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This paper presents L1-adaptive controller for controlling uncertain parameters and time-varying unknown parameters to control the position of a DC servomotor. For the purpose of comparison, the effectiveness of L1-adaptive controller for position control of studied servomotor has been examined and compared with another adaptive controller; Model Reference Adaptive Controller (MRAC). Robustness of both L1-adaptive controller and model reference adaptive controller to different input reference signals and different structures of uncertainty were studied. Three different types of input signals are taken into account; ramp, step and sinusoidal. The L1-adaptive controller ensured uniformly bounded transient and asymptotic tracking for both system's input and output signals, simultaneously with asymptotic tracking. Simulations of a DC servomotor with time-varying friction and disturbance are presented to verify the theoretical findings.

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L1-adaptive controller, DC servomotor position control.

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In the present work, the design of an L1 adaptive controller forposition control of a linear servo motor for X-Y table application has beendeveloped. The AC Permanent Magnet Linear Synchronous Servo Motor(PMLSM) is considered. A comparative study between L1 adaptive control andModel Reference Adaptive Control (MRAC) has been made. The effectiveness ofthe L1 adaptive controller against uncertain parameters is analyzed based onsimulated results. Robustness characteristics of both L1 adaptive controller andmodel reference adaptive controller to different input reference signals anddifferent structures of uncertainty have been evaluated. The L1-adaptivecontroller could ensure uniformly bounded transient and asymptotic trackingfor input and output signals. Simulations based on MATLAB of an x-y tablebased on PMLSM with time-varying friction and disturbance are presented toverify the theoretical findings. The simulation results within the environment ofMATLAB/SIMULINK showed that L1-adaptive controller could give bettertracking performance, dynamic and steady-state characteristics, than thatobtained from MRAC for considered types of input and for various structures ofuncertainties.

Keywords

L1-Adaptive Control, MRAC, X-Y table, PMLSM, Position control

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L1 adaptive controller has proven to provide fast adaptation with guaranteed transients in a large variety of systems. It is commonly used for controlling systems with uncertain time-varying unknown parameters. The effectiveness of L1 adaptive controller for position control of single axis has been examined and compared with Model Reference Adaptive Controller (MRAC). The Linear servo motor is one of the main constituting elements of the x-y table which is mostly used in automation application. It is characterized by time-varying friction and disturbance. The tracking and steady state performances of both controllers have been assessed for two different types of input signals ramp and step inputs. The simulated results based on MATLAB (2012a) package showed that L1 adaptive controller could outperform MRAC in terms of robustness and tracking.

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L1 adaptive controller, position control, servo motor, x-y table

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A low profile compact microstrip antenna for GPS (L1/L2) application has beenpresented in this paper. The proposed antenna design is based on the 3rd iterationMinkowski-like pre-fractal geometry. The resulting antenna design offers a compact size,low profile and light weight making it suitable for use in handheld applications. Antennaperformance has been evaluated using the EMSightTM from the Applied Wave Research.The proposed antenna has shown to possess two resonance bands (for return loss .-10dB) covering the two GPS bands. Reasonable radiation characteristics have been achievedat the GPS frequencies (L1:1575.42 } 10.23 MHz, L2:1227.60 } 10.23 MHz) with goodcircular polarization characteristics. Realized circular polarization Bandwidths (for axialratio . 3 dB) are found to cover adequately those required for these GPS bands.

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GPS, L1/L2, Fractal Antenna, Dual Band Antenna, Circular Polarization, Axial Ratio

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This paper aims at bringing into account the importance of raising pragmatic competence in the language classroom with language learners (EFL) It also considers the possibility and the challenges of teaching pragmatic competence in EFL classes.The paper answers: How can Pragmatic instruction help develop learners’ Pragmatic awareness? The study considers the role of the textbooks and the role of language teacher's talk as demanding possibilities of teaching pragmatics in EFL classes. It concludes that pragmatic knowledge of a language is better acquired by exposing the learners to natural environment and authentic materials. In the case of EFL, students are deprived of such conditions; moreover, these conditions cannot be completely provided for in the classrooms, so students may need special training in this aspect.

Keywords

Pragmatics, Pragmatic Competence, EFL, L1, L2.

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This study aims at examining teachers' attitudes of Basra University towards using Code-Switching(henceforth as CS), as an instructional strategy during the Language teaching process.The theoretical part of the study presents the various definitions of the term CS ,its types , its functions, the reasons that lie behind using it, the different attitudes towards using it in ELT and the use of CS as a pedagogical tool in teaching English as an FL. The practical part of the study deals with the research methodology . The study ends up with some conclusions and recommendations that regard CS as a sufficient means by which teachers can hold a positive attitude towards using it when they give their teaching lectures in the classrooms.

Keywords

Code-Switching, CS, Code-Mixing, CM, Foreign Language, FL, First Language, L1, pedagogical strategy, teachers’ attitudes

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The present study attempts to identify and analyse the collocational errors committed in writing by Iraqi EFL researchers whose major is English. The corpus involves (10 ) papers chosen randomly from various Iraqi universities. The research aims at identifying and analyzing both lexical and grammatical collocationalerrors. The results show that the performance of Iraqi researchers in both patterns seems to be influenced by L1 transfer. Moreover, it is found that other factors contribute to the high frequency of collocation errors committed by them, namely the lack knowledge of collocationalskills, especially with regard to collocationalrestriction,the misuse of synonyms, and thetendencyforovergeneralization. Furthermore, it is found that lexical collocation is the most recurrent error throughout the data. This is due to the grammar-based method ,which is broadly adopted in Iraqi classes.

Keywords

Collocationalerrors, Error Analysis, L1 transfer, Collocational restriction

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The current paper is concerned with providing a comprehensive analysis of one of the most recently discussed concepts within the framework of pragmatics and SLA researches, namely; the concept of negative pragmatic transfer. It shows in detail most of the aspects of this phenomenon including how it can be manifested in language and how it can be significant for linguistic analysis in addition to the influence it may have on the performance of language. The paper shows that negative pragmatic transfer is a crucial phenomenon that directly influences the performance of language being a linguistic strategy that is used by non-native speakers while trying to communicate in the target language due to certain pragmatic assumptions. Such an influence is noted to be mostly a deviation (therefore it is often referred to as negative pragmatic transfer) or non-native performance. The current paper surveys some related studies to get a better and a more comprehensive understanding and to get along with the theoretical framework. The paper finally provides a conclusion and some implied recommendations.

Keywords

•Pragmatics •Negative transfer •Cultural differences •L1 Influenc •TL Performance

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A number of new complexes of the general formulaes [M(L1)2Cl2]and [M(L1)2(γ-pic)2]Cl2{where L1= bis-(2-thiophenelidene) thiosemcarbazone; M= Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and γ-pic= 4-methyl pyridine} have been prepared and characterized by molar conductance, magnetic properties and metal contents analysis, infrared, and electronic spectra. The electronic and magnetic susceptibility indicated that the complexes have distorted octahedral geometry either non regular for some complexes due to the differences in the two coordinated ligand and distorted copper complexes due to the above reason and also to Jahn teller effect.

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A number of new complexes of the general formulaes [M, L12Cl2]and [M, L12, γ-pic2]Cl2{where L1= bis-, 2-thiophenelidene thiosemcarbazone

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Setting-up a 3D geological model both from field and subsurface data is a typical task in geological studies involving natural resource evaluation and hazard assessment. In this study a 3D geological model for Mishrif Formation in Garraf oil field has been set-up using Petrel software. Mishrif Formation represents the most important reservoir in Garraf oil field. Four vertical oil wells (GA-4, GA-A1P, GA-3 and GA-5) and one directional well (GA-B8P) were selected in Garraf Oil Field in order to set-up structural and petrophysical (porosity and water saturation) models represented by a 3D static geological model in three dimensions. Structural model shows that Garraf oil field represents a domal structure that shows continuous growth as indicated by the structural maps at top of reservoir units. The structural closure is shifted from GA-3 well to GA-A1P well. Mishrif Formation was divided into ten zones (top Mishrif, M1, M1.2, M2, L1, L1.2, L2, L2.2, L2.3 and L2.4.). Petrophysical model (porosity and water saturation) for Mishrif Formation was set-up from values of porosity and water saturation using Sequential Gaussian Simulation algorithm. According to data analyses and the results from modeling the units (M1.2, L1 and L1.2) are considered as high quality reservoir units due to the high PHIE and low water saturation. Units (L2, L2.2, L2.3 and L2.4) are considered as poor reservoirs because of low PHIE and high water saturation, and non-reservoir units include (Top Mishrif, M1 and M2) therefore, they represent cap units. Cross sections of petrophysical model were conducted to illustrate the vertical and horizontal distribution of porosity and water saturation between wells in the field.

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Setting-up a 3D geological model both from field and subsurface data is a typical task in geological studies involving natural resource evaluation and hazard assessment. In this study a 3D geological model for Mishrif Formation in Garraf oil field has been set-up using Petrel software. Mishrif Formation represents the most important reservoir in Garraf oil field. Four vertical oil wells, GA-4, GA-A1P, GA-3 and GA-5 and one directional well, GA-B8P were selected in Garraf Oil Field in order to set-up structural and petrophysical, porosity and water saturation models represented by a 3D static geological model in three dimensions. Structural model shows that Garraf oil field represents a domal structure that shows continuous growth as indicated by the structural maps at top of reservoir units. The structural closure is shifted from GA-3 well to GA-A1P well. Mishrif Formation was divided into ten zones, top Mishrif, M1, M1.2, M2, L1, L1.2, L2, L2.2, L2.3 and L2.4.. Petrophysical model, porosity and water saturation for Mishrif Formation was set-up from values of porosity and water saturation using Sequential Gaussian Simulation algorithm. According to data analyses and the results from modeling the units, M1.2, L1 and L1.2 are considered as high quality reservoir units due to the high PHIE and low water saturation. Units, L2, L2.2, L2.3 and L2.4 are considered as poor reservoirs because of low PHIE and high water saturation, and non-reservoir units include, Top Mishrif, M1 and M2 therefore, they represent cap units. Cross sections of petrophysical model were conducted to illustrate the vertical and horizontal distribution of porosity and water saturation between wells in the field.

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