High capacity steganographic method based upon JPEG

The two most important aspects of any image-based steganographic system are the quality of the stegoimage and the capacity of the cover image. This paper proposes a novel and high capacity steganographic approach based on Discrete Cosine Transformation (DCT) and JPEG compression. JPEG technique divides the input image into non-overlapping blocks of 8x8 pixels and uses the DCT transformation. However, our proposed method divides the cover image into nonoverlapping blocks of 16x16 pixels. For each quantized DCT block, the least two-significant bits (2-LSBs) of each middle frequency coefficient are modified to embed two secret bits. Our aim is to investigate the data hiding efficiency using larger blocks for JPEG compression. Our experiment result shows that the proposed approach can provide a higher information hiding capacity than Jpeg-Jsteg and Chang et al. methods based on the conventional blocks of 8x8 pixels. Furthermore, the produced stego-images are almost identical to the original cover images

Management of strawberry blossom weevil and European tarnished plant bug in organic strawberry and raspberry using semiochemical traps

In the absence of effective control measures, the strawberry blossom weevil (Anthonomus rubi), the European tarnished plant bug (Lygus rugulipennis) and the raspberry beetle (Byturus tomentosus) cause large (10 - >80%) losses in yield and quality in organically grown strawberry (A. rubi and L .rugulipennis) and raspberry (A. rubi and B. tomentosus). In this project the natural semiochemical mechanisms of sexual attraction and host plant finding of these key pests will be exploited to develop effective semiochemical traps for their management through mass trapping. Attractive lures will be combined into a single multitrap for economic management of these pests simultaneously in each crop. This will be one of the first approaches to pest management of non-lepidopteran insect pests of horticultural crops using semiochemicals in the EU, and probably the first to target multiple species from different insect orders. Growers of organic raspberry and strawberry crops currently have few options for effective control of these pests and development of semiochemical-based, non-pesticidal management techniques will make a major contribution to reduction of significant economic losses

ZFIRE: A KECK/MOSFIRE Spectroscopic Survey of Galaxies in Rich Environments at z~2

We present an overview and the first data release of ZFIRE, a spectroscopic redshift survey of star-forming galaxies that utilizes the MOSFIRE instrument on Keck-I to study galaxy properties in rich environments at $1.5<z<2.5$. ZFIRE measures accurate spectroscopic redshifts and basic galaxy properties derived from multiple emission lines. The galaxies are selected from a stellar mass limited sample based on deep near infra-red imaging ($\mathrm{K_{AB}<25}$) and precise photometric redshifts from the ZFOURGE and UKIDSS surveys as well as grism redshifts from 3DHST. Between 2013--2015 ZFIRE has observed the COSMOS and UDS legacy fields over 13 nights and has obtained 211 galaxy redshifts over $1.57<z<2.66$ from a combination of nebular emission lines (such as \Halpha, \NII, \Hbeta, \OII, \OIII, \SII) observed at 1--2\micron. Based on our medium-band NIR photometry, we are able to spectrophotometrically flux calibrate our spectra to \around10\% accuracy. ZFIRE reaches $5\sigma$ emission line flux limits of \around$\mathrm{3\times10^{-18}~erg/s/cm^2}$ with a resolving power of $R=3500$ and reaches masses down to \around10$^{9}$\msol. We confirm that the primary input survey, ZFOURGE, has produced photometric redshifts for star-forming galaxies (including highly attenuated ones) accurate to $\Delta z/(1+z\mathrm{_{spec})}=0.015$ with $0.7\%$ outliers. We measure a slight redshift bias of $<0.001$, and we note that the redshift bias tends to be larger at higher masses. We also examine the role of redshift on the derivation of rest-frame colours and stellar population parameters from SED fitting techniques. The ZFIRE survey extends spectroscopically-confirmed $z\sim 2$ samples across a richer range of environments, here we make available the first public release of the data for use by the community.\footnote{\url{http://zfire.swinburne.edu.au}}Comment: Published in ApJ. Data available at http://zfire.swinburne.edu.au, Code for figures at https://github.com/themiyan/zfire_survey, 31 pages, 24 figure

Modeling microevolution in a changing environment: The evolving quasispecies and the Diluted Champion Process

Several pathogens use evolvability as a survival strategy against acquired immunity of the host. Despite their high variability in time, some of them exhibit quite low variability within the population at any given time, a somehow paradoxical behavior often called the evolving quasispecies. In this paper we introduce a simplified model of an evolving viral population in which the effects of the acquired immunity of the host are represented by the decrease of the fitness of the corresponding viral strains, depending on the frequency of the strain in the viral population. The model exhibits evolving quasispecies behavior in a certain range of its parameters, ans suggests how punctuated evolution can be induced by a simple feedback mechanism.Comment: 15 pages, 12 figures. Figures redrawn, some additional clarifications in the text. To appear in Journal of Statistical Mechanics: Theory and Experimen

ADOPTION OF BACKGROUNDING ON COW-CALF FARMS

A discrete choice model is used to analyze the decision to feed or sell calves at weaning. After accounting for regional factors, results show that operator perceptions toward profitability, risk, and facilities as well as control over production and attention to marketing impacted retained ownership of calves. Farm size had a minimal impact.Livestock Production/Industries,

Mobile technologies for (English) language learning: An exploration in the context of Bangladesh

Milton’s (2002) literature review of languages, technology and learning found that language laboratories “…proved to be a useful tool, but only one tool, in the hands of a good teacher, and a huge waste of time and money in the hands of a bad teacher” (p16) with computer language labs being “..something of an oddity… [with] no clear method or best practice for using them’ (p17). Instead, Milton identified numerous examples of effective language learning supported by broadcast (radio) or recorded (tape, CD) audio. Recently, research has begun to focus upon mobile learning (e.g. Naismith et al, 2004), but the potential of mobile media players (for example, the iPod) is only recently being explored. It has been suggested that language learning is one of the disciplines particularly likely to benefit from widespread ownership of mobile devices such as phones and media players (Kukulska-Hulme, 2006). For example, Rosell-Aguilar (2007) has begun to develop a theoretically informed pedagogy of podcasting, as a means of providing language-learning resources on mobile devices, suggesting podcasts offer a number of advantages for language learning (p. 479). This paper examines the opportunities for mobile language learning in the context of Bangladesh, where mobile devices are becoming increasingly affordable and ubiquitous. It is hoped that this paper also provides some insights into mobile learning for language education policy makers, distance education institutions and language teachers

Agricultural Research Service research highlights in remote sensing for calendar year 1981

Selected examples of research accomplishments related to remote sensing are compiled. A brief statement is given to highlight the significant results of each research project. A list of 1981 publication and location contacts is given also. The projects cover emission and reflectance analysis, identification of crop and soil parameters, and the utilization of remote sensing data