scholarly journals A Survey on Wireless Transmitter Localization Using Signal Strength Measurements

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Henri Nurminen ◽  
Marzieh Dashti ◽  
Robert Piché
Keyword(s):  
Large Scale ◽  
Empirical Evaluation ◽  
Signal Strength ◽  
Low Energy ◽  
Small Scale ◽  
Energy Data ◽  
Building Administrators ◽  
Wireless Transmitter ◽  
Received Signal Strength Indication ◽  
Indoor And Outdoor

Knowledge of deployed transmitters’ (Tx) locations in a wireless network improves many aspects of network management. Operators and building administrators are interested in locating unknown Txs for optimizing new Tx placement, detecting and removing unauthorized Txs, selecting the nearest Tx to offload traffic onto it, and constructing radio maps for indoor and outdoor navigation. This survey provides a comprehensive review of existing algorithms that estimate the location of a wireless Tx given a set of observations with the received signal strength indication. Algorithms that require the observations to be location-tagged are suitable for outdoor mapping or small-scale indoor mapping, while algorithms that allow most observations to be unlocated trade off some accuracy to enable large-scale crowdsourcing. This article presents empirical evaluation of the algorithms using numerical simulations and real-world Bluetooth Low Energy data.

scholarly journals Position Tracking Techniques Using Multiple Receivers for Anti-Drone Systems

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 35
Author(s):  
Jae-Min Shin ◽  
Yu-Sin Kim ◽  
Tae-Won Ban ◽  
Suna Choi ◽  
Kyu-Min Kang ◽  
...  
Keyword(s):  
Traffic Control ◽  
Tracking System ◽  
Estimation Method ◽  
Signal Strength ◽  
Low Energy ◽  
Position Tracking ◽  
Memory Process ◽  
Multiple Receivers ◽  
Received Signal Strength Indication ◽  
Control Management

The need for drone traffic control management has emerged as the demand for drones increased. Particularly, in order to control unauthorized drones, the systems to detect and track drones have to be developed. In this paper, we propose the drone position tracking system using multiple Bluetooth low energy (BLE) receivers. The proposed system first estimates the target’s location, which consists of the distance and angle, while using the received signal strength indication (RSSI) signals at four BLE receivers and gradually tracks the target based on the estimated distance and angle. We propose two tracking algorithms, depending on the estimation method and also apply the memory process, improving the tracking performance by using stored previous movement information. We evaluate the proposed system’s performance in terms of the average number of movements that are required to track and the tracking success rate.

Sedimentary structures and paleocurrents in a Tertiary deltaic succession, northern Banks Basin, Arctic Canada

1976 ◽  
Vol 13 (10) ◽  
pp. 1422-1432 ◽  
Author(s):  
Andrew D. Miall
Keyword(s):  
Large Scale ◽  
Low Energy ◽  
Small Scale ◽  
Sedimentary Structure ◽  
Channel Processes ◽  
Point Bar ◽  
Medium Scale ◽  
Delta Plain ◽  
Mouth Bar ◽  
Delta Lobe

The Eureka Sound Formation of northern Banks Basin is a deltaic unit of Paleocene to Eocene age. A basal member of shale, approximately 100 m thick, passes vertically and, in part, laterally into a succession of sand, silt, shale, and lignitic coal approximately 1000 m thick, which is referred to as the cyclic member because of the abundance of coarsening-upward cycles, averaging 7.4 m in thickness.Sand beds in the cyclic member can be divided into four lithofacies: (1) A facires dominated by medium- to large-scale planar crossbedding, formed by channel processes, including lateral point bar accretion, in the delta plain environment. (2) A predominance of medium-scale trough and (minor) planar crossbeds, formed by migrating dunes in distributary mouth bar sands. (3) A predominance of small-scale ripple-marks, formed by low energy, unimodal currents in distal distributary mouth sands. (4) A lack of current structures, indicating quiet-water, interdeltaic and prodeltaic deposition. The distribution of these four facies outlines a series of small lobate deltas.Paleocurrent data suggest a pattern of radiating distributaries within each delta lobe. Directional variance, when analyzed at various levels of the sedimentary structure hierarchy, provides information regarding channel sinuosity and enables comparisons to be made with other deltaic deposits. High variance for the directions of the distributaries is consistent with a fluvially dominated delta.

scholarly journals Penerapan Kalman Filter Pada Metode Trilaterasi Untuk Peningkatan Akurasi Estimasi Perhitungan Jarak Di Dalam Ruangan

2018 ◽  
Vol 9 (02) ◽  
pp. 96-102
Author(s):  
Fahrudin Wibowo ◽  
Aulia Burhanudin
Keyword(s):  
Kalman Filter ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Low Energy ◽  
Bluetooth Low Energy ◽  
Received Signal Strength Indication

Penelitian tentang posisi maupun jarak suatu obyek di dalam ruangan telah banyak dilakukan. Metode trilaterasi adalah salah satu metode yang dapat dipergunakan untuk menghitung nilai estimasi jarak atau posisi suatu obyek di dalam ruangan, berdasarkan nilai RSSI (Received Signal Strength Indication) yang diterima suatu receiver. Namun, nilai RSSI yang diterima tidak dapat stabil dikarenakan sinyal yang diterima oleh receiver sangat dipengaruhi kondisi lingkungan pada ruangan yang pada umumnya memiliki nilai noise yang cukup tinggi. Sehingga dapat berakibat pada nilai estimasi jarak yang diperoleh menjadi kurang akurat. Sehubungan dengan hal tersebut maka setelah dilakukan perhitungan dengan trilaterasi, dilanjutkan dengan menambahkan metode Kalman Filter untuk meningkatkan nilai akurasi. Penelitian ini menggunakan BLE (Bluetooth Low Energy) sebagai transmitter, sedangkan receiver menggunakan smartphone yang sudah ter-install aplikasi untuk menerima nilai RSSI. Setelah menggunakan Kalman Filter diperoleh peningkatan nilai akurasi sebesar 0, 1 meter dari nilai perhitungan trilaterasi

scholarly journals Water Resistance of Torrefied Wood Pellets Prepared by Different Methods

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1618
Author(s):  
Takahiro Yoshida ◽  
Katsushi Kuroda ◽  
Daisuke Kamikawa ◽  
Yoshitaka Kubojima ◽  
Takashi Nomura ◽  
...  
Keyword(s):  
Moisture Content ◽  
Large Scale ◽  
Water Resistance ◽  
Wood Chips ◽  
Small Scale ◽  
Wood Pellets ◽  
Solid Biofuels ◽  
Rate Of Increase ◽  
Torrefied Biomass ◽  
Indoor And Outdoor

Torrefaction used in combination with pelletization is a promising technology to upgrade solid biofuels and has been demonstrated worldwide. In comparison with normal biomass pellets, which disintegrate under wet conditions, one of the advantages of torrefied biomass pellets is better water resistance. An understanding of the differences in water proof properties for torrefied biomass pellets by different production schemes can promote their further application. In the communication, various torrefied pellets were exposed to indoor and outdoor conditions, and changes in moisture content and diameter were examined. Two production schemes for the torrefied pellets were used for comparison: the torrefaction of wood chips followed by pelletization (pre-torrefaction) and the pelletization of wood chips followed by torrefaction (post-torrefaction). It was found that the post-torrefied pellets had much lower moisture levels than the pre-torrefied pellets in both indoor and outdoor tests. In the outdoor test with no-roof condition, the rate of increase in moisture content for the pre-torrefied pellets was more than double that for the post-torrefied pellets, and the post-torrefied pellets exhibited almost no diameter change. The results on the superior water resistance of post-torrefied pellets were nearly consistent with those reported in previous literature. Torrefied pellets have been considered for industrial use, such as in co-combustion and gasification on a large scale. Taking advantage of the different water resistances, torrefied pellets could also be used by personal and community consumers on a small scale for long-term indoor and outdoor storages as advanced solid biofuels with high waterproof performance, energy density, and lower biodegradation.

scholarly journals Experimental Evaluation of Advertisement-Based Bluetooth Low Energy Communication

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 107 ◽  
Author(s):  
Maciej Nikodem ◽  
Marek Bawiec
Keyword(s):  
Experimental Evaluation ◽  
Large Scale ◽  
Low Energy ◽  
Small Scale ◽  
Angle Of Arrival ◽  
Communication Performance ◽  
Bluetooth Low Energy ◽  
Iot Applications ◽  
Wide Range ◽  
The Impact

This paper addresses the efficiency of Bluetooth Low Energy (BLE) communication in a network composed of a large number of tags that transmit information to a single hub using advertisement mode. Theoretical results show that the use of advertisements enables hundreds and thousands of BLE devices to coexist in the same area and at the same time effectively transmit messages. Together with other properties (low power consumption, medium communication range, capability to detect a signal’s angle-of-arrival, etc.), this makes BLE a competing technology for the Internet of Things (IoT) applications. However, as the number of communicating devices increases, the advertisement collision intensifies and the communication performance of BLE drops. This phenomena was so far analyzed theoretically, in simulations and in small-scale experiments, but large-scale experiments are not presented in the literature. This paper complements previous results and presents an experimental evaluation of a real IoT-use case, which is the deployment of over 200 tags communicating using advertisements. We evaluate the impact of the number of advertisements on the effective data reception rate and throughput. Despite the advertisement collision rate in our experiment varying between 0.22 and 0.33, we show that BLE, thanks to the multiple transmission of advertisements, can still ensure acceptable data reception rates and fulfill the requirements of a wide range of IoT applications.

scholarly journals Comparison of 2.4 and 5 GHz WLAN Network for Purpose of Indoor and Outdoor Location

2016 ◽  
Vol 62 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Łukasz Chruszczyk ◽  
Adam Zając ◽  
Damian Grzechca
Keyword(s):  
Signal Strength ◽  
Is Research ◽  
Outdoor Environments ◽  
Indoor And Outdoor Environments ◽  
5 Ghz ◽  
Network Adapters ◽  
Received Signal Strength Indication ◽  
Outdoor Location ◽  
Standard Components ◽  
Indoor And Outdoor

Abstract This paper presents comparison of prototype location system built with standard components of 2.4 and 5 GHz WLAN network infrastructure. The system can be used for personal or other objects’ positioning, both for indoor and outdoor environments. The system is local, i.e. its operational area is limited to WLAN network operating range. The system is based on standard and widely available WLAN components (access points, network adapters). The goal is to avoid any hardware and software modifications. Also position calculation should not be power hungry operation. Method of location is based in Received Signal Strength Indication (RSSI) returned by most of RF ICs (including WLAN). The main focus is research of how much accuracy (and usefulness) can be expected from standard WLAN hardware. Both static and dynamic scenarios have been tested and compared.

scholarly journals Tripolarizated MIMO: Experimental Analysis and Modeling of Channel Properties in Both Indoor and Outdoor Scenarios

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Pan Tang ◽  
Jianhua Zhang ◽  
Zuolong Ying ◽  
Yuxiang Zhang ◽  
Lei Tian ◽  
...  
Keyword(s):  
Communication Systems ◽  
Large Scale ◽  
Mimo Systems ◽  
Mimo System ◽  
High Capacity ◽  
Small Scale ◽  
Delay Spread ◽  
Channel Measurements ◽  
Channel Properties ◽  
Indoor And Outdoor

The tripolarized MIMO system can provide one more degree of freedom and have a more compacted size over a dual-polarized MIMO system, which is attractive for high-capacity wireless communication systems. In this paper, we analyze and model channel properties for tripolarized MIMO systems based on experimental channel measurements in typical indoor and outdoor scenarios. Firstly, channel measurement campaigns in the laboratory and the Urban Micro (UMi) scenarios on sub-6 GHz bands are presented. Then, based on measured data, path loss, delay spread (DS), and cross-polarization discrimination (XPD) for 9 polarization combinations are analyzed and modeled in a statistical way. Statistical results of these channel properties are also given. It is observed that channel properties of both large-scale fading and small-scale fading depend strongly on the polarization direction. Furthermore, we evaluate the performance of tripolarized MIMO systems by analyzing the Demmel condition number and channel capacity gain (CG). For both the indoor and the outdoor scenarios, it is found that colocated tripolarized antenna can bring a nearly threefold CG with respect to the unipolarized one. These results can give good insights into the design and evaluation of tripolarized MIMO systems.

Small-Scale Science to Large-Scale Profession

2000 ◽  
Vol 45 (4) ◽  
pp. 396-398
Author(s):  
Roger Smith
Keyword(s):  
Large Scale ◽  
Small Scale

Development of Physics Learning Module Based on Guided Inquiry with Light Wave Material in Class XI of Senior High School

2020 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Evi Rahmawati ◽  
Irnin Agustina Dwi Astuti ◽  
N Nurhayati
Keyword(s):  
Large Scale ◽  
Learning Strategy ◽  
Student Response ◽  
Average Score ◽  
Small Scale ◽  
Design Development ◽  
Teacher Response ◽  
Student Responses ◽  
Analysis Design ◽  
Scientific Skills

IPA Integrated is a place for students to study themselves and the surrounding environment applied in daily life. Integrated IPA Learning provides a direct experience to students through the use and development of scientific skills and attitudes. The importance of integrated IPA requires to pack learning well, integrated IPA integration with the preparation of modules combined with learning strategy can maximize the learning process in school. In SMP 209 Jakarta, the value of the integrated IPA is obtained from 34 students there are 10 students completed and 24 students are not complete because they get the value below the KKM of 68. This research is a development study with the development model of ADDIE (Analysis, Design, Development, Implementation, and Evaluation). The use of KPS-based integrated IPA modules (Science Process sSkills) on the theme of rainbow phenomenon obtained by media expert validation results with an average score of 84.38%, average material expert 82.18%, average linguist 75.37%. So the average of all aspects obtained by 80.55% is worth using and tested to students. The results of the teacher response obtained 88.69% value with excellent criteria. Student responses on a small scale acquired an average score of 85.19% with highly agreed criteria and on the large-scale student response gained a yield of 86.44% with very agreed criteria. So the module can be concluded receiving a good response by the teacher and students.

Planetary gentrification and urban (re)development

2019 ◽  
Vol 61 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Loretta Lees
Keyword(s):  
Low Income ◽  
Policy Making ◽  
Large Scale ◽  
Urban Redevelopment ◽  
Urban Transformation ◽  
Small Scale ◽  
Income Groups ◽  
Low Income Groups

Abstract Gentrification is no-longer, if it ever was, a small scale process of urban transformation. Gentrification globally is more often practised as large scale urban redevelopment. It is state-led or state-induced. The results are clear – the displacement and disenfranchisement of low income groups in favour of wealthier in-movers. So, why has gentrification come to dominate policy making worldwide and what can be done about it?

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