Real time video frames allocation in mobile networks using cooperative pre-fetching

In this paper, we study the bandwidth allocation problem for serving video requests in a mobile real-time video player system. One of the main issues to maintain the quality of services (QoS) in mobile video playback is to ensure sufficient number of video frames available at the client side while a video is being played. However, due to the limited bandwidth of a mobile network and variable workload streaming video, this is not easy to achieve in practice. In addition, the communication link between mobile clients and a video server is subject to frequent errors and temporary disconnection. In this paper, we propose to use the notion of buffered bandwidth in addition to the network bandwidth to support real-time playback of videos at mobile clients. Based on this, we designed a bandwidth allocation scheme called Cooperative Pre-Fetching (CP) in which the amount of bandwidth to be allocated to serve a video request depends on the current buffer level of the video at the client relative to the target buffer level of the client. In determining the target buffer level, we consider the errors in communication to the client as well as the other clients who are concurrently served by the system. The buffered video frames at the clients are then used to minimize the impact of error in communications on the overall QoS of video playbacks in the whole system.

Supporting command and control training functions in the emergency management domain using cognitive systems engineering

The design and implementation of MERMAIDS, a computer-based training system in the domain of emergency command and control, is described. The research investigates the use of cognitive systems engineering and information management tools for modelling and representing training knowledge of emergency system operators. We propose a decision-centric human-computer interface as a new method of supporting computer-based modelling in the domain of emergency systems. Several interacting themes in information management relevant to emergency response planning are discussed.     

Perceptual Issues in Music Pattern Recognition: Complexity of Rhythm and Key Finding

We consider several perceptual issues in the context of machine recognition ofmusic patterns. It is argued that a successful implementation of a musicrecognition system must incorporate perceptual information and error criteria.We discuss several measures of rhythm complexity which are used fordetermining relative weights of pitch and rhythm errors. Then, a new methodfor determining a localized tonal context is proposed. This method is based onempirically derived key distances. The generated key assignments are then usedto construct the perceptual pitch error criterion which is based on noterelatedness ratings obtained from experiments with human listeners.     

Balancing Misclassification Rates in Classification-Tree Models of Software Quality

Software product and process metrics can be useful predictorsof which modules are likely to have faults during operations.Developers and managers can use such predictions by softwarequality models to focus enhancement efforts before release.However, in practice, software quality modeling methods in theliterature may not produce a useful balance between the two kindsof misclassification rates, especially when there are few faultymodules.This paper presents a practical classificationrule in the context of classification tree models that allowsappropriate emphasis on each type of misclassification accordingto the needs of the project. This is especially important whenthe faulty modules are rare.An industrial case study using classification trees, illustrates the tradeoffs.The trees were built using the TREEDISC algorithm whichis a refinement of the CHAID algorithm. We examinedtwo releases of a very large telecommunications system, and builtmodels suited to two points in the development life cycle: theend of coding and the end of beta testing. Both trees had onlyfive significant predictors, out of 28 and 42 candidates, respectively.We interpreted the structure of the classification trees, andwe found the models had useful accuracy.     

Craze intersections in biaxially-stressed polystyrene

Crazes are produced on two orthogonal planes in both thin film and macroscopic samples of polystyrene by sequentially applying two orthogonal tensile strains ₁ and ₂. Although many crazes produced by the second strain ₂ (secondary crazes) are stopped when they meet a primary craze, some intersections occur. The fraction of craze meetings resulting in intersection increases from 20% at ₁= ₂=3% to 55% at ₁= ₂=5%; intersections also occur preferentially in thin regions of primary crazes. The craze fibril structure in the intersection has a much lower fibril volume fraction, v _f, than either of the two crazes from which it formed. The fibril volume fraction in the intersection is approximately given by the product of the fibril volume fractions of the two crazes, in agreement with a prediction based on the surface drawing mechanism of craze thickening. At higher strain levels the v _fs of the intersections are lower, leading to higher fibril stresses and enhanced fibril fracture; an increasing fraction of intersections breaks down to form large voids at these higher strain levels. Fractography of macroscopic samples containing intersecting crazes demonstrates that voids formed at the intersections can act as nuclei for cracks causing premature fracture of the material.     

Reduction of NOx Stored at Low Temperatures on a NOx Adsorbing Catalyst

Isothermal storage and reduction of NO₂ with CO, C₃H₆ and H₂ as reducing agents on a lean NO _x adsorber was investigated by temperature programmed desorption (TPD) and temperature programmed reduction (TPR) studies. The reduction of NO _x was clearly favoured with H₂ as reducing agent. Carbon monoxide and C₃H₆ showed fairly low reduction of NO _x . The NO _x reduction at low temperatures with H₂ as reducing agent was found to be effective, clearly much more effective than for CO.     

Probabilistic analysis of a grouping algorithm

We study thegrouping by swapping problem, which occurs in memory compaction and in computing the exponential of a matrix. In this problem we are given a sequence ofn numbers drawn from {0,1, 2,...,m?1} with repetitions allowed; we are to rearrange them, using as few swaps of adjacent elements as possible, into an order such that all the like numbers are grouped together. It is known that this problem is NP-hard. We present a probabilistic analysis of a grouping algorithm calledMEDIAN that works by sorting the numbers in the sequence according to their median positions. Our results show that the expected behavior ofMEDIAN is within 10% of optimal and is asymptotically optimal asn/m→∞ or asn/m→0.     

Delivery of nutrients and seston from the Muskegon River Watershed to near shore Lake Michigan

Drowned river mouth lakes are major features of coastal Great Lakes habitats and may influence nutrient and organic matter contributions from watersheds to near shore coastal zones. In May through October 2003, we measured loads of nutrients, surficial sediment, and seston to track the delivery of riverine-derived materials from the lower Muskegon River Watershed (MRW) into the near shore area of southeast Lake Michigan. Nutrient flux data indicated that seasonal loads of 1800 metric tons (MT) of particulate organic carbon, 3400 MT of dissolved organic carbon, and 24 MT of total phosphorus were discharged from the lower Muskegon River, with approximately 33% of TP load and 53% of the POC load intercepted within the drowned river mouth terminus, Muskegon Lake. Carbon: phosphorus molar ratios of seston in Muskegon River (C:P = 187) and Muskegon Lake (C:P = 176) were lower than in Lake Michigan (C:P = 334), indicating phosphorus limitation of phytoplankton in near shore Lake Michigan. Isotopic signatures of seston collected in Muskegon Lake were depleted in δ¹³C (− 30.8 ± 1.6‰) relative to the isotope signatures of seston from Lake Michigan (− 26.2 ± 1.3‰) or the mouth of the Muskegon River (− 28.1 ± 0.5‰), likely due to the presence of biogenic methane in Muskegon Lake. Seston δ¹⁵N increased on a strong east-to-west gradient within Muskegon Lake, indicating significant microbial processing of nutrients. The extent of nutrient uptake in Muskegon Lake altered the chemical and isotopic characterization of seston flowing into Lake Michigan from Muskegon River.     

The Mahomet Aquifer

Abstract

Emerging intrastate transboundary issues focus on use of the Mahomet aquifer, which underlies about fifteen counties and many other political entities in east-central Illinois. This sand and gravel aquifer in the lower part of the buried Mahomet Bedrock Valley ranges between four and fourteen miles wide and from about 50 to 200 feet thick. Much of the region's rural population, several large communities, and many small towns obtain water from the Mahomet aquifer, as do industrial, agricultural, and commercial users. Increased development of the Mahomet aquifer to meet growing demands for water has caused conflicts over real or perceived adverse effects. One result has been the creation of fifteen resource protection zones and twelve water authorities. For groundwater supplies, resource protection zones help municipalities protect water-supply wells from potential adverse impacts. Many resource protection zones overlap one another, however, so this situation could lead to disputes over use of the resource. The reason that several of the twelve water authorities were organized was to meet a challenge perceived from a demand to be placed on the aquifer, in other words, a potential for conflict of use. Complicating the situation is that some of the water authorities overlap the resource protection zones. This could lead to disputes not only about water use, but also over which jurisdiction has the authority to settle a dispute. The Mahomet Aquifer Consortium was recently organized by concerned people representing diverse groundwater interests at the local level, including the private sector, professional organizations, and various governmental units. The consortium brings together representatives of some groups that typically did not communicate with each other in the past. The consortium may provide a forum through which emerging transboundary issues pertaining to use of the Mahomet aquifer can be addressed. Because the consortium is a voluntary organization that relies on consensus building, the success it may achieve in resolving future conflicts over groundwater use from the Mahomet aquifer remains to be seen.