http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Design Optimization, Modeling, and Control of Unmanned Aerial Vehicle Lifted By Coandă Effect
Lee, Hyunyong,Han, Seonhye,Lee, Hyoju,Jeon, Jaehyeok,Lee, Choonghan,Kim, Yong Bum,Song, Seung Hwan,Choi, Hyouk Ryeol IEEE 2017 IEEE/ASME transactions on mechatronics Vol.22 No.3
<P>The Coanda effect is a natural phenomenon, which is that flowing fluid on a certain surface is pulled to the surface due to the viscosity of the fluid. This phenomenon can be utilized to produce the lift force of a flying object. This paper presents a new type of unmanned aerial vehicle (UAV) lifted by the Coanda effect, called SCoanda. We introduce the empirical study of its design and implementations. The principle of the Coanda effect is briefly explained in the first section. The design optimization and control of the UAV, and implementation issues are explained. The structural design of SCoanda is devised to use the maximum lift force produced by the Coanda effect. Since there are a plenty of cases about the shape of SCoanda, it has been limited to oval. It is investigated through computational fluid dynamics. As the result, an optimized design is determined among several candidates and appropriate structural materials are selected via tests. Also, dynamic modeling is suggested under several conditions of SCoanda before simulations are conducted to build up a controller and determine gains according to the dynamic modeling. Finally, the UAV is manufactured and its performances are successfully demonstrated in the indoor and the outdoor environments.</P>
Temperature-dependent Differences in Heading Response at Different Growth Stages of Rice
Lee, HyeonSeok,Choi, MyoungGoo,Lee, YunHo,Hwang, WoonHa,Jeong, JaeHyeok,Yang, SeoYeong,Lim, YeonHwa,Lee, ChungGen,Choi, KyungJin The Korean Society of Crop Science 2019 한국작물학회지 Vol.64 No.3
There is an increasing frequency in the occurrence of abnormal weather phenomena such as sharp increases and decreases in temperature. Under these weather conditions, the heading time of rice changes unexpectedly, which poses problems in agriculture. Therefore, we investigated the effect of temperature on the heading response at different growth stages in rice. During the period from transplanting to heading, the plants were subjected to different temperature treatments, each for a 9-day period, to observe the heading response. For the heading date analysis, "heading date" was defined as the number of days from transplanting to the appearance of the first spikelet. We found that the influence of temperature increased in the order of rooting stage, followed by meiosis, early tillering, spikelet differentiation, and panicle initiation stage in all ecological types and cultivars. In particular, unlike the results reported previously, the effect of temperature on heading during the photo-sensitive period was very small. Meanwhile, the influence of temperature on vegetative growth response at different growth stages was not consistent with heading response. These results can be used as basic data for predicting the variation in heading date owing to temperature variation at each growth stage. In addition, we propose that the concept of day length should be included in determining the influence of temperature on the photo-sensitive period.
Improved HOG Pedestrian Detection Means Using V-disparity Map
Jaehyeok Lee,Jongchul Lee,Hyunki Hong 중앙대학교 영상콘텐츠융합연구소 2016 TechArt :Journal of Arts and Imaging Science Vol.3 No.2
In order for a driverless car to drive safe, it is important to accurately estimate information about any obstacles near the car and especially the existence and position of pedestrians. A histogram of oriented gradient (HOG) support vector machine (SVM) is widely used in pedestrian detection algorithms but can cause a false positive problem. This paper will suggest an improved pedestrian detecting means that is using Euclidean distance of coordinate values of the center in extracted foreground objectives after removing ground and background and in the extracted HOG based SVM from an input sequence through V-disparity map to achieve safe pedestrian detecting in dynamic conditions. Its superior performance compared to the existing HOG-based SVM was proven through the results of an image sequence.