537 research outputs found
Determining The Reliability And Validity Of The Adapted Wechsler Intelligence Scale-Fourth Edition (WISC-IV) For Libyan Children And Adolescents
Kajian ini bertujuan untuk menterjemahkan dan mengadaptasikan Skala Kecerdasan Wechsler bagi Kanak-Kanak-Edisi Keempat (WISC-IV; Wechsler et al., 2004) di Libya. Sampel terdiri daripada 210 orang peserta yang berumur dalam lingkungan 6 hingga 15 tahun (umur 6-7: n = 42; umur 8-9: n = 42; umur 10-11: n = 42; umur 12-13: n = 42; umur 14-15: n = 42)
The present study aimed to translate and adapt the Wechsler Intelligence Scale for Children–Fourth Edition (WISC-IV; Wechsler et al., 2004) in Libya. The sample consisted of 210 Libyan children and adolescents aged 6 to 15 years (age 6-7: n = 42; age 8-9: n = 42; age 10-11: n = 42; age 12-13: n = 42; age 14-15: n = 42
Collaborative problem solving using public social network media: analyzing student interaction and its impact to learning process
Article published in International Journal of Digital Information and Wireless Communications (IJDIWC)This paper examines the use of social network media at three aspects in African and Libyan perspective. Firstly, to use social network media as an open network learning environment that provide service for interaction necessary for learners to support socialization and collaboration during problem solving. Secondly, to use social media as a tool to support blended learning in e-learning system and encourage non-native English students to express their ideas and fill the gap of communication problems. Thirdly, to analyze the interaction of the learner in social media threaded messages and its relation to group and individual performance using different social schema and social network analyses. Quasi-experimental results indicate that there is an increase on the cognitive level of students at different level while qualitative results reveal that it helps deepen learning, memorable, have freedom to express opinions and lessen pressure and increase communication and socialization.This paper examines the use of social network media at three aspects in African and Libyan perspective. Firstly, to use social network media as an open network learning environment that provide service for interaction necessary for learners to support socialization and collaboration during problem solving. Secondly, to use social media as a tool to support blended learning in e-learning system and encourage non-native English students to express their ideas and fill the gap of communication problems. Thirdly, to analyze the interaction of the learner in social media threaded messages and its relation to group and individual performance using different social schema and social network analyses. Quasi-experimental results indicate that there is an increase on the cognitive level of students at different level while qualitative results reveal that it helps deepen learning, memorable, have freedom to express opinions and lessen pressure and increase communication and socialization
Development of new data partitioning and allocation algorithms for query optimization of distributed data warehouse systems
Distributed databases and in particular distributed data warehousing are becoming an increasingly important technology for information integration and data analysis. Data Warehouse (DW) systems are used by decision makers for performance measurement and decision support. However, although data warehousing and on-line analytical processing (OLAP) are essential elements of decision support, the OLAP query response time is strongly affected by the volume of data need to be accessed from storage disks.
Data partitioning is one of the physical design techniques that may be used to optimize query processing cost in DWs. It is a non redundant optimization technique because it does not replicate data, contrary to redundant techniques like materialized views and indexes.
The warehouse partitioning problem is concerned with determining the set of dimension tables to be partitioned and using them to generate the fact table fragments.
In this work an enhanced grouping algorithm that avoids the limitations of some existing vertical partitioning algorithms is proposed. Furthermore, a static partitioning algorithm that allows fragmentation at early stages of schema design is presented.
The thesis also, investigates the performance of the data warehouse after implementing a combination of Genetic Algorithm (GA) and Simulated Annealing (SA) techniques to horizontally partition the data warehouse star schema. It, then presents the experimentation and implementation results of the proposed algorithm.
This research presented different approaches to optimize data fragments allocation cost using a greedy mathematical model and a combination of simulated annealing and genetic algorithm to determine the site by site allocation leading to optimal solutions for fragments distribution.
Throughout this thesis, the term fragmentation and partitioning will be used interchangeably
HIV prevalence and characteristics of sex work among female sex workers in Hargeisa, Somaliland, Somalia.
OBJECTIVE: To measure prevalence of HIV and syphilis and describe characteristics of sex work among female sex workers (FSWs) in Hargeisa, Somaliland, Somalia. METHODS: A cross-sectional survey recruited 237 FSWs using respondent-driven sampling (RDS). A face-to-face, structured interview using handheld-assisted personal interviewing (HAPI) on personal digital assistants (PDAs) was completed and blood collected for serological testing. RESULTS: FSWs 15-19 years old accounted for 6.9% of the population; 20-24 year-old constituted an additional 18.0%. The majority (86.6%) never attended school. International (59.0%) and interzonal (10.7%) migration was common. Most (95.7%) reported no other source of income; 13.8% had five or more clients in the last 7 days. A minority (38.4%) had heard of STIs, even fewer (6.9%) held no misconceptions about HIV. Only 24% of FSW reported using a condom at last transactional sex, and 4% reported ever been tested for HIV. HIV prevalence was 5.2% and syphilis prevalence was 3.1%. CONCLUSION: Sex work in Hargeisa, Somaliland, Somalia, is characterized by high numbers of sexual acts and extremely low knowledge of HIV. This study illustrates the need for targeted HIV prevention interventions focusing on HIV testing, risk-reduction awareness raising, and review of condom availability and distribution mechanisms among FSWs and males engaging with FSWs
Performance, genetic variation and interrelationships in different traits of some safflower (Carthamus tinctorius L.) genotypes
The success of safflower improvement and production activities can be enhanced with scientific information generated from the study of genotypes, environments and genotype by environment interactions (GEI). In this study, 15 safflower genotypes were evaluated during two consecutive winter seasons (2013/14 and 2014/15) at three locations viz Gezira, El- Suki and Hudeiba Research Station farms of the Agricultural Research Corporation, Sudan. The objectives of this study were to evaluate seed yield potential, the extent of genetic variability and interrelationships in 15 safflower genotypes under different environments in Sudan. Data were collected on days to 50% flowering, days to maturity, plant height (cm), number of branches per plant, number of capitula per plant, number of seeds per capitula, 100 seed weight (g), seed yield (kg/ha), and oil content. A wide range of genetic variability was observed among the genotypes for most of the studied traits. The results also indicated that the tallest genotype (Saff 1) was the latest maturing, and the shortest genotype (Saff 13) was the earliest maturing. Simple linear correlation and path coefficient analyses indicated that days to 50% flowering, plant height, number of branches/plant and number of capitula per plant could be used as potential selection criteria in breeding programs for developing high yielding safflower genotypes. Genotypes Saff 1, Saff 12 and Saff 14 were high yielders (582.4, 507.9 and 572.8, kg/ha, respectively). Also, Saff 14 showed the highest oil content (37.5 %) followed by Saff 12 (31.0 %) and Saff 1 (29.1 %), therefore, they could be grown successfully under irrigated winter condition of central and northern Sudan.
القرطم من المحاصيل الزيتية المهمة في العالم، وفي السودان يزرع المحصول فقط في الولاية الشمالية في المساحة الواقعة علي طول النيل. إن نجاح تحسينِ محصول القرطمِ ونشاطاتِ إنتاجِه يُمْكِنُ أَنْ يُحَسّنا بالمعلومات العلمية التي تنتج منْ دراسة التراكيب الوراثية. قُيّمَت في هذه الدراسةِ خمسة عشرَ تركيباً وراثياً من القرطمَ علي مدي فصلي شتاء متتاليينِ (2013/14-2014/15) في ثلاثة مواقعِ هي محطات بحوث الجزيرة و السوكي والحديبة التابعة لهيئة البحوث الزراعية بالسودان. هدفت الدراسةِ إلي تُقييم هذه التراكيب الوراثية من حيث الانتاجية ومكوّناتِها و دراسة العلاقات المترابطة بين الانتاجية والصفات المرتبطة بها بإستعمال الإرتباطَ الخطي البسيط و معامل تحليل المسار وتمييز التراكيب الأعلى إنتاجية. كانت الصفات المدروسة هي عدد الأيام حتي 50% إزهار و عدد الأيام حتي النضج و طول النبات و عدد الفروع بالنبات و عدد الكبسولات بالنبات و عدد البذور بالكبسولة و وزن المائة حبة بالجرام و الإنتاجية بالكيلوجرام للهكتار ونسبة الزيت بالبذور. أوضحت النتائج وجود مدي واسع من التباين الوراثي بين التراكيب الوراثية لمعظم الصفات المدروسة. أوضحت النَتائِج إلي أنّ التركيب الوراثي (Saff 1) هو الاطول من بين التراكيب الوراثية الاخري و متأخر النُضُج، بينما التركيب الوراثي (Saff 13) مبكر النُضُج وهوأقصرالتراكيب الوراثية. من ناحية أخري، باستخدام الارتباط الخطي البسيط ومعامل تحليل المسار، أوضحت الدراسة أن صفات عدد أيام 50% إزهار و طول النبات و عدد الفروع في النبات و عدد الرؤوس بالنبات يمكن استعمالهما كصفات إنتخاب غير مباشر في برامج التربية لاستنباط أصناف عالية الإنتاجية من القرطم. خلصت الدراسة إلي أن التراكيب الوراثية Saff 1 و Saff 12 و Saff 14 كانت عالية الإنتاجيةً ( 582.4 ، 507.9 و 572.8 :جم/ ه علي التوالي)، كما وأن التركيب الوراثي Saff 14 له أعلي محتوي من نسبة الزيت (37.5 %) يعقبه في ذلك (31.0 %) Saff 12 و(29.1 %) Saff 1 لذلك يمكن زراعتها بنجاح تحت ظروف الري الشتوي بأواسط وشمال بالسودان
Assessment of genotype x environment interactions and stability for seed yield of selected safflower (Carthamus tinctorius L.) genotypes in central and northern Sudan
Safflower is an important oilseed crop worldwide. In Sudan, safflower is only cultivated in the Northern State along the River Nile. The success of safflower improvement and production activities can be enhanced with scientific information generated from the study of genotypes, environments and genotype by environment interactions (GEI). In this study, 15 safflower genotypes were evaluated during two consecutive winter seasons (2013/14 and 2014/15) at three locations viz Gezira, El- Suki and Hudeiba Research Station Farms of the Agricultural Research Corporation, Sudan. The objectives of this study were to estimate G x E interactions and identify the highest yielding and stable genotypes under different environments. A wide range of genetic variability was observed among the genotypes for most of the studied traits. Combined analyses of variance revealed highly significant environment, genotype and genotype x environment (GE) component of interaction and indicated wide differences among the environments and differential genotypic behavior to the tested environments. Additive main effects and multiplicative interactions (AMMI) analyses have higher efficiency in partitioning and analyzing stability studies compared to regression analysis. First and second principal component axis (PCA 1 and PCA 2) in AMMI explained 64.6% and 25.3% of the interaction sum of squares, respectively, and together they accounted for 89.9 % of the G X E sum of squares, while the regression model accounted only for 13.8% of the G X E sum of squares. Hence, AMMI analysis was superior to regression techniques in accounting for the large part of the G X E sum of squares and more effective in partitioning the interaction sum of squares. In conclusion, genotypes Saff 1, Saff 12 and Saff 14 were high yielding (582.4, 507.9 and 572.8, kg/ha, respectively) and stable under all environments. Therefore, they are recommended to be grown under winter irrigated conditions of central and northern Sudan.
يعتبر القرطم من المحاصيل الزيتية المهمة في العالم و يزرع في السودان فقط في الولاية الشمالية في المساحة الواقعة علي طول النيل. إن نجاح تحسينِ محصول القرطمِ ونشاطاتِ إنتاجِه يُمْكِنُ أَنْ يُحَسّنا بالمعلومات العلمية التي تنتج منْ دراسة التراكيب الوراثية وتفاعلاتِ البيئة والتفاعل بين التراكيب الوراثية والبيئة. قُيّمَت في هذه الدراسةِ خمسة عشرَ تركيباً وراثياً من القرطمَ علي مدي فصلي شتاء متتاليينِ (2013/14-2014/15) في ثلاثة مواقعِ هي محطات بحوث الجزيرة و السوكي والحديبة التابعة لهيئة البحوث الزراعية بالسودان. هدفت الدراسةِ إلي تُقييم هذه التراكيب الوراثية من حيث الانتاجية ومكوّناتِها و دراسة التفاعل بين البيئة و التراكيب الوراثية المختلفة وتمييز التراكيب الوراثية الأعلى إنتاجية و المستقرةّ في البيئاتِ المختلفة. أوضحت النتائج وجود مدي واسع من التباين الوراثي بين التراكيب الوراثية لمعظم الصفات المدروسة. أيضاً أظهرت النتائج وجود فروقات معنوية كبيرة بين التراكيب الوراثية و البيئة والتفاعل بينهما. أوضحت الدراسة أنه في طريقة الأثر التجميعي الرئيسي والتفاعل المتراكم لتحليل التباين (AMMI)الناتج عن التفاعل بين التركيب الوراثي والبيئة أن محور المكون الأول والثاني قد فسرا حوالي 64.6 % و25.3 %، علي التوالي من هذا التباين، بينما وجد في طريقة معامل الارتدادEberhart and Russell’s (1966) أنه قد فُّسَر حوالي 13.8 % منه. عليه فإن طريقة الأثر التجميعي الرئيسي والتفاعل المتراكم أعلي كفاءةً من طريقة معامل الارتداد الخطي في تقسيم التباين الناتج عن التفاعل بين التراكيب الوراثية والبيئة. خلصت الدراسة إلي أن التراكيب الوراثية Saff 1 و Saff 12و Saff 14 كانت عالية الإنتاجيةً ولها ثباتاً وراثياً في كل بيئات التقييم لذلك يوصى بزراعتها بنجاح تحت ظروف الري الشتوي بأواسط وشمال السودا
The migration behaviour of xenon implanted into glassy carbon
This study is in two parts. Both parts are geared towards the study of the effectiveness of glassy carbon as a good storage material was investigated. Firstly, 200 keV Xe ions were implanted into glassy carbon substrates to a fluence of 1×1016 ions/cm2 at room temperature. Also, we have also investigated the effect of SHI irradiation on Xe as-implanted samples at a fluence of 1×1014 ions/cm2. After implantation and swift heavy ion irradiation, the samples were investigated using several techniques. This was with a view to characterizing the level of damage created by the ion bombardment, the distributions of the Xe ions in glassy carbon and the effect of SHI irradiation on these distributions. The irradiated and un-irradiated but implanted with Xe samples were isochronally annealed in a vacuum in steps of 100 C for 5 hours at temperatures ranging from 300 C – 800 C and 900 C – 1500 C, respectively.Thesis (PhD (Physics))--University of Pretoria, 2019.PhysicsPhD (Physics)Unrestricte
Optimized Load Balancing based Task Scheduling in Cloud Environment
The fundamental issue of Task scheduling is one important factor to load balance between the virtual machines in a Cloud Computing network. However, the optimal broadcast methods which have been proposed so far focus only on cluster or grid environment. In this paper, task scheduling strategy based on load balancing Quantum Particles Swarm algorithm (BLQPSO) was proposed. The fitness function based minimizing the makespan and data transmission cost. In addition, the salient feature of this algorithm is to optimize node available throughput dynamically using MatLab10A software. Furthermore, the performance of proposed algorithm had been compared with existing PSO and shows their effectiveness in balancing the load
Mobile Robot Controlled through Mobile Communication
AbstractThis paper is about designing a robot which is controlled using a mobile phone that is connected to the robot through GSM network as a remote controller. The mobile phone's keypad is used to control the robot movement toward a desired location. The present robot is not an Automated Guided Vehicle (AGV), the user should provide extra caution for the robot movement to avoid collisions with static fixed objects as well as moving objects
Radon Calibration System
In this chapter, an irradiation radon system was explained in detail. This system is based on soil gas as a natural radon source. The radon system was used to determine both the calibration factor of the radon detector and the equilibrium factor between radon and its short-lived daughters. Also, the calibration factor has been calculated theoretically and experimentally. The effect of humidity upon the calibration factor has been investigated. The diffusion of radon through polyethylene membrane has been determined using new nuclear method. This method depends upon the physical decay of radon
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