Interference Alignment for Cognitive Radio Communications and Networks: A Survey

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Interference alignment (IA) is an innovative wireless transmission strategy that has shown to be a promising technique for achieving optimal capacity scaling of a multiuser interference channel at asymptotically high-signal-to-noise ratio (SNR). Transmitters exploit the availability of multiple signaling dimensions in order to align their mutual interference at the receivers. Most of the research has focused on developing algorithms for determining alignment solutions as well as proving interference alignment’s theoretical ability to achieve the maximum degrees of freedom in a wireless network. Cognitive radio, on the other hand, is a technique used to improve the utilization of the radio spectrum by opportunistically sensing and accessing unused licensed frequency spectrum, without causing harmful interference to the licensed users. With the increased deployment of wireless services, the possibility of detecting unused frequency spectrum becomes diminished. Thus, the concept of introducing interference alignment in cognitive radio has become a very attractive proposition. This paper provides a survey of the implementation of IA in cognitive radio under the main research paradigms, along with a summary and analysis of results under each system model.Peer reviewe

A Kosambi-Karhunen–Loève Learning Approach to Cooperative Spectrum Sensing in Cognitive Radio Networks

This paper focuses on the issues of cooperative spectrum sensing (CSS) in a large cognitive radio network (CRN) where cognitive radio (CR) nodes can cooperative with neighboring nodes using spatial cooperation. A novel optimal global primary user (PU) detection framework with geographical cooperation using a deflection coefficient metric measure to characterize detection performance is proposed. It is assumed that only a small fraction of CR nodes communicate with the fusion center (FC). Optimal cooperative techniques which are global for class deterministic PU signals are proposed. By establishing the relationship between the CSS technique design issues and Kosambi-Karhunen–Loève transform (KLT) the problem is solved efficiently and the impact on detection performance is evaluated using simulation.Peer reviewedFinal Accepted Versio

Spectrum Sensing of DVB-T2 Signals in Multipath Channels for Cognitive Radio Networks

© 2018 VDE VERLAG GMBHIn this paper, spectrum sensing of digital video broadcasting-second generation terrestrial (DVB-T2) signals in different fading environments with energy detection (ED) is considered. ED is known to achieve an increased performance among low computational complexity detectors, but it is susceptible to noise uncertainty. By taking into consideration the edge pilot and scattered pilot periodicity in DVB-T2 signals, a low computational complex noise power estimator is proposed. It is shown analytically that the choice of detector depends on the environment, the detector requirements, the available prior knowledge and with the noise power estimator. Simulation confirm that with the noise power estimator, ED significantly outperforms the pilot correlation-based detectors. Simulation also show that the proposed scheme enables ED to obtain increased detection performance in fading channels

Spectrum Sensing of DVB-T2 Signals using a Low Computational Noise Power Estimation

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted ncomponent of this work in other works.Cognitive radio is a promising technology that answers the spectrum scarcity problem arising from the proliferation of wireless networks and mobile services. In this paper, spectrum sensing of digital video broadcasting-second generation terrestrial (DVB-T2) signals in AWGN, WRAN and COST207 multipath fading environment are considered. ED is known to achieve an increased performance among low computational complexity detectors, but it is susceptible to noise uncertainty. Taking into consideration the edge pilot and scattered pilot periodicity in DVB-T2 signals, a low computational noise power estimator is proposed. Analytical forms for the detector are derived. Simulation results show that with the noise power estimator, ED significantly outperforms the pilot correlation-based detectors. Simulation also show that the proposed scheme enables ED to obtain increased detection performance in multi-path fading environments. Moreover, based on this algorithm a practical sensing scheme for cognitive radio networks is proposed.Peer reviewedFinal Accepted Versio

SOCIAL MEDIA TECHNOLOGIES AS DETERMINANTS TO INFORMATION SHARING AMONG LIS STUDENTS IN KWARA STATE UNIVERSITY, MALETE

This study examines social media technologies as determinants to information sharing among Library and Information science students in Kwara State University, Malete. This study adopts descriptive survey method of research design. The population includes the students of Library and Information Science, Kwara State University, Malete with population of 1431. The sample size was selected using Raosoft sample size table. However the study used simple random sampling technique with sample size of 304 while web-based questionnaire was used in the data collection. Link to the web-based questionnaire was shared on the different social media platforms of WhatsApp and Telegram of students. However, only 192 students responded to the questionnaire which represent 63% return rate. This is consider enough and accepted for the study. The study found out that majority of respondents use Facebook, Linkedln, WhatsApp and YouTube as social media technologies to share information. The study also revealed that LIS students in Kwara state university use social media technologies to share information on political, education, economic and entertainment. Finally, the study also revealed that inadequate power supply, lack of internet access, lack of proper maintenance of infrastructure and equipment and lack of enthusiasm on the part of instructors as challenges LIS students encountered in using social media technologies to sharing information in Kwara State University, Malete. The study recommends that Alternative power supply should be provided and training and workshop should be stage for students to have better skills on the use social media technologies

The Effect of Performance Management on Employee Productivity in Telecom Companies in Mogadishu Somalia

Somalia is currently in the midst of a telecommunications boom driven by private investors, who have created a mass market with the cheapest calling rates in Africa. Private investors have put an estimated $194 million into Somalia’s telecommunications sector over the last ten years. Despite all, it is believed that in Somalia, Lack of proper training, reward system, lack of recognition and feedback, are the main aspects that hinder the level of the employee’s productivity in Telecommunication Sector. Therefore, the objective of this study is to examine the relationship between performance appraisals, reward system, training, and employee productivity in telecom companies in Mogadishu Somalia. The respondents of this study were management staff of Hormuud, Somnet, and Somtel headquarters in Mogadishu Somalia. A total of 162 questionnaires were distributed to employees of these three companies by using an online survey, only 110 were useable for analysis. The data was analyzed using SPSS Version 25 to achieve the objectives of the study. The finding of this study has revealed that Performance Appraisal, Reward system, and Training have a positive and significant correlation with employee Productivity. Furthermore, the research framework of this study will contribute to the literature in the context of employee productivity. It will also help Hormuud, Somnet, and Somtel managers to have a further understanding of the correlation of performance appraisal, Reward system, and Training on Employee Productivity. Finally, some limitations have paved the direction for future research

Seroprevalence of Varicella Zoster Virus Infection among Primary school Children In Northern Nigeria

Background: Varicella Zoster infection occurs exclusively in man and commonly affects children with predilection for school age children. Following infection the course of the disease in immunocompetent children is often mild and self limited but in older age groups infection may be severe with poor outcomes ranging from complicating bacterial morbidities to death. In Kaduna State, Northern Nigeria the seroprevalence ofVaricella - zoster virus (VZV) infection is unknown The current cross - sectional study was conducted to assess the seroprevalence of VZV infection among nursery and primary school pupils in Kaduna State. Mathods: Nursery and primary school pupils between the ages 4 and 15 years were randomly selected from the three geopolitical zones of Kaduna State . Demographic data on each subject  were obtained by administration of a questionnaire and blood samples were collected for serum analysis of Varicella - zoster virus immunoglobulin G (IgG) using the Automat ion ELISA IgG Kit manufactured by Automation INC. USA. Data obtained were summarized using percentages and frequency tables. Results were analyzed using Epi- info version 3.0. Results: Three hundred and fifty three pupils were recruited for the study. The overall prevalence rate for VZV infection was 66.3% with the value in males being 68.5% and in females 63.9%. The prevalence of VZV infection increased with age in both sexes. A high percentage of children (60%) were seropositive at 4-6 years. Conclusion: The study shows a 66.3% prevalence of VZV infection among children in Kaduna State. Thi s high pr eva l enc e r a t e necessitates further studies to establish the burden of the problem in Nigeria and rationalize the institution of preventive measures against the infection, particularly immunocompromi sed young children

Pelatihan Kader dalam Rangka Pembentukan Forum Tangguh Cegah Stunting di Desa Dutohe Barat, Kecamatan Kabila, Kabupaten Bone Bolango

Hasil Studi Status Gizi Balita Indonesia (SSGBI) tahun 2019 menunjukan telah terjadi penurunan prevalensi Stunting dari 30,8% tahun 2018 menjadi 27,67% tahun 2019. Meski menurun, angka ini masih dinilai tinggi, karena angka toleransi WHO untuk Stunting sebesar 20 %. Kondisi ini diperberat dengan adanya pandemi COVID-19, yang menyebabkan banyak pemutusan hubungan kerja (PHK) sehingga pengangguran meningkat dan akibatnya daya beli masyarakat khususnya pangan menurun. Secara tidak langsung berdampak pada peningkatan kejadian Stunting.  Provinsi Gorontalo termasuk provinsi dengan jumlah penduduk muda yang signifikan. Sebanyak 395.000 orang atau 35 persen dari total penduduk di provinsi ini adalah anak-anak. Dua dari tiga anak tinggal di wilayah perdesaan. Gorontalo merupakan salah satu provinsi yang memiliki masalah Stunting di Indonesia. Pada tahun 2018 provinsi Gorontalo masih tinggi angka Stunting yaitu di Kabupaten Bone Bolango, angka prevalensi Stunting di Bone Bolango cukup tinggi, yaitu 25,1%. Angka itu masih di atas angka standar yang ditoleransi World Health Organization (WHO), yaitu di bawah 20%. Tujuan pelaksanaan KKN Profesi Kesehatan ini yakni terbentuknya kader kesehatan peduli stunting. Program KKN Profesi Kesehatan dilaksanakan selama 45 hari, bersama Dosen Pembimbing Lapangan dan 13 orang mahasiswa, diharapkan dapat menjadi solusi alternatif yang ditawarkan untuk meningkatkan kualitas pelayanan terhadap masyarakat, khususnya dalam bidang kesehatan dalam Percepatan Penurunan Stunting Di Kabupaten Bone Bolango. Hasil yang ditargetkan dalam program ini yakni meningkatnya produktifitas pengabdian dosen kepada masyarakat serta mendorong terwujudnya peningkatan derajat kesehatan masyarakat melalui kader Kesehatan sehingga memiliki kesiapsiagaan yang baik dalam menangani dan mencegah stunting.

Trypanocidal efficacy of two indigeneous ethanolic plant extracts (Mimosa pigra and Ipomoea asarifolia) against Trypanosoma evansi phospholipase A2 activity

AbstractObjectiveTo study the inhibitory activity of ethanolic extract from Mimosa pigra and Ipomoea asarifolia against Trypanosoma evansi (T. evansi) calcium dependent phospholipase A2.MethodsThe calcium dependent phospholipase A2 (E C 3.1.1.4) enzyme was isolated from T. evansi and purified to electrophoretic homogeneity under non denaturing conditions. It was solubilized from T. evansi cells recovered from white albino rats which were previously inoculated by intraperitoneal injection of infected camel blood. Two indigeneous ethanolic plant extracts used locally for treatment of trypanosomiasis were tested for the inhibition of phospholipases A2.ResultsDouble reciprocal plots of the initial velocity data of the inhibition by the indigenous plant extracts revealed a noncompetitive pattern of inhibition for the Ipomoea asarifolia and a competitive inhibition for Mimosa pigra in a dose dependent fashion. The extrapolated inhibition binding constant (Ki) of these extracts were found to be 2.0×102 μg/mL and 1.12×102 μg/mL respectively.ConclusionsThe low Ki values obtained for these extracts towards this enzyme are an indication of high affinity of the extract or the active components (present in the plants) are for these enzyme and therefore, could be explored to serve as a cheap source of T. evansi PLA2 antidote and as well help in designing a novel drug with high efficiency

Phytotherapy as an alternative for the treatment of human papilloma virus infections in Nigeria: a review

Human papillomavirus (HPV) has been incriminated as the causal agent of cervical cancer which has been rated as the second most common cancers among women in developing countries and seventh most common cancers in the developed world. In spite of the fact that HPV has been the major cause of cervical cancer, the dilemma lies in finding a cost-effective therapy. Approximately 291 million women are infected with HPV worldwide, 32% of whom are infected with HPV16 or HPV18. The estimated prevalence of HPV in sub-Saharan Africa is 24% and 11.7% globally. There have been studies reporting specific HPV prevalence rates in some part of Nigeria, with 37% in Abuja, 10% in Port Harcourt, and 26.3% in Ibadan. In the Nigeria population, awareness of HPV infections is low, HPV vaccines are inadequate, and the cost of HPV vaccination per person is beyond what an average citizen can afford. It has been suggested that herbal therapy such as Echinacea therapy reduces HPV replication and enhances the immune system. Although there is yet no scientific proof of the efficacy of Echinacea therapy against HPV infections, future emphasis should be placed on scientific research into this alternative therapy. There is need for more studies on development of antiviral agents against HPV, with a prospect of easy accessibility and affordability in Nigeria.Keywords: Phytotherapy; HPV; Cervical cancer; Nigeri