23,498 research outputs found
Secure two-party quantum evaluation of unitaries against specious adversaries
We describe how any two-party quantum computation, specified by a unitary
which simultaneously acts on the registers of both parties, can be privately
implemented against a quantum version of classical semi-honest adversaries that
we call specious. Our construction requires two ideal functionalities to
garantee privacy: a private SWAP between registers held by the two parties and
a classical private AND-box equivalent to oblivious transfer. If the unitary to
be evaluated is in the Clifford group then only one call to SWAP is required
for privacy. On the other hand, any unitary not in the Clifford requires one
call to an AND-box per R-gate in the circuit. Since SWAP is itself in the
Clifford group, this functionality is universal for the private evaluation of
any unitary in that group. SWAP can be built from a classical bit commitment
scheme or an AND-box but an AND-box cannot be constructed from SWAP. It follows
that unitaries in the Clifford group are to some extent the easy ones. We also
show that SWAP cannot be implemented privately in the bare model
Template-based Gravitational-Wave Echoes Search Using Bayesian Model Selection
The ringdown of the gravitational-wave signal from a merger of two black
holes has been suggested as a probe of the structure of the remnant compact
object, which may be more exotic than a black hole. It has been pointed out
that there will be a train of echoes in the late-time ringdown stage for
different types of exotic compact objects. In this paper, we present a
template-based search methodology using Bayesian statistics to search for
echoes of gravitational waves. Evidence for the presence or absence of echoes
in gravitational-wave events can be established by performing Bayesian model
selection. The Occam factor in Bayesian model selection will automatically
penalize the more complicated model that echoes are present in
gravitational-wave strain data because of its higher degree of freedom to fit
the data. We find that the search methodology was able to identify
gravitational-wave echoes with Abedi et al.'s echoes waveform model about 82.3%
of the time in simulated Gaussian noise in the Advanced LIGO and Virgo network
and about 61.1% of the time in real noise in the first observing run of
Advanced LIGO with significance. Analyses using this method are
performed on the data of Advanced LIGO's first observing run, and we find no
statistical significant evidence for the detection of gravitational-wave
echoes. In particular, we find combined evidence of the three events
in Advanced LIGO's first observing run. The analysis technique developed in
this paper is independent of the waveform model used, and can be used with
different parametrized echoes waveform models to provide more realistic
evidence of the existence of echoes from exotic compact objects.Comment: 16 pages, 6 figure
The international right to health: what does it mean in legal practice and how can it affect priority setting for universal health coverage?
The international right to health is enshrined in national and international law. In a growing number of cases, individuals denied access to high-cost medicines and technologies under universal coverage systems have turned to the courts to challenge the denial of access as against their right to health. In some instances, patients seek access to medicines, services, or technologies that they would have access to under universal coverage if not for government, health system, or service delivery shortfalls. In others, patients seek access to medicines, services, or technologies that have not been included or that have been explicitly denied for coverage due to prioritization. In the former, judicialization of the right to health is critical to ensure patients access to the technologies or services to which they are entitled. In the latter, courts may grant patients access to medicines not covered as a result of explicit priority setting to allocate finite resources. By doing so, courts may give priority to those with the means and incentive to turn to the courts, at the expense of the maximization of equity- and population-based health. Evidence-based, informed decision-making processes could ensure that the most clinically and cost-effective products aligning with social value judgments are prioritized. Governments should be equipped to engage in and defend rational priority setting, and the priority setting process and institutions involved should be held accountable through an opportunity for appeal and judicial review. As a result, the courts could place greater reliance on the government's coverage choices, and the population's health could be most equitably distributed
On the communication cost of entanglement transformations
We study the amount of communication needed for two parties to transform some
given joint pure state into another one, either exactly or with some fidelity.
Specifically, we present a method to lower bound this communication cost even
when the amount of entanglement does not increase. Moreover, the bound applies
even if the initial state is supplemented with unlimited entanglement in the
form of EPR pairs, and the communication is allowed to be quantum mechanical.
We then apply the method to the determination of the communication cost of
asymptotic entanglement concentration and dilution. While concentration is
known to require no communication whatsoever, the best known protocol for
dilution, discovered by Lo and Popescu [Phys. Rev. Lett. 83(7):1459--1462,
1999], requires a number of bits to be exchanged which is of the order of the
square root of the number of EPR pairs. Here we prove a matching lower bound of
the same asymptotic order, demonstrating the optimality of the Lo-Popescu
protocol up to a constant factor and establishing the existence of a
fundamental asymmetry between the concentration and dilution tasks.
We also discuss states for which the minimal communication cost is
proportional to their entanglement, such as the states recently introduced in
the context of ``embezzling entanglement'' [W. van Dam and P. Hayden,
quant-ph/0201041].Comment: 9 pages, 1 figure. Added a reference and some further explanations.
In v3 some arguments are given in more detai
Interpretation and the Constraints on International Courts
This paper argues that methodologies of interpretation do not do what they promise – they do not constrain interpretation by providing neutral steps that one can follow in finding out a meaning of a text – but nevertheless do their constraining work by being part of what can be described as the legal practice
Implementasi Algoritma Kunang-Kunang Untuk Penjadwalan Mata Kuliah Di Universitas Ma Chung
. Course scheduling is considered as a complex matter because the generated schedule must guarantee that there are no clashes of classes, lecturers, and students’ schedules. At Ma Chung University, course scheduling is still accomplished manually. Due to the limited number of rooms and lecturers r, resource sharing system is applied. This causes complication in manual scheduling. Firefly algorithm is implemented in this application to schedule the course automatically. A schedule solution is represented as a firefly. Firefly with lower light intensity will move toward firefly with higher light intensity, so that a better solution is found. Based on a scheduling test, the best light intensity value of firefly is reached when firefly algorithm’s parameters, β0 and γ, are given 1 and 10 with light intensity value of 0,0003831
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