• Journal of KIISE:Software and Applications
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• v.34 no.3
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• pp.212-218
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• 2007

Not enough verification or enough design of test is not performing in many software developments organization as yet. Therefore, defects that can be detected and corrected during the beginning phases of development are usually found during dynamic testing, it is often observed that testing is inefficient compared to effort for testing. This study aims to suggest a method for effective testing through case study. It is useful in case of not verification and not enough design of test in the previous phase than coding. We show in a concrete way major activities that determine prioritization of testing and level of test case design through static testing, i.e. code review and analysis of code quality. And also we show role between test team and development team.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.1
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• pp.82-89
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• 2001

This paper proposes several methods to analyze dynamic and static characteristics of HVDC inverter system. The characteristic analysis is essential of the controller and filter design of the HVDC inverter system. Dynamic characteristic can be analyzed with EMTP simulation and static characteristic can be obtained by solving newly proposed load flow equation which includes the filter and load characteristic. New simple per-phase-equivalent circuit is also proposed. In this circuit, HVDC inverter is considered as a current source depending on the on-off status of switch. Dynamic and static characteristic can be analyzed by the proposed per-phase-equivalent circuit. For the optimal filter design, various performance criteria are proposed. The performance index, based on the per-phase-equivalent circuit, is calculated. Voltage harmonics and filter power loss are selected as criteria. Optimization procedure is explained to find optimal passive filter parameters.

• Earthquakes and Structures
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• v.14 no.6
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• pp.505-523
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• 2018

Static pushover analyses of typical existing reinforced concrete frames, designed according to the previous generations of design codes in Greece, have established these structures' inelastic characteristics, namely overstrength, global ductility capacity and available behaviour factor q, under planar response. These were compared with the corresponding demands at the collapse limit state target performance point. The building stock considered accounted for the typical variability, among different generations of constructed buildings in Greece, in the form, the seismic design code in effect and the material characteristics. These static pushover analyses are extended, in the present study, in the time history domain. Consequently, the static analysis predictions are compared with Incremental Dynamic Analysis results herein, using a large number of spectrum compatible recorded base excitations of recent destructive earthquakes in Greece and abroad, following, for comparison, similar conventional limiting failure criteria as before. It is shown that the buildings constructed in the 70s exhibit the least desirable behaviour, followed by the buildings constructed in the 60s. As the seismic codes evolved, there is a notable improvement for buildings of the 80s, when the seismic code introduced end member confinement and the requirement for a joint capacity criterion. Finally, buildings of the 90s, designed to modern codes exhibit an exceptionally good performance, as expected by the compliance of this code to currently enforced seismic provisions worldwide.

• Journal of Power System Engineering
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• v.9 no.3
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• pp.33-38
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• 2005

The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this paper is to investigate the effects of a rear-guider and a stabilizer on the aerodynamic performance of a cross-flow fan. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. This experiment was carried out with a constant revolution number of 700 rpm in a cross-flow fan installed in the fan tester. The static pressure, flowrate, torque, and revolution number were measured in this paper. Also, the pressure coefficient and the efficiency were analysed according to the various assembly conditions using a stabilizer setup angle, a stabilizer clearance, and a rear-guider clearance in the indoor room air-conditioner.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.5
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• pp.103-111
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• 2008

This study proposes a technique to estimate the material property of a paper by using an experimental methods and commercial CAE software. Under gravitation, if one side of the paper is attached to the ground, the opposite side of paper is largely deformed, and vibrates freely. Since the paper has an orthotropic characteristic due to its treatment, the deformations in two orthogonal directions of the dry paper are different. An experimental method to measure the static deformation of the paper introduces this phenomenon. And dynamic behavior, frequency of free vibration is measured. And then. virtual prototypes that can represent the static and dynamic behavior are modeled by using the commercial CAE software $RecurDyn^{MT}$/MTT3D, which has been widely used by the printer makers. While comparing the deformation and frequency from the experiment and simulation, a design optimization technique in the commercial CAE software of R-INOPL, $RecurDyn^{TM}$/AutoDesign is used to estimate the material property such as Young's modulus, shear modulus and density of the paper.

• Wind and Structures
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• v.17 no.5
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• pp.495-513
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• 2013

Thin, high-strength steel roof cladding is widely used in residential and industrial low-rise buildings and is susceptible to failure during severe wind storms such as cyclones. Current cladding design is heavily reliant on experimental testing for the determination of roof cladding performance. Further study is necessary to evolve current design standards, and numerical modelling of roof cladding can provide an efficient and cost effective means of studying the response of cladding in great detail. This paper details the development of a numerical model that can simulate the static response of corrugated roof cladding. Finite element analysis (FEA) was utilised to determine the response of corrugated cladding subject to a static wind pressure, which included the anisotropic material properties and strain-hardening characteristics of the thin steel roof cladding. The model was then validated by comparing the numerical data with corresponding experimental test results. Based on this comparison, the model was found to successfully predict the fastener reaction, deflection and the characteristics in deformed shape of the cladding. The validated numerical model was then used to predict the response of the cladding subject to a design cyclone pressure trace, excluding fatigue effects, to demonstrate the potential of the model to investigate more complicated loading circumstances.

• Archives of Plastic Surgery
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• v.46 no.4
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• pp.386-389
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• 2019

The development of breast implant technology continues to evolve over time, but changes in breast shape after implantation have not been fully elucidated. Thus, we performed computerized finite element analysis in order to better understand the trajectory of changes and stress variation after breast implantation. The finite element analysis of changes in breast shape involved two components: a static analysis of the position where the implant is inserted, and a dynamic analysis of the downward pressure applied in the direction of gravity during physical activity. Through this finite element analysis, in terms of extrinsic changes, it was found that the dimensions of the breast implant and the position of the top-point did not directly correspond to the trajectory of changes in the breast after implantation. In addition, in terms of internal changes, static and dynamic analysis showed that implants with a lower top-point led to an increased amount of stress applied to the lower thorax. The maximum stress values were 1.6 to 2 times larger in the dynamic analysis than in the static analysis. This finding has important implications for plastic surgeons who are concerned with long-term changes or side effects, such as bottoming-out, after anatomic implant placement.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.974-987
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• 2021

This paper presents ductile fracture simulation of full-scale cracked pipe for nuclear piping materials using the cohesive zone model (CZM). The main objective of this study is to investigate the applicability of CZM to predict ductile fracture of cracked pipes with various crack shapes and under quasi-static/dynamic loadings. The transferability of the traction-separation (T-S) curve from a small-scale specimen to a full-scale pipe is demonstrated by simulating small- and full-scale tests. T-S curves are calibrated by comparing experimental data of compact tension specimens with finite element analysis results. The calibrated T-S curves are utilized to predict the fracture behavior of cracked pipes. Three types of full-scale pipe tests are considered: pipe with circumferential through-wall crack under quasistatic/dynamic loadings, and with 360° internal surface crack under quasi-static loading. Computational results using the calibrated T-S curves show a good agreement with experimental data, demonstrating the transferability of the T-S curves from small-scale specimen.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.190-196
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• 2009

This study proposes a structural design method for the upper control arm installed at the rear side of a SUV. The weight of control arm can be reduced by applying the design and material technologies. In this research, the former includes optimization technology, and the latter the technologies for selecting aluminum as a steel-substitute material. Strength assessment is the most important design criterion in the structural design of a control arm. At the proto design stage of a new control arm, FE (finite element) analysis is often utilized to predict its strength. This study considers the static strength in the optimization process. The inertia relief method for FE analysis is utilized to simulate the static loading conditions. According to the classification of structural optimization, the structural design of a control arm is included in the category of shape optimization. In this study, the kriging interpolation method is adopted to obtain the minimum weight satisfying the strength constraint. Optimum designs are obtained by ANSYS WORKBENCH and the in-house program, EXCEL-kriging program. The optimum results determined from the in-house program are compared with those of ANSYS WORKBENCH.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.1 s.47
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• pp.9-16
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• 2006

The design practice of the lateral resisting system has been traditionally dependent on the experience and know-how of a structural engineer. And the method to reflect the evaluation results of building's capacity on design process doesn't exist. The proposal of a rational design of the lateral load resisting system is based on the available full capacity $(R_{ac})$ of a building and the minimum required capacity $(R_{code})$ suggested in the code. This study suggests thai nonlinear static analysis, which is the estimation of the lateral capacity with the pushover analysis, be included in the existing design procedure of the structure. After finishing the basic structural design, the lateral resisting capacity ol a building is estimated. At the phase of nonlinear static analysis, pushover analysis is peformed to define the fully yielded baseshear $(V_Y)$. When the design wind baseshear $(V_{wind})$ is bigger than the design seismic baseshear $(V_D)$, the value is checked to determine whether or not it is smaller than the $V_Y$. After confirming that it is smaller, the $R_{ac}$ of the structure is computed. If the $V_D$ is bigger at first, only the $R_{ac}$ is computed. When the value of the estimation shows remarkable differences with the $R_{code}$, repetition of the design modification is needed for those approximate to the $R_{code}$. Application of the proposed design procedure to 2-D steel braced RC buildings has proven to be efficient.