1,638 research outputs found

    A System Dynamics Approach for Technology Improvement Policy Analysis: The Case for Turkey

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    Technology has been one of the most important factors of the economic and social growth and globally scaled competitiveness, although not respected as a separate factor by traditional economists until recently. It is now widely accepted that technology improvement plays a very major role on national growth. Technology has a number of interactive and conflicting variables and parameters, which are not allowing an analysis with quantitative tools only. Complex dynamic analysis seems to be a proper tool to handle this sophistication. A system dynamics model constructed for policy analysis in Turkey with respect to technology improvement and comparison of various technology improvement policies. Under the scope of this paper; the elements effecting technology improvement are identified and analyzed by qualitative/quantitative methods, the key relations among these elements are identified, the influence model and the system model are drawn and some scenario analysis are performed for the comparison of possible technology improvement policies.System Dynamics, Economic Growth, Technological Capability, Technology Improvement, Technology Policies

    Adsorption and Diffusion of Pt and Au on the Stoichiometric and Reduced TiO2 Rutile (110) Surfaces

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    A comparative first principles pseudopotential study of the adsorption and migration profiles of single Pt and Au atoms on the stoichiometric and reduced TiO2 rutile (110) surfaces is presented. Pt and Au behave similarly with respect to (i) most favorable adsorption sites, which are found to be the hollow and substitutional sites on the stoichiometric and reduced surfaces, respectively, (ii) the large increase in their binding energy (by ~1.7 eV) when the surface is reduced, and (iii) their low migration barrier near 0.15 eV on the stoichiometric surface. Pt, on the other hand, binds more strongly (by ~2 eV) to both surfaces. On the stoichiometric surface, Pt migration pattern is expected to be one-dimensional, which is primarily influenced by interactions with O atoms. Au migration is expected to be two-dimensional, with Au-Ti interactions playing a more important role. On the reduced surface, the migration barrier for Pt diffusion is significantly larger compared to Au.Comment: 3 figures, 1 table, submitted to PR

    Militarism or peace and justice: Psychology at the crossroads of climate change

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    Psychological research on climate change has shifted its focus toward the way climate change influences psychological well-being. An exclusive focus on the consequences of climate change is misleading because there is an urgent need to address causes of climate change. The leading institutional user of fossil fuel and the single largest producer of greenhouse gases is a military force. The common argument that individuals must think differently about climate change also applies to psychologists: Psychologists must start considering the impact of militarism on climate change and abandon their reluctance to address military pollution, environmental destruction, and the environmental impact of nuclear weapons. This reluctance is linked with the long-standing militarism within mainstream psychology. Psychologists cannot continue ignore or ally with militarism while militarism produces two global threats: A total nuclear war and climate change. Psychologists can find a more meaningful role in any society focusing on peace, justice and human rights, rather than militarism and national security. In the context of the environment, psychologists must choose to defend the planet, which is home to all. In the context of climate change, psychologists can chart a meaningful course of action only if they focus on environmental justice

    An investigation into the pharmacology of tics and tic-like movements

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    The study of tic-like movements in mice has demonstrated close parallels both in characteristics and in pharmacology with the tics which occur in TS. Head-shakes and/or other tic-like behaviours occurring spontaneously or induced by the selective 5-HT2/1C agonist DOI, alpha-melanocyte stimulating hormone, adrenocorticotrophic hormone (1-39), thyrotropin releasing hormone, or RX336-M were blocked when tested with neuroleptics such as haloperidol and/or the alpha-2 adrenoceptor agonist clonidine. The selective dopamine D1 antagonists SCH23390 and SCH39166 dose-dependently blocked spontaneous and DOI head-shakes but the selective dopamine D2 antagonists sulpiride and raclopride were ineffective. The 5-HT1A receptor agonists 8-OH-DPAT, ipsapirone, gepirone, MDL 73005EF and buspirone (i.p) dose-dependently blocked DOI head-shakes, pindolol blocked the inhibitory effect of 8-OH-DPAT on DOI head-shakes. Parachlorophenylalanine blocked the inhibitory effect of 8-OH-DPAT and buspirone, suggesting that the 5-HT1A receptor involved is located presynaptically. The alpha-2 adrenoceptor antagonists yohimbine, idazoxan, 1-PP and RX811059 prevented the inhibitory effect of 8-OH-DPAT on DOI head-shakes suggesting that this 5-HT1A - 5-HT2 receptor interaction is under the modulatory control of adrenoceptors. Because kynurenine has previously been found to potentiate head-shaking, plasma kynurenine concentrations were measured in seven TS patients and were significantly higher than controls, but neopterin and biopterin were unchanged. The relationship between tic-like movements in rodents and their implications for understanding the aetiology and treatment of TS is discussed

    Introduction

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    Değirmencioğlu, Serdar M. (Dogus Author)Debt and personal indebtedness have become a global problem as consumption-driven economies have spread across the world. These days, outstanding consumer debt is a normal feature of many economies and for a large number of people, the source of great mental distress. However, an understanding of personal debt requires an understanding of the complex social systems that produce poverty. This book frames credit use as a social phenomenon, and explores the dynamic interplays between consumers who need credit and credit granting institutions. By drawing upon a range of international perspectives, this book sheds much needed light on the social and psychological factors that contribute to the growth of personal debt and its associated impact on wellbeing. In so doing, the book contributes to an understanding of why more and more people are in debt, why it is causing so much harm to so many people and exactly who is benefiting from what has become the world's number one growth industry

    Composites of reactive silica nanoparticles and poly(glycidyl methacrylate) with linear and crosslinked chains by in situ bulk polymerization

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    Composites of poly(glycidyl methacrylate) (PGMA) and L-lysine-coated silica nanoparticles with varying contents were prepared by in situ bulk polymerization using benzoyl peroxide (BPO) as free radical initiator. Silica nanoparticles covered by L-lysine molecules were synthesized using emulsion method. Dynamic light scattering measurements confirmed that the particles are highly monodisperse with the diameter of 10 nm and free of aggregates in the monomer (glycidyl methacrylate, GMA). Upon polymerization of the homogeneous particle/monomer dispersion, aggregates of individual silica nanoparticles are observed by tapping mode atomic force microscope (AFM). Amine and/or carboxylic acid sites on particle surface covalently react with the oxirane groups of the polymer backbone. The aggregation was substantially suppressed by using a difunctional comonomer divinyl benzene (DVB) in polymerization. A three-dimensional polymer network, P(GMA-DVB), forms throughout the system. This structure leads to significant progress in particle dispersion, therefore in physical properties of the resulting composite. We demonstrated that the composites prepared by crosslinked chains are thermally more stable and mechanically stiffer than those prepared by linear ones.TÜBİTAK TBAG-109T905; TÜBİTAK TBAG-108T446; State Planning Organization (DPT-2003K120690-6

    Unitary Precoding and Basis Dependency of MMSE Performance for Gaussian Erasure Channels

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    We consider the transmission of a Gaussian vector source over a multi-dimensional Gaussian channel where a random or a fixed subset of the channel outputs are erased. Within the setup where the only encoding operation allowed is a linear unitary transformation on the source, we investigate the MMSE performance, both in average, and also in terms of guarantees that hold with high probability as a function of the system parameters. Under the performance criterion of average MMSE, necessary conditions that should be satisfied by the optimal unitary encoders are established and explicit solutions for a class of settings are presented. For random sampling of signals that have a low number of degrees of freedom, we present MMSE bounds that hold with high probability. Our results illustrate how the spread of the eigenvalue distribution and the unitary transformation contribute to these performance guarantees. The performance of the discrete Fourier transform (DFT) is also investigated. As a benchmark, we investigate the equidistant sampling of circularly wide-sense stationary (c.w.s.s.) signals, and present the explicit error expression that quantifies the effects of the sampling rate and the eigenvalue distribution of the covariance matrix of the signal. These findings may be useful in understanding the geometric dependence of signal uncertainty in a stochastic process. In particular, unlike information theoretic measures such as entropy, we highlight the basis dependence of uncertainty in a signal with another perspective. The unitary encoding space restriction exhibits the most and least favorable signal bases for estimation.Comment: Accepted for publication in IEEE Transactions on Information Theor
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