• 제목/요약/키워드: cones

검색결과 295건 처리시간 0.031초

THE F-VECTORS OF SOME TORIC FANO VARIETIES

  • Park, Hye-Sook
    • Journal of applied mathematics & informatics
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    • 제11권1_2호
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    • pp.437-444
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    • 2003
  • A toric variety is defined by a certain collection of cones. Especially a toric Fano variety is obtained from a special nonsingular fan. In this paper, we define the f-vectors of toric Fano varieties as the numbers of faces of the corresponding fans, and investigate the f-vectors of some toric Fano varieties.

Reference line for computed tomogram of the mandible (하악골 전산화단층사진촬영시 기준선에 관한 연구)

  • You Choong-Hyun;Kim Jae-Duk
    • Imaging Science in Dentistry
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    • 제32권3호
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    • pp.153-157
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    • 2002
  • Purpose : This study was performed to determine the proper reference line for taking axial computed tomograms from which the good cross-sectional views can be reformatted by multiplanar reconstruction. Methods : Three dry mandibles with implanted gutta percha cones in the extracted socket were scanned axially according to 6 reference lines of 2 mandibular positions with computed tomogram Hitachi W550. The accuracy of measurements of the lengths of implanted gutta perch a cones in the each cross-sectional view reformatted from axial computed tomogram by multiplanar reconstruction was evaluated. Results: The difference between the measurements and the real length of implant was smallest in the bucco-lingual views reformatted from the axial views scanned according to the reference line of group V-a. The smaller the angle difference between reference line and occlusal line was, the smaller the difference between the measurements in the bucco-lingual views reformatted from axial views and the real length of implant. The majority of measured widths of implants in the bucco-lingually reformatted views were larger than the actual values. Conclusions : When the mandible is inclined within the limitation of gantry angle and scanned with the reference line coincident with occlusal plane, the bucco-lingual view can be reformatted without deformation of images from the axially scanned images.

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Comparative Studies on the Growth and Differentiation in Three Different Varieties of Hop (Hop의 생장과 분화에 대한 식품간의 차이에 관하여)

  • 임웅규
    • Journal of Plant Biology
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    • 제17권4호
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    • pp.11-17
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    • 1974
  • The present investigation dealt with observation and experiments concerning the growth and differentiation of hop plant, using the varieties of Cascade(C), Shinshuwase(Sh), and Hallertau(H). The results were as follows: (1) Life cycle of hop plants. The annual growth period of hop plant was devided chiefly into 3 phases, dormant, vegetative and reproductive. (2) Growth of main stem. The hop vine begun to grow in the middle of May and grow vigorousely in the middle and latter of June, then gradually decline or stops at the middle of July and the early of August. (3) Growth of lateral vines. By the statistical analysis, it is judged that the varieties of H and Sh were more grown than that of C. H and Sh were not significant, but H and Sh from C were significant in 5% level. (4) Fresh weight and water content of hop cone. Hop cone in fresh weight of C variety was higher than those of other two varieties and water content of hop cone was decreased with time elapse in three races together. (5) Growing point. Histological view of hop varities in each was different. C showed form of sweet potato, H showed form of round, and Sh showed form of ellipse. (6) Shape of the leaf. C and H were 3 lobes, but Sh is 3∼5 lobes. Generally, the color is dark green. (7) Hop cones. Hop cones are as follows.

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Effects of Tree Form on Number of Cone Formation in Korean White Pine (Pinus koraiensis S. et Z.) (잣나무에 있어서 수형(樹形)이 결실량(結實量)에 미치는 영향(影響))

  • Chon, Sang Keun;Noh, Youn Hee
    • Journal of Korean Society of Forest Science
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    • 제62권1호
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    • pp.19-23
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    • 1983
  • Number of 1-year-old cone in Pinus koraiensis was influenced by the factors consisting of the tree form. Number of cones increased with increasing DBH, diameter, volume of crown and number of forked stems. However, tree height, crown length, and the ratio of crown diameter to crown length showed no significant relations with number of cones.

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Microstructure of the antennal sensory organs in female millipede Oxidus gracilis (Polydesmida: Paradoxomatidae)

  • Chung, Kyung-Hwun;Moon, Myung-Jin
    • Animal cells and systems
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    • 제15권1호
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    • pp.53-61
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    • 2011
  • The fine structural characteristics of the antennal sensory organs of a female millipede Oxidus gracilis (Polydesmida: Paradoxomatidae) were observed with both field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). We could identify four apical cones and three basic types of antennal sensillae in a. gracilis as follows: chaetiform sensilla (CS), trichoid sensilla (TS) and basiconic sensilla (BS). Of these, both types of CS and TS can be observed throughout all antennal segments except the terminal 8th article, whereas the BS are observed within the cuticular depressed regions of the articles from the 5th to the 7th segment. According to their relative microstructure and location, the BS arc divided further into three subtypes: large ($BS_1$) small ($BS_2$) and spiniform ($BS_3$). The $BS_1$ can be seen on the 5th article only, while $BS_2$ can be seen on the 5th and 6th articles. The $BS_3$ is characteristically seen within the depressive region of the 7th article. Both the CS and TS of O. gracilis are similar in structure, and they are related to the function of mechanical reception; however, four large apical cones (AP) and three subtypes of BS are likely to function in gustatory and olfactory reception.

Inhibitory Effects of Pine Cone (Pinus densiflora) on Melanogenesis in B16F10 Melanoma Cells

  • Lee, Seung-Hyun;Jang, Tae-Won;Choi, Ji-Soo;Mun, Jeong-Yun;Park, Jae-Ho
    • Korean Journal of Plant Resources
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    • 제32권4호
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    • pp.275-281
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    • 2019
  • The pathological condition of excessive melanogenesis causing freckles, melasma, senile lentigo, pigmented acne scars, and cancer has a critical impact on the wellness of individuals. The mechanism of melanogenesis is related to the expression of melanogenic enzymes. Here, we evaluated the inhibitory effect of pine cone (Pinus densiflora) extracts on melanogenesis. P. densiflora, the Korean Red Pine, is the predominant tree species in the cool, temperate forests of northeast Asia, occurring in pure stands across Korea, Japan, and parts of northern China and Russia. P. densiflora leaves, pollen, and bark have been widely used for traditional medicine, or edible purposes. However, pine cones are rarely used as natural raw materials, although they contain many bioactive phytochemicals. The pine cone ethyl acetate fraction (PEF) showed no toxicity to B16F10 cells at a concentration of less than $100{\mu}g/mL$. PEF inhibited the expression of microphthalmiaassociated transcription factor (MITF), tyrosinase and tyrosinase-related factors in B16F10 cells treated with 3-Isobutyl1-methylxanthine (IBMX). These results suggest that pine cones can be used as an effective natural melanogenesis inhibitory agent.

Monte Carlo Study Using GEANT4 of Cyberknife Stereotactic Radiosurgery System (GEANT4를 이용한 정위적 사이버나이프 선량분포의 계산과 측정에 관한 연구)

  • Lee, Chung-Il;Shin, Jae-Won;Shin, Hun-Joo;Jung, Jae-Yong;Kim, Yon-Lae;Min, Jeong-Hwan;Hong, Seung-Woo;Chung, Su-Mi;Jung, Won-Gyun;Suh, Tae-Suk
    • Progress in Medical Physics
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    • 제21권2호
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    • pp.192-200
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    • 2010
  • Cyberknife with small field size is more difficult and complex for dosimetry compared with conventional radiotherapy due to electronic disequilibrium, steep dose gradients and spectrum change of photons and electrons. The purpose of this study demonstrate the usefulness of Geant4 as verification tool of measurement dose for delivering accurate dose by comparing measurement data using the diode detector with results by Geant4 simulation. The development of Monte Carlo Model for Cyberknife was done through the two-step process. In the first step, the treatment head was simulated and Bremsstrahlung spectrum was calculated. Secondly, percent depth dose (PDD) was calculated for six cones with different size, i.e., 5 mm, 10 mm, 20 mm, 30 mm, 50 mm and 60 mm in the model of water phantom. The relative output factor was calculated about 12 fields from 5 mm to 60 mm and then it compared with measurement data by the diode detector. The beam profiles and depth profiles were calculated about different six cones and about each depth of 1.5 cm, 10 cm and 20 cm, respectively. The results about PDD were shown the error the less than 2% which means acceptable in clinical setting. For comparison of relative output factors, the difference was less than 3% in the cones lager than 7.5 mm. However, there was the difference of 6.91% in the 5 mm cone. Although beam profiles were shown the difference less than 2% in the cones larger than 20 mm, there was the error less than 3.5% in the cones smaller than 20 mm. From results, we could demonstrate the usefulness of Geant4 as dose verification tool.

Visual Cells in the Retina of Iksookimia longicorpa (Pisces; Cobitidae) of Korea (한국산 미꾸리과 어류 왕종개 Iksookimia longicorpa 망막의 시각세포)

  • Kim, Jae Goo;Park, Jong Young
    • Korean Journal of Ichthyology
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    • 제27권4호
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    • pp.257-262
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    • 2015
  • The visual cells in the retina of Iksookimia longicorpa (Pisces, Cobitidae) were investigated by light and scanning electron microscopes. The retina ($216.42{\pm}13.36{\mu}m$) has several layers, and the visual cell layer consists of unequal double cones and large rods. In a double cone, two members are unequal such that one cone is longer than the other (long element $26.42{\pm}1.7{\mu}m$, short element $16.82{\pm}1.1{\mu}m$). The cones form a row mosaic pattern in which the partners of double cones are linearly oriented with a large rod. The visual cells observed have an outer segment (hematophilic), inner segment (eosinophilic). In scanning electron microscopy, the outer segment links to inner segment by so-called calyceal piles (calyceal processes) of membrane discs surrounded by double membranes.

Growth Changes in Abies koreana Seedlings of the Hallasan Mountain Over a 10-year Period (한라산 구상나무 치수의 10년간 생장 변화)

  • Song, Kuk-Man;Kim, Jae Hoon;Choi, Hyung Soon
    • Journal of Environmental Science International
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    • 제29권3호
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    • pp.209-218
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    • 2020
  • This study was conducted to monitor the growth and development of Abies koreana seedlings in the Hallasan Mountain. Accordingly, the obtained results indicate that the number of A. koreana seedlings increased by 2.6 and 4.8 times in the Yeongsil and Jindallaebat areas, respectively, over the 10-year period. Most of these seedlings were found to be growing on moss-covered rocks. The average tree height over the last 10 years was obtained as 20.4 cm in the Yeongsil area and 3.6 cm in Jindallaebat with growths of 4.1 cm and 1.4 cm, respectively over the last 2 years. Of all the mature trees that were surviving in 2009, 6 died in Yeongsil in 2014 (with an additional 4 in 2018) and 13 in Jindallaebat in 2016. Over the 10-year period, the diameter at breast height of the trees in Yeongsil and Jindallaebat has increased by an average of 0.6 cm and 4.2 cm. Similarly, an average of 6.8 cones was found in the Yeongsil area in 2014 and 26.3 in Jindallaebat in 2016. However, in 2018, no additional cones were found in the former, although an average of 1.4 cones was observed in the latter. With respect to the average temperature and relative humidity, no significant difference could be observed between two monitored areas from 2016 to 2018. However, in July 2017 and February 2018, the average temperature was higher in the Jindallaebat area, while relative humidity was higher in Yeongsil, there by possibly affecting cone growth and flowering between areas. These results indicate the survival and growth of A. koreana seedlings in the Hallasan Mountain is sensitive to the environments of each area. Hence, continuous monitoring of the environment changes and in-depth studies on the flowering and fruiting of A. koreana seedlings needs to be carried out in order to analyze the relationship between their survival rates and changes in weather conditions.