fat in broiler chickens (P &amp;gt; 0.05). Heavier carcasses at slaughter (on the 56&lt;sup&gt;th&lt;/sup&gt; day of fattening) were recorded in the male broilers compared to the female ones, the differences being statistically significant (P &amp;lt; 0.01). The drumstick proportion in the male broiler carcasses was statistically significantly higher (P &amp;lt; 0.05) than the proportion in the female broilers. The interaction between the investigated effects (of sex and rearing system) did not exert a statistically significant effect on the proportions of major basic carcass parts and abdominal fat in broiler chickens (P &amp;gt; 0.05). The rearing system (free-range and extensive indoor) and the interaction between the investigated effects (of sex and rearing system) did not affect statistically significantly the differences expressed in the meat, skin and bone proportions in breasts, drumsticks and thighs of the broilers (P &amp;gt; 0.05). The sex effect on the skin proportions in breasts, drumsticks and thighs was not statistically significant (P &amp;gt; 0.05). Average muscle proportions in drumsticks and thighs of the female broilers were statistically highly significantly (P &amp;lt; 0.01) and significantly (P &amp;lt; 0.05) higher compared to those in the male broilers. Average bone proportions in the breasts of the male broilers were statistically significantly higher (P &amp;lt; 0.05) than those in the female ones, and statistically highly significantly higher (P &amp;lt; 0.01) in drumsticks and thighs. &amp;nbsp;

An extensive indoor 222Rn/ 220Rn monitoring in North-East India

The behaviour of ubiquitous radon ( Rn 222 ), thoron ( Rn 220 ) and their progeny in the indoor atmosphere generally reflect a complex interplay between a number of processes, the most important of which are radioactive α -decay, ventilation, attachment to aerosols and deposition on the surfaces. The present work involved a long-term (1997–2000) passive monitoring of Rn 222 and Rn 220 in the indoor environment of the North-Eastern region of India. This region being a zone of high seismicity, the indoor radon and thoron measurement of the region will provide a better insight and a valuable database for any study related to radon and thoron anomalies.

Aspergillus surveillance project at a large tertiary-care hospital

A one-year surveillance project was conducted at a large tertiary hospital, which had extensive indoor renovation and extensive demolition/building at several nearby sites. This study collected viable fungi samples in the hospital every six days and analysed 74 duct dust samples for Aspergillus fumigatus mycelial asp f1 protein. Mean total fungi were 257.8 cfu/m 3 outdoors, 53.2 cfu/m 3 in all indoor samples and 83.5 cfu/m 3 in the bone marrow transplant patient rooms. Mean total aspergillus was 6.8 cfu/m 3 outdoors, 12.1 cfu/m 3 in all indoor samples and 7.3 cfu/m 3 in the bone marrow transplant patient rooms. The five most prevalent Aspergillus species collected inside the hospital (mean cfu/m 3) were Aspergillus niger 7.57 cfu/m 3, Aspergillus candidus 1.72 cfu/m 3, Aspergillus flavus 0.97 cfu/m 3, A. fumigatus 0.88 cfu/m 3 and Aspergillus glaucus 0.45 cfu/m 3. In rooms undergoing duct cleaning, mean A. fumigatus concentrations were 11.0 cfu/m 3. Forty-eight of 74 (65%) duct dust samples had measurable levels of asp f1 protein, with a mean level of 0.41 ppm and maximum level of 1.94 ppm. Three major incidents involved increased hospital aspergillus concentrations. A. niger levels reached 680 cfu/m 3 in an organ transplant room after a water leak from a ceiling pipe. Total aspergillus concentrations rose to 77 cfu/m 3 in a bone marrow transplant patient room after improper sealing and water infiltration of the unit’s dedicated high-efficiency particulate air filter system. Total aspergillus levels of 160 cfu/m 3 were recorded in a renovation area during wood cutting. The higher concentrations of aspergillus seen inside the hospital compared with outdoors and the various moisture/HEPA filter/renovation incidents suggest that numerous small to moderate sources of aspergillus exist in the hospital.

An extensive indoor 222Rn/220Rn monitoring in Shillong, India

The behaviour of ubiquitous radon (222Rn), thoron (220Rn) and their progeny in the indoor atmosphere generally reflects a complex interplay between a number of processes, the most important of which are radioactive alpha-decay, ventilation, attachment to aerosols and deposition on surfaces. The present work involved a long-term (1997-2000) passive monitoring of 222Rn and 220Rn in the indoor environment of Shillong, Meghalaya. The north-east region of India being a zone of high seismicity, the indoor radon and thoron map of the region will provide a better insight and a valuable database for any study related to radon and thoron anomalies.