• KIEAE Journal
• /
• v.13 no.6
• /
• pp.137-143
• /
• 2013

The purpose of this study is to suggest optimum micro-filler experiment method to select the optimal particle size of earth for using in earth construction works and test this suggestion through compressive strength measurement. According to the results of selecting the method to choose the optimum micro-filler mixing of earth and sand, three-stage filling(plate tamping) showed relatively high results and so was estimated to be the proper filling method. According to the results of optimum micro-filler experiment of earth and sand by the maximal sizes of sand, between 80% and 90% showed the highest result values. The larger the maximum size of sand was, the lower the addition ratio of sand was in optimum micro-filler mixing. According to the results of compressive strength experiment by the particle sizes of earth and sand, 90% in the addition ratio of sand showed the highest results, and so tended to be similar to the results of unit volume weight experiment.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.11
• /
• pp.167-173
• /
• 2002

The look up table method conventionally applied to control the inner temperature and humidity of a laver drying machine has repeatedly occurred not only laver's damage but also inferior goods since the reaching time at the optimum state takes a long time. In this paper, a fuzzy control theory instead of the look up table was proposed to reduce the reaching time at the optimum state. The proposed method used six input variables and four output variables for the fuzzy control, and a triangle rule for a fuzzifier, The Mandani's min-max method was applied to a fuzzy inference. Also, the mean method of maximum was applied to a defuzzifier. The method applied to the fuzzy controller contributed to reduce the reaching time at the optimum state, and to minimize not only laver's damage but also inferior goods.

• Steel and Composite Structures
• /
• v.21 no.5
• /
• pp.1069-1084
• /
• 2016

This paper introduces a new and effective design amplification factor-based approach for reliable optimum design of trusses. This paper may be categorized as in the family of decoupled methods that aiming for a reliable optimum design based on a Design Amplification Factor (DAF). To reduce the computational expenses of reliability analysis, an improved version of Response Surface Method (RSM) was used. Having applied this approach to two planar and one spatial truss problems, it exhibited a satisfactory performance.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.09a
• /
• pp.395-402
• /
• 2003

Characteristics of base isolators including frictional and hysteretic types may be described by Bouc-Wen model. A probabilistic optimum design method of the base isolation system using Bouc-Wen model is presented in this paper. For optimum design, the objective function and constraints are derived based on the stochastic responses of the system. As a numerical example, the optimum design problem of a three-story base isolated shear type structure is formulated and solved by the sequential quadratic programming method.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.22 no.3
• /
• pp.27-37
• /
• 1985

The optimum design of the transverse strength member was carried out with respect to the minimum hull weight taken account of the 2-dimensional analysis by using Finite Element Method. The optimum sizes of the member such as web height, web thickness, lower flange breadth, lower flange thickness, radii, were calculated by using Hooke and Jeeves direct search method. The optimum structure satisfies requirements to allowable bending and shear stresses in each strength member. The optimum design results were compared with the practical ship design. The optimum design saves the hull weight than that of practical design amounts to 9.6% of that.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.46-48
• /
• 2007

In this study, we determined the optimum electrode pair for measuring the abdominal pressure using bio-impedance method. Because impedance changes differ from a weight, a height, contractile force, volume of muscle and blood other or whatever of individuals, it was quantified using values of impedance change, correlation coefficient and SNR. Our results showed the optimum electrode pair (1, 9) which could detect impedance changes due to an increase of the intensity of the abdominal pressure. The correlation coefficient and quadratic function between the RMS values of EMG and the impedance changes were 0.87 and $y=0.0014x^2$+0.0620x+0.6958, respectively. It demonstrated that the abdominal pressure could be measured non-invasively and simply using bio-impedance method. We propose that this optimum electrode configuration would be useful for future studies involving the convenient measurement of abdominal pressure by ambulatory urodynamics monitoring study.

• Journal of Power System Engineering
• /
• v.7 no.3
• /
• pp.29-34
• /
• 2003

Genetic algorithm is a optimization technique based on the mechanics of natural selection and natural genetics. Global optimum solution can be obtained efficiently by operations of reproduction, crossover and mutation in genetic algorithm. The authors developed a computer program which can optimize marine propulsion shafting by using binary-coded genetic algorithm and modal analysis method. In order to confirm the effectiveness of the developed computer program, we apply the program to a optimum design problem which is to obtain optimum diameters of intermediate shaft and propeller shaft in marine propulsion shafting. Objective function is to minimize total mass of shafts and constraints are that torsional vibration stresses of shafts in marine propulsion shafting can not exceed the permissible torsional vibration stresses of the ship classification society. The computational results by the program were compared with those of conventional design technique.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.55 no.4
• /
• pp.155-160
• /
• 2006

In this paper, deduced suitable optimization to request output condition after taking closely characteristic data of single phase induction motor(SIM) which is the possibility becoming economic is coming to be demanded. Motor proper move connection data took advantage of result of existing data and iron loss and copper loss, mechanical loss took advantage of statistical data, and decide motor move laking advantage of saving data and secondary resistance and optimum purpose of method that is proposed through single phase induction motor and comparison performance evaluation having on the same output parameter. That decide material factor, electric power damage ratio, and coefficient of utilization for optimum function by method that search request output and optimum values of efficiency case by case and decided is proper that is saved after take magnetizing reactance relationship. This research result which it sees against a material expense with use coefficient of utilization which is included in loss expense decides the same plan variable back the place efficiency is useful and will be applied.

• Journal of Ocean Engineering and Technology
• /
• v.27 no.5
• /
• pp.36-42
• /
• 2013

We present the optimum design for the cross-sectional(sizing) and shape optimization of truss structures with natural frequency constraints. The optimum design method used in this paper employs continuous design variables and the Harmony Search Algorithm(HSA). HSA is a meta-heuristic search method for global optimization problems. In this paper, HSA uses the method of random number selection in an update process, along with penalty parameters, to construct the initial harmony memory in order to improve the fitness in the initial and update processes. In examples, 10-bar and 72-bar trusses are optimized for sizing, and 37-bar bridge type truss and 52-bar(like dome) for sizing and shape. Four typical truss optimization examples are employed to demonstrate the availability of HSA for finding the minimum weight optimum truss with multiple natural frequency constraints.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1992.03a
• /
• pp.103-114
• /
• 1992

The jointing method of PC pile installation, which utilizes steel sleeve, is most popular for the deep bearing stratum( deeper than 15m ) or the irregular bearing stratum depths. However, this method has some difficulties in safety because there is no optimum standards of steel sleeve. This research attempts to determine the optimum standard of steel sleeve for 350mm PC pile, which is most widely used, through bending moment test designated by KS and numerical analysis using finite element method. According to the results, the optimum length of steel sleeve is three times longer than diameter of pile, and the thickness of steel sleeve is more than 2.5mm.