Delineation of climate regions using in-situ and remotely-sensed data for the Carolinas

Climatologically homogeneous regions in the Carolinas were delineated using a multi-step approach integrating in-situ and remotely-sensed data. We adopted a consensus clustering technique that obtains climate regions for precipitation and temperature separately. Both average linkage hierarchical and k-means non-hierarchical clustering methods were used to create weather station clusters. Using the resulting precipitation and temperature clusters as training data, we performed a machine-learning decision tree classification of remotely-sensed data (i.e., MODIS and TRMM) to map five precipitation classes and seven temperature classes for the Carolinas. These data were intersected to produce 17 consensus clusters for the Carolinas, and 16 climate regions when summarized by counties.The resultant climate regions showed rational climate regionalization reflecting controls on Carolina climate including topography, latitude, storm tracks, and proximity to the Atlantic Ocean. The use of remotely-sensed data effectively helped the delineation between weather station clusters and even detected consensus clusters that were not identified by intersecting weather station clusters grouped using only in-situ data. We compared the regions with the 15 existing National Climatic Data Center climate divisions using within- and between-cluster standard deviations for both in-situ and remotely-sensed data. Climate regions could improve the existing climate divisions in delineating climatologically homogeneous regions and in separating heterogeneous regions.     

The effects of perceived risk and technology type on users’ acceptance of technologies

Previous studies on technology adoption disagree regarding the relative magnitude of the effects of perceived usefulness and perceived ease of use. However these studies did not consider moderating variables. We investigated four potential moderating variables – perceived risk, technology type, user experience, and gender – in users’ technology adoption. Their moderating effects were tested in an empirical study of 161 subjects. Results showed that perceived risk, technology type, and gender were significant moderating variables. However the effects of user experience were marginal after the variance of errors was removed.     

Sintering period dependence of composition and superconducting properties of (BiPb)SrCaCu,1.8Ox system

The material system (Bi_0.7Pb_0.3)Sr₁ Ca₁ Cu_1.8O _x forms, at 840° C, two major phases having a highT _c (100K) and a lowT _c (70 K) both of which consist of platelets and a non-superconducting minor phase which has a rod-like shape and is isolated by the major phases. As the sintering period increases, the amount of highT _c phase increases accompanying the decrease in lowT _c phase while the amount of the non-superconducting phase is independent of sintering period, resulting in a superconductor withT _c of 100 K. Changes in compositions of each phase also occur during sintering due to evaporation of bismuth and lead.     

Effect of hydrogen bonding on the crystallization behavior of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/silica hybrid composites

Biodegradable poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHB-HHx)/hydrophobically modified silica hybrid composites were prepared using simple melt compounding and the effect of hydrogen bonding on their crystallization behavior was observed. The intermolecular hydrogen bonding between PHB-HHx and silica increased gradually with the increase of silica content of the hybrid composites. However, the extent of intermolecular hydrogen bonding was not directly proportional to the silica content. Although, the crystallization rates of the PHB-HHx/silica hybrids decreased as the strength of intermolecular hydrogen bonding increased, the constant value of the Avrami exponent indicates that the presence of silica does not alter the nucleation mechanism or the geometry of the crystal growth of the PHB-HHx hybrids. The calculated crystallization activation energy increased with the addition of silica, suggesting that silica retards the overall crystallization rate of the PHB-HHx hybrid composites as a result of the existence of intermolecular hydrogen bonding. The relationship between the extent of intermolecular hydrogen bond and crystallization rate is described by the empirical second-order equation.     

Use of activate sludge model no. 3 and Bio-P module for simulating five-stage step-feed enhanced biological phosphorous removal process

The ASM3 with EAWAG Bio-P Module (ASM3+P) was used for simulating a five-stage step-feed Enhanced Biological Phosphorous Removal (fsEBPR) process and its applicability was compared with the ASM2d. The fsEBPR process was predicted to achieve effective nitrogen and phosphorus removal from the wastewater even with low C/N and C/P ratios without additional carbon sources. Application of the ASM3+P on this configuration will be an ample chance for expanding the new models in the activated sludge process. Sensitivity analysis and parameter estimation were conducted with the ASM2d and the ASM3+P prior to model application so that calibration of the models could focus only on the sensitive parameters. The ASM2d was less successful for predicting the process behavior. Moreover, the ASM2d required 6 times more computation time than that for the AMS3+P due to its decay-regeneration model structure. To confirm the applicability of parameters determined from the pilot-scale reactor operating results, those were tested on the field data without further correction. Only the ASM3+P successfully predicted nitrogen and phosphate variations in the full-scale plants. Overall examination of simulation results using the pilot and full-scale data has led to the conclusion that the ASM3+P is better than the ASM2d for simulating fsEBPR processes.     

Fabrication of a graded‐index polymer optical fiber preform without cavity via the automatic refilling process

When two monomers with different densities and refractive indices are polymerized under a centrifugal force field, a cavity is generated in the rotational axis as a result of inherent volume shrinkage. Accordingly, an additional monomer‐refilling process is necessary to compensate for the undesirable cavity. In this study, we modified the stepwise refilling process to an automatic process and have successfully fabricated a graded‐index polymer optical fiber preform without a cavity. The process could also reduce the processing time and enhance the transmission speed of a polymer optical fiber compared with the stepwise process. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Phase behavior and morphology in blends of poly(L‐lactic acid) and poly(butylene succinate)

Blends of poly(L ‐lactic acid) (PLA) and poly(butylene succinate) (PBS) were prepared with various compositions by a melt‐mixing method and the phase behavior, miscibility, and morphology were investigated using differential scanning calorimetry, wide‐angle X‐ray diffraction, small‐angle X‐ray scattering techniques, and polarized optical microscopy. The blend system exhibited a single glass transition over the entire composition range and its temperature decreased with an increasing weight fraction of the PBS component, but this depression was not significantly large. The DSC thermograms showed two distinct melting peaks over the entire composition range, indicating that these materials was classified as semicrystalline/semicrystalline blends. A depression of the equilibrium melting point of the PLA component was observed and the interaction parameter between PLA and PBS showed a negative value of ?0.15, which was derived using the Flory–Huggins equation. Small‐angle X‐ray scattering revealed that, in the blend system, the PBS component was expelled out of the interlamellar regions of PLA, which led to a significant decrease of a long‐period, amorphous layer thickness of PLA. For more than a 40% PBS content, significant crystallization‐induced phase separation was observed by polarized optical microscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 647–655, 2002     

Fabrication of a graded-index polymer optical fiber preform by using a centrifugal force

We have investigated a fabricating method for a graded index polymer optical fiber preform using a centrifugal force. When two monomers with different densities and refractive indices are polymerized under a centrifugal force, a concentration gradient is generated due to their density difference. Therefore, a graded refractive index can be obtained according to the concentration gradient. When a monomer is polymerized under a centrifugal force, a preform with a hollow is obtained because of volume shrinkage. To compensate for this practically, additional monomer should be filled into the hollow. Monomer should be fed to obtain a continuous gradient of refractive index at the interface before the first polymerized product is perfectly glassified. Two different types of feeding additional monomer were experimented with: monomer-monomer pair (case I) and monomer-polymer pair (case II). The graded index profile with a proper δn (about 0.01) was successfully obtained in either case.     

EEG-Based Brain-Computer Interfaces: A Thorough Literature Survey

Brain–computer interface (BCI) technology has been studied with the fundamental goal of helping disabled people communicate with the outside world using brain signals. In particular, a large body of research has been reported in the electroencephalography (EEG)-based BCI research field during recent years. To provide a thorough summary of recent research trends in EEG-based BCIs, the present study reviewed BCI research articles published from 2007 to 2011 and investigated (a) the number of published BCI articles, (b) BCI paradigms, (c) aims of the articles, (d) target applications, (e) feature types, (f) classification algorithms, (g) BCI system types, and (h) nationalities of the author. The detailed survey results are presented and discussed one by one.

[Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Human-Computer Interaction to view the free supplemental file: Supplementary Tables.pdf.]