• Title/Summary/Keyword: Developing Measurement

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Experimental Investigation of Two-dimensionality of Flow around the Vertical Fence Submerged in a Turbulent Boundary Layer (난류 경계층에 잠긴 수직벽 주위 유동의 2차원성 연구)

  • Cha, Jae-Eun;Kim, Hyoung-Woo;Kim, Hyoung-Bum
    • Journal of the Korean Society of Visualization
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    • v.8 no.1
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    • pp.13-18
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    • 2010
  • An experimental investigation of the flow around a vertical fence was carried out using a PIV velocity field measurement technique. The vertical fence was embedded in a turbulent boundary layer. The instantaneous velocity fields measured at cross-sectional planes reveal complex longitudinal vortices that vary in size and strength, developing from the upstream location. In the instantaneous vorticity and velocity field data, the shear flow separated from the fence top is highly turbulent and shows unsteady flow characteristics. The topography of the ensemble averaged velocity fields, especially the separation bubble formed behind the fence, shows that the spatial distributions of streamwise velocity (U) and vertical (V) are symmetric, the spanwise velocity (W) is skew-symmetric with respect to the central xy-plane(z=0).

Investigating Uncertainty in Flow Measurement and Developing Rating Curves (유량측정시 불확실성의 검토와 수위-유량곡선식의 개발)

  • Lee, Kil Seong;Lee, Kyung Ho
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.1242-1246
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    • 2004
  • 본 연구에서는 유속계와 봉부자를 동한 측정값의 불확실성를 검토한 후, 한강의 7개 지류의 실측 자료들의 불확실성을 ISO 규정을 통하여 추정하였다. Simulated Annealing 기법과 황금비 분할법을 이용한 비선형회귀식을 적용하여 기존의 수위-유량 곡선식자 비교해보았다. 불확실성 추정결과 유량 측정치들의 불확실성이 ISO 규정의 기준에 비해 높게 추정되었으며, 특히 무작위 오차와 계통 오차 중에 무작위 오차의 불착실성이 높게 나타났다. 또한, 기존 수위-유량곡선식과 Simulated Annealing 기법과 황금비 분할법을 이용한 방법을 비교해본 결과 황금비 분할법이 가장 좋은 결과를 얻었다. 이때 수위-유량곡선식의 영수위값을 황금비 분할법을 이용해 구한 후 비교해 본 결과는 기존의 선형회귀방법과 비선형방법에서 큰 차이를 보이지 않았다. 또한 곡선 분리시에는 하나의 수위-유량곡선일때보다 오차가 줄어드는 경향을 보였다.

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Analysis of Work Load for Developing the Control Strategy of Hybrid Agricultural Tractor (하이브리드 농업용 트랙터의 제어 전략 개발을 위한 작업 부하 분석)

  • Kim, Jinseong;Park, Yeongil
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.2
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    • pp.239-245
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    • 2015
  • In order to control the hybrid power system efficiently, the knowledge for the required load of the system is important. The agricultural tractor performs various farm works such as plow, rotary, and baler. When it performs rotary tillage and baler operation, the generated work load is analyzed. To analyze trend of work load, moving average technique is applied to the measurement data. Optimal control inputs for the two works are obtained from simulation using the dynamic programming. The novel fundamental control strategy for parallel hybrid tractor called Max. SOC is proposed.

Preparation of Lip Balm Utilizing Functionalities of Colorants Extracted from Marine Algae (해조류 추출색소의 기능성을 활용한 립밤 제조)

  • Choi, Min;Yoo, Dong Il;Shin, Younsook
    • Textile Coloration and Finishing
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    • v.26 no.2
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    • pp.124-130
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    • 2014
  • The aim of this study is to utilize the algae extracts with functionalities such as antioxidant and antimicrobial properties for preparing lip balm. Functional properties of extracts from Dictyota coriacea and Ulva pertusa were evaluated in terms of DPPH radical scavenging activity and antimicrobial activity. Lip balms contained the algae extracts were tested its efficacy by measuring the moisture retention of lip skin after applying human subjects. According to the results of skin moisture retention measurement, lip balm was effective to increase the moisture retention of lip skin. It is considered that the utilization of colorants extracted from algae which are verified of antioxidant effect and antimicrobial activity is valuable and useful in developing the cosmetic products.

The Analysis of 3 Dimensional hydraulic experiment model (근접수치사진측량을 이용한 3차원 수리모형의 분석)

  • 최현;홍순헌;김민화;강인준
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.137-142
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    • 2004
  • Recently. the number of the use of Digital Photogrammetry is increasing, and photogrammetry instruments are developing rapidly and the pression is improving continuously. In this study, using the Rollei d7 metric that is a measurement digital camera which has capacity of keeping numerial value by itself and easy carrying, we analyze the 3 dimensional hydraulic experiment model. First, we calculated RMSE by carrying out bundle adjustment. Second, we try to find a effective 3D DEM with the Kriging Interpolation, Third make a comparative study the DEM of the Triangulation with the DEM of the close-range digital photogrammetry.

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Building Materials Thermal Conductivity Measurement and Correlation with Heat Flow Meter, Laser Flash Analysis and C-Therm TCi (HFM, LFA와 TCi를 이용한 건축 재료의 열전도율 측정과 상관관계 분석)

  • Cha, Jung-Hoon;Seo, Jung-Ki;Su-Min, Kim
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.92-97
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    • 2011
  • Nowdays the most critical problem is global warming and the most important reason is the high emition of carbondioxide. 23% of the use of carbondioxide is used in building and decreasing the use of it is very important. One of the biggest factor that can decrease the use of energy is developing the heat conducting ratio of the materials we use in building. Heat conducting ratio is the important factor in the use of reducing energy comsumation. In this research, there are methods about how to measure the heat conducting ratio, and the existing the representing measuring method which is Heat Flow Meter HFM 436, Laser Flash Analysis and find out about the TCi of the new method C-Therm and compare the results.

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In-Situ Diagnosis of Vapor-Compressed Chiller Performance for Energy Saving

  • Shin Younggy;Kim Youngil;Moon Guee-Won;Choi Seok-Weon
    • Journal of Mechanical Science and Technology
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    • v.19 no.8
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    • pp.1670-1681
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    • 2005
  • In-situ diagnosis of chiller performance is an essential step for energy saving business. The main purpose of the in-situ diagnosis is to predict the performance of a target chiller. Many models based on thermodynamics have been proposed for the purpose. However, they have to be modified from chiller to chiller and require profound knowledge of thermodynamics and heat transfer. This study focuses on developing an easy-to-use diagnostic technique that is based on adaptive neuro-fuzzy inference system (ANFIS). The effect of sample data distribution on training the ANFIS is investigated. It is found that the data sampling over 10 days during summer results in a reliable ANFIS whose performance prediction error is within measurement errors. The reliable ANFIS makes it possible to prepare an energy audit and suggest an energy saving plan based on the diagnosed chilled water supply system.

A Survey of Architectural Barriers on Public Building and Facilities to the Physically Disabled in An-Dong (장애인을 위한 안동시내의 공공건물 실태조사)

  • Chu, Min
    • Journal of Korean Physical Therapy Science
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    • v.3 no.1
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    • pp.881-894
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    • 1996
  • The most frustrating of all problems to physically disabled individuals are building and facilities, supposedly created for the public. that are designed and constructed in such a manner that probit the full participation of the physically. The first problem is to determine what might be done to make accessible and fuctional existing buildings that are now nonaccessible. The second task, the simpler of the two, is the development of the standards for proper design and construction of new building and facilities. thus the purpose of this study was co obtain precise information about the inconvenience of architectural barriers in the pubic building and facilities that having the physically disabled. Those listed in this survey 22 pubic building and facilities and 3 general hospital in An-dong city from December 20 to 28. 1995. Measurement obtained were compare with available international criteria and standards. These findings are offered to the appropriate autority as a guide for developing barriers-free design suit able to the Korean situation.

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Transient heat transfer analysis of inertial measurement devices by outside frictional heat (외부 마찰열에 의한 내부 관성측정장치의 과도 열전달 해석)

  • Tak, Seungmin;Park, Jiwon;Kang, Minkyu;Park, Dongjin;Lee, Jongsu;Lee, Seoksoon
    • Journal of Aerospace System Engineering
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    • v.4 no.1
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    • pp.32-37
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    • 2010
  • Guided weapon is very excellent strategy system than conventional weapons. Recently, several devices and a technology developed much developing more, inertia measuring device is one example. Inertia measuring device is device that is used to improe more accuracy of guided weapon, this device is operated by sensors of inside. Sensors of inside are parts that is very sensitive about impact or shock, heat that interact when shoot, it is main purpose that verify durability of sensor by heat delivered from outside in this study.

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Development and Application of Science Drawing Program to Improve Science Process Skills (과학 탐구 능력 향상을 위한 과학 그리기 프로그램 개발 및 적용)

  • Park, Mi-Jin;Lee, Yong-Seob
    • Journal of Korean Elementary Science Education
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    • v.29 no.2
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    • pp.186-194
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    • 2010
  • The purpose of this study is developing a Science Drawing Program to improve Science Process Skills and examining the effect of it. For this study two classes (missed classes with boys and girls) of 3th grade students participated and the subject of the instruction was domain of Air and Weather. The result of this study were as follows: First, the Science Drawing Program was effective in improving the science process skills. Development and Application of the Science Drawing Program brought positive effects especially on the observation, measurement, reasoning power. Second, student showed positive recognition on the Science Drawing Program. Many students showed interests and want to use it in class. And they thought Drawing Program helpful in their learning. Therefore the Science Drawing Program is very effective method in science education.

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