Ferry–Based Directional Forwarding Mechanism for Improved Network Life-Time in Cluster-Based Wireless Sensor Network

Considerable energy saving can be achieved with mobility-based wireless sensor networks (WSN's), where a mobile node (ferry) visits sensing nodes in a network to collect sensed data. However, the critical issues of such WSN's are limited networks lifetime and high data latency, these critical issues are due to the slow mobility and relatively long route distance for ferries to collect and forward data to the sink. Incorporating ferries in WSNs eliminates the need for multi-hop forwarding of data, and as a result, reduce energy consumption at sensing nodes. In this paper, we introduce the One Hop Cluster-Head Algorithm (OHCH), where a subset of ferries serve as cluster heads (CH), travel between nodes with short distance mobility, collect data originated from sources, and transfer it to the sink with minimum hop count possible, this approach can achieve more balance between network energy saving and data collection delay, also, it is an efficient design to combine between ferries and noise

Analysis of OFDM and WPOFDM Systems in Different Wireless Multipath Channels

In this paper, the performance analysis for orthogonal frequency division multiplexing (OFDM) and wavelet packet based OFDM (WPOFDM) systems over different wireless multipath channels has been investigated. The bit error rate (BER) performance for both systems is shown to be comparable and even at times better for OFDM especially in frequency selective fading channel at high values of S/N. Simulation results also show a significant enhancement for WPOFDM in terms of spectral efficiency and side-lobes suppression comparing to OFDM. Keywords: OFDM, WPOFDM, PSD, BER performance, wavelet filters, fading channels.

Rak tarczycy po terapii jodem radioaktywnym z powodu nadczynności tarczycy — opis serii przypadków i przegląd piśmiennictwa

Introduction: To assess the rate of thyroid cancer and mortality rate in a cohort of patients who received RAI131 treatment for hyperthyroidism and to report the index cases’ characteristics and management Material and methods: A cohort of 264 patients who received RAI131 treatment for different causes of thyrotoxicosis were followed up over a period of 18 years (1996–2014) by physical exam, radiological evaluation and serial thyroid function tests. Results: During the follow up period, three cases of thyroid cancer were identified. The prevalence of thyroid cancer was 1.136% of cases who received RAI131. The relative risk was 378.79 (95% CI: 76.8 < RR < 1868.23). The P value was < 0.0000004 and the SMR is 1.99/1000. Conclusions: The prevalence of thyroid cancer was 1.136% in the cohort of patients treated with RAI131. Despite the fact that no direct cause-effect relationship between RAI and thyroid cancer could be established, these cases highlights the importance of life-long surveillance of patients who receive RAI131.Wstęp: Badanie przeprowadzono w celu oceny częstości występowania raka tarczycy i odsetka zgonów w kohorcie chorych poddanych terapii RAI131 z powodu nadczynności tarczycy oraz przedstawienia charakterystyki tych chorych i stosowanego u nich leczenia. Materiał i metody: U kohorty 264 chorych poddanych terapii RAI131 z uwagi na tyreotoksykozę o różnej etiologii przez ponad 18 lat (1996–2014) prowadzono obserwację obejmującą badanie przedmiotowe, ocenę radiologiczną i serię badań czynności tarczycy. Wyniki: W okresie obserwacji wykryto 3 przypadki raka tarczycy. Częstość występowania raka tarczycy w grupie chorych poddanych terapii RAI131 wynosiła 1,136%. Ryzyko względne wynosiło 378,79 (95% CI: 76,8 < RR < 1868,23). Wartości p i SMR wynosiły odpowiednio < 0,0000004 i 1,99/1000. Wnioski: Częstość występowania raka tarczycy w kohorcie chorych poddanych terapii RAI131 wynosiła 1,136%. Mimo że nie wykazano bezpośredniego związku przyczynowo-skutkowego między RAI a rakiem tarczycy, opisane przypadki zwracają uwagę na znaczenie bezterminowej obserwacji chorych poddanych terapii RAI131

Coincidence summing corrections in HPGe gamma-ray spectrometry for Marinelli-beakers geometry using peak to total (P/T) calibration

The coincidence summing corrections for an HPGe spectrometer with Marinelli-beaker geometry were calculated using the peak-to-total (P/T) calibration method in combination with the algorithms implemented in the Genie 2000 software. The P/T ratios were calculated for different energies and three types of beaker contents: air, powder milk and soil. The validity of the correction was tested against a standard sample and showed excellent agreement with the certified data. The corrections were also in good agreement with published data in the literature

A Collocation-Based Algorithm for Analyzing Bifurcations in Phase Locked Loops with Tanlock and Sawtooth Phase Detectors

Analysis of bifurcation of second-order analog phase locked loop (PLL) with tanlock and sawtooth phase detectors is investigated. Both qualitative and quantitative analyses are carried out. Qualitatively, the basin boundaries of the attractors were constructed by plotting the stable and the unstable manifolds of the system. The basin boundaries show that the PLL under consideration for certain loop parameters has a separatrix cycle which terminates the limit cycle (out-of-lock state) and the loop pulls-in. This behavior is known in literature as homoclinic bifurcation and the value of the bifurcation parameter where this process occurs is called the pull-in range. Quantitatively, we propose a collocation-based algorithm to compute the separatrix cycle and the pull-in range. The separatrix cycle is approximated by a finite set of harmonics N with unknown amplitudes and by utilizing the fact that this limit cycle bifurcates from a separatrix cycle, a system of nonlinear algebraic equations is derived. For given values of filter parameters and gain, the algorithm numerically solves for the unknown amplitude of the harmonics and the value of the pull-in range simultaneously by evaluating the system at the collocation points. Results demonstrate that phase locked loop with sawtooth phase detector characteristics has the wider pull-in range followed by tanlock and sinusoidal, respectively

Screening for obstructive sleep apnea among patients undergoing coronary catheterization in Jordan

Mohamad I Jarrah,1 Ahmed M Yassin,2 Rasheed K Ibdah,1 Ali M Ibnian,1 Ahmad A Eyadeh,1 Basheer Y Khassawneh11Department of Internal Medicine, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Neuro sciences, Faculty of Medicine, Jordan University of Science and Technology, Irbid, JordanAims: This study aimed to utilize a validated sleep questionnaire as a screening tool for symptoms and risk of obstructive sleep apnea in patients undergoing coronary catheterization in Jordan.Materials and methods: A cross-sectional design was used to screen adult patients undergoing coronary catheterization for obstructive sleep apnea (OSA). The Berlin sleep questionnaire was used to record nocturnal and daytime symptoms of OSA and to stratify patients into “low-risk” or “high-risk” for OSA. Coronary artery disease was defined as ≥50% intraluminal stenosis in at least one coronary vessel.Results: A total of 398 patients were studied, mean age was 58.7 years (SD=10.70), ranging from 21–92 years, and 68.6% were males. Based on the Berlin sleep questionnaire’s definition, 176 patients (44.2%) were at high-risk for obstructive sleep apnea. Snoring was reported by 61%; loud in 42.1%, and frequent in 62%. Daytime sleepiness was reported by 36%, and 18.9% had fallen asleep while driving. Witnessed apnea during sleep was less reported (7.8%). Prevalence of symptoms and risk of OSA were not different between patients with and without coronary artery disease, P>0.05. In addition, logistic regression indicated that there was no significant association between risk of OSA and coronary artery disease, adjusted (odds ratio=0.93, 95% Confidence Interval=0.60–1.44, P=0.752).Conclusions: Symptoms and risk of obstructive sleep apnea were common among adult Jordanians undergoing coronary catheterization. There was no association between risk of obstructive sleep apnea and coronary artery disease. Larger studies are needed to assess the role of screening for obstructive sleep apnea in this patient population.Keywords: obstructive sleep apnea, coronary artery disease, snoring, screening, Berlin sleep questionnaire, coronary catheterizatio

Improved Dose Response of N-(hydroxymethyl)acrylamide Gel Dosimeter with Calcium Chloride for Radiotherapy

The impact of calcium chloride (CaCl2) on the performance of N-(hydroxymethyl)acrylamide (NHMA) polymer gel dosimeter is studied in this article. The dosimeter was exposed to doses of up to 10 Gy with radiation beam-energy of 10 MV and dose-rates of 300 cGy/min. The relaxation rate (R2) parameter was utilized to explore the performance of irradiated NHMAGAT gels. The dose response in terms of R2 increased from 0.29 to 0.63 Gy−1·s−1 with increasing calcium chloride concentration from 0 to 1000 mM. The results show no substantial impact of dose-rates as well as radiation energies on NHMAGAT samples. For the steadiness of irradiated NHMAGAT dosimeters, it was found that there is no apparent variation in R2 (less than ±3%; standard deviation) up to 3 days. The overall uncertainty of the gel dosimeter with calcium chloride is 4.96% (double standard deviation, 95% confidence level)