• 대한소아치과학회지
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• 제45권3호
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• pp.334-343
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• 2018

이번 연구에서는 상악 중절치의 편측성 맹출 장애의 원인을 조사하고 매복된 치아들의 매복깊이, 매복각도, 치근발육 상태를 치과용 Cone-beam CT로 분석하여 치료방향을 예측하는데 도움이 되고자 하였다. 총 134명의 환자 중 상악 중절치의 편측성 맹출 장애로 진단된 평균연령은 7.9세였으며, 남자가 여자보다 2.1배 더 높은 빈도를 나타냈다. 맹출 장애의 주원인은 물리적 장애물로 과잉치와 치아종이 대부분을 차지하였다. 편측성 맹출 장애를 보였던 치아 중 물리적 장애물을 제거한 후, 78증례는 자발적으로 맹출하였으며 56증례는 비자발적으로 맹출하였다. 또한 편측성 매복 상악 중절치의 자발적 혹은 비자발적 맹출은 매복깊이, 매복각도, 치근발육 정도와 연관성이 있었다. 정상적으로 맹출한 치아의 매복 각도는 $50^{\circ}-90^{\circ}$ 사이였으며, 매복 상악 중절치의 자발적 맹출 빈도도 이 범위에서 가장 높았다. 또한 자발적 맹출에 걸린 시간은 매복각도와 치근 발육보다 매복깊이와 높은 상관관계를 보였다. 비자발적 맹출을 보였던 치아들 중 대부분은 교정적 견인에 의해 구강내로 맹출 되었고, 그 기간은 약 12개월 정도 걸렸으며, 교정적 견인기간은 매복깊이, 매복각도, 치근발육 정도와 통계적인 유의성을 나타내지 않았다. 이번 연구의 결과들은 편측성 상악 중절치 맹출 장애의 원인과 치료에 대한 정보를 제공할 수 있었으며, 치료 결과를 제공함으로써 향후 치료계획을 세우는데 도움이 될 수 있으리라 생각된다.

• 대한기계학회논문집A
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• 제36권3호
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• pp.297-304
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• 2012

블레이드의 성능 평가를 위하여 실제 사용 환경과 근접한 하중 모사에 따른 이축 하중의 필요성이 제기되고 있으며, 본 본문에서는 이러한 이축 하중에 따른 블레이드의 거동을 해석하였다. 100kW급 풍력 블레이드를 대상으로 하였으며, ANSYS를 사용하여 정적거동을 분석하였다. 정적거동은 파손해석과 좌굴거동으로 분석하였으며, 파손 평가는 Puck이 제안한 파손 방정식을 이용하여 섬유 파손과 섬유간 파손 기준을 검토하였다. 이축하중의 하중비가 증가함에 따라 루트부 단면이 변하는 후연부와 루트에서 Z+ 3300~3600인 지점에서 응력이 상대적으로 크게 나타났다. 또한 이축 하중비가 증가함에 따라 블레이드 좌굴 지점이 루트부 쪽으로 이동되고 있음을 확인하였다. 따라서 블레이드의 사용 신뢰성을 검증하기 위해서는 이축 하중에 의한 시험이 요구되고 있음을 본 해석을 통해서 확인하였다.

• 한국식품과학회지
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• 제9권1호
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• pp.19-23
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• 1977

The variation of the amount of starch, size and shape of the starch granules, amylose content, and blue value of the starch in the Korean ginseng roots from one year old to five year old cultivated at Kumsan was studied. The results obtained were as follows; 1) The starch content of the ginseng root(dried) was increased with the age of the root; that is, 9.62% for one-year-old roots, 10.35% for two-year-old root, 15.50% for three-year-old root, 17.05% for four-year-old root, and 18.32% for five-year-old root. 2) The shape of the ginseng starch granules was round or short oval, and in the latter case the ratio of minor axis to major axis was 1 to 1.1. Diameter of the starch granules was in the range of $1.48\;{\mu}\;to\;8.14\;{\mu}$ and the most frequent granule size was $3\;{\mu}\;(32.1{\sim}35.7%)$. The number of big size starch granules was increased during the five years of growing, while, the number of small size granules was decreased. 3) The amylose content in the ginseng starch was varied with the age of the root, in the range of $53.6{\sim}70.5%$. 4. The blue value of the ginseng starch was in the range of 0.60 to 0.71.

• 한국재료학회지
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• 제26권12호
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• pp.676-680
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• 2016

We have investigated the properties of thin film transistors(TFT) fabricated using zinc tin oxide(ZTO) thin films deposited via on-axis sputtering and FTS methods. ZTO thin films deposited by FTS showed lower root-mean-square(RMS) roughness and more uniformity than those deposited via on-axis sputtering. We observed enhanced electrical properties of ZTO TFT deposited via FTS. The ZTO films were deposited at room temperature via on-axis sputtering and FTS. The as-deposited ZTO films were annealed at $400^{\circ}C$. The TFT using the ZTO films deposited via FTS process exhibited a high mobility of $12.91cm^2/V.s$, a low swing of 0.80 V/decade, $V_{th}$ of 5.78 V, and a high $I_{on/off}$ ratio of $2.52{\times}10^6$.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2001년도 동계 학술대회 논문집
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• pp.16-21
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• 2001

The ride quality of agricultural tractor seats is evaluated based on the vibration of the human bodies. Tractor ride vibration levels have been measured at the person-seat interface along 7 axes(3 translational axes at the feet, 3 translational axes on a seat surface and 1 axis at the seat back), under different operating conditions. Since one of the most important parameters for ride comfort is the level and duration of the root mean square acceleration experienced, the ride values, such as the seat effective amplitude transmissibility, the component ride value, and the overall ride value based on acceleration root mean square are evaluated for a conventional tractor using frequency weighting functions and axis multiplying factors. The ride indices are also studied considering to the variation of vehicle speed and road profile.

• 대한수학회보
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• 제53권1호
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• pp.21-28
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• 2016

It is known that no two of the roots of the polynomial equation (1) $$\prod\limits_{l=1}^{n}(x-r_l)+\prod\limits_{l=1}^{n}(x+r_l)=0$$, where 0 < $r_1{\leq}r_2{\leq}{\cdots}{\leq}r_n$, can be equal and all of its roots lie on the imaginary axis. In this paper we show that for 0 < h < $r_k$, the roots of $$(x-r_k+h)\prod\limits_{{l=1}\\{l{\neq}k}}^{n}(x-r_l)+(x+r_k-h)\prod\limits_{{l=1}\\{l{\neq}k}}^{n}(x+r_l)=0$$ and the roots of (1) in the upper half-plane lie alternatively on the imaginary axis.

• Wind and Structures
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• 제16권3호
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• pp.241-248
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• 2013

The wind turbine blade is a very important part of the rotor. Extraction of energy from wind depends on the design of blade. In this work, the analysis is done on a blade of length 38.95 m which is designed for V82-1.65 MW horizontal axis wind turbine (supplied by Vestas). The airfoil taken for the blade is NACA 634-221 which is same from root to tip. The analysis of designed blade is done in flap-wise loading. Two shapes of the spar are taken, one of them is of square shape and the other one is combination of square and cross shape. The blade and spar are of the same composite material. The Finite element analysis of designed blade is done in ANSYS. This work is focused on the two segments of blade, root segment and transition segment. Result obtained from ANSYS is compared with the experimental work.

• Applied Microscopy
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• 제15권2호
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• pp.69-79
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• 1985

Ultrastructural and cytochemical studies of the root hair cell and the trichoblast were undertaken with light and electron microscopes to clarify the type of root hair, fine structure and the activities of acid phosphatase and ATPase. The root hair was differentiated from the middle portion of the cell, and perpendicularly to the long axis of the cell. Consequently, the type of root hair comes under the panicoid type. In the trichoblast, nucleus and cytoplasm are located in the vicinity of cortex. On the contrary, after the root hair is formed, they migrate to the apical region of the root hair, and the basal region of the root hair is filled with numerous vacuoles. Cell walls of actively growing root hairs are subdivided into two layers on the basis of the arrangement of cellulose microfibrils. New cell wall of the root hair is presumptively formed from Golgi complex-derived vesicles. Activity of acid phosphatase appeared on tonoplast, plasma membrane, and nuclear envelope, whereas ATPase activity appeared on the plasma membrane, heterochromatin, and mitochondrial cristae.

• Journal of Crop Science and Biotechnology
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• 제11권1호
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• pp.57-62
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• 2008

Isoflavone content in various parts of six soybean cultivars and soybean sprout during germination was analyzed by high performance liquid chromatography. The parts analyzed were seed coat, cotyledon, and axis for seeds and whole sprout, root, hypocotyl, and cotyledon for sprout. Two cultivars, Aga3 which is known to have the smallest seed size and the highest isoflavone content among the Korean soybean cultivars and Pungsannamulkong which is the most widely being used as soy-sprout, were selected for sampling from 1 to 10 days after germination. At the same weight, the order of isoflavone content increased from seed coat to cotyledon to axis. The highest total isoflavone(isoflavone$\times$dry weight) content was observed in the cotyledon and the lowest in the seed coat. The cotyledon of the Aga3 variety had the highest total isoflavone content and the lowest was measured in the Pungsannamulkong variety. The highest total isoflavone content, $10,788{\mu}g/g$, was observed in whole sprouts(cotyledon+hypocotyl+root) on day 7 for Aga3. After day 7, there was a decreasing trend in isoflavone content as the germination period increased. Total isoflavone content in the cotyledon of Aga3 significantly increased after seed germination, whereas the isoflavone content in the cotyledon of Pungsannamulkong decreased. However, total isoflavone content in the root of both varieties increased while isoflavone content in the hypocotyls decreased after seed germination.

• Journal of Plant Biology
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• 제26권4호
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• pp.207-216
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• 1983

Mature embryo and developing seedlings of Ginkgo biloba L. were embedded in a paraplast and serially sectioned at 10${\mu}{\textrm}{m}$ to examine vascular differentiation and vascular transition. Procambium and protophloem formed a continuous system along the epicotylhypocotyl root axis and cotyledons in mature embryo, whereas protoxylem was differentiated discontinuously in the cotyledons and rarely in the upper hypocotyl. The traces of the first and second leaf primordia apeared almost at the same time oppositely to each otehr at the epicotyl and alternately with the cotyledon traces in the upper hypocotyl. The trace differentiated bidirectionally toward the epicotyl and root tips. the young root initially formed a diarch xylem. Then, as the traces of the first and second leaves were superimposed, the diarch xylem. Then, as the traces of the first and second leaves were superimposed, the diarch xylem of the root was changed totriarch and tetrarch xylem, respectively. On the formation of primary vascular system of Ginkgo biloba, it is suggested that the primary phloem forms a continuous system throughout the seedling, whereas the primary xylem of the epicotyl is formed independently from that of the root-hypocotyl cotyledon system.