Makine Mühendisliği Bölümü

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Citation Count: Yildirim, E.; Kulah, H.; Arikan, M.A.S.,"An Electrostatically Actuated Parylene Microvalve for Lab-On-A-Chip Applications", 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference, Transducers'11, pp. 250-253, (2011).
An Electrostatically Actuated Parylene Microvalve for Lab-On-A-Chip Applications
(2011) Yıldırım, Ender; Arıkan, M. A. Sahir; Kulah, Haluk; 31835
This paper presents a novel electrostatic microvalve to control in-plane flow on parylene based lab-on-a-chip-devices. Normally-closed design of the microvalve insulates the working fluid from the electric field, while providing low leakage up to 40 kPa inlet pressure. Prototypes are fabricated and tested for pull-in and flow characterization. Pull-in voltage is measured to be 150 V independent of the working fluid. No leakage is detected up to 20 kPa inlet pressure.
Citation Count: Yapıcı Özgirgin, Ekin; Haj İbrahim, Mahmoud Awn; Türkoğlu, H. (2022). "Analysıs Of Heat Transfer Enhancement In Tubes Wıth Capsule Dımpled Surfaces And Al2o3-Water Nanofluıd", Isı Bilimi ve Tekniği Dergisi, Vol.42, No.2, pp.269-280.
Analysıs Of Heat Transfer Enhancement In Tubes Wıth Capsule Dımpled Surfaces And Al2o3-Water Nanofluıd
(2022) Yapıcı Özgirgin, Ekin; Haj İbrahim, Mahmoud Awni; Türkoğlu, Haşmet; 31329
This study aims to numerically investigate and evaluate the enhancement of heat transfer by new capsule dimples on tube surfaces for flow of water and Al2O3-water nanofluid with different concentrations, under uniform surface heat flux. The originality of this work lies in combining two passive heat transfer enhancement methods such as geometrical improvements and nanofluids together. Capsule dimples with different depths were considered. Al2O3-water nanofluid was modeled as a single-phase flow based on the mixture properties. The effects of dimple depth and nanoparticle concentrations on Nusselt number, friction factor and performance evaluation criteria (PEC) were studied. Numerical computations were performed using ANSYS Fluent commercial software for 2000 14000 Reynolds number range. It was found that when laminar, transient and fully developed turbulent flow cases are considered, increase in the dimple depth increases the Nusselt number and friction factor for both pure water and Al2O3-water nanofluids cases. Also, the friction factor increases as dimple depth increases. Results show that increase in PEC is more pronounced in the laminar region than in the transition region, it starts to decrease for turbulent flows. For nanofluid, PEC values are considerably higher than pure water cases. The variation of PEC for capsule dimpled tubes are dependent on flow regimes and dimple depths. Increasing the nano particle volume concentration and dimple depth in laminar flows increase the PEC significantly.
Citation Count: Akyürek, Turgut (2017). "Assessment of the Use of AutoCAD in Mechanical Engineering Technical Drawing Education", Çankaya University Journal of Science and Engineering, Vol. 14, no. 1, pp. 42-98.
Assessment of the Use of AutoCAD in Mechanical Engineering Technical Drawing Education
(2017) Akyürek, Turgut
AutoCAD is one of the widely used software tools in engineering education. In this study, a general assessment of AutoCAD for the usage in the mechanical engineering technical drawing education is made. AutoCAD is assessed in terms of the fulfilment of the requirements defined for the main two technical drawing courses. AutoCAD is assessed in terms of its capability in meeting the requirements of the technical drawing courses.
Citation Count: Ayli, Ece, "Cavitation in Hydraulic Turbines", International Journal of Heat and Technology, Vol. 37, No. 1, pp. 334-344, (March 2019).
Cavitation in Hydraulic Turbines
(Edizioni Ets, 2019) Aylı, Ece; 265836
Hydroenergy is one of the richest and most useful renewable energy sources in the world. Hydropower is a vital source as it is the clean energy source, sustainable and last but not least it is also cost-effective. One of the most important parameters that affect the performance of the hydraulic machines is the cavitation phenomenon, which is defined as the formation of the vapor bubbles in the liquid through any hydraulic turbine. In this paper, hydraulic machines, cavitation, types of cavitation are briefly described. After theoretical studies, analytical and numerical researches about cavitation in hydraulic machinery are discussed extensively. With those studies which are summarized in this paper covers a lot of ground about cavitation on the other hand further studies are needed about cavitation in hydro turbines. Numerical methods provide sufficient predictions for cavitation. However, numerical results should be verified by experimental measurements and detection methods to decide what intensity and which shape of cavitation is hazardous and vital, where the local pressure is lower than the vapor pressure and at which static pressure cavities start to grow and collapse.
Citation Count: Farukoğlu, Ö.C.; Korkut, İ.; Motameni, A. (2023). "Comprehensive elastic analysis of functionally graded variable thickness pressurized disk", ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik, Vol.103, No.11.
Comprehensive elastic analysis of functionally graded variable thickness pressurized disk
(2023) Farukoğlu, Ömer Can; Korkut, İhsan; Motameni, Ali
This study analytically examines internally pressurized power-law functionally graded variable thickness disk. The power-law consideration is applied to the Young's modulus and the Poisson's ratio of the graded material as well as the radial thickness profile variation of the disk. Under this scheme, the solution yields to different Bessel functions including the first, second, and modified types. Stress and displacement fields are investigated at the elastic limits by operating with these functions. The limits are calculated with the well-known von Mises criteria. Following the analytical modeling, numerical examples are built. Therein the examples, some noteworthy nuances have been achieved. It has been observed that unlike the usual prediction in the literature, constant Poisson's ratio, the effect of variable Poisson's ratio on stresses and displacements is still evident, although not as much as variable Young's modulus and disk geometry. We suggest assigning it as a variable in similar applications to be more precise. Additionally, according to the von Mises criterion, yielding may begin at the inner radius, the outer radius, or both at the same time. Parameters in the simultaneous flow initiation state are critical. These parameters allow the disk to reach the highest elastic limit pressure.
Citation Count: Selvi, Ö.; Ceccarelli, M., "Design and Optimization of A Walking Over-Constrained Mechanism", Mechanisms and Machine Science, Vol. 73, pp. 681-687, (2019).
Design and Optimization of A Walking Over-Constrained Mechanism
(Springer Netherlands, 2019) Özgün, Selvi; Ceccarelli, Marco; Yavuz, Samet; 46949
In this paper, a walking overconstrained mechanism with one DoF is presented. Firstly, its dimensional parameters and geometry are shown and a step profile which is wanted to be followed by end point of the walking mechanism is proposed. Kinematic equations of the walking mechanism are extracted to use them later as constraints for Firefly Algorithm. Algorithm is run in get the optimized dimensional parameters to provide the desired step profile. Results are presented.
Citation Count: Özdemir, Mustafa; İder, Sıtkı Kemal (2021). "Desingularization of Flexible-Joint Parallel Robots", Acta Polytechnica Hungarica, Vol. 18, No.6, pp. 85-106.
Desingularization of Flexible-Joint Parallel Robots
(2021) Özdemir, Mustafa; İder, Sıtkı Kemal; 108608
Parallel robots possess a characteristic type of singularities, called type II or drive singularities, inside their workspace. In the neighborhood of these singularities, the inverse dynamics solution grows unboundedly and the robot becomes uncontrollable. There is growing literature on methods that enable parallel robots to pass through drive singularities. Most of this literature relies on dynamic models that presume rigid joints. However, the flexibility of the drive train elements should also be taken into account for high accuracy. In this paper, we propose a systematic trajectory planning method for enabling flexible-joint parallel robots to pass through drive singular configurations. Our method generates admissible polynomial trajectories of degree eleven. Four conditions are derived and incorporated into the method to prevent undesired back-and-forth motion of the endpoint. This ensures not only an efficient operation of the robot but also the avoidance of unintended multiple occurrences of the same singularity. The boundedness of the inverse dynamics solution is also guaranteed.
Citation Count: Clarke, P.; O'Connor, RV.; Leavy, B., "Exploring the relationship between software process adaptive capability and organisational performance" Ieee Transactions On Software Engineering, Vol.41, No.2, pp.1169-1183, (2015)
Exploring the relationship between software process adaptive capability and organizational performance
(IEEE Computer Soc, 2015) Clarke, Paul; O'Connor, Rory V.; Leavy, Brian; Yılmaz, Murat
Software development is a complex socio-technical activity, with the result that software development organisations need to establish and maintain robust software development processes. While much debate exists regarding the effectiveness of various software development approaches, no single approach is perfectly suited to all settings and no setting is unchanging. The capability to adapt the software process is therefore essential to sustaining an optimal software process. We designed an exploratory study to concurrently examine software process adaptive capability and organisational performance in 15 software development organisations, finding that companies with greater software process adaptive capability are shown to also experience greater business success. While our exploratory study of the complex relationship between these phenomena is limited in some respects, the findings indicate that software process adaptive capability may be worthy of further integration into software process engineering techniques. Software process adaptive capability may be an important organisational strength when deriving competitive advantage, and those responsible for the creation and evolution of software process models and methodologies may want to focus some of their future efforts in this area.
Citation Count: Tanriover, Hakan, "Finite Element Method Application For Nonlinear Mechanical Response Of Three-Dimensonal Beams Using Mathematica", Journal of Polytechnic-Politeknik Dergisi, Vol. 22, No. 4, pp. 961-966, (December 2019).
Finite Element Method Application For Nonlinear Mechanical Response Of Three-Dimensonal Beams Using Mathematica
(Gazi Univ, 2019) Tanrıöver, Hakan; 153029
Mechanical behavior of beams under large rotations and displacements was investigated. Using co-rotational approach given by Crisfield, three dimensional beam finite elements was modeled in Mathematica environment. The symbolic process of Mathematica provides keeping the parameters in the model as variables and beams having different geometries can be modelled easily. The yielding non-linear equation system was solved by utilizing Newton-Raphson technique. Dynamic balance equations and numerical time integration method were introduced, the solution process was left as a future work, however. Comparisons with the results of ANSYS and those of the works from the literature are accomplished.
Citation Count: Elibol, Emre Aşkın; Türkoğlu, H. (2017). " Gözenekli Düz Bir Yüzeye Çarpan Jetin Sayısal Olarak İncelenmesi", Karadeniz Fen Bilimleri Dergisi, Vol. 7, No.1, pp.1-9.
Gözenekli Düz Bir Yüzeye Çarpan Jetin Sayısal Olarak İncelenmesi
(2017) Elibol, Emre Aşkın; Türkoğlu, Haşmet; 12941
Bu çalışmada, gözenekli malzeme ile kaplanmış sabit sıcaklıkta tutulan düz levha üzerine çarpan jetin akış ve ısı transferine etkileri nümerik olarak incelenmiştir. Birbirine paralel olarak duran, iki yatay levhadan biri olan alt levha, gözenekli bir tabaka ile kaplanmış ve üst levhanın ortasında bulunan lüleden çıkan hava jeti alt levhaya çarptırılmıştır. Gözenekli tabakanın katı matrisi ile akışkan arasında yerel ısıl denge olduğu kabul edilerek, laminar ve kararlı rejim için çözümler yapılmıştır. Gözeneklilik, gözenekli tabakanın kalınlığı ve jet Reynolds sayısının farklı değerlerinde simülasyonlar yapılarak, bu parametrelerin yerel Nusselt sayısı’na (Nu) etkileri analiz edilmiştir. Sonuçlar, yatay (x) yönde; yerel Nu sayıları ve sıcak alt levhadan olan ısı akıları, gözenekli tabaka bulunmayan durum ile karşılaştırılarak yorumlanmıştır. Analizler için yazılım paketi olan ANSYS Fluent yazılımı kullanılmıştır. Sonuçlar, sıcak levha yüzeyinin gözenekli tabaka ile kaplandığı durumlarda, gözenekli malzemenin belirli gözeneklilik ve kalınlık değerleri aralığında olması halinde, ısı transferinin gözenekli tabaka kullanılmayan duruma göre daha etkin olduğunu göstermiştir.
Citation Count: Kilicaslan, Sinan; Özgören, Mustafa Kemal; Ider, Sıtkı Kemal. (2022). Hybrid Force and Motion Control of a Three-Dimensional Flexible Robot Considering Measurement Noises", Machines, Vol.10, No.7.
Hybrid Force and Motion Control of a Three-Dimensional Flexible Robot Considering Measurement Noises
(2022) Kilicaslan, Sinan; Özgören, Mustafa Kemal; Ider, Sıtkı Kemal; 108608
This work addresses the end-effector trajectory-tracking force and motion control of a three-dimensional three-link robot considering measurement noises. The last two links of the manipulator are considered as structurally flexible. An absolute coordinate approach is used while obtaining the dynamic equations to avoid complex dynamic equations. In this approach, each link is modeled as if there is no connection between the links. Then, joint connections are expressed as constraint equations. After that, these constraint equations are used in dynamic equations to decrease the number of equations. Then, the resulting dynamic equations are transformed into a form which is suitable for controller design. Furthermore, the dynamic equations are divided as pseudostatic equilibrium and deviation equations. The control torques resulting from the pseudostatic equilibrium and the elastic deflections are obtained easily as the solution of algebraic equations. On the other hand, the control torques corresponding to the deviations are obtained without any linearization. Encoders, strain gauges, position sensors and force and moment sensors are required for measurements. Low pass filters are considered for the sensors. For the crossover frequencies of the sensors, low and high values are chosen to observe the filtering effect on the robot output.
Citation Count: Özdemir, M.; İder, S.K. (2023). "Integrated Force/Motion Trajectory Design of Parallel Robots for Singularity Robustness during Contact Tasks", Acta Polytechnica Hungarica, Vol.20, No.2, pp.41-61.
Integrated Force/Motion Trajectory Design of Parallel Robots for Singularity Robustness during Contact Tasks
(2023) Özdemir, Mustafa; İder, Sıtkı Kemal; 108608
Parallel robots have an increasing use in industrial and medical applications. Many of these applications require the execution of contact tasks. However, parallel robots possess drive singularities, which act as invisible barriers inside their workspace. In this paper, we develop an integrated force and motion trajectory planning method for removing drive singularities of parallel robots which perform contact tasks. The method is based on satisfaction of a consistency condition at the singularity, which is stated in terms of the generalized velocities, accelerations and contact forces, provided that the derivative of the associated determinant with respect to time does not simultaneously vanish. It is shown that, in the presence of singularity crossing, either the motion or the force trajectory can be arbitrarily chosen while the other is planned to satisfy the necessary conditions.
Citation Count: Ahmadi Khatir, Farzad; Hossein Sadeghi, Mohammad; Akar, Samet (2020). "Investigation of surface roughness in laser-assisted hard turning of AISI 4340", 1st International Conference and Exposition on Mechanical, Material and Manufacturing Technology, ICE3MT 2020, Materials Today: Proceeding, Vol. 38, pp. 3085-3090.
Investigation of surface roughness in laser-assisted hard turning of AISI 4340
(2020) Ahmadi Khatir, Farzad; Hossein Sadeghi, Mohammad; Akar, Samet; 315516
In recent years, new materials such as titanium, nickel alloys, and high-strength steels have been widely used in medical, nuclear, and other industries. Since the manufacturing of different components from these materials has always been associated with the machining process, the use of hard machining in their production is unavoidable. The short life of the cutting tool, the poor quality of the machined surfaces, and the long machining time are some of the challenging issues involved in the traditional machining of these materials. Therefore, researchers have investigated new machining techniques to increase the efficiency and quality of produced parts. Thermal-assisted machining, especially laser-assisted machining is one of the promising methods of machining difficult-to-machine materials. However, this process faces some challenges in terms of the achievable surface integrity of the machined surfaces. This research studies the effect of cutting and thermal parameters on the surface roughness in the laser-assisted turning (LAT) process of AISI 4340 hard steel with a hardness of 560 HV. The results illustrated that by selecting a proper combination of process parameters, the damage caused by the heat penetration into the workpiece can be minimized and the advantages of LAT can be benefited from. © 2020 Elsevier Ltd. All rights reserved.
Citation Count: Budak, Y.; Özgirgin Yapıcı, E.; Devrim, Y. (2018). "Investigation Of Working Temperature Effect On Micro-Cogeneration Application Of Proton Exchange Membrane Fuel Cells", Hittite Journal of Science and Engineering, Vol.5, pp.25-32.
Investigation Of Working Temperature Effect On Micro-Cogeneration Application Of Proton Exchange Membrane Fuel Cells
(2018) Budak, Yağmur; Özgirgin Yapıcı, Ekin; Devrim, Yılser; 31329
I n this study, micro-cogeneration application is used to increase the efficiency of Proton Exchange Membrane Fuel Cell (PEMFC) systems and effect of different operation temperatures on system performance is observed. For this reason, two different PEMFC systems were comparatively studied operating at 70o C and 160o C, respectively. Micro-cogeneration system design has done considering experimentally determined current density, power and temperature values. Since the amount of heat extracted from each PEMFC system is different related to the operating temperatures, different heat transfer fluids have been used for the cooling systems. These systems are designed for utilization of electricity and hot water for Atılım University Hydrogen Energy Laboratory. Heat loss calculation is made for the laboratory and thermal energy needed for heating the laboratory is calculated. Parallel to the design calculations, simple payback times for PEMFCs with micro-cogeneration applications were determined. LT-PEMFC and HT-PEMFC systems have 402 W and 456 W thermal powers respectively and 87.4 % and 92.8 % total cogeneration efficiencies were calculated for each system respectively. For each system maximum water temperatures and flow rates are calculated as a result of micro-cogeneration application. HT-PEMFC system has found to be capable of higher amount of heating. Even LT-PEMFC system has a lower thermal power and efficiency; it is determined to be more economical and has a lower pay pack time then HT-PEMFC system. For both systems, necessary number of stacks to be used for laboratory heating is calculated as four.
Citation Count: Budak, Yağmur; Özgirgin Yapıcı, Ekin; Devrim, Yılser (2018). "Investigation of Working Temperature Effect on Micro-Cogeneration Application of Proton Exchange Membrane Fuel Cells", Hittite Journal of Science and Engineering, Vol. 5, No. Özel Sayı, pp. 25-32.
Investigation of Working Temperature Effect on Micro-Cogeneration Application of Proton Exchange Membrane Fuel Cells
(2018) Budak, Yağmur; Özgirgin Yapıcı, Ekin; Devrim, Yılser
In this study, micro-cogeneration application is used to increase the efficiency of Proton Exchange Membrane Fuel Cell (PEMFC) systems and effect of different operation temperatures on system performance are observed. For his reason, two different PEMFC systems were comparatively studied operating at 70oC and 160oC respectively. Micro-cogeneration system design is done considering experimentally determined current density, power and temperature values. Since the amount of heat extracted from each PEMFC system is different related to the operating temperatures, different heat transfer fluids have been used for the cooling systems. These systems are designed for utilization of electricity and hot water for Atılım University Hydrogen Energy Laboratory. Heat loss calculation is made for the laboratory and thermal energy needed for heating the laboratory is calculated. Parallel to the design calculations, simple payback times for PEMFCs with micro-cogeneration applications were determined. LT-PEMFC and HT-PEMFC systems have 402 W and 456 W thermal powers respectively and 87.4 % and 92.8 % total cogeneration efficiencies are calculated for each system respectively. For each system maximum water temperatures and flow rates are calculated as a result of micro-cogeneration application. HT-PEMFC system is found to be capable of higher amount of heating. Even LT-PEMFC system has a lower thermal power and efficiency, it is determined to be more economical and has a lower pay pack time then HT-PEMFC system. For both systems, necessary number of stacks to be used for laboratory heating are calculated as four.
Citation Count: Yılmaz, O.D.; Oliaei, S.D.B. (2020). "Kesici Takım Geometrisinin Ti-6Al-4V’nin İşlenmesi Sırasında Oluşan Tırtıklı Talaş Üzerindeki Etkisinin Sonlu Elemanlar Yöntemi ile Araştırılması"Dicle Üniversitesi Mühendislik Fakültesi Mühendislik Dergisi, Vol.11, No.3, pp.1131-1138.
Kesici Takım Geometrisinin Ti-6Al-4V’nin İşlenmesi Sırasında Oluşan Tırtıklı Talaş Üzerindeki Etkisinin Sonlu Elemanlar Yöntemi ile Araştırılması
(2020) Yılmaz, Okan Deniz; Oliaei, Samad Nadimi Bavil
Ti-6Al-4V titanyum alaşımının işlenmesi sırasında tırtıklı talaş (serrated chip) oluşumunun modellenmesi oldukçazordur ve takım ömrünü, işlenmiş parçanın doğruluğunu ve yüzey kalitesini etkilediği için hayati öneme sahiptir.Kesici uç geometrisinin tırtıklı talaş oluşumu üzerindeki etkisi daha ileri araştırmalar gerektirirken, termalyumuşama, deformasyon yumuşaması ve hasara dayanan modeller olmak üzere bu sorunu çözmek için çeşitlimalzeme modelleri geliştirilmiştir. Bu çalışmada, teğet hiperbolik (TANH) fonksiyon kullanarak deformasyonyumuşama etkisini dikkate alan modifiye edilmiş bir Johnson-Cook temel malzeme modeli ele alınmıştır. Farklıgeometrilere (talaş açısı, boşluk açısı ve kenar yarıçapı) sahip olan kesici takımların tırtıklı talaş oluşumu üzerindeetkileri modellenmiş ve analiz edilmiştir. Kesme kuvveti, talaş morfolojisi ve tırtıklı talaşın derecesi talaşlı imalatverisi olarak kullanılmıştır
Citation Count: Selvi, Özgün; Al-dulaimi, Hasan. (2015). "Kinematic Analysis Of A 5 Dof Overconstrained Manipulator For Rehabilitation Of Upper Extremite", Journal of Naval Sciences and Engineering, Vol.11, No.2, pp.52-69.
Kinematic Analysis Of A 5 Dof Overconstrained Manipulator For Rehabilitation Of Upper Extremite
(2015) Selvi, Özgün; Al-dulaimi, Hasan
This study deals with one of the applications of parallel manipulator as a rehabilitation robot. This device is an over –constrained parallel manipulator 5 degree of freedom with 3 legs. This manipulator consists of a moving platform which is connected to a fixed base via three legs. Each leg is made of RRR(RR) (revolute) joints where the first three joint in all legs are parallel and the recent two joint are intersecting .Inverse kinematics of this device is solved by dividing manipulator into two sub-manipulators with the help of three imaginary joints placed at the intersection of platform joints with a direction parallel to base joints.
Citation Count: Turgut, Oguz; Ozcan, Ahmet Cem; Turkoglu, Hasmet, "Laminar Forced Convection Over An Inclined Flat Plate With Unheated Starting Length", Journal of Polytechnic-Politeknik Dergisi, Vol. 22, No. 1, pp. 58-62, (March 2019).
Laminar Forced Convection Over An Inclined Flat Plate With Unheated Starting Length
(Gazi Univ, 2019) Turgut, Oğuz; Özcan, Ahmet Can; Türkoğlu, Haşmet; 12941
Two-dimensional laminar forced convection over an inclined flat plate with an unheated starting length was investigated numerically for both constant surface temperature and constant heat flux boundary conditions. The numerical study was implemented using the commercial software ANSYS Fluent 15.0. Air is used as working fluid. The influence of Reynolds number, inclination angle and the length of unheated plate on velocity and temperature distributions, surface temperature, surface heat flux and local Nusselt number was investigated. The results show that Reynolds number, inclination angle and the length of unheated region of plate play important role on heat transfer from the plate. It is seen that Nusselt number increases with increasing Reynolds number and inclination angle of inclined flat plate but decreases with increasing the length of unheated region of plate.
Citation Count: Totuk, Onat Halis; Mistikoğlu, Selçuk. (2023). "Modeling and Optimization of a Peano-HASEL Actuator Peristaltic Pump", Journal of Scientific and Industrial Research, Vol.82, No.7, pp.776-782.
Modeling and Optimization of a Peano-HASEL Actuator Peristaltic Pump
(2023) Totuk, Onat Halis; Mistikoğlu, Selçuk; 284521
Peano-Hasel (hydraulically amplified self-healing electrostatic) pumps are crucial devices with unique mechanisms and versatile applications. They simulate muscle contractions to move fluids or materials through tubes. The Peano-Hasel method, a specific design, achieves flow by compressing a segmented tube externally. Exploring the design aspects of Peano-Hasel pumps can lead to advancements in optimizing their performance, efficiency, reliability, and control systems. This paper presents a novel method of peristaltic pumping on soft pipes using Peano-HASEL actuators. In the study, a design evaluation of an external ring-type pump over a PDMS (Polydimethylsiloxane - commonly referred to as silicone) tube containing Newtonian fluids is made, and a novel multi-pouch ring shape design is proposed. Our method utilizes a peripheral and compact design that allows for more efficient sinusoidal pumping action. The close proximity of the rings in the longitudinal direction enhances the effectiveness of the pumping process. The actuator is analytically modeled and optimized for maximum areal contraction and flow rate using a differential evolution algorithm. A MATLAB Simulink Simscape model is generated, and the system is simulated. As a result, an optimal solution for the number of pouches was found to be eight, considering ring geometry and applicability. It was also seen from the simulation that a sinusoidal squeezing scheme of a ring-type pump creates the desired action. Based on the analytical model presented, it has been demonstrated that the optimal flow rate is achieved when there are eight pouches, and they are fully circular after being energized.
Citation Count: Alhebshi, Reemah M.;...et.al. (2023). "Modeling of Computer Virus Propagation with Fuzzy Parameters", Computers, Materials and Continua, Vol.74, no.3, pp.5663-5678.
Modeling of Computer Virus Propagation with Fuzzy Parameters
(2023) Alhebshi, Reemah M.; Ahmed, Nauman; Baleanu, Dumitru; Fatima, Umbreen; Dayan, Fazal; Rafiq, Muhammad; Raza, Ali; Ahmad, Muhammad Ozair; Mahmoud, Emad E.; 56389
Typically, a computer has infectivity as soon as it is infected. It is a reality that no antivirus programming can identify and eliminate all kinds of viruses, suggesting that infections would persevere on the Internet. To understand the dynamics of the virus propagation in a better way, a computer virus spread model with fuzzy parameters is presented in this work. It is assumed that all infected computers do not have the same contribution to the virus transmission process and each computer has a different degree of infectivity, which depends on the quantity of virus.Considering this, the parameters β and γ being functions of the computer virus load, are considered fuzzy numbers. Using fuzzy theory helps us understand the spread of computer viruses more realistically as these parameters have fixed values in classical models. The essential features of the model, like reproduction number and equilibrium analysis, are discussed in fuzzy senses.Moreover, with fuzziness, two numerical methods, the forward Euler technique, and a nonstandard finite difference (NSFD) scheme, respectively, are developed and analyzed. In the evidence of the numerical simulations, the proposed NSFD method preserves the main features of the dynamic system. It can be considered a reliable tool to predict such types of solutions.

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