• 한국공작기계학회논문집
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• 제17권4호
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• pp.51-58
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• 2008

This paper presents a new design of the precision stage for the reticle in lithography process and a low hunting control method for the stage. The stage has three axes for X, Y, ${\theta}_z$ those actuated by three voice coil motors individually. The designed reticle stage system has three gap sensors and voice coil motors, and supported by four air bearings and the forward/inverse kinematics of the stage were solved to get an accurate reference position. When a stage is in regulating control mode, there always exist small fluctuations(stage hunting) in the stage movement. Because the low stage hunting characteristic is very important in recent lithography and nano-level applications, a special regulating controller for ultra low hunting is proposed in this paper. Also this research proposed the 2-step transmission system for preventing the noise infection from environmental devices. The experimental results showed the proposed regulating control system reduced hunting noise as 35nm(rms) when a conventional PID generates 77nm(rms) in the same mechanical system. Besides the reticle stage has 100nm linear accuracy and $1{\mu}rad$ rotation accuracy at the control frequency of 8kHz.

• Journal of the Korean Wood Science and Technology
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• 제20권3호
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• pp.55-60
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• 1992

Japanese red pine (Pinus densiflora S. et. Z.) decayed by brown-rot fungi Tyromyces palustris and Gloeophyllum trabeum were subjected to X-ray diffraction analysis and infrared spectral examinations. Pine woods decayed by T. palustris showed the increase of relative crystallinity in the initial stage of degradation. When the weight loss was above 30%, then the crystallinity went down slowly. In contrast, the wood samples degraded by G. trabeum showed the decrease of crystallinity from the beginning stage of decay. The changes of crystallinity in brown-rotted woods suggested that the degradation rate of crystalline cellulose was varied with the brown rot fungal species. X-ray diffraction analyses also indicated that crystalline cellulose was much more slowly broken down than the amorphous one. The most notable difference in the IR spectra of the brown-rotted wood samples was that the adsorption band centered at 1,730$cm^{-1}$ was significantly diminished in the decayed wood. indicating the degradation of hemicellulose by brown-rot fungi. However, no marked changes of intensities at 1,000, 1,060 and 1,040$cm^{-1}$ were observed in the brown rotted wood samples, suggesting that crystal line cellulose was resistant against the attack by brown rot fungi.

• 디지털융복합연구
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• 제17권4호
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• pp.177-185
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• 2019

본 연구는 인체 골격의 좌표형 임상용어체계 표준을 개발하기 위한 방법론적 연구이다. 문헌고찰과 자료 수집을 통해 연구 계획을 수립하여 예비 표준(안)을 만들고 전문가 세미나와 자문을 통해 수정 표준(안)을 만든 후 내용타당도 검증 후 최종(안)을 제시하는 4단계를 거쳐 표준을 개발하였다. 좌표형 임상용어체계 표준은 인체 이미지를 2D는 x, y축, 3D는 x,y,z축으로 좌표화하고, 좌표의 개념과 정의는 SNOMED CT의 FSN, Synonym, Preferred name으로 선조합하고 후조합은 개발 된 18개의 Relationship을 통해 정의되고, 개발된 Relationship 표준의 내용타당도 지수는 평균 4.01점이었다. 본 연구를 통해 인체 골격 이외의 뇌, 장기, 조직 등의 인체의 다른 부분에 대한 후속 표준 개발을 제언하고 임상에서 활용성을 높이기 위한 방법 연구를 제언한다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권10호
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• pp.1374-1380
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• 2012

The changes in yields and nutritive composition of whole crop wheat (Triticum aestivum L.) during maturation and effects of maturity stage and lactic acid bacteria (LAB) inoculants on the fermentation quality and aerobic stability were investigated under laboratory conditions. Whole crop wheat harvested at three maturation stages: flowering stage, milk stage and dough stage. Two strains of LAB (Lactobacillus plantarum: LAB1, Lactobacillus parafarraqinis: LAB2) were inoculated for wheat ensiling at $1.0{\times}10^5$ colony forming units per gram of fresh forage. The results indicated that wheat had higher dry matter yields at the milk and dough stages. The highest water-soluble carbohydrates content, crude protein yields and relative feed value of wheat were obtained at the milk stage, while contents of crude fiber, neutral detergent fiber and acid detergent fiber were the lowest, compared to the flowering and dough stages. Lactic acid contents of wheat silage significantly decreased with maturity. Inoculating homofermentative LAB1 markedly reduced pH values and ammonia-nitrogen ($NH_3$-N) content (p<0.05) of silages at three maturity stages compared with their corresponding controls. Inoculating heterofermentative LAB2 did not significantly influence pH values, whereas it notably lowered lactic acid and $NH_3$-N content (p<0.05) and effectively improved the aerobic stability of silages. In conclusion, considering both yields and nutritive value, whole crop wheat as forage should be harvested at the milk stage. Inoculating LAB1 improved the fermentation quality, while inoculating LAB2 enhanced the aerobic stability of wheat silages at different maturity stages.

• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.190-195
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• 1995

Temperature dependences of the dielectric constant K(T), remanent polarization $P_{r}$, (T), effective birefringence overbar .DELTA.n(T), transmitted light intensity and quadratic electro optic coefficient R(T) of the two-stage sintered xBa(L $a_{1}$2/N $b_{1}$2/) $O_{3}$-(1-x)Pb(Z $r_{y}$ $Ti_{1-y}$) $O_{3}$(x=0.085, 0.09, 0.40.leq.y.leq.0.70) ceramics were investigated. Increasing the PbZr $O_{3}$ contents, the crystal structure of a specimen was changed from a tetragonal phase to a rhombohedral and cubic phase, and the phase transition was showed a diffuse phase transition(DPT) characteristics. In the compositions which located on the PE-FE phase boundary, the discrepancy was observed between the Curie temperature and temperature which a microscopic polarization and effective birefringence were disappeared.red.d.

• 한국가축번식학회지
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• 제20권1호
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• pp.19-26
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• 1996

본 연구는 체외에서 생산된 돼지수정란에 외래유전자를 미세주입후 체외 배 발달과 유전자 발현을 조사하기 위하여 실시하였다. 체외수정후 18∼20 시간 사이에 LacZ 유전자와 산양 성장호르몬 유전자를 미세주입하였으며, 체외 배 발달율과 유전자 발현은 미세주입후 9일간 체외배양을 실시한 다음 조사하였다. 돼지수정란을 원심분리하여 전핵을 관찰한 결과 60.3%의 난자에서 전핵이 가시화되었다. 또한 유전자가 미세주입된 수정란중 상실배와 배반포까지 발달한 비율은 각각 8.6, 9.1%로 대조구의 발달율 19.0, 20.8%보다 유의하게 낮았다. 그러나, NCSU23 배양액에 4일간 배양후 EMEM 배양액으로 교체하여 배양한 결과, 배반포 및 부화배반포까지 높은 발달율(19.4%)을 나타내었다. X-gal 염색의 결과로서, LacZ의 발현을 나타낸 수정란의 비율은 상살배, 배반포 단계에서 40.0, 42.9%로 나타났으나, 이들 형질전환 수정란의 대부분은 mosaic 현상이 관찰되었다. 또한 PCR 부분에서, gGH 유전자가 도입된 수정란의 비율은 상실배, 배반포단계에서 45.0, 44.4%로 X-gal 염색의 결과와 유의한 차이가 없었다. 따라서 본 실험에서 얻어진 결과들은 체외에서 생산된 돼지수정란은 미세주입후에도 배반포 및 부화배반포까지 성공적으로 발달할 수 있다는 것을 입증하였다. 또한 체외성숙, 수정된 돼지수정란을 이용하여 형질전환 돼지 생산의 가능성을 시사하고 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권4호
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• pp.453-459
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• 2004

Chick embryos from stage 14 to stage 31 were studied by means of serial section and light microscopy in order to learn the relationship between the settlement sites of the primordial germ cells (PGCs) and the forming genital ridge. The results showed that: when embryo hatched for 53-56 h, the PGCs reached the coelomic epithelial tissue where gonad would be formed, meanwhile the epithelial tissue began thicker before the PGCs reached. Before stage 19, the final region the PGCs arrived was the thickened portion of the coelomic epithelium, the glycogen in the PGCs cytoplasm maintenance remained unchanged. However at the 3.5-5th hatching day, the glycogen in the PGCs cytoplasm reduced gradually. On the 6th hatching day, the gonad of the embryo appeared the feature of ovary, and the glycogen in the PGCs cytoplasm reduced further. On the 7th hatching day, the differentiation of ovary or testis was obvious and the glycogen in the PGCs cytoplasm later disappeared.

• 한국동물학회지
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• 제33권1호
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• pp.94-102
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• 1990

무미 양서류발생중에 근절 예정 부위의 최전방에 나타나는 cranial myotomes인 W, X, Y, Z는 후기 배 발생중에 "reduction"을 나타내는 특이한 체절이다. Cranial Myotome이 programmed autonomous death를 수행하는지 또는 otic vesicle과 같은 주위 조직의 영향에 의해 reduction을 일으키는지에 대한 가설을 검증하기 위해 Xenopus를 재료로 하여 서술적인 면과 조직이식을 통한 발생학적 실험을 수행하였다. 먼저 주위의 otic vesicle을 제거하여도 W, X, Y, Z degeneration에는 아무런 영향도 없었으며 otic vesicle을 체절을 따라 새로운 지역으로 이식하여도 그 부위에서 체절이 사라지는 현상이 유도되지 않았다. 한편, WXYZ형성 예정지역을 trunk somite 부위로 이식한 결과 원래대로 reduction을 나타내었고 truck somite 형성조직을 WXYZ 부위로 이식하여도 원래의 운명대로 분화하였다. 따라서 cranial myotome은 근육이 분절되는 발생시기에 도달하면 주위의 조직에 상관없이 예정된 운명에 따라 자동적으로 소멸되는 것으로 결론지을 수 있다.결론지을 수 있다.

• 한국공작기계학회논문집
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• 제15권1호
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• pp.8-16
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• 2006

The communication through optical fiber is taking an important role of the expansion of communication network with excellent transmitting rate and quality. As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement of the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1219-1222
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• 2005

As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement to the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.