• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.472-481
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• 2009

Cementation phenomenon has a huge influence on geotechnical stiffness and strength under low confining pressure. The goal of this study is to evaluate the characteristics of stiffness according to the depth. The piezo disk elements are installed at each layer of the cell for the detection of the compressional waves. The change of compressional wave velocity is classified by three stages. The compressional wave velocities are shown different according to the depth. The compressional wave velocity is especially influenced by cementation, effective stress, and coordinate number. Furthermore, the electrical conductivity and cone tip resistance are measured according to the depth. The electrical conductivity and the cone tip resistance show the similar trend with the compressional wave velocity. This study shows that the cementation by salt is affected by the depth on the granular materials.

• Korean Journal of Crystallography
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• 제8권2호
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• pp.111-118
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• 1997

The structrue of hydroxy-bisbenzoyloxy-allyloxycalix[4]arene (C45H36O6) has been determined by X-ray crystallography. The crystals are monoclinic, space group P21, unit cell constants a=11.045(3), b=33.545(2) c=10.319(4)Å, β=113.86(2)˚, Z=4, V=3496.0(1.8) Å3, DC=1.28 gcm-3. The intensity data were collected on an Enraf-Noninus CAD-4 Diffractometer with a graphite monochromated Mo-Kα radiation. The structure was solved by direct method and refined by full-matrix least-squares calculations to a final R value of 0.076 for 2945 observed reflections. Two independent enantiomeric molecules are crystallized in a 1:1 racemate mixture. They have the flattened cone conformation with the flattening hydroxy1 pheny1 rings. There is an intramolecular hydrogen bond in both molecules.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.179-179
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• 1999

Cu3AU(100) 단결정은 fcc 구조를 가지고 있으며 (100)면은 Cu와 Au가 1:1로 존재하고 가운데(200)면은 Cu만 존재한다. 따라서 Au 층은 (100)면에서만 존재하여 각 Au층은 서로 0.5nm 떨어져 있다. 이와 같은 Cu3Au(100) 단결정을 MEIS(Medium Energy Ion Scattering Spectroscopy) 실험 장비를 사용하여 0.35nm 떨어져 있는 Single unit cell의 윗면과 아래면, 즉 첫 층의 Au와 셋째층의 Au의 층분리를 통해서, 온도 변화에 따른 Cu3Au(100) 단결정의 표면 물리적 현상인 surface induced disorder을 밝혀내고자 한다. 우선 두 Au층의 분리 시도는 수소이온을 이용한 실험 조건에서는 extremely glancing exit angle 등 극한의 산란조거에서도 성공하지 못하였다. 깊이 분해능을 정해주는 electronic energy loss를 극대화하기 위해 수소이온이 아닌 질소 이온을 사용하여 energy spectra를 측정해 본 결과 아래 그림에서와 같이 표면 Au 층과 표면 셋째 Au층을 구분할 수 있었다. <110>으로 align된 조건에서는 셋째층의 Au 원자들이 완전히 shadow cone 내부에 존재하여 관측되지 않지만 9.75$^{\circ}$ tilt 한 경우 셋째층의 Au 원자들이 shadow cone 바깥으로 나오게 되어 그림에서와 같이 첫째 층과 셋째 층이 확실히 분리되어 측정되었다. 이를 바탕을 Cu3Au(100)의 온도변화에 다른 order disorder and segregation 현상을 측정하였다. ordered Cu3Au(100)은 28$0^{\circ}C$ 근처에서 surface층이 먼저 disordered상으로 바뀌는 surface induced disorder 현상이 일어나고 bulk transition 온도 39$0^{\circ}C$ 이하에서 R.T으로 온도를 낮추면 본래의 ordered 구조로 되돌아간다. 하지만 bulk transition 온도를 지나면 order-disorder transition이 비가역적이고 segregation 현상이 일어난다.

• Development and Reproduction
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• 제23권2호
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• pp.171-181
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• 2019

To produce healthy and stable seed production, we need to obtain information and understand vision that affects behavior of red spotted grouper. We examined their expression and retinal development during the juvenile development. Short-wavelength sensitive opsin (SWS2), a cone photoreceptor, began to be expressed from lens and ear vesicle formation stage and its expression increased until 10 days after hatching (dah). In case of middle-wavelength sensitive opsin (MWS), its expression was detected at 3 dah and reached the highest level at 21 dah. The expression of long-wavelength sensitive opsin (LWS) was first observed from 3 dah and their expression decreased thereafter. Rhodopsin, a rod photoreceptor, was found to be expressed from 2 dah and its expression reached the highest level at 50 dah. The outer nuclear layer (ONL), inner nuclear layer (INL) and ganglion cell layer began to differentiate at 2 dah, while choroid first appeared at 4 dah so that the eyes became black. These results indicate that the development of retina mostly completes around 4 dah. It seems that the development of the retina and the expression of the opsin genes are closely related to the behavior such as hunting prey, considering that the timing of the completion of the development of the retina, the timing of gene expression, and the timing of completion of yolk absorption are similar.

• Journal of Oral Medicine and Pain
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• 제38권4호
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• pp.291-298
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• 2013

On this study, we treated rats with restraint stress, and observed the changes with an optical microscope. Within the salivary gland tissue, we measured cell apoptosis cycle evaluation which show positive reaction on TUNEL assay, and compared within the groups. For this study, 18 rats were divided into 3 groups; 1) 2 rats of group I were selected as a normal control. 2) 2 rats of group II, as a experimental control were placed in the restraint cone for 2 hours 3) 14 rats of group III were placed in the restraint cone for 2 hours once a day. The rats were sacrificed immediately (group II, as a experimental control), 1, 2, 3, 4, 5, 6 and 7days after application of the stress and the both parotid glands were excised. The conclusions follow. 1. 5 days after giving an confining stress to the parotid gland of Rats, we can observe the hypotropy and pus and inflammation of Rat parotid gland acinar cells, and after 7 days, we can see a cell apoptosis. 2. Through the In situ DNA end labeling assay and TUNEL dye, on serous glands, benign tumor cell increased with statistically significant result after 5 days from confining stress. And the index shows maximum value on 7th days, which is same result with histological opinion. Therefore, our study shows that a cell apoptosis can be induced by restraint stress on salivary gland tissue, and we think more study should be accomplished about the cell signaling pathway in the future.

• Radiation Oncology Journal
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• 제9권2호
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• pp.221-225
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• 1991

Twenty five patients with unresectable non-small cell carcinoma of the lung have been treated with hyperfractionated radiotherapy with concomitant boost technique since September, 1989. Those patients with history of previous surgery or chemotherapy, pleural effusion or significant weight loss (greater than $10\%$ of body weight) were excluded from the study. Initially, 27 Gy were delivered in 15 fractions in 3 weeks to the large field. Thereafter, large field received 1.8 Gy and cone down boost field received 1.4 Gy with twice a day fractinations up to 49.4 Gy. After 49.4Gy, only boost field was treated twice a day with 1.8 and 1.4 Gy. Total tumor doses were 62.2 Gy for 12 patients and 65.4 Gy for remaining 13 patients. Follow up period was ranged from 6 to 24 month. Actuarial survival rates at 6, 12, and 18 month were $88\%,\;62\%,\;and\;38\%$, respectively. Corresponding disease free suwival rates were $88\%,\;41\%,\;and\;21\%$, respectively. Actuarial cumulative local failure rates at 9, 12 and 15 month were $36\%,\;43\%,\;and\;59\%$, respectively. No significant increase of acute or late complications including radiation pneumonitis was noted with maximum follow up of 24 month. Although the longer follow up is needed, it is worthwhile to try the prospective randomized study to evaluate the efficacy of hyperfractionated radiotherapy with concomitant boost technique for unresectable non-small cell lung cancers in view of excellent tolerance of this treatment. In the future, further increase of total radiation dose might be necessary to improve local control for non-small cell lung cancer.

• Journal of the Korean Mathematical Society
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• 제33권3호
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• pp.625-639
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• 1996

A convex $RP^n$-structure on a smooth anifold M is a representation of M as a quotient of a convex domain $\Omega \subset RP^n$ by a discrete group $\Gamma$ of collineations of $RP^n$ acting properly on $\Omega$. When M is a closed surface of genus g > 1, then the equivalence classes of such structures form a moduli space $B(M)$ homeomorphic to an open cell of dimension 16(g-1) (Goldman [2]). This cell contains the Teichmuller space $T(M)$ of M and it is of interest to know what of the rich geometric structure extends to $B(M)$. In [3], a symplectic structure on $B(M)$ is defined, which extends the symplectic structure on $T(M)$ defined by the Weil-Petersson Kahler form.

• Biomedical Science Letters
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• 제12권4호
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• pp.385-391
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• 2006

Heterotrimeric GTP binding proteins (G proteins) mediate signals generated by neurotransmitters and hormones Among G proteins, Go is found in a large quantity in brain and growth cone membranes of neurons. In spite of its abundance in neurons, the role of Go is not fully understood. In our previous study, we identified promyelocytic leukemia zinc finger protein (PLZF) as an interacting partner of alpha subunit of Go ($Go{\alpha}$) and confirmed their interaction employing several biochemical assays. To date, it is reported that PLZF functioned as a cell growth suppressor and a transcription repressor. To determine effect of $Go{\alpha}$ and PLZF interaction on the cellular function of PLZF, we performed luciferase reporter gene assay and BrdU incorporation assay. Co-expression of $Go{\alpha}$ and PLZF synergistically increased the effect of PLZF alone. These results suggest that $Go{\alpha}$ may act as cellular activator of PLZF. This novel feature of Go may provide insights into understanding diverse role of Go-coupled receptor as well as its cellular actions.

• Applied Microscopy
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• 제46권2호
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• pp.89-92
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• 2016

The bluegill Lepomis macrochirus is an invasive species, not native to Korea, introduced for aquaculture. This species is ranked as a new top predator due to its massive aquatic carnivorous and herbivorous nature by acute vision and the absence of a natural enemy. The visual cells of the retina of L. macrochirus are composed of short single cones and equal double cones and long and bulky rods by light and electron microscopes. In particular, the cones show a regular square mosaic arrangement. This pattern is widely considered as a strong predator. With regard to the visual system, this mosaic pattern may closely be related to a dynamic visual acuity to track and hunt prey.

• Proceeding of EDISON Challenge
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• 제5회(2016년)
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• pp.228-233
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• 2016

Auxetic material is a material which has negative Poisson's ratio(NPR). Auxetic material shows some distinctive property like high energy absorbing property and high shear modulus. Among these, synclastic curvature is very interesting characteristic. When synclastic-curvature-material bends, it changes its shape like dome, contrary to non-auxetic material which changes its shape like saddle(anticlastic). This distinctive property could make it easy to manufacture curved structure like nose cone or wing panel in aerospace engineering. In this study, we studied a quantitative analysis about synclastic curvature of re-entrant panel with finite element model. We suggested a concept 'Degree of Synclasticity(DOS)', which means a ratio of curvature of load-direction and load-orthogonal direction. We studied the variation of DOS with two factor, unit cell inner angle(${\theta}$) and load position angle(${\phi}$). DOS decreases as ${\theta}$ increases because the unit cell goes out of auxetic-shape. As ${\phi}$ varies, DOS changes in a large range. So proper optimization of ${\phi}$ would be needed for application.