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1
SUKACHEV, E. A. "THE DYNAMICS OF THE INTERFERENCE SITUATION IN THE DOWNLINK DIRECTION OF THE MOBILE COMMUNICATION NETWORK WITH CDMA TECHNOLOGY." Digital Technologies 26 (2019): 61–68. http://dx.doi.org/10.33243/2313-7010-26-61-68.
Повний текст джерелаАнотація:
The work is devoted to the investigation of inter-cell interference in the radio access network, provided that subscribers are moving in cells along the route indicated earlier. Very often, the trajectory of the movement of mobile stations coincides with the grid of city streets, where subscribers are moving in public transport. For a network where the cluster dimension is K = 1, the proposed methodology for studying changes in the level of intra-system interference at the input of the receiver of a mobile station when a subscriber is moving along the given path. The features of the situation where the control mode of the transmitter power of the base station is used in each cell, which provides a constant power level of the input signal when the subscriber is moving within the cell, are analyzed. The level of inter-cell interference is estimated as one of the factors on which the quality of services depends, namely, the signal-to-interference ratio at the input of the receiver of the mobile station. For specific trajectories of the movement of subscribers in neighboring cells, a law of changing the transmitter power of the base station was found, which interferes with the receiver of the mobile station in the neighboring cell. Estimated ratios are obtained for determining the level of interference when subscribers in neighboring cells are moving along parallel streets. This assessment of the dependence of the signal / interference ratio at the input of the subscriber's receiver on the speed and direction of its movement. This dependence shows that serious problems with the quality of service provided by the operator will not arise. Such an investigation allows modeling the cellular network in order to optimize the work on improving the services provided to mobile subscribers.
2
Wang, James Z., Zhidian Du, and Pradip K. Srimani. "Cooperative Proxy Caching for Wireless Base Stations." Mobile Information Systems 3, no. 1 (2007): 1–18. http://dx.doi.org/10.1155/2007/371572.
Повний текст джерелаАнотація:
This paper proposes a mobile cache model to facilitate the cooperative proxy caching in wireless base stations. This mobile cache model uses a network cache line to record the caching state information about a web document for effective data search and cache space management. Based on the proposed mobile cache model, a P2P cooperative proxy caching scheme is proposed to use a self-configured and self-managed virtual proxy graph (VPG), independent of the underlying wireless network structure and adaptive to the network and geographic environment changes, to achieve efficient data search, data cache and date replication. Based on demand, the aggregate effect of data caching, searching and replicating actions by individual proxy servers automatically migrates the cached web documents closer to the interested clients. In addition, a cache line migration (CLM) strategy is proposed to flow and replicate the heads of network cache lines of web documents associated with a moving mobile host to the new base station during the mobile host handoff. These replicated cache line heads provide direct links to the cached web documents accessed by the moving mobile hosts in the previous base station, thus improving the mobile web caching performance. Performance studies have shown that the proposed P2P cooperative proxy caching schemes significantly outperform existing caching schemes.
3
LUZHANSKY, V., L. V. KARPOVA, and A. POVKH. "INVESTIGATION OF SIGNAL DISTURBANCE OF THE SIGNAL AT THE INPUT OF THE MOBILE STATION RECEIVER WITH DIFFERENT CHARACTERISTICS OF BASE STATIONS IN THE CONDITIONS OF CITY BUILDING." HERALD OF KHMELNYTSKYI NATIONAL UNIVERSITY 295, no. 2 (May 2021): 206–13. http://dx.doi.org/10.31891/2307-5732-2021-295-2-206-213.
Повний текст джерелаАнотація:
The purpose of the scientific paper is to study the effects of internal system interference caused by the movement of a mobile station in the cell of the service area, which involves the use of the same frequencies, which worsens the communication conditions. The article provides calculation formulas for determining the signal-to-noise ratio at the input of the receiver of the mobile station. Calculations, including tables and figures, for different characteristics of base stations (BS) of the mobile network are also given. The analysis of literature sources shows insufficient depth of the conducted researches in directions for improving the noise immunity of the signal under different conditions in particular: city development, terrain, interference from other base stations. The use of radio networks with moving objects makes it possible to repeatedly use the same dedicated frequency band to increase the speed of digital information transmission and economical use of the frequency range. This method has a significant disadvantage, which is the presence of mutual internal system interference between base and mobile stations that use the same frequency range. The purpose of the scientific article is to study the noise immunity of the signal at the input of the receiver of the mobile station at different characteristics of the base stations in terms of urban development
4
Le, Zichun, Xianyu Zeng, and Minglei Fu. "Optimized Base Station Location Planning for Indoor Positioning in Visible Light Communication System." Journal of Optical Communications 39, no. 4 (October 25, 2018): 437–47. http://dx.doi.org/10.1515/joc-2017-0004.
Повний текст джерелаАнотація:
Abstract Visible light communication (VLC) is an emerging optical communication technology, and indoor positioning of moving target devices is one of most important issues in the VLC system. In this study, we focused on LED base station location planning to improve the accuracy of the positioning method based on the received signal strength intensity (RSS) and the Kalman filter (KF). We developed a new base station location-planning scheme called equilateral triangle distribution. We proved theoretically that the equilateral triangle distribution scheme reduced the positioning error area when compared with the rectangular distribution scheme. The simulation results showed that the measuring error of the equilateral triangle distribution method using KF was less than 5 cm, even when the receiver was located at the boundary of the room. Our method verified that the VLC indoor positioning accuracy can be improved when LED base stations are distributed according to our equilateral triangle distribution scheme.
5
Wu, Yuzhan, Susheng Ding, Yuanhao Ding, and Meng Li. "UWB Base Station Cluster Localization for Unmanned Ground Vehicle Guidance." Mathematical Problems in Engineering 2021 (April 22, 2021): 1–23. http://dx.doi.org/10.1155/2021/6639574.
Повний текст джерелаАнотація:
In this paper, we seek to provide unmanned ground vehicles with positioning service using ultrawideband (UWB) technology, a high-accuracy positioning approach. UWB is chosen for two distinct reasons. First, it does not rely on global navigation satellite systems like GPS, making it able to be applied indoors or in an environment where GPS signal is unstable. Second, it is immune to interference from other signals and accurate enough to guide unmanned ground vehicles moving precisely in a complex environment within a narrow road. In this paper, three UWB base stations are aggregated as a group in a 2D space for localization. A large number of tests are performed with a UWB base station cluster in order to validate its positioning performance. Based on the experiment results, we further develop a dynamic particle swarm optimization-based algorithm and a genetic algorithm to deploy multiple clusters of UWB base stations to cover an area of interest. The performance of the proposed algorithms has been tested through a series of simulations. Finally, experiments using unmanned ground vehicles are carried out to validate the localization performance. The results confirm that the robots can follow complex paths accurately with the proposed UWB-based positioning system.
6
Mitić, Dragan, Aleksandar Lebl, Branimir Trenkić, and Žarko Markov. "How users' moving in a cell affects the necessary base station power." Tehnika 74, no. 2 (2019): 245–50. http://dx.doi.org/10.5937/tehnika1902245m.
Повний текст джерела
7
Enayati, Saeede, Hamid Saeedi, Hossein Pishro-Nik, and Halim Yanikomeroglu. "Moving Aerial Base Station Networks: A Stochastic Geometry Analysis and Design Perspective." IEEE Transactions on Wireless Communications 18, no. 6 (June 2019): 2977–88. http://dx.doi.org/10.1109/twc.2019.2907849.
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8
Rodimtsev, Sergey, Alexander Psaryov, and Andrey Chuykin. "Monitoring of moving objects in the absence of a GSM signal." MATEC Web of Conferences 341 (2021): 00029. http://dx.doi.org/10.1051/matecconf/202134100029.
Повний текст джерелаАнотація:
Many modern transport processes require constant on-line monitoring and management. However, the main difficulty lies in the lack of a stable GSM connection. One of the possible solutions to this issue is the use of MESH networks. These represent the possibility of wireless communication between multiple entities, which are nodes on a distributed network. The article presents the results of the development of original local radio modules and a base station to ensure uninterrupted transmission of digital data from the monitoring object, in conditions of insufficient GSM coverage. The complex provides the following operating modes: simple interaction via a GSM channel, data transmission via a self-organizing network, as well as sensory interaction between objects. In the absence of GSM communication, the repeater provides on-line data transmission from the monitoring object, at a distance of up to 860 m, at a distance from the base station - at least 500 m. The use of the new complex makes it possible to promptly respond to changes in operating factors and prevent emergency situations during the operation of vehicles.
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Do, Dinh-Thuan, Thanh-Luan Nguyen, and Byung Moo Lee. "Transmit Antenna Selection Schemes for NOMA with Randomly Moving Interferers in Interference-Limited Environment." Electronics 9, no. 1 (December 27, 2019): 36. http://dx.doi.org/10.3390/electronics9010036.
Повний текст джерелаАнотація:
In this paper, non-orthogonal multiple access (NOMA) is studied at downlink under impact of surrounding interference. This study benefits the practical NOMA system since spatially random interference is adopted. More specifically, we consider the antenna selection strategy applied at the base station and compare the performance of two users. By applying a stochastic geometry-based model, homogeneous Poisson point process (PPP) is employed to consider the spatial topology of interference which is located near to users, and such a model is extremely suitable for practical consideration. We first consider outage probability and then ergodic capacity is examined as main metrics to recommend such model in practice. According to the considered antenna section scheme of the base station, we compare these schemes related to selected antenna serving each user. To confirm exactness of derived expressions, we perform Monte Carlo simulations to verify the analytical results.
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Rode, Henryk. "A research station with a two-disc cutting unit for studying the cutting process of energy." E3S Web of Conferences 46 (2018): 00001. http://dx.doi.org/10.1051/e3sconf/20184600001.
Повний текст джерелаАнотація:
The paper presents the construction of a new research station for studying the cutting process of energy plants. The station consists of 3 basic units: a truck with drive and cutting units, a frame which is a guide for the truck moving on it, and a base for placing the plant’s stems. The station allows to determine the unitary energy of the cutting process for various rotary and travelling speeds of the cutting unit and for various sizes, spacing and angles of inclination of the cutting discs. It also allows to form freely the cut plants’ stems’ sockets.
11
Iashchuk, Oleksandr, Iuliia Iashchuk, and Konstantin Sunduchkov. "Analysis of Signal Formation and Conversion in Hybrid Radio Over Fibre Network." Transport and Telecommunication Journal 14, no. 3 (September 1, 2013): 196–205. http://dx.doi.org/10.2478/ttj-2013-0016.
Повний текст джерелаАнотація:
Calculation methods of the signal formation parameters at the central station and of selective conversion in mobile terminal receiver of the vehicle moving at speed of 200-300 km per h are described. Architecture features of radio over fibre networks to operate without handover between base stations lead to additional requirements for transmitting and receiving signal methods in the network. The solution of this problem will provide high-rate services (up to 12 Mbit per second) for subscribers moving on the highway or high-speed railway using hybrid radio over fibre network. It allows providing services of any content at any time. Objective: calculation methods development of the signal formation and conversion parameters. Signal is a set of services in the form of OFDM-symbols, the total bandwidth of which is much higher than 1 GHz.
12
Wu, Zhouyi, Yasser Qaragoez, Vladimir Volskiy, Jiangtao Huangfu, Lixin Ran, and Dominique Schreurs. "A Joint Design of Radar Sensing, Wireless Power Transfer, and Communication Based on Reconfigurable Software Defined Radio." Electronics 11, no. 23 (December 6, 2022): 4050. http://dx.doi.org/10.3390/electronics11234050.
Повний текст джерелаАнотація:
This paper proposes a compact three-mode base station capable of performing radar sensing, communication, and wireless power transfer (WPT) in collaboration with indoor sensor networks. With regard to the wireless sensor node, the base station transmits two-tone signals in the downlink to support its operation and provides two-way communication. The sensor node sends uplink information through backscattering using the third order intermodulation (IM3) product of the rectification. In the radar mode, a single-tone continuous wave (CW) is used to monitor if there is a moving target in the static environment. If a speed is detected, the transmit signal to the node is stopped, while the single-tone CW excitation will continue until the speed of the target is zero, and then the base station transmits a stepped frequency continuous wave (SFCW) signal to measure the distance of the target. The repeat between the two radar waveforms continues until the target is undetectable within the detection range. The software defined radio PlutoSDR is adopted as the base station. The system can wirelessly supply power and bi-directionally communicate with a CO2 sensor node 2 m away. It gives a range resolution of 2.5 cm and a minimum detectable speed of 0.25 m/s in the radar mode.
13
Farasat, Madiha, Dushmantha Thalakotuna, Yang Yang, Zhonghao Hu, and Karu Esselle. "Suppression of Common-Mode Resonance in Multiband Base Station Antennas." Sensors 23, no. 6 (March 7, 2023): 2905. http://dx.doi.org/10.3390/s23062905.
Повний текст джерелаАнотація:
5G demands a significant increment in the number of connected devices. As a result, gNodeBs are constantly pushed to serve more spectrum and smaller sectors. These increased capacity demands are met by using multiband antennas in base stations. One of the key challenges with multiband antennas is the pattern distortions due to the presence of other surrounding antenna element structures. This work provides a novel approach to address the challenge of pattern distortion in the lower frequency band 690–960 MHz due to common-mode (CM) currents in the high- frequency-band antenna element operating in the 1810–2690 MHz band. A common-mode suppression circuit is integrated with the impedance matching network of the high-band antenna element to reduce these common-mode currents. The experimental results verified that the common-mode suppression circuit reduces the common-mode currents at low-band frequencies by moving the common-mode resonance frequency outside the low frequency band, resulting in cleaner low-band patterns meeting pattern specifications.
14
Oh, Soon-Soo, and Young-Hwan Lee. "An EIRP Measurement Method for Base-Station Antennas Using Field Strengths Measured along a Single Straight Line." International Journal of Antennas and Propagation 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/742636.
Повний текст джерелаАнотація:
We describe an EIRP measurement technique for a base-station antenna. The proposed method especially can be applied to the base-station antenna installed in real environments. Fresnel region measurement method is an optimal technique to avoid the far-field multipath interference, and, furthermore, it could shorten the measurement time. For detecting only the field strengths along a single straight line, we also propose a simple phase-retrieval method. For verification, a simulation and experiment have been performed. An anechoic chamber was utilized in this paper before the real environment test with the outdoor measurement system. The transformed far-field pattern and EIRP agree closely with the reference data within a valid angle. The proposed method can be applied for the EIRPin situmeasurements without moving a vehicle loading the EIRP measurement apparatus.
15
Singh, Ashutosh Kumar, N. Purohit, and S. Varma. "Analysis of lifetime of wireless sensor network with base station moving on different paths." International Journal of Electronics 101, no. 5 (June 8, 2013): 605–20. http://dx.doi.org/10.1080/00207217.2013.794480.
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16
Chen, Chien-Bang, Tsu-Yu Lo, Je-Yao Chang, Shih-Ping Huang, Wei-Ting Tsai, Chong-Yi Liou, and Shau-Gang Mao. "Precision Enhancement of Wireless Localization System Using Passive DOA Multiple Sensor Network for Moving Target." Sensors 22, no. 19 (October 6, 2022): 7563. http://dx.doi.org/10.3390/s22197563.
Повний текст джерелаАнотація:
Determining the direction-of-arrival (DOA) of any signal of interest has long been of great interest to the wireless localization research community for military and civilian applications. To efficiently facilitate the deployment of DOA systems, the accuracy of wireless localization is critical. Hence, this paper proposes a novel method to improve the prediction result of a wireless DOA localization system. By considering the signal variation existing in the complex environment, the actual location of the target can be determined including the maximum prediction error. Moreover, the scenario of the moving target is further investigated by incorporating the adaptive Kalman Filter algorithm to obtain the prediction route of the flying drone based on the accuracy assessment method. This proposed adaptive Kalman Filter is a high-efficiency algorithm that can filter out the noise in the multipath area and optimize the predicted data in real-time. The simulation result agrees well with the measured data and thus validates the proposed DOA system with the adaptive Kalman Filter algorithm. The measured DOA of the fixed radiation source obtained by a single base station and the moving route of a flying drone from a two-base station localization system are presented and compared with the calculated results. Results show that the prediction error in an outdoor region of 500×500 m2 is about 10–20 m, which demonstrate the usefulness of the proposed wireless DOA system deployment in practical applications.
17
Aldosary, Abdallah Mobark, Saud Alhajaj Aldossari, Kwang-Cheng Chen, Ehab Mahmoud Mohamed, and Ahmed Al-Saman. "Predictive Wireless Channel Modeling of MmWave Bands Using Machine Learning." Electronics 10, no. 24 (December 14, 2021): 3114. http://dx.doi.org/10.3390/electronics10243114.
Повний текст джерелаАнотація:
The exploitation of higher millimeter wave (MmWave) is promising for wireless communication systems. The goals of machine learning (ML) and its subcategories of deep learning beyond 5G (B5G) is to learn from the data and make a prediction or a decision other than relying on the classical procedures to enhance the wireless design. The new wireless generation should be proactive and predictive to avoid the previous drawbacks in the existing wireless generations to meet the 5G target services pillars. One of the aspects of Ultra-Reliable Low Latency Communications (URLLC) is moving the data processing tasks to the cellular base stations. With the rapid usage of wireless communications devices, base stations are required to execute and make decisions to ensure communication reliability. In this paper, an efficient new methodology using ML is applied to assist base stations in predicting the frequency bands and the path loss based on a data-driven approach. The ML algorithms that are used and compared are Multilelayers Perceptrons (MLP) as a neural networks branch and Random Forests. Systems that consume different bands such as base stations in telecommunications with uplink and downlink transmissions and other internet of things (IoT) devices need an urgent response between devices to alter bands to maintain the requirements of the new radios (NR). Thus, ML techniques are needed to learn and assist a base station to fluctuate between different bands based on a data-driven system. Then, to testify the proposed idea, we compare the analysis with other deep learning methods. Furthermore, to validate the proposed models, we applied these techniques to different case studies to ensure the success of the proposed works. To enhance the accuracy of supervised data learning, we modified the random forests by combining an unsupervised algorithm to the learning process. Eventually, the superiority of ML towards wireless communication demonstrated great accuracy at 90.24%.
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Banitsas, Konstantinos A., Konstantinos Perakis, Sapal Tachakra, and Dimitrios Koutsouris. "Use of 3G mobile phone links for teleconsultation between a moving ambulance and a hospital base station." Journal of Telemedicine and Telecare 12, no. 1 (January 2006): 23–26. http://dx.doi.org/10.1258/135763306775321335.
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Bagjadab, Amiya Bhusan, and Sushree Bibhuprada B. Priyadarshini. "A Novel Nature Instilled Moving Sink Architecture for Data Gathering in Wireless Sensor Networks." International Journal of Synthetic Emotions 11, no. 1 (January 2020): 36–48. http://dx.doi.org/10.4018/ijse.2020010104.
Повний текст джерелаАнотація:
Wireless sensor networks are commonly used to monitor certain regions and to collect data for several application domains. Generally, in wireless sensor networks, data are routed in a multi-hop fashion towards a static sink. In this scenario, the nodes closer to the sink become heavily involved in packet forwarding, and their battery power is exhausted rapidly. This article proposes that a special node (i.e., mobile sink) will move in the specified region and collect the data from the sensors and transmit it to the base station such that the communication distance of the sensors will be reduced. The aim is to provide a track for the sink such that it covers maximum sensor nodes. Here, the authors compared two tracks theoretically and in the future will try to simulate the two tracks for the sink movement so as to identify the better one.
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Chen, Joy Iong-Zong. "VANET-based Secure Information Exchange for Smart Charging." Journal of Electrical Engineering and Automation 2, no. 3 (January 29, 2021): 141–45. http://dx.doi.org/10.36548/jeea.2020.3.006.
Повний текст джерелаАнотація:
Smart inventions have led to smart grids, which have paved the way to smart charging means. This smart charging information about a vehicle needs to be properly maintained in order to use it to exchange information between charging stations and electric vehicles. In this work, we have introduced an efficient methodology for managing and disseminating energy from the charging station to the smart vehicle in an urban area where the number of electric vehicles is high. We have designed and implemented a novel concept involving mobile edge computing in VANET. Moreover, we have also used an effective mechanism for communicating the information on charging with the moving electric vehicles and servers. A local relay scheme is used for reducing redundant overheads, increase delivery efficiency of charging information. This scheme is implemented with delay wait model as the base. The output is recorded by means of simulation environment and based on the observations the proposed work is found to be optimal in maintaining, accessing and disseminating the charging information.
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Li, Hai Ning, and Dai An Deng. "Research on Influence Factors of Hydraulic Support Moving Velocity in Coal Mining Based on AMESim." Advanced Materials Research 1014 (July 2014): 180–84. http://dx.doi.org/10.4028/www.scientific.net/amr.1014.180.
Повний текст джерелаАнотація:
In view of the high efficiency modernization coal demand, in this paper, the hydraulic support moving velocity influence factors were studied. Building simulation model of the thrust jack of hydraulic support with the simulation software AMESim, and run the simulation. Comparing the simulation results by setting different parameters value. It is concluded that the rated flow of pump station and hydraulic controlled check valve opening quantity will affect the speed of hydraulic support moving frame. This result provides reference for the optimal design of hydraulic support and improving the efficiency of coal mining. Key words: Moving velocity of hydraulic support; Rated flow; Hydraulic controlled check valve; AMESim 1 Tntroduction In the process of coal mining,the movement of hydraulic support needs in a timely manner with coal mining progresses, thrust jack plays a vital role for the movement of the hydraulic support. Therefore, it is very meaningful to research the influence factors of hydraulic support moving velocity With thrust control loop as the breakthrough point . 2 The working principle of the thrust control loop The movement of the hydraulic support and push the slide are achieved by thrust jack. Thrust jack is located in the middle part of the base of the hydraulic support, its end hinged with the base of the hydraulic support, the other end is connected with flexible scraper conveyor. When the hydraulic support moving, uninstall first, then the hydraulic controlled check valve make high pressure liquid into the piston rod cavity of thrust jack, the liquid in piston chamber flow back. At the same time, make thrust jack cylinder to move forward with the support of conveyor, thus, the whole hydraulic support is pulled to the coal wall, to complete the move. when pushing the slide, make high pressure liquid into the piston chamber , the liquid in piston rod cavity flow back, and, make the piston rod out with the support of hydraulic support. so,the conveyor is pushed to the coal wall,it is completed.
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Luo, Zhen Hua, Jing Zhi Ye, and Wen Feng Luo. "An Adaptive Clustering and Inter-Cluster Negotiation Protocol for Multi-Target Tracking Based on WSN." Advanced Materials Research 457-458 (January 2012): 1083–88. http://dx.doi.org/10.4028/www.scientific.net/amr.457-458.1083.
Повний текст джерелаАнотація:
In many wireless sensor networks (WSNs), target tracking is an essential application. This paper studies the real-time target tracking algorithm and the implementation for a multi-target real-time tracking system. The system consists of a wireless sensor network which includes several distributed ultrasonic sensor nodes and a monitoring base station, and two robots as moving targets. To avoid the conflicts in the network, a sensor node task scheduling scheme, and an adaptive clustering and inter-cluster negotiation network protocol (ACICN) are proposed for the system. To cope with distributed and asynchronous measurements, data synchronization and Extended Kalman Filter (EKF) location algorithm are studied for the system. The experiments show that the system can effectively track multi targets simultaneously.
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Cheng, Tianhao, Buhong Wang, Zhen Wang, Kunrui Cao, Runze Dong, and Jiang Weng. "Intelligent Reflecting Surface Assisted Secure Transmission in UAV-MIMO Communication Systems." Entropy 24, no. 11 (November 4, 2022): 1605. http://dx.doi.org/10.3390/e24111605.
Повний текст джерелаАнотація:
This paper studies the intelligent reflecting surface (IRS) assisted secure transmission in unmanned aerial vehicle (UAV) communication systems, where the UAV base station, the legitimate receiver, and the malicious eavesdropper in the system are all equipped with multiple antennas. By deploying an IRS on the facade of a building, the UAV base station can be assisted to realize the secure transmission in this multiple-input multiple-output (MIMO) system. In order to maximize the secrecy rate (SR), the transmit precoding (TPC) matrix, artificial noise (AN) matrix, IRS phase shift matrix, and UAV position are jointly optimized subject to the constraints of transmit power limit, unit modulus of IRS phase shift, and maximum moving distance of UAV. Since the problem is non-convex, an alternating optimization (AO) algorithm is proposed to solve it. Specifically, the TPC matrix and AN covariance matrix are derived by the Lagrange dual method. The alternating direction method of multipliers (ADMM), majorization-minimization (MM), and Riemannian manifold gradient (RCG) algorithms are presented, respectively, to solve the IRS phase shift matrix, and then the performance of the three algorithms is compared. Based on the proportional integral (PI) control theory, a secrecy rate gradient (SRG) algorithm is proposed to iteratively search for the UAV position by following the direction of the secrecy rate gradient. The theoretic analysis and simulation results show that our proposed AO algorithm has a good convergence performance and can increase the SR by 40.5% compared with the method without IRS assistance.
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Szurgacz, Dawid. "Impact of geometry of the powered roof support section on the rock mass." E3S Web of Conferences 71 (2018): 00001. http://dx.doi.org/10.1051/e3sconf/20187100001.
Повний текст джерелаАнотація:
The required functions of the powered roof support, the functions it must fulfil and the mechanical elements cause that the support practically continuously works with the rock mass. This applies to the canopy, the floor base and the shield support. Due to the different susceptibility and strength of the rocks, the roof support may lose its stability. This condition results in an uneven section load and difficulties with moving forward the support in the underground excavation. This, in turn, can lead to disturbances in the operation of the entire longwall system. In order to avoid this situation, it is necessary to conduct geometry tests, e.g. section tests for a dedicated testing station using innovative measuring inclinometers. They indicate the importance of proper geometry for proper and correct operation of the support section. The research was carried out with the use of a new methodology designed to test the geometry of powered roof supports. The solutions were developed by the author of the article.
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Ludwig-Barbosa, Vinícius, Edson Schlosser, Renato Machado, Filipe Guterres Ferreira, Sabrina Müller Tolfo, and Marcos Vinício Thomas Heckler. "Linear Array Design with Switched Beams for Wireless Communications Systems." International Journal of Antennas and Propagation 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/278160.
Повний текст джерелаАнотація:
This paper presents an analysis for optimal design of switched beamforming applied to a linear array for wireless communication systems. The beam switching scheme provides coverage of a given sector in azimuth and controls the sidelobe level simultaneously. The analysis was developed considering arrays composed of Quasi-Yagi elements. The model assumes a user moving in the azimuthal direction under a constant velocity and with an estimation of the signal-to-noise ratio (SNR) at the mobile user (MU). The radio base station applies the beam that yields the best performance during transmission. The decision is based on the feedback information received from the MU. The goal of the analysis is to determine the best trade-off between the array size and number of feedback bits necessary to maximize the SNR at the receiver. The results show that a compromise between the number of beam-pointing directions and the array size should be taken into consideration for a wireless communication system design.
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Feiroz Khan, T. H., and D. Siva Kumar. "An obstacle aware mobile sink path strategy in WSN." Indonesian Journal of Electrical Engineering and Computer Science 15, no. 2 (August 1, 2019): 879. http://dx.doi.org/10.11591/ijeecs.v15.i2.pp879-887.
Повний текст джерелаАнотація:
<span>In Wireless Sensor Networks, Mobile Sink accomplishes considerable achievement on network lifetime improvement. In sensing environment, more chances to present the obstacle. But, in the mobile sink, how to identify the obstacle and make the obstacle aware path strategy is a challenging task. To overcome this problem, we propose an Obstacle Aware Mobile sink Path Strategy (OAMPS) that detects any obstacles which enter within the network lifetime and design a shortest mobile sink movement path avoiding detected obstacles. In this scheme, the mobile sink collects the sensing data from the super node then it sends the data to the base station. Here, static or moving obstacles are present when the mobile sink moves the path scheduling by spanning graph. This algorithm is introduced to discovering the obstacle avoiding shortest path. The source selects the route by the updated cuckoo search algorithm. The simulation results show that the OAMPS improved the throughput and minimized the delay in the network.</span>
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Chen, Yingjue, Yingnan Gu, Panfeng Li, and Feng Lin. "Minimizing the number of wireless charging PAD for unmanned aerial vehicle–based wireless rechargeable sensor networks." International Journal of Distributed Sensor Networks 17, no. 12 (December 2021): 155014772110559. http://dx.doi.org/10.1177/15501477211055958.
Повний текст джерелаАнотація:
In wireless rechargeable sensor networks, most researchers address energy scarcity by introducing one or multiple ground mobile vehicles to recharge energy-hungry sensor nodes. The charging efficiency is limited by the moving speed of ground chargers and rough environments, especially in large-scale or challenging scenarios. To address the limitations, researchers consider replacing ground mobile chargers with lightweight unmanned aerial vehicles to support large-scale scenarios because of the unmanned aerial vehicle moving at a higher speed without geographical limitation. Moreover, multiple automatic landing wireless charging PADs are deployed to recharge unmanned aerial vehicles automatically. In this work, we investigate the problem of introducing the minimal number of PADs in unmanned aerial vehicle–based wireless rechargeable sensor networks. We propose a novel PAD deployment scheme named clustering-with-double-constraints and disks-shift-combining that can adapt to arbitrary locations of the base station, arbitrary geographic distributions of sensor nodes, and arbitrary sizes of network areas. In the proposed scheme, we first obtain an initial PAD deployment solution by clustering nodes in geographic locations. Then, we propose a center shift combining algorithm to optimize this solution by shifting the location of PADs and attempting to merge the adjacent PADs. The simulation results show that compared to existing algorithms, our scheme can charge the network with fewer PADs.
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Huttunen, Jari, Olli Salmela, Topi Volkov, and Eva Pongrácz. "Reducing the Cooling Energy Consumption of Telecom Sites by Liquid Cooling." Proceedings 58, no. 1 (September 11, 2020): 19. http://dx.doi.org/10.3390/wef-06908.
Повний текст джерелаАнотація:
The use of mobile data has increased and will continue to increase in the future, because more data is moving to wireless networks such as 5G. Cooling energy need is also expected to increase in indoor telecom rooms, and can be as high as the equipment’s own power consumption. The world’s first liquid Base Transceiver Station (BTS) was adopted into commercial use in 2018, in Helsinki, Finland. Conventional air-cooled BTS hardware was converted into liquid-cooled BTS equipment. Heat from the BTS was pumped out of the site room, and thus ventilation or air conditioning was not needed for the heat load from the BTS. Heat stored in the liquid was released into the ventilation duct of the building, still providing annual cooling energy savings of 70%, when compared to air cooling. In the future, 80% of the total dissipated energy, 13450 kWh/a in total, can potentially be used for heating purposes. In terms of CO2 emissions, adapting liquid cooling showed an 80% reduction potential when compared to air cooling.
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Cai, Zengyu, Xi Chen, Jianwei Zhang, Liang Zhu, and Xinhua Hu. "Echo State Network-Based Content Prediction for Mobile Edge Caching Networks." International Journal of Information Technology and Web Engineering 18, no. 1 (February 3, 2023): 1–16. http://dx.doi.org/10.4018/ijitwe.317219.
Повний текст джерелаАнотація:
With the rapid development of internet communication and the wide application of intelligent terminal, moving the cache to the edge of the network is an effective solution to shorten the delay of users accessing content. However, the existing cache work lacks the comprehensive consideration of users and content, resulting in low cache hit ratio and low accuracy of the whole system. In this paper, the authors propose a collaborative caching model that considers both user request content and content prediction, so as to improve the caching performance of the whole network. Firstly, the model uses the clustering algorithm based on Akike information criterion to cluster users. Then, combined with the clustering results, echo state network is used as the machine learning framework to predict the content. Finally, the cache contents are selected according to the prediction results and cached in the cache unit of the small base station. Simulation results show that compared with the existing cache algorithms, the proposed method has obvious improvement in cache hit ratio, accuracy, and recall rate.
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Liu, Xuanlin, Sihua Wang, and Changchuan Yin. "Biological Intelligence Inspired Trajectory Design for Energy Harvesting UAV Networks." Sensors 23, no. 2 (January 11, 2023): 863. http://dx.doi.org/10.3390/s23020863.
Повний текст джерелаАнотація:
In this paper, the problem of trajectory design for energy harvesting unmanned aerial vehicles (UAVs) is studied. In the considered model, the UAV acts as a moving base station to serve the ground users, while collecting energy from the charging stations located at the center of a user group. For this purpose, the UAV must be examined and repaired regularly. In consequence, it is necessary to optimize the trajectory design of the UAV while jointly considering the maintenance costs, the reward of serving users, the energy management, and the user service time. To capture the relationship among these factors, we first model the completion of service and the harvested energy as the reward, and the energy consumption during the deployment as the cost. Then, the deployment profitability is defined as the ratio of the reward to the cost of the UAV trajectory. Based on this definition, the trajectory design problem is formulated as an optimization problem whose goal is to maximize the deployment profitability of the UAV. To solve this problem, a foraging-based algorithm is proposed to find the optimal trajectory so as to maximize the deployment profitability and minimize the average user service time. The proposed algorithm can find the optimal trajectory for the UAV with low time complexity at the level of polynomial. Fundamental analysis shows that the proposed algorithm achieves the maximal deployment profitability. Simulation results show that, compared to Q-learning algorithm, the proposed algorithm effectively reduces the operation time and the average user service time while achieving the maximal deployment profitability.
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Podolskaia, Ekaterina. "Automated construction of ground access routes for the management of regional forest fires." Journal of Forest Science 66, No. 8 (August 21, 2020): 329–88. http://dx.doi.org/10.17221/59/2020-jfs.
Повний текст джерелаАнотація:
Modern geospatial technologies and permanently updated wildfire monitoring datasets are the basis of improving forest firefighting on different administrative scales. One of the tasks is to use the spatial representation of forest fire locations during the fire season and offer timely suitable technical options for accessing them. We developed a GIS technology to create forest fire ground access routes for special firefighting vehicles moving from a ground firefighting base (fire-chemical station) to the place of the forest fire detection; the technology includes a statistical and geospatial accessibility analysis of the routes. The key data are a transport model consisting of public roads and forest glades on the regional scale. We described the main principles of the transport model construction and usage, and their implementation for the Russian Federal Districts. An access routes database for the 2002–2019 fire seasons, a central part of the Siberian Federal District, was produced and analysed. By using a hot spot analysis, we confirmed that forest fires are poorly accessible away from the centre of the Siberian District. The created road accessibility maps show “a proposed ground access zone” within the key area to fight forest fires for the fire seasons to come.
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Lee, Sol, Jeehyeong Kim, Joohan Park, and Sunghyun Cho. "Grant-Free Resource Allocation for NOMA V2X Uplink Systems Using a Genetic Algorithm Approach." Electronics 9, no. 7 (July 8, 2020): 1111. http://dx.doi.org/10.3390/electronics9071111.
Повний текст джерелаАнотація:
While NOMA-V2V (non-orthogonal multiple accesscan-vehicle-to-vehicle) effectively achieve massive connectivity requirements in 5G network systems, minimizing communication latency is a very crucial challenge. To address the latency problem, we propose a channel allocation method called hyper-fraction, which divides the road into many zones and allocates a channel to each zone. Then, a vehicle located within the corresponding zone uses the channel allocated to the zone. Hyper-fraction will allow the system to minimize communication latency between a user equipment (UE) and a base station (BS) caused by scheduling processes and consequentially reduce the overall latency of the system. In the simulation, a novel concept of genetic algorithm (GA) is utilized, called GA with continuous pool. It is an approach to enable conventional GA to solve optimization problems for continuous situations within much less computation, especially in situations where the elements in the system keep moving such as vehicular networks. As a result, GA with continuous pool is proven to be an effective heuristic method to improve throughput rate, as well as hyper-fraction improving the latency of NOMA V2V and vehicle-to-infrastructure (V2I) systems.
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Beran, Tomas, Lee Danisch, Adam Chrzanowski, and Maciej Bazanowski. "Measurement of Deformations by MEMS Arrays, Verified at Sub-millimetre Level Using Robotic Total Stations." Geoinformatics FCE CTU 12 (June 3, 2014): 34–40. http://dx.doi.org/10.14311/gi.12.6.
Повний текст джерелаАнотація:
Measurement of sub-millimetre-level deformations of structures in the presence of ambient temperature changes can be challenging. This paper describes the measurement of a structure moving due to temperature changes, using two ShapeAccelArray (SAA) instruments, and verified by a geodetic monitoring system. SAA is a geotechnical instrument often used for monitoring of displacements in soil. SAA uses micro-electromechanical system (MEMS) sensors to measure tilt in the gravity field. The geodetic monitoring system, which uses ALERT software, senses the displacements of targets relative to control points, using a robotic total station (RTS). The test setup consists of a central four-metre free-standing steel tube with other steel tubes welded to most of its length. The central tube is anchored in a concrete foundation. This composite “pole” is equipped with two SAAs as well as three geodetic prisms mounted on the top, in the middle, and in the foundation. The geodetic system uses multiple control targets mounted in concrete foundations of nearby buildings, and at the base of the pole. Long-term observations using two SAAs indicate that the pole is subject to deformations due to cyclical ambient temperature variations causing the pole to move by a few millimetres each day. In a multiple-day experiment, it was possible to track this movement using SAA as well as the RTS system. This paper presents data comparing the measurements of the two instruments and provides a good example of the detection of two-dimensional movements of seemingly rigid objects due to temperature changes.
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Guru, Siddeswara Mayura, Arthur Hsu, Saman Halgamuge, and Saman Fernando. "An Extended Growing Self-Organizing Map for Selection of Clusters in Sensor Networks." International Journal of Distributed Sensor Networks 1, no. 2 (March 2005): 227–43. http://dx.doi.org/10.1080/15501320590966477.
Повний текст джерелаАнотація:
Sensor networks consist of wireless enabled sensor nodes with limited energy. As sensors could be deployed in a large area, data transmitting and receiving are energy consuming operations. One of the methods to save energy is to reduce the communication distance of each node by grouping them in to clusters. Each cluster will have a cluster-head (CH), which will communicate with all the other nodes of that cluster and transmit the data to the remote base station. In this paper, we propose an extension to Growing Self-Organizing Map (GSOM) and describe the use of evolutionary computing technique to cluster wireless sensor nodes and to identify the cluster-heads. We compare the proposed method with clustering solutions based on Genetic Algorithm (GA), an extended version of Particle Swarm Optimisation (PSO) and four general purpose clustering algorithms. This could help to discover the clusters to reduce the communication energy used to transmit data when exact locations of all sensors are known and computational resources are centrally available. This method is useful in the applications where sensors are deployed in a controlled environment and are not moving. We have derived an energy minimisation model that is used as a criterion for clustering. The proposed method can also be used as a design tool to study and analyze the cluster formation for a given node placement.
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Popov, A. Y. U. "Simulation modeling of the volumetric hydraulic drive." Traktory i sel hozmashiny 85, no. 3 (June 15, 2018): 45–53. http://dx.doi.org/10.17816/0321-4443-66397.
Повний текст джерелаАнотація:
In the design of a variety of the modern agricultural machines, the hydraulic drive with reciprocating motion for lifting, lowering and moving the working bodies has obtained a wide application. One of the important stages in the design of hydraulic drives and transmissions is a simulation. In connection with the laboriousness of carrying out the full-scale experiment and the cumbersome calculation of mathematical models of hydrosystems, as well as the development of the computing machinery, the simulation modeling has obtained a widespread usage. This type of computer simulation allows to investigate complex systems based on the development of multilink factor models with the visualization of a numerical experiment. The article presents the procedure for the simulation modeling of dynamic processes occurring in the volumetric hydraulic drive. The model is developed on the basis of standard libraries of the computing system MATLAB Simulink. The volumetric hydraulic drive is presented in the form of a structural model and consists of interconnected blocks that on the base of differential equations modeling the operation of a pumping station with a mechanical drive, a safety valve, a three-section four-line hydraulic distributor, double-acting power cylinder with special rod, a hydraulic tank. During the calculation of the simulation model takes into account a change of the modulus of elasticity of the fluid depending on the pressure in the hydraulic system, the parameters of the working fluid, the stiff stop when the extreme positions are reached by the rod of the hydraulic cylinder, the friction between the moving parts in the power hydrocylinder. The developed program allows to simulate working processes at the design stage and obtain the necessary data on the dynamic properties of the hydraulic system in all modes of operation, to demonstrate in the form of graphs and oscillograms, to simplify the analysis of transient processes in the hydraulic system, and also to select the rational design parameters of constituent elements of the volumetric hydraulic drive.
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Ma, Ming, Yuanyuan Yang, and Miao Zhao. "Tour Planning for Mobile Data-Gathering Mechanisms in Wireless Sensor Networks." Vehicular Technology, IEEE Transactions on 62, no. 4 (May 2013): 1472–83. http://dx.doi.org/10.1109/tvt.2012.2229309.
Повний текст джерелаАнотація:
In this paper, we propose a new data-gathering mechanism for large-scale wireless sensor networks by introducing mobility into the network. A mobile data collector, for convenience called an M-collector in this paper, could be a mobile robot or a vehicle equipped with a powerful transceiver and battery, working like a mobile base station and gathering data while moving through the field. An M-collector starts the data-gathering tour periodically from the static data sink, polls each sensor while traversing its transmission range, then directly collects data from the sensor in single-hop communications, and finally transports the data to the static sink. Since data packets are directly gathered without relays and collisions, the lifetime of sensors is expected to be prolonged. In this paper, we mainly focus on the problem of minimizing the length of each data-gathering tour and refer to this as the single-hop data-gathering problem (SHDGP). We first formalize the SHDGP into a mixed-integer program and then present a heuristic tour-planning algorithm for the case where a single M-collector is employed. For the applications with strict distance/time constraints, we consider utilizing multiple M-collectors and propose a data-gathering algorithm where multiple M-collectors traverse through several shorter subtours concurrently to satisfy the distance/time constraints. Our single-hop mobile data-gathering scheme can improve the scalability and balance the energy consumption among sensors. It can be used in both connected and disconnected networks. Simulation results demonstrate that the proposed data-gathering algorithm can greatly shorten the moving distance of the collectors compared with the covering line approximation algorithm and is close to the optimal algorithm for small networks. In addition, the proposed data-gathering scheme can significantly prolong the network lifetime compared with a network with static data sink or a network in which the mobile collector c- n only move along straight lines.
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Eska, Andrita Ceriana. "Cellular Communication Propagation at Drone around Building Environment with Single Knife Edge at 10 GHz." JURNAL INFOTEL 13, no. 1 (February 28, 2021): 25–30. http://dx.doi.org/10.20895/infotel.v13i1.541.
Повний текст джерелаАнотація:
The drone communication systems used a cellular network for controlling a drone from a long distance. That communication propagations between drone and base station were analyzed. The drone moved at the track around building environment. That environment used variations in building height. The communication propagation around building environment caused diffraction mechanism. Single knife edge method is used for that diffraction mechanism. The frequency of communication used 10 GHz. That frequency was influenced by atmospheric attenuation. This research was using some variations such as height of drone track location, transmitter power, and AMC (Adaptive Modulation Coding). MCS (Modulation Coding Scheme) was used AMC such as QPSK, 16 QAM, and 64 QAM. Some result was obtained at this research consist of LOS and NLOS distance, SNR, MCS probability, and percentage of drone coverage. NLOS propagation was caused by building height. The SNR value become increase when higher at drone position, such as drone was moving at 20 meters with height of flying drone 80 m and transmitter power 30 dBm obtained SNR 38.21 dBm. That SNR is affected AMC, so a higher SNR value increases AMC. The drone’s coverage 100%, with a height of flying drone 80 meters and transmitter power of 30 dBm. That condition showed more increasing coverage percentage than 64.8% for height of flying drone 20 meters and transmitter power 30 dBm. That result showed that more drone height increased of coverage percentage, probability modulation, and SNR value.
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Wei, Hua, Hong Luo, and Yan Sun. "Mobility-Aware Service Caching in Mobile Edge Computing for Internet of Things." Sensors 20, no. 3 (January 22, 2020): 610. http://dx.doi.org/10.3390/s20030610.
Повний текст джерелаАнотація:
The mobile edge computing architecture successfully solves the problem of high latency in cloud computing. However, current research focuses on computation offloading and lacks research on service caching issues. To solve the service caching problem, especially for scenarios with high mobility in the Sensor Networks environment, we study the mobility-aware service caching mechanism. Our goal is to maximize the number of users who are served by the local edge-cloud, and we need to make predictions about the user’s target location to avoid invalid service requests. First, we propose an idealized geometric model to predict the target area of a user’s movement. Since it is difficult to obtain all the data needed by the model in practical applications, we use frequent patterns to mine local moving track information. Then, by using the results of the trajectory data mining and the proposed geometric model, we make predictions about the user’s target location. Based on the prediction result and existing service cache, the service request is forwarded to the appropriate base station through the service allocation algorithm. Finally, to be able to train and predict the most popular services online, we propose a service cache selection algorithm based on back-propagation (BP) neural network. The simulation experiments show that our service cache algorithm reduces the service response time by about 13.21% on average compared to other algorithms, and increases the local service proportion by about 15.19% on average compared to the algorithm without mobility prediction.
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Ogden, C. S., I. D. Bastow, A. Gilligan та S. Rondenay. "A reappraisal of the H–κ stacking technique: implications for global crustal structure". Geophysical Journal International 219, № 3 (5 серпня 2019): 1491–513. http://dx.doi.org/10.1093/gji/ggz364.
Повний текст джерелаАнотація:
SUMMARY H–κ stacking is used routinely to infer crustal thickness and bulk-crustal VP/VS ratio from teleseismic receiver functions. The method assumes that the largest amplitude P-to-S conversions beneath the seismograph station are generated at the Moho. This is reasonable where the crust is simple and the Moho marks a relatively abrupt transition from crust to mantle, but not if the crust–mantle transition is gradational and/or complex intracrustal structure exists. We demonstrate via synthetic seismogram analysis that H–κ results can be strongly dependent on the choice of stacking parameters (the relative weights assigned to the Moho P-to-S conversion and its subsequent reverberations, the choice of linear or phase-weighted stacking, input crustal P-wave velocity) and associated data parameters (receiver function frequency content and the sample of receiver functions analysed). To address this parameter sensitivity issue, we develop an H–κ approach in which cluster analysis selects a final solution from 1000 individual H–κ results, each calculated using randomly selected receiver functions, and H–κ input parameters. 10 quality control criteria that variously assess the final numerical result, the receiver function data set, and the extent to which the results are tightly clustered, are used to assess the reliability of H–κ stacking at a station. Analysis of synthetic data sets indicates H–κ works reliably when the Moho is sharp and intracrustal structure is lacking but is less successful when the Moho is gradational. Limiting the frequency content of receiver functions can improve the H–κ solutions in such settings, provided intracrustal structure is simple. In cratonic Canada, India and Australia, H–κ solutions generally cluster tightly, indicative of simple crust and a sharp Moho. In contrast, on the Ethiopian plateau, where Palaeogene flood-basalts overlie marine sediments, H–κ results are unstable and erroneous. For stations that lie on thinner flood-basalt outcrops, and/or in regions where Blue Nile river incision has eroded through to the sediments below, limiting the receiver function frequency content to longer periods improves the H–κ solution and reveals a 6–10 km gradational Moho, readily interpreted as a lower crustal intrusion layer at the base of a mafic (VP/VS = 1.77–1.87) crust. Moving off the flood-basalt province, H–κ results are reliable and the crust is thinner and more felsic (VP/VS = 1.70–1.77), indicating the lower crustal intrusion layer is confined to the region covered by flood-basaltic volcanism. Analysis of data from other tectonically complex settings (e.g. Japan, Cyprus) shows H–κ stacking results should be treated cautiously. Only in regions of relatively simple crust can H–κ stacking analysis be considered truly reliable.
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Chang, Haowei, Chunlei Pang, Liang Zhang, and Zehui Guo. "Rotating Single-Antenna Spoofing Signal Detection Method Based on IPNN." Sensors 22, no. 19 (September 21, 2022): 7141. http://dx.doi.org/10.3390/s22197141.
Повний текст джерелаАнотація:
The traditional carrier-phase differential detection technology mainly relies on the spatial processing method, which uses antenna arrays or moving antennas to detect spoofing signals, but it cannot be applied to static single-antenna receivers. Aiming at this problem, this paper proposes a rotating single-antenna spoofing signal detection method based on the improved probabilistic neural network (IPNN). When the receiver antenna rotates at a constant speed, the carrier-phase double difference of the real signal will change with the incident angle of the satellite. According to this feature, the classification and detection of spoofing signals can be realized. Firstly, the rotating single-antenna receiver collects carrier-phase values and performs double-difference processing. Then, we construct an IPNN model, whose smoothing factor can be adaptively adjusted according to the type of failure mode. Finally, we use the IPNN model to realize the classification and processing of the carrier-phase double-difference observations and obtain the deception detection results. In addition, in order to reflect that the method has a certain practical value, we simulate the spoofing scenario of satellite signals and effectively identify abnormal satellite signals according to the detection results of the inter-satellite differential combination. Actual experiments indicate that the detection accuracy of the proposed method for spoofing signals reaches 98.84%, which is significantly better than the classical probabilistic neural network (PNN) and back-propagation neural network (BPNN), and the method can be implemented in fixed base station receivers for the real-time detection of forwarding spoofing.
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Ryan, Kathy L. "Walter B. Cannon’s World War I experience: treatment of traumatic shock then and now." Advances in Physiology Education 42, no. 2 (June 1, 2018): 267–76. http://dx.doi.org/10.1152/advan.00187.2017.
Повний текст джерелаАнотація:
Walter B. Cannon (1871–1945), perhaps America’s preeminent physiologist, volunteered for service with the Army Expeditionary Force (AEF) during World War I. He initially served with Base Hospital No. 5, a unit made up of Harvard clinicians, before moving forward to the front lines to serve at a casualty clearing station run by the British. During his time there, he performed research on wounded soldiers to understand the nature and causes of traumatic shock. Subsequently, Cannon performed animal experimentation on the causes of traumatic shock in the London laboratory of Dr. William Bayliss before being assigned to the AEF Central Medical Laboratory in Dijon, France, where he continued his experimental studies. During this time, he also developed and taught a curriculum on resuscitation of wounded soldiers to medical providers. Although primarily a researcher and teacher, Cannon also performed clinical duties throughout the war, serving with distinction under fire. After the war, Cannon wrote a monograph entitled Traumatic Shock (New York: Appleton, 1923), which encapsulated the knowledge that had been gained during the war, both from direct observation of wounded soldiers, as well as laboratory experimentation on the causes and treatment of traumatic shock. In his monograph, Cannon elucidates a number of principles concerning hemorrhagic shock that were later forgotten, only to be “rediscovered” during the current conflicts in Iraq and Afghanistan. This paper summarizes Cannon’s wartime experiences and the knowledge gained concerning traumatic shock during World War I, with a comparison of current combat casualty care practices and knowledge to that which Cannon and his colleagues understood a century ago.
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Аnisimov, O., and O. Ivanyk. "Methods of creating a conveyor lift route in a deep pit." Collection of Research Papers of the National Mining University 71 (December 2022): 29–41. http://dx.doi.org/10.33271/crpnmu/71.029.
Повний текст джерелаАнотація:
Purpose. Improving the technology of stripping and schemes for creating a steep trench in a deep pit makes it possible to create new cargo flows and develop mining operations. The purpose of the research work is to determine a more attractive scheme for the formation of the conveyor route. The paper compares two technological schemes: the creation of a steep half-trench to the lower horizons with the hilling of rocks and the formation of a working in the rocks in the form of a trench. The above purpose of the work is to substantiate an effective scheme for creating a steep trench for the subsequent placement of a conveyor stack on its base. This will allow moving the rock mass from the lower horizons to the upper ones at a lower cost. The considered schemes for creating the steep trench allowed it possible to determine the volume of preparatory work, the most attractive scheme for creating an inclined working during opening lower horizons in the conditions of the operating open pit of Poltava GOK, which makes it possible to reduce the use of dump trucks inside the open pit. The methods. The method of vertical sections was used for the calculation of the volumes of run-off-mine during the formation of the trench. A geographic information system (GIS), and a software package K-MINE was used for research. The method of comparing the scope of work and creating a conveyor route by options allowed to determine the most appropriate way of doing work. Findings. The parameters of a steep trench and half-trench were studied, including the established scope of work within the steep layers of the western side of the PGOK open pit. Opening with steep trenches allows for the placement of an existing elevator with the placement of a crushing and transfer station containing a mobile crusher from KRUPP. Implementing the scheme with a steep trench in the rocks, the scope of work is 79.555 thousand m3. For the construction of a half-trench, the amount of work is 733,887 thousand m3. Building capital trenches and semi-tranches in the conditions of the open pit of the Poltava Mining and Processing Plant, preference is given to semi-trenches, which are created from rocks (without drilling and blasting). The originality. The options and parameters for creating steep trenches for further placement of a conveyor stack on its base are considered. The scheme for moving the rock mass from the lower horizons to the upper ones has been improved, graphical dependencies of the scope of work have been established, and a comparison of technical indicators has been made for creating a steep trench and a half-trench. Practical implimintation. The considered schemes for creating a steep trench allowed to determine the volume of preparatory work, to establish the most attractive scheme for the creation of an inclined work in opening the lower horizons in the conditions of the active open pit of the Poltava GOK, what makes it possible to reduce the use of dump trucks inside the open pit and improve the schemes for moving rock mass.
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Tang Min’an, 汤旻安, та 王晨雨 Wang Chenyu. "基于改进ViBe算法的静态场景运动目标检测". Laser & Optoelectronics Progress 58, № 14 (2021): 1410011. http://dx.doi.org/10.3788/lop202158.1410011.
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Cipriano, Marco, Luca Colomba, and Paolo Garza. "A Data-Driven Based Dynamic Rebalancing Methodology for Bike Sharing Systems." Applied Sciences 11, no. 15 (July 28, 2021): 6967. http://dx.doi.org/10.3390/app11156967.
Повний текст джерелаАнотація:
Mobility in cities is a fundamental asset and opens several problems in decision making and the creation of new services for citizens. In the last years, transportation sharing systems have been continuously growing. Among these, bike sharing systems became commonly adopted. There exist two different categories of bike sharing systems: station-based systems and free-floating services. In this paper, we concentrate our analyses on station-based systems. Such systems require periodic rebalancing operations to guarantee good quality of service and system usability by moving bicycles from full stations to empty stations. In particular, in this paper, we propose a dynamic bicycle rebalancing methodology based on frequent pattern mining and its implementation. The extracted patterns represent frequent unbalanced situations among nearby stations. They are used to predict upcoming critical statuses and plan the most effective rebalancing operations using an entirely data-driven approach. Experiments performed on real data of the Barcelona bike sharing system show the effectiveness of the proposed approach.
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Sarkar, R., and SS Mohapatra. "Accident of a civil passenger aircraft at a military airfield: The Casevac experience." Indian Journal of Aerospace Medicine 63 (October 3, 2020): 96–101. http://dx.doi.org/10.25259/ijasm_7_2019.
Повний текст джерелаАнотація:
Introduction: There are many civil airports in India wherein the airfield and flying operations are controlled by the military whereas, the Airports Authority of India (AAI) controls the civil terminal. Accident of a civil aircraft on such a base poses unique challenges. This paper discusses the medical contingency plan of a Naval Air Station to deal with civil aircraft crashes based on a civil aircraft incident. Case Details: In the early morning of late Dec in 2016, a Mumbai bound civil flight (Boeing 737) took off from an Indian Navy controlled airfield. While initiating the take-off roll from RW, it veered off the runway towards right and came to halt along the perimeter road 230 m north of the runway edge, on hard rocky ground. There were 154 passengers and 7 crew members who were evacuated from the aircraft, through emergency chutes. Few passengers escaped through the over wing hatches. Twenty passengers sustained injuries, mostly involving the lower limbs. This was primarily due to jumping on hard rocky ground and falling and tripping on rocks while moving away from the aircraft. An analysis was done to understand the limitations on the existing medical contingency plan. Discussion: The ICAO Airport Services Manual Part 7 on Airport Emergency Planning (Doc 9137-AN/898 Part 7) is the guiding reference for all airports on Airport Disaster and Planning. The Medical Services portion delineates clearly the role of the Medical Aid Providers. In the instant case, the medical department had successfully handled the casualty evacuation and their medical management. SOP and the existing medical contingencies were effectively used. A post-accident analysis in the instant case revealed that 17 out of 25 checklist points were satisfied. The lessons learned from the incident have been discussed in the paper.
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Navulur, Sridevi, A. S. C. S. Sastry, and M. N. Giri Prasad. "Agricultural Management through Wireless Sensors and Internet of Things." International Journal of Electrical and Computer Engineering (IJECE) 7, no. 6 (December 1, 2017): 3492. http://dx.doi.org/10.11591/ijece.v7i6.pp3492-3499.
Повний текст джерелаАнотація:
Agriculture plays a significant role in most countries and there is an enoromous need for this industry to become “Smart”. The Industry is now moving towards agricultural modernization by using modern smart technologies to find solutions for effective utilization of scarce resources there by meeting the ever increasing consumtion needs of global population. With the advent of Internet of Things and Digital transformation of rural areas, these technologies can be leveraged to remotely monitor soil moisture, crop growth and take preventive measures to detect crop damages and threats. Utilize artificial intelligence based analytics to quickly analyze operational data combined with 3rd party information, such as weather services, expert advises etc., to provide new insights and improved decision making there by enabling farmers to perform “Smart Agriculture”. Remote management of agricultural activities and their automation using new technologies is the area of focus for this research activity. A solar powered remote management and automation system for agricultural activities through wireless sensors and Internet of Things comprising, a hardware platform based on Raspberry Pi Micro controller configured to connect with a user device and accessed through the internet network. The data collection unit comprises a set of wireless sensors for sensing agricultural activities and collecting data related to agricultural parameters; the base station unit comprising: a data logger; a server; and a software application for processing, collecting, and sending the data to the user device. The user device ex: mobile, tablet etc. can be connected to an internet network, whereby an application platform (mobile-app) installed in the user device facilitates in displaying a list of wireless sensor collected data using Internet of Things and a set of power buttons. This paper is a study and proposal paper which discusses the factors and studies that lead towards this patent pending invention, AGRIPI.
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Du, Fangfang. "International Trade Balance Algorithm Based on the Ownership Principle of Mobile Edge Computing." Mathematical Problems in Engineering 2021 (March 19, 2021): 1–11. http://dx.doi.org/10.1155/2021/5569833.
Повний текст джерелаАнотація:
As an emerging mobile computing technology, mobile edge computing is an important key technology to improve the computing services of mobile devices. This paper mainly studies the balance of international trade algorithm based on the principle of moving edge computing ownership. In order to obtain all the data needed to perform the task, each mobile device can exchange data information with its connected base station through the wireless network. On the basis of satisfying the quality of service of users, including considering the user connection and service configuration, the network energy consumption is minimized in continuous t period by shutting down some servers whose resources are not fully utilized. At the same time, in order to reduce the switching cost of edge server and ensure the stability of service, frequent switching of edge server should be avoided. At the beginning, there is division of labor economy. With the development of specialized production, the degree of international division of labor is increasing due to the effect of experience accumulation. The trade efficiency is growing endogenously. The international division of labor is further deepened, and the types and quantity of products participating in the international division of labor are greatly increased, so as to realize the upgrading of trade structure. Before constructing the structural VAR model of Bti, R/W, K/L, and TFP, we need to test its stationarity. Using Eviews 5.0 software, ADF test and PP test were carried out on the unit root of BTI, r/ w , K/L, and TFP time series data. With the increase of user task arrival rate, the average time revenue increases continuously. However, when the arrival rate is greater than 3 kbit/slot, the average time revenue increases slowly. The results show that the research results in system model and resource optimization algorithm will provide reliable theoretical and technical support for the practical application of mobile edge computing.
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Guptha M, Nageswara, Y. K. Guruprasad, Yuvaraja Teekaraman, Ramya Kuppusamy, and Amruth Ramesh Thelkar. "Generative Adversarial Networks for Unmanned Aerial Vehicle Object Detection with Fusion Technology." Journal of Advanced Transportation 2022 (April 4, 2022): 1–13. http://dx.doi.org/10.1155/2022/7111248.
Повний текст джерелаАнотація:
Unmanned aerial vehicles (UAVs) also called as a drone comprises of a controller from the base station along with a communications system with the UAV. The UAV plane can be precisely controlled by a machine operator, similar to remotely directed aircraft, or with increasing grades of autonomy, as like autopilot assistance, up to completely self-directed aircraft that require no human input. Obstacle detection and avoidance is important for UAVs, particularly lightweight micro aerial vehicles, but it is a difficult problem to solve because pay load restrictions limit the number of sensors that can be mounted onto the vehicle. Lidar uses Laser for finding the distance between objects and vehicle. The speed and direction of the moving objects are detected and tracked with the help of radar. When many sensors are deployed, both thermal and electro-optro cameras have great clustering capabilities as well as accurate localization and ranging. The purpose of the proposed architecture is to create a fusion system that is cost-effective, lightweight, modular, and robust as well. Also, for tiny object detection, we recommend a novel Perceptual Generative Adversarial Network method that bridges the representation gap between small and large objects. It employs the Generative Adversarial Networks (GAN) algorithm, which iimproves object detection accuracy above benchmark models at the same time maintaining real-time efficiency in an embedded computer for UAVs. Its generator, in particular, learns to turn unsatisfactory tiny object representations into super-resolved items that are similar to large objects to deceive a rival discriminator. At the same time, its discriminator contests with the generator to classify the engendered representation, imposing a perceptual restriction on the generator: created representations of tiny objects must be helpful for detection. With three different obstacles, we were able to successfully identify and determine the magnitude of the barriers in the first trial. The accuracy of proposed models is 83.65% and recall is 81% which is higher than the existing models.
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Chen, L., Q. Gao, Y. Deng, and J. Liu. "Moving-mass-based station keeping of stratospheric airships." Aeronautical Journal 125, no. 1289 (June 15, 2021): 1231–44. http://dx.doi.org/10.1017/aer.2021.9.
Повний текст джерелаАнотація:
ABSTRACTStratospheric airships are lighter-than-air vehicles that work at an altitude of 20km in the lower calm portion of the stratosphere. They can be used as real-time surveillance platforms for environment monitoring and civil communication. Solar energy is the ideal power choice for long-endurance stratospheric airships. Attitude control is important for airships so that they can point at a target for observation or adjust the attitude to improve the output performance of solar panels. Stratospheric airships have a large volume and semi-flexible structure. The typical actuators used are aerodynamic surfaces, vectored thrust and ballonets. However, not all these actuators can work well under special working conditions, such as low density and low speed. In this study, moving-mass control is introduced to stratospheric airships because its control efficiency is independent of airspeed and atmospheric density. A nonlinear feedback controller based on generalised inverse with a nonlinear mapping module is designed to implement moving-mass control. Such a new station keeping scheme with moving masses is proposed for airships with different working situations.
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Ye, Ziyuan. "Air Pollutants Prediction in Shenzhen Based on ARIMA and Prophet Method." E3S Web of Conferences 136 (2019): 05001. http://dx.doi.org/10.1051/e3sconf/201913605001.
Повний текст джерелаАнотація:
In order to improve the accuracy of predicting the air pollutants in Shenzhen, a hybrid model based on ARIMA (Autoregressive Integrated Moving Average model) and prophet for mixing time and space relationships was proposed. First, ARIMA and Prophet method were applied to train the data from 11 air quality monitoring stations and gave them different weights. Then, finished the calculation about weight of impact in each air quality monitoring station to final results. Finally, built up the hybrid model and did the error evaluation. The result of the experiments illustrated that this hybrid method can improve the air pollutants prediction in Shenzhen.