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Reinforcement Learning based Flight Path Planning of a Solar Powered UAV
Giancarlo Eder Guerra Padilla,Kun-Jung Kim,Kee-Ho Yu 제어로봇시스템학회 2021 제어로봇시스템학회 각 지부별 자료집 Vol.2021 No.12
This paper presents the analysis of the flight path of a solar-powered Unmanned Aerial Vehicle (UAV) using Reinforcement Learning (RL) algorithm as a preliminary study for the optimal flight path planning considering weather conditions. The RL algorithm has the advantage of being able to learn from online simulations as well as offline hardware equipment. For the flight path generation a RL algorithm was trained using the UAV"s equations of motion as environment parameters. First, the UAV"s kinematic and dynamic equations of motion as environment parameters. First, the UAV"s kinematic and dynamic equations were specified in order to train the model. Then, using a critic-actor learning method for the agent model, the policy was obtained as a function of the state observations and rewards. The learning process was carried out with a waypoint follower problem, and the results analyzed.
Giancarlo Eder Guerra Padilla,Seong-Hwan Kim,Kee-Ho Yu 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10
In the occurrence of natural disasters or any other event that causes damage to the communication system’s infrastructure of a city, logistics and rescue works tend to lack in countermeasures to assure a stable communication when needed. This study is aimed to developing a collision-free optimal flight path of a solar-powered UAV, exploiting its capability for long endurance flights, using it as a Low Altitude Platform (LAP) for communication relay. The model considers the solar incidence angle, aircraft attitude, influence of Artificial Potential Fields, and Free-space transmission signal. Apart from this considerations, a flight altitude restriction is defined and bounded to maximum antenna range. As a result of the simulation, a collision-free flight path considering antenna specifications for communication relay was tested resulting in the acquisition of significant data regarding the feasibility of the approach.
Transanal Endoscopic Microsurgery: Endoscopy Assisted Treatment of Colorectal Anastomotic Stenosis
Giancarlo D’Ambrosio,Antonietta Lamazza,Rossella Palma,Andrea Picchetto,Cristina Panetta,Antonello Trecca,Stefano Pontone,Emanuele Lezoche 대한대장항문학회 2020 Annals of Coloproctolgy Vol.36 No.4
Transanal endoscopic microsurgery (TEM) is a type of natural orifice transluminal endoscopic surgery, developed for rectal tumors and used also to treat other rectal diseases. Anastomotic complications after colorectal surgery, including stenosis, represent a challenging problem. We present the case of a 36-year-old woman with a diagnosis of Hirschsprung disease that was submitted to a modified Duhamel operation. A postoperative barium enema showed a complete stricture of the anastomosis that was impossible to resolve by flexible endoscopic approach. Then an intraoperative endoscopic approach to facilitate the localization of preanastomotic colon (proximal colon from the anastomosis) was performed by a small colotomy and the colonic recanalization was obtained by the creation of a neo-anastomosis by TEM, under fluoroscopic-endoscopic control. The patient underwent a control barium enema showing regular retrograde transit of contrast medium without evidence of stenosis. In our experience, transanal approach by TEM-colonoscopy assisted is safe and feasible and represents a model of combined minimally invasive technique.
Giancarlo Cordasco,Antonino Lo Giudice,Angela Militi,Riccardo Nucera,Giuseppe Triolo,Giovanni Matarese 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.4
Objective: To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Methods: Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; elastomeric ligatures (1 mm inner diameter) were used in the latter system. The alignment wire used was 0.014 inch heat-activated NiTi (austenitic finish temperature set at 36°C by the manufacturer). A custom-made testing machine was used to measure frictional resistance. Tests were repeated 5 times at every angulation simulated. All data were analyzed statistically. Results: The RS increased significantly with increasing angulation in both SL and CL groups (p < 0.0001). However, the RS values were significantly higher at every angulation (p < 0.0001) in the CL group. Conclusions: Despite the relevance of the binding phenomenon, ligation forces predominantly affect the RS when lowstiffness alignment wires are used.
Seed Dispersal by Water, Wind, Birds, and Bats in the Caliraya Watershed, Laguna
Giancarlo Pocholo L. Enriquez,Lillian Jennifer V. Rodriguez National Institute of Ecology 2023 국립생태원회보(PNIE) Vol.4 No.1
Seed dispersal supports community structure, maintains genetic connectivity across fragmented landscapes, and influences vegetation assemblages. In the Philippines, only two seed dispersal studies have compared different dispersal agents. We examined the seed dispersal patterns of water, wind, birds, and bats in the Caliraya Watershed, Philippines. We aimed to determine the floral species that were dispersed and how the forest characteristics influenced seed dispersal. By running seed rain traps and drift litter collection from March to June 2022, we analyzed 14,090 seeds in a privately owned study site within the watershed. Water did not exclusively disperse any species and acted as a secondary disperser. Seed density (seeds/trap) was significantly higher for bird-dispersed (n=166) and bat-dispersed (n=145) seeds than for wind-dispersed (n=79) seeds (One-way analysis of variance [ANOVA]: F<sub>2,87</sub>=16.21, P<0.0001). Species number (species/trap) was significantly higher for bird-dispersed (n=3.7) and bat-dispersed (n=3.9) seeds than for wind-dispersed (n=0.2) seeds (One-way ANOVA: F<sub>2,87</sub> =16.67, P<0.0001). Birds dispersed more species because they are more diverse and access a wider variety of fruits, unlike bats. Birds and bats target different fruits and provide separate seed dispersal services. Generalized linear model analyses revealed that the number and basal area of fleshy fruit trees most strongly influenced the bird seed dispersal patterns. Therefore, we recommend a three-way approach to restoration efforts in the Caliraya Watershed: (1) ensure the presence of fleshy fruit trees in restoration zones, (2) assist the establishment of mid-successional and wind-dispersed trees, and (3) intensify the conservation efforts for both flora and faunal diversity.