A Novel Mathematical Model for Radio Mean Square Labeling Problem

A radio mean square labeling of a connected graph is motivated by the channel assignment problem for radio transmitters to avoid interference of signals sent by transmitters. It is an injective map h from the set of vertices of the graph G to the set of positive integers N , such that for any two distinct vertices x , y , the inequality d x , y + h x 2 + h y 2 / 2 ≥ dim G + 1 holds. For a particular radio mean square labeling h , the maximum number of h v taken over all vertices of G is called its spam, denoted by rmsn h , and the minimum value of rmsn h taking over all radio mean square labeling h of G is called the radio mean square number of G , denoted by rmsn G . In this study, we investigate the radio mean square numbers rmsn P n and rmsn C n for path and cycle, respectively. Then, we present an approximate algorithm to determine rmsn G for graph G . Finally, a new mathematical model to find the upper bound of rmsn G for graph G is introduced. A comparison between the proposed approximate algorithm and the proposed mathematical model is given. We also show that the computational results and their analysis prove that the proposed approximate algorithm overcomes the integer linear programming model (ILPM) according to the radio mean square number. On the other hand, the proposed ILPM outperforms the proposed approximate algorithm according to the running time.

ASSESSMENT OF THE QUALITY OF RADIO COMMUNICATION CHANNELS OF UNMANNED AERIAL SURVEILLANCE SYSTEMS

Unmanned aerial vehicles (UAVs) allow effective solving the problems of reconnaissance, relaying information on targets to means of fire destruction and striking on any type of object. However, there are many problematic issues regarding the creation of a communication system for remote control of UAV of medium and long range, obtaining video information about reconnaissance objects in real time. The methods allow to estimate the value of the deviation of the carrier frequency of the transmitter of the radio communication channel of unmanned aerial system (UAS) in the normal mode of its operation from the value of the prototype stated by the Developer based on the instrumental measurement of the average or assigned frequency of modulated radio emission. The purpose of the article is to consider the methods, technical means and conditions of instrumental evaluation of the radio emission frequency of UAV‟s radio channels transmitters by means of radio frequency control. This technique defines a set of procedures and rules for instrumental evaluation (measurement) of radio frequency of UAVs prototypes radio transmitters by means of radio frequency control in order to verify compliance of its parameters with the requirements of technical conditions or specifications for experimental aircraft.

Synthesis method of circulant polynomial encoding matrices for the implementation of code-division multiplexing

The method of the synthesis of circulant polynomial matrices for the implementation of the operation of code combining of channels on the transmitting side of the communication system has been developed. The structure of these matrices is the basis for reducing the complexity of encoder schemes and, consequently, the radiated power of radio transmitters of subscriber devices. The research results can be applied in communication systems with multiple access, with a wide coverage area, high quality of data transmission, high noise immunity, stability of communication channels from interception and eavesdropping.

Implementasi bandpass filter m-derived pada pemancar radio FM

Pemancar siaran radio FM adalah salah satu sistem komunikasi nirkabel, bekerja rentang frekuensi 88-108 MHz membutuhkan sebuah filter bandpass untuk menghindari adanya interferensi dengan frekuensi yang berdekatan dengan pemancara radio. Jenis filter yang memiliki performansi cukup baik adalah filter dengan tingkat kecuraman yang cukup tinggi. Namun, untuk mendapatkan tingkat faktor kecuraman yang tinggi dengan menambah beberapa elemen. Maka, pada penelitian ini menambahkan rangkaian m-derived utnuk memberikan respon filter yang lebih curam tanpa menambahkan nilai elemen yang banyak. Tujuan penelitian ini mengetahui perbandingan daya pemancar tanpa filter, dengan bandpass filter, dan menggunakan bandpass filter m-derived. Hasil pengujian daya pancar tanpa filter sebesar 2 Watt, dengan menggunakan bandpass filter daya pancar sebesar 1,05 Watt, sedangkan dengan menggunakan bandpass filter m-derived daya pancar sebesar 1,4 Watt. Kesimpulannya pelemahan (insertion loss) pada Bandpass Filter sebesar 2,53 dB sedangkan pelemahan (insertion loss) pada BPF m-derived section sebesar 1,54 dB dengan menambahkan BPF m-derived section memperbaiki daya keluaran pemancar lebih besar 0,35 W atau 1,01 dB dibandingkan dengan pemancar yang menggunakan BPF tanpa m-derived. FM radio broadcast transmitter is a wireless communication system, with frequency range of 88-108 MHz requires a bandpass filter to avoid interference with frequencies adjacent to radio transmitters. The type of filter that has a fairly good performance is a filter with a fairly high level of steepness. However, to get a high level of steepness factor by adding some elements. So, in this study, we added an m-derived circuit to provide a steeper filter response without adding a lot of element values. The purpose of this study is to compare the transmitter power without a filter, with a bandpass filter, and using an m-derived bandpass filter. The result of testing the unfiltered transmit power is 2 Watt, using a bandpass filter the transmit power is 1.05 Watt, while using the m-derived bandpass filter the transmit power is 1.4 Watt. In conclusion, the insertion loss in the Bandpass Filter is 2.53 dB, while the insertion loss in the BPF m-derived section is 1.54 dB by adding the BPF m-derived section to improve the transmitter output power by 0.35 W or 1 .01 dB compared to transmitters using BPF without m-derived.

Effect of the Social Environment on Spring Migration Timing of a Songbird

The influence of the social environment on the timing of the annual cycle is poorly understood. Seasonally migratory birds are under pressure to accurately time their spring migration, and throughout the annual cycle, they may experience variability of the local sex-ratio. A population-level male-biased sex ratio is predicted to advance spring migration timing in males and is attributed to the increased intra-specific competition for access to females and/or breeding territories. The present study had two goals. First, to develop a method that utilizes digitally coded radio-transmitters to quantify the activity of flocked individuals in captivity. Second, to use this method to test the hypothesis that the social environment influences the spring migration traits of male yellow-rumped warblers (Setophaga coronata coronata). To accomplish this, birds were captured in the fall in Long Point, Ontario, and transferred to the Advanced Facility for Avian Research, London, Ontario. In the winter, they were assigned to a slightly male- or female-biased treatment and housed in flocks in large free-flight rooms. Throughout the experimental period, we took body mass measurements and standardized photos to monitor body condition and molt progression. To measure locomotor activity, the birds were outfitted with digitally coded radio-transmitters in April and photo-triggered to enter a migratory phenotype. The tagged birds were released at their capture site in May and the Motus Wildlife Tracking System was used to determine stopover departure timing and migratory movements. Sex ratio did not influence body mass or molt progression. However, males from the male-biased treatment had significantly less locomotor movement than those from the female-biased treatment. Additionally, a lower proportion of males from the male-biased treatment initiated migratory restlessness, an indicator of the urge to migrate. Overall, these findings suggest that the social environment can influence behavior of songbirds, but do not support the hypothesis that a male-biased sex ratio accelerates migration.

SELECTIVE MEASUREMENTS FOR THE RADIO TRANSMITTERS ELECTROMAGNETIC FIELD EXPOSURE HYGIENIC ASSESSMENT

Introduction: The problems of electromagnetic fields control methods and hygienic assessment improvement are of high importance due to telecommunications development and new generation networks deployment. Goal: methodological approach enhancement for hygienic assessment of electromagnetic fields from of cellular communication system radio transmitters. Methods: selective methods application is promising for Russian evaluation system development with regard to environment and occupational electromagnetic fields. Selective methods provide an opportunity to electromagnetic background monitoring in detail for selected parts of the spectrum. Results: a general scheme for instrumental control and assessment of cellular communication systems electromagnetic fields is presented; the conditions for broadband, frequency-selective and code-selective measurements usage are proposed, depending on the total actual levels. Conclusion: the proposed approach for electromagnetic fields hygienic assessment includes broadband and selective measurements in addition on each other. It allows a detailed evaluation of the electromagnetic levels and additional parameters for human exposure to electromagnetic fields – actual levels and predicted maximum levels from separated sources.

A comparison of methods for the long-term harness-based attachment of radio-transmitters to juvenile Japanese quail (Coturnix japonica)

Background While the period from fledging through first breeding for waterbird species such as terns (e.g., genus Sterna, Sternula) is of great interest to researchers and conservationists, this period remains understudied due in large part to the difficulty of marking growing juveniles with radio transmitters that remain attached for extended periods. Methods In an effort to facilitate such research, we examined the impact of various combinations of harness types (backpack, leg-loop, and 3D-printed harnesses), harness materials (Automotive ribbon, Elastic cord, and PFTE ribbon), and transmitter types (center-weighted and rear-weighted) on a surrogate for juvenile terns, 28-day-old Japanese quail (Coturnix japonica; selected due to similarities in adult mass and downy feathering of juveniles), in a 30-day experiment. We monitored for abrasion at points of contact and tag gap issues via daily exams while also recording mass and wing cord as indices of growth. This study was designed to serve as an initial examination of the impacts of marking on the growth and development of young birds and does not account for any impacts of tags on movement or behavior. Results While we found that treatment (the specific combination of the transmitter type, harness type, and harness material) had no impact on bird growth relative to unmarked control birds (P ≥ 0.05), we did observe differences in abrasion and tag gap between treatments (P ≤ 0.05). Our results suggest that leg-loop harnesses constructed from elastic cord and backpack harnesses from PFTE ribbon are suitable options for long-term attachment to growing juveniles. Conversely, we found that automotive ribbon led to extensive abrasion with these small-bodied birds, and that elastic cord induced blisters when used to make a backpack harness. Conclusions While these results indicate that long-term tagging of juvenile birds is possible with limited impacts on growth, this work does not preclude the need for small-scale studies with individual species. Instead, we hope this provides an informed starting point for further exploration of this topic.