• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.201-203
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• 2001

This paper describes the information for quantitative simulation of weakly ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. In this paper, the drift velocity of electron in Xenon gas calculated for range of E/N values from 0.01~500[Td] at the temperature is $300[^{\circ}K]$ and pressure is 1[Torr], using a set of electron collision cross sections determined by the authors and the values of drift velocity of electrons are obtained for TOF, PT, SST sampling method of Backward Prolongation by two term approximation Boltzmann equation method. it has also been used to predict swarm parameter using the values of cross section as input. The result of Boltzmann equation, the drift velocity of electrons, has been compared with experimental data by L. S. Frost and A. V. Phelps for a range of E/N. The swarm parameter from the study are expected to server as a critical test of current theories of low energy scattering by atoms and molecules.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.237-240
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• 2005

As a part of the effort for improving the durability design based on a set of the deem-to-satisfy specifications, it is important and primary to quantitatively identify the environmental impact to a target reinforced concrete structure. In this work, an effort is made to quantitatively calculate the environmental affecting factor with using a fuzzy inference that it indicates the severity of environmental impact to the exposed reinforced concrete structure or member. This system is composed of input region, output region and rule base. For developing the fuzzy inference system surface chloride concentration{chloride), cyclic degree of wet and dry(CWD), relative humidity(RH) and temperature (TEMP) were selected as the input parameter to environmental affecting factor(EAF) of output parameter. The Rules in inference engine are generated from the engineering knowledge and intuition based on some international code of practises as well as various researcher's experimental data. The devised fuzzy inference system was verified comparing the inferred value with the investigation data, and proved to be validated. Thus it is anticipated that this system for quantifying EAF is certain to be considered into the starting point to develop the performance-based durability design considering the service life of structure.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.4
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• pp.432-440
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• 2007

In this study, we have investigated the closure behavior of fatigue cracks in SAPH440 steel plates under a mixed-mode I+II loading. A crack image capturing system as a direct measuring method was used to measure the closure levels at a crack tip. The crack closure levels in the fluctuation and stable sections were increased with the increase of the mode mixture ratio. The mode mixture ratio independent fatigue crack propagation rates equation was calculated by considering mixed-mode crack closure levels. The equation was examined according to the application method of crack opening ratio. The fracture surface analysis by C-scan method was also performed in order to investigate the closure mechanism and propagation mode of crack under the mixed-mode I+II loading. The crack closure under the mixed mode I+II is confirmed as a surface roughness closure by the quantitative analysis of fracture surface using the proposed surface roughness parameter.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.269-272
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• 2000

It is need to develop and apply a human pulse diagnosis system providing a quantitative and automatic analysis in the the oriental medicine. In order to analyze quantitatively the characteristic of pulsation, each of points had to be recognized accurately notifying the existence and the position of feature point in the wave form. And getting the period of human pulse. Thus, in this paper, it is proposed the preprocessing method of human pulse and the detection method of period by Wavelet Transformation. The human pulse is seprated from each band through Wavelet Transformation and feature points can be recognized through over the fact, and then the parameter of proposed Mac-Jin parameter is measured. Commonly, Human pulse signal has often various noises which are baseline drift, high frequency noise and so on. So it is significant to remove that noises. Thus, in this paper, the one period of human pulse is deciede and the feature points are detected after doing the preprocessing by wavelet transformation. As a result, it could be confirmed that this method is effective as a real program for the auto-diagnosis of human pulse.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.3
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• pp.467-476
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• 2022

The Bank of Korea raised the benchmark interest rate by a quarter percentage point to 1.75 percent per year, and analysts predict that South Korea's policy rate will reach 2.00 percent by the end of calendar year 2022. Furthermore, because market volatility has been significantly increased by a variety of factors, including rising rates, inflation, and market volatility, many investors have struggled to meet their financial objectives or deliver returns. Banks and financial institutions are attempting to provide Robo-Advisors to manage client portfolios without human intervention in this situation. In this regard, determining the best hyper-parameter combination is becoming increasingly important. This study compares some activation functions of the Deep Deterministic Policy Gradient(DDPG) and Twin-delayed Deep Deterministic Policy Gradient (TD3) Algorithms to choose a sequence of actions that maximizes long-term reward. The DDPG and TD3 outperformed its benchmark index, according to the results. One reason for this is that we need to understand the action probabilities in order to choose an action and receive a reward, which we then compare to the state value to determine an advantage. As interest in machine learning has grown and research into deep reinforcement learning has become more active, finding an optimal hyper-parameter combination for DDPG and TD3 has become increasingly important.

• International Journal of Korean Welding Society
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• v.1 no.1
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• pp.17-22
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• 2001

Because the quantitative relationships between welding parameters and welding result are not yet blown, optimal values of welding parameters for $CO_2$ robotic arc welding is a difficult task. Using the various artificial data processing methods may solve this difficulty. This research aims to develop an expert system for $CO_2$ robotic arc welding to recommend the optimal values of welding parameters. This system has three main functions. First is the recommendation of reasonable values of welding parameters. For such work, the relationships in between the welding parameters are investigated by the use of regression analysis and fuzzy system. The second is the estimation of bead shape by a neural network system. In this study the welding current voltage, speed, weaving width, and root gap are considered as the main parameters influencing a bead shape. The neural network system uses the 3-layer back-propagation model and a generalized delta rule as teaming algorithm. The last is the optimization of the parameters for the correction of undesirable weld bead. The causalities of undesirable weld bead are represented in the form of rules. The inference engine derives conclusions from these rules. The conclusions give the corrected values of the welding parameters. This expert system was developed as a PC-based system of which can be used for the automatic or semi-automatic $CO_2$ fillet welding with 1.2, 1.4, and 1.6mm diameter the solid wires or flux-cored wires.

• KSBB Journal
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• v.15 no.3
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• pp.299-306
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• 2000

Concern for the effects of toxic chemicals on the environment leads the search for better bioassay test organisms and test procedures. Photobacterium phosphoreum was used successfully as a test organism and the luminometer detection technique was an effective and simple method for determining the concentration of toxic chemicals. With EC50 a total of 14 chlorine substituted phenols benzenes and ethanes were used for the experiments. The test results showed that the toxicity to P. phosphoreum increased in the order of phenol > benzene > ethane and the toxicity also increased with the number of chlorine substitution. Quantitative structure activity relationship (QSARO) model can be used to predict EC50 to save time and endeavor. Correlation was well established with the QSAR parameters such as log P, log S and solvatochromic parameter(Vi/100 $\pi$, ${\beta}$m and am). The QSAR modeling was used with multi-regression analysis and mono-regression analysis. These analyses resulted in the following QSAR : $log EC_{50} =2.48 + 0.914 log S(n=9 R2=85.5% RE=0.378) log EC_{50}=0.35 - 4.48 Vi/100 + 2.84 \pi^* +9.46{\beta}m-4.48am (n =14 R2=98.2% RE=0.012) log EC_{50} =2.64 -1.66 log P(n=5, R2=98.8% RE=0.16) log EC_{50}=3.44 -1.09 log P(n=9 R2= 80.8% Re=0.207)$

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.383-387
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• 2015

Bowel and rectal diseases are on the increase by irregular life and westernized eating habits of modern people, especially rectal cancer, which accounts for 50% of the entire colon cancer. For the initial rectal cancer, because there is no portion projecting on the surface, if not see inside the tissue with ultrasound, you make an errors that misdiagnosis as rectal abscess. However there is a need for more accurate diagnosis, because it is sometimes difficult to distinguish abscess from rectal cancer depending on staging, in spite of the ultrasonic diagnosis. Therefore, this study was performed quantitative analysis by using a computer algorithm for rectal cancer and abscess image. Each of 20 cases about normal, abscess and cancer by setting analysis region ($50{\times}50$ pixels) applies to GLCM algorithm and Autocorrelation, Max probability, Sum average, Sum variance in each image were analyzed by comparing the 4 single parameter. Consequently, The high lesion detection efficiency was presented 100% by the 3 parameter of Autocorrelation, Max probability, Sum variance and the parameter of Sum average presents 95% in cancer, more than 90% in abscess. Those parameters are valuable in distinction standard about normal, cancer and abscess in rectum. It is sufficient availability as a computer assisted diagnosis system depended on clinical using.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.243-253
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• 2014

This paper deals with the Quantitative Feedback Thoery(QFT) guaranteeing robustness in spite of the plant parametric uncertainty. In the frequency domain, the QFT guarantees the robustness of the design specification on the uncertainty of plant parameters and disturbance. In order to use the QFT, a selected plant is a Quad Rotor Vehicle(QRV) which has excellent maneuverability and possibility of vertical take-off and landing like the helicopter. And attitude control is examined the possibility satisfied the requirement specification under the setting parametric uncertainty of motors driving 4-blades. Additionally, in an attitude control, the pre-filter considering parameter range and operating range of a QRV was used. For these purpose, in this paper, by using QFTCT, that is the QFT Control Toolbox designing the controller in MATLAB by the QFT, each design phases are introduced.

• Journal of Ginseng Research
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• v.42 no.1
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• pp.21-26
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• 2018

Background: Furosine (${\varepsilon}$-N-2-furoylmethyl-L-lysine, FML) is an amino acid derivative, which is considered to be an important indicator of the extent of damage (deteriorating the quality of amino acid and proteins due to a blockage of lysine and a decrease in the digestibility of proteins) during the early stages of the Maillard reaction. In addition, FML has been proven to be harmful because it is closely related to a variety of diseases such as diabetes. The qualitative analysis of FML in fresh and processed ginsengs was confirmed using HPLC-MS. Methods: An ion-pair reversed-phase LC method was used for the quantitative analysis of FML in various ginseng samples. Results: The contents of FML in the ginseng samples were 3.35-42.28 g/kg protein. The lowest value was observed in the freshly collected ginseng samples, and the highest value was found in the black ginseng concentrate. Heat treatment and honey addition significantly increased the FML content from 3.35 g/kg protein to 42.28 g/kg protein. Conclusion: These results indicate that FML is a promising indicator to estimate the heat treatment degree and honey addition level during the manufacture of ginseng products. The FML content is also an important parameter to identity the quality of ginseng products. In addition, the generation and regulation of potentially harmful Maillard reaction products-FML in ginseng processing was also investigated, providing a solid theoretical foundation and valuable reference for safe ginseng processing.