Experimental scaling study of fluid amplifier elements Final report

Scaling parameters of three fluid amplifier elements - bistable, boundary layer control, and vortex device

A Two-step Statistical Approach for Inferring Network Traffic Demands (Revises Technical Report BUCS-2003-003)

Accurate knowledge of traffic demands in a communication network enables or enhances a variety of traffic engineering and network management tasks of paramount importance for operational networks. Directly measuring a complete set of these demands is prohibitively expensive because of the huge amounts of data that must be collected and the performance impact that such measurements would impose on the regular behavior of the network. As a consequence, we must rely on statistical techniques to produce estimates of actual traffic demands from partial information. The performance of such techniques is however limited due to their reliance on limited information and the high amount of computations they incur, which limits their convergence behavior. In this paper we study a two-step approach for inferring network traffic demands. First we elaborate and evaluate a modeling approach for generating good starting points to be fed to iterative statistical inference techniques. We call these starting points informed priors since they are obtained using actual network information such as packet traces and SNMP link counts. Second we provide a very fast variant of the EM algorithm which extends its computation range, increasing its accuracy and decreasing its dependence on the quality of the starting point. Finally, we evaluate and compare alternative mechanisms for generating starting points and the convergence characteristics of our EM algorithm against a recently proposed Weighted Least Squares approach.National Science Foundation (ANI-0095988, EIA-0202067, ITR ANI-0205294

Health-related quality of life in long-term head and neck cancer survivors: a comparison with general population norms

To examine the health-related quality of life (HRQL) in long-term head and neck (H&N) cancer survivors compared with general population norms. HRQL was assessed with three standardized questionnaires: the SF-36 Health Survey (Short Form 36) and the EORTC QLQ-C30 and QLQ-H&N35 (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, -Core 30 and -Head and Neck 35 cancer module). Altogether 135 H&N cancer patients (mean age 62 years, 31% females) of 151 survivors (89% acceptance) from a longitudinal HRQL study (n = 232) were included 3 years after diagnosis. The H&N cancer patients' SF-36 scores did not differ significantly from those of an age- and sex-matched sample (n = 871) from the Swedish normative population, except on the role-physical functioning scale. On the other hand, treatment-related side-effects and disease-specific problems (e.g., swallowing, local pain and dry mouth) measured by the H&N cancer module were, with few exceptions, significantly worse than norm values. Gender comparisons revealed that female H&N cancer patients generally scored better than the norms on both the SF-36 and the EORTC QLQ-C30, while the male patients scored significantly worse on most SF-36 scales. Patients ≥65 years more often scored worse than the norm than did patients <65. Clinically relevant differences were found on the majority of SF-36 scales in comparison of tumour sites, however, comparisons of patients with small (stage I+II) versus advanced (stage III+IV) tumours revealed few differences. Three years after diagnosis H&N cancer patients still suffer significant functional limitations/problems related to their disease and its treatment but these problems do not generally affect their overall HRQL. Tumour stage no longer differentiates HRQL at 3 years, however, factors related to the patients' age, gender and location of the tumour appear to have bearing on their reported health status. © 2001 Cancer Research Campaign http://www.bjcancer.co

Applications of control theory

Applications of control theory are considered in the areas of decoupling and wake steering control of submersibles, a method of electrohydraulic conversion with no moving parts, and socio-economic system modelling

Magnetization Process of Nanoscale Iron Cluster

Low-temperature magnetization process of the nanoscale iron cluster in linearly sweeped fields is investigated by a numerical analysis of time-dependent Schr$\ddot{\rm o}$dinger equation and the quantum master equation. We introduce an effective basis method extracting important states, by which we can obtain the magnetization process effectively. We investigate the structure of the field derivative of the magnetization. We find out that the antisymmetric interaction determined from the lattice structure reproduces well the experimental results of the iron magnets and that this interaction plays an important role in the iron cluster. Deviations from the adiabatic process are also studied. In the fast sweeping case, our calculations indicate that the nonadiabatic transition dominantly occurs at the level crossing for the lowest field. In slow sweeping case, due to the influence of the thermal environment to the spin system, the field derivative of the magnetization shows an asymmetric behavior, the magnetic F$\ddot{\rm o}$hn effect, which explains the substructure of the experimental results in the pulsed field.Comment: 5 pages of text and 2 pages of 6 figures. To appear in J. Phys. Soc. Jp

FERAL SWINE---ARE THEY A DISEASE THREAT TO LIVESTOCK IN THE UNITED STATES?

Feral swine populations provide both benefits and liabilities to citizens of the United States. Their expanding range and increasing densities, however, have raised concern over the adverse environmental and agricultural effects and the increased risk of disease transmission between feral swine and livestock. We discuss the role of feral swine in the transmission of wildlife diseases and, in particular, in diseases of national significance to the livestock industry. We also discuss available management tools and strategies for reducing feral swine populations, minimizing damage or disease occurrences and eradicating populations when deemed appropriate. Finally, we note areas of research that may provide valuable management tools in the future

Bottom water variability in the Samoa Passage

The Samoa Passage (near 10S, 170W) is the channel through which the coldest, saltiest, densest bottom water approaches the North Pacific Ocean from its southern source. Over the past 25 years, three hydrographic sections have been made across the passage. A section occupied in 1968 shows little sign of modified North Atlantic Deep Water (NADW) within the northward flowing Lower Circumpolar Water (LCPW). In contrast, a section occupied in 1987 shows a strong negative curvature in -S (potential temperature-salinity) and a local maximum in salinity characteristic of NADW. A third section occupied in 1992 reveals a marginal NADW signature. The three sections are objectively mapped and very fine-scale bivariate areal -S censuses are made for a quantitative comparison of differences in water-mass structure. The strength of the NADW signature could fluctuate over a wide range of time-scales. However, these data are consistent with decadal variability, with no NADW signal in the passage in 1968, a strong signal in 1987, and a weak one in 1992. The geostrophic volume transport through the passage is 1.0 ± 0.2, 5.6 ± 1.3, and 4.8 ± 0.6 × 106 m3•s−1 below a zero-velocity surface (ZVS) of = 1.2°C for the 1968, 1987, and 1992 sections respectively. The transport estimates, made for comparison with those from velocity data presently being collected by a current meter array in the passage, are sensitive to variations in the choice of ZVS

A Pragmatic Definition of Elephants in Internet Backbone Traffic

Studies of the Internet traffic at the level of network prefixes, fixed length prefixes, TCP flows, AS’s, and WWW traffic, have all shown that a very small percentage of the flows carries the largest part of the information. This behavior is commonly referred to as “the elephants and mice phenomenon”. Traffic engineering applications, such as re-routing or load balancing, could exploit this property by treating elephant flows differently. In this context, though, elephants should not only contribute significantly to the overall load, but also exhibit sufficient persistence in time. The challenge is to be able to examine a flow’s bandwidth and classify it as an elephant based on the data collected across all the flows on a link. In this paper, we present a classification scheme that is based on the definition of a separation threshold, that elephants have to exceed. We introduce two single-feature classification schemes, and show that the resulting elephants are highly volatile. We then propose a two-feature classification scheme that incorporates temporal characteristics and show that this approach is more successful in isolating elephants that exhibit consistency thus making them more attractive for traffic engineering applications

New Perspectives in Sinographic Language Processing Through the Use of Character Structure

Chinese characters have a complex and hierarchical graphical structure carrying both semantic and phonetic information. We use this structure to enhance the text model and obtain better results in standard NLP operations. First of all, to tackle the problem of graphical variation we define allographic classes of characters. Next, the relation of inclusion of a subcharacter in a characters, provides us with a directed graph of allographic classes. We provide this graph with two weights: semanticity (semantic relation between subcharacter and character) and phoneticity (phonetic relation) and calculate "most semantic subcharacter paths" for each character. Finally, adding the information contained in these paths to unigrams we claim to increase the efficiency of text mining methods. We evaluate our method on a text classification task on two corpora (Chinese and Japanese) of a total of 18 million characters and get an improvement of 3% on an already high baseline of 89.6% precision, obtained by a linear SVM classifier. Other possible applications and perspectives of the system are discussed.Comment: 17 pages, 5 figures, presented at CICLing 201