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Optimization-Driven Design and Experimental Validation of a Hydraulic Robot Leg Mechanism
No full textBarghi Jond, Hossein/0000-0002-8418-805XHydraulic-actuated legs for quadruped robots excel in producing high force and offering precise control. Although the overall efficiency of hydraulic servo systems can be limited by pump and valve losses, the local mechanical efficiency from the actuator to the leg mechanism can be relatively high. This study introduces an optimization driven methodology for designing and validating robotic leg mechanisms using evolutionary algorithms. By solving three distinct optimization problems, the study addresses trajectory tracking accuracy and force transmission efficiency. The resulting design was experimentally validated, demonstrating reliable motion reproduction with minimal deviation and achieving a force transmission efficiency of 94%. These results demonstrate the feasibility of translating optimization outcomes into high-performing physical prototypes, providing a robust framework for future robotic mechanism development.The authors Veli Bak ; imath;rc ; imath;o ; gbreve;lu and Hossein B. Jond were partially supported by the CTU grant no. SGS23/177/OHK3/3T/13, the Czech Science Foundation (GACR) under research project no. 23-07517S, and the European Union under the project Robotics and Advanced Industrial Production (reg. no. CZ.02.01.01/00/22_008/0004590).CTU [SGS23/177/OHK3/3T/13]; Czech Science Foundation (GACR) [23-07517S]; European Union [CZ.02.01.01/00/22_008/0004590
Search for Heavy Neutral Resonances Decaying to Tau Lepton Pairs in Proton-Proton Collisions at √s=13 TeV
No full textDiaz, Daniel/0000-0001-6834-1176; D'Enterria, David/0000-0002-5754-4303; Heredia De La Cruz, Ivan/0000-0002-8133-6467; De La Cruz Burelo, Eduard/0000-0002-7469-6974; Sculac, Ana/0000-0001-7938-7559; Klyukhin, Vyacheslav/0000-0002-8577-6531; Bruschini, Davide/0000-0001-7248-2967; Zhang, Yousen/0000-0002-6812-761X; Legger, Federica/0000-0003-1400-0709; Karneyeu, Anton/0000-0001-9983-1004; Fouz Iglesias, Maria Cruz/0000-0003-2950-976X; Yazgan, Efe/0000-0001-5732-7950; Ivanov, Andrew/0000-0002-9270-5643; Vannerom, David/0000-0002-2747-5095; You, Zhengyun/0000-0001-8324-3291; Calderon Tazon, Alicia/0000-0002-7205-2040; Garcia, Francisco/0000-0002-4023-7964; Ferencek, Dinko/0000-0001-9116-1202; De Moor, Alexandre/0000-0001-5964-1935; Hernandez Calama, Jose Maria/0000-0001-6436-7547; Dozen, Candan/0000-0002-4301-634X; Barroso Ferreira, Mapse/0000-0003-3904-0571; Azzi, Patrizia/0000-0002-3129-828X; Geurts, Frank/0000-0003-2856-9090; Lo Meo, Sergio/0000-0003-3249-9208; Smith, Nicholas/0000-0002-0324-3054; Colaleo, Anna/0000-0002-0711-6319; D'Anzi, Brunella/0000-0002-9361-3142; Delgado Peris, Antonio/0000-0002-8511-7958; Kunnawalkam Elayavalli, Raghav/0000-0002-9202-1516; Ecklund, Karl/0000-0002-6976-4637; Chatterjee, Suman/0000-0003-2660-0349; Singh, Jasbir/0000-0001-9029-2462; Mitra, Soureek/0000-0002-3060-2278; /0000-0002-6047-4211; Kontaxakis, Pantelis/0000-0002-4860-5979; Pesaresi, Mark/0000-0002-9759-1083A search for heavy neutral gauge bosons (Z ') decaying into a pair of tau leptons is performed in proton-proton collisions at root s =13 TeV at the CERN LHC. The data were collected with the CMS detector and correspond to an integrated luminosity of 138 fb(-1). The observations are found to be in agreement with the expectation from standard model processes. Limits at 95% confidence level are set on the product of the Z ' production cross section and its branching fraction to tau lepton pairs for a range of Z ' boson masses. For a narrow resonance in the sequential standard model scenario, a Z ' boson with a mass below 3.5 TeV is excluded. This is the most stringent limit to date from this type of search
Uydu Görüntülerinden Arazinin Güneş Yansıma Katsayılarının Belirlenmesi ve Sayısal Yükseklik Modeli Üzerinden Eğik Radyasyon Modelinin Oluşturulması
No full textIn many solar radiation models, a combination of physical measurements and mathematical models is used to achieve results close to actual values. However, since these calculations are typically based on a horizontal surface, terrain irregularities and shading effects are often overlooked. Additionally, total solar radiation can only be calculated considering three dimensional (3D) terrain model and albedo effect since albedo effect is ignored in classical solar radiation calculation formulas. In two-dimensional (2D) evaluations, total radiation is generally defined as the sum of direct and stray radiation. Moreover, reflected radiation appears when the studies are conducted in three dimensional (3D) model. To compute reflected radiation, the albedo value of the corresponding pixel and slope must be taken into account. This study aims to improve global solar radiation calculations—one of the most critical indicators in site selection—by utilizing a 3D Digital Surface Model (DSM) which can instead of traditional formulas that operate on a horizontal plane. It is desired to obtain real radiation and sunshine duration thanks to this approach. Additionally, the study seeks to analyze the impact of reflected radiation on total radiation by incorporating albedo values into the global solar radiation computation. As a case study, a 1.600 km² test area located south of Karaman was selected due to its high solar energy potential, varied topography, and diverse land surface types with different albedo values. Using the Google Earth Engine (GEE) platform, albedo values were calculated for summer and winter seasons based on atmospherically corrected SENTINEL-2A satellite imagery with a spatial resolution of up to 10 meters. The results showed that the albedo value for snow-covered surfaces in winter was 0,86, while for light-colored buildings, it was 0,36 in summer and 0,28 in winter. These findings, which closely align with reference values, it is examined that the albedo value for the surfaces may change due to angle of incidence in summer and winter by obtaining closely aligned results to the reference values. The slopes of pixels were determined using 5-meter resolution digital surface models to compute reflected radiation after calculating pixel-based albedo values for both seasons. 3D solar radiation maps were generated using the ArcGIS Area Solar Radiation Module to calculate shading effects in required total radiation while reflected radiation is calculated. As a result, it was determined that reflected radiation can contribute to an increase of approximately 5% to 7% in total radiation on especially steep sloped terrain.Birçok güneş radyasyonu modelinde, gerçek değerlere yakın sonuçlar elde etmek için fiziksel ölçümler ve matematiksel modellerin bir kombinasyonu kullanılmaktadır. Ancak bu hesaplamalarda genellikle yatay bir yüzey kullandığından arazi yüzeyindeki engebelere ve gölgelere bağlı değişimler göz ardı edilmektedir. Tüm bunlara ek olarak albedo değeri, klasik güneş radyasyonu hesaplama formüllerinde göz ardı edildiğinden albedo etkili toplam güneş radyasyonu değeri ancak 3 boyutlu arazi modeli ve albedo etkisi göz önüne alınarak hesaplanabilmektedir. 2 boyutlu değerlendirmelerde toplam radyasyon doğrudan ve dağınık radyasyonun toplamı olarak tanımlanmaktadır. Çalışmalar, 3 boyutlu ortamda gerçekleştirildiğinde ayrıca yansıyan radyasyon değeri ortaya çıkmaktadır. Yansıyan radyasyonun hesaplanması için çalışılan pikselin albedo değerine ve eğim değerine ihtiyaç duyulmaktadır. Bu çalışmada; uygun yer seçiminde göz önüne alınacak en önemli gösterge olan global güneş radyasyonu hesabının yapılması için klasik yatay düzlemde hesap yapan formüllere ve uygulamaların aksine bölgenin gerçek radyasyon ve güneşlenme süresini belirleyebilmek için 3 boyutlu sayısal yüzey modeli kullanmak amaçlanmıştır. Ayrıca; küresel güneş radyasyonu hesabına albedo değerleri vasıtasıyla yansıyan radyasyon etkilerinin de hesaplanarak toplam radyasyon değerine etkilerinin irdelenmesi amaçlanmıştır. Çalışma kapsamında, Karaman'ın güneyinde 1.600 km² büyüklüğünde bir alan test bölgesi olarak seçilmiştir. Bu bölge, yüksek güneş enerjisi potansiyeline sahip olması, engebeli alanlar içermesi ve albedo değeri açısından çok farklı arazi yüzeyleri içermesinden dolayı seçilerek farklı bölgelerdeki sonuçların incelenmesi gerçekleştirilmiştir. Google Earth Engine (GEE) platformu aracılığıyla yaz ve kış mevsimleri için 10 metreye kadar mekânsal çözünürlüğe sahip SENTINEL 2A atmosfer etkileri düzeltilmiş uydu görüntüleri kullanılarak GEE platformu üzerinden yazılan kodlar yardımıyla albedo değerleri hesaplanmıştır. Karlı yüzeyler için kış döneminde albedo değeri 0,86 olarak, açık renkli binalar için ise yaz döneminde 0,36, kış döneminde ise 0,28 olarak hesaplanmıştır. Buradan referans değerlere yakın sonuçlar elde edilerek güneş gelme açısından dolayı yaz ve kış aylarında yüzeylerin farklı albedo değerleri alabileceği de irdelenmiştir. Piksellerin yaz ve kış dönemi için albedo değerleri hesaplandıktan sonra 5 metre çözünürlüklü sayısal yüzey modelleri yardımıyla yansıyan radyasyonun hesaplanabilmesi için piksellerin eğimleri hesaplanmıştır. Burada yansıyan radyasyon hesaplanırken gereken toplam radyasyon değerlerinde gölgelenme etiketlerini de hesaplanabilmesi için ArcGIS Area Solar Radiation modülünden yararlanılarak 3 boyutlu güneş haritaları oluşturulmuştur. Sonuç olarak, özellikle yüksek eğimli yamaçlarda yansıyan radyasyonun toplam radyasyona etkisinin %5 ila %7 oranında artış meydana getirebileceği belirlenmiştir
Experimental, Theoretical and Digital Image Correlation Methods to Assess Bending Performance of RC Beams With Recycled Glass Powder Replacing Cement
No full textThis study investigates the use of Waste Glass Powder (WGP) as a proportional replacement for cement in sustainable concrete production. In addition, changes in the bending capacity of the Reinforced Concrete (RC) Beams were examined by adding WGP at different rates (0%, 10%, 20%, 30%) to RC Beams with different steel reinforcement ratios (rho s = 0.0077 i.e. Phi 8, rho s = 0.0121 i.e. Phi 10, rho s = 0.0174 i.e. Phi 12). To pursue this goal, 12 test specimens were evaluated and then confirmed to explore the bending productivity. The amount of longitudinal bar section area and WGP proportion were chosen as the key parameters. For this aim, experimental and analytical investigations were carried out by replacing cement with WGP in weight ratios of 10%, 20%, and 30% and considering three different longitudinal reinforcements (rho s = 0.0077 i.e. Phi 8, Phi 10, Phi 12). The test results showed that tension reinforcement section area and WGP proportion dimensions had dissimilar rupture and flexure effects on RC Beams. Furthermore, investigational tests are confirmed with the help of the Digital Imagining Method, and the image processing method was used to identify the cracks/microcracks in RC Beams. Consequently, it is observed that each WGP ratio in the concrete combination has dissimilar bending and rupture properties on the RC Beams for experimental tests-10% of partial replacement of cement. It was found that a WGP ratio of more than 10% can significantly reduce the bending capacity of RC Beams. When the experimental test beams were compared with the analytical results, it was observed that the experimental results and analytical calculations are in agreement.Deanship of Scientific Research, King Khalid University [RGP2/539/46]; Deanship of Scientific Research at King Khalid University, Abha, Saudi Arabia, through Large GroupsThe authors are thankful for the financial support provided for this research by the Deanship of Scientific Research at King Khalid University, Abha, Saudi Arabia, through Large Groups RGP2/539/46
Experimental Flow Control Around Circular Cylinders with Porous Media Coatings
No full textFlow structures have been experimentally obtained for the circular cylinders with porous media coatings (PMC) at Reynolds number values from Re = 5000 to Re = 10,000. Furthermore, flow characteristics have been exhibited for different contour graphics and the velocity profiles have been indicated at four downstream stations. The regions having minimum streamwise velocity component values approached the circular cylinders by increasing Reynolds numbers. Nevertheless, it is not valid for the cases of PMC1 and PMC2 from Re = 7500 to Re = 10,000. Because of the separated flows from the upper and lower cylinder surfaces, the maximum streamwise velocity components have been attained. The same effect has been observed for the cross-stream velocity component values, and these clusters approached the circular cylinders. As expected, the flow separations caused wake fluctuations. Nonetheless, the cluster sizes have also been decreased by the decrement of Reynolds numbers. It is significant for the occurrence of turbulence intensity in the wake regions of the circular cylinders. However, there is no obvious difference between the bare cylinder and the PMC3 in terms of flow patterns. Another important result is that the coating effect is explicitly exhibited by the increase in Reynolds numbers. As explained by the velocity values, these zones moved away from the bodies due to the decrement of Reynolds numbers. As a parameter, Reynolds number is considerably dominant on the cluster positions. Similar patterns have been approximately observed for PMC1, PMC2 and PMC4 in terms of Reynolds stress correlations
Lavender Field Detection via Remote Sensing and Machine Learning for Optimal Hive Placement to Maximize Lavender Honey Production
No full textLavender is a plant widely used in the cosmetic, pharmaceutical, and food industries, and it is also well known for producing nectar and pollen that bees use to make honey. However, due to increasingly adverse atmospheric conditions in recent years, characterized by prolonged dry spells or intense rainfall focused in short periods, the production of monofloral honey, such as lavender honey, has become increasingly challenging. Therefore, accurate mapping of monofloral zones in order to support beekeepers in placing their beehives in the best location is required. In this context, the town of Kuyucak in Isparta Province (Turkey), renowned for its extensive lavender fields, was selected. Using true orthophoto images from 2020 with a ground sampling distance (GSD) of 30 cm, machine learning classification methods and deep learning techniques were applied to identify and map the correspondent lavender fields. Lavender plants within the region were detected using Maximum Likelihood (ML), Support Vector Machine (SVM), and Random Forest (RF) classifiers, as well as the Mask R-CNN deep learning method. The classification achieved an overall accuracy of 95% and a kappa coefficient of 0.94. Subsequently, assuming a bee foraging range of 3 km, a moving squared window (sizing 3 x 3 km) was used to estimate local areas with potential forage resources and the corresponding honey production potential. The resulting honey potential production maps then used to identify optimal location for beekeepers' hives in order to maximize lavender honey production
Approximation by Bivariate Szasz-Mirakyan Operators Preserving E-2(p1+p2)
No full textThe present paper is dedicated to the modification of the bivariate generalized Szasz-Mirakyan operators while preserving the exponential functions exp(2, 2) where exp(tau(1), tau(2)) = e(-tau 1p1 - tau 2p2), tau(1), tau(2) is an element of R-0(+) , and p(1), p(2) >= 0. We thoroughly investigate the weighted approximation properties and also obtain the convergence rate for these operators by utilizing a weighted modulus of continuity. Additionally, we delve into the order of approximation by investigating local approximation results through Peetre's K-functional. Furthermore, we present the GBS (Generalized Boolean Sum) operators of Szasz-Mirakyan operators and obtain the order of approximation in terms of the Lipschitz class of Bogel continuous functions and the mixed modulus of smoothness. In order to enhance our theoretical findings and effectively showcase the efficiency of our developed operators, we have included a wide range of numerical examples using various values
Vision-Based Analysis of Soft Story, Short Columns, and Vertical Geometry in RC Structures
No full textIn countries located in active seismic zones, it is very important to carry out a risk analysis of the existing building stock and to priorities buildings according to their risk status in order to implement effective and improvable measures. In this context, the earthquake risks of hundreds of thousands of buildings in cities, especially residential buildings, need to be assessed, especially in countries that experience major earthquakes, such as Türkiye. Due to the uneconomical and time-consuming nature of detailed analyses for such a large building stock, Rapid Seismic Assessment Methods (RSAM) are very useful for prioritising at-risk structures. However, rapid assessment methods can also require the use of many technical experts, which can lead to differences in interpretation based on their knowledge, expertise and experience in the relevant field. It is very important that the assessment is as standardized as possible to be able to predict the presence of significant structural irregularities for a large building stock and to make decisions on seismic risk quickly and measurably. To achieve this, this paper proposes a two-step deep learning-based framework to automatically extract structural features such as soft stories, short columns, and standard floor windows from building facade images and to estimate the total building height. In the first step, the You Only Look Once version 5 (YOLOv5) object detection model is used to identify key architectural elements associated with seismic vulnerability. In the second step, the detected architectural elements along with the facade image are analyzed to estimate building height. The framework is trained and evaluated using a dataset of 4500 facade images collected from Google Street View (GSV). The results demonstrate the method's potential for large-scale, standardized, and rapid seismic risk assessment in urban environments. © 2025 Elsevier B.V., All rights reserved
Comparison of Different Interpolation Methods on the Estimation of Mean Gravity Anomaly in Geoid Determination
No full textOne of the most important goals and tasks of geodesy is to determine the ±1 cm accurate geoid model. However, this accuracy has not been achieved in many parts of the world today. In gravimetric geoid determination, free-air gravity anomaly is used as input data. Therefore, gravity measurements taken on the physical Earth's surface are reduced to mean sea level and referred to free-air gravity anomalies. After the reduction, free-air gravity anomalies should be interpolated to grid centres for geoid determination studies. However, since free-air gravity anomalies contain topographic effects, they create an undulating surface and are not suitable for interpolation. To eliminate topographic effects, the Bouguer plate effect is removed from the free-air gravity anomalies, resulting in Bouguer gravity anomalies. After this step, Bouguer anomalies can be interpolated to grid centre. A review of the literature shows that there are several options for the interpolation process. In this study, it was aimed to determine the most accurate approach by using different interpolation methods to see the effects of the interpolation process. The state of Colorado, USA, was selected as the study area. The minimum, maximum and average topography in the study area are 1306 m, 4372 m and 2469 m, respectively. Thus, the KTH method providing successful results in mountainous regions, was chosen as the geoid determination method. The numerical results demonstrates that the inverse distance weighting method supplies the most accurate geoid model. In addition, the inverse distance weighting geoid model was used as a reference in the study and the geoid models obtained from other interpolation methods were compared. The comparisons showed that there were significant differences between the interpolation methods in high-altitude regions.Jeodezin en önemli amaç ve görevlerinden biri ±1 cm doğruluklu jeoit modelini belirlemektir. Fakat günümüzde dünyanın birçok bölgesinde halen bu doğruluğa ulaşılmamıştır. Gravimetrik jeoit belirlemede girdi verisi olarak serbest hava (free-air) gravite anomalisi kullanılmaktadır. Bu nedenle fiziksel yeryüzünde ölçülen gravite büyüklükleri, ortalama deniz seviyesine indirgenir ve serbest hava anomalisi olarak adlandırılır. Bu indirgemeden sonra serbest gravite anomalileri, jeoit belirleme çalışmaları için grid merkezlerine enterpole edilmelidir. Ancak, serbest gravite anomalileri, topografik etkileri içerdiği için dalgalı bir yüzey oluşturmaktadır ve enterpolasyona elverişli değildir. Topografik etkileri ortadan kaldırmak amacıyla Bouguer plakası etkisi, serbest hava gravite anomalilerinden çıkarılır. Sonuçta Bouguer gravite anomalileri elde edilir. Bundan sonra Bouguer anomalileri grid merkezlerine enterpole edilebilir. Literatür incelendiğinde enterpolasyon sürecinde birçok seçenek vardır. Bu çalışmada enterpolasyon sürecinin etkilerini görmek amacıyla farklı enterpolasyon yöntemleri kullanılarak en doğru yaklaşımın belirlenmesi hedeflenmiştir. Çalışma sahası olarak Amerika Birleşik Devletleri'nin Colorado eyaleti seçilmiştir. Sahada topoğrafyanın minimum, maksimum ve ortalama yüksekliği sırasıyla 1306 m, 4372 m ve 2469 m'dir. Bu nedenle, jeoit belirleme yöntemi olarak dağlık alanlarda başarılı sonuç veren KTH yöntemi tercih edilmiştir. Sayısal sonuçlar ters mesafe ağırlık yönteminin en yüksek doğruluklu jeoidi verdiği belirlenmiştir. Ayrıca çalışmada ters mesafe ağırlıklı jeoit modeli referans alınarak diğer enterpolasyon yöntemleri ile elde edilen jeoit modelleri karşılaştırılmıştır. Karşılaştırmalar, yüksek bölgelerde enterpolasyon yöntemleri arasında kayda değer farklar olduğunu göstermiştir
Production of Fluorine-Free Hydrophobic Thin Films by PECVD Method
No full textFluorinated chemicals are widely used in the production of hydrophobic thin films. However, concerns about the risks of these chemicals on the environment and human health continue to grow day by day. Therefore, it is important to develop alternative fluorine-free hydrophobic coating materials. Poly(2-ethylhexyl acrylate) (PEHA), with its long carbon chains, has a significant potential for the production of hydrophobic coatings. In this thesis, PEHA thin films were coated on the surfaces of different substrates by low temperature, one-step and environmentally friendly plasma enhanced chemical vapor deposition (PECVD) method. The effects of reactor pressure, substrate temperature and plasma power on the deposition rate of PEHA thin film were investigated and the highest deposition rate was measured as 19.1 nm/min at 5°C substrate temperature, 30 W plasma power and 150 mTorr reactor pressure. Wetting, chemical and morphological properties of PEHA thin film were investigated. The PEHA thin film exhibited hydrophobic properties and the contact angle of the coated fabric with water was measured as 139.8°. The hydrophobicity of the PEHA thin film was also tested against various liquids used in daily life besides water. In addition, PEHA thin films showed excellent resistance to solvent resistance, washing and adhesion tests.Florlu kimyasallar, hidrofobik ince filmlerin üretiminde yaygın olarak kullanılmaktadır. Ancak, bu kimyasalların çevre ve insan sağlığı üzerindeki riskleri konusundaki endişeler her geçen gün artarak devam etmektedir. Bu nedenle, flor içermeyen alternatif hidrofobik kaplama malzemelerinin geliştirilmesi önemlidir. Poli(2-etilheksil akrilat) (PEHA), uzun karbon zincirleri ile hidrofobik kaplamaların üretimi için önemli bir potansiyele sahiptir. Bu tez çalışmasında, PEHA ince filmleri düşük sıcaklıkta, tek aşamalı ve çevre dostu plazma destekli kimyasal buhar biriktirme (PECVD) yöntemiyle farklı alttaşların yüzeylerine kaplanmıştır. Reaktör basıncı, alttaş sıcaklığı ve plazma gücünün PEHA ince filminin kaplama hızı üzerindeki etkileri araştırılmış ve en yüksek kaplama hızı; 5°C alttaş sıcaklığı, 30 W plazma gücü ve 150 mTorr reaktör basıncında 19,1 nm/dak olarak ölçülmüştür. PEHA ince filminin ıslatma, kimyasal ve morfolojik özellikleri incelenmiştir. PEHA ince filmi, hidrofobik özellikler sergilemiş ve kaplanmış kumaşın su ile temas açısı 139,8° olarak ölçülmüştür. PEHA ince filminin hidrofobikliği, su dışında, gündelik yaşamda kullanılan çeşitli sıvılara karşı da test edilmiştir. Ayrıca, PEHA ince filmleri; çözücü direnci, yıkama ve yapışma testlerine karşı da mükemmel dayanıklılık göstermiştir