892 research outputs found
Mechanism design for aggregating energy consumption and quality of service in speed scaling scheduling
We consider a strategic game, where players submit jobs to a machine that
executes all jobs in a way that minimizes energy while respecting the given
deadlines. The energy consumption is then charged to the players in some way.
Each player wants to minimize the sum of that charge and of their job's
deadline multiplied by a priority weight. Two charging schemes are studied, the
proportional cost share which does not always admit pure Nash equilibria, and
the marginal cost share, which does always admit pure Nash equilibria, at the
price of overcharging by a constant factor
Concrete Semantics with Coq and CoqHammer
The "Concrete Semantics" book gives an introduction to imperative programming
languages accompanied by an Isabelle/HOL formalization. In this paper we
discuss a re-formalization of the book using the Coq proof assistant. In order
to achieve a similar brevity of the formal text we extensively use CoqHammer,
as well as Coq Ltac-level automation. We compare the formalization efficiency,
compactness, and the readability of the proof scripts originating from a Coq
re-formalization of two chapters from the book
Constructive counterexamples to additivity of minimum output R\'enyi entropy of quantum channels for all p>2
We present a constructive example of violation of additivity of minimum
output R\'enyi entropy for each p>2. The example is provided by antisymmetric
subspace of a suitable dimension. We discuss possibility of extension of the
result to go beyond p>2 and obtain additivity for p=0 for a class of
entanglement breaking channels.Comment: 4 pages; a reference adde
SEM-EDS and water chemistry characteristics at the early stages of glacier recession reveal biogeochemical coupling between proglacial sediments and meltwater
Most glaciers worldwide are undergoing climate-forced recession, but the impact of glacier changes on biogeochemical cycles is unclear. This study examines the influence of proglacial sediment weathering on meltwater chemistry at the early stages of glacier recession in the High Arctic of Svalbard. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) in combination with a wide range of geochemical analyses were used in this study. The SEM-EDS analyses of sediments collected in front of Werenskioldbreen show general degradation of pyrite and carbonate grains with age. The outer parts of pyrite grains have a gradual decrease in sulphur and gradual increase in iron oxides due to pyrite oxidation. This process was less advanced in the proglacial zone younger than 100 years compared to older sites such as the terminal moraine from the Little Ice Age. In both the proglacial zone and the terminal moraine, physical weathering of mineral grains, including formation of microcracks and microfractures, clearly enhanced pyrite oxidation. A consequence of proglacial sediment weathering is that the river chemistry is strongly affected by carbonate dissolution driven by sulphuric acid from sulphide oxidation. Also, reactive iron oxides, a product of sulphide oxidation, are mobilized in the proglacial zone. The results of this study show that proglacial weathering in the High Arctic of Svalbard is strongly coupled to river geochemistry, especially during the early stages of proglacial exposure after glacier recession
Redescription of Doryphoribius vietnamensis (Iharos, 1969) (Tardigrada) comb. nov. on the basis of the holotype and additional material from China
Hypsibius vietnamensis IHAROS, 1969 was described from Huong tich, 60 km south-west of Hanoi in Vietnam. RAMAZZOTTI andMAUCCI (1983) transferred it to the genus Isohypsibius on the basis of drawings of claws. BEASLEY and CLEVELAND (1996) reported Isohypsibius vietnamensis (IHAROS, 1969) from Yunnan Province in China. We have re-examined specimens described by IHAROS (holotype) and those from China and determined that they should be transferred to the genus Doryphoribius due to their bucco-pharyngeal apparatus structure. Many years ago Hypsibius (Isohypsibius) flavus IHAROS 1966 was also transferred to the genus Doryphoribius SCHUSTER and TOFTNER (1982). It may suggest that some other species of genus Isohypsibius should also by transferred to genus Doryphoribius. Genus Doryphoribius differs from Isohypsibius by the presence of the ventral reinforcement bar on the buccal tube
Possible gravitational microlensing events in the optical lightcurve of active galaxy S5 0716+714
A well-known active galaxy of the blazar type, S5 0716+714, is characterized by a particularly high-variability duty cycle on short timescales at optical frequencies. As such, the source was subjected to numerous monitoring programs, including both ground-based as well as spaceborne telescopes. On closer inspection of the most recent accumulation of the data provided by the Transiting Exoplanet Survey Satellite, we have noticed several conspicuous events with "volcano-like" symmetric shape, all lasting for several hours, which closely resemble the achromatic events detected with the previous Whole Earth Blazar Telescope campaigns targeting the source. We propose that those peculiar features could be due to the gravitational microlensing of the innermost segments of the precessing jet in the system by a binary lens. We study the magnification pattern of the lens with the inverse-ray shooting method and the source trajectory parameters with the Python package MuLensModel. In this way, we were able to fit successfully all the selected events with a single lens, adjusting slightly only the source trajectory parameters for each lensing event. Based on the fit results, we postulate the presence of a massive binary lens containing an intermediate-mass black hole, possibly even a supermassive one, and a much less massive companion (by a factor of ≲ 0.01) located within the host galaxy of the blazar, most likely the central kiloparsec region. We discuss the major physical implications of the proposed scenario regarding the quest for the intermediate-mass and dual supermassive black holes in active galaxies
Flagellate Dermatitis due to Bleomycin Intake
Flagellate dermatitis is a rare cutaneous manifestation in which
long, striated erythematous lesion appear on the patient’s skin. It is most frequently
associated with bleomycin treatment or Shiitake mushroom intake,
but it may also be attributed to many other possible causes. Herein we present
a case of striated, hyperpigmented lesions which occurred after bleomycin
intake. The typical flagellate lesions appeared for the first time on the patient’s
back and shoulders after the first course of chemotherapy for seminoma
(bleomycin, etoposide, and cisplatin). The active lesions disappeared with
the discontinuation of chemotherapy. Clinicians should be aware of flagellate
pattern of dermatitis which may accompany different clinical situation
Entropic trade-off relations for quantum operations
Spectral properties of an arbitrary matrix can be characterized by the
entropy of its rescaled singular values. Any quantum operation can be described
by the associated dynamical matrix or by the corresponding superoperator. The
entropy of the dynamical matrix describes the degree of decoherence introduced
by the map, while the entropy of the superoperator characterizes the a priori
knowledge of the receiver of the outcome of a quantum channel Phi. We prove
that for any map acting on a N--dimensional quantum system the sum of both
entropies is not smaller than ln N. For any bistochastic map this lower bound
reads 2 ln N. We investigate also the corresponding R\'enyi entropies,
providing an upper bound for their sum and analyze entanglement of the
bi-partite quantum state associated with the channel.Comment: 10 pages, 4 figure
Flagellate Dermatitis due to Bleomycin Intake
Flagellate dermatitis is a rare cutaneous manifestation in which
long, striated erythematous lesion appear on the patient’s skin. It is most frequently
associated with bleomycin treatment or Shiitake mushroom intake,
but it may also be attributed to many other possible causes. Herein we present
a case of striated, hyperpigmented lesions which occurred after bleomycin
intake. The typical flagellate lesions appeared for the first time on the patient’s
back and shoulders after the first course of chemotherapy for seminoma
(bleomycin, etoposide, and cisplatin). The active lesions disappeared with
the discontinuation of chemotherapy. Clinicians should be aware of flagellate
pattern of dermatitis which may accompany different clinical situation
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