• Title/Summary/Keyword: leaf shape

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Design of Omnidirectional Shock Absorption Mechanism and Stabilizing Dynamic Posture of Miniature Sphere Type Throwing Robot (구형 투척 로봇의 전방향 충격흡수 구조 설계 및 동적 자세 안정화)

  • Jung, Wonsuk;Kim, Young-Keun;Kim, Soohyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.4
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    • pp.281-287
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    • 2016
  • In this paper, we propose a novel compact surveillance throwing robot which has an omnidirectional shock absorption mechanism and an active control part of wheel treads to stabilize the dynamic posture of a miniature sphere type throwing robot. This throwing robot, which weighs 1.14kg and is 110mm in height, is designed in a spherical shape to be easily grabbed for throwing. Also, the omnidirectional shock absorbing aspect is designed using several leaf springs connected with inner and outer wheels. The wheel treads control part consists of a link mechanism. Through the field experiments, this robot is validated to withstand higher than 17Ns of omnidirectional impulse and increase the stabilized max speed three times from 11 rad/s to 33rad/s by increasing wheel treads.

Intraspecific variations of the Yam (Dioscorea alata L.) based on external morphology and DNA marker analysis

  • Chang, Kwang-Jin;Yoo, Ki-Oug;Park, Cheol-Ho;Lim, Hak-Tae;Michio Onjo;Park, Byoung-Jae
    • Plant Resources
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    • v.3 no.3
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    • pp.211-218
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    • 2000
  • Intraspecific genetic relationship of 19 variation types of the Yam (Dioscorea alata) classified by their external morphological characteristics such as leaf and tuber shape were assessed by DNA using random and specific primer. Twenty two out of 113 primers (100 random[10-mer] primers, two 15 mer [M13 core sequence, and (GGAT)$_4$ sequence]) had been used in PCR-amplification. Only 12 primers, however, were success in DNA amplification in all of the analyzed plants, resulting in 93 randomly and specifically amplified DNA fragments. The analyzed taxa showed very high polymorphisms(69 bands, 71.0 %), allowing individual taxon to be identified based on DNA fingerprinting. Monomorphic bands among total amplified DNA bands of each primer was low under the 50%. Similarity indices between accessions were computed from PCR(polymerase chain reaction) data, and genetic relationships among intraspecific variations were closely related at the levels ranging from 0.66 to 0.90. These DNA data were not matched well with those of morphological characters since they were divided into two major groups at the similarity coefficient value of 0.70. Therefore, Grouping of species into variation types by mainly morphological charactistics was suggested unreasonable.

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Comparison of 29 Diagrams of Lung Originated from Ming Tang Zang Fu Tu (明堂臟腑圖) (명당장부도(明堂臟腑圖)에서 기원한 폐장도(肺臟圖) 29종의 비교)

  • Jo, Hak-Jun
    • The Journal of Korean Medical History
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    • v.29 no.1
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    • pp.11-31
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    • 2016
  • Objectives : The goal of this paper is to research what affected diagrams of lung originated from Ming Tang Zang Fu Tu during the time they were changed in. Methods : Diagrams of lung in Traditional Chinese and Japanese medical books had been collected as many as possible. Besides being grouped by Huang Longxiang (黃龍祥)'s classification, they were analysed by 4 form factors, e.g. shape, number, veins and petiole of leafs. Results : Reliability of this methods had been checked on by the correspondence with Huang's 14 standard books, before 29 diagrams of lung were selected from 33 books including 13 books that Huang had already made his proposal. The lobes in most of diagrams resembled 6 lanceolate or long oval leafs, or a maple leaf with 5 indentations. In most of diagrams, veins of leafs were described variously, more or less than 9 nodes often drew in petioles. Conclusions : Suwen (素問), Nan Jing (難經) and Wang Bing would had steadily worked on 29 diagrams of lung, since diagram of lung stemmed from Ming Tang Zang Fu Tu, went out into the world in Zhen Jiu Ju Ying (鍼灸聚英). But they were not drawn through dissection during same periods.

Ultrastructural study of Glandular Trichomes in Pelargonium peltatum (Pelargonium peltatum 분비모의 미세구조 연구)

  • Cho, Bum-Suk;Ko, Kyoung-Nam;Kim, Eun-Soo
    • Applied Microscopy
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    • v.29 no.1
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    • pp.125-136
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    • 1999
  • The ultrastructure of glandular trichomes in Pelargonium peltatum has been studied with a light microscope, transmission, and scanning electron microscope. Two types of the glands, long-stalked and short-stalked capitate glands, are distinguished with their shape and size of the total glands. Both glands are extreamly abundant in the leaf veins and petioles. These glandular trichomes are consisted of one secretory cell, three stalk cells, and one basal cell. The secretory cells contain a large amount of smooth endoplasmic reticulum. They have also much plastids, vacuoles, Golgi apparati, and mitochondria. High electron-dense deposits are frequently present in vacuoles of secretory cells. It seems to be phenolic compounds which is thought as the major secretory precursors.

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DRASTIC IMPROVEMENT OF THERMAL EFFICIENCY BY RAPID PISTON-MOVEMENT NEAR TDC

  • Moriyoshi, Y.;Sano, M.;Morikawa, K.;Kaneko, M.
    • International Journal of Automotive Technology
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    • v.7 no.3
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    • pp.295-301
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    • 2006
  • A new combustion method of high compression ratio SI engine was studied and proposed in order to achieve high thermal efficiency, comparable to that of CI engine. Compression ratio of SI engine is generally restricted by the knocking phenomena. A combustion chamber profile and a cranking mechanism were studied to avoid knocking with high compression ratio. Because reducing the end-gas temperature will suppress knocking, a combustion chamber was considered to have a wide surface at the end-gas region. However, wide surface will lead to large heat loss, which may cancel the gain of higher compression ratio operation. Thereby, a special cranking mechanism was adapted which allowed the piston to move rapidly near TDC. Numerical simulations were performed to optimize the cranking mechanism for achieving high thermal efficiency. An elliptic gear system and a leaf-shape gear system were employed in numerical simulations. Livengood-Wu integral, which is widely used to judge knocking occurrence, was calculated to verify the effect for the new concept. As a result, this concept can be operated at compression ratio of fourteen using a regular gasoline. A new single cylinder engine with compression ratio of twelve and TGV(Tumble Generation Valve) to enhance the turbulence and combustion speed was designed and built for proving its performance. The test results verified the predictions. Thermal efficiency was improve over 10% with compression ratio of twelve compared to an original engine with compression ratio of ten when strong turbulence was generated using TGV, leading to a fast combustion speed and reduced heat loss.

A comparative morphological study of Thymelaeaceae in Korea (한국산 팥꽃나무과의 비교형태학적 연구)

  • Lee, Jae-Jin;Oh, Sang-Hun
    • Korean Journal of Plant Taxonomy
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    • v.47 no.3
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    • pp.207-221
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    • 2017
  • Thymelaeaceae in Korea includes ten species in five genera (Daphne, Diarthron, Edgeworthia, Stellera, and Wikstroemia). This study investigated the morphology of these species using herbarium specimens and fresh materials obtained during fieldwork to understand the variation level and to delineate each taxon in the family. Our comparative morphological analysis showed that the Korean taxa in Thymelaeaceae were easily distinguished based on their morphologies. It is easy to distinguish Daphne from Wikstroemia when the Korean taxa are considered. However, Daphne genkwa is morphologically similar to Wikstroemia based on the leaf arrangement, pubescence of the leaves, and the ovary shape. The results here suggest that further systematic studies of the Daphne group using more data are necessary.

A Taxonomic Study on Sedum Section Telephium in Korea (한국산 돌나물속 Telephium 절 식물의 분류학적 연구)

  • 정영호
    • Journal of Plant Biology
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    • v.33 no.1
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    • pp.1-24
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    • 1990
  • This study was attempted to clarify the taxonomic problems that have been raised up to now in the study o section Telephium, genus, Sedum: the delimitation of taxa belong to Telephium group, their relationship, and nomenclatural confusion and the rank of Telephium group. Specimens were collected at 19 sites in Korea. The habitat, distribution, external morphological characters of habit, leaf shape, phyllotaxy, inflorescence, color of floral organs, floral formula, carpel, capsule, and micro-characters of pollen, seed coat, stigma and anther with SEM were examined. Through this study, the following results were obtained. The delimitation of taxa that belong to section Telephium in Korea and their relationship Nomenclatural errors were corrected. In S. rotundifolium Lee, species epithet“rotundifolium”is later homonym of s. rothundifolium Lamarck, so corrected to S. duckbongii Chung and Kim by article 64 of ICBN. Phyllotaxy was elucidated to meaningless, character in sect. Telephium. S. taquetii was a separate species from S. viridescens and not of its synonym. S. alboroseum Baker in Korea was S. erythrostictum sensu Master not of S. erythrostictum Miquel. By this study , taxa of sect. Telephium in Korea were arranged to 7 species. Considering interspecific relationship of sect. Telephium, S. duckbongii and S. alboroseum are considered to be more advanced forms and S. viridescens, S. taquetii, and S. viviparum to be more primitive forms among 7 species.

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Cytological and Morphological Characterization of Anther Derived Plants from Sweet Pepper (Capsicum annuum L.) cv. 'Special'

  • Shrestha, Surendra Lal;Luitel, Binod Prasad;Lee, Taek Jong;Kang, Won Hee
    • Korean Journal of Breeding Science
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    • v.42 no.5
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    • pp.431-438
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    • 2010
  • Anthers of sweet pepper $F_1$ cultivar 'Special' were cultured on Dumas De Vaulx (C medium), supplemented with $0.1mgL^{-1}$ 2, 4-D and $0.1mg{\cdot}L^{-1}$ kinetin with 3% sucrose, and 0.32% phytagel. The calluses obtained were further sub-cultured on Murashige and Skoog (MS) medium without growth regulators for regeneration. Regenerated plantlets were grown in plastic pots under plastic house and characterized their cytological and morphological characters in spring, 2008. Twenty percent plantlets were identified as haploid plants after chromosome and ploidy analysis. Haploid plants contained 12 chromosomes, high stomatal density with small stomatal length as compared to diploid plants. Stomatal length in haploids was 23.3% smaller than diploids. Haploid plants were characterized as small leaf and petiole size, poor vigor, thin stem and short plant height, short internodes and small flower buds, fruit size and fruit weight as compared to diploid plants and most of the haploid fruits were seedless. SP55, SP62, SP68, SP72 and SP77 are found high yielding double haploids with high total soluble content (8.6, 8.7, 9.2, 9.1 and $9.8^{\circ}Brix$, respectively) and desirable fruit shape, and recommended them to exploit as inbred lines for heterosis breeding.

Study on sloshing simulation in the independent tank for an ice-breaking LNG carrier

  • Ding, Shifeng;Wang, Gang;Luo, Qiuming
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.667-679
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    • 2020
  • As the LNG carrier operates in ice covered waters, it is key to ensure the overall safety, which is related to the coupling effect of ice-breaking process and internal liquid sloshing. This paper focuses on the sloshing simulation of the ice-breaking LNG carrier, and the numerical method is proposed using Circumferential Crack Method (CCM) and Volume of Vluid (VOF) with two main key factors (velocity νx and force Fx). The ship motion analysis is carried out by CCM when the ship navigates in the ice-covered waters with a constant propulsion power. The velocity νx is gained, which is the initial excitation condition for the calculation of internal sloshing force Fx. Then, the ship motion is modified based on iterative computations under the union action of ice-breaking force and liquid sloshing load. The sloshing simulation under the LNG tank is studied with the modified ship motion. Moreover, an ice-breaking LNG ship with three-leaf type tank is used for case study. The internal LNG sloshing is simulated with three different liquid heights, including free surface shape and sloshing pressure distribution at a given moment, pressure curves at monitoring points on the bulkhead. This present method is effective to solve the sloshing simulation during ice-breaking process, which could be a good reference for the design of the polar ice-breaking LNG carrier.

Development of Manual Multi-Leaf Collimator for Proton Therapy in National Cancer Center (국립암센터의 양성자 치료를 위한 수동형 다엽 콜리메이터 개발)

  • Lee, Nuri;Kim, Tae Yoon;Kang, Dong Yun;Choi, Jae Hyock;Jeong, Jong Hwi;Shin, Dongho;Lim, Young Kyung;Park, Jeonghoon;Kim, Tae Hyun;Lee, Se Byeong
    • Progress in Medical Physics
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    • v.26 no.4
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    • pp.250-257
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    • 2015
  • Multi-leaf collimator (MLC) systems are frequently used to deliver photon-based radiation, and allow conformal shaping of treatment beams. Many proton beam centers currently make use of aperture and snout systems, which involve use of a snout to shape and focus the proton beam, a brass aperture to modify field shape, and an acrylic compensator to modulate depth. However, it needs a lot of time and cost of preparing treatment, therefore, we developed the manual MLC for solving this problem. This study was carried out with the intent of designing an MLC system as an alternative to an aperture block system. Radio-activation and dose due to primary proton beam leakage and the presence of secondary neutrons were taken into account during these iterations. Analytical calculations were used to study the effects of leaf material on activation. We have fabricated tray model for adoption with a wobbling snout ($30{\times}40cm^2$) system which used uniform scanning beam. We designed the manual MLC and tray and can reduce the cost and time for treatment. After leakage test of new tray, we upgrade the tray with brass and made the safety tool. First, we have tested the radio-activation with usually brass and new brass for new manual MLC. It shows similar behavior and decay trend. In addition, we have measured the leakage test of a gantry with new tray and MLC tray, while we exposed the high energy with full modulation process on film dosimetry. The radiation leakage is less than 1%. From these results, we have developed the design of the tray and upgrade for safety. Through the radio-activation behavior, we figure out the proton beam leakage level of safety, where there detects the secondary particle, including neutron. After developing new design of the tray, it will be able to reduce the time and cost of proton treatment. Finally, we have applied in clinic test with original brass aperture and manual MLC and calculated the gamma index, 99.74% between them.