7,364 research outputs found
Development of a container for handling, testing, and storing discrete microelectronic components
A container has been developed for handling, testing, burning-in, and storing discrete microelectronic components without removal from the protective package. The package was designed to accommodate the leadless inverted device and other carrier-mounted active devices and chip-type discrete resistors and capacitors. Before the indicated development, components were handled and tested in various ways, some of which resulted in damage or contamination. The basic design of the container utilizes precision machined printed circuit boards and chemically milled (photoetched) contact springs. Included in this design for protection is an O-ring-sealed cover. Methods of fabrication and limitations of the current hardware are presented. Current applications of and possible extensions to the technology are discussed
Evolution of twin-beam in active optical media
We study the evolution of twin-beam propagating inside active media that may
be used to establish a continuous variable entangled channel between two
distant users. In particular, we analyze how entanglement is degraded during
propagation, and determine a threshold value for the interaction time, above
which the state become separable, and thus useless for entanglement based
manipulations. We explicitly calculate the fidelity for coherent state
teleportation and show that it is larger than one half for the whole range of
parameters preserving entanglemenent.Comment: several misprints correcte
Restrictions on Expression as a Counter-Terror Policy in the United States and France: Divergence by Design or Curious Convergence?
This paper explores how restrictions on expression – a dimension of US and French counterterror policy – are realized given the socio-political and legal-procedural differences between the two countries. Theoretically, the US – with its strong constitutional free speech protections and its tradition of limited government – should respond less aggressively than France, which has a more flexible constitution and a statist tradition. This paper contends that while France restricts terror-related expression to a greater degree than the US, the US possesses more tools to counter terror-related expression than its constitution suggests. The primary explanation for less forceful US action stems not from constitutional limits, but from a US proclivity for military counterterrorism abroad, which takes focus away from domestic measures to disrupt terrorist propaganda. The policy inconsistencies identified in this paper contribute to not only the theoretical debate on responses to terrorism, but also the practical one playing out on legislative floors today
Squeezed state purification with linear optics and feed forward
A scheme for optimal and deterministic linear optical purification of mixed
squeezed Gaussian states is proposed and experimentally demonstrated. The
scheme requires only linear optical elements and homodyne detectors, and allows
the balance between purification efficacy and squeezing degradation to be
controlled. One particular choice of parameters gave a ten-fold reduction of
the thermal noise with a corresponding squeezing degradation of only 11%. We
prove optimality of the protocol, and show that it can be used to enhance the
performance of quantum informational protocols such as dense coding and
entanglement generation.Comment: 4 pages, 3 figure
Finding the Limits of France\u27s State of Emergency
Since 2015, France has experienced a particularly high number of terrorist attacks. This paper examines the French state response to such events and analyzes its effect on the relationship between civil liberties and national security. The activation of the state of emergency – as an exceptional measure that suspends warranted searches and certain freedoms – highlights a potential impediment to reconciling France’s national values such as liberté with the urgent need to mitigate terrorist activity. Following the fifth consecutive renewal of this exceptional measure in December 2016, a close scrutiny of its legitimacy, its effectiveness, and its objectives is both timely and warranted. I thus ask the following two questions: In what ways have exceptional crisis measures been historically entrenched in the French socio-political order? In the aftermath of the attacks of November 2015, how does the state of emergency build on these measures and normalize the use of inherently exceptional policies
Thermal Equilibration of 176-Lu via K-Mixing
In astrophysical environments, the long-lived (\T_1/2 = 37.6 Gy) ground state
of 176-Lu can communicate with a short-lived (T_1/2 = 3.664 h) isomeric level
through thermal excitations. Thus, the lifetime of 176-Lu in an astrophysical
environment can be quite different than in the laboratory. We examine the
possibility that the rate of equilibration can be enhanced via K-mixing of two
levels near E_x = 725 keV and estimate the relevant gamma-decay rates. We use
this result to illustrate the effect of K-mixing on the effective stellar
half-life. We also present a network calculation that includes the
equilibrating transitions allowed by K-mixing. Even a small amount of K-mixing
will ensure that 176-Lu reaches at least a quasi-equilibrium during an
s-process triggered by the 22-Ne neutron source.Comment: 9 pages, 6 figure
Moisture absorption kinetics of FruitPad for packaging of fresh strawberry
This study analysed the moisture absorption kinetics of FruitPad embedded with different concentrations of fructose with further application of such pads in packaging of fresh strawberries. The FruitPad was exposed to different storage conditions (temperature and RH) and moisture absorption kinetics was gravimetrically determined over 5 days of storage. FruitPad with 30% fructose showed highest amount of moisture absorption (0.94 g of water/g of pad) at 20 °C and 100% RH. The Weibull model combined with the Flory-Huggins model adequately described changes in moisture content of the FruitPad with respect to storage time and humidity (R2 = 93–96%). The FruitPad containing fructose minimized in-package condensation compared to the pad without fructose. Weight loss of packaged strawberry was less than 0.9% which was much below the acceptable limit of 6% for strawberry
Proactive multi-tenant cache management for virtualized ISP networks
The content delivery market has mainly been dominated by large Content Delivery Networks (CDNs) such as Akamai and Limelight. However, CDN traffic exerts a lot of pressure on Internet Service Provider (ISP) networks. Recently, ISPs have begun deploying so-called Telco CDNs, which have many advantages, such as reduced ISP network bandwidth utilization and improved Quality of Service (QoS) by bringing content closer to the end-user. Virtualization of storage and networking resources can enable the ISP to simultaneously lease its Telco CDN infrastructure to multiple third parties, opening up new business models and revenue streams. In this paper, we propose a proactive cache management system for ISP-operated multi-tenant Telco CDNs. The associated algorithm optimizes content placement and server selection across tenants and users, based on predicted content popularity and the geographical distribution of requests. Based on a Video-on-Demand (VoD) request trace of a leading European telecom operator, the presented algorithm is shown to reduce bandwidth usage by 17% compared to the traditional Least Recently Used (LRU) caching strategy, both inside the network and on the ingress links, while at the same time offering enhanced load balancing capabilities. Increasing the prediction accuracy is shown to have the potential to further improve bandwidth efficiency by up to 79%
An elementary proof of Marcellini Sbordone semicontinuity theorem
summary:The weak lower semicontinuity of the functional is a classical topic that was studied thoroughly. It was shown that if the function is continuous and convex in the last variable, the functional is sequentially weakly lower semicontinuous on . However, the known proofs use advanced instruments of real and functional analysis. Our aim here is to present a proof understandable even for students familiar only with the elementary measure theory
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