• Title/Summary/Keyword: parallel arrangement

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Study on the Satellite Thermal Control Hardware Composed of Two Parallel Channels Working for Heat Pipe and Phase Change Material (열관과 상변화물질을 일체형으로 병렬 배열한 위성용 열제어 부품 연구)

  • Kim, Taig-Young;Hyun, Bum-Seok;Lee, Jang-Joon;Rhee, Ju-Hun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.11
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    • pp.1087-1093
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    • 2010
  • The satellite thermal control H/W composed of two parallel channels working for heat pipe (HP) and phase change material (PCM) is suggested for the high heat dissipating component which works intermittently with short duty. In a limited point of view, the HP-PCM device is a kind of off-the-shelf component that requires no dedicated configuration and thermal designs to PCM. Therefore, it can be used with less impact on the program cost and schedule different from most of the PCM applications. In present study the typical honeycomb structure radiator applying the HP-PCM device is designed and the detail thermal math model is developed for numerical analyses. The result comparison between without and with PCM shows that the HP-PCM device redistributes the peak heat around the whole mission period through the alternate melting and freezing of PCM, and, as a result, the maximum and minimum temperatures are effectively alleviated. The drawback of PCM application due to low thermal conductivity can be successfully resolved by means of parallel arrangement of HP channel.

Efficiency Evaluation of Genetic Algorithm Considering Building Block Hypothesis for Water Pipe Optimal Design Problems (상수관로 최적설계 문제에 있어 빌딩블록가설을 고려한 유전 알고리즘의 효율성 평가)

  • Lim, Seung Hyun;Lee, Chan Wook;Hong, Sung Jin;Yoo, Do Guen
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.294-302
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    • 2020
  • In a genetic algorithm, computer simulations are performed based on the natural evolution process of life, such as selection, crossover, and mutation. The genetic algorithm searches the approximate optimal solution by the parallel arrangement of Schema, which has a short definition length, low order, and high adaptability. This study examined the possibility of improving the efficiency of the optimal solution by considering the characteristics of the building block hypothesis, which are one of the key operating principles of a genetic algorithm. This study evaluated the efficiency of the optimization results according to the gene sequence for the implementation in solving problems. The optimal design problem of the water pipe was selected, and the genetic arrangement order reflected the engineering specificity by dividing into the existing, the network topology-based, and the flowrate-based arrangement. The optimization results with a flowrate-based arrangement were, on average, approximately 2-3% better than the other batches. This means that to increase the efficiency of the actual engineering optimization problem, a methodology that utilizes clear prior knowledge (such as hydraulic properties) to prevent such excellent solution characteristics from disappearing is essential. The proposed method will be considered as a tool to improve the efficiency of large-scale water supply network optimization in the future.

Determination on the component arrangement of a hybrid rain garden system for effective stormwater runoff treatment (강우유출수 처리를 위한 하이브리드 빗물정원 시스템의 구성요소 배열 연구)

  • Flores, Precious Eureka D.;Geronimo, Franz Kevin F.;Alihan, Jawara Christian P.;Kim, Lee-Hyung
    • Journal of Wetlands Research
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    • v.19 no.3
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    • pp.271-278
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    • 2017
  • Low impact development (LID) technology has been recently applied for the treatment of nonpoint source pollutants. Rain garden is one of the widely used LIDs since it utilizes various mechanisms such as biological and physico-chemical treatment to reduce pollutants. However, problem such as clogging has been one of the issues encountered by the rain garden that do not undergo constant maintenance. Therefore, this research was conducted to develop and determine the component arrangement of a rain garden system for a more efficient volume and pollutant reduction. Two hybrid rain garden systems having different characteristics were developed and evaluated to determine the optimum design and arrangement of the system. The results showed that the components arranged in a series manner showed a volume reduction of 93% and a pollutant reduction efficiency of approximately 99%, 93% and 95% was observed for particulates, nutrients and heavy metals, respectively. While when the system is connected in a combined series-parallel, the volume and average pollutant reduction efficiency for the TSS, nutrients and heavy metals are 65%, 94%, 80% and 85%, respectively. Moreover, the component arrangement in the order of sedimentation tank, infiltration tank and plant bed exhibited a high pollutant reduction efficiency compared when the infiltration tank and plant bed were interchanged. The findings of this research will help in the further development and optimization of rain garden systems.

Developmental Morphology of Osmundea crispa (Ceramiales, Rhodophyta) from California

  • Nam Ki Wan;Choi Han Gil
    • Fisheries and Aquatic Sciences
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    • v.2 no.1
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    • pp.25-31
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    • 1999
  • Developmental morphology of the red alga, Osmundea crispa (Hollenberg) Nam from California was studied on the basis of liquid-preserved and herbarium specimens. Vegetative axial segment of the species produces two pericentral cells and one trichoblast. Spermatangial filaments (branches) are derived from apical and epidermal cells in pocket-shaped apical pit with an ostiole-like upper opening. Procarp-bearing segment of female trichoblast produces five pericentral cells, of which the fifth functions as supporting cell of carpogonial branch. Tetrasporangial production occurs in random epidermal cells in apical pit of branchlets, and two presporangial cover cells show parallel arrangement to stichidial axis. As this vegetative and reproductive development is included in the generic delineation of Osmundea Stackhouse, O. crispa among the known Osmundea species is characterized by habit forming compact cushion-like clump with angular to terete thallus. It is also distinguished from O. hybrida (AP. de Candolle) Nam without the compressed thallus by the number of pericentral cells in procarp-bearing segment and shape of spermatangial pit. Taxonomic implication of the shape of spermatangial pit is also included.

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Increase of resistive type superconducting fault current limiter capacity (박막 저항형 초전도 한류기의 용량증대를 위한 방안)

  • Cha, Sang-Do;Kim, H.R.;Choi, H.S.;Hyun, O.B.
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.790-792
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    • 2002
  • The resistive type superconducting fault current limiter(SFCL) is a current limiter using the Quench mechanism of superconductors. When Quench occurs in superconductors, the resistance of superconductors increases abruptly. In order to increase SFCL capacity, current limiting elements were connected in series. If the Quench current of each element was different, voltage distribution was imbalanced. This imbalance could be removed by arrangement including series and parallel connection of elements. Based on this result, an SFCL of 1.8kV/50A was designed and experimented, expecially, in terms of increasing the voltage rating.

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Task based design of modular robot manipulator using efficient genetic algorithms

  • Han, Jeongheon;Chung, Wankyun;Youm, Youngil;Kim, Seungho
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.243-246
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    • 1996
  • Modular robot manipulator is a robotic system assembled from discrete joints and links into one of many possible manipulator configurations. This paper describes the design method of newly developed modular robot manipulator and the methodology of a task based reconfiguration of it. New locking mechanism is proposed and it provides quick coupling and decoupling. A parallel connection method is devised and it makes modular robot manipulator working well and the number of components on each module reduced. To automatically determine a sufficient or optimal arrangement of the modules for a given task, we also devise an algorithm that automatically generates forward and inverse manipulator kinematics, and we propose an algorithm which maps task specifications to the optimized manipulator configurations. Efficient genetic algorithms are generated and used to search for a optimal manipulator from task specifications. A few of design examples are shown.

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Four New Records of Holaxonia (Anthozoa: Octocorallia: Alcyonacea) from Korea

  • Kim, Min-Sun;Song, Jun-Im
    • Animal Systematics, Evolution and Diversity
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    • v.30 no.2
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    • pp.95-102
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    • 2014
  • The four species of the suborder Holaxonia, Anthogorgia japonica Studer, 1889 of family Acanthogorgiidae, Astrogorgia rubra (Thomson & Henderson, 1906), Euplexaura attenuata (Nutting, 1910), and E. erecta (Kukenthal, 1908) of family Plexauridae have been newly recorded in Korea. They were collected from intertidal and sublittoral zones in the western and southern coasts and Jeju-do Island of Korea by SCUBA diving and fishing nets from 1969 to 2010. This study approaches holaxonians by focusing on external and internal morphologies including size, form, and color of colonies, branches, polyps, coenenchyme, axis, and spicules. Anthogorgia japonica is characterized by its planar growth form, dichotomously branched form, non-retractile polyps, and Astrogorgia rubra by arrangement of calyxes being situated in lateral side at stems and alternately in all sides at branches. Euplexaura attenuata is sparsely and laterally branched colony, and has straight wand-like stems. Euplexaura erecta has branches which run parallel to the main stem.

A Study on the Planning of Children's Room (아동실의 실내계획방향에 관한 연구)

  • 황연숙;오찬옥
    • Korean Institute of Interior Design Journal
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    • no.11
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    • pp.64-69
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    • 1997
  • The purpose of this study was to examine the current interior conditions of children's rooms and to suggest theplanning guidelines of children's rooms. Data were collected through questionnaire survey including measurements and observations. The sample consisted of 291 households with the 3-5 years old children in Pusav. Data were analyzed by using SPSS-PC. The major findings were as follows : 1) It was found that most of children lived in small rooms. Considering their furnitures and equipments, the size of children's rooms should be 10-13 $m^2$. 2) Children's rooms should be closed to their parent's room and living room to take care of children and far from kitchen, balcony, diming room to prevent hazards. 3) Interior finishings such as wall papers, floor coverings should be chosen to consider the children's tastes and their preferred styles. 4) The types of furniture arrangement were divided by 5 types: one wall type, parallel type, ㄱ type, ㄷ type, ㅁ type. 5) The local lighting such as task lighting for studying and playing night lamp for sleeping should be used.

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PECULIARITY IN SCALE CHARACTERS OF ENGRAULIDAE FISHES (멸치과어류의 비늘의 특이성)

  • KIM Yong Uk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.11 no.4
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    • pp.249-256
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    • 1978
  • Morphological characters of the scales of Engraulidae fishes, Engraulis japonica and Thrissa kammalensis, are described with illustrative figures. The scales are primitive cycloid and quadrangular or pentagonal without concentric foci. In Engraulis japonica arrangements of the grooves are irregular, and tile grooves converge from the outer margin to the central part of the scale. In Thrissa kammalensis the arrangements of the grooves are transverse in the major part of the scale except the apical part. The ridge of the apical part form a network arrangement, and parallel with the grooves. In the central part of the scales of the both species there are several fingerprint-like structures.

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Design of Adaptive Linearization Controller for Nonlinear System Using RBF Networks (RBF 회로망을 이용한 비선형 시스템의 적응 선형화 제어기의 설계)

  • 탁한호;김명규
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.3
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    • pp.525-531
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    • 2001
  • The paper demonstrates that RBF(Radial Basis Function) networks can be used effective for the identification of inverted pendulum system. With the parallel arrangement of the RBF networks controller and PD controller, some characteristics were compared through simulation performance.

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