Yazar "Toz, Metin" seçeneğine göre listele
Listeleniyor 1 - 11 / 11
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe 3D3A class of parallel mechanisms: Design and performance evaluation(Elsevier B.V., 2025) Yılmaz, Savaş; Küçük, Serdar; Toz, MetinThis paper presents a study of 20 six-degrees-of-freedom (DoF) Generalized Stewart–Gough Platform (GSP) type mechanisms in 3D3A class. These mechanisms are characterized by three distance and three angular constraints between their base platforms (BPs) and moving platforms (MPs). The mechanisms are categorized into two groups based on the geometric shapes of their BPs and MPs. The platform shapes are determined by the types of joints and their connection configurations on the platforms. The platforms are designed with regular polygonal shapes. Two groups are generated according to whether the geometric shapes of the platforms are the same or different. There are 10 types of mechanisms in the first group, where the BP and the MP shapes of each are the same. The second group also includes 10 types of mechanisms, each with two design variations, resulting in 20 designs. Thus, a total of 30 mechanisms are designed. The reachable workspaces and dexterities of these manipulators are computed to assess the impact of design parameters such as the ratio between the BP and MP radii and the rotation of one end of the BP edges. The reachable workspace volume and the Global Conditioning Index (GCI) are selected as the performance metrics. The results of all mechanisms are presented in the paper, with a comparison of the two best mechanisms against the classical 3×3 Stewart Platform. The study shows that the D43A13 type mechanism achieves a large reachable workspace while maintaining a high GCI value. © 2024 Elsevier B.V.Öğe Değişken bağlantı nokta sayısına sahip kablo kontrollü düzlemsel bir paralel robot mekanizmasının geometrik optimizasyonu(Karamanoğlu Mehmetbey Üniversitesi, 2021) Telci, Serkan; Toz, MetinBu çalışmada düzlemsel kablo kontrollü bir çizim robotu için geometrik optimizasyon yapan bir sistem önerilmiştir. Bu sistem, kullanıcıdan aldığı örnek resmin robot tarafından çizilebilmesini sağlayacak optimum geometrik tasarımı önermektedir. Sistem giriş olarak, örnek resim ve kablo kontrollü robot için istenilen köşe noktası sayısını almakta ve bu bilgileri kullanarak robot mekanizmasının kablo uzunluklarını ve kabloların kaleme bağlantı noktalarını optimize etmektedir. Optimizasyon aracı olarak Genetik Algoritma kullanılmıştır. Önerilen sistemin test edilmesi amacıyla iki farklı resim ve üç farklı köşe nokta sayısı için geometrik optimizasyon yapılmış ve elde edilen sonuçlar karşılaştırmalı olarak sunulmuştur.Öğe Design and kinematic analysis of a 6-DOF asymmetric parallel robot manipulator with 4-SPS and 2-CPS Type legs(Institute of Electrical and Electronics Engineers Inc., 2021) Toz, MetinThis paper presents the design, inverse kinematic, Jacobian and workspace analysis of a six Degrees of Freedom (6-DOF) asymmetric parallel robot manipulator. The manipulator was designed by two CPS and four SPS type legs (C: passive cylindrical joint, P: active prismatic joint, S: passive spherical joint). The mechanism includes two passive cylindrical joints at the lower ends of its two legs instead of the spherical joints as in its symmetrical counterparts. Thus, the asymmetry of the mechanism is because of the two cylindrical joints. The basic mathematical formulations for inverse kinematic and Jacobian matrix analyses are given, and the effects of the cylindrical joints on the reachable workspace of the mechanism are presented. Moreover, the dextrous translational workspace of the mechanism is also obtained and compared by the workspace of the classic symmetrical six DOF SPS parallel manipulator. The results show that using cylindrical joints make the mechanism has better workspace characteristics than the classical one.Öğe Designing human–robot ınteraction algorithms for developing metacognitive skills(John Wiley and Sons Inc, 2025) Barın Özkan, Sibel; Burak İnner, A.; Toz, Metin; Ünlü, BerkeIn today's technology, robots are involved in all life aspects. Therefore, it is inconceivable that robots will not affect the field of education either. Robot simulators can help developers test and improve intelligent systems before putting them in natural environments. In this study, the use of robots in education has been discussed in relation to the development of metacognitive abilities. A simulation environment was prepared for testing and developing the methods that follow learning models in human–robot interaction. The simulation is about a humanoid robot making an engineering lesson plan. It has been tested on a group of academicians consisting of 64 (32 persons in the experimental group and 32 persons in the control group) persons working in Computer Engineering in the 2021–2022 academic year. The application process includes an 8-week course period. The data as the result of the test were collected from both groups using the MCQ-30 scale and from the experimental group by the metacognitive strategy questions after preparing the engineering lesson plans made by robot simulation. Evaluation of the data showed that the robot simulation was effective in the metacognition scores of the people in the experimental group, and the success level of the people in the control group did not change significantly, considering the results of the pretest and the posttest. © 2024 Wiley Periodicals LLC.Öğe Mathematical Model Developed Using Heat Transfer Coefficient and Clothing Permeability Factor Parameters to Prevent Pressure Ulcer(Prof. Dr. Mehmet Zeki SARIKAYA, 2022) Öğülmüş Demircan, Fadime; Yücedağ, İbrahim; Toz, MetinPressure ulcers are wounds that occur in bedridden patients as a result of staying in the same position for a long time, due to external causes such as pressure, friction, shearing and moisture. Pressure ulcer is a serious problem all over the world when evaluated in terms of hospital capacity, nurse employment and treatment costs. Prevention studies gain importance as the cost of pressure ulcer prevention is less than the cost of treatment. In this study, we improved a mathematical model obtained in one of our previous study in order to prevent pressure ulcers or delay wound formation. In addition to the previous model, the new model calculates the effect of hc (heat transfer coefficient) and Fpcl (clothing permeability factor) parameters on the risk of pressure ulcer formation through the body area value. The effects of these parameters on the formation of pressure ulcers are shown in graphics. The results obtained from the new model shown that the sensitivity in the determination of the risk of pressure ulcer formation has increased. Thus, early detection of wound formation was provided by calculating the risk of pressure ulcer formation. © 2022, Prof. Dr. Mehmet Zeki SARIKAYA. All rights reserved.Öğe A novel approach for nature-based optimization algorithms: The threat factor approach(Wiley, 2021) Toz, Metin; Toz, GülizNature-inspired optimization algorithms especially those based on the hunting behaviors of the creatures assume that the hunting operations are performed in a safe environment. However, generally, there are threats in real-life for the hunter-animals. This paper focuses on these threat factors and proposes that they can be used to improve the searching abilities of the algorithms. Gray wolf optimization (GWO) algorithm was selected to present the proposed approach and it was assumed that there was a mountain lion as the threat factor living in the same habitat with the wolf pack. The relations between the two predators were modeled and used to improve the performance of the algorithm. Five experiments were conducted to test the performance of the proposed method and the results were compared with the GWO and four optimization algorithms from the literature. It is shown that the proposed algorithm obtained best results for 21 of the 50 benchmark functions, while its closest competitor achieved the best results for 16 functions. Besides, the results of the Wilcoxon signed-rank test indicated that the proposed method is superior to all other methods. In addition, it was shown that the threat factor approach does not cause a significant increase in the processing time.Öğe A novel mathematical model including the wetness parameter as a variable for prevention of pressure ulcers(SAGE Publications Ltd, 2021) Demircan, Fadime Öğülmüş; Yücedaǧ, İbrahim; Toz, MetinPressure ulcers are injuries caused by external conditions such as pressure, friction, shear, and humidity resulting from staying in the same position for a long time in bedridden patients. It is a serious problem worldwide when assessed in terms of hospital capacity, nursing staff employment and treatment costs. In this study, we developed a novel mathematical model based on one of our previous models to prevent pressure ulcers or delay injuries. The proposed model uses a human thermal model that includes skin temperature, hypothalamus temperature, regional perspiration coefficient, and unconsciously loss of water amount. Moreover, in our model, we defined a variable wetness parameter in addition to the parameters, pressure, temperature, and humidity. The proposed model is mathematically defined in detail and tested for a wide range of parameters to show the model’s effectiveness in determining the pressure ulcer formation risk. The model is also compared with a model from the literature that based on only the general parameters, pressure, temperature, and humidity. The obtained results showed that the model determines the risk of the occurrence of the pressure ulcer more precisely than the compared one.Öğe Re-formulated snowflake optimization algorithm (SFO-R)(Springer Heidelberg, 2023) Toz, Metin; Toz, GuelizModeling snowflake movements as an optimization algorithm is a recently proposed idea with a straightforward formulation. In this paper, we proposed to use different formulations for the movements of the snowflakes and presented a new nature-inspired optimization algorithm based on the same phenomenon. The algorithm is based on the forces that affect a snowflake during the snowfall and the collisions between them. We tested the algorithm on three benchmark sets, CEC 2017, CEC 2020 and CEC 2011 and compared its performance with PSO, WOA, BBO, GWO, BAT and MFO in solving these three benchmark sets. We evaluated the results both statistically and with the Wilcoxon signed-rank test. The evaluations shown that the proposed algorithm has well-balanced exploration and exploitation abilities and outperformed the other algorithms for all the comparison criteria except the execution time. Also, the pairwise comparisons indicated that it is more stable than the other algorithms in solving CEC 2017 and CEC 2020 benchmark problems.Öğe A review study on the investigation of the effects of using robots in education on metacognitive behaviors(Wiley, 2022) Özkan, Sibel B.; Toz, MetinIn today's technology, robots are now involved in all aspects of life. Therefore, it is inconceivable that robots will not affect the field of education either. In this study, the use of robots in education has been explicitly discussed in terms of the development of metacognitive abilities. For this purpose, literature studies have been conducted both on the development of metacognitive skills and on how robots are used in education. According to the results obtained, although robots have been used in many fields of education, they have not been used primarily in the field of developing metacognitive skills. From this point of view, in this study, some research questions and suggestions for the application of metacognitive models through robots and, therefore, the use of robots to improve metacognitive skills are presented to the researchers. It is expected that it will benefit researchers related to this question and the proposed topic to direct their research and help close the lack of research in this area.Öğe Two design proposals and working space comparison for 3-CCC type robot with 6 degrees of freedom(Gazi University, 2022) Yılmaz, Savaş; Küçük, Serdar; Toz, MetinIn this study, inverse kinematic analysis of 3-CCC type asymmetric parallel mechanism, which is one of the 3D3A class parallel robot structures with 6 degrees of freedom, was made and two design proposals were performed. Working spaces of the proposed designs have been calculated. In the designs, CPAC (P: Active prismatic joint) leg structure provided with D4 type constraint and CPAC (A: Active rotational joint) leg structure provided with A1 type constraint were used. In addition, the CPAC (A: Active rotational joint, P: Active prismatic joint) leg structure obtained by using two active joints in a single leg was also used in the designs. This robot type is also referred to as a 3-CCC mechanism in the literature. In the first design proposal, the fixed and mobile platforms were determined to be equilateral triangles with cylindrical joints. Platforms are connected to each other by 3 CCC leg types. In the second design proposal, the movable platform with fixed cylindrical joints placed in XY, XZ and YZ planes and pointwise end-effector is connected with 3 CCC leg types. The lengths of the cylindrical joints used in the fixed and mobile platform were kept the same in both designs. While calculating the working spaces, the limit points that the end functionalist can reach were determined and the inside area was scanned at 5 mm intervals and its accessibility was checked. Working spaces are calculated by first holding the mobile platform fixed at 0o and then rotating it between -30 degrees + 30 degrees angles. With the results obtained, it has been seen that the working space can be expanded with different designs.Öğe Workspace, singularity, and dexterity analyses of a six-degrees-of-freedom sdelta robot with an orthogonal base platform(Asme, 2024) Toz, Metin; Han, Hasiaoqier; Angeles, JorgeThe SDelta is a three-limb, six-degrees-of-freedom parallel kinematics machine, a pertinent candidate for high-speed operations by virtue of its simple architecture. The original design of the SDelta includes a planar base and moving platforms. Here, we propose a novel architecture for an improved SDelta, the orthogonal SDelta (OSD), with a cube-shaped orthogonal base platform. Inverse and forward position models are reported, along with singularity and dexterity analyses. Moreover, design parameters and mechanical constraints leading to a singularity-free workspace are provided. An evaluation of the system translational workspace and orientational capability, upon consideration of volume and dexterity, is included. The SDelta as well as a generic 6SPS mechanism (C, P, and S denote, respectively, the cylindrical, prismatic, and spherical kinematic pairs, the actuated pair is represented underlined, as P) are designed with the same parameters, then the performance of the SDelta, the OSD, and the 6SPS mechanisms are being compared. The results show that the orientational capability of the OSD is better than those of the 6SPS and the SDelta. Furthermore, the OSD has an average condition number of 2.9 over its translational workspace and 1.69 over a predefined effective regular workspace, which make the OSD a good candidate for operations that need both a high orientational capability and high dexterity.
