The Effect of Modified Atmosphere Packaging (MAP) on Some Physiochemical Characteristics and Texture of Iranian Apple 'Shafi

Younes Mostofi,Hanifeh S. Hajizadeh,Ali reza Talaie,Mousavi M. Ebrahim Zadeh 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Space-Time Block Coding Techniques for MIMO 2×2 System using Walsh-Hadamard Codes

Younes Djemamar,Saida Ibnyaich,Abdelouhab Zeroual 한국정보통신학회 2022 Journal of information and communication convergen Vol.20 No.1

Herein, a new space–time block coding technique is proposed for a MIMO 2 × 2 multiple-input multiple output (MIMO) system to minimize the bit error rate (BER) in Rayleigh fading channels with reduced decoding complexity using ZF and MMSE linear detection techniques. The main objective is to improve the service quality of wireless communication systems and optimize the number of antennas used in base stations and terminals. The idea is to exploit the correlation product technique between both information symbols to transmit per space–time block code and their own orthogonal Walsh–Hadamard sequences to ensure orthogonality between both symbol vectors and create a full-rate orthogonal STBC code. Using 16 quadrature amplitude modulation and the quasi-static Rayleigh channel model in the MATLAB environment, the simulation results show that the proposed space–time block code performs better than the Alamouti code in terms of BER performance in the 2 × 2 MIMO system for both cases of linear decoding ZF and MMSE.

NUMERICAL SIMULATION AND PARAMETRIC STUDIES FOR EVALUATION OF BALANCED VENTILATION AND EARTH AIR EXCHANGERS SYSTEM COUPLED TO A DOMESTIC BUILDING

YOUNES KARTACHI,ABDELLAH MECHAQRANE 대한설비공학회 2013 International Journal Of Air-Conditioning and Refr Vol.21 No.1

In this study, we analyze the impact of ventilation heat recovery with the heating and cooling potential of earth air heat exchanger in real climatic conditions in domestic buildings in the Middle Atlas region. In our case study, we calculate the primary energy used by a domestic building built as per the conventional house design parameters required by the Moroccan regulation. We use climate data for the city of Fes in Northern Moroccan. Three system con¯gurations were considered. The ¯rst was the mechanical extract ventilation system both with and without heat recovery. The second was the mechanical extract ventilation system with earth to air heat exchanger system (EAHEX), and the third system was the mechanical balanced ventilation system coupled with EAHEX system. Primary energy use strongly in°uences natural resources e±ciency and the environmental impacts of energy supply activities. In this study we explore the primary energy implications of the mechanical balanced ventilation system coupled with the EAHEX system in residential buildings. The results of this study shows that the use of a balanced ventilation system, with a high e±ciency instead of a mechanical extract ventilation system, decreases the ¯nal and primary energy consumption. Moreover, it decreases or increases the CO2 emission depending on the primary energy sources.

An integrator based wind speed estimator for wind turbine control

Younes Ait Elmaati,Lhoussain El Bahir,Khalid Faitah 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.21 No.4

In this paper, an integrator based method to estimate the effective wind speed in wind turbine systems is proposed. First, the aerodynamic torque was accurately estimated through a proportional gain based observer where the generator speed is the measured output of the system. The torque signal contains not only useful frequencies of the wind, but also high frequencies and the ones due to structural vibration. The useful information of the wind signal is low frequency. A spectral analysis permitted the determination of the useful frequencies. The high frequencies were then filtered before introducing the torque signal in the wind speed observer. The desired effective wind speed was extracted through an integrator based observer using the previously estimated aerodynamic torque. The strength of the method is to avoid numerical solutions used in literature of the wind speed estimation. The effectiveness of the proposed wind speed estimator and its use to control the generator speed has been tested under turbulent situations using the FAST software (Fatigue, Aerodynamics, Structures, and Turbulence), for large scale Megawatt turbine.

Linguistic and Pedagogical Aspects of Ibn Khaldoon

( Younes Mohamed ) 한국아랍어아랍문학회 2018 아랍어와 아랍문학 Vol.22 No.4

The aim of this research is to study the linguistic and pedagogical aspects of Ibn Khaldoon's work. Several ideas from Ibn Khaldoon's work show us that he was well ahead of his contemporaries due to his thought and foresight. His ideas on linguistics and education are a valuable source required by all scholars. Ibn Khaldoon theorised that language is a social phenomenon that has come as a result of a number of necessary interactions brought about by a society to allow for a choice and use of speech between individuals. As many scholars accept today, language is a personal acquisition that requires a social branch to appear and develop. As such, Ibn Khaldoon was ahead of other scholars of pedagogy when he confirmed that a strict approach towards pupils is harmful to them, as methods of teaching and its effect on pupils explain to us in detail.

Experimental Investigation of Dynamic Errors in Coordinate Measuring Machines for High Speed Measurement

Younes Echerfaoui,Abderrazak El Ouafi,Ahmed Chebak 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.8

Accuracy enhancement of coordinate measuring machine (CMM) by software compensation for geometric and thermal error has proved its effectiveness in the modern manufacturing. In some applications, measurement errors can be reduced by more than 70% when using error compensation. However, due to the demand for shorter cycle times of measurement tasks, CMMs are increasingly required to be used at high measuring velocity. In such conditions, dynamic errors will certainly have a much more influence on the measurement accuracy and constitutes a barrier to the reduction of measuring cycle time. This paper presents an experimental investigation of dynamic errors in CMMs. A structured experimental design and improved statistical analysis tools are combined to evaluate the measurement parameters effects at high measuring velocity. Carried out on a bridge type CMM, these parameters are combined and used to investigate the variation of several dynamic error attributes. A laser interferometer system is used to assess error components under different dynamic conditions. Based on these results, the contributions of each parameter in the variation of the dynamic error attributes are estimated revealing many options to consider for building an efficient prediction model for error compensation. Neural network based prediction model suggests a promising performance.

Quarter Car Active Suspension System: Minimum Time Controller Design Using Singular Perturbation Method

Younes Mohammadi,Soheil Ganjefar 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.6

Suspension systems have been widely applied to vehicles. Every vehicle moving on the randomly profiledroad is exposed to vibration and shocks which is harmful both for the passengers in terms of comfort andfor the durability of the vehicle itself. From this point of view, it is important to reset to zero displacement, velocityand acceleration of car in minimum time. So, this paper proposes a new minimum time controller basedon bang-bang control for the quarter car active suspension systems. First by using singular perturbation methodthe original suspension system is decomposed into two fast and slow singular subsystems in theory, and then byPontryagain’s Minimum Principle (PMP) and switching functions, the controller is designed for each subsystemand finally the optimal final time is obtained as maximum optimal time concluded of two subsystems. By using adegree of stability technique with two parameters (instead of four parameters), the optimal time is more reducedand leads to great simplifications in practical implementation. The performance of the controller is compared withthe Sub optimal Linear Quadratic Regulator (SLQR) controller using two types of road profiles (step and bump)implemented in MATLAB/Simulink. Test results demonstrate the proposed controller is very more effective andsimpler in eliminating fluctuations in suspension systems that finally provide the passengers comfort.

Predictors of outcomes 3 to 12 months after traumatic brain injury: a systematic review and meta-analysis

Younes Iderdar,Maryem Arraji,Nadia Al Wachami,Morad Guennouni,Karima Boumendil,Yassmine Mourajid,Noureddine Elkhoudri,Elmadani Saad,Mohamed Chahboune 질병관리청 2024 Osong Public Health and Research Persptectives Vol.15 No.1

The exact factors predicting outcomes following traumatic brain injury (TBI) remain elusive. In this systematic review and meta-analysis, we examined factors influencing outcomes in adult patients with TBI, from 3 months to 1 year after injury. A search of four electronic databases—PubMed, Scopus, Web of Science, and ScienceDirect—yielded 29 studies for review and 16 for meta-analysis, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. In patients with TBI of any severity, mean differences were observed in age (8.72 years; 95% confidence interval [CI], 4.77–12.66 years), lymphocyte count (−0.15 109/L; 95% CI, −0.18 to −0.11), glucose levels (1.20 mmol/L; 95% CI, 0.73–1.68), and haemoglobin levels (−0.91 g/dL; 95% CI, −1.49 to −0.33) between those with favourable and unfavourable outcomes. The prevalence rates of unfavourable outcomes were as follows: abnormal cisterns, 65.7%; intracranial pressure above 20 mmHg, 52.9%; midline shift of 5 mm or more, 63%; hypotension, 71%; hypoxia, 86.8%; blood transfusion, 70.3%; and mechanical ventilation, 90%. Several predictors were strongly associated with outcome. Specifically, age, lymphocyte count, glucose level, haemoglobin level, severity of TBI, pupillary reaction, and type of injury were identified as potential predictors of long-term outcomes.

On $\phi$-$(n,d)$ rings and $\phi$-$n$-coherent rings

Younes El Haddaoui,김환구,Najib Mahdou 대한수학회 2024 대한수학회논문집 Vol.39 No.3

This paper introduces and studies a generalization of $(n,d)$-rings introduced and studied by Costa in 1994 to rings with prime nilradical. Among other things, we establish that the $\phi$-von Neumann regular rings are exactly either $\phi$-$(0,0)$ or $\phi$-$(1,0)$ rings and that the $\phi$-Pr\"ufer rings which are strongly $\phi$-rings are the $\phi$-$(1,1)$ rings. We then introduce a new class of rings generalizing the class of $n$-coherent rings to characterize the nonnil-coherent rings introduced and studied by Bacem and Benhissi.

Systems Biology Engineering of the Pantothenate Pathway to Enhance 3HB Productivity in Escherichia coli

Samer Younes,Dania Awad,Elias Kassab,Martina Haack,Claudia Schuler,Norbert Mehlmer,Thomas Brueck 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.4

The monomer, 3-hydroxybutyrate (3HB), plays an interesting role as a precursor for antibiotics, vitamins, and bioplastics such as polyhydroxybutyrates (PHB). The biotechnological production of both compounds in Escherichia coli has seen increased interest in the last decade. The central metabolite in the 3HB production pathway is acetyl-CoA, the derivative of coenzyme A (CoA). Enriching the intracellular pool of these cofactors could improve 3HB titers. In our study, we opted to increase CoA titers by upregulating pantothenate kinase (PanK), the rate limiting step in CoA biosynthetic pathway. To this end, 4 PanKs genes of different taxonomic origins (mammalian, fungal, and bacterial) were individually expressed and evaluated in 3HB producing E. coli cells. In shake flask studies, strains expressing Aspergillus nidulans PankII and Mus musculus PanK1β achieved the highest 3HB titers. In a bioreactor fermentation, the strain harboring murine PanK1β resulted in 7.6 g/L compared to 5.4 g/L of 3HB in the control strain. Although structurally different from the bacterial PankI, our study showed that eukaryotic Panks can supplement the kinase activity in prokaryotes. Expressing the exogenous PanKs offer several advantages over the host’s enzyme; PanKII is only inhibited by acetyl- CoA, for which the 3HB-production system would provide a constant metabolic sink. Additionally, PanK1β is weakly regulated by acetyl-CoA, and its activity is stimulated by free CoA. Overexpressing eukaryotic PanKs constitutes a suitable strategy for improving 3HB titers in E. coli.