• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.342-351
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• 1997

The objective of this study was to compare acid-neutralizing and buffering capacity of four tree species against soil acidification by acid rain. About 30-year-old forests composed of Pinus rigida, Alnus hirsuta, Quercus mongolica, and Liriodendron tulipifera in a provincial experimental forest located 15km east from Banwol Industrial Complex in Kyonggido were used in this study. Incident precipitation, throughfall and stemflow, and soil samples were collected from May to September, 1996 to analyze their pH and canon concentrations. Internal leaf pH, external acid neutralizing capacity(ENC), and buffering capacity index(BCI) of leaves were also determined. The incident precipitation showed an average pH of 4.56, with the percentage of acid rain incidents being 74%. The average soil pH of the study area was 4.15. The pH of throughfall and stemflow in all four species was higher than that of precipitation except that of the stemflow of Pinus rigida which showed a pH of 3.73. The throughfall of Liriodendron tulipifera showed the highest pH of 5.38. The pH of throughfall and stemflow showed a positive correlation and no correlation, respectively, with precipitations. The most abundant cation in precipitation was Ca. The canon concentraions in throughfall and stemflow decreased in the following order of K, Na, Ca, and Mg. Cation concentrations in stemflow were highest in Lirioendron tulipifera and lowest in Pines rigida. Nutrient leaching from above ground increased with decreasing pH of precipitation. The pH of stemflow showed a positive correlation with ENC and BCI. The highest values in ENC, BCI, soil pH, and soil cation concentrations were observed in Liriodendron tulipifera, while the lowest values were obtained in Pinus rigida, It was concluded that Liriodendron tulipifera had highest neutralizing capacity against acid rain, while Pinus rigida had the lowest capacity and even promoted acidification of soil.

• Journal of KIISE
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• v.44 no.6
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• pp.587-594
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• 2017

Recently, motor imagery electroencephalogram(EEG) based Brain-Computer Interface(BCI) systems have received a significant amount of attention in various fields, including medicine and engineering. The Common Spatial Pattern(CSP) algorithm is the most commonly-used method to extract the features from motor imagery EEG. However, the CSP algorithm has limited applicability in Small-Sample Setting(SSS) situations because these situations rely on a covariance matrix. In addition, large differences in performance depend on the frequency bands that are being used. To address these problems, 4-40Hz band EEG signals are divided using nine filter-banks and Regularized CSP(R-CSP) is applied to individual frequency bands. Then, the Mutual Information-Based Individual Feature(MIBIF) algorithm is applied to the features of R-CSP for selecting discriminative features. Thereafter, selected features are used as inputs of the classifier Least Square Support Vector Machine(LS-SVM). The proposed method yielded a classification accuracy of 87.5%, 100%, 63.78%, 82.14%, and 86.11% in five subjects("aa", "al", "av", "aw", and "ay", respectively) for BCI competition III dataset IVa by using 18 channels in the vicinity of the motor area of the cerebral cortex. The proposed method improved the mean classification accuracy by 16.21%, 10.77% and 3.32% compared to the CSP, R-CSP and FBCSP, respectively The proposed method shows a particularly excellent performance in the SSS situation.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.369-375
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• 2011

Purpose: Many hemostatic agents and dressings have been tested with variable degree of success. Chitosan has a positive charge, it attracts red blood cells, which have a negative charge. Our goal is to test the efficacy of new developed chitosan-based hemostatic materials in providing durable hemostasis in a high-flow arterial wound model. Methods: We compared each group with SD rats motality tests and in vitro blood compatibility test by blood clotting index (BCI). We devided the SD rats into 6 groups (N =15) by type of hemostatic agents. A: 100% nonwoven chitosan (degree of the deacetylation: 90%). B: 50% N-acetylation on nonwoven of chitosan gel (degree of the deacetylation: 50%). C: 60% N-acetylation on nonwoven of chitosan ge (degree of the deacetylation: 40%)l. D: Cutanplast$^{(R)}$. E: HemCon$^{(R)}$ F: Gauze. In vivo test, a proximal arterial injury was created in unilateral femoral arteries of 90 anesthetized SD rats. Each materials was made same size and thickness then applied to the injury site for 3 minutes. In vitro test, we compared each group with BCI in human blood. Results: In vivo test, group A showed lower motality rate of 46% than any other groups, Group B and C showed lower motality rate of 60% than group D and E's motality rate of 66%. In vitro test, BCI of group A ($30.6{\pm}1.2$) and B ($29.3{\pm}1.0$) were showed nearly about group D ($29.1{\pm}1.8$) and E ($27.4{\pm}1.6$). Group C ($37.1{\pm}2.0$) showed higher BCI than group A and B, it means group C decreased blood clotting. Conclusion: In conclusion, this study suggests a newly developed chitosan-based hemostatic materials induced durable hemostasis and increased blood clotting, and are considered as effective biologic hemostatic agents.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.199-203
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• 2016

A brain-computer interface or BCI provides an alternative method for acting on the world. Brain signals can be recorded from the electrical activity along the scalp using an electrode cap. By analyzing the EEG, it is possible to determine whether a person is thinking about his/her hand or foot movement and this information can be transferred to a machine and then translated into commands. However, we do not know which information relates to motor imagery and which channel is good for extracting features. A general approach is to use all electronic channels to analyze the EEG signals, but this causes many problems, such as overfitting and problems removing noisy and artificial signals. To overcome these problems, in this paper we used a new optimization method called the Fruit Fly optimization algorithm (FOA) to select the best channels and then combine them with CSP method to extract features to improve the classification accuracy by linear discriminant analysis. We also used particle swarm optimization (PSO) and a genetic algorithm (GA) to select the optimal EEG channel and compared the performance with that of the FOA algorithm. The results show that for some subjects, the FOA algorithm is a better method for selecting the optimal EEG channel in a short time.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.3
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• pp.254-259
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• 2015

In this paper, The wireless robot control system was proposed using Brain-computer interface(BCI) systems based on the steady-state visual evoked potential(SSVEP). Cross Power Spectral Density(CPSD) was used for analysis of electroencephalogram(EEG) and extraction of feature data. And Linear Discriminant Analysis(LDA) and Support Vector Machine(SVM) was used for patterns classification. We obtained the average classification rates of about 70% of each subject. Robot control was implemented using the results of classification of EEG and commanded using bluetooth communication for robot moving.

• Honam Mathematical Journal
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• v.36 no.3
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• pp.623-635
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• 2014

Classications of (${\alpha},{\beta}$)-fuzzy subalgebras of BCK/BCI-algebras are discussed. Relations between (${\in},{\in}{\vee}q$)-fuzzy subalgebras and ($q,{\in}{\vee}q$)-fuzzy subalgebras are established. Given special sets, so called t-q-set and t-${\in}{\vee}q$-set, conditions for the t-q-set and t-${\in}{\vee}q$-set to be subalgebras are considered. The notions of $({\in},q)^{max}$-fuzzy subalgebra, $(q,{\in})^{max}$-fuzzy subalgebra and $(q,{\in}{\vee}q)^{max}$-fuzzy subalgebra are introduced. Conditions for a fuzzy set to be an $({\in},q)^{max}$-fuzzy subalgebra, a $(q,{\in})^{max}$-fuzzy subalgebra and a $(q,{\in}{\vee}q)^{max}$-fuzzy subalgebra are considered.

• Kyungpook Mathematical Journal
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• v.47 no.3
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• pp.403-410
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• 2007

Using the belongs to relation (${\in}$) and quasi-coincidence with relation (q) between fuzzy points and fuzzy sets, the concept of (${\alpha}$, ${\beta}$)-fuzzy subalgebras where ${\alpha}$ and ${\beta}$ areany two of {${\in}$, q, ${\in}{\vee}q$, ${\in}{\wedge}q$} with ${\alpha}{\neq}{\in}{\wedge}q$ was already introduced, and related properties were investigated (see [3]). In this paper, we give a condition for an (${\in}$, ${\in}{\vee}q$)-fuzzy subalgebra to be an (${\in}$, ${\in}$)-fuzzy subalgebra. We provide characterizations of an (${\in}$, ${\in}{\vee}q$)-fuzzy subalgebra. We show that a proper (${\in}$, ${\in}$)-fuzzy subalgebra $\mathfrak{A}$ of X with additional conditions can be expressed as the union of two proper non-equivalent (${\in}$, ${\in}$)-fuzzy subalgebras of X. We also prove that if $\mathfrak{A}$ is a proper (${\in}$, ${\in}{\vee}q$)-fuzzy subalgebra of a CK/BCI-algebra X such that #($\mathfrak{A}(x){\mid}\mathfrak{A}(x)$ < 0.5} ${\geq}2$, then there exist two prope non-equivalent (${\in}$, ${\in}{\vee}q$)-fuzzy subalgebras of X such that $\mathfrak{A}$ can be expressed as the union of them.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12S
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• pp.1187-1194
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• 2003

A BCl$_3$/Ne plasma chemistry was used to etch Ga-based (GaAs, AIGaAs, GaSb) and In-based (InGaP, InP, InAs and InGaAsP) compound semiconductors in a Planar Inductively Coupled Plasma (ICP) reactor. The addition of the Ne instead of Ar can minimize electrical and optical damage during dry etching of III-V semiconductors due to its light mass compared to that of Ar All of the materials exhibited a maximum etch rate at BCl$_3$ to Ne ratios of 0.25-0.5. Under all conditions, the Ga-based materials etched at significantly higher rates than the In-based materials, due to relatively high volatilities of their trichloride etch products (boiling point CaCl$_3$ : 201 $^{\circ}C$, AsCl$_3$ : 130 $^{\circ}C$, PCl$_3$: 76 $^{\circ}C$) compared to InCl$_3$ (boiling point : 600 $^{\circ}C$). We obtained low root-mean-square(RMS) roughness of the etched sulfate of both AIGaAs and GaAs, which is quite comparable to the unetched control samples. Excellent etch anisotropy ( > 85$^{\circ}$) of the GaAs and AIGaAs in our PICP BCl$_3$/Ne etching relies on some degree of sidewall passivation by redeposition of etch products and photoresist from the mask. However, the surfaces of In-based materials are somewhat degraded during the BCl$_3$/Ne etching due to the low volatility of InCl$_{x}$./.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.1
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• pp.29-34
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• 2015

Brain-computer interface (BCI) is being studied for convenient life in various application fields. The purpose of this study is to investigate a changing electroencephalography (EEG) for precise motion of a robot or an artificial arm. Three subjects who participated in this experiment performed three-task: Grip, Move, Relax. Acquired EEG data was extracted feature data using two feature extraction algorithm (power spectrum analysis and multi-common spatial pattern). Support vector machine (SVM) were applied the extracted feature data for classification. The classification accuracy was the highest at Grip class of two subjects. The results of this research are expected to be useful for patients required prosthetic limb using EEG.

• Proceedings of the Korean Vacuum Society Conference
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• 2005.02a
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• pp.101-101
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• 2005