611 research outputs found
Reduce side lobes using linear Antenna Arrays by comparing PSO, GA, and FPA algorithms
ان مصفوفات الهوائي الخطي هي نظام كهرومغناطيسي يستخدم على نطاق واسع في الاتصالات اللاسلكية الحديثة، وقد تم استخدام خوارزميات الميتاهوريستس لتقليل مستوى الفص الجانبي والوصول إلى الحل الأمثل. يستخدم هذه البحث ثلاث خوارزميات: الأولى، تحسين سرب الجسيمات، والثانية، الخوارزمية الجينية، والثالثة، خوارزمية تلقيح الزهور. يتكون كل اختبار من عدد العناصر 8و16و32و64و128و256. عنصرًا من مجموعة عناصر الهوائي. لتقليل مستوى الفص الجانبي وتركيز الطاقة المشعة في الفص الرئيسي، تقارن كل خوارزمية نمط الحزمة بنمط الحزمة النظرية. بالإضافة إلى ذلك، تمت مقارنة الخوارزميات بوجود نمط الحزمة النظرية، وتم اكتشاف وجود خوارزمية فائقة لكل عدد من عناصر الهوائي؛ في ن= 8 عند مقارنة خوارزمية التلقيح بالخوارزميات الأخرى، تم اكتشاف أنها قللت مستوى الفص الجانبي بقيمة 20.8492- ديسبل، والتي كانت متفوقة على الخوارزميات الأخرى. انخفض مستوى الفص الجانبي بمقدار 27.2992- ديسبل، عند مقارنة خوارزمية تحسين سرب الجسيمات مع الخوارزميات الأخرى عند ن=16, عندما ن = 32,64 يمثل خوارزمية تلقيح الجسيمات بشكل أكثر دقة من الخوارزميات الأخرى حيث انخفض الفص الجانبي إلى 28.3071-ديسبل و 28.0148- ديسبل، على التوالي. ان الخوارزمية الجينية متفوقة على الخوارزميات الأخرى عندما ن= 128و256، مما يقلل الفصوص الجانبية بنسبة 28.5568- ديسبل -28.6204- ديسبل، على التوالي.Linear Antenna Arrays (LAAs) are widely used electromagnetic systems in modern wireless communication, and Metaheuristics algorithms have been utilized to reduce side lobe level SLL and reach the optimal solution. This paper employs three algorithms: the first, Particle Swarm Optimization PSO, the second, Genetic Algorithm GA, and the third, Flower Pollination Algorithm FPA. Each test consists of N = 8, 16, 32, 64, 128, and 256 antenna array elements. To reduce SLL and the concentration of radioactive energy in the main lobe, each algorithm compares the beam pattern to the theoretical beam pattern. In addition, the algorithms were compared with the existence of the theoretical beam pattern, and it was discovered that there is a superior algorithm for each number of antenna elements; in N = 8, when comparing FPA to other algorithms, it was discovered that FPA reduced SLL by a value of -20.8492dB, which was superior to the other algorithms. SLL decreased by -27.2992dB when comparing PSO with other algorithms at N = 16. When N = 32,64 represents FPA more accurately than other algorithms where the SLL plummeted to -28.3071dB and -28.0148dB, respectively. GA is superior to other algorithms when N = 128,256, reducing SLL by -28.5568 dB and -28.6204 dB, respectively
Performance of supplementary irrigation systems for corn silage in the sub-humid areas
In the humid and sub-humid areas, agricultural production is largely rain fed and this needs to be urgently supplemented by irrigation practice if the country is to meet its food demand. A two years study was carried out at the experimental site of the Institute of Agricultural Technology and Biosystems Engineering, Johan Heinrich von Thünen Institute (vTI), Braunschweig, Germany to compare performance of maize crop for silage production using three different irrigation systems; rain fed, drip and rain-gun sprinkler. Growth parameters such as plant height, stem diameter were measured. The total yields of silage were obtained for all treatments at the harvesting. The experimental results reveal that total yields obtained from different treatments were 25.76, 24.23 and 9.30 Mg ha-1 in drip, rain-gun and rain fed irrigated maize, respectively. The results also showed that the water use efficiency reached 11.01 kg m-3 for drip irrigation in while it was 8.84 kg m-3 for rain-gun system. Keywords: Silage, performance, drip, rain-gun, rain-fed irrigation, water use efficienc
IMO and internal branding outcomes: an employee perspective in UK HE
This study extends our knowledge of internal branding in the context of employees in the higher education sector. Employing a quantitative methodology in UK universities, a conceptual model is presented and tested on 235 employees. Internal market orientation (IMO) is examined as a management tool to drive employees’ university brand commitment en route to brand supportive behavior. The results show that the effect of IMO on employees’ university brand commitment varies among employees of different demographic groups. A two-step cluster analysis is carried out to highlight the impact of demographic heterogeneity. The results show that universities with higher level of IMO perform better relating to their internal branding outcomes in terms of employee university brand commitment as well as brand supportive behavior. However significant differences are found for the effect of IMO on employees’ university brand commitment especially in the cluster of the ‘Mature Male Academics’, suggesting specific managerial attention
Principally Pseudo-Injective Semimodule
نقدم في هذا البحث, مفهوم شبه المقاس الرئيس الاغماري الكاذب الذي هو تعميم لمفهوم شبه المقاس الرئيس شبه الاغماري رئيسا, وندرس بعض خواص شبه المقاس الرئيس الاغماري الكاذب والعلاقة بين شبه المقاس الرئيس الاغماري الكاذب و شبه المقاس الرئيس شبه الاغماري. يسمى شبه المقاس اغماري كاذب رئيسيا اذا كان لكل احاد تشاكل من اي شبه مقاس جزئي دوري من الى يمكن توسيعه الى تشاكل في شبه حلقة التشاكلات في . In this paper, the connotation principally pseudo-injective semimodule which is a generalization of the notion principally quasi-injective semimodule will be introduced, we study some properties of principally pseudo-injective semimodule. Relationship between principally pseudo-injective and principally quasi-injective semimodule is given. A semimodule is called principally pseudo-injective (shortly, P.P.-injective) if for any cyclic subsemimodule Ų of, any monomorphism from Ų into can be extended to an endomorphism of
A beamforming comparative study of least mean square, genetic algorithm and grey wolf optimization algorithms for multipath smart antenna system
Multipath environment is a limitation fact in optimized usage of wireless networks. Using smart antenna and beamforming algorithms contributed to that subscribers get a higher-gain signal and better directivity as well as reduce the consumed power for users and the mobile base stations by adjusting the appropriate weights for each element in the antenna array that leads to reducing interference anddirecting the main beam to wanted user. In this paper, the performance of three of beamforming algorithms in multipath environment in terms of directivity and side lobe level reduction has been studied and compared, which are least mean square (LMS), genetic algorithm (GA) and grey wolf optimization (GWO) technique. The simulation result appears that LMS algorithm aids us to get the best directivity followed by the GWO, and we may get most sidelobe level reduction by using the GA algorithm, followed by LMS algorithm in second rank.
Antimicrobial activity of crude henna extract against Gram-positive bacteria
Henna plant has been used in herbal medicine for ages, but the medical uses of this plant as antimicrobial agent had not been well discussed. In this study we aim to examine the effect of ethanolic extract of local Basra henna leaves on Gram-positive bacteria species. Also, to assess the antibacterial properties of henna crude extract in vitro and compare them with antibiotics. Lawsonia inermis (henna) leaves were extracted with ethanol via using the solvent extraction technique. The pathogens were isolated from wound samples obtained from hospitalized patients in two different hospitals in Duhok city. Culture of thirty isolates had been recognized by routine methods. Different concentrations of ethanol crude extract were acquired and bio-assayed in vitro to inhibit the growth of five human pathogenic Gram-positive bacteria. Agar well diffusion assay was used for achieving henna antibiotic activity. Moreover, antibiotics susceptibility test was done by the disk diffusion method using Muller-Hinton agar medium. The growth of all tested bacteria was suppressed to various degrees by increasing the concentration of the extract. The data has revealed that Staphylococcus aureus was more sensitive than other examined isolates, where the diameter zone of inhibition were ranging from 16-27, 14-25, and 8-18 mm for Staphylococcus epidermidis, Lactobacillus spp. and Streptococcus pneumoniae respectively. The antimicrobial activity of henna extract indicates that it is suitable for being used as significant certain medications. Consequently, henna is active to serve as an anti-bacterial agent against multi-drug resistant Gram-positive bacteria.
DOI: http://dx.doi.org/10.5281/zenodo.456911
On Finitely Null-additive and Finitely Weakly Null-additive Relative to the σ–ring
يهدف هذا البحث الى تقديــم مفهوم المضافات الفارغة المنتهية نسبةً الى الحلقة من النمط –σ ومناقشــة العديد من الخصائص لهذا المفهوم. اضافةً الى ذلك قدمنا ودرســنا مفهوم المضافات الفارغة الضعيفة المنتهية نسبةً الى الحلقة من النمط–σ وهي أعـم من بعض المفاهيم كالقياس والمضافات المعدودة والمضافات المنتهية والمضافات الفارغة المعدودة والمضافات الفارغة الضعيفة المعدودة والمضافات الفارغة المنتهية و على هذا الاســاس برهـــنا ان كل المضاف الفارغ المنتهي يــؤدي الى المضاف الفارغ الضعيف المنتهــي . واخـــيراً درســـنا مفهوم القياس الخارجي إذ يكون اقــوى من مفهـــوم المضافات الفارغة الضعيفــة المنتهية. This article introduces the concept of finitely null-additive set function relative to the σ– ring and many properties of this concept have been discussed. Furthermore, to introduce and study the notion of finitely weakly null-additive set function relative to the σ– ring as a generalization of some concepts such as measure, countably additive, finitely additive, countably null-additive, countably weakly null-additive and finitely null-additive. As the first result, it has been proved that every finitely null-additive is a finitely weakly null-additive. Finally, the paper introduces a study of the concept of outer measure as a stronger form of finitely weakly null-additive
Violence and abuse among working children in urban and suburban areas of lower Sindh, Pakistan
Background: Child labourers are exposed to an insecure environment and higher risk of violence. Violence among child labourers is an under-studied phenomenon which requires contextual assessment.Aims: We applied Bronfenbrenner\u27s ecological model (micro-, exo- and macro-system) to understand the interplay of individual, community, societal and policy context fuelling violence.Methods: Focus group discussions and family ethnographies of child-labourers working in common occupational sectors of suburban areas of Sindh were carried out to gain in-depth understanding of their immediate environment and abuse (micro-system). Frequency of emotional, physical and sexual violence (5-14 years; n = 634) was also determined. Indepth interviews with employers (exo-system, n = 4) and key-informant-interviews of prominent stakeholders in Pakistan (macro-system, n = 4) working against labour/violence were carried out Thematic-content analysis was performed using MAXQDA, version 8.0.Results: We estimated that 21%, 19% and 9% of children suffered from emotional, physical and sexual violence respectively. Child labourers\u27 interviews indicated the existence of all forms of abuse at home and in the workplace; sexual violence by grandfathers was highlighted (micro-system). Children reported frequent scolding and insults in the workplace along with physical violence that could be fatal (exo-system). The legal environment of violence in Pakistan was considered deficient as it did not address the hidden forms (touching, kissing, etc.; macro-system).Conclusion: We documented that all forms of violence were rampant among the child labourers, and improved efforts and comprehensive legislation is direly needed to alleviate the situation
Situation analysis of child labour in Karachi, Pakistan: A qualitative study
In Karachi, large employment opportunities, burgeoning population and the availability of cheap labour might be the contributing factors for the increasing prevalence of child labour. A literature review was conducted in 2007 that included published and unpublished literature since 2000. Various organizations working in the field were also covered, while the perception of the child labourers was covered through three focus group discussions. Common health issues among the child labourers in Karachi included respiratory illnesses, fever and generalised pains, as well as drug and sexual abuse. Organisations working for child labour could be broadly categorised into those working for legal advice and advocacy; those generating statistics; and those that are providing interventions. Discussion with children showed that irrespective of the immediate cause, the underlying determinant for child labour was poverty. The best practices identified included evening schools and drop-in centers for working children with provision for skill-based education and basic health facilities. There is need to have more such centres
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