265 research outputs found
Die Entwicklung von Bewegungsleistung der Volleybalispieler ohne Ball
Volleyball is a game that is played on a rather small court, demanding a considerable speed level of the top players. The speed in volleyball becomes apparent mostly in the performance of the technical-tactical elements and specific movements aiming at attacking quickly and efficiently (especially in a combination and feint attacks) or at covering optimally the largest possible part of the court in defense actions (block or field defense).
By suggesting a number of exercises, the authors wish to draw attention to the development of the specific speed of volleyball players without the ball as well as to the specification and regularity of the technique of movements around the volleyball court (ābacking offā the block to defense, defenders moving from Tempo 1 to Tempo 2 defense, ābacking offā the net and run-up fora spike, etc.). A certain number of exercises suggest a different approach to the development of the specific speed in volleyball players (exercises stressing the āstep hopā movements and āfoot fireā exercises) and can by all means be considered a novelty in volleyball training. They are the result of empirical knowledge exclusively.Der Volleyball ist ein Mannschaftsballspiel, auf einem relativ kleinen Spielfeld gespielt, wobei von den Leistungssportler ein beneidenswertes HƶchstmaĆ an Schnellbewegungen erwartet wird. Die Schnellbewegungen im Volleyball zeigen sich bei der DurchfĆ¼hrung von technisch-taktischen Elementen und spezifischen Bewegungsarten aus, -wodurch beabsichtigt wird, den Angriff mƶglichst schnell und effektvoll zu machen (besonders im kombinatorischen und fintierten Angriff) oder optimal einen grƶĆeren Spielfeld beim Gegenangriff zu verteidigen (Blockade oder Feldverteidigung).
Durch die vorgeschlagenen Ćbungen soll die Aufmerksamkeit auf spezifische Schnellbewegungen der Volleyballspieler ohne den Ball gelenkt werden wie auch auf die richtige Bewegungstechnik auf dem Spielfeld (Ćbergang von Blockade auf Feldverteidigung, Ćbergang von Feldverteidigung im Tempo I. zum Tempo IL, Ćbergang vom Netz und Aufschwung zum Schmetterschlag, u.a.)
Die Entwicklung von Bewegungsleistung der Volleybalispieler ohne Ball
Volleyball is a game that is played on a rather small court, demanding a considerable speed level of the top players. The speed in volleyball becomes apparent mostly in the performance of the technical-tactical elements and specific movements aiming at attacking quickly and efficiently (especially in a combination and feint attacks) or at covering optimally the largest possible part of the court in defense actions (block or field defense).
By suggesting a number of exercises, the authors wish to draw attention to the development of the specific speed of volleyball players without the ball as well as to the specification and regularity of the technique of movements around the volleyball court (ābacking offā the block to defense, defenders moving from Tempo 1 to Tempo 2 defense, ābacking offā the net and run-up fora spike, etc.). A certain number of exercises suggest a different approach to the development of the specific speed in volleyball players (exercises stressing the āstep hopā movements and āfoot fireā exercises) and can by all means be considered a novelty in volleyball training. They are the result of empirical knowledge exclusively.Der Volleyball ist ein Mannschaftsballspiel, auf einem relativ kleinen Spielfeld gespielt, wobei von den Leistungssportler ein beneidenswertes HƶchstmaĆ an Schnellbewegungen erwartet wird. Die Schnellbewegungen im Volleyball zeigen sich bei der DurchfĆ¼hrung von technisch-taktischen Elementen und spezifischen Bewegungsarten aus, -wodurch beabsichtigt wird, den Angriff mƶglichst schnell und effektvoll zu machen (besonders im kombinatorischen und fintierten Angriff) oder optimal einen grƶĆeren Spielfeld beim Gegenangriff zu verteidigen (Blockade oder Feldverteidigung).
Durch die vorgeschlagenen Ćbungen soll die Aufmerksamkeit auf spezifische Schnellbewegungen der Volleyballspieler ohne den Ball gelenkt werden wie auch auf die richtige Bewegungstechnik auf dem Spielfeld (Ćbergang von Blockade auf Feldverteidigung, Ćbergang von Feldverteidigung im Tempo I. zum Tempo IL, Ćbergang vom Netz und Aufschwung zum Schmetterschlag, u.a.)
Die Strukturanalyse der spielelemente im Volleyball aufgrund einiger anthropologischen Eigenschaften
The importance of the morphological features and motor, functional and specific cognitive abilities as regards successful performance of six elements of the volleyball game (SERVE, SERVE RECEIVING, SETTING, SPIKE, BLOCK and COURT DEFENSE) was assessed by 9 volleyball experts. Three groups were established by using hierarchical cluster analysis according to the playing distance from the net. Block and spike elements belong to group A hence this group is named āplaying above the netā; the serve receiving, setting and defense elements make group B, so it is named āplaying in oneās half of the courtā; the serve makes group C. Based on the arithmetic means of the judgesā rating it might be concluded that group A is characterized by a very high level of explosive power, longitudinal dimensionality of the skeleton and coordination, and in general a higher level of power and endurance than in the other groups. Group B is characterized by a very high level of accuracy and coordination. The characteristic of this group is a very high level of anticipation, speed of reaction, agility, a highly developed sense of distance and flexibility. Group C is characterized by a very high level of accuracy and a highly developed sense of distance and explosive power though not so high as in the other groups.Die Bedeutung der morphologischen Eigenschaften sowie der motorischen, funktionellen und_ spezifischen kognitiven FƤhigkeiten fĆ¼r die erfolgreiche AusfĆ¼hrung von 6 Segmenten, bzw. Spielelementen im Volleyball (Aufgabe, Aufgabenannahme, Stellen, Schmetterschlag, Block und Feldverteidigung) wurden von 9 Volleyballexperten bewertet. Mittels der hierarchischen Clusteranalyse der Spielelemente wurden drei Gruppen ermittelt, die durch den Abstand des AusfĆ¼hrungsplatzes vom Netz definiert wurden. Die Gruppe A umfasst den Block und den Schmetterschlag und wird "Spielen oberhalb des Netzes" genannt; die Gruppe B schlieĆt den Aufgabenannahme, das Stellen und das Verteidigungsspiel ein und wird "Spielen im eigenen Feld" genannt und in der Gruppe C ist Aufgabe. Aufgrund der arithmetischen Mitte der Schiedsrichtersnoten fĆ¼r die einzelnen Gruppen, kann beschlossen werden, da die Gruppe A durch ein hohes Explosivkraftsgrad, die longitudinale Skelettdimension und Koordination sowie im allgemeinen durch mehr Kraft und Aushaltung als die anderen Gruppen charakterisiert ist. Ein hohes Niveau der PrƤzision und Koordination kennzeichnet die Gruppe B, fĆ¼r die auch ein sehr hohes Antizipationsgrad sowie die Reaktionsschnelligkeit, Gewandtheit, das SpielraumgefĆ¼hl und die FlexibilitƤt spezifisch sind. Die Eigenschaften der Gruppe C sind ein sehr hohes PrƤzisionsgrad und ein hohes (obwohl nicht so hoch als in den anderen Gruppen) Grad des SpielraumgefĆ¼hls und der Explosivkraft
Zapis o zemlji iz 1001 dana
Prikaz knjige Sveina Monneslanda (2001.) 1001 dan, Bosna i Hercegovina slikom i rijeÄju
kroz stoljeÄa. Oslo: Sypress Forlag, 344. str
MoguÄnosti primene hedžing strategija na inostranim robnim berzama
The aim of the paper is to determine the possibilities of implementing hedging strategies of Serbian agricultural producers on foreign commodity exchanges. Considerable fluctuations in prices of agricultural products in Serbia create the need for the use of futures in commodity exchanges in order to protect against unfavourable change in prices of agricultural products in the future period. Due to the fact that Serbia has not established the trading in commodity derivatives, Serbian producers are having to use developed commodity exchanges abroad. The paper analyses the possibilities of using the Chicago Mercantile Exchange in the USA and the MATIF commodity exchange in Paris, looking at two aspects of the activities. First, the correlation of corn prices on domestic and foreign commodity exchanges was investigated, given that it is the basic prerequisite for the application of successful hedging strategies and, secondly, legal requirements, primarily tax policies related to trade of futures contracts. This paper has found that there is a high correlation between the crops price in the foreign commodity markets and spot market in Serbia, which provides a solid basis for the implementation of hedging strategies for underlying assets in foreign commodity markets. However, it has been found that inadequate taxation policy is an aggravating factor for the implementation of hedging strategies.Cilj rada je utvrÄivanje moguÄnosti za primenu hedžing strategija srpskih poljoprivrednih proizvoÄaÄa na inostranim robnim berzama. Visoka fluktacija cena poljoprivrednih proizvoda u Srbiji uslovljava potrebu za koriÅ”Äenjem terminskih robnih berzi, u cilju zaÅ”tite od nepovoljnog kretanja cena poljoprivrednih proizvoda u buduÄem periodu. S obzirom na to da u Srbiji nije uspostavljeno terminsko trgovanje robnim derivatima, srpski proizvoÄaÄi su upuÄeni na koriÅ”Äenje razvijenih robnih berzi u inostranstvu. U radu su analizirane moguÄnosti koriÅ”Äenja ÄikaÅ”ke robne berze u SAD i MATIF robne berze u Parizu. IzvrÅ”ena je analiza sa dva aspekta: prvi, korelisanost cena kukuruza sa domaÄe berze i inostranih berzi, s obzirom na to da je ona osnovni preduslov za primenu uspeÅ”nih hedžing strategija i drugi, zakonski uslovi, prevashodno poreske politike u vezi sa trgovinom terminskim ugovorima. U radu je utvrÄen visok stepen povezanosti cena žitarica na inostranim robnim berzama i spot tržiÅ”tu u Srbiji, Å”to daje dobru osnovu za primenu hedžing strategija na ovu baznu aktivu na inostranim robnim berzama. Ipak, neadekvatni poreski propisi otežavaju primenu ovih strategija
Diskriminanzanalyse der von einer Mannschaft gewonnenen und verlorenen SƤtze in der italienischen a1 volleyball-liga - eine Fallstudie
Chain of factors determines success or failure in any sport match, but the measurable part of it is related to the indicators of efficient performance of technical-tactical elements or game phases during the matches. The sample consisting of 76 sets, obtained from 20 matches played by one team in Italian men\u27s A1 league, was used in this study to determine, on the basis of five play-specific situational parameters, the differences between the sets won and the sets lost. A discriminant analysis was used. The canonical discriminant function significantly differentiated between the sets won and the sets lost, at the level of significance p<0.00. The discriminant function was defined by the highest projection of the variable spike in the phase of attack, and by somewhat lower projections of the variables spike in the phase of counterattack, serve reception, block and serve.Uvod
Promatranje i analiza odbojkaÅ”ke igre najÄeÅ”Äe se zasnivaju na procjenjivanju parametara situacijske uÄinkovitost dobivenih iz odbojkaÅ”kog zapisnika, stenograma utakmice, video zapisa ili raÄunalnih programa. U odbojci su statistiÄki podaci dobiveni na utakmicama vrhunskih ekipa Äesto nedostupni i nepotpuni, pa se na njima ne mogu primjenjivati postupci inferencijalne statistike. Na sreÄu, danas u Europi mnoge reprezentacije koriste unificirani raÄunalni program (Datavolley), pa tako i specijaliste-statistiÄare za praÄenje odbojkaÅ”ke igre.
Materijal i metode
Uzorak entiteta Äinilo je 76 setova dobivenih u 20 utakmica talijanske A1 lige u sezoni 1999./2000. god. koje je odigrala momÄad Zetaline (Padova) s ekipama: Brescial-Montichiari, Modena, Sisley-Treviso, Cosmogas-Forli, Del Monte-Ferrara, Maxicono-Parma, Piaggio-Roma, Tnt Alpitour-Cuneo, Lube-Macerata, Iveco-Palermo i Vallever-Ravenna.
Podaci su prikupljeni specijaliziranim raÄunalnim sustavom bilježenja sadržanim u programskoj podrÅ”ci Datavolley Rel. 5.0 tvrtke DATAPROJECT.
Na ordinalnoj skali od pet stupnjeva ocjenjivala se uÄinkovitost izvedbe situacijskih elemenata igre, odnosno odbojkaÅ”kih faza: 1. SERVIS, 2. PRIJEM SERVISA, 3. SMEÄ IZ NAPADA, 4. BLOK i 5. SMEÄ IZ KONTRANAPADA.
Prva dva stupnja oznaÄavaju negativnu realizaciju, npr. greÅ”ku i akciju koja donosi prednost protivniku, treÄi stupanj na skali oznaÄava izvoÄenje nakon kojeg se akcija nastavlja bez prednosti i za jednu ekipu, dok posljednja dva stupnja oznaÄavaju da je izvedba donijela prednost ili bod.
Kriterijsku varijablu Äini binarno definiran rezultat svakog pojedinog seta na utakmici (pobjeda ili poraz za momÄad Zetaline). Ulazni podaci su frekvencije odbojkaÅ”kih faza, a nakon Å”to je svaka izvedba procijenjena na skali od pet stupnjeva, frekvencije su uvrÅ”tene u formulu.
Takvim naÄinom raÄunanja dobivamo numeriÄke vrijednosti na ordinalnoj skali za svaku od pet faza igre koje možemo koristiti kao podatke za statistiÄku obradu.
Rezultati i rasprava
Iz podataka dobivenih deskriptivnom statistikom (tablica 1, dijagram 1) vidljivo je da su znaÄajnije razlike po kriteriju dobivenih i izgubljenih setova postignute u varijablama SMEÄ U FAZI NAPADA (3,99 dobiveni naspram 3,66 izgubljeni setovi), SMEÄ U FAZI KONTRANAPADA (3,92 dobiveni prema 3,57 izgubljeni setovi) te u varijabli BLOK (2,84 dobiveni prema 2,56 izgubljeni setovi), najvjerojatnije zbog toga Å”to se tim elementima igre osvaja najveÄi broj poena u setu. U tablici 2 prikazani su rezultati svojstvene vrijednosti, kanoniÄke korelacije, hi-kvadrat testa, broj stupnjeva slobode i razina znaÄajnosti diskriminacijske funkcije. Iz dobivenih vrijednosti možemo ustvrditi da diskriminacijska funkcija znaÄajno razlikuje dobivene od izgubljenih setova na razini znaÄajnosti od 0.00 (p<0.00), uz relativno visoku kanoniÄku korelaciju (.58).
Tablica 3 prikazuje korelacije varijabli s diskriminacijskom funkcijom i položaj centroida dobivenih i izgubljenih setova na diskriminacijskoj funkciji. Na negativnom polu diskriminacijske funkcije nalaze se izgubljeni, a na pozitivnom polu dobiveni setovi. Struktura diskriminacijske funkcije je bipolarna. Pozitivni pol definiraju sve varijable, dok se na negativnom polu nije smjestila nijedna varijabla. NajveÄom projekcijom diskriminacijsku funkciju definira varijabla SMEÄ U FAZI NAPADA (SMNAP), neÅ”to nižom projekcijom varijable SMEÄ U FAZI KONTRANAPADA (SMKNAP) i PRIJEM SERVISA (PRIJEM), dok najmanjim projekcijama funkciju definiraju BLOK i SERVIS. SliÄno je dobio i MareliÄ (1998).
U ovom se istraživanju varijabla SMEÄ U FAZI NAPADA (.71) pokazala kao najsnažnija prediktorska varijabla. ObjaÅ”njenje za tako veliku prediktivnost nalazimo u tome da se smeÄ u procesu napada veÄinom izvodi nakon idealnog prijema servisa nakon kojega je dizaÄ u moguÄnosti organizirati brz i kombinacijski napad koji otežava anticipaciju protivniÄke obrane, a time i pravovremeno formiranje protivniÄkog bloka. Ovome u prilog ide i Äinjenica da se u novom sustavu igre (RPS - rally point system) uspjeÅ”nom realizacijom smeÄa u napadu osvaja bod, za razliku od starog sustava gdje se nakon smeÄa u napadu osvajala samo promjena servisa.
SMEÄ U FAZI KONTRANAPADA (.37) ima neÅ”to manju vrijednost, vjerojatno zato Å”to se, novim pravilima, skratilo vrijeme igre za poen. Razlog možda leži i u izuzetno opasnom skok servisu koji ima dva cilja: osvojiti poen ili otežati prijem servisa tako da se dvojnim ili trojnim blokom osvoji poen. Tek ako se servisom i blokom poen ne osvoji, a obrana polja Ā«uhvatiĀ» protivniÄki napad, organizira se smeÄ za kontranapad.
NeÅ”to nižu statistiÄki znaÄajnu vrijednost ima varijabla PRIJEM (.33). Važnost prijema servisa meÄu trenerima nije upitna, Äak je težnja za Å”to boljim odgovorom na opasne servise rezultirala time da je u pravila uveden novi igraÄ ā specijalist samo za prijem servisa i smeÄa (libero).
Varijable SERVIS (.25) i BLOK (.28) takoÄer su se pokazale statistiÄki znaÄajnima i prediktivnima. U setu se servisom u prosjeku postiže 1-2 poena, ali je uloga servisa poput uloge bijelih figura u Å”ahu - njegovim Ā«otvaranjemĀ» diktiramo daljnji tijek igre. Ne samo da osvajanje poena servisom ima znaÄajnu ulogu u stvaranju rezultata, veÄ jednako tako i greÅ”ka servisa. Prihvatljiv broj greÅ”aka servisa kod uspjeÅ”nih odbojkaÅ”kih ekipa iznosi oko 3,5 poena po jednom setu (MareliÄ, 1998). To znaÄi da na utakmici od pet setova ekipe prosjeÄno smiju pogrijeÅ”iti i u 15-ak servisa, a da joÅ” uvijek mogu ostvariti pobjedu. Blokom se prosjeÄno postiže neÅ”to viÅ”e poena po setu nego servisom (oko 3-4), ali je uvoÄenje libera (precizniji prijem servisa i bolja organizacija napada) rezultiralo time da blokeri moraju Äesto individualnim blokom parirati protivniÄkim smeÄerima, Å”to smanjuje uspjeÅ”nost bloka.
Tablica 4 prikazuje rezultate klasificiranja dobivenih i izgubljenih setova momÄadi Zetaline na temelju diskriminacijske funkcije. Od 50 izgubljenih setova, 38 je dobro klasificirano (82,61), dok je od 26 dobivenih setova, 18 dobro klasificirano (60).
ZakljuÄak
Rezultati kanoniÄke diskriminacijske funkcija pokazuju znaÄajne razlike izmeÄu dobivenih i izgubljenih setova na razini znaÄajnosti od p<0.00 uz kanoniÄku korelaciju (.58), te možemo ustvrditi da prediktorske varijable (servis, prijem, blok, smeÄ u procesu napada i smeÄ u procesu kontranapada) statistiÄki znaÄajno razlikuju dobivene od izgubljenih odbojkaÅ”kih setova. Pozitivni pol definiraju sve varijable. NajveÄom projekcijom diskriminacijsku funkciju definira varijabla smeÄ u procesu napada, neÅ”to nižim projekcijama varijable smeÄ u procesu kontranapada i prijem servisa te najnižim projekcijama varijable blok i servis.Die GrĆ¼nde eines erfolgreichen oder erfolglosen Spielresultats sind in einer Reihe von Faktoren zu suchen, aber der meĆbare Teil ist mit einem Indikator der situationsbezogenen Effizienz der technischen Elemente, der Elemente der Taktik oder der Spielphasen im Laufe des Spiels verbunden. 76 von einer Mannschaft gespielten SƤtzen aus 20 Volleyballspiele der italienischen A1 Liga fĆ¼r MƤnner wurden analysiert, um aufgrund von fĆ¼nf situationsbezogenen spielspezifischen Parametern die Unterschiede festzustellen, zwischen den gewonnennen und verlorenen SƤtzen. Um diese Unterschiede zu bestimmen wurde die Diskriminanzanalyse angewandt. Die kanonische Diskriminanzfunktion machte einen wesentlichen Unterschied zwischen den gewonnennen und verlorenen SƤtzen; das Signifikanzniveau war p<0,00. Die Diskriminanzfunktion wurde mit der hƶchsten Projektion definiert durch die Variable Schmetterschlag in der Angriffsphase und mit etwas niedrigerer Projektion der folgenden Variablen: Schmetterschlag in der Gegenangriffsphase, Aufgabeannahme, Block und Aufgabe
Lantentnaja struktura tehniko-taktiÄeskih elementov v volejbole
Glavne komponene matrice interkorelacije tehniÄko-taktiÄkih elemenata bile su interpretirane kao opÄa efikasnost u igri, efikasnost izvoÄenja elemenata u zadnjoj liniji i tok igre u kontranapadu. Rezultati analize latentne strukture tehniÄko-taktiÄkih elemenata u odbojci pokazali su da je skupina ortogonalnih dimenzija smisleno opisala struktura igre u odbojci.The sample for this study involved four best Yugoslav volleyball teams that had that had taken part in the tournament of the Yugoslav Cup (1981). The registration of basic data of closed system of volleyball matches was taken with the aim to check the dimensionality and structure of elements in the game of volleyball. The procedure was done with the help of system of assessments for each element of the game on the scale of 3 or 4. The method of component analysis of the intercorrelation matrix of elements was applied. In this was major components were obtained, significant according to the GK criterion, that sensibly describe the structure of volleyball game.
The first major component, interpreted as general efficiency and the second major component, interpreted as lifting efficiency explain the greatest part of variability of elements that directly have an effect on the success of the game as whole.
However, the third major component, explained as progress of the game in counter-attack, although more poorly defined and the fourth major component explained as progress of the game in counter-attack. although more poorly defined and interpretable (probably due to poorer technics in the rear and during the counter - attack of Yugoslav teams) correspond with the development tendencies in world volleyball and therefore confirm their existence in the structure of volleyball
Multicomponent Modelling Kinetics and Simultaneous Thermal Analysis of Apricot Kernel Shell Pyrolysis
Apricot kernel shells are naturally available source of biomass with potential for conversion to clean energy through a thermo-chemical process such as pyrolysis. To facilitate further process development, an advanced mathematical model which represents the process kinetics is developed and validated on the thermal decomposition studies using simultaneous thermal analysis, over a temperature range of 30-900 degrees C, at four heating rates of 5, 10, 15 and 20 degrees C min(-1), under argon atmosphere. Model-free analysis and numerically developed methods were utilized for determination of effective activation energies, pre-exponential factors and the fractional contribution. A novel approach is introduced in order to determine actual pseudo-components of studied biomass that are included in its composition. The comparative study of the obtained kinetic results was also presented. The results obtained strongly indicated that the pseudo-component reaction modelling method could be employed to predict the experimental devolatilization rate and biomass composition with a high likelihood of success
Perceptions of private security : a case study of students from Serbia and North Macedonia
In the last two decades of the 21st century, the significant development of the private security industry has taken place in Serbia and North Macedonia. However, the private security industry in these two countries did not
reach professional standards as in other states of the former Yugoslavia. The aim
of this paper was to determine studentsā perception of private security and its
employees. The survey data were collected using an anonymous survey of 354
students (296 from Serbia and 58 from North Macedonia). In both countries
the attitudes are heterogeneous, but a relatively small number of respondents
have expressed a high level of perception of private security. The research has
shown that gender, as one of demographic characteristics, has its role in shaping young pexopleās views on the private security, that is, the female population
has more positive views about private security officers, their integrity, and the
nature of the private security job. The findings offer policy-makers and private
security companies the opportunity to deploy new strategies to upgrade public
attitudes towards private security, especially aimed at the male population
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