• Title/Summary/Keyword: the shape of water

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Design of Bow Shape to Decrease Green Water Impact Loading in Regular Waves (규칙파 중 갑판침입수 충격하중 감소를 위한 선수형상 설계)

  • Ha, Yoon-Jin;Lee, Young-Gill;Jeong, Kwang-Leol
    • Journal of Ocean Engineering and Technology
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    • v.26 no.4
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    • pp.15-22
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    • 2012
  • In this research, the relationship between the bow shape and green water phenomenon on the bow deck of an FPSO was studied using an experimental method. A 140,000 DWT FPSO was used as the objective hull form in the present research. The incident waves were regular types. The heights were 1.0 and 1.5 times the freeboard, and the length was equal in size to LBP. The wave heights and pressures on the deck were measured in experiments. Model tests were performed to determine the effects of bow flare angles, bow shapes, and a forecastle deck. The free heave and pitch conditions were applied to the models in these experiments. From the results of the model tests, an optimized bow shape was designed, which was found to decrease the green water impact loading. The results of this research could be used as fundamental data in the design of a bow shape.

Identification of Morphological Appearance of Fine Seed Herbs Using Stereoscope (Report I) - Celosiae Semen, Celoisae Cristatae Semen, Cuscutae Semen, Perillae Semen (Stereoscope를 이용한 미세종자류 한약재 외부형태 감별연구(제1보(報)) - 청상자(靑葙子) 계관자(鷄冠子) 토사자(菟絲子) 자소자(紫蘇子))

  • Ji, Chang-Yoon;Kim, Tae-Ju;Lee, Seung-Ho;Kim, Young-Sik;Lee, Guem-San;Kim, Jung-Hoon;Choi, Goya;Ju, Young-Sung
    • The Journal of Korean Medicine
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    • v.34 no.3
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    • pp.1-12
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    • 2013
  • Objectives: This was study about identifying fine seed herbs that are highly mixed together: Celosiae Semen, Celoisae Cristatae Semen, Cuscutae Semen, Perillae Semen. Methods: In non-distinctive herbs through sensory test, we can find accurate discriminative points by using a stereoscope. As a result, a new discriminative key was completed. Results: We identified a comparison of herbs which are mixed up in distribution. 1) In the case of Celosiae Semen and Celoisae Cristatae Semen, Celoisae Cristatae Semen which is mixed up is bigger and more glossy and especially have the sunk umbilicus. 2) In the case of Cuscutae Semen and Perillae Semen, Perillae Semen is discriminated by characteristic morado netting surface and impression of fruit stalk in the single-ended. 3) In the case of Cuscutae Semen which is distributed in three species, we discriminated by beak shape, location of umbilicus and vomiting thread shape or not when put in water. (1) Cuscuta chinensis has a weak beaky shape, an umbilicus in center and is vomiting thread shape when put in water. (2) C. australis has very weak beaky shape, an umbilicus beneath and is vomiting thread shape when put in water. (3) C. japonica has clear beaky shape, an umbilicus beneath and is not vomiting thread shape when put in water. Conclusions: A stereoscope can be effectively used for identifying fine seed herbs hardly distinguishable by sensory tests.

Reduced Density Matrix Theory for Vibrational Absorption Line Shape in Energy Transfer Systems: Non-Condon Effects in Water

  • Yang, Mi-No
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.439-443
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    • 2011
  • Using the projection operator technique, a reduced density matrix theory for linear absorption spectrum of energy transfer systems is developed for the theoretical absorption line shape of the systems with non-Condon transitions. As an application, we considered a model system of OH vibrations of water. In the present model calculation, the OH vibration modes are coupled to each other via intra-molecular coupling mechanism while their intermolecular couplings are turned off. The time-correlation functions appearing in the formulation are calculated from a mixed quantum/classical mechanics method. The present theory is successful in reproducing the exact absorption line shape. Also the present theory was improved from an existing approximate theory, time-averaged approximation approach.

Model test and numerical simulation on the bearing mechanism of tunnel-type anchorage

  • Li, Yujie;Luo, Rong;Zhang, Qihua;Xiao, Guoqiang;Zhou, Liming;Zhang, Yuting
    • Geomechanics and Engineering
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    • v.12 no.1
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    • pp.139-160
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    • 2017
  • The bearing mechanism of tunnel-type anchorage (TTA) for suspension bridges is studied. Model tests are conducted using different shapes of plug bodies, which are circular column shape and circular truncated cone shape. The results show that the plug body of the latter shape possesses much larger bearing capacity, namely 4.48 times at elastic deformation stage and 4.54 times at failure stage compared to the former shape. Numerical simulation is then conducted to understand the mechanical and structural responses of plug body and surrounding rock mass. The mechanical parameters of the surrounding rock mass are firstly back-analyzed based on the monitoring data. The calculation laws of deformation and equivalent plastic strain show that the numerical simulation results are rational and provide subsequent mechanism analysis with an established basis. Afterwards, the bearing mechanism of TTA is studied. It is concluded that the plug body of circular truncated cone shape is able to take advantage of the material strength of the surrounding rock mass, which greatly enhances its bearing capacity. The ultimate bearing capacity of TTA, therefore, is concluded to be determined by the material strength of surrounding rock mass. Finally, recommendations for TTA design are proposed and discussed.

The Meaning of Water in Contemporary Fashion -Viewed as Human Desire- (현대패션에 나타난 물의의미 -인간의 욕망을 중심으로-)

  • 임영자
    • Journal of the Korean Society of Costume
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    • v.43
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    • pp.53-68
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    • 1999
  • Water allows us to have artistic experiences of searching for the source of hints and techniques by bring about the emergence of the new representation new themes and new forms of arts. The water that holds a great deal of hidden meaning shape the image. This study attempted to investigate what mental relationship the concept of water had the mental phenomenon of water in hea-sang-kun-sun-do in terms of the event of contemporary fashion in the present-day age. This means the stream of thought to grope a new paradign of multi-cultruism that claims the coexistence of East and West civilizations in the contemporary civilization. The meaning of water is developed fabrics connected with the water and the water emerge the issue in contemporary fashion. And the concept of water as the meaning concept is used as the tool to represent a certain issue in silhouette and fabrics not only the introduction as substantial water into fashion giving the fashion designer's emotion to shape and representing the fashion designer's aesthetic needs by emphasizing with the designer.

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A Study of the Seepage through Sand-Constructed Model Dams. (모래로 축조된 댐 모형의 침투에 관한 연구(I))

  • 신방웅
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.22 no.2
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    • pp.64-82
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    • 1980
  • The aim of this thesis, when water permeates dam, is to study the shape of seepage line and seepage quantity. As for the process, various sand model dams of same capacity were constructed in the water tank : they are a central, middle, inclined, up and down stream point of which is paralled, and filter-installed types. And the slope of seepage line and seepage quantity in these various models for experiment were measured, observed data were analyzed, and several formulas which already published were compared and examined. As for the shape of seepage line, the relation between upstream water level and exit: slope of seepage line, near the entrance and exit point, geometrically similar model, and the shape of seepage line filter-installed were examined. As regards to the seepage quantity, several formulas which already published and testing result values were compared and examined, and relation with the slope of seepage line, the seepage quantity, the slope of upstream point, and the upstream water level were mutually studied. Particulary, when horizontal filter was installed, propriety of the existing formulas for effective filter length w as examined, and the relative position of exit point in various. conditions was also studied.

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Analysis of Intercepted Flow Characteristics by Accumulated Debris (부유잡목에 의한 흐름차단이 하천에 미치는 영향 분석)

  • Choi, Gye-Woon;Kim, Young-Gyu;Hwang, Young-Man;Cho, Sang-Wook
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.846-850
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    • 2007
  • In this study debris like branch or trash are washed and flowed from land to stream by rainfall runoff at mountain or urban stream specially rainy season. These kinds of debris are accumulated at hydraulic construct on the way of flow along the stream. The shape or ratio of like these accumulated debris are various according to the location where it is accumulated and the material what it is, so that it is influenced to be varied to flow characteristics. To be simple of accumulated debris shape, it was made experiments though the variation of open ratio and the shape of accumulated debris by lab experiment using straight channel with two piers. From the result, the water level is inverse proportion to open ratio, and the water level more sensitive to the debris‘ width than length at the same area of accumulated debris.

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Effect of Shape of Discharge Port on Hydraulic Performance of Automotive Closed Type Water Pump (자동차 밀폐형 워터펌프의 토출구 형상이 수력성능에 미치는 영향)

  • Heo, Hyung-Seok;Lee, Gee-Soo;Bae, Suk-Jung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.1
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    • pp.39-47
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    • 2006
  • Recent trend in pursuit of high performance and effectiveness for automotive cooling system has changed the application of material for impeller of automotive water pump from metal to high ability engineering resin, which can achieve optimization of design of impeller geometry and realize lightweight high efficiency water pump. Closed type water pump improves hydraulic loss of fluid through the clearance between volute casing and impeller compared with that of the existing open type water pump(Although closed type is heavier than open type for the same size and same material, adoption of plastics can solve the problem.). In the present study, the characteristics of hydraulic performance of closed type water pump were investigated with respect to the angle between shroud and hub of impeller and the shape of discharge port of volute casing. Performance tests were carried out for 4 cases, that is, for 2 impellers and 2 casings. The modification of shape of only discharge port can enhance the hydraulic performance by 10 percent and the pump efficiency by 4-6 percent.

a biologically inspired small-scale water jumping robot (작은 스케일의 생체 모방 수상 점프 로봇)

  • Shin, Bong-Su;Kim, Ho-Young;Cho, Kyu-Jin
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1427-1432
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    • 2008
  • This paper describes the locomotion of a water jumping robot which attempts to emulate the fishing spider’s ability to jump on the water surface. While previous studies of the robots mimicking arthropods living on water were focused on recreating their horizontal skating motions, here we aim to achieve a vertical jumping motion. The robot jumps by pushing the water surface with rapidly released legs which were initially bent. The motion is triggered with a latch driven by the shape memory alloy actuator. The robot is capable of jumping to the maximum height of 26mm. Jumping efficiency, defined the maximum jumping height on water over the maximum jumping height on rigid ground, is 0.26 This work represents a first step toward robots that can locomote on water with superior versatility including skating and jumping.

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Simulation for the Flowing Water Purification with Spring Shape Inside Chamber (챔버 내측에 스프링형상을 갖는 유수형 자외선 살균장치 시뮬레이션)

  • Jung, Byung-Gyeon;Jeong, Byeong-Ho;Lee, Jin-Jong;Jung, Byeong-Soo
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.4
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    • pp.411-416
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    • 2010
  • Interest in application of ultraviolet light technology for primary disinfection of potable water in drinking water treatment plants has increased significantly in recent years. The efficacy of disinfection processes in water purification systems is governed by several key factors, including reactor hydraulics, disinfectant chemistry, and microbial inactivation kinetics. The objective of this work was to develop a computational fluid dynamics(CFD) model to predict velocity fields, mass transport, chlorine decay, and microbial inactivation in a continuous flow reactor. In this paper, It describe the how to design optimal UV disinfection device for ground water, BWT and rainwater. Spring shape instrument silver coated located in inner side of disinfection chamber. It make lead the active flowing movement target water and maximize disinfection performance. To search the optimal design method, it was performed computer simulation with 3D-CFD discrete ordinates model and manufactured prototype. Using proposed design method, performed simulation and proved satisfied performance.