4,078 research outputs found
On Computing Shannon’s Sphere Packing Bound and Applications
file: :home/zaki/.local/share/data/Mendeley Ltd./Mendeley Desktop/Downloaded/Ahmed, Ambroze, Tomlinson - 2007 - On Computing Shannon’s Sphere Packing Bound and Applications.pdf:pdf keywords: SPB mendeley-tags: SPBA new method to numerically evalu- ate Shannon’s lower bound is presented in this pa- per. This new method is based on the Incomplete Beta function and permits the exact evaluation of the Sphere Packing Bound for a large range of code sizes, rates and probability of error. Comparisons with cur- rent standards (DVB–RCS, DVB–S2 and 3GPP) are also presented and discussed. It is shown that cur- rent standard coding schemes are about 0.6dB from the Shannon Limit corrected for Binary Signalling
Multi-track 2D joint signal detection and decoding for TDMR system using single parity-check coding.
Effect of Dimethoate Residues on Soil Micro-arthropods Population in the Valley of Zendan,Yemen
The present study aimed to screen the effect of overuse of the insecticide Dimethoate and its residues within 0 -15 cm soil layer on the soil micro-arthropods population, which play a very important role in maintenance of the fertility of the soil. The valley of Zendan is located in Arhab Destrict, Sana’a Governorate, Yemen. The valley is about 50 km north-east of Sana’a city and this geographical area is a large producer of Qat(Catha edulis Forsk); the plant which most of the people in the country chew. In this study the valley divided into three stations, each station contained three treated substations and three control substations. The control substations selected from the farms, which are historically free from pesticides. Due care has been taken to insure that the treatedsub-stations were from the closest area to the control substations. The average use of Dimethoate 40% E.C is 1-2 ml/L water. The treatment replication was 1-3 times within the period of 2-3 weeks. In this study also, we analyzed the total concentration of Dimethoate, and its metabolite; Omethoate in the soil layer of 0-15 cm. The analysis of Dimethoate and Omethoate residues from representative soil samples covered the major part of the Zendan valley was done by the technique of LC-MS, and the results revealed that the detected levels ranged from 0.914 to 5.180mg/kg air-dried soil for Dimethoate residues and 0.001 to 0.067 mg/kg air-dried soil for Omethoate residues. For studying the effect of Dimethoate residues on the soil micro-arthropods population, soil samples from each substation were collected with core sampler. The soil micro-arthropods were extracted for 48 hours and collected in vials containing 70% alcohol by using the extraction funnels technique. The number and type of soil microarthropods extracted from each substation were separated and recorded and the data obtained was analyzed. Theoutcomes of the study revealed that Dimethoate and Omethoate residues are beyond the Total Threshold Limit Concentration (TTLC) and significantly reduced the population of the non-target soil micro-arthropods that included mainly mites, collembolans, beetle larvae, trips, cutworms, symphyla and seed corn maggot. Mites and collembolanswere the most affected micro-arthropods by Dimethoate and Omethoate residues. The reduction in the soil microarthropods population varied from 59% to 69% as compared to its population in control substations. The maximum decline of soil microarthropods was found to be in substations where the highest residues of Dimethoate and Omethoate were recorded. Thus indiscriminate use of pesticides such as Dimethoate will definitely affect the soil fertility in the area and that will reduce the crop yield in future. @JASE
Joint unscented kalman filter for dual estimation in a bifilar pendulum for a small UAV
It has always been difficult to accurately estimate the moment of inertia of an object, e.g. an unmanned aerial vehicle (UAV). Whilst various offline estimation methods exist to allow accurate parametric estimation by minimizing an error cost function, they require large memory consumption, high computational effort, and a long convergence time. The initial estimate's accuracy is also vital in attaining convergence. In this paper, a new real time solution to the model identification problem is provided with the use of a Joint Unscented Kalman Filter for dual estimation. The identification procedures can be easily implemented using a microcontroller, a gyroscope sensor, and a simple bifilar pendulum setup. Accuracy, robustness, and convergence speed are achieved.published_or_final_versio
Paying for Likes? Understanding Facebook like fraud using honeypots
Facebook pages offer an easy way to reach out to a very large audience as they can easily be promoted using Facebook's advertising platform. Recently, the number of likes of a Facebook page has become a measure of its popularity and profitability, and an underground market of services boosting page likes, aka like farms, has emerged. Some reports have suggested that like farms use a network of profiles that also like other pages to elude fraud protection algorithms, however, to the best of our knowledge, there has been no systematic analysis of Facebook pages' promotion methods. This paper presents a comparative measurement study of page likes garnered via Facebook ads and by a few like farms. We deploy a set of honeypot pages, promote them using both methods, and analyze garnered likes based on likers' demographic, temporal, and social characteristics. We highlight a few interesting findings, including that some farms seem to be operated by bots and do not really try to hide the nature of their operations, while others follow a stealthier approach, mimicking regular users' behavior
Overexpression Of Chd1l Is Positively Associated With Metastasis Of Lung Adenocarcinoma And Predicts Patients Poor Survival
CHD1L (chromodomain helicase/ATPase DNA binding protein 1-like gene) has been demonstrated as an oncogene in hepatocellular carcinoma (HCC), however, the role of CHD1L in non-small-cell lung cancer (NSCLC) tumorigenesis hasn't been elucidated. In this study, the expression and amplification status of CHD1L were examined by immunohistochemistry and fluorescence in situ hybridization respectively in 248 surgically resected NSCLCs. The associations between CHD1L expression and clinicopathologic features and the prognostic value of CHD1L were analyzed. Overexpression and amplification of CHD1L was found in 42.1% and 17.7% of NSCLCs, respectively. The frequency of CHD1L overexpression (53.2% vs. 28.1%, P = 0.002) and amplification (25.2% vs. 8.2%, P = 0.020) in adenocarcinoma (ADC), was much higher than that in squamous cell carcinoma (SCC). CHD1L overexpression was associated closely with ascending pN status (P < 0.001), advanced clinical stage (P = 0.001) and tumor distant metastasis (P = 0.001) in ADCs, but not in SCCs. For the whole cohort and ADC patients, univariate survival analysis demonstrated a significant association of CHD1L overexpression with shortened survival; and in multivariate analysis, CHD1L overexpression was evaluated as a independent predictor for overall survival and distant metastasis free survival. These results suggested that overexpression of CHD1L is positively associated with tumor metastasis of lung ADC, and might serve as a novel prognostic biomarker and potential therapeutic target for lung ADC patients.published_or_final_versio
WLAN aware cognitive medium access control protocol for IoT applications
© 2020 by the authors. Internet of Things (IoT)-based devices consist of wireless sensor nodes that are battery-powered; thus, energy efficiency is a major issue. IEEE 802.15.4-compliant IoT devices operate in the unlicensed Industrial, Scientific, and Medical (ISM) band of 2.4 GHz and are subject to interference caused by high-powered IEEE 802.11-compliant Wireless Local Area Network (WLAN) users. This interference causes frequent packet drop and energy loss for IoT users. In this work, we propose a WLAN Aware Cognitive Medium Access Control (WAC-MAC) protocol for IoT users that uses techniques, such as energy detection based sensing, adaptive wake-up scheduling, and adaptive backoff, to reduce interference with the WSN and improve network lifetime of the IoT users. Results show that the proposedWAC-MAC achieves a higher packet reception rate and reduces the energy consumption of IoT nodes
Effects of palm oil mill effluent (POME) anaerobic sludge from 500 m3 of closed anaerobic methane digested tank on pressed-shredded empty fruit bunch (EFB) composting process
In this study, co-composting of pressed-shredded empty fruit bunches (EFB) and palm oil mill effluent (POME) anaerobic sludge from 500 m3 closed anaerobic methane digested tank was carried out. High nitrogen and nutrients content were observed in the POME anaerobic sludge. The sludge was subjected to the pressed-shredded EFB to accelerate the co-composting treatment. In the present study, changes in the physicochemical characteristics of co-composting process were recorded and evaluated. The cocomposting treatment was completed in a short time within 40 days with a final C/N ratio of 12.4. The co-composting process exhibited a higher temperature (60 - 67°C) in the thermophilic phase followed by curing phase after four weeks of treatment. Meanwhile, pH of the composting pile (8.1 - 8.6) was almost constant during the process and moisture content was reduced from 64.5% (initial treatment) to52.0% (final matured compost). The use of pressed-shredded EFB as a main carbon source and bulking agent contributed to the optimum oxygen level in the composting piles (10 - 15%). The biodegradation of composting materials is shown by the reduction of cellulose (34.0%) and hemicellulose (27.0%) content towards the end of treatment. In addition, considerable amount of nutrients and low level of heavy metals were detected in the final matured compost. It can be concluded that the addition of POME anaerobic sludge into the pressed-shredded EFB composting process could produce acceptable and consistent quality of compost product in a short time
Inequalities in the prevalence of undiagnosed hypertension among Bangladeshi adults: evidence from a nationwide survey
Background
In recent years, developing countries like Bangladesh are facing a higher burden of non-communicable diseases such as hypertension as a result of demographic transition. Prevalence of hypertension is often studied in this setting. However, evidence on undiagnosed hypertension is not widely available in the existing literature. Therefore, the current study focuses on inequalities in the prevalence of undiagnosed hypertension in Bangladesh.
Methods
A total of 8835 participants aged 35+ years were included in this study using nationally representative Bangladesh Demographic and Health Survey 2011 (BDHS). In the survey, systolic blood pressure (SBP) and diastolic blood pressure (DBP) of these participants were measured three times with approximately 10 minutes of an interval between each measurement. Any respondent with either SBP ≥ 140 mmHg or DBP ≥ 90 mmHg was considered as patient with hypertension as per the guidelines from American Heart Association. Among the participants, undiagnosed hypertension was defined as having SBP > =140 mmHg or DBP > =90 mmHg and never taking prescribed medicine or being told by health professionals to lower/control blood pressure. Multiple logistic regression analysis was applied for identifying factors associated with undiagnosed hypertension. Further, socioeconomic inequalities in the prevalence of undiagnosed hypertension were estimated using Concentration Index (C).
Results
We found 978 (59.9% of the total) were undiagnosed among 1685 hypertensive patients studied. Regression analysis showed individuals with being underweight, having poor socioeconomic conditions, and lower educational qualifications were more likely to have undiagnosed hypertension. A similar association between undiagnosed hypertension and socioeconomic quintiles was observed using concentration index (C = − 0.07). On the other hand, individuals from higher age group (50–64 or above), female sex, and Sylhet region were at lower risk of undiagnosed hypertension.
Conclusions
This study showed that a large proportion of the cases with hypertension are remained undiagnosed in Bangladesh, especially among the poor and low educated population. Screening and awareness building initiatives on hypertension should be taken for this group of population to reduce the burden of undiagnosed hypertension
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