• Journal of IKEEE
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• v.25 no.1
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• pp.174-179
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• 2021

An Edwards curve cryptography (EdCC) core supporting point scalar multiplication (PSM) on Edwards curves of Edwards25519 and Edwards448 was designed. For area-efficient implementation, finite field multiplier based on word-based Montgomery multiplication algorithm was designed, and the extended twisted Edwards coordinates system was adopted to implement point operations without division operation. As a result of synthesizing the EdCC core with 100 MHz clock, it was implemented with 24,073 equivalent gates and 11 kbits RAM, and the maximum operating frequency was estimated to be 285 MHz. The evaluation results show that the EdCC core can compute 299 and 66 PSMs per second on Edwards25519 and Edwards448 curves, respectively. Compared to the ECC core with similar structure, the number of clock cycles required for 256-bit PSM was reduced by about 60%, resulting in 7.3 times improvement in computational performance.

• English & American cultural studies
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• v.18 no.4
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• pp.33-64
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• 2018

Through the experimental narrative construction by authorial divinity, Muriel Spark's novels and films based on her fiction show the difficulty of living like a human being under various inhumane and manipulative circumstances of the modern capitalistic society. By adopting flash-forward, self-reflection, and deceptive omnipotent viewpoints, her work has surprisingly predicted the post-modern trend in which humans are increasingly attracted and interpellated to the digitalized media. Muriel Spark called the recent anesthetic situation by stimulation "a driver's seat" because it is a symbol of how humans should act to maintain the critical subject. Emphasizing the value of self-reflection, religion and morality in the mechanized society, Muriel Spark stressed literature should play the role of helmsman who sails safely in the rough sea. In Muriel Spark's works, God is often synonymous with writers. As a Jewish immigrant she experienced alienation in Scotland, marital violence, prejudices of the London-based publishing world, Nazism, and Watergate. For her, the harsh reality of the modern society needs to be guided and complemented by something beyond human control. But rather than relying entirely on traditional Catholic doctrines such as Graham Greene and Evelyn Waugh, Muriel Spark has taken a personal, religious view of literature and insists that the genuine writer must play God's play. Seeking for the speculative vision for the future of human life in God's plan, she tries to understand the complex twisted motives of human beings which are often far from the ideal form. Simply put, her search of self-reflection, religion and ethics is modeled on the God's plan for the ideal human being who is supposed as the writer with the transfigurative imagination of the trinity.

• Archives of Craniofacial Surgery
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• v.22 no.6
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• pp.296-302
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• 2021

Background: The reconstruction of large full-thickness alar defects requires complex surgical procedures that are usually performed in two stages, with concomitant disadvantages in terms of patient trauma, surgical risk, and cost. This study presents a functional folded nasolabial island flap (FNIF) that can be used to repair large-sized full-thickness alar defects in a straightforward manner. Methods: This retrospective study included seven patients who received a FNIF for a full-thickness alar defect between January 2007 and December 2020. The FNIF is different from the conventional nasolabial flap in that it is folded and twisted to achieve nostril reconstruction with a satisfactory three-dimensional mucosal lining in a single stage. The cosmetic and functional results of FNIF were evaluated by both patients and physicians. Results: The age ranged from 51 to 82 years (mean, 65.6 years). The causes of the defects were squamous cell carcinoma, basal cell carcinoma, and trigeminal trophic syndrome. The nostril lining did not collapse, there was no hypertrophic scarring, and air movement through the nostrils on the flap side was normal. Overall, FNIF produced excellent aesthetic and functional outcomes, with minimal patient discomfort. There were no postoperative complications. Conclusion: Compared with existing reconstruction methods for large full-thickness alar defects, FNIF can easily achieve aesthetic and functional success in a single-stage procedure. It provides satisfactory results for both the patient and the surgeon.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.1
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• pp.58-65
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• 2022

The field of liquid crystal display (LCD) is constantly in the spotlight and the process of depositing an alignment layer in the LCD manufacturing process is very important to obtain excellent performance such as low-power driving and high-speed response to improve LCD performance. Therefore, research on liquid crystal (LC) alignment is being actively conducted. When manufacturing LCD, it is necessary to consider the effect of the alignment layer thickness as one of the factors affecting various LCD performances. In addition, previous studies confirmed the LC alignment characteristics correlate with the rotation speed in the spin coating process. Therefore, the electro-optical properties of the LCD were investigated by manufacturing a polyimide alignment layer by varying the rotation speed in the spin coating process in this study. It was confirmed that the thickness of the polyimide alignment layer was controlled according to the spin coating conditions. The average transmittances of anti-parallel LC cells at the spin coating speed of 2,500 rpm and 3,000 rpm are about 60%, which indicates that the LC cell has relatively higher performance. At the spin coating speed of 3,000 rpm, the voltage-transmittance curve of twisted nematic (TN) LC cell was below 1.5 V, which means that the TN LC cell operated at a low power. In addition, high-speed operating characteristics were confirmed with a response time of less than 30 ms. From these derived data, we confirmed that the ideal spin coating speed is 3,000 rpm. And these results provide an optimized polyimide alignment layer process when considering enhanced future LCD manufacturing.

• Animal Systematics, Evolution and Diversity
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• v.38 no.4
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• pp.226-237
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• 2022

Arcuospathidium is a haptorian ciliate genus composed of 18 species, and only one species has been reported in Korea. Here, we identify two unrecorded Arcuospathidium subspecies by morphological observation of both living and protargol-impregnated specimens with the small subunit ribosomal RNA (18S rRNA) gene sequence. These subspecies, Arcuospathidium cultriforme cultriforme (Penard, 1922) Foissner, 1984 and A. cultriforme scalpriforme (Kahl, 1930) Foissner, 2003, were isolated from various terrestrial habitats in July and August 2013, respectivley. Arcuospathidium cultriforme cultriforme is similar to A. cultriforme scalpriforme by a knife-shaped body, a twisted-shaped macronucleus, number of dorsal brushes, position of dorsal brushes, and shape of macronucleus but former mainly differs from the body length to oral bulge length ratio (27-38% vs. 41-53%), extrusome (one types vs. three types), cyst shape (roughly faceted wall vs. smooth surface and thin wall) and number of somatic kinety rows(18-30 vs. 30-44). Additionally, we analyzed the 18S rRNA gene sequences of two A. cultriforme subspecies and compared them with the sequences from GenBank to confirm their identification at the molecular level. As the results of genetic analysis, the 18S rRNA gene sequence of the Korean A. cultriforme cultriforme population is most similar to that of Austrian population. Also, the sequence of the Korean A. cultriforme scalpriforme population is most similar to that of another population with some nucleotide differences.

• Design & Manufacturing
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• v.16 no.1
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• pp.36-42
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• 2022

Globally, as population growth and economic development continue, resource consumption is increasing rapidly. As an alternative to electric vehicles was suggested as the environmental pollution problem emerged, the number of registered electric vehicles in Korea increased by more than 137 times compared to 2013. Secondary batteries are expected to expand into various markets such as small IT devices and electric vehicles, and the most important part of electric vehicles is the battery (secondary battery). Therefore, in this study, to analyze the stability of the CSM (Classifier Separator Mill) grinding disc that crushes secondary battery raw materials, structural analysis and vibration analysis of the 1st to 4th grinding discs and the final model were performed. The change of bending by the weight of the Grinding Disc is at least 0.065㎛ and maximum 0.075㎛, and the change by the standard gravity is judged to be very low. The strain is at least 0.00031㎛/㎛ and maximum 0.00078㎛/㎛, and even if the number of Hamer increases, the change by the weight is judged to be insignificant. When the Grinding Disc rotates at a maximum of 6000rpm, the deformation and deformation rate of the first to third models are similar, but the fourth model (Hamer 10EA) is more than three times and the final model (Hamer 12EA) is about four times. However, the maximum deformation is 28.21㎛, which is considered to be insignificant when the change is 6000rpm. Six modes of natural Frequency analysis of the 1st~4th order and final model of the grinding disc appeared to be bent or twisted.

• Journal of the Korean Wood Science and Technology
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• v.50 no.4
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• pp.219-236
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• 2022

Wood-based nanocomposite electrode materials were synthesized for application in supercapacitors by mixing nanostructured hematite (Fe₂O₃) with highly porous activated carbon (AC) produced from the wood-waste of Pinus roxburghii. The AC was characterized using various instrumental techniques and the results showed admirable electrochemical properties, such as high surface area and reasonable porosity. Firstly, AC was tested as an electrode material for supercapacitors and it showed a specific capacitance of 59.02 Fg^-1 at a current density of 1 Ag^-1, cycle life of 84.2% after 1,000 cycles (at a current density of 3 Ag^-1), and energy density of 5.1 Wh/kg at a power density of 135 Wkg^-1. However, when the AC was composited with different ratios of Fe₂O₃ (1:1, 2:1, and 1:2), there was an overall improvement in its electrochemical performance. Among the 3 ratios, 2:1 (AC:Fe₂O₃) had the best specific capacitance of 102.42 Fg^-1 at 1 Ag^-1, cycle life of 94.4% capacitance after 1,000 cycles (at a current density of 3 Ag^-1), and energy density of 8.34 Wh/kg at a power density of 395.15 Wkg^-1 in 6 M KOH electrolyte in a 3-electrode experimental setup with a high working voltage of 1.55 V. Furthermore, when Fe₂O₃ was doubled, 1:2 (AC:Fe₂O₃), the electrochemical capacitive performance of the electrode twisted and deteriorated due to either the accumulation of Fe₂O₃ particles within the composite or higher bulk resistance value of pure Fe₂O₃.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.1
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• pp.1-9
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• 2023

In order to improve the propeller cavitation performance composed of Cavitation Inception Speed (CIS), cavitation extent and pressure fluctuation, it needs to improve the wake distribution that flows into the propeller. The warship propeller cavitation is strongly influenced by the wake created at the V-strut of various appendages. The inflow characteristics of the V-strut were investigated using Computational Fluid Dynamics (CFD) and the twisted angles of the V-strut were aligned with upstream flow. The resistance and self-propulsion tests for the model ship with the existing and modified V-struts were conducted in Towing Tank (TT), and wake distribution, CIS, cavitation observation and pressure fluctuation tests were conducted in Large Cavitation Tunnel (LCT). The propeller behind the modified V-strut showed better cavitation characteristics than that behind the existing V-strut. Another model test was conducted to investigate rudder cavitation performance by the change of the V-strut. The rudder cavitation characteristics were not improved by the change of the operating conditions. On the basis of the present study, it is thought that the stern appendages for better propeller cavitation performance would be developed.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.4
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• pp.231-239
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• 2023

In order to improve the propeller Cavitation Inception Speed (CIS) performance, it needs to modify the propeller geometry and the wake distribution that flows into the propeller. In the previous study, the twisted angles of the V-strut were modified to improve propeller CIS, cavitation behavior and pressure fluctuation performances. Then the propeller behind the modified V-strut (New strut) showed better cavitation characteristics than that behind the existing V-strut (Old strut). However, the CIS of Suction Side Tip Vortex (SSTV) and Pressure Side Tp Vortex (PSTV) showed a big difference at behind each V-strut. In this study, the balance design is conducted to minimize the difference between SSTV CIS and PSTV CIS at behind each V-strut. To improve the propeller CIS performance, 1 propeller is designed at behind the old strut and 3 propellers are designed at behind the new strut. The propeller CIS is increased through the balance design and the stern appendage modification. The final propeller CIS is increased about 5.3 knots higher than that of the existing propeller at behind the old strut. On the basis of the present study, it is thought that the better improvement method for the propeller CIS would be suggested.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.665-681
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• 2022

This article compared and analyzed the SF films Snowpiercer and Space Sweepers, which embody the imagination of disaster for the future dystopian society. In common, the two films represent the future society as a society with a serious climate crisis and an extremely widening gap between the rich and the poor. Both films use similar narrative strategies: representing a isolated, twisted-willed scientist figure, building a main stage as catastrophic hierarchical capitalist society, and focusing on the conflicts between a dominant group possessing the science-capital-power and a resistant but ordinary subjects. However, there is the different framing on the future society in terms of representing nature, science technology, and human-nonhuman agency. This distinction is shaped by the narrative function of the objects represented by two films.