Ivan Macuzic

A new fuzzy model for determining risk level on the workplaces in manufacturing small and medium enterprises

Crucial part of the reduction and prevention of workplace injuries and maintaining occupational safety and health system takes risk assessment model, which appears as one of the most important. Frequent advances in all fields cause changes in risk assessment models in relation to the traditional approach. This article is focused on providing reliable assessment tool that will enable suitable and easy usage of methodology for risk evaluation in the workplaces in manufacturing small and medium enterprises. For that purpose, three groups of factors are introduced and their hierarchical structures are defined. Pre-defined linguistic expressions are used to describe relative importance of factors, sub-factors and values of sub-factors. Fuzzy set theory is used for modeling of existing uncertainties. The levels of identified risks are given by exact way, using fuzzy logic. The proposed model is tested with real-life data from manufacturing small and medium enterprises.

Static Friction at High Contact Temperatures and Low Contact Pressure

The problem of measuring static friction at high temperatures and low contact pressures is theoretically analyzed, as well as the instruments for the accurate determination of the coefficient of static friction at high temperatures for contact pairs made of steel and bronze. The results of experimental investigation show that at low contact pressure and temperature above 120°C coefficient of static friction dramatically increases. This increase in the coefficient of friction can be of great practical value with regard to the load capacity of contacts where external forces are balanced with friction forces.

An assessment of maintenance performance indicators using the fuzzy sets approach and genetic algorithms

In this article, a novel approach for assessment and ranking of maintenance process indicators as well as maintenance cost indicators and maintenance equipment indicators using the fuzzy sets approach and genetic algorithms is presented. Weight values of these indicators are defined using the experience of decision makers from analyzed small and medium enterprises (total number of 197 persons) and calculated using the fuzzy sets approach. In the second step, a model for ranking and optimization of maintenance performance indicators and small and medium enterprises by using genetic algorithm is presented. The presented approach enables multi-objective optimization of selected key performance indicators in the scope of optimization of maintenance performances. The value of optimization was tested on a group of small and medium enterprises which proved that improvement of maintenance performance could be more significant (or performed at the shorter period of time) if the specific key performance indicators were targeted for improvement. The presented solution could provide identification of strengths and weaknesses (comparing key performance indicators), learning from a leading organization (in prioritization of key performance indicator improvement) and improvement of maintenance performance.

Continuous controllable balloon dilation: a novel approach for cervix dilation

BackgroundCervical dilation using mechanical dilators is associated with various complications, such as uterine perforation, cervical laceration, infections and intraperitoneal hemorrhage. To achieve safe and painless cervical dilation, we constructed a new medical device to achieve confident mechanical cervical dilation: a continuous controllable balloon dilator (CCBD).MethodsControlled pumping of incompressible fluid into the CCBD increases the pressure and outer diameter of the CCBD, continuously dilating the cervical canal. The reliability of the CCBD was confirmed in vitro (testing for consistency and endurance, with no detected risk for breakage) and in vivo. A multi-center clinical study was conducted,with 120 pregnant women randomly assigned to one of three groups: Group I,control group, no dilation;Group II,mechanical dilation, Hegar dilator (HeD); and Group III,CCBD. The tissue material for histological evaluation was obtained from the endocervical mucosa before and after dilation using the HeD or CCBD.ResultsThe CCBD dilations were successful and had no complications in all 40 patients of Group III. The cervical tissue was markedly less damaged after CCBD dilation compared with HeD dilation (epithelium damage: 95% (HeD) vs. 45% (CCBD), P <0.001; basal membrane damage: 82.5% (HeD) vs. 27.5% (CCBD), P <0.001; stromal damage: 62.5% (HeD) vs. 37.5% (CCBD), P <0.01). Cervical hemorrhagia was observed in 90% of the patients after HeD dilation versus in 32.5% of the patients after CCBD dilation.ConclusionsThe CCBD should be used as a replacement for mechanical dilators to prevent uterine and cervical injury during cervical dilation.Trial registrationISRCTN54007498

Software for Occupational Health and Safety Risk Analysis Based on a Fuzzy Model

Abstract Risk and safety management are very important issues in healthcare systems. Those are complex systems with many entities, hazards and uncertainties. In such an environment, it is very hard to introduce a system for evaluating and simulating significant hazards. In this paper, we analyzed different types of hazards in healthcare systems and we introduced a new fuzzy model for evaluating and ranking hazards. Finally, we presented a developed software solution, based on the suggested fuzzy model for evaluating and monitoring risk.

Occupational safety and health education under the lifelong learning framework in Serbia

Serbia is aligning with European Union requirements and the occupational safety and health (OSH) administration is one of the most representative sectors of this alignment. Many efforts were made in this field, by introducing new laws and regulations, but it turned out to be insufficient. OSH professionals need to renovate and strengthen their knowledge in accordance with continuous, updated and improved OSH standards and regulation. Lifelong learning (LLL) programmes can contribute to forming professionals who are always up to date. This paper presents an implemented LLL programme, over the duration of two academic years, dedicated to OSH professionals, and investigates whether this programme will be helpful and accepted by professionals. The results from the study show that the given LLL programme had indeed a positive influence on the professional careers of the participants and that the LLL presents the future trend in OSH education.