We address the reachability problem in acyclic networks of pushdown systems. We consider communication based either on shared memory or on message passing through unbounded lossy channels. We prove mainly that the reachability problem between recognizable sets of configurations (i.e., definable by a finite union of products of finite-state automata) is decidable for such networks, and that for ...

A new color image watermarking algorithm with resistance to JPEG lossy compression based on Quantization Index Modulation (QIM) is proposed in this paper. As it is known, QIM method can achieve a good balance between the embedding bit rate, robustness and distortion between the original image and the composited image by modulating the source signal into different clusters. The corresponding DCT...

In the paper is presented one new approach for adaptive processing and compression of images of scanned documents, which contain text and pictures. In order to achieve high compression with maximum retained quality, the document content is analyzed and two corresponding regions of interest are set. Then, each region is processed as follows: the text – with lossless and the picture – with lossy ...

Lossy dielectric bars have potential applications in high power microwave (HPM) radiation-effect experiments performed wind tunnels. Under plane excitation, beat wave patterns are observed along lossy and lossless 3-D electromagnetic simulation results. Mode analysis is to clarify the two main modes waves—the leaky guided modes. Comparisons made between theoretical simulated results acceptable ...

Large amount of medical image sequences are available in various hospitals and medical organizations, which occupies considerable storage space. Hence to reduce the storage space there is a need for compressing medical images. There are several lossy and lossless compression techniques. Using lossy compression the original images are not recovered exactly but using lossless compression techniqu...

This paper compares several, text and image, lossless and lossy, compression techniques for regular gridded elevation data, such as DEMs. Sp compress and progcode, the best lossless methods average 2.0 bits per point on USGS DEMs, about half the size of gzipped files, and 6.2 bits per point on ETOPO5 samples. Lossy compression produces even smaller files at moderate error rates. Finally, some t...

We provide a model of weighted distributed systems and give a logical characterization thereof. Distributed systems are represented as weighted asynchronous cellular automata. Running over directed acyclic graphs, Mazurkiewicz traces, or (lossy) message sequence charts, they allow for modeling several communication paradigms in a unifying framework, among them probabilistic sharedvariable and p...

The Internet of Things is the idea that everything around us from cars to ovens can be connected. If everything around us is linked and collecting information, these networks must be able to provide security and privacy to the end-user particularly in low-power lossy networks. Certain features including energy conservation and automation differentiate low-power lossy networks from the standard ...

“All-but-many lossy trapdoor functions” (ABM-LTF) are a powerful cryptographic primitive studied by Hofheinz (Eurocrypt 2012). ABM-LTFs are parametrised with tags: a lossy tag makes the function lossy; an injective tag makes the function injective, and invertible with a trapdoor. Existing ABM-LTFs rely on non-standard assumptions. Our first result is an ABM-LTF construction from lattices, based...

The degradation of Transport Control Protocol (TCP) throughput in networks with lossy links is mainly due to the coexistence of two types of losses, congestion losses and link corruption losses. This is very similar to processor performance degradation due to control hazards in CPU design. First, two types of loss events in networks with lossy links can be considered as two possibilities of a b...