• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.6
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• pp.814-820
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• 2009

The arrangement of the general 12-button cellular phone keypad is unified with one or two kind. In general, the several alphabets are arranged in one key. When inputting an English, countries which do not speak English use multi-tap method. We can input next alphabet by pressing key repeatedly. We address the problem of finding multi-tap-based keypad designs which minimize the number of key presses for various case. Genetic algorithms is proposed method for optimal keypad designs. We are to maintain the number of keys, which is ranged from 8 to 12. We also show experimental using non-alphabetically-constrained and alphabetically-constrained arrangement, respectively. Finally, we give improved keypad designs.

• Journal of the Korean Dietetic Association
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• v.23 no.1
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• pp.14-26
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• 2017

The purpose of this study was to determine the optimal recipe of rice cookies with two different amounts of Stevia rebaudiana leaf and grape seed oil, using a central composite design (CCD). In addition, mixing conditions of rice cookies were optimized by sensory evaluation and mechanical and physicochemical analysis using response surface methodology (RSM). RSM was used to obtain 10 experimental points (including two replicates of Stevia rebaudiana leaf and Grape seed oil), and the formulation of Stevia rebaudiana leaf added rice cookies was optimized using rheology. The results of mechanical and physicochemical analysis showed significant values for lightness, redness, yellowness, hardness, spread factor, loss rate, leavening rate, sweetness, moisture, pH, and density (P<0.001), results of the sensory evaluation showed significant values for color, flavor, taste, texture, appearance, and overall quality (P<0.05). As a results, optimal sensory ratio was found to be 1.98 g of Stevia rebaudiana leaf and 37.94 g of Grape seed oil.

• Proceedings of the KAIS Fall Conference
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• 2003.11a
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• pp.178-184
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• 2003

Case-based reasoning (CBR) often shows significant promise for improving effectiveness of complex and unstructured decision making. Consequently, it has been applied to various problem-solving areas including manufacturing, finance and marketing. However, the design of appropriate case indexing and retrieval mechanisms to improve the performance of CBR is still challenging issue. Most of previous studies to improve the effectiveness for CBR have focused on the similarity function or optimization of case features and their weights. However, according to some of prior researches, finding the optimal k parameter for k-nearest neighbor (k-NN) is also crucial to improve the performance of CBR system. Nonetheless, there have been few attempts which have tried to optimize the number of neighbors, especially using artificial intelligence (AI) techniques. In this study, we introduce a genetic algorithm (GA) to optimize the number of neighbors to combine. This study applies the new model to the real-world case provided by an online shopping mall in Korea. Experimental results show that a GA-optimized k-NN approach outperforms other AI techniques for purchasing behavior forecasting.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.10-17
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• 2007

For the purpose of optimal control of anti-lock brake system, precise dynamic characteristics analysis of the hydraulic modulator, especially solenoid valve is necessary. However, most of researches so law have dealt with dynamic characteristic analysis of valve itself and the results have been restrictive to apply on the actual ABS modulator, where hydraulic pressure is acting. In this study, mathematical modeling and experimental analysis were executed in order to evaluate the valve dynamic characteristics when the hydraulic pressure applied. High pressure on the master cylinder effects on the valve dynamic characteristics have been analyzed quantitatively and performance improvement methods have been suggested varying the design factor. Consequently, results of solenoid valve dynamic characteristics analysis derived in the study can be utilized criteria for the optimal control of anti-lock brake system.

• Journal of Korean Society for Quality Management
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• v.42 no.1
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• pp.63-70
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• 2014

Purpose: This article introduces a case study of using Taguchi Method to improve lecture satisfaction. Developed by Taguchi Genichi, this method has its strength in finding the control factor that is robust against noise factor. Finding the condition for such control factor has an effect of reducing the dispersion of the Lecture satisfaction. Methods: There are various factors in university classrooms. The factors which influenced the Lecture Satisfaction are analyzed by control factors and noise factors, control factors which is controllable are lecture completeness and thoroughly test the degree of supervision and noise factors which is not controllable is degree of physical and psychological Lecturer tired, then the experiment is conducted as guided by Taguchi's experimental design, one semester are experimented by eight professor with 2 classes, after discussion of the results the optimal lecture condition is suggested. Results: To improve Lecture Satisfaction under noise factor of physical and psychological Lecturer tired, optimal condition are that lecture completeness have scenario note during lecture and thoroughly test the degree of supervision have two proctors during test. Conclusion: In this paper, we have succession case by applying Taguchi methods in Lecture Satisfaction. We can apply to improve service by applying the Taguchi methods. In the future we hope to have many succession cases.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.349-353
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• 2004

A study on optimal placement of constrained layer damping treatment for vibration control of automotive panels is presented. The effectiveness of damping treatment depends upon design parameters such as choice of damping materials, locations and size of the treatment. This paper proposes a CAE (Computer Aided Engineering) methodology based on finite element analysis to optimize damping treatment. From the equivalent modeling technique, it is found that the best damping performance occurs as the viscoelstic patch is placed by means of the modal strain energy method of bare structural panels to identify flexible regions, which in turn facilitates optimizations of damping treatment with respect to location and size. Different configurations of partially applied damping layer treatment have been analyzed for their effectiveness in realizing maximum system damping with minimum mass of the applied damping material. Moreover, simulated frequency response function of the automotive roof with and without damping treatments are compared, which show the benefits of applying damping treatment. Finally, the optimized damping treatment configuration is validated by comparing the locations and the size of the treatment with that of an experimental modal test conducted on roof compartment.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.1
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• pp.27-32
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• 2022

Microbubble technology has been widely applied in various industrial fields. Recently, research on many types of microbubble application technology has been conducted experimentally, but there is a limit in deriving the optimal design and operating conditions. Therefore, if the computational fluid dynamics (CFD) analysis of multiphase flow is used to supplement these experimental studies, it is expected that the time and cost required for prototype production and evaluation tests will be minimized and optimal results will be derived. However, few studies have been conducted on multiphase flow CFD analysis to interpret fluid flow in microbubble generators using swirl flow. In this study, CFD simulation of multiphase flow was performed to analyze the air-water mixing process and fluid flow characteristics in a microbubble generator with a dual-chamber structure. Based on the simulation results, it was confirmed that a negative pressure was formed on the central axis of rotation due to the strong swirling flow. And it could be seen that the air inside the suction tube was introduced into the inner chamber of the microbubble generator. In addition, as the high-speed mixed fluid collided with external water sucked by the negative pressure near the outlet, a large amount of microbubbles was ejected due to the shear force between the two flows flowing in opposite directions.

• Design & Manufacturing
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• v.17 no.1
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• pp.7-12
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• 2023

Recently, with the emergence of the 4th industrial revolution, the demand for smart factories and factory automation is increasing. In this study, a tool life prediction program was developed to select optimal machining conditions using CNC milling equipment, which is widely used in flexible production and automation. The equipment used in the experiment was Hwacheon Machine Tool's 5-axis machining equipment, and the tool used was a 17F2R tool. For the machining path, the down-milling cutting method was selected and long-term machining was performed. The analysis standard for side wear on the tool was set at 0.1 to 0.2 mm, and tool life data and wear data were obtained in the cutting experiment. The program was created through the data obtained from the experiment, and a prediction rate of over 90% was secured when comparing the experimental data and the predicted data.

• Journal of Mushroom
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• v.21 no.3
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• pp.110-117
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• 2023

Cordycepin (3'-deoxyadenosine) is a nucleoside analog known for its diverse range of biological activities. This study investigated the effect of different types of sawdust on the production of the bioactive compound cordycepin. The results of the study showed that different types of wood sawdust affected the biosynthesis of cordycepin and a significant increase was observed when the conventional SDB medium was replaced with 1% NaOH treated pine sawdust. To optimize cordycepin production from Paecilomyces tenuipes in a medium containing 1% NaOH-pretreated pine sawdust, we employed Response Surface Methodology (RSM) in its Box-Behnken design (BBD) canonical form. The optimal conditions were determined as follows: a particle size of 109.5111-mesh (140 ㎛) for 1% NaOH-pretreated pine sawdust, an input weight of 21.1679 g/L, and an incubation time of 73.8423 hours. According to our model, this combination is expected to yield a maximum cordycepin content of 896.1428 ㎍/mL. Experimental validation of this prediction was performed using the suggested optimal conditions, resulting in an average cordycepin content of 922.6771 ㎍/mL across three replicates, thus confirming the model's accuracy.

• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.47-52
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• 2007

This paper presents characteristics analysis of persistent current switch(PCS) system on a small scale by using YBCO coated conductor(CC). A high temperature superconductor(HTS) PCS system mainly consists of a PCS, a HTS magnet load and a magnet power supply(MPS). To design the optimal heater triggering switch. the three-dimensional heat conduction model was analyzed by finite element method(FEM). The electrical equivalent model considering the n-value of CC was applied to analyze current decay during persistent current mode. In the experiment and simulation, the heater was applied with a current of 0.43A and the current was ramped up to 10A and 20A with 0.2A/s. Finally, experimental results of the HTS PCS system have been compared with the theoretical results. It has been concluded that flux creep can not influence the results because the operating current was 40% of critical current and optimal sequential operation of the PCS system is indispensable to enhance its performance.