The paper presents a new conception of building probabilistic models of communication delays in wireless networks that basis on using a delta function sequence to describe retransmissions between a transmitter and a receiver. It is assumed that the access time of the transmitter is described by a probability density function and the communication channel established in the wireless medium is disturbed by passive or active factors which cause that the transmission can be not correct and the sent data have to be retransmitted. Theoretical considerations have been verified by measurement results obtained by using the experimental system developed for investigating delays caused by external disturbances influencing the wireless transmission. A method of identification of the proposed model parameters and verification of the identified values has been presented.

Proficiency testing is an important way of meeting the requirements of ISO/IEC 17025 in the area of quality assurance of laboratory results. Laboratory for dimensional measuring technique on Mechanical Engineering Faculty participated in comparison of dial gauge and external micrometer. The key requirements of such comparisons are that the samples are same or similar, and also thatthe set of samples measured are appropriate to test and display similarities and differences in results. A proficiency testing scheme is a system for objectively evaluating laboratory results by external means, and includes regular comparison of a laboratory's results at intervals with those of other laboratories. The main objective of a proficiency testing scheme is to help the participating laboratory to assess the accuracy of its test results. Regular participation in a proficiency testing scheme provides independent verification of measurement capability of a laboratory and shows a commitment to a maintenance and improvementof performance. Participants were three laboratories from Bosnia and Herzegovina and one pilot laboratory wasfrom Norway. Included laboratories calibrated the instruments using their own procedures and issue their standard calibration certificates according to their accreditation scope. Circulation of testing instruments was from pilot laboratory to the participating laboratories one by one and again to the pilot laboratory for checking. The values compared were: f_max for external micrometer and f_e, f_ges and f_u for dial gauge.

Angular relationships of lift and control surfaces, wings and all the elements needed to determine the model for wind tunnel testing are essential to the quality of the final assembly. In relation to the measurement of airfoil shape deviation from this determination is complicated and requires complex mathematical models and calculation. It is necessary to find the plane that represents the wing and calculate the required angular relationships such as the wing setting angle and the dihedral angle. Such a plane exists on the wing and is called the Wing Reference Plane (WRP). This plane is not material and its direct measurement is impossible.
Identifying dihendral angle, wing seting angle and local airfoil twisting of models aircraft is accomplished by measuring the WRP. Detection of these parameters are required to model the quality of the final geometric inspection. The developed method requires the preparation of measurement and calculation of the CAD/CAM system. It takes information about the relationship between WRP and the upper and lower wing surface transferred to the coordinate inspection program. Over the measured coordinates apply a special system of equations. The result of the calculation is measured WRP. The developed method can also be successfully applied to measure the deflection angle of canards, slats and flaps.
Wing of wind tunnel model LASTA-2 (Swallow P2), is taken as an example of application of the developed computer aided inspection method.

This report presents a functional diagram of the Ukrainian primary standard of electrolytic conductivity (EC) and construction of primary four electrode conductivity cell with the calculated coupling constant. The equations for calculating the cell constant and budget of errors for calculating uncertainty are presented. The components of budget are: error due to the non-uniformity of the force lines of the electric field; the error due to accuracy of measurement standards and measuring instruments when determining length and diameter of the tube; the error due to manufacturing techniques of tubes and their assemblage. The article considered in details the error due to non- ideal profile of the central part of the tube.
The process of precision machining and quality control of the inner surface of the tube are complex and expensive procedures. The report gives an algorithm for measuring of length and diameter of the tube. Experimental data show that distortion of profile may be two types. The first type is deviation of the tube profile from the rectangle along the longitudinal section. The reason is the precession of the grinding tool. The second type is deviation of the profile of the tube from circumference in the cross section. The reason is the presence of wedge-shaped cracks on the inner surfaces of the work piece. The presence of deterministic component in the distortion of the profile leads to a significant increase in the standard deviation of the mean (SDM).
The paper presents two methods to reduce the standard deviation: the method of linear interpolation for compensation of the concaveness which occurs along the axis of the tube and the method of equivalent triangles to compensate deviations from the circle that occurs across the axis of the tube.

Six Sigma improvement projects are increasingly conducted in Brandenburg’s SMEs. A brief overview is given on completed projects. Brandenburg’s SMEs demand for education in this field. The conceptual structure of Six Sigma training concepts in Germany poses a problem for SMEs, due to the lack of flexibility. SME employees have to allow up to 25 days for this training, which often take place far away. The concept presented herein designs individual onsite training for the needs of regional SMEs. The complex educational content is offered in a modular form, based on the individual level of knowledge. That way a gradual completion of the training is possible without the need to schedule long absences in SMEs. The modular system takes out the “time pressure”. This is also an improvement for young professionals with families. After successful completion of a one week intensive training that can be carried out in two blocks, improvement projects are carried out on-site by the new Six Sigma specialists and are instructed by Six Sigma experts. Simultaneously, the corporate network of the Department of Quality Management, BTU Cottbus, is further developed. Network partners are those enterprises, where students conducted improvement projects over the last four years. The student teams are integrated into the training concept. In the future, they will be instructed by the SMEs Six Sigma specialists. This way, students are able to develop business contacts with regional SMEs at an early stage of their studies, contacts that are continuously expanded and reinforced with the help of the corporate network. Should, due to this practice further training needs arise, they can be met in a modularized way through so-called micro-modules. These might comprise, for example, only a few hours. The training concept can be designed individually and aims to enhance the competitiveness of regional SMEs, by means of a university knowledge transfer.