427 research outputs found

    Search for serendipitous TNO occultation in X-rays

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    To study the population properties of small, remote objects beyond Neptune's orbit in the outer solar system, of kilometer size or smaller, serendipitous occultation search is so far the only way. For hectometer-sized Trans-Neptunian Objects (TNOs), optical shadows actually disappear because of diffraction. Observations at shorter wave lengths are needed. Here we report the effort of TNO occultation search in X-rays using RXTE/PCA data of Sco X-1 taken from June 2007 to October 2011. No definite TNO occultation events were found in the 334 ks data. We investigate the detection efficiency dependence on the TNO size to better define the sensible size range of our approach and suggest upper limits to the TNO size distribution in the size range from 30 m to 300 m. A list of X-ray sources suitable for future larger facilities to observe is proposed.Comment: Accepted to publish in MNRA

    Alternative Ingredient Recommendation: A Co-occurrence and Ingredient Category Importance Based Approach

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    As many people will refer to a recipe when cooking, there are several recipe-sharing websites that include lots of recipes and make recipes easier to access than before. However, there is often the case that we could not get all the ingredients listed on the recipe. Prior research on alternative ingredient substitution has built a recommendation system considering the suitability of a recommended ingredient with the remained ingredients. In this paper, in addition to suitability, we also take the diversity of the ingredient categories and the novelty of new combination of ingredients into account. Besides, we combine suitability with novelty as an index, to see whether our method could help find out a new combination of ingredients that is possibly to be a new dish. Our evaluation results show that our proposed method attains a comparable or even better performance on each perspective

    Poly[(ÎŒ6-benzene-1,3,5-tricarboxyl­ato-Îș6 O 1:O 1â€Č:O 3:O 3â€Č:O 5:O 5â€Č)tris­(N,N-dimethyl­formamide-ÎșO)tris­(ÎŒ3-formato-Îș2 O:Oâ€Č)trimagnesium(II)]

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    The title complex, [Mg3(CHO2)3(C9H3O6)(C3H7NO)3]n, exhib­its a two-dimensional structure parallel to (001), which is built up from the MgII atoms and bridging carboxyl­ate ligands (3 symmetry). The MgII atom is six-coordinated by one O atom from a dimethyl­formamide mol­ecule, two O atoms from two Ό6-benzene-1,3,5-tricarboxyl­ate ligands and three O atoms from three Ό3-formate ligands in a distorted octa­hedral geometry

    Millisecond dips in the 2007-2009 RXTE/PCA lightcurve of Sco X-1 and one possible occultation event

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    Serendipitous stellar occultation search is so far the only way to detect the existence of very small, very dim, remote objects in the solar system. To date, however, there are only very few reported detections for trans-Neptunian objects (TNOs) in optical bands. In the X-ray band, with the RXTE/PCA data of Sco X-1 taken from June 2007 to October 2009, we found one possible X-ray occultation event. We discuss the veracity and properties of this event, and suggest upper limits to the size distribution of TNOs at hectometer size and of Main-Belt Asteroids (MBAs) at decameter size.Comment: 8 pages, 5 figures, to appear in MNRAS (accepted on Sep. 10, 2010

    Robotic Pick-and-Place of Novel Objects in Clutter with Multi-Affordance Grasping and Cross-Domain Image Matching

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    This paper presents a robotic pick-and-place system that is capable of grasping and recognizing both known and novel objects in cluttered environments. The key new feature of the system is that it handles a wide range of object categories without needing any task-specific training data for novel objects. To achieve this, it first uses a category-agnostic affordance prediction algorithm to select and execute among four different grasping primitive behaviors. It then recognizes picked objects with a cross-domain image classification framework that matches observed images to product images. Since product images are readily available for a wide range of objects (e.g., from the web), the system works out-of-the-box for novel objects without requiring any additional training data. Exhaustive experimental results demonstrate that our multi-affordance grasping achieves high success rates for a wide variety of objects in clutter, and our recognition algorithm achieves high accuracy for both known and novel grasped objects. The approach was part of the MIT-Princeton Team system that took 1st place in the stowing task at the 2017 Amazon Robotics Challenge. All code, datasets, and pre-trained models are available online at http://arc.cs.princeton.eduComment: Project webpage: http://arc.cs.princeton.edu Summary video: https://youtu.be/6fG7zwGfIk

    “I can’t see an end in sight.” How the COVID-19 pandemic may influence suicide risk: a qualitative study

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    <jats:p> Zusammenfassung: Theoretischer Hintergrund: Das Ziel der vorliegenden Studie war es, eine deutschsprachige Adaptation der Bergen Study Addiction Scale (BStAS), einer Skala zur Erfassung von exzessivem Studierverhalten, zu entwickeln und zu validieren. Methode: Die Daten von 615 Studierenden wurden analysiert. Die DimensionalitĂ€t der BStAS wurde mittels konfirmatorischer Faktorenanalyse ĂŒberprĂŒft. Außerdem wurden Korrelations- und hierarchische Regressionsanalysen durchgefĂŒhrt, um ZusammenhĂ€nge von exzessivem Studierverhalten mit Persönlichkeit und Gesundheit zu untersuchen. Ergebnisse: Der Vergleich mit Dynamic Fit Index Cutoffs deutete auf eine moderate Missspezifikation des einfaktoriellen Modells hin. Wie erwartet war exzessives Studierverhalten positiv mit wöchentlichen Lernstunden, Neurotizismus, wahrgenommenem Stress, psychosomatischen Beschwerden und Schlafproblemen assoziiert und hing negativ mit Lebenszufriedenheit zusammen. Schlussfolgerung: Es ist fraglich, ob alle Items der BStAS Aspekte einer Verhaltenssucht erfassen. Die Ergebnisse legen dennoch nahe, dass die BStAS ein Studierverhalten misst, das in Bezug auf physische und psychische Gesundheit von Relevanz ist. </jats:p&gt
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