JPIP Proxy Server for Remote Browsing of JPEG2000 Images

The JPEG2000 image compression standard offers scalability features in support of remote browsing applications. In particular Part 9 of the JPEG2000 standard defines a protocol called JPIP for interactivity with JPEG2000 code-streams and files. In client-server application based on JPIP, a client does not directly interact with the compressed file, but formulates requests using a simple syntax which identifies the current ldquoFocus Windowrdquo. In this kind of application particularly useful could be a proxy server, that potentially can improve the performance of the system through a better use of the network infrastructure. The aim of this work is to propose a proxy server with JPIP capabilities and shows the benefits that can be brought to remote browsing applications

Scalable Compression of Deep Neural Networks

Deep neural networks generally involve some layers with mil- lions of parameters, making them difficult to be deployed and updated on devices with limited resources such as mobile phones and other smart embedded systems. In this paper, we propose a scalable representation of the network parameters, so that different applications can select the most suitable bit rate of the network based on their own storage constraints. Moreover, when a device needs to upgrade to a high-rate network, the existing low-rate network can be reused, and only some incremental data are needed to be downloaded. We first hierarchically quantize the weights of a pre-trained deep neural network to enforce weight sharing. Next, we adaptively select the bits assigned to each layer given the total bit budget. After that, we retrain the network to fine-tune the quantized centroids. Experimental results show that our method can achieve scalable compression with graceful degradation in the performance.Comment: 5 pages, 4 figures, ACM Multimedia 201

The Legal Character and Practical Implementation of a TRIPS Waiver for COVID-19 Vaccines

Almost two years after initial proposals for a COVID-19 waiver of TRIPS obligations, a Ministerial decision adopted at the 12th Ministerial Conference in June 2022 waived obligations under Article 31(f) and the System for pharmaceutical export under the TRIPS Annex, and clarified existing options under TRIPS for increasing access to COVID-19 vaccines. As support for a more expansive pandemic waiver continues and WTO waivers remain legitimate mechanisms under WTO law, further waivers may be contemplated as viable options to address obstacles identified in the current pandemic or future health crises. This article explores what additional options are or may be open to Members under a COVID-19 waiver in its current or proposed forms, and the practical considerations for implementing them. To guide practical choices in selecting appropriate and adapted responses to public health and other crises, this article also investigates more theoretical questions about the nature of a waiver, its legal character and effect, and its interaction with other international agreements

Generating continuous variable quantum codewords in the near-field atomic lithography

Recently, D. Gottesman et al. [Phys. Rev. A 64, 012310 (2001)] showed how to encode a qubit into a continuous variable quantum system. This encoding was realized by using non-normalizable quantum codewords, which therefore can only be approximated in any real physical setup. Here we show how a neutral atom, falling through an optical cavity and interacting with a single mode of the intracavity electromagnetic field, can be used to safely encode a qubit into its external degrees of freedom. In fact, the localization induced by a homodyne detection of the cavity field is able to project the near-field atomic motional state into an approximate quantum codeword. The performance of this encoding process is then analyzed by evaluating the intrinsic errors induced in the recovery process by the approximated form of the generated codeword.Comment: 9 pages, 5 figure

Analyzing Scheduling Performance for Real-time Traffic in Wireless Networks

This paper is a sequel to an earlier study on scheduling real-time traffic in wireless TDMA channels. In particular, we develop mathematical analysis to model the system behavior of the equal-delay scheme and its extension of the multi-class scheme, both of which were proposed previously. The main usefulness of the proposed scheduling mechanisms is the improvement on the worst-case delay, and consequently the reduction in probability of delay violation or loss. We achieve the analytical solution by evaluating the corresponding cumulative distribution of delay. The derivation of the distribution function is based on a well-known method of solving a set of first order differential equations and eliminating all unstable modes. However, the existence of channel variations generate unique difficulties which renders the original method unsuitable. To solve this problem, we devise novel transformation techniques and an algorithm to recursively estimate the state probabilities in steady-state, so the original method can be applied in an alternative manner. Furthermore, we develop a reduced state model for homogeneous systems to alleviate the requirement on computational complexity of the full model. On the other hand, an additional challenge to extend the mathematical model to support the multi-class system is to overcome the varying progression rates of individual transmissions. To tackle this problem, we model the system aggregate delay value and recalculate the scaled statistics for each class of flows according to their pre-assigned weights. Finally, numerical results and computational complexity analysis are presented

Squashed States of Light: Theory and Applications to Quantum Spectroscopy

Using a feedback loop it is possible to reduce the fluctuations in one quadrature of an in-loop field without increasing the fluctuations in the other. This effect has been known for a long time, and has recently been called ``squashing'' [B.C. Buchler et al., Optics Letters {\bf 24}, 259 (1999)], as opposed to the ``squeezing'' of a free field in which the conjugate fluctuations are increased. In this paper I present a general theory of squashing, including simultaneous squashing of both quadratures and simultaneous squeezing and squashing. I show that a two-level atom coupled to the in-loop light feels the effect of the fluctuations as calculated by the theory. In the ideal limit of light squeezed in one quadrature and squashed in the other, the atomic decay can be completely suppressed.Comment: 8 pages plus one figure. Submitted to JEOS-B for Dan Walls Special Issu

Arteriography during ex vivo renal perfusion A complication

A case of bilateral renal-cell carcinoma unsuccessfully treated with bench surgery is reported. The reason for failure was apparently the toxicity of the contrast media used during the ex vivo arteriographic studies. © 1973

A bio-inspired image coder with temporal scalability

We present a novel bio-inspired and dynamic coding scheme for static images. Our coder aims at reproducing the main steps of the visual stimulus processing in the mammalian retina taking into account its time behavior. The main novelty of this work is to show how to exploit the time behavior of the retina cells to ensure, in a simple way, scalability and bit allocation. To do so, our main source of inspiration will be the biologically plausible retina model called Virtual Retina. Following a similar structure, our model has two stages. The first stage is an image transform which is performed by the outer layers in the retina. Here it is modelled by filtering the image with a bank of difference of Gaussians with time-delays. The second stage is a time-dependent analog-to-digital conversion which is performed by the inner layers in the retina. Thanks to its conception, our coder enables scalability and bit allocation across time. Also, our decoded images do not show annoying artefacts such as ringing and block effects. As a whole, this article shows how to capture the main properties of a biological system, here the retina, in order to design a new efficient coder.Comment: 12 pages; Advanced Concepts for Intelligent Vision Systems (ACIVS 2011

Experiments with Lasers and Frequency Doublers

Solid state laser sources, such as diode-pumped Nd:YAG lasers, have given us CW laser light of high power with unprecedented stability and low noise performance. In these lasers most of the technical sources of noise can be eliminated allowing them to be operated close to the theoretical noise limit set by the quantum properties of light. The next step of reducing the noise below the standard limit is known as squeezing. We present experimental progress in generating reliably squeezed light using the process of frequency doubling. We emphasize the long term stability that makes this a truly practical source of squeezed light. Our experimental results match noise spectra calculated with our recently developed models of coupled systems which include the noise generated inside the laser and its interaction with the frequency doubler. We conclude with some observations on evaluating quadrature squeezed states of light