• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.196-202
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• 2011

In this paper, a series of alkyl succinic acid esters for base oil were synthesized by condensation reaction of succinic anhydride and fatty alcohol. The structures of the synthesized esters were confirmed by $^1H-NMR$, FT-IR spectrum and GC analysis. Basic properties of esters such as kinematic viscosity (KV), refractive index (RI), total acid number (TAN) and pour points were measured and lubricating properties such as SRV wear scar diameter (SRV WSD), fraction coefficient (COF) and 4-ball wear (4-ball WSD) were also evaluated. As the results of basic properties, KV, RI and pour point of synthetic esters increased as the carbon chain of the esters increased. Measurement value of total acid number (TAN) was indicated between 0.2~4 mgKOH/g, and that metal working fluids and pressure working oils are acceptable to use as base oil. Also, lubricating properties of the esters showed as follows: 0.391~0.689 mm of SRV WSD, 0.110~0.138 of SRV COF and 0.49~0.55 mm of 4-ball WSD depended on the structure of the esters. In a comparison on the lubrication capacity of the SRV test based on polyester TMPTO, SRV WSD result showed that a better performance caused by the alkyl group. On the other hand, SRV COF test was not influenced of the alkyl group which the capacity of the lubricant was sightly diminished than the comparison material, regardless of the alkyl group.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.4
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• pp.1-13
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• 2014

As part of reconsideration on naming of the scenic site No.1 "Myeongju Cheonghak-dong Sogumgang," this study attempts to identify whether there is any mistake with reference to place naming of Korea's No.1 scenic site and if so, to correct the problem by examining the origin of the name and its transition progress through analysis and interpretation of old maps, ancient documents such as traditional geographic books, Yusangi(遊山記) and Letters Carved on the Rocks. The findings of this study are as follows: In traditional geographic books, a term of 'Mt. Cheonghak(靑鶴山)' was first found from "SinjungDonggookyeojisungram(新增東國輿地勝覽)" and after a place name, 'Sogumgang(小金剛)' first appeared in "Yeojidoseo(輿地圖書)" in the middle of the 17th century, it was reproduced in "Jungsuimyeongji(增修臨瀛誌)", which was published in the early 20th century. However, as a result of analyzing old maps, the place name, Sogumgang cannot be found in any local or national map except place names such as Cheonghak-dong, Mt. Cheonghak and Temple Cheonghak. Even though 'Biseonam,' 'Cheonyudong,' 'Gyeongdam' and 'Mt. Cheonghak' appear in Yulgok's "Yucheonghaksangi(遊靑鶴山記)", any part in which 'Sogumgang' was referred is not found. Later, Cheonghak-dong Sogumgang seemed to had been called 'Mt. Cheonghak' or 'Cheonghak-dong(靑鶴洞)' for more than three centuries as seen in Lee Sun-il's "Godamilgo(孤潭逸稿)", Heo Geun's farewell records, Heo Mok's "Cheonghak-dong Guryongyeongi(靑鶴洞九龍淵記)", Yoon Sun-geo(尹宣擧)'s "Padongilgi(巴東日記)" and Lee Won-jo's letters and a poem composed by Gang Jae-hang in the middle of the 18th century is the only record in which the place name, 'Sogumgang' is shown. Meanwhile, 'Sogumgang' carved on Inung Rock(二能巖) in front of Temple Gumgang is presumed to be carved by Inunggyeoone(二能契員) in the 1870s or in 1930s, considering the size of each character, calligraphy, overall layout, wear extent and records in Jiriji. Therefore, no evidence can be found to say that each character of 'Sogumgang' was written by Yulgok because 'Sogumgang' has strong evidences of the origin of its place name. To sum up the findings stated above, since Yulgok's "Yucheonghaksangi", this place seems to have been referred as 'Mt. Cheonghak Cheonghak-dong' and as it is confirmed that the place name, 'Sogumgang' first appeared in "Ohyeongosijo(五言古時調)" of "Ibjaeseonsangyugo(立齋先生遺稿)" and "Yeojidoseo" in the middle of the 18th century, it can be inferred that the place name, Sogumgang had been partly mingled as an another name of Mt. Cheonghak. Therefore, even though it is difficult to say the existing place name has a significant problem, it is thought that it will be better to name 'Mt. Cheonghak Cheonghak-dong' rather than 'Cheonghak-dong Sogumgang' in order to stress on this place's traditional identity as a scenic site related to Yulgok. In addition, as confirmed in this study process, it is said that each character of place names, 'Mt. Cheonghak' and 'Gyeongdam(鏡潭)' and name 'Yoon Sun-geo' carved in Rock Sikdang stated in Yoon Sun-geo's "Padongilgi" in 1964 is a pledge showing the influence of "Yucheonghaksangi" as an ancient travel literature as well as a mark of the Giho school scholars' respect and spirit to honor Yulgok.

• MISULJARYO - National Museum of Korea Art Journal
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• v.98
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• pp.104-129
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• 2020

Designated as a national treasure of Korea and inscribed on the UNESCO World Heritage List, the Tripitaka Koreana at Haeinsa Temple is the world's oldest and most comprehensive extant version of the Tripitaka in Hanja script (i.e., Chinese characters). The set consists of 81,352 carved woodblocks, some of which have two or more copies, which are known as "duplicate woodblocks." These duplicates are supplementary woodblocks (bogakpan) that were carved some time after the original production, likely to replace blocks that had been eroded or damaged by repeated printings. According to the most recent survey, the number of supplementary woodblocks is 118, or approximately 0.14% of the total set, which attests to the outstanding preservation of the original woodblocks. Research on the supplementary woodblocks can reveal important details about the preservation and management of the Tripitaka Koreana woodblocks. Most of the supplementary woodblocks were carved during the Joseon period (1392-1910) or Japanese colonial period (1910-1945). Although the details of the woodblocks from the Japanese colonial period have been recorded and organized to a certain extent, no such efforts have been made with regards to the woodblocks from the Joseon period. This paper analyzes the characteristics and production date of the supplementary woodblocks of the Tripitaka Koreana. The sutra with the most supplementary woodblocks is the Maha Prajnaparamita Sutra (Perfection of Transcendental Wisdom), often known as the Heart Sutra. In fact, 76 of the total 118 supplementary woodblocks (64.4%) are for this sutra. Hence, analyses of printed versions of the Maha Prajnaparamita Sutra should illuminate trends in the carving of supplementary woodblocks for the Tripitaka Koreana, including the representative characteristics of different periods. According to analysis of the 76 supplementary woodblocks of the Maha Prajnaparamita Sutra, 23 were carved during the Japanese colonial period: 12 in 1915 and 11 in 1937. The remaining 53 were carved during the Joseon period at three separate times. First, 14 of the woodblocks bear the inscription "carved in the mujin year by Haeji" ("戊辰年更刻海志"). Here, the "mujin year" is estimated to correspond to 1448, or the thirtieth year of the reign of King Sejong. On many of these 14 woodblocks, the name of the person who did the carving is engraved outside the border. One of these names is Seonggyeong, an artisan who is known to have been active in 1446, thus supporting the conclusion that the mujin year corresponds to 1448. The vertical length of these woodblocks (inside the border) is 21 cm, which is about 1 cm shorter than the original woodblocks. Some of these blocks were carved in the Zhao Mengfu script. Distinguishing features include the appearance of faint lines on some plates, and the rough finish of the bottoms. The second group of supplementary woodblocks was carved shortly after 1865, when the monks Namho Yeonggi and Haemyeong Jangung had two copies of the Tripitaka Koreana printed. At the time, some of the pages could not be printed because the original woodblocks were damaged. This is confirmed by the missing pages of the extant copy that is now preserved at Woljeongsa Temple. As a result, the supplementary woodblocks are estimated to have been produced immediately after the printing. Evidently, however, not all of the damaged woodblocks could be replaced at this time, as only six woodblocks (comprising eight pages) were carved. On the 1865 woodblocks, lines can be seen between the columns, no red paint was applied, and the prayers of patrons were also carved into the plates. The third carving of supplementary woodblocks occurred just before 1899, when the imperial court of the Korean Empire sponsored a new printing of the Tripitaka Koreana. Government officials who were dispatched to supervise the printing likely inspected the existing blocks and ordered supplementary woodblocks to be carved to replace those that were damaged. A total of 33 supplementary woodblocks (comprising 56 pages) were carved at this time, accounting for the largest number of supplementary woodblocks for the Maha Prajnaparamita Sutra. On the 1899 supplementary woodblocks, red paint was applied to each plate and one line was left blank at both ends.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.1035-1041
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• 2013

To evaluate the structural integrity and dynamic characteristic of the knuckle part of a KTX anti-roll bar, an experimental and a numerical approach were used in this study. In the experimental approach, the acceleration and strain data for the knuckle parts of the KTX and KTX-SANCHUN anti-roll bar were respectively measured to evaluate and compare its structural dynamic characteristics under the operating environments of the Honam line. In the numerical approach, the evaluation of its structural integrity was conducted using LS-DYNA 3D, and then, the reliability of the finite element model used was ensured by a comparative evaluation with the experiment. The numerical results showed that the stress and velocity field of the knuckle part composed of a layered structure of a thin steel plate and rubber were more moderate than those of the knuckle part made of only a thick steel block owing to the reduction of relative contact between the knuckle and the connecting rod. It was found that the knuckle part made of a thin steel plate and rubber was recommended as the best solution to improve its structural integrity resulting from the elastic behavior of the KTX anti-roll bar being enabled under a repeating external force.

• Progress in Medical Physics
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• v.21 no.3
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• pp.261-273
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• 2010

For the use of Indirect-conversion CMOS (complementary metal-oxide-semiconductor) detectors for digital x-ray radiography and their better designs, we have theoretically evaluated the spatial-frequency-dependent detective quantum efficiency (DQE) using the cascaded linear-systems transfer theory. In order to validate the developed model, the DQE was experimentally determined by the measured modulation-transfer function (MTF) and noise-power spectrum, and the estimated incident x-ray fluence under the mammography beam quality of W/Al. From the comparison between the theoretical and experimental DQEs, the overall tendencies were well agreed. Based on the developed model, we have investigated the DQEs values with respect to various design parameters of the CMOS x-ray detector such as phosphor quantum efficiency, Swank noise, photodiode quantum efficiency and the MTF of various scintillator screens. This theoretical approach is very useful tool for the understanding of the developed imaging systems as well as helpful for the better design or optimization for new development.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.150-159
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• 2007

The remark by Andy Clark that the cleverer our world is, the more difficult we perceive our world and ourselves, is very significant to us living in digital world. As the huge power of Technology are dominating the world, the people are drifting with their body fragmented in diverse kinds of chaos, being are faced with the situation that they should reorganize themselves about personal life and ways of thinking in a new technological environment. This paper approach some characteristics of contemporary society through 'Cyborg' which is the product of limitless human desire and technology. The characteristics in modern times, such as boundary disjoint, hybridity, transformation, fusion, communication with image, digital sensitivity, womanness correspond to those of the Cyborg. This paper also investigates the history of modern Cyborg through animation, one of the remarkable medium in digital age and analyze the cyber punk animation, and by Oshii Mamoru, which provoked the extension of the concept of Cyborg. This paper will give a moment to diagnose what this age is like and to present a reference line of our contemporaries exposed to the surplus images and technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.603-610
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• 2016

Over 12 years have passed since the first commercial operation of a Korean high-speed train. Since then, the transport capacity of the high-speed lines has become almost saturated. Therefore, studies have been carried out to increase the operating speed of the trains in order to increase their transportation capacity. This study was carried out to improve the critical speed of the KTX-Sancheon, Korean high-speed train, in order to increase its operating speed. A dynamic analysis of the KTX-Sancheon train was performed using the contact data obtained from the wheel wear profiles that were measured from a KTX-Sancheon train in commercial operation. The analysis results were verified by comparing them with the measurement acceleration data obtained from KTX-Sancheon. The suspension parameters were optimized to improve the operation speed. The critical speed of KTX-Sancheon was increased by 9.4% after the optimization by the response surface method. The optimized suspension parameters are expected to be used for the new bogie design to increase the operating speed of KTX-Sancheon from 300km/h to 350km/h.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.4
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• pp.39-42
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• 2011

The composite electroplating is accomplished by adding inert materials during the electroplating. Permalloy is the term for Ni-Fe alloy and it is used for industrial applications due to its high magnetic permeability, surface wear resistance, corrosion protection. Microhardness for microdevices is enhanced after composite coating and it increases the life cycle. However, the hydroxyl group on the silica makes their surface susceptible to moisture and it causes the silica nanoparticles to be agglomerated in the aqueous solution. The agglomeration problem causes poor dispersion which eventually interrupts uniform deposition of silica nanoparticles. In this study, the dispersion of silica nanoparticles in the permalloy electroplated layer is reported with variation of additives and current densities. The optimum current density was 20 $mA/cm^2$ and the silica content was 9 at% at $50^{\circ}C$. The amount of silica nanopowder codeposition and surface morphologies were influenced with variation of additives. In the bath, smooth surface morphology and relatively high contents of silica nanopowder codeposition were obtained with addition of sodium lauryl sulfate.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.533-540
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• 2018

Graphene has been reported to be an excellent lubricant additive that reduces friction and wear when coated on the surface of various materials or when dispersed in lubricants as an atomic thin material with the low surface energy. In this study, alkyl functionalized graphene oxide (FGO) nanosheets for oil-based lubricant additives were prepared by using three types of alkyl chloride chemicals (butyl chloride, octyl chloride, and tetradecyl chloride). The chemical and structural properties of the synthesized FGOs were analyzed by Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), and transmission electron microscope (TEM). The synthesized FGOs were dispersed at 0.02 wt% in PAO-0W40 oil and its tribological characteristics were investigated using a high frequency friction/wear tester. The friction coefficient and the wear track width of poly alpha olefin (PAO) oil added with FGO-14 were tested by a ball-on-disk method, and the measured results were reduced by ~5.88 and ~3.8%, respectively compared with those of the conventional PAO oil. Thus, it was found that the wear resistance of PAO oil was improved. In this study, we demonstrated the successful functionalization of GO as well as the improvement of dispersion stability and tribological characteristics of FGOs based on various alkyl chain lengths.

• Korean Journal of Agricultural Science
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• v.9 no.2
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• pp.519-539
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• 1982

An preliminary study was made with special references on the insect fauna of Mt. Gyeryong during the period from mid-May to mid-September 1981. The results were obtained as follows; 1. 673 species of insects within 156 families of 20 orders were identified and listed herewith. 2. The 16 species are first records from Korea : Phaneraptera nigro-antennata (Tettigoniidae : Orthop.), Phraraortes kumamotoensis(Phasmidae : Phasm.), Nesogaster lewisi (Nesogasteridae : Dermap), Polymerus palustris(Miridae : Hemip.), Agrosteomela indica (Chrysomelidae:Col.), Monochimus sparsutus (Cermbicidae : Col.), Oberthiiria ialcigera (Bombycidae: Lep.), Alcis albiiera (Geometridae : Lep.), Proplepsis diazama (G eometridae : Lep.) Pandemis cinnamomeana (Tortricidae : Lep.), Hypenodes squalida (Noctuidae : Lep.), Hypolimnas bolina (Nymphalidae : Lep.), Ctenophora nohirae (Tipulidae: Dip.), Ortalotrypeta isshiki (Trypetidaedae : Dip.), Trypeta artemisicola (Trypetidae : Dip.), Ichneumom 8-guttatus ( Ichneumonidae : Hymenop.). 3. We could find a considerable number of Oriental fauna species, Lepismachilis nipponica, Nezara antennata, Parapolybia varia, Anthophora zonata, Parnara guttata, Byasa alcinous, Eurema laeta, Pieris canidia, Eizera maha, Kaniska canace, Danaus sita including two newly recorded species, Monochimus sparstus and Hypolimnas bolina.