• Title/Summary/Keyword: 원뿔

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A New Species of Cellular Slime Molds from Korea, Dictyostelium floridum sp. nov. (한국산 세포성 점균의 1신종 Dictyostelium floridum sp. nov.)

  • 홍정수
    • Journal of Plant Biology
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    • v.35 no.4
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    • pp.393-401
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    • 1992
  • A new species of Dictyostelium, isolated from the subalpine coniferous forests of Halla mountain, was described. The most noteworthy morphological characteristics of this new species were broad petal-like aggregates, concentrated long branches near the bases, typically clustered and delicate sorocarps. DictyosLeLium jloridurn sp. novo was also characterized by 1) elliptical spores with distinctive polar granules, 2) strongly tapering and rough surface of sorophores, 3) frequent occurrence of expanded conical bases, 4) the congealed slime substrate where the several bases were anchored into, 5) compound and c1avata tips. It was quite sensitive to environmental conditions, particularly temperature. Macrocysts and microcysts were not observed. This species can be cultured satisfactorily in assosiation with Esch'||'&'||'pound;richia coLi upon agar media of weak nutrient content, 0_1% lactosepeptone, under diffuse light and darkness. Optimum temperature for growth and develoi)ment was about $18-22^{\circ}C$, below that of most other species of the family.

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Sperm Ultrastructure of Bombina orientalis (무당개구리 (Bombina orientalis) 정자의 미세구조)

  • Lee, Jung-Hun;Kwon, Jung-Kyun
    • Applied Microscopy
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    • v.35 no.4
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    • pp.42-54
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    • 2005
  • This study described the spermatozoa of the discoglossidae Bombina orientalis using light, scanning and transmission electron microscopes. Sperm head possess a crescent or leaf shape, with a moderately flexible head, and with a sharp anterior and posterior tips. The nucleus are a thick cone shaped in the widest middle part of nucleus, and a slender anterior and posterior of nuclear tips. The chromatin is not completely compact, but irregularly imbricated such as roof. Some nuclear lacunae, irregular in shape, are scattered within the nucleus. No neck and middle piece were developed. The flagellum is composed of 9+2 axoneme, axial rod and undulating membrane. The mitochondria were distributed only in cytoplasmic membrane around the nucleus. In particular, the nuclear rod contains bundles of fibers, the rod penetrating from anterior portion to the middle of the nucleus, is extended roughly two-thirds of the nucleus such as eyelashes shaped.

Acceleration of Feature-Based Image Morphing Using GPU (GPU를 이용한 특징 기반 영상모핑의 가속화)

  • Kim, Eun-Ji;Yoon, Seung-Hyun;Lee, Jieun
    • Journal of the Korea Computer Graphics Society
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    • v.20 no.2
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    • pp.13-24
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    • 2014
  • In this study, a graphics-processing-unit (GPU)-based acceleration technique is proposed for the feature-based image morphing. This technique uses the depth-buffer of the graphics hardware to calculate efficiently the shortest distance between a pixel and the control lines. The pairs of control lines between the source image and the destination image are determined by user's input, and the distance function of each control line is rendered using two rectangles and two cones. The distance between each pixel and its nearest control line is stored in the depth buffer through the graphics pipeline, and this is used to conduct the morphing operation efficiently. The pixel-unit morphing operation is parallelized using the compute unified device architecture (CUDA) to reduce the morphing time. We demonstrate the efficiency of the proposed technique using several experimental results.

Experimental results on Shape Reconstruction of Underwater Object Using Imaging Sonar (영상 소나를 이용한 수중 물체 외형 복원에 관한 기초 실험)

  • Lee, Yeongjun;Kim, Taejin;Choi, Jinwoo;Choi, Hyun-Taek
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.10
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    • pp.116-122
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    • 2016
  • This paper proposes a practical object shape reconstruction method using an underwater imaging sonar. In order to reconstruct the object shape, three methods are utilized. Firstly, the vertical field of view of imaging sonar is modified to narrow angle to reduce an uncertainty of estimated 3D position. The wide vertical field of view makes the incorrect estimation result about the 3D position of the underwater object. Secondly, simple noise filtering and range detection methods are designed to extract a distance from the sonar image. Lastly, a low pass filter is adopted to estimate a probability of voxel occupancy. To demonstrate the proposed methods, object shape reconstruction for three sample objects was performed in a basin and results are explained.

INCONTINENTIA PIGMENTI : CASE REPORTS (색소실조증 환아의 치험례)

  • Shin, Hye-Sung;Kim, Seon-Mi;Choi, Nam-Ki;Yang, Kyu-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.36 no.4
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    • pp.563-567
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    • 2009
  • Incontinentia pigmenti(Bloch-Sulzberger syndrome) is a sex-linked hereditary disorder so girls are almost exclusively affected. The frequency rate is approximately 1:40,000 among girls. It is associated with skin, ocular, dental, skeletal and central nervous deformities. We reported 2 cases of medically diagnosed IP patients who were 4 and 5 years old girls. They had thin and sparse hair, and represented congenital missing of multiple primary and permanent teeth, accessory cusps and cone-shaped crowns. Therefore we report the dental manifestations and treatment progress.

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Identification of Grovesinia moricola Causing Zonate Leaf Spots on Lespedeza cyrtobotrya in Korea (참싸리 겹둥근무늬병균 Grovesinia moricola 동정)

  • Park, Ji-Hyun;Jung, Bok-Nam;Lee, Sang-Hyun;Shin, Hyeon-Dong
    • The Korean Journal of Mycology
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    • v.48 no.1
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    • pp.69-74
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    • 2020
  • In September 2017, a heavy damage by premature defoliation with the zonate leaf spots was observed in several shrubs of Lespedeza cyrtobotrya growing at Mt. Obongsan in Chuncheon, Korea. Numerous cone-shaped, white sporophores of a fungus were observed on lesions of the abaxial leaf surface. A similar fungus was isolated in September 2019 from the leaves of L. cyrtobotrya growing at Mt. Taegisan in Hoengseong, Korea. The morphological characteristics of the sporophores were consistent with those of Grovesinia moricola. The species identification was confirmed by sequencing the internal transcribed spacer (ITS) region of the ribosomal DNA from the two isolates (KACC48417 and KACC48934). The fungal pathogenicity was determined by an artificial inoculation in conditions of relative humidity and temperature of 100% and 15±2℃, respectively. This is the first report of association of G. moricola with L. cyrtobotrya in Korea.

A Study on the Understanding of Height Concept of Figures of Sixth Grade Students of Elementary Schools (초등학교 6학년 학생들의 도형의 높이 개념 이해에 대한 연구)

  • Im, Seung-Hyun;Park, Young-Hee
    • Journal of Elementary Mathematics Education in Korea
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    • v.15 no.1
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    • pp.141-159
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    • 2011
  • The purpose of the present research is to suggest implications on guidance of height concept understanding of figures by investigating concept understanding how sixth grade's elementary school students understand a height concept of figures. In order to achieve this research purpose, a height concept understanding test of figures was carried out with the target of 54 sixth grade students who already learned a height concept of plane figures and three-dimensional solid figures and thus this research analyzed characteristics and errors appeared there. When analyzing its characteristics and errors interviews with students were carried out for in-depth analysis. And as a result the following implications could be obtained. First, students felt more difficulty in measuring height in a figure that its lower base is not horizontal in questions measuring height of a plane figure. Second, there were cases that students associate a height concept of figures with experience of height experienced in daily life. Third, students were feeling difficulty in linguistically expressing a concept called height that oneself has. Expressing a concept linguistically plays an important role in understanding a concept clearly. Accordingly activities for raising this mathematical communication ability are required, Fourth, the present research can suggest implications in designing classes that students can clearly understand the height concept of figures.

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An Analysis about the Features of Mathematical Learning of Middle School Students through the Distribution Graphs of the Responses Percentages in National Assessment of Educational Achievement (학업성취도 평가에서 답지 반응률 분포 그래프를 활용한 중학생의 수학과 학업 특성 분석)

  • Jo, Yun Dong;Lee, Kwang Sang
    • Journal of Educational Research in Mathematics
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    • v.25 no.1
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    • pp.1-19
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    • 2015
  • This paper aims to explore what we can improve in the curriculum, teaching-learning, and evaluation on the bases of the analyses of multiple-choice items set in National Assessment of Educational Achievement. For this goal, by using the distribution curves of the responses percentages, we will grasp the features of educational achievement which appear to students through an in-depth analysis about not only item itself but also the contents included in particular distracters. These analyses provide more information than the descriptive statistical values such as the mean of correct answer percentage and the discrimination of whole group and the mean of responses percentages of replies of subgroups. Because the distribution curves of the responses percentages reveal the transition from the lowest to the highest educational achievement very well. From these analyses we acquire the implications about the concept of prime factor or prime factorization, ratio(proportion) such as velocity, linear function, volume of cone, properties of solid figure, and probabilities of empty event and total event.

On The Hydrodynamic Resistance of the Sablefish Pot in Hauling-up (은대구 통발 권양중의 유체저항에 관하여)

  • 이병기
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.13 no.2
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    • pp.1-4
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    • 1977
  • The author determined the relationship between the hauling veloicty and the hydrodynamic resistance of the sablefish pot shaped conic frustum like, and induced the formulae to determine the diameter of the main line and the net horse power of the pot hauler. The results are summarized as follows: 1. The maximum hydrodynamic resistance (with its weight in water) of the pot T(kg), when the bottom webbing is covered by a cloth to imitate the catches are scattered on the bottom, is eatimated as $$ T=120v^{1.1} (0.3{\leqq}v{\leqq}0.8) $$ where v denotes the hauling velocity of the pot in m/sec. 2. When P. P. 3 strand rope is used as main line, the diameter d(mm)is recommended to satisfy the formula $$ d=72 \frac{D}{H} V^{1.1} where H denotes the depth of the fishing ground and D the intervals of the pots linked to the main in m respectively. 3. The pot hauler must displace the net horse power p(ps) of $$ P= \frac{75}{120} \frac{D}{H} v^{2.1}$$

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Forward-Looking Ultrasound Imaging Transducer : I. Analysis and Design (전향 초음파 영상 트랜스듀서 : I. 해석 및 설계)

  • Lee, Chan-Kil
    • The Journal of the Acoustical Society of Korea
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    • v.14 no.2E
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    • pp.73-86
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    • 1995
  • The transducer section of the forward-looking ultrasound imaging catheter (FLUIC) consists of a circular piezoelectric element as a vibrator and a conical acoustic mirror as a perfect reflector. A small diameter piezoelectric transducer element is mounted on the side of a catheter's rotating shaft. The unique design of FLUIC provides the capability to form a two-dimensional image of a cross-section of vessel in front of the catheter, which is lacking in the present generation of intravascular ultrasound (IVUS) transducers, as well as a conventional side view image. The mirror configuration for the transducer section of the FLUIC is designed using an approximated ray tracing techniques. The diffraction transfer function approach [1] developed for the field prediction from primary sources is generalized and extended to predict the secondary diffraction characterstics from an acoustic mirror. The extended model is verified by simulation and experiment through a simple plane reflector and employed to analyzed the field characteristics of a FLUIC.

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