Abstract Portable communication devices such as WLAN, WiMAX, LTE, ISM, and 5G utilize one or more of the triple bands at (2.32.7 GHz,3.4–3.6GHz,and5–6GHz)andsufferfromtheeffectofmultipathproblemsbecausetheyareusedinurbanregions.To date, no one has performed a review of the antennas used for these types of wireless communications. This study reviewed two types of microstrip antennas (slot and fractal) that have been reported by researchers (as a single element) using a survey that included the evaluation of several important specifications of the antennas in previous research, such as operating bandwidth, gain, efficiency, axial ratio bandwidth (ARBW), and size. The weaknesses in the design of all antennas were carefully identified to determine the most important challenges in the design of these antennas and name the most important limits in the design to be overcome in future research. This study also indicated some antennas that have circular polarization characteristics, the techniques used to generate the circular polarization characteristics, and the challenges. Finally, several suggestions as a guideline for antenna design and future work in designing antennas for Wi-Fi, LTE, and WiMAX communications, according to the market demands, and methods for overcoming the identified limits are presented.
In this paper, previous studies about Fuzzy regression had been presented. The fuzzy regression is a generalization of the traditional regression model that formulates a fuzzy environment's relationship to independent and dependent variables. All this can be introduced by non-parametric model, as well as a semi-parametric model. Moreover, results obtained from the previous studies and their conclusions were put forward in this context. So, we suggest a novel method of estimation via new weights instead of the old weights and introduce
Paper Type: Review article.
another suggestion based on artificial neural networks.
Reconstruction project management in the cities of Mosul, Anbar, and Tikrit, in Iraq still faces major obstacles that impede the comprehensive performance of these projects. It is thus necessary to improve the arising challenge estimation in the implementation of reconstruction projects and evaluate their components: time, cost, quality, and scope. This study used the Analytical Hierarchy Process (AHP) to prioritize major and minor criteria in the influential causes of challenges and formulate a mathematical model to help decision-makers estimate them. Using the Super Decisions software, the final results indicated that changes in scope reached 40.8%, which is the greatest difficulty, followed by changes in cost at 27.6%, changes in
... Show MoreAs population growth increases the demand for crops increases and their quality improves, and it becomes necessary to find innovative and modern solutions to enhance production. In this context, artificial intelligence plays a pivotal role in developing new technologies to improve crop sorting and increase agricultural yields. The present review discusses the main differences between manual and mechanical potato harvesting, explaining the advantages and disadvantages of each method. Manual harvesting is highlighted as a traditional method that allows for greater precision in handling the crop, but it requires more time and effort. In contrast, mechanical harvesting provides greater efficiency and speed in the process, but it may damage some
... Show MoreGiven the growing interest in digital marketing operations and the technology imposed by the reality in which both companies and their customers are affected, the researchers attempted to shed light on the reality and challenges of digital marketing from the faculty members viewpoint at Jouf university, the problem is that technology has imposed a new reality that has resulted in a major change in behavioral patterns of customers with a number of obstacles and challenges confronted customers in digital marketing, it is expected that the outcomes of this study help companies in overcoming the obstacles that prevent the desire and ability of the customer to change his behavioral style to deal with electronic shopping operations and
... Show MoreBackground Rectal cancer is one of the most common malignant tumors of gastrointestinal tract. Combining chemotherapy with radiotherapy has a sound effect on its management.
Objectives Assessment the patterns of characterizations of rectal cancer. Evaluation of the efficacy, and long-term survival of pre-/ postoperative chemoradiation. Collecting all eligible evidence articles and summarize the results.
Methods By this systematic review and meta-analysis study, we include data of chemoradiation of rectal cancer articles from 2015 until 2019. The research was carried out at Baghdad Medical City oncology centers. Accordance with the
Interested in this research shed light on the reality of foreign trade to Iraq Who suffers from a marked deterioration due to poor economic diversification of the country And increase the degree of economic exposure , Which creates a state of extreme caution towards the question of accession to the (WTO) , As controls Iraq's foreign trade commodity , a president of one oil As well as the contribution of this item , and by a large formation in GDP , And that such a large and dangerous decline in the degree of economic diversification will create negative effects On overall economic activity components&
... Show MoreObesity is disorder in a foremost nutritional health it’s developed with countries developing. Also is known as increasingin fat accumulation that lead toproblem in health, besidesmay coin one of the reasons lead toloss of life,the obesity not effect on adults just but effect onoffspringand juveniles. In some ofinhabitants the incidence of obesity is superior in female than in male; on the other hand, the variation degree of the between the genderdifferby country.Obesity is generally measured by body mass index and waist circumference, Obesity are classified according to body mass index into:Pre obesity sort 1 : (25 - 29.9) kg/m2, Obesity sort 2 : (30 - 34.9 kg/m2) and extreme obesity sort 3: (40 kg/m2) or greater. Obesity is described by
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