Indoor System Research Articles

A PRELIMINARY SURVEY STUDY ON THE RECEPTION OF INDOOR HYDROPONICS SYSTEM FOR LOW-INCOME HOUSEHOLD IN SELANGOR

Indoor hydroponics system is gaining acceptance and traction in providing practical indoor farming capabilities for urban dwellers, including in low income housing estates. However, for the low income urban dwellers, the size of their residence might restrict the design of the indoor hydroponics system, especially in terms of available floor space. Furthermore, before one starts to develop an indoor hydroponics system, it is imperative to identify users’ preferences, in terms of the types of plants to grow, price, and design to enable the researchers to develop a better indoor hydroponics system. In this study, opinions from 53 participants on indoor hydroponics systems were obtained and analysed. Four aspects were analysed via the survey: (1) customer evaluations; (2) positive value; (3) costing; and (4) purchasing proclivity. The study shows that participants prefer to grow edible plants because of their benefits. Participants also prefer systems priced at below RM100 (60.40% of the respondent). Aloe Vera (56.6% preference) and Brazilian Spinach(49.1% preference) are two types of plants most preferred by the participants. As mentioned previously, the output of this survey will be used to guide the process of developing a suitable indoor hydroponics system for the low-income urban dwellers.

Visual Monitoring as a Tool in Industrial Security Engineering. Case Study

Abstract The article presents the use of video monitoring in a production company on the example of municipal thermal power plant. After analyzing the hazards and work inconvenience occurring in the analyzed enterprise, video surveillance zones have been designated with the division into the indoor and outdoor monitoring system. Video surveillance is provided for production, auxiliary and delivery processes. Moreover, video monitoring performs a control function over the occupation health in workstations at risk of explosion or fire. In addition, observation points have been set up in the visual monitoring system, among which the internal ones are served by the dispatcher responsible for the production process, while the external are operated by security guards of the facility.

Interactions between the seaweed Gracilaria and dinoflagellate Akashiwo sanguinea in an indoor co-cultivation system and the interference of bacteria

Interactions between the seaweed Gracilaria and dinoflagellate Akashiwo sanguinea in an indoor co-cultivation system and the interference of bacteria

UJAmI Location: A Fuzzy Indoor Location System for the Elderly

Due to the large number of elderly people with physical and cognitive issues, there is a strong need to provide indoor location systems that help caregivers monitor as many people as possible and with the best quality possible. In this paper, a fuzzy indoor location methodology is proposed in a smart environment based on mobile devices and Bluetooth Low Energy (BLE) beacons where a set of Received Signal Strength Indicators (RSSI) is received by mobile devices worn by the inhabitants. The use of fuzzy logic and a fuzzy linguistic approach is proposed to deal with the imprecise nature of the RSSI values, which are influenced by external factors such as radio waves, causing significant fluctuations. A case study carried out at the Smart Lab of the University of Jaén (UJAmI Smart Lab) is presented to demonstrate the effectiveness of the proposed methodology, where our proposal is compared with a non-fuzzy logic approach, obtaining an accuracy of 91.63%, approximately 10 points higher than the methodology without using fuzzy logic. Finally, our theoretical proposal is accompanied by a description of the UJAmI Location system, which applies the theory to the functionality of locating elderly people in indoor environments.

Study on the adaptability of binary flooding in a certain oil field

Abstract To explore the synergistic mechanism of polymer and surfactant in the binary combination flooding of low-permeability reservoirs, the adaptability experiment of polymer salt-resistant partially hydrolyzed polyacrylamide and nonionic surfactant was carried out in the indoor system. Experiments at different ratios are also performed. The results show that the selected poly/surface binary flooding system increases with the concentration of polymer or surfactant, the viscosity of the poly/surface binary system also increases and, at the same time, has better temperature and salt resistance. The viscosity of the binary system will decrease when the salinity increases. When the surfactant concentration CS = 0.2% and the polymer concentration CP = 0.2%, the viscosity of the system is the highest. The viscosity of the poly/table binary system at different concentrations decreases when the temperature rises: pure polymer (CP = 0.2%), poly/table binary system displacement fluid CP = 0.1% + CS = 0.2% and CP = 0.2% + CS = 0.2%; and the injection pressure first rises and then drops. The final recovery rate is 51.8%, which meets the development of most oil reservoirs.

Reliable Wi-Fi Indoor Localization in Case of AP Loss by Using Integrated Model Based on Signal Anomaly Detector and Signal Distance Corrector

When developing a Wi-Fi indoor positioning system in a real-world environment, the problems we have to face are that some access points’ signal strength fluctuates extensively or even loses contact due to the cybersecurity threats, leading to the fact that the indoor location system cannot get reliable application in a real-world environment. To solve this problem, we propose a new integrated model based on signal anomaly detector and signal distance corrector to provide reliable position estimation when the access points’ signal is lost under cybersecurity threats. The signal anomaly detector improves recognition capability of the uncertain signal and noise, while the signal distance corrector improves the robustness and fault tolerance of the highly variable Wi-Fi signals. To fully reflect the performance of the proposed method, experiments have been carried out in the real environment of indoor parking lots. The results show that the proposed integrated model successfully provides reliable position estimation when the access points are lost under cybersecurity threats.

RANCANG BANGUN SMART GROW BOX HIDROPONIK UNTUK PERTUMBUHAN TANAMAN MICROGREEN BERBASIS INTERNET OF THINGS

Abstract - Smart Grow Box is a place that is used as a medium for growing microgreen plants with an indoor system. In this study, a hydroponic Smart Grow Box was designed for smartphone-based microgreen plant growth. This study aims to monitor and control the environmental parameters of microgreen plant growth in the grow box that has been made. The system is designed using the DHT22 sensor as a temperature and humidity reader and the RTC DS3231 as a time control. The output from the sensor and RTC will be processed by the ESP32 microcontroller unit which is then forwarded to the system actuators and smartphones via the internet. This system designed uses the Blynk App application which can perform monitoring and control processes remotely based on the internet of things. This Smart Grow Box can reduce air humidity up to 4.71% lower than room air humidity, can increase air humidity to 90% within 54 seconds, and can lower air temperature close to room air temperature by a difference of 0.07 ℃. Smart Grow Boxes can also increase the quality of microgreen harvests by up to 40%.

Muscle fibre membrane lipid composition in <i>musculus biceps femoris</i> of pigs reared in indoor or outdoor systems

Muscle fibre membrane lipid composition in <i>musculus biceps femoris</i> of pigs reared in indoor or outdoor systems

Effects of season, genotype and rearing system on some meat quality traits for broilers raised in semi-intensive systems.

We compared fast-growing and slow-growing broilers raised in extensive indoor, free-range, and traditional free-range systems in terms of meat quality in spring and summer. Five different semi-intensive broiler production applications (fast- in extensive indoor, slow- in extensive indoor, fast- in free-range, slow- in free-range and slow- in traditional free-range) were used according to EU standards. Extensive indoor and free-range birds were slaughtered at 57days of age and traditional free-range chickens at 82days. The higher (P < 0.05) skin yellowness (b*) values found in spring compared to summer may have been due to better pasture conditions in spring. The pH24 value of breast meat during the summer period was higher (P < 0.05) than that in spring, but lightness (L*) was similar. Thawing and cooking losses were higher (P < 0.05) in breast meat samples from the summer experiment. The season affected (P < 0.05) all sensory attributes of breast meat; spring samples were appreciated more in terms of all the features discussed. Regarding the skin b* value, the highest average value was detected for slow chickens in the slow- in free-range and traditional free-range groups, most likely because slow chickens spent more time grazing. Fast- showed higher pH24 values than slow- (P < 0.05) in extensive indoor and free-range groups. We did not observe differences in pH24 due to grazing in fast-, but grazing slow- showed lower pH24 values than their indoor counterparts. Further, in the extensive indoor system, both genotypes were similar in terms of breast meat L* and b*, whereas slow- in the free-range system showed higher (P < 0.05) averages than fast-. Based on our results, the traditional grazing system has a positive impact on meat sensory features.

User Localization and Upstream Signaling for Beam-Steered Infrared Light Communication System

Beam-steered infrared light can provide ultra-high wireless capacity to individual user devices for indoor communication systems. The optical beams used to obtain such high capacities are relatively narrow with the average beam divergence of less than 2.55°, hence an accurate localization system to pinpoint multiple user devices at the same time is required. In addition, an indoor communication should provide mobile coverage to all users, therefore a dynamic and fast localization equipped with a capability of conveying the channel link status of the user devices to optical access points is necessary. In this work, we propose a vision-based technique to simultaneously localize the user devices in a room. A LED-tag system positioned around a photodetector enables the access points to recognize active users. A localization accuracy of 0.018° is achieved within milliseconds. Furthermore, taking advantage of this vision-based system, upstream signaling for channel status information is proposed using M-ary intensity modulation. Experimental results show that an upstream signaling rate of 2.4kbps can be achieved with our simple and low-cost prototype, enabling >10Gbit/s link per user.

Exploiting Fingerprint Correlation for Fingerprint-Based Indoor Localization: A Deep Learning Based Approach

For indoor localization system, the integration of various fingerprints could intuitively improve localization accuracy since different fingerprints complement each other. In spite of the potential benefits, however, the limitation of applying various fingerprints in improving localization accuracy still remains unknown. Moreover, how to design efficient indoor localization methods through fully exploiting the features of different fingerprints is to be explored as well. In this work, we investigate the location error of a fingerprint-based indoor system with the application of hybrid fingerprints. It manifests that the location error is dependent on correlation coefficient of different types of fingerprints. For instance, the exploiting correlation between different types of fingerprints is shown to effectively reduce the location error, which gradually decreases with the number of adopted fingerprints. On this basis, we propose a hybrid received signal strength (RSS) and channel state information (CSI) localization algorithm (HRC), which is designed based on deep learning. The HRC fully exploits quick construction of fingerprint database with coarse-grained RSS and rich multipath information of fine-grained CSI. The RSS and CSI with high correlation are selected to construct fingerprint database, aiming to improve localization accuracy. Moreover, a deep auto-encoder is used to reduce the computation complexity and the deep neural network is trained for location estimation. Experimental results, which are obtained by designed indoor localization system, validate that the location error of HRC can be reduced by 77.3% and 20.3%, compared with the existing localization methods and HRC without RSS/CSI selection by correlation coefficient, respectively.

Millimeter-Wave Reflector Based on a Ferroelectric Material with Electrical Beam Steering

Millimeter waves are increasingly used in modern telecommunication systems for wireless data transmission. However, higher path loss, especially caused by non-line-of-sight scenarios, remains challenging. The design of an electrically controllable reflector for the millimeter-wave range is elaborated and presented in this manuscript. The reflector design was based on distributed ferroelectric ceramic elements and could be used in a frequency range up to 100 GHz. The issue of the ferroelectric reflector impedance matching was analyzed in detail. Two possible implementations of the reflector for indoor and outdoor communication systems were considered and simulated. The prototype of the proposed reflector for an operating frequency of 60 GHz was manufactured. Both simulation and measurement results demonstrated the beam steering by the proposed ferroelectric reflector.

Least minimum symbol error rate based post-distortion for adaptive mobile VLC transmission with receiver selection

In the context of beyond-5G indoor communication systems, visible light communication (VLC) has emerged as a viable supplement for existing RF-based systems and as an enabler for high data-rate communications. However, the existing indoor VLC systems are limited by detrimental outages caused by fluctuations in the VLC channel-gain due to user-mobility. Furthermore, the nonlinear characteristics of the light-emitting diode (LED) degrade the performance of VLC systems in the high-power regime by warping the input constellation. Additional performance-limits are introduced by inter-symbol interference (ISI) due to finite modulation-bandwidth of LEDs, and reflections from walls. In this paper, a random Fourier feature (RFF) based post-distorter is considered for mitigating the LED nonlinearity, and relevant expressions for the signal to noise ratio (SNR) are derived for a direct current biased optical orthogonal frequency division multiplexing (DCO-OFDM) system. Based on the derived expressions for SNR, the effects of user-mobility and ISI are mitigated by a DCO-OFDM based adaptive VLC transmission technique, which varies the transmission-rate/modulation-order under a specified error-rate constraint. Simulations are presented over channels obtained by ray-tracing, which indicates that the proposed algorithm achieves superior data-rates with a significantly lower error-rate.

Effect of temperature rise on growth performance, feed intake, feed conversion ratio and sex ratio of the Nile Tilapia, Oreochromis niloticus

This study was conducted to investigate the effect of increasing water temperature on growth performance, feed intake, feed conversion ratio, and sex ratio of Oreochromis niloticus. Two groups of O. niloticus fries (3 days post-hatching) were reared in an indoor system, at 30°C and 34°C. In the second group, the water temperature was increased to 36°C for only four hours a day, for the first 25 days of the experiment. At the end of the experiment, the values of body weight, length, specific and daily growth rates, and feed intake were comparable but slightly higher at 30°C. The feed conversion ratio was better in the control tank (30°C) than in the experimental one (36°C). Condition factor was higher than 1 at both temperatures indicating the general well-being of fries along the study period. The sex was skewed towards males under the effect of high temperature (36°C) in the experimental tank.

Metamaterial‐based, compact, wide beam‐width circularly polarized antenna for 5G indoor application

AbstractThis paper describes a metamaterial‐based miniaturized circularly polarized (CP) antenna with high radiation efficiency and wide beam‐width or coverage for 5G indoor application. A novel meta‐resonator is first proposed, which is investigated by transmission line and equivalent circuit models. By exploring a split‐ring resonator‐like meta‐resonator structure, a high‐Q LC resonator tank is formed. Substantial size reduction and a wide beam‐width are achieved. Owing to a uniform field on these multiple capacitive gaps incorporated on this meta‐resonator surface, enhanced aperture efficiency and gain are obtained. It is partly inspired by the classical metasurface‐based antenna. For validation, a miniaturized CP antenna with a size of 0.29 λ0 × 0.29 λ0 × 0.04 λ0 (where, λ0 is the free‐space wavelength at 3.55 GHz) is fabricated and measured. The fabricated antenna achieves a good bandwidth of 3.30–3.80 GHz that well covers 5G‐N78 band, a peak radiation gain of 5.4 dBic, a high radiation efficiency of 90% and a wide half‐power beam‐width of 91°. It exhibits the merits of compact size, good bandwidth and beam‐width, high efficiency, and low‐cost, demonstrating good potential in miniaturized 5G indoor systems demanding wide‐beam coverage.

Enhancing growth, phycoerythrin production, and pigment composition in the red alga Colaconema sp. Through optimal environmental conditions in an indoor system

Phycoerythrin (PE) is a compound with strong potential for both basic research and industrial applications, but short supply and high prices have so far hindered its development. One common problem is a shortage of biomass for extraction. The aim of the present study was to determine a cultivation strategy (optimizing temperature, irradiance, photoperiod, and light quality) to produce greater biomass and higher PE concentrations in the alga Colaconema sp. We found that an optimized culture process could increase algae growth 7–9 fold while allowing extraction of 9–10 mg g−1 total phycobiliproteins, containing 60%–65% PE. Low energy costs make this approach economically feasible and competitive when compared with existing methods. Our results suggest an improved strategy for the large-scale production of PE and offer valuable applications in the algae industry.

Contact Tracing in Healthcare Settings During the COVID-19 Pandemic Using Bluetooth Low Energy and Artificial Intelligence-A Viewpoint.

The COVID-19 pandemic has inflicted great damage with effects that will likely linger for a long time. This crisis has highlighted the importance of contact tracing in healthcare settings because hospitalized patients are among the high risk for complications and death. Moreover, effective contact tracing schemes are not yet available in healthcare settings. A good contact tracing technology in healthcare settings should be equipped with six features: promptness, simplicity, high precision, integration, minimized privacy concerns, and social fairness. One potential solution that addresses all of these elements leverages an indoor real-time location system based on Bluetooth Low Energy and artificial intelligence.

Distribution characteristics of indoor oxygen concentration under natural ventilation in oxygen-enriched buildings at high altitudes

Diffuse oxygen supply is an important means to improve the indoor oxygen environment of buildings and ensure physiological and psychological health of immigrants in plateau areas. Existing research on oxygen enrichment strategies at high altitudes has mainly focused on confined spaces under mechanical ventilation, with few studies on the distribution of indoor oxygen concentration under natural ventilation in actual buildings. This study used a verified computational fluid dynamics (CFD) method to investigate the indoor oxygen distribution with practical consideration of natural ventilation at high altitudes. The results showed that the oxygen distribution under wind-driven natural ventilation was more nonuniform than that under buoyancy-driven natural ventilation, with the ratio of local oxygen concentration to overall-mean oxygen concentration, the k value, between 0.8 and 1.3 under wind-driven natural ventilation and between 0.9 and 1.1 under buoyancy-driven natural ventilation. The effects of meteorological condition and oxygen source position on indoor spatial oxygen distribution characteristics were explored with careful examination in human occupied zone under lying, sitting and standing postures. The results can provide implications for effective and energy saving design of indoor oxygen supply system in plateau buildings.

Wayfinding Techniques at Common First Year King Saud University - An Indoor Localization Approach for Navigation

The development of ICT technologies in recent years has shown remarkable changes with the internet of things and smart gadgets. This presented an opportunity for indoor navigation to develop a system for indoor positioning systems, such as GPS, that can assist any beneficiary in navigating inside the building and locating themselves. This paper focuses on the educational sector, specifically in King Saud University's Common First Year. To fit the educational setting, a detailed study using various techniques was reviewed. Overall, a meta-analysis was completed that will aid in the implementation of the sensors nodes technique in the future as a prototype on Common First Year campuses.

Ultra-Low-Power Wide Range Backscatter Communication Using Cellular Generated Carrier.

With the popularization of Internet-of-things (IoT) and wireless communication systems, a diverse set of applications in smart cities are emerging to improve the city-life. These applications usually require a large coverage area and minimal operation and maintenance cost. To this end, the recently emerging backscatter communication (BC) is gaining interest in both industry and academia as a new communication paradigm that provides high energy efficient communications that may even work in a battery-less mode and, thus, it is well suited for smart city applications. However, the coverage of BC in urban area deployments is not available, and the feasibility of its utilization for smart city applications is not known. In this article, we present a comprehensive coverage study of a practical cellular carrier-based BC system for indoor and outdoor scenarios in a downtown area of a Helsinki city. In particular, we evaluate the coverage outage performance of different low-power and wide area technologies, i.e., long range (LoRa) backscatter, arrow band-Internet of Things (NB-IoT), and Bluetooth low energy (BLE) based BC at different frequencies of operation. To do so, we carry out a comprehensive campaign of simulations while using a sophisticated three-dimensional (3D) ray tracing (RT) tool, ITU outdoor model, and 3rd generation partnership project (3GPP) indoor hotspot model. This study also covers the energy harvesting aspects of backscatter device, and it highlights the importance of future backscatter devices with high energy harvesting efficiency. The simulation results and discussion provided in this article will be helpful in understanding the coverage aspects of practical backscatter communication system in a smart city environment.