High speed sequential decoder

Operation of sequential decoding of data at high rates using Fano algorithm is discussed. Actions followed by decoder in systematically searching branches are described. Technique of diagonal steps is explained and illustrated

Comparison of CDMA and FDMA for the MobileStar(sm) system

Spread-spectrum code division multiple access (CDMA) and single channel per carrier frequency division multiple access (FDMA) systems are compared for spectrum efficiency. CDMA is shown to have greater maximum throughput than FDMA for the MobileStar(sm) system which uses digital voice activated carriers and directive circularly polarized satellite antennas

Robustness of optimal channel reservation using handover prediction in multiservice wireless networks

The aim of our study is to obtain theoretical limits for the gain that can be expected when using handover prediction and to determine the sensitivity of the system performance against different parameters. We apply an average-reward reinforcement learning approach based on afterstates to the design of optimal admission control policies in mobile multimedia cellular networks where predictive information related to the occurrence of future handovers is available. We consider a type of predictor that labels active mobile terminals in the cell neighborhood a fixed amount of time before handovers are predicted to occur, which we call the anticipation time. The admission controller exploits this information to reserve resources efficiently. We show that there exists an optimum value for the anticipation time at which the highest performance gain is obtained. 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Recurrent Die-Offs of Adult Coho Salmon Returning to Spawn in Puget Sound Lowland Urban Streams

Several Seattle-area streams in Puget Sound were the focus of habitat restoration projects in the 1990s. Post-project effectiveness monitoring surveys revealed anomalous behaviors among adult coho salmon returning to spawn in restored reaches. These included erratic surface swimming, gaping, fin splaying, and loss of orientation and equilibrium. Affected fish died within hours, and female carcasses generally showed high rates (>90%) of egg retention. Beginning in the fall of 2002, systematic spawner surveys were conducted to 1) assess the severity of the adult die-offs, 2) compare spawner mortality in urban vs. non-urban streams, and 3) identify water quality and spawner condition factors that might be associated with the recurrent fish kills. The forensic investigation focused on conventional water quality parameters (e.g., dissolved oxygen, temperature, ammonia), fish condition, pathogen exposure and disease status, and exposures to metals, polycyclic aromatic hydrocarbons, and current use pesticides. Daily surveys of a representative urban stream (Longfellow Creek) from 2002–2009 revealed premature spawner mortality rates that ranged from 60–100% of each fall run. The comparable rate in a non-urban stream was <1% (Fortson Creek, surveyed in 2002). Conventional water quality, pesticide exposure, disease, and spawner condition showed no relationship to the syndrome. Coho salmon did show evidence of exposure to metals and petroleum hydrocarbons, both of which commonly originate from motor vehicles in urban landscapes. The weight of evidence suggests that freshwater-transitional coho are particularly vulnerable to an as-yet unidentified toxic contaminant (or contaminant mixture) in urban runoff. Stormwater may therefore place important constraints on efforts to conserve and recover coho populations in urban and urbanizing watersheds throughout the western United States

A Synthesis of Tagging Studies Examining the Behaviour and Survival of Anadromous Salmonids in Marine Environments

This paper synthesizes tagging studies to highlight the current state of knowledge concerning the behaviour and survival of anadromous salmonids in the marine environment. Scientific literature was reviewed to quantify the number and type of studies that have investigated behaviour and survival of anadromous forms of Pacific salmon (Oncorhynchus spp.), Atlantic salmon (Salmo salar), brown trout (Salmo trutta), steelhead (Oncorhynchus mykiss), and cutthroat trout (Oncorhynchus clarkii). We examined three categories of tags including electronic (e.g. acoustic, radio, archival), passive (e.g. external marks, Carlin, coded wire, passive integrated transponder [PIT]), and biological (e.g. otolith, genetic, scale, parasites). Based on 207 papers, survival rates and behaviour in marine environments were found to be extremely variable spatially and temporally, with some of the most influential factors being temperature, population, physiological state, and fish size. Salmonids at all life stages were consistently found to swim at an average speed of approximately one body length per second, which likely corresponds with the speed at which transport costs are minimal. We found that there is relatively little research conducted on open-ocean migrating salmonids, and some species (e.g. masu [O. masou] and amago [O. rhodurus]) are underrepresented in the literature. The most common forms of tagging used across life stages were various forms of external tags, coded wire tags, and acoustic tags, however, the majority of studies did not measure tagging/handling effects on the fish, tag loss/failure, or tag detection probabilities when estimating survival. Through the interdisciplinary application of existing and novel technologies, future research examining the behaviour and survival of anadromous salmonids could incorporate important drivers such as oceanography, tagging/handling effects, predation, and physiology

A VERY HIGH SPEED HARD DECISION SEQUENTIAL DECODER

International Telemetering Conference Proceedings / October 10-12, 1972 / International Hotel, Los Angeles, CaliforniaThere are numerous applications for high data rate coding systems for earth orbiting space-missions with power limited links. Studies indicated that a 40 Mbps hard decision sequential decoder would best meet the requirements. A prototype decoder has been designed and fabricated using the fastest commercially available digital integrated circuits, MECL III. Thus far, an internal computational rate of 70 Million computations per second has been achieved. Computational efficiency of the decoding algorithm was greatly improved by incorporating two modifications to the Fano algorithm; “double quick threshold loosening” and “diagonal steps.” Preliminary results indicate that an output error rate of 10^-5 can be achieved with E(b)/N(o) less than 5.4 dB at data rates up to 40 Mbps. At lower data rates, even less signal energy is required. This decoder is believed to be at least 5 times faster than any previous sequential decoder.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

The Implications of Financial Distress

PURPOSE OF THE STUDY This thesis aims to be the first paper to study comprehensively the full implications of financial distress and its indirect costs. Specifically, I investigate whether financially distressed companies operationally underperform their more conservatively financed counterparts and whether the distressed companies engage in inefficient asset sales. This is the first paper to study the effects of financial distress as the earlier literature concentrates purely on the effects of leverage. I combine the leading financial distress indicators to create my own distress score. Unlike past papers I control for differing business strategies when analyzing the operational performance of distressed companies. DATA This study targets all common shares that are traded in NYSE, AMEX and NASDAQ during the period between 1994 and 2009. This is the first thesis to include the current financial crisis to the literature of financial distress. The market data is obtained from Datastream and the accounting data from Compustat, Datastream and Thomson databases. The sample consists of 9 405 unique stocks. RESULTS My thesis documents significant indirect costs of financial distress by showing that financial distress leads to poor operational performance, abnormally low stock returns and lower transaction multiples in M&A. Financial distress is shown to be even more detrimental to operational performance during economic downturns when the distressed companies suffer additional market share and profitability losses. It’s observed that the distressed firms first significantly outperform their peers in the stock market two years before the distress measurement date but start to give back these gains a year before the actual distress. The underperformance then also continues one year after the measurement point for distress. When looking at distressed firms as acquisition targets, the thesis finds that they generally sell at lower valuations compared to financially healthy peers. It’s shown that the sale is driven by the tight liquidity situation of the target firm or its parent. The low purchase price is recognized by the stock market as the share prices of the acquirers significantly outperform the general market post acquisition. On the other hand, financially distressed firms also acquire companies at lower prices than their peers