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Copyright of Chinese Journal of Wildlife / Yesheng Dongwu Xuebao is the property of Chinese Journal of Wildlife Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The foraging preferences of lesser spotted woodpeckers (Dryobates minor) was investigated in the National Field Scientific Observation and Research Station of Maoershan Forest Ecosystem in Heilongjiang Province during March to June 2022. We tracked lesser spotted woodpecker by using quadrat combined with transect method and radio tracking technology. Foraging tree characteristics and foraging habitat preferences of lesser spotted woodpeckers were analyzed by Bailey’s method based on utilization-availability method. The main factors influencing their choices of foraging tree and foraging habitat were analyzed by principal component analysis. The differences of sexes in foraging behavior and main influential factors of foraging selection were explored by Fisher’s exact test, Mann-Whitney U test and Kendall’s tau-b correlation analysis. The results are as follows. Lesser spotted woodpeckers preferred pecking on branches of the upper canopy of standing trees for a short time. The wood density, height of foraging trees, slope degree, dominant species, nearest dis⁃ tance of human disturbance, and the mean tree height in quadrat are the main factors affecting the selection of foraging trees and foraging habitats for lesser spotted woodpeckers. Both males and females preferred to forage on habitats with moderate density and trees of about 15 m height. They selected flat slope area as preferred foraging habitat. They pre⁃ ferred to foraging in the forest with Ulmus davidiana var. japonica or Juglans mandshurica as the dominant species, average tree height of 13 m, and near human disturbance. Compared with females, males also preferred to forage on habitats with low density and trees of 3-5 m height. [ABSTRACT FROM AUTHOR]

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate the food composition, feeding preference and the influence of nutrition on food selection of chipmunks (Tamias sibiricus) in a broad-leaved Korean pine (Pinus koraiensis) forest, wild chipmunks in Liangshui National Nature Reserve of Heilongjiang Province were selected as the research object. Direct field observation, cage rearing in laboratory combined with nutritional measurement were used to investigate the food composition and feeding preference of chipmunks across different seasons. The results of the field investigation showed that the chipmunks were mainly planteating rodents, and plant based foods accounted for more than 95% of their food composition across different seasons, while the other 5% were animal based foods such as snails and earthworms. The species of feeding plants were different in spring and summer. The plant species with the highest feeding frequency was Corydalis yanhusuo in spring，Pilea pumila in summer, and Pinus koraiensis seeds in autumn. The results of cage rearing in laboratory were consistent with those of field investigation. The results of nutritional measurement showed that chipmunks preferred to eat foods with high crude fat, high energy content and low cellulose content, while there was no significant correlation between crude protein content and chipmunks’ intake. [ABSTRACT FROM AUTHOR]

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Data Acquisition & Processing / Shu Ju Cai Ji Yu Chu Li is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the performance of the agricultural machinery automatic navigation system, an automatic navigation path searching method of agricultural machinery based on GNSS (global navigation satellite system) was proposed. According to different demands of farm working, the system could generate the straight line or curve path for agricultural machinery automatic navigation according to users setting. In order to get the straight navigation path, the user should drive the tractor and record the current position marked as point A, and then choose the position marked as Point B at least 10 m far away from Point A. The straight line presupposed navigation path could be obtained by connecting Point A and B and extending the segment AB. The way of obtaining the curve presupposed navigation path is similar to the straight path searching method; the curve fits with several segments, and every segment is analyzed with the straight path searching method. When the navigation task began, the system would compare the current position and heading information of the tractor with the presupposed path to get the lateral deviation and heading deviation. In addition, a pure pursuit mode based on preview points research was proposed for steering control. The method didn't involve the complicated control theory, so that it could adapt the navigation system better. In the aspect of turning control, arcuate turning and pyriform turning patterns were selected as the major research objects. The turning path could be generated by the navigation system according to the tractor working width and the minimum turning radius after the users chose the kind of turning pattern, and a series of points could be chosen according to the tractor speed and each point was evenly spaced. When the navigation task began, the searching radius and preview point should be set according to the speed of the tractor. There were several points on the default navigation path falling in the searching circle; the point with the largest ID (identification) number would be selected as the preview point, and then the path of the tractor arriving to the preview point and the control turning angle would be obtained. To verify the path search method and the model of pure tracking performance, a tractor automatic navigation software was designed and implemented. The industrial computer as the carrier of navigation software, processed the GNSS data, IMU (inertial measurement unit) data and PLC (programmable logic controller) data, and then generated the corresponding decisions. A John Deere tractor was used as the platform for experiments, and the straight line / curve navigation experiments based on GNSS positioning technology were designed. The results of experiments were as follows: In the straight line navigation experiments, when the speed of the tractor was 0.8, 1.0 and 1.2 m/s, the root-mean-square error was 3.79, 4.28 and 5.39 cm respectively; in the turning navigation experiments, when the speed of the tractor was 0.6 m/s, the root-mean-square error of the arcuate turning navigation was 25.23 cm and the root-mean-square error of the pyriform turning navigation was 14.42 cm; for the comparison experiment, the root-mean-square error using the proposed method and fuzzy control method was 4.30 and 5.95 cm respectively in straight line navigation module, and 13.73 and 21.40 cm respectively in curve navigation module. The path searching method and the pure pursuit mode based on the researching of preview points can satisfy the requirement of the farmland works effectively. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)