Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257516
Fatma YAŞAR ÇIKLAÇANDIR, Semih UTKU
Remote sensing is the technology of collecting and examining data about the earth with special sensors. The data obtained are used in many application areas. The classification success of remote sensing images is closely related to the accuracy and reliability of the information to be used. For this reason, especially in recent studies, it is seen that Convolutional Neural Network (CNN), which has become popular in many fields, is used and high successes have been achieved. However, it is also an important need to obtain this information quickly. Therefore, in this study, it is aimed to get results as successful as CNN and in a shorter time than CNN. Hybrid systems in which features are extracted with CNN and then classification is performed with machine learning algorithms have been tested. The successes of binary combinations of two different CNN architectures (ResNet18, GoogLeNet) and four different classifiers (Support Vector Machine, K Nearest Neighbor, Decision Tree, Discriminant Analysis) have been compared with various metrics. GoogLeNet & Support Vector Machine (93.33%) is the method with the highest accuracy rate, while ResNet18 & Decision Tree (50.95%) is the method with the lowest accuracy rate.
{"title":"Performance Comparison of CNN Based Hybrid Systems Using UC Merced Land-Use Dataset","authors":"Fatma YAŞAR ÇIKLAÇANDIR, Semih UTKU","doi":"10.21205/deufmd.2023257516","DOIUrl":"https://doi.org/10.21205/deufmd.2023257516","url":null,"abstract":"Remote sensing is the technology of collecting and examining data about the earth with special sensors. The data obtained are used in many application areas. The classification success of remote sensing images is closely related to the accuracy and reliability of the information to be used. For this reason, especially in recent studies, it is seen that Convolutional Neural Network (CNN), which has become popular in many fields, is used and high successes have been achieved. However, it is also an important need to obtain this information quickly. Therefore, in this study, it is aimed to get results as successful as CNN and in a shorter time than CNN. Hybrid systems in which features are extracted with CNN and then classification is performed with machine learning algorithms have been tested. The successes of binary combinations of two different CNN architectures (ResNet18, GoogLeNet) and four different classifiers (Support Vector Machine, K Nearest Neighbor, Decision Tree, Discriminant Analysis) have been compared with various metrics. GoogLeNet & Support Vector Machine (93.33%) is the method with the highest accuracy rate, while ResNet18 & Decision Tree (50.95%) is the method with the lowest accuracy rate.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257510
Nurettin KÖRÖZLÜ
Akustik ışıma kuvvetlerinden faydalanarak hava ortamında mm boyutundaki parçacıkların tuzaklanması ve manipülasyonu son zamanlarda yoğun ilgi gören çalışma alanlarından biridir. İki boyutlu fononik kristallerin çizgisel kusur durumları ile akustik ışıma kuvvetinden faydalanılarak havada mm boyutunda katı parçacıkların akustik metamalzeme mercekler ile manipülasyonu ve boyutlarına göre ayrıştırılması sayısal hesaplamalar ile gösterilmiştir. Bu yapılırken, Sonlu Elemanlar Yöntemiyle simülasyon hesabı yapılarak fononik kristallerin band yapıları elde edilmiştir. Çalışmada iki boyutlu fononik kristal ile oluşturulan bir dairesel halka çınlaçta yerçekimi ve akustik ışıma kuvvetlerinin birlikte etkisi ile küresel parçacıkların dairesel yörüngede hareketi sağlanmıştır. Hesaplamalarda 0.25 mm, 0.4 mm ve 0.55 mm çaplı polistiren küreciklerin hareketi t=0, 50, 100, 150, 200 ve 400 ms deki konumları incelenmeştir. Bütün parçacıklar dairesel düğüm çizgisini izleyerek belirtilen sürelerde yörüngenin yaklaşık olarak ¼, ½, ¾ ve 1 oranındaki kısımlarını kat etmişlerdir. t=400 ms anında 0.55 mm çaplı parçacık yaklaşık olarak iki turu tamamlarken, diğer parçacıklar sürüklenme kuvvetinden dolayı çizgisel hızlarını kaybetmekte ve düğüm çizgisinin en alt noktasında ayrışarak tuzaklanmaktadır.
{"title":"Akustik Işıma Kuvvetiyle Milimetre Boyutundaki Katı Parçacıkların Tuzaklanması ve Ayrıştırılması","authors":"Nurettin KÖRÖZLÜ","doi":"10.21205/deufmd.2023257510","DOIUrl":"https://doi.org/10.21205/deufmd.2023257510","url":null,"abstract":"Akustik ışıma kuvvetlerinden faydalanarak hava ortamında mm boyutundaki parçacıkların tuzaklanması ve manipülasyonu son zamanlarda yoğun ilgi gören çalışma alanlarından biridir. İki boyutlu fononik kristallerin çizgisel kusur durumları ile akustik ışıma kuvvetinden faydalanılarak havada mm boyutunda katı parçacıkların akustik metamalzeme mercekler ile manipülasyonu ve boyutlarına göre ayrıştırılması sayısal hesaplamalar ile gösterilmiştir. Bu yapılırken, Sonlu Elemanlar Yöntemiyle simülasyon hesabı yapılarak fononik kristallerin band yapıları elde edilmiştir. Çalışmada iki boyutlu fononik kristal ile oluşturulan bir dairesel halka çınlaçta yerçekimi ve akustik ışıma kuvvetlerinin birlikte etkisi ile küresel parçacıkların dairesel yörüngede hareketi sağlanmıştır. Hesaplamalarda 0.25 mm, 0.4 mm ve 0.55 mm çaplı polistiren küreciklerin hareketi t=0, 50, 100, 150, 200 ve 400 ms deki konumları incelenmeştir. Bütün parçacıklar dairesel düğüm çizgisini izleyerek belirtilen sürelerde yörüngenin yaklaşık olarak ¼, ½, ¾ ve 1 oranındaki kısımlarını kat etmişlerdir. t=400 ms anında 0.55 mm çaplı parçacık yaklaşık olarak iki turu tamamlarken, diğer parçacıklar sürüklenme kuvvetinden dolayı çizgisel hızlarını kaybetmekte ve düğüm çizgisinin en alt noktasında ayrışarak tuzaklanmaktadır.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135586706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257514
Uğur SORGUCU
The interaction between electromagnetic fields and biological masses is increasing day by day. There are thousands of studies in the literature on this interaction. Until now, most of the studies on bio heat transfer have focused on damage caused by electromagnetic fields. However, the therapeutic side of electromagnetic fields has been neglected. This study aimed to bring a new perspective. Using the bio heat transfer equation, the temperature effect of different parameters due to the electromagnetic field was investigated. In the present study, the analytical solution of Pennes' bioheat transfer equation was evaluated together with real muscle tissue parameters. By trying different parameter variations, the effect of parameters such as perfusion constant and thermal conductivity coefficient on tissue warming was observed. In the light of this study, device designs for magnetic heating processes applied in physiotherapy will be possible. After entering the tissue parameters and electromagnetic field values, it was possible to find out what kind of temperature change can be observed as a result of the formulation obtained in this study. The effects of thermal conductivity coefficient, blood perfusion value and heat transfer coefficient on temperature distribution were graphically analyzed. Effect of randomly selected thermal parameters are evaluated within the study. This study has shown to what extent the increasing thermal parameters of the tissue will be affected by the electromagnetic field.
{"title":"Elektromanyetik Alana Maruz Kalmış Kas Dokusunun Termal Analizi","authors":"Uğur SORGUCU","doi":"10.21205/deufmd.2023257514","DOIUrl":"https://doi.org/10.21205/deufmd.2023257514","url":null,"abstract":"The interaction between electromagnetic fields and biological masses is increasing day by day. There are thousands of studies in the literature on this interaction. Until now, most of the studies on bio heat transfer have focused on damage caused by electromagnetic fields. However, the therapeutic side of electromagnetic fields has been neglected. This study aimed to bring a new perspective. Using the bio heat transfer equation, the temperature effect of different parameters due to the electromagnetic field was investigated. In the present study, the analytical solution of Pennes' bioheat transfer equation was evaluated together with real muscle tissue parameters. By trying different parameter variations, the effect of parameters such as perfusion constant and thermal conductivity coefficient on tissue warming was observed. In the light of this study, device designs for magnetic heating processes applied in physiotherapy will be possible. After entering the tissue parameters and electromagnetic field values, it was possible to find out what kind of temperature change can be observed as a result of the formulation obtained in this study. The effects of thermal conductivity coefficient, blood perfusion value and heat transfer coefficient on temperature distribution were graphically analyzed. Effect of randomly selected thermal parameters are evaluated within the study. This study has shown to what extent the increasing thermal parameters of the tissue will be affected by the electromagnetic field.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135586714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257513
Mehmet Alptug BOYLU, Umut CEYHAN
The use of self-driven flows in microfluidic devices attracts many researchers as the external flow-driving mechanism is diminished or eliminated. One of the mechanisms providing such motions is generating a pressure difference across interfaces as in the case of the motion in capillary tubes. The capillarity, namely, the pressure difference across the interface due to its curvature drives the motion. This pressure depends on the interaction with the capillary walls and is controlled if one varies the surface energy of the walls. In this study, we search for the effects of surface energy on the motion of interfaces in capillary-driven flow. To this end, we model the motion of fluid particles in a capillary channel and integrate the governing equations using the binary lattice Boltzmann method for the two-phase flow. We, first, validate our solver for canonical static and dynamic problems. We, then, discuss two main contributions; we show how to deviate the interface speed from the ones moving in channels with uniform wall energies and discuss the conditions under which such an interface stagnates (like a passive valve in a channel). Tuning the wettability of the channel walls, we provide a simple condition for stopping the interface: the summation of the equilibrium contact angles interface make with the channel walls at the bottom and top wall need to satisfy $theta_{eq}^{top}+theta_{eq}^{bot} geq pi$. Configurations and wetting properties of different wettability regions play major roles together
{"title":"Controlling the Motion of Interfaces in Capillary Channels with Non-uniform Surface Wettability","authors":"Mehmet Alptug BOYLU, Umut CEYHAN","doi":"10.21205/deufmd.2023257513","DOIUrl":"https://doi.org/10.21205/deufmd.2023257513","url":null,"abstract":"The use of self-driven flows in microfluidic devices attracts many researchers as the external flow-driving mechanism is diminished or eliminated. One of the mechanisms providing such motions is generating a pressure difference across interfaces as in the case of the motion in capillary tubes. The capillarity, namely, the pressure difference across the interface due to its curvature drives the motion. This pressure depends on the interaction with the capillary walls and is controlled if one varies the surface energy of the walls. In this study, we search for the effects of surface energy on the motion of interfaces in capillary-driven flow. To this end, we model the motion of fluid particles in a capillary channel and integrate the governing equations using the binary lattice Boltzmann method for the two-phase flow. We, first, validate our solver for canonical static and dynamic problems. We, then, discuss two main contributions; we show how to deviate the interface speed from the ones moving in channels with uniform wall energies and discuss the conditions under which such an interface stagnates (like a passive valve in a channel). Tuning the wettability of the channel walls, we provide a simple condition for stopping the interface: the summation of the equilibrium contact angles interface make with the channel walls at the bottom and top wall need to satisfy $theta_{eq}^{top}+theta_{eq}^{bot} geq pi$. Configurations and wetting properties of different wettability regions play major roles together","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257511
Özgür TAMER
Wireless sensor network is a popular area for both academic research and commercial applications. A wireless sensor network is made up of several sensor nodes connected over various wireless infrastructures such as Wi-Fi, Bluetooth, ZigBee, or WiMAX. Determining the relative or absolute position of the sensor nodes is essential information for many applications. In this work, we present a novel method for estimating the position of sensor nodes using the Received Signal Strength Indicator and Time of Arrival metrics of the preferred wireless communication infrastructure. Localization results based on both of the metrics and comparison of them with respect to distance between the nodes are presented, and a novel combined method using both the RSSI and ToA based distance estimations is presented. The proposed method estimates the position of the WSN using both methods, but the result of a single method is preferred depending on the distance between the nodes since within the first 5 m. The RSSI based method is superior to ToA and for farther distances ToA outperforms RSSI. The measurement results show that the combined method reduces the estimation error and performs better than both methods it is based on.
{"title":"Relative Localization of Wireless Sensor Nodes by Using the RSSI and ToA based distance estimations","authors":"Özgür TAMER","doi":"10.21205/deufmd.2023257511","DOIUrl":"https://doi.org/10.21205/deufmd.2023257511","url":null,"abstract":"Wireless sensor network is a popular area for both academic research and commercial applications. A wireless sensor network is made up of several sensor nodes connected over various wireless infrastructures such as Wi-Fi, Bluetooth, ZigBee, or WiMAX. Determining the relative or absolute position of the sensor nodes is essential information for many applications. In this work, we present a novel method for estimating the position of sensor nodes using the Received Signal Strength Indicator and Time of Arrival metrics of the preferred wireless communication infrastructure. Localization results based on both of the metrics and comparison of them with respect to distance between the nodes are presented, and a novel combined method using both the RSSI and ToA based distance estimations is presented. The proposed method estimates the position of the WSN using both methods, but the result of a single method is preferred depending on the distance between the nodes since within the first 5 m. The RSSI based method is superior to ToA and for farther distances ToA outperforms RSSI. The measurement results show that the combined method reduces the estimation error and performs better than both methods it is based on.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135586705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257503
Didem GENÇ, Emrah TOMUR, Tuncay ERCAN
Endüstri 4.0 ile birlikte üretimin her alanında gittikçe artan bilgisayar destekli sistemlerin yarattığı farklı ve karmaşık ağ topolojileri, artan veri miktarı, firmaların güvenlik ihtiyaçlarını artırmaktadır. Bundan dolayı farklı endüstriyel sektörlerde kullanılan farklı cihaz ve veri kullanımı şirketler, kendi kritik akıllı üretim sistemlerine yönelik güvenilir bir risk yönetim sistemine ihtiyaç duymaktadır. İşletmeler bu yüzden sahip oldukları Endüstriyel Kontrol ve Bilişim Sistemlerini korumayı amaçlarlar. Bu çalışmada üretim alanında kullanılabilecek, endüstriyel cihazlar ve/veya bunlara bağlı sensörlerin erişim kontrolü bağlamında güvenlik ihtiyaçlarını karşılayacak ve kenar bilişim kapsamında çalışacak FPGA (Alanda Programlanabilir Kapı Dizileri) destekli bir güvenlik platformu tasarlanmış ve çalışma yöntemi açıklanmıştır. Akıllı üretim cihazlarının bulunduğu bir imalathane ortamında çalışan cihaz, sensor, akıllı kontrol kutusu ve ağ geçidi gibi bileşenler üzerinde bağlam-tabanlı bir erişim denetim sistemi kullanımı gösterilmiş ve örnek bir çoklu kimlik doğrulama yöntemi tasarlanmıştır.
{"title":"Endüstriyel Nesnelerin İnterneti Uygulamaları için FPGA Destekli ve Bağlam Tabanlı Erişim Kontrol Güvenlik Sistemi","authors":"Didem GENÇ, Emrah TOMUR, Tuncay ERCAN","doi":"10.21205/deufmd.2023257503","DOIUrl":"https://doi.org/10.21205/deufmd.2023257503","url":null,"abstract":"Endüstri 4.0 ile birlikte üretimin her alanında gittikçe artan bilgisayar destekli sistemlerin yarattığı farklı ve karmaşık ağ topolojileri, artan veri miktarı, firmaların güvenlik ihtiyaçlarını artırmaktadır. Bundan dolayı farklı endüstriyel sektörlerde kullanılan farklı cihaz ve veri kullanımı şirketler, kendi kritik akıllı üretim sistemlerine yönelik güvenilir bir risk yönetim sistemine ihtiyaç duymaktadır. İşletmeler bu yüzden sahip oldukları Endüstriyel Kontrol ve Bilişim Sistemlerini korumayı amaçlarlar. Bu çalışmada üretim alanında kullanılabilecek, endüstriyel cihazlar ve/veya bunlara bağlı sensörlerin erişim kontrolü bağlamında güvenlik ihtiyaçlarını karşılayacak ve kenar bilişim kapsamında çalışacak FPGA (Alanda Programlanabilir Kapı Dizileri) destekli bir güvenlik platformu tasarlanmış ve çalışma yöntemi açıklanmıştır. Akıllı üretim cihazlarının bulunduğu bir imalathane ortamında çalışan cihaz, sensor, akıllı kontrol kutusu ve ağ geçidi gibi bileşenler üzerinde bağlam-tabanlı bir erişim denetim sistemi kullanımı gösterilmiş ve örnek bir çoklu kimlik doğrulama yöntemi tasarlanmıştır.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257504
Aysun SEZER, Emre ALPTEKİN
In modern medicine, image recognition via segmentation of anatomical regions and automatic classification of diseases using medical images has a growing potential role in diagnosis of various diseases. Scintigraphy of thyroid is one of the established imaging modalities for diagnosis of thyroid gland disorders. In our study, the speckle noise was reduced in the scintigraphy images with the optimized Bayesian nonlocal mean filter. The thyroid gland was automatically segmented by local based active contour method and the thyroid gland pathologies were classified with convolutional neural networks (CNN). The proposed computer aided diagnosis (CAD) system was compared with Pyramid of Histograms of Orientation Gradients (PHOG), Gray Level Co occurrence Matrix (GLCM), Local Configuration Pattern (LCP) and Bag of Feature (BoF) methods. The common pathological patterns of scintigraphic images of the thyroid gland were successfully classified by CNN with an overall success rate of 91.19%. The comparative methods were PHOG, GLCM, LCP and BoF methods which provided overall success rates of 7.61%, 86.04%, 88.91% and 85.72% respectively. The proposed CNN based automatic diagnosis system provided promising results compared to handcrafted methods.
{"title":"Sintigrafik Görüntülerden Tiroid Nodülleri için Bilgisayar Destekli Tanı Sistemi","authors":"Aysun SEZER, Emre ALPTEKİN","doi":"10.21205/deufmd.2023257504","DOIUrl":"https://doi.org/10.21205/deufmd.2023257504","url":null,"abstract":"In modern medicine, image recognition via segmentation of anatomical regions and automatic classification of diseases using medical images has a growing potential role in diagnosis of various diseases. Scintigraphy of thyroid is one of the established imaging modalities for diagnosis of thyroid gland disorders. In our study, the speckle noise was reduced in the scintigraphy images with the optimized Bayesian nonlocal mean filter. The thyroid gland was automatically segmented by local based active contour method and the thyroid gland pathologies were classified with convolutional neural networks (CNN). The proposed computer aided diagnosis (CAD) system was compared with Pyramid of Histograms of Orientation Gradients (PHOG), Gray Level Co occurrence Matrix (GLCM), Local Configuration Pattern (LCP) and Bag of Feature (BoF) methods. The common pathological patterns of scintigraphic images of the thyroid gland were successfully classified by CNN with an overall success rate of 91.19%. The comparative methods were PHOG, GLCM, LCP and BoF methods which provided overall success rates of 7.61%, 86.04%, 88.91% and 85.72% respectively. The proposed CNN based automatic diagnosis system provided promising results compared to handcrafted methods.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rüzgâr enerjisi, dünya genelinde hızla artan enerji ihtiyacı ve bu ihtiyacın çevreci çözümlerle giderilmesi gerekliliğiyle önemini her geçen gün arttırmaktadır. Kısa zamanda daha çok enerji üretebilen görece büyük rüzgâr türbinleri, rüzgâr enerji potansiyelinin fazla olması nedeniyle deprem bölgelerinde de inşa edilmektedir. Rüzgâr türbinlerinin ekonomik ömrü boyunca operasyonel kalabilmesi için yapısal bütünlüğünün izlenmesi ve dinamik özelliklerinin değişken operasyonel ve çevresel faktörler altında belirlenmesi büyük önem taşımaktadır. Bu çalışmada, kullanımda olan 2,5 MW üretim kapasiteli bir rüzgâr türbini için özgün veri toplama sistemi tasarlanmıştır. Sistemin kendi sensörlerinin topladığı ivme, sıcaklık ve nem verilerine ek olarak türbin SCADA sisteminden alınan rüzgâr hızı, rüzgâr yönü, rotor hızı, nasel yönü, pitch açısı ve anlık enerji üretim değeri verileri senkronize olarak kaydedilmiştir. Farklı çevresel ve operasyonel koşullar altında toplanan ivme verileri ile operasyonel modal analizler yapılmış ve türbinin dinamik özellikleri belirlenmiştir. Son olarak mod frekanslarının çevresel ve operasyonel faktörler ile ilişkisi de göz önünde bulundurularak, türbinin sayısal modeli güncellenmiştir.
{"title":"Kullanımda Olan 2,5 MW Kapasiteli Bir Rüzgâr Türbininden Veri Toplanması, Sistem Tanımlama ve Model Güncelleme","authors":"Onur ÖZTÜRKOĞLU, Yaşar TANER, Veysel YURTSEVEN, Özgür ÖZÇELİK, Serkan GÜNEL","doi":"10.21205/deufmd.2023257508","DOIUrl":"https://doi.org/10.21205/deufmd.2023257508","url":null,"abstract":"Rüzgâr enerjisi, dünya genelinde hızla artan enerji ihtiyacı ve bu ihtiyacın çevreci çözümlerle giderilmesi gerekliliğiyle önemini her geçen gün arttırmaktadır. Kısa zamanda daha çok enerji üretebilen görece büyük rüzgâr türbinleri, rüzgâr enerji potansiyelinin fazla olması nedeniyle deprem bölgelerinde de inşa edilmektedir. Rüzgâr türbinlerinin ekonomik ömrü boyunca operasyonel kalabilmesi için yapısal bütünlüğünün izlenmesi ve dinamik özelliklerinin değişken operasyonel ve çevresel faktörler altında belirlenmesi büyük önem taşımaktadır. Bu çalışmada, kullanımda olan 2,5 MW üretim kapasiteli bir rüzgâr türbini için özgün veri toplama sistemi tasarlanmıştır. Sistemin kendi sensörlerinin topladığı ivme, sıcaklık ve nem verilerine ek olarak türbin SCADA sisteminden alınan rüzgâr hızı, rüzgâr yönü, rotor hızı, nasel yönü, pitch açısı ve anlık enerji üretim değeri verileri senkronize olarak kaydedilmiştir. Farklı çevresel ve operasyonel koşullar altında toplanan ivme verileri ile operasyonel modal analizler yapılmış ve türbinin dinamik özellikleri belirlenmiştir. Son olarak mod frekanslarının çevresel ve operasyonel faktörler ile ilişkisi de göz önünde bulundurularak, türbinin sayısal modeli güncellenmiştir.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.21205/deufmd.2023257519
Şahin GÜNGÖR
Additive manufacturing enables researchers to form unique and unconventional topologies satisfying design compactness, improved efficiency, and lower cost. Design freedom introduced by the additive manufacturing reveals the idea of implementing the topology optimization approach into thermal systems. In this study, changes in thermal performance of three types of topologies: gyroid, hexagon (honeycomb), and rectilinear are experimentally investigated. In addition, porosity level of each topology is varied in between 25%, 50% and 75% to improve the impact of the study. The experimental results indicate that gyroid structures are thermally more efficient (up to 15.6%) than the remaining topologies. Furthermore, thermal diffusivities of the rectilinear and gyroid topologies with 25% porosity level are measured as the extremes, and it is detected that these structures propagate heat 1.1 times greater than the hexagon structure.
{"title":"Eklemeli imal edilmiş gözenekli topolojilerin ısıl performansı üzerine deneysel incelemeler","authors":"Şahin GÜNGÖR","doi":"10.21205/deufmd.2023257519","DOIUrl":"https://doi.org/10.21205/deufmd.2023257519","url":null,"abstract":"Additive manufacturing enables researchers to form unique and unconventional topologies satisfying design compactness, improved efficiency, and lower cost. Design freedom introduced by the additive manufacturing reveals the idea of implementing the topology optimization approach into thermal systems. In this study, changes in thermal performance of three types of topologies: gyroid, hexagon (honeycomb), and rectilinear are experimentally investigated. In addition, porosity level of each topology is varied in between 25%, 50% and 75% to improve the impact of the study. The experimental results indicate that gyroid structures are thermally more efficient (up to 15.6%) than the remaining topologies. Furthermore, thermal diffusivities of the rectilinear and gyroid topologies with 25% porosity level are measured as the extremes, and it is detected that these structures propagate heat 1.1 times greater than the hexagon structure.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135586710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to investigate the effects of irrigation needles geometries on the flow inside the root canal and compare their irrigation performances based on Computational Fluid Dynamics (CFD) analyzes. CFD simulations of three commonly used close-ended irrigation needles were performed for various inlet Reynolds numbers and working lengths. Their irrigation performances were evaluated based on apical pressure and wall shear stress. The flow was assumed to be incompressible, turbulent and steady at all inlet Reynolds numbers. The closed-ended needles showed similar limited irrigant penetration toward the apex. Among all configurations, the Model C outperforms others as it provides the highest wall shear stress around the needle tip and the lowest apical pressures in the apical foramen, which reduces the risk of apical extrusion. The needle tip designs influence important parameters for the effectiveness and safety of the irrigation process.
{"title":"Farklı İğne Tasarımlarının Diş Kanalı İrrigasyonu Üzerindeki Etkilerinin Hesaplamalı Akışkanlar Dinamiği ile İncelenmesi","authors":"Selin BULGU, Alperen YILDIZELİ, Sertaç ÇADIRCI, Sema YILDIRIM","doi":"10.21205/deufmd.2023257520","DOIUrl":"https://doi.org/10.21205/deufmd.2023257520","url":null,"abstract":"This study aims to investigate the effects of irrigation needles geometries on the flow inside the root canal and compare their irrigation performances based on Computational Fluid Dynamics (CFD) analyzes. CFD simulations of three commonly used close-ended irrigation needles were performed for various inlet Reynolds numbers and working lengths. Their irrigation performances were evaluated based on apical pressure and wall shear stress. The flow was assumed to be incompressible, turbulent and steady at all inlet Reynolds numbers. The closed-ended needles showed similar limited irrigant penetration toward the apex. Among all configurations, the Model C outperforms others as it provides the highest wall shear stress around the needle tip and the lowest apical pressures in the apical foramen, which reduces the risk of apical extrusion. The needle tip designs influence important parameters for the effectiveness and safety of the irrigation process.","PeriodicalId":11622,"journal":{"name":"El-Cezeri Fen ve Mühendislik Dergisi","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135586712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：