scholarly journals Multi-channel DMA Based Design of Voltage Monitoring Using Synchronous Frequency Trace-Sampling Technique

2020 ◽  
Vol 4 (2) ◽  
pp. 17
Author(s):  
Yuan Lei ◽  
Li Lei ◽  
Lei Xia ◽  
Mingxiang Liu ◽  
Yueming Cai ◽  
...  

In order to eliminate the influence of frequency change on real-time voltage acquisition, a low-cost solution of voltage monitoring was proposed using the multi-channel DMA synchronous frequency trace-sampling technique. In-chip resources of the designed voltage monitor were fully utilized in hardware design to reduce external devices. The MQX RTOS was used to perform the functional tasks flexibly and efficiently; especially the Ethernet communication applications and USB device connection were realized using its TCP/IP protocol stack and USB driver. In addition, to ensure the safety of electrical records, data statistics and alarm information management were also implemented through the management of the storage in FLASH. The test results show that the voltage monitor designed in this paper has the advantages of accurate measurement, strong resistance to frequency interference and low cost, and can be widely applied in the field of voltage monitoring in distribution networks.

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4999
Author(s):  
Xuejun Zheng ◽  
Shaorong Wang ◽  
Xin Su ◽  
Mengmeng Xiao ◽  
Zia Ullah ◽  
...  

The investigation of real-time dynamic behavior evaluation in the active distribution networks (ADNs) is a challenging task, and it has great importance due to the emerging trend of distributed generations, electric vehicles, and flexible loads integration. The advent of new elements influences the dynamic behavior of the electric distribution networks and increases the assessment complexity. However, the proper implementation of low-cost phasor measurement units (PMUs) together with the development of power system applications offer tremendous benefits. Therefore, this paper proposes a PMU-based multi-dimensional dynamic index approach for real-time dynamic behavior evaluation of ADNs. The proposed evaluation model follows the assessment principles of accuracy, integrity, practicability, and adaptability. Additionally, we introduced low-cost PMUs in the assessment model and implemented them for real-time and high-precision monitoring of dynamic behaviors in the entire distribution network. Finally, a complete model called the real-time dynamic characteristics evaluation system is presented and applied to the ADN. It is pertinent to mention that our proposed evaluation methodology does not rely on the network topology or line parameters of the distribution network since only the phasor measurements of node voltage and line current are involved in the dynamic index system. Thus, the presented methodology is well adaptive to different operation states of ADN despite frequent topology changes. The validation of the proposed approach was verified by conducting simulations on the modified IEEE 123-node distribution network. The obtained results verify the effectiveness and relevance of the proposed model for the real-time dynamic behavior evaluation of ADNs.


2014 ◽  
Vol 686 ◽  
pp. 402-406
Author(s):  
Hong Zhang

The paper design hardware platform based on network node, and analyze ZigBee protocol architecture and standards of each layer; on based of ZigBee protocol stack, we design the application program of network coordinator and terminal node to realize the data acquisition; design of network system has the characteristics of low cost, small volume, test results show that the mesh topology, network support, can be rapidly deployed, temperature, humidity, light intensity information of the smooth reading environment, that can be used for domestic environmental monitoring field.


Author(s):  
Andrew Pekosz ◽  
Charles K. Cooper ◽  
Valentin Parvu ◽  
Maggie Li ◽  
Jeffrey C. Andrews ◽  
...  

SUMMARYIndividuals can test positive for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR) after no longer being infectious.1-8 Positive SARS-CoV-2 antigen-based testing exhibits a temporal pattern that corresponds with active, replicating virus and could therefore be a more accurate predictor of an individual’s potential to transmit SARS-CoV-2.2,3,9 Using the BD Veritor System for Rapid Detection of SARS-CoV-2 later flow antigen detection test, we demonstrate a higher concordance of antigen-positive test results with the presence of cultured, infectious virus when compared to RT-PCR. When compared to infectious virus isolation, the sensitivity of antigen-based testing is similar to RT-PCR. The correlation between SARS-CoV-2 antigen and SARS-CoV-2 culture represents a significant advancement in determining the risk for potential transmissibility beyond that which can be achieved by detection of SARS-CoV-2 genomic RNA. Coupled with a rapid time-to-result, low cost, and scalability, antigen-based testing should facilitate effective implementation of testing and public health interventions that will better contain COVID-19.


Author(s):  
Long Di ◽  
Haiyang Chao ◽  
Jinlu Han ◽  
YangQuan Chen

Cooperative UAV systems can have great advantages over isolated UAV systems, regarding application, safety, efficiency and many other perspectives. Motivated by challenges from practical multiple UAV formation flight, this paper presents our approaches towards cognitive formation flight. It introduces the principle ofmulti-UAV cognitive formation flight and the control structure utilized in our development, describes a low-cost UAV testbed developed by ourselves, and details the tuning procedures of the implemented multi-agent flight controller for stable and consistent formation flights. Different formation flight scenarios are also discussed and the experimental setup is presented including real-time issues and the formation flight test protocol. Routinized comprehensive flight test results are also shown at the end.


2013 ◽  
Vol 373-375 ◽  
pp. 752-757
Author(s):  
Zhong Hu Yuan ◽  
Xiu Zhen Yu ◽  
Wen Wu Hua

This paper has designed a wireless sensor network (WSN) system which is suitable for the subway security environment. The system uses ZigBee wireless communication technology to form a network, uses the chip CC2530 as the core processor to design the hardware circuit for the network node, and the design of the embedded software is based on Z-Stack protocol stack. Through analyzing the factors having affection on the security environment, the system collects a variety of environmental information with some sensors, and completes the design of the sensor modules. The test results show that this system has the characteristics of low-power, low-cost and high reliability.


2021 ◽  
pp. 1-26
Author(s):  
E. Çetin ◽  
C. Barrado ◽  
E. Pastor

Abstract The number of unmanned aerial vehicles (UAVs, also known as drones) has increased dramatically in the airspace worldwide for tasks such as surveillance, reconnaissance, shipping and delivery. However, a small number of them, acting maliciously, can raise many security risks. Recent Artificial Intelligence (AI) capabilities for object detection can be very useful for the identification and classification of drones flying in the airspace and, in particular, are a good solution against malicious drones. A number of counter-drone solutions are being developed, but the cost of drone detection ground systems can also be very high, depending on the number of sensors deployed and powerful fusion algorithms. We propose a low-cost counter-drone solution composed uniquely by a guard-drone that should be able to detect, locate and eliminate any malicious drone. In this paper, a state-of-the-art object detection algorithm is used to train the system to detect drones. Three existing object detection models are improved by transfer learning and tested for real-time drone detection. Training is done with a new dataset of drone images, constructed automatically from a very realistic flight simulator. While flying, the guard-drone captures random images of the area, while at the same time, a malicious drone is flying too. The drone images are auto-labelled using the location and attitude information available in the simulator for both drones. The world coordinates for the malicious drone position must then be projected into image pixel coordinates. The training and test results show a minimum accuracy improvement of 22% with respect to state-of-the-art object detection models, representing promising results that enable a step towards the construction of a fully autonomous counter-drone system.


2020 ◽  
Vol 5 (3) ◽  
pp. 875
Author(s):  
Asfri Sri Rahmadeni

<p class="Normal1"><em>Commitment is the attitude or behavior of likes or dislikes shown by someone against the organization at work. Indonesia is recorded as a nurse who has a low organizational commitment (76%) so it harms services. This phenomenon in the hospital can be seen from the indicator of the high turnover rate of nurses which reaches 30.9% which exceeds the standard &lt;5%. Many factors affect organizational commitment. The purpose of this study was to analyze the Personal Factors Associated with Organizational Commitment of Hospital Nurses. This study is a cross-sectional analytic study and purposive sampling technique with a sample of 59 nurses. Chi-Square test results obtained personal factors that have a relationship with organizational commitment Nurse Hospital is age with p = 0,000 and education with p = 0,000, personal factors not related to organizational commitment are gender p = 1,053 and years of service with p = 1,147. Hospitals should conduct research/surveys on Organizational Commitment periodically as an evaluation material in the context of the organization's development and development in the future</em>.</p>


2020 ◽  
Vol 2 (2) ◽  
pp. 72-80
Author(s):  
Niluh Nita Silfia

Partographs are guidelines for childbirth observations that will facilitate labor assistants in first identifying emergency cases and complications for mothers and fetuses. Preliminary survey at the Sigi Community Health Sub-Center (Pustu) of the 8 Pustu midwives found two midwives (25%) to complete a complete partograph, six midwives (75%) incomplete. The purpose of this study was to determine the determinant factors associated with the use of partographs in labor. The design of this study used observational analytic methods with a cross-sectional approach. 24 BPM survey results were obtained with 30 samples of midwives who met the research criteria and data completeness. The sampling technique was by the total population. Data analysis used logistic regression. The multivariate analysis results showed that APN training was the most influential factor in the use of partographs in labor by midwives. Statistical test results obtained a POR value of 37.7 (95% CI 12.1 - 60.2). This study suggests that midwives must have APN certificates to be valid in providing services.


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