Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : regression analysis


Forecasting the Final Cost of Iraqi Public School Projects Using Regression Analysis

Zeyad S. M. Khaled; Qais Jawad Frayyeh; Gafel Kareem Aswed

Engineering and Technology Journal, 2015, Volume 33, Issue 2, Pages 477-486

The actual final cost of public school building projects, like other construction projects, is unknown to the owner till the final account statement is prepared. An attempt to predict the final cost of such projects before work starts, using backward elimination regression analysis technique is carried out. The study covers two story (12 classes) school projects awarded by the lowest bid system. Records of (65) school projects completed during (2007-2012) are employed to develop and verify the regression model. Based on experts ‘convictions, nine factors are considered to have the most significant impact on the final cost. Hence they are used as model input parameters. These factors are; awarded bid price, average bid price, estimated cost, contractor rank, resident engineer experience, project location, number of bidders, year of contracting, and contractual project duration. It was found that the developed regression model have the ability to predict the final cost (FC) for school projects, as an output, with a very good accuracy having a correlation coefficient (R) of (93%), determination coefficient (R2)of(86.5%)and average accuracy percentage of(92.02%).

Improving a Model for Speed / Density Relationship on Arterial Roads in Baghdad City

Abeer Khudher Jameel

Engineering and Technology Journal, 2011, Volume 29, Issue 3, Pages 625-638

This paper was undertaken to investigate the relationships between speed
and density on urban arterial roads of Baghdad City. This research work was based
on the traffic survey data (PC volume and average speed) collected in Palestine
Street in 3 sections at two directions through 12 hours within 3 weekdays. The
density is computed using fundamental formula of traffic flow. Eight theoretical
Speed-Density models (5 are single Regime Models and 3 are Multi-Regime
models) are validated by the field data by two statistical test methods (CHISQ test
and Paired T-test). The results show that no one of the theoretical models is good
in fit with the real data. Then a Multi-Regime Model is improved under two ranges
of density (<70 and >70) at south approach and (<60 and >60) at north appraoch .
This model is tested using regression analysis, CHISQ test, and Paired T-test. This
analysis shows that the model has good fit with the field data.

Methodology for Water Balance in Hemren Reservoir

Mustafa Majeed Al-Mukhtar

Engineering and Technology Journal, 2010, Volume 28, Issue 22, Pages 6506-6517

The water balance is considered as an important subject in the present time which has a great role in estimation of the quantity of water entering a dam. In this paper approach to estimate the water balance in Hemren dam, an equation has been found to calculate the discharge entering to Hemren dam through relate the variables (Qout from Derbendi-Khan, Qin to Hemren reservoir and rainfall intensity falling on the intermediate catchment area between Hemren-Derbendi- Khan dams) by using the regression analysis. The data were collected for the
interval from 1980 to 2004. The equation gives a correlation oefficient 0.956 for the relation between the observed and calculated discharges.