Using an experimental coherent high-resolution X-band radar, we show that micro-Doppler signatures from one or more walking persons can be retrieved off the radar line of sight in a realistic urban environment. The off-sightline objects are illuminated by the radar wave multipath wall reflections. Velocity-time diagrams are created for specific walking targets using the short-time Fourier transform. Two scenarios are studied, with one and two persons, respectively, walking along a closed path.

In this poster, we would like to present the current state of the Kludd system. Kludd is a web-based collaboration tool, enabling users to collaborate around various media objects like images, videos, texts and audio in a shared workspace. The design metaphor is an online whiteboard, where multiple actors can add, manipulate and remove objects, all while everyone sees the same view. The system is made with standard components like HTML5, CSS3 and a number of open-source javascript libraries enabling real-time collaboration in a browser. Utilizing a Design Science Research methodology, the initial design was based on 9 design requirements. In this poster, a further four requirements are presented as a result of the analysis of the first phase, and an initial design of the second phase of the project is presented.

Detection of moving objects concealed behind a concrete wall corner has been demonstrated, using Doppler-based techniques with a stepped-frequency radar centered at 10 GHz, in a reduced-scale model of a street scenario. Micro-Doppler signatures have been traced in the return from a human target, both for walking and for breathing. Separate material measurements of the reflection and transmission of the concrete in the wall have showed that wall reflections are the dominating wave propagation mechanism for producing target detections, while wave components transmitted through the walls could be neglected. Weaker detections have been made of target returns via diffraction in the wall corner. A simple and fast algorithm for the detection and generation of detection tracks in down range has been developed, based on moving target indication technique.

There has been a notable interest in the organization of routing information to enable fast lookup of IP addresses. The interest is primarily motivated by the goal of building multigigabit routers for the Internet, without having to rely on multilayer switching techniques. We address this problem by using an LC-trie, a trie structure with combined path and level compression. This data structure enables us to build efficient, compact, and easily searchable implementations of an IP-routing table. The structure can store both unicast and multicast addresses with the same average search times. The search depth increases as /spl Theta/(log log n) with the number of entries in the table for a large class of distributions, and it is independent of the length of the addresses. A node in the trie can be coded with four bytes. Only the size of the base vector, which contains the search strings, grows linearly with the length of the addresses when extended from 4 to 16 bytes, as mandated by the shift from IP version 4 to IP version 6. We present the basic structure as well as an adaptive version that roughly doubles the number of lookups/s. More general classifications of packets that are needed for link sharing, quality-of-service provisioning, and multicast and multipath routing are also discussed. Our experimental results compare favorably with those reported previously in the research literature.

We show that a unit-cost RAM with a word length of w bits can sort n integers in the range O. .2W -1 in O (n log log n) time, for arbitrary w z log n, a significant improvement over the bound of O (n-) achieved by the fusion trees of Fredman and Willard.Provided that w 2 (log n)z+', for some fixed e > 0, the sorting can even be accomplished in linear expected time with a randomized algorithm.Both of our algorithms parallelize without loss on a unitcost PRAM with a word length of w bits.The first one yields an algorithm that uses O (log n) time and O (n log log n) operations on a deterministic CRCW PRAM.The second one yields an algorithm that uses O(log n) expected time and O(n) expected operations on a randomized EREW PRAM, provided that w 2 (log n)2+' for some fixed c >0.Our deterministic and randomized sequential and parallel algorithms generalize to the lexicographic sorting problem of sorting multiple-precision integers represented in several words.

Abstract We study the problem of string searching using the traditional approach of storing all unique substrings of the text in a suffix tree. The methods of path compression, level compression and data compression are combined to build a simple, compact and efficient implementation of a suffix tree. Based on a comparative discussion and extensive experiments, we argue that our new data structure is superior to previous methods in many practical situations.

We present new improved algorithms for the sorting problem. The algorithms are not only efficient but also clear and simple. First, we introduce Forward Radix Sort which combines the advantages of traditional left-to-right and right-to-left radix sort in a simple manner. We argue that this algorithm will work very well in practice. Adding a preprocessing step, we obtain an algorithm with attractive theoretical properties. For example, n binary strings can be sorted in /spl Theta/ (n log(B/(n log n)+2)) time, where B is the minimum number of bits that have to be inspected to distinguish the strings. This is an improvement over the previously best known result by Paige and Tarjan (1987). The complexity may also be expressed in terms of H, the entropy of the input: n strings from a stationary ergodic process can be sorted in /spl Theta/ (n log(1/H+1)) time an improvement over the result recently presented by Chen and Reif (1993).>