Performanse bežičnog telekomunikacionog sistema u prisustvu n-m fedinga

In this thesis characteristics of wireless communication system operating over η-μ fading channel are considered together with diversity reception techniques which reduce the influence of η-μ fading on the system’s outage probability, average bit error rate, channel capacity, level crossing rate and average fade duration. Performance improvement is very significant within radio systems operating into cell network configuration. Cell network configuration realization could be used for increasing capacity of wireless communication system. With the increase of number of cells, i.e. with reducing the surface area of each cell, channel capacity increases. With the increase of number of cells, co-channel interference level increase, which degrades system performance values. In this work the compromise between the system capacity and reception quality is inquired. By applying diversity reception techniques, system performance values, degraded by the influences of slow fading, multipath fading and co-channel interference, are improved, so it is possible to reduce the cell area and to increase system capacity. In the second part of Phd thesis, various distributions for modeling the envelope variations in fading channels have been presented, cases in which these models are used have been pointed out, and advantages and imperfections of corresponding models for corresponding propagation scenarios have been presented. In third chapter, statistical characteristics of the first order of η-μ random variable, α-η-μ random variable and squared η-μ random variable are considered. For each mentioned variables, expressions for probability density function, cumulative distributive function, characteristic function and moments have been derived. Also for each observed case sum of two random variables, product of two random variables, ratio of two random variables, maximal value of two random variables and minimum value of two random variables have been determined. Obtained results are used for determining performances of wirelles reception with applied diversity technique for mitigation fading influence on system performances. Based on obtained expressions, graphs are depicted for probability density functions and cumulative distribution functions for the various values of propagation environment parameters. Probability density function and cumulative distribution function values are also graphically presented for α-η-μ random variable in the function of α and μ parameter change. For the purpose of performance analysis in η-μ fading environment, in the fourth chapter have been considered transformations of three η-μ random variables. Based on presented transformations of η-μ random variables, transmission performances estimation has been conducted, for the η-μ fading channel. Estimation of signal performances for the cases when diversity techniques are applied are carried out based on standard signal performance measures, i.e. outage probability (OP), average bit error probability (ABER), for observed modulation format and channel capacity. Graphically are presented ABER values for various values of system parameters when transmission is carried out with different modulation formats. By comparing obtained values it can be seen received signal performance improvement for the cases when diversity techniques are apliied over the reception case when there is no diversity technique applied. In the fifth chapter statistical characteristics of the second order of η-μ radnom proccess, and random proccesses which represent various variations of η-μ radnom proccess, are considered. Brand new random proccesses, for describing fading in special channel conditions are fromed. For all this cases level crossing rates are determined. In the sixth chapter of this Phd thesis are considered wireless communication systems with reception with applied diversity techniques for mitigating the influence of η-μ fading on system performances. Space diveristy technique has been used. Useful signals are accepted at the antennas, envelopes of these signals are combined and decision is made based on the signal values at the combiner outputs. System performances are determined for the cases of SC and MRC combining. For bouth cases probability density function and cumulative distribution function of the signal at the combiners outouts are derived, as well as the average bit error rate for the various used modualtion formats and level crossing rate. Results for ABER for various modulation formats are graphically presented as well as the improvement of the outage probability at the reception obtained by applying SC with two reception branches. In this part it has also been considered the case when bouth desired and interferring signal are described with η-μ distribution, as well as the case when desired signal has been described with η-μ distribution while interference has been described with κ-μ distribution. In the seventh chapter macrodiversity sistem with SC reception and two MRC microdiversity combiners has been considered. At the inputs at the microdiversity combiners η-μ fading is present, while at the inputs as macrodiversity combiners slow Gamma fading is present. For this model of system it has been calculated probability density function, cumulative distribution function, characteristic function, moments, variance, outage probability and level crossing rate for the signal at the macrodiversity combiner output. Results obtained for level croosing rate at the macrodiversity combiner output are graphically presented

LEVEL CROSSING RATE OF MACRODIVERSITY OUTPUT PROCESS IN THE PRESENCE OF η-μ SHORT TERM FADING AND GAMMA LONG TERM FADING

In this paper macrodiversity reception with macrodiversity selection combining (SC) receiver and two microdiversity MRC receivers operating over shadowed multipath fading channel is studied. Received signal experiences  short term fading and correlated Gamma long term fading resulting in system performance degradation. Level crossing rate (LCR) of η-μ random process and level crossing rate of signals at outputs of microdiversity MRC receivers are efficiently calculated. By using these derived formulas, level crossing rate of macrodiversity SC receiver output signal process is calculated. By using this result, average fade duration (AFD) of the proposed wireless communication system can be calculated. The influence of  η-μ  short term fading severity parameter, Gamma long term fading severity parameter and Gamma long term correlation coefficient on level crossing rate is analysed and studied

THE RELATIONSHIP BETWEEN TECHNICAL AND TACTICAL ELEMENTS OF DIRECT POINTS WITH REGARD TO THE QUALIFICATIONS FOR THE 2018 VOLLEYBALL WOMEN’S WORLD CHAMPIONSHIP

The goal of this paper is to analyse the relationships and differences among volleyball teams, participants of the 2018 World Cup in Japan, divided into three categories by their final standings (1st to 4th place, 5th to 8th place and others), based on the elements of situation-based efficiency. For the purposes of this paper, information from the official match reports (p 2 report) related to the way of winning points in the match was used, and these data were analysed using the program Volleyball Information System (VIS). The data obtained were analysed in relation to the team category and the outcome of the match. The data were obtained using descriptive and comparative statistical procedures. The survey sample includes all the women’s volleyball championship games played in Japan in 2018. Based on the final standings, the teams were divided into three groups: 1) the teams who reached the 3rd stage of the tournament (6 teams, from 1st to 6th place); 2) the teams that finished the competition in phase 2 (10 national teams, ranking 7th to 16th); 3) national teams that finished the competition in phase 1 (8 national teams, ranking 17th to 24th). The results obtained indicate that the teams had an equally good performance of the block and serve game elements; statistically these were not significant for the match outcome, but they rather serve as an aid for the overall game and for the final outcome of the match. The results of this research also highlight the spike as the key element affecting the positive end result of the match. It is important to emphasize that the opponent errors are a factor that depends exclusively on the opponent, but they also determine the overall score of the winning team

The role of a pharmacist in prevention and detection of OTC drug interactions: Nominal group technique

Introduction: Nowadays number of newly approved OTC medicines continuously increases, which can make certain difficulties in drug dispensing process. This fact particularly relates to drug-drug interactions-problems due to lack of data and insufficient of knowledge about the interactions. Aim: To identify the problems pharmacists face when dispensing OTC drugs and to recommend concrete ideas and methods for improving system for detecting OTC drugs interactions. Participants and method: The study was carried out in accordance with methodological principles of nominal group technique. Two meetings of nominal group were conducted, enrolling pharmacists employed in public pharmacies. During the meetings, moderator imposed aset of questions to participants, who gave answers in the form of individual statements. In order to examine agreement of the participants about the individual statements, at the end of both sessions the statements were rated on a Likert's scale. Meetings were recorded and audio recordings later used for qualitative analysis. Results: Nine pharmacists of both sex (7/2 females/males) participated in this study. Average age of the participants was 25.0±1.0 years. During nominal group meetings, participants presented 30 statements on 7 research questions, and after the second meeting agreement was reached about 29 of them. Qualitative analysis of data indicated three categories of statements: (1) pharmacists' knowledge of OTC drugs interactions, (2) problems pharmacists face when dispensing OTC drugs and (3) options of improving system for prevention and detection of OTC drugs interactions. Conclusion: For adequate prevention of potential OTC drugs interactions it is necessary to make guidelines with recommendations referring to proper dispensing procedure and to use regularly available online interaction checkers

THE PATH TOWARDS ACHIEVING A LEAN SIX SIGMA COMPANY USING THE EXAMPLE OF THE SHINWON COMPANY IN SERBIA

In the last twenty years, many companies have realized that the demands of the global market, including more demanding and receptive customers, have set new standards for production flexibility. Gradual reduction of mass production, characteristic of a large number of companies, has opened space for the introduction of a new system which focuses exclusively on the customer. The customer-oriented system was created with the idea that process optimization would lead to the production of a relatively cheap product, delivered on time and with the best possible quality. Such a system is achieved by applying the Lean Six Sigma concept. The aim of this paper is to identify all of the defects that occur as losses and complicate the process of production in order to achieve the Lean Six Sigma level in the Shinwon Company. The original data from the Shinwon company were identified, collected and analyzed, using the methods and tools of the Lean Six Sigma concept (Process Mapping, 5S audit, Pareto diagram, Ishikawa diagram, Seven basic wastes and SPC analysis), in order to present the effectiveness of the quality management system and to evaluate the possibility of its continuous improvement

САВРЕМЕНИ СОФТВЕРСКИ ПРОИЗВОДИ У СТРАТЕГИЈСКОМ МЕНАЏМЕНТУ

The efficiency of the management companies in modern business conditions, the significant level is determined by the possibilities timely accepting data from different sources, and their adequate treatment and care, as well as making it available to those entities on the basis of their use make important managerial decisions. Considering that the economy in the contemporary business environment is characterized by the influence of a large number of controlled and uncontrolled factors of different volume and intensity, successfully tracking changes and an adequate response to them, implies the existence of modern drafted strategic information systems, that its operation based on the use of modern information technology

ЕКСПЕРТНИ СИСТЕМ ЗА ПРИМЕНУ ПОРТФОЛИО КОНЦЕПТА У СТРАТЕГИЈСКОМ УПРАВЉАЊУ

Domain problems that need to solve the model of expert system processed in this paper, refers to the determination of the position of strategic business units in the combined portfolio matrix, and the determined position of proposing appropriate strategic options. The aim is to evaluate the strength of the business position of each strategic business unit, or perspektivnosti relevant environment in which they operate, identify strategic options for each business unit, in order to determine the main directions of restructuring the business portfolio in order to achieve projected targets the entire enterprise

The latent structure of anthropometric variables in female volleyball players aged 12-14 years

The goal of this transverse research was to establish the correlations between morphological characteristics, and identifying the latent morphological structure. In the morphological space, a group of 12 standard anthropometric variables was measured. The sample encompassed 158 female subjects, aged 12 to 14 years, from volleyball clubs of the Kolubara-Macva Inter regional Serbian league. Statistical data analysis was conducted using Pearson's coefficient of correlation and Principal component analysis (PCA). Results from the correlation analysis showed statistically significant linear correlations in almost all anthropometric variables of female U14 volleyball players. Using the method of Principal Component Analysis (PCA), together with the Kaiser-Guttman criteria and Varimax rotation, a threecomponent model was extracted which comprised 83,35% of proportion of the total variance of manifested anthropometric variables. This model was structured by the hypothetical factors with their characteristic roots (ƛ > 1), which were interpreted as: longitudinal skeleton dimensionality (F1), body volume and body mass (F2), and subcutaneous fat tissue (F3). The limitations of this study were discussed, as well as recommendations for future longitudinal research. Objectively, an insufficient amount of conducted empiric studies so far presents a motive for other authors to establish a relationship between morphological landmarks and defining the build of the morphological space in preadolescent population of female volleyball population

FUNKCIONALNE SPOSOBNOSTI FUDBALERA PREDPUBERTETSKOG UZRASTA U FUNKCIJI RANGA TAKMIČENJA I POZICIJE U TIMU

TThe aim of this paper was to examine the differences in the motor skills of soccer players aged 16-18 years who play in different competition levels (National League and Regional League), as well as players who play in different positions in the team. The standard testing battery for the motor skills assessment of soccer players was used to evaluate the motor skills. As for the evaluation of the differences between the different playing positions, a two-factor ANOVA with the factor Competition Level (National and Regional Level) and the factor Position (forward, midfielder, side defender, central defender) was used. A two-factor ANOVA with the factor Competition Level (National and Regional Level) and the factor Age (16, 17 and 18 years of age) was used to evaluate the differences between the different quality levels. The study included 126 male soccer players 16 to 18 years of age (N16=45, N17=41, N18=40) divided into 4 positions on the team: forwards (N=37, BH=179.2±5.0, BM=70.1±6.6), midfielders (N=48, BH=177.9±6.3, BM=69.6±7.9), side defenders (N=22, BH=176.6±5.4, BM=67.5±5.7) and central defenders (N=19, BH=184.0±4.3, BM=72.3±6.6). Because of significantly different activities in the field, the goalkeeper position was excluded from this study. The results indicate that motor skills do not differentiate players of different competition levels, and that there is a gap between players aged 18 years in aerobic endurance which is the basis of success in soccer.  Also, the obtained results suggest that motor skills could differentiate players at certain positions. However, it was specifically found that only alactic capabilities type of speed and agility, differentiate forwards from other positions, especially from midfielders.Cilj rada je da se ispitaju razlike u motoričkim sposobnostima fudbalera uzrasta 16 – 18 godina koji igraju u različitim nivoima takmičenja (Lige Srbije i Lige Beograda), kao i fudbalera koji igraju na različitim pozicijama u fudbalskom timu. Za procenu motoričkih sposobnosti korišćena je standardna baterija testova za procenu motoričkih sposobnosti fudbalera. Za procenu razlika između pojedinih pozicija u timu korišćena je dvofaktorska analiza varijanse sa faktorima rang takmičenja (Savezni i Regionalni rang) i pozicije u timu (napadač, vezni, spoljni i odbrambeni). Za procenu razlika između različitih kvalitativnih nivoa primenjena je dvofaktorska analiza varijanse sa faktorima rang takmičenja (Savezni i Regionalni rang) i uzrast (16, 17 i 18 godina). Istraživanjem je obuhvaćeno 126 momaka, uzrasta od 16 do 18 godina (N16=45, N17=41, N18=40), podeljenih na 4 pozicije: napadač (N=37, VT=179.2±5.0, MT=70.1±6.6), vezni (N=48, VT=177.9±6.3, MT=69.6±7.9), spoljni (N=22, VT=176.6±5.4, MT=67.5±5.7) i odbrambeni igrači (N=19, VT=184.0±4.3, MT=72.3±6.6). Kako se aktivnosti golmana u osnovi značajno razlikuju od ostalih igrača, pozicija golmana je isključena. Rezultati istraživanja navode da motoričke sposobnosti ne diferenciraju igrače prema rangu takmičenja, kao i da postoji razika u uzrastu 18 godina u aerobnoj izdržljivosti koja je osnova uspešnosti u fudbalu. Dobijeni rezultati ukazuju da se može tvrditi da motoričke sposobnosti diferenciraju igrače na pojedinim pozicijama. Međutim, pojedinačno gledano jedino se pokazalo da alaktatne sposobnosti tipa brzine i agilnosti, diferenciraju napadače od ostalih pozicija, naročito od veznih igrača u fudbalskoj igri