Intermediate checksums for improving goodput over error-prone links

When a frame transmitted over an error-prone link is hit by bit errors, it is retransmitted entirely, despite the fact that often only a few bits are erroneous. In this paper we propose to not use a single checksum covering all data bits, but multiple checksums covering only parts of a frames data block (a chunk). In case of a retransmission only the chunks with a wrong checksum are retransmitted. We show analytically that for high bit error rates and a time-invariant binary symmetric channel this approach can give significant advantages in terms of goodput over the traditional scheme using only a single checksum per frame. In addition, we propose a simple scheme for adapting the chunk size to the current channel conditions and present first results for this, indicating that for bad channel conditions close-to-optimal goodput is achieved

Analysis of Antiviral and Chemoprotective Effects of Strawberry Anthocyanins

This study investigated the antiviral, chemoprotective and proliferative effects of strawberry anthocyanins on herpes simplex virus type-1, cancerous cell lines HT-29 and AGS, and normal cell lines Hs 738.St/Int and CCD-18Co. Antiviral properties were measured by infecting vero cells from adult grivet (Cercopithecus aethiops) with herpes simplex virus type-1 (HSV-1) and treating with a concentration of 1.25-20 µg/mL of strawberry anthocyanins. Infectivity and replication were quantified for herpes simplex virus type-1 using the direct plaque assay and reporting PFU/mL. Strawberry anthocyanins (\u3e20 µg/mL) inhibited the herpes simplex virus infectivity in vero cells by 100% (p\u3c0.05). Strawberry anthocyanins at concentrations of 5, 10 and 20 μg/mL were reduced to 75.36, 57.98, and 31.46 percent of the control (100%) (p\u3c0.05). Chemoprotective and proliferative effects of strawberry anthocyanins were analyzed for the human cell lines AGS, Hs 738.St/Int, HT-29, and CCD-18Co at a concentration of 25-200 µg/mL and quantified using the sulforhodamine-B assay. Growth inhibition occurred at a level of ≥87% for treatment concentrations 100 and 200 µg/mL for the cancerous AGS and HT-29 cell lines (p\u3c0.0001). Proliferation rates for the normal Hs 738.St/Int and CCD-18Co cell lines increased at all treatment concentrations of 25-200 μg/mL (p\u3c0.0001); suggestingthat the observed proliferative activity may be associated with anthocyanin treatment.Strawberry anthocyanin treatment concentration worked in a dose dependent manner for the HSV-1 and the cancerous AGS and HT-29 cells. The caspase-3 assay was performed to demonstrate potential mechanism of action and confirmed thatanthocyanin treatments play a role in apoptosisby the up regulation of caspase-3.Significantdifferences were seen between the growth characteristics of cancerous cell linescompared to their equivalent normal cell lines (p\u3c0.0001). In summary, the antiviral findings suggest that strawberry anthocyanin extracts could be an effective topical treatment and/or prophylactic agent for oral herpetic infections (HSV-1). Also, the in vitro chemoprotective effect of strawberry anthocyanins found may be relevant to in vivo work in the future because when anthocyanins are consumed in the diet they come in direct contact with the gastrointestinal tract and may provide chemoprotection upon contact with the stomach and gastrointestinal tract’s epithelial cell layer

Competition and innovation-driven inclusive growth

The paper investigates the strength of innovation-driven employment growth, the role of competition in stimulating and facilitating it, and whether it is inclusive. In a sample of more than 26,000 manufacturing establishments across 71 countries (both OECD and developing), the authors find that firms that innovate in products or processes, or that have attained higher total factor productivity, exhibit higher employment growth than non-innovative firms. The strength of firms'innovation-driven employment growth is significantly positively associated with the share of the firms'workforce that is unskilled, debunking the conventional wisdom that innovation-driven growth is not inclusive in that it is focused on jobs characterized by higher levels of qualification. They also find that young firms have higher propensities for product or process innovation in countries with better Doing Business ranks (both overall and ranks for constituent components focused on credit availability and property registration). Firms generally innovate more and show greater employment growth if they are exposed to more information (through internet use and membership in business organizations) and are exporters. The empirical results support the policy propositions that innovation is a powerful driver of employment growth, that innovation-driven growth is inclusive in its creation of unskilled jobs, and that the underlying innovations are fostered by a pro-competitive business environment providing ready access to information, financing, export opportunities, and other essential business services that facilitate the entry and expansion of young firms.Environmental Economics&Policies,Labor Policies,Labor Markets,E-Business,Microfinance

Parity Pricing and Its Critics: A Necessary Condition for Efficiency in the Provision of Bottleneck Services to Competitors

This paper discusses proper pricing of a monopoly input needed by both its owner and its owner\u27s competitors in the final-product market. This issue is central to current litigation in courts and regulatory agencies throughout the world\u27s industrial nations as competitive entry, deregulation, and privatization proceed. A new, simplified proof shows that only pricing based on what has come to be called the parity-pricing formula or efficient component-pricing rule ( ECPR ) permits economic efficiency and competitive neutrality-giving neither the bottleneck owner nor its rivals a competitive advantage in final-product sales, aside from any derived from superior productive efficiency. This paper comments on a number of recent discussions of ECPR, showing that the bulk of their reservations, while valid, do not undermine ECPR, but, instead, call for supplementary rules that we have advocated all along

Cabinet Gorge Dam Spillway Modifications for TDG Abatement - Design Evolution and Field Performance

Avista is implementing spillway modifications to reduce TDG supersaturation downstream of Cabinet Gorge Dam.The key feature of the modifications is the addition of roughness elements, similar to supercavitating baffle blocks,to break up the spillway jet thereby reducing the depth of plunge and TDG supersaturation. The work is progressing in a step-wise manner. A single bay was modified in 2012 and field tested in 2013. Following the initial field tests, aCFD model was developed to aid in design refinements for the prototype and to improve the design prior to modification of subsequent spillway bays. The prototype demonstrated that spillway modifications are an effective method to reduce TDG downstream of a spillway discharging freely into a deep plunge pool. The CFD model has allowed the design to be simplified while maintaining the plunge depth improvements of the initial prototype and reducing the effect of the modifications on spillway capacity. This paper presents the prototype design and the design that will be implemented for the next two bays, summarizes the results from the prototype field tests, and describes the CFD model and results

Pre-notched dog bone small punch specimens for the estimation of fracture properties

In recent years, the pre-notched or pre-cracked small punch test (P-SPT) has been successfully used to estimate the fracture properties of metallic materials for cases in which there is not sufficient material to identify these properties from standard tests, such as CT or SENB specimens. The P-SPT basically consists of deforming a pre-notched miniature specimen, whose edges are firmly gripped by a die, using a high strength punch. The novelty of this paper lies in the estimation of fracture properties using dog-bone-shaped specimens with different confinement levels. With these specimens, three confinement variations have been studied. The results obtained enable the establishment of a variation of fracture properties depending on the level of confinement of each miniature specimen and selection of the most appropriate confinement for this goal

Mutual Interference in Large Populations of Co-Located IEEE 802.15.4 Body Sensor Networks - A Sensitivity Analysis

We consider scenarios where a large number of wireless body sensor networks (WBSN) meets at the same location, as can happen for example at sports events, and assess the impact of their mutual interference on their achievable transmission reliability. In particular, we consider several of MAC- and application parameters for a range of static and dynamic schemes for allocating WBSNs to frequencies, and determine their relative impacts on achievable performance. Our results indicate that parameters related to the MAC backoff scheme have by far the largest impact on performance, and that frequency adaptation can provide substantial performance benefits