• 제목/요약/키워드: Irregular shape

검색결과 748건 처리시간 0.027초

On wave damping effect due to the crest width variation of a permeable submerged breakwater (투과성 잠제의 폭 변화에 따른 파랑감쇠 효과에 관하여)

  • Hur, Dong-Soo;Choi, Dong-Seok;Bae, Ki-Seong
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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    • pp.453-456
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    • 2006
  • To examine the effect of shape and crest width variation of a permeable submerged breakwater on the wave energy dissipation, Two-Dimensional numerical model with Large Eddy Simulation, which is able to simulate directly WAve Structure Seabed interaction (hereafter, LES-WASS-2D) has been newly developed. A good agreement has been obtained by the comparison between the existing experimental results and LES-WASS-2D model's results for the permeable submerged breakwater. Moreover, based on the LES-WASS-2D model, the wave energy dissipation due to a permeable submerged breakwater are discussed for regular and irregular waves with relation to its crest width and shape.

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Microstructural Change of $Cd_{1-x}Zn_xS$ Films Sintered with $CdCl_2$ ($CdCl_2$를 첨가한 $Cd_{1-x}Zn_xS$소결막의 미세구조 변화)

  • Seol, Yeo-Song;Im, Ho-Bin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 1988년도 춘계학술대회 논문집
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    • pp.35-37
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    • 1988
  • Polycrystalline $Cd_{1-x}Zn_xS$ films were prepared by coaling a slurry which consisted of CdS, ZnS, $CdCl_2$ and propylene glycol on gloss substrates and by sintering in a nitrogen atmosphere. Microstructures, optical transmittance and electrical resistance of the sintered films have been investigatd. Grain shape of $Cd_{1-x}Zn_xS$ films sintered in a sealed boat was nearly spherical but the shape became, irregular when sintered in evaporating condition due to occurrence of CIGM (Chemically Induced Grain-boundary Migration). Controlling the rate of evaporation of $CdCl_2$, sintered $Cd_{1-x}Zn_xS$ films with high optical transmittance and low electrical resistance could be obtained.

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Improvement of Feeling Quality of a Stamped Member for an Autobody with the Finite Element Analysis (유한요소해석을 이용한 자동차용 박판부재의 감성품질 개선)

  • Kim S. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2004년도 추계학술대회논문집
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    • pp.252-255
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    • 2004
  • Design modification of the stamping die for the upper member of a front end module carrier is carried out in order to improve the feeling qualify of the final product. The small inferiority induced by wrinkling near the wall of the FEM upper member has been inspected after the draw-forming process. The finite element simulation shows that the excess metal is developed by the irregular contact of the blank the tool and it remains after the final stroke. This paper proposes two guidelines for the modification: one is to add the draw-bead; and the other is to modify the tool shape such as the forming shape at the wall. Simulation results show that the proposed guidelines both guarantee the improved feeling quality.

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Zebrina pendula의 웅성배우에 관한 연구

  • 한창열
    • Journal of Plant Biology
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    • 제5권2호
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    • pp.1-5
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    • 1962
  • Attempts were made in order to make clear the meiotic irregularities, male gametophyte formation and spermatogenesis for the purpose of applying these embryological facts to taxonomic works. Followings are the results obtained : 1. Meiosis is extremely irregular, giving rise to giant, micro, and empty, pollens. Meiotic division in each PMC is observed synchronizing. 2. In the microspore immediately before the vegetative-generative nuclear division, the nucleus locates appressed to the inner wall, most of the other part of the cell being occupied by large vacuoles. 3. Spindle symmetry in the microspore nuclear division is of intermediate type. 4. Nuclear divisions in each micropore are not synchronized as in meiosis. 5. Generative nucleus is located in close contact with the inner wall, while the vegetative nucleus occupies the central part of pollen grain. The pollen in this stage looks somewhat like broad bean. Afterward the generative nucleus loses contact with the wall, the nuclear shape changing from lenticular to roundsh. 6. The generative nucleus in fully matured pollen grain usually takes the shape of crescence, those in abortive pollen, lenticular or ellipsoidal, etc.

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A Study on the Characteristics of Vertical Motions due to Changes of Submerged Shape in the Multi-Purpose Small Floating Body (다목적 소형 부유시설의 몰수부 형상변화에 따른 파랑중 수직운동 특성에 관한 연구)

  • OH, Yu-Na;KIM, Sang-Won;LEE, Gyoung-Woo;HAN, Seung-Jae;KIM, In-chul
    • Journal of Fisheries and Marine Sciences Education
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    • 제28권4호
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    • pp.1024-1030
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    • 2016
  • This study gives the vertical motion analysis due to changes in Submerged shape of Multi-Purpose Small Floating Body in irregular waves using the commercial code(MAXSURF v.20) based on the Panel method. To verify the commercial code prior to the analysis, we guarantees the reliability of this paper's results using the commercial code by comparing with the results of experimental results on Catamaran. The anlysis conditions are ITTC wave spectrum, each encounter angle. Finally, we analyze the result of ship's response spectra for vertical motions.

Comparison of performance of cooling tower with various shape of packings (충전재 형상에 따른 냉각탑 성능비교에 관한 연구)

  • 이강현;최우영;이재헌;소헌영
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • 제10권3호
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    • pp.358-367
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    • 1998
  • Since the performance of cooling tower is strongly dependent on the thermal performance of the packing, the evaluations of heat transfer rate and fan power from various packing have attracted intense interest. In the present study, two new packings have been devised and their performances have been compared with those of two existing packings to find better shape characteristic. It is found that one of the existing packings, which showed high heat transfer rate and medium fan power due to zig -zag flow passages and highly irregular surfaces, should be adapted.

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A Study on the Heat Transfer in Radial Fin of Hyperbolic Profile (쌍곡선 단면을 가진 반경휜에서의 열전달에 관한 연구)

  • Kim, Kwang-Soo;Seoh, Jeong-Il
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • 제11권3호
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    • pp.9-17
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    • 1982
  • In this paper, temperature distributions in radial fin of hyperbolic profile for steady -state with no heat generation are obtained by one-dimensional analytical method, finite difference method and experiment respectively. Heat flow rate and fin efficiency from the fin model are obtained by analytical method. To compare the exact solutions obtained by theoretical analysis with the results obtained by finite difference method, cylindrical shape is selected. Particularly, equations of finite difference method for cylindrical shape with irregular boundary are rearranged and formulated. Consequently, temperature distributions in radial fin can certify that are similar to exact solutions. From theoretical analysis, the effects according to heat flow rate and fin efficiency are related to variation of parameters which are fin thickness ${\delta}_o$, fin base temperature $T_o$, thermal conductivity K with same basic dimensions and the fleets are studied and compared.

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Wave propagation in a nonlocal prestressed piezoelectric polygonal plate with non-homogeneity and hygroscopic effect

  • Rajendran Selvamani;Hepzibah Christinal;Farzad Ebrahimi
    • Advances in materials Research
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    • 제12권4호
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    • pp.309-330
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    • 2023
  • The humid thermal vibration characteristics of a nonhomogeneous thermopiezoelectric nonlocal plate of polygonal shape are addressed in the purview of generalized nonlocal thermoelasticity. The plate is initially stressed, and the three-dimensional linear elasticity equations are taken to form motion equations. The problem is solved using the Fourier expansion collocation method along the irregular boundary conditions. The numerical results of physical variables have been discussed for the triangle, square, pentagon, and hexagon shapes of the plates and are given as dispersion curves. The amplitude of non-dimensional frequencies is tabulated for the longitudinal and flexural symmetric modes of the thermopiezoelectric plate via moisture and thermal constants. Also, a comparison of numerical results is made with existing literature, and good agreement is reached.

The external and internal morphological standard of original plants and herbal states in 2 kind of Arisaematis Rhizoma (2종 천남성(天南星)의 외부(外部) 및 내부형태(內部形態)에 대한 연구)

  • Kim, Hong-Jun;Yun, Ju-Bong;Ju, Young-Sung
    • Korean Journal of Oriental Medicine
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    • 제12권2호통권17호
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    • pp.63-73
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    • 2006
  • In the original plant of Arisaematis Rhizomas, the features of external and internal shape of Arisaema amurense var. serratum $N_{AKAI}$ and A. amurense $_{MAXIM}$. are as follows. 1. In the external shape of original plant, Arisaema amurense var. serratum $N_{AKAI}$ has high stem, an oval-elliptic leaflet and a serrate leaf margin. But A. amurense $M_{AXIM}$ has a relatively low stem, an upside oval leaflet and no serrate leaf margin. 2. On the herbs character of original plant, Ansaema amurense var. serratum $N_{AKAI}$ is small in height and diameter, but A. amurense $M_{AXIM}$ is relatively large in height and diameter. 3. On the gathered herbs character of original plant, the section of Arisaema amurense var. serratum $N_{AKAI}$ is brightly white, easily spilt and strong scent. But the section of A. amurense $M_{AXIM}$ is thin yellowish brown, not easily spilt and weak scent. Also the grade of gathered herbs, both can be classified by diameter and external scent. 4. In the current herbs character, Korean and Sichuan Province products are irregullar shape and have no scent, Jilin Province products are regular shape. Also, Guangxi Province products are small size and concave in one side, Hebei Province products are irregular size and shape. 5. In internal shape of original plant, epidermal cell of Arisaema amurense var. serratum is very tight. With the except of micro difference in parenchyma cell of cortex, on the whole there are nearly no differences with A. amurense $M_{AXIM}$. Also, samely in the internal shape, according to collecting sites, epidermis exhibits a lot layer in curving state and secreting duct is developed and vascular bundle and exists between parenchyma cell of cortex. In the future, additional study is needed to distinguish herb and effect between same genus-degree of relatedness.

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Electron Microscopic Studies on Adenohypophysis of Korean Native Goat (한국재래산양(韓國在來山羊)의 선하수체(腺下垂體) 분필세포(分泌細胞)에 관(關)한 전자현미경적(電子顯微鏡的) 연구(硏究))

  • Lee, I.S.;Lee, H.S.
    • Applied Microscopy
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    • 제14권2호
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    • pp.52-65
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    • 1984
  • The ultrastructure of the pars distalis of the adenohypophysis was studied in the female Korean native goat ($10{\sim}16kg$, B.W.) by electron microscopy. Six granular cells and one agranular cell were recognized according to the characteristic patterns of secretory granules and cell organelles. Type I cells were. large, round or oval and contained the largest granules of 290 to 490 nm in diameter, Their endoplasmic reticula were well developed and packed with parallel lamellae close to nuclear membrane. Type II cells were elongate or polygonal. They contained granules of 220 to 390 nm in diameter and well developed Golgi complex. Type III cells were round, oval or angular and contained granules of 150 to 300 nm in diameter. Their endoplasmic reticula were coarsely scattered among the granules and provided an intracellular compartment for segregation in groups. Type IV cells were oval or round and contained granules of 120 to 280 nm in diameter. Their endoplasmic reticula were arranged at one pole of cytoplasm. Type V cells were round or polygonal and contained small granules of 110 to 140 nm in diameter Their endoplasmic reticula were packed with regularly parallel lamellae. Type VI cells were stellate and irregular in shape and had cytoplasmic processes projecting between the neighboring cells. Their granules were less than 130 nm in diameter, the smallest among the cells of the pars distalis. Agranular cells had no granules or a few, if any. They were stellate or irregular in shape.

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