• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.29-39
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• 1999

Both conventional and PI3 implanters require dense sources for high productivity rate, and small sheath expansion in PI3 besides. The problem of the creation of large volume uniform plasma in PI3 facilities replaces that of beam forming in accelerators. Some aspects of ion extraction in both cases and Langmuir probe plasma diagnostics with be discussed. Plasma parameters of large volume multicusp dc hot cathode and inductively coupled RF plasma sources obtained with Langmuir probe and ion mass analyzer with be presented. Design features and performances of high current Freeman and ECR ion sources will be described.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.213-218
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• 2017

High-voltage power systems operate in order to generate and transmit electric power at power stations. Compared to low-power systems, high-power systems are complex in structure, large-scale, and expensive. When high-power cable accidents occur, most facilities are incapacitated-including low-power systems-causing huge economic losses. Great care must therefore be taken in designing, installing and managing power systems. Although dependent on installation circumstances and usage conditions, in some cases the cross-sectional areas of cables fall short of the critical area due to the expansion of and improper design and installation of power facilities. In this situation, the exceeded ampacity (allowable current) above the critical value caused by the operating current initiates the deterioration processes of power cables. In order to systematically monitor power cables operating at power stations, we have developed the first device of its kind in Korea. In this paper, we present the analyzed characteristics of expected temperatures of cables based on the load current of high-voltage cables operating at Korean Western Power Co. Ltd. We can predict the lifetime of cables by analyzing the temperature obtained from our device.

• Journal of The Korean Astronomical Society
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• v.50 no.2
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• pp.29-39
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• 2017

We investigate two abnormal CME-Storm pairs that occurred on 2014 September 10 - 12 and 2015 March 15 - 17, respectively. The first one was a moderate geomagnetic storm ($Dst_{min}{\sim}-75nT$) driven by the X1.6 high speed flare-associated CME ($1267km\;s^{-1}$) in AR 12158 (N14E02) near solar disk center. The other was a very intense geomagnetic storm ($Dst_{min}{\sim}-223nT$) caused by a CME with moderate speed ($719km\;s^{-1}$) and associated with a filament eruption accompanied by a weak flare (C9.1) in AR 12297 (S17W38). Both CMEs have large direction parameters facing the Earth and southward magnetic field orientation in their solar source region. In this study, we inspect the structure of Interplanetary Flux Ropes (IFRs) at the Earth estimated by using the torus fitting technique assuming self-similar expansion. As results, we find that the moderate storm on 2014 September 12 was caused by small-scale southward magnetic fields in the sheath region ahead of the IFR. The Earth traversed the portion of the IFR where only the northward fields are observed. Meanwhile, in case of the 2015 March 17 storm, our IFR analysis revealed that the Earth passed the very portion where only the southward magnetic fields are observed throughout the passage. The resultant southward magnetic field with long-duration is the main cause of the intense storm. We suggest that 3D magnetic field geometry of an IFR at the IFR-Earth encounter is important and the strength of a geomagnetic storm is strongly affected by the relative location of the Earth with respect to the IFR structure.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.180-184
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• 2003

The intrauterine inseminator (IUI) was developed to provide the method of depositing dog semen into the uterine body instead of the vagina. The IUI consists of a vaginal endoscope, a balloon sheath, and injection catheter. When the endoscope is inserted into the vagina and the balloon expanded with air, the cervical os becomes visible so a injection catheter can be inserted through the cervix for deposition of the frozen-thawed semen. The efficacy of the IUI device was compared to intra-vaginal artificial insemination using semen that had been collected and frozen from pooled sperm-rich fraction of ejaculates collected from two Jindo dog donors. Aliquots of semen were extended with a Tris-egg yolk diluent, centrifuged, the seminal plasma removed, the pellet resuspended with the same diluent, and cooled to $5^{\circ}C$ over a 2 h period. A Tris-egg yolk-glycerol extender was added at $5^{\circ}C$; after 1 h, semen was loaded into 0.5 ml straws, and straws were frozen in LN vapor for 5 min, and immersed in LN for storage. The final sperm concentration for freezing was approximately $100{\times}10^{6}cells/ml$. The straws were thawed at $70^{\circ}C$ for precisely 6 sec, 1.5 ml Tris-egg yolk buffer at $38^{\circ}C$ added, and the 2 ml of thawed semen was used for a single insemination using the IUI device. Each bitch was inseminated at optimal insemination point, which was estimated by vaginal epithelial cells staining and progesterone concentration analysis. Use of the IUI device resulted in 21 of 26 females giving birth to 89 pups ($4.2{\pm}1.6$ pups per litter), while intra-vaginal AI resulted in 6 of 15 females whelping a total of 17 pups ($2.8{\pm}1.2$ pups per litter). We believe the IUI device is easier to use than previously described devices used for intrauterine insemination. In our experience the expansion of the balloon has a calming effect on the bitch that aids the inseminator. These results indicate that the IUI device was able to provide high fertility with 50 million frozen sperm per insemination and two inseminations.