Distributed hybrid P2P networking systems

Peer-to-Peer Networking and Applications -     

The Intensity and Externality Effects of Information Technology Investments on National Productivity Growth

This study investigates the relation between information technology (IT) expenditures and national productivity based on a production estimation approach by using a pooled time-series country-level data set for the period from 1992 to 2000. The results, which confirm the findings of earlier studies on country-level IT investment effect, show IT has significant and positive effects on national productivity growth. We find that IT intensity improves the positive effect of IT investment on national productivity growth and that the existence of IT externalities, through which spillovers of knowledge and innovation occur, may eventually lead to long-run persistent national productivity growth.     

P2P computing for intelligence of things

Peer-to-Peer Networking and Applications -     

Predicting the performance and NOx emissions of a turbocharged spark-ignition engine generator fueled with biogases and hydrogen addition under down-boosting condition

The characteristics of an engine generator fueled with methane-based biogas and its blend with hydrogen (H₂) were numerically investigated using a one-dimensional cycle simulation and the fractional factorial design of experiment method. Based on the experimental results, the numerical model was validated and calibrated under various excess air ratio (EAR), boost pressure, spark timing, and biogas composition conditions. The conventional and current optimization methods, maximum brake torque (MBT), and minimum input fuel (MIF) conditions, were compared in terms of engine performance, NO_x emission, and generating efficiency. Under MBT conditions, although higher torque and mass fraction burned (MFB) could be achieved, boosting degradation was evident at the optimum MBT timing. On the contrary, under MIF conditions with down-boosting, reduced NO_x formation and improved generating efficiency could be achieved, but was accompanied by an MFB decrease. Moreover, the reduced MFB could be enhanced by H₂ addition and spark-timing control. Compared to MBT, MIF optimization had advantages in terms of generating efficiency, NO_x emission reduction, and spark-timing control, and could avoid boosting degradation over the entire operating range for various fuel compositions.     

Molecular dynamics simulation study of the growth of a rough amorphous carbon film by the grazing incidence of energetic carbon atoms

The morphological evolution of an amorphous carbon film deposited by energetic carbon atoms of 75 eV with various angles of incidence was investigated by molecular dynamics simulation. Normal or near-normal incidence of carbon atoms resulted in a smooth surface of the deposited film. In contrast, a bump-like surface structure emerged and led to rough surfaces at grazing incidences, in agreement with the experiments. The bifurcated growth mode was explained by the impact-induced transport of atoms on the growing surface. The downhill transport of atoms on a sloping surface dominates at normal incidence, which suppresses the evolution of surface irregularities to form a rough surface. However, the dominance of uphill transport at a grazing incidence made the surface irregularities grow to a seed structure, which provided the shadowing effect during carbon deposition. This mechanism mediates initial seed formation and subsequent roughening together with shadowing effects under grazing incidence.     

BOSSA: a multidimensional post-occupancy evaluation tool

Research findings point to three methodological shortcomings of current post-occupancy evaluation (POE) tools: (1) contextualizing results, (2) adding instrumental data side by side to survey results and (3) producing meaningful feedback to its key stakeholders. This paper introduces the holistic BOSSA (Building Occupants Survey System Australia) and tools developed under this project's scope in close collaboration with industry. It aims to present and discuss the statistical analysis used in the BOSSA tool, distilling the survey results down to nine indoor environmental quality (IEQ) dimensions and their association with four overall indices. Principal component analysis (PCA) extracted nine IEQ dimensions that were uncorrelated with each other: spatial comfort, indoor air quality, personal control, noise distraction and privacy, connection to the outdoor environment, building image and maintenance, individual space, thermal comfort, and visual comfort. Four separate multiple regression analyses were conducted, one for each global evaluation item as an independent variable: work area comfort, building satisfaction, productivity and health. This statistical analysis provided the rational basis of BOSSA's scoring system, designed to simplify how occupant survey results are communicated to key stakeholders from the property industry and researchers.     

Development and analysis of an online tool condition monitoring and diagnosis system for a milling process and its real-time implementation

This paper addresses the development of an online tool condition monitoring and diagnosis system for a milling process. To establish a tool condition monitoring and diagnosis system, three modeling algorithms–an Adaptive neuro fuzzy inference system (ANFIS), a Back-propagation neural network (BPNN) and a Response surface methodology (RSM)–are considered. In the course of modeling, the measured milling force signals are processed, and critical features such as Root mean square (RMS) values and node energies are extracted. The RMS values are input variables for the models based on ANFIS and RSM, and the node energies are those for the BPNN-based model. The output variable is the confidence value, which indicates the tool condition states–initial, workable and dull. The tool condition states are defined based on the measured flank wear values of the endmills. During training of the models, numerical confidence values are assigned to each tool condition state: 0 for the initial, 0.5 for the workable and 1 for the dull. An experimental validation was conducted for all three models, and it was found that the RSM-based model is best in terms of lowest root mean square error and highest diagnosis accuracy. Finally, the RSM-based model was used to build an online system to monitor and diagnose the tool condition in the milling process in a real-time manner, and its applicability was successfully demonstrated.     

PLGA Spherical Nucleic Acids

A new class of polymer spherical nucleic acid (SNA) conjugates comprised of poly(lactic‐co‐glycolic acid) (PLGA) nanoparticle (NP) cores is reported. The nucleic acid shell that defines the PLGA‐SNA exhibits a half‐life of more than 2 h in fetal bovine serum. Importantly, the PLGA‐SNAs can be utilized to encapsulate a hydrophobic model drug, coumarin 6, which can then be released in a polymer composition‐dependent tunable manner, while the dissociation rate of the nucleic acid shell remains relatively constant, regardless of core composition. Like prototypical gold NP conjugate SNAs, PLGA‐SNAs freely enter Raw‐Blue cells and can be used to activate toll‐like receptor 9 in a sequence‐ and dose‐dependent manner. Taken together, the data show that this novel nanoconstruct provides a means for controlling the release kinetics of encapsulated cargos in the context of the SNA platform, which may be useful for developing combination therapeutics.