Impact of GoP on the video quality of VP9 compression standard for full HD resolution

In the last years, the interest on multimedia services has significantly increased. This leads to requirements for quality assessment, especially in video domain. Compression together with the transmission link imperfection are two main factors that influence the quality. This paper deals with the assessment of the Group of Pictures (GoP) impact on the video quality of VP9 compression standard. The evaluation was done using selected objective and subjective methods for two types of Full HD sequences depending on content. These results are part of a new model that is still being created and will be used for predicting the video quality in networks based on IP

Perceived quality of full HD video - subjective quality assessment

In recent years, an interest in multimedia services has become a global trend and this trend is still rising. The video quality is a very significant part from the bundle of multimedia services, which leads to a requirement for quality assessment in the video domain. Video quality of a streamed video across IP networks is generally influenced by two factors “transmission link imperfection and efficiency of compression standards. This paper deals with subjective video quality assessment and the impact of the compression standards H.264, H.265 and VP9 on perceived video quality of these compression standards. The evaluation is done for four full HD sequences, the difference of scenes is in the content“ distinction is based on Spatial (SI) and Temporal (TI) Index of test sequences. Finally, experimental results follow up to 30% bitrate reducing of H.265 and VP9 compared with the reference H.264

Personality traits and workaholism

The paper focuses on understanding the relationship between workaholism and personality. The main goal was to examine the personality antecedents of workaholism, specifically the role of conscientiousness, neuroticism and perfectionism in workaholism. Workaholism is viewed as a three-dimensional phenomenon consisting of excessive involvement in work, compulsive need to work, and lack of satisfaction from work. Based on the multiple linear regressions, the authors constructed a model of relations between personality traits and workaholism. While neuroticism predicted overall workaholism (positive relationship), conscientiousness was positively related to all three workaholism components. Furthermore, perfectionism predicted feeling driven to work (positive relationship) and neuroticism was related to joy in work (negative relationship).The results underline the possibility of predicting workaholism from personality traits. Based on the findings, employers and study counselors can implement preventive measures in order to help employees and students to preserve their performance and avoid maladaptive patterns of work behaviour.The paper focuses on understanding the relationship between workaholism and personality. The main goal was to examine the personality antecedents of workaholism, specifically the role of conscientiousness, neuroticism and perfectionism in workaholism. Workaholism is viewed as a three-dimensional phenomenon consisting of excessive involvement in work, compulsive need to work, and lack of satisfaction from work. Based on the multiple linear regressions, the authors constructed a model of relations between personality traits and workaholism. While neuroticism predicted overall workaholism (positive relationship), conscientiousness was positively related to all three workaholism components. Furthermore, perfectionism predicted feeling driven to work (positive relationship) and neuroticism was related to joy in work (negative relationship).The results underline the possibility of predicting workaholism from personality traits. Based on the findings, employers and study counselors can implement preventive measures in order to help employees and students to preserve their performance and avoid maladaptive patterns of work behaviour

Subjective video quality assessment of H.265 compression standard for full HD resolution

Recently increasing interest in multimedia services leads to requirements for quality assessment, especially in the video domain. There are many factors that influence the video quality. Compression technology and transmission link imperfection can be considered as the main ones. This paper deals with the assessment of the impact of H.265/HEVC compression standard on the video quality using subjective metrics. The evaluation is done for two types of sequences with Full HD resolution depending on content. The paper is divided as follows. In the first part of the article, a short characteristic of the H.265/HEVC compression standard is written. In the second part, the subjective video quality methods used in our experiments are described. The last part of this article deals with the measurements and experimental results. They showed that quality of sequences coded between 5 and 7 Mbps is for observers sufficient, so there is no need for providers to use higher bitrates in streaming than this threshold. These results are part of a new model that is still being created and will be used for predicting the video quality in networks based on IP

Dominance as a moderator in the relationship between leader's warmth and effectiveness

The study examines the relationship between a leader’s warmth, dominance and three different indicators of leader effectiveness in the environment of a four-month long Managerial Simulation Game. Data about 184 CEOs were gained via self-reports, from the results of the simulation game, and from 3,340 of their followers. Each CEO completed an Interpersonal Checklist (ICL) and was evaluated, on average, by 18 followers in terms of her leadership emergence and perceived leader effectiveness. Group performance was assessed based on the results of game companies. Neither leader warmth nor leader dominance correlated with any of the three indicators of leader’s effectiveness. The analysis of moderation effect however revealed a significant effect of interaction of leader warmth and dominance on group performance, perceived leader effectiveness, and leadership emergence. CEOs with greater warmth are less effective when possessing a low degree of dominance. On the contrary, the relationship between warmth and leader effectiveness is positive when the degree of dominance is high. An effective leader therefore has to be both warm and dominant. A low degree of dominance combined with excessive warmth might yield a counterproductive effect. The results of the study elucidate an underexplored relationship between leader warmth and effectiveness and illustrate the importance of examining various antecedents of leadership simultaneously.Studie se zabývá vlivem interpersonálních rysů leadera vztahovost a dominance na tři indikátory efektivity leadera v prostředí čtyři měsíce trvající manažerské simulační hry. Pro studii byla získána data z výsledků 184 podniků v simulační hře, ze sebehodnocení 184 generálních ředitelů těchto podniků a z hodnocení jejich 3 340 podřízených. Každý generální ředitel vyplnil Learyho interpersonální dotazník (ICL) a v průměru 18 podřízených hodnotilo jeho leadership emergence a vnímanou efektivitu. Objektivní výkon leaderem vedené skupiny byl posuzován na základě výsledků podniků v manažerské simulační hře. Vztahovost ani dominance nekorelovaly s žádným indikátorem efektivity leadera. Analýza interakce mezi vztahovostí a dominancí ale prokázala signifikantní moderační efekt dominance ve vztahu mezi vztahovostí a výkonem skupiny, vnímanou efektivitou leadera i leadership emergence. Více vztahoví leadeři jsou málo efektivní, pokud jsou zároveň i málo dominantní. Naopak při vysoké úrovni dominance je vztah mezi vztahovostí a efektivitou leadera pozitivní. Efektivní leader tedy musí být jak vztahový, tak dominantní. Naopak při nízké dominanci je přílišná vztahovost kontraproduktivní. Výsledky studie vysvětlují dosud nejasný vztah mezi vztahovostí a efektivitou leadera a ukazují na nutnost zkoumat faktory ovlivňující leadership ve vzájemném kontextu.The study examines the relationship between a leader’s warmth, dominance and three different indicators of leader effectiveness in the environment of a four-month long Managerial Simulation Game. Data about 184 CEOs were gained via self-reports, from the results of the simulation game, and from 3,340 of their followers. Each CEO completed an Interpersonal Checklist (ICL) and was evaluated, on average, by 18 followers in terms of her leadership emergence and perceived leader effectiveness. Group performance was assessed based on the results of game companies. Neither leader warmth nor leader dominance correlated with any of the three indicators of leader’s effectiveness. The analysis of moderation effect however revealed a significant effect of interaction of leader warmth and dominance on group performance, perceived leader effectiveness, and leadership emergence. CEOs with greater warmth are less effective when possessing a low degree of dominance. On the contrary, the relationship between warmth and leader effectiveness is positive when the degree of dominance is high. An effective leader therefore has to be both warm and dominant. A low degree of dominance combined with excessive warmth might yield a counterproductive effect. The results of the study elucidate an underexplored relationship between leader warmth and effectiveness and illustrate the importance of examining various antecedents of leadership simultaneously

Prosociální chování a jeho vztah k sourozeneckým konstelacím a k vyžadování prosociálního chování

Příspěvek je zaměřen na prosociální chování a jeho vývoj na základě stimulace v rodině a na souvislost mezi prosociálním chováním a očekáváním člověka. Autoři ve dvou souběžně prováděných studiích kladli následující otázky: 1. Zda se prvorození adolescenti s mladšími sourozenci a adolescenti s více sourozenci chovají více prosociálně než ostatní. 2. Zda prosociální chování souvisí s vyšší tendencí vyžadovat prosociální chování od ostatních. Prezentovány jsou dva výzkumy, jejichž cílem byla odpověď na výše položené otázky. Výzkumnou skupinu obou výzkumů tvořilo 80 studentů středních škol. Každý z nich vyplnil dotazník tendence vyžadovat prosociální chování, byl pozorován při třech příležitostech k prosociálnímu chování a uvedl informace o počtu a pořadí svých sourozenců. Na základě prováděných analýz došli autoři k následujícím závěrům: Nelze prokázat vztah mezi prosociálním chováním a počtem sourozenců a ani vztah mezi prosociálním chováním a pořadím, v jakém se člověk narodil (tzv. sourozeneckou konstelací). Podle prezentovaných výsledků výzkumu neexistuje ani žádný statisticky významný vztah mezi prosociálním chováním a tendencí vyžadovat prosociální chování.The paper is focused on the relation between the prosocial behaviour and the sibling constellation and on the relation between the prosocial behaviour and claiming prosocial bahaviour. There are no significant realitions between examinated variables. The birth order, the number of siblings and claiming prosocial behaviour does not correlate with the prosocial behaviour measured by two different methods - the questionnaire and the observation

Correlation between objective and subjective methods used for video quality evaluation

The article deals with the correlation between the objective and the subjective methods. In the first part the short characteristic of the MPEG compression standards is written. The second part focuses on the objective metrics and the third part on the subjective methods, which were used for testing. In the fourth part regression and correlation analysis are written. In the fifth part the measurements and the experimental results using the objective metrics and in the fifth part the measurements and the experimental results using the subjective methods are described. The last part deals with the correlation between the objective and the subjective methods, mapping and approximation

Impact of Background Traffic on Speech Quality in VoWLAN

This paper describes measurements of the impact of background traffic on speech quality in an environment of WLANs (IEEE 802.11). The simulated background traffic consists of three types of current traffics in telecommunication networks such as data transfer service, multimedia streaming service, and Web service. The background traffic was generated by means of the accomplished Distributed Internet Traffic Generator (D-ITG). The impact of these types of traffic and traffic load on speech quality using the test sequence and speech sequences is the aim of this paper. The assessment of speech quality is carried out by means of the accomplished Perceptual Evaluation of Speech Quality (PESQ) algorithm. The proposal of a new method for improved detection of the critical conditions in wireless telecommunication networks from the speech quality point of view is presented in this paper. Conclusion implies the next application of the method of improved detection of critical conditions for the purpose of algorithms for link adaptation from the speech quality point of view in an environment of WLANs. The primary goal of these algorithms is improving speech quality in the VoWLAN connections, which are established in the competent link

Competencies measured in assessment centers: Predictors of transformational leadership and leader's effectiveness

The objective of this study is to explore which competencies predict leader effectiveness. Based on theory and job analysis, we observed the effects of five leaders' competencies (achievement orientation, problem analysis and problem solving, social sensitivity, influence, and integrity) on three indicators of effectiveness (perceived leader's effectiveness, leadership emergence, and team performance). Furthermore, we examined whether transformational leadership mediates these effects. We collected the data during an interuniversity student team competition. A total of 57 team leaders and 364 team members participated in the study. At the beginning of the competition, we measured the leaders' competencies through assessment centers. Each leader was assessed by 4 trained assessors in a one day long assessment center consisting of multiple individual and group model situations. After 6 months of teamwork, we measured the perceived leaders' effectiveness, leadership emergence and transformational leadership using questionnaires, and we estimated the teams' performance based on the ranking of the teams in the competition. The results show that leader achievement orientation is a significant predictor of perceived leader effectiveness, leadership emergence and team performance. The other four competencies do not predict leader effectiveness. There is no relation between competencies and transformational leadership; therefore, transformational leadership does not mediate the relation between competencies and effectiveness. The advantages of this study were that we obtained the data regarding the competencies and effectiveness from three different sources and that we measured competencies before the teamwork began. An average of more than 6 subordinates per leader ensures highly reliable evaluations of leaders' transformational leadership, perceived effectiveness and leadership emergence. The results can be applied to leader selection for short-term team projects.Studie se věnuje vztahu mezi kompetencemi leadera a jeho/její efektivitou. Zkoumali jsme pět kompetencí (orientaci na výsledky, analytické myšlení a řešení problémů, interpersonální citlivost, vliv a integritu) a tři ukazatele efektivity (efektivitu leadera vnímanou následovníky, leadership emergence, výkon týmu na základě skutečných výsledků). Sledovali jsme také, zda transformační přístup leadera mediuje vztah mezi kompetencemi a efektivitou. Data jsme získali v rámci meziuniverzitní projektové soutěže. Respondenty bylo 364 členů týmů a 57 jejich leaderů. Na začátku soutěže prošli všichni leadeři celodenním assessment centrem, kde 4 trénovaní hodnotitelé posuzovali jejich kompetence. Po šesti měsících soutěže hodnotili členové týmu efektivitu, leadership emergence a transformační přístup svých vedoucích. Výkon týmu jsme měřili skrze výsledky týmu v projektové soutěži. Ze všech kompetencí se jako jediný prediktor efektivity leadera projevila orientace na výsledky, která souvisela se všemi třemi sledovanými indikátory efektivity. Transformační leadership nesouvisel s žádnou ze sledovaných kompetencí a také nemedioval vztah mezi kompetencemi a efektivitou leadera. Silnou stránkou výzkumu je získání dat ze tří různých zdrojů a v různých časech. Další silnou stránkou je v průměru více než 6 následovníků hodnotících každého leadera.The objective of this study is to explore which competencies predict leader effectiveness. Based on theory and job analysis, we observed the effects of five leaders' competencies (achievement orientation, problem analysis and problem solving, social sensitivity, influence, and integrity) on three indicators of effectiveness (perceived leader's effectiveness, leadership emergence, and team performance). Furthermore, we examined whether transformational leadership mediates these effects. We collected the data during an interuniversity student team competition. A total of 57 team leaders and 364 team members participated in the study. At the beginning of the competition, we measured the leaders' competencies through assessment centers. Each leader was assessed by 4 trained assessors in a one day long assessment center consisting of multiple individual and group model situations. After 6 months of teamwork, we measured the perceived leaders' effectiveness, leadership emergence and transformational leadership using questionnaires, and we estimated the teams' performance based on the ranking of the teams in the competition. The results show that leader achievement orientation is a significant predictor of perceived leader effectiveness, leadership emergence and team performance. The other four competencies do not predict leader effectiveness. There is no relation between competencies and transformational leadership; therefore, transformational leadership does not mediate the relation between competencies and effectiveness. The advantages of this study were that we obtained the data regarding the competencies and effectiveness from three different sources and that we measured competencies before the teamwork began. An average of more than 6 subordinates per leader ensures highly reliable evaluations of leaders' transformational leadership, perceived effectiveness and leadership emergence. The results can be applied to leader selection for short-term team projects

Competencies and leadership effectiveness: Which skills predict effective leadership?

This study explores the relationship between leadership effectiveness and generic and stable competencies. Task- related, people-related and self-related competencies were examined as predictors of leadership effectiveness as measured by four different criteria: group performance, leader effectiveness, leadership emergence and leadership self–efficacy. 134 top managers were evaluated by 2,482 subordinates after a four-month management simulation game. Task-related competencies were shown to be the best predictor of leadership effectiveness; they were a very strong predictor of leadership emergence, a strong predictor of leadership self–efficacy and perceived leadership effectiveness, medium strong predictor of group performance. People-related and self-related competencies weakly predicted leadership emergence. The results can be applied when selecting leaders for working groups that have short-term durations and do not require frequent personal contact.Studie se zaměřuje na vztah mezi efektivitou leadera a jeho stabilními generickými kompetencemi. Kompetence řešení problémů, vztahové kompetence a kompetence sebeřízení byly ověřovány jako prediktory efektivity leadershipu měřené čtyřmi různými ukazateli – objektivně měřeným výkonem skupiny, vnímanou efektivitou leadera, leadership emergence a leadership self–efficacy. Výzkum probíhal v prostředí tříměsíční manažerské simulační hry. Zúčastnilo se ho 134 leaderů a 2 446 následovníků, kteří leadery hodnotili. Všichni respondenti byli vysokoškolskými studenty. Nejlepším prediktorem efektivity leadera jsou kompetence řešení problémů, které jsou středně silným prediktorem výkonu skupiny, silným prediktorem vnímané efektivity leadera, velmi silným prediktorem leadership emergence a silným prediktorem leadership self–efficacy. Vztahové kompetence a kompetence sebeřízení predikují slabě pouze leadership emergence. Kompetenční model obecně nejlépe predikuje leadership emergence a nejhůře výkon skupiny. Výsledky lze využít při výběru leaderů pracovních týmů, které fungují krátkodobě, a vzájemná spolupráce nevyžaduje častý osobní kontakt.This study explores the relationship between leadership effectiveness and generic and stable competencies. Task- related, people-related and self-related competencies were examined as predictors of leadership effectiveness as measured by four different criteria: group performance, leader effectiveness, leadership emergence and leadership self–efficacy. 134 top managers were evaluated by 2,482 subordinates after a four-month management simulation game. Task-related competencies were shown to be the best predictor of leadership effectiveness; they were a very strong predictor of leadership emergence, a strong predictor of leadership self–efficacy and perceived leadership effectiveness, medium strong predictor of group performance. People-related and self-related competencies weakly predicted leadership emergence. The results can be applied when selecting leaders for working groups that have short-term durations and do not require frequent personal contact