46,798 research outputs found
Feed quality problems and management strategies
Feed is the single most important input in increasing aquaculture production and profits. Success or failure in augmenting yield with feeding depends, to a large extent, on the quality of the diet. Feed quality, generally perceived as the responsibility of the feed manufacturer, is affected by factors outside of the plant such as handling, storage, and use. Thus, the maintenance of feed quality becomes partly the responsibility of the farmer. Every fish farmer must be familiar with the nature and occurrence of major feed quality problems and able to prevent and control them. This paper is based on a farmer's viewpoint. Valuable insights are provided for the feed manufacturer
Stellar Equilibrium in 2+1 Dimensions
The hydrostatic equilibrium of a dimensional perfect fluid star in
asymptotically anti-de Sitter space is discussed. The interior geometry matches
the exterior black-hole solution. An upper mass limit is found, analogous
to Buchdahl's theorem in 3+1, and the possibility of collapse is discussed. The
case of a uniform matter density is solved exactly and a new interior solution
is presented.Comment: 11 pages, revtex, no figure
DoWitcher: Effective Worm Detection and Containment in the Internet Core
Enterprise networks are increasingly offloading the responsibility for worm detection and containment to the carrier networks. However, current approaches to the zero-day worm detection problem such as those based on content similarity of packet payloads are not scalable to the carrier link speeds (OC-48 and up-wards). In this paper, we introduce a new system, namely DoWitcher, which in contrast to previous approaches is scalable as well as able to detect the stealthiest worms that employ low-propagation rates or polymorphisms to evade detection. DoWitcher uses an incremental approach toward worm detection: First, it examines the layer-4 traffic features to discern the presence of a worm anomaly; Next, it determines a flow-filter mask that can be applied to isolate the suspect worm flows and; Finally, it enables full-packet capture of only those flows that match the mask, which are then processed by a longest common subsequence algorithm to extract the worm content signature. Via a proof-of-concept implementation on a commercially available network analyzer processing raw packets from an OC-48 link, we demonstrate the capability of DoWitcher to detect low-rate worms and extract signatures for even the polymorphic worm
Multilingual Information Framework for Handling textual data in Digital Media
This document presents MLIF (Multi Lingual Information Framework), a high-level model for describing multilingual data across a wide range of possible applications in the translation/localization process within several multimedia domains (e.g. broadcasting interactive programs within a multilingual community)
Subsonic Dynamic Testing of a Subscale ADEPT Entry Vehicle
The Adaptive Deployable Entry and Placement Technology (ADEPT) is a mechanically-deployed entry system. A sounding rocket test flight of an ADEPT vehicle, known as ADEPT SR-1, was conducted in September 2018. Prior to this sounding rocket test, an investigation was performed using the NASA Langley Research Center 20-ft Vertical Spin Tunnel (VST) to assess the free-flight dynamic characteristics of ADEPT SR-1 at subsonic speeds. The model of ADEPT SR-1 for this VST test was fabricated at 50-percent geometric scale, with dynamically scaled mass properties (Froude scaled) to represent full-scale flight at an altitude of 1.2 km above sea level. The subsonic dynamic characteristics of ADEPT SR-1 were of interest prior to the sounding rocket test because of payload recovery considerations. At low roll rates the model was found to have acceptable dynamic characteristics. It was statically stable in pitch and yaw, exhibiting limit cycle pitch/yaw oscillations of no greater than 20 degrees (the angle between the models longitudinal axis and nadir). The model was able to recover from large upsets in pitch and yaw, although if sufficiently provoked it tumbled. Damping in roll was low. At high roll rates the pitch and yaw oscillations grew in magnitude and rate. This behavior was also observed during the sounding rocket flight test
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