PID vs LQR controller for tilt rotor airplane

The main thematic of this paper is controlling the main manoeuvers of a tilt rotor UAV airplane in several modes such as vertical takeoff and landing, longitudinal translation and the most important phase which deal with the transition from the helicopter mode to the airplane mode and visversa based on a new actuators combination technique for specially the yaw motion with not referring to rotor speed control strategy which is used in controlling the attitude of a huge number of vehicles nowadays. This new actuator combination is inspired from that the transient response of a trirotor using tilting motion dynamics provides a faster response than using rotor speed dynamics. In the literature, a lot of control technics are used for stabilizing and guarantee the necessary manoeuvers for executing such task, a multiple Attitude and Altitude PID controllers were chosen for a simple linear model of our tilt rotor airplane in order to fulfill the desired trajectory, for reasons of complexity of our model the multiple PID controller doesnt take into consideration all the coupling that exists between the degrees of freedom in our model, so an LQR controller is adopted for more feasible solution of complex manoeuvering, the both controllers need linearization of the model for an easy implementation

Nd:YAG laser welding of stainless steel 304 for photonics device packaging

Although pulsed Nd:YAG laser welding has been widely used in microelectronics and photonics packaging industry, a full understanding of various phenomena involved is still a matter of trials and speculations. In this research, an ultra compact pulsed Nd:YAG laser with wavelength of 1.064 µm has been used to produce a spot weld on stainless steel 304. The principal objective of this research is to examine the effects of laser welding parameters such as laser beam peak powers, pulse durations, incident angles, focus point positions and number of shots on the weld dimensions: penetration depth and bead width. The ratio of the penetration depth to the bead width is considered as one of the most critical parameters to determine the weld quality. It is found that the penetration depth and bead width increase when the laser beam peak power, pulse duration and number of shot increase. In contrast, the penetration depth decreases when the laser beam defocus position and incident angle increase. This is due to the reduction of the laser beam intensity causing by the widening of the laser spot size. These experimental results provide a reference on an optimal laser welding operations for a reliable photonics device packaging. The results obtained shows that stainless steel 304 is suitable to be used as a base material for photonics device packaging employing Nd:YAG laser welding technique

Spatiotemporal Mapping and Monitoring of Mangrove Forests Changes From 1990 to 2019 in the Northern Emirates, UAE Using Random Forest, Kernel Logistic Regression and Naive Bayes Tree Models

© Copyright © 2020 Elmahdy, Ali, Mohamed, Howari, Abouleish and Simonet. Mangrove forests are acting as a green lung for the coastal cities of the United Arab Emirates, providing a habitat for wildlife, storing blue carbon in sediment and protecting shoreline. Thus, the first step toward conservation and a better understanding of the ecological setting of mangroves is mapping and monitoring mangrove extent over multiple spatial scales. This study aims to develop a novel low-cost remote sensing approach for spatiotemporal mapping and monitoring mangrove forest extent in the northern part of the United Arab Emirates. The approach was developed based on random forest (RF), Kernel logistic regression (KLR), and Naive Bayes Tree machine learning algorithms which use multitemporal Landsat images. Our results of accuracy metrics include accuracy, precision, and recall, F1 score revealed that RF outperformed the KLR and NB with an F1 score of more than 0.90. Each pair of produced mangrove maps (1990–2000, 2000–2010, 2010–2019, and 1990–2019) was used to image difference algorithm to monitor mangrove extent by applying a threshold ranges from +1 to −1. Our results are of great importance to the ecological and research community. The new maps presented in this study will be a good reference and a useful source for the coastal management organization

Effects of soil amendment treatments on growth, yield and fruit quality of selected banana (Musa AAA) cultivars

       Banana cultivation in Sudan is restricted to the narrow strip of silt deposits along the banks of the Blue Nile and the River Nile. Hence, there is a need to expand banana cultivation in the high terrace, heavy clay soils. Banana performance in heavy clay soils is very poor, unless soil amendments are applied. Therefore, the objective of this research was to study the effects of soil amendment treatments on growth, yield and fruit quality of selected banana cultivars. The experiment was conducted in the Research Farm of the National Institute for the Promotion of Horticultural Exports, University of Gezira, during 2009-2011. Treatments consisted of three selected banana cultivars : Two introduced cultivars, namely, Grand Nain 1824 (GN) and William’s Hybrid 172 (WH) and the local cultivar Dwarf Cavendish (DC). Soil amendment treatments were : 1, 50% heavy clay (HC) + 50% loam (L); 2, 50% HC + 50% chicken manure (CM); 3, 50% HC + 25% L + 25% CM; 4, 33% HC + 33% L + 34% CM; 5, 100% HC (control). Treatments were arranged in a randomized complete block design with three replicates. Results showed that the introduced cultivars GN and WH had more vigorous vegetative growth, higher yield components, total yield and better fruit quality than the local cultivar DC. Soil amendment treatments of 50% HC + 25% L + 25% CM and 33% HC + 33% L + 34% CM resulted in the most vigorous vegetative growth, the highest yield components and total yield and the best fruit quality, followed by 50% HC + 50% L and 50% HC +50%CM, whereas the least vegetative growth, the lowest yield components, total yield and the worst fruit quality were produced by bananas grown in 100% HC (control). In order to expand banana production for the local market and export, it is recommended to amend heavy clay soils with loams and chicken manure at 33% each and grow the introduced cultivars GN and WH.      تنحصر زراعة الموز في السودان على الشريط الضيق للتربة الغرينية على ضفاف النيل الأزرق ونهر النيل. هنالك حاجة ماسة للتوسع في زراعة الموز في السودان ولذلك لا بد من محاولة زراعته في الاراضي الطينية الثقيلة و التي لا تصلح لزراعة الموز إلا إذا تمت بعض المعالجات. لذلك فإن الهدف من هذا البحث هو دراسة تأثير بعض مستصلحات التربة على النمو ومكونات الإنتاج والإنتاج الكلي لثلاثة أصناف منتخبة من الموز في هذا النوع من الأراضي. أجريت التجربة في مزرعة بحوث المعهد القومي لتنمية الصادرات البستانية بجامعة الجزيرة خلال الفترة 2009-2011. اشتملت المعاملات على ثلاثة أصناف منتخبة من الموز: صنفان مستجلبان من خارج السودان وهما جراندنين 1824 (GN) وهجين وليامز172 (WH) بالإضافة إلى الصنف المحلي الكافندش القزم (DC). إشتملت مستصلحات التربة على: (1) 50% تربة طينية ثقيلة + 50% تربة غرينية ، (2) 50% تربة طينية + 50% ماروق دواجن ، (3) 50% تربة طينية + 25% تربة غرينية + 25% ماروق دواجن، (4) 33% تربة طينية + 33% تربة غرينية + 34% ماروق دواجن ، (5) 100% تربة طينية (شاهد). أستخدم تصميم القطع العشوائية الكاملة  بثلاثة مكررات . أظهرت النتائج أن الأصناف المستجلبة من الخارج GN وWH كانت أفضل في النمو الخضري وأعلى إنتاجية وأفضل جودة للثمار من الصنف المحلي DC. معاملات مستصلحات التربة 50% تربة طينية + 25% تربة غرينية + 25% ماروق دواجن و 33% تربة طينية و33% تربة غرينية و34% ماروق دواجن أعطت أفضل نمو خضري وأعلى إنتاجية وأفضل نوعية للثمار ، تليها المعاملات 50% تربة طينية + 50% تربة غرينية و50% تربة طينية + 50% ماروق دواجن. أما زراعة الموز في الأراضي الطينية الثقيلة بدون مستصلحات أدت  إلى أقل نمو خضري وأقل إنتاجية وأدنى نوعية للثمار. لذلك لكي يتم التوسع في زراعة الموز فى الاراضى الطينية الثقيلة للسوق المحلي والتصدير ، فإنه يوصى بإضافة  التربة الغرينية و ماروق الدواجن بنسبة 33% لكل منهما وزراعة الأصناف المستجلبة GN و WH. &nbsp