Anxiety and worry have been related to exaggerated cardiovascular reactivity and delayed recovery to laboratory stressors, and to increased risk of cardiovascular disease. This study examined cardiovascular responses in high and low worriers to a range of laboratory tasks. The aim of this study was to determine if there is a task-specific relationship between worry and aberrant cardiovascular responding. Forty-one undergraduate women were recruited online to form low and high worry groups by use of the Penn State Worry Questionnaire. Four common laboratory tasks and two conditions designed to elicit worry and relaxation were used: hand cold pressor, mental arithmetic, orthostatic position, supine position, worry imagery, and relaxation imagery. Heart rate, heart rate variability, impedance cardiography, and blood pressure indices were collected to assess task reactivity and recovery, particularly in relation to autonomic nervous system activity. The high worry group had significantly higher heart rates throughout the study. The low worry group presented increased cardiovascular recovery to various tasks. The high worry group during task and post-task periods also increased parasympathetic withdrawal and sympathetic activation. The results of the study suggest that high worriers have decreased vagal control of the heart. The implications of this study suggest a potential link between the post-task period in high worriers and cardiovascular disease. Further research is recommended. / Master of Science

In modern data analysis, privacy is a critical concern when dealing with user-related databases. Ensuring user anonymity while extracting meaningful correlations from the data poses a significant challenge, especially when side information can potentially enable de-anonymization. This dissertation explores the standard information-theoretic problems in the correlated databases model. We define a "database" as a simple probabilistic model that contains a random feature vector for each user, with user labels shuffled to ensure anonymity. We first investigate correlation detection between two databases, formulating it as a composite binary hypothesis testing problem. Under the alternate hypothesis, there exists an unknown permutation that aligns users in the first database with those in the second, thereby matching correlated entries. The null hypothesis assumes that the databases are independent, with no such alignment. For the special case of Gaussian feature vectors, we derive both upper and lower bounds on the correlation required to achieve or fail to achieve this statistical problem. Our results are tight up to a constant factor when the feature length exceeds the number of users. Regarding our achievability boundary, we draw connections to the user labeling recovery problem, highlighting significant parallels and insights. Additionally, for the two databases model, we initially examine the potential gaps in the statistical analysis conducted thus far for the large number of users regime by drawing parallels with similar problems in the literature. Motivated by these comparisons, we propose a novel approach to address the detection problem, focusing on the hidden permutation structure and intricate dependencies characterizing these relationships. Building on our research, we present a comprehensive model for handling multiple correlated databases. In this multiple-databases setting, we address another fundamental information-theoretic problem: user label recovery. We evaluate the performance of the typicality matching estimator in relation to the asymptotic behavior of feature length, demonstrating an impossibility result that holds up to a multiplicative constant factor. This exploration into multiple databases not only broadens the scope of our study but also underscores the complexity and richness of correlation detection in a more generalized framework. In conclusion, we summarize the statistical gaps identified in our findings, exploring their possible origins. We also discuss the limitations of our simple probabilistic model and propose strategies to address them. Finally, we outline potential future research directions, including the information-theoretic problem of change detection, which remains an open area of significant interest.

Defensive hostility has been attributed as an early risk factor of coronary heart disease. The autonomic characteristics of high defensive, high hostile (HD) and low defensive, high hostile (LD) men and women were assessed with a variety of cardiovascular (CV) measures. Reactivity and recovery to an active laboratory stressor (video game, VG) and a passive laboratory stressor (hand cold pressor, CP) of 15 HD men, 16 LD men, 16 HD women, and 16 LD women were recorded. It was predicted that the CV patterning associated with the HD participants would display more sympathetic and less vagal control as well as the least pronounced recovery from the stressors in comparison to LD participants. Results revealed differential CV responses to the lab tasks by group. HD women displayed consistently high levels of low frequency power heart rate variability (HRV) during baseline and across conditions. HD men exhibited significantly pronounced heart rate reactivity and reduced high frequency power HRV to the CP task in comparison to LD men. Interestingly, LD women displayed weaker blood pressure (BP) recovery to the VG in comparison to HD women, whereas the opposite pattern was observed in BP recovery to the CP. These results suggest that defensiveness and sex may moderate the CV reactivity and recovery to different types of stressors in hostile participants. / Master of Science

Containers are an alternative to virtual machines rapidly increasing in popularity due to their minimal overhead. To help facilitate their adoption, containers use management systems with central registries to store and distribute container images. However, these registries rely on other, preexisting services to provide load balancing and storage, which limits their scalability. This thesis introduces a new registry design for Docker, the most prevalent container management system. The new design coalesces all the services into a single, highly scalable, registry. By increasing the scalability of the registry, the new design greatly decreases the distribution time for container images. This work also describes a new Docker registry benchmarking tool, the trace player, that uses real Docker registry workload traces to test the performance of new registry designs and setups. / Master of Science / Cloud services allow many different web applications to run on shared machines. The applications can be owned by a variety of customers to provide many different types of services. Because these applications are owned by different customers, they need to be isolated to ensure the users’ privacy and security. Containers are one technology that can provide isolation to the applications on a single machine, and they are rapidly gaining popularity as they incur less overhead on the applications that use them. This means the applications will run faster with the same isolation guarantees as other isolation technologies. Containers also allow the cloud provider to run more applications on a single machine, letting them serve more customers. Docker is by far the most popular container management system on the market. It provides a registry service for containerized application storage and distribution. Users can store snapshots of their applications on the registry, and then use the snapshots to run multiple copies of the application on different machines. As more and more users use the registry service, the registry becomes slower, making it take longer for users to pull their applications from the registry. This will increase the start time of their application, making them harder to scale out their application to more machines to accommodate more customers of their services. This work creates a new registry design that will allow the registry to handle more users, and allow them to retrieve their applications even faster than what’s currently possible. This will allow them to more rapidly scale their applications out to more machines to handle more customers. The customers, in turn, will have a better experience.

Rugby union training and match-play are physiologically and psychologically very demanding and the execution of post-exercise recovery techniques in players‟ training regimes are therefore necessary to aid in the physiological and psychological restoration of athletes‟ training and performance abilities. However, despite numerous research findings with regard to the efficiency of especially cold water immersion (CWI), contrast water therapy (CWT) and passive recovery (PAR) on the physiological recovery of athletes post-exercise, only a limited number of researchers have examined the possible benefits of these recovery techniques on the psychological recovery of athletes. Consequently, the objectives of this study were firstly to determine the difference between the acute effects of CWI and PAR on the mood states (anger, confusion, depression, fatigue, tension and vigour) and the energy index of university-level rugby players post-exercise, and secondly to determine the difference between the acute effects of CWT and PAR on the mood states and the energy index of university-level rugby players post-exercise. Twenty-three under/21 university-level rugby players (age 20.1 ± 0.41) of a South African university club voluntarily participated in this study. The players were randomly divided into a control group (PAR) and an experimental group (CWI or CWT). Participants completed the Stellenbosch Mood Scale (STEMS) questionnaire over four time periods: during the morning (baseline); before completion of a high-intensity anaerobic training session (pre-anaerobic); after completion of a high-intensity anaerobic training session of 15 minutes (post-anaerobic) and after completion of a 20-minute recovery session (post-recovery). Blood lactate measurements were also taken 3 minutes after completion of the anaerobic session. To test the first objective, the experimental group completed 20 minutes of CWI, whereas the control group recovered passively for the same time period. For the purpose of the second objective, the experimental group completed 20 minutes of CWT, whereas the control group recovered passively for the same time period. Although the dependent t-test and effect size results of the first study showed that the experimental group (CWI) experienced no significant changes from the pre-anaerobic to post-recovery time periods for any of the STEMS subscale values or the energy index, the control group‟s (PAR) confusion, depression and tension subscale values decreased significantly (p < 0.05) from the pre-anaerobic to the post-recovery time periods. Despite these changes, the one-way between groups‟ analysis of covariance (ANCOVA) revealed no significant differences, except for the vigour subscale, which obtained a medium practical significant increase [Effect size (ES) = 0.65)] for the experimental compared to the control group when the pre-anaerobic and post-recovery changes in the STEMS subscale and energy index values between groups were compared. The dependent t-test and effect size results of the second study indicated that neither the experimental (CWT) nor the control group (PAR) experienced significant changes from pre-anaerobic to post-recovery time periods for any of the STEMS subscale or energy index values. However, the ANCOVA revealed that the experimental group showed a statistically significant higher value for the vigour subscale (p = 0.05) when compared to the control group. In addition, for vigour, the experimental group recorded a large practically significant higher value (ES = 0.92) for vigour as well as a large practically significant lower value for fatigue (ES = 0.88) compared to the control group. To the researchers‟ knowledge, this was the first study to compare the efficacy of CWI, CWT and PAR on the recovery of athletes‟ STEMS-derived mood states. Previous studies mainly focused on perceived fatigue, muscle soreness, Profile of Mood States- (POMS-) derived mood states and rate of perceived exertion (RPE) when investigating psychological recovery in athletes. However, despite the uniqueness of this study, results showed that when compared to PAR, CWI and CWT did not aid more in the acute psychological recovery of university-level rugby players‟ mood states. Vigour was the only mood state subscale for which both the CWI and CWT groups showed a practical or statistically significant higher value compared to the PAR group, while fatigue obtained a higher practical significant value for only CWT when compared to PAR. Therefore, although the study results support the use of CWI and CWT to alleviate vigour and fatigue post-exercise when compared to PAR, further research is required to gain understanding into the psychological mechanisms of both CWT and PAR, with an emphasis on knowledge and information in recovery of mood disturbances after exercise. / MSc (Sport Science), North-West University, Potchefstroom Campus, 2015

Rugby union training and match-play are physiologically and psychologically very demanding and the execution of post-exercise recovery techniques in players‟ training regimes are therefore necessary to aid in the physiological and psychological restoration of athletes‟ training and performance abilities. However, despite numerous research findings with regard to the efficiency of especially cold water immersion (CWI), contrast water therapy (CWT) and passive recovery (PAR) on the physiological recovery of athletes post-exercise, only a limited number of researchers have examined the possible benefits of these recovery techniques on the psychological recovery of athletes. Consequently, the objectives of this study were firstly to determine the difference between the acute effects of CWI and PAR on the mood states (anger, confusion, depression, fatigue, tension and vigour) and the energy index of university-level rugby players post-exercise, and secondly to determine the difference between the acute effects of CWT and PAR on the mood states and the energy index of university-level rugby players post-exercise. Twenty-three under/21 university-level rugby players (age 20.1 ± 0.41) of a South African university club voluntarily participated in this study. The players were randomly divided into a control group (PAR) and an experimental group (CWI or CWT). Participants completed the Stellenbosch Mood Scale (STEMS) questionnaire over four time periods: during the morning (baseline); before completion of a high-intensity anaerobic training session (pre-anaerobic); after completion of a high-intensity anaerobic training session of 15 minutes (post-anaerobic) and after completion of a 20-minute recovery session (post-recovery). Blood lactate measurements were also taken 3 minutes after completion of the anaerobic session. To test the first objective, the experimental group completed 20 minutes of CWI, whereas the control group recovered passively for the same time period. For the purpose of the second objective, the experimental group completed 20 minutes of CWT, whereas the control group recovered passively for the same time period. Although the dependent t-test and effect size results of the first study showed that the experimental group (CWI) experienced no significant changes from the pre-anaerobic to post-recovery time periods for any of the STEMS subscale values or the energy index, the control group‟s (PAR) confusion, depression and tension subscale values decreased significantly (p < 0.05) from the pre-anaerobic to the post-recovery time periods. Despite these changes, the one-way between groups‟ analysis of covariance (ANCOVA) revealed no significant differences, except for the vigour subscale, which obtained a medium practical significant increase [Effect size (ES) = 0.65)] for the experimental compared to the control group when the pre-anaerobic and post-recovery changes in the STEMS subscale and energy index values between groups were compared. The dependent t-test and effect size results of the second study indicated that neither the experimental (CWT) nor the control group (PAR) experienced significant changes from pre-anaerobic to post-recovery time periods for any of the STEMS subscale or energy index values. However, the ANCOVA revealed that the experimental group showed a statistically significant higher value for the vigour subscale (p = 0.05) when compared to the control group. In addition, for vigour, the experimental group recorded a large practically significant higher value (ES = 0.92) for vigour as well as a large practically significant lower value for fatigue (ES = 0.88) compared to the control group. To the researchers‟ knowledge, this was the first study to compare the efficacy of CWI, CWT and PAR on the recovery of athletes‟ STEMS-derived mood states. Previous studies mainly focused on perceived fatigue, muscle soreness, Profile of Mood States- (POMS-) derived mood states and rate of perceived exertion (RPE) when investigating psychological recovery in athletes. However, despite the uniqueness of this study, results showed that when compared to PAR, CWI and CWT did not aid more in the acute psychological recovery of university-level rugby players‟ mood states. Vigour was the only mood state subscale for which both the CWI and CWT groups showed a practical or statistically significant higher value compared to the PAR group, while fatigue obtained a higher practical significant value for only CWT when compared to PAR. Therefore, although the study results support the use of CWI and CWT to alleviate vigour and fatigue post-exercise when compared to PAR, further research is required to gain understanding into the psychological mechanisms of both CWT and PAR, with an emphasis on knowledge and information in recovery of mood disturbances after exercise. / MSc (Sport Science), North-West University, Potchefstroom Campus, 2015

Heating, ventilation and air-conditioning (HVAC) systems are widely distributed over the world due to their capacity to adjust some local climate parameters, like temperature, relative humidity, cleanliness and distribution of the air until the desired levels verified in a hypothetical ideal climate. A review of buildings’ energy usage in developed countries shows that in the present this energy service is responsible for a portion of about 20% of the final energy usage on them, increasing up to 50% in hot-humid countries. In order to decrease this value, more and more different heat recovery systems have been developed and implemented over the last decades. Nowadays it is mandatory to install one of these units when the design conditions are above the limit values to avoid such components, what is possible to verify mostly in non-residential buildings. Each one of those units has its own performance and working characteristics that turns it more indicated to make part of a certain ventilation system in particular. Air-to-air energy recovery ventilation is based on the heat recovery transfer (latent and/or sensible) from the flow at high temperature to the flow at lower temperature, pre-warming the outdoor supply air (in the case of the winter). Therefore, it is important to understand in which concept those units have to be used and more important than that, how they work, helping to visualize their final effect on the HVAC system. The major aims of this study were to investigate the actual performance of the heat recovery units for LB20 and LB21 in building 99 at the University of Gävle and make some suggestions that could enhance their actual efficiency. Furthermore, the energy transfer rates associated to the heat recovery units were calculated in order to understand the impact of such components in the overall HVAC system as also the possible financial opportunity by making small improvements in the same units. To assess the system, values of temperature and flow (among others) were collected in the air stream and in the ethylene-glycol solution that works as heat transfer medium between air streams and is  enclosed in pipes that make part of the actual run-around heat recovery units. After some calculations, it was obtained that for the coldest day of measurements, the sensible effectiveness was 42% in LB20 and 47% in LB21, changing to 44% and 43% in the warmer day, respectively. The actual heat transfer representing the savings in the supply air stream is higher on the coldest day, with values of 46 kW in LB20 and 84 kW in LB21, justifying the existence of the heat recovery units even if those ones imply the use of hydraulic pumps to ensure the loop. The low values of efficiency have shown that both heat recovery units are working below the desired performance similarly to the pumps that make part of the same units.  This fact, together with the degradation of the units that is possible to observe in the local, indicates that a complete cleaning (followed by a change of the heat transfer medium) of the heat recovery units and a new adjustment of pumps and valves for the further changes, are necessary. By doing this, it is expected to see the year average sensible effectiveness increase to close to 45% in both units which will lead to a potential economic saving of around 41 000 SEK per year.

Quantitative modelling of reverse logistics networks and product recovery have been the focus of many research activities in the past few decades. Interest to these models are mostly due to the complexity of reverse logistics networks that necessitates further analysis with the help of mathematical models. In comparison to the traditional forward logistics networks, reverse logistics networks have to deal with the quality of returns issues as well as a high degree of uncertainty in return flow. Additionally, a variety of recovery routes, such as reuse, repair, remanufacturing and recycling, exist. The decision making for utilising these routes requires the quality of returns and uncertainty of return flow to be considered. In this research, integrated forward and reverse logistics networks with repair, remanufacturing and disposal routes are considered. Returns are assumed to be classified based on their quality in ordinal quality levels and quality thresholds are used to split the returned products into repairable, remanufacturable and disposable returns. Fuzzy numbers are used to model the uncertainty in demand and return quantities of different quality levels. Setup costs, non-stationary demand and return quantities, and different lead times have been considered. To facilitate decision making in such networks, a two phase optimisation model is proposed. Given quality thresholds as parameters, the decision variables including the quantities of products being sent to repair, disassembly and disposal, components to be procured and products to be repaired, disassembled or produced for each time period within the time horizon are determined using a fuzzy optimisation model. A sensitivity analysis of the fuzzy optimisation model is carried out on the network parameters including quantity of returned products, unit repair an disassembly costs and procurement, production, disassembly and repair setup costs. A fuzzy controller is proposed to determine quality thresholds based on some ratios of the reverse logistics network parameters including repair to new unit cost, disassembly to new unit cost, repair to disassembly setup, disassembly to procurement setup and return to demand ratios. Fuzzy controller’s sensitivity is also examined in relation to parameters such as average repair and disassembly costs, repair, disassembly, production and procurement setup costs and return to demand ratio. Finally, a genetic fuzzy method is developed to tune the fuzzy controller and improve its rule base. The rule base obtained and the results of sensitivity analyses are utilised to gain better managerial insights into these reverse logistics networks.

Denna studie handlar om den rättspsykiatriska personalens erfarenheter av patienternas återhämtningsprocesser. Studien syftar till att försöka belysa de erfarenheter som personalen besitter, med fokus på återhämtning. Studien bygger på en kvalitativ metod och består av intervjuer som gjorts med personal som arbetar inom en av Sveriges rättspsykiatriska vårdkliniker. Resultatet visar att personalen har erfarenheter av att det finns både gynnsamma och hindrande faktorer som påverkar patienternas återhämtning. Resultatet visar även att relationerna mellan personalen och patienten är en viktig förutsättning för patienternas återhämtning. / This study is about the forensic psychiatry staff experiences of patients ' recovery processes. The study aims to highlight the experience staff possesses. The study is based on a qualitative approach and consists of interviews conducted with staff who works in one of the forensic psychiatric care clinics. The study is based on a qualitative approach and consists of interviews conducted with personnel working in one of the forensic psychiatric care clinics. The results show that the staffs have experience of both beneficial and hindering factors that influence patients ' recovery. The result also shows that relations between staff and patient are essential for patients ' recovery.

<p>Research has shown that companies encourage customers to complain and gather huge amounts of service recovery information, although most of this information isn´t used by the companies. Our purpose with this thesis is to explore what determines the filtering of service recovery feedback, and if possible to identify its underlying reasons. This was accomplished through a qualitative case study at Handelsbanken Uppsala City. Empirical material was mainly collected through interviews with the office manager, frontline employees, and the regional complaints manager. When analyzing the empirical material Tax and Brown model of service recovery was used as an analytical framework.</p><p>The analysis shows that the employees at Handelsbanken Uppsala city aren’t controlled by many guidelines and policies; instead emphasis is put on the independence, trust, and responsibility of each individual employee. This is probably due to the decentralized organization of Handelsbanken and the belief in the employee’s capability to better understand what is of importance to filter, due to their close interaction with customers.</p>