An Empirical Model for Information Retrieval System Evaluation: The User's perspective

The aspect of time has become an issue since computers were introduced into management studies and thus highlights the need for efficient paradigm that will enable easy access to information, with much ease. But this is not the case yet, since finding the desired search engine and learning how to use them for this purpose is still time consuming. The continued dominance of measures for use in the system-centered aspect of IR evaluation, which is weak for use in user-centered IR system evaluation process, remains a challenge. Therefore the purpose of this study is to present usable measures through using an empirical from user's perspective for use in the evaluation of IR system. The survey method, a robust multivariate mathematical model and the factor analytic method were experimented upon. Results showed that the model presented is promising concerning the challenges highlighted. Therefore user's own knowledge, experience and searching abilities could be harnessed and implicated in IR design and evaluation. This study therefore serves as a test bed and guide to studies in this area, which results could contribute immensely to the overall improvement of the system. However, more data and a larger sample size are required to verify the proposed model in future, with other extraction techniques

Geophysical and hydro-physicochemical evaluation of hand-dug wells near a dumpsite in Oyo state, Nigeria

Access to potable water has become a difficult task in many countries of the world including Nigeria. In Nigeria, the government is trying her best to make water supply available to the masses but till now this vision has never been accomplished. If those living in urban areas could not have access to water supply by government, what is the fate of the people living in rural areas? Therefore, exploitation of groundwater through the construction of hand-dug wells is a major source of drinking water for majority of the populace as many could not afford the high cost of drilling borehole. Many people construct these hand-dug wells without linings because they believe that groundwater is the safest water for consumption without considering the environment these wells will be sited and other factors regarding to its construction. The aim of this present study is to evaluate the groundwater resources at Aarada waste disposal site, Ogbomoso, Oyo State, Nigeria. An electromagnetic survey to locate leachate plumes migration pathways was conducted around Aarada refuse dumpsite, Ogbomosho, Oyo State, Nigeria using the VLFEM method. A total of seven VLF-EM profiles were carried out with length ranging between 60 to 150m. Hydrophysicochemical analysis was also conducted at the peak of the raining season on six water samples taken from six different hand-dug wells in the research area. The result obtained from the processed VLF-EM data revealed the presence of leachate (contaminant fluid) at the subsurface in the area. The water quality analysis report showed hazardously high values of Fe2+, Pb2+, Zn2+, Cu2+ and NO3 - to confirm the findings from the VLF-EM surve

Groundwater Contaminats’ Investigation at Aarada Waste Disposal Site Using Geophysical and Hydro-Physicochemical Approach.

A research on the impact of waste disposal site on groundwater resources was conducted around Aarada area, Ogbomosho, Oyo State, Nigeria using electrical resistivity (vertical electrical sounding) and hydro-physicochemical methods. This study was carried out to map the contamination patches at the subsurface and investigate the contamination level of the various hand dug wells situated in the area. A total of seven VES were carried out with length ranging between 80 to 130m. The hydro-physicochemical analysis was conducted at the peak of the wet season on nine water samples taken from nine different hand-dug wells in the research area. The result obtained from the interpreted VES data revealed leachate plumes at the subsurface in the study area. The outcome of the hydro-physicochemical method revealed hazardously high values of Fe2+, Pb2+, Zn2+, Cu2+ and NO3 - to further support the findings from the VES surve

Interpretation of groundmagnetic data in Oke-Ogba Area, Akure, Southwestern Nigeria

Groundmagnetic method was used to delineate into the subsurface in Oke-Ogba area, Akure, which falls within latitude 070 14′ to 070 19′ North and longitude 0050 06′ to 0050 12′ East Southwestern Nigeria, with a view to determining the competent areas for engineering purposes and the promising areas for hydrogeologic prospects. A total of four traverses were established for the purpose of the groundmagnetic study, and the results were presented as groundmagnetic profiles of varying magnetic intensities. The result of investigation revealed that the intensities and characteristics nature of the magnetic anomalies as expressed by all profiles are indicative of the different rock types producing them. Qualitative and quantitative interpretation of individual magnetic anomaly and geological knowledge of the survey area yielded information on the depth of geological features (e.g. rock contact, faults or fractures), structures and magnetic properties of rock units. From the preliminary interpretation, the existence of some structural features such as a likely fault, fracture and contacts between rocks as well as relatively mineralized zones that might contain magnetic minerals of essential magnetite origin is revealed. It was also revealed that Oke- Ogba area, Akure, Southwestern Nigeria is averagely competent for both engineering purposes and hydrogeologic purposes

IMPACT ASSESSMENT OF SOLID WASTE ON GROUNDWATER: A CASE STUDY OF AARADA DUMPSITE, NIGERIA

A research on the impact of waste disposal site on groundwater resources was conducted around Aarada refuse dumpsite, Ogbomosho, Oyo State, Nigeria using electrical resistivity (Vertical Electrical Sounding) and hydrophysicochemical methods. World Health Organization (WHO) standard was used as yard stick for the hydrophysicochemical method. A total of seven VES were carried out with electrode spacing ranging between 80 to 130m. The hydro-physicochemical analysis was conducted at the peak of the dry season on nine water samples taken from nine different hand-dug wells in the research area. The result obtained from the interpreted VES data revealed leachate plumes at the subsurface in the study area. The outcome of the hydro-physicochemical method revealed hazardously high values of Fe2+, Pb2+, Zn2+, Cu2+ and NO3 -

GROUNDMAGNETIC INVESTIGATION INTO THE CAUSE OF THE SUBSIDENCE IN THE ABANDONED LOCAL GOVERNMENT SECRETARIAT, OGBOMOSO, NIGERIA

Groundmagnetic was used to investigate the cause of the subsidence at an Abandoned Local Government Secretariat, Ogbomoso, Southwestern Nigeria with a view to determining whether the sinking and cracks in the plasterworks experienced at the Eastern side of the study area is due to subsurface features or insufficient use of building materials. The study took place at an Abandoned Local Government Secretariat Ogbomoso, Southwestern Nigeria which falls within latitude 080 09′ 50.6″ - 080 09′ 55.9″ and longitude 0040 15′ 36.1″ - 0040 15′ 42.3″. Proton Precision Magnetometer model GSM-19T was used to carry out the geophysical survey along four traverses in East-West and North- South directions. The traverses length ranges from 70m to 150m with inter station spacing of 10m. The results were presented as groundmagnetic profiles of varying magnetic intensities, groundmagnetic contoured map and groundmagnetic surface map. The basement topography was obtained from the profiles using half-width of the amplitude method. Areas with high magnetic values are the competent zones for construction while areas with low magnetic values are the weak zones. The quantitative interpretation gave the overburden thickness to the top of the magnetic basement rock as varied between 7.0m to 13.0m. Interpretation of groundmagnetic data revealed that the weak zones present at the Southeastern, Eastern and Northeastern part of the study area are the cause for the subsidence that occurred towards the Eastern side of the building. Contrary to the opinion of people that the building contractor used inferior building materials for the construction, we found out that half of the building is constructed on either collapse tunnel, fault or fracture which resulted into the sinking and new cracks in plasterworks experienced at the Eastern part of the abandoned Local Government secretariat

The groundwater potential evaluation at industrial estate Ogbomoso, Southwestern Nigeria

Vertical Electrical Sounding method was used to map Oyo State industrial estate Ogbomoso with a view to determining the groundwater potential of the study area. Ten Vertical Electrical Soundings (VES) were carried out across the area using the schlumberger electrode array configuration with current electrode separation (AB) varying from 130 m to 200 m. Nine out of the ten modeled curves were H-type where the remaining one was KH-type. The geoelectric sections obtained from the sounding curves revealed 3-layer and 4-layer earth models respectively. The models showed the subsurface layers categorized into the topsoil, weathered/clay, fractured layers and the fresh bedrock. The weathered basement and fractured basement are the aquifer types delineated for the area. Groundwater potential evaluated from the maps (i.e. overburden thickness, anisotropic coefficient, weathered layer isothickness, weathered layer isoresistivity, transverse resistance and bedrock relief maps) revealed that the Southern and Eastern parts of the study area are the most promising region for borehole development. However, Northeastern region of the study area can also be considered as fair for borehole development

RESTORING TONE-MARKS IN STANDARD YORÙBÁ ELECTRONIC TEXT: IMPROVED MODEL

Diacritic Restoration is a necessity in the processing of languages with Latinbased scripts that utilizes letters outside the basic Latin alphabet used by English language. Yorùbá is one such languages, marking underdot (dot-below)on three characters and tone marks on all seven vowels and two syllabic nasals. The problem of restoring underdotted characters has been fairly addressed using character as linguistic units for restoration. However, the existing characterbased approaches and word-based approach has not been able to sufficiently address restoration of tone marks in Yorùbá. We address in this study tone marks restoration as a subset of diacritic restoration.We proposed using the syllable (derived from word) as the linguistic token for tone marks restoration. In our experimental setup, we used Yoruba text collected from various sources as data with total word count of 250,336 words. These words, on syllabification, yielded 464,274 syllables. The syllables were divided into training and testing data in different proportions ranging from 99% used for training and 1% used for testing to 70% used for training and 30% used for testing. The aim of evaluation different proportions was to determine how the ratio of training-to-test data affect the variations that may occur in the result. We applied Memory-based learning to train the models. We also set up a similar experiment using character token to be able to compare the performance.The result showed that using syllable was able to increase accuracy at word level to 96.23% and an average of almost 15% over that gotten from using character. We also found out that using 75% of data for training and the remaining 25% for testing gives the results with the least variation in a ten-fold cross validation test. Hybridizing the syllable „based approach with other methods like lexicon lookup might likely lead to improvement over the current result

Geophysical Investigation for Groundwater Development at Oyo State Housing Estate Ogbomosho, Southwestern Nigeria

Water is life because it is one of the inevitable ingredients for life survival. The urge for ground water development is very high in Oyo state Housing Estate, Ogbomosho, Southwestern Nigeria. Because the site is experiencing structural developments and there is no other source of water nearby. Surface water is becoming inadequate, thus this study aimed at investigating the hydro geological prospects of the area with a view to delineating for groundwater and its development. Geophysical investigation was carried out in the study area using Very Low Frequency (VLF) method. VLF profiling of 20 m inter stations and 50 m of inter profiling distances were established. This study revealed a number of conductive zones for ground water development for both domestic and commercial purposes