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ÖgeAnalog neural network based on memristor crossbar arrays(İstanbul Teknik Üniversitesi, 2019) Yıldız, Hacer A. ; Altun, Mustafa ; Güngördü, Doğuş ; Stan, Mircea ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communications EngineeringIn this paper, a new feed forward analog neural network is designed using a memristor based crossbar array architecture. This structure consists of positive and negative polarity connection matrices. In order to show the performance and usefulness of the proposed circuit, it is considered a sample application of iris data recognition. The proposed neural network implementation is approved by the simulation in Cadence design environment using 0.35µm CMOS technology. The results obtained are promising for the implementation of high density neural network.
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ÖgeAntifungal Activities of Different Essential Oils and Their Electrospun Nanofibers against Aspergillus and Penicillium Species Isolated from Bread(American Chemical Society, 2022) Karbancıoğlu Güler, Funda ; Devecioğlu, Tuğba ; Türker, Mustafa ; 0000-0001-6576-0084 ; 0000-0001-6681-0944 ; Food EngineeringMold growth, especially Aspergillus spp. and Penicillium spp., deteriorates the quality of bakery products. Essential oils (EOs) have been categorized as good natural antimicrobials. Hereby, this study aimed to evaluate the antifungal activity of six EOs, ginger, cumin, cinnamon, black pepper, origanum, and clove, and their volatile compounds against fungal strains isolated from bread: Penicillium carneum DDS4, Aspergillus flavus DDS6, and Aspergillus niger DDS7 by disc diffusion and disc volatilization methods, respectively. Among EOs, cumin, cinnamon, origanum, and clove were found to be effective against fungal strains, and their minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined. The observed lowest MIC value of EOs was obtained at 1000 μg/mL concentration, and the lowest MFC value was obtained from the results of clove at a concentration of 1000 μg/mL. Based on the MIC and MFC values, clove and cinnamon EOs were found to be more effective at lower concentrations. Electrospun nanofiber films of clove and cinnamon were produced with 6% poly(vinyl alcohol) (PVA), 2% β-cyclodextrin (β-CD), and 2% EO to overcome the unfavorable sensory impact of EOs on food products. The inhibitory activity of cinnamon EO film (2.64–2.51 log(CFU/mg)) was considerably lower than clove EO film (3.18–3.24 log(CFU/mg)) against P. carneum DDS4 and A. niger DDS7. Furthermore, these nanofiber films prevented fungal growth on bread samples visibly and were shown to be an alternative application for active food packaging.
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ÖgeAssessment of Microbial Diversity during Thermophilic Anaerobic Co-Digestion for an Effective Valorization of Food Waste and Wheat Straw( 2022-12-21) Yangın Gömeç, Çiğdem ; Agnihotri, Swarnima ; Ylitervo, Päivi ; Sárvári Horváth, Ilona ; 0000-0003-3519-4821 ; Environmental EngineeringIn this study, predominant bacterial and archaeal populations and their roles during anaerobic mono-digestion of food waste (FW) and co-digestion of FW with straw pellets (SP) at thermophilic temperature (53 ± 1 °C) were assessed by Next Generation Sequencing (NGS) analysis at organic loading rates (OLRs) of 3.0 and 7.0 gVS/L/d. Depending on the seed; results revealed that Firmicutes, Bacteroidetes, and Proteobacteria were, respectively the most prevalent bacterial phyla at both OLRs investigated. On the other hand, Euryarchaeota was dominated by methanogens playing crucial role in biogas production and correlated mainly with the activities of Methanobacteria and Methanomicrobia at class level. Acetoclastic Methanosaetae was the predominant genus at OLR = 3.0 gVS/L/d; however, shared the same predominance with hydrogenotrophic methanogens Methanospirillium at the highest OLR. Although no clear effect in response to straw addition at OLR of 3.0 gVS/L/d could be seen in terms of methanogenic archaea at genus level, hydrogenotrophic methanogens revealed some shift from Methanobacterium to Methanospirillium at higher OLR. Nevertheless, no prominent microbial shift in the presence of wheat straw at increased OLR was likely due to adapted inoculation at start-up which was also demonstrated by relatively stable biogas yields during co-digestion.
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ÖgeDefect Tolerant Logic Synthesis for Memristor Crossbars with Performance Evaluation(IEEE, 2018) Tunali, Onur ; Morgül, M. Ceylan ; Altun, Mustafa ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication EngineeringIn this paper, we study defect-tolerant logic synthesis of memristor-based crossbar architectures. We propose a hybrid algorithm, combining heuristic and exact algorithms, that achieves perfect tolerance for 10-percent stuck-at open defect rates. Along with defect tolerance, we also consider area, delay, and power costs of the memristor crossbars to elaborate on two-level and multi-level logic designs.
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ÖgeElastic Stability of a Cylindrical Strip Subjected to Simple Bending(Bulletin of the Technical University of Istanbul, 1952-09-05) İnan, Mustafa ; Mustafa İnan Kütüphanesiİnan'ın "Bulletin of the Technical University of Istanbul, 1952, Cilt 5"de yayımlanan makalesi ve makalenin el yazması ile daktilo edilmiş hali.
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ÖgeEnergy Production from Biomass Valorization( 2023-05-24) Yangın Gömeç, Çiğdem ; Sárvári Horváth, Ilona ; Martin, Carlos ; 0000-0003-3519-4821 ; Environmental Engineering
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ÖgeA Fast Hill Climbing Algorithm for Defect and Variation Tolerant Logic Mapping of Nano-Crossbar Arrays(IEEE, 2018) Peker, Furkan ; Altun, Mustafa ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication EngineeringNano-crossbar arrays are area and power efficient structures, generally realized with self-assembly based bottom-up fabrication methods as opposed to relatively costly traditional top-down lithography techniques. This advantage comes with a price: very high process variations. In this work, we focus on the worst-case delay optimization problem in the presence of high process variations. As a variation tolerant logic mapping scheme, a fast hill climbing algorithm is proposed; it offers similar or better delay improvements with much smaller runtimes compared to the methods in the literature. Our algorithm first performs a reducing operation for the crossbar motivated by the fact that the whole crossbar is not necessarily needed for the problem. This significantly decreases the computational load up to 72% percent for benchmark functions. Next, initial column mapping is applied. After the first two steps that can be considered as preparatory, the algorithm proceeds to the last step of hill climbing row search with column reordering where optimization for variation tolerance is performed. As an extension to this work, we directly apply our hill climbing algorithm on defective arrays to perform both defect and variation tolerance. Again, simulation results approve the speed of our algorithm, up to 600 times higher compared to the related algorithms in the literature without sacrificing defect and variation tolerance performance.
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ÖgeA fast logic mapping algorithm for multiple-type-defect tolerance in reconfigurable nano-crossbar arrays(Institute of Electrical and Electronics Engineers (IEEE), 2017-09-21) Tunali, Onur ; Altun, Mustafa ; https://orcid.org/0000-0002-3103-1809 ; Electronics and Communication EngineeringUnlike conventional CMOS circuits, nano-crossbar arrays have considerably high defect rates. Multiple-type defects randomly occur both on crosspoint switches and wires that substantially complicates the design phase of the circuits with an elimination of systematic design choices. In order to overcome this problem, a logic mapping methodology is presented in this paper. A fast heuristic algorithm using pre-mapping logic morphing, defect oriented adaptive sorting, matching with Hadamard multiplication, and backtracking is introduced. The proposed algorithm covers both crosspoint defects including stuck-open and stuck-closed types and wire defects including bridging and broken types. Effects of stuck-closed defects, mostly disregarded in the literature, are studied in depth. In simulations, an industrial benchmark suit is used for obtaining runtime and success rate values of the proposed algorithm in comparison with those of the existing algorithms in the literature. A relative accuracy evaluation is also given in comparison with exact mapping techniques. Finally, the steps of the algorithm that are based on pre-mapping and heuristic matching techniques, are separately justified with experimental results.
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ÖgeIn vivo dielectric properties of healthy and benign rat mammary tissues from 500 MHz to 18 GHz(MDPI, 2020-04) Yılmaz, Tuba ; Ateş Alkan, Fatma ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication EngineeringThis work investigates the in vivo dielectric properties of healthy and benign rat mammary tissues in an attempt to expand the dielectric property knowledge of animal models. The outcomes of this study can enable testing of microwave medical technologies on animal models and interpretation of tissue alteration-dependent in vivo dielectric properties of mammary tissues. Towards this end, in vivo dielectric properties of healthy rat mammary tissues and chemically induced benign rat mammary tumors including low-grade adenosis, sclerosing adenosis, and adenosis were collected with open-ended coaxial probes from 500 MHz to 18 GHz. The in vivo measurements revealed that the dielectric properties of benign rat mammary tumors are higher than the healthy rat mammary tissues by 9.3% to 35.5% and 19.6% to 48.7% for relative permittivity and conductivity, respectively. Furthermore, to our surprise, we found that the grade of the benign tissue affects the dielectric properties for this study. Finally, a comparison with ex vivo healthy human mammary tissue dielectric properties revealed that the healthy rat mammary tissues best replicate the dielectric properties of healthy medium density human samples.
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Öge"İnsan ve Otomat" başlıklı makale( 1966-02-09) İnan, Mustafa ; Mustafa İnan Kütüphanesiİnan'ın, İ.T.Ü. Elektronik Hesap Merkezi tarafından düzenlenen Elektronik Hesap Seminerinde, 8 Eylül 1965 tarihinde sunduğu bildiri metnidir.
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ÖgeK Dergisi'nde yayımlanmış Oğuz Atay üzerine bir yazı(K Dergisi, 2007-08-17) Yılmazçelik, Cansu ; Mustafa İnan KütüphanesiK Dergisi'nin 17.08.2007 tarihli 46. sayısında yayımlanmış Oğuz Atay üzerine bir yazı. Yazının içinde Bir Bilim Adamının Romanı: Mustafa İnan kitabına da değiniliyor.
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ÖgeLogic Synthesis and Testing Techniques for Switching Nano-Crossbar Arrays(Elsevier, 2017) Alexandrescua, Dan ; Altun, Mustafa ; Anghel, Lorena ; Bernasconi, Anna ; Cirianie, Valentina ; Frontini, Luca ; Tahoori, Mehdi ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication EngineeringBeyond CMOS, new technologies are emerging to extend electronic systems with features unavailable to silicon-based devices. Emerging technologies provide new logic and interconnection structures for computation, storage and communication that may require new design paradigms, and therefore trigger the development of a new generation of design automation tools. In the last decade, several emerging technologies have been proposed and the time has come for studying new ad-hoc techniques and tools for logic synthesis, physical design and testing. The main goal of this project is developing a complete synthesis and optimization methodology for switching nano-crossbar arrays that leads to the design and construction of an emerging nanocomputer. New models for diode, FET, and four-terminal switch based nanoarrays are developed. The proposed methodology implements logic, arithmetic, and memory elements by considering performance parameters such as area, delay, power dissipation, and reliability. With combination of logic, arithmetic, and memory elements a synchronous state machine (SSM), representation of a computer, is realized. The proposed methodology targets variety of emerging technologies including nanowire/nanotube crossbar arrays, magnetic switch-based structures, and crossbar memories. The results of this project will be a foundation of nano-crossbar based circuit design techniques and greatly contribute to the construction of emerging computers beyond CMOS. The topic of this project can be considered under the research area of “Emerging Computing Models” or “Computational Nanoelectronics”, more specifically the design, modeling, and simulation of new nanoscale switches beyond CMOS.
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ÖgeMicrowave dielectric property based classification of renal calculi: Application of a kNN algorithm(Elsevier, 2019) Saçlı, Banu ; Aydınalp, Cemanur ; Cansız, Gökhan ; joof, Sulayman ; Yılmaz, Tuba ; Çayören, Mehmet ; Önal, Bülent ; Akduman, İbrahim ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication EngineeringThe proper management of renal lithiasis presents a challenge, with the recur- rence rate of the disease being as high as 46%. To prevent recurrence, the first step is the accurate categorization of the discarded renal calculi. Currently, the discarded renal calculi type is determined with the X-ray powder diffraction method which requires a cumbersome sample preparation. This work presents a new approach that can enable fast and accurate classification of discarded renal calculi with minimal sample preparation requirements. To do so, first, the measurements of the dielectric properties of naturally formed renal calculi are collected with the open-ended contact probe technique between 500 MHz to 6 GHz with 100 MHz intervals. Cole–Cole parameters are fitted to the measured dielectric properties with the generalized Newton–Raphson method. The re- nal calculi types are classified based on their Cole–Cole parameters as calcium oxalate, cystine, or struvite. The classification is performed using nearest neigh- bors (kNN) machine learning algorithm with the 10 nearest neighbors, where accuracy as high as 98.17% is achieved.
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ÖgeMicrowave dielectric spectroscopy of renal calculi: A large scale study on dielectric properties from 500 MHz to 18 GHz(IEEE, 2019) Yılmaz, Tuba ; Saçlı, Banu ; Cansız, Gökhan ; joof, Sulayman ; Aydınalp, Cemanur ; Çayören, Mehmet ; Akduman, İbrahim ; Önal, Bülent ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication EngineeringInherent dielectric property discrepancy between biological anomalies and healthy tissue enables the microwave diagnostic and therapeutic technologies. To reveal this discrepancy, microwave dielectric properties of many different biological tissues are tabulated. Although the dielectric properties of biological tissues are well documented in the literature, the knowledge on microwave dielectric property behavior of the renal calculi is limited. This work presents ultra wideband dielectric properties of three renal calculi types between 500 MHz to 18 GHz to pave the way for possible application of microwave technologies for diagnosis, treatment, and prevention of urolithiasis. Microwave dielectric spectroscopy is performed on a total of 66 natural stone samples with open-ended coaxial probe technique. The samples belong to three commonly diagnosed renal calculi categories, namely calcium oxalate, cystine, struvite. Analysis of variance (ANOVA) test is performed on fitted Cole-Cole parameters and it was concluded that there is a statistically significant difference between the dielectric properties of the renal calculi types. A patient-to-patient statistical test is also performed and it was concluded that there is no statistical difference between the samples belonging to the same renal calculi category. To this end, based on the relative permittivity discrepancy between the renal calculi types, the category of renal calculi can be identified by measuring the dielectric properties of renal calculi with open-ended coaxial probe technique.
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ÖgeMicrowave spectroscopy based classification of rat hepatic tissues: On the significance of dataset(BAJECE, 2020-10) 0000-0003-3052-2945 ; Elektronik ve Haberleşme MühendisliğiWith the advancements in machine learning (ML) algorithms, microwave dielectric spectroscopy emerged as a potential new technology for biological tissue and material categorization. Recent studies reported the successful utilization of dielectric properties and Cole-Cole parameters. However, the role of the dataset was not investigated. Particularly, both dielectric properties and Cole-Cole parameters are derived from the S parameter response. This work investigates the possibility of using S parameters as a dataset to categorize the rat hepatic tissues into cirrhosis, malignant, and healthy categories. Using S parameters can potentially remove the need to derive the dielectric properties and enable the utilization of microwave structures such as narrow or wideband antennas or resonators. To this end, in vivo dielectric properties and S parameters collected from hepatic tissues were classified using logistic regression (LR) and adaptive boosting (AdaBoost) algorithms. Cole-Cole parameters and a reproduced dielectric property data set were also investigated. Data preprocessing is performed by using standardization a principal component analysis (PCA). Using the AdaBoost algorithm over 93% and 88% accuracy is obtained for dielectric properties and S parameters, respectively. These results indicate that the classification can be performed with a 5% accuracy decrease indicating that S parameters can be an alternative dataset for tissue classification.
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ÖgeThe mobile future of university libraries and an analysis of the Turkish case(emerald Publishing, 2017-05) Kubat, Gulcin ; Kubat, Gulcin [0000-0001-9009-8758]Purpose: Smartphones will very soon become the standard means by which the Internet is accessed, and the rates of connection from mobile devices will supercede those which are computer-based.The hypothesis of this study is that a university library accessible by mobile technology will be the model of the future, and its purpose is to search for any evidence for which the university libraries in Turkey are prepared to meet this challenge. Design/methodology/approach-In the study, both domestic and foreign literature surveys were undertaken to determine which mobile library services are offered in university libraries. 30 random central libraries of both private and state universities were selected from across the 7 regions of Turkey. To gather data, a 26-question electronic survey was generated and e-mailed to the library managers. The questions were based on findings regarding the mobile library services provided by university libraries around the world. Findings-By examining the survey results, it was determined that Turkish university libraries utilise a comparable level of mobile technology, and demonstrate a similar level of care with regard to the services they offer. There are mobile sites (separate sites or mobile sites as applications), mobile library catalogues, SMS services, chatrooms, consultations via IM tools, mobile device lending services, and augmented reality and QR code applications. Research limitations/implications. In Turkey, the structures of university libraries operate under variable conditions due to the lack of established standards. This causes negative results for the delivery of library services. For this reason, university library standards should be set practicable as soon as reasonable, considering the social/economic and cultural structure of the country. Practical implications-Due to the transformative effect technology and the Internet have had on services, “information and communication technologies infrastructure” has been added as a sixth element to the five traditional library items; namely building, budget, personnel, collection, and users. Globalisation through the web has resulted in the individualisation of services, and the slogan “content is king” has been changed to the “customer experience is king”. Fundamental library services are being adapted to allow mobile technology access, and this approach best reflects the new slogan. Therefore, the university library of the future may well be the one entirely based on mobile technology. Social implications: mobile devices lead to new forms of engagement with student learning; so academic libraries are expected to be strong partners in the teaching and learning processes of their institution. Originality/value: The hypothesis of this study is that a university library accessible by mobile technology will be the model of the future, and its purpose is to search for any evidence for which the university libraries in Turkey are prepared to meet this challenge. This study is also meaningful because there have not been any study of Turkish university libraries in terms of mobile library services to users. This paper is the first time that a comprehensive study has been made of current mobile technology-based services, and is also the first comparison of the applications in Turkish university libraries. Additionally paper synthesizes developments and provides suggestions for the future. © Emerald Publishing Limited.
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ÖgeMulticlass classification of hepatic anomalies with dielectric properties: From phantom materials to rat hepatic tissues(MDPI, 2020-01) Yılmaz, Tuba ; Elektronik ve Haberleşme Mühendisliği ; Electronics and Communication EngineeringOpen-ended coaxial probes can be used as tissue characterization devices. However, the technique suffers from a high error rate. To improve this technology, there is a need to decrease the measurement error which is reported to be more than 30% for an in vivo measurement setting. This work investigates the machine learning (ML) algorithms’ ability to decrease the measurement error of open-ended coaxial probe techniques to enable tissue characterization devices. To explore the potential of this technique as a tissue characterization device, performances of multiclass ML algorithms on collected in vivo rat hepatic tissue and phantom dielectric property data were evaluated. Phantoms were used for investigating the potential of proliferating the data set due to difficulty of in vivo data collection from tissues. The dielectric property measurements were collected from 16 rats with hepatic anomalies, 8 rats with healthy hepatic tissues, and in house phantoms. Three ML algorithms, k-nearest neighbors (kNN), logistic regression (LR), and random forests (RF) were used to classify the collected data. The best performance for the classification of hepatic tissues was obtained with 76% accuracy using the LR algorithm. The LR algorithm performed classification with over 98% accuracy within the phantom data and the model generalized to in vivo dielectric property data with 48% accuracy. These findings indicate first, linear models, such as logistic regression, perform better on dielectric property data sets. Second, ML models fitted to the data collected from phantom materials can partly generalize to in vivo dielectric property data due to the discrepancy between dielectric property variability.
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ÖgeMustafa İnan'a ithaf edilen İstanbul Teknik Üniversitesi Dergisi sayısı ve bir makale( 1987) İnan, Mustafa ; Mustafa İnan KütüphanesiVefatının 20. yılı dolayısıyla İstanbul Teknik Üniversitesi Dergisi'nin 45.cilt, 1-2.sayısı İnan'ın anısına ithaf edilmiştir. Dergide dönemin rektörü Prof. İlhan Kayan'ın ithaf yazısının yanında, İnan'ın "Eğilme Momenti Etkisine Maruz Silindirik Şeritlerin Vurgu Stabilitesi" başlıklı bir makalesine de yer verilmiştir. Arşiv çalışması kapsamında yalnızca İnan ile doğrudan ilgili yerler sayısallaştırılmıştır.
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ÖgeMustafa İnan'ın Eighth International Congress on Theoretical and Applied Mechanics'te sunduğu tebliğ( 1955) İnan, Mustafa ; Mustafa İnan Kütüphanesiİnan'ın Eighth International Congress on Theoretical and Applied Mechanics'te sunduğu "Durchschlagsstabilität eines zylindirischen flächenstreifens unter der wirkung des biegemomentes" başlıklı tebliğinin tıpkıbasımı.
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ÖgeMustafa İnan'ın Schweizer Archiv'de yayımlanmış makaleleri(Schweizer Archiv, 1939) İnan, Mustafa ; Baud, R.V. ; Mustafa İnan Kütüphanesiİnan'ın, birisini R.V. Baud ile ortak yazdığı iki ayrı makalesi. "Beispiele aus der Elastizitätstheorie betreffend die Ueberführung verwickelter mathematischer Ergebnisse in gebrauchsfertige Formeln" başlıklı makalesi Schweizer Archiv'in Januar 1939, Heft 1 sayısında yayımlanmış. R.V. Baud ile birlikte kaleme aldıkları "Zur ermittlung der inneren Spannungen von Profilträgern" başlıklı makalesi ise aynı yayının September 1943, Heft 9 sayısında yayımlanmış. Derginin sağ üst köşesinde İnan'ın sonradan basılmış kaşesi de yer alıyor.