• 한국자원식물학회지
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• 제11권3호
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• pp.319-325
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• 1998

The developmental changes occuring in the secondary xylem of Aristolochia manshuriensis Komarov have been studied in different ages of vine stems. A. manshuriensis possesses typical storeyed cambium comprising both vertically elongated fusiform initials and almost isodiametric ray cell initials. Stems of A. manshuriensis have wide rays that make the secondary xylem appear dissected as other vine types. The length of vessel member and fiber remained relatively constant throughout the secondary growth. However, vessel diameter increases with the increasing age of stem till the cell reaches their maximum limit and later more or less stabilize in diameter while number of vessel per $\textrm{mm}^2$ is vice versa. Width and relative proportion of ray to axial elements gradually increased with the increasing age of stem and later remained relatively constant.

• 한국항해학회지
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• 제22권2호
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• pp.81-87
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• 1998

On this paper, the methods of optimization research of the fishing navigation using the graph theory are substantiated on the basis of the proposed probable model of the fishing vessel navigator's activity. The graph theory is concered about the transitionform the top graph to the rib one. And the definition of the additional system elements (quasi elements) necessary to provide the effectiveness during the fishing navigation are also substantiated herein. This approach helps to optimize the structure of any fishing vessel monitoring system.

• Journal of the Korean Wood Science and Technology
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• 제25권3호
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• pp.43-49
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• 1997

The lengths of fibers and vessel elements, vessel diameters, and ray spacings of tension and opposite woods in Quercus mongolica Fischer and their radial variations were examined. Crystallinity indices and crystallites orientations of tension, opposite and lateral woods were also investigated. The lengths of fibers and vessel elements, and ray spacings of tension wood were longer and denser than those of opposite wood, respectively. In the latewood, the vessels of tension wood had a little larger diameters than those of opposite wood. whereas the vessel diameters of earlywood were similar in both woods. With the exception of vessel diameters of earlywood, there were differences between tension and opposite woods in all anatomical characteristics examined. In the radial variation pattern, the fiber lengths of both woods increased markedly to about 15th annual ring and thereafter remained virtually constant. The vessel element lengths of earlywood in tension wood increased to certain annual ring and thereafter were stabilized, but opposite wood had a relatively constant trend from pith to bark. Those of late wood in both woods increased to certain annual ring and thereafter showed constant patterns. Vessel diameters appeared to show similar trend in both woods. Ray spacings decreased to about 15 annual ring and thereafter were stabilized in both woods. In the fine structures, tension wood had higher crystallinity index and better crystallites orientation than opposite and lateral woods.

• 한국산림과학회지
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• 제86권3호
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• pp.319-323
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• 1997

본(本) 연구(硏究)는 수국과(科)의 물참대(댕강말발도리), 둥근잎말발도리(꽃말발도리), 나무수국 및 고광나무에 있어서 목부(木部) 방사조직(放射組織)내에 천공(穿孔)을 지니는 방사조직(放射組織) 구성세포(構成細胞)가 존재(存在)함을 처음으로 보고(報告)하는 것으로써 천공(穿孔)을 지니는 이들 방사조직(放射組織) 세포(細胞)는 도관요소(導管要素)에 발달(發達)하는 계단상(階段狀) 천공(穿孔)과는 달리 물참대는 단일(單一) 내지 계단상(階段狀) 천공(穿孔)을 그리고 나무수국, 둥근잎말발도리 및 고광나무는 계단상(階段狀) 내지 망상(網狀) 천공(穿孔)을 지니는 것으로 밝혀졌다. 그러나 조사 수종 가운데 애기말발도리에서는 천공(穿孔)을 지니는 방사조직(放射組織) 구성세포(構成細胞)가 관찰되지 않았다.

• 한국기계가공학회지
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• 제9권5호
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• pp.76-82
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• 2010

In this study, we carried out to evaluate the shock-proof of a large scale motor for the naval vessel using dynamic design analysis method (DDAM) and full transient dynamic analysis. Analytical models for main assemblies (motor frame, rotor and stator assembly) were consisted of the tetrahedral solid elements and the equipments which installed in the upper side of the motor were substituted the mass elements. And we also modelled resilient mounts of a motor using the beam elements with appropriate directional stiffness. The DDAM was conducted according to NRL memorandum report 1396 and the full transient dynamic analysis was performed applying directional triple half triangle shock wave to the motor using ANSYS 12. As a result, we could compare of the results according to each analytic method and find the motor to satisfy the design criteria of the maximum stress and deformation.

• Journal of the Korean Wood Science and Technology
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• 제32권3호
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• pp.15-24
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• 2004

The present work was undertaken to investigate the anatomical and chemical characteristics of transgenic poplar down-regulated with antisense OMT gene. Also the distribution of lignin in transgenic poplar trees was investigated at cellular level. No visible abnormal phenotype was observed in the fibers and vessel elements of transgenic poplar. Any marked differences in the staining intensities of Wiesner and Mäule color reaction were not identified in the transgenic poplar. TEM micrographs did not show any staining intensities in the cell walls stained with KMnO₄. Interestingly, the UV spectroscopy of semi-thin sections exhibited a distinct decrease of lignin absorption at 280 nm in the vessel walls, indicating transgenic poplar wood with lower amount of guaiacyl lignin in vessel elements. Chemical composition of antisense OMT poplar was almost identical to that of wild-type poplar. Klason lignin content of transgenic poplar did not show any significant difference from that of the controls. The solid state NMR spectra revealed the transgenic poplar with only slightly more syringyl lignin than the control. The present work showed that antisense OMT gene constructed in the poplar was not enough to reduce the overall content of Klason lignin, and suggested that the expression of transformation was confined to vessel walls.

• Journal of the Korean Wood Science and Technology
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• 제17권2호
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• pp.1-12
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• 1989

To study the structure of opposite wood in the angiosperms. samples were cut from stems and branchs of 10 spcies growing in Korea. The opposite side was defined as being along a line passing from the most wide annual ring of the tension wood on the upper side to the pith and extrapolated through the opposite side. lateral sides being on the right and left of this line. The stem woods growing almost horizontally were surveyed the structural features of the well-developed opposite wood for the tension wood. In the annual-ring of the well-developed opposite woods. an investigation was made on how the dimension of elements, microfibril angles. and cell wall layers change from tension side to opposite side. The structural characteristics of opposite wood in hardwoods realized in this study are as follows: 1. The vessel diameters increased continuously to ward the opposite side in which the values were maximum. The vessel length also increased toward opposite side. but the rates of increase were smaller than those in the vessel diameters. 2. The wood fiber length were decreased from tension toward opposite side. but the rates of decrement were f1actuated within the sampled species. 3. The microfibril angles had the minimum values on the tension side. then increased steeply toward the opposite side in which the values maximum. 4. In the percentage of elements the vessel elements increased continously at a relative rate from the tension to opposite side, whereas the values of the wood fibers were lower in the opposite than the tension side, but the' variation patterns of rays were not seem distinctly. 5. The component layers of the wood fiber in the opposite woods were very similar to the lateral woods.

• 한국전산구조공학회논문집
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• 제27권5호
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• pp.369-377
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• 2014

본 논문에서는 해중터널와 수중운항체의 충돌거동을 파악하기 위하여 두 구조체를 모델링하고 해석을 수행하였다. 충돌이 일어나는 해중터널은 원통형으로 단면을 가정하고 콘크리트와 라이닝강판을 가진 구조로 가정하였다. 충돌부위를 제외한 인접부분은 탄성거동을 하는 보요소로 모델링하고 계류라인은 장력을 받는 케이블로 모델링하였다. 수중운항체는 1800톤급 잠수함을 가정하였으며 수리동역학적 부가질량을 고려하여 충돌질량을 산정하였다. 해중터널에 작용하는 부력은 동적완화방법을 사용하여 초기조건에 포함시켰다. 부력비의 변화와 충돌속도의 변화를 고려하여 충돌해석을 수행한 결과, 충돌에너지의 소산은 주로 해중터널에서 발생하고 수중운항체에 의한 에너지 소산은 미미한 것으로 나타났다. 또한 계류라인의 장력과 부력비의 변화에 따라 해중터널의 충돌거동은 큰 영향을 받았다. 특히 충돌력은 기존의 설계기준의 선박충돌력과는 상이한 경향을 보이는 것으로 나타났다.

• Journal of Plant Biology
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• 제28권1호
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• pp.9-20
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• 1985

물오리나무와 사방오리나무의 뿌리 줄기 및 가지에 있어서 목부요소의 크기의 변이에 관해서 연구하였다. 도관요소의 직경은 뿌리에서 가장 넓고 그 다음은 줄기이며 가지에서 가장 좁다. 그런데 도관요소의 길이는 줄기에서 가장 길고 다음은 뿌리이며 가지에서 가장 짧은 것으로 밝혀졌다. 섬유의 직경 및 길이는 뿌리에서 가장 넓고 길며 그 다음은 줄기 가지의 순이다. 각 기관의 일정위치에서 중심부로부터 연륜이 증가함에 따라 목부요소의 크기는 뚜렷하게 증가되었다.

• Journal of the Korean Wood Science and Technology
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• 제26권2호
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• pp.24-28
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• 1998

Ray cells with perforations are recorded for the first time in the Korean Celastraceae species of Euonymus sieboldiana and Tripterygium regelii and the Oleaceae species of Abeliophyllum distichum, Forsythia ovata, Ligustrum japonicum, and Osmanthus heterophylla, All these anomalous ray cells have simple perforations, and the vessel elements of all these species have simple perforation plates, Thus, in the Korean Celastraceae and Oleaceae, the perforations of ray cells appear to be identical with the types of perforation plates in the vessel elements of the same wood, The diagnostic value of the perforated ray cells is also discussed.