Adeseko A. Ayeni

ON THE STUDY OF EMPIRICAL PATH LOSS MODELS FOR ACCURATE PREDICTION OF TV SIGNAL FOR SECONDARY USERS

Demand for wireless communication technologies and systems keep increasing and has reached the peak where the capacity can only be achieved by improving spectrum utilization. The spectrum allocated to TV broadcast systems can be shared by wireless data services through exploiting spatial reuse opportunities (Spatial TV white space). Path loss models are used extensively in signal prediction, coverage optimization and interference analysis. Recently it is being used in estimating distances for safe operation of secondary users in TV white space. Peculiarities of these models give rise to high prediction errors when deployed in a difierent environment other than the one initially built for. It is however not very clear which model gives the best flt and what the penalties are for using the models outside the intended coverage area. In this paper, we assess the fltness of nine empirical widely used path loss models using flve novel metrics to gauge their performance. In order to achieve this, fleld strength measurements were conducted in the VHF and UHF regions along six difierent routes that spanned through the urban, suburban and rural areas of Kwara State, Nigeria. A program was developed in VB 6.0 language to compute the path losses for the empirical models. The measurement results were converted to path losses and are compared with the models prediction. The results show that no single model provides a good flt consistently. However, Hata and Davidson models provide good fltness along some selected routes with measured RMSE values of less than 10dB. ITU-R P.1546-4, Walflsch Ikegami (WI),

Error bounds of empirical path loss models at VHF/UHF bands in Kwara State, Nigeria

Propagation models are used extensively in signal prediction and interference analysis. Peculiarity of these models gives rise to high prediction errors when deployed in a different environment other than the one initially built for. In this paper, we provide the error bounds on the efficacy at predicting path loss for 10 empirical widely used path loss models. The results show that no single model provides a good fit consistently. However, Hata and Davidson models provide good fitness along some selected routes with measured RMSE values of less than 8 dB. ITU-R P.1546-3, Walfisch Ikegami, ECC, Egli, CCIR and FSPL perform woefully, with higher RMSE and SC-RMSE (Spread Corrected RMSE) values. In terms of mean value errors, Hata, Davidson and ITU-R P.5293 models give mean values close to zero. However, COST 231 also provides better skew, while CCIR and ECC gives fair results but ITU-R P. 1546, WI and FSPL give worst results. The prediction errors for Davidson are nearly distributed symmetrically around the mean error of 2.15 dB. It was also observed that, the Gaussian error distribution within the window of ±5 dB dominates the frequency counts. However, the error counts for CCIR model are quite high but spread along the distribution but HATA, FSPL, Walfisch Ikegami and ITU-R P. 5293 models does not follow normal distribution.

Improved path-loss model for predicting TV coverage for secondary access

Path-loss model is essential for proper planning of emerging technologies in the broadcast frequency band. Characterisation of the radio channel is paramount for accurate prediction of TV coverage, and achievement of peaceful coexistence between the TV (primary users) and other new infrastructures (secondary users). In this paper, field strength measurements are conducted along six routes that spanned through urban, suburban and rural areas of Kwara State, Nigeria. The measurement results are compared with path-loss prediction of eight widely used empirical models. Least squares and linear iterative methods are employed to optimise Hata-Davidsons model, as it showed best fit compared with other models. The predictions of the tuned model are compared with other models in terms of relative error, mean error, skewness, root mean square errors and normalised error probability density function. Results of the simulations indicate that the optimised model gives better values for the metrics considered.

DTV coverage and protection contour estimation for spatial white space

TV white spaces are vacant, unused or interleaved frequencies located between broadcast TV channels in the VHF/UHF range, which can be found between 54 MHz and 806 MHz. Utilization of these vacant channels has become a major challenge since the idea of cognitive radio (CR) technology, which aims to exploit the available TV white space may not be guaranteed for deployment at the present stage. This calls for alternative spectrum management models and techniques that would allow efficient utilization of the TV white space. In this work, we develop an algorithm that predicts the service contour and makes decision on the availability of the white space. The algorithm recovers the region outside global no-talk zone of the primary user. Results of simulation show that the amount of white space recovered depends on the threshold rule applied. It was also found that the keep-out-distance varies as a function of the operating frequency and the propagation characteristics of the area.

IMPACT OF EMPIRICAL PATH LOSS MODELS ON SPATIAL TV WHITE SPACE UTILIZATION

The study determined the frequency of practice of the health care waste management practices on segregation, minimization, collection, storage, transport, disposal and treatment in the hospitals in Tabuk City. The study utilized a descriptive cross-sectional design. Interviews and ocular surveys/on-site observation, and the interviewer-administered questionnaire were utilized to gather data from the head nurse, waste handler during collection, waste handler during transport and waste manager. Data collected were treated using a five point Likert scale, and quantified using the frequency count, ranking, percentage and the Weighted Mean. The revealed that the health care wastes management practices are sometimes implemented in the hospitals in Tabuk City; segregation of wastes was generally often practiced, however, the use of plastic bags/plastic-lined cardboard boxes/leak-proof as containers of infectious and pathological wastes was seldom practiced. Waste minimization was often practiced, but composting was seldom practiced. Waste collection was sometimes practiced, but the collection of general wastes every shift and collection of biohazard wastes every shift was seldom practiced by the respondents. Waste storage and waste transport were sometimes practiced by the hospitals; but labeling properly all bags/containers with basic information of content, written or attached on the bag, and using transport vehicles exclusively for HCW were never practiced. Waste disposal was sometimes practiced, but offsite disposal exclusively for HCW was never practiced. Waste treatment was seldom practiced. Treating HCW before disposal, onsite treatment and using chemical disinfection as a type of treatment were seldom practiced while categorizing HCW when treating and treating wastewater prior to discharge off-site” were never practiced. From the conclusive results, the following recommendations were formulated: There is a need for the DOH to monitor regularly the management of health care wastes in each hospital 1. For waste segregation, in the use of labels and color coding scheme, all body fluids and excreta should be disposed in the infectious category. 2. Waste minimization through source reduction and recycling not only of plastics but also other recyclable materials such as papers 3. Strengthen the practice of composting 4. Due to the lack of appropriate storage area, collection and transport of biohazard waste should be done daily. 5. The city government should propose a separate disposal site for all healthcare wastes and set limit to public access to decrease the risk of infectious diseases 6. Burial pits should be lined with material of low permeability, such as clay, to prevent groundwater contamination. However, burial pits are recommended if they are located within the premises of the establishment. Encapsulation is the best method for disposal of sharps and should be practiced. 7. Waste treatment should be done to all infectious wastes. 8. The KASC Midwifery Department can initiate and conduct education and information campaign (IEC) for the hospital personnel, patients and guests at least once a yearMICROMEGAS (MICROMEsh GAs Structure) detector which is among the major families of position detectors in High Energy Physics, introduced in the late sixties, detects and localizes energy deposit by charged particles over large areas, is widely used in particle physics. This detector is in a sealed in which mixture gas circulates. This mixture usually based, on a noble gas and a few proportions a “quencher”. In this paper, we use 55Fe source that produces X-ray photons of 5.9 keV and a mixture gas on Argon (Ar) with quencher as isobutane (iC4H10) and dimethyl-Ether. We will present the results of the MATLAB simulations of MICROMEGAS performance taking into account all the processes from the primary ionization, the distribution of charges in the electrodes and the electron avalanche amplification (first Townsend coefficient and amplification gain). All the simulated results obtained indicate that the performances of the detector depend on many parameters. The simulation results are nearly consistent with the data that are published in other references, and provide important information in the MICROMEGAS design, making and operating. Our simulation predicts that further improvements are still possible for give a best spatial and temporal resolution for a MICROMEGAS detector.At the beginning the article focuses on general thematic considerations und explains why the implementation of approaches towards innovation management of public administrations into the private sector can be regarded as a reasonable aim. Furthermore, the underlying basic hypotheses are being established. Afterwards, the individual steps of a generally applicable implementation model will be described in detail and additional considerations on implementations and instructions on the course of action will be provided. At the end of each process that has been realized this way, a structured evaluation of the implemented methods and actions will be conducted. On the basis of a specific instruction on the course of action the article describes a generally usable model with the necessary work stages, instruments and required accompanying measures.The aim of this paper is to give a general view of the history of “Llaiko Vima” newspaper of the Ethnic Greek Minority in Albania from the year 1945-2012 in which will be mentioned the general characteristics of “Llaiko Vima” newspaper and mainly its purpose, its publishing team, its circulation, its personality and its ideology, the ideological action frame of its correspodents, its economics and circulation.Insurance, which was created in the early centuries, is of great interest even today. As a result, private insurance had to be distinguished. A great part of society is interested in protecting property. The basic of insurance must be juridical connection of subjects and people that was called insurance title. In the conditions of modern life, it is necessary for a person to be insured.Egypt has witnessed several waves of Armenian immigration through history particularly during the Ottoman era in Egypt and Arab world from the sixteenth century until the nineteenth century. After years of settlement and immigration, the Armenian minority became part and parcel of the multi-ethic/multi-cultural Egyptian society. Due to their commitment and dedication, the Armenians gained a reputation as experts in the fields of business and commerce244. This paper investigates the effect of this immigration on Egypt in the 19th century and the participation of the Armenian people in Mohamed Aly’s civilizational project which put Egypt on the map of the modern world. The paper will explore the significant role, played by Boghos Yosefyan, the central political and economic advisor of Mohamed Ali, in the development of the Egypt Renaissance. Based on the mutual correspondences (and letters) between the two parties (Mohamed Ali and Boghos) in addition to other historical documents, pursued in the Egyptian historical Archive, this study traces the nature of the role played by Boghoss Yosefyan in the construction of the Egyptian Renaissance during the first half of the nineteenth- century.The article considers the problems of conducting women nature research. The author offers to study women social behavior by reading fiction by Kazakh women writers. The author of the paper supposes that by analyzing Kazakh authors’ literature it is possible to find out problems that Kazakh women faced in the families, society, business, etc.Ten years have passed since the resources of the second tier- Mandatory State Funded Pension Scheme- have been transferred to the private fund managers. The second tier has started to pay accumulated capitals to the participants of pension schemes in 2013; therefore the aim of this paper is to assess the contribution of the private fund managers to the accumulation of the above-mentioned capitals.The amount of money accumulated on the second tier account depends on the amount of shares and their value. The last factor is the most considerable and it depends on the performance of investments made by the private fund manager. Profitability is one of the main indices for assessing the gain derived from the participation in the Mandatory State Funded Pension Scheme. For the analysis of profitability 26 pension plans have been divided into different groups. Then the authors have analyzed the following indices: profitability of 26 pension plans in different years and during the whole existence period; profitability depending on the declared risk of pension plan, its assets value and operation duration; deviation of profitability for all plans and for different groups of plans with similar declared risks, assets value and operation duration.The conclusions about the distinctions between the profitability of plans with different risks, assets and existence duration have been drawn. On the basis of conclusions the authors have estimated the contribution of the private fund managers to the accumulation of pension capital in the second tier of Latvian pension system.In the concluding remarks of the paper the authors have made proposals for increasing the contribution of private fund managers to the accumulation of capital in the Mandatory State Funded Pension Scheme.The subject of a surrogate motherhood in Georgia is no longer banned in Georgia at present. There are a lot of discussions currently occurring in the society. Moreover, medical technologies have gone even further and become more efficient in this respect. Therefore, these programs have become more popular all over country. People, who formerly tried to adopt children, now think of acquiring children through this particular method, which they would be genetically bound to.The article is devoted to the political and legal aspects of international cooperation against spectator violence and misbehavior at sports. The measures taken by the states and international intergovernmental and non-governmental organizations to maintain public order to prevent the acts of violence and misbehavior at sports is reviewed, as well as cooperation coordination problem on these issues at the national (the level of ministries, governmental agencies and sports organizations) and international levelsDefining demand at a national level is problematic in terms of the total volume of the structure, as to the performance of transnational corporations. Reviving of unemployment can not only be assessed at the national level, but an important aspect affecting national labor market is the revival of global economy which leads to the growth of the global labor needs. Currently, the focus of new jobs is shifting from partial professions towards cross-cutting and systemic professions, which must give a comprehensive response to developments in a particular industry. Slovakia is a small market economy significantly tied to major European economies, dominated by linkage to the German economy. Due to the high openness of the economy, the crisis has significantly affected the rate of growth of countrys performance and caused a drop in demand, a decrease in both production and unemployment. High unemployment in this period was related to revenue shortfalls in the state budget and deepening of the budget deficit.The compiling of Greek - Albanian and Albanian - Greek dictionaries after the 90’s has been a necessity due to the contacts which were established between the Greek and Albanian people after the fall of Communism in Albania and after the Albanian people came out of the half- century isolation. The efforts for compiling bilingual dictionaries during this period have been very important although there didn’t exist models which could be used to compile such dictionariesThe searches for solution to overcome the problems of prevention and deviant behavior in teenagers have focused our attention on the concept of personality-oriented approach in learner - centered education. In the psycho-pedagogical science it is established to be quite clear criteria that reveal the essence of deviant behavior of juveniles (teacher isolation, maladjusted, delinquency, instability of values, psychological aggression, social passivity, increased anxiety, conflictprone). The study of the etiology of deviant behavior allows the scientists to isolate the multiplicity of factors that produce such behavior. Causes of deviant behavior of teenagers is a pedagogical isolation, indocileness, tortfeasor, instability of value orientations, psychological aggression, social passivity, increased anxiety, conflict potential.The given article deals with the interests towards fit of passion of murder in the Science of Criminal Law of Georgia which already exists for a long time. It is stipulated by two causes: firstly, by permanent necessity towards investigation – judiciary practice which demands precise criteria of qualification of the act; secondly, by essential changes of criminal law doctrine in Georgia which caused working out of the new approach towards the problem of guilt. Consequently, Georgian scientists had to review a whole range of conceptions which did not answer demands of the present day. It is clear that due to complexity of the issue, it is hard to discuss approach of all conceptions in one article. We shall light briefly peculiarities of approach of Georgian scientists towards some conceptions. We should single out only so called argumentations of estimation for criminal and subject conceptions of psychological crime of guilt.Thу article describes one of the modern problems – political condition of international relations, relations between nations and inter-ethnical consent. The authors analyze the experience of Kazakhstan and Germany in ethnic politics, explore the importance of these issues in the world today.In modern conditions of oil and gas functioning there is exigency in search of field reserves of development at the expense of rational use of investment resources and efficient realization of investment projects. In the present situation such tasks solution is possible only in the framework of strategy development of component parts of the complex, including efficient attraction of foreign investment and mechanisms formation of its use.The availability of solar energy and its use for heating sanitary water is a resource that has been used since ancient times. However, current technologies allow optimization and its widespread use. In the project carried out by the National University of General Sarmiento (UNGS), it has designed an experimental system hybrid solar concentrator unit for heating water for sanitary use. This project was intended as a complement to traditional water heating for domestic use , based on a parabolic concentrator . The system was designed so that it can be used in existing conventional facilities or be installed as the primary system for heating water.All components are within the structure of the base parabolic concentrator, which allows transport and fixation. The proposed project conserves the energy consumption of a traditional water heater, develop applications and combine existing technologies in a solar tracking parabolic concentrator, so to optimize its operation. Not used the traditional flat panel, but experimented with a heat exchanger mounted in the focal zone of the concentrator. One of the main objectives of this project was to arrive at a design of an integrated product that contains all the necessary elements for operation in a single platform. This adjusted the designs and location of components achieving optimal layout of the facility, giving greater freedom in the design development and implementation of design concepts. This system will allow conventional energy saving which is normally used for purposes of domestic water heating, but plans to integrate these conventional systems. That is why we speak of a hybrid system, which uses solar energy and conventional energy (electricity or gas). Considering the average consumption that occur in a house with four people, this system can replace between 45% and 91% of the energy used for water heating use , depending on time of year and considering its application in the Argentina northwestern area. The components were sized according to the proposed operating conditions. In the case of solar energy utilization, the analysis was extended to different geographic locations of the country, analyzing performance and selecting different areas favorable for the implementation of the system. This project will lay the foundation for the future development of associated projects conducted by researchers and students of the university, such as the study of the control loops, the solar tracker system development and the possible construction of a prototype, for academic use.For nearly a decade, a significant amount of research, investigations, and scandals in mass media has produced a new understanding about the threat of violence in penitentiaries and the changing the international approaches to this phenomenon. Experience has shown that almost no country is immune from practices that amount to torture and ill-treatment. In the article author explores the reasons and scope of torture in the law enforcement and penitentiary systems of Georgia. Particularly author analyzed: reasons for the torture of the accused offenders on the stage of preliminary investigation; violence as a result of overcrowding in closed correctional facilities public policy and investigation of torture; and reasons for the use of force in prisons.

Performance analysis of empirical path loss models in VHF & UHF bands

In this work, signal path loss prediction from nine different empirical path loss models were statistically compared with those measured from four television transmitters along five routes that span through urban and rural environments of Osun State, Nigeria. In this respect, results obtained show that both Hata and Davidson prediction models provide best fit prediction consistently along the five measurement routes with 90% to 98% prediction accuracy, Ilorin, CCIR, Cost 231, Ericsson 9999 and ECC-33 show prediction accuracy within the range of 65% to 80% while SUI and Okumura models offer prediction accuracy within the range of 15% to 21%. Generally the results show that Davidson and Hata models have better results in all the five routes examined. SUI and Okumura models show the least performance results.