85 results
Search Results
Now showing 1 - 10 of 85
Article Citation - WoS: 5Citation - Scopus: 4Avoiding Contingent Incidents by Quadrotors Due To One or Two Propellers Failure(Public Library Science, 2023) Altinuc, Kemal Orcun; Khan, Muhammad Umer; Iqbal, JamshedWith the increasing impact of drones in our daily lives, safety issues have become a primary concern. In this study, a novel supervisor-based active fault-tolerant (FT) control system is presented for a rotary-wing quadrotor to maintain its pose in 3D space upon losing one or two propellers. Our approach allows the quadrotor to make controlled movements about a primary axis attached to the body-fixed frame. A multi-loop cascaded control architecture is designed to ensure robustness, stability, reference tracking, and safe landing. The altitude control is performed using a proportional-integral-derivative (PID) controller, whereas linear-quadratic-integral (LQI) and model-predictive-control (MPC) have been investigated for reduced attitude control and their performance is compared based on absolute and mean-squared error. The simulation results affirm that the quadrotor remains in a stable region, successfully performs the reference tracking, and ensures a safe landing while counteracting the effects of propeller(s) failures.Article Citation - WoS: 15Citation - Scopus: 9Structural and Optical Properties of Interfacial Inse Thin Film(Amer Chemical Soc, 2024) Emir, Cansu; Tataroglu, Adem; Coskun, Emre; Ocak, Sema BilgeThis study presents a comprehensive investigation of the optical and structural characteristics of the indium selenide (InSe) film prepared on a glass substrate. The structural characteristics of the InSe film were analyzed using characterization techniques including X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy while the UV-vis spectrophotometry method was used in the spectral range between 500 and 1000 nm to examine the optical characteristics. Thus, the UV-vis spectroscopic data were used to extract several optical parameters including extinction coefficient (k), optical band gap (E-g), refractive index (n), absorption coefficient (alpha), and optical conductivity (sigma(opt)). The optical transition of InSe was found as a direct transition. However, the optical analysis of this study has revealed that the InSe film has the potential to be used in various optoelectronic and photovoltaic applications.Article Citation - WoS: 137Citation - Scopus: 173Re-Usage of Waste Foundry Sand in High-Strength Concrete(Pergamon-elsevier Science Ltd, 2010) Guney, Yucel; Sari, Yasin Dursun; Yalcin, Muhsin; Tuncan, Ahmet; Donmez, SenayiIn this study, the potential re-use of waste foundry sand in high-strength concrete production was investigated. The natural fine sand is replaced with waste foundry sand (0%, 5%, 10%, and 15%). The findings from a series of test program has shown reduction in compressive and tensile strengths, and the elasticity modulus which is directly related to waste foundry inclusion in concrete. Nevertheless the concrete with 10% waste foundry sand exhibits almost similar results to that of the control one. The slump and the workability of the fresh concrete decreases with the increase of the waste foundry sand ratio. Although the freezing and thawing significantly reduces the mechanical and physical properties of the concrete. The obtained results satisfies the acceptable limits set by the American Concrete Institute (Ad). (C) 2010 Elsevier Ltd. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Complex Nodal Structure Phonons Formed by Open and Closed Nodal Lines in Coass and Na2cup Solids(Royal Soc Chemistry, 2022) Ding, Guangqian; Sun, Tingting; Surucu, Gokhan; Surucu, Ozge; Gencer, Aysenur; Wang, XiaotianTopological phononic states with nodal lines not only have updated our knowledge of the phases of matter in a fundamental way, but also have become a major frontier research direction in condensed matter physics. From a mathematical perspective, nodal line phonons can be divided into open and closed types. The present attempt is a report on the coexistence of such open and closed nodal line phonons in two realistic solids, CoAsS and Na2CuP, based on first-principles calculations. Furthermore, it is shown that the closed and the open nodal line states in CoAsS and Na2CuP have touching points and can form a complex nodal structure phonon in a momentum space. Due to the topologically non-trivial behavior of the complex nodal structure in both phonons, evident phononic surface states occur in the projected surfaces of both materials. In this way, these states, arising from the projected crossing points, can benefit experimental detection in follow-up studies. It has been stated that the open and closed nodal line states are formed by the crossings of two phonon branches and, hence, these two types of nodal line phonons are coupled with each other. The results obtained here could be considered as a breakthrough in clearly demonstrating the coexistence of the open and closed nodal line states in phonons and, for this reason, may inspire researchers seeking materials with such topological states in other bosons, such as photons.Article Citation - WoS: 2Citation - Scopus: 1Cerebellar Developmental Venous Anomaly Causing Tinnitus and Hemifacial Spasm: a Case Report(Sage Publications inc, 2022) Ogul, Hayri; Unlu, Elif Nisa; Guclu, Derya; Koksal, Ali[No Abstract Available]Editorial Pontine Capillary Telangiectasia Mimicking Active Demyelinating Plaque in a Patient With Multiple Sclerosis(Springer-verlag Italia Srl, 2023) Koksal, Ali; Kiziloglu, Alper; Ogul, Hayri[No Abstract Available]Article Citation - WoS: 6Citation - Scopus: 9Experimental Simulation-Based Performance Evaluation of an Sms-Based Emergency Geolocation Notification System(Hindawi Ltd, 2017) Osebor, Isibor; Misra, Sanjay; Omoregbe, Nicholas; Adewumi, Adewole; Fernandez-Sanz, LuisIn an emergency, a prompt response can save the lives of victims. This statement generates an imperative issue in emergency medical services (EMS). Designing a system that brings simplicity in locating emergency scenes is a step towards improving response time. This paper therefore implemented and evaluated the performance of an SMS-based emergency geolocation notification system with emphasis on its SMS delivery time and the system's geolocation and dispatch time. Using the RAS metrics recommended by IEEE for evaluation, the designed system was found to be efficient and effective as its reliability stood within 62.7% to 70.0% while its availability stood at 99% with a downtime of 3.65 days/year.Editorial A Rare Cause of Unilateral Opaque Lung: Giant Primary Myxoid Spindle Cell Liposarcoma(Ma Healthcare Ltd, 2022) Ayyildiz, Veysel; Koksal, Ali; Aydin, Yener; Ogul, Hayri[No Abstract Available]Editorial Transcatheter Aortic Valve Implantation in Bicuspid Aortic Valve Patients With Coagulation Factor 7 and 11 Deficiency and Atrial Fibrillation(Kare Publ, 2023) Guney, Murat Can; Karaduman, Bilge Duran; Ayhan, Huseyin; Keles, Telat; Bozkurt, Engin[No Abstract Available]Article Citation - WoS: 4Citation - Scopus: 6Surgical Outcomes of Posterior Persistent Fetal Vasculature Syndrome: Cases With Tent-Shaped and Closed Funnel-Shaped Retinal Detachment(Springernature, 2023) Zeydanli, Ece Ozdemir; Ozdek, Sengul; Acar, Burak; Ozdemir, Huseyin Baran; Aktas, Zeynep; Gurelik, Gokhan; Atalay, Hatice TubaBackground/objectives To determine the role of vitreoretinal surgery (VRS) for two different forms of posterior persistent fetal vasculature syndrome (PFVS); with tent-shaped tractional retinal detachment (TRD) and closed funnel-shaped TRD. Subjects/methods Retrospective, single surgeon, consecutive case series of 52 eyes of 44 patients with posterior PFVS who underwent VRS. Cases were divided into "tent-shaped TRD" and "funnel-shaped TRD" groups based on the preoperative TRD configuration. Associated anomalies, functional and anatomical outcomes were evaluated. The cosmetic appearance was defined as poor if there was phthisis bulbi, gross buphthalmos, or corneal opacification; acceptable if there was apparent leukocoria; and excellent if none were noted at the last follow-up. Results Thirty eyes of 29 patients presented with tent-shaped TRD; 70% of which obtained counting fingers or better vision and 90% showed significant reversal of tenting achieving retinal reattachment. The cosmetic appearance was excellent in 87%. Two eyes (7%) became phthisic. Twenty-two eyes of 15 patients presented with funnel-shaped TRD and leukocoria; 45% achieved LP vision and 70% of patients with bilateral pathology had LP in at least one eye. The cosmetic appearance was acceptable to excellent in 73%. Three eyes (14%) became phthisic, one (5%) of which required enucleation. The median follow-up time was 16 (6-71) months. Conclusions VRS often provides functional vision and anatomy in posterior PFVS with tent-shaped TRD morphology. In the funnel-shaped TRD morphology, where no treatment has historically been recommended, surgery may be considered with an aim of restoring light perception and globe preservation, particularly in bilateral cases.
