• Journal of the Microelectronics and Packaging Society
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• v.22 no.1
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• pp.69-74
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• 2015

With difficulties during the cleaning of reflow flux residues due to the decrease of the part size and interconnection pitch in the advanced electronic devices, the need for the no-clean solder paste is increasing. In this study, an epoxy curable solder paste was made with SAC305 solder powder and the curable flux of which the main ingredient is epoxy resin and its reflow solderability, flux residue corrosivity and solder joint mechanical properties was investigated with comparison to the commercial rosin type solder paste. The fillet shape of the cured product around the reflowed solder joint revealed that the curing reaction occurred following the fluxing reaction and solder joint formation. The copper plate solderability test result also revealed that the wettability of the epoxy curable solder paste was comparable to those of the commercial rosin type solder pastes. In the highly accelerated temperature and humidity test, the cured product residue of the curable solder paste showed no corrosion of copper plate. From FT-IR analysis, it was considered to be resulted from the formation of tight bond through epoxy curing reaction. Ball shear, ball pull and die shear tests revealed that the adhesive bonding was formed with the solder surface and the increase of die shear strength of about 15~40% was achieved. It was considered that the epoxy curable solder paste could contribute to the improvement of the package reliability as well as the removal of the flux residue cleaning process.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.1
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• pp.103-111
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• 2020

Pulling-type cutting devices, which use a diamond wire saw, have been used generally for cutting concrete structures. In this study, a pushing-type cutting device with a collection cover was developed by overcoming the disadvantages of pulling-type devices. In this device, dry or liquid methods can be selected to cool frictional heat. Operation and leakage tests of the dust generated during the dismantling of a concrete structure were carried out, confirming the suitable operation of the fabricated cutting device; the leakage rate was approximately 1.7%. For a conservative evaluation, the internal dose of workers was estimated in dismantling the core center part of biological shield concrete with a specific activity of 99.5 Bq·g^-1. The committed effective dose per worker was 0.25 mSv. The developed cutting device contributed to reducing radioactive concrete waste and minimizing worker exposure due to its easy installation. Therefore, it can be utilized as a cutting apparatus for dismantling not only reinforced concrete structures but also radioactive biological shield concrete in nuclear power plant decommissioning efforts.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.77-83
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• 2007

It is essential that second order nonlinear optical materials have low optical propagation losses in the wavelengths of second harmonic generation for practical applications in waveguides. Three dipolar chromophores substituted with nitro, cyano, and alkyl sulfone as an electron withdrawing group were prepared. The UV-Vis absorption spectra of the cyano and alkylsulfone chromophores showed a blue-shift compared to the nitro chromophore. The introduction of oxadiazole segment in the chromophore structure led to similar spectral shift. The blue-shift can produce low optical loses at second harmonics. The chromophores were successfully attached to a polyimide, yielding side chain polymers. The nonlinear optical property of the prepared optical polymers was determined by measuring electro-optic coefficient at 1.55 mm. The polymers exhibited high glass transition temperature of over $185^{\circ}C$ and thermal stability to $300^{\circ}C$ through differential scanning calorimeter analysis and thermal gravimetric analysis.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.178-185
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• 2023

This study was described the microscopic anatomy of male reproductive organs and spermatophore necessary for understanding the reproductive ecology of the long arm octopus Octopus minor. The long arm octopus was a species that has sexual dimorphism that can distinguish between sex based on the presence of hectocotylus. Male reproductive organs consisted of testis, primary spermatic duct, spermatic gland, secondary spermatic duct, spermatophoric gland and spermatophoric sac. Histologically, the testis was testicular tubule type and male germ cells showed a layered arrangement. The primary spermatic duct was a tube connecting the testis and spermatic gland, and consisted with epithelial layer and connective tissue. The spermatic gland was located between the primary and secondary spermatic duct, and the epithelial layer was composed of epithelial cells and mucous cells. Mucous cells reacted blue in the AB-PAS (pH 2.5) reaction and purple in the AF-AB (pH 2.5) reaction. The secondary spermatic duct was a short tube connecting spermatic gland and spermatophoric gland, and folds were developed in lumen. The spermatophoric gland consisted of numerous tubular glands and secretory cells had eosinophilic granules. The spermatophoric sac was shape of pouch, folds were developed in lumen, and vacuolar secretory cells were present in the epithelial layer. The spermatophore was 83.5 mm long and consisted of cap thread in anterior portion, ejaculatory apparatus and cement body in medial portion, sperm mass in posterior portion.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.147-160
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• 2024

Purpose To define an MRI scoring system for differentiating xanthogranulomatous cholecystitis (XGC) from wall-thickening type gallbladder cancer (GBC) and compare the diagnostic performance of the scoring system with the visual assessment of radiologists. Materials and Methods We retrospectively analyzed 23 and 35 patients who underwent abdominal MRI and were pathologically diagnosed with XGC and wall-thickening-type GBC after surgery, respectively. Three radiologists reviewed all MRI findings. We defined a scoring system using these MRI findings for differentiating XGC from wall-thickening type GBC and compared the area under the curve (AUC) of the scoring system with the visual assessment of radiologists. Results Nine MRI findings showed significant differences in differentiating the two diseases: diffuse gallbladder wall thickening (p < 0.001), mucosal uniformity (p = 0.002), intramural T2-high signal intensity (p < 0.001), mucosal retraction (p = 0.016), gallbladder stones (p < 0.001), T1-intermediate to high-signal intensity (p = 0.033), diffusion restriction (p = 0.005), enhancement pattern (p < 0.001), and phase of peak enhancement (p = 0.008). The MRI scoring system showed excellent diagnostic performance with an AUC of 0.972, which was significantly higher than the visual assessment of the reviewers. Conclusion The MRI scoring system showed better diagnostic performance than the visual assessment of radiologists to differentiate XGC from wall-thickening-type GBC.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.47-52
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• 2012

Purpose: This study was to evaluate visual fatigue with passing of watching 3D TV in short term and with experience of watching 3DTV in long term. Methods: 98 adult subjects aged $33.5{\pm}5.5$ years (22 to 51 years; 12 females and 86 males) agreed to participate in this study. Subjects were asked to watch 52 inch LED 2D and 3D television (Shutter glasses method) at 2.7 meters for 65minutes with wearing their habitual glasses or contact lenses. For evaluating visual fatigue, subjects were verbally responded to 11 questions : eye straining, eye paining, dry eye, sore eye, watery eye, photophobia, blur vision, diplopia, eye fatigue, headache, and dizziness with scale 0 to 3 at each measurement while watching 3D and 2D TV. Results: The mean scores of visual fatigue were $2.08{\pm}2.14$, $3.19{\pm}3.02$, $3.40{\pm}3.37$, $3.53{\pm}3.07 $for after 5 minutes, 25 minutes, 45 minutes, and 65 minutes respectively for 3D TV, and $0.40{\pm}1.03$, $0.22{\pm}0.70$, $0.22{\pm}0.58$, and $0.17{\pm}0.52$ after 25, 45, and 65 minutes respectively for 2D TV. Visual fatigue for watching 3D TV was significantly higher than for watching 2D TV at all measurements sessions (paired t-test, p < 0.001). The visual fatigue significantly increased during watching 3D TV for 65 minutes (p < 0.001, RM-ANOVA). The visual fatigue during watching 3D TV was significantly increased until 25 minutes (paired t-test, p < 0.001), stable after that. For correlation between visual fatigue and 3D watching experience, the more 3D watching experiences were significantly the less visual fatigues in photophobia, blur vision, diplopic and dizzy symptoms (ANOVA, all F(1, 96) = 4.500, all p < 0.05), but there was not significantly different in the other symptoms (ANOVA, F (1, 96) = 2.123, p = 0.148). Conclusions: Visual fatigue for watching 3D TV was higher than for watching 2D TV, increase by 25 minutes. It was different by symptoms for correlation between visual fatigue and 3D watching experience.

• Cross-Cultural Studies
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• v.46
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• pp.435-463
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• 2017

This paper aims to identify the structural characteristics of Okawa Syumei(大川周明), Wakamiya Unosuke(若宮卯之助) and Okakura Tensin(岡倉天心). In fact, after Okawa Syumei studied the Principles of Wakamiya Unosuke and Okakura Tensin, he derived a conclusion and wrote a book named "yeolseongjeon". This book talks about the emperor dynasty. Based on this, the theory presented by Wakamiya Unosuke and Okakura Tensin described the characteristics of the East European culture. Okakura Tensin crossed the western part and discovered that western culture is only western culture and not a universal culture. Western culture has developed from its own experience. Wakamiya Unosuke translated a book by William Knox, The spirt of the orient. They have the same point of view, but they have a different culture and they must follow their own culture. Okakura Tensin insisted that culture is dynamic and it improves by adapting different cultures of different countries. Wakamiya appealed and he opposed Tensin's studies about culture. Wakamiya's definition of culture has not changed or is fixed from the past, which still exists in the modern times. Culture must be cultivated and it must be introduced to people who have forgotten their own culture. Despite such methodological differences, the commonality between Okakura and Wakamiya is that Western civilization is nothing more than a regional culture, as the West is not a universal civilization, but as a whole, it is a regional culture. Okawa Syumei learned the Okakura and Wakamiya's theory about culture and derived a conclusion. He stated that both opinions are correct as culture can be adapted as explained by Okakura. For example, Japanese people are now adapting and embracing the culture of Chinese people and Indian people. On the other hand, he also learned Wakamiya Unosuke's theory that culture does not change. Japanese have their own culture that was created in the past or it was developed by their ancestors; for example, the emperor dynasty. Okawa Syumei learned different cultures of different countries and Japanese people are adapting those cultures, and Wakamiya stated that the emperor dynasty must be instilled and it must be universal. Japanese emperors have different cultures, especially the Meiji emperor who is willing to accept different cultures of different countries. Finally, he claimed that the emperor dynasty created a new Japanese civilization and they are now embracing the new adapted culture.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.182-195
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• 2011

Old big tree transcends the simple meaning of trees as they are the natural monuments that embody the people's history and culture of this land. The Cultural Heritage Administration of Korea (CHA) defines and protects old big tree based not only on the size of the tree but also on its definitive cultural and natural factors such as value, implications, and originality. This research aims to identify and analyze the habitation and measurements, the soil conditions, as well as the protective facilities of 14 old big tree spread throughout the Gangwondo. The research examined the soundness of the arboreal form, the degree of damage on the bark, as well as the quantity of leafs levels to evaluate the overall condition of growth and development. Then, the tree height, the eastwest and south-north width of the crown, the sternum circumference, and the root circumference were recorded to identify the measurements of the selected old big tree. Also, the research analyzed 9 elements such as soil texture, pH levels, and organic contents in order to determine the scientific characteristics of soil upon which the trees draw nutrition. Finally, the research evaluated supporting pillars, lightning rods, iron pulling-facilities, as well as notice boards to study the protective facilities of old big tree. The research procedures revealed that 78.57% of the old big tree identified as natural monuments in the Gangwondo have average to above average habitation conditions. Also, the average tree height reaches 18.80m above ground while the average root circumference measures 7.34m. Moreover, the results of the scientific analyses conducted on the soil elements determined that most chemical values were within the defined levels, with the exception of phosphoric acid levels falling within the hyper-nutritious range. Finally, although most of the protective facilities did support the habitation of the Old big tree, there were some supporting pillars and iron pulling-facilities that actually damaged the trees. This research means to provide foundational reference data for the analysis of the habitation and management conditions of natural monument old big tree within the Gangwondo. A follow-up topic led by the results of this research is the identification and analysis of correlating environmental elements that affect the habitation of the old big tree.

• (The) Research of the performance art and culture
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• no.34
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• pp.277-313
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• 2017

This study is to find out the correlation with buddhist music after analyzing the rhythm of six pieces of PanYeombul sung by Kim Janggil out of Ogu exorcism of East coast the findings summarized are as follows. First, PanYeombul by Kim Janggil, performed on Oct, 16, 2016, was composed of , , , , , , , , , , and . Still, even if PanYeombul is performed by the same male shaman, the composition can be added or left out depending on some circumstances, which means the procedures are flexible. Seeing that there is common component of in additoin to compared with Kimyongtaek, it can be said that the component of is an important part in PanYeombul of Ogu exorcism of East coast Second, is usually referred to 'SinmyojangguDaedalani' in buddhist ritual, While Kim yongtaek accepts this practice in title, Kim Janggil uses 'YeomhwajangguDaedalani' as the title which makes his song different from others. Yeomhwa means "picking up flowers with fingers" which has been used in buddhism, not in common Considering this fact, the conclusion can be reached that by using the term 'Daedalani' from a buddhist chant, but making differentiation from buddhism, Kim Janggil is making the effort to be different from buddhist rituals. give some unique meaning to shaman rituals. Third, PanYeombul of Ogu exorcism of East coast may be divided into two main parts - the former part is PanYeombul and the latter part is Jiokga. In performing PanYeombul, male shaman sits singing alone and playing Jing himself, on the other hand, in case of Jiokga, he stands singing a solo with gwaeggwari in his hand accompanied by other musicians with the rhythm of Samgongjaebi. As the song and the accompaniment are in the form of giving and taking like duet. it is in peak in terms of music. Accordingly, PanYeombul can be divided into PanYeombul and Jiokga, But since it is performed by one male shaman and sung a solo, it is usually seen as one procedure. Jing, which is a kind of accompaniment in PanYeombul by Kim Janggil, has the role to distinguish a phrase and settle the musical paragraph. When the buddhist chant with one word-one note is performed. it requires the performer to catch his or her breath or clear throat. Just then, Jing comes out for filling out the intervals. Also, its role to distinguish a phrase and settle the musical paragraph helps make it clear to deliver words. The rhythm of Jing is mostly made up of small triple time except equal small binary time, comes out with overwhelmingly more frequency of Sutsoe(♪♩) than Amsoe(♩♪), and often shows syncopation. By often using Off Beat or short-long rhythm even in accompaniment of equal small binary time, he tris to give some variation to monotonous and equal rhythm for the musical vitality. These are similar to Sutsoe rhythm which can evoke tension and Kim Janggil makes these things his characierisiic of rhythm. Fifth, all the pieces consist of mi, sol, la, do, re and the descending melody like do'${\searrow}$la${\searrow}$sol${\searrow}$mi appears most frequently. The descending melody usually arouses the feeling of sorrow, so the sadness for the deceased is presented properly, which suggests his musical talent. Generally, pieces take on Menari-tori as a whole where the length of sol appears for a short time in descending la${\searrow}$sol${\searrow}$mi of perfect four degrees. Sixth, Even he accepts the lines of buddhist chant, he changes them in some degree. For example, he inserted some words between lines like 'Wonwangsaeng' and 'NamuAmitabul' and added Korean words like hapsosa to the lines of buddhist service written in Chinese character. Also, he inserted some words like 'iiiiiii~' to express the feeling of sadness. These are to maximize the desire of the deceased to go to the heaven and at the same time to diminish the sign of buddhism and strengthen the features of shamanism. Seventh, the effort to decrease the sign of buddhism is made in pasting lines of two songs. For example, Between the last words 'Wonsuaenapsu of Dage and the first words 'Jisimgwimyeongrye' of Chiljeongrye, there is usually a short pause to distinguish paragraphs, But he continues two songs without any pause to get rid of the feelings of buddhist chant. In terms of melody, he makes a distance from buddhist chant in an effort that he gives some traits to shaman rituals which are different from buddhist even if he uses the lines of buddhist rituals. Eighth, the analyzed pieces can be in four categories - no regular melody , , equal small binary time , eotmori melody of ten eighth time with 3+2+3+2 mixed small time . and Samgongjaebi melody 3+2+3 mixed small time . Each piece has its unique melody. Although of buddhist ritual is often performed, by using eotmori melody, he evokes the feeling of shaman and is another example of giving unique characteristic to the shaman of East coast by using Samgongjaebi melody.