Vojnotehnicki glasnik / Military Technical Courier

377-386

Authors: Stanojević Petar

Investments in the improvement of maintenance systems are often brought into question as to whether they are justified or not. Introducing maintenance strategies, eg. RCM, TPM, on-condition maintenance, etc., is nowadays a worldurde tendency in the improvement of maintenance systems. The simulation method based on system dynamics has been applied to a model of a taxi business in order to analyze the effects of introducing modern maintenance strategies into that system. The obtained results show good accordance with experiences wordurde. The stabilization and adequate dimensioning of the maintenance system should proceed the system improvement using adequate strategies. Bringing maintenance strategies into use predominantly suits the systems with a high duty factor, ie. the systems with continually operating elements. Every 10% of reduction in the number of failures, preventive maintenance time and frequency of preventive actions gives an average rise of about 5% to the overall profit of a business. Improvements in the field of knowledge and quality of work bring further 5% rise in profit

397-405

Authors: Radosavljević Zvonko M.

A case of image filtering in air target detecting and tracking systems is described in this paper. Two image filtering methods are given. The first method is performed using a low pass convolving filter and the second one uses the mean value of gray level filter. The main goal of the cited filtering is implementation in IR (infra red) systems. Some statistical features of the images were used for selecting the threshold level. The next step in the algorithm is the determination of a 'tracking window' that can be fixed or adaptive in size. A false estimation of a target existing in the window may be influenced by the background noise, low noise amplifier detector, etc.

413-419

Authors: Pokorni Slavko

Some important details of creation and realization of a test program for the mean time between failures for fighter aircraft electronic equipment are discussed. Experiences from such a reliability testing program, concerning the calculated and required mean time between failures and choosing a proper test plan, are summarized. The conclusion stresses the importance of the calculation of the mean time between failures before testing.

433-446

Authors: Milošević Boban, Mišković Vasilije

Ranking and choice of sites and resources for dislocation of material supplies have been treated. Possible sites for dislocation and available resources are of different characteristics, thus being more or less suitable for dislocation of material supplies. Their ranking and choice are possible with the application of multicriteria ranking methods. However, since these methods are time-consuming, they are not suitable for time-restricted decision making. Therefore, this paper proposes an expert method (rank summing method) which gives fast results after an adequate preparation. Ranking of sites and means of transport is used to illustrate the application of this method.

457-464

Authors: Radić Vlado N.

When a mine detonates, a blast wave is generated, along with an impulsive burst of fragments, and an intense fire flash. However, the strength of the blast wave emanating from the mine decreases rapidly with standoff distance. The effects of a detonating mine can lead to a wide range of injuries, from amputations and lacerations to internal injuries in the head and torso. By making small adjustments in standoff distance and orientation when facing a mine, in conjunction with using effective protective equipment, injury potential can be reduced.

472-477

Authors: Stjelja Živko, Jelenković Zoran, Dželetović Slobodan

The paper presents a global approach to problems of qualification testing of complex technical systems, from programming and planning, through test performing of various performances and/or equipment, to the evaluation on the basis of test data and requirements specified by the customer. The new approach to the device quality concept is characterized by deficiency of test methods and proper evaluation criteria. The problem of proper evaluation for CTS based on test results from specialized laboratories is emphaszed in particular. The paper has identified main tasks for further research and development of testing methods and evaluation of CTS based on shown analyses.

485-490

Authors: Suruliz Sanja

In absence of primary standards for microwave power, a group of microwave power secondary standards was compared as a method of sustaining metrological traceability. The comparison included thermoelectric and thermistor mounts in the frequency range from 18 to 26,5 GHz.