1,310 research outputs found
Neural Attentive Session-based Recommendation
Given e-commerce scenarios that user profiles are invisible, session-based
recommendation is proposed to generate recommendation results from short
sessions. Previous work only considers the user's sequential behavior in the
current session, whereas the user's main purpose in the current session is not
emphasized. In this paper, we propose a novel neural networks framework, i.e.,
Neural Attentive Recommendation Machine (NARM), to tackle this problem.
Specifically, we explore a hybrid encoder with an attention mechanism to model
the user's sequential behavior and capture the user's main purpose in the
current session, which are combined as a unified session representation later.
We then compute the recommendation scores for each candidate item with a
bi-linear matching scheme based on this unified session representation. We
train NARM by jointly learning the item and session representations as well as
their matchings. We carried out extensive experiments on two benchmark
datasets. Our experimental results show that NARM outperforms state-of-the-art
baselines on both datasets. Furthermore, we also find that NARM achieves a
significant improvement on long sessions, which demonstrates its advantages in
modeling the user's sequential behavior and main purpose simultaneously.Comment: Proceedings of the 2017 ACM on Conference on Information and
Knowledge Management. arXiv admin note: text overlap with arXiv:1511.06939,
arXiv:1606.08117 by other author
Two-dimensional array of microtraps with atomic shift register on a chip
Arrays of trapped atoms are the ideal starting point for developing registers
comprising large numbers of physical qubits for storing and processing quantum
information. One very promising approach involves neutral atom traps produced
on microfabricated devices known as atom chips, as almost arbitrary trap
configurations can be realised in a robust and compact package. Until now,
however, atom chip experiments have focused on small systems incorporating
single or only a few individual traps. Here we report experiments on a
two-dimensional array of trapped ultracold atom clouds prepared using a simple
magnetic-film atom chip. We are able to load atoms into hundreds of tightly
confining and optically resolved array sites. We then cool the individual atom
clouds in parallel to the critical temperature required for quantum degeneracy.
Atoms are shuttled across the chip surface utilising the atom chip as an atomic
shift register and local manipulation of atoms is implemented using a focused
laser to rapidly empty individual traps.Comment: 6 pages, 4 figure
The twoâway relationship between ionospheric outflow and the ring current
It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring current dynamics. However, because the ring current deposits energy into the ionosphere, the inverse may also be true: the ring current can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, firstâprinciplesâbased numerical models to test the dependence of ionospheric outflow on ring currentâdriven region 2 fieldâaligned currents (FACs). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptive Tree Solar wind Roeâtype Upwind Scheme, BATSâRâUS), a polar wind model (Polar Wind Outflow Model), and a bounceâaveraged kinetic ring current model (ring current atmosphere interaction model with selfâconsistent magnetic field, RAMâSCB). Initially, each code is twoâway coupled to all others except for RAMâSCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 FACs in BATSâRâUS. It is found that the region 2 FACs increase heavy ion outflow by up to 6 times over the noncoupled results. The additional outflow further energizes the ring current, establishing an ionosphereâmagnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphereâmagnetosphereâring current system.Key PointsRegion 2 fieldâaligned currents drive additional ionospheric O+ outflowThis additional outflow feeds the ring current, creating a feedback systemIonospheric outflow is a tightly coupled piece of the MâI systemPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112284/1/jgra51836.pd
Maternal inheritance on reproductive traits in Brangus-Ibagé cattle.
A influĂȘncia da herança citoplasmĂĄtica sobre caracterĂsticas reprodutivas foi investigada em bovinos Brangus-IbagĂ© (3/8 Nelore x 5/8 Aberdeen Angus). Os efeitos genĂ©ticos aditivos foram responsĂĄveis por 12% ± 11% da variação fenotĂpica observada no primeiro intervalo entre partos, mas esta contribuição decresceu para zero quando todos os intervalos entre partos (IEP) foram considerados. A herdabilidade da idade para o primeiro parto (IPP, em dias) foi estimada em 0,19 ± 0,09. A linhagem mitocondrial teve um efeito negligenciĂĄvel na variĂąncia fenotĂpica do intervalo entre partos (0,0 ± 0,02), peso do terneiro ao nascer (0,0 ± 0,01) e peso da vaca ao parto (0,0 ± 0,01). No entanto, para a idade ao primeiro parto, a linhagem mitocondrial contribuiu com 0,15 ± 0,07 da variação total. O peso da vaca ao parto teve efeito linear significante em IEP e IPP. TrĂȘs mutaçÔes na regiĂŁo D-loop do mtDNA afetaram significantemente o IEP (T C nos sĂtios 16.113 e 16.119) ou o peso do terneiro ao nascer (T C no sĂtio 16.113). As variantes C diminuĂram o intervalo entre partos (29 e 32 dias, respectivamente) e aumentaram o peso do terneiro (0,6kg). Embora os efeitos sejam pequenos, a seleção de fĂȘmeas portadoras dessas mutaçÔes poderia melhorar o desempenho reprodutivo e o desenvolvimento deste rebanho
Transfer-free graphene passivation of sub 100 nm thin Pt and PtâCu electrodes for memristive devices
Memristive switches are among the most promising building blocks for future neuromorphic computing. These devices are based on a complex interplay of redox reactions on the nanoscale. Nanoionic phenomena enable non-linear and low-power resistance transition in ultra-short programming times. However, when not controlled, the same electrochemical reactions can result in device degradation and instability over time. Two-dimensional barriers have been suggested to precisely manipulate the nanoionic processes. But fabrication-friendly integration of these materials in memristive devices is challenging.Here we report on a novel process for graphene passivation of thin platinum and platinum/copper electrodes. We also studied the level of defects of graphene after deposition of selected oxides that are relevant for memristive switching
Consequences of a saturated convection electric field on the ring current
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94778/1/grl15466.pd
Dressing of Ultracold Atoms by their Rydberg States in a Ioffe-Pritchard Trap
We explore how the extraordinary properties of Rydberg atoms can be employed
to impact the motion of ultracold ground state atoms. Specifically, we use an
off-resonant two-photon laser dressing to map features of the Rydberg states on
ground state atoms. It is demonstrated that the interplay between the spatially
varying quantization axis of the considered Ioffe-Pritchard field and the fixed
polarizations of the laser transitions provides the possibility of
substantially manipulating the ground state trapping potential.Comment: 11 pages, 4 figure
Observation of mesoscopic crystalline structures in a two-dimensional Rydberg gas
The ability to control and tune interactions in ultracold atomic gases has
paved the way towards the realization of new phases of matter. Whereas
experiments have so far achieved a high degree of control over short-ranged
interactions, the realization of long-range interactions would open up a whole
new realm of many-body physics and has become a central focus of research.
Rydberg atoms are very well-suited to achieve this goal, as the van der Waals
forces between them are many orders of magnitude larger than for ground state
atoms. Consequently, the mere laser excitation of ultracold gases can cause
strongly correlated many-body states to emerge directly when atoms are
transferred to Rydberg states. A key example are quantum crystals, composed of
coherent superpositions of different spatially ordered configurations of
collective excitations. Here we report on the direct measurement of strong
correlations in a laser excited two-dimensional atomic Mott insulator using
high-resolution, in-situ Rydberg atom imaging. The observations reveal the
emergence of spatially ordered excitation patterns in the high-density
components of the prepared many-body state. They have random orientation, but
well defined geometry, forming mesoscopic crystals of collective excitations
delocalised throughout the gas. Our experiment demonstrates the potential of
Rydberg gases to realise exotic phases of matter, thereby laying the basis for
quantum simulations of long-range interacting quantum magnets.Comment: 10 pages, 7 figure
Communityâwide validation of geospace model ground magnetic field perturbation predictions to support model transition to operations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98787/1/swe20056.pd
Searching for Novel Biomarkers Using a Mouse Model of CLN3-Batten Disease
CLN3-Batten disease is a rare, autosomal recessive disorder involving seizures, visual, motor and cognitive decline, and premature death. The Cln3Îex7/8 mouse model recapitulates several phenotypic characteristics of the most common 1.02kb disease-associated deletion. Identification of reproducible biomarker(s) to facilitate longitudinal monitoring of disease progression and provide readouts for therapeutic response has remained elusive. One factor that has complicated the identification of suitable biomarkers in this mouse model has been that variations in animal husbandry appear to significantly influence readouts. In the current study, we cross-compared a number of biological parameters in blood from Cln3Îex7/8 mice and control, non-disease mice on the same genetic background from multiple animal facilities in an attempt to better define a surrogate marker of CLN3-Batten disease. Interestingly, we found that significant differences between Batten and non-disease mice found at one site were generally not maintained across different facilities. Our results suggest that colony variation in the Cln3Îex7/8 mouse model of CLN3-Batten disease can influence potential biomarkers of the disease
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