Balogun, Oluwatimilehin B.1, and Osazuwa Isaac B.2
Physical geodetic survey of the Nigeria landmass was undertaken with the aim of furnishing engineers and scientists with vital geodetic information which have not been adequately available but required for the development of a standard national economic framework. The basic data used for the study were the absolute gravity field values, and the recorded coordinates and elevations at the Primary Gravity Network of Nigeria (PGNN) base stations. The absolute gravity data were processed using the appropriate mathematical and computational procedures to deduce geodetic information which include geoid undulation, height above the geoid, deflections of the vertical, distance from the earth’s centre of mass to the reference ellipsoid and geoid, and the gravity potential value at the geoid. Comparison was also made between the WGS’84 and the geoid in the study area. Geoid undulations were found to range from 16.53 to 28.35 m and the deflections of the vertical ranged between 0.738685 to 10.28328 arc second. Height above the topography ranged from -16.38 m in Warri to +1257.13 in Jos. The distance from the earth’s centre of mass to the WGS’84 reference ellipsoidal surface was maximum at Oron (6377988.04 m) and least at Illela (6376941.31 m). Similarly, the distance from the earth’s centre of mass to the geoid was also maximum at Oron (6378008.39 m) and minimum in Illela (6376961.659 m). The interpolation of the distances from the earth’s centre of mass to the spheroidal surface at each base station gave the definition of the WGS’84 ellipsoid over the continental Nigeria landmass while the interpolation of the distances from the earth’s centre of mass to the geoidal surface gave the definition of the geoid over the continental Nigeria landmass. The average gravity potential at the geoid was evaluated as 62375050.41 m 2 s -2 . The geoid over the continental Nigeria landmass was found to be comparably smooth as the WGS’84 ellipsoid over the region though they differ in terms of vertical separation. The quantitative difference in mGal corresponding to the vertical separation between the WGS’84 reference ellipsoid and the geoid was computed as 6.8042 mGal. The values of the deflections of the vertical at each station of the PGNN gave the angular correction to be applied when combining satellite-based ellipsoidal measurements and geoid-based physical geodetic measurement. Based on the significant range of the deflections of the vertical across the continental area of Nigeria, it was concluded that the physical structure of the lithosphere beneath the study area must be highly complex and heterogeneous.
Physical geodetic survey Primary Gravity Network of Nigeria (PGNN)geoid undulationsdeflections of the vertical
F. A. Kasali, J. A. Balogun, O. D. Adekola et al. (4 contributing authors)
In the education sector, constructing a personalized timetable is an important aspect that should be given uppermost priorities when it comes to academic planning and implementation. Basically, in most schools, the timetable is done to encompass all courses, segregation only comes in departmentally, by faculty or by programs being studied by the students involved. This could be cumbersome especially for schools with numerous programs, departments or faculties as students and faculty members have to glance through such complex timetables before they are able to map out theirs. This could lead to resource wastage in terms of time, misinterpretation by students involved, clashing of courses being taken by students, poor utilization of available venues amongst other issues. In other to proffer solutions to some of the identified problems, a personalized and user-centric timetable system was designed for the College of Basic and Applied Sciences (CBAS), Mountain Top University, Ogun State, Nigeria. System design was specified using unified modeling language (UML) diagrams such as use-case, sequence and activity diagrams. The system was implemented using mobile application development technologies. The android based timetable system presented an administrative module who could schedule lecture periods, specify time amongst other constraints and overall management of course scheduling based on courses registered for by the students. Evaluation of the system was done using Post Study System Usability Questionnaire (PSSUQ) version 3 measuring tool and analysed using descriptive statistics with SPSS version 21. One hundred and twenty five (125) participants were chosen randomly and purposefully for the study. Results of analysis gave the perceived satisfaction score as 2.56, system usefulness with 1.98, information quality with a mean score of 2.72 while interface quality performed the lowest with a mean score of 3.19 since in PSSUQ analysis, the higher the mean score, the poorer the performance. The timetable system was basically designed to reduce the problem of accessibility and better convenience especially on the part of the students. Future works would also consider a fully automated system with the use of scheduling algorithms and the integration of examination and invigilation scheduling in the same system.
J. A. Balogun, F. A. Kasali, O. D. Adekola et al. (5 contributing authors)
Hepatitis C is an infectious disease caused by the hepatitis C virus and it primarily affects the liver. Hepatitis C often leads to liver disease and occasionally cirrhosis while in some cases, those with cirrhosis will develop complications such as liver failure. This study was aimed at developing a classification model for the classification of the survival of patients living with hepatitis C. The study collected data containing 19 attributes and 155 records from an online repository created by UCI machine learning repository following which C4.5 decision trees algorithm was adopted for developing the classification model. The results of the study showed that the decision tree is suitable for developing the classification model because of its structural representation of the classification of the survival of Hepatitis C disease. The evaluation of the model simulation process showed that the best performance using the percentage split was achieved using 90 percent for training and 10 percent for testing with an accuracy of 86.67% while using the k-fold cross validation was achieved using 10-fold with an accuracy of 83.87%. Overall, the best performance was achieved using 90 percent of the dataset for training and 10 percent for testing owing for an accuracy of 86.67%. The results also showed that a number of variables were extracted from the initially identified variables and were deemed more relevant for the classification of survival. The study concluded that the If-Then rules which were extracted from the decision tree proved effective in providing decision-support to experts due to its simplicity in interpretation thus mitigating deaths associated with hepatitis C disease.
Hepatitis Cclassification modelingsurvival classificationdecision trees algorithm.
