• 통합자연과학논문집
• /
• 제11권2호
• /
• pp.76-81
• /
• 2018

Robust design is an approach to reducing performance variation of quality characteristic values in quality engineering. Product array approach which is used in the Taguchi parameter design has a number of advantages by considering the noise factor. Taguchi has an idea that mean and variation are handled simultaneously to reduce the expected loss in products and processes. Taguchi has used the signal-to-noise ratio (SN) to achieve the appropriate set of operating conditions where variability around target is low in the Taguchi parameter design. Many Statisticians criticize the Taguchi techniques of analysis, particularly those based on the SN. In this paper we propose a substantially simpler optimization procedure for robust design using desirability function without resorting to SN.

• 한국염색가공학회:학술대회논문집
• /
• 한국염색가공학회 2008년도 제39차 학술발표회
• /
• pp.115-116
• /
• 2008

The textile wastewater discharged from printing and dyeing processes is characterized by high chemical oxygen demand(COD), low biochemical oxygen demand(BOD), and heavy color. The release of dyes into the environment constitutes only small proportion of water pollution, but dyes are visible in small quantities due to their brilliance. In this study, We are investigated to optimization of Ozone Oxidation process for Decolorization.

• 전산구조공학
• /
• 제9권3호
• /
• pp.157-167
• /
• 1996

본 연구에서는 Boland C언어를 사용하여 최적설계 수행에 필요한 작업을 쉽게 수행할 수 있는 전처리기와 후처리기를 개발하였다. 전처리기는 선택된 최적설계 알고리즘에 필요한 입력 데이터나 서브루틴 작성을 도와준다. 후처리기에서는 반복 계산중에 생성된 수치값을 그래프로 도시해 줌으로써 문제에 대한 전반적인 파악이 가능하도록 하였다. 수치예제는 선형문제와 삼부재 구조물에 대해서 제시하였다.

• International Journal of Precision Engineering and Manufacturing
• /
• 제9권4호
• /
• pp.51-56
• /
• 2008

Thermoforming is one of the most versatile and economical processes available for shaping polymer products, but obtaining a uniform thickness of the final product using this method is difficult. Heater power adjustment is very important because the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the steady-state optimum distribution of heater power is first ascertained by a numerical optimization to obtain a uniform sheet temperature. The time-dependent optimal heater input is then determined to decrease the temperature difference through the direction of the thickness using the response surface method and the D-optimal method. The optimal results show that the time-dependent optimum heater power distribution gives an acceptable uniform sheet temperature in the forming temperature range by the end of the heating process.

• 소성∙가공
• /
• 제12권4호
• /
• pp.340-347
• /
• 2003

In the rigid-plastic finite element simulation of hot forging processes using hexahedral mesh, remeshing of a flash is important for design and control of the process to obtain desirable defect-free products. The mesh compression method is a remeshing technique which enables the construction of an effective hexahedral mesh in the flash. However, because the mesh is distorted during the compression procedure of the mesh compression method, when it is used in resuming the analysis, it causes discretization error and decreases the conversance rate. Therefore, mesh smoothing is necessary to improve the mesh quality. In this study, several geometric mesh smoothing techniques and optimization techniques are introduced and modified to improve mesh quality. Then, the most adaptive technique is recommended for the mesh compression method.

• 소성∙가공
• /
• 제9권6호
• /
• pp.644-652
• /
• 2000

Tube hydroforming is recently drawing attention of automotive industries due to its several advantages over conventional methods. It can produce wide range of products such as subframes, engine cradles, and exhaust manifolds with cheaper production cost by reducing overall number of processes. h successful tube hydroforming depends on the reasonable combination of the internal pressure and axial load at the tube ends. This paper deals with the optimal process design of hydroforming process using the genetic algorithm and neural network. An optimization technique is used in order to minimize the tube thickness variation by determining the optimal loading path in the tube expansion forming and the tube T-shape forming process.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.1029-1034
• /
• 2004

Recent engineering process requires fast development and manufacturing of the products. This paper mainly discusses the process of rapid product development (RPD) from the reverse engineering to the optimal design. A laser scanning system scans a product and the efficient data processing method reduces the scanned point data. The reduced (scanned) points model is transformed to a finite element model without the construction of a CAD model. Since CAD modeling is a time-consuming work, skipping this step can save much time. This FE model is updated from the result based on the structural characteristics from modal test of the real model. For FE model updating, Response Surface Method is adopted. Finally, the updated FE model is optimized using the reliability-based topology optimization, which is developed recently. All these processes are applied to the design of an upper part model of a cellular phone.

• 국제초고층학회논문집
• /
• 제6권4호
• /
• pp.307-313
• /
• 2017

This paper outlines the processes and strategies studied and selected by the team during the design stages of the project for the incorporation of BIPV into the tower's façade. The goal was to create a system that helps reduce internal heating and cooling loads while collecting energy through photovoltaic panels located throughout the building. The process used to develop this façade system can be broken down into three stages. 1. Concept: BIPV as design catalyst for a high-rise building. 2. Optimization: Balancing BIPV and Human comfort. 3. Integration: Incorporating BIPV into a custom curtain wall design. The FKI Project clearly illustrates the evolution building enclosures from simple wall systems to high performance integrated architectural and engineering design solutions. This design process and execution of this project represent the design philosophy of our firm.

• Journal of the Optical Society of Korea
• /
• 제16권3호
• /
• pp.292-298
• /
• 2012

The epitaxial layer structures for blue InGaN light emitting diodes have been optimized for high brightness applications with the output power levels exceeding 1000 $W/cm^2$ by using a self-consistent finite element method. The light-current-voltage relationship has been directly estimated from the multiband Hamiltonian for wurtzite crystals. To analyze the efficiency droop at high injection levels, the major nonradiative recombination processes and carrier spillover have also been taken into account. The wall-plug efficiency at high injection levels up to several thousand $A/cm^2$ has been successfully evaluated for various epilayer structures facilitating optimization of the epitaxial structures for desired output power levels.

• 산업경영시스템학회지
• /
• 제34권2호
• /
• pp.112-120
• /
• 2011

The early phase of design intrinsically contains multiple sources of uncertainty in describing design, and nevertheless the decision-making process at this phase exerts a critical effect upon drawing a successful design. This paper proposes a set-based design approach for multi-objective design problem under uncertainty. The proposed design approach consists of four design processes including set representation, set propagation, set modification, and set narrowing. This approach enables the flexible and robust design while incorporating designer's preference structure. In contrast to existing optimization techniques, this approach generates a ranged set of design solutions that satisfy changing sets of performance requirements.