951 research outputs found

    Scale space consistency of piecewise constant least squares estimators -- another look at the regressogram

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    We study the asymptotic behavior of piecewise constant least squares regression estimates, when the number of partitions of the estimate is penalized. We show that the estimator is consistent in the relevant metric if the signal is in L2([0,1])L^2([0,1]), the space of c\`{a}dl\`{a}g functions equipped with the Skorokhod metric or C([0,1])C([0,1]) equipped with the supremum metric. Moreover, we consider the family of estimates under a varying smoothing parameter, also called scale space. We prove convergence of the empirical scale space towards its deterministic target.Comment: Published at http://dx.doi.org/10.1214/074921707000000274 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

    Size Matters: Impact of Item Size and Quantity on Array Choice by Chimpanzees (Pan troglodytes)

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    The authors previously reported that chimpanzees (Pan troglodytes) showed a striking bias to select the larger of 2 candy arrays, despite a reversed reward contingency in which the animals received the smaller, nonselected array as a reward, except when Arabic numerals were used as stimuli. A perceptual or incentive-based interference occurred that was overcome by symbolic stimuli. The authors of the present study examined the impact of element size in choice arrays, using 1 to 5 large and small candies. Five test-sophisticated chimpanzees selected an array from the 2 presented during each trial. Their responses were not optimal, as animals generally selected arrays with larger total mass; thus, they received the smaller remaining array as a reward. When choice stimuli differed in size and quantity, element size was more heavily weighted, although choices reflected total candy mass. These results replicate previous findings showing chimpanzees\u27 difficulties with quantity judgments under reverse reward contingencies and also show that individual item size exerts a more powerful interference effect

    Apes communicate about absent and displaced objects: methodology matters

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    Displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. Several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities) human infants display displaced reference but chimpanzees do not. Here we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced reference to absent and displaced objects. It is likely that some of the conflicting findings from animal cognition studies are due to relatively minor methodological differences, but are compounded by interpretation errors. Comparative studies are of great importance in elucidating the evolution of human cognition, however, greater care must be taken with methodology and interpretation for these studies to accurately reflect species differences

    Scale-Model Comprehension by Chimpanzees (Pan troglodytes)

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    The ability of chimpanzees (Pan troglodytes) to recognize the correspondence between a scale model and its real-world referent was examined. In Experiments 1 and 2, an adult female and a young adult male watched as an experimenter hid a miniature model food in 1 of 4 sites in a scale model. Then, the chimpanzees were given the opportunity to find the real food item that had been hidden in the analogous location in the real room. The female performed significantly above chance, whereas the male performed at chance level. Experiments 3 and 4 tested 5 adult and 2 adolescent chimpanzees in a similar paradigm, using a scale model of the chimpanzees\u27 outdoor area. Results indicate that some adult chimpanzees were able to reliably demonstrate an understanding of the relationship between a scale model and the larger space it represented, whereas other subjects were constrained by inefficient and unsuccessful search patterns

    Scale-Model Comprehension by Chimpanzees (Pan troglodytes)

    Get PDF
    The ability of chimpanzees (Pan troglodytes) to recognize the correspondence between a scale model and its real-world referent was examined. In Experiments 1 and 2, an adult female and a young adult male watched as an experimenter hid a miniature model food in 1 of 4 sites in a scale model. Then, the chimpanzees were given the opportunity to find the real food item that had been hidden in the analogous location in the real room. The female performed significantly above chance, whereas the male performed at chance level. Experiments 3 and 4 tested 5 adult and 2 adolescent chimpanzees in a similar paradigm, using a scale model of the chimpanzees\u27 outdoor area. Results indicate that some adult chimpanzees were able to reliably demonstrate an understanding of the relationship between a scale model and the larger space it represented, whereas other subjects were constrained by inefficient and unsuccessful search patterns

    Child care assistance: the benefit of the 1990's

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    Call number: LD2668 .R4 HDFS 1989 B69Master of ScienceFamily Studies and Human Service

    Scale-Model Comprehension by Chimpanzees (Pan troglodytes)

    Get PDF
    The ability of chimpanzees (Pan troglodytes) to recognize the correspondence between a scale model and its real-world referent was examined. In Experiments 1 and 2, an adult female and a young adult male watched as an experimenter hid a miniature model food in 1 of 4 sites in a scale model. Then, the chimpanzees were given the opportunity to find the real food item that had been hidden in the analogous location in the real room. The female performed significantly above chance, whereas the male performed at chance level. Experiments 3 and 4 tested 5 adult and 2 adolescent chimpanzees in a similar paradigm, using a scale model of the chimpanzees\u27 outdoor area. Results indicate that some adult chimpanzees were able to reliably demonstrate an understanding of the relationship between a scale model and the larger space it represented, whereas other subjects were constrained by inefficient and unsuccessful search patterns

    Language-Naive Chimpanzees (Pan troglodytes) Judge Relations Between Relations in a Conceptual Matching-to-Sample Task

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    Three chimpanzees with a history of conditional and numeric token training spontaneously matched relations between relations under conditions of nondifferential reinforcement. Heretofore, this conceptual ability was demonstrated only in language-trained chimpanzees. The performance levels of the language-naive animals in this study, however, were equivalent to those of a 4th animal—Sarah—whose history included language training and analogical problem solving. There was no evidence that associative factors mediated successful performance in any of the animals. Prior claims of a profound disparity between language-trained and language-naive chimpanzees apparently can be attributed to prior experience with arbitrary tokens consistently associated with abstract relations and not language per se

    Wave-vector dependent intensity variations of the Kondo peak in photoemission from CePd3_3

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    Strong angle-dependent intensity variations of the Fermi-level feature are observed in 4d - 4f resonant photoemission spectra of CePd3_3(111), that reveal the periodicity of the lattice and largest intensity close to the Gamma points of the surface Brillouin zone. In the framework of a simplified periodic Anderson model the phenomena may quantitatively be described by a wave-vector dependence of the electron hopping matrix elements caused by Fermi-level crossings of non-4f-derived energy bands
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