• 한국기계가공학회지
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• 제19권11호
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• pp.64-69
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• 2020

To determine the effective factors for microparticle blasting with precise sequence position control in the x-axis and y-axis directions, we conducted a statistical experimental analysis of blasted square shapes by considering five condition factors. The control input and output were operated simultaneously by rotation-linear motion conversion and fine particles were blasted onto the aluminum specimen by precise position control driving using multiple execution codes. The micro-driving device used for processing was capable of microparticle blasting and of controlling the system through contact with a limit sensor at high speed and a two-degree-of-freedom driving mechanism. Our experiments were conducted on 1,050 specimens of pure aluminum (containing <1% of other elements). The effects of several factors (e.g., particle and nozzle diameters, blasting pressure, and federate and blasting cycle numbers) on the surface roughness and blasted surface's depth were verified through a statistical experimental analysis by applying the dispersion analysis method. This statistical analysis revealed that the nozzle diameter, the blasting pressure, and the blasting cycle number were the dominant factors.

• Structural Engineering and Mechanics
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• 제87권2호
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• pp.107-116
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• 2023

The three-dimensional Hashin criterion and user subroutine VUMAT were used to simulate the damage in the composite layer, and the secondary stress criterion was used to simulate the interlayer failure of the cohesive element of the bonding layer and the propagation characteristics under the layer. The results showed that when the shear stress wave (shear wave) propagates on the surface of the laminate, the stress wave attenuation along the fiber strength direction is small, and thus producing a large stress profile. When the compressive stress wave (longitudinal wave) is transmitted between the layers, it is reflected immediately instead of being transmitted immediately. This phenomenon occurs only when the energy has accumulated to a certain degree between the layers. The transmission of longitudinal waves is related to the thickness and the layer orientation. Along the symmetry across the thickness direction, the greater is the stress amplitude along the layer direction. Based on the detailed investigation on the impact on various laminated composites carried out in this paper, the propagation characteristics of stress waves, the damage and the destruction of laminates can be explained from the perspective of stress waves and a reasonable layering sequence of the composite can be designed against damage and failure from low velocity impact.

• Structural Engineering and Mechanics
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• 제84권2호
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• pp.225-238
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• 2022

In order to improve the cracking resistance of reinforced concrete and give full play to the advantages of prefabricated assembly structure in construction, prestressed reinforced concrete composite beam (PRCC) is proposed. Through the bending static test of seven I-shaped beam specimens, the bending failure modes and bearing capacity of PRCC and reinforced concrete composite beam are compared and analyzed, and the effects of prestress size, prestressed reinforcement layout and prestress application sequence on the flexural behavior of PRCC beams are studied. The results show that the cracking load and ultimate load of PRCC beams significantly increased after prestressing, and prestressed tendons can effectively control the crack development. With the increase of prestressing degree, the deformation resistance and bending stiffness of PRCC beams are increased. The application sequence of prestress has little influence on the mechanical properties of PRCC beams. The crack width, stiffness and normal section bearing capacity of PRCC beam are analyzed, and the calculated results are in good agreement with the experimental results.

• 생명과학회지
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• 제26권11호
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• pp.1341-1344
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• 2016

보길도에서 자라고 있는 황칠나무(Dendropanax morbifera)를 구입하여, 캘러스로 유도한 후, ribosomal DNA(nrDNA)의 internal transcribed spacer (ITS) region의 염기서열을 결정하였다 보길도의 황칠나무(Dendropanax morbifera)의 ITS region의 염기서열을 분석한 결과, 총 689염기를 결정하였다. 결정된 689염기 중에서 ITS1은 222 개염기, 5.8S rDNA는 160염기, ITS2는 233염기인 것으로 판명되었다. GenBank의 BLAST 프로그램(http://www.ncbi.nlm.nih.BLAST)을 사용하여 GenBank/EMBL/DDBJ에 등록되어 있는 Dendropanax 속 33의 염기서열을 수집한 후 multiple alignment를 수행한 결과, 유사도는 99.7%(D. chevalieri)에서 92.6%(Dendropanax arboreus)로 나타났으며, 일본황칠나무(D. trifidus)와는 유사도가 99.4%로 판명되었다.

• Journal of Astronomy and Space Sciences
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• 제28권3호
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• pp.203-216
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• 2011

To prepare for a future Korean lunar orbiter mission, semi-optimal lunar capture orbits using finite thrust are designed and analyzed. Finite burn delta-V losses during lunar capture sequence are also analyzed by comparing those with values derived with impulsive thrusts in previous research. To design a hypothetical lunar capture sequence, two different intermediate capture orbits having orbital periods of about 12 hours and 3.5 hours are assumed, and final mission operation orbit around the Moon is assumed to be 100 km altitude with 90 degree of inclination. For the performance of the on-board thruster, three different performances (150 N with $I_{sp}$ of 200 seconds, 300 N with $I_{sp}$ of 250 seconds, 450 N with $I_{sp}$ of 300 seconds) are assumed, to provide a broad range of estimates of delta-V losses. As expected, it is found that the finite burn-arc sweeps almost symmetric orbital portions with respect to the perilune vector to minimize the delta-Vs required to achieve the final orbit. In addition, a difference of up to about 2% delta-V can occur during the lunar capture sequences with the use of assumed engine configurations, compared to scenarios with impulsive thrust. However, these delta-V losses will differ for every assumed lunar explorer's on-board thrust capability. Therefore, at the early stage of mission planning, careful consideration must be made while estimating mission budgets, particularly if the preliminary mission studies were assumed using impulsive thrust. The results provided in this paper are expected to lead to further progress in the design field of Korea's lunar orbiter mission, particularly the lunar capture sequences using finite thrust.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.892-897
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• 2005

Macrophage colony-stimulating factor (M-CSF) is a growth factor required for growth and differentiation of mononuclear phagocyte lineage. Total and 16 poly (A) mRNA of bovine M-CSF were isolated from healthy bovine peripheral mononuclear cells stimulated by phobol 12-myristste 13-acetate (TPA). The more compatible cultured mononuclear cells were 5${\times}$10/ml for RNA isolation. TPA-activated mononuclear cells increased the level of M-CSF-mRNA more than concanavalin A (Con A) and lipopolysaccharide (LPS). The optimal analysis of reverse transcriptase-polymerase chain reaction (RT-PCR) for14 Macrophage colonystimulating factor (M-CSF) as a growth factor required for bovine M-CSF was denaturation at 94$^{\circ}C$ for 1 minute, annealing at 57$^{\circ}C$ for 1 minute, extension at 72$^{\circ}C$ for 1 minute for 30 cycles. The size of cDNA of bovine M-CSF by RT-PCR was 774 base pairs. A 774 base pairs cDNA encoding bovine M-CSF was synthesized by reverse transcriptase polymerase chain reaction (RT-PCR). Ligated cDNA was transformed to competent cells and then plasmid isolation and digestion was performed. Molecular cloning and sequencing were performed for cDNA of bovine M-CSF. The size of cloned cDNA of bovine M-CSF was 774base pairs. The homology of base sequence and amino acid sequence was 88% and 86% compared with known human M-CSF, respectively. From a high degree of sequence similarity, the obtained cDNA of bovine M-CSF is thought be a specific gene of bovine M-CSF.

• Asian-Australasian Journal of Animal Sciences
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• 제17권7호
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• pp.897-902
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• 2004

PSMC5 subunit, which belongs to the 26S proteasomal subunit family, plays an important role in the antigen presentation mediated by MHC class I molecular. Full-length cDNA of porcine PSMC5 was isolated using the in silico cloning and rapid amplification of cDNA ends (RACE). Amino acid was deduced and the primary structure was analyzed. Results revealed that the porcine PSMC5 gene shares the high degree of sequence similarity with its mammalian counterparts at both the nucleotide level and the amino acid level. The RT-PCR was performed to detect the porcine PSMC5 expression pattern in seven tissues and the result showed that high express level was observed in spleen, lung, marrow and liver while the low express level was in muscle. The full-length genomic DNA sequence of porcine PSMC5 gene was amplified by PCR and the genomic structure revealed that this gene was comprised by 12 exons and 11 introns. Best alignment of the cDNA and genomic exon DNA sequence presents 4 mismatches and this information potentially bears further study in gene polymorphisms.

• The Plant Pathology Journal
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• 제16권6호
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• pp.306-311
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• 2000

A new strain of Cucumber mosaic virus (CMV) from easter lily (Lilium longiflorum), Ly2-CMV, was identified and compared to the well-characterized Mf-CMV (subgroupⅠ) and LS-CMV (subgroupⅡ) by host reaction in several indicator plants, dsRNA analysis, serological property, RT-PCR analysis, restriction enzyme profile of the PCR products and nucleotide sequence of coat protein (CP) gene. Remarkable differences in symptoms of Ly2-CMV were found between Mf-CMV or LS-CMV in tobacco plants and Datura stramoinium. Ly2-CMV induced small necrotic ringspots on the inoculated leaves of Nicotiana tabacum cvs. Xanthi nc and Burley 21 and D. stramonium, and failed to infect these species systemically. Of the indicator plants tested, N. benthamiana only reacted with systemic infection by inoculation of Lr2-CMV. In experiments of dsRNA analysis, serology and RT-PCR of CP gene, Ly2-CMV was come within subgroupⅠ CMV. However, restriction enzyme analysis of the PCR products using MspⅠ showed that Ly2-CMV was distinct to Mf-CMV. The CP gene of Ly2-CMV contains 657 nucleotides, and the nucleotide sequence is similar to that of Mf-CMV. There is also a high degree of conservation between their putative gene products in Ly2-CMV and Mf-CMV, with five amino acid changes in the 218 amino acids of the CPs.

• Journal of Plant Biotechnology
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• 제46권3호
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• pp.158-164
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• 2019

Molecular characterization of different genotypes reveals accurate information about the degree of genetic diversity that helps to develop a proper breeding program. In this study, a total of 30 EST-based simple sequence repeat (EST-SSR) markers derived from trumpet lily (Lilium longiflorum) were used across 11 native lily species for their genetic relationship. Among these 30 markers, 24 SSR markers that showed polymorphism were used for evaluation of diversity spectrum. The allelic number at per locus ranged from 1 at SSR2 locus to 34 alleles at SSR15 locus, with an average of 11.25 alleles across 24 loci observed. The polymorphic information content, PIC, values ranged from 0.0523 for SSR9 to 0.9919 for SSR2 in all 24 loci with an average of 0.3827. The allelic frequency at every locus ranged from 0.81% at SSR2 locus to 99.6% at SSR14 locus. The pairwise genetic dissimilarity coefficient revealed the highest genetic distance with a value of 81.7% was in between L. dauricum and L. amabile. A relatively closer genetic distance was found between L. lancifolium and L. dauricum, L. maximowiczii and L. concolor, L. maximowiczii and L. distichum (Jeju), L. tsingtauense and L. callosum, L. cernuum and L. distichum (Jeju ecotype), of which dissimilarity coefficient was 50.0%. The molecular fingerprinting based on microsatellite marker could serve boldly to recognize genetically distant accessions and to sort morphologically close as well as duplicate accessions.

• 방송공학회논문지
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• 제27권2호
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• pp.207-215
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• 2022

최신 볼류메트릭 기술이 제공하는 높은 기하학적 정확도와 사실성은 실제 객체와 캡춰된 3D 모델 간 높은 일치도를 보장한다. 그럼에도 불구하고 이렇게 획득된 3D 모델은 프레임 간 완전히 독립적인 3D모델로 시퀀스를 구성하고 있다는 측면에서, 매 프레임 모델 표면 구조(Geometry)의 일관성이 보장 되지 않으며, 정점(Vertex)의 밀도가 매우 높고 정점 간 연결 노드(Edge)가 매우 복잡해지는 특징을 확인 할 수 있다. 이 기술을 통해 생성된 3D 모델은 영화나 비디오 게임 제작 파이프라인에서 제작된 모델과는 본질적으로 다르며, 실시간 렌더링, 애니메이션 및 시뮬레이션, 압축과 같은 응용 분야에서 직접 사용하기에 적합하지 않다. 이와는 대조적으로 우리의 방법은 프레임 간 3D 모델 표면 구조의 높은 일관성을 확보하는 리메싱(Remeshing)과 비강체 표면(Non-rigid Shape)의 대응(Correspondences) 및 매칭(Matching)을 통한 점진적 변형(Deformation) 과정 및 텍스쳐 전달(Texture Transfer) 과정을 연결함으로서 볼류메트릭 3D 모델 시퀀스 품질의 일관성을 유지하며, 후 처리 과정의 자동화를 제공한다.