• Title/Summary/Keyword: knowledge flow

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A multilayer Model for Dynamics of Upper and Intermediate Layer Circulation of the East Sea (동해의 상, 중층 순환 역학에 대한 다층모델)

  • 승영호;김국진
    • 한국해양학회지
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    • v.30 no.3
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    • pp.227-236
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    • 1995
  • A simple layer model based on isophcnal coordinate is applied to the East Sea to examine the dynamics of circulation. The results confirm the existing knowledge about role of inflow-outflow and wind in driving the circulation. It is found, however, that the buoyancy flux generates quite different circulation pattern; it enhances the inflow-outflow driven circulation and has a convective nature. The circulation considering all these effects resembles the schematic one presently known. In the circulation, the intermediate layer is outcropped in the north off the northern boundary, ventilated here and flows cyclonically in the northern part of basin. This water, however, does not flow southward directly because of the strong eastward (separating from the coast) current in the layer above. This water also loses its potential vorticity while traveling around the periphery of the outcropping region and is thus characterized by minimum potential vorticity in the interior of the basin.

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Ecological studies of Cobitid Fish, Cobitis koreensis in Jeonju-cheon Creek, Jeonrabug-do province, Korea (전주천 참종개 Cobitis Koreensis 의 생태)

  • Ik Soo Kim
    • The Korean Journal of Ecology
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    • v.2 no.1
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    • pp.9-14
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    • 1978
  • The study was made to expand the knowledge of the ecology of Cobitis koreensis which is very common in the upper and middle part of rivers in western part of Korea. A number of C. koreensis are found in the creek of Jeonju-cheon located at Segjang-ri, Wanju-gun, Jeonrabug-do Province. The area studied has pebble bottoms. The flow velocity of the river ranges from 20cm to 40cm per second under normal conditions. The sex ratio of male to female was 1:1.34 and the female was 10~25mm larger than the male in total length. Length-frequencies in this population indicate that 20~40 mm fish group is underyearling, 40~60mm is a yearling, and 60~85mm is two-year-old. And the fish longer than 90mm in total length is regarded as being over three-year-old. Based on the ratio of gonadal weight to body weight, spawning in this species began in April and expanded well into June with water temperature 20~26。C, and the individuals became sexually mature over the two-year-old. The number of the eggs was counted from ten matured female fishes. The mean number of eggs in seven 72.6~81.4mm fishes was 908 (595-1, 229) and that of the rest three 86.0~89.0mm was 1, 674 (1, 337-2, 023). The contents of stomach in the other fifteen specimens captured in September 1977 were investigated. While the younger fed almost on the algae, the foods in the adult were largely aquatic insects.

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Implementation of Automation System for the Fluid Analysis of Axial Fan Using Supercomputer (슈퍼컴퓨터 활용 축류팬 유동해석 자동화 시스템 개발)

  • Kim, Myung-Il;Lee, Seung-Min;Lee, Sang-Min
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.288-291
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    • 2008
  • Recently, the importance and necessity of engineering analysis has shown a steady growth. However, researchers working in small and medium enterprises know little about the usefulness of engineering analysis and suffer from lack of technical knowledge. Axial fan is air fluid machinery in various fields of industry such as automobile, electric appliance, and heavy machinery. It is also a time and budget consuming equipment to develop the axial fan through physical experiments. In order to overcome this problem, we have designed and developed a web-base automated simulator for axial fan's fluid analysis using supercomputer. Automated simulator means that all of processes for engineering analysis including pre-process, solving, and post-process can be performed automatically without user intervention after transferring fan model(CAD files) made by user. After executing the simulator with some parameters, user can receive the report including pressure P and flow rate Q. In this paper, we introduce the architecture of our easy and efficient automated engineering analysis simulator, related techniques and result of development.

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Effect of Chuna on circulatory system - Based on Experimental Chuna Science - (추나의 순환계에 미치는 영향에 대한 고찰 - 실험추나학을 중심으로-)

  • Ahn, Min-Youn;Song, Yun-Kyung;Lim, Hyoung-Ho
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.9 no.2
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    • pp.1-9
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    • 2014
  • Objectives : Many studies are being done in the method of experimental chuna science in China. The aim of this review is to understand and study the methods of experimental chuna science, focusing on the effects of chuna on circulatory system. Methods : We reviewed "實驗推拿學" and Chinese journals were searched using China National Knowledge Infrastructure(CNKI). Korean journals were searched using 3 Korean web databases(OASIS, NDSL, RISS). Results : By experimental chuna science, effect of chuna on blood pressure, cardiovascular system, hemorheologic system, blood flow velocity, circulation and lymphatic system were proved. Conclusions : Experimental chuna science is necessary for improvement of chuna to a higher level. In Korea, not many experimental studies are being done, especially in chuna and it has very narrow target diseases. For this reason we need to learn and adapt the methods of experimental chuna science of China.

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Research on the nasal airflow and heat and mass transfer (비강 내 공기유동과 열 및 물질전달에 관한 연구)

  • Kim, Sung-Kyun;Liem, Huynh Quang;Park, Joon-Hyung
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1479-1483
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    • 2008
  • The three main physiological functions of nose are air-conditioning, filtering and smelling. Knowledge of airflow characteristics in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. In our laboratory, there have been a series of experimental investigations on the nasal airflow in normal and deformed nasal cavity models by PIV under both constant and periodic flow conditions. In this time, airflow inside normal nasal cavity is investigated numerically by the FVM general purpose code. The comparisons with PIV measurement are appreciated. Heat and humidity transfer is dealt numerically. Dense CT data and careful treatment of model surface under the ENT doctor’s advice provide more sophisticated cavity models for both PIV experiment and numerical grid system. Average and RMS velocity distributions have been obtained for inspirational and expirational nasal. Temperature distribution, heat and humidity transfer through the mucosa are obtained.

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Implementation of the Function Block Builder for the Distributed Control System (분산 제어 시스템용 기능 블록 작성기 구현)

  • 권만준
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.6
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    • pp.974-979
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    • 2002
  • There are so many kind of a control program that is applied in various process fields such as power generation plant, water treatment plant, incinerator plant, chemical plant, cement plant etc.. Because an engineer in field edits and changes and debugs and tests properly control programs using text-based control language, it is very hard for the him to apply to plant. Therefore, this research implemented a graphical tool for control program builder that is applicable to various plants and usable engineers having a little knowledge for control language. I wish to run more efficiently precision process control offering function that can see visual expression about flow of control signal and intermediate output values of control program displayed in screen using this implemented function block builder.

Hypopituitarism and Legg-Calve-Perthes disease related to difficult delivery

  • Bas, Veysel Nijat;Uytun, Salih;Vurdem, Umit Erkan;Torun, Yasemin Altuner
    • Clinical and Experimental Pediatrics
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    • v.58 no.7
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    • pp.270-273
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    • 2015
  • Legg-Calve-Perthes (LCP) disease is characterized by idiopathic avascular osteonecrosis of the epiphysis of the femur head. The main factor that plays a role in the etiology of the disease is decreased blood flow to the epiphysis. Many predisposing factors have been suggested in the etiology of LCP disease, and most have varying degrees of effects. Here we present the case of a boy aged 4 years and 10 months with complaints of short stature and a diagnosis of multiple hypophyseal hormone deficiency, in whom LCP disease and difficult birth-related pituitary stalk interruption syndrome were identified by anamnesis. The present case revealed that LCP disease and hypophyseal hormone deficiency could be secondary to difficult birth and that LCP disease could be secondary to insulin-like growth factor 1 deficiency. Additionally, to the best of our knowledge there is no published case on the relation between LCP disease and insulin-like growth factor 1 deficiency. Therefore, we believe that this case is worthy of presentation.

Simulation and Three-dimensional Animation of Skipjack Behavior as Capture Process during Purse Seining

  • Kim, Yong-Hae;Park, Myeong-Chul;Ha, Suk-Wun
    • Fisheries and Aquatic Sciences
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    • v.11 no.2
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    • pp.113-123
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    • 2008
  • We modeled fish school movements as a capture process in relation to the purse seine method using the three steps of the stimulus-response process (i.e., input stimuli, central decision-making and output reaction). Input stimuli of the model were categorized as either physical stimuli such as visual stimulus, sound stimulus, water flow, and weather or as biological stimuli such as species and size, swimming performance, sensual sensitivity, and presence of prey or predators. The output process determining the spatial orientation of the fish school for 3-D movements was based on swimming speed and angular change in the fish response, and these movements were animated as the relative geometry between the fish school and the purse seine. Simulations were carried out for skipjack tuna (Katsuwonus pelamis) schools reacting to a pelagic purse seine in the southwest Pacific Ocean. Simulation results showed that escape ratios varied from 20 to 70% by the relevant ranges in the stimulus-response thresholds, swimming speeds, and angular changes of fish schools were similar to those observed in the field. Therefore, with knowledge of relevant parameters, this model can be used to predict capture and escape probabilities of purse seine operations for different fish species or conditions.

Construction of Ground Effective Thermal Conductivity Database for Design of Closed-Loop Ground Heat Exchangers (밀폐형 지중열교환기 설계를 위한 지중 유효열전도도 데이터베이스 구축)

  • Choi, Jae-Ho;Sohn, Byong-Hu;Lim, Hyo-Jae
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.776-781
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    • 2008
  • A ground heat exchanger in a GSHP system is an important unit that determines the thermal performance of a system and its initial cost. The Size and performance of this heat exchanger is highly dependent on the thermal properties. A proper design requires certain site-specific parameters, most importantly the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. This paper is part of a research project aiming at constructing a database of these site-specific properties, especially ground effective thermal conductivity. The objective was to develop and evaluation method, and to provide this knowledge to design engineers. To achieve these goals, thermal response tests were conducted using a testing device at nearly 150 locations in Korea. The in-situ thermal response is the temperature development over time when a known heating load imposed, e.g. by circulating a heat carrier fluid through the test exchangers. The line-source model was then applied to the response test data because of its simplicity. From the data analysis, the range of ground effective thermal conductivity at various sites is $1.5{\sim}4.0\;W$/mK. The results also show that the ground effective thermal conductivity varies with grouting materials as well as regional geological conditions and groundwater flow.

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The Implementation of Visual Effects on Physical Phenomena of Nature Using Particle System (파티클 시스템을 이용한 자연의 물리적 현상의 비주얼 효과 구현)

  • Kim, Kyoung-Nam;Lee, Myoun-Jae
    • Journal of Digital Convergence
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    • v.10 no.4
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    • pp.347-352
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    • 2012
  • Uncertain physical phenomena of nature are a frequently researched area in emotional engineering technology and visual expression of art. This paper suggests possibility for implementation of physical phenomena (percolation, dispersion, and flow) of nature using Unity 3D engine's particle system, which have already been analyzed in a previous study [1] on modern paintings that emphasized physical properties. This paper proposes an easy implementation method for uncertain physical phenomena of nature for artists experiencing difficulty in acquisition of knowledge on computer graphics programming, providing an idea for engineers conducting research on emotion-based technology.