9,994 research outputs found

    Integration of Cost andWork Breakdown Structures in the Management of Construction Projects

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    Scope management allows project managers to react when a project underperforms regarding schedule, budget, and/or quality at the execution stage. Scope management can also minimize project changes and budget omissions, as well as improve the accuracy of project cost estimates and risk responses. For scope management to be effective, though, it needs to rely on a robust work breakdown structure (WBS). A robust WBS hierarchically and faithfully reflects all project tasks and work packages so that projects are easier to manage. If done properly, the WBS also allows meeting the project objectives while delivering the project on time, on budget, and with the required quality. This paper analyzes whether the integration of a cost breakdown structure (CBS) can lead to the generation of more robust WBSs in construction projects. Over the last years, some international organizations have standardized and harmonized different cost classification systems (e.g., ISO 12006-2, ISO 81346-12, OmniClass, CoClass, UniClass). These cost databases have also been introduced into building information modeling (BIM) frameworks. We hypothesize that in BIM environments, if these CBSs are used to generate the project WBS, several advantages are gained such as sharper project definition. This enhanced project definition reduces project contradictions at both planning and execution stages, anticipates potential schedule and budget deviations, improves resource allocation, and overall it allows a better response to potential project risks. The hypothesis that the use of CBSs can generate more robust WBSs is tested by the response analysis of a questionnaire survey distributed among construction practitioners and project managers. By means of structural equation modeling (SEM), the correlation (agreement) and perception differences between two 250-respondent subsamples (technical project staff vs. project management staff) are also discussed. Results of this research support the use of CBSs by construction professionals as a basis to generate WBSs for enhanced project management (PM)

    A semiotic and usability analysis of Diegetic UI: Metro - Last Light

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    A narrativa de um jogo é um dos principais componentes da criação da imersão do jogador. À medida que a tecnologia avança, novas ferramentas possibilitam aos desenvolvedores de jogos a criação mundos digitais cada vez mais complexos. A Interface de Usuário tem um papel crucial, fornecendo ao jogador feedback sobre os vários atributos e mecânicas do jogo. Alguns jogos buscaram integrar a interface tradicionalmente intrusiva dentro da narrativa e da arte do jogo, por meio das Interfaces Diegética. O objetivo desta tese é entender como a integração da interface na arte e na narrativa do jogo - criando o que é chamado de Interface Diegética - pode aumentar a sensação de imersão do jogador. Para identificar os processos através dos quais o significado é observado na Interface Diegética, contamos com a Semiótica Discursiva proposta por A.J. Greimas e para avaliar se essas representações Diegéticas afetam a Usabilidade, empregamos as Heurísticas proposta por Desurvire e Wiberg. A metodologia mostrou resultados interessantes acerca das relações entre Interface e Narrativa, bem como o impacto de Usabilidade derivado de tal implementação no jogo Metro: Last Light.A Game’s narrative is one of the key components of creating Player immersion. As technology advances, game developers increase their toolset for creating increasingly complex game worlds. The UI has a crucial role, providing the Player with feedback about the various attributes and mechanics within the game. Some games sought to integrate the traditionally intrusive UI within the game’s narrative and art, by the means of Diegetic UI. The goal of this Thesis is to understand how integrating the User Interface into the game’s art and narrative – creating what is called a Diegetic Interface – can increase the feeling of immersion for the Player. To identify the processes through which meaning is observed in Diegetic UI, we’ve relied on the Discoursive Semiotics proposed by A.J. Greimas and to assess if these Diegetic Representations affect usability, we employed Game Usability Heuristics proposed by Desurvire and Wiberg. The methodology proved to yield interesting results regarding the relationships between UI and Narrative as well as the Usability impact derived from such implementation in the game Metro: Last Light

    A rapid simulation modelling process for novice software process simulation modellers

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    In recent years, simulation modelling of software processes have has promoted as a tool to understand, study, control, and manage software development processes. Claims have been made that simulation models are useful and effective at gaining insight into software development processes. However, little has been said about the process of developing simulation models for software engineering problems. Simulation modelling is a young discipline in software engineering. Consequently, many number software process simulation modellers are thought to be novices. The simulation modelling process is believed to have had an effect on the quality of a simulation study. Although there is a body of knowledge available in the general simulation literature to guide and educate novices, the software process simulation modelling literature lacks information for novice software process simulation modellers to understand and adopt a simulation modelling process. This thesis aims to develop a simulation modelling process for novice software process simulation modellers. This thesis reports how the development and evaluation of a simulation modelling process for novice software process simulation modellers. The rapid simulation modelling process (RSMP) is based on an empirical study of the contexts and practices of expert simulation modellers in SPSM and Operational Research (OR). The RSMP is intended to be independent of a particular simulation technique (i. e. system dynamics or discrete event simulation) and guides novice software process simulation modellers through a set of steps that should be undertaken during a simulation study; the RSMP emphasises heavy client contact and provides guidelines for model documentation. The RSMP has been evaluated through controlled experiments with novice software process simulation modellers using system dynamics (SD) modelling. In the future, it will be further evaluated with software process simulation modellers using discrete event simulation. The RSMP has also been evaluated with a panel of expert software process simulation modellers. The main contribution of this study lies in providing novice software process simulation modellers with a simulation modelling process, which embodies real world simulation practice and is intended to be independent of a particular simulation technique

    Biofeedback for training balance and mobility tasks in older populations: a systematic review

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    <p>Abstract</p> <p>Context</p> <p>An effective application of biofeedback for interventions in older adults with balance and mobility disorders may be compromised due to co-morbidity.</p> <p>Objective</p> <p>To evaluate the feasibility and the effectiveness of biofeedback-based training of balance and/or mobility in older adults.</p> <p>Data Sources</p> <p>PubMed (1950-2009), EMBASE (1988-2009), Web of Science (1945-2009), the Cochrane Controlled Trials Register (1960-2009), CINAHL (1982-2009) and PsycINFO (1840-2009). The search strategy was composed of terms referring to biofeedback, balance or mobility, and older adults. Additional studies were identified by scanning reference lists.</p> <p>Study Selection</p> <p>For evaluating effectiveness, 2 reviewers independently screened papers and included controlled studies in older adults (i.e. mean age equal to or greater than 60 years) if they applied biofeedback during repeated practice sessions, and if they used at least one objective outcome measure of a balance or mobility task.</p> <p>Data Extraction</p> <p>Rating of study quality, with use of the Physiotherapy Evidence Database rating scale (PEDro scale), was performed independently by the 2 reviewers. Indications for (non)effectiveness were identified if 2 or more similar studies reported a (non)significant effect for the same type of outcome. Effect sizes were calculated.</p> <p>Results and Conclusions</p> <p>Although most available studies did not systematically evaluate feasibility aspects, reports of high participation rates, low drop-out rates, absence of adverse events and positive training experiences suggest that biofeedback methods can be applied in older adults. Effectiveness was evaluated based on 21 studies, mostly of moderate quality. An indication for effectiveness of visual feedback-based training of balance in (frail) older adults was identified for postural sway, weight-shifting and reaction time in standing, and for the Berg Balance Scale. Indications for added effectiveness of applying biofeedback during training of balance, gait, or sit-to-stand transfers in older patients post-stroke were identified for training-specific aspects. The same applies for auditory feedback-based training of gait in older patients with lower-limb surgery.</p> <p>Implications</p> <p>Further appropriate studies are needed in different populations of older adults to be able to make definitive statements regarding the (long-term) added effectiveness, particularly on measures of functioning.</p

    A Measure of Human-Integrated System Performance under Time-Varying Circumstances

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    There are many methods to evaluate a system from given options in discrete or fixed situations (‘circumstance’). However, most systems are operated under time-varying circumstances and it’s not known how to evaluate the best system design when the operator in that system moves between time varying circumstances. In this dissertation, an adaptability model has been formalized using symbolic notion, which is based on learning curve theory and the adaptability measures are proposed. In the first study (‘the demonstration study’), the measures proved that they could be calculated and the learning curves could be plotted in continuous varying-circumstances. In the second study (‘the empirical study’), we tested two systems under three varying-circumstances. The primary purpose of this experiment was to study whether the order and delay of changing circumstances affect the adaptability measures, in which influential circumstances are randomly arranged. The statistical tests showed that order and delay do not have effects on adaptability measures. However, the results from the graphical analysis provide useful information to adjust the setting of circumstances regarding the levels of order and delay factors in practice. The findings are expected to provide an insight into understanding how human operators adapt to changing circumstances while still continuing to achieve the goal. The results also are envisioned to provide new metrics for evaluating the effectiveness of alternatives in system design
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