Exploring urban commuting imbalance by jobs and gender

Previous findings support that distance matters for job access. Typically, long distances act negatively on job access either due to the lack of information about the opportunities or the cost (time, transportation, etc.). Disparities in job access are explained with the workers’ demographic and socioeconomic characteristics and their spatial condition. Nevertheless, job access was not fully explored in multi-dimensional ways because of data and computational limitations. Recently, the wealth of commuting data, combined with the growing capacity of computation and methodological development, enables us to examine more commuting pattern details than what existing data provide at an aggregate level. This study uses a disaggregate journey-to-work model on 2000 Census Transportation Planning Package (CTPP) commuting data to investigate access to job by gender and occupation, in a more localized context. To explore this varying degree of job access and associated explanation, we analyzed disaggregate commuting flows and ran a regression model on them. This study has three main objectives: (1) to disaggregate journey-to-work flows by gender and occupation to estimate the number of commute trips between census tracts, (2) to explore the variations in job access by gender and occupation, and (3) to draw relationships between job access and various worker’s situations. The results show the details of commuting patterns, suggesting that some occupations have more gender imbalance than others. Further, the findings indicate that the same demographic, socioeconomic and spatial conditions have different effects on workers, and the effect is related to the workers’ demographic-socioeconomic status in complex ways. Unlike conventional research in which a particular worker group is compared to a control group of opposite characteristics, our methodology makes it possible to examine an overview of all the job and gender groups, providing advantages in 2-way comparisons between gender and occupation groups beyond a conventional comparison between two groups. Therefore, our study adds an additional dimension to the conventional comparison.     

The Early Tertiary chemical remagnetization in the Bakjisan Syncline, Korea: Its geotectonic implications

The Bakjisan Syncline is located in the northwestern part of the Taebaeksan Basin, Korea. New paleomagnetic data for the Upper Carboniferous–Lower Triassic Pyeongan Supergroup from the Pyeongchang area on the west limb of the Bakjisan Syncline have been obtained, and synthesized and compared with previous data from the Jeongseon area on the east limb of the syncline. A total of 350 specimens were collected from 21 sites to clarify the relationship between the spatial distribution of remagnetized areas and the thrust system in the Taebaeksan Basin. The characteristic remanent magnetization (ChRM) isolated from all samples was a remagnetized component acquired after tilting of the strata and carried by various magnetic minerals (magnetite, hematite and pyrrhotite). From rock magnetic studies, electron microscope observations and XRD analyses, the pervasive remagnetization is interpreted to be associated mainly with a fluid-mediated chemical remanent magnetization (CRM). This is consistent with the results of previous work in adjacent areas. The paleomagnetic pole position (88.3°E, 83.9°N, A₉₅ = 4.9°) from the Pyeongan Supergroup in the Bakjisan Syncline indicates that the timing of the remagnetization event is Early Tertiary times (i.e. Paleocene to Eocene) by comparison with reliable paleopoles from the Korean Peninsula. Early Tertiary CRMs are also reported from previous studies of an adjacent region within the northwestern part of the Taebaeksan Basin. In contrast, a primary remanent magnetization was reported in the southeastern part of the Taebaeksan Basin. This implies that the major thrust system (the Gakdong thrust) which separates the two regions has caused them to experience substantially different geologic histories since deposition of the strata. Since many thrusts with NS trend are observed in the northwestern part of the Taebaeksan Basin compared with the southeastern region, it appears that the remagnetizing fluids pervasively penetrated the northwestern part of the basin by utilizing the already well-developed thrust system.     

The system NaAlSi3O8−H2O−H2 (1200° C, 2 kbar): the solubility and interaction mechanism of fluid species with melt

The H₂O and H₂ solubilities in an albite melt at 1200° C and 2 kbar over the entire range of gas phase composition, from pure hydrogen to pure water were studied in gas-media pressure vessels. The water solubility initially increases with increasing hydrogen content until a maximum of 9.19 wt% H₂O atXH ₂ ^v =0.1 is reached, withXH ₂ ^v >0.1 the water solubility decreases. The hydrogen solubility curve has a maximum atXH ₂ ^v =0.42 where the concentration reaches 0.206 wt% H₂O. Over the entire compositional range¹H NMR (nuclear magnetic resonance) spectra show distinct absorption lines due to protons bound to OH groups and to isolated firmly bound water molecules. In NMR and Raman spectra there were no bands attributable to the H–H vibrations of molecular hydrogen. The X-ray photo-electronic spectra of hydrogen-bearing glasses show the Si2p (99 eV) band which corresponds to the zero-valency silicon. The formation of OH groups and molecular water during interaction between hydrogen-bearing fluids and melts under reducing conditions has a qualitative effect, the same as for water dissolution. Another point of interest is that hydrogen-bearing melts undergo more depolymerization than do hydrous melts.     

Phase Distribution of Rare and Rare-Earth Elements in the Silicate–Fluoride Systems at Т = 800–1200°С and Р = 1–2 kbar (Experimental Investigations)

Doklady Earth Sciences - The melt in the alumosilicate (granite) melt–molten fluoride salt system is experimentally studied at Т = 800–1200°С and Р = 1–2...     

Multiphase flow modeling with general boundary conditions and automatic phase-configuration changes using a fractional-flow approach

The multiphase flow simulator moving particle semi-implicit (MPS) method is developed based on the fractional-flow approach, originated in the petroleum engineering literature, considering the fully three-phase flow with general boundary conditions. The fractional flow approach employs water saturation, total liquid saturation, and total pressure as primary variables. Most existing models based upon fractional flow are limited to two-phase flow and specific boundary conditions. Although there appear a number of three-phase flow models, they were mostly developed using pressure-based approaches, which require variable-switch techniques to deal with phase appearance and disappearance. The use of fractional flow-based approaches in MPS makes it unnecessary to use variable-switching to handle the change of phase configurations because the water saturation, total liquid saturation, and total pressure exist throughout the solution domain regardless of whether certain phases are present or not. Furthermore, most existing fractional flow-based models consider only specific boundary conditions, usually Dirichlet-type pressure for water phase and flux-type boundary for nonaqueous phase liquid or particular combinations for individual phase. However, the present model considers general boundary conditions of ten most possible and plausible cases. The first eight cases are the combinations of the phase pressure or the phase flux of each of the three individual phases. The other two cases are the variable boundary conditions: one for water-medium interface and the other for the air-medium interface when the directions of fluxes are not known a priori. Thus, the model’s capabilities of handling general boundary conditions extend the simulators’ usefulness in the field system.     

Exploring job centers by accessibility using fuzzy set approach: the case study of the Columbus MSA

When comparing accessibility, the interpretation of results is complex because of lack of standard or universal norm. This uncertainty issue of the distinction from the lack of standard can be solved using the multi-level approach of fuzzy set: universal, relative, and absolute index. Since a fuzzy set approach deals with the vagueness and indiscernibility of accessibility index, the proposed approach suggests a better solution to classify the index than a crisp set or even a single-level fuzzy set approach. In this study, we evaluate job accessibility of locations in the Columbus MSA in Ohio, USA for 18 worker groups. The uncertain distinction between strong/weak, rich/poor, and higher/lower accessibility is improved by the multi-level approach. Moreover, this study attempts to enhance our understanding of spatial structure of job accessibility disaggregated by occupation type and gender.