Indoor Environment Research Papers - Academia.edu (original) (raw)

There is nowadays no single fully satisfactory method for VOC removal from indoor air due to the difficulties linked to the very low concentration (μg m − 3 range), diversity, and variability at which VOCs are typically found in the indoor environment. Although biological methods have shown a certain potential for this purpose, the specific characteristic of indoor air and the indoor air environment brings numerous challenges. In particular, new methods must be developed to inoculate, express, and maintain a suitable and diverse catabolic ability under conditions of trace substrate concentration which might not sustain microbial growth. In addition, the biological treatment of indoor air must be able to purify large amounts of air in confined environments with minimal nuisances and release of microorganisms. This requires technical innovations, the development of specific testing protocols and a deep understanding of microbial activities and the mechanisms of substrate uptake at trace concentrations.

- by and +3
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- Engineering, Technology, Indoor Air Quality, Biotechnology

This paper presents an obstacle detection and avoidance of mobile robot using stereo camera for indoor environment. Block matching algorithm is solved the correspondence problem occurred in comparing stereo images (left and right sensors of the camera). The algorithm uses Sum of Absolute Differences (SAD). Left image works as a reference block to the right image and the output is disparity mapping or depth maps with the left coordinate system. A pair of camera or stereo vision baseline is based on horizontal configuration. The block matching technique is briefly described with the performance of its output. The curve fitting tool would determine the range of each obstacle detected in disparity mapping. The programming activities are using Matlab software starting from capturing images until navigation of mobile robot.

- by Syed Hamid
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- Computer Science, Robot Vision, Navigation, Mobile Robots
- by Bing-Fang Hwang
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- Air pollution, Risk assessment, Adolescent, Students

Abstract This work introduces an Ambient Assisted Route Planner (A2RP) aimed for providing route planning in unknown indoor environments. System was first designed as an assistive mobility aid to be used by intelligent powered wheelchairs, although it can be suitable also for other autonomous mobile robotics systems, non-automated mobility device users or pedestrians. A2RP system is based on a set of XML description files that can be retrieved from the internet. These files contain all the information needed to access public or private buildings: floor maps, accessibility information, available routes and calibration landmarks. XML description files must be created, located and maintained in an internet server specially dedicated for this purpose. This paper presents description files structure and the associated software applications: a visual editor to build and maintain XML accessibility information files and a navigation setup program to be run on board of the intelligent wheelchair processor.

- by juan garcia
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- Signal Processing, Route Planning, Mobile Device, Indoor Environment

The objective of this work is to evaluate the quality of the predictions of the indoor airflow behaviour by the zonal method in comparison to the CFD results. The isothermal airflow of the International Energy Agency Annex 20 test cell was chosen to perform the proposed comparative analysis. This cell represents a rectangular room where the air is supplied horizontally on the upper left and is exhausted through an opening located on the lower right on the opposite side. Results are presented in terms of dimensionless mean velocity between zones considering different zonal grid schemes of the indoor environment.

- by Tiago Czelusniak
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- Environmental Science, Comparative Analysis, Indoor Environment
- by Alessandro Saffiotti
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- Computer Science, Space Technology, Image segmentation, Space Exploration

People positioning and tracking in 3D indoor environments are challenging tasks due to background clutter and occlusions. Current works are focused on solving people occlusions in low-cluttered backgrounds, but fail in high-cluttered scenarios, specially when foreground objects occlude people. In this paper, a novel 3D people positioning and tracking system is presented, which shows itself robust to both possible occlusion sources: static scene objects and other people. The system holds on a set oí múltiple cameras with partially overlapped fields of view. Moving regions are segmented independently in each camera stream by means oí a new background modeling strategy based on Gabor filters. People detection is carried out on these segmentations through a template-based correlation strategy. Detected people are tracked independently in each camera view by means oí a graph-based matching strategy, which estimates the best correspondences between consecutive people segmentations. Finally, 3D tracking and positioning of people is achieved by geometrical consistency analysis over the tracked 2D candidates, using head position (instead of object centroids) to increase robustness to foreground occlusions.

- by Carlos Roberto del Blanco and +1
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- Background modeling, People Tracking, Indoor Environment, Field of View

Several methods for providing location based service (LBS) to mobile devices in indoor environment using wireless technologies like WLAN, RFID and Bluetooth have been proposed, implemented and evaluated. However, most of them do not focus on heterogeneity of mobile platforms, memory constraint of mobile devices, the adaptability of client device to the new services it discovers whenever it reaches a new location. In this paper, we have proposed a Middleware based approach of LBS provision in the indoor environment, where a Bluetooth enabled Base Station (BS) detects Bluetooth enabled mobile devices and pushes a proper client application only to those devices that belong to some registered subscriber of LBS. This dynamic deployment enables the mobile clients to access any new service without having preinstalled interface to that service beforehand and thus the client s memory consumption is reduced. Our proposed work also addresses the other issues like authenticating the clients before providing them LBSs and introducing paid services. We have evaluated its performance in term of file transfer time with respect to file size and throughput with respect to distance. Experimental results on service consumption time by the mobile client for different services are also presented.

- by Pampa Sadhukhan
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- Middleware, Mobile Device, Location Based Service, Indoor Environment

The physical and social characteristics of internal and external environments of the YTU Library Building were examined and the results were compared with the required levels and standards. Negative characteristics which may cause health problems on temporary and permanent users were determined, and potential health risks due to those characteristics were identified. r

- by Gülay ZORER GEDİK
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- Architecture, Building, Social Environment, Health Problems

Indoor hydroxyl radical concentrations were estimated using a new indoor air quality model which employs the SAPRC-99 atmospheric chemistry model to simulate indoor homogenous reactions. Model results indicate that typical indoor hydroxyl radical concentrations are lower than typical outdoor summertime urban hydroxyl radical levels of 5-10 Â 10 6 molecules cm À3 ; however, indoor levels can be similar to or greater than typical nighttime outdoor hydroxyl radical levels of approximately 5 Â 10 4 molecules cm À3 . Effects of selected parameters on indoor hydroxyl radical concentrations are presented herein. Indoor hydroxyl radical concentrations are predicted to increase non-linearly with increasing outdoor ozone concentrations, indoor alkene emission rates, and air exchange rates. Indoor hydroxyl radical concentrations decrease with increasing outdoor nitric oxide concentrations. Indoor temperature and indoor light intensity have moderate impacts on indoor hydroxyl radical concentrations. Outdoor hydroxyl radical concentrations, outdoor nitrate (NO 3 d ) radical concentrations, outdoor hydroperoxy radical concentrations, and hydroxyl radical removal by indoor surfaces are predicted to have no appreciable impact on indoor hydroxyl radical concentrations. Production of hydroxyl radicals in indoor environments appears to be controlled primarily by reactions of alkenes with ozone, and nitric oxide with hydroperoxy radical. Estimated indoor hydroxyl radical levels may potentially affect indoor air quality. Two examples are presented in which reactions of d-limonene and a-pinene with indoor hydroxyl radicals produce aldehydes, which may be of greater concern than the original compounds. r

- by Charles Weschler
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- Environmental Engineering, Chemistry, Atmospheric Chemistry, Atmospheric Science

With the rapid development and wide deployment of wireless Local Area Networks (WLANs), WLAN-based po- sitioning system employing signal-strength-based technique has become an attractive solution for location estimation in indoor environment. In recent years, a number of such systems has been presented, and most of the systems use the common Nearest Neighbor in Signal Space (NNSS) algorithm. In this paper,

- by Quang Tran
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- Indoor Positioning, Performance Evaluation, Nearest Neighbor, Indoor Environment

Conducting an independent life is probably the most important issue for visually impaired people. In this paper, we suggest a contribution to the solution of this problem using wearable computer technology. We present a visual support system that provides acoustic information about the objects in the surrounding environment, obtained by remotely reading barcode tags sticked on significant objects and surrounding elements, such as doors, windows and so on. The user, walking in an indoor environment, is informed in realtime about the location (direction, distance and pose) of the available objects. Barcode tags deployed in the environment can act as reliable stimuli that trigger local navigation behaviours to achieve global navigation objectives. The proposed system is expected to be useful in the real-time interaction with dynamic environments. To illustrate our work, we introduce a proof-of-concept multimodal, sensorbased application and discuss its implementation and the obtained experimental results.

Aspergillus niger is perhaps the most important fungus used in biotechnology, and is also one of the most commonly encountered fungi contaminating foods and feedstuffs, and occurring in soil and indoor environments. Many of its industrial applications have been given GRAS status (generally regarded as safe). However, A. niger has the potential to produce two groups of potentially carcinogenic mycotoxins: fumonisins and ochratoxins. In this study all available industrial and many non-industrial strains of A. niger (180 strains) as well as 228 strains from 17 related black Aspergillus species were examined for mycotoxin production. None of the related 17 species of black Aspergilli produced fumonisins. Fumonisins (B 2 , B 4 , and B 6 ) were detected in 81% of A. niger, and ochratoxin A in 17%, while 10% of the strains produced both mycotoxins. Among the industrial strains the same ratios were 83%, 33% and 26% respectively. Some of the most frequently used strains in industry NRRL 337, 3112 and 3122 produced both toxins and several strains used for citric acid production were among the best producers of fumonisins in pure agar culture. Most strains used for other biotechnological processes also produced fumonisins. Strains optimized through random mutagenesis usually maintained their mycotoxin production capability. Toxigenic strains were also able to produce the toxins on media suggested for citric acid production with most of the toxins found in the biomass, thereby questioning the use of the remaining biomass as animal feed. In conclusion it is recommended to use strains of A. niger with inactive or inactivated gene clusters for fumonisins and ochratoxins, or to choose isolates for biotechnological uses in related non-toxigenic species such as A. tubingensis, A. brasiliensis, A vadensis or A. acidus, which neither produce fumonisins nor ochratoxins.

- by Thomas Larsen
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- Multidisciplinary, Industrial microbiology, Aspergillus niger, PLoS one

A study has been carried out to examine the suitability of a passive, deposition-based technique for estimating the time-integrated equilibrium equivalent thoron concentration (EETC) in indoor environment using a direct thoron progeny sensor (DTPS). DTPS is an absorber-mounted LR-115-type nuclear track detector tuned to respond only to the 8.78 MeV alpha particles emitted from the deposited activity of 212 Po on the absorber surface. The study has been carried out in two steps, the first step comprising the estimation of track registration efficiency ( ) and the second step comprising the estimation of effective deposition velocity of thoron progeny aerosols on the detector surface in natural and laboratory environments. The track registration efficiency is found to be 8.3% for 212 Po and less than 0.02% for all other alpha emitters including 222 Rn (radon) progeny, thereby enabling a precise discrimination of thoron progeny. The deposition velocity of thoron progeny aerosols on DTPS surface has been measured in conjunction with active air sampling techniques for different orientations of the deposition surface. The geometric mean deposition velocity was found to be 0.077 m h −1 having a narrow spread (geometric standard deviation of 1.35). Upon combining these factors, the overall sensitivity factor is estimated to be 0.94 Tr cm −2 d −1 /EETC(Bq m −3 ), which indicates ∼ 45 times higher sensitivity as compared with conventional bare detector techniques (which register alpha particles emitted directly from air). The results obtained have been compared with currently used aerosol deposition models and progeny equilibrium models by using the aerosol number size and progeny activity distributions measured with scanning mobility particle sizer (SMPS) and low-pressure cascade impactor, respectively. The results are in good agreement with each other. A sensitivity analysis of the response characteristics of DTPS with respect to room ventilation rate and aerosol concentrations has been carried out to assess the variability of the sensitivity factor in the context of indoor dosimetry. The results are further discussed.

- by Rosaline Mishra
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- Geology, Sensitivity Analysis, Air Sampling, Radiation Measurements

This paper builds on the findings of a thermal comfort field study carried out in air conditioned offices in Makati City (Manila), Philippines to investigate the applicability of the universal values of comfort temperatures recommended by international comfort standards. The analyses of the responses of the Filipino office workers indicate that some conventional thinking about comfort preferences is open to question. As a background to explaining the findings, the paper will discuss the transformations, first colonization, and then the introduction of air conditioning, have caused to the social and cultural practices in the Philippines of what people take to be normal and ordinary conditions of comfort. The paper will highlight the variations in definitions, perceptions and expectations of thermal comfort to emphasize the different socio-cultural aspects of interactions between people, technologies and indoor environments. The framework advocating the separation of the technical and social constructions of comfort, on which conventional approaches to thermal comfort are predicated, shape and maintain practices and conventions that have ill-considered consequences on energy use and consumption.

- by V. Soebarto
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- Air Conditioning, Thermal comfort, Cultural Practice, Field Study

We propose a new approach for stereo matching in Autonomous Mobile Robot applications. In this framework an accurate but slow reconstruction of the 3D scene is not needed; rather, it is more important to have a fast localization of the obstacles to avoid them. All the methods in the literature are based on a punctual correspondence, but they are inefficient

- by Jean-michel Jolion
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- Graph matching, Stereo Matching, Performance Comparison, Indoor Environment

The millimeter-wave (mmWave) is expected to deliver a huge bandwidth to address the future demands for higher data rate transmissions. However, one of the major challenges in the mmWave band is the increase in signal loss as the operating frequency increases. This has attracted several research interests both from academia and the industry for indoor and outdoor mmWave operations. This paper focuses on the works that have been carried out in the study of the mmWave channel measurement in indoor environments. A survey of the measurement techniques, prominent path loss models, analysis of path loss and delay spread for mmWave in different indoor environments is presented. This covers the mmWave frequencies from 28 GHz to 100 GHz that have been considered in the last two decades. In addition, the possible future trends for the mmWave indoor propagation studies and measurements have been discussed. These include the critical indoor environment, the roles of artificial intelligence, channel characterization for indoor devices, reconfigurable intelligent surfaces, and mmWave for 6G systems. This survey can help engineers and researchers to plan, design, and optimize reliable 5G wireless indoor networks. It will also motivate the researchers and engineering communities towards finding a better outcome in the future trends of the mmWave indoor wireless network for 6G systems and beyond.

- by Yousef Al-Gumaei and +1
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- Millimeter Waves, Radio Channel Modelling, Indoor Environment, 5G Mobile Communications
- by Yuichi Miyake
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- Indoor Environment

In the past mobile robot research was often focused to various kinds of point-to-point transportation tasks. Service tasks, such as floor cleaning, require specific approaches for path planning and vehicle guidance in real indoor environments. This article discusses automatic planning of a feasible cleaning path considering a 2D-map as well as kinematic and geometric robot models. Path construction makes use of two typical motion patterns. Each pattern is defined by a sequence of subgoals indicating robot position and orientation. Results of automatic path planning are illustrated by realistic examples of typical robots and cleaning environments. Vehicle guidance includes initialization of robot location, path execution, accurate path tracking and detection of unexpected environmental changes. Path tracking is achieved by subgoal modification during cleaning motion using data from the dead-reckoning and landmark localization systems. If obstacles permanently block the preplanned path, an automatic map update and path replanning is performed. Experimental results with the mobile robot MACROBE confirm the feasibility of the developed planning and guidance system.

- by Josué Enríquez
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- Mechanical Engineering, Environmental Change, Path planning, Geometric model

Motion vision (visual odometry, the estimation of camera egomotion) is a well researched field, yet has seen relatively limited use despite strong evidence from biological systems that vision can be extremely valuable for navigation. The limited use of such vision techniques has been attributed to a lack of good algorithms and insufficient computer power, but both of those problems were resolved as long as a decade ago. A gap presently yawns between theory and practice, perhaps due to perceptions of robot vision as less reliable and more complex than other types of sensing. We present an experimental methodology for assessing the realworld precision and reliability of visual odometry techniques in both normal and extreme terrain. This paper evaluates the performance of a mobile robot equipped with a simple vision system in common outdoor and indoor environments, including grass, pavement, ice, and carpet. Our results show that motion vision algorithms can be robust and effective, and suggest a number of directions for further development.

- by jason campbell
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- Robot Vision, Motion estimation, Optical Flow, Mobile Robots

The Port Pirie Lead Program commenced in 1984. The abatement program involves identification of children with elevated blood lead levels, house decontamination, soil treatment, development of heavily vegetated buffer zones around the smelter, family education and support and community education. Since 1984 the smelter has also implemented substantial new emission controls and environmental improvements. Blood lead and air monitoring programs as well as investigations of emission sources, ongoing household contamination and infant exposure mechanisms are in place. Although capillary blood lead monitoring has shown a significant decrease in the mean blood lead levels of the children, 61% of children aged 1-4 years still exceed 10 mgydl, with 28% at or above 15 mgydl. Re-entrainment of lead from the contaminated areas within the city is only a small contributor to air-borne lead levels compared with that from the smelter and its environs. The smelter has undertaken extensive work to reduce windborne fugitive emissions. While attempts to demonstrate reductions in air lead have been hampered by large annual variations in wind speed and direction, air lead studies have confirmed that only small losses are now arising from the stockpile area of the smelter site. Evidence suggests that worker hygiene improvements, relocation of children to lower exposure suburbs, community education, house decontamination, specific measures for individual children with elevated blood lead, and avoidance of tank rainwater have all been partially successful. A substantial investigation program has refocused intervention efforts towards reducing exposure from indoor environments during the first year of life and contributed to improved identification and ranking of ongoing smelter emission sources. ᮊ

- by David Acosta Simon
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- Epidemiology, Child Welfare, Housing, Environmental Pollution

Femtocells are envisioned to be deployed in indoor environments in order to improve both radio coverage and system capacity. This paper focuses on the self-organization of enterprise femtocells, which is certainly more challenging than that of home femtocells. In the context of 3GPP LTE, we propose solutions to automatically tune parameters such as radio spectrum, pilot power, resource blocks, and access control mechanisms for optimal performance via self-organization network (SON). Furthermore, on-site radio measurements and system-level simulations are used to benchmark their performance.

- by Akos Ladanyi
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- Access Control, Self Organization, Spectrum, Network Planning

A feature detection system has been developed for real-time identification of lines, circles and people legs from laser range data. A new method suitable for arc/circle detection is proposed: the Inscribed Angle Variance (IAV). Lines are detected using a recursive line fitting method. The people leg detection is based on geometrical relations. The system was implemented as a plugin driver in Player, a mobile robot server. Real results are presented to verify the effectiveness of the proposed algorithms in indoor environment with moving objects.

- by Joao Xavier
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- Mobile Robotics, Automation, Feature Detection, Laser Scanning

Abstract For indoor environments, thermal discomfort must be clearly distinguished from the air pollution caused by outdoor air as well as by inside polluting agents. Full air conditioning of a room requires the introduction of a minimum... more

- by Juan Castejon
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- Environmental Science, Air Quality, Energy Consumption, Air pollution
- by Stephen Pernal
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- Time Use, Animal Behaviour, Biological Sciences, Apis mellifera

The emission of volatile organic compounds (VOC) from wood and wood products are important in evaluating the impact on the indoor environment from different materials. The results from analyses of emissions from nine different wood species are presented in this article. The measurements were made with Field and Laboratory Emission Cell (FLEe) and with Head-Space (HS) analyses and the results from the different methods are discussed. The main emissions are terpenes from softwood and acetic acid from hardwood.

- by Paulien Herder
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- Building, Wood Products, European, Forestry Sciences

UWB (Ultra Wide Band) technology is a wireless application technology that works at a frequency of 3.1–10.6 GHz. This technology is designed to transmit high-speed data in an indoor environment. MB-OFDM (Multiband Orthogonal Frequency Division Multiplexing) UWB is one of the UWB data transmission system. The symbol on the system is not sent continuously on a single frequency band, but

- by Risanuri Hidayat
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- Performance Analysis, Bit Error Rate, High Speed, Multiple-access Interference

The phenomenon of Sick Building Syndrome (SBS), Building Related Illness (BRI) and some other indoor related diseases have been attributed to mould and fungi exposure in the indoor environment. Despite the growing concern over mould and fungi infestations on building materials, little has been reported in the literature on the development of an objective tool and criteria for measuring and characterizing the shape and the level of severity of such parasitic phenomenon.

- by Amir Shafie
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- Fire, Digital Image Processing, Domain Analysis, Frequency-domain analysis

The WiFi-based indoor localization problem (WILP) aims to detect the location of a client device given the signals received from various access points. WILP is a complex and very important task for many AI and ubiquitous computing applications. A major approach to solving this task is through machine learning, where upto-date labeled training data are required in a large scale indoor environment. In this paper, we identify WILP as a transfer learning problem, because the WiFi data are highly dependent on contextual changes. We show that WILP can be modeled as a transfer learning problem for regression modeling, where we identify several important cases of knowledge transfer that range from transferring the localization models over time, across space and across client devices. We also share our working experience in WILP and transfer learning research in a realistic problem solving setting, and discuss a data set we have made public for advancing this research.

- by Vincent Zheng
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- Machine Learning, Transfer Learning, Knowledge Transfer, Problem Solving

Corona discharge based unipolar ionizers are commonly used for reducing aerosol particle concentrations in indoor environments. The ions (usually negative) emitted from the ionizer help in charging the airborne particles, which are then removed from air space by electro-migration e ects to the walls of the room due to the space charge induced electric ÿelds. A system of equations has been formulated by considering various processes responsible for aerosol removal in the presence of the ionizers. These pertain to the space charge generated electric ÿelds, particle charging, ion and particle removal rates under the combined action of di usion, gravitational sedimentation, external ventilation and electric ÿelds. The study includes steady-state situations corresponding to a continuous injection of particles as well as time dependent depletion of an initially injected aerosol. Model computations have been made to examine the dependence of the particle depletion characteristics and concentration reduction factors (CRFs) on particle sizes, concentrations and external ventilation rates. The ionizer induced concentration reduction factor is found to increase at higher particle concentrations. However, it is considerably reduced in the presence of even a small amount of external ventilation. The model predictions are found to compare favourably with the results of some of the experimental studies reported by earlier investigators as well as that carried out as a part of the present study. ?

- by Yelia Mayya and +1
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- Chemical Engineering, Atmospheric sciences, Corona Discharge, Experimental Study

Humla Province is a remote mountainous region of northwest Nepal. The climate is harsh and the local people are extremely poor. Most people endure a subsistence culture, living in traditional housing. Energy for cooking and heating comes from fuelwood, supplies of which are diminishing. In order to improve the indoor environment and reduce fuelwood use, smokeless stoves are being introduced to replace the open fire in Humli homes. There is some concern, however, that comfort levels may not be as acceptable with these stoves. The aim of this research was therefore to investigate ways in which the comfort levels in traditional Humli housing might be improved using simple and low cost strategies. Temperature data was recorded in four rooms of a traditional Humli home over a 12-day period and used with fuelwood data to validate a TRNSYS simulation model of the house. This model was then used to evaluate the impact on comfort levels in the house of various energy conservation strategies using PMV and PPD indicators. As a single strategy, it was found that reducing infiltration of outside air was likely to be more effective than increasing the insulation level in the ceilings. The most successful strategy, however, was the creation of sunspaces at the entrances to the living rooms. This strategy increased average internal temperatures by 1.7 and 2.3 1C. In combination with increased insulation levels, the sunspaces reduced comfort dissatisfaction levels by over 50%.

- by A. Zahnd
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- Architecture, Energy Conservation, Building, Building Environment

In this paper we describe a system that enables a mobile robot equipped with a color vision system to track humans in indoor environments. We developed a method for tracking humans when they are within the field of view of the camera, based on motion and color cues. However, the robot also has to keep track of humans which leave the field of view and re-enter later. We developed a dynamic Bayesian network for such a global tracking task. Experimental results on real data confirm the viability of the developed method.

- by Zoran Zivkovic
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- Machine Vision, Trajectory, Mobile Robots, Tracking

The introduction of green plants in indoor spaces has raised a great amount of interest motivated by plants’ supposed capacity to improve the quality of indoor built environments. Subsequent studies have covered a broad range of topics, testing plants in indoor environments for their climate-mitigating effects, acoustic benefits, potential energy savings and the enhancement of the indoor microbial communities. Despite the diversity of focus in these studies, no major breakthroughs been made involving the use of plants in indoor environments after nearly thirty years
of research. To identify major inconsistencies and gaps in the research, this review, of an explorative nature, presents an analysis of plant-related parameters reported in 31 cases of experimental research involving the use of plants in indoor environments. The papers were identified by searching the online databases Google Scholar, ResearchGate, Scopus and MDPI and were selected based on their relevance to the topic and diversity of focus. Two classifications in table form provide an overview of the 38 plant-related parameters used in the reviewed research. The conclusions drawn from the analysis of the tables highlight a strongly anthropocentric frame of reference across the majority of the studies, which prioritize human and experimental convenience above plant physiology, and display an overall scarcity and inconsistency in the plant-related parameters reported.

The ongoing "Indoor Environment and Children's Health" (IECH) study investigates the environmental risk factors in homes and their association with asthma and allergy among children aged 1e5 years. As part of the study, the homes of 500 children between 3 and 5 years of age were inspected. The selected children included 200 symptomatic children (cases) and 300 randomly selected children (bases). As part of the inspection, the concentration of carbon dioxide in the bedrooms of the children was continuously measured over an average of 2.5 days. The ventilation rates in the rooms during the nights when the children were sleeping in the room were calculated using a single-zone mass balance for the occupantgenerated CO 2 . The calculated air change rates were log-normally distributed (R 2 > 0.98). The geometric mean of the air change rates in both the case and the base group was 0.46 air changes per hour (h À1 ; geom. SD ¼ 2.08 and 2.13, respectively). Approximately 57% of both cases and bases slept at a lower ventilation rate than the minimum required ventilation rate of 0.5 h À1 in new Danish dwellings. Only 32% of the bedrooms had an average CO 2 concentration below 1000 ppm during the measured nights. Twenty-three percent of the rooms experienced at least a 20-minute period during the night when the CO 2 concentration was above 2000 ppm and 6% of the rooms experienced concentrations above 3000 ppm. The average air change rate was higher with more people sleeping in the room. The air change rate did not change with the increasing outdoor temperature over the 10-week experimental period. The calculation method provides an estimate of the total airflow into the bedroom, including airflows both from outdoors and from adjacent spaces. To study the accuracy of the calculated air change rates and their deviation from the true outside air change rates, we calculated CO 2 concentrations at different given air change rates using an indoor air quality and ventilation model (Contam). Subsequently we applied our calculation procedure to the obtained data. The air change rate calculated from the generated CO 2 concentrations was found to be between 0% and 51% lower than the total air change rate defined in the input variables for the model. It was, however, higher than the true outside air change rate. The relative error depended on the position of the room in relation to the adjacent rooms, occupancy in the adjacent room, the nominal air change rate and room-to-room airflows.

- by Gabriel Bekö and +1
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- Architecture, Indoor Air Quality, Carbon Dioxide, Concentration

The EcoEffect method of assessing external and internal impacts of building properties is briefly described. The external impacts of manufacturing and transport of the building materials, the generation of power and heat consumed during the operation phase are assessed using life-cycle methodology. Emissions and waste; natural resource depletion and toxic substances in building materials are accounted for. Here methodologies from natural sciences are employed. The internal impacts involve the assessment of the risk for discomfort and ill-being due to features and properties of both the indoor environment and outdoor environment within the boundary of the building properties. This risk is calculated based on data and information from questionnaires; measurements and inspection where methodologies mainly from social sciences are used. Life-cycle costs covering investment and utilities costs as well as maintenance costs summed up over the lifetime of the building are also calculated. The result presentation offers extensive layers of diagrams and data tables ranging from an aggregated diagram of environmental efficiency to quantitative indicators of different aspects and factors. Environmental efficiency provides a relative measure of the internal quality of a building property in relation to its external impact vis-a`-vis its performance relative to other building properties.

- by Marie Hult
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- Civil Engineering, Architecture, Methodology, Life Cycle Assessment

The type and amount of indoor air pollutants affects the comfort and quality of indoor environments. Therefore, indoor air quality is an important issue with different social, economic, and health aspects because people in developing countries spend most of their time indoors being exposed to different kinds of indoor pollutants. The indoor air quality can be assessed empirically by measuring the pollutant concentrations or can be predicted by means of mathematical models. An indoor aerosol model describes the dynamic behavior of indoor air pollutants. The basic concept of indoor air models is the mass-balance-conservation where several factors that govern the indoor particle concentrations can be described. These factors may include direct emissions from indoor sources, outdoor aerosol particles penetrating indoors as a result of the ventilation and filtration processes, deposition onto indoor surfaces, and removal from indoor air by means of ventilation. Here we present principles of indoor aerosol models and we also give examples of different kind of models.

- by Tareq Hussein
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- Indoor Air Quality, Multidisciplinary, Numerical Simulation, Developing Country

Cool roofs are an emerging technique with a recent growing interest worldwide. The aim of the present paper is to present the application of cool roofs’ technology in a laboratory building located in Iraklion, Crete, Greece. The building is monitored towards its energy performance and indoor environment before and after the implementation of the cool roof technology. The specific case study is intended as a shining example of the cool roof capabilities in improving the thermal conditions in non-air conditioned and in reducing the energy consumption in air conditioned buildings.► In this study the cool roofs performance is examined. ► Cool roofs are applied in a building at Iraklion, Crete, Greece. ► The energy efficiency on yearly basis is almost 20%. ► Cool roofs show better performance in terms of energy efficiency than roof insulation and windows replacement.

- by Sotiris Papantoniou
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- Engineering, Energy Efficiency Buildings, Energy Consumption, Case Study

The aim was to develop and validate a standardized questionnaire -the Stockholm Indoor Environment Questionnaire (SIEQ). The validation procedure was based on sociological principles and test procedures for validation. The indicators of indoor environment are air quality, thermal climate, noise, and illumination. The indicators of health are symptoms comprised in the sick building syndrome (SBS). The questionnaire also contains questions about the apartment, individual behavior, and personal factors. The everyday language describing the building and its function was first obtained by qualitative personal interviews, then by standardized questions. The interview questionnaire was transformed into a postal self-administered questionnaire. The reduction of the questionnaire was based on correlation analysis. It was found that to obtain a good validity, general questions are not sufficient, but specific question on perceptions and observations are needed. Good test-retest agreement was found both on an area level, building level, and individually. For each indicator, a set of questions are constructed and validated. SIEQ has been used in several studies, and the results are presented in graphic problem profiles. Reference data has been calculated for the Stockholm area.

- by Karin Engvall
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- Engineering, Earth Sciences, Social Sciences, Sweden

The Robot Operating System (ROS) provides operating system-like services to operate robots. Mapping, localization, and autonomous navigation in an indoor environment are popular issues in the field of autonomous robots. Autonomous navigation in a dynamic environment is not only challenging but also uncovers many indoor environmental factors which affect the process of mapping and navigation. The presented work describes how a ROS-based control system is used with a Pioneer 3-DX robot for indoor mapping, localization, and autonomous navigation. Mapping of different challenging environments is presented in this work. Moreover, some factors associated with indoor environments that can affect mapping, localization, and automatic navigation, are also presented. For experiments, three environments (one artificial and two real) have been tested. Some implementation was done in C and Python.

- by Safdar Zaman
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- Control system, OPERATING SYSTEM, Autonomous navigation, Collision Avoidance
- by Jan Sundell
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- Engineering, Earth Sciences, Air Quality, Water

In-room air cleaners (ACs) and upper-room air ultraviolet germicidal irradiation (UVGI) are engineering control technologies that can help reduce the concentrations of airborne bacteria and fungal spores in the indoor environment. This study investigated six different types of ACs and quantified their ability to remove and/or inactivate airborne bacteria and fungal spores.Four of the air cleaners incorporatedUVlamp(s) into their flow

- by Elmira Kujundzic and +1
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- Aerosols, Aspergillus, Infection Control, Mycobacterium
- by Rabia Riaz
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- Computer Science, Distributed Computing, Forestry, Machine Learning

The present study reports the development and comparative testing of thermochromic coating to be used in buildings and urban structures. Experimental results from an extensive comparative analysis of the thermal and physical behaviour of thermochromic, highly reflective (cool), and common coatings are reported and analyzed. The surface temperature was monitored on 24 h basis from August to mid-September 2007. It was revealing that the temperature of thermochromic coatings was lower than cool and common coatings. Measurements of spectral reflectance indicated that the thermochromic coatings at the colored phase (below the transition temperature of 30°C) are energy-absorbing while at the colorless phase (above the transition temperature of 30°C) are energy-reflecting. The data obtained was used for the calculation of solar reflectance. The results showed that the solar reflectance of the thermochromic samples was significally higher compared to the cool and common ones. A 10-day period test was also performed showing the impact of solar radiation on thermochromism.

- by Theoni Karlessi
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- Engineering, Solar Energy, Urban heat island, Energy Saving

A rapid and facile TLC staining method is reported for the qualitative analysis of boronic acids and related boron-containing derivatives. A red colouration is observed when boron is present due to the formation of a boron-curcumin complex. The structure of the phenylboronic acid-curcumin complex was confirmed using single crystal X-ray diffraction data.

- by Stephen Flower
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- Sensors and Sensing, Colorimetry, Chromatography, Detection & Estimation

Occupants' behaviour when improving the indoor environment plays a significant role in saving energy in buildings. Therefore the key step to reducing energy consumption and carbon emissions from buildings is to understand how occupants interact with the environment they are exposed to in terms of achieving thermal comfort and well-being; though such interaction is complex. This paper presents a dynamic process of occupant behaviours involving technological, personal and psychological adaptations in response to varied thermal conditions based on the data covering four seasons gathered from the field study in Chongqing, China. It demonstrates that occupants are active players in environmental control and their adaptive responses are driven strongly by ambient thermal stimuli and vary from season to season and from time to time, even on the same day. Positive, dynamic, behavioural adaptation will help save energy used in heating and cooling buildings. However, when environmental parameters cannot fully satisfy occupants' requirements, negative behaviours could conflict with energy saving. The survey revealed that about 23% of windows are partly open for fresh air when air-conditioners are in operation in summer. This paper addresses the issues how the building and environmental systems should be designed, operated and managed in a way that meets the requirements of energy efficiency without compromising wellbeing and productivity.

- by Juan Wang and +1
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- Mechanical Engineering, Energy Consumption, Seasonality, Air Conditioning

Air cleaning techniques have been applied worldwide with the goal of improving indoor air quality. The effectiveness of applying these techniques varies widely, and pollutant removal efficiency is usually determined in controlled laboratory environments which may not be realized in practice. Some air cleaners are largely ineffective, and some produce harmful by-products. To summarize what is known regarding the effectiveness of fan-driven air cleaning technologies, a state-of-the-art review of the scientific literature was undertaken by a multidisciplinary panel of experts from Europe, North America, and Asia with expertise in air cleaning, aerosol science, medicine, chemistry and ventilation. The effects on health were not examined. Over 26,000 articles were identified in major literature databases; 400 were selected as being relevant based on their titles and abstracts by the first two authors, who further reduced the number of articles to 160 based on the full texts. These articles were reviewed by the panel using predefined inclusion criteria during their first meeting. Additions were also made by the panel. Of these, 133 articles were finally selected for detailed review. Each article was assessed independently by two members of the panel and then judged by the entire panel during a consensus meeting. During this process 59 articles were deemed conclusive and their results were used for final reporting at their second meeting. The conclusions are that: (1) None of the reviewed technologies was able to effectively remove all indoor pollutants and many were found to generate undesirable by-products during operation. (2) Particle filtration and sorption of gaseous pollutants were among the most effective air cleaning technologies, but there is insufficient information regarding long-term performance and proper maintenance. (3) The existing data make it difficult to extract information such as Clean Air Delivery Rate (CADR), which represents a common benchmark for comparing the performance of different air cleaning technologies. (4) To compare and select suitable indoor air cleaning devices, a labeling system accounting for characteristics such as CADR, energy consumption, volume, harmful by-products, and life span is necessary. For that purpose, a standard test room and condition should be built and studied. (5) Although there is evidence that some air cleaning technologies improve indoor air quality, further research is needed before any of them can be confidently recommended for use in indoor environments.

- by John Little
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- Environmental Engineering, Air Quality, Atmospheric Science, Indoor Air Quality

The climatic conditions of the tropical regions are characterized by high air temperatures, high relative humidity and very low wind speeds, which make the environmental conditions uncomfortable. A good dwelling design can keep the indoor environment favorable and comfortable during most of the year without the use of any mechanical devices. Depending on ambient conditions, natural ventilation may lead to

- by Agung Nugroho
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- Indoor Air Quality, Thermal comfort, Natural ventilation, Relative Humidity

The warming climate, projected increase in frequency and severity of extreme heat events, and the long-established heat island phenomenon are all expected to exacerbate urban environmental thermal loading. Active means used for addressing such risks are likely to increase energy consumption and emission trends to create a positive feedback loop that could threaten the health and wellbeing of urban citizens. In response, passive approaches such as green infrastructure enhancements are widely advocated, and to meet the challenges of implementing enhancements in dense cities, attention has been directed toward encouraging surface greening. This paper recognises this trend and considers vertical greening as a developing interest with application opportunity in both exterior and interior urban environments. A review of available studies and interviews with experts found most observations available to be derived from exterior applications. Interior applications consequently have yet to be investigated to determine relative value to indoor environments where most of human habitation is typically concentrated. The integration of plant science studies in this regard is highlighted as essential to develop a balanced evidence base for the enthusiasm observed for promoting indoor living wall installations.