• Journal of the Ergonomics Society of Korea
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• v.35 no.4
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• pp.225-235
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• 2016

Objective: The aim of this study is to model all levels of situation awareness (SA), which would be able to predict situation awareness quantitatively. Background: When measuring situation awareness, directly measuring SA methods such as SAGAT and SART have been utilized. Several approaches (cognitive modeling approaches) were introduced to model SA but level 3 SA was not completed. For real-life situation, however, it is necessary to detect the problematic level of SA rather than overall SA. Therefore, we proposed a new model of all levels of SA in this study. Method: In order to model all levels of SA, this study chose factors in ACT-R architecture through literature review. ATC (Air Traffic Control)-related simulation task was video-taped to analyze human behaviors in order to model all levels of SA including level 3. Results: As a result, regression analyses show that cognitive activities (neural activations) represented for all levels of SA were highly correlated with SAGAT. Conclusion: In conclusion, neural activations in ACT-R could be proved to be effective to model all levels of SA. Application: Our SA model could be used to predict all levels of SA quantitatively without directly measuring the SA of operators.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.1
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• pp.43-49
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• 2015

The aim of this study was to model unusual association with declarative knowledge by positive affect using ACT-R cognitive architecture. Existing research related with cognitive modeling tends to pay a lot of attention to strong and negative cognitive moderator. Mild positive affect, however, has far-reaching effects on problem solving and decision making. Typically, subjects with positive affect were more likely to respond to unusual associates in a word association task than subjects with neutral affect. In this study, a cognitive model using ACT-R cognitive architecture was developed to show the effect of positive affect on the cognitive organization related with memory. First, we organized the memory structure of stimulus word 'palm' based on published results in a word association task. Then, we decreased an ACT-R parameter that reflects the amount of weighting given to the dissimilarity between the stimulus word and the associate word to represent reorganized memory structure of the model by positive affect. As a result, no significant associate probability difference between model prediction and existing empirical data was found. The ACT-R cognitive architecture could be used to model the effect of positive affect on the unusual association by decreasing (manipulating) the weight of the dissimilarity. This study is useful in conducting model-based evaluation of the effects of positive affect in complex tasks involving memory, such as creative problem solving.

• Journal of the Ergonomics Society of Korea
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• v.31 no.6
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• pp.705-713
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• 2012

Objective: The aim of this study is to predict human visual target search using ACT-R cognitive architecture in real scene images. Background: Human uses both the method of bottom-up and top-down process at the same time using characteristics of image itself and knowledge about images. Modeling of human visual search also needs to include both processes. Method: In this study, visual target object search performance in real scene images was analyzed comparing experimental data and result of ACT-R model. 10 students participated in this experiment and the model was simulated ten times. This experiment was conducted in two conditions, indoor images and outdoor images. The ACT-R model considering the first saccade region through calculating the saliency map and spatial layout was established. Proposed model in this study used the guide of visual search and adopted visual search strategies according to the guide. Results: In the analysis results, no significant difference on performance time between model prediction and empirical data was found. Conclusion: The proposed ACT-R model is able to predict the human visual search process in real scene images using salience map and spatial layout. Application: This study is useful in conducting model-based evaluation in visual search, particularly in real images. Also, this study is able to adopt in diverse image processing program such as helper of the visually impaired.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.907-914
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• 2010

Cognitive model, that is cognitive architecture, is the model expressed with computer program to show the process how human solve a certain problem and it is continuously under investigation through various fields of study such as cognitive engineering, computer engineering, and cognitive psychology. In addition, the much extensive applicability of cognitive model usually helps it to be used for quantitative prediction of human Behavior or Natural programming of human performance in many HCI areas including User Interface Usability, artificial intelligence, natural programming language and also Robot engineering. Meanwhile, when a system designed, an usability test about conceptual design of interface is needed and in this case, analysis evaluation using cognitive model like GOMS or ACT-R is much more effective than empirical evaluation which naturally needs products and subjects. In particular, if we consider the recent trend of very short-end term between a previous technology development and the next new one, it would take time and much efforts to choose subjects and train them in order to conduct usability test which is repeatedly followed in the process of a system development and this finally would bring delays of development of a new system. In this study, we predicted quantitatively the human behavior processes which contains cognitive processes for menu selection in touch screen interface through ACT-R, one of the common method of usability test. Throughout the study, it was shown that the result using cognitive model was equal with the result using existing empirical evaluation. And it is expected that cognitive model has a possibility not only to be used as an effective methodology for evaluation of HCI products or system but also to contribute the activation of HCI cognitive modeling in Korea.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.397-403
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• 2009

For the research of the natural antioxidant from marine sources, an antioxidant-producing marine actinomycetes was isolated from sea water in Jeju coastal area. The strain was identified based on 16S rDNA sequencing, the morphology by a method of scanning electron microscopy, physiological and biochemical characteristics and cellular fatty acid analysis. The isolated strain ACT-1 cell size was $0.5\sim1.0{\mu}m$ and gram positive, aerobic, nonmotile, substrate mycelium are red and gray aerial mycelium. 16S rRNA sequence analysis showed that were Gram-positive bacteria grouped on Streptomyces genus. Results of cellular fatty acid analysis showed that major cellular fatty acids were $C_{15:0}$ anteiso (39.33%), $C_{16:1}$ cis 9 (11.96%), $C_{16:0}$ (13.08%) and $C_{17:0}$ anteiso (10.99%). Finally, strain was identified Streptomyces sp. ACT-1. The antioxidant activity of methanol extract from Streptomyces sp. ACT-1 was evaluated by measuring DPPH, hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. DPPH radical scavenging activity of SBME-1 (Streptomyces broth methanol extract) was 67% at $1,000{\mu}g$/ml. Hydroxyl radical scavenging activity of SBME-1 was 84% at $500{\mu}g$/ml. Alkyl radical scavenging activity of SBME-1 was 71% at $1,000{\mu}g$/ml.

• Journal of the Korean Institute of Navigation
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• v.15 no.2
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• pp.61-86
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• 1991

This paper aims to investigated the reasonable objectiveness of trading areas on the Korea Ship Safety Act and to make a regulated proposal of trading areas. To achieve the above mentioned object, we analyzed the existing rules and other related circumstances of maritime fields. On the basis of this viewpoint, this paper was focused on three topics of concern : (1) the relationship between the ship Safety Act and other Maritime Acts. (2) the legislative examples of foreign countries, (3) the reasonable revised reasons of trading areas. In this paper, we proposed following four matters such as (1) the modification of ship's length and speed which are the designative basis of trading areas, (2) the extension of the smooth sea area to limit of territorial seas (3) the extension of the near-coastal area to the coasts of the P.R.C., Japan, the U.S.S.R and the R.O.C ., and rename of its area into the near & greater coastal area, (4) the annulment of greater-coastal area.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1134-1145
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• 2022

SCO6993 (606 amino acids) in Streptomyces coelicolor belongs to the large ATP-binding regulators of the LuxR family regulators having one DNA-binding motif. Our previous findings predicted that SCO6993 may suppress the production of pigmented antibiotics, actinorhodin, and undecylprodigiosin, in S. coelicolor, resulting in the characterization of its properties at the molecular level. SCO6993-disruptant, S. coelicolor ΔSCO6993 produced excess pigments in R2YE plates as early as the third day of culture and showed 9.0-fold and 1.8-fold increased production of actinorhodin and undecylprodigiosin in R2YE broth, respectively, compared with that by the wild strain and S. coelicolor ΔSCO6993/SCO6993⁺. Real-time polymerase chain reaction analysis showed that the transcription of actA and actII-ORF4 in the actinorhodin biosynthetic gene cluster and that of redD and redQ in the undecylprodigiosin biosynthetic gene cluster were significantly increased by SCO6993-disruptant. Electrophoretic mobility shift assay and DNase footprinting analysis confirmed that SCO6993 protein could bind only to the promoters of pathway-specific transcriptional activator genes, actII-ORF4 and redD, and a specific palindromic sequence is essential for SCO6993 binding. Moreover, SCO6993 bound to two palindromic sequences on its promoter region. These results indicate that SCO6993 suppresses the expression of other biosynthetic genes in the cluster by repressing the transcription of actII-ORF4 and redD and consequently negatively regulating antibiotic production.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.147-153
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• 2023

Lampung is a malaria-endemic region in Indonesia with an annual parasite incidence of 0.06 per 1,000 population. The socio-demographic factors, clinical conditions, and artemisinin combination therapy (ACT) types might affect parasite clearance and parasite density. This study aims to investigate factors that influence parasite clearance and parasite density in malaria patients. A retrospective analytic observational and a cross-sectional approach was used to conduct this study. A total of 66 malaria patients were examined to investigate parasite density and clearance, socio-demographic profiles, clinical conditions, and ACT types. To analyze data, univariate, bivariate, and multivariate tests were used. Age (P=0.045; r=0.238) and ACT type (P=0.021; r=0.273) were the only variables that had a significant correlation with parasite clearance. Age (P=0.003; r=0.345) had a significant correlation with parasite density. The most influential factors related to parasite clearance were the ACT type (dihydroartemisinin piperaquine) (P=0.017; odds ratio (OR) 0.109; 95.0% confidence interval (CI), 0.018-0.675) and age (P=0.030; OR 0.132; 95.0% CI, 0.021-0.823). Age (P=0.046; OR 0.320; 0.105-0.978, 95.0% CI) was the most significant variable associated with parasite density.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.1
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• pp.75-81
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• 2011

The effect of lactic acid bacteria.fermented ginseng berry extract (FGBE) on physiological activities was evaluated. The contents of ginsenosides Re, Rc, and Rb1 in ginseng berry extract (GBE) were increased after fermentation by lactic acid bacteria when analyzed by high performance liquid chromatography. Antioxidant activity of GBE and FGBE was also analyzed by DPPH radical scavenging activity assay and SOD.like activity assay. FGBE showed a 86.34 % inhibition of DPPH radical and a 76.82 % inhibition by SOD.like activity at a concentration of 1.00 %. GBE showed a 49.78 % inhibition of DPPH radical and a 40.80 % inhibition by SOD.like activity at the same concentration. Furthermore, procollagen type I (COL1A1) gene expression increased by 823.13 % and matrix metal-loproteinase(MMP)-1 and tumor necrosis factor (TNF)-${\alpha}$ gene expression decreased by 87.88 % and 99.92 %, respectively, in human fibroblast cultured with FGBE at a concentration of 0.50 %. These results suggest that FGBE could be used as an active ingredient for functional cosmetics.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.24-31
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• 2010

For the research of the natural marine antioxidant, an antioxidant-producing marine actinomycetes was isolated from sea water in Jeju coastal area. The strain was identified based on 16S rDNA sequencing, the morphology by a method of scanning electron microscopy, physiological and biochemical characteristics and cellular fatty acid analysis. The isolated strain ACT-18 was gram positive, aerobic, non-motile spores. Substrate mycelia are dark green and yellow gray aerial mycelia. The cell size of the strain was $0.5{\sim}1.0\;{\mu}m$. 16S rDNA sequence analysis showed that were Gram-positive bacteria grouped on Streptomyces sp. Results of cellular fatty acid analysis showed that major cellular fatty acids were $C_{15:0}$ anteiso (39.33%), $C_{16:1}$ cis 9 (11.96%), $C_{16:0}$ (13.08%) and $C_{17:0}$ anteiso (10.99%). The antioxidant activity of methanol extract from Streptomyce sp. ACT-18 was evaluated by measuring 1,1-diphenyl- 2-picrylhydrazyl (DPPH), hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. DPPH radical scavenging activity of SBME (Streptomyces Broth Methanol Extract) A-18 was 46% at 0.1 mg/mL. Hydroxyl radical scavenging activity of SBME A-18 was 63% at 0.1 mg/mL. Alkyl radical scavenging activity of SBME A-18 was 39% at 0.1 mg/mL.