scholarly journals Method for automatic antenna matching with transmitter output stage

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 31-39
Author(s):  
D. A. Kovalevich

This work is devoted to the study of automatic antenna tuning units of the short-wave range. Devices of narrowband matching based on discrete sets of reactive elements are considered. A classification of the most frequently used automatic matching methods has been made. The advantages and disadvantages of each method are analyzed. Examples of using different approaches in commercially available devices are given. Particular attention  is  paid  to  the  calculation  method  of  matching,  as  the most  promising  for  use  in  modern communications. Assumptions are made about the reasons for its rare use in serial devices. Circuits have been developed to simulate the influence of parasitic parameters of the components of the matching circuit and the body of the tuning unit on the resulting standing wave ratio when using this method. Based on the simulation results,  conclusions  were  drawn  about  the  reasons  for  the  low  quality  of  the  calculation  method.  As  an alternative, a new method of automatic tuning is proposed, combining the advantages of computation and search methods,  which  is  based  on  modeling  the  search  process  using  a simulation  model.  The  conditions  for  its application in automatic antenna tuning units are determined. Acomparative analysis of the features of both the known methods of automatic tuning and the newly proposed one ismade.

2020 ◽  
Vol 30 (2) ◽  
pp. 297-303
Author(s):  
Farbood Kalantari ◽  
Shahin Rajaeih ◽  
Ali Daneshvar ◽  
Zahra Karbasi ◽  
Mohammad Mahdi Salem

Head and neck cancers are the most common cancers in the body. Treatments are determined on the basis of the location and stage of the primary tumor. The goal of treatment is to eliminate the tumor, prevent recurrence or metastasis, and maintain the quality of life. There are several treatments available for the management of head and neck cancers, including surgery, radiation therapy, chemotherapy, new molecular agents, and a combination of them. Transoral robotic technique is a short-time operation using a type of robotic machine in which the patient undergoes anesthesia for a shorter time and the side effects of this operation and the time of hospitalization are less than open surgery. Due to the importance of speed and accuracy in head and neck cancer surgery and the importance of application of robotics in surgery, the present study was designed and implemented to review the application of robotics in the management of head and neck cancers. In this review study, the keywords: application, robotic, surgical, head cancer, transoral robotic surgery (TORS), and neck cancer, were searched in ISI, PubMed, Scopus, Google scholar databases. Related articles written domestically or abroad that have covered areas such as the background of transoral robotic surgery, maintaining organ function and approaches, the advantages and disadvantages of TORS, the affordability of TORS, the combination of TORS with other therapeutic approaches published from 2003 to 2019 were reviewed. The use of robotic surgery for precise operations such as head and neck cancers seems to be essential. More advanced robotic devices are expected to expand the surgery treatment for head and neck cancers as well as the results of using TORS for oncologic optimization and acceptability of results while maintaining organ function and patient's quality of life.


Author(s):  
Farbood Kalantari ◽  
Shahin Rajaeih ◽  
Ali Daneshvar ◽  
Zahra Karbasi ◽  
Mohammad Mahdi Salem

Head and neck cancers are the most common cancers in the body. Treatments are determined on the basis of the location and stage of the primary tumor. The goal of treatment is to eliminate the tumor, prevent recurrence or metastasis, and maintain the quality of life. There are several treatments available for the management of head and neck cancers, including surgery, radiation therapy, chemotherapy, new molecular agents, and a combination of them. Transoral robotic technique is a short-time operation using a type of robotic machine in which the patient undergoes anesthesia for a shorter time and the side effects of this operation and the time of hospitalization are less than open surgery. Due to the importance of speed and accuracy in head and neck cancer surgery and the importance of application of robotics in surgery, the present study was designed and implemented to review the application of robotics in the management of head and neck cancers. In this review study, the keywords: application, robotic, surgical, head cancer, transoral robotic surgery (TORS), and neck cancer, were searched in ISI, PubMed, Scopus, Google scholar databases. Related articles written domestically or abroad that have covered areas such as the background of transoral robotic surgery, maintaining organ function and approaches, the advantages and disadvantages of TORS, the affordability of TORS, the combination of TORS with other therapeutic approaches published from 2003 to 2019 were reviewed. The use of robotic surgery for precise operations such as head and neck cancers seems to be essential. More advanced robotic devices are expected to expand the surgery treatment for head and neck cancers as well as the results of using TORS for oncologic optimization and acceptability of results while maintaining organ function and patient's quality of life.


2021 ◽  
Vol 100 (1) ◽  
pp. 13-18
Author(s):  
Svetlana P. Babenko ◽  
Andrey V. Bad’in

Introduction. This article refers to the authors’ calculation method for studying the effects UF6 (uranium hexafluoride, UHF) on the human body. A review of this method’s main ideas and the features of the approach to solving the problem at certain stages of the movement of UHF from being released into the air before entering the body is offered. The possibilities of the proposed method and its place in many well-known studies in this direction are described. Material and methods. The research material is UHF. It serves as the primary working substance in technologies for enriching natural uranium with the 235U isotope. UHF, due to various circumstances, appears in the production room in a gaseous state. A method for studying the effects of UHF on humans is to describe the distribution processes of UHF molecules in the volume of the working room, chemical transformations of UHF, physical transformations of the resulting products, i.e., all processes accompanied by the delivery of toxic substances and their transfer from the source to the person and before excretion from the body in a natural way. The description of these processes is carried out analytically. Results. Lists the results that can be obtained by calculation. Discussion. A discussion of the results is carried out in the following areas. The issue of the possibility of using the described calculation method to solve the problems of ensuring labor safety at work is considered. The question of trust in the calculated values characterizing the effect of UHF on the human body is being studied. To solve this problem, we compared the calculated results obtained for a particular process and the experimental ones implemented in a similar process. Conclusion. A conclusion is made regarding the advantages and disadvantages of the method under investigation for studying the effects of UHF on humans and determining their place among existing methods.


2010 ◽  
Vol 168-170 ◽  
pp. 13-16
Author(s):  
Yin Xu ◽  
Sheng Hong Chen

Discrete element method is emerging as a useful numerical analysis tool for engineers interested in granular materials such as soil, concrete, or pharmaceutical powders. Simulated the concrete’s microscopic property and its impact on the macroscopic property by using particle discrete element method is one of the important research topics. Obviously, the first step in a discrete element simulation is the generation of the geometry of the system concerned, the quality of which will directly decide the quality of the simulation result. An integrated approach termed random adjusted calculation method is proposed in this paper after detailed analysis of the advantages and disadvantages of the existing aggregate delivery methods. The new method is a method which combined both the advantages of random method and non-geometry methods, such as hopper method and explosive repulsion method. Through out the analysis of the basic process of aggregate delivery and indicated by the result of the examples, random adjusted calculation method has the advantages of good overall density and easily controlled grading; and the computational time is smaller than the existing methods of non-geometry aggregate delivery; furthermore, the new method is easily carried out and provides a new idea for the delivery of concrete aggregate.


2020 ◽  
pp. 92-107 ◽  
Author(s):  
A. I. Bakhtigaraeva ◽  
A. A. Stavinskaya

The article considers the role of trust in the economy, the mechanisms of its accumulation and the possibility of using it as one of the growth factors in the future. The advantages and disadvantages of measuring the level of generalized trust using two alternative questions — about trusting people in general and trusting strangers — are analyzed. The results of the analysis of dynamics of the level of generalized trust among Russian youth, obtained within the study of the Institute for National Projects in 10 regions of Russia, are presented. It is shown that there are no significant changes in trust in people in general during the study at university. At the same time, the level of trust in strangers falls, which can negatively affect the level of trust in the country as a whole, and as a result have negative effects on the development of the economy in the future. Possible causes of the observed trends and the role of universities are discussed. Also the question about the connection between the level of education and generalized trust in countries with different quality of the institutional environment is raised.


Author(s):  
B. G. Shadrin ◽  
◽  
D. E. Zachateyskiy ◽  
V. A. Dvoryanchikov Dvoryanchikov ◽  
◽  
...  

Author(s):  
Neha Thakur ◽  
Aman Kumar Sharma

Cloud computing has been envisioned as the definite and concerning solution to the rising storage costs of IT Enterprises. There are many cloud computing initiatives from IT giants such as Google, Amazon, Microsoft, IBM. Integrity monitoring is essential in cloud storage for the same reasons that data integrity is critical for any data centre. Data integrity is defined as the accuracy and consistency of stored data, in absence of any alteration to the data between two updates of a file or record.  In order to ensure the integrity and availability of data in Cloud and enforce the quality of cloud storage service, efficient methods that enable on-demand data correctness verification on behalf of cloud users have to be designed. To overcome data integrity problem, many techniques are proposed under different systems and security models. This paper will focus on some of the integrity proving techniques in detail along with their advantages and disadvantages.


Author(s):  
Rostislav Fojtík

Abstract Distance learning and e-learning have significantly developed in recent years. It is also due to changing educational requirements, especially for adults. The article aims to show the advantages and disadvantages of distance learning. Examples of the 20-year use of the distance learning form of computer science describe the difficulties associated with the implementation and implementation of this form of teaching. The results of students in the full-time and distance form of teaching in the bachelor’s study of computer science are compared. Long-term findings show that distant students have significantly lower scores in the first years of study than full-time bachelor students. In the following years of study, the differences diminish, and students’ results are comparable. The article describes the possibilities of improving the quality of distance learning.


Author(s):  
Elena A. Beigel ◽  
Natalya G. Kuptsova ◽  
Elena V. Katamanova ◽  
Oksana V. Ushakova ◽  
Oleg L. Lakhman

Introduction. Occupational chronic obstructive pulmonary disease (COPD) is one of the leading nosological forms of occupational respiratory disease. Numerous studies have shown high effectiveness of the combination of indacaterol/glycopyrronium (Ultibro®breezhaler®) on the impact on clinical and functional indicators in the treatment of COPD in General practice.The aim of the investigation the case of occupational COPD with the analysis of the dynamics of functional indicators, tolerance to physical load and evaluation of the quality of life of workers engaged in aluminum production by using combination of indacaterol/glycopyrronium.Materials and methods. The random sampling method included 20 men, workers of aluminum production, with the established diagnosis of professional COPD at the age of 40 to 60 years. The survey was conducted (Borg scale, medical Research Council scale (mMRC) and COPD Assessment Test (CAT). Functional methods of studies were conducted: spirometry, body plethysmography, electrocardiography (ECG) and the six-minute stepper test (6-MST).Results. Against the background of 8 weeks of therapy, the volume of forced exhalation for 1 minute (FEV1) increased by 14.7% and amounted to 67.90% of the due values, the forced vital capacity of the lungs (FVC) increased by 11.3% and amounted to 76.95% of the due. According to the body plethysmography (BPG) is set to decrease in residual lung volume on average by 13.4% and static hyperinflation, confirmed by the decrease in functional residual volume (FRV) of 18.8%. During the study period increased physical activity of patients. The average difference between the distance traveled in the six-minute step test before and after treatment was 58.8 m. The analysis of personal data showed that the quality of life of patients improved, the total score in the questionnaire CAT at the beginning of the study was 16.9 points, and after 8 weeks decreased by 63% and amounted to 10.7 points.Conclusions: The Results indicate a positive effect of combination therapy with indacaterol/glycopyrronium on the course and progression of occupational COPD.


Edum Journal ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 106-117
Author(s):  
Khamim Khamim ◽  
Wresni Pujiyati

The main focus of this research is on the self-concept and pedagogical competence of the teacher and its influence on the quality of the learning process both partially and double. The research method used is a survey method in which the authors go directly to the empirical level by distributing questionnaires to 47 teachers. The processing and analysis techniques used are linear and multiple regression. The results of the study show that: (1) There is a positive and significant influence of the teacher's self-concept on the quality of the learning process (2) There is a positive and significant influence on the teacher's pedagogical competence on the quality of the learning process. (3) There is a positive and significant effect of self-concept and pedagogical competence of teachers together on the quality of the learning process. Therefore, the authors suggest: (1) So that the teacher improves health and appearance because the results of the study show that the weakness of the teacher's self-concept is in the appearance and significance of the body. So that the teacher needs to be given enlightenment related to how to maintain health and fitness through the implementation of joint gymnastics or conducting group discussions related to the dirt to maintain a prime body. (2) To face future competition and improve the quality of education it is deemed necessary to further increase the pedagogical competence of teachers, especially those related to planning and evaluation of learning.


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