415 research outputs found
Nonparametric and Semiparametric Estimation of Additive Models with both Discrete and Continuous Variables under Dependence
This paper is concerned with the estimation and inference of nonparametric and semiparametric additive models in the presence of discrete variables and dependent observations. Among the different estimation procedures, the method introduced by Linton and Nielsen, based in marginal integration, has became quite popular because both its computational simplicity and the fact that it allows an asymptotic distribution theory. Here, an asymptotic treatment of the marginal integration estimator under different mixtures of continuous-discrete variables is offered, and furthermore, in the semiparametric partially additive setting, an estimator for the parametric part that is consistent and asymptotically efficient is proposed. The estimator is based in minimizing the L2 distance between the additive nonparametric component and its correspondent linear direction. Finally, we present an application to show the feasibility of all methods introduced in the paper
Semiparametric estimation of weak and strong separable models
In
this paper we introduce a general method for estimating semiparametrically the different
components in weak or strong separable models. The family of separable models is quite
popular in economic theory and empirical research as this structure offers clear interpretation,
has straight forward economic consequences and often is justified by theory. As will be seen in
this article they are also of statistical interest since they allow to estimate semiparametrically
high dimensional complexity without running in the so called curse of dimensionality.
Generalized additive models and generalized partial linear models are special cases in this family
of models. The idea of the new method is mainly based on a combination of local likelihood and
efficient estimators in non or semiparametric models. Although this imposes some hypothesis on
the error distribution this yields a very general usable method with little computational costs and
high exactness even for small samples. E. g. it enables us to include models for censored and
truncated variables which are quite common in quantitative economics. We give the estimation
procedures and provide asymptotic theory for them. Implementation is discussed, simulations
and an application demonstrate its feasibility in finite sample behavio
Developing a corpus of strategic conversation in The Settlers of Catan
International audienceWe describe a dialogue model and an implemented annotation scheme for a pilot corpus of annotated online chats concerning bargaining negotiations in the game The Settlers of Catan. We will use this model and data to analyze how conversations proceed in the absence of strong forms of cooperativity, where agents have diverging motives. Here we concentrate on the description of our annotation scheme for negotiation dialogues, illustrated with our pilot data, and some perspectives for future research on the issue
Artifact and Artifact Categorization: Comparing Humans and Capuchin Monkeys
International audienceWe aim to show that far-related primates like humans and the capuchin monkeys show interesting correspondences in terms of artifact characterization and categorization. We investigate this issue by using a philosophically-inspired definition of physical artifact which, developed for human artifacts, turns out to be applicable for cross-species comparison. In this approach an artifact is created when an entity is intentionally selected and some capacities attributed to it (often characterizing a purpose). Behavioral studies suggest that this notion of artifact is not specific to the human kind. On the basis of the results of a series of field observations and experiments on wild capuchin monkeys that routinely use stone hammers and anvils, we show that the notions of intentional selection and attributed capacity appear to be at play in capuchins as well. The study also suggests that functional criteria and contextualization play a fundamental role in terms of artifact recognition and categorization in nonhuman primates
Topologically Protected Quantum State Transfer in a Chiral Spin Liquid
Topology plays a central role in ensuring the robustness of a wide variety of
physical phenomena. Notable examples range from the robust current carrying
edge states associated with the quantum Hall and the quantum spin Hall effects
to proposals involving topologically protected quantum memory and quantum logic
operations. Here, we propose and analyze a topologically protected channel for
the transfer of quantum states between remote quantum nodes. In our approach,
state transfer is mediated by the edge mode of a chiral spin liquid. We
demonstrate that the proposed method is intrinsically robust to realistic
imperfections associated with disorder and decoherence. Possible experimental
implementations and applications to the detection and characterization of spin
liquid phases are discussed.Comment: 14 pages, 7 figure
A 160-kilobit molecular electronic memory patterned at 10^(11) bits per square centimetre
The primary metric for gauging progress in the various semiconductor integrated circuit technologies is the spacing, or pitch, between the most closely spaced wires within a dynamic random access memory (DRAM) circuit. Modern DRAM circuits have 140nm pitch wires and a memory cell size of 0.0408 μm^2. Improving integrated circuit technology will require that these dimensions decrease over time. However, at present a large fraction of the patterning and materials requirements that we expect
to need for the construction of new integrated circuit technologies in 2013 have ‘no known solution’. Promising ingredients for advances in integrated circuit technology are nanowires, molecular electronics and defect-tolerant architectures, as demonstrated by reports of single devices and small circuits. Methods of extending these approaches to large-scale, high-density circuitry are largely undeveloped. Here we describe a 160,000-bit molecular electronic memory circuit, fabricated at a density of 10^(11) bits cm^(-2) (pitch 33 nm; memory cell size 0.0011 mm^2), that is, roughly analogous to the dimensions of a DRAM circuit projected to be available by 2020. A monolayer of bistable, [2]rotaxane molecules 10 served as the data storage elements. Although the circuit has large numbers of defects, those defects could be readily identified through electronic testing and isolated using software coding. The working bits were then configured to form a fully functional random access memory circuit for storing and retrieving information
Specification testing when the null is nonparametric or semiparametric.
This paper discusses the problem of testing misspecifications in semiparametric regression models for a large family of econometric models under rather general conditions. We focus on two main issues that typically arise in econometrics. First, many econometric models are estimated through maximum likelihood or pseudoML
methods like, for example, limited dependent variable or gravity models. Second, often one might not want to fully specify the null hypothesis. Instead, one would rather impose some structure like separability or monotonicity. In order to address these points we introduce an adaptive omnibus test. Special emphasis is
given to practical issues like adaptive bandwidth choice, general but simple requirements on the estimates, and finite sample performance, including the resampling approximations.We acknowledge nancial support from FUNCAS, the Spanish Projects MTM2008-03010 and
ECO2010-15455, and the DAAD Project 50119348
Arrays of Nano-Electromechanical Biosensors Functionalized by Microcontact Printing
The biofunctionalization of nanoelectromechanical structures is critical for
the development of new classes of biosensors displaying improved performances
and higher-level of integration. We propose a modified microcontact printing
method for the functionalization and passivation of large arrays of
nanocantilevers in a single, self-aligned step. Using fluorescence microscopy
and resonant frequency measurements, we demonstrate (1) the bioactivity and the
anti-fouling property of deposited antibodies and BSA molecules and (2) the
preservation of the nanostructures' mechanical integrity.Comment: 20 pages, 5 figure
Developing a corpus of strategic conversation in The Settlers of Catan
We describe a dialogue model and an implemented annotation schemefor a pilot corpus of annotated online chats concerning bargaining negotiationsin the game The Settlers of Catan. We will use this model and data to analyzehow conversations proceed in the absence of strong forms of cooperativity, whereagents have diverging motives. Here we concentrate on the description of ourannotation scheme for negotiation dialogues, illustrated with our pilot data, andsome perspectives for future research on the issue
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