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Öğe Self-tuning resonant mode microscanner control system(İstanbul Bilgi Üniversitesi, 2023) Arseven, Ayşin; Sarıoğlu, Baykal; Gökdel, Yiğit DağhanABSTRACT: This thesis demonstrates design, implementation, and experimental results of a low-cost, and low-power one-dimensional two gimballed magnetically actuated scanner capable of unidirectional scanning with piezoresistive feedback system that can be used for bioscanning applications. The proposed exible scanner structure consists of an embedded planar electrocoil with the main fabrication material polyimide. Moreover, the system ensures real-time feedback signal by means of the graphite that is coated onto the exure for the sake of the closed-loop systems. The system is auto-tuned in order to maintain the resonant mode of the microscanner. The slight, and exible substrate material of the scanner reduces the energy consumption and performs as 1D-scanning. The optimization and characterization of the planar electrocoil embedded in the scanner, which activates the scanner by creating an electromagnetic eld with the e ect of the external magnet, has been completed. The size of the outer frame of the structure is 40 mm 40 mm, and the moving scanning surface is 15 mm 14 mm with a thickness of 150 m. In order to maximize the amount of scanner displacement and total optical scanning angle (TOSA), the positions of the system components is optimized. Polyimide-based scanner's optical scanning angle is 73:59 in slow-scan direction at the approximately 82 Hz. Moreover, the saturation point frequency from the real-time piezoresistive feedback is approximately 81 Hz. The average error rate result is a 1.2%. The proposed scanner structure is characterized and tested in various experiments using a laser doppler vibrometer setup, and a piezoresistive feedback setup.Öğe Development and characterization of a wearable ring providing haptic feedback(İstanbul Bilgi Üniversitesi, 2022) Pehn Mayo, Franck Paulin Ludovig; Ayyıldız, MehmetABSTRACT: Touchscreens can be found on a variety of devices, including ATMs, phones, laptops, kiosks, automobiles, and many others. In those applications, the user navigates to the interface with his finger to interact with the tactile information using instincts. Roughly, every haptic device uses vibration to interact with the user. The user's haptic experience is delicate due to the complexity of the tactile information. Associating kinesthetic experience is a key subject in enhancing the human haptic experience. In this investigation, we developed a novel characterized haptic ring equipped with up to four LRA motors in order to improve the human haptic perception. The proposed device uses subcutaneous clues to replicate the forces and moments applied to the proximal interphalangeal joint of the index finger. Thresholding experiments are conducted using a total of nine subjects to evaluate the effects of the vibration amplitude, line thickness, and orientation on human perception. The results showed that as the line's thickness and amplitude increased, so did the participants' ability to identify the shapes. The human participants can detect a minimum thickness of 2 mm at the lowest possible vibration level with a single motor. Additionally, the second vibration amplitude and vertical orientation result in the best recognition rates and times besides the control.Öğe Cell separation using microcoil array integrated polyimide and fr4 printed circuit board(İstanbul Bilgi Üniversitesi, 2022) Kacar, İpek Hilal; Gökdel, Yiğit DağhanABSTRACT: In this thesis, a cell separation system using planar coil arrays is proposed with double layered PCBs. The system has been designed, fabricated, and tested as an alternative method for magnetic cell isolation. Here it is not aimed to propose a highly effective and sensitive standard cell separation device, but we have presented a cheap, less harmful, and sufficiently sensitive device with a novel method. Within this thesis, we proposed FR4 (Rigid) and Polyimide (Flexible) based, easy and quickto-fabricate, printed circuit board having double layered different sized planar coils to measure the total magnetic field output. In this work, the working principles of a simple magnetic cell separator is improved using this proposed magnetic cell separation methodology. Also, the sensitivity of planar coil printed circuit boards, which are used old-fashioned and unrepeatable fabrication methods is enhanced. Our work does not aim to separate cells high-sensitively, but it proposes a novel method which decreases damage of the cells. The planar coil size that gets optimum efficiency is selected by checking the planar coil tests performed. By using square planar coils of different sizes and turns, first the values to optimize the planar coil design were found, and then the magnetic field comparison was made by printing on two different substrates as FR4 and polyimide. After the overheating problem of the circuit was resolved, the damage to the cells approached almost zero. Our work does not aim to separate cells high-sensitively, but it proposes a novel and more advanced version of cell isolation process. Although cell separation does not contain 100% purity, our project has made it a preferable system since it is a perfectible method by converting it into a flexible structure. As can be seen in the Experimental Results Chapter, the results obtained were successful and a successful alternative method to the traditional method could be proposed.Öğe Control and optimization of islanded mode micro GRID(İstanbul Bilgi Üniversitesi, 2022) Ali, Natasha Qurban; Haklıdır, Füsun S. TutABSTRACT: Electrical energy plays a significant role in society since it maintains a high standard of living and stable economic development. Electric energy consumption has been gradually increasing in recent history, and this need is expected to increase more in the future. The majority of power today is generated by the combustion of fossil fuels, and there are considerable worries about the associated emissions. Renewable energy sources emerged as a feasible substitute for ecologically damaging ones. However, renewable energy sources have significantly unpredictable environmental circumstances when it comes to power generation and cannot be immediately integrated into the existing electrical system. The increased usage of renewable energy systems in recent years has increased the necessity of establishing microgrids. Energy is used where it is produced in microgrids. As a result, transmission and line losses are reduced to zero. At the same time, the micro grid model eliminates the negative impacts of commercial plants that disturb electricity standards, and more efficient and dependable grids are frequently built. A micro-grid is a grouping of micro-sources with a load and an optional energy device inside a certain area. The microgrid is normally operated in one of three modes: autonomous, non-autonomous, or dual. A micro-grid should generate and control its own energy in an independent operation. In this study, control applications on microgrids and the hierarchical control approach applied for microgrid architectures are investigated from a literature review. The pros and cons of these control methods are compared with one another. The key feature is to retain the frequency and voltage values of an islanded micro grid system within acceptable limits. Clean and green energy will be provided to the consumers of Büyükada (project’s site). The island will be self-sufficient for its energy needs.Öğe Developing a microgrid system for Büyükada Island in Istanbul(İstanbul Bilgi Üniversitesi, 2022) Masry, Salah; Haklıdır Tut, Füsun S.ABSTRACT: There is a strong link between access to energy and overall quality of life. Currently, around 1.4 billion people worldwide do not have access to electricity. Microgrids become a reality as a result of the massive shifts that have occurred in the energy sector over the last few decades. The micro grid concept anticipates a large number of loads and smaller-scale sources working together as a single controlled system providing both electricity and heat to its neighborhood. Microgrids can be used in a decentralized mode to offer complete control over the energy in a small region, or in a grid-connected mode to supply backup power to the national grid. Among the numerous islands around Istanbul, Büyükada is the fourth largest and most populous, and energy is provided beneath the water from the metropolis. In this regard, it is conceivable to deploy micro grid systems on this island in order to utilize renewable energy sources in Büyükada. Initial research revealed the island's potential for renewable energy sources. Solar, wind, and biomass demonstrated to have sufficient capacity to meet the energy demands. The study's goal is to evolve renewable energy, create a microgrid, and determine the most efficient and cost-effective approach to supply the island's needs. Environmentalists advocate for the use of renewable energy as a result of global warming, CO2 emissions, and the need for green and sustainable energy. The micro grid is one of the greatest choices for powering islands like Büyükada and extending the idea for the future chain of Micro grids. After using Homer Pro for designing and optimizing the microgrid which is around 128 million $ for a levelized cost of energy (LCOE) 0.2$/KWh which consists of PV panels, wind turbine, biogas generator, battery systems and a diesel generator for reducing the price around 85% renewable, however another microgrid is taken into account which is 100% renewable energy but the price is almost triple the price around 338 million $ with 0.53$/KWh for LCOE. All the details are mentioned in the chapter of methodology and the chapter of results.Öğe Diagnosis and prognosis of Covid-19 from medical images using deep learning(İstanbul Bilgi Üniversitesi, 2022) Fadlallah, Nouran; Denker, AhmetABSTRACT: Covid-19, with its high death rate, was discovered nearly three years ago. New variants resistant to vaccines still emerge while travel and export restrictions can not be held for longer. An accurate and fast diagnosis of such a disease is crucial to reducing its global spread. Computed Tomography CT scans have shown to be the most precise method for covid-19 diagnosis. However, it is a slow process to read and diagnose a disease from a CT scan due to the scarcity of skilled radiologists and the limited information and data available about covid-19. Computer vision has been successfully used in assisting professionals in diagnosis tasks both in terms of speed and accuracy when trained on large datasets. This work is an effort to develop a fast and accurate AI model for covid-19 diagnosis trained on a small dataset. We developed an ensemble model consisting of a 3D CNN LeNet-based model and a 2D Convolutional-Like Vision transformer to diagnose CT scans as covid-19 and healthy. A total of 508 CT scans were used to train the model as a subset of the publicly available MosMed dataset. This results in an accuracy of 90%, specificity of 92%, and a sensitivity of 88%.Öğe Design, fabrication, and implementation of a low-cost piezoresistive force encoding sensor(İstanbul Bilgi Üniversitesi, 2022) Akcan, Ömer Gökalp; Gökdel, Yiğit Dağhan; Baran, Eray A.ABSTRACT: This thesis demonstrates design, implementation, and experimental results of a low-cost disposable ?exible sensor system capable of both impact localization and measurement. Proposed ?exible sensor structure utilizes a special series of Bristol paper as the main fabrication material, which is coated with electric paint graphite paste and silver paste. Implemented sensor system uses a planar absolute encoder-like sensing topology to locate the impact and has a low-cost and quick manufacturing process. The size of the structure is 210 mm × 18.56 mm with the thickness of approximately 340 µm. It has an electronic read-out consisting of three identical Wheatstone bridge circuits and instrumentation ampli?ers for each bit. It can detect the external forces in the range of 0.6N to 12N with a spatial resolution of 2.4 cm and 0.55 cm in horizontal and vertical axes, respectively. The proposed sensor structure is tested in a series of experiments using a robotic setup consisted of a pantograph mechanism and a direct drive linear motor. The experiments illustrate the results with measurement sensitivity as small as 1N and proper fatigue resilience against repetitive loads.Öğe Time-delayed teleoperation with virtual environment reconstruction(İstanbul Bilgi Üniversitesi, 2021) Azeem, Hafiz Huzaifa; Baran, Abdurrahman ErayABSTRACT: Teleoperations have achieved a milestone in the field of robotics, performing ex tremely difficult tasks in hazardous environments such as undersea, nuclear sites, space exploration and tele-surgery. Their ability to perform tasks previously performed by a master device and to execute commands through a distant slave has opened many doors in the field of advanced robotics. When the distance between the master and the slave is long, the communication channel is subjected to time delays. In this thesis, our motivation was to find a way to reduce the effects of the time delay problem by estimating the parameters of remote environment contact force and render ing a virtual environment on the master side in a bilateral teleoperation system. First, Deep Learning Algorithm, Long Short Term Memory (LSTM) was used to estimate the parameters of the remote environment. After careful consideration, it was concluded that LSTM was not suitable for real-time implementation. Following the progress, the use of Recursive Least Squares (RLS) is demonstrated for estimating the parameters of remote environment contact force and rendering a virtual environment on the master side in a bilateral teleoperation system. Proper and fast estimation of the remote environment impedance plays a crucial role in the realization of local force controller for time delayed teleoperation systems. Three different variants of RLS estimator were implemented and compared against three different impedance models. The algorithms were initially tested in the sim ulation environment making use of a recorded real experiment data set. The force reconstruction performances are compared to evaluate the implemented models and estimators. Based on the simulation results, one of the estimators and one of the mod els are selected for experimental validation on a single degree of freedom motion control system. In a set of real experiments performed, the estimated force was rendered on the master side as a virtual environment, this way a local force feedback control loop was estab lished. The local force control loop was based on the predicted environment using the estimated parameters of RLS running in real time. Therefore, the master side was able to feel same force felt at the slave side without any time delay.Öğe Cellulose binding protein based generic biosensors(İstanbul Bilgi Üniversitesi, 2021) Kara, Ali Sinan; Gökdel, Yiğit DağhanABSTRACT: Biosensors are used in various industries. They have great importance in medicine and food industry. Quick prototype production is important for new biosensor production. In this work, a novel method for enzyme immobilization is described to make way for quick biosensor prototype production. Cellulosomes are enzyme complexes that target and degrade cellulosic materials. They utilize a Cellulose binding protein/module (CBM) to attach themselves to the cellulosic material. CBM fused enzymes are used in this work to immobilize enzymes on nanofibril cellulose (NFC) covered screen-printed electrodes. Cellulosic materials are abundant and cheap, thus making them a suitable immobilization material. It is shown in this work that enzymes can be expressed as CBM-fused chimeric proteins to create quick and reliable biosensors.Öğe Virtual and augmented reality with application to cultural heritage(İstanbul Bilgi Üniversitesi, 2021) Gencan, Civan Berk; Denker, AhmetABSTRACT: In recent years, virtual and augmented reality have become more and more involved in our lives due to developing computer graphics technology. Reality solutions are used in a not only wide variety of known fields such as architecture, engineering, industrial design and gaming but also digital reconstruction of historical artifacts. However, traditional modeling techniques which are generally used today, must be improved with new drawing and modeling processes in digital reconstruction of ancient monuments and historical artifacts in order to obtain efficient satisfactory results. The process that tries to receive efficient results need more detailed research and optimization method in three-dimensional modeling. This work aims to create an efficient digital reconstruction process for reconstruction of ancient monuments and historical artifacts. Digital reconstruction of Classical Temple of Artemis in Ephesus (one of the seven wonders of the antique world) has been taken as a case study with the help of multiple graphics software. The utilitarian function of the state-of-theart computer graphics technology is shown to be worthy of a place in the reconstruction of lost monuments of our cultural heritage.Öğe Analysis of photovoltaic solar panels with tracking system(İstanbul Bilgi Üniversitesi, 2020) Jnani, Muaaz; Günay, Mehmet ErdemABSTRACT: Year by year our demands for energy have been increasing and one day we may not have a good source for energy so we would need to concern some solutions for that. Actually, in my humble thesis, I am going to show the population and energy demands, the interesting in the manufacture and development of solar panels with the cost of PV modules, absorption of solar radiation, the benefits of the solar panels with the tracking solar system and how much this technology effect to our performance. Considering the primary source of energy is solar energy, which is sustainable, free and reachable from anywhere. Today, the usage of photovoltaic technology has increased. Because photovoltaic could be settled in any place to take to solar radiation, it is clean energy that means environmentally friendly, maintenance easy and installation of panels cheaper rather than all the other kind of energy. In this thesis, the types of solar panels and differences between them are analyzed, and the effects of orbit and the rotation of the earth to the efficiency of the panels were studied. Then, for a case power plant, a detailed feasibility analysis was made by observing the solar irradiation and sunshine duration data for a variety of regions. After finding the optimum location, the performances of different solar panels were compared and the maximum power output with the minimum cost was estimated. It is my greatest hope that the readers of this thesis will devote themselves to building a world in which kids and grandkids could be been with both pure water and air could be breathed, in which individuals and the remainder of nature will nurture themselves.Öğe Low power smart wireless mobile electronic control system(İstanbul Bilgi Üniversitesi, 2019) Anıl, Emin Cihan; Sarıoğlu, BaykalABSTRACT: Microsystems which can be placed on the patient with micro size and very low power consumption and will be able to work continuously to monitor the course of the disease are needed in biomedical area. Complementary Metal Oxide Semiconductor (CMOS) technology is preferred for most of biomedical systems due its common usage, design conveniences and low cost. The design and results of oscillator based capacitive and resistive sensing circuits with low supply voltage and low power consumption are presented for an optically powered biomedical microsystem. The oscillator based sensing circuits are designed and simulated using 180 nm United Microelectronics Corporation (UMC) CMOS technology. Also, the theoretical relationships between the output frequency and sensor resistance/capacitance are derived. For optical microsystem, communication protocols which are pulse width modulation (PWM) and pulse amplitude modulation (PAM) are presented to transmit the data. Arduino Uno is used to represent the microsystem. Raspberry Pi 3B is used as a transmitter. Mutual data transmission is carried out by means of Infrared Radiation (IR) Light Emitting Diode (LED) which is transmitter and phototransistor which is receiver. Thanks to infrared beam, the power consumption of designed circuit is very low. A Graphical User Interface (GUI) is designed on the Raspberry Pi. The Raspberry Pi serves as a control panel and so different data is sent to the receiver.Öğe Aptamer based biosensor design for gluten detection(İstanbul Bilgi Üniversitesi, 2019) Yeşilyurt, Gökay Su; Gül, ÖzgürABSTRACT: A lot of people are suffering because of gluten intolerance or celiac disease which is caused by gluten. Additionally, there is a growing demand for the gluten-free diet as a part of healthy lifestyle. The only treatment for the celiac disease or gluten intolerance is to follow a strict gluten-free diet. As a result, there is an increasing need for the gluten detection for not only raw food but also for the processed food. The goal of our study was to design an aptamer-based biosensor for the gluten detection. To achieve this goal, we have optimized sample preprocessing and compared the results with industry standard gluten from Prolamine Working Group (PWG). We have also, modified some aptamers that are already used in some scientific reports with biotin and tested their ability to recognize gluten using ELISA. Finally, we have used lateral flow assay format to detect gluten using biotinylated aptamers on our homemade strips. Therefore; we designed specific biosensor that has the potential to detect and quantify different sources of gluten. We choose aptamer as the biological recognition element because it is easy to produce, it is stable under different conditions and it is fast for the detection of proteins. Since aptamers are new generation of biosensor, which is called aptasensors, they will be well adapted to our conditions.Öğe Paper based low cost biosensor design and fabrication(İstanbul Bilgi Üniversitesi, 2017) Önder, Melike Nur; Gökdel, Yiğit Dağhan[Abstract Not Available]Öğe Design and implementation of a mobile search and rescue robot(İstanbul Bilgi Üniversitesi, 2017) İşeri, Mehmet Can; Denker, Ahmet[Abstract Not Available]Öğe Micromachined platform design for all optical microsystems(İstanbul Bilgi Üniversitesi, 2017) Kızılcabel, Hilal; Sarıoğlu, Baykal[Abstract Not Available]Öğe Determination of the dynamics of wind turbines by remote measurement methods(İstanbul Bilgi Üniversitesi, 2017) Dilek, Ahmet Uğur; Gökdel, Yiğit Dağhan[Abstract Not Available]Öğe A pressure sensor fabricated with 3d printer for a biomedical microsystem(İstanbul Bilgi Üniversitesi, 2017) Tuna, Ahmet; Gökdel, Yiğit Dağhan[Abstract Not Available]
