Performance evaluation of open source seismic data processing packages

In many businesses, including hydrocarbon industries, reducing cost is of high priority. Although hydrocarbon industries appear able to afford the expensive computing infrastructure and software packages used to process seismic data in the search for hydrocarbon traps, it is always imperative to find ways to minimize cost. Seismic processing costs can be significantly reduced by using inexpensive, open source seismic data processing packages. However, hydrocarbon industries question the processing performance capability of open source packages, claiming that their seismic functions are less integrated and provide almost no technical guarantees for one to use. The objective of this paper is to demonstrate, through a comparative analysis, that open source seismic data processing packages are capable of executing the required seismic functions on an actual industrial workload. To achieve this objective we investigate whether or not open source seismic data processing packages can be executed using the same set of seismic data through data format conversions, and whether or not they can achieve reasonable performance and speedup when executing parallel seismic functions on a HPC cluster. Among the few open source packages available on the Internet, the subjects of our study are two popular packages: Seismic UNIX (SU) and Madagascar.

We ‘are’ rhetoric. Get over it!

This paper argues that a better understanding of public relations would help us to get an urgently needed better understanding of people. It explains why public relations should be considered the contemporary manifestation of the millennia-old art of rhetoric which in turn should be considered the basis of, at least western culture. This article introduces a thesis that understanding rhetoric properly will lead to the best way of understanding public relations properly. It will critique existing writers about the rhetoric to public relations nexus to suggest that there is a crucial need to more carefully consider the true relevance
of massively organised deliberate persuasive discourse. The urgency is because few of these commentators quite capture the extent to which public relations and related  activities are creating us. It will explain why we are almost unconscious of this process and it will point out that by contrast ancient sophists and the more accomplished pre-modern rhetoricians have always been aware of this ‘construction of people process’. The approach of this paper is premised on the observation of classicist Werner Jaeger who explains that rhetoric is at the centre of being human. When explaining the use of  grammar, rhetoric and dialectic by Greek Enlightenment sophists he writes that: “This educational technique is one of the greatest discoveries which the mind of man has ever made: it was not until it explored these three of its activities that the mind apprehended the hidden law of its own structure.” (Jaeger, 1947:314)

Our anonymous online research participants are not always anonymous: Is this a problem?

When educational research is conducted online, we sometimes promise our participants that they will be anonymous—but do we deliver on this promise? We have been warned since 1996 to be careful when using direct quotes in Internet research, as full-text web search engines make it easy to find chunks of text online. This paper details an empirical study into the prevalence of direct quotes from participants in a subset of the educational technology literature. Using basic web search techniques, the source of direct quotes could be found in 10 of 112 articles. Analysis of the articles revealed previously undiscussed threats from data triangulation and expert analysis/diagnosis. Issues of ethical obliviousness, obscurity and concern for future privacy-invasive technologies are also discussed. Recommendations for researchers, journals and institutional ethics review boards are made for how to better protect participants' anonymity against current and future threats.

Comparison between nanofiltration and forward osmosis in the treatment of dye solutions

Colour removal and the flux behaviour of nanofiltration (NF-DOW FILMTEC-NF245) and forward osmosis (FO-a flat sheet cellulose triacetate membrane with a woven embedded backing support) membranes were investigated in this study. The NF membrane was employed to perform dye removal experiments with aqueous solutions containing 15 g/L of NaCl and different concentrations of Acid Green 25, Remazol Brilliant Orange FR and Remazol Blue BR dyes. The increase in dye concentration resulted in a decline in water permeability and an increase in colour removal. When the concentrations of dye solutions varied from 250 to 1000 mg/L, at 0.8 bar of trans-membrane pressure, the NF system exhibited a steady permeate flux of more 30 L/m2h and a colour removal of more than 99%; salt rejection was more than 20.0%. Furthermore, the FO system possessed high dye rejection efficiency (almost 100%), with low permeate flux of around 2.0 L/m2h, when using dye solutions as feed streams and seawater as draw stream. The mode of operation (either FO or pressure retarded osmosis (PRO) did not change the flux significantly but PRO mode always produced higher fluxes than FO mode under the operating conditions used in this study. While both NF and FO can be used to reduce the volume of effluent containing dyes from textile industries, the energy spent in NF on applied pressure can be substituted by the osmotic pressure of draw solution in FO when concentrated draw solutions such as sea water or reverse osmosis concentrate are readily available.

Are the popular users always important for information dissemination in online social networks?

This article verifies the importance of popular users in OSNs. The results are counter-intuitive. First, for dissemination speed, a large amount of users can swiftly distribute information to the masses, but they are not highly-connected users. Second, for dissemination scale, many powerful forwarders in OSNs cannot be identified by the degree measure. Furthermore, to control dissemination, popular users cannot capture most bridges of social communities.

Does supply always come on the heels of demand? Matches and mismatches in e-learning

Developing sustainable e-learning requires a better understanding of the perceptions and preferences of e-learning providers and e-learners on the four crucial dimensions for elearning success including pedagogies, technologies, learning resources and management of learning resources. There is, however, little research on evaluating whether these critical dimensions are perceived as critical by e-learning providers and e-learners. To address this issue, this study investigates the gap between e-learners’ and e-learning providers’ perceptions and preferences on these critical dimensions for e-learning effectiveness. Such an investigation paves the way for developing appropriate measures to reduce the gap between the supply and the demand for sustainable e-learning.

Dietary sources, current intakes, and nutritional role of omega-3 docosapentaenoic acid

Fish oils and long-chain omega-3 fatty acids are well recognized for their critical role in human diets. Docosapentaenoic acid (DPA, 22:5n-3) has always been a part of healthy nutrition, since infants obtain almost as much DPA as DHA from human milk. Fish oil supplements and ingredients, oily fish, and grass-fed beef can serve as the primary DPA sources for the general population. Although the DPA levels in fish oils are substantially lower than those of EPA and DHA, concentrated DPA products are now becoming commercially available, and DPA-based drugs are under development. Epidemiological studies show that similar to eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids, DPA is linked to various improvements in human health, perhaps owing to its structural similarity to the other two molecules. Studies in mammals, platelets, and cell cultures have demonstrated that DPA reduces platelet aggregation, and improves lipid metabolism, endothelial cell migration, and resolution of chronic inflammation. Further, other in vivo and in vitro studies have shown that DPA can improve neural health. A human supplementation trial with 99.8% pure DPA suggested that it serves as a storage depot for EPA and DHA in the human body. Future randomized controlled human trials with purified DPA will help clarify its effects on human health. They may confirm the available evidence pointing to its nutritional and biological functions, unique or overlapping with those of EPA and DHA.