Strategic alignment and value maximization for IT project portfolios

Managing project portfolios has been a challenge to many IT organizations due to the size and complexity of their initiatives that are often cross-functional, fast changing, and transformational in nature. A governance process on project solicitation, evaluation, and monitoring is thus essential to ensure the resulting portfolio creates tangible values, balances across priorities, and supports business objectives. An optimization model to streamline the decision processes for IT portfolios and programs is proposed. We consider project characteristics such as the extent of strategic alignment, expected benefit, development cost, and cross-project synergy to maximize the portfolio value. We also consider team proficiency and resource availability to determine a project portfolio that could be implemented within the overall development time. The multi-objective model identifies the optimal mix among project types and the solution procedure efficiently produces recommendations that are superior to those found with current empirical techniques. We also describe an evolutionary algorithm to find approximate solutions to the optimization model. Possible extensions on how the optimization procedure can go beyond projects to also streamline decisions such as the renewal or replacement of in-flight applications is discussed.     

Critical Success Factors for Bond Financing of Construction Projects in Asia

Although bonds have been commonly used for financing construction works in developed countries such as the United States, Asian governments would like to see their construction growth increasingly funded by alternative sources such as the capital market, instead of overrelying on bank loans. Yet even in relatively active markets such as Hong Kong and Singapore, the use of bond financing for infrastructure development is limited. In a recent study based on two questionnaire surveys with subsequent interviews about retail and institutional investors, results demonstrated that credit risk was a major concern and that deterrents include lack of bond market information, illiquidity of domestic bonds, and the reliability of external credit ratings. Institutional investors, however, welcome infrastructure bonds because of the stable income stream matching their long-term commitments. To address these practical concerns, we have proposed credit and liquidity enhancement measures in this paper as the critical success factors for international construction promoters to tap into the bond market for financing construction works in Asia. Hence, this paper will be of interest to academics and practitioners who are working on project financing, because empirical findings reveal investors’ concerns, which are then addressed with recommendations.     

Modeling and analyzing the effects of heat treatment on the characteristics of magnesium alloy joint welded by the tungsten-arc inert gas welding

The objective of this paper is to present the mathematical models for modeling and analysis of the effects of heat treatment on the characteristics of magnesium alloy joint welded by the tungsten-arc inert gas (TIG) welding. The process of heat treatment adopts the tempering process with varying processing parameters, including tempering temperature and tempering time. The microstructure and mechanical properties of the welded joint are considered in the characteristic evaluation and explored by experiment. An experimental plan of the face-centered central composite design (CCD) based on the response surface methodology (RSM) has been employed to carry out the experimental study. The results of analysis of variance (ANOVA) and comparisons of experimental data show that the mathematical models of the value of the maximum tensile strength and elongation are fairly well fitted with the experimental values with a 95% confidence interval. In the tempering process, the microstructure of welded joint in the weld bead displays two main microstructures of hcp-α-phase Mg and bcc-β-phase Mg₁₇Al₁₂. Results show that the average size and proportion of α-phase Mg grains decreases with the increase of the tempering time and temperature. But, the increase of the tempering time and temperature promote increasing the average size and proportion of β-phase Mg₁₇Al₁₂ grains. An increase in both the high value of tempering temperature and tempering time leads to an increase of the maximum tensile strength. The values of the elongation increase with increasing in both the value of tempering temperature and tempering time.     

Statistical analysis and modeling of the temperature-dependent sleep behavior of drosophila

The sleep behavior of drosophila is analyzed under different temperatures. The activity per minute of the flies is recorded automatically. Sleep for a fruit fly is defined as the periods without any activity and longer than 5 minutes. Several parameters such as total sleep time, circadian sleep profile, quality of sleep are analyzed. The sleep behaviors are significantly different for flies at different temperature. Interestingly, the durations of daytime sleep periods show a common scale-free power law distribution. We propose a stochastic model to simulate the activities of the population of neurons which regulate the dynamics of sleep–wake process to explain the distribution of daytime sleep.     

Spindle position regulation for wind power generators

The three-time-scale plant model of a wind power generator, including a wind turbine, a flexible vertical shaft, a variable inertia flywheel (VIF) module, an active magnetic bearing (AMB) unit and the applied wind sequence, is constructed. In order to make the wind power generator be still able to operate as the spindle speed exceeds its rated speed, the VIF is equipped so that the spindle speed can be appropriately slowed down once any stronger wind field is exerted. Currently, most of wind energy input is, as a matter of fact, a waste since the commercially available wind power generators only operate for fairly mild or low-speed wind field. To prevent any potential damage due to collision by shaft against conventional bearings, the AMB unit is proposed to replace the traditional bearings and regulate the shaft position deviation. By singular perturbation order-reduction technique, a lower-order plant model can be established for the synthesis of feedback controller. It is found that two major system parameter uncertainties, an additive uncertainty and a multiplicative uncertainty, are constituted by the wind turbine and the VIF, respectively. The upper bounds of system parameters variation can be therefore estimated and the frequency shaping sliding mode control (FSSMC) loop is proposed to account for these uncertainties and suppress the unmodeled higher-order plant dynamics. At last, the efficacy of the FSSMC is verified by intensive computer and experimental simulations for regulation on position deviation of the shaft and counter-balance of unpredictable wind disturbance.     

Thermal evaluation of vertical greenery systems for building walls

This research involves the study of 8 different vertical greenery systems (VGSs) installed in HortPark to evaluate the thermal impacts on the performance of buildings and their immediate environment based on the surface and ambient temperatures. VGSs 3 and 4 have the best cooling efficiency according to the maximum temperature reduction of the wall and substrate surfaces. These results point to the potential thermal benefits of vertical greenery systems in reducing the surface temperature of buildings facades in the tropical climate, leading to a reduction in the cooling load and energy cost. In terms of the lowest diurnal range of average wall surface temperature fluctuation, VGSs 4 and 1 show the highest capacities. No vertical greenery system performs well in term of the diurnal range of average substrate temperature fluctuation. By limiting the diurnal fluctuation of wall surface temperatures, the lifespan of building facades is prolonged, slowing down wear and tear as well as savings in maintenance cost and the replacement of façade parts. The effects of vertical greenery systems on ambient temperature are found to depend on specific vertical greenery systems. VGS 2 has hardly any effect on the ambient temperature while the effects of VGS 4 are felt as far as 0.60 m away. Given the preponderance of wall facades in the built environment, the use of vertical greenery systems to cool the ambient temperature in building canyons is promising. Furthermore, air intakes of air-conditioning at a cooler ambient temperature translate into saving in energy cooling load.     

Knowledge contribution in information system development teams: An empirical research from a social cognitive perspective

The extent of knowledge contribution is the key to the success of system development projects. Knowledge contribution refers to the knowledge that is provided to increase a team's efficiency and achieve its goal. This study proposes a research model exploring factors that influence the extent of knowledge contribution from a social cognitive perspective. These factors include the team relationship commitment, team relationship norms, and awareness of expertise location. Additionally, this study argues that a team's awareness of expertise location mediates the effects of affective commitment and relationship norms on knowledge contribution. The result shows that the awareness of expertise location plays a crucial mediating role in the relationships between the two socially prescribed motivations and knowledge contribution. Moreover, team relationship commitment has an important impact on team established relational norms.     

Mechanical and dynamic properties of graft polyurethane/allyl novolac resin simultaneous interpenetrating network

Two series of polyurethane (PU)/allyl novolac resin simultaneous interpenetra ing networks (SINs) were synthesized. The PU components were prepared by reacting 4,4′-diphenyl methane diisocyanate with poly(tetramethylene oxide) (PTMO), whose molecular weight range was 600–700 (for convenience, this polymer was called UT1), 900–1050 (UT2) and 1900–2100 (UT3), respectively. The phenolic resin component was synthesized by substituting the hydroxy groups of the phenolic resin with the allyl group. To prove that the alkene group can be applied as a binding element between the networks to improve the network compatibility, trimethylol propane monoally ether (TMPME) with a double bond was chosen as the PU chain extender in one series of the PU/allyl novolac resin SINs (designated TUT1, TUT2 and TUT3 for different molecular weights of PTMO used as PU soft segments). After a detailed study of the thermal, mechanical, and dynamic properties and morphology, the extent of phase mixing of the graft PU/allyl novolac resin SINs (TUT series SINs) was significantly improved over that of UT series SINs. This result is consistent with the loss tangent shift in dynamic mechanical analysis measurements and with transmission electron microscope micrographs. The mechanical properties of the graft SINs (TUT series) were lower than those of the original SINs (UT series) because TMPME with bulky structure was used as the chain extender of PU.