Sam, Thomas; Dr. Bhasi, M(Cochin University of Science and Technology, July , 2008)
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Abstract:
This research was undertaken with an objective of studying software development project risk, risk management, project outcomes and their inter-relationship in the Indian context. Validated instruments were used to measure risk, risk management and project outcome in software development projects undertaken in India. A second order factor model was developed for risk with five first order factors. Risk management was also identified as a second order construct with four first order factors. These structures were validated using confirmatory factor analysis. Variation in risk across categories of select organization / project characteristics was studied through a series of one way ANOVA tests. Regression model was developed for each of the risk factors by linking it to risk management factors and project /organization characteristics. Similarly regression models were developed for the project outcome measures linking them to risk factors. Integrated models linking risk factors, risk management factors and project outcome measures were tested through structural equation modeling. Quality of the software developed was seen to have a positive relationship with risk management and negative relationship with risk. The other outcome variables, namely time overrun and cost over run, had strong positive relationship with risk. Risk management did not have direct effect on overrun variables. Risk was seen to be acting as an intervening variable between risk management and overrun variables.
Description:
School of Management Studies, Cochin University of Science and Technology
Josephkunju, Paul C; Dr. Sreejith, P S(Cochin University of Science & Technology, September , 2008)
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Abstract:
The thesis presented here unveils an experimental study of the hydrodynamic
characteristics of swirling fluidized bed viz. pressure drop across the distributor and the
bed, minimum fluidizing velocity, bed behaviour and angle of air injection. In swirling
fluidized bed the air is admitted to the bed at an angle 'Ѳ' to the horizontal. The vertical
component of the velocity v sin Ѳ causes fluidization and the horizontal component
v cos Ѳ contributes to swirl motion of the bed material.The study was conducted using spherical particles having sizes 3.2 mm, 5.5 mm & 7.4
mm as the bed materials. Each of these particles was made from high density
polyethylene, nylon and acetal having relative densities of 0.93, 1.05 and 1.47
respectively.The experiments were conducted using conidour type distributors having four rows of
slits. Altogether four distributors having angles of air injection (Φ)- 0°, 5°, 10° & 15°
were designed and fabricated for the study. The total number of slits in each distributor
was 144. The area of opening was 6220 mm2 making the percentage area of opening to
9.17. But the percentage useful area of opening of the distributor was 96.The experiments on the variation of distributor pressure drop with superficial velocity
revealed that the distributor pressure drop decreases with angle of air injection.
Investigations related to bed hydrodynamics were conducted using 2.5 kg of bed
material. The bed pressure drop measurements were made along the radial direction of
the distributor at distances of 60 mm, 90 mm, 120 mm & 150 mm from the centre of
the distributor. It was noticed that after attaining minimum fluidizing velocity, the bed pressure drop increases along the radial direction of the distributor. But at a radial
distance of 90 mm from the distributor centre, after attaining minimum fluidizing
velocity the bed pressure drop remains almost constant. It was also observed that the
bed pressure drop varies inversely with particle size as well as particle density.An attempt was made to determine the effect of various parameters on minimum
fluidizing velocity. It was noticed that the minimum fluidizing velocity varies directly
with angle of air injection (Φ), particle size and particle density.The study on the bed behaviour showed that the superficial velocity required for
initiating various bed phenomena (such as swirl motion and separation of particles from
the cone at the centre) increase with increase in particle size as well as particle density.
It was also observed that the particle size and particle density directly influence the
superficial velocity required for various regimes of bed behaviour such as linear
variation of bed pressure drop, constant bed pressure drop and sudden increase or
decrease in bed pressure drop.Experiments were also performed to study the effect of angle of air injection (Φ). It was
noticed that the bed pressure drop decreases with angle of air injection. It was also
noticed that the angle of air injection directly influence the superficial velocity required
for initiating various bed phenomena as well as the various regimes of bed behaviour.
Description:
Division of Mechanical Engineering,
Cochin University of Science and Technology
Samuel Varghese, K; Dr. Nampoori, V P N; Dr. Girijavallabhan, C P(Cochin University of Science and Technology, December , 2008)
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Abstract:
This Thesis deals with the fabrication and characterization of novel all-fiber components for access networks. All fiber components offer distinctive advantages due to low forward and backward losses, epoxy free optical path and high power handling. A novel fabrication method for monolithic 1x4 couplers, which are vital components in distributed passive optical networks, is realized. The fabrication method differs from conventional structures with a symmetric coupling profile and hence offers ultra wideband performance and easy process control. New structure for 1x4 couplers, by fusing five fibers is proposed to achieve high uniformity, which gives equivalent uniformity performance to 1x4 planar lightwave splitters, isolation in fused fiber WDM is improved with integration of long period gratings. Packaging techniques of fused couplers are analyzed for long term stability.
Description:
International School of Photonics, Cochin University of Science and Technology