• The Korean Journal of Quaternary Research
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• v.20 no.2
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• pp.30-50
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• 2006

The long-lived radionuclide, $^{10}Be$, is produced by cosmic-ray effects in the atmosphere of the earth as well as its surface and that of other planetary surfaces and atmospheres. Accelerator mass spectrometry (AMS) was developed in late 1970s, which made $^{10}Be$ terrestrial measurements more feasible. Since then, many research applications of $^{10}Be$ for both terrestrial and extraterrestrial applications have been developed, which parallel the wide range of radiocarbon ($^{14}C$) research applications. This paper summarizes production mechanisms of $^{10}Be$ both in the atmosphere and on the surface of terrestrial and extraterrestrial environments and also provides numerous $^{10}Be$ research applications in the fields of geomorphology, oceanography, archaeology, glaciology, cosmochemistry, climatology, and planetary science. We also review some $^{10}Be$ AMS research applications.

• Journal of The Geomorphological Association of Korea
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• v.26 no.4
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• pp.21-31
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• 2019

Timing of terrace formation is a key information for understanding the evolution of fluvial systems. In particular, dating strath terrace (i.e. timing of terrace abandonment) is more difficult than depositional terrace that is conventionally constrained by radiocarbon, OSL and other dating methods targeting samples within terrace deposit. Surface exposure dating utilizing cosmogenic ¹⁰Be provides more reliability because it can be applied directly to the surface of a fluvial terrace. Thus, this method has been increasingly used for alluvial deposits. As well as other geomorphic surfaces over the last decades. Some inherent conditions, however, such as post-depositional ¹⁰Be concentration (i.e. inheritance), surface erosion rate, and density change challenge the application of cosmogenic ¹⁰Be to depositional terrace surface against simple bedrock surface. Here we present the first application of ¹⁰Be depth profile dating to a thin-gravel covered strath terrace in Korea. Monte Carlo simulation (MCS) helped us in better constraining the timing of abandonment of the strath terrace, since which its surface stochastically denuded with time, causing unexpected change of ¹⁰Be production with depth. The age of the strath terrace estimated by MCS was 109 ka, ~4% older than the one (104 ka) calculated by simple depth profile dating, which yielded the best-fit surface erosion rate of 2.1 mm/ka. Our study demonstrates that the application of ¹⁰Be depth profile dating of strath terrace using MCS is more robust and reliable because it considers post-depositional change of initial conditions such as erosion rate.

• Journal of the Korean Vacuum Society
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• v.20 no.2
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• pp.135-140
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• 2011

By investigating photoluminescence (PL) spectra (20 K) of undoped and Be-doped p-type GaSb/GaAs epilayers, the origin has been analyzed by the change due to doping density. We have observed that the PL peak shifts to higher energy and the full-width half-maximum (FWHM) decreases with increasing the doping density below ${\sim}10^{17}cm^{-3}$, contrasted to shift to low energy and increasing FWHM above the density of ${\sim}10^{17}cm^{-3}$. From the variation of the integrated PL intensities of three peaks dissolved by Gaussian fit, it has been analyzed that, as the density increases, the $Be[Be_{Ga}]$ acceptor level (0.794 eV) reduces, whereas the intrinsic defect of $A[Ga_{Sb}]$ (0.778 eV) enhances together with a new $Be^*$ level (0.787 eV) locating between A and Be. We have discussed that it is due to coexistence of the Be acceptor level (${\Delta}E=16meV$) and the complex level (${\Delta}E=23meV$), $Be^*[Ga_{Sb}-Be_{Ga}]$combined by Be and A, in Be-doped p-GaSb, and that the level density of $Be[Be_{Ga}]$ may be reduced above ${\sim}10^{17}cm^{-3}$.

• Journal of the Korean Chemical Society
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• v.19 no.2
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• pp.98-103
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• 1975

The synthesis of two new ligands, 1,10-dibenzyltriethylenetetraamine (1,10-$Be_2trien$) and 1,10-dibenzyl-5R-methyltriethylenetetraamine (1,10-$Be_2$-5R-Metrien), and the preparation of the dichloro cobalt(III) complexes of these ligands are reported. Both tetraamine ligands yield exclusively trans geometry upon coordination to the cobalt(III) ion.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.2
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• pp.104-115
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• 2002

Core is the main component of inductor. This core should be classified into around 10 classes according to the value of inductance and Q. The coil should be winded with the outer-boundary of this core by different number of turns. Theses kind of precise inductors would be required in the future environment which PCs and communication devices demand more high speed and lower voltage level. It would be quite unefficient that only one core is classified once a time. There, it will be developed so that 10 cores are classified simultaneously. For the operation of classifying 10 cores once in a time, suppose 10 test instruments could be used. In this case, it would take much cost since a test instrument Is expensive. So, by using only one test instrument, it is really more desirable that this system is developed. Each core classified by 10 different classes is to be stored into the corresponding box through the corresponding rubber hose. 10 cores are passed on a serial line and are placed on each testing slot. Here, each core located at each slot is tested, and then the bowl located on the top of a step motor is moved into the corresponding spot by rotating step motor with some angles. Each bowl connected with the corresponding box through rubber hose. Actually 100 hoses are connected, 10 step motors are rotated at 10 different angles, so the size is really so big, the shape of connecting 100 hoses is so complicated. Therefore it is anticipated that the system would be going to be easily out of ordered. In this paper the main purpose is to make several suggestions to be able to work well in these kinds of being affected by the abnormal operation of motors and the flow of cores.

• Journal of the Korean earth science society
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• v.36 no.6
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• pp.512-519
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• 2015

Although Quaternary marine terraces and onshore paleo-shoreline records provide clues to our understanding for the mode and nature of neotectonics in the Korean peninsula, it cannot be accomplished without knowledge on both independent information of the past sea level records and tectonic deformation field together with precise results of numerical dating for higher terraces. This study reported cosmogenic radionuclides ($^{10}Be$) dating results conducted in higher terraces in the eastern and western coasts of the Korean peninsula. As a result, the measured concentration ratio of $^9Be/^{10}Be$ and the exposure ages were much younger than expected. It implies that either there is possibility of error in experimental processes or the samples experienced a complex exposure history probably included a burial at some stage. Considering the past climatic conditions around the Korean peninsula and a possible complex exposure history after the emergence of marine terrace, the discovery of a suitable study area and a sampling site are an essential part of successful $^{10}Be$ dating technique.

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.174-202
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• 2002

Twenty five patients, 14 males and 11 females with an average age of 75years with chronic Low Back Pain were tested before, during, and after 10minutes transcutaneous electrical nerve stimulation. It is important to consider the effect of TENS on the autonomic function because the pain pathway and the ANS pathway are somehow correlated to each other. There is still controversy among researchers who have reported the effect of TENS on autonomic function. So the purpose of this study is to measure the effect of TENS on the ANS and to see the relation of the pain control mechanism and the change in the ANS. The results were as follows : 1) Systolic blood pressure between before and during the experiment was apt to be a little increased, but statistically there was no significant change(P>.05). 2) Systolic blood pressure between during and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 3) Systolic blood pressure between before and after 10 minutes experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 4) Diastolic blood pressure between before and during experiment was apt to be a little increased, but statistically there was no significant change(P>.05). 5) Diastolic blood pressure between during and after 10 minutes experiment was significantly decreased(P<.05). 6) Diastolic blood pressure between before and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 7) Heart rate between before and during the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05). 8) Heart rate between during and after 10 minutes the experiment was significantly decreased(P<.05). 9) Heart rate between before and after 10 minutes the experiment was significantly decreased(P<.05). 10) Skin temperature between before and during the experiment was significantly increased(P<.05). 11) Skin temperature between during and after 10 minutes the experiment was apt to be a little increased, but statistically there was no significant change(P>.05). 12) Skin temperature between before and after 10 minutes the experiment was significantly increased(P>.05). 13) Respiratory rate between before and during the experiment was apt to be a little increased, but statistically there was no significant change(Pgt;.05). 14) Respiratory rate between during and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(Pgt;.05). 15) Respiratory rate between before and after 10 minutes the experiment was apt to be a little decreased, but statistically there was no significant change(P>.05).

• Journal of Korea Multimedia Society
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• v.24 no.5
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• pp.717-726
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• 2021

The zombies in AVG games are not divided into different game occupations. To address this issue, this paper starts by selecting those popular zombie games as the research object. Then, a number of samples will be collected from the roles of zombie and these different roles of zombie will be classified by profession depending on the characteristics of these roles. On this basis, the roles will be given a new title to describe their profession. Then, semantic analysis will be conducted to search for the words that can be used to describe the roles of zombie. Besides, there will be 10 experts in design and 10 professional zombie game players invited to choose from the collected adjectives. The most selected words will be used in this study to conduct cognition assessment, before the making of questionnaire. Then, the questionnaire data will be collected and converted into a statistical model form for indicating the value of ability by group and profession.

• Journal of Surface Science and Engineering
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• v.48 no.3
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• pp.93-99
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• 2015

This test focuses on the correlations between joining axial force at non-room temperature and at room temperature according to the surface treatment (Geomet, Dacro, Green Kote, Armore Galv.). The quality characteristics of the fastening axial force required by the KSB 2819 and EN14399-10 standards were discussed. Surface treatment was implemented to S10T and 10.9HRC sets of bolts under the same environmental factors. Development for the stabilization of the fastening axial force required by each standard should continually be enforced, and the fastening and storage in the field should be maintained at room temperature. Managing stabilization of torque enumerated data is required after application of surface treatment. It is concluded that, by conducting the test of applying surface treatment to effectively manage, each lot-specific rate of axial force at room temperature conditions should be maintained below the maximum 4.47%. The decline rate of axial force should be maintained under 2.15% maximum, and the standard deviation of the room temperature condition should be maintained below 0.5.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.12
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• pp.31-38
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• 1991

The current-voltage characteristics at annealed Be-Cu alloy(1.8-2 wt% Be, 0.2 wt% Co+Ni) interfaces have been studied by means of the cyclic voltammetric method. The specimens were annealed in nitrogen gas($N_{2}$) furnace at 36$0^{\circ}C$ for 1.5 hours. After annealing, the vickers hardness(HV) was increased from 210 to 385. The used solutions were distilled water(H$_{2}$O), 10$^{-3}M\;CsNO_{2},10^{-2}M\;KCl,10^{-2}M\;KOH,10^{-4}M\;H_{2}SO_{4}$ aqueous electrolytes, and ethylalcohol ($C_{2}H_{5}OH$), etc. The cyclic voltammograms showed significant current-voltage characteristics between the annealed and unannealed specimens at the same conditions. The age hardening and the related surface potential barrer and dissolution effects have been observed during the whole experimental process. The dissolution process of annealed Be-Cu alloys was effectively retarded by the age hardening phenomenon. The age hardening effect also raised the surface potential barrier of Be-Cu alloys. The interfacial phenomena of Be-Cu alloys seem to be one of good models for understanding the activation process.