• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.946-949
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• 2006

This study is a trial to make a design chart of sound insulation for multiple panel. Dilatational frequency, ${\Large f}_d$ becomes a key factor for optimal design since it acts like a turning point in sound insulation performance of such panels. Hence, in tuning the ${\Large f}_d$ optimally, elastic modulus of core material and thickness of the skin panel is designated to parameters. Based on these parameter, a design chart of sound insulation for multiple panel is made. Its applicability is proved by the case study of High noise reduction panel.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.361.2-361
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• 2002

Substructures position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics. In conventional SDM (structural dynamics modification) method, the layout of modifying substructures position is first fixed and at that condition the structural optimization is performed by using the substructures size and/or material property as design parameters. But in this paper as a design variable substructures global translational and rotational position is treated. (omitted)

• Transactions on Electrical and Electronic Materials
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• 제17권6호
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• pp.311-316
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• 2016

Batteries are critical components of electric vehicles and energy storage systems. The connection of a battery to the power grid for charge and discharge greatly affects energy storage. Therefore, an accurate and easy-to-observe battery model should be established to achieve systematic design, simulation, and SOC (state of charge) estimations. In this review, several equivalent circuit models of representative significance are explained, and their respective advantages and disadvantages are compared to determine and outline their reasonable applications to Li-ion batteries. Numerous commonly used model parameter identification principles are summarized as well, and basic model verification methods are briefly introduced for the convenient use of such models.

• Advances in Computational Design
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• 제7권3호
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• pp.211-227
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• 2022

In this research, the size-dependent impact of an embedded piezoelectric nanoplate subjected to in-plane loading on free vibration characteristic is studied. The foundation is two-parameter viscoelastic. The nonlocal elasticity is employed in order to capture the influence of size of the plate. By utilizing Hamilton's principle as well as the first- order shear deformation theory, the governing equation and boundary conditions are achieved. Then, using Navier method the equations associated with the free vibration of a plate constructed piezoelectric material under in-plane loads are solved analytically. The presented formulation and solution procedure are validated using other papers. Also, the impacts of nonlocal parameter, mode number, constant of spring, electric potential, and geometry of the nanoplate on the vibrational frequency are examined. As this paper is the first research in which the vibration associated with piezoelectric nanoplate on the basis of FSDT and nonlocal elasticity is investigated analytically, this results can be used in future investigation in this area.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.415-415
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• 2007

In this study. it was investigated about optical simulation in direct-type backlight design. Direct-type backlight has been used high-brightness backlight such as LCD television application. The key parameter in designing direct-type backlight was consists of three geometrical dimension such as the distance of two lamps. the gap of lamp and reflection plate and the number of lamps. It has many variation in optical design and it causes the different properties in backlight system. It shows the best values of above parameters; 26mm of the distance of two lamps. 4.5mm of the gap of lamp and reflection plate and 16 lamps. And we produced the specimen as above condition. and acquired good result in backlight such as the value of the brightness is 6436 nit in center of emission area and less than 5% in brightness uniformity. It shows the effective ways of designing backlight system using optical simulation method.

• 한국기계가공학회지
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• 제18권4호
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• pp.34-40
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• 2019

We performed shape optimization of an anti-vibration rubber assembly which is used in the field option cabin of agricultural tractors to improve the vibration isolation capability. To characterize the hyper-elastic material property of rubber, we performed uniaxial and biaxial tension tests and used the data to calibrate the material model applied in the finite element analyses. We conducted a field test to characterize the input excitation from the tractor and the output response at the cabin frame. To account for the nonlinear behavior of rubber, we performed static analyses to derive the load-displacement curve of the anti-vibration rubber assembly. The stiffness of the rubber assembly could be calculated from this curve and was input to the harmonic analyses of the cabin. We compared the results with the test data for verification. We utilized Taguchi's parameter design method to determine the optimal shape of the anti-vibration rubber assembly and found two distinct shapes with reduced stiffness. Results show that the vibration at the cabin frame was reduced by approximately 35% or 47.6% compared with the initial design using the two optimized models.

• Advances in materials Research
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• 제6권1호
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• pp.79-91
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• 2017

In the present work, a design of experiment (DOE) technique using Taguchi method, has been applied to optimize the properties of ODS tungsten heavy alloys(WHAs). In this work Taguchi method involves nine experiments groups for four processing parameters (compaction pressure, sintering temperature, binding material type, and oxide type) with three levels was implemented. The signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to obtain the optimal process parameter levels and to analyze the effect of these parameters on density, electrical conductivity, hardness and compressive strength values. The results showed that all the chosen factors have significant effects on all properties of ODS tungsten heavy alloys samples. The density, electrical conductivity and hardness increases with the increase in sintering temperature. The analysis of the verification experiments for the physical properties (density and Electrical conductivity) has shown that Taguchi parameter design can successfully verify the optimal parameters, where the difference between the predicted and the verified values of relative density and electrical conductivity is about 1.01% and 1.15% respectively.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.87-90
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• 2005

The drawbead is used to control the material flow into the die and increase the forming quality during the binder wrap process and the stamping process in the sheet metal forming. Drawbead restraining force (DBRF) is controlled by geometrical parameters and influenced by process parameters such as friction coefficient and blank thickness. In order to inspect the effect of process parameters, parameter studies are performed with the variation of parameters using finite element model of drawbead which is utilized reliably for the calculation of the drawbead restraining force. Drawbead analysis is carried out with 2-D plane-strain element and 3-D shell element. After the verification of the accuracy of the drawbead model with 3-D shell element, it is utilized to the prediction and the investigation of the effect of process parameters. The result of parameter studies can be utilized to the die design in the tryout stage.

• 한국가스학회지
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• 제25권6호
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• pp.14-21
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• 2021

-162℃ 초저온 상태의 LNG를 저장하는 저장탱크의 내조는 균열과 같은 결함에 대한 구조 건전성 평가가 필요하다. 전통적인 파괴역학 관점에서는 응력확대계수 K, J-적분 그리고 CTOD를 이용한 단일 매개변수 평가가 주로 수행되어왔다. 그러나 실제 구조에서 발생되는 균열선단은 구조물의 크기, 시편형상 그리고 인장과 굽힘과 같은 하중의 형태에 따라 구속효과의 차이로 인한 영향이 발생하게 된다. 단일 매개변수 파괴역학을 보완하기 위해 다양한 시도가 있었고, 대표적으로 Q-응력법이 있다. 본 논문에서는 비선형 탄성영역의 균열선단 응력장 평가에 적합한 J적분에 Q응력을 유도하여 2 매개변수 접근법을 사용하고자 한다. SENB 시편의 균열비 0.1~0.7 그리고 광폭시편 균열비 0.2~0.6에 시편 균열선단의 응력을 J-Q 평가법을 이용하여 구속효과를 정량적으로 평가 하였다.

• 한국공간구조학회논문집
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• 제7권3호
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• pp.87-95
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• 2007

The recent completions of free-form spatial structures provide us a very attractive form. To realize such an extraordinary shape, it is absolutely necessary that the connector systems have to be investigated the characteristics of the systems and analyzed with a practicable method. In this context, this research consists of not only literature research but also numerical analysis with selected connector systems, which was adopted in real free-form spatial structures. For numerical analysis, especially, finite element analysis (FEA) is performed with a various test parameter using a commercial program ANSYS. Consequently, the general characteristics of node connectors the moment-rotation-curves are presented by considering a large deformation effect as well as a multi-linear material properties.