Rate Maximization Using Cooperative Ratio Over Rayleigh Fading Channels

Cooperative Diversity transmission, a newly upcoming field in the area of wireless communication, has been receiving great attention. This diversity transmission exploits the spatial diversity created by antenna sharing to improve the performance of a wireless network. The working of a cooperative diversity system is such that a source node communicates with a destination node with the help of another partner node. One important question usually raised regarding the operation of this system is that of the amount of power allocation among partnering nodes. Initial stages of research in this area had assumed equal distribution of power resources between the nodes. This approach has been proven as clearly suboptimal. Several works to allocate power optimally are coming up. In this project, optimal power allocation is used as a key approach to analyze the rate performance of the system. This is done with the help of a parameter called cooperative ratio which is the ratio of the power used for cooperative transmission to total power. Simulation results to support the analysis have also been provided.

Rate Maximization Using Cooperative Ratio Over Rayleigh Fading Channels

Cooperative Diversity transmission, a newly upcoming field in the area of wireless communication, has been receiving great attention. This diversity transmission exploits the spatial diversity created by antenna sharing to improve the performance of a wireless network. The working of a cooperative diversity system is such that a source node communicates with a destination node with the help of another partner node. One important question usually raised regarding the operation of this system is that of the amount of power allocation among partnering nodes. Initial stages of research in this area had assumed equal distribution of power resources between the nodes. This approach has been proven as clearly suboptimal. Several works to allocate power optimally are coming up. In this project, optimal power allocation is used as a key approach to analyze the rate performance of the system. This is done with the help of a parameter called cooperative ratio which is the ratio of the power used for cooperative transmission to total power. Simulation results to support the analysis have also been provided.

Methodology for estimating reception efficiency of mutually correlated or in- phase signals at diversity transmission

The article describes and theoretically substantiates the potential technical capabilities of spatially separated earth stations (ES). When several ESs emit in-phase or mutually pairwise correlated signals in the direction of one received antenna of the object, the total level of the sum of emissions at its output (at the input of the receiving path) may be several times higher than the sum of the powers of these signals. In this regard, the article investigates the influence of the phase difference of the transmitted signals on the value of their total average power at the input of the receiving path. In the case of addition of common-mode signals, a formula is used to calculate in which the power of harmonic radiation is proportional to the square of the sum of the amplitude of the common-mode signals. This paradox is also valid for pairwise cross-correlated signals. The presented technique for evaluatingтthe effectivenessтallows one to establish not only the dependence of the energy ratios on the nonтenergy parameter, but also to determine the number of low-power ESs required to ensureтthe required signal level at the input of the receiving device. The use of the presented technique makes it possible to evaluate the efficiency of receiving a combined high-power signal for a differentтnumber of emitters that form in-phase or pairwise mutual correlation of signals at the receiving point.

Drawing Comparisons between SARS-CoV-2 and the Animal Coronaviruses

The COVID-19 pandemic, caused by a novel zoonotic coronavirus (CoV), SARS-CoV-2, has infected 46,182 million people, resulting in 1,197,026 deaths (as of 1 November 2020), with devastating and far-reaching impacts on economies and societies worldwide. The complex origin, extended human-to-human transmission, pathogenesis, host immune responses, and various clinical presentations of SARS-CoV-2 have presented serious challenges in understanding and combating the pandemic situation. Human CoVs gained attention only after the SARS-CoV outbreak of 2002–2003. On the other hand, animal CoVs have been studied extensively for many decades, providing a plethora of important information on their genetic diversity, transmission, tissue tropism and pathology, host immunity, and therapeutic and prophylactic strategies, some of which have striking resemblance to those seen with SARS-CoV-2. Moreover, the evolution of human CoVs, including SARS-CoV-2, is intermingled with those of animal CoVs. In this comprehensive review, attempts have been made to compare the current knowledge on evolution, transmission, pathogenesis, immunopathology, therapeutics, and prophylaxis of SARS-CoV-2 with those of various animal CoVs. Information on animal CoVs might enhance our understanding of SARS-CoV-2, and accordingly, benefit the development of effective control and prevention strategies against COVID-19.

Diversity, Transmission, and Cophylogeny of Ledanteviruses (Rhabdoviridae: Ledantevirus) and Nycteribiid Bat Flies Parasitizing Angolan Soft-Furred Fruit Bats in Bundibugyo District, Uganda

Obligate hematophagous ectoparasitic flies of the superfamily Hippoboscoidea are distributed worldwide, but their role as vectors and reservoirs of viruses remains understudied. We examined hippoboscoid bat flies (family Nycteribiidae) parasitizing Angolan soft-furred fruit bats (Lissonycteris angolensis ruwenzorii) from Bundibugyo District, Uganda. Using metagenomic methods, we detected 21 variants of the rhabdovirid genus Ledantevirus, which contains medically important “bat-associated” viruses. These 21 viruses, representing at least two divergent viral lineages, infected 26 bat flies from 8 bats in a single roost. Cophylogenetic analyses of viruses and bat flies resulted in strong evidence of virus-host codivergence, indicating vertical transmission of bat fly ledanteviruses. Examination of oral swabs from bats revealed ledantevirus RNA in the saliva of 1 out of 11 bats, with no evidence of insect genetic material in the mouth of this bat. These data demonstrate that bat flies can harbor diverse ledanteviruses even in a single roost and that the predominant mode of transmission is likely vertical (among bat flies), but that bats can become infected and shed viruses orally. In conclusion, bat flies may serve as ectoparasitic reservoirs of “bat-associated” viruses that only transiently or sporadically infect bats.

Joint Power Allocation for Coordinated Multi-Point Diversity Transmission in Rayleigh Fading Channels

We consider the problem of joint power allocation (JPA) in a coordinated multi-point (CoMP) joint diversity transmission (JDT) network with a total coordination point power (TCPP) constraint, aimed at maximizing the ergodic cooperative capacity (ECC) in Rayleigh fading channels. In this paper, we first extend the JPA problem in the coordinated two-point (Co2P) JDT networkto the case of a non-unity TCPP constraint. Furthermore, we introduce more accurate log-quadratic approximated (LQA) expressions to obtain the coordinated transmission point (CTP) powers. Next, we extend our study to a coordinated three-point (Co3P) JDT network. Given the mean branch gain-to-noise ratios, we first obtain a log-linear approximated (LLA) expression for obtaining the optimum power of the third CTP (i.e., the worst quality-providing CTP). After obtaining the third-CTP power, we obtain the CTP powers of two better quality-providing CTPs by invoking the LLA CTP power expressions for Co2P JDT power allocation, under the remaining power given by the TCPP minus the third-CTP power. The numerical results demonstrate that the LQA and LLA CTP power expressions for Co2P JDT and the LLA CTP power expressions for Co3P JDT are very efficient in terms of the simplicity for JPA and CoMP set selection, as well as the resulting ECC.

VISUALISASI SEBARAN SPESIES NYAMUK TERTANGKAP DI ENAM EKOSISTEM DI KABUPATEN KOTABARU PROVINSI KALIMANTAN SELATAN TAHUN 2016 MENGGUNAKAN METODE BIPLOT

Various types of flora and fauna are able to grow well because Indonesia has excellent environmental carrying capacity for the growth of its diversity. Transmission of vector infectious diseases is influenced by many factors, one of which is the topography of the region closely related to the pattern of transmission. One type of fauna that develops well is insects (insecta). To be achieved in writing this article is to obtain a mapping of the most dominant species of mosquito-causing diseases in six ecosystems in Kotabaru, South Kalimantan ie. Near Forest Settlement ecosystems, Remote Forest Settlements, Non Forest Near Settlements, Non Forest Remote Settlement, Near Beach Settlements and Beaches Deep Residential. The analysis used is biplot multivariate method using singular value and eigen value so that obtained visualization picture of data which have many object and variable. Biplot graphs provide a more practical visual illustration so that it can practically determine the proximity picture between the ecosystems of each other that have similar characteristics of mosquito species. This effort is useful for preventing the spread of certain species mosquito vectors, so that it can be utilized by the policy manager for the vector mosquito elimination program. ABSTRAK Berbagai jenis flora dan fauna mampu tumbuh dengan baik karena Indonesia mempunyai daya dukung lingkungan yang sangat baik untuk pertumbuhan keanekaragamannya. Penularan penyakit tular vektor dipengaruhi oleh banyak faktor, salah satunya adalah topografi wilayah yang erat hubungan dengan pola penularan. Salah satu jenis fauna yang berkembang dengan baik adalah serangga (insecta). Tujuan yang ingin dicapai pada penulisan artikel ini adalah memperoleh pemetaan mengenai sebaran spesies nyamuk penyebab penyakit yang paling dominan di 6 ekosistem di Kabupaten Kotabaru, Provinsi Kalimantan Selatan yaitu ekosistem Hutan Dekat Pemukiman, Hutan Jauh Pemukiman, Non Hutan Dekat Pemukiman, Non Hutan Jauh Pemukiman, Pantai Dekat Pemukiman dan Pantai Jauh Pemukiman. Analisis yang digunakan adalah metode multivariat biplot menggunakan nilai singular dan nilai eigen sehingga diperoleh gambaran visualisasi data yang memiliki banyak obyek dan variabel. Grafik Biplot memberikan gambaran visualisasi yang lebih praktis sehingga dapat dengan mudah menentukan gambaran kedekatan antara ekosistem satu sama lain yang memiliki karakteristik spesies nyamuk yang hampir sama. Upaya ini bermanfaat untuk pencegahan penyebaran vektor nyamuk spesies tertentu, sehingga dapat dimanfaatkan oleh pengelola kebijakan untuk program eliminasi nyamuk vektor penyakit.