• Korean Journal of Materials Research
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• v.30 no.7
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• pp.333-337
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• 2020

Orthorhombic DyMnO₃ films are fabricated epitaxially on Nb-1.0 wt%-doped SrTiO₃ single crystal substrates using pulsed laser deposition technique. The structure of the deposited DyMnO₃ films is studied by X-ray diffraction, and the epitaxial relationship between the film and the substrate is determined. The electrical transport properties reveal the diodelike rectifying behaviors in the all-perovskite oxide junctions over a wide temperature range (100 ~ 340 K). The forward current is exponentially related to the forward bias voltage, and the extracted ideality factors show distinct transport mechanisms in high and low positive regions. The leakage current increases with increasing reverse bias voltage, and the breakdown voltage decreases with decrease temperature, a consequence of tunneling effects because the leakage current at low temperature is larger than that at high temperature. The determined built-in potentials are 0.37 V in the low bias region, and 0.11 V in the high bias region, respectively. The results show the importance of temperature and applied bias in determining the electrical transport characteristics of all-perovskite oxide heterostructures.

• Ocean and Polar Research
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• v.24 no.1
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• pp.1-18
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• 2002

Seasonal variation in global transport calculated from an ocean general circulation model (OGCM) has been assessed through the comparison with observational estimates. The OGCM based on the GFDL MOM1.1 has honzontal grid interval of 10 and 21 verticle levels, and was integrated for 31 years forced by climatological wind stress, freshwater flux, and heat flux with restoring. General features of the world ocean circulation are well reproduced, which include the western boundary currents such as the Kuroshio and the Agulhas Current, the Equatorial Current system, the Antarctic Circumpolar Current, and the Weddell Sea gyres. Also well resolved is the remarkable seasonal variation in the depth-integrated flows in the northern Indian Ocean due to the monsoonal wind. Monthly variation is found to be dominant in the transport of the Antarctic Circumpolar Current through the Drake Passage in accordance with observational estimates. It has been shown that the mid-latitude depth-integrated flows obey the Sverdrup relation, except for some regions such as continental shelf regions where the interaction between stratification and bottom topography is critical.

• Progress in Superconductivity and Cryogenics
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• v.9 no.3
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• pp.1-4
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• 2007

The current profiles in a coated conductor with transport current were calculated using an iterative inversion method from the data of the magnetic flux density profiles measured. The applied current was increased from 0 to 60 A by 10A step and decreased down to -60A by 20A step. The magnetic flux profiles were measured at a distance of 400 mm above the surface of the coated conductor using a scanning hall probe method. The current profiles calculated were very different from the Bean model: current density profile is not a constant in the critical region. However the aspect of the change of the current and magnetic flux density profiles in the case of decreasing applied current are similar to the theoretical calculations in Brandt's paper.

• Progress in Superconductivity and Cryogenics
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• v.15 no.2
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• pp.34-38
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• 2013

AC Losses for face to face stacks of four identical coated conductors (CCs) were numerically calculated using the H-formulation combined with the E-J power law and the Kim model. The motive sample was the face to face stack of four 2 mm-wide CC tapes with 2 ${\mu}m$ thick superconducting layer of which the critical current density, $J_c$, was $2.16{\times}10^6A/cm^2$ on IBAD-MgO template, which was suggested for the mitigation of ac loss as a round shaped wire by Korea Electrotechnology Research Institute. For the calculation the cross section of the stack was simply modeled as vertically aligned 4 rectangles of superconducting (SC) layers with $E=E_o(J(x,y,t)/J_c(B))^n$ in x-y plane where $E_o$ was $10^{-6}$ V/cm, $J_c$(B) was the field dependence of current density and n was 21. The field dependence of the critical current of the sample measured in four-probe method was employed for $J_c$(B) in the equation. The model was implemented in the finite element method program by commercial software. The ac loss properties for the stacks were compared with those of single 4 cm-wide SC layers with the same critical current density or the same critical current. The constraint for the simulation was imposed in two different ways that the total current of the stack obtained by integrating J(x,y,t) over the cross sections was the same as that of the applied transport current: one is that one fourth of the external current was enforced to flow through each SC. In this case, the ac loss values for the stacks were lower than those of single wide SC layer. This mitigation of the loss is attributed to the reduction of the normal component of the magnetic field near the SC layers due to the strong expulsion of the magnetic field by the enforced transport current. On the contrary, for the other case of no such enforcement, the ac loss values were greater than those of single 4cm-wide SC layer and. In this case, the phase difference of the current flowing through the inner and the outer SC layers of the stack was observed as the transport current was increased, which was a cause of the abrupt increase of ac loss for higher transport current.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.418-421
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• 2007

Using gridded wind-stress products constructed by satellite scatterometers (ERS-1, 2 and QSCAT) data and those by numerical weather prediction(NWP) model(NCEP-reanalysis), we estimate wind-driven transports of the North Pacific subtropical gyre, and compare them in the central portion of the gyre (around 300 N) with geostrophic transports calculated from historical hydrographic data (World Ocean Database 2005). Even if there are some discrepancies between the wind-driven transports by the QSCAT and NCEP products, they are both in good agreement with the geostrophic transports within reasonable errors, except for the regional difference in the eastern part of the zone. The difference in the eastern part is characterized by an anticyclonic deviation of the geostrophic transport resulting from an anti-cyclonic anomalous flow in the surface layer, suggesting that it is related to the Eastern Gyral produced by the thermohaline process associated with the formation of the Eastern Subtropical Mode Water. We also examine the consistency of the Sverdrup transports estimated from these products by comparing them with the transports of the western boundary current, namely the Kuroshio regions, in previous studies. The net southward transport, based on the sum of the Sverdrup transports by QSCAT and NCEP products and the thermohaline transport, agrees well with the net northward transport of the western boundary current, namely the Kuroshio transport. From these results, it is concluded that the Sverdrup balance can hold in the North Pacific subtropical gyre.

• 한국초전도학회:학술대회논문집
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• v.13
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• pp.93-93
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• 2003

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.1
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• pp.119-124
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• 2017

Objective: The death of animals during transport for slaughter is a major factor indicating the level of welfare in transported animals. The aim of this study was to assess mortality related to the commercial transport of finisher pigs for slaughter in the Czech Republic. Methods: The inspectors of the State Veterinary Administration of the Czech Republic recorded the numbers of finisher pigs transported to processing plants in the Czech Republic for slaughter and the mortality in these pigs in relation to transport in the period from 2009 to 2014. Results: Our results show that the likelihood of death losses in transported pigs increases with increasing transport distance. The transport-related mortality ranged from 0.049% in pigs transported for distances below 50 km to 0.145% in pigs transported for distances exceeding 300 km. The impact of external air temperature on the transport-related mortality found in our study clearly shows that current transport practices fail to ensure the welfare of pigs transported under other than moderate weather. Particularly cold temperatures below $-2^{\circ}C$ were associated with increased death losses in winter transport. Conclusion: Despite a decreasing trend in the mortality of finisher pigs transported for slaughter in Europe, our study suggests that current transport conditions are not efficient at ensuring the welfare of pigs during transport for longer distances and the protection of pigs against the negative impact of extreme ambient temperatures. Further research should focus on developing practical guidelines to improve the welfare of pigs in transit accordingly.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.144-151
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• 1998

This paper review current situation of New Transit System (NTS) which mainly developed by the western countries. The paper classified NTS by it capacity, physical appearance, and so on. It reviewed the brief history of LRT, which became new guided transport system in terms of transport environment especially for transport handicapped. It also includes the merit of Linear Metro, which could be popular for the urban transport system. Finally, the paper prospects the future of NTS for the planning of urban transport system.

• Journal of Ecology and Environment
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• v.31 no.1
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• pp.45-67
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• 2008

Ocean climate variables ($1900{\sim}2005$), time series of catches ($1910{\sim}2005$) and body size data were used to assess the year-to-year and decadal scale fluctuations in abundance of the fish populations (Japanese sardine, anchovy, jack mackerel, chub mackerel, Pacific saury and common squid) that have spawning grounds in the East China Sea and its adjacent regions. A negative correlation between the abundance of pelagic fishes (e.g. jack mackerel) in the Tsushima Warm Current (TWC) region and the Kuroshio-Oyashio Current (KOC) region was attributed to the climatic modulation of larval transport and recruitment, which depends on the winter monsoon-induced drift, current systems, and spawning season and site. The changes in abundance and alternation of dominant fish populations in the two regions in the 1930s, 1970s, and late 1980s mirrored changes in the climate indices (ALPI, AOI and MOI). Oscillations in the decadal climate shifts between the two regions led to zonal differences in larval transport and recruitment, and hence differences in the abundance of the pelagic fish populations. During deep Aleutian Lows, as in the 1980s, larval transport from the East China Sea to the KOC region increases in association with the strong winter Asian monsoon, cool regime and increased volume transport of the Kuroshio Current systems, whereas during a weak Aleutian Low (as in the 1990s), larval transport to the TWC region increased in association with a weak winter Asian monsoon, a warm regime, and increased volume transport of the Tsushima current system. We postulate that the increased chub mackerel abundance in the TWC region and the decreased abundance in the KOC region in the 1990s are partly attributed to changes in recruitment and availability to the fishing fleets under the warm regime in the spawning and nursery grounds in the East China Sea in association with the quasi-steady state of mild winter monsoon in the 1990s. The fluctuations in chub mackerel and jack mackerel abundance are under the environment-dependant growth form, although the tropicalization was identified in the TWC region. The density-dependant growth form was found in Japanese sardine populations, but no tropicalization by fishing was identified in the long ($10{\sim}15$ year) periods of abundance despite their short ($3{\sim}4$ year) generation time, suggesting that the environment-dependant growth form drove the changes in abundance. Year-to-year and decadal scale variations in abundance and population structure of the Pacific saury responded to climate regime shifts (1976/1977, 1988/1989), suggesting that the fish is a key bio-indicators for changes in the ecosystem.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.241-242
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• 2015

According to globalization of world economy on distribution and sales, logistics and transportation parts are play important role. Especially, it important to know and study how to choose right transport route and which is the key factor of route choice model in multimodal transport system. Thus this study aims to consider 4 main factors: cost, delivery time, freight, and logistics service factors additionally dividing into 13 sub factors and object is forwarders between Mongolia and Korean freight transport. The survey is based on AHP through interview with company officials. The paper provides empirical insights about current status of Mongolian forwarders and difference of the important factors between transportation modes. Result shows that time factor is role factor to choose transport route and then cost factors. Additionally, this study shows 2 different route choose factors between air transport and shipping transport forwarders.