• Title/Summary/Keyword: 흐름유도

Search Result 489, Processing Time 0.028 seconds

A Study for an Efficient Utilization of the Linear Model (선형모형의 효율적 활용성에 관한 연구)

  • Kim Tae-Ho;Cho Eun Jung;Kim Mi Yun
    • The Korean Journal of Applied Statistics
    • /
    • v.18 no.1
    • /
    • pp.147-158
    • /
    • 2005
  • Most of the statistical models that real data can be applicable are static in nature, and thus it is not possible to analyze the effect of variations in the real world over time. Usual specification of the models does not produce the length and the time path of the effect even if the effect of an exogenous variation continues for periods of time. In this study, deriving the dynamic inherence from the static structure of the linear model for better utilization, we attempt to apply actual data to compare and analyze the long-run effect of variations in the market variables between the related markets by formulating a simultaneous equation system. Accordingly, it is proved to be possible to obtain efficient analytical results and to derive various useful implications.

Numerical Investgation of the Effect of Turbulent Flow on Fish Passing through Hydroturbine Draft Tube (수력터빈 드래프트관을 통과하는 물고기에 미치는 난류의 영향 수치모의)

  • Paik, Joong-Cheol
    • Journal of Korea Water Resources Association
    • /
    • v.38 no.5 s.154
    • /
    • pp.365-377
    • /
    • 2005
  • This paper presents numerical works carried out for developing an advanced computational framework for understanding injury- and mortality-inducing flow phenomena in hydropower facilities. Large-eddy simulation (LES) of a circular jet flow is carried out to help interpret the results of recent experiments that exposed live fish to the shear zone of a turbulent jet. The instantaneous flow field of LES is characterized by intense velocity, pressure, and vorticity fluctuations, which could exert forces and moments on a fish considerably larger than those exerted by the same fish exposed to the corresponding steady, time-averaged flow. In this study, also, unsteady modeling of flow in a hydroturbine draft tubewas carried out using a hybrid unsteady RANS/LES, so-called detached-eddy simulation (DES). Results from DES show that the potential for disorientation and excessive residence times of fish within the draft tube is certainly considerable.

Wave Deformation Model in Orthogonal Curvilinear Coordinate System around the Coastal Structure (파향선 좌표계에 의한 해암구조물 주변에서의 파랑변형 모형)

  • 이동수;이종섭;장선덕
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.1 no.1
    • /
    • pp.22-30
    • /
    • 1989
  • Wave propagation is changed by the effect of shoaling, current-depth refraction and shelter-ing etc. To solve these problems. numerous models have been developed. In the present study, a coordinate system is proposed based on the wave ray equation with the wave number equation including diffraction effects . The governing equation for the study was derived from the mild slope wave equation in non-steady state, including current effects (Kirby, 1986a) and trans-formed into an orthogonal curvilinear coordinate system on the basis of the wave ray equation. To obtain a numerical solution, an explicit finite difference scheme was used, and solved by the relaxation method. This model was tested for various cases: Firstly a submersed circular shoal and a constant unit depth. Secondly a submerged elliptic shoal on a slope, and finally a breakwater harbour with obliquely incident waves on a slope. The model was found to simulate the experimental results and other theoretical results in wave height and wave angle fairy well, and the applicability of the model around an arbitrary shaped coastal structure was also verified. To demonstrate the general usefullness of the present approach , the model is to be applied to a field situation with a complex bed topography.

  • PDF

A Business System Analysis Model with Extended Entity Concept (확장된 개체 개념의 비즈니스 시스템 분석 모델)

  • Lee, Seo-Jeong;Ko, Byung-Sun;Choi, Mi-Sook;Park, Jai-Nyun
    • Journal of KIISE:Software and Applications
    • /
    • v.28 no.12
    • /
    • pp.885-895
    • /
    • 2001
  • Existing system analysis models suggest various ideas to present entity relations and event flows for consistency between analysis and design paradigms. However, they are preferred to derive and arrange related entities on system flow than to identify entities. To identify entities systematically is a basic and important work of software development, and identified entities can be major assets of business system. In case of business systems the business rules or the computed or derived information like attendance lists of lecture system can be the most important system assets. The management information or meta data are also. In this paper, we suggest a business system analysis models to derive and present entities. System is identified entities, interfaces and event or behaviors through this model then entities are extended to independent entities, dependent entities, which are dependent to independent entities, constraint shows the physical and administrative notices. Various entity identification can reduce the incompleteness of entity analysis.

  • PDF

Boussinesq Modeling of a Rip Current at Haeundae Beach (Boussinesq 방정식 모형을 이용한 해운대 이안류 수치모의)

  • Choi, Jun-Woo;Park, Won-Kyung;Yoon, Sung-Bum
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.23 no.4
    • /
    • pp.276-284
    • /
    • 2011
  • The rip current occurred at Haeundae beach was numerically investigated under directional random wave environment. The numerical simulation was performed using a fully nonlinear Boussinesq equation model, FUNWAVE which is capable of simulating nearshore circulation since it includes the effect of wave-induced momentum flux and horizontal turbulent mixing. The results of numerical simulation show the time-dependent evolution of the wave-induced nearshore circulation system (including rip current) that are caused by nonlinear transformation of directional irregular waves due to unique topography of Haeundae. From the results, it was found that rip current is well generated and developed where relatively lower wave height and relatively deeper water depth along the longshore direction, and sudden and strong events of rip current were observed.

Air-tightness Evaluation of Tube Structures for Super-speed Tube Railway Systems: I. Analytical Modeling and Material Test (초고속 튜브철도 시스템을 위한 튜브 구조물의 기밀성 평가 : I. 해석모델 수립 및 재료 기밀성)

  • Park, Joo-Nam;Nam, Seong-Won;Kim, Lee-Hyeon;Yeo, In-Ho
    • Journal of the Korean Society for Railway
    • /
    • v.14 no.2
    • /
    • pp.143-150
    • /
    • 2011
  • This paper presents a preliminary study for air-tightness evaluation of vacuum tube structures for super-speed tube railway systems. The formula for flow rate of the air caused by the pressure difference of the inside and outside of the tube structure is derived based on Darcy's law. A test is then performed to measure the air-permeability of concrete with various compressive strengths, the result of which is used for analytical simulation of the air intrusion for a tube structure with a preliminarily defined section. It has been shown that concrete with the compressive strength of at least more than 50MPa is recommended for effective operation and maintenance of the vacuum pump systems, as the air-permeability of concrete is inversely proportional to the exponent of its compressive strength.

Development of Human Papillomavirus DNA Array by Using Lateral Flow Membrane Assay (Lateral Flow Membrane를 이용한 인유두종 바이러스 DNA Array의 개발)

  • Kim, Ki-Whang;Lee, Hyung-Ku;Cho, Hong-Bum
    • Korean Journal of Microbiology
    • /
    • v.44 no.4
    • /
    • pp.346-351
    • /
    • 2008
  • This study develops DNA array which can detect specific sequence of human papilomavirus (HPV) by using lateral flow membrane assay which is usually used for point of care test including pregnant diagnosis. Principle of HPV DNA array is as follow; fixing DNA probe which is peculiar to HPV type 6, 11, 16, 18, 31, 45 on a surface of lateral flow membrane and inducing hybridization response between probe and HPV PCR products which is obtained by using biotin-labeled MY09/l1 primers. And then, we can see the result of DNA hybridization that streptavidin labelled colloidal gold is responded with hybrid biotin. Lateral flow membrane array developed in this study confirms major HPV type economically and conveniently compared with existing HPV DNA chip method.

Study of Application of Impulse Turbine with Staggered Blades to Improve the Performance for Wave Energy Conversion (파력발전용 임펄스터빈의 효율 향상을 위한 Staggered Blade의 적용에 대한 연구)

  • Moon, Jae-Seung;Shin, Seung-Ho;Hyun, Beom-Soo;Kim, Gil-Won;Hong, Key-Yong
    • Journal of Navigation and Port Research
    • /
    • v.31 no.10
    • /
    • pp.845-852
    • /
    • 2007
  • An OWC-type Wave Energy Conversion passes through 3 steps energy conversion process. This paper deal with the impulse turbine with staggered blade to improved performance by numerical analysis using commercial CFD code, FLUENT Maximum value of axial airflow velocity during exhalation is higher than that during inhalation This paper deal with special-type of Impulse Turbine so-called "Staggered Blade" for more efficiency to making air flow direct to on pressure side. Also, this paper has proposed special-type turbine with self-pitched blade more efficient.

Physical Modelling for Consistent Reasonable Thought and Stock-Price Flow Patterns (합리적 생각의 물리적 모델링과 주가 흐름 패턴 분석)

  • Park, Sangup
    • New Physics: Sae Mulli
    • /
    • v.68 no.12
    • /
    • pp.1364-1373
    • /
    • 2018
  • A recognizable form having meaning is called a sign in semiotics. The sign is transformed into a physical counter form in this work. Its internal structure is restricted on the linguistic concept structure. We borrow the concept of a mathematical function from the utility function of a rational personal in the economy. Universalizing the utility function by introducing the consistency of independency on the manner of construction, we construct the probability. We introduce a random variable for the probability and join it to a position variable. Thus, we propose a physical sign and its serial changes in the forms of stochastic equations. The equations estimate three patterns (jumping, drifting, diffusing) of possible solutions, and we find them in the one-day stock-price flow. The periods of jumping, drifting and diffusing were about 2, 3.5, and 6 minutes for the Kia stock on 11/05/2014. Also, the semiotic sign (icon, index, symbol) can be expected from the equations.

A Study on the Paradigm Phenomenon of Traditional Dance - Focusing on the Jinsoechum by Lee Dong An (전통춤의 전승 패러다임 현상에 관한 연구 - 이동안류 진쇠춤을 중심으로)

  • Bong, Jung-Min;Choi, Ji-Won
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.5
    • /
    • pp.961-969
    • /
    • 2021
  • In the historical trend of Korean dance, Korean traditional dance continues to evolve through the transition to stage dance due to the modernization process, the tangibleization of traditional dance, the reconstruction or re-creation of traditional dance. Moreover, the trend of reconstruction and re-creation of traditional Korean dances has been common in traditional dance performances since the 2000s, with two directions: performance of original restoration and preservation and evolution of traditional dances. Therefore, this study is a study of the change in the form of traditional dance and the process of the evolution of traditional dance, and among them, the change of the traditional paradigm of the Lee Dong-an Ryu Jin-so dance. The paradigm shift of traditional dance was staged through the trend of the times to the extent that the original's meaning and form were not undermined, and we can recognize that the paradigm of traditional dance is a way of introducing new aspects as a way of transmission.