Towards implementing group membership in dynamic networks : a performance evaluation study

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 105-109).Support for dynamic groups is an integral part of the U.S. Department of Defense's vision of Network-Centric Operations. Group membership (GM) serves as the foundation of many group-oriented systems; its fundamental role in applications such as reliable group multicast, group key management, data replication, and distributed collaboration, makes optimization of its efficiency important. The impact of GM's performance is amplified in dynamic, failure-prone environments with intermittent connectivity and limited bandwidth, such as those that host military on the move operations. A recent theoretical result has proposed a novel GM algorithm, called Sigma, which solves the Group Membership problem within a single round of message exchange. In contrast, all other GM algorithms require more rounds in the worst case. Sigma's breakthrough design both makes and handles tradeoffs between fast agreement and possible transient disagreement, raising the question: how efficiently and accurately does Sigma perform in practice? We answer this question by implementing and studying Sigma in simulation, as well as two leading GM algorithms - Moshe and Ensemble - in a comparative performance analysis. Among the variants of Sigma that we study is Leader-Based Sigma, which we design as a more scalable alternative.(cont.) We also discuss parameters enabling Sigma's optimal practical deployment in a variety of applications and environments. Our simulations show that, consistently with theoretical results, Sigma always terminates within a single round of message exchange, faster than Moshe and Ensemble. Moreover, Sigma has less message overhead and produces virtually the same quality of views as Moshe and Ensemble, when used with a filter for limiting disagreement. These results strongly indicate that Sigma is not just a theoretical result, but indeed a result with important practical implications for Group Communication Systems: the efficiency of GM applications can be significantly improved, without compromising accuracy, by replacing current GM algorithms with Sigma.by Sophia Yuditskaya.M.Eng

Automatic vocal recognition of a child's perceived emotional state within the Speechome corpus

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 137-149).With over 230,000 hours of audio/video recordings of a child growing up in the home setting from birth to the age of three, the Human Speechome Project has pioneered a comprehensive, ecologically valid observational dataset that introduces far-reaching new possibilities for the study of child development. By offering In vivo observation of a child's daily life experience at ultra-dense, longitudinal time scales, the Speechome corpus holds great potential for discovering developmental insights that have thus far eluded observation. The work of this thesis aspires to enable the use of the Speechome corpus for empirical study of emotional factors in early child development. To fully harness the benefits of Speechome for this purpose, an automated mechanism must be created to perceive the child's emotional state within this medium. Due to the latent nature of emotion, we sought objective, directly measurable correlates of the child's perceived emotional state within the Speechome corpus, focusing exclusively on acoustic features of the child's vocalizations and surrounding caretaker speech. Using Partial Least Squares regression, we applied these features to build a model that simulates human perceptual heuristics for determining a child's emotional state. We evaluated the perceptual accuracy of models built across child-only, adult-only, and combined feature sets within the overall sampled dataset, as well as controlling for social situations, vocalization behaviors (e.g. crying, laughing, babble), individual caretakers, and developmental age between 9 and 24 months. Child and combined models consistently demonstrated high perceptual accuracy, with overall adjusted R-squared values of 0.54 and 0.58, respectively, and an average of 0.59 and 0.67 per month. Comparative analysis across longitudinal and socio-behavioral contexts yielded several notable developmental and dyadic insights. In the process, we have developed a data mining and analysis methodology for modeling perceived child emotion and quantifying caretaker intersubjectivity that we hope to extend to future datasets across multiple children, as new deployments of the Speechome recording technology are established. Such large-scale comparative studies promise an unprecedented view into the nature of emotional processes in early childhood and potentially enlightening discoveries about autism and other developmental disorders.by Sophia Yuditskaya.S.M

Сравнительный анализ пищевого поведения детей различных возрастных групп

The phenomenon of eating behavior in the development of obesity in the pediatric age group remains poorly understood.The purpose of the study. To determine the peculiarities of eating behavior of children of various age groups depending on body mass.Material and methods. A comparative prospective study of 905 children: 342 children 1–7 years (4.7 ± 1.29), 249 children aged 8–12 (11.08 ± 0.81) and 314 adolescents 13–18 (14.25 ± 1,34). A physical survey was conducted according to standard methods with calculation of body mass index. For the study of eating behavior of preschool children, a survey of the parents was conducted using the scales of CEBQ (Child Eating Behaviour Questionnaire; J. Wardle, 2001; by the license author), an assessment of eating behavior of children 8–12 years was conducted through the analysis of the questionnaire FEV - II, and an assessment of adolescents was done with the use of the Dutch questionnaire DEBQ (Dutch Eating Behavior Questionnaire). Statistical analysis: STATISTICA (version 8), Microsoft Excel 7,0.Results. Assessment of the frequency of occurrence of eating disorders in children and adolescents showed that regardless of age and body mass, all the children had eating disorders. The development of pathological disorders begins at 5-years of age and acquires a clear shape at 7 years. All children with normal body weight was dominated by external type of eating behavior, in subgroups of patients with overweight / obesity was the prevalent restrictive type. In patients with obesity, a third had combined forms of food behavior with the prevalence of the combination in children 8–12 years of restrictive and external types, in children 13–18 years of restrictive and emotional types. The frequency of occurrence of these combinations was increased together with the increase in children of body weight. Феномен пищевого поведения в развитии ожирения в детской возрастной группе остается недостаточно изученным.Цель исследования. Определить особенности пищевого поведения детей различных возрастных групп в зависимости от массы тела.Материалы и методы. Проведено сравнительное одномоментное исследование 905 детей: 342 ребенка 1–7 лет (4,7 ± 1,29), 249 детей в возрасте 8–12 (11,08 ± 0,81) и 314 подростков 13–18 (14,25 ± 1,34) лет. Физикальное исследование проведено по стандартной методике с расчетом индекса массы тела. Для изучения пищевого поведения младшей возрастной группы дошкольников анкетированы родители по шкалам CEBQ (Child Eating Behaviour Questionnaire; J. Wardle, 2001; по лицензии автора), анализ пищевого поведения детей 8–12 лет проведен путем оценки специального опросника FEV–II, детей пубертатного возраста – голландского опросника DEBQ (Dutch Eating Behavior Questionnaire). Для статистического анализа использованы Microsoft Excel 7.0, базовая программа Statistica 8.Результаты. Оценка частоты встречаемости различных типов пищевого поведения и их нарушений у детей и подростков показала, что все дети имели нарушения пищевого поведения вне связи с возрастом и массой тела. Формирование патологических нарушений начинается с 5-летнего возраста, и они приобретают определенные черты к 7 годам. В подгруппах детей различного возраста с массой тела, соответствующей возрасту и полу, преобладал внешний тип пищевого поведения, в подгруппах пациентов с избыточной массой тела и ожирением превалировал ограничительный тип. У 1/3 детей с ожирением диагностированы комбинированные формы пищевого поведения с преобладанием сочетания у детей 8–12 лет ограничительного и внешнего типов, у детей 13–18 лет – ограничительного и эмоционального типов. Частота этих комбинаций увеличивалась с нарастанием у детей массы тела.

Developing a Series of AI Challenges for the United States Department of the Air Force

Through a series of federal initiatives and orders, the U.S. Government has been making a concerted effort to ensure American leadership in AI. These broad strategy documents have influenced organizations such as the United States Department of the Air Force (DAF). The DAF-MIT AI Accelerator is an initiative between the DAF and MIT to bridge the gap between AI researchers and DAF mission requirements. Several projects supported by the DAF-MIT AI Accelerator are developing public challenge problems that address numerous Federal AI research priorities. These challenges target priorities by making large, AI-ready datasets publicly available, incentivizing open-source solutions, and creating a demand signal for dual use technologies that can stimulate further research. In this article, we describe these public challenges being developed and how their application contributes to scientific advances

Discovery of serum biomarkers of ovarian cancer using complementary proteomic profiling strategies.

Ovarian cancer is a devastating disease and biomarkers for its early diagnosis are urgently required. Serum may be a valuable source of biomarkers that may be revealed by proteomic profiling. Herein, complementary serum protein profiling strategies were employed for discovery of biomarkers that could discriminate cases of malignant and benign ovarian cancer

Born Global Challenges and Performance - A Study on Competences, Routines, and Corporate Governance Structure of Born Global Software Companies in Sweden and Norway

Problem: How do the born global firms overcome challenges and sustain performance in international markets through their competences, routines, and corporate governance structure? Purpose: The purpose of this thesis is to explore the competences, routines, and corporate governance structure of born global companies, and understand their role in overcoming challenges of early internationalization and sustaining performance in international markets from early days. Method: This research is conducted as multi-disciplinary, consisting of literature from International Business and Strategic Management. Relevant data is collected through six in-depth interviews with executives of born global companies from Sweden and Norway. Qualitative analysis has been used at data analysis stage. Originality: This study contributes to literature by examining relatively neglected areas of born global companies; competences, routines, and corporate governance structure. It is also original in distilling a wide literature to explore challenges of born globals. Conclusion: Our research reveals that despite their small size and limited resources, born global companies engage in competence building and leveraging activities, establish early international routines, and construct flexible governance structures to overcome challenges and achieve performance in the global arena

Comparative analysis of eating behavior of children of different age groups

The phenomenon of eating behavior in the development of obesity in the pediatric age group remains poorly understood.The purpose of the study. To determine the peculiarities of eating behavior of children of various age groups depending on body mass.Material and methods. A comparative prospective study of 905 children: 342 children 1–7 years (4.7 ± 1.29), 249 children aged 8–12 (11.08 ± 0.81) and 314 adolescents 13–18 (14.25 ± 1,34). A physical survey was conducted according to standard methods with calculation of body mass index. For the study of eating behavior of preschool children, a survey of the parents was conducted using the scales of CEBQ (Child Eating Behaviour Questionnaire; J. Wardle, 2001; by the license author), an assessment of eating behavior of children 8–12 years was conducted through the analysis of the questionnaire FEV - II, and an assessment of adolescents was done with the use of the Dutch questionnaire DEBQ (Dutch Eating Behavior Questionnaire). Statistical analysis: STATISTICA (version 8), Microsoft Excel 7,0.Results. Assessment of the frequency of occurrence of eating disorders in children and adolescents showed that regardless of age and body mass, all the children had eating disorders. The development of pathological disorders begins at 5-years of age and acquires a clear shape at 7 years. All children with normal body weight was dominated by external type of eating behavior, in subgroups of patients with overweight / obesity was the prevalent restrictive type. In patients with obesity, a third had combined forms of food behavior with the prevalence of the combination in children 8–12 years of restrictive and external types, in children 13–18 years of restrictive and emotional types. The frequency of occurrence of these combinations was increased together with the increase in children of body weight