1,231 research outputs found
Deterministic Dense Coding and Faithful Teleportation with Multipartite Graph States
We proposed novel schemes to perform the deterministic dense coding and
faithful teleportation with multipartite graph states. We also find the
sufficient and necessary condition of a viable graph state for the proposed
scheme. That is, for the associated graph, the reduced adjacency matrix of the
Tanner-type subgraph between senders and receivers should be invertible.Comment: 10 pages, 1 figure;v2. discussions improve
Multipartite Entanglement Measures and Quantum Criticality from Matrix and Tensor Product States
We compute the multipartite entanglement measures such as the global
entanglement of various one- and two-dimensional quantum systems to probe the
quantum criticality based on the matrix and tensor product states (MPSs/TPSs).
We use infinite time-evolving block decimation (iTEBD) method to find the
ground states numerically in the form of MPSs/TPSs, and then evaluate their
entanglement measures by the method of tensor renormalization group (TRG). We
find these entanglement measures can characterize the quantum phase transitions
by their derivative discontinuity right at the critical points in all models
considered here. We also comment on the scaling behaviors of the entanglement
measures by the ideas of quantum state renormalization group transformations.Comment: 22 pages, 11 figure
PowerPack: Energy Profiling and Analysis of High-Performance Systems and Applications
Energy efficiency is a major concern in modern high-performance computing system design. In the past few years, there has been mounting evidence that power usage limits system scale and computing density, and thus, ultimately system performance. However, despite the impact of power and energy on the computer systems community, few studies provide insight to where and how power is consumed on high-performance systems and applications. In previous work, we designed a framework called PowerPack that was the first tool to isolate the power consumption of devices including disks, memory, NICs, and processors in a high-performance cluster and correlate these measurements to application functions. In this work, we extend our framework to support systems with multicore, multiprocessor-based nodes, and then provide in-depth analyses of the energy consumption of parallel applications on clusters of these systems. These analyses include the impacts of chip multiprocessing on power and energy efficiency, and its interaction with application executions. In addition, we use PowerPack to study the power dynamics and energy efficiencies of dynamic voltage and frequency scaling (DVFS) techniques on clusters. Our experiments reveal conclusively how intelligent DVFS scheduling can enhance system energy efficiency while maintaining performance
Symmetry Protected Quantum State Renormalization
Symmetry protected topological (SPT) phases with gapless edge excitations
have been shown to exist in principle in strongly interacting bosonic/fermionic
systems and it is highly desirable to find practical systems to realize such
phases through numerical calculation. A central question to be addressed is how
to determine the SPT order in the system given the numerical simulation result
while no local order parameter can be measured to distinguish the phases from a
trivial one. In the tensor network approach to simulate strongly interacting
systems, the quantum state renormalization algorithm has been demonstrated to
be effective in identifying the intrinsic topological orders. Here we show that
a modified algorithm can identify SPT orders by extracting the fixed point
entanglement pattern in the ground state wave function which is essential for
the existence of SPT order. The key to this approach is to add symmetry
protection to the quantum state renormalization process and we demonstrate the
effectiveness of this algorithm with the example of AKLT states in both 1D and
2D
Ordered Variational Inequalities and Ordered Complementarity Problems in Banach Lattices
We introduce the concepts of ordered variational inequalities and ordered complementarity problems with both domain and range in Banach lattices. Then we apply the Fan-KKM theorem and KKM mappings to study the solvability of these problems
Ordered Variational Inequalities and Ordered Complementarity Problems in Banach Lattices
We introduce the concepts of ordered variational inequalities and ordered complementarity problems with both domain and range in Banach lattices. Then we apply the Fan-KKM theorem and KKM mappings to study the solvability of these problems
Novel CMOS RFIC Layout Generation with Concurrent Device Placement and Fixed-Length Microstrip Routing
With advancing process technologies and booming IoT markets, millimeter-wave
CMOS RFICs have been widely developed in re- cent years. Since the performance
of CMOS RFICs is very sensi- tive to the precision of the layout, precise
placement of devices and precisely matched microstrip lengths to given values
have been a labor-intensive and time-consuming task, and thus become a major
bottleneck for time to market. This paper introduces a progressive
integer-linear-programming-based method to gener- ate high-quality RFIC layouts
satisfying very stringent routing requirements of microstrip lines, including
spacing/non-crossing rules, precise length, and bend number minimization,
within a given layout area. The resulting RFIC layouts excel in both per-
formance and area with much fewer bends compared with the simulation-tuning
based manual layout, while the layout gener- ation time is significantly
reduced from weeks to half an hour.Comment: ACM/IEEE Design Automation Conference (DAC), 201
Niche Relationships of Carnivores in a Subtropical Primary Forest in Southern Taiwan
Carnivores are at the higher trophic levels and have garnered much attention in conservation and management efforts. In this study, we attempted to understand resource partitioning among sympatric carnivores existing in a primary forest with minimal human disturbance in southern Taiwan by camera trapping after the disappearance of the top carnivore, the clouded leopard (Neofelis nebulosa). Niche relationships were studied in terms of habitat, diet, and time dimensions. Six carnivore species were recorded, but the Asiatic black bear (Ursus thibetanus formosanus) was very rare. Canonical correspondence analysis of photographic rates and habitat factors of the other 5 carnivores showed that elevation was the strongest factor explaining the composition of the carnivore community in the habitat dimension. Carnivores could be divided into 3 groups. The low- to mid-elevation group consisted of the gem-faced palm civet (Paguma larvata taivana) and crab-eating mongoose (Herpestes urva formosanus) which had contrasting activity patterns and different diets; the mid- to high-elevation group consisted of yellow-throated marten (Martes flavigula chrysospila) and Siberian weasel (Mustela sibirica taivana). These 2 mustelids had similar diets, but Siberian weasels tended to avoid yellow-throated martens temporally. The Formosan ferret badger (Melogale moschata subaurantiaca) was more widely distributed along the elevational gradient. Ferret badgers partitioned resource use in either diet, activity patterns, or other habitat gradients from the other carnivores. Niche segregation and complementary resource use were observed in these 5 carnivores
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