Grids provide an infrastructure for seamless, secure access to a globally distributed set of shared computing resources. Grid computing has reached the stage where deployments are run in production mode. In the most active Grid community, the scientific community, jobs are data and compute intensive. Scientific Grid deployments offer the opportunity for revisiting and perhaps updating traditional beliefs related to workload models and hence reevaluate traditional resource management techniques. In this thesis, we study usage patterns from a large-scale scientificGrid collaboration in high-energy physics. We focus mainly on data usage, since data is the major resource for this class of applications. We perform a detailed workload characterization which led us to propose a new data abstraction, filecule, that groups correlated files. We characterize filecules and show that they are an appropriate data granularity for resource management. In scientific applications, job scheduling and data staging are tightly coupled. The only algorithm previously proposed for this class of applications, Greedy Request Value (GRV), uses a function that assigns a relative value to a job. We wrote a cache simulator that uses the same technique of combining cache replacement with job reordering to evaluate and compare quantitatively a set of alternative solutions. These solutions are combinations of Least Recently Used (LRU) and GRV from the cache replacement space with First-Come First-Served (FCFS) and the GRV-specific job reordering from the scheduling space. Using real workload from the DZero Experiment at Fermi National Accelerator Laboratory, we measure and compare performance based on byte hit rate, cache change, job waiting time, job waiting queue length, and scheduling overhead. Based on our experimental investigations, we propose a new technique that combines LRU for cache replacement and job scheduling based onthe relative request value. This technique incurs less data transfer costs than the GRV algorithm and shorter job processing delays than FCFS. We also propose using filecules for data management to further improve the results obtained from the above LRU and GRV combination. We show that filecules can be identified in practical situations and demonstrate how the accuracy of filecule identification influences caching performance.

Organisationer idag är ständigt i rörelse, vilket ställer stora krav på att organisationer aktivt och systematiskt jobbar med kvalitetsfrågor i alla delar inom organisationen. Bakgrunden till den här studien grundar sig i den tidigare genomförda förstudien på den idrottsmedicinska rehabiliteringsmottagning Sportrehab Ab. Förstudien visade på att det finns förbättringsmöjligheter inom områdena arbetsbelastning och delaktighet, vilka är områden som är viktiga förutsättningar för en optimalt fungerande organisation. Syftet med den här studien var att vidare undersöka det av personalen upplevda brister i förhållande till arbetsbelastning och delaktighet. För att tydliggöra syftet upprättades följande tre frågeställningar: (1) Vad består de upplevda bristerna av? (2) Hur kan arbetsbelastningen förbättras? samt (3) Hur kan personalen bli mer delaktig i arbetsprocesserna? Den teoretiska bakgrunden innehåller metoder och arbetssätt inom den offensiva kvalitetsutvecklingen, ledarskapets betydelse och tidigare forskning kring arbetsbelastning och delaktighet. Datainsamlingen för rapporten är baserad på en medarbetarenkät med både kvalitativ och kvantitativ ansats. Vidare genomfördes en fokusgruppsintervju som ett komplement till medarbetarenkäten. Det insamlade materialet har analyserats med kvalitetstekniska verktyg för att på djupet reda ut potentiella orsaker till problemområdena. Resultatet visar att de bakomliggande orsakerna till både för hög arbetsbelastning och låg känsla av delaktighet kan relateras till samma problem. De anställda upplever en avsaknad av tydlighet och kommunikation gällande organisationen mål och visioner vilket medför att de inte säkert vet vad som förväntas av dem i det dagliga arbetet. Vidare visar resultatet att de anställda inte upplever förtroende och delaktighet i utvecklingsarbeten vilket kan härledas till avsaknaden av välformulerade mål och visioner. Förbättringsförslaget och tillika slutsatsen för att förbättra arbetsbelastningen och känslan av delaktighet är att ledningen tillsammans med de anställda bör upprätta en tydlig vision över vad organisationen vill uppnå. Detta innebär även förtydligande av mål på kort och lång sikt, viktiga värderingar och arbetssätt. Att skapa en gemensam framtidsbild kan leda till en ökad delaktighetskänsla. Vidare kan kravbilden tydliggöras genom att ledningen tydligt förankrat vad som förväntas av de anställda i relation till organisationens policy, värderingar och vision. Något som i slutändan kan leda till att den för höga upplevda arbetsbelastningen kan förbättras då de anställda tydligt vet vad som förväntas. Nyckelord: arbetsbelastning, delaktighet, förbättring, kommunikation, ledarskap / The customer’s needs are constantly changing which means that organizations today needs to be adaptive. This study is based on a pilot study at Sportrehab AB. The pilot study showed that there was a possibility of improvement in the areas of workload and participation. The purpose of this study was to further investigate the shortcomings experienced by the employees in relation to workload and participation. The data collection for the report is based on an employee survey and a focus group interview. The data was analyzed with quality management tools. The result showed that the underlying cause could be related to the same problem. The employees experienced a lack of clarity and communication regarding the organization’s goals and visions. Furthermore, the results showed that the employees did not experience trust and participation in development work, which can be deduced from the lack of well-formulated goals and visions. The proposal for improving the workload and the feeling of participation is that the management together with the employees need to establish a clear vision of what the organization wants to achieve. Creating a collective vision of the future can lead to an increased sense of participation. Furthermore, the requirements can be made clear by the fact that the management clearly establishes what is expected of the employees in relation to the organization’s policy, values and vision. Something that ultimately can lead to an improvement in the perceived workload as the employees clearly know what is expected. Keywords: communication, improvement, leadership, participation, workload

Les environnements virtuels (EVs) sont de plus en plus utilisés dans le domaine de la recherche et de la clinique avec pour avantage que chaque environnement peut être adapté au besoin du participant mais avec pour inconvénient que la pluralité des variables mesurées lors des tests virtuels rend la performance du sujet de plus en plus difficile à expertiser. L’objectif de la thèse est de proposer une approche permettant de qualifier, de façon la plus pertinente possible, la performance du participant dans un EV en tentant de comprendre la charge mentale associée à chaque technique d’interaction et comment celle-ci peut venir influencer la performance du participant. Cinquante-trois participants ont réalisé des tâches dans un EV avec une des cinq techniques d’interaction disponible : la souris, le gamepad, le Razer Hydra, le Razer Hydra avec un tracking de tête et le Razer Hydra avec un casque de RV. Ils étaient attribués à une des deux conditions de difficulté de la tâche : une facile et une difficile avec des tâches additionnelles. Le rythme cardiaque du participant était enregistré et ceux-ci ont renseigné des questionnaires de charge mentale, présence et cybermalaise. L’expérimentation a permis de mettre en avant que la différence de charge mentale entre les différentes techniques d’interaction est faible et que celle-ci se manifeste plus sensiblement lorsque les techniques sont regroupées par leurs caractéristiques. Ainsi les techniques avec une sélection en 3D et un steering effectué par les mouvements de la tête demande plus de charge mentale. Le degré d’expertise avec l’utilisation d’une technique d’interaction n’est pas lié à une modulation de la charge mentale. Cependant les utilisateurs qualifiés d’experts sont plus à même d’explorer le VMT que les novices. De plus, la charge mentale est plus perçue dans les conditions où la difficulté de la tâche est faible alors que dans le cas où la difficulté de la tâche est élevée, ce sont les problèmes d’utilisabilité des techniques d’interaction qui s’expriment. Les participants qui ont une charge mentale élevée ont un score plus faible que les participants qui ont une faible charge mentale, en particulier lors des tâches qui réclament des fonctions cognitives variées. / Virtual environments (Ves) can be modulated and be adapted to the need of each user but the several variables used during cognitiv assessment during virtual tests give the user’s performance uneasy to expertise. The objective of the thesis is to propose an approach to qualify user performance taking acount of his/her workload during the task realization. Fifty-three participants realiazed tasks in a VE with one of five interaction technique: mouse, gamepad, Razer Hydra, Razer Hydra and head tracking and Razer Hydra and HMD. They participate in one of the two conditions: the easy one or the more difficult with additionnal tasks. Heart rate, workload, presence and cybersickness were measured. Results showed that there is only a weak difference of workload accross the several interaction technique and the difference is stronger when interaction technique are grouped according their similiarities. Interaction with 3D selection and with head steering ask for more workload. User habilities with the use of an interaction technique is not related to workload but experts are more likely to explore the VE. What’s more the perceived workload is higher in easy condition whereas usability issues are perceived higher in hard condition. Users with high workload have lower score than those with low workload especially for tasks with high cognitiv demand.

Power-performance efficiency has become a central focus that is challenging in heterogeneous processing platforms as the power constraints have to be established without hindering the high performance. In this dissertation, a framework for optimizing the power and performance of GPUs in the context of general-purpose computing in GPUs (GPGPU) is proposed. To optimize the leakage power of caches in GPUs, we dynamically switch the L1 and L2 caches into low power modes during periods of inactivity to reduce leakage power. The L1 cache can be put into a low-leakage (sleep) state when a processing unit is stalled due to no ready threads to be scheduled and the L2 can be put into sleep state during its idle period when there is no memory request. The sleep mode is state-retentive, which obviates the necessity to flush the caches after they are woken up, thereby, avoiding any performance degradation. Experimental results indicate that this technique can reduce the leakage power by 52% on average. Further, to improve performance, we redistribute the GPGPU workload across the computing units of the GPU during application execution. The fundamental idea is to monitor the workload on each multi-processing unit and redistribute it by having a portion of its unfinished threads executed in a neighboring multi-processing unit. Experimental results show this technique improves the performance of the GPGPU workload by 15.7%. Finally, to improve both performance and dynamic power of GPUs, we propose two dynamic frequency scaling (DFS) techniques implemented on CPU host threads, one of which is motivated by the significance of the pipeline stalls during GPGPU execution. It applies a feedback controlling algorithm, Proportional-Integral-Derivative (PID), to regulate the frequency of parallel processors and memory channels based on the occupancy of the memory buffering queues. The other technique targets on maximizing the average throughput of all parallel processors under the dynamic power constraints. We formalize this target as a linear programming problem and solve it on the runtime. According to the simulation results, the first technique achieves more than 22% power savings with a 4% improvement in performance and the second technique saves 11% power consumption with 9% performance improvement. The contributions of this dissertation represent a significant advancement in the quest for improving performance and reducing energy consumption of GPGPU.

As knowledge workers in post-compulsory education, contemporary women Technical and Further Education (TAFE) teachers help train Australia's skilled workforce. Their work is instrumental in government strategies to enhance national competitiveness in global markets. Yet their contributions to Australian education have been neglected, their work/lives have remained unremarked, and their voices unheard. My research focus, therefore, was to examine how these teachers fared in recent, dramatic restructurings of the TAFE sector, part of the national Vocational Education and Training (VET) system, and to look particularly at how they responded to TAFE and other work/life changes / thesis (PhD)--University of South Australia, 2002.

The aim of the present research was to examine the impact of mental workload on conflict resolution decision making in air traffic control (ATC). While previous studies have examined the effect of workload on performance (Averty, 2004; Kopardekar & Magyrits, 2002) and conflict detection (Mogford, 1997; Seamster, Redding, Cannon, Ryder & Purcell, 1993), limited research examines the effect of workload on conflict resolution decisions. The aim of the first study was to gain an initial understanding of how controllers manage their airspace. Results demonstrated that controllers scan repetitively, in a clockwise and top-bottom pattern; group aircraft with similar characteristics and use at least five lateral and eight vertical conflict resolution heuristics. Study two examined the effect of conflict type on conflict resolution under different levels of workload. Under moderate workload controllers used a mix of solutions, while under high workload, solutions became more conservative. Study three examined the effect of other contextual factors on conflict resolution. Results again suggested conflict type affects conflict resolution decisions and also that other contextual parameters, such as aircraft performance may play a role in solution preferences. Study four examined the effect of workload on conflict resolution using a realistic ATC task. Workload not only impacted on controllers’ performance scores, but interacted with conflict type to determine whether an efficient solution was preferred over a less efficient solution. This research identifies some of the heuristics experts use when competing priorities are present and provides an understanding of how conflict type, contextual factors and workload affect decisions. Findings contribute to the naturalistic decision making (NDM) literature by demonstrating how the situation can influence decision making.

<p>Arbetet i ett fängelse är annorlunda mot de flesta andra arbetsplatser. Det är en isolerad arbetsplats med lite insyn från det övriga samhället, samt i hög grad styrt av lagar och förordningar. Det framgick i forskning att fängelseanställda har högre arbetsengagemang då de upplever sin arbetsplats som rättvis, och då de får stöd från arbetsledare. Studien ämnade undersöka om det fanns ett samband mellan konflikten mellan arbete och familj och arbetsengagemang, samt om det fanns samband mellan arbetsmiljö (rättvisa, kontroll i arbetet och arbetsbörda) och arbetsengagemang. Undersökningen hade en svarsfrekvens på 15 % vilket påverkade studiens tillförlitlighet. Den visade ett samband mellan rättvisa och arbetsengagenmang. Inget samband hittades hos konflikten mellan arbete och familj och arbetsengagemang.</p>

<p>The goal of this thesis has been to study the behaviour of the closed loop driver-vehicle-environment in simulation and to find parameters of the synthetic vehicle model, which minimise certain optimisation criteria. A method of optimising parameters using genetic algorithms has been implemented and has proven to work well. Two different driving strategies have been tried in the optimisation of an ISO lane-change maneouvre. The first approach has simulated a beginner driver and his or her behaviour. The second approach simulates an experienced driver and also the possibility of driver adaption to different vehicle types. The implemented driver model has shown to be sufficient to describe the driver's behaviour during lateral maneouvres. A parameter set which minimises the lateral acceleration response on steering wheel angle has proven to be the optimum. This includes a small steering wheel ratio, and a small but positive under steer gradient. The driver has demonstrated the ability to adapt to different vehicles, and therefore different parameter sets, describing the driver, should be used for different problems.</p>

<p> </p><p>Stress och symtom på stress, ökar inom hela den svenska befolkningen. I synnerhet har stressen ökat hos hälso- och sjukvårdens professioner. Stressrelaterade sjukdomar som hjärtkärlsjukdomar och depression leder till sjukskrivningar. Sjuksköterskan löper hög risk att utsättas för hög stress på arbetsplatsen och stressens påverkan på sjuksköterskan står i relation till hur hon värderar situationen samt vilka hanteringsmöjligheter hon ser. Ett ineffektivt hanteringsmönster kan få svåra konsekvenser för hälsa och socialt liv. En litteraturstudie sammanställdes med syfte att identifiera stressfyllda situationer i sjuksköterskans arbetssituation samt hur dessa värderas och hanteras med hjälp av olika copingstrategier. Resultatet visar att arbetsbelastning är den största källan till stress och påverkas av underbemanning och ökande antal uppgifter för sjuksköterskan. Ju mer stress sjuksköterskan utsätts för desto mindre används problemfokuserade hanteringsmetoder. Konflikter ökar stressen på arbetsplatsen samtidigt som kollegialt stöd används för att hantera stress. Sjuksköterskan behöver få ökad kunskap om stress och stresshantering. Därtill krävs ökad kunskap och förståelse från ledningen kring den stress sjuksköterskan utsätts för. Vidare forskning bör fokusera stressupplevelser hos sjuksköterskor inom specifika områden i sjukvården.</p> / <p> </p><p>Stress and the symptoms of stress are continuing to increase among the total Swedish population. This is particularly visible in healthcare-professions. Stress related diseases like coronary disease and depression leads to increasing numbers of sick-leaves. The nurse has a high risk of experiencing stress in the workplace and the effects of stress on the nurse stands in relation to her appraisal of the situation and the opportunities of coping visible to her. An ineffective coping pattern can result in severe consequences both in health and in social life. A literature review was conducted with the aim to identify stressful events in the nurse’s workplace as well as the appraisal of the same and coping strategies used. Results indicate that workload is the main-source of stress and is affected by understaffing and increases in the number of nursing-tasks. The more stress the nurse is exposed to, the less problem-focused coping is used. Conflicts increase the stress at the work-place at the same time as support from colleagues is used as a copingstrategy. Nurses need to widen their knowledge concerning stress and coping. There is also a need for more knowledge and understanding among managers, of stressful situations experienced by nurses. Implications for further research should focus on stressful experiences among nurses in specific areas in healthcare.</p>

Thesis (Ph.D.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 206-219.