Polymethyl Methacrylate as a Binder for Pyrotechnic Compositions

Studies on polymethyl methacrylate (PMMA) as a binder for igniter and delay compositions are reported. Igniter compositions based on magnesium and boron as fuels and potassium nitrate as oxidiser, delay compositions comprising ferrosilicon and red lead, have been investigated. These compositions were subjected to various tests, such as linear burning rate, sensitivity, calorimetric value, compatibility, pelleting properties, spark sensitivity, ignition temperatures and performance characteristics. The results indicate that the igniter compositions Mg:KNO/sub 3/:PMMA (42:50:8) and B:KNO/sub 3/:PMMA (30:70:10) as well as the delay composition comprising FeSi:Pb/sub 3/O/sub 4:PMMA (25:75:1) have improved properties and therefore could find practical applications

Development of 3 DOF Kinematics

In today’s society, robots are used in various areas especially in those where high precision is required. Robots have improved life standards and we are upgrading their performances in order to make our lives easier and more comfortable. Many applications in the field of medicine and industry use different kind of motor-based systems such as robots because of their wide-range of sufficient characteristics like the fact that they can be used as constant power devices with accurate positioning and fast response. This project describes implementation of the proposed control of the stepper motor and robotic arm by development of suitable transfer function. In this work a motorized robot arm with a 3 degree of freedom is designed. For this design control algorithm will be developed using MATLAB software which is widely used in controlling application

HAND HYGIENE AND HEALTH: AN EPIDEMIOLOGICAL STUDY OF STUDENTS IN AMRAVATI

Hands may be the most important means by which enteric pathogens are transmitted. Skin hygiene particularly of the hands, has been accepted as a primary mechanism to control the spread of infectious agents. Therefore the present study was undertaken to evaluate the number and type of enteric bacterial pathogens associated with hands. A total of 160 hands swab samples of 80 students of KG, PS, SS, UG, and PG were analyzed. Pathogens were isolated from hands includes Escherichia coli (22%), Pseudomonas aeruginosa (12%), Staphylococcus aureus (15%), Proteus mirabilis (11%), Citrobacter freundii (10%), Enterobacter aerogenes (8%), Streptococcus sp. (7%), Klebsiella sp. (6%), Micrococcus sp. (5%) and Salmonella typhi (4%). The prevalence of the bacterial pathogens was high in students of K.G. and primary than those in secondary schools and colleges. The data indicated that the hands of the female were more contaminated than male and the left hand was more contaminated than the right hand. Thus, the potential risk factors for transmission of enteric pathogens through hands should be investigated in order to improve the general health of the students

Engineering Design with Digital Thread

Digital Thread offers the opportunity to use information generated across the product lifecycle to design the next generation of products. In this paper, we introduce a mathematical methodology that establishes the data-driven design and decision problem associated with Digital Thread. Our objectives are twofold: 1) Provide a mathematical definition of Digital Thread in the context of conceptual and preliminary design and establish a methodology for how information along the Digital Thread enters into the design problem as well how design decisions affect the Digital Thread. 2) Develop a data-driven design method that incorporates data from different sources from across the product life cycle. We illustrate aspects of our methodology through an example design of a structural fiber-steered composite component.United States. Air Force. Office of Scientific Research (Grant FA9550-16-1-0108)SUTD-MIT International Design Centre (IDC

Retrospective model-based inference guides model-free credit assignment

An extensive reinforcement learning literature shows that organisms assign credit efficiently, even under conditions of state uncertainty. However, little is known about credit-assignment when state uncertainty is subsequently resolved. Here, we address this problem within the framework of an interaction between model-free (MF) and model-based (MB) control systems. We present and support experimentally a theory of MB retrospective-inference. Within this framework, a MB system resolves uncertainty that prevailed when actions were taken thus guiding an MF credit-assignment. Using a task in which there was initial uncertainty about the lotteries that were chosen, we found that when participants’ momentary uncertainty about which lottery had generated an outcome was resolved by provision of subsequent information, participants preferentially assigned credit within a MF system to the lottery they retrospectively inferred was responsible for this outcome. These findings extend our knowledge about the range of MB functions and the scope of system interactions

Evidence for surprise minimization over value maximization in choice behavior

Classical economic models are predicated on the idea that the ultimate aim of choice is to maximize utility or reward. In contrast, an alternative perspective highlights the fact that adaptive behavior requires agents' to model their environment and minimize surprise about the states they frequent. We propose that choice behavior can be more accurately accounted for by surprise minimization compared to reward or utility maximization alone. Minimizing surprise makes a prediction at variance with expected utility models; namely, that in addition to attaining valuable states, agents attempt to maximize the entropy over outcomes and thus 'keep their options open'. We tested this prediction using a simple binary choice paradigm and show that human decision-making is better explained by surprise minimization compared to utility maximization. Furthermore, we replicated this entropy-seeking behavior in a control task with no explicit utilities. These findings highlight a limitation of purely economic motivations in explaining choice behavior and instead emphasize the importance of belief-based motivations

Robustness and Generalization

We derive generalization bounds for learning algorithms based on their robustness: the property that if a testing sample is "similar" to a training sample, then the testing error is close to the training error. This provides a novel approach, different from the complexity or stability arguments, to study generalization of learning algorithms. We further show that a weak notion of robustness is both sufficient and necessary for generalizability, which implies that robustness is a fundamental property for learning algorithms to work

Association of Genetic Variants in XPC and XPG Genes with Cervical Cancer Risk in a Rural Population: A Hospital Based Case Control Study

Background: Cervical cancer is a major concern of health risk in urban and rural parts of India.. Aim and Objectives: This study was aimed to find out frequency of polymorphisms in DNA repair genes including Xeroderma pigmentosum complementation group C (XPC) and Xenoderma pigmentosum complementation group G (XPG) in patients of cervical cancer from Maharashtra and to evaluate their association with risk of cervical cancer. Materials and Methods: We used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to examine gene polymorphisms in 350 patients with cancer of cervix and 400 age and sex matched normal controls. Results: The results obtained indicated that there was no significant difference in the genotype distribution between cervical cancer patients and controls for XPC Lys939Gln, -371promoter and XPG His 1104 Asp. The result showed that genotype frequencies of XPC Val 499 Arg of codon 499 in exon 15 (OR=4.26; 95% CI=(3.007-6.03); p= <0.0001) were increased significantly. Conclusion: This study indicates that polymorphisms in Val499Arg haplotype of XPC gene appear to influence genetic susceptibility of individual to cervical cancer in Maharashtrian patients

Reinforcement learning or active inference?

This paper questions the need for reinforcement learning or control theory when optimising behaviour. We show that it is fairly simple to teach an agent complicated and adaptive behaviours using a free-energy formulation of perception. In this formulation, agents adjust their internal states and sampling of the environment to minimize their free-energy. Such agents learn causal structure in the environment and sample it in an adaptive and self-supervised fashion. This results in behavioural policies that reproduce those optimised by reinforcement learning and dynamic programming. Critically, we do not need to invoke the notion of reward, value or utility. We illustrate these points by solving a benchmark problem in dynamic programming; namely the mountain-car problem, using active perception or inference under the free-energy principle. The ensuing proof-of-concept may be important because the free-energy formulation furnishes a unified account of both action and perception and may speak to a reappraisal of the role of dopamine in the brain

Robust water repellent ZnO nanorod array by Swift Heavy Ion Irradiation: Effect of Electronic Excitation Induced Local Chemical State Modification

Tailoring the surface properties by varying the chemistry and roughness could be of interest for self-cleaning applications. We demonstrate the transformation of hydrophobic ZnO Nano rod (NR) array into superhydrophobic nature by changing the local chemical state and without altering the surface roughness by swift heavy ion (SHI) irradiation. The aligned ZnO NR arrays were irradiated using 150 MeV Ag ions with different fluences from 5E10 to 3E12 ions/cm2. The observed static water contact angles of ZnO NRs samples were 103° ± 3°, 152° ± 4°,161° ± 3°, 164° ± 2°, 167° ± 2°,154 ± 3° and 151° ± 2° for the pristine, ion fluencies of 1E11, 3E11, 5E11, 7E11, 1E12 and 3E12 ions cm−2, respectively. The change in local surface chemistry via formation of surface oxygen related defects due to electronic excitations induced by ion irradiation determine the water dewetting properties. It is found that surface oxygen related defects could be tuned by varying the fluence of the SHIs. Durability tests show that the SHI induced surface oxygen-deficient ZnO NRs have the stable superhydrophobic behavior for more than a year