• Electronics and Telecommunications Trends
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• v.32 no.6
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• pp.83-95
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• 2017

The trend of manycore hardware has recently evolved more quickly than expected. However, an operating system, which is software used for managing computer resources, is still optimized for a multicore system. To handle this issue, we started a research project called 'Research on High Performance and Scalable Manycore Operating Systems' in 2014. This article briefly examines the technology trends of manycore hardware and operating systems, and introduces the research areas and outcomes during the first stage of the project(2014-2017). The core technologies improving the performance scalability of manycore systems are publicly available, and anyone can use the source code or apply the ideas of the core technique to other research activities. In addition, the research plans of the second stage of the project(2018-2021) are also included.

• Restorative Dentistry and Endodontics
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• v.45 no.3
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• pp.27.1-27.9
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• 2020

Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical 'bone-window technique' using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess. Periapical lesions were confirmed using cone-beam computed tomography (CBCT). Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.97-103
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• 2015

The first part of this study reviewed the characteristics of calcium hydroxide ($Ca(OH)_2$) and summarized the results of in vitro studies related to its antimicrobial effects. The second part of this review covers in vivo studies including human clinical studies and animal studies. The use of $Ca(OH)_2$ as an intracanal medicament represented better histological results in animal studies. However, human clinical studies showed limited antimicrobial effects that microorganisms were reduced but not eliminated through the treatment, and that some species had resistance to $Ca(OH)_2$. Most of clinical outcome studies supported that there is no improvement in healing of periapical lesions when $Ca(OH)_2$ was applied between appointments. Further studies are required for the antimicrobial effects of $Ca(OH)_2$, and search for the ideal material and technique to completely clean infected root canals should be continued.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.241-252
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• 2014

The goal of endodontic treatment is the prevention and control of pulpal and periradicular infections. Calcium hydroxide ($Ca(OH)_2$) has been widely used in endodontics as an intracanal medicament to eliminate the remaining microorganisms after chemomechanical preparation. The purpose of this article is to review the antimicrobial properties of $Ca(OH)_2$ as an intracanal medicament in root canal treatment. The first part of this review details the characteristics of $Ca(OH)_2$ and summarizes the results of in vitro studies related to its antimicrobial effect. The antimicrobial effect of $Ca(OH)_2$ results from the release of hydroxyl ions when it comes into contact with aqueous fluids. $Ca(OH)_2$ has a wide range of antimicrobial effects against common endodontic pathogens, but is less effective against Enterococcus faecalis and Candida albicans. The addition of vehicles or other agents might contribute to the antimicrobial effect of $Ca(OH)_2$.

• Restorative Dentistry and Endodontics
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• v.38 no.3
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• pp.113-118
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• 2013

Nowadays, oral anticoagulants are commonly prescribed to numerous patients for preventing cardiovascular accident such as thromboembolism. An important side effect of anticoagulant is anti-hemostasis. In a major surgery, the oral anticoagulant therapy (OAT) regimen must be changed before the surgery for proper post-operative bleeding control. However, in a minor dental surgery and endodontic surgery, the necessity for changing or discontinuing the OAT is open to debate. In this study, risks of the consequences were weighed and analyzed. In patients who stop the OAT, the occurrence of thromboembolic complication is rare but the result is fatal. In patients who continuing the OAT, post-operative bleeding can be controlled well with the local hemostatic measures. In the endodontic surgery, there are almost no studies about this issue. The intra-operative bleeding control is particularly important in the endodontic surgery because of its delicate and sensitive procedures such as inspection of resected root surface using dental microscope and retrograde filling. Further studies are necessary about this issue in the viewpoint of endodontic surgery.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.871-878
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• 2018

The government of Gyeongbuk in Korea increased the financial input in the agricultural sector by 43% from 2008 through 2012. However, the productivity of the agricultural sector in Gyeongbuk rose only about 3.6% during the same period. This study evaluated the agricultural competitiveness of each city or county in Gyeongbuk using six evaluation indices (scale, productivity, finance input, location quotient, technical education, and total) and investigated the relationship between the indices and total values of agricultural productions. The results show that Sangju, Gyeongju, Andong, Uiseong, and Seongju have high competitiveness for the scale index. For the productivity index, Gimcheon, Mungyeong, Ulleung, Yeongju, and Seongju were highly evaluated. For the location quotient index, Yeongcheon, Uiseong, Cheongdo, Seongju, and Sangju have high competitiveness. Uiseong, Yeongdeok, Cheongsong, Gunwi, and Yeongyang were highly evaluated for the agricultural finance input index. For the agricultural technical education index, Chilgok, Sangju, Mungyeong, Uiseong, and Gyeongju have high competitiveness. Finally, Sangju, Euiseong, Yeongcheon, Gyeongju, and Andong were highly evaluated for the total competitive index, while Yeongdeok, Yeongyang, Goryeong, Uljin, and Cheongsong have a low competitiveness for the total competitive index. This study also found that out of five indices, scale, location quotient, and technical education indices have a positive and statistically significant effect on the total values of agricultural production. However, we did not find any statistically significant effect of the productivity and finance input indices on the total values of agricultural production. Hence, we can conclude that the government should focus their agricultural policy on scale, location quotient and education to improve total agricultural production.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.207-211
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• 2019

Research and development are underway to connect the network to all things in the world and to manage the objects through the Internet. The Internet of Things is expected to play an important role in building ecosystem of next generation mobile communication service. The most significant communication technology is LPWAN. In this paper, we analyze the performance according to each data transmission rate to reduce and manage resource waste by using many LPWAN nodes more efficiently in accordance with the demands of the times. The LPWAN communication technology used in this paper was designed based on LoRaWAN, a long-distance low-power wireless platform developed by Semtech, and analyzed by implementing a virtual IoT base using Network Simulator-3.

• Economic and Environmental Geology
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• v.25 no.4
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• pp.417-433
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• 1992

Lead-zinc-copper deposits of the Jeonheung and the Oksan mines around Euiseong area occur as hydrothermal quartz and calcite veins that crosscut Cretaceous sedimentary rocks of the Gyeongsang Basin. The mineralization occurred in three distinct stages (I, II, and III): (I) quartz-sulfides-sulfosalts-hematite mineralization stage; (II) barren quartz-fluorite stage; and (III) barren calcite stage. Stage I ore minerals comprise pyrite, chalcopyrite, sphalerite, galena and Pb-Ag-Bi-Sb sulfosalts. Mineralogies of the two mines are different, and arsenopyrite, pyrrhotite, tetrahedrite and iron-rich (up to 21 mole % FeS) sphalerite are restricted to the Oksan mine. A K-Ar radiometric dating for sericite indicates that the Pb-Zn-Cu deposits of the Euiseong area were formed during late Cretaceous age ($62.3{\pm}2.8Ma$), likely associated with a subvolcanic activity related to the volcanic complex in the nearby Geumseongsan Caldera and the ubiquitous felsite dykes. Stage I mineralization occurred at temperatures between > $380^{\circ}C$ and $240^{\circ}C$ from fluids with salinities between 6.3 and 0.7 equiv. wt. % NaCl. The chalcopyrite deposition occurred mostly at higher temperatures of > $300^{\circ}C$. Fluid inclusion data indicate that the Pb-Zn-Cu ore mineralization resulted from a complex history of boiling, cooling and dilution of ore fluids. The mineralization at Jeonheung resulted mainly from cooling and dilution by an influx of cooler meteoric waters, whereas the mineralization at Oksan was largely due to fluid boiling. Evidence of fluid boiling suggests that pressures decreased from about 210 bars to 80 bars. This corresponds to a depth of about 900 m in a hydrothermal system that changed from lithostatic (closed) toward hydrostatic (open) conditions. Sulfur isotope compositions of sulfide minerals (${\delta}^{34}S=2.9{\sim}9.6$ per mil) indicate that the ${\delta}^{34}S_{{\Sigma}S}$ value of ore fluids was ${\approx}8.6$ per mil. This ${\delta}^{34}S_{{\Sigma}S}$ value is likely consistent with an igneous sulfur mixed with sulfates (?) in surrounding sedimentary rocks. Measured and calculated hydrogen and oxygen isotope values of ore-forming fluids suggest meteoric water dominance, approaching unexchanged meteoric water values. Equilibrium thermodynamic interpretation indicates that the temperature versus $fs_2$ variation of stage I ore fluids differed between the two mines as follows: the $fs_2$ of ore fluids at Jeonheung changed with decreasing temperature constantly near the pyrite-hematite-magnetite sulfidation curve, whereas those at Oksan changed from the pyrite-pyrrhotite sulfidation state towards the pyrite-hematite-magnetite state. The shift in minerals precipitated during stage I also reflects a concomitant $fo_2$ increase, probably due to mixing of ore fluids with cooler, more oxidizing meteoric waters. Thermodynamic consideration of copper solubility suggests that the ore-forming fluids cooled through boiling at Oksan and mixing with less-evolved meteoric waters at Jeonheung, and that this cooling was the main cause of copper deposition through destabilization of copper chloride complexes.

• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.298-302
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• 2005

In order to decide the optimum planting time for Bupleurum falcatum L. which is grown widely in Korea, some experiments were carried out in different regions such as mid-north area (Gangwon-do, Gyeonggi-do and Chungcheongnamdo), mid-south area (Jeollanam-do, Jeollabuk-do, Gyeongsangnam-do and Gyeongsangbuk-do). The mid-south area had the highest total saikosaponin contents of 1.001, which is the medicinal ingredients of Bupleurum falcatum L., in accordance with the different Bupleurum falcatum L. regions. Also this area has the highest extract contents of 24.3%. Average dry root yields in mid-north area (Gangwon-do) were $450{\sim}460$ kg/ha at planting time of March 20th to March 30th, 500 kg/ha at the time of March 30th to April 10th, and $470{\sim}480$ kg/ha at the time of March 10th to March 20th in Chungcheongnam-do. The optimum planting time in the mid-south area (Jeollabuk-do) was March 10th to March 30th with the average dry root yield of $490{\sim}550$ kg/ha. Average dry root yield in Euiseong, Gyeongsangbuk-do area was 470 kg/ha, and the optimum planting time was April 10th, which suggested that the yield increased as the planting time was delayed. At Jeju-do, the volcanic soil of farsouthern area, average dry root yield was 510 kg/ha at the time of March 10th, but the yield from non-volcanic soil was lower than from volcanic soil, which had a dry root yield of 470 kg/ha.

• The Journal of the Korean dental association
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• v.54 no.11
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• pp.865-873
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• 2016

Background/Purpose: The purpose of this study was to evaluate the effect of Nd:YAG irradiation on adherence of retrograde filling materials (mineral trioxide aggregate [MTA] and Super-EBA) by micro-computed tomography (CT) measurement and to observe the dentinal surface after irradiation by scanning electron microscopy (SEM). Materials and methods: Forty retrofilling models using extracted human teeth were divided into four groups according to the material and method used: ProRoot MTA (MTA group), Super-EBA (EBA group), MTA with Nd:YAG laser irradiation (LMTA group), and Super-EBA with Nd:YAG laser irradiation (LEBA group). All specimens were stored in 100% humidity for 24 hours until micro-CT was performed. The gap volume of the tooth/material interface was measured using the CTAn program. In six samples, the laser-irradiated dentin surface was observed using SEM. Results: The mean percent difference in gap volume was not statistically significant between the Nd:YAG laser-irradiated groups and non-irradiated in both materials(P > 0.05). The gap volume in the MTA group was significantly lower than that in the EBA group (P < 0.05). Examination of the non-irradiated specimens by SEM showed patent dentinal tubules. In contrast, alterations in the texture of the dentin surface and obliteration of the dentinal tubules were evident in the Nd:YAG laser-irradiated specimens. Conclusion: In this study, changes in the dentinal surface after Nd:YAG irradiation did not affect adherence between the apical filling material and the dentin wall.