• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.2
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• pp.248-255
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• 2013

The objective of this study is to optimize the Metal Injection Molding(MIM) process with design of experiments(DOE) and numerical analysis. To derive the optimal process condition, experiment or numerical analysis was performed under various process conditions. To analyze the interaction among influential factors contributing to the temperature at flow front and response surface in MIM, both central point and axial point were added to the full factorial design with 2 levels and 5 factors and then their impacts on response variable in 43 experimental conditions were analyzed and the significance was evaluated. As a result, sprue, runner, and gate were completely filled in about 0.247 seconds after injection, the front part of the green body was filled in about 0.3344 seconds, the green body except gate, etc changed to almost solid state in about 3.29 seconds, the Packinging pressure was completed in about 6.29 seconds, and the green body inside and outside and sprue, etc became solid in 13.2 seconds. The impact of individual or reciprocal action of factors on the temperature at flow front was analyzed through regular probability, test statistics, main effect, and interaction effect. As a result, of a total of 31 combinations of factors, 9 unit factors and reciprocal actions were significant, and the screening was also possible. A proper regression equation was drawn with regression analysis and response surface design on the response variable of temperature at flow front, and the applicability could be verified.

• Journal of Environmental Health Sciences
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• v.36 no.4
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• pp.313-322
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• 2010

The aim of this research was to apply experimental design methodology to optimization of conditions of electrochemical oxidation of Rhodamine B (RhB) and N, N-Dimethyl-4-nitrosoaniline (RNO, indicative of the OH radical). The reactions of electrochemical oxidation of RhB degradation were mathematically described as a function of the parameters of current ($X_1$), NaCl dosage ($X_2$) and pH ($X_3$) and modeled by the use of the central composite design. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the removal efficiency of RhB and RNO and test variables in a coded unit: RhB removal efficiency (%) = $94.21+7.02X_1+10.94X_2-16.06X_3+3.70X_1X_3+9.05X_2X_3-{3.46X_1}^2-{4.67X_2}^2-{7.09X_3}^2$; RNO removal efficiency (%) = $54.78+13.33X_1+14.93X_2- 16.90X_3$. The model predictions agreed well with the experimentally observed result. Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the RhB degradation using canonical analysis was 100.0%(current, 0.80 A; NaCl dosage, 2.97% and pH 6.37).

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.6
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• pp.324-332
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• 2005

In general, bus system consumes a very significant portion of power in a chip. Bus splitting can be used to reduce the energy dissipation and to reduce the Propagation delay on the bus by lowering the parasitic load of each bus segment. Data exchange probability distribution between a set of interconnected processing elements affects the average energy dissipation of the splitted bus architectures. In this research, we have developed tree-based bus splitting techniques and design methodologies, as an extension of horizontally aligned bus splitting. We have developed the methodology to select near-optimal bus architectures for low energy dissipation when data exchange probability distribution of a system is given. Experimental results show that the proposed techniques can reduce energy dissipation on the bus by up to 83$\%$.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.815-824
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• 2006

This study was performed to determine the optimum ratio of each ingredient in the steamed foam cake with barley (Hordeum vulgare L.) sproutling powder. The experiment was designed according to the D-optimal design of mixture design, which showed 14 experimental points including 4 replicates for three independent variables (sugar 112${\sim}$139%, barley sproutling powder 1${\sim}$8%, and oil 5${\sim}$25%). The compositional and functional properties of test were measured, and these values were applied to the mathematical models. A canonical form and trace plot showed the influence of each ingredient on the mixture final product. The results of F-test, volume, color values (L, a, b), textural properties (hardness, gumminess, chewiness) and sensory characteristics (softness) decided a linear model, while the sensory characteristics (color, smell, taste, overall acceptance) decided a quadratic model. The volume of steamed foam cake was increased by sugar addition, and a negative effect was exerted by barley sproutling powder and oil. L and a of color values increased but the b value decreased with increasing sugar and oil content, whereas barley sproutling powder tended to decrease all color values. The addition of barley sproutling powder also had a positive effect on the textural properties (hardness, gumminess, chewiness). Sensory characteristics (color, smell, softness, taste, overall acceptance) could suffer counter results with the excessive addition of sugar, barley sproutling powder, and oil. The optimum formulations by numerical and graphical methods were similar: sugar, barley sproutling powder, and oil were 130.4%, 4.0%, and 10.7% by numerical method, compared to 130.4%, 4.0%, and 10.7% by graphical method, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.06a
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• pp.77-89
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• 2002

To analyze a bearing capacity for pile groups, a number of model tests have been done and theoretical methods studied. In the case of design of group pile bearing capacity is calculated with only pile capacity. But uncertainty of bearing capacity and behavior of foundation cap(raft) leads to conservative design ignoring bearing effects of foundation cap. In the case of considering bearing capacity of foundation cap, the simple sum of bearing capacity of foundation cap and pile groups cannot be the bearing capacity of total foundation system. Since cap-pile-soil interaction affects the behavior of pile groups. Thus, understanding cap-pile-soil interaction is very important in optimal design. In this paper, the piled raft behavior is studied through model tests of 2$\times$2, 2$\times$3, 3$\times$3 pile group. Changes of behavior of pile group foundation by touching effects of foundation cap with soil are studied. Also changes of spacing between piles. Foundation cap is made of rigid steel plate and piles are made steel pipes. From this model tests, the changes of behavior changes of pile groups by touching effects of foundation cap with soil are studied.

• Journal of Information Technology Services
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• v.19 no.6
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• pp.131-144
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• 2020

As the blockchain technology attracts attention, interest in cryptocurrency that is received as a reward is also increasing. Currently, investments and transactions are continuing with the expectation and increasing value of cryptocurrency. Accordingly, prediction for cryptocurrency price has been attempted through artificial intelligence technology and social sentiment analysis. The purpose of this paper is to develop a deep learning ensemble model for predicting the price fluctuations and one-day lag price of cryptocurrency based on the design science research method. This paper intends to perform predictive modeling on Ethereum among cryptocurrencies to make predictions more efficiently and accurately than existing models. Therefore, it collects data for five years related to Ethereum price and performs pre-processing through customized functions. In the model development stage, four LSTM models, which are efficient for time series data processing, are utilized to build an ensemble model with the optimal combination of hyperparameters found in the experimental process. Then, based on the performance evaluation scale, the superiority of the model is evaluated through comparison with other deep learning models. The results of this paper have a practical contribution that can be used as a model that shows high performance and predictive rate for cryptocurrency price prediction and price fluctuations. Besides, it shows academic contribution in that it improves the quality of research by following scientific design research procedures that solve scientific problems and create and evaluate new and innovative products in the field of information systems.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.1-9
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• 2023

Malware files containing concealed malicious scripts have recently been identified within MS Office documents frequently. In response, this paper describes the design and implementation of a system that automatically detects malicious digital files using machine learning techniques. The system is proficient in identifying malicious scripts within MS Office files that exploit the OLE VBA macro functionality, detecting malicious scripts embedded within the CDH/LFH/ECDR internal field values through OOXML structure analysis, and recognizing abnormal CDH/LFH information introduced within the OOXML structure, which is not conventionally referenced. Furthermore, this paper presents a mechanism for utilizing the VirusTotal malicious script detection feature to autonomously determine instances of malicious tampering within MS Office files. This leads to the design and implementation of a machine learning-based integrated software. Experimental results confirm the software's capacity to autonomously assess MS Office file's integrity and provide enhanced detection performance for arbitrary MS Office files when employing the optimal machine learning model.

• Journal of Hydrogen and New Energy
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• v.35 no.3
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• pp.324-335
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• 2024

The container package type sealed water electrolysis production system installs mechanical balance of plant and electrical balance of plant as an integrated unit to enable independent operation within the package module. The auxiliary equipment required to operate the water electrolysis system must be integrated to reduce the installation area and shorten the installation time. At this time, as leak risk factors are placed in a dense space, when a hydrogen gas leak accident occurs, it can have a mutual influence on other adjacent facilities, so it contains various risk factors. In this study, when a gas leak occurs in a container packaged water electrolysis system, possible sources of leakage in the system according to the KS C IEC 60079-10-1:2015 and KGS GC101 standards were identified, and the leak rate and leak characteristics were calculated. did. The hazardous area and its range were calculated according to ventilation and dilution characteristics. In order to optimize ventilation characteristics, design of experiment was used to analyze the influence to evaluate the adequacy of ventilation, and overseas ventilation standards were analyzed and compared. In addition, the optimal ventilation structure and characteristics of the container packaged water electrolysis system were presented according to the results of the experimental design method.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.2
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• pp.63-71
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• 2002

This paper examines the ASCE first generation benchmark problem for a seismically excited cable-stayed bridge, and proposes a new semi-active control strategy focusing on inclusion of effects of control-structure interaction. This benchmark problem focuses on a cable-stayed bridge in Cope Girardeau, Missouri, USA, for which construction is expected to be completed in 2003. Seismic considerations were strongly considered in the design of this bridge due to the location of the bridge in the New Madrid seismic zone and its critical role as a principal crossing of the Mississippi River. In this paper, magnetorheological(MR) fluid dampers are proposed as the supplemental damping devices, and a clipped-optimal control algorithm is employed. Several types of dynamic models for MR fluid dampers, such as a Bingham model, a Bouc-Wen model, and a modified Bouc-Wen model, are considered, which are obtained from data based on experimental results for full-scale dampers. Because the MR fluid damper is a controllable energy-dissipation device that cannot add mechanical energy to the structural system, the proposed control strategy is fail-safe in that bounded-input, bounded-output stability of the controlled structure is guaranteed. Numerical simulation results show that the performance of the proposed semi-active control strategy using MR fluid dampers is quite effective.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.215-220
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• 2006

Response surface methodology was implemented to determine an optimal extraction condition in Phellinus linteus water extract. Extraction was performed on 10 experimental conditions including independent variables such as extraction time $(1{\sim}5\;hrs)$ and water volume over sample (sample : $H_2O$ = 1 : $40{\sim}200$, W/V), color browning, reducing and total sugar, that were based on the significant levels of 10% of central composition design. Color browning, reducing and total sugar contents were found to be more affected when the water volume was increased rather than extraction time. Maximum extraction condition was acquired at extraction time of $3.0{\sim}4.5\;hrs$ and water volume of $40{\sim}58.2\;ml$. Being extracted at the optimal extraction condition two of the free sugars, sucrose (0.126%) and glucose (0.012%), were detected. Total content of the free amino acids was found to be $503.26\;{\mu}g%$. Among them, essential amino acid contents were revealed as 5.4%. One major peak from gel permeation chromatography contained polysaccharide(s) with the molecular weights of 10 KDa.