1,469 research outputs found
Efficiently Disassemble-and-Pack for Mechanism
In this paper, we present a disassemble-and-pack approach for a mechanism to
seek a box which contains total mechanical parts with high space utilization.
Its key feature is that mechanism contains not only geometric shapes but also
internal motion structures which can be calculated to adjust geometric shapes
of the mechanical parts. Our system consists of two steps: disassemble
mechanical object into a group set and pack them within a box efficiently. The
first step is to create a hierarchy of possible group set of parts which is
generated by disconnecting the selected joints and adjust motion structures of
parts in groups. The aim of this step is seeking total minimum volume of each
group. The second step is to exploit the hierarchy based on
breadth-first-search to obtain a group set. Every group in the set is inserted
into specified box from maximum volume to minimum based on our packing
strategy. Until an approximated result with satisfied efficiency is accepted,
our approach finish exploiting the hierarchy.Comment: 2 pages, 2 figure
Design Methodology for Six-Port Equal/Unequal Quadrature and Rat-Race Couplers With Balanced and Unbalanced Ports Terminated by Arbitrary Resistances
For the first time, the 6-port quadrature and rat-race couplers with balanced-unbalanced-hybrid ports are proposed. The corresponding design methodology is presented, which is capable of designing the proposed couplers with arbitrary power divisions and terminated resistances. In this paper, four types including quadrature and rat-race couplers are fully analyzed, covering all the application configurations of the balanced/unbalanced ports. Besides, the design equations are rigorously derived, with the final design procedures presented. Eventually, prototypes of the four coupler types are fabricated and experimentally measured. The final results sufficiently validate the proposed methodology
Spin Fluctuation Induced Linear Magnetoresistance in Ultrathin Superconducting FeSe Films
The discovery of high-temperature superconductivity in FeSe/STO has trigged
great research interest to reveal a range of exotic physical phenomena in this
novel material. Here we present a temperature dependent magnetotransport
measurement for ultrathin FeSe/STO films with different thickness and
protection layers. Remarkably, a surprising linear magnetoresistance (LMR) is
observed around the superconducting transition temperatures but absent
otherwise. The experimental LMR can be reproduced by magnetotransport
calculations based on a model of magnetic field dependent disorder induced by
spin fluctuation. Thus, the observed LMR in coexistence with superconductivity
provides the first magnetotransport signature for spin fluctuation around the
superconducting transition region in ultrathin FeSe/STO films
Neural Chinese Word Segmentation with Lexicon and Unlabeled Data via Posterior Regularization
Existing methods for CWS usually rely on a large number of labeled sentences
to train word segmentation models, which are expensive and time-consuming to
annotate. Luckily, the unlabeled data is usually easy to collect and many
high-quality Chinese lexicons are off-the-shelf, both of which can provide
useful information for CWS. In this paper, we propose a neural approach for
Chinese word segmentation which can exploit both lexicon and unlabeled data.
Our approach is based on a variant of posterior regularization algorithm, and
the unlabeled data and lexicon are incorporated into model training as indirect
supervision by regularizing the prediction space of CWS models. Extensive
experiments on multiple benchmark datasets in both in-domain and cross-domain
scenarios validate the effectiveness of our approach.Comment: 7 pages, 11 figures, accepted by the 2019 World Wide Web Conference
(WWW '19
The Effects of Abandonment Options on Investment Timing and Profit Sharing of FDI
The paper incorporates cooperative game theory into a real option method in a foreign direct investment setting and examines the operational decisions of a multinational corporation in a cooperative framework, where the corporation is endowed with an abandonment option and shares its profit with the host country. In particular, we investigate how the abandonment options affect the optimal investment timing and the optimal profit share of a foreign direct investment using a real option game method. We show that the flexibility of the abandonment option induces the corporation to investment earlier, which indicates the negative effects on investment trigger. The result is consistent with intuition since the abandonment option provides insurance and thus reduces the overall risk of the project. We also find that the introduction of the abandonment option reduces the optimal profit share in a cooperative framework and in turn the lower profit share increases the investment trigger, thereby having a positive effect on the investment threshold to hinder the investment. By numerical analysis, we find that the overall effect of the abandonment options is inversely related to the investment trigger. These findings provide quantitative analysis about the decisions regarding cooperation in international investment extraction projects
An Evolutionary Computation Based Feature Selection Method for Intrusion Detection
Data Availability: The data used to support the fndings of this study are available from the corresponding author upon request. This work was supported by the National Natural Science Foundation of China (61403206, 61771258, and 61876089), the Natural Science Foundation of Jiangsu Province (BK20141005 and BK20160910), the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (14KJB520025), the Priority Academic Program Development of Jiangsu Higher Education Institutions, the Open Research Fund of Jiangsu Engineering Research Center of Communication and Network Technology, NJUPT (JSGCZX17001), and the Natural Science Foundation of Jiangsu Province of China under Grant BK20140883.Peer reviewedPublisher PD
Pulsar discovery prospect of FASTA
The Five-hundred-meter Aperture Spherical radio Telescope (FAST) has
discovered more than 650 new pulsars, which account for 20% of our known
Galactic pulsar population. In this paper, we estimate the prospect of a pulsar
survey with a radio telescope array to be planned -- the FAST Array (FASTA),
consists of six "FAST-type" telescopes. Such a sensitive radio telescope array
would be a powerful instrument in probing the pulsar population deep into our
Galaxy as well as in nearby galaxies. We simulate the FASTA pulsar discovery
prospects with different Galactic pulsar population models and instrumental
parameter combinations. We find that FASTA could detect tens of thousands of
canonical pulsars and well-over thousands of millisecond pulsars. We also
estimate the potential yield if the FASTA is used to search for pulsars from
the nearby spiral galaxy M31, and find that it would probably discover around a
hundred new radio pulsars
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