851 resultados para Neighbourhood Aesthetics


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We review some recently published methods to represent atomic neighbourhood environments, and analyse their relative merits in terms of their faithfulness and suitability for fitting potential energy surfaces. The crucial properties that such representations (sometimes called descriptors) must have are differentiability with respect to moving the atoms, and invariance to the basic symmetries of physics: rotation, reflection, translation, and permutation of atoms of the same species. We demonstrate that certain widely used descriptors that initially look quite different are specific cases of a general approach, in which a finite set of basis functions with increasing angular wave numbers are used to expand the atomic neighbourhood density function. Using the example system of small clusters, we quantitatively show that this expansion needs to be carried to higher and higher wave numbers as the number of neighbours increases in order to obtain a faithful representation, and that variants of the descriptors converge at very different rates. We also propose an altogether new approach, called Smooth Overlap of Atomic Positions (SOAP), that sidesteps these difficulties by directly defining the similarity between any two neighbourhood environments, and show that it is still closely connected to the invariant descriptors. We test the performance of the various representations by fitting models to the potential energy surface of small silicon clusters and the bulk crystal.

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Simulation of materials at the atomistic level is an important tool in studying microscopic structure and processes. The atomic interactions necessary for the simulation are correctly described by Quantum Mechanics. However, the computational resources required to solve the quantum mechanical equations limits the use of Quantum Mechanics at most to a few hundreds of atoms and only to a small fraction of the available configurational space. This thesis presents the results of my research on the development of a new interatomic potential generation scheme, which we refer to as Gaussian Approximation Potentials. In our framework, the quantum mechanical potential energy surface is interpolated between a set of predetermined values at different points in atomic configurational space by a non-linear, non-parametric regression method, the Gaussian Process. To perform the fitting, we represent the atomic environments by the bispectrum, which is invariant to permutations of the atoms in the neighbourhood and to global rotations. The result is a general scheme, that allows one to generate interatomic potentials based on arbitrary quantum mechanical data. We built a series of Gaussian Approximation Potentials using data obtained from Density Functional Theory and tested the capabilities of the method. We showed that our models reproduce the quantum mechanical potential energy surface remarkably well for the group IV semiconductors, iron and gallium nitride. Our potentials, while maintaining quantum mechanical accuracy, are several orders of magnitude faster than Quantum Mechanical methods.

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Energy performance labelling and certification have been introduced widely to address market failures affecting the uptake of energy efficient technologies, by providing a signal to support decision making during contracting processes. The UK has recently introduced the Energy Performance Certificate (EPC) as a signal of building energy performance. The aims of this article are: to evaluate how valid EPC's are signals of occupier satisfaction with office facilities; and to understand whether occupant attitudes towards environmental issues have affected commercial office rental values. This was achieved by surveying occupant satisfaction with their workplaces holistically using a novel multi-item rating scale which gathered 204 responses. Responses to this satisfaction scale were matched with the corresponding EPC and rental value of occupier's workplaces. The satisfaction scale was found to be both a reliable and valid measure. The analysis found that EPC asset rating correlates significantly with occupant satisfaction with all facility attributes. Therefore, EPC ratings may be considered valid signals of overall facility satisfaction within the survey sample. Rental value was found to correlate significantly only with facility aesthetics. No evidence suggests rental value has been affected by occupants' perceptions towards the environmental impact of facilities. © 2013 The Authors.

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1993 年以来,在生物局的协调和推动下,美国各州相继开展间隙分析项目。随 后,间隙分析项目在加拿大、意大利、埃及等多个国家广泛开展。经过多年的发展, 其经验和方法可为我国所借鉴。植被与动物分布制图,以及保护优先地区评估,是 间隙分析项目的几项主要任务。本研究将探讨在高山峡谷地区完成这些任务的方法。 山区植被制图一直是遥感制图领域的难点。在发展中国家,由于缺乏高质量的 数字地形图,问题显得尤为突出。为提高山区林地制图效率与准确度,我们提出一 种基于Landsat 卫星影像的准自动化分类方法。按WRS-2 (the World Reference System-2)分幅系统和地形,将大面积的项目区划分为若干子区域。通过对Landsat 影像进行光谱增强处理,使用ISODATA 分类方法,依次将各个子区域划分为林地 和非林地。接着,集成粗分辨率地形数据和Landsat ETM+ 影像,使用基于原型的 最大似然分类方法,将林地划分为不同的林型。在云南西北部地区应用这种分类方 法,滇西北四县的林地覆盖图总体准确率高达96.8%,两个实验子区域的林地分类 图的总体制图准确度也分别达80.0%和82.9%。结果证明,我们提出的分层分类方 法,能提高山区林地制图的效率与准确度,可向整个横断山地区推广。 动物生境研究在生物多样性保护研究和实践中具有重要作用和意义。2007 年5 月,我们在西藏芒康小昌都村进行雉类生境研究考察。其间,我们初步分析了白马 鸡觅食生境特征。按不同坡向和地貌,分别调查了15 条沟谷和3 条山脊的白马鸡刨 食痕迹。结果显示,白马鸡春季偏好于东坡、西坡3800-4000 m 海拔范围的冷杉 林沟谷觅食,但回避北坡。结果暗示,水热条件是影响白马鸡觅食地选择的重要因 子。 为了使有限的保护资源发挥最大的作用,我们使用层次分析法建立了一个保护 优先地区评估模型。此模型综合不同评价标准,既考虑了珍稀濒危物种,也关注了 普通物种,可定量评估各地理单元的保护优先度。通过输入鸟、兽分布历史资料(标 本和文献),使用本模型评价了滇西北15 县的动物保护优先度,结果显示,贡山、 丽江、泸水、香格里拉、福贡、德钦和维西等县市具有较高的动物保护优先度。

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This report describes a computer system that creates simple computer animation in response to high-level, vague, and incomplete descriptions of films. It makes its films by collecting and evaluating suggestions from several different bodies of knowledge. The order in which it makes its choices is influenced by the focus of the film. Difficult choices are postponed to be resumed when more of the film has been determined. The system was implemented in an object-oriented language based upon computational entities called "actors". The goal behind the construction of the system is that, whenever faced with a choice, it should sensibly choose between alternatives based upon the description of the film and as much general knowledge as possible. The system is presented as a computational model of creativity and aesthetics.

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As an animator and practice-based researcher with a background in games development, I am interested in technological change in the video game medium, with a focus on the tools and technologies that drive game character animation and interactive story. In particular, I am concerned with the issue of ‘user agency’, or the ability of the end user to affect story development—a key quality of the gaming experience and essential to the aesthetics of gaming, which is defined in large measure by its interactive elements. In this paper I consider the unique qualities of the video game1 as an artistic medium and the impact that these qualities have on the production of animated virtual character performances. I discuss the somewhat oppositional nature of animated character performances found in games from recent years, which range from inactive to active—in other words, low to high agency. Where procedural techniques (based on coded rules of movement) are used to model dynamic character performances, the user has the ability to interactively affect characters in real-time within the larger sphere of the game. This game play creates a high degree of user agency. However, it lacks the aesthetic nuances of the more crafted sections of games: the short cut-scenes, or narrative interludes where entire acted performances are mapped onto game characters (often via performance capture)2 and constructed into relatively cinematic representations. While visually spectacular, cut-scenes involve minimal interactivity, so user agency is low. Contemporary games typically float between these two distinct methods of animation, from a focus on user agency and dynamically responsive animation to a focus on animated character performance in sections where the user is a passive participant. We tend to think of the majority of action in games as taking place via playable figures: an avatar or central character that represents a player. However, there is another realm of characters that also partake in actions ranging from significant to incidental: non-playable characters, or NPCs, which populate action sequences where game play takes place as well as cut scenes that unfold without much or any interaction on the part of the player. NPCs are the equivalent to supporting roles, bit characters, or extras in the world of cinema. Minor NPCs may simply be background characters or enemies to defeat, but many NPCs are crucial to the overall game story. It is my argument that, thus far, no game has successfully utilized the full potential of these characters to contribute toward development of interactive, high performance action. In particular, a type of NPC that I have identified as ‘pivotal’3—those constituting the supporting cast of a video game—are essential to the telling of a game story, particularly in genres that focus on story and characters: adventure games, action games, and role-playing games. A game story can be defined as the entirety of the narrative, told through non-interactive cut-scenes as well a interactive sections of play, and development of more complex stories in games clearly impacts the animation of NPCs. I argue that NPCs in games must be capable of acting with emotion throughout a game—in the cutscenes, which are tightly controlled, but also in sections of game play, where player agency can potentially alter the story in real-time. When the animated performance of NPCs and user agency are not continuous throughout the game, the implication is that game stories may be primarily told through short movies within games, making it more difficult to define video games animation as a distinct artistic medium.

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Slocombe, William, Nihilism and the Sublime Postmodern (New York: Routledge, 2005) RAE2008

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Woods, Timothy, The Poetics of the Limit (New York: Palgrave Macmillan, 2003) RAE2008

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Haycock, Marged, 'Sy abl fodd Sibli fain: Sibyl in Medieval Wales', In: Heroic Poets and Poetic Heroes in Celtic Tradition, Joseph Falaky Nagy and Leslie Ellen Jones (eds), (Dublin: Four Courts Press), pp.115-130, 2005 RAE2008

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Monografia apresentada à Universidade Fernando Pessoa para obtenção do grau de Licenciada em Medicina Dentária

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas