Faculty of Mechanical Engineering
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Item type:Publication, Common fixed point theorems for pairs of self-mappings on (3,2)-W-symmetrizable spaces(Union of Mathematicians of Macedonia, 2023) ;Dimovski, TomiDimovski, DončoIn this paper,we prove the existence and the uniqueness of a fixed point for pairs of self-mappings on (3, 2)-W-symmetrizable spaces using self-mappings similar to Tf contractions in ordinary metric spaces, and we obtain two corollaries. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Some fixed point theorems in (3,2)-metric spaces(World Scientific Pub Co Pte Ltd, 2024-10-30) ;Dimovski, TomiDimovski, Dončo<jats:p> In this paper, we consider [Formula: see text]-metric spaces and prove several fixed point theorems for self-mappings on [Formula: see text]-metric spaces satisfying some conditions similar to contractions in ordinary metric spaces. </jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A survey on (3,1,ρ)-metrics, j∈{1,2}, and topologies induced by them(Macedonian Academy of Sciences and Arts, 2026)Tomi DimovskiIn this survey, we summarize recent progress in the study of (3,j,ρ)-metrics, j∈{1,2}, and the topologies induced by them. We give connections among topologies induced by (3,j,ρ)-metrics and those induced by previously known generalized metrics. We present some properties from a topological viewpoint, such as sequence convergence, separation properties, and selection principles. We also present some fixed-point theorems obtained in these settings. Finally, we state some open problems on the topic. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, On sequence convergence in (3,j)-metric spaces, j∈{1,2}(Union of Mathematicians of Macedonia, 2024)Donco Dimovski, Pavel Dimovski, Tomi DimovskiIn this article, we show that a convergent sequence in (3, 2)-metric spaces has a unique limit. We give several examples in (3, 1, ρ)-metric spaces and (3, 1)-metric spaces in which a convergent sequence has more than one limit. We obtain sufficient conditions for a sequence in (3, 1)-metric space to have a unique limit. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Hardering alloys for excavator teeth coating(Centre for Evaluation in Education and Science (CEON/CEES), 2024)M. Poser, F. Zdraveski, M. Petreski, M. Pavlović, V. JeremićThe capacity of the rotоr excavator depends to a significant extent on the backet teeth. Abrasive wear of cutting teeth and cutting edges is typical when digging sand, sandy clay and gravel in common rock environments. Of particular importance is the contribution of the correct geometry of the teeth, their position on the backet, and especially their sharpness, which they lose over time. Over time, teeth become blunt due to abrasive wear and their geometry changes. The digging resistance becomes greater, and therefore the efficiency of the rotor excavator decreases. White cast iron stands out as a base alloy that has wear resistance, but has very low toughness and often brittle fracture under impact loads. Manganese steel, although it has the property of deformation strengthening, has no wear resistance when digging in sand. This condition can be improved by choosing a material more resistant to abrasive action. Excavator teeth that fail due to abrasive wear can be protected from abrasive wear by the use of hardface coating. These hardfacing alloys are presented in this paper. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, MBSE APPROACH FOR FACILITATING THE APPLICATION OF STANDARDS IN THE VEHICLE DEVELOPMENT PROCESS(Faculty of Engineering, University of Kragujevac, 2023-08-14) ;Angeleska, Elena ;Changoski, Vasko ;Rizov, TaskoSidorenko, SThe development of complex vehicle systems that integrate latest trends and user needs with regulations, standards, and engineering requirements needs to rely on a strong multi-disciplinary collaboration between experts who exchange information from all relevant fields included in the vehicle development process. Constantly following, updating and applying the input information from various sources when working on vehicle systems can be a daunting task. The Model-Based Systems Engineering (MBSE) approach can provide a strategy for easier coping with the complexity of vehicle systems. This is extremely beneficial since it helps to create an information base where the information is represented in an integrated and consistent system model rather than in isolated documents. This paper presents a concept of an information platform based on MBSE. The goal of the platform is to become an engineering tool for incorporating all relevant data (requirements, standards, regulations) in a manner that they can be directly linked to the adequate system components, simple to interpret and be used by all members of the development team. The purpose of this platform is to: (1) facilitate the development process and interdisciplinary collaboration; (2) help to follow regulations correctly and avoid mistakes; and (3) keep all project data systematized. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, VEHICLE HANDLING ENHANCEMENT EMPLOYING FOUR-WHEEL INDEPENDENT STEERING SYSTEM USING SLIDING MODE CONTROL(University Ss. Cyril and Methodius in Skopje, 2023) ;Changoski, Vasko ;Gjurkov, Igor; The demand for safer vehicle transportation and future automated vehicles will open the possibility for implementation of steer-by-wire (SbW) vehicle steering system. Application of this system would not be exclusive only for the front axle, but for the rear axle as well. Current four-wheel steering (4WS) systems are designed and applied using Ackermann steering geometry. Due to the vehicle designs requirements, an ideal Ackermann geometry is never achieved and steering kinematics may result in two instantaneous centres of rotation during vehicle cornering. To avoid this, a control strategy for a four-wheel independent steering (4WIS) is proposed where the four independently steered wheels attempt to achieve single instantaneous centre of rotation using sliding mode controller (SMC). As a reference model a 2DOF nonlinear vehicle bicycle model is used. The 4WS and 4WIS two-track vehicle models are created using MATLAB/Simulink and tested with manoeuvres defined by the standard ISO 7401. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, DESIGN, ANALYSIS AND OPTIMIZATION OF THE STEERING COLUMN SYSTEM FOR ANELECTRIC STREET SWEEPER(University Ss. Cyril and Methodius in Skopje, 2024) ;Angeleska, Elena ;Changoski, Vasko ;Nestorovski, BlagojaVasileva, AnitaThis study explores the challenges and solutions related to improving the interior ergonomics of a small street sweeper, with a specific focus on redesigning the steering column and brake pedal system. The initial design faces issues such as obstructed field of view and limited space in the operator's knee area. The primary objective is to enhance comfort and safety for the operator within the constraints of the existing design. The proposed solution involves a new steering column structure that integrates the brake pedal system. Siemens Jack software was employed for ergonomic analysis, revealing improved operator comfort and larger field of view with the modified design. Dynamic analysis using ADAMS View confirmed that the new brake pedal system met the requirements outlined in the ECE R13 regulation. This solution improves ergonomics, offers larger field of view, and ensures optimal brake performance. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, HANDLING AND STABILITY ANALYSIS OF AN AUTOMATED VEHICLE WITH INTEGRATED FOUR-WHEEL INDEPENDENT STEERING (4WIS)(Faculty of Engineering, University of Kragujevac, 2024-11-01) ;Changoski, Vasko ;Gjurkov, IgorJanushevska, VaseThe latest revisions of the UN and the European Union regulations regarding the steering system allow implementation of novel technologies in automated vehicles. Four-wheel independent steering (4WIS) system represents an upgrade of the steer-by-wire concept that enhances the capabilities of the steering system. The primary focus of this research is to enhance vehicle handling and stability performance by integration of four-wheel independent steering (4WIS) and vehicle stability control (VSC) system in an automated vehicle. A virtual vehicle equipped with 4WIS and VSC is created in ADAMS/Car. The proposed control algorithms are implemented in MATLAB/Simulink and their effect is tested in co-simulation environment. As a control method, Sliding Mode Control (SMC) is used to improve vehicle handling while maintaining vehicle stability under different driving conditions. The proposed concept is evaluated through different open-loop and path following manoeuvres to thoroughly assess its performance. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, MECHANICAL TESTING OF HLAW WELDED JOINTS IN ACCORDANCE WITH EUROPEAN STANDARDS –THEORETICAL APPROАCH(University Ss. Cyril and Methodius in Skopje, 2023) ;Petreski, Martin ;Krstevska, Aleksandra
