Blind Channel Estimation and Equalization

Said Elkassimi,Said Safi,B. Manaut 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.12

This paper presents the problem of blind channel estimation of a non-minimum phase system using three algorithms. These algorithms play an important role for blindly estimate the parameters of radio mobile channel. Thus studying the problem of blind channel equalization based on, the proposed algorithm, CMA and SKMAA algorithms. The simulation results in noisy environment and for different SNR values demonstrate that the proposed algorithm is more performing than other algorithms. In addition the Sign Kurtosis Maximization Adaptive Algorithm (SKMAA) is more powerful in comparison to constant modulus algorithm (CMA) at the blind channel equalization, that is to say gives the right equalization.

Highly Efficient Control of the Doubly Fed Induction Motor

Said Drid,Abdesslam Makouf,Mohamed-Said Nait-Said,Mohamed Tadjine 대한전기학회 2007 Journal of Electrical Engineering & Technology Vol.2 No.4

This paper deals with the high efficient vector control for the reduction of copper losses of the doubly fed motor. Firstly, the feedback linearization control based on Lyapunov approach is employed to design the underlying controller achieving the double fluxes orientation. The fluxes' controllers are designed independently of the speed. The speed controller is designed using the Lyapunov method especially employed to the unknown load torques. The global asymptotic stability of the overall system is theoretically proven. Secondly, a new Torque Copper Losses Factor is proposed to deal with the problem of the machine copper losses. Its main function is to optimize the torque in keeping the machine saturation at an acceptable level. This leads to a reduction in machine currents and therefore their accompanied copper losses guaranteeing improved machine efficiency. The simulation and experimental results in comparative presentation confirm largely the effectiveness of the proposed DFIM control with a very interesting energy saving contribution.

Highly Efficient Control of the Doubly Fed Induction Motor

Drid, Said,Makouf, Abdesslam,Nait-Said, Mohamed-Said,Tadjine, Mohamed The Korean Institute of Electrical Engineers 2007 Journal of Electrical Engineering & Technology Vol.2 No.4

This paper deals with the high efficient vector control for the reduction of copper losses of the doubly fed motor. Firstly, the feedback linearization control based on Lyapunov approach is employed to design the underlying controller achieving the double fluxes orientation. The fluxes# controllers are designed independently of the speed. The speed controller is designed using the Lyapunov method especially employed to the unknown load torques. The global asymptotic stability of the overall system is theoretically proven. Secondly, a new Torque Copper Losses Factor is proposed to deal with the problem of the machine copper losses. Its main function is to optimize the torque in keeping the machine saturation at an acceptable level. This leads to a reduction in machine currents and therefore their accompanied copper losses guaranteeing improved machine efficiency. The simulation and experimental results in comparative presentation confirm largely the effectiveness of the proposed DFIM control with a very interesting energy saving contribution.

Association of trainee involvement in an acute pain service with postoperative opioid use in patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

Said Engy T.,Sztain Jacklynn F.,Martin Erin I.,Abramson Wendy B.,Meineke Minhthy N.,Furnish Timothy J.,Swisher Matthew W,Gabriel Rodney A. 대한마취통증의학회 2020 Korean Journal of Anesthesiology Vol.73 No.3

Background: Several hospitals have implemented a multidisciplinary Acute Pain Service (APS) to execute surgery-specific opioid sparing analgesic pathways. Implementation of an anesthesia attending-only APS has been associated with decreased postoperative opioid consumption, time to ambulation, and time to solid food intake for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy. In this study, we evaluated the impact of introducing an APS trainee on postoperative opioid consumption in patients undergoing hyperthermic intraperitoneal chemotherapy during postoperative day (POD) 0–3. Methods: We performed a retrospective propensity-matched cohort study where we compared opioid consumption and hospital length of stay among two historical cohorts: attending-only APS service versus service involving a regional anesthesia fellow. Results: In the matched cohorts, the median POD 0–3 opioid use [25%, 75% quartile] for the single attending and trainee involvement cohort were 38.5 mg morphine equivalents (MEQ) [14.1 mg, 106.3 mg] and 50.4 mg MEQ [28.4 mg, 91.2 mg], respectively. The median difference was –9.8 mg MEQ (95% CI –30.7 to 16.5 mg; P = 0.43). There was no difference in hospital length of stay between both cohorts (P = 0.67). Conclusions: We found that the addition of a regional anesthesia fellow to the APS team was not associated with statistically significant differences in total opioid consumption or hospital length of stay in this surgical population. The addition of trainees to the infrastructure, with vigilant supervision, is not associated with change in outcomes.

Effects of Anthropogenic Interventions on the Entisols of Al-Khoud Dam Area in a Dry Region of Oman

Said Al-Ismaily,Ali Al-Maktoumi,Anvar Kacimov,Hamad Al-Busaidi,Said Al-Saqri 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Production and Characterization of Cellulase from E. coli EgRK2 Recombinant Based on Oil Palm Empty Fruit Bunches

Said Zul Amraini,Lina Putri Ariyani,Heri Hermansyah,Siswa Setyahadi,Siti Fauziyah Rahman,박돈희,Misri Gozan 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.3

Oil Palm Empty Fruit Bunch (OPEFB) is an abundant biomass resource in Indonesia, which contains 41.3 ~ 46.5% (w/w) of cellulose. This research examined the production of cellulase by the E. coli EgRK2 recombinant strain using an OPEFB substrate. The production of the enzyme was initially examined to identify optimum growth conditions, by observing the growth and activity of E. coli EgRK2 compared to its wild type. Our results showed that the optimum production time, pH and temperature of the recombinant growth and cellulase activity were achieved at 24 h, and at 7 and 40°C, respectively. Using these optimum conditions, the enzyme was produced, and experiments were carried out to examine the enzyme characteristics, produced from both strains, on hydrolysis of cellulose from OPEFB. Our results showed that the activity of the enzyme produced by the recombinant almost doubled compared to that of the wild type, although the optimum pH for both strains was pH 6. Higher activity was achieved by the recombinant compared to the wild type strain, and values were 1.905 and 1.366 U/mL, respectively. The optimum temperature for hydrolysis by cellulase occurred at 50°C for Bacillus sp. RK2, and 60°C for Bacillus sp. EgRK2. The Michaelis-Menten constant (Km) and maximum velocity (Vmax) for OPEFB degradation by E. coli EgRK2 were 0.26% and 1.750 μmol/mL/sec, which were significantly better values than those of the wild type. Control experiments for the degradation test using CMC also showed a better Vmax value for E. coli EgRK2 compared to the wild type, which is 2.543 and 1.605 μmol/mL/sec, respectively.

The burden and management strategies of hypertensive crisis in adult patients presenting to emergency departments of district and regional hospitals in Sub-Saharan Africa

Said S. Kilindimo,Abdulkarim Ahmed,Alphonce N. Simbila,Raynald Harrison,Lucy Shirima,Farida Abdallah,Aliasghar G. Mukhtar,Juma Mfinanga,Joseph Saika,Kisanga Emanuel,Hendry R. Sawe 대한고혈압학회 2023 Clinical Hypertension Vol.29 No.-

Background Hypertensive crisis is among the causes of morbidity and mortality in adult patients with hypertension in Sub-Saharan Africa. We aimed to determine the burden, risk factors and describe the management strategies of hypertensive crisis among adult patients seen at emergency departments of district and regional hospitals in Tanzania. Methods This was a prospective multicenter longitudinal study which included all 162 district and regional hospitals in Tanzania. It was part of the Tanzania Emergency Care Capacity Survey (TECCS), a large assessment of burden of acute illness and emergency care capacity in Tanzania. Adult patients who presented to emergency departments with blood pressure ≥ 180/110mmHg were enrolled. Demographics, clinical presentation, management, and 24-hours outcomes were recorded using a structured case report form. Descriptive statistics were summarized in frequency and median, while logistic regression was used to evaluate the association between risk factors and presence of hypertensive crisis. Results We screened 2700 patients and enrolled 169 adults, henceforth proportion of adult patients with hypertensive crisis was 63 per 1000. Median age was 62 years (IQR 50–70 years) and predominantly females, 112 (66.3%). Majority 151(89.3%) were self-referred with two-wheel motorcycle being the commonest 46 (27.2%) mode of arrival to the hospital. Hypertensive emergency was found in over half 96 (56.8%) of the patients with hypertensive crisis, with oral medications administered in more than half of them, 71 (74%) as means to control the high blood pressure, and one-third 33 (34.4%) were discharged home. On multivariate analysis increasing age (AOR 4.53, p < 0.001), use of illicit drug (AOR 4.14, p-0.04) and pre-existing hypertension (AOR 8.1, p < 0.001) were independent risk factors for hypertensive crisis occurrence. Conclusion Hypertensive crisis among adult patients attending district and regional hospitals is common (63 patients per every 1000 patients). Increasing age, use of illicit drug and pre-existing hypertension are independent associated factors for developing hypertensive crisis.

Modeling of Unsymmetrical Single-lane Roundabouts based on Stopping Sight Distance

Said M. Easa 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2

Evaluation of the adequacy of sight distance at roundabout is usually performed graphically as no quantitative guidelines are available for the lateral clearance needs. This paper presents analytical lateral clearance models to satisfy Stopping Sight Distance (SSD) at unsymmetrical single-lane roundabouts (with different entry and exit radii). The models are developed for three critical locations: approach sight distance, sight distance to exist crosswalk, and circulatory roadway sight distance. Two cases of approach sight distance are presented: sight distance to the crosswalk and sight distance to the yield line. The required lateral clearance at any specified point along the curve can also be determined. Design aids for the required maximum lateral clearance are established for the three locations of sight distance based on accurate SSD formula that accounts for effect of the radial deceleration component of the vehicle. For the circulatory roadway sight distance, infeasible combinations of the circulatory roadway radius and speed are identified based on acceptable driver’s field of peripheral vision. The models and results of this paper, which are applicable to both symmetrical and unsymmetrical roundabouts, should be of interest to highway engineers and designers.

Antecedents and Consequences of Employees Empowerment

Said Shaban Hamed KINFORMS 2010 Management Review Vol.5 No.1

This research examines the relationship between role clarity, organizational trust and employees empowerment , the relationship between employees empowerment and job involvement, job satisfaction. The research used a cross-sectional design. A random sample of 862 employees was selected to participate in this research. Self-administered questionnaires were used in data collection .The results show statistically significant positive relationships between role clarity , organizational trust and employees empowerment, and also a statistically significant positive relationships between employees empowerment and job involvement, job satisfaction. The article discusses implications of these findings.

Performance Improvement of GMSK Signaling in Fast Frequency-Selective Mobile Channels using Combined Offset Receiver Diversity and Decision Feedback Equalization

Said E. El Khamy,El Sayed A. Youssef,Abbas A. El Shamly 한국통신학회 1993 Asia-Pacific Conference on Communications Vol.2 No.1