Wireless measurement system for CDMA base station transmit power

Author(s):  
Huipeng Shi ◽  
Jingbo Sai ◽  
Chunping Bao
2012 ◽  
Vol 263-266 ◽  
pp. 392-397
Author(s):  
Jie Luo ◽  
Yun Hui Wang ◽  
Qian Wen Zhao ◽  
Hui Guo ◽  
Fei She

Based on hydraulic sensors and wireless transmission, a new wireless measurement method of liquid volume in a tank is introduced. This measurement system includes hydraulic pressure sensors, A/D converter, GPRS (General Packet Radio Service) module and upper monitor in a computer, from which the users can get aware of the liquid volume in a tank at any time. The measurement system has been built,calibrated and tested. The experimental results show that this measurement system works well and the measurement error is less than 1%.


2019 ◽  
Vol 35 (2) ◽  
pp. 135-147
Author(s):  
Jun Wang ◽  
Haiyang Zhang ◽  
Jiangtao Ji ◽  
Kaixuan Zhao ◽  
Gang Liu

Abstract. A wireless measurement system for assessing behavior patterns in dairy cows has been designed and constructed. The system mainly consisted of 12 leg-tags, 6 location sensors, and a laptop computer. Twelve lactating Holstein dairy cows were selected in the trial. The leg-tags used a 433 MHz radio channel for transmitting the acceleration data and location data at 1 Hz. The data were logged to a laptop computer in real time. An ensemble classification algorithm was proposed in our study. The algorithm can be divided into two stages: at the first stage, the Semi-Supervised Fuzzy C-Means (SS-FCM) algorithm was used to interpret the acceleration data and classify all classes of behavior. Classified behavior patterns included feeding, lying, standing, lying down, standing up, normal walking, and active walking. Accuracy, sensitivity, and precision were used as statistical parameters of classification performance. The SS-FCM algorithm achieved a reasonable identification level of feeding (80% accuracy, 53% sensitivity, 56% precision), lying (92%, 96%, 89%), standing (90%, 51%, 58%), lying down (99%, 82%, 91%), standing up (99%, 66%, 78%), normal walking (97%, 95%, 86%), and active walking (99%, 95%, 88%). At the second stage, a D-S evidence theory method fused the result of SS-FCM algorithm and the cow position to classify all the behaviors predicted as feeding or standing at the previous stage. The sensitivity and precision of the two behaviors increased by an average of 17% and 16.5%, respectively. Overall, we found that the wireless measurement system provided an accurate, remote measure for cow behavior over the trial period, and the ensemble algorithm could effectively recognize various behavior patterns in dairy cows. Keywords: Behavior classification, Back propagation, D-S evidence theory, Received signal strength indication, Three-dimensional accelerometer.


2014 ◽  
Vol 17 (11) ◽  
pp. 1657-1668 ◽  
Author(s):  
Yan Yu ◽  
Chunwei Zhang ◽  
Xinqun Zhu ◽  
Won Hee Kang ◽  
Xingquan Mao ◽  
...  

Cables are important components of a cable-stayed bridge, and the cable tension is a crucial factor in determining the overall condition assessment of a cable-stayed bridge structure. Based on the vibration frequency method, a wireless monitoring system for bridge cable tension force monitoring has been investigated and experimentally validated through laboratory and field tests in this paper. The vibration frequency-based method for cable tension measurement, the design method of the wireless measurement system with embedded identification algorithm, the test procedures, and relevant results are discussed, respectively. The developed wireless monitoring system is verified by a bridge model test in the laboratory and full-scale bridge tests in the field. Field experimental results show that the relative error between this wireless monitoring system and the reference wired system values is within 0.5%. Therefore, the developed wireless measurement system can provide an estimation of cable tension with sufficient accuracy. Moreover, the developed system is highly integrated and convenient in terms of installation and dismantling, and it has potential applicability prospects in emergency for the quick detection of cable tension.


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