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1.
Natural Hazards - A strong understanding of severe drought conditions is important for its mitigation and damage alleviation. Given the Peninsular Malaysia’s drought vulnerability and its... 相似文献
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The paper investigates the roles and nature of postgraduate education on the professionalization of the shipping industry. The recent growth of postgraduate education is marked by the massive expansion of professional programmes on disciplines which traditionally emphasized non-academic, apprentice-style learning approach, including shipping business and management. The reasons behind such growth of demands, however, have remained scarce and empirically under-researched. Understanding this deficiency, in this study, we have undertaken a questionnaire survey completed by students/graduates who are pursuing/have recently pursued masters' programmes in shipping-related business and management offered by six Asian and European universities. Specifically, we analyze student motivations, considerations, and sources of information before enrolling such programmes, the extent that the shipping industry or other forces act as driving forces towards such enrollment, as well as students' evaluation of the postgraduate programmes that they are pursing/have pursued. Integrated in these discussions are comparative analyses of the data provided by different student groups based on their professional experiences and cultural backgrounds. We believe that this study has provided the lacking empirical inputs essential for achieving the sustainable development of postgraduate education in shipping business and management. 相似文献
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The architecture of macrofaunal burrows and the total area of the sediment-water interface created by biogenic structure were
investigated in the Donggeomdo tidal flat on the west coast of Korea. Resin casting methods were applied to recover burrows
of four dominant species, Macrophthalmus japonicus, Cleistostoma dilatatum, Perinereis aibuhitensis, and Periserrula leucophryna,
and whole burrows within the casting area at three sites in different tidal levels.P. leucophryna excavated the largest burrow in terms of a surface area among them. In the case of whole burrow casting, the space occupied
by the biogenic structure was extended into deeper and expanded more greatly at the higher tidal level. In the uppermost flat,
the burrow wall surface area within sediment was more extensive than the sediment surface area. Increased oxygen supply through
the extended interface could enhance the degradation rates of organic carbon and also change the pathways of degradation.
Quantifying the relationship between the extended interface and mineralization rate and pathway requires more extensive study. 相似文献
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Nonlinear interactions between large waves and freely floating bodies are investigated by a 2D fully nonlinear numerical wave tank (NWT). The fully nonlinear 2D NWT is developed based on the potential theory, MEL/material-node time-marching approach, and boundary element method (BEM). A robust and stable 4th-order Runge–Kutta fully updated time-integration scheme is used with regriding (every time step) and smoothing (every five steps). A special φn-η type numerical beach on the free surface is developed to minimize wave reflection from end-wall and wave maker. The acceleration-potential formulation and direct mode-decomposition method are used for calculating the time derivative of velocity potential. The indirect mode-decomposition method is also independently developed for cross-checking. The present fully nonlinear simulations for a 2D freely floating barge are compared with the corresponding linear results, Nojiri and Murayama’s (Trans. West-Jpn. Soc. Nav. Archit. 51 (1975)) experimental results, and Tanizawa and Minami’s (Abstract for the 6th Symposium on Nonlinear and Free-surface Flow, 1998) fully nonlinear simulation results. It is shown that the fully nonlinear results converge to the corresponding linear results as incident wave heights decrease. A noticeable discrepancy between linear and fully nonlinear simulations is observed near the resonance area, where the second and third harmonic sway forces are even bigger than the first harmonic component causing highly nonlinear features in sway time series. The surprisingly large second harmonic heave forces in short waves are also successfully reproduced. The fully updated time-marching scheme is found to be much more robust than the frozen-coefficient method in fully nonlinear simulations with floating bodies. To compare the role of free-surface and body-surface nonlinearities, the body-nonlinear-only case with linearized free-surface condition was separately developed and simulated. 相似文献
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Namin Koo Kwon-Rae Kim Youn-Jung Choi Sang-Hwan Lee Gary Owens Jeong-Gyu Kim 《Environmental Earth Sciences》2012,65(3):689-697
To determine the appropriate allocation of resources for the future restoration of the abandoned mining district of Kangwon
in Korea, identification of the main pollutants and the main sources discharging these pollutants is crucial. Therefore, a
2-year study was undertaken to quantify the amount of pollutants in the Uchen stream (a potential sink for contamination),
which runs through the district, and to determine the potential sources of these pollutants, including mine drainage and soil.
Arsenic (As) was the main pollutant in mine drainage and soils showing concentrations above the Korean regulated standard
levels of 50 μg L−1 and 50 mg kg−1 for water and soil, respectively. In addition, the pollution index (PI) showed that mine drainages were polluted by As to
a moderate (2 ≤ PI < 3) or strong (4 ≤ PI < 5) degree. Consequently, As load in mine drainage and soil contributed to increased
amounts of As in the stream. The As loads in mine drainages (11 and 587 g month−1 for mine adit 1 and 2, respectively) accounted for only 9% of the total As load to the stream (6,378 g month−1); and the influence of mine drainages on As contents in the stream was more reliant on the total volume of mine drainage
generated rather than the As concentration in the mine drainage. Approximately 91% of the As in the stream was derived from
the soils within the study area. 相似文献
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Weoncheol Koo 《Ocean Engineering》2009,36(9-10):723-731
A pneumatic-type floating breakwater is simulated in the time–domain to evaluate wave blocking and wave energy absorption. For accurate nonlinear time–domain simulation, a fully nonlinear numerical wave tank (NWT) technique has been used. In the present study, the NWT for the pneumatic breakwater is extended to the case of restrained body motion using the mode-decomposition method in the acceleration potential field. In particular, the effect of individual body motion coupled with pneumatic damping in the chamber is investigated for the case in which the breakwater is only allowed to move one degree-of-freedom: for instance, using a heave-only allowable body. The present results are compared with various motion cases as well as a box-shaped breakwater. 相似文献
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Stochastic representation of forecast uncertainties has been taken into account to improve dynamical seasonal prediction. In this study, perturbing the dynamic tendency by a random number is introduced to account for inherent uncertainties associated with computational representations of the underlying partial differential equations that govern the atmospheric motion. Compared to the traditional approach to perturb the physical tendency, the sensitivity of fluctuations in forecast variables to the magnitude of random forcing is found to be greater in the case of perturbing the dynamical tendency. Realizing that the major advantage of stochastic tendency in traditional approaches lies in the increase in ensemble spread, our approach manifests a greater potential in the field of dynamical ensemble prediction. An evaluation of a simulated climate for a boreal summer demonstrates a significant enhancement in forecast skill in terms of the large-scale features and precipitation, when both the dynamical and physical tendencies are simultaneously perturbed. This finding implies that model uncertainties could be addressed in terms of not only the physical parameterization but also the dynamical portion that used to be regarded as deterministically solved. 相似文献
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