7,214 research outputs found
Irreducible MultiQutrit Correlations in Greenberger-Horne-Zeilinger Type States
Following the idea of the continuity approach in [D. L. Zhou, Phys. Rev.
Lett. 101, 180505 (2008)], we obtain the degrees of irreducible multi-party
correlations in two families of -qutrit Greenberger-Horne-Zeilinger type
states. For the pure states in one of the families, the irreducible 2-party,
-party and -party () correlations are nonzero, which is
different from the -qubit case. We also derive the correlation distributions
in the -qutrit maximal slice state, which can be uniquely determined by its
-qutrit reduced density matrices among pure states. It is proved that
there is no irreducible -qutrit correlation in the maximal slice state. This
enlightens us to give a discussion about how to characterize the pure states
with irreducible -party correlation in arbitrarily high-dimensional systems
by the way of the continuity approach.Comment: 5p, no fi
Analysis of Power-aware Buffering Schemes in Wireless Sensor Networks
We study the power-aware buffering problem in battery-powered sensor
networks, focusing on the fixed-size and fixed-interval buffering schemes. The
main motivation is to address the yet poorly understood size variation-induced
effect on power-aware buffering schemes. Our theoretical analysis elucidates
the fundamental differences between the fixed-size and fixed-interval buffering
schemes in the presence of data size variation. It shows that data size
variation has detrimental effects on the power expenditure of the fixed-size
buffering in general, and reveals that the size variation induced effects can
be either mitigated by a positive skewness or promoted by a negative skewness
in size distribution. By contrast, the fixed-interval buffering scheme has an
obvious advantage of being eminently immune to the data-size variation. Hence
the fixed-interval buffering scheme is a risk-averse strategy for its
robustness in a variety of operational environments. In addition, based on the
fixed-interval buffering scheme, we establish the power consumption
relationship between child nodes and parent node in a static data collection
tree, and give an in-depth analysis of the impact of child bandwidth
distribution on parent's power consumption.
This study is of practical significance: it sheds new light on the
relationship among power consumption of buffering schemes, power parameters of
radio module and memory bank, data arrival rate and data size variation,
thereby providing well-informed guidance in determining an optimal buffer size
(interval) to maximize the operational lifespan of sensor networks
TimeMachine: Timeline Generation for Knowledge-Base Entities
We present a method called TIMEMACHINE to generate a timeline of events and
relations for entities in a knowledge base. For example for an actor, such a
timeline should show the most important professional and personal milestones
and relationships such as works, awards, collaborations, and family
relationships. We develop three orthogonal timeline quality criteria that an
ideal timeline should satisfy: (1) it shows events that are relevant to the
entity; (2) it shows events that are temporally diverse, so they distribute
along the time axis, avoiding visual crowding and allowing for easy user
interaction, such as zooming in and out; and (3) it shows events that are
content diverse, so they contain many different types of events (e.g., for an
actor, it should show movies and marriages and awards, not just movies). We
present an algorithm to generate such timelines for a given time period and
screen size, based on submodular optimization and web-co-occurrence statistics
with provable performance guarantees. A series of user studies using Mechanical
Turk shows that all three quality criteria are crucial to produce quality
timelines and that our algorithm significantly outperforms various baseline and
state-of-the-art methods.Comment: To appear at ACM SIGKDD KDD'15. 12pp, 7 fig. With appendix. Demo and
other info available at http://cs.stanford.edu/~althoff/timemachine
Gauge group topology of 8D Chaudhuri-Hockney-Lykken vacua
Compactifications of the Chaudhuri-Hockney-Lykken (CHL) string to eight dimensions can be characterized by embeddings of root lattices into the rank 12 momentum lattice Lambda(M), the so-called Mikhailov lattice. Based on these data, we devise a method to determine the global gauge group structure including all U(1) factors. The key observation is that, while the physical states correspond to vectors in the momentum lattice, the gauge group topology is encoded in its dual. Interpreting a nontrivial pi(1)(G) = Z for the non-Abelian gauge group G as having gauged a Z 1-form symmetry, we also prove that all CHL gauge groups are free of a certain anomaly [1] that would obstruct this gauging. We verify this by explicitly computing Z for all 8D CHL vacua with rank(G) = 10. Since our method applies also to T-2 compactifications of heterotic strings, we further establish a map that determines any CHL gauge group topology from that of a "parent" heterotic model
Yukawa Hierarchies in Global F-theory Models
We argue that global F-theory compactifications to four dimensions generally
exhibit higher rank Yukawa matrices from multiple geometric contributions known
as Yukawa points. The holomorphic couplings furthermore have large hierarchies
for generic complex structure moduli. Unlike local considerations, the compact
setup realizes these features all through geometry, and requires no instanton
corrections. As an example, we consider a concrete toy model with gauge symmetry. From the geometry, we find two Yukawa points for the
coupling, producing a rank
two Yukawa matrix. Our methods allow us to track all complex structure
dependencies of the holomorphic couplings and study the ratio numerically. This
reveals hierarchies of and larger on a full-dimensional
subspace of the moduli space.Comment: 25 pages + appendix and references; v2: matched published version
(typos corrected
High intrinsic biosorption efficiency of cattle manure on Cr(VI): a potential low-cost fibre-rich biosorbent
Fibre-rich manure derived from grass-fed cattle showed significantly higher intrinsic sorption efficiency on Cr(VI) solution as compared to corncob, sawdust and cogon grass. This observation could be attributed to the ligneous nature and rough surface morphology of the cattle manure. Four-factor, three-level, face-centred composite design (FCCD) suggested the process was greatly affected by initial pH of the solution, contact time and sorbent dosage (p50% adsorption efficiency. It is predicted that both physisorption and chemisorption are involved in the sorption process
Higgs algebraic symmetry of screened system in a spherical geometry
The orbits and the dynamical symmetries for the screened Coulomb potentials
and isotropic harmonic oscillators have been studied by Wu and Zeng [Z. B. Wu
and J. Y. Zeng, Phys. Rev. A 62,032509 (2000)]. We find the similar properties
in the responding systems in a spherical space, whose dynamical symmetries are
described by Higgs Algebra. There exists a conserved aphelion and perihelion
vector, which, together with angular momentum, constitute the generators of the
geometrical symmetry group at the aphelia and perihelia points .Comment: 8 pages, 1 fi
Hepatic Arterial Infusion Chemotherapy vs Transcatheter Arterial Chemoembolization as Adjuvant Therapy Following Surgery for MVI-Positive Hepatocellular Carcinoma: A Multicenter Propensity Score Matching Analysis
Yuhua Wen,1,2,* Lianghe Lu,1,2,* Jie Mei,1,2 Yihong Ling,2,3 Renguo Guan,1,2 Wenping Lin,1,2 Wei Wei,1,2 Rongping Guo1,2 1State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, People’s Republic of China; 2Department of Liver Surgery, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, People’s Republic of China; 3Department of Pathology of Sun Yat-sen University Cancer Center, Guangzhou, 510060, People’s Republic of China*These authors contributed equally to this workCorrespondence: Rongping Guo; Wei Wei, Department of Hepatobiliary Oncology, Sun Yat-sen University Cancer Center, Guangzhou, 510060, People’s Republic of China, Email [email protected]; [email protected]: Microvascular invasion (MVI) is a significant pathological feature in hepatocellular carcinoma (HCC), adjuvant hepatic arterial infusion chemotherapy (a-HAIC) and adjuvant transcatheter arterial chemoembolization (a-TACE), are commonly used for HCC patients with MVI. This study aims to evaluate the efficacies of two adjuvant therapies after surgical treatment for HCC, compare them, and identify the significant factors.Methods: Clinical data from two randomized controlled trials involving HCC patients with MVI after surgical treatment were retrospectively reviewed. Propensity score matching (PSM) analysis was performed to balance baseline differences between patients who received a-HAIC or a-TACE, and control groups who underwent hepatectomy alone. Disease-free survival (DFS) and overall survival (OS) rates were compared.Results: In total of 549 patients were collected from two randomized controlled trials. Using the PSM and Kaplan-Meier method, the median DFS of the a-HAIC, a-TACE, and control groups was 63.2, 21.7, and 11.2 months (
Entanglement and quantum phase transition in the asymmetric Hubbard chain: density-matrix renormalization group calculations
We study the ground state quantum phase transition by means of entanglement
in the one-dimensional asymmetric Hubbard model with open boundary condition.
The local entanglement between the middle two sites and the rest of the system,
and the block entanglement between the left and right portions of the system,
are calculated using the density-matrix renormalization group (DMRG) method. We
find that the entanglement shows interesting scaling and singular behavior
around the phase transition line.Comment: 9 pages, 17 figures. One figure is remove
Doubly Differential Cross Sections of Low-Energy Electrons Emitted in the Ionization of Molecular Hydrogen by Bare Carbon Ions
We have measured the double differential cross sections (DDCS) (d2σ/dεedΩe) of low-energy electron emission in the ionization of H2 bombarded by bare carbon ions of energy 30 MeV. The energy and angular distributions of the electron DDCS have been obtained for 12 different emission angles and for electron energies varying between 0.1 and 300 eV. We have also deduced the single differential and total ionization cross section from the measured DDCS. The data have been compared with the predictions of first Born approximations and the CDW-EIS (continuum distorted wave–eikonal initial state) model. The CDW-EIS model provides an excellent agreement with the data. [S1050-2947~96!10109-8
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