828 research outputs found

    Dynamics of history-dependent perceptual judgment

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    Identical physical inputs do not always evoke identical percepts. To investigate the role of stimulus history in tactile perception, we designed a task in which rats had to judge each vibrissal vibration, in a long series, as strong or weak depending on its mean speed. After a low-speed stimulus (trial n − 1), rats were more likely to report the next stimulus (trial n) as strong, and after a high-speed stimulus, they were more likely to report the next stimulus as weak, a repulsive effect that did not depend on choice or reward on trial n − 1. This effect could be tracked over several preceding trials (i.e., n − 2 and earlier) and was characterized by an exponential decay function, reflecting a trial-by-trial incorporation of sensory history. Surprisingly, the influence of trial n − 1 strengthened as the time interval between n − 1 and n grew. Human subjects receiving fingertip vibrations showed these same key findings. We are able to account for the repulsive stimulus history effect, and its detailed time scale, through a single-parameter model, wherein each new stimulus gradually updates the subject’s decision criterion. This model points to mechanisms underlying how the past affects the ongoing subjective experience

    Oscillation Effects On Neutrinos From The Early Phase Of a Nearby Supernova

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    Neutrinos emitted during stellar core collapse leading to a supernova are primarily of the electron neutrino type at source which may undergo oscillation between flavor eigenstates during propagation to an earth-bound detector. Although the number of neutrinos emitted during the pre-bounce collapse phase is much smaller than that emitted in the post-bounce phase (in which all flavors of neutrinos are emitted), a nearby supernova event may nevertheless register a substantial number of detections from the pre-bounce phase at SuperKamiokande (SK) and the Sudbury Neutrino Observatory (SNO). The calorimetric measurement of the supernova neutrino fluence from this stage via the charge current and neutral current detection channels in SNO and the corresponding distortion of detected spectrum in SK over the no-oscillation spectrum, can probe information about neutrino mass difference and mixing which are illustrated here in terms of two- and three-flavor oscillation models

    Driver behaviour with adaptive cruise control

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    This paper reports on the evaluation of adaptive cruise control (ACC) from a psychological perspective. It was anticipated that ACC would have an effect upon the psychology of driving, i.e. make the driver feel like they have less control, reduce the level of trust in the vehicle, make drivers less situationally aware, but workload might be reduced and driving might be less stressful. Drivers were asked to drive in a driving simulator under manual and ACC conditions. Analysis of variance techniques were used to determine the effects of workload (i.e. amount of traffic) and feedback (i.e. degree of information from the ACC system) on the psychological variables measured (i.e. locus of control, trust, workload, stress, mental models and situation awareness). The results showed that: locus of control and trust were unaffected by ACC, whereas situation awareness, workload and stress were reduced by ACC. Ways of improving situation awareness could include cues to help the driver predict vehicle trajectory and identify conflicts

    A methodology based on profitability criteria for defining the partial defection of customers in non-contractual settings

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    The defection or churn of customers represents an important concern for any company and a central matter of interest in customer base analysis. An additional complication arises in non-contractual settings, where the characteristics that should be observed to saying that a customer has totally or partially defected are not clearly defined. As a matter of fact, different definitions of the churn situation could be used in this context. Focusing on non-contractual settings, in this paper we propose a methodology for evaluating the short-time economic effects that using a certain definition of churn would have on a company. With this aim, we have defined two efficiency measures for the economic results of a marketing campaign implemented against churn, and these measures have been computed using a set of definitions of partial defection. Our methodology finds that definition maximizing both efficiency measures and moreover, the monetary amount that the company should invest per customer in the campaign for achieving the optimal solution. This has been modelled as a multiobjective optimization problem that we solved using compromise programming. Numerical results using real data from a Spanish retailing company are presented and discussed in order to show the performance and validity of our proposal.Clemente Císcar, M.; San Matías Izquierdo, S.; Giner Bosch, V. (2014). A methodology based on profitability criteria for defining the partial defection of customers in non-contractual settings. European Journal of Operational Research. 239(1):276-285. doi:10.1016/j.ejor.2014.04.029S276285239

    Ensembles of probability estimation trees for customer churn prediction

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    Customer churn prediction is one of the most, important elements tents of a company's Customer Relationship Management, (CRM) strategy In tins study, two strategies are investigated to increase the lift. performance of ensemble classification models, i.e (1) using probability estimation trees (PETs) instead of standard decision trees as base classifiers; and (n) implementing alternative fusion rules based on lift weights lot the combination of ensemble member's outputs Experiments ale conducted lot font popular ensemble strategics on five real-life chin n data sets In general, the results demonstrate how lift performance can be substantially improved by using alternative base classifiers and fusion tides However: the effect vanes lot the (Idol cut ensemble strategies lit particular, the results indicate an increase of lift performance of (1) Bagging by implementing C4 4 base classifiets. (n) the Random Subspace Method (RSM) by using lift-weighted fusion rules, and (in) AdaBoost, by implementing both

    A Missense Mutation in the Collagen Triple Helix of EDA Is Associated with X-Linked Recessive Hypohidrotic Ectodermal Dysplasia in Fleckvieh Cattle.

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    Mutations within the ectodysplasin A (EDA) gene have been associated with congenital hypotrichosis and anodontia (HAD/XHED) in humans, mice, dogs and cattle. We identified a three-generation family of Fleckvieh cattle with male calves exhibiting clinical and histopathological signs consistent with an X-linked recessive HAD (XHED). Whole genome and Sanger sequencing of cDNA showed a perfect association of the missense mutation g.85716041G>A (ss2019497443, rs1114816375) within the EDA gene with all three cases following an X-linked recessive inheritance, but normal EDAR and EDARADD. This mutation causes an exchange of glycine (G) with arginine (R) at amino acid position 227 (p.227G>R) in the second collagen triple helix repeat domain of EDA. The EDA variant was associated with a significant reduction and underdevelopment of hair follicles along with a reduced outgrowth of hairs, a complete loss of seromucous nasolabial and mucous tracheal and bronchial glands and a malformation of and reduction in number of teeth. Thermostability of EDA G227R was reduced, consistent with a relatively mild hair and tooth phenotype. However, incisors and canines were more severely affected in one of the calves, which correlated with the presence of a homozygous missense mutation of RNF111 (g.51306765T>G), a putative candidate gene possibly associated with tooth number in EDA-deficient Fleckvieh calves

    VEHICLE OCCLUSION REMOVAL FROM SINGLE AERIAL IMAGES USING GENERATIVE ADVERSARIAL NETWORKS

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    Removing occluding objects such as vehicles from drivable areas allows precise extraction of road boundaries and related semantic objects such as lane-markings, which is crucial for several applications such as generating high-definition maps for autonomous driving. Conventionally, multiple images of the same area taken at different times or from various perspectives are used to remove occlusions and to reconstruct the occluded areas. Nevertheless, these approaches require large amounts of data, which are not always available. Furthermore, they do not work for static occlusions caused by, among others, parked vehicles. In this paper, we address occlusion removal based on single aerial images using generative adversarial networks (GANs), which are able to deal with the mentioned challenges. To this end, we adapt several state-of-the-art GAN-based image inpainting algorithms to reconstruct the missing information. Results indicate that the StructureFlow algorithm outperforms the competitors and the restorations obtained are robust, with high visual fidelity in real-world applications. Furthermore, due to the lack of annotated aerial vehicle removal datasets, we generate a new dataset for training and validating the algorithms, the Aerial Vehicle Occlusion Removal (AVOR) dataset. To the best of our knowledge, our work is the first to address vehicle removal using deep learning algorithms to enhance maps

    The impact of customer-specific marketing expenses on customer retention and customer profitability

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    We study the effects of customer-specific marketing expenses on customer retention and customer profitability in a business-to-business setting. Using data from a company providing hygiene services, we look at the impact of a hitherto unstudied type of expense targeted at individual customer relationships: the offering of free equipment to customers. The data allow tracking the activities performed in more than 4,500 customer relationships over a period of 4 years. Retention rates are higher for customers targeted with free equipment, but this effect results from an interaction with customer size. First-order dynamic panel data analyses show that the impact of targeted marketing expenses on customer dollar profit is positive for large customers, but there is no effect for smaller customers. Thus, targeted marketing expenses seem to be a tool for relationship maintenance rather than customer development: they help in retaining large customers that generate more profit, but they do not seem to work in developing new customers into larger, more profitable ones
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