• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.12
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• pp.1087-1092
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• 2010

A micro 3D-PTV system has been constructed using a single camera system. Two viewing holes were created behind the object lens of the microscopic system to construct a stereoscopic viewing image. A hybrid recursive PTV algorithm was used. A concept of epipolar line was adopted to eliminate many spurious candidates. Three-dimensional velocity vector fields were obtained by calculating the three-dimensional displacements of particles that were identified as being identical. The system consists of a laser light source (Ar-ion, 500 mW), one high-definition camera ($1028{\times}1024$ pixels, 500 fps), a circular plate with two viewing holes, and a host computer. The performance of the developed algorithm was tested using artificial images. The characteristic of the vector recovery ratio was investigated for the particle numbers. A micro backward-facing step channel ($H{\times}h{\times}W:\;36{\mu}m{\times}70{\mu}m{\times}3000{\mu}m$) was measured using the developed measurement system. The results were in good qualitative agreement with other results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.9
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• pp.815-820
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• 2016

An elastic polymer (e.g., PDMS) blended with EFG particles is a promising conductive composite for fabricating soft sensors that can detect an object's deformation up to or more than 50%. Here, we develop large-strain, sprayable soft sensors using a mixture of PDMS and EFG particles, which are used as a host elastomer and electrically conductive particles, respectively. A solution for a conductive composite mixture is prepared by the microwave-assisted graphite exfoliation, followed by ultrasonication-induced fragmentation of the exfoliated graphite and ultrasonic blending of PDMS and EFG. Using the prepared solutions for composite and pure PDMS, 1-, 2-, and 3-axis soft sensors are fabricated by airbrush stencil technique where composite mixture and pure PDMS are materials for sensing and insulating layers, respectively. We characterize the soft strain sensors after investigating the effect of PDMS/EFG wt% on mechanical compliance and electrical conductance of the conductive composite.

• Sijohaknonchong
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• v.20
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• pp.75-96
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• 2004

A pavilion is located in the place with beautiful scenery, which maximizes the poetical features of nature. So a scholar in the Chosun Dynasty had the dream of possessing it. This trends of the Chosun scholar resulted in producing lots of literary works related with the pavilion. In this thesis, I researched the characters of Pavilion Si-Jo in accordance with the function of pavilion. First, the pavilion, which is surrounded by the beautiful scenery, is a good place to see the beauty of nature. It is needless to walk around to see the scenery thanks to its open structure. So the feeling in the pavilion Si-Jo is distinguished from other sightseeing Si-Jos: those show the way of seeing the scenery walking here and there, but this shows the way of seeing the scenery only just looking up, looking down, and looking in the distance. Second, the pavilion functions as an academic place. In this case, it can be said that it functions like a lecture hall. It is more effective to study in the pavilion than in the closed structure, a lecture hall. Furthermore, the scholar studying in the pavilion understand the principle of nature with seeing the beautiful mountain and river, and it can be a place for growing a vast-flowing spirit. This kind of poetry has been handed down with the Chinese poetry, and the character who operated the pavilion often appears in the work. Third, the pavilion functions as a space for a fraternity or poetry circles. The poetic exchange was conducted by host of pavilion. which is the key ingredient for organizing a poetry circles. Finally, the pavilion functions as an entertainment. Although it is a space for an entertainment, there is no deviation as a man of novel birth. If the pavilion has the feature of closeness, there are sometimes works which shows the deviation of them.

• Journal of Ginseng Research
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• v.44 no.5
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• pp.704-716
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• 2020

Background: Ginsenoside Rh2 (GRh2) is a characterized component in red ginseng widely used in Korea and China. GRh2 exhibits a wide range of pharmacological activities, such as anti-inflammatory, antioxidant, and anticancer properties. However, its effects on Toxoplasma gondii (T. gondii) infection have not been clarified yet. Methods: The effect of GRh2 against T. gondii was assessed under in vitro and in vivo experiments. The BV2 cells were infected with tachyzoites of T. gondii RH strain, and the effects of GRh2 were evaluated by MTT assay, morphological observations, immunofluorescence staining, a trypan blue exclusion assay, reverse transcription PCR, and Western blot analyses. The in vivo experiment was conducted with BALB/c mice inoculated with lethal amounts of tachyzoites with or without GRh2 treatment. Results and conclusion: The GRh2 treatment significantly inhibited the proliferation of T. gondii under in vitro and in vivo studies. Furthermore, GRh2 blocked the activation of microglia and specifically decreased the release of inflammatory mediators in response to T. gondii infection through TLR4/NF-κB signaling pathway. In mice, GRh2 conferred modest protection from a lethal dose of T. gondii. After the treatment, the proliferation of tachyzoites in the peritoneal cavity of infected mice markedly decreased. Moreover, GRh2 also significantly decreased the T. gondii burden in mouse brain tissues. These findings indicate that GRh2 exhibits an antieT. gondii effect and inhibits the microglial activation through TLR4/NF-κB signaling pathway, providing the basic pharmacological basis for the development of new drugs to treat toxoplasmic encephalitis.

• Journal of the Korean Magnetics Society
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• v.23 no.1
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• pp.1-6
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• 2013

Spin-orbit coupling (SOC) effect is known to be the physical origin for various exotic magnetic phenomena in the low-dimensional systems. Recently, SOC also draws lots of attention in the study on magnetically doped thermoelectric alloys to determine their properties as the thermoelectric application as well as the topological insulator via the exact electronic structures determination near the Fermi level. In this research, aiming to investigate the spin-orbit coupling effect on the structural properties such as the lattice constants and the bulk modulus of the most widely investigated thermoelectric host material, $Bi_2Te_3$, we carried out the first-principles electronic structure calculation using the all-electron FLAPW (full-potential linearized augmented plane-wave) method. Employing both the local density approximation (LDA) and the generalized gradient approximation (GGA), the structural optimization is achieved by varying the in-plane lattice constant fixing the perpendicular lattice constant and vice versa, to find that the SOC effect increases the equilibrium lattices slightly in both directions while it markedly reduces the bulk modulus value implying the strong orientational dependence, which are attributed to the material's intrinsic structural anisotropy.

• The Journal of the Petrological Society of Korea
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• v.18 no.3
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• pp.211-221
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• 2009

This study illustrates the relationship between the petrographic characteristics of micrographic granite and the topographic features around Ijin-ri. Light-brown to light- gray granite is composed of intergrown fine-grained quartz + orthoclase, displaying micrographic textures. Miarolitic cavities are abundant. Many micro-landforms including tor, tafoni, and gnamma occurred in the micrographic granite of the study area. Tafoni is dominant in the north and gnamma is dominant in south. From our study of the occurrence and textural properties, two alteration zones were clearly identified; one is an external zone (A) characterized by abundant of small sized miarolitic cavities and the other is an internal zone (B) having them less than zone A. The former is dominant in north, and the latter is dominant in south. Particular geomorphologic features such as fluting cores and raised rims are present in the Ijin-ri area. This suggests that development of miarolitic cavities played an important role in the formation of the various geomorphologic features. Consequently, the petrogenesis of the micrographic granite is related to geomorphologic features in the external zone typified by abundant tafoni such as the tiger rock, and the formation of a platform as micro-landforms is influenced by thetextural differences of host rock in the internal zone.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.199-205
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• 2005

Seasonal occurrence and ovarian development of the bean bug, Riptortus clavatus Thunberg (Heteroptera: Alydidae), were studied at a soybean field and an university campus in which host plants are less available for the bug in Gyeongnam province with aggregation pheromone traps in 2004. It was assumed that the bug passed three generations per year at the university campus. Adults of the 1st generation might occur from early July to early August and that of the 2nd one from mid August to late September. Adults of the 3rd generation occurred from early October to mid November, entered reproductive diapause without carrying eggs in the ovaries of females during winter, and resumed activity from late March of the next year. Full-grown eggs in the ovaries of the overwintered females were first observed at the 1st half of May. Two peaks of occurrence, from early August to mid September and from mid October to mid November, were shown at soybean field that was sowed on May 24. The two peaks almost corresponded to those of the 2nd and 3rd generations at the university campus, respectively.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.227-231
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• 1974

During the period from 1971 to 73 physiologic races of potato late blight pathogen, Phytophthora infestans, causing severe losses of seed potato production at Alpine area, Korea, were investigated. In 1971, 68 isolates of the pathogen from various potato varieties were identified by the use of differential host Plants, and found that there were 10 races; 0, 1, 2, 3, 1.3, 1.4, 3.4, 1.3.4, 2.3.4. The most Predominant races for the year were 0 and 3. In 1972, the same procedure was repeated with 62 isolates of the pathogen, and found 5 different races; 0, 1, 4, 1.3 and 1.3.4. The most predominant race for the year was race 0. In 1973, six races; 0, 3, 4, 1.3, 3.4 and 1.3.4 were found from 76 isolates of the year, and the race 0 and 4 apperared as the most Predominant races for the year. Total of 11 races; 0, 1, 3, 4, 1.3, 1.4, 3.4, 1.3.4, 2.3.4 and 1.2.3.4, were found during the period from 1971 to 73 at Alpine area, among which the most predominant races were race 0, 3, and 4. The investigation indicated that the anual incidence of these races largely depended on the climatic conditions of the year.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.209-216
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• 1974

Life history and control methods of Aphanostigma iakusuiense Kishida were studied during April to November, 1974, in the Naju pear orchard area, Cholla Namdo. The results are summarized as follows: 1. More than $60\%$ of wintering eggs were found at the height of 1.5 to 2.0m from the soil surface, with approximately $10\%$ at 0.5 to 1.5m and 1.5 to 2.5m respectively. 2. There was little difference in the size of egg masses and hatching ratio $(12.7-13.7\%)$ between the varieties of host trees, Mansamkil and Kooksoo. 3. Hatching was not observed until April 6, but hatches of $12.8\%$ on April 13 and $90.6\%$ on May 4 were found. 4. During the hatching season in early spring, 8 chemicals were applied to test effectiveness of control. C8514, Metasystox, Acar 338, and Parathion were more effective than either Sevin or Malix for control of this insect. 5. Highest populations of pear phylloxera ocurred from August 20 to September 20 at which time levels of eggs and larvae were simillar in abundance. 6. In tests for control of this insect after in paper bags, DDVP, Loxon, C8514, Sevin, and Binapacryl were more effective than either EPN or Otran. 7. Predacious mite, Protolaelape pygmaeus Miller, and several species of lady beetles (Coccinellidae) preying on this insect as natural enemies were collected. The predation ratio of mites varied according to region: that is 0.77 to $18.6\%$ in Bia Orchard; $7.88-48.7\%$ in Noan Orchard and almost none in Youngsanoo Orchard. 8. The varietal difference in fruit damage by this insect was in the order of Choseng Chuck, Kooksoo, followed by Sin Ko, Mansamkil, Keumchon Choo, and Changsimrang.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.257-265
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• 2011

To investigate host preferencse of Myzus persicae on 15 sweet pepper cultivars grown in Jeonnam Province, EPG (electrical penetration graph) and life table experiments were carried out in the laboratory. Phloem phase times were significantly longer on Ferrari, Jinju, Debla, and Rapido than Orobell and Thialf. Non-penetration times were conversely observed. Life span, reproduction period, total fecundity, and intrinsic rate of increase ($r_m$) of M. persicae, were higher on Ferrari, Debla, Orange glory, and Jinju than on Purple, GreenAce, Orobell, and Thialf. On the bases of these results, we conclude that M. persicae preferred Ferrari, Jinju, Orange glory, and Debla among the 15 tested sweet pepper varieties. However, we could not show the preference of the aphid for Purple, Orobell, and Thialf.