York University
Civil Engineering
This research evaluates air transportation safety in Nigeria. Records of aircraft crashes in Nigeria were extracted from different archives to create a database of air traffic incidences within the air space of Nigeria since Independence.... more
This research evaluates air transportation safety in Nigeria. Records of aircraft
crashes in Nigeria were extracted from different archives to create a database of air traffic
incidences within the air space of Nigeria since Independence. Statistical overview of air
transportation accidents in Nigeria using accident data to examine a national trend in air
transportation disasters was carried out. Results of the analysis showed that air traffic
accidents in Nigeria have increased per decade with 2 incidences between 1960 and 1969,
27 incidences between 2000 and 2009 with an increasing trend in the preceding decades.
Impacts of season on aircraft accident in Nigeria were less significant. Airplanes constitute
larger proportion of aircraft involved in accident with 86% incidences, and 14% for
helicopter. Passenger plane constitute the largest proportion with 46 incidences occurring
in the commercial plane category while 8 and 2 crashes occur in Military and Cargo
operation. Majority of the accidents in Nigeria occurred in Lagos with 14 crashes involving
plane majorly, followed by Abuja (FCT) and, Kano and Rivers with 4 each. Year 2005
however has the highest number of plane incidences in Nigeria with 11 crashes.
crashes in Nigeria were extracted from different archives to create a database of air traffic
incidences within the air space of Nigeria since Independence. Statistical overview of air
transportation accidents in Nigeria using accident data to examine a national trend in air
transportation disasters was carried out. Results of the analysis showed that air traffic
accidents in Nigeria have increased per decade with 2 incidences between 1960 and 1969,
27 incidences between 2000 and 2009 with an increasing trend in the preceding decades.
Impacts of season on aircraft accident in Nigeria were less significant. Airplanes constitute
larger proportion of aircraft involved in accident with 86% incidences, and 14% for
helicopter. Passenger plane constitute the largest proportion with 46 incidences occurring
in the commercial plane category while 8 and 2 crashes occur in Military and Cargo
operation. Majority of the accidents in Nigeria occurred in Lagos with 14 crashes involving
plane majorly, followed by Abuja (FCT) and, Kano and Rivers with 4 each. Year 2005
however has the highest number of plane incidences in Nigeria with 11 crashes.
The concrete mix ratio of 1:2:4. was prepared using water/cement of 0.65 with 0%, 25%, 50%, 75% and 100% sawdust as partial replacement for fine sand. The coefficient of uniformity and coefficient of curvature of the sand used in this... more
The concrete mix ratio of 1:2:4. was prepared using water/cement of 0.65 with 0%, 25%, 50%, 75% and 100% sawdust as partial replacement for fine sand. The coefficient of uniformity and coefficient of curvature of the sand used in this study was 1.049 and 1.324 respectively which shows that the sand is a well graded sand as it does not exceed the range of 1 and 3 for ; and maximum of 6 for specified by the British standard. The aggregate crushing value (ACV) obtained is 43.75 which is within the specified value of 45 as specified by the British standard (BS 812-110 1992). However, values of 40mm, 9mm and 5mm respectively was obtained for workability at 0%, 25% and 50% addition of sawdust as partial replacement for sand, while 14.15 N/mm 2 , 12.96 N/mm 2 and 11.93 N/mm 2 , were obtained for compressive strength with 25%, 75% and 100% sawdust as partial replacement. The Compressive strength values obtained were found not to conform to the minimum requirement of 17N/mm 2 for light weight concrete. Using sawdust in a proportion greater than 25% replacement of sand is however detrimental to strength and density properties of concrete.
The number of violent crimes and fatal-injury collisions concerns many jurisdictions. Traditional enforcement tactics are often reactive, relying on historical crime and collision data to select locations for law enforcement. Advanced law... more
The number of violent crimes and fatal-injury collisions concerns many jurisdictions. Traditional enforcement tactics are often reactive, relying on historical crime and collision data to select locations for law enforcement. Advanced law enforcement tactics take a proactive approach. Such tactics include Data-Driven Approaches to Crime and Traffic Safety (DDACTS), which uses predicted numbers of crimes and collisions to identify locations for law enforcement. This DDACTS study was conducted in Regina, Saskatchewan, Canada. The research developed macro-level prediction models to predict violent crimes and collisions in each traffic analysis zone (TAZ) in Regina. The zonal nature of the analysis is important for overcoming confidentiality and privacy issues associated with violent crimes and fatal-injury collisions. Fifty-four input variables were used to describe each TAZ's crimes, collisions, socio-demographic, road inventory, traffic, and land use characteristics. The analysis used negative binomial regression coupled with the empirical Bayes method (a popular approach in transportation, but relatively new to crime mapping) to develop two statistical models that predict the long-term mean value for the number of violent crimes/collisions per zone. Cumulative residual plots were used as the main goodness-of-fit test. The findings are summarized on a map showing the top ten hotzones for violent crimes, the top ten hotzones for fatal-injury collisions, and the zones where the crime and collisions zones overlap. The overlapping zones are the DDACTS zones. By focusing law enforcement in the DDACTS zones, it may be possible to reduce violent crimes and fatal-injury collisions simultaneously and use limited resources more cost effectively.
Transportation is an important part of campus life. The need to study the male-female differences in the choice of walking is essential in calibrating a robust travel demand model of the university environment. Subsequently, there is a... more
Transportation is an important part of campus life. The need to study the male-female differences in the choice of walking is essential in calibrating a robust travel demand model of the university environment. Subsequently, there is a need for a novel approach in the trip pattern of the university environment. This study assessed the Spatio-temporal commuting pattern in three universities in Nigeria, with a special focus on gender. Information sheets (n = 1500) were distributed to three categories of universities in Southwestern Nigeria: private university, State government-owned university, Federal government university. This was backed up with focus group discussions in the selected schools. We assessed the frequency of trips, trip distance, trip pattern, gender and the modal split of the respondents. Results showed that the female gender accounted for the highest frequency of trips, but the lowest frequency of long-distance trips. The results also revealed that distance, time, travel cost, comfortability and accessibility had a positive influence on the volume of trips. Pearson's Correlation of the variables was done and the Pearson's r value for distance was 0.844 and time, 0.77. The results showed a strong positive correlation for gender, as compared to the other variables, affecting trip-making. The research showed that gender difference influences the choice of mode and frequency of trips, which are essential variables in travel demand models.
We developed and tested geographically weighted Poisson regression and geographically weighted negative binomial regression models using five year's collisions, traffic, socio-demographic, road inventory, and land use data for Regina,... more
We developed and tested geographically weighted Poisson regression and geographically weighted negative binomial regression models using five year's collisions, traffic, socio-demographic, road inventory, and land use data for Regina, Saskatchewan, Canada. The need for geographically weighted models became clear when Moran's I local indicator showed that our study data contained statistically significant levels of spatial autocorrelation. Bandwidth is a required input for geographically weighted regression models. We tested fixed and adaptive bandwidths. We found that fixed bandwidth was more suitable than adaptive bandwidth in our study. Models that used fixed and adaptive bandwidth produced a wide range of parameters across zones. We think the wide range of parameters helped explain unobserved heterogeneity issues within the zones. To compare the geographically weighted Poisson and geographically weighted negative binomial models , we applied seven well-known goodness-of-fit tests. The results were inconsistent, but the cumulative residual plot developed for each model showed that the fixed bandwidth geographically weighted Poisson model and the geographically weighted negative binomial model were better at predicting collisions than were the adaptive bandwidth models. Based on the CURE plots obtained, we concluded that the geographically weighted negative binomial model with fixed bandwidth was the best model for our study data.
This study uses a data-driven approach to crimes and traffic safety (DDACTS) approach to identify hotzones where focused law enforcement can reduce the number of crimes and number of collisions simultaneously. The authors applied... more
This study uses a data-driven approach to crimes and traffic safety (DDACTS) approach to identify hotzones where focused law enforcement can reduce the number of crimes and number of collisions simultaneously. The authors applied macrole-vel (zonal-level) crime and collision prediction models that use geographically weighted negative binomial regression coupled with the empirical Bayes method. Unlike early work, this approach takes spatial correlation into account. Our models are based on 5 years (2009-2013) of zonal level data for the City of Regina, Saskatchewan's 244 traffic analysis zones. The authors used two response variables (total number of crimes and total number of collisions) and 18 explanatory variables. The explanatory variables include traffic volume, roadway, land use and sociodemographic data. The analysis identifies four DDACTS zones for total crimes and total collisions. These four zones cover only 1.4% of the City's area but account for 10.9% of expected total crimes and 5.8% of expected total collisions. The approach offers an impartial scientific procedure that identifies areas for targeted law enforcement and opportunities to increase the effectiveness and efficiency of limited law enforcement resources. KEYWORDS
The number of violent crimes and fatal-injury collisions concerns many jurisdictions. Traditional enforcement tactics are often reactive, relying on historical crime and collision data to select locations for law enforcement. Advanced law... more
The number of violent crimes and fatal-injury collisions concerns many jurisdictions. Traditional enforcement tactics are often reactive, relying on historical crime and collision data to select locations for law enforcement. Advanced law enforcement tactics take a proactive approach. Such tactics include Data-Driven Approaches to Crime and Traffic Safety (DDACTS), which uses predicted numbers of crimes and collisions to identify locations for law enforcement. This DDACTS study was conducted in Regina, Saskatchewan, Canada. The research developed macro-level prediction models to predict violent crimes and collisions in each traffic analysis zone (TAZ) in Regina. The zonal nature of the analysis is important for overcoming confidentiality and privacy issues associated with violent crimes and fatal-injury collisions. Fifty-four input variables were used to describe each TAZ’s crimes, collisions, socio-demographic, road inventory, traffic, and land use characteristics. The analysis use...
The concrete mix ratio of 1:2:4. was prepared using water/cement of 0.65 with 0%, 25%, 50%, 75% and 100% sawdust as partial replacement for fine sand. The coefficient of uniformity and coefficient of curvature of the sand used in this... more
The concrete mix ratio of 1:2:4. was prepared using water/cement of 0.65 with 0%, 25%, 50%, 75% and 100% sawdust as partial replacement for fine sand. The coefficient of uniformity and coefficient of curvature of the sand used in this study was 1.049 and 1.324 respectively which shows that the sand is a well graded sand as it does not exceed the range of 1 and 3 for ; and maximum of 6 for specified by the British standard. The aggregate crushing value (ACV) obtained is 43.75 which is within the specified value of 45 as specified by the British standard (BS 812-110 1992). However, values of 40mm, 9mm and 5mm respectively was obtained for workability at 0%, 25% and 50% addition of sawdust as partial replacement for sand, while 14.15 N/mm 2 , 12.96 N/mm 2 and 11.93 N/mm 2 , were obtained for compressive strength with 25%, 75% and 100% sawdust as partial replacement. The Compressive strength values obtained were found not to conform to the minimum requirement of 17N/mm 2 for light weight concrete. Using sawdust in a proportion greater than 25% replacement of sand is however detrimental to strength and density properties of concrete.