The Effects of Index Storage on Ranked Information Retrieval

Information retrieval is the process of recalling and ordering all relevant documents based on a user\u27s search query. Examples of information retrieval systems are Google, Bing, and Yahoo search. In order to perform an effective search, these systems utilize an inverted index for mapping content, such as words, to the original document. It is widely believed there are two options for implementing an inverted index and these options are in memory or as a file. This investigation looks at implementing an inverted index as a table in a database as compared to the other two options. In addition, this investigation will look at the optimal combination of inverted index implementation to retrieval algorithms such as TD-IDF, Best Match 25, and a unigram model with Jelinek-Mercer smoothing. This is determined by designing and developing a system which will index and search three different collections of various data, size, and complexities. By doing this, it is found that utilizing an inverted index implemented in a database is a viable option for information retrieval. It is also noteworthy that Best Match 25 or a unigram language model consistently outperforms TD-IDF. In conclusion, if the collection cannot be indexed in memory, then utilizing a database implemented index is a sufficient second option

From walking to running: robust and 3D humanoid gait generation via MPC

Humanoid robots are platforms that can succeed in tasks conceived for humans. From locomotion in unstructured environments, to driving cars, or working in industrial plants, these robots have a potential that is yet to be disclosed in systematic every-day-life applications. Such a perspective, however, is opposed by the need of solving complex engineering problems under the hardware and software point of view. In this thesis, we focus on the software side of the problem, and in particular on locomotion control. The operativity of a legged humanoid is subordinate to its capability of realizing a reliable locomotion. In many settings, perturbations may undermine the balance and make the robot fall. Moreover, complex and dynamic motions might be required by the context, as for instance it could be needed to start running or climbing stairs to achieve a certain location in the shortest time. We present gait generation schemes based on Model Predictive Control (MPC) that tackle both the problem of robustness and tridimensional dynamic motions. The proposed control schemes adopt the typical paradigm of centroidal MPC for reference motion generation, enforcing dynamic balance through the Zero Moment Point condition, plus a whole-body controller that maps the generated trajectories to joint commands. Each of the described predictive controllers also feature a so-called stability constraint, preventing the generation of diverging Center of Mass trajectories with respect to the Zero Moment Point. Robustness is addressed by modeling the humanoid as a Linear Inverted Pendulum and devising two types of strategies. For persistent perturbations, a way to use a disturbance observer and a technique for constraint tightening (to ensure robust constraint satisfaction) are presented. In the case of impulsive pushes instead, techniques for footstep and timing adaptation are introduced. The underlying approach is to interpret robustness as a MPC feasibility problem, thus aiming at ensuring the existence of a solution for the constrained optimization problem to be solved at each iteration in spite of the perturbations. This perspective allows to devise simple solutions to complex problems, favoring a reliable real-time implementation. For the tridimensional locomotion, on the other hand, the humanoid is modeled as a Variable Height Inverted Pendulum. Based on it, a two stage MPC is introduced with particular emphasis on the implementation of the stability constraint. The overall result is a gait generation scheme that allows the robot to overcome relatively complex environments constituted by a non-flat terrain, with also the capability of realizing running gaits. The proposed methods are validated in different settings: from conceptual simulations in Matlab to validations in the DART dynamic environment, up to experimental tests on the NAO and the OP3 platforms

Anxious Intimacy: Negotiating Gender, Value and Belonging among Japanese Retirees in Malaysia

This is a study of Japanese retirees who have elected to retire in Malaysia. I arrived in Kuala Lumpur in 2014 to study sensory responses of Japanese retirees to the Malaysian landscape, but discovered instead that the gender differences in the experiences of their overseas move into retirement were dominating everyday discussions among the retirees. Retired baby boomers had lived through Japan’s high growth period in which family and firm were strictly demarcated into a normative division of labour between women and men. Men’s retirement seemed to have unsettled many taken-for-granted categories including gender and intergenerational norms. I observed that their movement to Malaysia led retirees to reimagine and restructure relations between themselves and their spouses, with their children, and the wider Japanese state. The thesis focuses on three aspects of their lives: (1) their partial refashioning of retirement as affective labour; (2) their reconstitution of relationships with wives, children and other retirees; and (3) the sense of anxiety they felt around these transitions, and how that shaped the new relationships. I engage with a growing body of literature in feminist economic anthropology that looks at how economic transformations shape people’s intimate lives and how their lives in turn shape wider economic practices. The anxiety around belonging felt by those who were outside the productivist scheme was a kind of experience profoundly entwined with a contemporary global economy. The distinctiveness of the Malaysian field site provided a unique place from which my thesis addresses larger debates over the politics of intimacy and productivity. I move outward from their sense of anxieties to theorise how intimate relations are both shaped by, and shaping, the operations of society’s multiple regulatory forms in global capitalism today

Whim of the trivial

The author begins by saying that before he was born, he lived with his parents (of course) and ends his story 86 years later with an evanescent farewell. In the interval: a life of no importance. So why tell it? For lack of a better answer, he adduces mysterious voices in the second part of Goethe's Faust: We immer streben sich bemüthn Der können wir elössen The triviality of the story is redeemed thanks to a slight seasoning of humour, and philosophy in the style of Petrarch: Si vedrem chiaro poi como sovente Per le cose dubbiose altri s’avanza E come spesso inarno si sospir

La narrativa gráfica de la memoria: Nakazawa, Spiegelman y Sacco

393 páginas. Doctorado en Historiografía.Pretendo conocer las formas en que la memoria se ha configurado en los relatos del cómic. Para esto, concentraré el análisis sobre tres obras de tres narradores gráficos contemporáneos fundamentales: I Saw It (1972), de Keiji Nakazawa; Maus (1980-1991), de Art Spiegelman; y Palestina (1993), de Joe Sacco. Como preguntas particulares: a) me interesa conocer por qué la memoria se volvió tema fundamental del cómic con posterioridad al fin de la Segunda Guerra Mundial; b) pensar qué tipos de discursos sobre la memoria se pueden producir en la narrativa gráfica; c) y, finalmente, entender cómo son posibles la referencialidad y la veracidad en el lenguaje del cómic.Consejo Nacional de Ciencia y Tecnología (México)

After postmodernity

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Political Science, 1996.Includes bibliographical references (p. 562-587).by Peter Baofu.Ph.D

A study in cross-cultural transmission of natural philosophy: the Kenkon Bensetsu

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em História dos Descobrimentos e da Expansão PortuguesaThis work shows that the transmission of European natural philosophy by Christian missionaries in Japan during the sixteenth and seventeenth centuries was made in a systematic way, even if at an elementary level. The Kenkon Bensetsu is used as main evidence of this. This text was introduced into Japan by Antonio Rubino, on the orders of Inoue Masashige it was translated by Sawano Chuan, at the request of Kainosho Masanobu it was transliterated by Nishi Kichibei and Mukai Gensho, and this last one also wrote a commentary on its theories from a neo-Confucian perspective. The historical setting and the process that led to the production of the Kenkon Bensetsu are described. From this it is established that the Japanese of all walks of life were curious about the causes of natural phenomena; that the missionaries had the ability to provide those explanations, drawing from the pool of theories provided by sixteenth century Aristotelian natural philosophy, adjusted to the interests and talents of their audience; and that the Japanese authorities considered that these theories were important in some way and thus took the necessary steps to ensure that that they would not be consigned into oblivion as a consequence of their efforts to stamp out Christianity. The text is integrally translated following explicit criteria, therefore opening the way to further exploration by many researchers. Some of its most striking characteristics concerning content and style are analysed