• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.1
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• pp.24-32
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• 2016

The mortality rate of car-pedestrian accidents is quite high, compared to the frequency of accidents. Researches on pedestrian protection are being actively performed worldwide. The A-pillar and lower part of the wind shield cause the most serious damage to the pedestrians. Typical devises to protect the pedestrians are the hood lift system and pedestrian airbag. The design of such devices for an sport utility vehicle is performed based on a design process using design of experiments (DOE). The design results are obtained by an orthogonal array (OA), analysis of mean (ANOM) and analysis of variance (ANOVA). A metamodel is also used in the design process.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.3
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• pp.514-526
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• 1992

본 연구에서는 Taguchi 방법에 사용된 직교배열 이용 실험 계획법에 의한 최 적화 방법으로 보강된 복합재 쉘 구조의 좌굴강도 최적화를 수행하고 타당성을 고찰하 였다.한 방향의 압축하중을 받는 단순 지지된 복합재 평판과 Cut-out을 가진 원통 형 판넬의 보강재 및 섬유방향 최적 설계에 본 방법을 적용시켜 본 결과, 현저한 설계 개선과 아울러 각 설계 변수가 좌굴강도에 미치는 영향을 파악할 수 있었다. 특히 이 방법은 함수의 미분값을 이용한 민감도 해석대신에 함수값의 평균치 분석(ANOM)및 분산 분석(ANOVA)을 사용하기 때문에 설계변수의 변화에 덜 민감한 설계를 얻을 수 있 다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.6
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• pp.423-429
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• 2003

On this study. we improved the efficiency applying algorithm that is repeatedly using table of orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result of optimization achievement repeatedly using statistical table of orthogonal array of experimental design and the BFGS optimal design method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.8
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• pp.711-719
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• 2017

Bladeless fan is becoming increasingly popular owing to its advantages, such as improved safety, easy to clean, and attractive shape. However, many people are reluctant to purchase it because of several disadvantages, such as noise and moderate wind; therefore, research on how improve wind generation without increasing the motor speed is required. This study investigates the optimization of the shape of the nozzle and nearby surface using CFD (Computational Fluid Dynamics) simulation, ANSYS fluent. The results are analyzed by ANOM (analysis of mean) and interaction analysis; therefore this study suggests the variables of affecting Coanda effect and satisfy the govern equation, the conservation of momentum. The optimal combination was found through a predictive equation. In this study, factors and levels that affect the mass flow rate were selected and experimental points were arranged using the orthogonal array table. The value of the mass flow rate was confirmed by ANSYS fluent, which is a CFD program. Through the ANOM, it was confirmed that the nozzle distance is the most influential parameter affecting the mass flow rate. Furthermore, the mass flow rate obtained from the predictive equation and the mass flow rate from the CFD correspond to the largest values. Results from this study confirmed that the mass flow rate is increased by a change in the shape, even if the motor speed did not increase.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2952-2962
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• 2000

The design of experiment(DOE) is getting more attention in the engineering community since it is easy to understand and apply. Recently, engineering designers are adopting DOE with orthogonal arrays when they want to design products in a discrete design space. In this research, a design flow with orthogonal arrays is defined for structural design according to the general DOE. The design problem is defined as a general structural optimization problem. Sensitivity information is evaluated by the analysis of variance(ANOVA), and an optimum design is determined from analysis of means(ANOM). Interactions between design variables are investigated to achieve additivity which should be valid in DOE. When strong interactions exit, a method is proposed. Some methods to consider the problem are suggested.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.2
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• pp.83-91
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• 2003

Pantograph design Process must be considered in terms of stability of aerodynamics and reduction of aeroacoustics. Furthermore pantograph needs to be insensible to severe circumstance condition like typhoon, tunnel, a change of season. In this paper, robust design of panhead sections is conducted based on the Taguchi's design of experiment method. In the aeroacoustic noise analysis, an acoustic analogy using the Ffowcs Williams and Hawkings(FW-H) equation is used to calculate the flow induced sound pressure level in aeroacoustics. From the near-field CFD analysis data, the far-field noise is predicted at the positions of 25 m away from Pantograph. Based on aerodynamic(CFD) and aeroacoustic(FW-H) analysis data, the optimal sizing and Positioning of panhead elements are determined using robust design optimization method. Design parameters such as thickness, length and radius are controllable factors, while outdoor air temperature and atmospheric pressure are considered as uncontrollable factors in the context of Taguchi's approach. A number of CFD simulation and aeroacoustic analysis are performed based on orthogonal arrays. In this paper, two-step optimization method is used as a parameter design procedure. It is executed using signal to noise(S/N) ratio and analysis of means(ANOM) method. So Thus, an optimal level of design parameters Is extracted to minimize the disconnection ration between contact strips and catenary system, and reduce the far-field aeroacoustic noise.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.10
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• pp.1196-1203
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• 2011

Statistical optimum methodology of table of orthogonal array, ANOM, ANOVA and RSM are applied to formulate optimum allocation design with design variables. It can be minimized average SPL of control volume, the objective function in closed system by optimal allocated positions of absorbing material. Structural natural frequency and acoustic natural frequency of cavity are analyzed by FEM and BEM in the closed system. Using BEM, average SPL of specific control volume is calculated according to the condition before using absorbing material and after using it. It is shown that noise is reduced by $5.02dB_{RMS}$ by absorbing material located at optimal position and minimum $1.83dB_{RMS}$ and maximum $3.47dB_{RMS}$ by the table of orthogonal array.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1621-1626
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• 2001

The structural optimization have been carried out in the continuous design space or in the discrete design space. Methods fur discrete variables such as genetic algorithms , are extremely expensive in computational cost. In this research, an iterative optimization algorithm using orthogonal arrays is developed for design in discrete space. An orthogonal array is selected on a discrete des inn space and levels are selected from candidate values. Matrix experiments with the orthogonal array are conducted. New results of matrix experiments are obtained with penalty functions leer constraints. A new design is determined from analysis of means(ANOM). An orthogonal array is defined around the new values and matrix experiments are conducted. The final optimum design is found from iterative process. The suggested algorithm has been applied to various problems such as truss and frame type structures. The results are compared with those from a genetic algorithm and discussed.

• Computers and Concrete
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• v.13 no.4
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• pp.423-436
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• 2014

Ground Granulated Blast Furnace Slag (GGBFS) is widely used as an effective partial cement replacement material. GGBFS inclusion has already been proven to improve several performance characteristics of concrete. GGBFS provides enhanced durability, including high resistance to chloride penetration and protection against alkali silica reaction. In this paper results of an experimental research work on influence of low-reactivity GGBFS (which is largely available in Iran) on the properties of mortars and concretes are reported. In the first stage, influence of GGBFS replacement level and fineness on the compressive strength of mortars was investigated using Taguchi method. The analysis of mean (ANOM) statistical approach was also adopted to develop the optimal conditions. Next, based on the obtained results, concrete mixtures were designed and water penetration, capillary absorption, surface resistivity, and compressive strength tests were carried out on highstrength concrete specimens at different ages up to 90 days. The results indicated that 7-day compressive strength is adversely affected by GGBFS inclusion, while the negative effect is less evident at later ages. Also, it was inferred that use of low-reactivity GGBFS (at moderate levels such as 20% and 30%) can enhance the impermeability of high-strength concrete since 28 days age.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.147-149
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• 2005

On this study, we optimized maximizing thrust force of weight ratio and minimizing detent force of weight ratio at the TFLM(Transverse Flux Linear Motor) using design of experiments by the table of orthogonal array, characteristic function and analysis of means(ANOM), For two functions or more, the effectiveness of design change can be evaluated in accordance with change in design parameters. Also, The stator and mover weight of TFLM is reduced by up to 20 percent while its thrust force of weight ratio and detent force of weight improved. From now on, we are going to apply the required technique to design various uses and shares of the TFLM.