• Journal of Electrochemical Science and Technology
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• v.14 no.2
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• pp.174-183
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• 2023

The dye wastewater discharge from the textile industries mainly affects the aquatic environment. Hence, the treatment of this wastewater is essential for a pollutant-free environment. The purpose of this research is to optimize the dye removal efficiency for process influencing independent variables such as pH, electrolysis time (ET), and current density (CD) by using Box-Behnken design (BBD) optimization and Genetic Algorithm (GA) modelling. The electrocoagulation treatment technique was used to treat the synthetically prepared Reactive Black dye solution under batch mode potentiometric operations. The percentage of error for the BBD optimization was significantly greater than for the GA modelling results. The optimum factors determined by GA modelling were CD-59.11 mA/cm², ET-24.17 minutes, and pH-8.4. At this moment, the experimental and predicted dye removal efficiencies were found to be 96.25% and 98.26%, respectively. The most and least predominant factors found by the beta coefficient were ET and pH respectively. The outcome of this research shows GA modeling is a better tool for predicting dye removal efficiencies as well as process influencing factors.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.32-47
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• 1996

Systematic theoretical arm experimental studies have been performed to establish the methods of the hull form design, the optimum dimension selection and the resistance estimation for the displacement type super high-speed ships. In this study, theoretical hull form design method of the displacement type super high-speed ships has been developed first by the minimum resistance theory and the sectionally-varying hull form equation. Utilizing the established hull form design method, sixty(60) series hull forms have been prepared according to the systematic variations of the important design variables, and model tests were conducted for the sixty(60) series ship models. Finally, regression analyses have been performed for the results of model tests. It is considered that this is the first systematic and multi-purpose study in the world for the super high-speed ships. The study has been completed very successfully. The prepared computer program is now being actively utilized as an efficient tool for the design of the displacement type super high-speed ships.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.29-34
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• 2017

In this paper, we report a method of improving the productivity of lead wire fabricated through the rolling process by increasing its linear velocity. The most important point to consider when raising the linear velocity is that the original specifications must still be adhered to. In other words, the dimensional tolerance must be satisfied when increasing the linear velocity of the wire without causing cracks. However, if the linear velocity of the wire is increased, the degree of reduction must also be increased, which causes more damage to the wire and increases the load on its surface. Therefore, we studied a three step rolling process which can satisfy the specifications of the wire produced through the two step rolling process and improve the productivity. In this study, only the roll gap of the three-stage rolling roller is assumed to be a variable, while the other conditions are the same as the field conditions. In addition, through the PIANO (Process Integration, Design and Optimization) tool, the (optimum?) surface roughness and maximum stress are maintained.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.146-152
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• 2007

An active micro-mixer, which was composed of an oscillating micro-stirrer in the microchannel to provide rapid, effective mixing at high flow, rates was analyzed. The effects of molecular diffusion and disturbance by the stirrer were considered with regard to two types of mixer models: the simple straight microchannel and microchannel with an oscillating stirrer. Two types of mixer models were studied by analyzing mixing behaviors such as their interaction after the stirrer. The mixing was calculated by Lattice Boltzmann methods using the D2Q9 model. In this study, the time-averaged mixing index formula was used to estimate the mixing performance of time-dependent flow. The mixing indices of the two models compared. From the results, it was found that the mixer with an oscillating stirrer was much more enhanced and stabilized. Therefore, an optimum design for a dynamic micro-mixer with an oscillating stirrer was performed using Taguchi method in order to obtain a robust solution. The design parameters were established as the frequency, the length and the angle of the stirrer and the optimal values were determined to be 2, 0.8D and ${\pm}75^{\circ}$, respectively. It was found that the mixing index of the optimal design increased 80.72% compared with that of the original design.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.93-101
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• 2015

Zero energy building is a self sufficient building that minimizes energy consumption through passive elements such as insulation, high performance window system and installing of high efficiency HVAC system and uses renewable energy sources. The Korea Government has been strengthening the building energy efficiency standard and code for zero energy building. The building energy performance is determined by the performance of building envelope. Therefore it is important to optimize facade design such as insulation, window properties and shading, that affect the heating and cooling loads. In particular, shading devices are necessary to reduce the cooling load in summer season. Meanwhile, BIPV shading system functions as a renewable energy technology applied in solar control facade system to reduce cooling load and produce electricity simultaneously. Therefore, when installing the BIPV shading system, the length of shadings and angle that affect the electricity production must be considered. This study focused on the facade design applied with BIPV shading system for maximizing energy saving of the selected standard building. The impact of changing insulation on roof and walls, window properties and length of BIPV shading device on energy performance of the building were investigated. In conclusion, energy consumption and electricity production were analyzed based on building energy simulations using energyplus 8.1 building simulation program and jEPlus+EA optimization tool.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.3
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• pp.43-48
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• 2019

Since the revision of the Rationalization of Energy Use Law, the spread of new and renewable energy in buildings has been promoted. In addition, the production of electric power and thermal energy is an important issue in the change of energy paradigm centered on the use of distributed energy. Among them, geothermal energy is attracting attention as a high-performance energy-saving technology capable of coping with heating / cooling and hot water load by utilizing the constant temperature zone of the earth. However, there is a disadvantage that the initial investment cost is high as a method of calculating the capacity of a geothermal facility by calculating the maximum load. The disadvantages of these disadvantages are that the geothermal energy supply is getting stagnant and the design of the geothermal system needs to be supplemented. In this study, optimization design of geothermal system was carried out using optimization tool. As a result of the optimization, the ground heat exchanger decreased by 30.8%, the capacity of the heat pump decreased by 7.7%, and the capacity of the heat storage tank decreased by about 40%. The simulation was performed by applying the optimized value to the program and confirmed that it corresponds to the load of the building. We also confirmed that all of the constraints used in the optimization design were satisfied. The initial investment cost of the optimized geothermal system is about 18.6% lower than the initial investment cost.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.6
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• pp.914-919
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• 2000

A simple orthogonal mode transducer(OMT) for X-band has been proposed in this paper. This OMT is designed such that a polarized wave can be guided in a direction using several thin guiding posts, and the other orthogonally polarized wave can be guided in the other direction using other thin guiding posts. The OMT consists of a T-shaped waveguide section with guiding posts, two tapering waveguide arms, and has three flanges for connection with two adapters and an antenna. The optimum numbers and the optimum positions of the guiding posts were obtained numerically using the HFSS CAD tool. The isolation between two polarizations in a manufactured OMT is higher than 42.8 dB and the reflection from the OMT is lower than -17.5 dB at the frequency band of 9.5 GHz

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.1-7
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• 2015

A gutter is generally a fixed beneath the edge of a roof to carry off rainwater, or a narrow trough that collects rainwater from the roof of a building to diverts it from the structure, typically into a drain. Reasonable designs reduce the mass of the gutters (~ 16.9%), make it faster and easier to assemble, and gives it consistent strength and integrity (about 10%). New gutter systems are presented according to the results of structural analyses performed by ANSYS and ADAMS/Durability Hot Spots. In addition, the CATIA program can improve the precision of the 3D system simulations. The design of a gutter system installations also needs to comply with the specific rainfall intensities and adequate overflow provisions needs to be provided to prevent water from sides of the roofs during heavy rainfall periods. The principle outcome of this work is a computational design tool that can be used to improve the gutter performance considering a variety of factors (gutter geometry, drainage and rainfall intensity). A good gutter design must satisfy many criteria, including durability, low cost, and ease of repair and cleaning.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.417-420
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• 1990

The conventional quantitative techniques of system analysis are intrinsically unsuited for dealing with humanistic systems. Therefore, the rule based modeling of fuzzy linguistic type has been developed for the analysis of humanistic systems and complex systems and it is very significant for analysis and design of fuzzy logic controller. The activated sludge process is a commonly used method for treating sewage and waste waters. A mathematical tool to build a fuzzy model of the activated sludge process where fuzzy implications and linear reasoning are used is presented in here. A root-mean square error is used as the criterion of the fuzzy model's adequacy to the A.S.P. and the least square method is used for the identification of optimum consequence parameters. A method of modeling of the activated sludge process using its input-output data and simulation results for its application are shown.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.621-626
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• 2001

Microcellular foaming process was developed at MIT in 1980's to save a quantity of raw materials and improve mechanical properties. There are many process variables in appling microcellular foaming process to the conventional injection molding process. Of all process variables, part dimension control and shrinkage are the most influential on the post molded dimension. The post molding dimensional change of thermoplastic resins is important to tool designers for predicting the specific difference of molded part vs. actual mold cavity. Generally, articles injection molded are smaller in size than the cavity; hence, the term shrinkage factor is used to define the allowance a designer specifies. It is important to consider the factors that influence molded part dimension. According to ASTM Designation: D 955, shrinkage from mold dimensions of molded plastics was measured. In injection molding, the difference between the dimensions of the mold and of the molded article produced therein from a given material may vary according to the design and operation of the mold. In this paper, shrinkage data of molded plastic parts was obtained. It can be an important information for designing optimum mold system in a microcellular foaming injection molding process.