A child’s level of physical activity is an important component of that child’s health. Our understanding of physical activity patterns in children is limited in rural settings, and virtually absent for climates with snow cover. Opportunities for physical activity intervention need to be identified. PURPOSE: Investigation of the relationships between pedometer-measured physical activity, body composition and aerobic performance in rural children in the winter and examination of within-day variation in stepping behavior using interval pedometry. METHODS: Aerobic performance (20 m shuttle run) with “talk test” validation and body composition (BMI, BF) were measured during mid-winter during the school year in 8 to 10 year old children. Pedometer step counts were recorded at 6 intervals throughout the day for 7 days. RESULTS: Fifty-six subjects (22 males and 34 females, mean age 9.09 (0.49), had the following measurements; BMI 17.9 (3.3), BF% 24.3 (9.5) (tricep/calf), 10,465 (±2506) steps/day, VO2 45.12 ml/kg/min (±2.87), shuttle run stage 3.0 (±1.34). Weekday steps/day (11,422 ±2573) were greater than weekend (8,112, ±3499) steps/day for both boys and girls (p<0.01). Town children recorded 1800 more steps/day than out of town children (p<0.01). All measures of body composition were found to be significantly related to aerobic power (p<0.01). Weekday steps were related to aerobic performance. The fittest (upper 1/3) children were leaner and had more afternoon school steps, and higher afternoon school step rates. CONCLUSION: Daily step counts were 2000-4000 steps lower than other studies and may be an impact of winter in Manitoba or the rural setting. This was consistent with overall low aerobic performance and higher adiposity of the children. Interval pedometry was capable of identifying differences in activity patterns between most and least fit children in rural Manitoba providing for targeted intervention strategies. / October 2006

A child’s level of physical activity is an important component of that child’s health. Our understanding of physical activity patterns in children is limited in rural settings, and virtually absent for climates with snow cover. Opportunities for physical activity intervention need to be identified. PURPOSE: Investigation of the relationships between pedometer-measured physical activity, body composition and aerobic performance in rural children in the winter and examination of within-day variation in stepping behavior using interval pedometry. METHODS: Aerobic performance (20 m shuttle run) with “talk test” validation and body composition (BMI, BF) were measured during mid-winter during the school year in 8 to 10 year old children. Pedometer step counts were recorded at 6 intervals throughout the day for 7 days. RESULTS: Fifty-six subjects (22 males and 34 females, mean age 9.09 (0.49), had the following measurements; BMI 17.9 (3.3), BF% 24.3 (9.5) (tricep/calf), 10,465 (±2506) steps/day, VO2 45.12 ml/kg/min (±2.87), shuttle run stage 3.0 (±1.34). Weekday steps/day (11,422 ±2573) were greater than weekend (8,112, ±3499) steps/day for both boys and girls (p<0.01). Town children recorded 1800 more steps/day than out of town children (p<0.01). All measures of body composition were found to be significantly related to aerobic power (p<0.01). Weekday steps were related to aerobic performance. The fittest (upper 1/3) children were leaner and had more afternoon school steps, and higher afternoon school step rates. CONCLUSION: Daily step counts were 2000-4000 steps lower than other studies and may be an impact of winter in Manitoba or the rural setting. This was consistent with overall low aerobic performance and higher adiposity of the children. Interval pedometry was capable of identifying differences in activity patterns between most and least fit children in rural Manitoba providing for targeted intervention strategies.

A child’s level of physical activity is an important component of that child’s health. Our understanding of physical activity patterns in children is limited in rural settings, and virtually absent for climates with snow cover. Opportunities for physical activity intervention need to be identified. PURPOSE: Investigation of the relationships between pedometer-measured physical activity, body composition and aerobic performance in rural children in the winter and examination of within-day variation in stepping behavior using interval pedometry. METHODS: Aerobic performance (20 m shuttle run) with “talk test” validation and body composition (BMI, BF) were measured during mid-winter during the school year in 8 to 10 year old children. Pedometer step counts were recorded at 6 intervals throughout the day for 7 days. RESULTS: Fifty-six subjects (22 males and 34 females, mean age 9.09 (0.49), had the following measurements; BMI 17.9 (3.3), BF% 24.3 (9.5) (tricep/calf), 10,465 (±2506) steps/day, VO2 45.12 ml/kg/min (±2.87), shuttle run stage 3.0 (±1.34). Weekday steps/day (11,422 ±2573) were greater than weekend (8,112, ±3499) steps/day for both boys and girls (p<0.01). Town children recorded 1800 more steps/day than out of town children (p<0.01). All measures of body composition were found to be significantly related to aerobic power (p<0.01). Weekday steps were related to aerobic performance. The fittest (upper 1/3) children were leaner and had more afternoon school steps, and higher afternoon school step rates. CONCLUSION: Daily step counts were 2000-4000 steps lower than other studies and may be an impact of winter in Manitoba or the rural setting. This was consistent with overall low aerobic performance and higher adiposity of the children. Interval pedometry was capable of identifying differences in activity patterns between most and least fit children in rural Manitoba providing for targeted intervention strategies.

The forest species have been used since the beginning of the times for the most several ends. However, the unrestricted and inadequate use, especially of native examples of great economical value, it is causing great environmental problems. The form, commonly adopted, to reduce the pressure on the native forests it is the use of exotic species. For the importance that those species reached, it exists at the country a vast area planted with homogeneous stands, prevailing the Pinus and Eucalyptus. That demand generates a demand every time larger for more productive forests and of quality, contemplating, this way, in the production of seedlings. However, there is still a lot to be improved in that section, especially in the scientific field. The statistics, if well explored, it can contribute to that. Therefore, this work had as objectives, to verify the distribution of the variables diameter and height of the seedlings of Pinus spp. and to characterize similar behaviors of the variables, in seedlings production trays, as well as, to estimate the sample size for seedlings of Pinus spp. in forest nursery. For the present study data were collected from seedlings of Pinus spp., produced in the Technological Center of Forestry of Santa Maria's Federal University. The data used for the development of the works were coming of experiments with Pinus taeda, accomplished in the first semester of the year of 2005 and other with Pinus elliottii var. elliottii, accomplished in the second semester of the year of 2005. The seedlings were willing in three trays (B1, B2 and B3). The observed variables were diameter and height of the seedling, appraised of 15 in 15 days (B1 and B2) and of 25 in 25 days (B3), where the first evaluation was accomplished to the 50 (B1 and B2) and 25 (B3) days after the emergency of the seedlings and the last to the 140 (B1 and B2) and 175 (B3) days. The statistical analyses were accomplished through application of the Run Test and sample size. The growth in seedlings of Pinus taeda was heterogeneous, being verified the non randomness in the distribution of the observations of the variables height and diameter. Already, for Pinus elliottii var. elliottii the growth of the seedlings was aleatory. The sample size varies in function of the age and randomness of the seedlings for both studied variables, where the number of sample units, for a semi-width of 10%, for Pinus taeda, went from 25 to height and twelve seedlings for the diameter and for Pinus elliottii var. elliottii went of nine seedlings to height and ten for the diameter, when considered the non randomness. / As espécies florestais têm sido utilizadas desde o início dos tempos para os mais diversos fins. Porém, o uso irrestrito e inadequado, principalmente de exemplares nativos de grande valor econômico, vem causando grandes problemas ambientais. A forma, comumente adotada, para reduzir a pressão sobre as florestas nativas é a utilização de espécies exóticas. Pela importância que essas espécies alcançaram, existe no país uma vasta área plantada com povoamentos homogêneos, predominando os de Pinus e Eucalyptus. Essa demanda gera uma exigência cada vez maior por florestas mais produtivas e de qualidade, refletindo, desta forma, na produção de mudas. Entretanto, ainda há muito que ser melhorado nesse setor, especialmente no campo científico. A estatística, se bem explorada, pode contribuir para isso. Portanto, este trabalho teve como objetivos, verificar a distribuição das variáveis diâmetro do colo e altura das mudas de Pinus spp. e caracterizar comportamentos similares das variáveis, dentro das bandejas de produção de mudas, assim como, estimar o tamanho de amostra para mudas de Pinus spp. em viveiro florestal. Para o presente estudo foram coletados dados de mudas de Pinus spp., produzidas no Centro Tecnológico de Silvicultura da Universidade Federal de Santa Maria. Os dados utilizados para o desenvolvimento dos trabalhos foram provenientes de experimentos com Pinus taeda, realizado no primeiro semestre do ano de 2005 e outro com Pinus elliottii var. elliottii, realizado no segundo semestre do ano de 2005. As mudas foram dispostas em três bandejas (B1, B2 e B3). As variáveis observadas foram diâmetro do colo e altura da muda, avaliadas de 15 em 15 dias (B1 e B2) e de 25 em 25 dias (B3), onde a primeira avaliação foi realizada aos 50 (B1 e B2) e 25 (B3) dias após a emergência das plântulas e a última aos 140 (B1 e B2) e 175 (B3) dias. As análises estatísticas foram realizadas via aplicação do Teste de Seqüência e tamanho de amostra. O crescimento em mudas de Pinus taeda foi heterogêneo, sendo constatada a não aleatoriedade na distribuição das observações das variáveis altura e diâmetro do colo. Já, para Pinus elliottii var. elliottii o crescimento das mudas foi aleatório. O tamanho de amostra varia em função da idade e aleatoriedade das mudas para ambas as variáveis estudadas, onde o número de unidades amostrais ideal, para uma semi-amplitude de 10%, para Pinus taeda, foi de 25 para altura e de doze mudas para o diâmetro e, para Pinus elliottii var. elliottii foi de nove mudas para altura e dez para o diâmetro, quando considerada a não aleatoriedade.

Abstract Background/problem definition: Mental illness, such as anxiety, is a health problem affecting about 10-20% of adolescents worldwide. Studies have found a person’s physical fitness to be associated with their mental health, but most studies have been done in the western world and few have investigated sub-Saharan African (SSA) countries. It has also been found that SSA countries’ guidelines regarding physical activity are few and incomplete, although the importance of it is well known.   Aim: To investigate to what extent physical fitness: grip strength (GS), 20 meter shuttle run test (20MSRT), body mass index (BMI) and waist circumference (WC) correlate to self-assessed anxiety in South African students at the UWC.   Methods: The study had a quantitative, cross-sectional and correlational research design with a non-randomized convenience sampling. The physical fitness data were collected through a hydraulic grip strength dynamometer, 20MSRT and by measuring anthropometric measurements in order to calculate BMI and WC. An electronic version of the GAD-7 form was used for self-assessed anxiety.   Results: The results showed a significant positive correlation between BMI and levels of anxiety in women, but not in men. The correlation of anxiety related to WC, GS and 20MSRT showed no significance for the whole sample or related to gender, respectively. Conclusion: No significant correlation could be determined between physical fitness and anxiety. Severe anxiety affected 25% of the population, supporting previous research indicating that students are a group prone to anxiety. / Sammanfattning Bakgrund: Mental ohälsa, till exempel ångest, är ett hälsorelaterat problem som drabbar cirka 10-20% av ungdomar i världen över. Studier har visat att en persons fysiska kondition (physical fitness) kan kopplas till mental hälsa och välmående, men de flesta studier har gjorts i västvärlden och det råder brist på forskning i länder söder om Sahara. Dessutom har afrikanska länder söder om Sahara få och inkompletta riktlinjer gällande fysisk aktivitet trots att betydelsen av fysisk aktivitet är väl etablerad. Syfte: Att undersöka om och till vilken utsträckning fysisk kondition (innefattande grepp styrka, beep-test, BMI och midjemått) korrelerar med självskattad ångest (GAD-7) hos Sydafrikanska studenter vid University of the Western Cape (UWC).   Metod: En kvantitativ tvärsnittsdesign användes och korrelationer studerades. Deltagarna rekryterades genom ett icke randomiserat bekvämlighetsurval. Datan för fysisk kondition och hälsa samlades in genom en greppstyrka-dynamometer, beep-test samt genom antropometriska mätningar för att mäta midjemått och räkna ut BMI. Självskattad ångest samlades in genom en elektronisk version av GAD-7 formuläret.   Resultat: Resultaten visade en statistiskt signifikant, positiv korrelation mellan BMI och ångest bland kvinnor. Inga signifikanta korrelationer kunde i övrigt ses i gruppen som helhet eller hos kvinnor respektive män. Konklusion: Ingen signifikant korrelation fastslogs mellan fysisk kondition och ångest. Svår ångest rapporterades av 25% av deltagarna, vilket stödjer tidigare forskning på området som indikerar att studenter är en grupp utsatt för ångest.

Bakgrund: Träning i naturliga miljöer har hälsofrämjande effekter och ökar välbefinnandet i jämförelse med träning som sker i inomhusmiljöer. Individer som utför träning i utomhusmiljöer visar sig ha högre hastighet, hjärtfrekvens och blodlaktatkoncentration, i jämförelse med individer som tränar inomhus vilket påverkar den fysiska prestationen.Syfte: Syftet med denna studie var att undersöka mätbara skillnader i fysisk prestation inomhus och utomhus genom ett maxpulstest.Metod: Studien genomfördes med en randomiserad kontrollerad cross- over design där åtta män och fem kvinnor (medelålder 26 ± 3.67), fysiskt aktiva, genomförde ett beeptest vid två tillfällen. Testet utfördes av samma person vid ett tillfälle inomhus och ett tillfälle utomhus. Analysen utgick från uppskattat VO2 max genom protokoll av beeptest, objektiv mätning och kontroll av puls direkt före tester och direkt efter genomförda tester.Resultat: Resultaten visade en signifikant skillnad i VO2 max (O2ml/kg/min) (p= 0.047), genom en högre fysisk prestation inomhus i jämförelse med utomhus (46.08 ± 8.76 och 44.73 ± 8.84). Puls (slag/min) efter genomförda tester visade ett högre medelvärde inomhus i jämförelse med utomhus (192.36 ± 10.13 och 190.45 ± 9.11), men ingen signifikant skillnad (p=0.11). Puls före tester visade ingen signifikant skillnad (p=0.898) mellan inomhusmiljön och utomhusmiljön (107.16 ± 18.78 och 107. 75 ± 18.49).Slutsats: Resultaten indikerar på att det är skillnader i fysisk prestation i olika miljöer. VO2 max var signifikant högre i inomhusmiljön i jämförelse med utomhusmiljön. Medel-maxpulsen tenderade ha ett högre medelvärde inomhus i jämförelse med utomhus. / Background: Exercise performed in natural environments produces health-promoting effects and increases well-being, in comparison with exercises performed in indoors-environments. Individuals who exercise outdoors has higher velocity, heartrate and blood lactate concentration compared to individuals who exercise indoors, which affects the physical performance.Purpose: The purpose of this study was to investigate measurable differences in physical performance indoors and outdoors through a maximum heartrate test.Method: The study was conducted with a randomized controlled cross over design where five women and eight men, physical active, in the middle age of 26 ± 3.67 years, performed a shuttle run test at two times. The test was repeated by the same individual one time indoors and one time outdoors. The analysis was made by estimated VO2 max using a protocol from the performed shuttle run test, and controlled objective measurements of pulse levels, directly before the test started and directly after finished test.Results: Significant differences were found between indoors and outdoors, where VO2 max (O2ml/lbs/min) (p= 0.047) was higher indoors than outdoors (46.08 ± 8.76 and 44.73 ± 8.84). Pulse levels (beats/min) was higher indoors than outdoors (192.36 ± 10.13 and 190.45 ± 9.11) after finished test, but significant differences were not found (p=0.11). Significant differences were not found in pulse levels before the test (p=0.898), between the different environments (107.16 ± 18.78 and 107. 75 ± 18.49).Conclusion: The results in this study show that there are differences in physical performance between different environments. VO2 max was significantly higher in the indoor environment compared to the outdoor environment. The average maximum pulse tended to have a higher average indoors compared to outdoors.

在國內外實證文獻中，已有許多學者研究市場過度反應的現象，但由採取的研究方法不盡相同，故結論也有所差異．本研究是希望能對台灣股市的個別股票報酬率作一較完整的檢視，先瞭解股票報酬率前後期的相關情形，試圖找出一些一致性，再提出股市交易的策略，並比較策略的獲利性。 將樣本分成對稱與不對稱的形成期及檢定期，採Spearman等級相關係數法先對台灣股市同一股票的報酬率在不同期間（形成期及檢定期）的表現是否有相關作一檢視，接著檢定此相關係數時間序列是否具有隨機的特質，而後將證券交易稅及手續費納入考慮後，比較三種投資策略－買入持有輸家、中間、贏家的獲利性、風險及績效表現。 本文的實證結果：由單位風險報酬率來看，投資股市應以買入有長期的策略才會有較好的績效表現，而買入持有短期的績效是最差的。以不同的樣本期間討論台灣股市是否有價格反彈，結果並不相同。在1980年-1998年的Spearman等級相關係數多為正值，表示市場在288天以下多沒有價格反彈，且以連檢定的結果多為顯著，以Jensen α檢定之，贏家投資策略能獲得超額報酬。在1990年-1998年不論是重覆取樣、未重覆取樣，Spearman等級相關係數，多為負值，表示市場應存有價格反彈的現象，且以連檢定的結果多為顯著，但以Jensen α檢定之，輸家卻無法獲得超額報酬。可能是因為考慮了交易稅與手續費，而影響了投資策略的獲利性。 / There have been many articles discussing overreaction. Because of the difference of methods and samples, the conclusions are different. This thesis tries to make a more complete examination of Taiwan Stock Market. We divide sample period to be formation period and test period which are symmetric and asymmetric. Besides that, we adopt overlapping and nonoverlapping sampling. The sample period is 1980 January 1 to 1998 January 22. Three investment strategies are buying and holding loser portfolio、middle portfolio and winner portfolio. We use Spearman rank correlation to discuss whether the return of Taiwan Stock Market has correlation between formation period and test period. Then we adopt one of nonparameter statitics analysis－run test to examine whether the time series of Spearman rank correlation is a random walk. Following are our summaries： 1.The longer period we hold the stock,the better return we acquire. 2.In the first sample (1980 Jan 1 to 1998 Jan 22), Spearman rank correlation. is almost positive, and the hypothesis of run test is significant. We imply buying and holding the winner portfolio is the best strategy. We can prove this by using Jense α. In this case, buying and holding winner can get excess return. 3.In the second sample(1990 Nov 1 to 1998 Jan 22), Spearman rank correlaion is almost negative, and the hypothesis of run test is signficant. We imply buying and holding the loser portfolio is the best strategy. But we can not prove the by using Jense α. As we can not acqure excess return by buying and holding loser portfolio.

Syfte och frågeställningar Syftet med studien var att undersöka för elitorienterare resultaten vid och korrelationen mellan ett så kallat 5 minuters pyramidtest (5MPT) och ett maximalt test för bestämning av maximalt syreupptag (VO2max) på rullband. Frågorna vi ställde oss var: Vilken korrelation föreligger mellan 5MPT och ett bestämt VO2max på rullband hos elitorienterare? Hur ser en jämförelse ut mellan uppmätt samt beräknat VO2max? Vilken är reliabiliteten för 5MPT? Hur ser ekvationen ut för att beskriva sambandet mellan dessa två olika maxtester? Metod I valideringsstudien deltog 16 elitorienterare (6 kvinnor och 10 män) i åldrarna 17 till 37 år. De två testerna som genomfördes var 5MPT och bestämning av VO2max på rullband. 5MPT är ett skytteltest som är fem minuter långt, där testpersonen (tp) tar sig fram och tillbaka mellan två stolpar (sträcka 5.5 m) där en vertikal trappa (formad likt en pyramid) passeras under varje vända. Antalet vändor, skattad ansträngning samt hjärtfrekvens (HF) registrerades. Utvecklad power (effekt) erhölls genom produkten av vikt, gravitation, antal vändor, höjd på högsta plinten (0,62 m) dividerat med total duration i 5MPT. Testet för att bestämma VO2max utfördes med löpning på ett motordrivet rullband. Under den första minuten av testet sprang tp på en hastighet av 8km/h (kvinnor) respektive10km/h (män) utan lutning. För varje minut ökades hastigheten med 1km/h. Lutningen höjdes med en grad efter minut ett och därefter med 0,5 grader/minut. Testet pågick till dess tp nått sin VO2max. Var 15:e sekund registrerades tp:s HF, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) och respiratorisk kvot (RER) med hjälp av ett datoriserat syreupptagningssystem. Resultat Korrelationen var signifikant och hög (r = 0,89, p&lt;0,0001) mellan utvecklad power på 5MPT och VO2max (l/min) och även mellan antalet vändor på 5MPT och VO2max (l/min) (r = 0,89, p&lt;0,0001) på detta material av elitorienterare. Följande formler, baserade på resultaten från elitorienterarna, kan användas för att predicera VO2max efter genomfört 5MPT: VO2max  (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTVÄNDOR – 74,447) / 9,7668 Slutsats 5MPT uppvisar en stark korrelation med bestämd VO2max sett till power och/eller antalet genomförda vändor. Beräkningsformler för prediktion av VO2max har varit möjligt att beskriva. Se resultatdelen för andra resultat och samband mellan 5MPT och VO2max. / Abstract Aim The aim of this study was to investigate for elite orienteers the results in and the correlation between a so called 5-minutes-pyramid test (5MPT) and a specific maximum oxygen uptake test (VO2max) on a treadmill. The questions we asked ourselves were: Which correlation exists between 5MPT and a specific VO2max on the treadmill for elite orienteers? How would a comparison look like between measured and estimated VO2max? What is the reliability for the 5MPT? How would an equation look like that describe the correlation above? Method In the validity the study 16 elite orienteers (6 women and 10 men) aged 17 to 37 years participated. The two tests that have been carried out were the 5MPT and determined VO2max during running on a treadmill. The 5MPT is a 5-minute-shuttle test, in which the participant moves back and forth in a short interval (5.5 m) over boxes (highest height: 0.62) formed like a pyramid. Power in the pyramid test (5MPTPOWER) was calculated as the product of numbers of laps, body weight, gravity and highest box level divided by time. To determine VO2max the method running on a treadmill was performed. During the first minute the running speed was 8km/h (women)/10 km/h (men) without elevation. Each minute the velocity increased with 1 km/h. The elevation increased with 1 degree after the first minute and thereafter with 0,5 degrees/minute.  The test was finished when the participant had reached her VO2max. Every 15 second the participants heart rate, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) and RER, was registered by means of an online system. Results The correlation between the developed power of the 5MPT and measured VO2max (l/min) was high (r = 0.89, p&lt;0,0001) and also between the number of laps in the 5MPT and measured VO2max (l/min) (r = 0.89, p &lt; 0,0001). The following formulas can be used to predict VO2max after completed 5MPT: VO2max  (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTLAPS – 74,447) / 9,7668 Conclusions 5MPT show a strong correlation with VO2max determined in terms of power and/or the number of completed laps. Calculated formulas for prediction of VO2max have been possible to describe. See results section for other results and relationships between 5MPT and VO2max. / Maximal Aerobic Power versus Performance in Two Aerobic Endurance Tests among Young and Old Adults.Andersson E, Lundahl N, Wecke L, Lindblom I, Nilsson, J.

The 20 Metre Multistage Shuttle Run Test (20 MST) was modified for application to ice-sports, more specifically for ice-hockey and figure-skating. Seventy two participants in ice-sports served as the total subject group. Subjects included in the study were National and Provincial standard male ice-hockey subjects (n=67) and female figure skaters (n=5) participating in the Gauteng area of South Africa (altitude of 1497 metres above sea level and barometric pressure of 655 mmHg). The mean age for the total group was 17.44±1.33 years. The research methodology entailed a repeated measures design to determine: a) velocity of motion on-ice vs. over-ground; b) energy expenditure on-ice vs. over-ground; and c) mechanical efficiency on-ice vs. over-ground. The mean velocity of motion measured over three distances (0 to 20, 0 to 30 and 0 to 40 m) indicated a significantly (p≤0.05) faster velocity on-ice (5.99±0.72 m/s) versus over-ground (5.75±0.63 m/s). The corresponding mean time-lapsed on-ice/over-ground ratio was 0.97±0.11. Differences in mean energy expenditure whilst performing the original 20 MST over-ground as opposed to on-ice were measured at low (at 4 minutes of exercise and 10 km/h), intermediate (after 8 minutes of exercise and 12 km/h), and high intensity (after 12 min of exercise and 14 km/h). The mean of the three indicated a significantly (p≤0.05) higher energy expenditure over-ground (14.04±4.86 kcal/min) as apposed to on-ice (10.51±2.95 kcal/min). The mean energy expenditure ratio for the three different intensities on-ice vs. over-ground was 0.74±0.21. Similarly, the mechanical efficiency index over-ground (4.92±0.59) was found to be significantly (p≤0.001) poorer than on-ice (6.83±1.49). The mean mechanical efficiency ratio over-ground/over-ice was 0.74±0.13. Subsequently, based on the above results, the 20 MST was modified by: a) adapting (increasing) the velocity of motion required for each level of the test (distance of 20 m per shuttle); and b) establishing the reliability and validity of the modified 20 MST for use on-ice. The adapted 20 Metre Multistage Shuttle Skating Test (the modified (skating) 20 MST) started at a velocity of 2.8 m/s (10.1 km/h) and permitted 7.1 seconds to complete each shuttle for the first level of the test, which then decreased progressively at each level. This was based on an over-all variable-derived on-ice to over ground ratio of 0.84. Test-retest, on-ice reliability measures (n=15) for predicted VO2max (49.5±8.37 vs. 49.29±7.95 ml/kg/min) showed a highly significant (p£0.001) consistency (r=0.87). Similarly test-retest concurrent validity measures (n=10) for predicted VO2max over-ground with the original 20 MST (48.09±6.25 ml/kg/min) as designed by Léger and Lambert (1982) versus on-ice values with the adapted on-ice 20 MST (49.98±7.23 ml/kg/min), showed a very significant (p£0.01) correlation of 0.73 between the two tests. In conclusion the original 20 MST, as designed by Léger and Lambert (1982) for over-ground, proved inappropriate for use on-ice. Modification of the starting velocity as well as a progressive increase in velocity for all subsequent stages renders the modified 20 MST for ice-sports a reliable and valid test for cardiorespiratory fitness (VO2max), with surface-specific utility. The 20 Metre Multistage Shuttle Run Test (20 MST) was modified for application to ice-sports, more specifically for ice-hockey and figure-skating. Seventy two participants in ice-sports served as the total subject group. Subjects included in the study were National and Provincial standard male ice-hockey subjects (n=67) and female figure skaters (n=5) participating in the Gauteng area of South Africa (altitude of 1497 metres above sea level and barometric pressure of 655 mmHg). The mean age for the total group was 17.44±1.33 years. The research methodology entailed a repeated measures design to determine: a) velocity of motion on-ice vs. over-ground; b) energy expenditure on-ice vs. over-ground; and c) mechanical efficiency on-ice vs. over-ground. The mean velocity of motion measured over three distances (0 to 20, 0 to 30 and 0 to 40 m) indicated a significantly (p≤0.05) faster velocity on-ice (5.99±0.72 m/s) versus over-ground (5.75±0.63 m/s). The corresponding mean time-lapsed on-ice/over-ground ratio was 0.97±0.11. Differences in mean energy expenditure whilst performing the original 20 MST over-ground as opposed to on-ice were measured at low (at 4 minutes of exercise and 10 km/h), intermediate (after 8 minutes of exercise and 12 km/h), and high intensity (after 12 min of exercise and 14 km/h). The mean of the three indicated a significantly (p≤0.05) higher energy expenditure over-ground (14.04±4.86 kcal/min) as apposed to on-ice (10.51±2.95 kcal/min). The mean energy expenditure ratio for the three different intensities on-ice vs. over-ground was 0.74±0.21. Similarly, the mechanical efficiency index over-ground (4.92±0.59) was found to be significantly (p≤0.001) poorer than on-ice (6.83±1.49). The mean mechanical efficiency ratio over-ground/over-ice was 0.74±0.13. Subsequently, based on the above results, the 20 MST was modified by: a) adapting (increasing) the velocity of motion required for each level of the test (distance of 20 m per shuttle); and b) establishing the reliability and validity of the modified 20 MST for use on-ice. The adapted 20 Metre Multistage Shuttle Skating Test (the modified (skating) 20 MST) started at a velocity of 2.8 m/s (10.1 km/h) and permitted 7.1 seconds to complete each shuttle for the first level of the test, which then decreased progressively at each level. This was based on an over-all variable-derived on-ice to over ground ratio of 0.84. Test-retest, on-ice reliability measures (n=15) for predicted VO2max (49.5±8.37 vs. 49.29±7.95 ml/kg/min) showed a highly significant (p£0.001) consistency (r=0.87). Similarly test-retest concurrent validity measures (n=10) for predicted VO2max over-ground with the original 20 MST (48.09±6.25 ml/kg/min) as designed by Léger and Lambert (1982) versus on-ice values with the adapted on-ice 20 MST (49.98±7.23 ml/kg/min), showed a very significant (p£0.01) correlation of 0.73 between the two tests. In conclusion the original 20 MST, as designed by Léger and Lambert (1982) for over-ground, proved inappropriate for use on-ice. Modification of the starting velocity as well as a progressive increase in velocity for all subsequent stages renders the modified 20 MST for ice-sports a reliable and valid test for cardiorespiratory fitness (VO2max), with surface-specific utility. / Dissertation (MA (Human Movement Science))--University of Pretoria, 2005. / Biokinetics, Sport and Leisure Sciences / unrestricted

Personalisierung ist ein wichtiger Bereich des Internet Marketings, zu dem es wenige experimentelle Untersuchungen mit großen Teilnehmerzahlen gibt. Für den erfolgreichen Einsatz von Empfehlungsverfahren sind umfangreiche Daten über das Käuferverhalten erforderlich. Diesen Problemstellungen nimmt sich die vorliegende Arbeit an. In ihr wird das Shop-übergreifende individuelle Käuferverhalten von bis zu 126.000 Newsletter-Empfängern eines deutschen Online-Bonussystems sowohl mittels ausgewählter Data-Mining-Methoden als auch experimentell untersucht. Dafür werden Prototypen eines Data-Mining-Systems, einer A/B-Test-Software-Komponente und einer Empfehlungssystem-Komponente entwickelt und im Rahmen des Data Minings und durch Online-Feldexperimente evaluiert. Dabei kann für die genannte Nutzergruppe in einem Experiment bereits mit einem einfachen Empfehlungsverfahren gezeigt werden, dass zum einen die Shop-übergreifenden individuellen Verhaltensdaten des Online-Bonus-Systems für die Erzeugung von Empfehlungen geeignet sind, und zum anderen, dass die dadurch erzeugten Empfehlungen zu signifikant mehr Bestellungen als bei der besten Empfehlung auf Basis durchschnittlichen Käuferverhaltens führten. In weiteren Experimenten im Rahmen der Evaluierung der A/B-Test-Komponente konnte gezeigt werden, dass absolute Rabattangebote nur dann zu signifikant mehr Bestellungen führten als relative Rabatt-Angebote, wenn sie mit einer Handlungsaufforderung verbunden waren. Die Arbeit ordnet sich damit in die Forschung zur Beeinflussung des Käuferverhaltens durch Personalisierung und durch unterschiedliche Rabatt-Darstellungen ein und trägt die genannten Ergebnisse und Artefakte bei.