Analog integrated circuit of a low level high voltage current source with capacitive load compensation

Ankara : Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent University, 1997.Thesis (Master's) -- Bilkent University, 1997.Includes bibliographical references leaves 77-79.Öner, Mustafa ErtuğrulM.S

Robust position control of a tilt-wing quadrotor

This paper presents a robust position controller for a tilt-wing quadrotor to track desired trajectories under external wind and aerodynamic disturbances. Wind effects are modeled using Dryden model and are included in the dynamic model of the vehicle. Robust position control is achieved by introducing a disturbance observer which estimates the total disturbance acting on the system. In the design of the disturbance observer, the nonlinear terms which appear in the dynamics of the aerial vehicle are also treated as disturbances and included in the total disturbance. Utilization of the disturbance observer implies a linear model with nominal parameters. Since the resulting dynamics are linear, only PID type simple controllers are designed for position and attitude control. Simulations and experimental results show that the performance of the observer based position control system is quite satisfactory

Use of Stem Cell Therapy in COVID-19

Severe acute respiratory syndrome coronavirus 2 is known to cause the new coronavirus disease 2019 (COVID-19), in which many organs and systems such as the lung, heart, and immune system can be severely affected. Currently, the treatment process is generally based on supportive and palliative care. Some potential drugs are being tested for treatment. At this point, perhaps a promising treatment method for many diseases in the future seems to be stem cell therapy in recent times. Stem cell therapy in COVID-19 may be a treatment method that can play an important role, especially in resistant and severe cases. In this review, we summarized the potential mechanisms of stem cell therapy and developments in this treat ment modality

Robust hovering control of a quad tilt-wing UAV

This paper presents design of a robust hovering controller for a quad tilt-wing UAV to hover at a desired position under external wind and aerodynamic disturbances. Wind and the aerodynamic disturbances are modeled using the Dryden model. In order to increase the robustness of the system, a disturbance observer is utilized to estimate the unknown disturbances acting on the system. Nonlinear terms which appear in the dynamics of the vehicle are also treated as disturbances and included in the total disturbance. Proper compensation of disturbances implies a linear model with nominal parameters. Thus, for robust hovering control, only PID type simple controllers have been employed and their performances have been found very satisfactory. Proposed hovering controller has been verified with several simulations and experiments

Development of Hypersensitivity Reactions after Using Different Oral Iron Preparations

Gastrointestinal side effects after using oral iron preparations have been usually observed, but skin reactions and allergic angioedema due to hypersensitivity have been rarely reported in the literature. We delineated 4 patients who were referred to us and who had shown hypersensitivity reactions following oral iron use, and their response to alternate oral iron preparations was evaluated. Initially prick and intradermal skin tests, and then oral provocations, were algorithmically performed in 4 patients to diagnose allergy to oral iron salts. Two of 4 cases showed hypersensitivity reactions after oral provocation. We were able to prevent the possible allergic reaction, which probably depends on IgE-mediated hypersensitivity, by simply changing the initial oral iron preparation to alternate one

LQR and SMC stabilization of a new unmanned aerial vehicle

We present our ongoing work on the development of a new quadrotor aerial vehicle which has a tilt-wing mechanism. The vehicle is capable of take-off/landing in vertical flight mode (VTOL) and flying over long distances in horizontal flight mode. Full dynamic model of the vehicle is derived using Newton-Euler formulation. Linear and nonlinear controllers for the stabilization of attitude of the vehicle and control of its altitude have been designed and implemented via simulations. In particular, an LQR controller has been shown to be quite effective in the vertical flight mode for all possible yaw angles. A sliding mode controller (SMC) with recursive nature has also been proposed to stabilize the vehicle’s attitude and altitude. Simulation results show that proposed controllers provide satisfactory performance in achieving desired maneuvers

KENT VE ÇEVRE SORUNLARINA AKILLI ÇÖZÜM: AÇIK VERİ PLATFORMU (İZMİR ÖRNEĞİ)

ÖZ: Bilgi ve iletişim teknolojilerinde (BİT) meydana gelen gelişmelerin günlük yaşantıya büyük etkisi olmuştur. Akıllı teknolojiler sadece insan yaşantısına değil kurumsal işleyişe de uyarlanmıştır. Dijitalizm ve kurum buluşması e-devlet platformları ile başlatılırken süreç içinde yeni platformlar devreye sokulmuştur. Özellikle Covid-19 salgını bireylerin bilgi erişimi konusundaki beklenti ve çabalarını arttırmıştır. Salgın sırasında eğitim, sağlık, iş yaşamı başta olmak üzere dijital platform ve akıllı teknoloji kullanımı büyük artış göstermiştir. Salgın süreci akıllı teknoloji kullanımı konusunda bireylerin-kurumların potansiyellerini ve becerileri ortaya çıkarmıştır. Pek çok kurum ve kişinin kısıtlamalar sırasında akıllı teknolojilere artan ilgisi halen sürmektedir. Salgın öncesinde başlayan ama salgınla öne çıkan konulardan biri ise çevre sorunlarının tespiti, izlenmesi, analizi ve çözüm üretilmesi olmuştur. Hava, su ve toprak üzerindeki insan kaynaklı tahribatın yol açtığı kirlilik acil tedbir alınması gereken kent sorunlarındandır. İklim değişikliği konusunda Birleşmiş Milletler (BM) öncülüğünde sürdürülen girişimlerin başarıya ulaşmasında yerel yönetimlerin ve yerel halkın büyük sorumluluğu bulunmaktadır. Bu sorumluluk artan kent nüfusuyla doğrudan ilişkilidir. Nüfus projeksiyonları açısından 2035 yılında metropollerde yaşayan insan sayısının dünya nüfusunun % 39'unu temsil eden 3,47 milyar kişiye ulaşacağı ve 15 yıl içinde yaklaşık 1 milyar insanın büyük kentlerde ikamet edeceği tahmin edilmektedir. BM, 2050 yılına kadar dünya nüfusunun % 68'inin kentsel alanlarda yaşayacağını öngörmektedir. Covid-19 salgınıyla elde edilen akıllı teknoloji deneyimlerinin çevre kirliliğiyle mücadelede kullanımı önem kazanmıştır. 28 Ocak 2021 tarihinde İzmir Büyükşehir Belediyesi tarafından erişime açılan “Açık veri platformu” içeriğinde akıllı teknoloji ve çevre buluşmasını sağlamaktadır. Çalışmamızın amacı artan çevre sorunlarıyla mücadele açısından akıllı teknoloji uygulamalarının katkısını ele almaktır. Literatür incelemesine dayalı tarama yöntemiyle gerçekleştirilen çalışmamızda açık veri platformu üzerinden gerçekleştirilen “akıllı çevre girişimleri” incelenmektedir. Bireylerin ve kurumların akıllı teknoloji konusunda gelişen yatkınlıkları ve talepleri temel motivasyonumuzu oluşturmuştur. ABSTRACT: Developments in information and communication technologies (ICT) have had a great impact on daily life. Smart technologies are not only adapted to human life, but also to corporate functioning. While digitalism and corporate meeting were started with e-devlet platforms, new platforms were introduced during process. Especially the Covid-19 pandemic has increased the expectations and efforts of individuals regarding information access. During the pandemic, the use of digital platforms and smart technology, especially in education, health and business life, has increased greatly. The pandemic process has revealed the potential and skills of individuals-institutions in the use of smart technology. Many institutions and individuals are still increasingly interested in smart technologies during the restrictions. One of the issues that started before the pandemic but came forward with the pandemic process was the detection, monitoring, analysis and solution of environmental problems. Pollution caused by human-induced destruction on air, water and soil is one of the urban problems that need urgent action. Local governments and local people have a great responsibility for the success of United Nations (UN) led initiatives on climate change. This responsibility is directly related to the increasing urban population. In terms of population projections, it is estimated that the number of people living in metropolises will reach 3.47 billion people, representing 39% of the world's population, in 2035, and approximately 1 billion people will reside in big cities in 15 years. The UN foresees that 68% of the world's population will live in urban areas by 2050. The use of smart technology experiences obtained with the Covid-19 pandemic in the fight against environmental pollution has gained importance. It provides the meeting of smart technology and environment in the content of the "Open data platform", which was opened to access by the İzmir Metropolitan Municipality on January 28, 2021. The goal of our study is to discuss the contribution of smart technology applications in terms of fighting to increasing environmental problems. In our study, which was carried out with the scanning method based on the literature review, "smart environment initiatives" carried out on the open data platform are examined. The developing tendencies and demands of individuals and institutions on smart technology have formed our main motivation

Dynamic model and control of a new quadrotor unmanned aerial vehicle with tilt-wing mechanism

In this work a dynamic model of a new quadrotor aerial vehicle that is equipped with a tilt-wing mechanism is presented. The vehicle has the capabilities of vertical take-off/landing (VTOL) like a helicopter and flying horizontal like an airplane. Dynamic model of the vehicle is derived both for vertical and horizontal flight modes using Newton-Euler formulation. An LQR controller for the vertical flight mode has also been developed and its performance has been tested with several simulations

Modeling and position control of a new quad-rotor unmanned aerial vehicle with tilt-wing mechanism

In this work a dynamic model of a new quadrotor aerial vehicle that is equipped with a tilt-wing mechanism is presented. The vehicle has the capabilities of vertical take-off/landing (VTOL) like a helicopter and flying horizontal like an airplane. Dynamic model of the vehicle is derived both for vertical and horizontal flight modes using Newton-Euler formulation. An LQR controller for the vertical flight mode has also been developed and its performance has been tested with several simulations