550 research outputs found
DESIGN AND PERFORMANCE ANALYSIS OF VCO FOR STANDARD GSM USING MEMS
The design of a prototype monolithic Micro Electro-Mechanical Systems (MEMS) electronic circuits, namely the Voltage Controlled Oscillators (VCOs) is presented. The components can achieve the stringent requirements of wireless communication applications such as GSM cellular telephony. The VCO meets the low phase noise specifications of -136 dBc/Hz at large offset frequency of 3MHz, over the appropriate frequency range. The model of the monolithic VCO is based on the topology of the Colpitts Oscillator. It is relatively less complicated, which facilitates the practical integration of the MEMS components into the configuration. The variable capacitor and the monolithic 3-D coil inductor are suitable for low phase-noise and low power consumption at the application frequencies. A PSpice simulation model was developed with MEMS switching devices that can be integrated into the system. The model helps in determining the design parameters, which affect the performance and operation reliability of the RF transceiver system, for which a prototype has been tested and proved successful
Evaluation of Language Skills of Upper Basic Stage Students in light of Language Performance Indicators
هدفت هذه الدراسة إلى تقويم المهارات اللغوية لدى طلبة المرحلة الأساسية العليا في ضوء مؤشرات الأداء اللغوي (مهارة الاستماع، والقراءة، والكتابة)، واستخدم المنهج الوصفي المسحي لمناسبته لطبيعة الدراسة وأهدافها. تكونت عينة الدراسة من (317) طالبًا وطالبةً، تم اختيارهم بالطريقة العشوائية البسيطة، ولتحقيق هدف الدراسة تم إعداد ثلاثة اختبارات لتقويم المهارات اللغوية في ضوء مؤشرات الأداء اللغوي، وقد جرى التأكد من صدقها وثباتها وتطبيقها على عينة الدراسة. وأظهرت نتائج الدراسة أن مهارة القراءة جاءت في المرتبة الأولى بدرجة متوسطة، بينما جاءت مهارة الكتابة في المرتبة الثانية بدرجة ضعيفة، بينما جاءت مهارة الاستماع في المرتبة الأخيرة وبدرجة ضعيفة. وجاء مستوى طلبة المرحلة الأساسية العليا في المهارات اللغوية في ضوء مؤشرات الأداء اللغوي ككل بدرجة ضعيفة. وأظهرت النتائج وجود فروق ذات دالة إحصائية تعزى لأثر الجنس في جميع المهارات، وقد جاءت الفروق لصالح الإناث، ووجود فروق بين مهارة الاستماع من جهة وكل من مهارة القراءة، ومهارة الكتابة من جهة أخرى، وجاءت الفروق لصالح كل من مهارة القراءة، ومهارة الكتابة. The study aimed to assess the linguistic skills (listening، reading، and writing (of upper basic stage students based on linguistic performance parameters. The descriptive survey method was used due to the suitability the nature and objectives of the study. The study sample consisted of 317 male and female students. Three tests were created to evaluate language skills in light of language performance parameters، and their validity and reliability were approved and applied to the study sample to achieve the goal of the study. The results revealed that reading came first with an average score، the reading skill came second with a weak score، while listening came last with a poor score. The level of linguistic skills of upper basic stage students was generally weak based on the entire linguistic performance parameters. The results also showed that the gender effect is statistically significant in all skills and total scores. Furthermore، all of the differences were in favor of female students. The results also revealed that there were differences between listening skill on one hand and the reading and writing skills on the other، with the reading and writing skills outperforming the listening and skill
Novel Framework for Hidden Data in the Image Page within Executable File Using Computation between Advanced Encryption Standard and Distortion Techniques
The hurried development of multimedia and internet allows for wide
distribution of digital media data. It becomes much easier to edit, modify and
duplicate digital information. In additional, digital document is also easy to
copy and distribute, therefore it may face many threats. It became necessary to
find an appropriate protection due to the significance, accuracy and
sensitivity of the information. Furthermore, there is no formal method to be
followed to discover a hidden data. In this paper, a new information hiding
framework is presented.The proposed framework aim is implementation of
framework computation between advance encryption standard (AES) and distortion
technique (DT) which embeds information in image page within executable file
(EXE file) to find a secure solution to cover file without change the size of
cover file. The framework includes two main functions; first is the hiding of
the information in the image page of EXE file, through the execution of four
process (specify the cover file, specify the information file, encryption of
the information, and hiding the information) and the second function is the
extraction of the hiding information through three process (specify the stego
file, extract the information, and decryption of the information).Comment: 6 Pages IEEE Format, International Journal of Computer Science and
Information Security, IJCSIS 2009, ISSN 1947 5500, Impact Factor 0.42
DEVELOPING OF CONCRETE TILES
A case study had been made to investigate the reasons of the repetitive failure during concrete tiles
testing. Cubes, cylinders, and prisms in addition to full-scale concrete tiles had been prepared. Half of these samples were made using the same popular concrete mix. Test results indicated that, these samples were below standard requirements. The second half of the test samples was prepared using a newly designed concrete mix. Based upon the recommended breaking load, the required flexural strength of the tiles was calculated. This mix was designed to comply a flexural strength that was recommended by specifications. Care had been also concentrated on aggregate grading and concrete curing. Tests showed positive results. In spite of this success it is still believed that there is a possibility of some failures may be due to mass production or due to bad quality control. A new proposed model had been prepared and tested. Finally these newly proposed tiles had shown that it was more resistant to breaking loads by +21% in comparison with the previous samples. This result might insure the production of safe concrete tile
Maxillary and mandibular dental arch forms in a Jordanian population with normal occlusion
Background: Ethnic background has been claimed to affect arch form. The purpose of this study was to describe and elucidate the maxillary and mandibular arch forms in Jordanian population and to develop a classification method for these forms which could be employed to construct orthodontic archwires accordingly. Methods: The sample was comprised of study casts of five hundred and twenty subjects (231 males and 289 females with a mean age of 15.4 ± 1.02 years). All subjects had permanent dentition with normal occlusion. A mathematical method associated with a polynomial function of 6th degree was employed to assess the dental arch forms. The resultant arch forms were classified into 5 groups for both the maxilla and mandible utilizing a computer software with special code designed for this study. Each group was subdivided into 3 subgroup sizes namely: small, medium, and large. Results: Catenary arch form was found in 47% and 41.2% (p ˂ 0.01) of maxilla and mandible arch forms, respectively. Form 2 (which is halfway between ellipse and U-shaped arch form) was found in 27.7% and 26.7%. Medium size arch form was found in 55.4% of the maxillary and 65.6% of the mandibular arch forms. Conclusion: Catenary arch form was the most prevalent arch form, followed by wide elliptical form. The other forms, which included tudor arch, tapered equilateral and quadrangular forms were less frequent. Regarding size, the medium size was the most prevalent among the studied samples.This study was bankrolled through a grant from the Deanship of Scientific Research/ Jordan University of Science and Technology (Grant No. 20090030). The Deanship of Scientific Research had absolutely no role in the design, collection, analysis, and interpretation of data and writing of the manuscript of this study
A Case of Chronic Cough and Pneumonia Secondary to a Foreign Body
Foreign body aspiration occurs when a solid or semisolid object becomes lodged in the larynx or trachea. It can be a life-threatening emergency, especially if it is large enough to occlude the airway. However, small aspirated objects may go unnoticed until symptoms occur. Therefore, it is frequently misdiagnosed. A high level of clinical suspicion, patient\u27s risk factors, and thorough history and physical examination are essential in making the diagnosis. It should be considered in cases where there is unresolved chronic cough with or without associated recurrent pneumonia especially in patients with risks for aspiration
The cellular senescence response and neuroinflammation in juvenile mice following controlled cortical impact and repetitive mild traumatic brain injury.
Traumatic brain injury (TBI) is a leading cause of disability and increases the risk of developing neurodegenerative diseases. The mechanisms linking TBI to neurodegeneration remain to be defined. It has been proposed that the induction of cellular senescence after injury could amplify neuroinflammation and induce long-term tissue changes. The induction of a senescence response post-injury in the immature brain has yet to be characterised. We carried out two types of brain injury in juvenile CD1 mice: invasive TBI using controlled cortical impact (CCI) and repetitive mild TBI (rmTBI) using weight drop injury. The analysis of senescence-related signals showed an increase in γH2AX-53BP1 nuclear foci, p53, p19ARF, and p16INK4a expression in the CCI group, 5 days post-injury (dpi). At 35 days, the difference was no longer statistically significant. Gene expression showed the activation of different senescence pathways in the ipsilateral and contralateral hemispheres in the injured mice. CCI-injured mice showed a neuroinflammatory early phase after injury (increased Iba1 and GFAP expression), which persisted for GFAP. After CCI, there was an increase at 5 days in p16INK4, whereas in rmTBI, a significant increase was seen at 35 dpi. Both injuries caused a decrease in p21 at 35 dpi. In rmTBI, other markers showed no significant change. The PCR array data predicted the activation of pathways connected to senescence after rmTBI. These results indicate the induction of a complex cellular senescence and glial reaction in the immature mouse brain, with clear differences between an invasive brain injury and a repetitive mild injury
Axiomatic/asymptotic evaluation of multilayered plate theories by using single and multi-points error criteria
AbstractThis paper deals with refined theories for multilayered composites plates. Layer-Wise (LW) and Equivalent Single Layer (ESL) theories are evaluated by means of axiomatic–asymptotic approach. Theories with forth order displacement fields in the thickness layer/plate direction z are implemented by referring to the Unified Formulation by Carrera. The effectiveness of each term of the made expansion is evaluated by comparing the related theories with a reference solution. As a result a reduced model is obtained which preserve the accuracy of the full-model (model that include the whole terms of the z-expansion) but it removes the not-significant terms in the same expansion (those terms that do no improve the results according to a given error criteria). Various single-point and multi-point error criteria have been analyzed and compared in order to establish such an effectiveness: error localized in an assigned point along z, error localized at each interface, error located at the z-value corresponding to the maximum value of the considered variables, etc. Applications are given in case of closed form solutions of orthotropic cross-ply, rectangular, simply supported plates loaded by bisinusoidal distribution of transverse pressure. Symmetrically and unsymmetrical laminated cases are considered along with sandwich plates. It is found the reduced model is strongly influenced by the used localized error and that in same case the reduced model which is obtained by of single point criteria can be very much improved by the use of multi-point criteria
An Expression for Nonlinear Noise in Optical Phase Conjugation Systems with Lumped Amplifiers
We develop an analytical formula for evaluating the impact of fiber nonlinearity in systems employing optical phase conjugation with multi-span lumped amplification, highlighting the detailed balance of effects leading to compensation when the phase conjugator is added to the middle of the link. We apply the approach to the effect of adding a pre-dispersion element to improve the symmetry, deriving the required optimum predispersion. The closed-form is validated through simulation and shows good matching with the results within a margin of error less than 0.2 dB
Cranial base measurements in different anteroposterior skeletal relationships using Bjork-Jarabak analysis.
To assess the linear and angular cranial base measurements (Bjork polygon) in different anteroposterior (AP) skeletal relationships using Bjork-Jarabak analysis. Pretreatment lateral cephalograms of 288 (146 women, 142 men, mean ages 21.24 ± 2.72 years and 22.94 ± 3.28 years, respectively) adult patients were divided into Class I, II, and III skeletal relationships according to their ANB angle. Linear and angular measurements of Bjork polygon were measured and compared among different skeletal relationships. Analysis of variance was performed to detect the differences among groups. Independent-sample t-test was used to detect differences between men and women. The Class II skeletal relationship has a significantly larger saddle angle than Class III does (P .05). Anterior (N-S) and posterior (S-Ar) cranial base lengths were similar in the different AP skeletal relationships (P > .05). The ramal height and body of the mandible length were significantly larger in Class III compared with Class I and II (P < .05). Women had a significantly larger articular angle than men did (P < .05), although men had significantly larger linear measurements of Bjork polygon than women did (P < .05). The Class III skeletal relationship has a smaller saddle angle and larger mandibular length and gonial angle. Men have a larger cranial base and mandibular linear measurements and a smaller articular angle compared with women.The study was funded by the Deanship of Research/Jordan University of Science and Technology (grant No. 2015-491)
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