This paper presents the design and evaluation of Pastry, a scalable, distributed object location and routing substrate for wide-area peer-to-peer ap- plications. Pastry performs application-level routing and object location in a po- tentially very large overlay network of nodes connected via the Internet. It can be used to support a variety of peer-to-peer applications, including global data storage, data sharing, group communication and naming. Each node in the Pastry network has a unique identifier (nodeId). When presented with a message and a key, a Pastry node efficiently routes the message to the node with a nodeId that is numerically closest to the key, among all currently live Pastry nodes. Each Pastry node keeps track of its immediate neighbors in the nodeId space, and notifies applications of new node arrivals, node failures and recoveries. Pastry takes into account network locality; it seeks to minimize the distance messages travel, according to a to scalar proximity metric like the number of IP routing hops. Pastry is completely decentralized, scalable, and self-organizing; it automatically adapts to the arrival, departure and failure of nodes. Experimental results obtained with a prototype implementation on an emulated network of up to 100,000 nodes confirm Pastry's scalability and efficiency, its ability to self-organize and adapt to node failures, and its good network locality properties.

/pdf/pastry-scalable-decentralized-object-location-and-routing-1u2equbbbp.pdf

Pastry: Scalable, Decentralized Object Location, and Routing for Large-Scale Peer-to-Peer Systems

The surface science of titanium dioxide

Satisfiability Modulo Theories (SMT) problem is a decision problem for logical first order formulas with respect to combinations of background theories such as: arithmetic, bit-vectors, arrays, and uninterpreted functions. Z3 is a new and efficient SMT Solver freely available from Microsoft Research. It is used in various software verification and analysis applications.

https://link.springer.com/content/pdf/10.1007%2F978-3-540-78800-3_24.pdf

Z3: an efficient SMT solver

Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

Medscape

MapReduce and its variants have been highly successful in implementing large-scale data-intensive applications on commodity clusters. However, most of these systems are built around an acyclic data flow model that is not suitable for other popular applications. This paper focuses on one such class of applications: those that reuse a working set of data across multiple parallel operations. This includes many iterative machine learning algorithms, as well as interactive data analysis tools. We propose a new framework called Spark that supports these applications while retaining the scalability and fault tolerance of MapReduce. To achieve these goals, Spark introduces an abstraction called resilient distributed datasets (RDDs). An RDD is a read-only collection of objects partitioned across a set of machines that can be rebuilt if a partition is lost. Spark can outperform Hadoop by 10x in iterative machine learning jobs, and can be used to interactively query a 39 GB dataset with sub-second response time.

/pdf/spark-cluster-computing-with-working-sets-2mqxkxxuqt.pdf

Spark: cluster computing with working sets

A facility for annotating a visual representation of a document is described. The facility presents on a display device visual representations of two or more portions of a document. The facility further present on the display on the display, in connection with each of one or more of the presented document portion visual representations, an annotation conveying a result of aggregating information describing two or more search transactions in whose results the represented document portion is included.

Document searching visualized within a document

A metallic coating on the surface of bulk high temper- ature superconductors (HTS) is a promising alternative in order to increase the HTS stability for large scale applications. The coating provides an evacuation path for the heat generated by hot spots within the HTS, which improves their thermal stability. This is even more evident in thick films geometries, which are frequently used in fault current limiters. In this paper, silver-gold alloys have been deposited on 1.8 mm in diameter Bi-2212 textured bars using an electrodeposition tech- nique in non-aqueous solvents. The deposition parameters have been adjusted to obtain a coating of different alloys with gold con- tents in the range 0-5 at % and with a thickness up to 45 . Elec- trical and thermal measurements have been performed. The results show the possibility of controlling the thermal and electrical con- ductivities of the composite material by adjusting the layer thick- ness and composition of the metallic coating. Index Terms—Bi-2212, coatings, electrodeposition.

Electrodeposition of Silver Gold Alloys on Ceramics

In network coding, a router in the network mixes information from different flows In the seminal work by Ahlswede et al [1], network coding is established as a technique to potentially increase the network capacity

Network coding with traffic engineering

As we become increasingly dependent on computers connected to the Internet, we must protect them from worm attacks. Worms can gain complete control of millions of hosts in a few minutes, and they can use the infected hosts for malicious activities such as distributed denial of service attacks, relaying spam, corrupting data, and disclosing confidential information. Since worms spread too fast for humans to respond, systems that strive to contain worm epidemics must be completely automatic. We propose Vigilante, a new end-to-end architecture to contain worms automatically that addresses the limitations of network-centric systems. Vigilante relies on collaborative worm detection at end hosts, but does not require hosts to trust each other. In Vigilante, hosts run instrumented software to detect worms. We introduce dynamic dataflow analysis, a broad-coverage detection algorithm, and we show how to integrate other detection mechanisms into the Vigilante architecture. Upon worm detection, hosts generate self-certifying alerts (SCAs), a new type of security alert that can be inexpensively verified by any vulnerable host. SCAs are then broadcast over a resilient overlay network that can propagate alerts with high probability, even when under active attack. Finally, hosts receiving an SCA generate protective filters with dynamic data and control flow analysis of the vulnerable software. Our results show that Vigilante can contain fast spreading worms that exploit unknown vulnerabilities without false positives. Vigilante does not require any changes to hardware, compilers, operating systems or to the source code of vulnerable programs, and therefore can be used to protect software as it exists today in binary form

Stopping Internet Epidemics

In this contribution, we summarize our efforts toward detection of TNT, from traces to bulk amounts, based on the absorption fingerprint of TNT. Light absorption by TNT is broken into three regions: (1) VIS light absorption by TNT, and (2) formation and detection of NO2 upon UV irradiation of TNT and (3) formation and detection of NO following UV absorption by NO2. The absorption spectrum of TNT powder and particles has been determined from spectral analysis of backscattered VIS light in traditional optical and near field optical microscopy measurements, respectively. The smallest amount of TNT detected in the near field measurements is 7 fg. The absorption spectra of TNT are rich in structure and similar to the one measured for gas phase NO2, with lines due to rovibronic coupling of electronic excited states. Measurements of the backscattered visible light on samples, placed about 5 to 10 meters from the laser source, indicate a clear change in intensity as compared to samples containing TNT. The second light absorption region, NO2 is detected upon UV irradiation of solid TNT.

Miguel Castro

Papers

Document searching visualized within a document

Electrodeposition of Silver Gold Alloys on Ceramics

Network coding with traffic engineering

Stopping Internet Epidemics

Nitroexplosives detection: from basic science to detection at a distance