Panel discussion

Panel discussion: summation and future projections. Introductory remarks by panelists followed by questions and comments from the floor. Panelists: Dr. Joseph Barnea (former director of Resources and Transport for the United Nations; energy consultant to the United Nations Institute for Training and Research (UNITAR)); the Honorable Clyde F. Bel, Jr. (member of the Louisiana House of Representatives representing District 90 and New Orleans); Dr. David Lombard (acting chief of the Advanced Systems Branch of the Division of Geothermal Energy Research and Technology, Energy Research and Development Administration (ERDA)); Fred C. Repper (vice-president of Central Power and Light Company in Corpus Christi, Texas); Dr. Hans Suter (environmental consultant in Corpus Christi, Texas; environmental columnist for the Corpus Christi Caller Times). Session chairman: Herbert Woodson

Spatter Tracking in Laser Machining

Abstract. In laser drilling, an assist gas is often used to remove material from the drilling point. In order to design assist gas nozzles to minimize spatter formation, measurements of spatter trajectories are required. We apply computer vision methods to measure the 3D trajectories of spatter particles in a laser cutting event using a stereo camera configuration. We also propose a novel method for calibration of a weak perspective camera that is effective in our application. The proposed method is evaluated with both computer-generated video and video taken from actual laser drilling events. The method performs well on different workpiece materials

A Framework for the Visualization of Finite-Time Continuum Mechanics Effects in Time-Varying Flow

Abstract. Integration-based flow visualization provides important visual cues about fluid transport. Analyzing the behavior of infinitesimal volumes as opposed to the behavior of rigid particles provides additional details valuable to flow visualization research. Our work concentrates on examining the local velocity gradient tensor along the path of a particle seeded within time-varying flow to produce a visualization highlighting temporal characteristics of particle behaviors, such as deformation. We present a framework for the analysis and visualization of such characteristics, focused on providing concise representations of physically meaningful flow features such as separation regions and vorticity. We apply the derived techniques to two data sets, highlighting the importance of such higher order Lagrangian analysis techniques to time-varying flow analysis

Health Physics Division annual progress report for period ending July 31, 1966

No abstract prepared

An Approach to Natural Language Equation Reading in Digital Talking Books

Abstract. Mathematic equations are, of necessity, a must in any mathematic textbooks but also in physics, communications and, in general, in any technology related texts. Furthermore, their usage in Digital Talking Books (DTB) can be eased if its corresponding counterpart in both text and/or spoken forms can be automatically generated. Therefore, an automatic system to translate or convert them into text and latter to speech is needed to broaden the scope of the DTBs. In this paper we address the implementation of a "translation" system that converts mathematical equations into text in such a way that it resembles as much as possible the "natural" reading of those entities. The system we implemented is more than just a translator from some form of mathematical notation into text, since reading heuristics were included. The goal is to mimic as much as possible the "usual" way someone reads equations. The reading heuristics can, and sometimes do, lead to ambiguity in the meaning or in the generated text. But, the naturalness of the results can be a better option when the reader is, at least, vaguely familiar with the topics. Evaluation results, although preliminary, are presented and surely validate our approach

On Using Genetic Algorithms for Intrinsic Side-Channel Resistance: The Case of AES S-Box

Abstract. Finding balanced S-boxes with high nonlinearity and low transparency order is a difficult problem. The property of transparency order is important since it specifies the resilience of an S-box against differential power analysis. Many S-boxes used today have high transparency order and are therefore intrinsically more susceptible to sidechannel analysis. Better values for transparency order and hence improved side-channel security often imply less in terms of nonlinearity. Therefore, it is impossible to find an S-box with all optimal values. However, well-balanced S-boxes with low transparency order and relatively high nonlinearity present a valuable alternative when implementing symmetric ciphers on embedded devices like smart cards. Currently, there are no algebraic procedures that can give the preferred and complete set of properties for an S-box. In this paper, we employ evolutionary algorithms to find S-boxes with desired cryptographic properties. Specifically, we conduct experiments for the 8×8 S-box case as used in the AES standard. The results of our experiments proved the feasibility of finding S-boxes with the desired properties in the case of AES. In addition, the results of our preliminary side-channel analysis on different versions of "improved" S-boxes show the method effective in terms of increasing DPA resistance

Janus: An Active Middleware for Accessing Sensor Networks

Abstract. One of the research challenges in sensor networking is how to access the resources of the sensor network from a remote location i.e., collecting information and reacting to events from the sensor network. Although access mechanisms already exist, they are typically application-specific and thus inflexible. This reduces the potential life-time of the sensor network by limiting how we can change it after deployment. We may wish to upgrade the sensor network after deployment due to changing application requirements and other unforeseen circumstances. Sensor network deployments in harsh or remote environments make upgrading very difficult. We present an architecture called Janus which comprises of an extensible middleware for interfacing with a sensor network and a code deployment platform which can be run inside of a sensor network. We model the sensor network as a collection of functions which provides us with a natural way to extend its functionality by adding more functions. We have implemented the middleware and tested it against a sample real-world sensor network and have implemented the code deployment platform in the Contiki network simulator