13 research outputs found
GPU Computing for Cognitive Robotics
This thesis presents the first investigation of the impact of GPU
computing on cognitive robotics by providing a series of novel experiments in
the area of action and language acquisition in humanoid robots and computer
vision. Cognitive robotics is concerned with endowing robots with high-level
cognitive capabilities to enable the achievement of complex goals in complex
environments. Reaching the ultimate goal of developing cognitive robots will
require tremendous amounts of computational power, which was until
recently provided mostly by standard CPU processors. CPU cores are
optimised for serial code execution at the expense of parallel execution, which
renders them relatively inefficient when it comes to high-performance
computing applications. The ever-increasing market demand for
high-performance, real-time 3D graphics has evolved the GPU into a highly
parallel, multithreaded, many-core processor extraordinary computational
power and very high memory bandwidth. These vast computational resources
of modern GPUs can now be used by the most of the cognitive robotics models
as they tend to be inherently parallel. Various interesting and insightful
cognitive models were developed and addressed important scientific questions
concerning action-language acquisition and computer vision. While they have
provided us with important scientific insights, their complexity and
application has not improved much over the last years. The experimental
tasks as well as the scale of these models are often minimised to avoid
excessive training times that grow exponentially with the number of neurons
and the training data. This impedes further progress and development of
complex neurocontrollers that would be able to take the cognitive robotics
research a step closer to reaching the ultimate goal of creating intelligent
machines. This thesis presents several cases where the application of the GPU
computing on cognitive robotics algorithms resulted in the development of
large-scale neurocontrollers of previously unseen complexity enabling the
conducting of the novel experiments described herein.European Commission Seventh Framework
Programm
Evolutionary Computation 2020
Intelligent optimization is based on the mechanism of computational intelligence to refine a suitable feature model, design an effective optimization algorithm, and then to obtain an optimal or satisfactory solution to a complex problem. Intelligent algorithms are key tools to ensure global optimization quality, fast optimization efficiency and robust optimization performance. Intelligent optimization algorithms have been studied by many researchers, leading to improvements in the performance of algorithms such as the evolutionary algorithm, whale optimization algorithm, differential evolution algorithm, and particle swarm optimization. Studies in this arena have also resulted in breakthroughs in solving complex problems including the green shop scheduling problem, the severe nonlinear problem in one-dimensional geodesic electromagnetic inversion, error and bug finding problem in software, the 0-1 backpack problem, traveler problem, and logistics distribution center siting problem. The editors are confident that this book can open a new avenue for further improvement and discoveries in the area of intelligent algorithms. The book is a valuable resource for researchers interested in understanding the principles and design of intelligent algorithms
Asynchronous Island Parallel GA Using Multiform Subpopulations
. Island Parallel GA divides a population into subpopulations and assigns them to processing elements on a parallel computer. Then each subpopulation searches the optimal solution independently, and exchanges individuals periodically. This exchange operation is called migration. In this research, we propose a new algorithm that migrants are exchanged asynchronously among multiform subpopulations which have different search conditions. The effect of our algorithm on combinational optimization problems was verified by applying the algorithm to Knapsack Problem and Royal Road Functions using parallel computer CRAY-T3E. We obtained the results that our algorithm maintained the population's diversity effectively and searches building blocks efficiently. 1 Introduction There are two typical problems in Genetic Algorithms (GAs). First, GAs require huge calculation time for their genetic operations, such as selection, crossover, mutation, and individuals' fitness evaluations. Secondly, mainten..
Molecular mechanisms of interleukin-2 gene inducibility: developmental control and combinatorial action of transcription factors
Interleukin-2 is one of the lymphokines secreted by T helper type 1 cells upon
activation mediated by T-cell receptor (TCR) and accessory molecules. The ability to
express IL-2 is correlated with T-lineage commitment and is regulated during T cell
development and differentiation. Understanding the molecular mechanism of how IL-2
gene inducibility is controlled at each transition and each differentiation process of T-cell
development is to understand one aspect of T-cell development. In the present study, we
first attempted to elucidate the molecular basis for the developmental changes of IL-2 gene
inducibility. We showed that IL-2 gene inducibility is acquired early in immature CD4-
CD8-TCR- thymocytes prior to TCR gene rearrangement. Similar to mature T cells, a
complete set of transcription factors can be induced at this early stage to activate IL-2 gene
expression. The progression of these cells to cortical CD4^+CD8^+TCR^(1o) cells is
accompanied by the loss of IL-2 gene inducibility. We demonstrated that DNA binding
activities of two transcription factors AP-1 and NF-AT are reduced in cells at this stage.
Further, the loss of factor binding, especially AP-1, is attributable to the reduced ability to
activate expression of three potential components of AP-1 and NF-AT, including c-Fos,
FosB, and Fra-2. We next examined the interaction of transcription factors and the IL-2
promoter in vivo by using the EL4 T cell line and two non-T cell lines. We showed an all-or-none phenomenon regarding the factor-DNA interaction, i.e., in activated T cells, the
IL-2 promoter is occupied by sequence-specific transcription factors when all the
transcription factors are available; in resting T cells or non-T cells, no specific protein-DNA
interaction is observed when only a subset of factors are present in the nuclei.
Purposefully reducing a particular set of factor binding activities in stimulated T cells using
pharmacological agents cyclosporin A or forskolin also abolished all interactions. The
results suggest that a combinatorial and coordinated protein-DNA interaction is required for
IL-2 gene activation.
The thymocyte experiments clearly illustrated that multiple transcription factors are
regulated during intrathymic T-cell development, and this regulation in tum controls the
inducibility of the lineage-specific IL-2 gene. The in vivo study of protein-DNA interaction
stressed the combinatorial action of transcription factors to stably occupy the IL-2 promoter
and to initiate its transcription, and provided a molecular mechanism for changes in IL-2
gene inducibility in T cells undergoing integration of multiple environmental signals
A longitudinal study of the experiences and psychological well-being of Indian surrogates
Study question: What is the psychological well-being of Indian surrogates during and after the surrogacy pregnancy?
Summary answer: Surrogates were similar to a matched group of expectant mothers on anxiety and stress. However, they scored higher on depression during and after pregnancy.
What is known already: The recent ban on trans-national commercial surrogacy in India has led to urgent policy discussions regarding surrogacy. Whilst previous studies have reported the motivations and experiences of Indian surrogates no studies have systematically examined the psychological well-being of Indian surrogates, especially from a longitudinal perspective. Previous research has shown that Indian surrogates are motivated by financial payment and may face criticism from their family and community due to negative social stigma attached to surrogacy. Indian surrogates often recruited by agencies and mainly live together in a “surrogacy house.”
Study design, size, duration: A longitudinal study was conducted comparing surrogates to a matched group of expectant mothers over two time points: (a) during pregnancy (Phase1: 50 surrogates, 70 expectant mothers) and (b) 4–6 months after delivery (Phase 2: 45 surrogates, 49 expectant mothers). The Surrogates were recruited from a fertility clinic in Mumbai and the matched comparison group was recruited from four public hospitals in Mumbai and Delhi.
Data collection was completed over 2 years.
Participants/materials, setting, methods: Surrogates and expectant mothers were aged between 23 and 36 years. All participants were from a low socio-economic background and had left school before 12–13 years of age. In-depth faceto-face semi-structured interviews and a psychological questionnaire assessing anxiety, stress and depression were administered in Hindi to both groups. Interviews took place in a private setting. Audio recordings of surrogate interviews were later translated and transcribed into English.
Main results and the role of chance: Stress and anxiety levels did not significantly differ between the two groups for both phases of the study. For depression, surrogates were found to be significantly more depressed than expectant mothers at phase 1 (p = 0.012) and phase 2 (p = 0.017). Within the surrogacy group, stress and depression did not change during and after pregnancy. However, a non-significant trend was found showing that anxiety decreased after delivery (p = 0.086). No participants reported being coerced into surrogacy, however nearly all kept it a secret from their wider family and community and hence did not face criticism. Surrogates lived at the surrogate house for different durations. During pregnancy, 66% (N = 33/50) reported their experiences of the surrogate house as positive, 24% (N = 12/50) as negative and 10% (N = 5/50) as neutral. After delivery, most surrogates (66%, N = 30/45) reported their experiences of surrogacy to be positive, with the remainder viewing it as neutral (28%) or negative (4%). In addition, most (66%, N = 30/45) reported that they had felt “socially supported and loved” during the surrogacy arrangement by friends in the surrogate hostel, clinic staff or family. Most surrogates did not meet the intending parents (49%, N = 22/45) or the resultant child (75%, N = 34/45).
Limitations, reasons for caution: Since the surrogates were recruited from only one clinic, the findings may not be representative of all Indian surrogates. Some were lost to follow-up which may have produced sampling bias.
Wider implications of the findings: This is the first study to examine the psychological well-being of surrogates in India. This research is of relevance to current policy discussions in India regarding legislation on surrogacy. Moreover, the findings are of relevance to clinicians, counselors and other professionals involved in surrogacy.
Trial registration number: N/A
The Superstitious Muse
For several decades David Bethea has written authoritatively on the “mythopoetic thinking” that lies at the heart of classical Russian literature, especially Russian poetry. His theoretically informed essays and books have made a point of turning back to issues of intentionality and biography at a time when authorial agency seems under threat of “erasure” and the question of how writers, and poets in particular, live their lives through their art is increasingly moot. The lichnost’ (personhood, psychic totality) of the given writer is all-important, argues Bethea, as it is that which combines the specifically biographical and the capaciously mythical in verbal units that speak simultaneously to different planes of being. Pushkin’s Evgeny can be one incarnation of the poet himself and an Everyman rising up to challenge Peter’s new world order; Brodsky can be, all at once, Dante and Mandelstam and himself, the exile paying an Orphic visit to Florence