• Title/Summary/Keyword: structure of stand

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Trophic Structure and Energy Flow of a Pond Ecosystem (연못 생태계의 영양구조와 에너지 유전)

  • 정연숙
    • Journal of Plant Biology
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    • v.25 no.3
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    • pp.123-133
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    • 1982
  • The tropic structure and the function of a small pone ecosystem under the tree stand were studied in terms of energy flow. About 28% of total solar radiation was intercepted by the tree canopy over the pond. Primary producers converted 1.1%(3,382 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) of solar radiation (320,000 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$) into gross primary production. The amount of energy availble to the pond snail was 1,683 kcal.m-2.y-1 of the net production by primary producers and 1,033 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$ of the litter fallen into the pond. The amount of gross secondary production by the pond snail was 245 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$. Judging from these, supply of both net primary production and the litter was indispensable for the maintenance of the pond ecosystem. The total amont of energy as gross primary production plus litter was 4,415 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(100%). Since the total respiration loss was calculated to be 1,917 kcal$\cdot$$m^{-2}$$\cdot$$y^{-1}$(43.4%), the rate of energy accumulation in the pond estimated to 56.6%.

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Determination of the Genital Structures using Ultrasound in Canine Prenatal Fetuses

  • Park, Chul-Ho;Oh, Ki-Seok;Son, Chang-Ho
    • Journal of Embryo Transfer
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    • v.30 no.4
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    • pp.335-340
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    • 2015
  • The objective of this study was to evaluate the initial detection time and development of the fetal genital structures using ultrasound in twelve pregnant small bitches. The initial detection time of the fetal genital structures was as follows: genital tubercle at days 32.6; os penis at days 45.2; labia at days 45.7; scrotum at days 47.5. Ultrasonograms of fetal genital structure according to gestational stage were as follows: Undifferentiated stage (before day 35), the genital tubercle was observed to have a small elevation and just a hyper-echogenic structure in the midline between the umbilical cord and the tail in male and female fetus. Migration stage (between day 35~45), the genital tubercle was observed as a hyper-echogenic, bilobular, oval shaped and the genital tubercle began to migrate from the initial position toward the umbilical cord in males, and toward the tail in females. Differentiated stage (after day 46), the penis and os penis were observed to stand out in the abdominal wall and the scrotum was observed toward the perineal region in male fetuses. The labia was detected at the base of the tail in female fetuses. These results indicate that ultrasound of fetal genital structures could be useful for fetal gender determination and a completely prepartum evaluation of the canine fetus.

Study of a Variable Single-tracked Crawler for Overcoming Obstacles (가변형 단일 궤도를 이용한 장애물 극복방법에 관한 연구)

  • Kim, Jee-Hong;Lee, Chang-Goo
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.4
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    • pp.391-395
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    • 2010
  • In our paper, we propose an asymmetric single-tracked wheel system, and describe its structure and the method for maintaining the length of a transformable track system. And the method is reducing the gap of lengths. Therefore, we propose an efficient structure for transforming and explain motions with kinematics. Our transformable shape single-tracked mobile system has an advantage to overcome an obstacle or stairs by the variable arms in the single unity track system. But we will make the variable shape of tracked system get a drive that has a force to stand against a wall. In this case, we can consider this system to a rigid body and have a notice that this single tracked system is able to get vary shape with the variable arm angle. Considering forces balance along x-axis and y-axis, and moments balance around the center of the mass we have. If this rigid body is standing against a wall and doesn't put in motion, the force of flat ground and the rigid body sets an equal by a friction. In the same way, the force of a wall and the rigid sets an equal by a friction.

Implementation of Component System for Computing Parts Required in BOM System (BOM 체계에서의 소요부품 산출 컴포넌트 시스템 구현)

  • Jin Chang-Hai;Shin Eun-Kyoung;Kim Byung-Ju;Kwon Young-Jik
    • Journal of Korea Multimedia Society
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    • v.8 no.3
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    • pp.421-427
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    • 2005
  • Bill Of Materials(BOM) is the technique document on illuminating the product structure and used to demonstrate the relationship and structure between the final product, sub-products, parts and materials. This paper implemented BOM system for need parts production that is need in production of finished goods that is display stand that is made by steel. After implementation the BOM system, there are changing of the corporation, which applied this system: (1) contraction by 2 weeks to 2 days of the time to calculate parts required for products (2) accuracy improvement of calculation for amounts parts required (3) contraction of business organization.

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A Study on the Transition of Korean Clothes Since the 1950's (한복 변천에 관한 연구 - 1950년대 이후 여자 한복 중심(中心)으로 -)

  • Jin, Mee-Hee
    • Journal of the Korean Society of Costume
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    • v.15
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    • pp.149-166
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    • 1990
  • Korean clothes is traditional folk costume native to Korea, Which is in Korea clothes. The past Korean costume was developed in the native costume, together influenced by chinese costume. But in the late Yi dynasty the contact with western countries brought about a turning point in Korean costume history, with rapid growth of economy since Korean war in the 1950's, the magnification of industrial structure, the development of productive technique, transformation of consumption pattern and the development of communication have been increased concerns for the western costume. In 1953 the introduction of nylon which was imported from Japanese brought about a fuming point in clothing habits. In 1967 the development of the fiber industry got a firm stand in ready-made clothes. Consequently our traditional Korean clothes was regarded as nonfunctional, nonproductive and it was pushed out of daily life little by little and it was deprived of the function of ordinary costume by the influence of western costume. But in these days the Korean clothes appears as the desire of pursuing traditional style in addition to mordern style of Korean clothes.

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Local damage detection of a fan blade under ambient excitation by three-dimensional digital image correlation

  • Hu, Yujia;Sun, Xi;Zhu, Weidong;Li, Haolin
    • Smart Structures and Systems
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    • v.24 no.5
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    • pp.597-606
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    • 2019
  • Damage detection based on dynamic characteristics of a structure is one of important roles in structural damage identification. It is difficult to detect local structural damage using traditional dynamic experimental methods due to a limited number of sensors used in an experiment. In this work, a non-contact test stand of fan blades is established, and a full-field noncontact test method, combined with three-dimensional digital image correlation, Bayesian operational modal analysis, and damage indices, is used to detect local damage of a fan blade under ambient excitation without use of baseline information before structural damage. The methodology is applied to detect invisible local damage on the fan blade. Such a method has a seemingly high potential as an alternative to detect local damage of blades with complex high-precision surfaces under extreme working conditions because it is a noncontact test method and can be used under ambient excitation without human participation.

The Study on the Invasion of Robinia pseudoacacia into Adjacent Forest Stand according to Forest Types, Stand Structures and Vegetation Units (인접(隣接) 임분(林分)의 종류(種類), 계층구조(階層構造) 및 식생단위(植生單位)에 따른 아까시나무의 이입(移入)에 관(關)한 연구(硏究))

  • Yun, Chung Weon;Oh, Seunghwan;Lee, Young-Geun;Hong, Sung Cheon;Kim, Jae Heun
    • Journal of Korean Society of Forest Science
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    • v.90 no.3
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    • pp.227-235
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    • 2001
  • This study was conducted to investigate the effects of adjacent stand on the invasion of Robinia pseudoacacia plantations. The results were as follows. 1) Robinia pseudoacacia tended to invade into all directions regardless of the kinds of adjacent stands. But it was estimated that the invasion of Robinia pseudoacacia into adjacent stands could be very difficult, if the layer structure of adjacent stands were well developed. Whereas, it was estimated that Robinia pseudoacacia more rapidly intruded into adjacent stands, if adjacent stands were opened and bared. 2) Robinia pseudoacacia tended to invade into all aspects regardless of the kinds of vegetation units in the adjacent stands. But the dominance class of Robinia pseudoacacia in the adjacent stands showed a little differences among the vegetation units. The dominance class of Robinia pseudoacacia in Quercus aliena community and Quercus serrata community showed low level as + ~2, while the dominance class of Pinus densiflora community, Pinus rigida community, Quercus variabilis community and Quercus acutissima community represented high level as 1~4. Also the dominance class of Isodon inflexus subgroup among three subgroups of Pinus densiflora community showed the lowest level as + ~2.

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On the Optimum Site Assessments of a Structure by GIS (GIS에 의한 구조물의 최적 위치 결정 기법)

  • Yang, In-Tae;Kim, Yeon-Jun;Kim, Dong-Moon;Park, Jae-Hoon
    • Journal of Industrial Technology
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    • v.17
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    • pp.43-50
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    • 1997
  • Local administration is closely related with intention of residents. Especially, a plan item is closely related with life of residents. Therefore, it has to be logical and objective solution for opinion convergence. Decision of opinion has to be in a triangular position standard and stand in a trio of criteria in standard. But, opinion convergence of residents very difficult. Recently, the technique of GIS presents method for oponion convergence with logical and objective and scientifically solution. And, this study present method for decision of intention to a complex element with GRID and NETWORK techniques of GIS. This study present optimun site of constructure with the GIS technique in consideration of a side face of transportation, technical, social economy and environments.

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A Design of the Solar Tracker for LED Streetlight in Using Solar Cell (태양전지를 이용한 LED 가로등의 태양광 추적 장치 설계)

  • Lee, Ok-Jae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.12
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    • pp.1-9
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    • 2013
  • A standalone LED lighting system in using solar energy has been used usually less than 70W of lighting power because of a troublesome installation and maintenance. In this system, as more and more LED lighting power increases, the capacity of photovoltaic panel does proportionally, and to improve the charging efficiency of solar energy, MPPT(Maximum Power Point Tracking) techniques is used frequently, but the solar tracker is not. In this paper, a solar tracker which traces the light of the sun in varying hour to hour is studied to apply to the standalone LED lighting system. This solar tracker consists of twin axis for tracing the azimuth and altitude respectively, and it has a robust structure with safe mode to stand a strong wind. As a result of analysis, generating efficiency of the traced type has improved on the fixed one 28.84% on average.

The improved efficiency Study of PV system for the Solar lamp lighting (태양광 가로등 발전 효율개선 연구)

  • Kang, Sin-Young;Lee, Yang-Guy;Kim, Kwang-Heon
    • Proceedings of the KIEE Conference
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    • 2002.11d
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    • pp.304-308
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    • 2002
  • This paper studies stand-alone photovoltaic array for solar lighting lamp. The solar lighting lamp has PV modules, batteries. and charge & discharge system. The charge efficiency is improved for the control of each battery which is divided the charge from the discharge to change the structure of existing solar lighting lamp charge & discharge system. so, the charge and discharge times are reduced of 50%. and the depth of discharge control can be controlled in the discharge cut off voltage. This can be effective of battery use. If a battery is out of order, this system can be executed for a regular period. so we saved the repair cost and developed of system's stabilization. It is possible economical effect to apply for solar lighting lamp used photovoltaic array.

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