• International journal of advanced smart convergence
• /
• 제10권1호
• /
• pp.105-116
• /
• 2021

In order to preserve the seeds of excellent Hanwoo(Korean traditional cattle) and secure quality competitiveness in the infinite competition with foreign imported beef, production of high-quality Hanwoo beef is absolutely necessary. %IMF (Intramuscular Fat Percentage) is one of the most important factors in evaluating the value of high-quality meat, although standards vary according to food culture and industrial conditions by country. Therefore, it is required to develop a %IMF estimation algorithm suitable for Hanwoo. In this study, we proposed a method of estimating %IMF of Hanwoo using CNN in ultrasound images. First, the proposed method classified the chemically measured %IMF into 10 classes using k-means clustering method to apply CNN. Next, ROI images were obtained at regular intervals from each ultrasound image and used for CNN training and estimation. The proposed CNN model is composed of three stages of convolution layer and fully connected layer. As a result of the experiment, it was confirmed that the %IMF of Hanwoo was estimated with an accuracy of 98.2%. The correlation coefficient between the estimated %IMF and the real %IMF by the proposed method is 0.97, which is about 10% better than the 0.88 of the previous method.

• Steel and Composite Structures
• /
• 제45권4호
• /
• pp.501-511
• /
• 2022

In this study, a two-dimensional model of the contact problem has been examined using the finite element method (FEM) based software ANSYS and based on the multilayer perceptron (MLP), an artificial neural network (ANN). For this purpose, a functionally graded (FG) half-infinite layer (HIL) with a crack pressed by means of two rigid blocks has been solved using FEM. Mass forces and friction are neglected in the solution. Since the problem is analyzed for the plane state, the thickness along the z-axis direction is taken as a unit. To check the accuracy of the contact problem model the results are compared with a study in the literature. In addition, ANSYS and MLP results are compared using Root Mean Square Error (RMSE) and coefficient of determination (R2), and good agreement is found. Numerical solutions are made by considering different values of external load, the width of blocks, crack depth, and material properties. The stresses on the contact surfaces between the blocks and the FG HIL are examined for these values, and the results are presented. Consequently, it is concluded that the considered non-dimensional quantities have a noteworthy influence on the contact stress distributions, and also, FEM and ANN can be efficient alternative methods to time-consuming analytical solutions if used correctly.

• 공업화학
• /
• 제17권5호
• /
• pp.458-464
• /
• 2006

팔라듐 합금 복합막의 제조는 니켈 분말과 무기화합물의 혼합물로 개질된 튜브형 다공성 스테인레스 스틸 지지체 표면 위에 무전해 도금법(elctroless plating technique)에 의해 팔라듐 - 니켈 - 은을 박막으로 도금하는 형태로 이루어졌다. 일반적인 다공성 금속 지지체는 기공이 크기 때문에 그 자체로서 도금에 적합한 지지층이 되기가 어렵고, 결함이 없는 팔라듐 복합막의 제조가 쉽지 않아 본 연구에서는 금속 지지체와 팔라듐 사이에 중간층(intermediate layer)을 형성하여 이와 같은 문제점을 극복하고자 하였다. 중간층의 소재인 실리카 졸, 알루미나 졸, 이산화티타늄 졸 등의 무기화합물과 니켈 분말의 혼합물로 다공성 금속 지지체 위에 코팅하여 박막을 형성하고 제조 조건에 따른 질소 투과도를 측정하고 비교하였다. SEM 분석법에 의해 니켈과 무기화합물 혼합물의 표면층의 형성 모습도 측정하였다. 제조된 중간층 가운데 이산화티타늄 졸과 니켈의 혼합물이 가장 낮은 질소 투과도와 치밀한 표면층을 나타내었다. 최종적으로 니켈과 실리카의 혼합 중간층으로 이루어진 팔라듐-니켈-은 합금 복합막을 제조하고 수소와 질소의 투과도를 측정하였다. 1기압 이하에서 질소에 대한 수소 선택도는 무한대였으며 수소투과 속도는 1 기압, $500^{\circ}C$에서 $1.39{\times}10^{-2}mol/m^2{\cdot}s$의 값을 나타냈다.

• 전자공학회논문지A
• /
• 제29A권11호
• /
• pp.19-24
• /
• 1992

In this paper, a high frequency method is developed which combines the uniform Geometrical Theory of Diffraction(GTD) and the Aperture Integration(AI) to analyze electromagnetic plane wave scattering by a perfectly-conducting, open-ended, semi-infinite parallel plate waveguide with a uniform layer of absorbing material on its inner wall, and with a slanted planar termination inside. In this method, first, the field of an arbitary point inside the paraller plate waveguide is computed by the GTD. Second, the field scattered into exterior region by the waveguide is found using the equivalent current, which can be obtaind from the aperture field of the waveguide and using the AI. Numerical results based on this GTD method are presented and compared with those based on the mode matching method.

• Journal of Computational Design and Engineering
• /
• 제3권4호
• /
• pp.330-336
• /
• 2016

The present work is concerned with heat and mass transfer of an electrically conducting second grade MHD fluid past a semi-infinite stretching sheet with convective surface heat flux. The analysis accounts for thermophoresis and thermal radiation. A similarity transformations is used to reduce the governing equations into a dimensionless form. The local similarity equations are derived and solved using Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. Results for various flow characteristics are presented through graphs and tables delineating the effect of various parameters characterizing the flow. Our analysis explores that the rate of heat transfer enhances with increasing the values of the surface convection parameter. Also the fluid velocity and temperature in the boundary layer region rise significantly for increasing the values of thermal radiation parameter.

• 대한수학회보
• /
• 제38권2호
• /
• pp.337-346
• /
• 2001

A linearization owing to Oseen originally is performed to study the recirculating Navier-Stokes flows at high Reynolds numbers. The procedure is generalized to produce higher order asymptotic expansion for the flow velocity. We call this the Oseen-type expansion of the given flow. As a concrete example, the velocity of a steady Navier-Stockes flow due to a swimming flexible sheet in two-dimensional infinite strip domain is calculated by an asymptotic expansion technic with two-parameters, the Reynolds number R and the perturbation parameter $\varepsilon$ first and then R secondly. The asymptotic result is up to second order in $\varepsilon$.

• 설비공학논문집
• /
• 제13권3호
• /
• pp.145-152
• /
• 2001

Low Rayleigh number thermal convection in a fluid layer confined between two-infinite horizontal walls kept at spatially sinusoidal temperature distributions, T_L=T_m+\Delta T\sin \kappax,\;T_U=T_m+\Delta T\sin(\kappax-\beta)$, is theoretically investigated by a regular perturbation expansion method. For small wave numbers, an upright cell is formed between the two walls at $\beta$=0. The cell is tilted, as the phase difference increases, and a flow with tow counter-rotating eddies occurs at $\beta=\pi$. when the wave number is large, isolated eddies are formed near the lower and upper walls, for all the phase differences. There exists a wave number at which maximum heat transfer rate at the walls occurs, at each of the phase differences. And the wave number increases with increase of the phase difference. for a fixed wave number, the heat transfer rate decrease with increase of the phase difference.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제11권1호
• /
• pp.57-70
• /
• 2007

The effects of variable viscosity, blowing or suction on mixed convection flow of a viscous incompressible fluid past a semi-infinite horizontal flat plate aligned parallel to a uniform free stream in the presence of the wall temperature distribution inversely proportional to the square root of the distance from the leading edge have been investigated. The equations governing the flow are transformed into a system of coupled non-linear ordinary differential equations by using similarity variables. The similarity equations have been solved numerically. The effect of the viscosity temperature parameter, the buoyancy parameter and the blowing or suction parameter on the velocity and temperature profiles as well as on the skin-friction coefficient and the Nusselt number are discussed.

• 한국초전도학회:학술대회논문집
• /
• 한국초전도학회 2004년도 High Temperature Superconductivity Vol.XIV
• /
• pp.8-8
• /
• 2004

• 전자공학회논문지S
• /
• 제34S권9호
• /
• pp.23-30
• /
• 1997

In this paper, a decision feedback recurrent neural equalization (DFRNE) scheme is proposed for adaptive equalization problems. The proposed equalizer models a nonlinear infinite impulse response (IIR) filter. The modified Real-Time recurrent Learning Algorithm (RTRL) is used to train the DFRNE. The DFRNE is applied to both linear channels with only intersymbol interference and nonlinear channels for digital video cassette recording (DVCR) system. And the performance of the DFRNE is compared to those of the conventional equalizaion schemes, such as a linear equalizer, a decision feedback equalizer, and neural equalizers based on multi-layer perceptron (MLP), in view of both bit error rate performance and mean squared error (MSE) convergence. It is shown that the DFRNE with a reasonable size not only gives improvement of compensating for the channel introduced distortions, but also makes the MSE converge fast and stable.