485 resultados para Path Planning
Resumo:
This thesis presents a new approach to compute and optimize feasible three dimensional (3D) flight trajectories using aspects of Human Decision Making (HDM) strategies, for fixed wing Unmanned Aircraft (UA) operating in low altitude environments in the presence of real time planning deadlines. The underlying trajectory generation strategy involves the application of Manoeuvre Automaton (MA) theory to create sets of candidate flight manoeuvres which implicitly incorporate platform dynamic constraints. Feasible trajectories are formed through the concatenation of predefined flight manoeuvres in an optimized manner. During typical UAS operations, multiple objectives may exist, therefore the use of multi-objective optimization can potentially allow for convergence to a solution which better reflects overall mission requirements and HDM preferences. A GUI interface was developed to allow for knowledge capture from a human expert during simulated mission scenarios. The expert decision data captured is converted into value functions and corresponding criteria weightings using UTilite Additive (UTA) theory. The inclusion of preferences elicited from HDM decision data within an Automated Decision System (ADS) allows for the generation of trajectories which more closely represent the candidate HDM’s decision strategies. A novel Computationally Adaptive Trajectory Decision optimization System (CATDS) has been developed and implemented in simulation to dynamically manage, calculate and schedule system execution parameters to ensure that the trajectory solution search can generate a feasible solution, if one exists, within a given length of time. The inclusion of the CATDS potentially increases overall mission efficiency and may allow for the implementation of the system on different UAS platforms with varying onboard computational capabilities. These approaches have been demonstrated in simulation using a fixed wing UAS operating in low altitude environments with obstacles present.
Resumo:
Parents are at risk for inactivity; however, research into understanding parental physical activity (PA) is scarce. We integrated self-determined motivation, planning, and the theory of planned behavior (TPB) to better understand parental PA. Parents (252 mothers, 206 fathers) completed a main questionnaire assessing measures underpinning these constructs and a 1-week follow-up of PA behavior to examine whether self-determined motivation indirectly influenced intention via the TPB variables (i.e., attitude, subjective norm, and perceived behavioral control) and intention indirectly influenced behavior via planning. We found self-determined motivation on intention was fully mediated by the TPB variables and intention on behavior was partially mediated by the planning variables. In addition, slight differences in the model’s paths between the sexes were revealed. The results illustrate the range of important determinants of parental PA and provide support for the integrated model in explaining PA decision making as well as the importance of examining sex differences.
Resumo:
Virtual world platforms such as Second Life have been successfully used in educational contexts to motivate and engage learners. This article reports on an exploratory workshop involving a group of high school students using Second Life for an urban planning project. Young people are traditionally an under-represented demographic when it comes to participating in urban planning and decision making processes. The research team developed activities that combined technology with a constructivist approach to learning. Real world experiences and purposes ensured that the workshop enabled students to see the relevance of their learning. Our design also ensured that play remained an important part of the learning. By conceiving of the workshop as a ‘serious playground’ we investigated the ludic potential of learning in a virtual world.
Resumo:
Urban and regional planners, in the era of globalization, require being equipped with skill sets to better deal with complex and rapidly changing economic, socio-cultural, political and environmental fabrics of cities and their regions. In order to provide such skill sets, urban and regional planning curriculum of Queensland University of Technology (Brisbane, Australia) offers regional planning practice in the international context. This paper reports the findings of the pedagogic analyses from the regional planning practice fieldtrips to Malaysia, Korea, Turkey, Taiwan, and discusses the opportunities and constraints of exposure of students to regional planning practice beyond the national context.
Resumo:
First year students overwhelmingly indicate that a strong interest in a field of study prompts them to enrol in university (McInnis et al 2000), yet over a quarter indicate that they have seriously considered dropping out of studies during their first year, with boredom most frequently cited by those domestic students who do depart before graduation (Coates and Ransom 2011). While it may be comforting to write off such withdrawals to the presumed apathy of youth, student “disquiet (in) their first year on campus may be a result of courses and institutions that do not match their needs and objectives, rather than any uncertainty or lack of purpose on their part” (James et al 1999). Voting with their mouse clicks, The current research investigate two conceptualized types of student participation in online discussion forums to increase understanding of student affinity for technology and its potential for fostering social network development amongst first year students.
Resumo:
A planner’s view of the purpose of their actions, the role they play, the focus of their work and in whose interest they operate greatly influence their approach to planning and the outcome of their work. However there is no common and established understanding within the profession on these themes. Contemporary planning theory, practice and education is characterised by the parallel existence of multiple, often contradictory schools of thought. What values and perspectives are held by the next generation of planning professionals as they emerge from contemporary planning programs? This preliminary investigation seeks to identify the views and perspectives of early career planners on the purpose and role of planning, the degree to which planning is oriented on the future and the nature of the public interest, using various schools of planning thought as a thematic framework. In the current phase of a larger project, extant students and recent graduates from planning courses at three Queensland universities were surveyed electronically to ascertain their views, with plans to undertake a broader study of similar populations across Australia. Within the current pilot, students and graduates did not identify strongly with a single school of planning thought, but favoured contrasting rational and collaborative definitions of the role and purpose of planning and the public interest and pragmatic concepts of partial knowledge of the future and the value of experience in managing present issues.
Resumo:
Starting from the vantage point that explaining success at creating a venture should be the unique contribution—or at least one unique contribution—of entrepreneurship research, we argue that this success construct has not yet been adequately defined an operationalized. We thus offer suggestions for more precise conceptualization and measurement of this central construct. Rather than regarding various success proxies used in prior research as poor operationalizations of success we argue that they represent other important aspects of the venture creation process: engagement, persistence and progress. We hold that in order to attain a better understanding of venture creation these constructs also need to be theoretically defined. Further, their respective drivers need to be theorized and tested separately. We suggest theoretical definitions of each. We then develop and test hypotheses concerning how human capital, venture idea novelty and business planning has different impact on the different assessments of the process represented by engagement, persistence, progress and success. The results largely confirm the stated hypotheses, suggesting that the conceptual and empirical approach we are suggesting is a path towards improved understanding of the central entrepreneurship phenomenon of new venture creation.
Resumo:
The relationships between business planning and performance have divided the entrepreneurship research community for decades (Brinckmann et al, 2010). One side of this debate is the assumption that business plans may lock the firm in a specific direction early on, impede the firm to adapt to the changing market conditions (Dencker et al., 2009) and eventually, cause escalation of commitments by introducing rigidity (Vesper, 1993). Conversely, feedback received from the production and presentation of business plans may also lead the firm to take corrective actions. However, the mechanisms underlying the relationships between changes in business ideas, business plans and the performance of nascent firms are still largely unknown. While too many business idea changes may confuse stakeholders, exhaust the firm’s resources and hinder the undergoing legitimization process, some flexibility during the early stages of the venture may be beneficial to cope with the uncertainties surrounding new venture creation (Knight, 1921; March, 1982; Stinchcombe, 1965; Weick, 1979). Previous research has emphasized adaptability and flexibility as key success factors through effectual logic and interaction with the market (Sarasvathy, 2001; 2007) or improvisation and trial-and-error (Miner et al, 2001). However, those studies did not specifically investigate the role of business planning. Our objective is to reconcile those seemingly opposing views (flexibility versus rigidity) by undertaking a more fine-grained analysis at the relationships between business planning and changes in business ideas on a large longitudinal sample of nascent firms.
Resumo:
Previous studies investigating the relationships between business planning and performance have led to inconclusive results (Brinckmann et al., 2010; Delmar & Shane, 2003; Frese, 2009; Gruber, 2007; Honig & Karlsson, 2004). Institutional theory argues that firms develop business plans as an answer to external and internal pressures to gain legitimization (Delmar & Shane, 2004) and funding from different stakeholders (Karlsson & Honig, 2009). Action theory suggests that planning will pave the new venture creation journey by providing milestones and a program to implement (Frese, 2009). However, studies with an institutional perspective imply that nascent firms are either conforming to or looking for the benefits of these external or internal pressures (Karlsson & Honig, 2009) while action theory assumes that the plans will be implemented (Frese, 2009). This paper attempts to (i) investigate if the intended uses of the business plans provided by nascent and young firms match their actual uses during their venture creation process and (ii) to examine how the types of uses of business plans impact the firms’ outcomes over three years.
Resumo:
The Midwest Independent Transmission System Operator (MISO) has experienced significant amounts of wind power development within the last decade. The MISO footprint spans the majority of the upper Midwest region of the country, from the Dakotas to Indiana and as far east as Michigan. These areas have a rich wind energy resource. States in the MISO footprint have passed laws or set goals that require load serving entities to supply a portion of their load using renewable energy. In order to meet these requirements, significant investments are needed to build the transmission infrastructure necessary to deliver the power from these often remote wind energy resources to the load centers. This paper presents some of the transmission planning related work done at MISO which was largely influenced by current and future needs for increased wind power generation in the footprint. Specifically, topics covered are generator interconnection, long-term planning coordination, and cost-allocation for new transmission lines.
Resumo:
Australia is rich in renewable energy resources such as wind, solar and geothermal. Geographical diversity of these renewable resources combined with developing climate change policies poses a great challenge for the long term interconnection planning. Intermittency of wind and solar potentially driving the development of new transmission lines bring additional complexity to power system operations and planning. This paper provides an overview of generation and transmission planning studies in Australia to meet 20% renewable energy target by 2020. Appraisal of the effectiveness of dispersed energy storage, non schedulable peaking plants, wide area controls and demand management techniques to aid the penetration of renewables is presented in this paper
Resumo:
Over the past few years, the Midwest ISO has experienced a surge in requests to interconnect large amounts of wind generation, driven largely by a favorable political environment and an abundant wind resource in the Midwestern US. This tremendous influx of proposed generators along with a highly constrained transmission system adversely impacted interconnection queue processing, resulting in an unmanageable backlog. Under these circumstances, Midwest ISO successfully reformed the interconnection tariff to improve cycle times and provide increased certainty to interconnection customers. One of the key features of the reformed queue process is the System Planning and Analysis (SPA) phase which allows integration of the interconnection studies with regional transmission planning. This paper presents a brief background of the queue reform effort and then delves deeply in to the work performed at the Midwest ISO during the first SPA cycle - the study approach, the challenges faced in having to study over 50,000 MWs of wind generation and the effective solutions designed to complete these studies within tariff timelines.
Resumo:
Today, a large number of wind generator interconnection requests have been queued and are being processed. The generator interconnection group study is a way to reduce the generator interconnection cycle time and increase interconnection certainty. However, it is very challenging to identify the “best” transmission upgrades for a large group of generator interconnections. It is also very important to differentiate the constraints caused by each generator interconnection request and identify their responsibilities for transmission upgrades. This paper outlines some innovative study approaches that can be used in a group study with large numbers of generator interconnection requests in a constrained area. Improved study methods are introduced, and a summary and conclusions are derived from the study.
Resumo:
Spatial navigation requires the processing of complex, disparate and often ambiguous sensory data. The neurocomputations underpinning this vital ability remain poorly understood. Controversy remains as to whether multimodal sensory information must be combined into a unified representation, consistent with Tolman's "cognitive map", or whether differential activation of independent navigation modules suffice to explain observed navigation behaviour. Here we demonstrate that key neural correlates of spatial navigation in darkness cannot be explained if the path integration system acted independently of boundary (landmark) information. In vivo recordings demonstrate that the rodent head direction (HD) system becomes unstable within three minutes without vision. In contrast, rodents maintain stable place fields and grid fields for over half an hour without vision. Using a simple HD error model, we show analytically that idiothetic path integration (iPI) alone cannot be used to maintain any stable place representation beyond two to three minutes. We then use a measure of place stability based on information theoretic principles to prove that featureless boundaries alone cannot be used to improve localization above chance level. Having shown that neither iPI nor boundaries alone are sufficient, we then address the question of whether their combination is sufficient and - we conjecture - necessary to maintain place stability for prolonged periods without vision. We addressed this question in simulations and robot experiments using a navigation model comprising of a particle filter and boundary map. The model replicates published experimental results on place field and grid field stability without vision, and makes testable predictions including place field splitting and grid field rescaling if the true arena geometry differs from the acquired boundary map. We discuss our findings in light of current theories of animal navigation and neuronal computation, and elaborate on their implications and significance for the design, analysis and interpretation of experiments.