Yes / To investigate the reliability and variability of Video Rasterstereography (VR) measurements of the spine and pelvis, for eight proposed standing postures, in order to help define an optimal standing position for erect pelvis radiography. Methods: Surface topography data were collected using the formetic 4D dynamic modelling (Diers) system. 61 healthy participants were recruited; each participant performed eight different standing positions. Four positions were performed with the feet shoulder width apart and parallel, and four positions were performed with the feet shoulder width apart and internally rotated. For the upper extremity, each of the (two sets of) four positions were performed with different arm positions (arms by the sides, arms crossed over the chest, arms 30° flexed and touching the medial end of the clavicle, arms 30° flexed with the hands holding a support). Three sets of surface topography were collected in the eight positions (n = 24). The variability was assessed by calculating standard error of the measurement (SEm) and the coefficient of variation (CV). Reliability was assessed using intra-class correlation coefficients (ICC ± 95% CI). Results: No significant differences in the SEm were found between the three paired measurements for all standing positions (P > 0.05). ICC values demonstrated excellent reliability for all measurements across the eight standing positions (range 0.879–1.00 [95% CI 0.813–1.00]). Conclusion: Evaluating eight standing positions radiographically would be unethical as it would involve repeat radiation exposures. Using the formetic 4D dynamic modelling (Diers) system, provides an alternative and has shown that there was only a minimal, non-statistically significant, differences between the eight different standing positions. / KA is supported by the Hashemite University/ Jordan.

A síncope neurocardiogênica (SINC) é causada por redução global e aguda do fluxo sanguíneo cerebral, subsequente à hipotensão arterial, com perda transitória da consciência e do tônus postural. Entretanto, existem divergências, quanto às repostas das variáveis cardiovasculares que antecedem o início da SINC, provocada pelo seu principal teste diagnóstico, a manobra postural passiva (MPP) ou Tilt-test. Recentemente, a possibilidade de analisar as variáveis cardiovasculares, com métodos computacionais não-invasivos, lineares (ML) e não lineares (MNL) tem permitido o estudo das entropias, da variabilidade da frequência cardíaca (VFC), da pressão arterial sistólica (VPAS) e da sensibilidade barorreflexa (SBR); estudos preliminares sugerem que a SINC poderia estar relacionada ao desequilíbrio da modulação autonômica dessas variáveis. Objetivo: usar métodos computacionais, ML e MNL, na análise da VFC, e ML na análise da VPAS e da SBR, em pacientes com história clínica de SINC, com resposta positiva ou negativa à MPP, e em indivíduos saudáveis. Métodos: Foram estudados 51 indivíduos, divididos em 3 grupos, sendo 16 positivos, 18 negativos e 17 saudáveis. Os ML usam algoritmos nos domínios do tempo (DT) e da frequência (DF) (Transformada rápida de Fourier), e os MNL usam alogarítmos da entropia amostral (SampEn) m=2 e r= 20%. Foram analisados 2 momentos: Pré-Tilt (posição supina; trechos com 1000-1500 pontos) e Tilt pré-síncope (70º de inclinação; trechos com 1000-1500 pontos; anteriores à síncope), sendo estudados os mesmos momentos para o grupo controle. Resultados: Não foram encontradas diferenças estatísticas entre os grupos TTP, TTN e Controle para os parâmetros: Idade (anos), Peso (kg), Altura (m) e IMC (kg/m2), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), frequência cardíaca (FC) e frequência respiratória. Na análise VFC por meio de ML no DT e DF, no momento Pré-Tilt e Tilt pré-síncope, não foi encontrada diferenças estatísticas 8 entre os grupos TTP, TTN e Controle para os parâmetros Mean-iRR(ms), SDiRR(ms), RMSSD(ms), LF(un) (ms2), HF(un) (ms2) e LF/HF. Comparando-se os momentos Pré-Tilt vs Tilt nos grupos TTP, TTN e Controle (análise intra-grupo) observamos diferenças significantes para as variáveis: Mean-iRR(ms), SD-iRR(ms), RMSSD(ms), LF(un), HF(un) (ms2) e LF/HF. Houve na análise da VFC por MNL (SampEn) no grupo Controle, redução significativa dos valores entre as fases Pré-Tilt vs Tilt (2,19 ± 0,40 vs 1,68 ± 0,50, p = 0,001). Houve em ambos os grupos (TTP, TTN e Controle) aumento significativo do LF-PAS, quando comparamos as fases Pré-Tilt vs Tilt (TTP: 6,72 ± 5,67 vs 13,03 ± 10,759 mmHg2, p = 0,001; TTN: 7,25 ± 4,22 vs 13,42 ± 8,62 mmHg2, p = 0,013; Controle: 5,99 ± 2,20 vs 23,07 ± 6,26 mmHg2, p < 0,0001). Além disso, evidenciaram-se maiores valores, estatisticamente significantes, quando comparamos os grupos Controle vs TTP no momento Tilt (23,07 ± 6,26 vs 13,03 ± 10,59 mmHg2, p < 0,001) e Controle vs TTN no momento Tilt (23,07 ± 6,26 vs 13,42 ± 8,62 mmHg2, p < 0,001). Houve em todos os grupos redução significativa da SBR, quando comparamos as fases Pré-Tilt vs Tilt (TTP: 30,22 ± 15,67 vs 13,16 ± 6,08 ms/mmHg, p < 0,0001; TTN: 22,98 ± 11,23 vs 11,55 ± 3,34 ms/mmHg, p < 0,0001; e Controle: 26,75 ± 6,94 vs 12,25 ± 3,88 ms/mmHg, p < 0,0001). Além disso, no grupo TTP e Controle, houve redução significativa dos valores do índice de efetividade barorreflexa (BEI) entre as fases Pré-Tilt vs Tilt (0,50 ± 0,15 vs 0,40 ± 0,13, p = 0,033) e (0,54 ± 0,07 vs 0,46 ± 0,16, p =0, 030) respectivamente. Conclusões: os achados do presente estudo permitiram as seguintes conclusões: 1- a VFC, com métodos lineares (domínios do tempo e frequência) e não lineares (Entropia Amostral), bem como a VPAS (domínios do tempo e da frequência) e a SBR não documentaram nas fases Pré-Tilt e Tilt pré- síncope (fase de estabilidade das variáveis, após a mudança postural até momento anterior ao aparecimento dos pródromos ou da síncope), diferenças estatísticas entre os 2 grupos de pacientes adultos e com história altamente sugestiva de SINC, como doença isolada, com Tilt-test positivo e negativo; 2- o grupo Controle saudável somente foi diferente dos grupos TTP e TTN no parâmetro LF da VPAS; a importância fisiológica desse achado é de difícil explicação, porque não existem na 9 literatura, para esse parâmetro, valores normais da média e dos intervalos de confiança. / Neurocardiogenic syncope (SYN) is caused by a global and acute reduction of cerebral blood flow, subsequent to hypotension, with transient loss of consciousness and postural tone. However, there are differences in the responses of the cardiovascular variables that precede the beginning of the SYN, caused by its main diagnostic test, the passive postural maneuver (PPM) or Tilt-test. Recently, the possibility of analyzing cardiovascular variables using non-invasive, linear (ML) and non-linear (MNL) computational methods has allowed the study of entropies, heart rate variability (HRV), systolic blood pressure variability (VPAS) and baroreflex sensitivity (SBR). Preliminary studies suggest that the SYN could be related to the imbalance of the autonomic modulation of these variables. Objective: To use computer methods, ML and MNL, in the analysis of HRV, and ML in the analysis of VPAS and SBR, in patients with a clinical history of SYN, with positive or negative response to PPM, and in healthy individuals. Methods: Fifty-one individuals were studied, divided into three groups: 16 positive, 18 negative and 17 healthy. MLs use algorithms in the time (DT) and frequency (DF) (Fast Fourier Transform) algorithms, and MNLs use sample entropy m (2) and r = 20%. Two moments were analyzed: Pre-Tilt (supine position, recording 1000-1500 points) and pre-syncope Tilt (70º inclination, recording 1000-1500 points, prior to syncope), being studied the same moments for the control group. Results: There were no statistical differences between the TTP, TTN and Control groups for the parameters: Age (years), Weight (kg), Height (m) and BMI (kg / m2), systolic blood pressure Diastolic (DBP), heart rate (HR) and respiratory rate. No statistical differences were found between the TTP, TTN and Control groups (in the Pre-Tilt and Tilt) for the Mean-iRR (ms), SD-iRR (ms), RMSSD (ms), LF (un) (ms2), HF (un) (ms2) and LF / HF. Comparing the Pre-Tilt vs Tilt moments in the TTP, TTN and Control groups (intra-group analysis) we observed significant differences for the variables: Mean-iRR (ms), SD-iRR (ms), RMSSD (ms), 11 LF (Un), HF (un) (ms2) and LF / HF. There was a significant reduction in the values between the Pre-Tilt vs Tilt phases (2.19 ± 0.40 vs 1.68 ± 0.50, p = 0.001) in the analysis of HRV by MNL (SampEn) in the Control group. There was a significant increase in LF-PAS in both groups (TTP, TTN and Control) when we compared the Pre-Tilt vs Tilt phases (TTP: 6.72 ± 5.67 vs 13.03 ± 10.759 mmHg2, p = 0.001; TTN: 7.25 ± 4.22 vs 13.42 ± 8.62 mmHg2, p = 0.013; Control: 5.99 ± 2.20 vs. 23.07 ± 6.26 mmHg2, p <0.0001). In addition, statistically significant higher values were found when we compared the Control vs TTP groups at the time of Tilt (23.07 ± 6.26 vs 13.03 ± 10.59 mmHg2, p <0.001) and Control vs. TTN at the time of Tilt (23.07 ± 6.26 vs 13.42 ± 8.62 mmHg2, p <0.001). There was a significant reduction of SBR in all groups when comparing the Pre-Tilt vs Tilt phases (TTP: 30.22 ± 15.67 vs. 13.16 ± 6.08 ms / mmHg, p <0.0001; P <0.0001, and control: 26.75 ± 6.94 vs 12.25 ± 3.88 ms / mmHg, p <0, 0001). In addition, in the TTP and Control group, there was a significant reduction in baroreflex effectiveness index (EIB) between the Pre-Tilt vs. Tilt phases (0.50 ± 0.15 vs. 0.40 ± 0.13, p = 0.033) and (0.54 ± 0.07 vs 0.46 ± 0.16, p = 0.030) respectively. Conclusions: The findings of the present study allowed the following conclusions: 1 - HRV, with linear methods (time and frequency domains) and nonlinear (Entropy Amostral), as well as VPAS (time domain and frequency domain) and SBR did not document Pre-Tilt and Tilt phases pre-syncope (Stability of variables, after postural change until the time before prodrome or syncope appeared), statistical differences between the 2 groups of adult patients and with a highly suggestive history of SYN, As isolated disease, with positive and negative Tilt-test; 2- the Healthy control group was only different from the TTP and TTN groups in the LF parameter of the VPAS; The physiological importance of this finding is difficult to explain because there are no normal values of the mean and confidence intervals in the literature for this parameter.

A síncope neurocardiogênica (SINC) é causada por redução global e aguda do fluxo sanguíneo cerebral, subsequente à hipotensão arterial, com perda transitória da consciência e do tônus postural. Entretanto, existem divergências, quanto às repostas das variáveis cardiovasculares que antecedem o início da SINC, provocada pelo seu principal teste diagnóstico, a manobra postural passiva (MPP) ou Tilt-test. Recentemente, a possibilidade de analisar as variáveis cardiovasculares, com métodos computacionais não-invasivos, lineares (ML) e não lineares (MNL) tem permitido o estudo das entropias, da variabilidade da frequência cardíaca (VFC), da pressão arterial sistólica (VPAS) e da sensibilidade barorreflexa (SBR); estudos preliminares sugerem que a SINC poderia estar relacionada ao desequilíbrio da modulação autonômica dessas variáveis. Objetivo: usar métodos computacionais, ML e MNL, na análise da VFC, e ML na análise da VPAS e da SBR, em pacientes com história clínica de SINC, com resposta positiva ou negativa à MPP, e em indivíduos saudáveis. Métodos: Foram estudados 51 indivíduos, divididos em 3 grupos, sendo 16 positivos, 18 negativos e 17 saudáveis. Os ML usam algoritmos nos domínios do tempo (DT) e da frequência (DF) (Transformada rápida de Fourier), e os MNL usam alogarítmos da entropia amostral (SampEn) m=2 e r= 20%. Foram analisados 2 momentos: Pré-Tilt (posição supina; trechos com 1000-1500 pontos) e Tilt pré-síncope (70º de inclinação; trechos com 1000-1500 pontos; anteriores à síncope), sendo estudados os mesmos momentos para o grupo controle. Resultados: Não foram encontradas diferenças estatísticas entre os grupos TTP, TTN e Controle para os parâmetros: Idade (anos), Peso (kg), Altura (m) e IMC (kg/m2), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), frequência cardíaca (FC) e frequência respiratória. Na análise VFC por meio de ML no DT e DF, no momento Pré-Tilt e Tilt pré-síncope, não foi encontrada diferenças estatísticas 8 entre os grupos TTP, TTN e Controle para os parâmetros Mean-iRR(ms), SDiRR(ms), RMSSD(ms), LF(un) (ms2), HF(un) (ms2) e LF/HF. Comparando-se os momentos Pré-Tilt vs Tilt nos grupos TTP, TTN e Controle (análise intra-grupo) observamos diferenças significantes para as variáveis: Mean-iRR(ms), SD-iRR(ms), RMSSD(ms), LF(un), HF(un) (ms2) e LF/HF. Houve na análise da VFC por MNL (SampEn) no grupo Controle, redução significativa dos valores entre as fases Pré-Tilt vs Tilt (2,19 ± 0,40 vs 1,68 ± 0,50, p = 0,001). Houve em ambos os grupos (TTP, TTN e Controle) aumento significativo do LF-PAS, quando comparamos as fases Pré-Tilt vs Tilt (TTP: 6,72 ± 5,67 vs 13,03 ± 10,759 mmHg2, p = 0,001; TTN: 7,25 ± 4,22 vs 13,42 ± 8,62 mmHg2, p = 0,013; Controle: 5,99 ± 2,20 vs 23,07 ± 6,26 mmHg2, p < 0,0001). Além disso, evidenciaram-se maiores valores, estatisticamente significantes, quando comparamos os grupos Controle vs TTP no momento Tilt (23,07 ± 6,26 vs 13,03 ± 10,59 mmHg2, p < 0,001) e Controle vs TTN no momento Tilt (23,07 ± 6,26 vs 13,42 ± 8,62 mmHg2, p < 0,001). Houve em todos os grupos redução significativa da SBR, quando comparamos as fases Pré-Tilt vs Tilt (TTP: 30,22 ± 15,67 vs 13,16 ± 6,08 ms/mmHg, p < 0,0001; TTN: 22,98 ± 11,23 vs 11,55 ± 3,34 ms/mmHg, p < 0,0001; e Controle: 26,75 ± 6,94 vs 12,25 ± 3,88 ms/mmHg, p < 0,0001). Além disso, no grupo TTP e Controle, houve redução significativa dos valores do índice de efetividade barorreflexa (BEI) entre as fases Pré-Tilt vs Tilt (0,50 ± 0,15 vs 0,40 ± 0,13, p = 0,033) e (0,54 ± 0,07 vs 0,46 ± 0,16, p =0, 030) respectivamente. Conclusões: os achados do presente estudo permitiram as seguintes conclusões: 1- a VFC, com métodos lineares (domínios do tempo e frequência) e não lineares (Entropia Amostral), bem como a VPAS (domínios do tempo e da frequência) e a SBR não documentaram nas fases Pré-Tilt e Tilt pré- síncope (fase de estabilidade das variáveis, após a mudança postural até momento anterior ao aparecimento dos pródromos ou da síncope), diferenças estatísticas entre os 2 grupos de pacientes adultos e com história altamente sugestiva de SINC, como doença isolada, com Tilt-test positivo e negativo; 2- o grupo Controle saudável somente foi diferente dos grupos TTP e TTN no parâmetro LF da VPAS; a importância fisiológica desse achado é de difícil explicação, porque não existem na 9 literatura, para esse parâmetro, valores normais da média e dos intervalos de confiança. / Neurocardiogenic syncope (SYN) is caused by a global and acute reduction of cerebral blood flow, subsequent to hypotension, with transient loss of consciousness and postural tone. However, there are differences in the responses of the cardiovascular variables that precede the beginning of the SYN, caused by its main diagnostic test, the passive postural maneuver (PPM) or Tilt-test. Recently, the possibility of analyzing cardiovascular variables using non-invasive, linear (ML) and non-linear (MNL) computational methods has allowed the study of entropies, heart rate variability (HRV), systolic blood pressure variability (VPAS) and baroreflex sensitivity (SBR). Preliminary studies suggest that the SYN could be related to the imbalance of the autonomic modulation of these variables. Objective: To use computer methods, ML and MNL, in the analysis of HRV, and ML in the analysis of VPAS and SBR, in patients with a clinical history of SYN, with positive or negative response to PPM, and in healthy individuals. Methods: Fifty-one individuals were studied, divided into three groups: 16 positive, 18 negative and 17 healthy. MLs use algorithms in the time (DT) and frequency (DF) (Fast Fourier Transform) algorithms, and MNLs use sample entropy m (2) and r = 20%. Two moments were analyzed: Pre-Tilt (supine position, recording 1000-1500 points) and pre-syncope Tilt (70º inclination, recording 1000-1500 points, prior to syncope), being studied the same moments for the control group. Results: There were no statistical differences between the TTP, TTN and Control groups for the parameters: Age (years), Weight (kg), Height (m) and BMI (kg / m2), systolic blood pressure Diastolic (DBP), heart rate (HR) and respiratory rate. No statistical differences were found between the TTP, TTN and Control groups (in the Pre-Tilt and Tilt) for the Mean-iRR (ms), SD-iRR (ms), RMSSD (ms), LF (un) (ms2), HF (un) (ms2) and LF / HF. Comparing the Pre-Tilt vs Tilt moments in the TTP, TTN and Control groups (intra-group analysis) we observed significant differences for the variables: Mean-iRR (ms), SD-iRR (ms), RMSSD (ms), 11 LF (Un), HF (un) (ms2) and LF / HF. There was a significant reduction in the values between the Pre-Tilt vs Tilt phases (2.19 ± 0.40 vs 1.68 ± 0.50, p = 0.001) in the analysis of HRV by MNL (SampEn) in the Control group. There was a significant increase in LF-PAS in both groups (TTP, TTN and Control) when we compared the Pre-Tilt vs Tilt phases (TTP: 6.72 ± 5.67 vs 13.03 ± 10.759 mmHg2, p = 0.001; TTN: 7.25 ± 4.22 vs 13.42 ± 8.62 mmHg2, p = 0.013; Control: 5.99 ± 2.20 vs. 23.07 ± 6.26 mmHg2, p <0.0001). In addition, statistically significant higher values were found when we compared the Control vs TTP groups at the time of Tilt (23.07 ± 6.26 vs 13.03 ± 10.59 mmHg2, p <0.001) and Control vs. TTN at the time of Tilt (23.07 ± 6.26 vs 13.42 ± 8.62 mmHg2, p <0.001). There was a significant reduction of SBR in all groups when comparing the Pre-Tilt vs Tilt phases (TTP: 30.22 ± 15.67 vs. 13.16 ± 6.08 ms / mmHg, p <0.0001; P <0.0001, and control: 26.75 ± 6.94 vs 12.25 ± 3.88 ms / mmHg, p <0, 0001). In addition, in the TTP and Control group, there was a significant reduction in baroreflex effectiveness index (EIB) between the Pre-Tilt vs. Tilt phases (0.50 ± 0.15 vs. 0.40 ± 0.13, p = 0.033) and (0.54 ± 0.07 vs 0.46 ± 0.16, p = 0.030) respectively. Conclusions: The findings of the present study allowed the following conclusions: 1 - HRV, with linear methods (time and frequency domains) and nonlinear (Entropy Amostral), as well as VPAS (time domain and frequency domain) and SBR did not document Pre-Tilt and Tilt phases pre-syncope (Stability of variables, after postural change until the time before prodrome or syncope appeared), statistical differences between the 2 groups of adult patients and with a highly suggestive history of SYN, As isolated disease, with positive and negative Tilt-test; 2- the Healthy control group was only different from the TTP and TTN groups in the LF parameter of the VPAS; The physiological importance of this finding is difficult to explain because there are no normal values of the mean and confidence intervals in the literature for this parameter.

Fracture of the distal radius is one of the most frequent injuries, and it represents about 20% of all adults taken into emergency rooms. A number of studies suggest various methods to reduce the dislocation and to secure fragments of the distal radius. In this study, the Non-Bridging External Wrist Fixator System (NBX), a pre-market-released product manufactured by NUTEK Inc. was biomechanically assessed by comparing with the Universal Distal Radius System (Volar Plate Fixator: VPF), a market-released product manufactured by Stryker Co. The comparison was performed in several parameters, which were wrist motion, radial tilt angle, radial length, volar tilt angle, stiffness, and failure load. Five pairs of fresh human cadaver arms were used for this study. The wrists were tested to obtain x-ray images for 1 normal and 2 injury conditions (intact, fractured, and fixed), 2 load conditions (gravity only and torque applied), and 4 postural conditions (volar flexion, dorsiflexion, ulnar deviation, and radial deviation). These tests yielded 24 (3×2×4) x-ray images for each wrist, and the images were analyzed to obtain the data for each parameter. Although the results were not statistically significant in some conditions, NBX fixation limited wrist motion more than VPF fixation. This result can be explained not only by the difference in the ability of fixation, but also by the difference in the surgical trauma (NBX is less invasive than VPF). Furthermore, in the measurement of radial tilt angle, radial length, and volar tilt angle, NBX was more effective than VPF to reduce and secure the bone fragments of the distal radius. In destructive test, the NBX is less strong than VPF. However, NBX is strong enough to sustain the expected forces of daily activity.

abstract: Photovoltaic (PV) systems are one of the next generation's renewable energy sources for our world energy demand. PV modules are highly reliable. However, in polluted environments, over time, they will collect grime and dust. There are also limited field data studies about soiling losses on PV modules. The study showed how important it is to investigate the effect of tilt angle on soiling. The study includes two sets of mini-modules. Each set has 9 PV modules tilted at 0, 5, 10, 15, 20, 23, 30, 33 and 40°. The first set called "Cleaned" was cleaned every other day. The second set called "Soiled" was never cleaned after the first day. The short circuit current, a measure of irradiance, and module temperature was monitored and recorded every two minutes over three months (January-March 2011). The data were analyzed to investigate the effect of tilt angle on daily and monthly soiling, and hence transmitted solar insolation and energy production by PV modules. The study shows that during the period of January through March 2011 there was an average loss due to soiling of approximately 2.02% for 0° tilt angle. Modules at tilt anlges 23° and 33° also have some insolation losses but do not come close to the module at 0° tilt angle. Tilt anlge 23° has approximately 1.05% monthly insolation loss, and 33° tilt angle has an insolation loss of approximately 0.96%. The soiling effect is present at any tilt angle, but the magnitude is evident: the flatter the solar module is placed the more energy it will lose. / Dissertation/Thesis / M.S.Tech Engineering 2011

The adjustment of the vertical tilt angle of Base Station (BS) antennas, also known as Remote Electrical Tilt (RET) optimization, is a simple and efficient method of optimizing modern telecommunications networks. Reinforcement Learning (RL) is a machine learning framework that can solve complex problems like RET optimization due to its capability to learn from experience and adapt to dynamic environments. However, conventional RL methods involve trial-and-error processes which can result in short periods of poor network performance which is unacceptable to mobile network operators. This unreliability has prevented RL solutions from being deployed in real-world mobile networks. In this thesis, we formulate the RET optimization problem as a Safe Reinforcement Learning (SRL) problem and attempt to train an RL policy that can offer performance improvement guarantees with respect to an existing baseline policy. We utilize a recent SRL method called Safe Policy Improvement through Baseline Bootstrapping (SPIBB) to improve over a baseline by training an RL agent on a offline dataset of environment interactions gathered by the baseline. We evaluate our solution using a simulated environment and show that it is effective at improving a tilt update policy in a safe manner, thus providing a more reliable RL solution to the RET optimization problem and potentially enabling future real-world deployment. / Justeringen av den vertikala lutningsvinkeln hos basstationens antenner, även kallad Remote Electrical Tilt (RET) optimering, är en enkel och effektiv metod för att optimera moderna telenät. Förstärkningsinlärning är en maskininlärningsram som kan lösa komplexa problem som RET-optimering tack vare dess förmåga att lära sig av erfarenhet och anpassa sig till dynamiska miljöer. Konventionella förstärkningsinlärning metoder innebär emellertid försök och felprocesser som kan leda till korta perioder av dålig nätverksprestanda, vilket är oacceptabelt förmobilnätoperatörerna. Denna otillförlitlighet har hindrat förstärkningsinlärning lösningar från att användas i verkliga mobila nätverk. I denna hypotes formulerar vi problemet med RET-optimering som ett problem med Säker Förstärkningsinlärning(SF) och försöker utbilda en förstärkningsinlärning policy som kan erbjuda garantier för förbättrad prestanda i förhållande till en befintlig grundläggandepolicy. Vi använder en nyligen genomförd SF-metod som kallas Safe PolicyImprovement by Baseline Bootstrapping (SPIBB) för att förbättra en baslinje genom att utbilda en förstärkningsinlärning agent på en offlinedatabaserad datamängdmed miljöinteraktioner som samlats in vid baslinjen. Vi utvärderar vår lösning med hjälp av en simulerad miljö och visar att den är effektiv när det gäller att förbättra politiken för tippuppdatering på ett säkert sätt, vilket ger en mer tillförlitligförstärkningsinlärning lösning på problemet med RET-optimering och eventuellt möjliggör framtida realglobal driftsättning.

Syftet med denna studie är att undersöka skillnader mellan en geodetisk och en icke-geodetisk metod för deformationsövervakning. För att undersöka detta konstruerades två experiment som båda efterliknar deformationsförloppet för en lutande vägg. Experiment 1 simulerades med hjälp av en whiteboardtavla som roterades runt en axel, där två sensorer placerades längst med rotationsaxeln. I experiment 2 placerades tre sensorer högst upp på en plywoodvägg, som sedan lutades med passbitar. Tanken var att simuleringarna skulle efterlikna en lutande vägg som deformeras över tiden. Alla mätningarna gjordes vid två olika tidpunkter eller epoker. Den geodetiska metoden bestod av att mäta längder och vinklar med en totalstation, vilka sedan användes för att beräkna väggens lutning. Inmätningen skedde via rutnätskanning och en minstakvadratanpassning av ett plan, från vilket trigonometriska sedan funktioner användes för att beräkna väggens lutning mot zenitriktningen, vilken benämns β. Den icke-geodetiska metoden utgjordes av sensorsystemet FlatMesh, som består av tre lutningssensorer samt en 3G-gateway. Utöver detta tillhandahålls en online-monitor som sammanställer och presenterar sensorernas data. Förhållandet mellan horisontalplanet och sensorns Y-axel bedömdes motsvara totalstationens vinkel β. Experiment 1 visade på en skillnad mellan de olika metoderna på enbart 13,392 bågsekunder, vilket motsvarar 0,065 mm/m. Experiment 2 visade på en skillnad om 316,08 bågsekunder eller 1,5324 mm/m. Detta visar att sensorerna ger olika resultat beroende på hur de placeras på objektet, ur vilket slutsatsen kan dras att sensorerna inte lämpar sig för monitorering av objekt där riktningen på deformationen ska studeras. Däremot lämpar de sig för att upptäcka mycket små lutningsförändringar på objekt. / This study aims to determine the differences between a geodetic and a non-geodetic method for deformation surveying. Two experiments were performed to investigate whether the locations of the sensors on the deformation object influence the results. The first experiment used two sensors that were mounted at the object’s rotation axis. The second experiment were performed using a plywood wall that could be tilted. In this experiment, three sensors were placed on the upper parts of the board. All measurements were carried out over two epochs. The geodetic method consisted of using a total station followed by a least-squares adjustment to calculate the tilt of the wall (denoted by β). The non-geodetic method was to use the sensor system FlatMesh. This system consists of three tilt sensors and a 3G-gateway. In addition, a web monitor is included, which enables computation and presentation of the sensor data. The tilt that was determined to best resemble the total station tilt β were the tilt of the sensor’s Y-axis in relation to the horizontal plane. According to the two surveys, the following can be stated. The first experiment showed a difference between the methods of 13.392 arcseconds, which corresponds to 0.065 millimetres per meter. The second experiment resulted in a difference of 316.08 arcseconds or 1.5324 millimetres per meter. This indicates that the sensors give different results depending on how or where they are mounted. It is concluded that the sensors are not suitable for monitoring objects where the direction of the deformation is of interest. However, they are suitable for detecting very small slope changes on objects.

Para avaliação da sincope neurocardiogênica, testes ativos e passivos de mudança postural são utilizados, e verificar o comportamento da musculatura e da oscilação do corpo pode auxiliar no melhor entendimento das respostas cardiovasculares e biomecânicas. O objetivo do presente estudo foi comparar protocolos ativo e passivo de mudança postural, padronizado de 15 minutos, associado a três manobras de Valsalva intervaladas, para os testes de mudança postural ativa, Acive Standing test (AS) e passiva, Head-Up Tilt test (HUT), utilizados no diagnóstico da síncope neurocardiogênica (SNC), em relação às mudanças nos valores de frequência cardíaca, pressão arterial sistólica e diastólica, atividade eletromiográfica dos músculos reto abdominal (RA), eretores da espinha (EE), tibial anterior (TA) e gastrocnêmio porção medial (GM) bilateral, em 23 mulheres saudáveis, além de analisar o deslocamento e velocidade média do centro de pressão do corpo sobre uma plataforma de força. Verificamos alterações com relevância estatística para todas variáveis ao longo dos testes, principalmente durante o período onde as manobras de Valsalva eram realizadas, sendo estas alterações maiores durante o teste ativo, além do centro de pressão do corpo demonstrar um maior deslocamento e velocidade de movimento durante o mesmo período. Concluímos que este protocolo proposto para os dois testes causa mudanças tanto cardiovasculares quanto biomecânicas, mas que foram mais evidentes no teste de mudança postural ativa. / To evaluate the neurocardiogenic syncope (NCS), active and passive postural change tests are used and verify the muscles and body oscilation behavior´s can be helpful to better understand the cardiovascular and biomechanics responses. The aim of the present study was compare a standard 15 minute tilt test protocol associated with three Valsalva maneuver during both Active Standing (AS) and passive Head-Up tilt test (HUT). These tests are used to diagnosis of neurocardiogenic syncope (NCS). We analysed the effects of orthostatic position in relation to changes in the values of heart rate, systolic and diastolic blood pressure, electromyographic activity of the rectus abdominis (RA), erector of spinae (ES), tibialis anterior (TA) and medial gastrocnemius (MG) bilateral in 23 healthy women, and analyze the displacement and average velocity of the body\'s center of pressure on a force platform. We found changes with statistical significance for all variables during the tests, especially around the period where the Valsalva maneuvers were performed, and these major changes occurred during the active test, beyond the center of body pressure what indicates a greater movement and speed of movement during the same period. We conclude that the proposed protocol for the two tests produce both cardiovascular and biomechanical changes and these alterations were more evident in active postural test.

Hamstring injuries have a high prevalence in rugby union players. Delayed transverse abdominus activation as well as lordosis is associated with hamstring injuries. No literature regarding this relationship in rugby players could have been found. The main purpose of this study was therefore to determine the relationship between pelvic biomechanics (transverse abdominus activation and pelvis tilt) and gluteus maximus, hamstring and erector spinae activation patterns in semi–professional rugby union players as well as the relationship of the above mentioned variables and hamstring injuries. A total of 65 players voluntarily participated in this study. Pelvis tilt (left and right) was assessed by Dartfish version 4.06.0 (Dartfish, Switzerland). Transverse abdominus activation (TrA) was assessed by pressure biofeedback and the mean onset times of the left and right gluteus maximus (GM), biceps femoris (BF), semitendinosus (ST) and lumbar erector spinae (LES) was measured with electromyography (EMG). In order to determine the role of the pelvic biomechanics and activation patterns on hamstring injuries, players were retrospectively grouped in injured and uninjured groups. Differences between the groups were determined with regards to the variables determined. Activation patterns were determined by means of descriptive statistics. The between–group pelvic biomechanic (pelvic tilt and TrA) differences in the muscle (GM, LES and hamstrings) onset times were analysed by determining practical significance by means of effect sizes. An anterior pelvic tilt on the left side was observed in 64.6% of the participants and on the right side in 83.1% of the participants. TrA testing indicated that 68.4% of participants were classified with bad activation and 31.6% with good activation. No practical significant difference was found in the mean onset times of each muscle relative to the other in the normal and anterior tilted pelvis groups as well as in the bad and good TrA groups. A total of 24.6% of the rugby players previously suffered from hamstring injuries, 37.5% of those injured participants were suffering from re–injury. No practical significant between group differences were found when the injured and uninjured groups were compared with regards to anterior pelvis tilt values (d=0.061) and TrA values (d=0.189). EMG results on the right and left side of the injured and uninjured participants present a pattern of the following activation order: LES, GM, BF and lastly ST. No practical significant between groups differences were found in the onset times of the muscles relative to each other in the injured compared to uninjured groups. The conclusions that can be drawn from this study is that semi–professional rugby union players (injured and uninjured) are prone to postural defects such as anterior tilt of the pelvis and bad TrA. Anterior pelvic tilt and bad TrA may be the reason for the earlier activation of the LES and hamstrings muscles relative to the GM in the prone hip extension to stabilize the lumbar spine. These activation patterns were however not influenced by previous hamstring injuries. / Thesis (M.A. (Biokinetics))--North-West University, Potchefstroom Campus, 2011.

Hamstring injuries have a high prevalence in rugby union players. Delayed transverse abdominus activation as well as lordosis is associated with hamstring injuries. No literature regarding this relationship in rugby players could have been found. The main purpose of this study was therefore to determine the relationship between pelvic biomechanics (transverse abdominus activation and pelvis tilt) and gluteus maximus, hamstring and erector spinae activation patterns in semi–professional rugby union players as well as the relationship of the above mentioned variables and hamstring injuries. A total of 65 players voluntarily participated in this study. Pelvis tilt (left and right) was assessed by Dartfish version 4.06.0 (Dartfish, Switzerland). Transverse abdominus activation (TrA) was assessed by pressure biofeedback and the mean onset times of the left and right gluteus maximus (GM), biceps femoris (BF), semitendinosus (ST) and lumbar erector spinae (LES) was measured with electromyography (EMG). In order to determine the role of the pelvic biomechanics and activation patterns on hamstring injuries, players were retrospectively grouped in injured and uninjured groups. Differences between the groups were determined with regards to the variables determined. Activation patterns were determined by means of descriptive statistics. The between–group pelvic biomechanic (pelvic tilt and TrA) differences in the muscle (GM, LES and hamstrings) onset times were analysed by determining practical significance by means of effect sizes. An anterior pelvic tilt on the left side was observed in 64.6% of the participants and on the right side in 83.1% of the participants. TrA testing indicated that 68.4% of participants were classified with bad activation and 31.6% with good activation. No practical significant difference was found in the mean onset times of each muscle relative to the other in the normal and anterior tilted pelvis groups as well as in the bad and good TrA groups. A total of 24.6% of the rugby players previously suffered from hamstring injuries, 37.5% of those injured participants were suffering from re–injury. No practical significant between group differences were found when the injured and uninjured groups were compared with regards to anterior pelvis tilt values (d=0.061) and TrA values (d=0.189). EMG results on the right and left side of the injured and uninjured participants present a pattern of the following activation order: LES, GM, BF and lastly ST. No practical significant between groups differences were found in the onset times of the muscles relative to each other in the injured compared to uninjured groups. The conclusions that can be drawn from this study is that semi–professional rugby union players (injured and uninjured) are prone to postural defects such as anterior tilt of the pelvis and bad TrA. Anterior pelvic tilt and bad TrA may be the reason for the earlier activation of the LES and hamstrings muscles relative to the GM in the prone hip extension to stabilize the lumbar spine. These activation patterns were however not influenced by previous hamstring injuries. / Thesis (M.A. (Biokinetics))--North-West University, Potchefstroom Campus, 2011.