343 research outputs found
Modeling Oligopolistic Price Adjustment in Micro Level Panel Data
Consumer prices in many markets are persistently dispersed both across retail outlets and over time. While the cross sectional distribution of prices is stable, individual stores change their position in the distribution over time. It is a challenge to model oligopolistic price adjustment to capture these features of consumer markets. In belief based models of price adjustment stores react to expected profits. The expectations are based on the observed vector of market prices in the previous periods. In a reinforcement model of price adjustment, if a strategy has proven fruitful in the past, it is apt to be the strategy relied upon at the present. We collect price data on a homogeneous consumer product in Israel. We estimate the structural parameter of the models. We find that the reinforcement model describes the data better than the belief based models. ZUSAMMENFASSUNG - ( Modeling Oligopolistic Price Adjustment in Micro Level Panel Data) Preise für viele Konsumgüter sind weit verteilt. Dies gilt sowohl für die Verteilung über die Zeit als auch für die Verteilung zwischen den Verkaufsstellen. Während die Querschnittsverteilung der Preise stabil ist, wechseln die einzelnen Verkaufsstellen ihre Position in der Verteilung über die Zeit. Es stellt eine Herausforderung dar, diese Merkmale der Märkte für Konsumgüter zu modellieren. Im Vermutungslernen bilden die Verkaufstätten Erwartungen über das zukünftige Preissetzungsverhalten der Konkurrenz. Die Erwartungen basieren auf dem vorherigen Entscheidungsverhalten der Konkurrenz. Im Bekräftigungslernen werden erfolgreiche Strategien gerne wiederholt. Preisdaten eines homogenen Gutes in Israel werden erhoben. Die strukturellen Parameter der Modelle werden geschätzt. Bekräftigungslernen beschreibt das tatsächliche Entscheidungsverhalten besser als Vermutungslernen.Experiments; Information; Learning
Generating Compact Geometric Track-Maps for Train Positioning Applications
In this paper, we present a method to generate compact geometric track-maps
for train-borne localization applications. Therefore, we first give a brief
overview on the purpose of track maps in train-positioning applications. It
becomes apparent that there are hardly any adequate methods to generate
suitable geometric track-maps. This is why we present a novel map generation
procedure. It uses an optimization formulation to find the continuous sequence
of track geometries that fits the available measurement data best. The
optimization is initialized with the results from a localization filter
developed in our previous work. The localization filter also provides the
required information for shape identification and measurement association. The
presented approach will be evaluated on simulated data as well as on real
measurements
Effects of haloperidol and atypical neuroleptics on psychomotor performance and driving ability in schizophrenic patients - Results from an experimental study
The influence of antipsychotic treatment on the neuropsychological and psychomotor performance of schizophrenic patients is still a subject of investigation. The present study was designed to evaluate the effects of atypical neuroleptics in comparison with a conventional dopamine antagonist neuroleptic (haloperidol) on several dimensions of psychomotor performance (visual perception, attention, reaction time, and sensorimotor performance) considered to be of relevance in evaluating driving fitness. Psychomotor performance was assessed by means of the ART 90, a computerized Act and React Test which is generally used in diagnosis of psychomotor performance. The 49 participating patients were examined at discharge following psychopathological stabilisation; 20 received haloperidol, 29 received an atypical neuroleptic. Our findings demonstrate a remarkably reduced psychomotor performance in the haloperidol-treated group of schizophrenic patients compared with patients treated with atypical neuroleptics. Only 1 (5%) subject passed all subtests without major failures and could be regarded as competent to drive. Among patients with atypical neuroleptics, 7 patients (24%) passed all test parameters without major failures. Copyright (C) 2003 S. Karger AG, Basel
Modeling oligopolistic price adjustment in micro level panel data
"Consumer prices in many markets are persistently dispersed both across retail outlets and over time. While the cross sectional distribution of prices is stable, individual stores change their position in the distribution over time. It is a challenge to model oligopolistic price adjustment to capture these features of consumer markets. In belief based models of price adjustment stores react to expected profits. The expectations are based on the observed vector of market prices in the previous periods. In a reinforcement model of price adjustment, if a strategy has proven fruitful in the past, it is apt to be the strategy relied upon at the present. We collect price data on a homogeneous consumer product in Israel. We estimate the structural parameter of the models. We find that the reinforcement model describes the data better than the belief based models." (author's abstract)"Preise für viele Konsumgüter sind weit verteilt. Dies gilt sowohl für die Verteilung über die Zeit als auch für die Verteilung zwischen den Verkaufsstellen. Während die Querschnittsverteilung der Preise stabil ist, wechseln die einzelnen Verkaufsstellen ihre Position in der Verteilung über die Zeit. Es stellt eine Herausforderung dar, diese Merkmale der Märkte für Konsumgüter zu modellieren. Im Vermutungslernen bilden die Verkaufstätten Erwartungen über das zukünftige Preissetzungsverhalten der Konkurrenz. Die Erwartungen basieren auf dem vorherigen Entscheidungsverhalten der Konkurrenz. Im Bekräftigungslernen werden erfolgreiche Strategien gerne wiederholt. Preisdaten eines homogenen Gutes in Israel werden erhoben. Die strukturellen Parameter der Modelle werden geschätzt. Bekräftigungslernen beschreibt das tatsächliche Entscheidungsverhalten besser als Vermutungslernen." (Autorenreferat
Detecting the Upturn of the Solar B Neutrino Spectrum with LENA
LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation
50 kt liquid scintillator detector. The large target mass allows a high
precision measurement of the solar B neutrino spectrum, with an
unprecedented energy threshold of 2 MeV. Hence, it can probe the MSW-LMA
prediction for the electron neutrino survival probability in the transition
region between vacuum and matter-dominated neutrino oscillations. Based on
Monte Carlo simulations of the solar neutrino and the corresponding background
spectra, it was found that the predicted upturn of the solar B neutrino
spectrum can be detected with 5 sigma significance after 5 y
Effects of haloperidol and atypical neuroleptics on psychomotor performance and driving ability in schizophrenic patients - Results from an experimental study
The influence of antipsychotic treatment on the neuropsychological and psychomotor performance of schizophrenic patients is still a subject of investigation. The present study was designed to evaluate the effects of atypical neuroleptics in comparison with a conventional dopamine antagonist neuroleptic (haloperidol) on several dimensions of psychomotor performance (visual perception, attention, reaction time, and sensorimotor performance) considered to be of relevance in evaluating driving fitness. Psychomotor performance was assessed by means of the ART 90, a computerized Act and React Test which is generally used in diagnosis of psychomotor performance. The 49 participating patients were examined at discharge following psychopathological stabilisation; 20 received haloperidol, 29 received an atypical neuroleptic. Our findings demonstrate a remarkably reduced psychomotor performance in the haloperidol-treated group of schizophrenic patients compared with patients treated with atypical neuroleptics. Only 1 (5%) subject passed all subtests without major failures and could be regarded as competent to drive. Among patients with atypical neuroleptics, 7 patients (24%) passed all test parameters without major failures. Copyright (C) 2003 S. Karger AG, Basel
Genomic Characterization of the Human Type I Cuticular Hair Keratin hHa2 and Identification of an Adjacent Novel Type I Hair Keratin Gene hHa5
Hair keratins, a subset of the keratin multigene family expressed in hard keratinizing structures, previously have been thought to comprise four members of each subfamily, designated Ha1-4 (type I) and Hb1-4 (type II), which are differentially expressed in the cuticle and cortex of the hair follicle. This report describes the genomic cloning and sequencing of the human type I cuticular hair keratin hHa2, as well as the identification of a previously unknown human type I hair keratin gene. The 12.5-kilobase pair genomic clone ghkI2.12, obtained by hybridization of a human genomic deoxyribonucleic acid library with a 3'–complementary deoxyribonucleic acid probe of hHa2, as well as the partially overlapping 14.4-kilobase pair genornic clone ghk12.17, isolated using a 5'-fragment of clone ghk12.12, allowed the characterization of the entire hHa2 genes The gene displays the same exon/intron structure as two previously characterized type I mouse and sheep hair/wool keratin genes with strict positional conservation of the six introns in the region coding for the central α-helix, At the 5'-extremity of clone ghk12.17, approximately 8.0 kilobase pairs upstream of the hHa2 gene and oriented in the same transcriptional direction, lies the gene for a hitherto unknown human type I hair keratin, Clone ghkl2.17 contains partial sequence information for this gene beginning with introit 5 and extending to the end of the gene. Screening of a human scalp complementary deoxyribonucleic acid library with a 3'-fragment of the gene yielded a full length complementary deoxyribonucleic acid clone of the new hair keratin, which in continuation of the current nomenclature for hair keratins was termed hHa5. Remarkably, the hHa5 gene, which contains an additional 7th intron in its 3'-noncoding region, is expressed mainly in supramatricial cells and lowermost cortical cells of the hair bulb and thus constitutes a very early component of hair morphogenesis. Our results confirm the type specific clustering of keratin genes and indicate that the human type I hair keratin subfamily contains more members than previously assume
Spatiotemporal expression patterns of sialoglycoconjugates during nephron morphogenesis and their regional and cell type-specific distribution in adult rat kidney
The expression of α2,6- and α2,3-linked sialic acids on N-glycans was studied in embryonic, postnatal, and adult rat kidney. Histochemistry and blotting using Polyporus squamosus and Sambucus nigra lectins for α2,6-linked sialic acids and the Maackia amurensis lectin for α2,3-linked sialic acids were performed and sialyltransferase activity was assayed. N-glycans with α2,6- and α2,3-linked sialic acid were differently expressed in the two embryonic anlagen and early stages of nephron. Metanephrogenic mesenchyme was positive for α2,3-linked sialic acid but not for the α2,6-linked one, which became detectable initially in the proximal part of S-shaped bodies. Collecting ducts were positive for α2,6-linked sialic acid, whereas α2,3-linked sialic acid was restricted to their ampullae. Although positive in embryonic kidney, S1 and S2 of proximal tubules became unreactive for α2,3-linked sialic acid in postnatal and adult kidneys. In adult kidney, intercalated but not principal cells of collecting ducts were reactive for α2,3-linked sialic acid. In contrast, α2,6-linked sialic acids were detected in all cells of adult kidney nephron. Blot analysis revealed a different but steady pattern of bands reactive for α2,6- and α2,3-linked sialic acid in embryonic, postnatal, and adult kidney. Activity of α2,6 and α2,3 sialyltransferases was highest in embryonic kidney and decreased over postnatal to adult kidney with the activity of α2,6 sialyltransferase always being three to fourfold that of α2,3 sialyltransferase. Thus, α2,6- and α2,3-linked sialic acids are differently expressed in embryonic anlagen and mesenchyme-derived early stages of nephron and show regional and cell type-specific differences in adult kidne
Increasing Accuracy in Train Localization Exploiting Track-Geometry Constraints
Train-borne localization systems as a key component of future signalling systems are expected to offer huge economic and operational advances for the railway transportation sector. However, the reliable provision of a track-selective and constantly available location information is still unsolved and prevents the introduction of such systems so far. A contribution to overcome this issue is presented here. We show a recursive multistage filtering approach with an increased cross-track positioning accuracy, which is decisive to ensure track-selectivity. This is achieved by exploiting track-geometry constraints known in advance, as there are strict rules for the construction of railway tracks. Additionally, compact geometric track-maps can be extracted during the filtering process which are beneficial for existing train localization approaches. The filter was derived applying approximate Bayesian inference. The geometry constraints are directly incorporated in the filter design, utilizing an interacting multiple model (IMM) filter and extended Kalman filters (EKF). Throughout simulations the performance of the filter is analyzed and discussed thereafter
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