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.

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.

Damage characterization of beam-column joints reinforced with GFRP under reversed cyclic loading

Said, A.M. Techno-Press 2009 Smart Structures and Systems, An International Jou Vol.5 No.4

The use of fiber reinforced polymer (FRP) reinforcement in concrete structures has been on the rise due to its advantages over conventional steel reinforcement such as corrosion. Reinforcing steel corrosion has been the primary cause of deterioration of reinforced concrete (RC) structures, resulting in tremendous annual repair costs. One application of FRP reinforcement to be further explored is its use in RC frames. Nonetheless, due to FRP's inherently elastic behavior, FRP-reinforced (FRP-RC) members exhibit low ductility and energy dissipation as well as different damage mechanisms. Furthermore, current design standards for FRP-RC structures do not address seismic design in which the beam-column joint is a key issue. During an earthquake, the safety of beam-column joints is essential to the whole structure integrity. Thus, research is needed to gain better understanding of the behavior of FRP-RC structures and their damage mechanisms under seismic loading. In this study, two full-scale beam-column joint specimens reinforced with steel and GFRP configurations were tested under quasi-static loading. The control steel-reinforced specimen was detailed according to current design code provisions. The GFRP-RC specimen was detailed in a similar scheme. The damage in the two specimens is characterized to compare their performance under simulated seismic loading.

2D Inverse Problem in a Distributed Parameter System

Said Rachidi,Rafik Channa,Asma Karama 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.6

In this paper, we present a numerical solution for an inverse heat problem to estimate 2D space-wise coefficient in a parabolic system describing heat transfer. The inverse problem is recast into an optimization problem solved with a conjugate gradient method. This approach use the non linear optimization formulation by minimizing a cost function taking into account both the measured outputs of the system and the outputs calculated by means of the model. The solution is performed by using the free finite element software FreeFem. Numerical example is carried out to check the validity of the proposed method.

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.

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.

Liver Cancer Stem Cell Induction from Induced Pluripotent Stem Cells

( Said M Afify ),( Ghmkin Hassan ),( Hend M Nawara ),( Hager M Mansour ),( Amira Osman ),( Sadia Monzur ),( Hagar Ali Abu Quora ),( Maram H Zahra ),( Akimasa Seno ),( Yoshiaki Iwasaki ),( Masaharu Sen 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Liver cancer stem cells represent a small fraction of cells in liver cancer tissues so that studying these cells is very hard. Generation of liver cancer stem cells considered as one of the most important issue in cancer biology research. For this reason, we tried to generate liver cancer stem cells from induced pluripotent stem (iPSCs). Methods: First of all, CM was collected from confluent culture of Huh7 cells. Then, mouse iPSCs cells without MEF feeder cells were cultured in the presence of 50% CM for 4 weeks. The medium was changed every day with fresh medium containing 50% of CM. Mouse iPSCs cultured is the complete medium with LIF were used as a control. The survived cells (5x105 cells) were suspended in HBSS and injected into the liver of BALB/ c nude mice. After 25 days malignant tumor was formed in the liver while benign teratoma was formed by the injection of iPSCs. Tumors were then excised and partly fixed in 10% neutral formalin buffer solution for HE staining and immunohistochemical analysis. The rest of tumors were subjected to rt-qPCR anaylsis and primary culture. Results: Immunohistochemical analysis with liver cancer associated markers and cancer stem cell marker showed that malignant liver tumor was developed. These results indicate that the primary cells from the malignant tumor are rich in CSCs. Conclusions: This model will be very important and useful to assess the significant molecular mechanisms necessary to maintain liver cancer stem cells, which will help in defat liver cancer.

DNA barcodes in Egyptian olive cultivars (Olea europaea L.) using the rbcL and matK coding sequences

Said Eglal M.,Hassan M. E. 한국작물학회 2023 Journal of crop science and biotechnology Vol.26 No.4

Olives (Olea europaea L.) are the most well-known trees of the Mediterranean basin. The genetic heritage of olive trees is very rich and characterized by an abundance of varieties, eventually leading to significant genotype mixing. Therefore, the classification and analysis of the genetic diversity of olive cultivars are challenges of high priority. It helps make more efficient use of the olive resources distributed globally and benefits the genetic improvement and breeding of olive varieties. DNA barcoding is a method for evaluating and classifying species that uses short, variable, and uniform DNA regions. This study used DNA sequencing data for the first time for DNA barcoding of Egyptian olive cultivars and assessed the genetic relationship between four local cultivars grown in Egypt and their relation to sequences within the database. PCR amplification and sequence characterization were used to assess the effectiveness of the two barcoding sites, rbcL and matK. Based on multiple alignments of all the sequences obtained from the analyzed regions, matK had the longest sequence (816 bp) and rbcL the shortest (411 bp) of the two barcoding loci. The matK gene region was the least varied, with a variability level of 77%, while the rbcL gene region had the highest amount of variability (98.7%). Because of the presence of unique variable sites, both barcoding loci rbcL and matK efficiencies discriminate the selective Egyptian olive cultivars. The DNA sequences from the individual and combined barcode loci were used in a maximum likelihood tree-based phylogenetic analysis to successfully distinguish the selected olive cultivars.