• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.957-964
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• 2004

The selected structure for the value engineering review is one section of cut and cover tunnel for Seoul Subway Line 9. The primary focus of the review is on the optimisation of the structures to save cost on the existing Line 9 contracts through variation of the design criteria as it affects the permanent works. This is to be achieved through comparison with design criteria for other selected international subways. Criteria resulting from the review must not compromise public safety and durability for the 100 year design life.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.135-136
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• 2017

In this paper, a spiral inductor is designed and its inductance is calculated by the expended Grover method. To verify this, a rectangular planar inductor is printed by inkjet printer using conductive ink and the calculated inductance value is compared with its measured value.

• 대한기계학회논문집A
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• 제39권1호
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• pp.111-115
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• 2015

핫 러너를 이용한 사출 공정에서는, 색교체가 중요한 문제이다. 이 연구는 열가소성 수지의 색교체 특성을 평가할 수 있는 방법을 제시하고자 한다. 캐필러리 다이를 이용하여 색교체도를 평가할 수 있는 방법을 고안하고 구현한다. 캐필러리 다이로부터의 토출물을 영상화하여, 회색음영으로 정량화하였다. 그 음영도를 기반으로 하여, 색교체도를 결정하였다. 주어진 온도와 토출 속도에서, 색교체도가 토출회수에 따라 변화하는 추이를 얻어 내고 분석하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.755-756
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• 2006

In this paper, We design the high performance 2D product Iterative decoder using three different external value design. We improved the external value operation in two ways to reduce the delay and speed. In this proposed operation, each design has been simulated on Matlab and MaxPlusII, and implemented on the FPGA to measure their performance.

• Structural Engineering and Mechanics
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• 제17권3_4호
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• pp.539-556
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• 2004

In this paper, the design, fabrication and characterization of a piezoelectric friction damper are presented. It was sized with the proposed practical procedure to minimize the story drift and floor acceleration of an existing 1/4-scale, three-story frame structure under both near-fault and far-field earthquakes. The design operation friction force in kip was numerically determined to range from 2.2 to 3.3 times the value of the peak ground acceleration in g (gravitational acceleration). Experimental results indicated that the load-displacement loop of the damper is nearly rectangular in shape and independent of the excitation frequency. The coefficient of friction of the damper is approximately 0.85 when the clamping force on the damper is above 400 lbs. It was found that the friction force variation of the damper generated by piezoelectric actuators with 1000 Volts is approximately 90% of the expected value. The properties of the damper are insensitive to its ambient temperature and remain almost the same after being tested for more than 12,000 cycles.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.116-118
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• 2014

A shape optimization problem is formulated to optimally design aluminum sandwich panel, which is used for high speed railway vehicle. An aluminum volume used in the panel is selected as a design objective with constraints on the stiffness and the transmission loss value. The formulated shape optimization problem is solved for a well -selected initial shape. The stiffness and transmission loss value of the obtained optimal shape are compared with those of the previously-reported panel.

• Structural Engineering and Mechanics
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• 제23권1호
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• pp.29-42
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• 2006

This paper describes the design scheme of the three-dimensional structures based on the concept of the cellular automata simulation. The cellular automata simulation is performed according to the local rule. In this paper, the local rule is derived in the mathematical formulation from the optimization problem. The cell density is taken as the design variable. Two objective functions are defined for reducing the total weight of the structure and obtaining the fully stressed structure. The constraint condition is defined for defining the local rule. The penalty function is defined from the objective functions and the constraint condition. Minimization of the penalty function with respect to the design parameter leads to the local rule. The derived rule is applied to the design of the three-dimensional structure first. The final structure can be obtained successfully. However, the computational cost is expensive. So, in order to reduce the computational cost, the material parameters $c_1$ and $c_2$ and the value of the cell rejection criterion (CRC) are changed. The results show that the computational cost depends on the parameters and the CRC value.

• 산업경영시스템학회지
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• 제39권1호
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• pp.123-129
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• 2016

In the manufacturing industry fields, thousands of quality characteristics are measured in a day because the systems of process have been automated through the development of computer and improvement of techniques. Also, the process has been monitored in database in real time. Particularly, the data in the design step of the process have contributed to the product that customers have required through getting useful information from the data and reflecting them to the design of product. In this study, first, characteristics and variables affecting to them in the data of the design step of the process were analyzed by decision tree to find out the relation between explanatory and target variables. Second, the tolerance of continuous variables influencing on the target variable primarily was shown by the application of algorithm of decision tree, C4.5. Finally, the target variable, loss, was calculated by a loss function of Taguchi and analyzed. In this paper, the general method that the value of continuous explanatory variables has been used intactly not to be transformed to the discrete value and new method that the value of continuous explanatory variables was divided into 3 categories were compared. As a result, first, the tolerance obtained from the new method was more effective in decreasing the target variable, loss, than general method. In addition, the tolerance levels for the continuous explanatory variables to be chosen of the major variables were calculated. In further research, a systematic method using decision tree of data mining needs to be developed in order to categorize continuous variables under various scenarios of loss function.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2005년도 춘계학술대회 및 특별심포지움
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• pp.210-210
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• 2005

• 한국해양공학회지
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• 제26권4호
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• pp.77-85
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• 2012

A study was performed on the design of a mooring line to maintain the position of a floating WEC (wave energy conversion) system. The procedure to design a mooring line is set up and the safety of the designed mooring system is evaluated using commercial software, Orcaflex. The characteristics curve for one line is analyzed to determine the properties and pretension of a mooring line. While considering the ocean environmental condition and importance of a floating WEC system, a multi-line layout is determined. A 4-point mooring system with 4 lines shows the instability in the yaw motion of the floating WEC system under a designed ocean environmental condition. The redesigned 4-point mooring system with 8 lines is found to be safe on the condition of a harsh ocean environment. The floating WEC system with the redesigned mooring system also shows stable motion in surge and pitch under operating conditions. From a parametric study on the mooring line length, the extreme value of the mooring line tension is found to be very sensitive to the pretension and length of mooring line. The results of this study can contribute to the establishment of a design procedure for mooring lines.