• Progress in Superconductivity and Cryogenics
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• v.17 no.1
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• pp.17-20
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• 2015

Coated conductor is an important candidate for power cable applications due to its high current density. Even for DC power cable transmission, we must study the transport properties of HTS tapes after slow and fast discharge. In order to evaluate relation of the magnetic field with applied current we developed a scanning magnetic field measurements system by employing a Hall probe. This work presents the measurements of the magnetic fields above a coated conductor by varying applied current pattern. In the work, a transport current of 100 A, less than the critical current, is applied to YBCO coated conductor. We measured the residual magnetic field distributions after cut off the transport current with slow and fast operations. The results show differences of the magnetic field profiles and the corresponding current profiles by an inverse solution from the magnetic field measurement between these two operations because of the hysteresis of coated conductor excited by the transport current.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.4
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• pp.261-266
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• 2018

When the clamp meter approaches the electric path where current is flowing, leakage current can be measured at a distance from the electric current because the induced current increases as the magnitude of the current increases and approaches nearer to the electric path. Therefore, measurements were carried out from a distance to avoid this effect. In addition, the measured values differ depending on the location of the power line that penetrates the ZCT of the clamp meter, thus measurements were performed at a location where this effect was minimized. The fraction of compliant branch circuits, whose leakage current was lower than 1.00 mA, was found to be 69.0% out of the total of 439 branch circuits, while the percentage of compliant branch circuits having an insulation resistance higher than $0.20M{\Omega}$ was found to be 93.2%. The reason why the percentage of compliant branch circuits with low leakage current was low might be due to the inclusion of capacitive leakage current in the total measured leakage current.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.9
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• pp.1397-1406
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• 2008

This research was to develop Taekwondo trunk protector(Hogu) and head protector's sizing systems corresponding the regulations by World Taekwondo Association. These sizing systems were established using 2003-2004 Size Korea anthropometric data. The result can be summarized as follows: According to the analysis of correlation, most measurements had high relationship with weight for Hogu and head girth for head protector. Six sizes(47, 54, 59, 64, 70, 76) for Hogu and 4 sizes(52, 54, 56, 60) for head protector were suggested in this study. Hogu sizes indicate body weights and head protector sizes express head girth measurements. By the comparison between current Hogu sizes and new sizes, the smaller sizes of new Hogu were bigger than current sizes in bust girth, back fastening length, shoulder length. On the other hand, the bigger sizes of new Hogu were larger than current sizes in bust girth, back fastening length, shoulder length. In addition, new Hogu's lengths were shorter than current Hogu in all sizes. The lengths of Neck to collar bone in new Hogu sizes were longer than current Hogu. In case of the head protector, there were no measurements besides outer circumference of helmet in recognized specifications of WTF. Therefore some referable measurements such as head girth, head length, bitragion arc, sagital arc were suggested in new size specification. When helmet sizes were suggested, the thickness of the NBR foam also were considered.

• 연구논문집
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• s.27
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• pp.175-181
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• 1997

Superconducting joints between Bi-2223/Ag tapes are fabricated by a press & reaction anneal and a multiple press & anneal. The silver sheath was mechanically or chemically removed from one side of each tape without altering the superconducting core. The exposed superconducting core of the two tapes were brought into contact and pressed so as to form a lap joint. The joined tapes were then subjected to a series of different thermomechanical treatments to achieve optimum heat treatment condition. The result from transport measurements shows that critical current ($I_c$) transmitting through joined area reaches 9A, approximately 60% of the current capacity of the tapes themselves. The critical current through joined area was improved by repeated press and reaction annealing. Measurements of the current-voltage relationship were made with several configuration of the voltage probes to characterize the critical current variation and I-V curve along the joint. Also discussed are microstructural aspects of the superconducting joint.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.426-429
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• 1999

In this paper, we have provided the measurement technique of the grounding mesh resistance by field measurements. The standard of measurement is specified in the IEEE Std 81.2-1991 and JEAC 5001-1988, which is the the fall-of-potential method by test-current injection, but this method is difficult to apply at field, where is small around a electric power substation of domestic. For the convenient measurement method, space of assistant probe and quantity of test-current injection are changed step for step. As the result, ' the proposed measurement technique of grounding mesh resistance is that the space of current and potential probes must be fixed at 150rn from a grounding mesh, the test-current injection has to keep 5A or more.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.43-59
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• 2017

This study used data from a survey of adult Korean women in their twenties to learn their current practices for wearing and purchasing tight-fit jeans available on the market as well as perceptions regarding size measurements and satisfaction levels. We then determined product sizes and pattern measurements for the type of jeans worn. This study also analyzed discrepancies in product size measurements among brands to determine whether the measurements were generally suitable for average body shapes and measurements of women in their twenties. The study results were as follows. First, the survey asked women in their twenties about current practices in wearing jeans. Many respondents answered that their preferred fit is "a perfectly snug fit" and that the most common fit style of jeans was the skinny fit. Second, we selected a test pair of jeans with an identical fiber content from brands that women prefer to wear, according to the survey results. We researched the product measurements of the size respectively labeled 27 inches for each of the 8 brands' test jeans; consequently, the results showed that there were significant differences among the brands in the product measurements of each part of jeans. Third, we analyzed the pattern measurements of 8 selected brands for each area and identified pattern characteristics by brand.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.100-108
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• 2006

Time-resolved current and voltage measurements for an inductive automotive spark system were made. Also presented are measurements of the total energy delivered to the spark gap. The measurements were made in air for a range of pressures from 1-18atm, at ambient temperatures. The measured voltage and current characteristics were found to be a function of many ignition parameters; some of these include: spark gap distance, internal resistance of the spark plug and high tension wire, and pressure. The voltages presented were measured either at the top of the spark plug or at the spark gap. The measurements were made at different time resolutions to more accurately resolve the voltage and current behavior throughout the discharge process. This was necessary because the breakdown event occurs on a time scale much shorter than the arc and glow phases. The breakdown, are, and glow voltages were found to be functions of spark plug resistance, gas density, and spark plug gap as expected from the literature. Spark duration was found to decrease as either pressure or gap was increased. The transition from the arc to glow phase is usually distinguished by a sudden rise in the voltage across the gap. At pressures above about 7atm this transition was not observed suggesting that a glow phase was not present. Energy delivered to the gap increased with increasing pressure. The effective resistance of the spark gap during discharge was about twice as large for the glow phase as the arc phase.

• 한국초전도학회:학술대회논문집
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• v.11
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• pp.57-57
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• 2001

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.2
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• pp.107-117
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• 2010

The atmospheric geochemistry of mercury is generalls represented by gaseous elemental phase that exhibits the high environmental mobility and relatively long atmospheric residence time (c.a., 1 year) with its high chemical stability. In the recognition of the environmental significance of its global cycling, enormous efforts have been devoted to the measurements of Hg exchange across air-soil boundary. To be able to describe the fundamental aspects on this subject, the current development in the measurements of atmospheric exchange rates of mercury has been summarized using the current database reported worldwide. As a first step, different techniques commonly employed in its measurements are introduced with the discussions on their merits and disadvantages. Then, the results derived from various field measurement campaigns are also compared and discussed. The direction for the future study of mercury is presented at last.

• Ocean and Polar Research
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• v.33 no.4
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• pp.409-419
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• 2011

Semi-diurnal internal tides and near-inertial waves are investigated using moored current meter measurements at four sites along the shelf break of the East China Sea during August 1987 and May-June 1988. Each mooring is equipped with four current meters spanning from near surface to near bottom. Spectral analyses of all current data reveal dominant spectra at the semi-diurnal frequency band, where the upper and lower current measurements show out-of-phase relationship between them with significant coherences. These are consistent with typical characteristics of the first-mode semi-diurnal internal tide. Strong intensification of the near-bottom baroclinic currents is observed only at one site, where the ratio of the bottom slope to the slope of the internal-wave characteristics at the semi-diurnal frequency is close to unity. An energetic near-inertial wave event is observed during the first half of May-June 1988 observation at two mooring sites. Rotary spectra reveal that the most dominant signal is clockwise rotating motion at the near-inertial frequency band. Upward phase and downward energy propagations, shown in time-depth contour plots of near-inertial bandpass filtered currents, are confirmed by cross correlations between the upper- and lower-layer current measurements. The upward-propagating phase speed is estimated to be about 0.13 cm $s^{-1}$ at both sites. Significant coherences and in-phase relationships of near-inertial currents at the same or similar depths between the two sites are observed in spite of their long distance of about 110 km.