Wenbin Li
Beijing Forestry University

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Simulation Analysis of Interface Circuits for Piezoelectric Energy Harvesting with Damped Sinusoidal Signals and Random Signals Shuai Pang; Wenbin Li; Jiangming Kan
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 13, No 3: September 2015
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v13i3.2093

Abstract

Various interface circuits for collecting the energy of piezoelectric cantilever beams have been widely investigated. Such circuits include the standard interface, series synchronized switch harvesting interface circuit, parallel synchronized switch harvesting interface, synchronized charge extraction interface, and others. Most studies focus on the performance of different interface circuits with standard sinusoidal excitations. However, in real situations where constant harmonic vibrations are not present, the equivalent voltage from piezoelectric cantilever beams with excitations is not necessarily sinusoidal. In the present study, a simulation analysis of four different interface circuits with signal sources that are both damped sinusoidal and random was performed using Matlab and PSpice. The results show that the interface circuits have improved performance under low load resistance values with damped sinusoidal signal. In addition, the parallel and series synchronized switch harvesting interface circuits may perform well in collecting piezoelectric energy with random excitations.
Image Deblurring via an Adaptive Dictionary Learning Strategy Lei Li; Ruiting Zhang; Jiangmin Kan; Wenbin Li
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 12, No 4: December 2014
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v12i4.532

Abstract

Recently, sparse representation has been applied to image deblurring. The dictionary is the fundamental part of it and the proper selection of dictionary is very important to achieve super performance. The global learned dictionary might achieve inferior performances since it could not mine the specific information such as the texture and edge which is contained in the blurred image. However, it is a computational burden to train a new dictionary for image deblurring which requires the whole image (or most parts) as input; training the dictionary on only a few patches would result in over-fitting. To address the problem, we instead propose an online adaption strategy to transfer the global learned dictionary to a specific image. In our deblurring algorithm, the sparse coefficients, latent image, blur kernel and the dictionary are updated alternatively. And in every step, the global learned dictionary is updated in an online form via sampling only a few training patches from the target noisy image. Since our adaptive dictionary exploits the specific information, our deblurring algorithm shows superior performance over other state-of-the-art algorithms. 
Segmentation Method of Lingwu Long Jujubes based on L*a*b* Color Space Yutan Wang; Wenbin Li; Shuai Pang; Jiangming Kan
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 9: September 2013
Publisher : Institute of Advanced Engineering and Science

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Abstract

Collecting Lingwu long jujubes’ growth characteristics and identifying maturity compared with growth model are important factors in automatic image monitoring system for fruit maturity. To segment and extract regions of Lingwu long jujubes’ against nature scenes in digital images is the key to image recognition. Color space transformation, is used to transform RGB color space to CIE L*a*b* color space, analyze characteristics of three-dimension histogram of each component and increase target display properties by using each component’s point operation. Also, the image pixel threshold segmentation method of each component is proposed; then the target image can be obtained by mathematical morphological and logical operation of the extracted image. 50 images of Lingwu long Jujubes are utilized to compare segmentation results of algorithm with those of manual segmentation method. Comparison results show that the proposed segmentation algorithm can be effectively applied to extracting Lingwu long jujubes’ images against nature scenes, and its accuracy has reached 92.6%.This algorithm has decreased the segmentation error caused by image noise while extracting targets which has strong robustness to the color distribution fluctuation as well. DOI: http://dx.doi.org/10.11591/telkomnika.v11i9.3289 
An Implementation of Remote Monitoring Standing Tree Diameter at Breast Height Liyuan Jiang; Wenbin Li; Jiangming Kan; Zhibin Hao; Qing Xu
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 11: November 2013
Publisher : Institute of Advanced Engineering and Science

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Abstract

Studies show that there is electric potential difference between the internal part of tree and the soil, but the mechanism is not clear, possibly associated with tree species, environmental factors and DBH (diameter at breast height) of tree. In order to research the mechanism and change rules, it is necessary to measure bioelectricity, environmental factors and DBH of tree, among which the DBH and its growth is an important indicator. A kind of DBH of tree and its growth automatic measuring system has been designed based on the angular displacement sensor. The system can realize remote monitoring function of DBH measurement and the growth, and can be set by structural parameters to measure the size of DBH. In this paper, the experiments require the DBH of tree ranges from 0~40cm, and calculation system can measure the DBH less than 0.0436mm theoretically, meeting the measurement requirements and providing reliable data for researching mechanism of trees. DOI: http://dx.doi.org/10.11591/telkomnika.v11i11.3489
Bioelectricity in Standing Trees - A Potential Energy For Wireless Sensor Networks Zhibin Hao; Wenbin Li; Jiangming Kan; Liyuan Jiang; Chao Feng
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 8: August 2013
Publisher : Institute of Advanced Engineering and Science

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Abstract

It has been observed that there are sustained electrical potential difference and current between a tree trunk and its surrounding soil, which have bright application prospects for powering wireless sensor networks in forests. But the mechanism of the bioelectricity has remained controversial. In order to provide more comprehensive data for further researches and to analyze the relationship between the bioelectricity in tree trunks and their surrounding environmental parameters, an experiment has been made. The output power of selected trees, xylem pH, as well as the environmental parameters such as air temperature, air relative humidity, soil temperature, soil moisture and soil pH were measured. Results supported the hypothesis that bioelectricity in xylem has a significant relativity with soil pH. Moreover, it was found that air relative humidity, soil temperature and material of electrode affected the bioelectricity in the xylem. DOI: http://dx.doi.org/10.11591/telkomnika.v11i8.3148