Development of Hotzone Identification Models for Simultaneous Crime and Collision Reduction

This research contributes to developing macro-level crime and collision prediction models using a new method designed to handle the problem of spatial dependency and over-dispersion in zonal data. A geographically weighted Poisson regression (GWPR) model and geographically weighted negative binomial regression (GWNBR) model were used for crime and collision prediction. Five years (2009-2013) of crime, collision, traffic, socio-demographic, road inventory, and land use data for Regina, Saskatchewan, Canada were used. The need for geographically weighted models became clear when Moran's I local indicator test showed statistically significant levels of spatial dependency. A bandwidth is a required input for geographically weighted regression models. This research tested two bandwidths: 1) fixed Gaussian and 2) adaptive bi-square bandwidth and investigated which was better suited to the study's database. Three crime models were developed: violent, non-violent and total crimes. Three collision models were developed: fatal-injury, property damage only and total collisions. The models were evaluated using seven goodness of fit (GOF) tests: 1) Akaike Information Criterion, 2) Bayesian Information Criteria, 3) Mean Square Error, 4) Mean Square Prediction Error, 5) Mean Prediction Bias, and 6) Mean Absolute Deviation. As the seven GOF tests did not produce consistent results, the cumulative residual (CURE) plot was explored. The CURE plots showed that the GWPR and GWNBR model using fixed Gaussian bandwidth was the better approach for predicting zonal level crimes and collisions in Regina. The GWNBR model has the important advantage that can be used with the empirical Bayes technique to further enhance prediction accuracy. The GWNBR crime and collision prediction models were used to identify crime and collision hotzones for simultaneous crime and collision reduction in Regina. The research used total collision and total crimes to demonstrate the determination of priority zones for focused law enforcement in Regina. Four enforcement priority zones were identified. These zones cover only 1.4% of the Citys area but account for 10.9% of total crimes and 5.8% of total collisions. The research advances knowledge by examining hotzones at a macro-level and suggesting zones where enforcement and planning for enforcement are likely to be most effective and efficient

Investigation of Properties of Concrete Using Sawdust as Partial Replacement for Sand

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/mm2, 12.96 N/mm2 and 11.93 N/mm2, 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/mm2 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. Keywords: Sawdust, Concrete, Workability, Aggregate Crushing value, Compressive strength

Post-Independence Evaluation of Air Transport Safety in Nigeria

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 crashe

SPATIO-TEMPORAL COMMUTING PATTERN IN THE UNIVERSITY ENVIRONMENT: A GENDER PERSPECTIVE

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 university 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