• International Journal of Precision Engineering and Manufacturing
• /
• 제9권2호
• /
• pp.50-53
• /
• 2008

A design approach using a one-dimensional (1D) lumped model was studied and applied to an industrial inkjet printing head design for micro patterning on printed circuit boards. For an accurate analysis, a three-dimensional piezoelectric-driven actuator model was analyzed and its jetting characteristics were applied to 1Danalysis model. The performance of the 1D lumped model was verified by comparing measured and simulated results. The developed 1D model helped to optimize the design and configuration of the inkjet head and could be implemented in the design of multi-nozzle inkjet printing heads to improve the jetting frequency and minimize crosstalk.

• 한국자동차공학회논문집
• /
• 제20권3호
• /
• pp.67-76
• /
• 2012

In this paper, collision analysis of the full rake for the Next Generation High-speed EMU is conducted using a 3D/1D hybrid model, which combines 3-dimensional (3D) front-end structure of finite element model and 1-dimensional (1D) multi-body dynamics model in order to analyze train collision with a standard 3D deformable obstacle. The crush forces, passengers' accelerations and energy absorptions of a full rake train can be easily obtained through a simulation of a 1D dynamics model composed of nonlinear springs, dampers and masses. Also the obtained simulation results are very similar to those of a 3D model if an overriding behavior does not occur during collision. The standard obstacle in TSI regulation has been changed from a rigid body to a deformable body, and therefore 3D collision simulations should be conducted because their simulation results depends on the front-end structure of a train. According to the obstacle collision analysis of this study, the obstacle collides with the driver's upper structure after overriding over the front-end module. The 3D/1D hybrid model is effective to evaluate a main energy-absorbing module that is frequently changed during design process and reduce the need time of the modeling and analysis when compared to a 3D full car body.

• KSTLE International Journal
• /
• 제6권1호
• /
• pp.1-7
• /
• 2005

Wear model for predicting the vehaviour of a depth is considered in this paper. It is deduced from the energy and volume based wear models such as the Archard equation and the workrate model. A new parameter of the equivalent depth ($D_e$= wear volume /worn area) is considered for the wear model of a depth prediction. A concenpt of a dissipated shear energy density is accommodated for in the suggested models. It is found that $D_e$ can distinguish the worn area shape. A cubic of $D_e$($D_e^3$) gives a better linear regression with the volume than that of the maximmum depth $D_{max}e$($D_{max}^3$) does. Both $D_{max}$ and $D_e$ are used for the presently suggested depth-based wear model. As a result, a wear depth profile can be simulated by a model using $D_{max}$. Wear resistance from the concern of an overall depth can be identified by the wear coefficient of the model using $D_e$.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제4C권5호
• /
• pp.220-229
• /
• 2004

We have examined a technique of one-dimensional (1D) fluid modeling for radio-frequency Ar capacitively coupled plasmas (CCP) between unequal-sized powered and grounded electrodes. In order to simulate a practical CCP reactor configuration with a grounded side wall by the 1D model, it has been assumed that the discharge space has a conic frustum shape; the grounded electrode is larger than the powered one and the discharge space expands with the distance from the powered electrode. In this paper, we focus on how much a 1D model can approximate a 2D model and evaluate their comparisons. The plasma density calculated by the 1D model has been compared with that by a two-dimensional (2D) fluid model, and a qualitative agreement between them has been obtained. In addition, 1D and 2D calculation results for another reactor configuration with equal-sized electrodes have also been presented together for comparison. In the discussion, four CCP models, which are 1D and 2D models with symmetric and asymmetric geometries, are compared with each other and the DC self-bias voltage has been focused on as a characteristic property that reflects the unequal electrode surface areas. Reactor configuration and experimental parameters, which the self-bias depends on, have been investigated to develop the ID modeling for reactor geometry with unequal-sized electrodes.

• Journal of Radiation Protection and Research
• /
• 제17권1호
• /
• pp.21-30
• /
• 1992

KCCH cyclotron neutron(30cCy/min) 및 $^{60}Co\;{\gamma}-ray(210cGy/min)$를 시험관내의 정상인체 말초혈액임파구에 조사하여 염색체이상(dicentric 및 centric ring)을 관찰하고 이의 선량-반응관계식을 linear model$(Y=K_1D+a)$, power-law model$(Y=K_2D^n)$, quadratic model$(Y=K_3D^2)$ 및 linear-quadratic model$(Y={\alpha}D+{\beta}D^2)$을 사용하여 구하고 이들 model중 염색체이상의 측정치와 가장 일치하는 관계식을 근거로 하여 ${\gamma}-ray$에 대한 neutron의 relative biological effectiveness (RBE)를 산출하였다. 염색체 이상(dicentric plus centric ring)의 발생분포는 ${\gamma}-ray$의 경우 linear model(P=0.067)을 제외한 power-law model$[Y=(5.81{\pm}1.96){\times}10^6D^{1.93+0.06},\;P=0.931]$, quadratic model$[Y=(3.91{\pm}0.09){\times}10^{-6}D^2,\;P=0.972]$ 및 linear-quadratic model $[Y=(6.55{\pm}6.83){\times}10^{-5}D+(3.72{\pm}0.22){\times}10^{-6}D^2$ P=0.922]에 적합하였다 neutron의 경우 linear model $(Y=(6.12{\pm}0.17){\times}10^{-3}\;D-0.22,\;P=0.987]$에 가장 일치하였고 quadratic model (P<0.005)을 제외한 power-law model $[Y=(5.36{\pm}3.02) {\times}10^{-4}D^{1.42+0.11},\;P=0.601]$ 및 linear-quadratic model $[Y=(2.43{\pm}0.70){\times}10^{-3}D+(1.21{\pm}0.39){\times}10^{-7}D^2,\;P=0.415]$에 비교적 적합하였다. 세포당 0.1-1.5개의 염색체이상을 나타내는 neutron의 ${\gamma}-ray$에 대한 RBE는 $2.714{\pm}0.408$이었다.

• 한국CDE학회논문집
• /
• 제11권6호
• /
• pp.393-402
• /
• 2006

The purpose of this study is to develop mechanisms of nD model-based design by the combination of 2D drawing standards and 3D building models from the current 2D and text-based design. The aim of this study can be archived by defining the 2D model extension definitions for the IFC model development and harmonizing existing 2D standards. The paper examines 1) 3D Representation of Building Element and Building Services element, and 2D Model extension of IFC2X.2, 2) Basic development of additional 2D element that should be added to IFC model, and 3) mapping method between current 2D standard and IFC2.X2. Following this approach, the interoperability problem between 3D model and 2D drawing can be solved and finally an extended data model could be developed.

• Nuclear Engineering and Technology
• /
• 제54권3호
• /
• pp.1109-1114
• /
• 2022

The SMART (System-integrated Modular Advanced ReacTor) is an integral-type small modular reactor developed by KAERI (Korea Atomic Energy Research Institute). This paper discusses the feasibility and applicability of a 3D-based equivalent model using dynamic condensation method for seismic analysis of a SMART control rod drive mechanism. The equivalent model is utilized for complicated seismic analysis during the design of the SMART. While the 1D-based beam-mass equivalent model is widely used in the nuclear industry for its calculation efficiency, the 3D-based equivalent model is suggested for the seismic analysis of SMART to enhance the analysis accuracy of the 1D-based equivalent model while maintaining its analysis efficiency. To verify the suggested model, acceleration response spectra from seismic analysis based on the 3D-based equivalent model are compared to those from the 1D-based beam-mass equivalent model and experiments. The accuracy and efficiency of the dynamic condensation method are investigated by comparison to analysis results based on the conventional modeling methodology used for seismic analysis.

• 한국융합학회논문지
• /
• 제11권12호
• /
• pp.155-159
• /
• 2020

본 연구에서는 대형트럭의 판스프링의 개수에 대한 구조 해석을 수행하였다. 변형량은 4가지 모델들이 공히 작게 나왔다. Model A의 응력이 가장 큰 것으로 나타났고 Model D의 응력이 가장 작은 것으로 나타났다. Model A의 최대 응력이 Model D에 비하여 약 1.87배로 크게 나왔고 Model B에 비하여 약 1.52배 정도로 크게 나타났다. Model C와 Model D의 최대응력은 적게 나왔다. Model D가 Model C에 비하여 겹판 스프링을 한 개 더 보강한 효과로 보면 그 강도의 향상의 효과는 작게 나타났다. 따라서 겹판 스프링 3개인 Model C가 설계상 효율적이고 강도면에서도 좋다고 사료된다. 본 연구 결과를 대형트럭에서의 판스프링에 적용함으로서 판스프링의 구조 강도를 평가할 수 있고 그리고 그 결과가 대형트럭에서의 내구성이 있는 판스프링의 설계와 미적인 융합이 될 수 있다고 보인다.

• Geomechanics and Engineering
• /
• 제25권4호
• /
• pp.341-345
• /
• 2021

1D sand compression response to ko-loading experiences volume contraction from low to high effective stress regimes. Previous study suggested compressibility model with physically correct asymptotic void ratios at low and high stress levels and examined only for both remolded clays and natural clays. This study extends the validity of Enhanced Terzaghi model for different sand types complied from 1D compression data. The model involved with four parameters can adequately fit 1D sand compression data for a wide stress range. The low stress obtained from fitting parameters helps to identify the initial fabric conditions. In addition, strong correlation between compressibility and the void ratio at low stress facilitates determination of self-consistent fitting parameters. The computed tangent constrained modulus can capture monotonic stiffening effect induced by an increase in effective stress. The magnitude of tangent stiffness during large strain test should not be associated with small strain stiffness values. The use of a single continuous function to capture 1D stress-strain sand response to ko-loading can improve numerical efficiency and systematically quantify the yield stress instead of ad hoc methods.

• 한국수소및신에너지학회논문집
• /
• 제33권6호
• /
• pp.723-732
• /
• 2022

Cracking ammonia inside solid oxide fuel cell (SOFC) stack is a compact and simple way. To prevent sharp temperature fluctuation and increase cell efficiency, the decomposition reaction should be spread on whole cell area. This leading to a question that, how does anode thickness affect the conversion rate of ammonia and the cell voltage? Since the 0D model of SOFC is useful for system level simulation, how accurate is it to use equilibrium solver for internal ammonia cracking reaction? The 1D model of ammonia fed SOFC was used to simulate the diffusion and reaction of ammonia inside the anode electrode, then the partial pressure of hydrogen and steam at triple phase boundary was used for cell voltage calculation. The result shows that, the ammonia conversion rate increases and reaches saturated value as anode thickness increase, and the saturated thickness is bigger for lower operating temperature. The similar cell voltage between 1D and 0D models can be reached with NH₃ conversion rate above 90%. The 0D model and 1D model of SOFC showed similar conversion rate at temperature over 750℃.