• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.101-108
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• 2002

Benthic organisms dwell in sediment-water interface that contains significant amount of organic and inorganic contaminants. Their feeding behavior is highly related with sediment itself and pore water in the sediments, especially in ease of deposit feeder (i.e. polychaete, amphipod). The acid volatile sulfide (AVS) is one of the important binding phases of sediment-bound metals in addition to organic matter and Fe and Mn oxide fractions in sediments, particularly in anoxic sediments. The AVS model is a powerful tool to predict metal bioavailability and bioaccumulation in benthic organisms considering SEM/AVS mole ratios in surficial sediments. However, several biogeochemical factors must be considered to use AVS model in the sediment-bound metal bioavailability.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.464-467
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• 1999

Rapid progress in the modeling of biological structures and simulation of their development has occurred over the last few years. Cellular automata (CA) and Lindenmayer-system(L-system) are the representative models of development/morphogenesis of multicellular organism. L-system is applied to the visualization of biological plant. Also, CA are applied to the study of artificial life and to the construction of an artificial brain. To design the L-system and CA automatically, we make this model evolve. It is necessary to code the developmental rules for evolution. In this paper, we propose a DNA coding method for evolution the models of development/morphogenesis of biological multicellular organisms. DNA coding has the redundancy and overlapping of gene and is apt for the representation of the rule. In this paper, we propose the DNA coding method of CA and L-system.

• Biomolecules & Therapeutics
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• v.21 no.3
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• pp.241-245
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• 2013

Aging is the single most important risk factor that increases susceptibility to many forms of diseases. As such, much effort has been put forward to elucidate the mechanisms behind the processes of aging and to discover novel compounds that retain anti-aging activities. Korean red ginseng has been used for a variety of medical purposes in eastern countries for several thousands of years. It has been shown that Korean red ginseng affects a number of biological activities including, but not limited to, anti-inflammatory, anti-oxidative and anti-diabetic pathways. However, few studies have been performed to evaluate its anti-aging effects with an in vivo system. Here Drosophila melanogaster as an in vivo model organism demonstrates that Korean red ginseng tonic extends lifespan, increases resistance to starvation stress and prevents weight gain. This data suggest that Korean red ginseng may regulate organisms' metabolism in favor of extending lifespan.

• Proceedings of the Korean Environmental Health Society Conference
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• 2001.11a
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• pp.42-48
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• 2001

A kinetic model was presented to estimate the uptake/release rate constants and thereafter, bioconcentration factor, $k_1$, $k_2$ and BCF (bioconcentration factor), for the uptake of PH by plankton were obtained. Implies that PH(petroleum hydrocarbon) caused no significant influence on the uptake of $N-NO_3$, but significant influence on that of $P-PO_4$. In addition, the application of kinetic model for the bioconcentration of volatile organic toxic compound by organism suggests that the uptake of PH by plankton was an important process for the environmental capacity of PH.

• Toxicological Research
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• v.25 no.1
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• pp.9-15
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• 2009

Historically, research in toxicology has utilized non-human mammalian species, particularly rats and mice, to study in vivo the effects of toxic exposure on physiology and behavior. However, ethical considerations and the overwhelming increase in the number of chemicals to be screened has led to a shift away from in vivo work. The decline in in vivo experimentation has been accompanied by an increase in alternative methods for detecting and predicting detrimental effects: in vitro experimentation and in silico modeling. Yet, these new methodologies can not replace the need for in vivo work on animal physiology and behavior. The development of new, non-mammalian model systems shows great promise in restoring our ability to use behavioral endpoints in toxicological testing. Of these systems, the zebrafish, Danio rerio, is the model organism for which we are accumulating enough knowledge in vivo, in vitro, and in silico to enable us to develop a comprehensive, high-throughput toxicology screening system.

• Molecules and Cells
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• v.45 no.11
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• pp.763-770
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• 2022

Caenorhabditis elegans has been used as a major model organism to identify genetic factors that regulate organismal aging and longevity. Insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) regulates aging in many species, ranging from nematodes to humans. C. elegans is a nonpathogenic genetic nematode model, which has been extensively utilized to identify molecular and cellular components that function in organismal aging and longevity. Here, we review the recent progress in the role of IIS in aging and longevity, which involves direct regulation of protein and RNA homeostasis, stress resistance, metabolism and the activities of the endocrine system. We also discuss recently identified genetic factors that interact with canonical IIS components to regulate aging and health span in C. elegans. We expect this review to provide valuable insights into understanding animal aging, which could eventually help develop anti-aging drugs for humans.

• Knowledge Management Research
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• v.14 no.4
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• pp.1-17
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• 2013

As online communities proliferate, online news sites have received great attention in news media research. Although most of the online news sites provide contents for free, some have adopted the Pay-What-You-Want (PWYW) model by offering a voluntary payment option to the readers. In this study, we investigate the factors which influence subscribers' voluntary payment behavior on an online news site. Drawing upon both the Stimulus-Organism-Response (SOR) framework and the Elaboration Likelihood Model (ELM), we hypothesize that appreciation has a direct effect on the subscribers' voluntary payment behavior, whereas central factors (positive emotional content, cognitive content) and peripheral factors (news sharing, news article length) of the news articles have indirect impacts on voluntary payment behavior through the enhanced appreciation. Based on an empirical analysis of 172 news articles from the Korean online news site that adopted the PWYW pricing model (i.e., Ohmynews.com), we find that appreciation plays a critical role in voluntary payment behavior and that peripheral factors have significant impacts on appreciation. However, the impacts of central factors on appreciation are not found. By identifying influencing factors of subscribers' voluntary payment behavior on online news sites for the first time, this paper suggests a prospective alternative profit model for online news providers faced with fierce competition.

• KSBB Journal
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• v.9 no.1
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• pp.72-84
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• 1994

A model to explain the observed kinetics in a whole process of Cheddar-cheese ripening has been developed. It includes growth and lysis of cells in the cheese matrix, cell-wall bound protelnases and intracellular dipeptidases that are released into cheese upon cell lysis, and the production of dipeptides and amino acids from casein in cheese. Model simulations have been conducted to figure out the crucial factors in the process of the cheese ripening. The influential factors have been found to be the cell numbers and the dipeptidase activity at the beginning of the cheese ripening, and the cell-lysis rate of cheese starters. The simulation results have also suggested the use of a mixed culture as well as the experimental screening for a more suitable organism as a cheese starter hence, the model shows how to accelerate the cheese ripening.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.264-271
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• 2004

An aquatic food chain was constructed to provide information of bioaccumulation of DEHP as followed: phytoplankton(Scenedesmus subspicatus) ${\rightarrow}$ zooplankton(Daphnia magna) ${\rightarrow}$ fish(Oryzias latipes). After 10 days of exposure to DEHP, the fish and culture water were analyzed for residual concentration of DEHP and BAF(Bioaccumulation Factor) was determined. In addition, BCF(Bioconcentration Factor) was calculated in exposure tank in which fish were only exposed DEHP by culture water. These experiments provide the relative importance between BAF and BCF. In this study, BCF and BAF did not show any significant difference. Another work in this study was model construction and application to investigate the effect of food chain structure to BAF in higher organism (fish). The model constructed in this study considered the biological characteristics of DEHP such as metabolic parameters, as well as the chemical characteristics such as solubility. This model could be used in prediction of bioaccumulation level in dependent of various food chain structures, when the target organisms or chemicals would be changed.

• Journal of Information Technology Services
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• v.21 no.5
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• pp.107-127
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• 2022

Personal broadcasting utilizing Vtuber, a virtual creator made of 2D or 3D avatars, has recently appeared and is growing in popularity. Vtuber is a virtual person who broadcasts on the Internet using 2D or 3D avatars with real-time motion capture and computer graphics technologies. While the personal broadcasting industry utilizing Vtuber is proliferating, related studies have mainly concentrated on technical issues. Therefore, in this study, the antecedent factors that form the technical characteristics and virtual creator characteristics of Vtuber personal broadcasting are derived using the Stimulus-Organism-Response (S-O-R) model. Then the effect of these factors on viewer pleasure and satisfaction, which lead to increased paid sponsorship is to be examined. Furthermore, we investigate how this influencing mechanism fluctuates based on the avatar type (2D vs. 3D). This study contributes to empirical examinations of viewers' paid sponsorship intention in Vtuber personal broadcasting through the S-O-R model. It also offers insights that technological or virtual creator characteristics could improve viewers' pleasure, satisfaction, and even paid sponsorship.