Comparative Analysis Spread Spectrum and Parity Coding Steganography in E-commerce

The transaction data online has increased compared to the previous communications that mostly in the form of voice and text messaging. To improve the security, data must be protected such a way that it cannot be attacked by unauthorized parties. In this case, a good security system must be able to transmit the original information to the second party without having to know the existence and validity by a third party. One of the security systems that can be used is steganography. In this paper, we will compare the performance of Spread Spectrum and Parity Coding in e-commerce based on Android in case of processing time between insertion and retrieval information, and the changing image size during the insertion process. Our experimental results show that parity coding has better performance on client side that use low performance smart phone based on Android operating system and spread spectrum has better performance on blackberry store server that use laptop PC

Test-bed development & measurement plan for evaluating transmit diversity in DVB networks

This paper presents a test-bed development and measurement plan for evaluating transmit diversity in the DVB network. Transmit diversity reduces the complexity and improves the power consumption of the personal receiving devices by improving the transmission of signals in NLOS cluttered environments. Also, it is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. Test service scenarios were developed to illustrate the benefits of such technologies so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems. The laboratory tests were designed to validate the theoretical measurements from the theoretical analysis and these results will be verified by a field measurement campaign in short and long time spans

Active-sterile neutrino oscillations in the early Universe: asymmetry generation at low |delta m^2| and the Landau-Zener approximation

It is well established that active-sterile neutrino oscillations generate large neutrino asymmetries for very small mixing angles ($\sin^2 2\theta_0\lesssim 10^{-4}$), negative values of $\delta m^2$ and provided that $|\delta m^2|\gtrsim 10^{-4} {\rm eV^2}$. By numerically solving the quantum kinetic equations, we show that the generation still occurs at much lower values of $|\delta m^2|$. We also describe the borders of the generation at small mixing angles and show how our numerical results can be analytically understood within the framework of the Landau-Zener approximation thereby extending previous work based on the adiabatic limit. This approximate approach leads to a fair description of the MSW dominated regime of the neutrino asymmetry evolution and is also able to correctly reproduce its final value. We also briefly discuss the impact that neutrino asymmetry generation could have on big bang nucleosynthesis, CMBR and relic neutrinos.Comment: 29 pages, 8 figures; to appear on Phys. ReV. D; figure 7 added, new curves in figure 5a, new figure

Measurements, processing functions and laboratory test-bed experiments for evaluating diversity in broadcast network

This paper presents a test-bed development and measurement plan for evaluating transmit diversity and on-channel repeaters in the Digital Video Broadcasting Network. Transmit diversity reduces the complexity and improves the power consumption of the personal receiving devices by enhancing the transmission of signals in NLOS cluttered environments. It is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. The on-channel repeater is to extend the coverage of the DVB-T/H network in areas where services are inaccessible by receiving the DVB-T/H signals off air, amplifying and then retransmitting it on the same frequency as received. Test service scenarios were developed to illustrate the benefits of such technologies so that effectiveness can be researched in a variety of service and terrain scenarios using purpose built test systems.The work presented in this paper was supported by the European Commission IST project PLUTO

Influence of CuO on temperature dependent H2S gas sensing performance of ZrO2 thick film resistor

Popular   screen printed   ZrO2 thick film resistor was formulated for characterization. These films were surface modified by dipping them in 0.1 M CuCl2 aqueous solution for the time intervals of 5,10,20, 30 and 40  minutes. Surface morphology and   elemental composition were studied using scanning electron microscopy coupled with energy dispersive   spectroscopy. It was observed that Cu converted into CuO at 200oC during sintering of the films and this p-type oxide plays role with n- type ZrO2 for H2S gas sensing. X-diffraction confirmed the polycrystalline nature of pure ZrO2 powder and influence of copper on film surface disappear the polymorphs and only strong crystalline peak was observed. It was good indication for gas sensing. Bandwidth reduction was observed   by characterizing film with UV spectroscopy techniques. Pure ZrO2 film sample was shown wide bandwidth than sintered and modified film.  The gas sensing performances of various gases were tested previously and it is reported for Ammonia except oxygen. Negative temperature coefficient of the CuO activated film shift response to H2S gas at elevated temperature between 300oC to 450 oC.  Maximum Gas sensing response was observed at operating temperature 450oc for 100ppm concentration. It was observed temperature, thickness and concentration dependent. Quick response time and fast recovery were recorded. Keywords: thick film , CuO activated, H2S gas sensor, bandwidth reduction, quick response and fast recover

Laboratory measurement campaign of DVB-T signal with transmit delay diversity

The requirements for future DVB-T/H networks demand that broadcasters design and deploy networks that provide ubiquitous reception in challenging indoors and other obstructed situations. It is essential that such networks are designed cost-effectively and with minimized environmental impact. The EC funded project PLUTO has since its start in 2006 explored the use of diversity to improve coverage in these difficult situations. The purpose of this paper is to investigate the performance of Transmit Delay Diversity (DD) with two antennas to improve the reception of DVB-T/H systems operating in different realistic propagation conditions through a series of tests using a SPIRENT SR5500 dual channel emulator. The relationship between correlation coefficient between channels, receiver velocity and diversity gain is nvestigated. It is shown that transmit delay diversity significantly improves the quality of reception particularly in simulated fast fading mobile broadcasting applications. This paper documents research conducted by Brunel University and Broadreach Systems

Early postoperative outcome after curative colorectal cancer surgery

Introduction:Colorectal cancer is uncommon in the Indian subcontinent, so there is a paucity of outcome data from this region. The aim of our study was to identify risk factors for early postoperative morbidity and mortality following curative colorectal cancer surgery in our set-up. Methods: The data on Patients with pathologically confirmed colorectal cancer who underwent curative surgery at Aga Khan University Hospital, Karachi, Pakistan, between January 1999 and December 2008 were recorded. Patients who developed early postoperative morbidity or mortality were compared with those who followed a healthy course after surgery. Results: A total of 250 consecutive Patients underwent colorectal cancer surgery during the study period. Postoperative complications were found in 34.8 percent of the Patients, out of which four deaths occurred. Serum albumin level less than 3.5 g/dl (odds ratio [OR] 3.75, 95 percent confidence interval [CI] 1.37-10.23) and tumours involving the left colon (OR 2.60, 95 percent CI 1.02-6.64) were identified as independent risk factors for early postoperative complications on multivariate analysis. Conclusions: A low serum albumin level and the presence of a left-sided colonic tumour were significant risk factors for early postoperative complications. Information on these complications and the risk factors for early postoperative outcome is an important consideration for Patients and surgeons

Performance study of Hybrid Wireless Mesh Protocol(HWMP) for IEEE 802.11s WLAN Mesh Networks

Wireless Mesh Network (WMN) have been envisioned as an important solution to the next generation wireless networking which can be used in wireless community networks, wireless enterprise networks, transportation systems, home networking and last-mile wireless internet access. Many proprietary mesh solutions were developed by individual vendor but in order to interoperability; IEEE forms a task group called IEEE 802.11s to develop an integrated mesh networking solution. Hybrid Wireless Mesh protocol (HWMP) and airtime metrics as default routing protocol and routing metrics set by the task group. There is few test bed and many simulation studies have been done to evaluate the performance of the HWMP protocol with the assumption of unique type of flow with fixed packet size and packet rate. However, real networks carry a diverse application (video, voice, FTP, Email etc) with different characteristics (packet size, data rate). In this paper, we are investigated and analyzed the performance of HWMP protocol under such heterogeneous application characteristics

Forecasting Monthly Precipitation in Sylhet City Using ARIMA Model

In this study a seasonal ARIMA model was built using Box and Jenkins method to forecast long term rainfall in Sylhet. For this purpose rainfall data from 1980 to 2010 of Sylhet station were used to build and check the model. Rainfall data from 1980 to 2006 were used to develop the model while data from 2007 to 2010 were used to verify the prediction precision. Four basic chronological steps namely: identification, estimation, diagnostic checking, and forecasting were fitted out in developing the model.  Validity of the model was tested using standard graphical explanation of residuals given by Box and Jenkins. As a second step of validation, forecasted values of monthly rainfall were checked using actual data series. After completion of necessary checking and forecast observation, the ARIMA(0, 0, 1) (1,1, 1)12 was found to be the most effective to predict future precipitation with a 95% confidence interval. It is expected that this long term prediction will help decision makers in efficient scheduling of flood prediction, urban planning, rainwater harvesting and crop management. Keywords: Nonlinear time series analysis, ARIMA model, rainfall forecasting, Sylhet