• Journal of Ginseng Research
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• v.44 no.4
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• pp.580-592
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• 2020

Background: Radix et Rhizoma Ginseng (thereafter called ginseng) has been used as a medicinal herb for thousands of years to maintain people's physical vitality and is also a non-organ-specific cancer preventive and therapeutic traditional medicine in several epidemiologic and preclinical studies. Owing to few toxic side effects and strong enhancement on body immunity, ginseng has admirable application potential and value in cancer chemoprevention. The study aims at investigating the chemopreventive effects of ginseng on cutaneous carcinoma and the underlying mechanisms. Methods: The mouse skin cancer model was induced by 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate. Ultraperformance liquid chromatography/mass spectrometry was used for identifying various ginsenosides, the main active ingredients of ginseng. Comprehensive approaches (including network pharmacology, bioinformatics, and experimental verification) were used to explore the potential targets of ginseng. Results: Ginseng treatment inhibited cutaneous carcinoma in terms of initiation and promotion. The content of Rb1, Rb2, Rc, and Rd ginsenosides was the highest in both mouse blood and skin tissues. Ginseng and its active components well maintained the redox homeostasis and modulated the immune response in the model. Specifically, ginseng treatment inhibited the initiation of skin cancer by enhancing T-cell-mediated immune response through upregulating HSP27 expression and inhibited the promotion of skin cancer by maintaining cellular redox homeostasis through promoting nuclear translocation of Nrf2. Conclusion: According to the study results, ginseng can be potentially used for cutaneous carcinoma as a chemopreventive agent by enhancing cell-mediated immunity and maintaining redox homeostasis with multiple components, targets, and links.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.133-144
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• 2004

A model and a measure which can evaluate the risk of rear end collision are developed. Most traffic accidents involve multiple causes such as the human factor, the vehicle factor, and the highway element at any given time. Thus, these factors should be considered in analyzing the risk of an accident and in developing safety models. Although most risky situations and accidents on the roads result from the poor response of a driver to various stimuli, many researchers have modeled the risk or accident by analyzing only the stimuli without considering the response of a driver. Hence, the reliabilities of those models turned out to be low. Thus in developing the model behaviors of a driver, such as reaction time and deceleration rate, are considered. In the past, most studies tried to analyze the relationships between a risk and an accident directly but they, due to the difficulty of finding out the directional relationships between these factors, developed a model by considering these factors, developed a model by considering indirect factors such as volume, speed, etc. However, if the relationships between risk and accidents are looked into in detail, it can be seen that they are linked by the behaviors of a driver, and depending on drivers the risk as it is on the road-vehicle system may be ignored or call drivers' attention. Therefore, an accident depends on how a driver handles risk, so that the more related risk to and accident occurrence is not the risk itself but the risk responded by a driver. Thus, in this study, the behaviors of a driver are considered in the model and to reflect these behaviors three concepts related to accidents are introduced. And safe stopping distance and accident occurrence probability were used for better understanding and for more reliable modeling of the risk. The index which can represent the risk is also developed based on measures used in evaluating noise level, and for the risk comparison between various situations, the equivalent risk level, considering the intensity and duration time, is developed by means of the weighted average. Validation is performed with field surveys on the expressway of Seoul, and the test vehicle was made to collect the traffic flow data, such as deceleration rate, speed and spacing. Based on this data, the risk by section, lane and traffic flow conditions are evaluated and compared with the accident data and traffic conditions. The evaluated risk level corresponds closely to the patterns of actual traffic conditions and counts of accident. The model and the method developed in this study can be applied to various fields, such as safety test of traffic flow, establishment of operation & management strategy for reliable traffic flow, and the safety test for the control algorithm in the advanced safety vehicles and many others.

• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.475-483
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• 2012

High capacitance X5R MLCCs based on $BaTiO_3$ ceramic dielectric layers exhibit a single broad, asymmetric arc shape impedance and modulus response over the wide frequency range between 1 MHz to 0.01 Hz. Analysis according to the conventional brick-layer model for polycrystalline conductors employing a series connection of multiple RC parallel circuits leads to parameters associated with large errors and of little physical significance. A new parametric impedance model is shown to satisfactorily describe the experimental spectra, which is a parallel network of one resistor R representing the DC conductivity thermally activated by 1.32 eV, one ideal capacitor C exactly representing bulk capacitance, and a constant phase element (CPE) Q with complex capacitance $A(i{\omega})^{{\alpha}-1}$ with ${\alpha}$ close to 2/3 and A thermally activated by 0.45 eV or ca. 1/3 of activation energy of DC conductivity. The feature strongly indicate the CK1 model by J. R. Macdonald, where the CPE with 2/3 power-law exponent represents the polarization effects originating from mobile charge carriers. The CPE term is suggested to be directly related to the trapping of the electronic charge carriers and indirectly related to the ionic defects responsible for the insulation resistance degradation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.68-78
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• 2020

Crop models have been used to predict vegetable crop yield, which would have a considerable economic impact on consumers as well as producers. A small number of models have been developed to estimate growth and yield of vegetables due to limited availability of growth observation data in high-quality. In this study, we aimed to analyze the protocols designed for collection of the observation data for major vegetable crops including cabbage, radish, garlic, onion and pepper. We also designed the protocols suitable for development and verification of a vegetable crop growth model. In particular, different measures were proposed to improve the existing protocol used by Statistics Korea (KOSTAT) and Rural Development Administration (RDA), which would enhance reliability of parameter estimation for the crop model. It would be advantageous to select sampling sites in areas where reliable weather observation data can be obtained because crop models quantify the response of crop growth to given weather conditions. It is recommended to choose multiple sampling sites where climate conditions would differ. It is crucial to collect time series data for comparison between observed and simulated crop growth and yield. A crop model can be developed to predict actual yield rather than attainable yield using data for crop damage caused by diseases and pests as well as weather anomalies. A bigdata platform where the observation data are to be shared would facilitate the development of crop models for vegetable crops.

• Journal of Intelligence and Information Systems
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• v.18 no.1
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• pp.39-57
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• 2012

Recently, due to the introduction of high-tech equipment in interactive exhibits, many people's attention has been concentrated on Interactive exhibits that can double the exhibition effect through the interaction with the audience. In addition, it is also possible to measure a variety of audience reaction in the interactive exhibition. Among various audience reactions, this research uses the change of the facial features that can be collected in an interactive exhibition space. This research develops an artificial neural network-based prediction model to predict the response of the audience by measuring the change of the facial features when the audience is given stimulation from the non-excited state. To present the emotion state of the audience, this research uses a Valence-Arousal model. So, this research suggests an overall framework composed of the following six steps. The first step is a step of collecting data for modeling. The data was collected from people participated in the 2012 Seoul DMC Culture Open, and the collected data was used for the experiments. The second step extracts 64 facial features from the collected data and compensates the facial feature values. The third step generates independent and dependent variables of an artificial neural network model. The fourth step extracts the independent variable that affects the dependent variable using the statistical technique. The fifth step builds an artificial neural network model and performs a learning process using train set and test set. Finally the last sixth step is to validate the prediction performance of artificial neural network model using the validation data set. The proposed model is compared with statistical predictive model to see whether it had better performance or not. As a result, although the data set in this experiment had much noise, the proposed model showed better results when the model was compared with multiple regression analysis model. If the prediction model of audience reaction was used in the real exhibition, it will be able to provide countermeasures and services appropriate to the audience's reaction viewing the exhibits. Specifically, if the arousal of audience about Exhibits is low, Action to increase arousal of the audience will be taken. For instance, we recommend the audience another preferred contents or using a light or sound to focus on these exhibits. In other words, when planning future exhibitions, planning the exhibition to satisfy various audience preferences would be possible. And it is expected to foster a personalized environment to concentrate on the exhibits. But, the proposed model in this research still shows the low prediction accuracy. The cause is in some parts as follows : First, the data covers diverse visitors of real exhibitions, so it was difficult to control the optimized experimental environment. So, the collected data has much noise, and it would results a lower accuracy. In further research, the data collection will be conducted in a more optimized experimental environment. The further research to increase the accuracy of the predictions of the model will be conducted. Second, using changes of facial expression only is thought to be not enough to extract audience emotions. If facial expression is combined with other responses, such as the sound, audience behavior, it would result a better result.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.470-487
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• 1996

The purpose of this study was to investigate the dynamic response of the mandible to impact and provide insight into the fracture mechanism of the mandible, by 3-dimensional finite element method. The finite element model of the mandible was developed and calculated using NASTRAN/XL (MSC co. U.S.A.) and the linear dynamic transient analysis was performed according to the impulsive force direction, force type and impulse time to the mandible. At first, the load was applied on the mandibular symphysis, body, angle and subcondylar area in the horizontal mandibular plane and the computed stress-time histories at 14 locations of the mandible were obtained. Secondly, the impulsive force was directed to the symphyseal area with changing the force magnitude and impulse time, and calculated the node displacement at 8 locations of mandible. The conclusions from from this study were as follows. 1. The appearance of impulsive energy transmission was different to the direction of impulse to the mandible. 2. The impulsive stress and deformation were larger in lingual or medial side than buccal or lateral in the mandible. 3. The velocity, appearance of energy transmission and the fracture pattern in mandible were affected rather impulse time than force. 4. The horizontal impact to the one side of mandible did not have effect on the stress and displacement of contralateral mandible. From the above results, fracture pattern in symphysis can be showed as simple or comminuted, multiple or associated in body and angle and solitary in subcondyle area.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.675-687
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• 2000

Multiple periodontal pathogens sequentially colonize the subgingival niche during the conversion from gingivitis to destructive periodontal disease. An animal model of sequential immunization with key periodontal pathogens has been developed to determine whether T and B lymppocyte effector functions are skewed and fail to protect the host from pathogenic challenge. The present study was performed to evaluate immunomodulatory effect of exposure to Fusobacterium nucleatum(F. nucleatum) prior to Porphyromonas gingivalis(P. gingi - valis). Group 1(control) mice were immunized with phosphate-buffered saline, Group 2 were immunized with F. nucleatum prior to P. gingivalis, while Group 3 were immunized P. gingivalis alone. All the T cell clones derived from Group 2 demonstrated type 2 helper T cell clone(Th2 subsets), while those from Group 3 mice demonstrated Th1 subsets. Exposure of mice to F . nucleatum prior to P. gingivalis interfered with opsonophagocytosis function of sera against P. gingivalis. In adoptive T cell transfer experiments, in vivo protective capacity type 2 helper T cell clones(Th2) from Group 2 was significantly lower than type 1 helper T cell clones(Th1) from Group 3 against the lethal dose infection of P. gingivalis. Western blot analysis indicated the different pattern of recognition of P .gingivalis fimbrial proteins between sera from Group 2 and Group 3. In conclusion, these study suggest that colonization of the subgingival niche by F .nucleatum prior to the periodontal pathogen, P. gingivalis, modulates the host immune responses to P. gingivalis at humoral, cellular and molecular levels.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.319-325
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• 2017

In this study, we optimized the coffee extraction conditions for instant coffee production in two stage percolators, which is the most common coffee extractor for instant coffee production. A central composite design was used to build mathematical model equations for response surface methodology (RSM). In these equations, the yield and overall acceptability of the coffee extracts were expressed as second-order functions of three factors, the feed water temperature, draw-off factor (DOF), and extraction time (cycle time). Based on the result of RSM, the optimum conditions were obtained with the use of desirability function approach (DFA) which find the best compromise area among multiple options. The optimum extraction conditions to maximize the yield and overall acceptability over 40% of yield were found with $163^{\circ}C$ of feed water temperature, 4.3 of DOF and 27 minutes of extraction time (cycle time). These results provide a basic data for the coffee extraction conditions for the competitive instant coffee in the industry.

• 대한예방의학회:학술대회논문집
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• 1994.02a
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• pp.651-657
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• 1994

To assess quantitatively the association between benzene exposure and leukemia, we examined the mortality rate of a cohort with occupational exposure to benzene. Cumulative exposure for each cohort member was estimated from historical air-sampling data and, when no sampling data existed, from interpolation on the basis of existing data. The overall standardized mortality ratio (a measure of relative risk multiplied by 100) for leukemia was 337 (95 percent confidence interval, 154 to 641), and that for multiple myeloma was 409 (95 percent confidence interval, 110 to 1047). With stratification according to levels of cumulative exposure, the standardized mortality ratios for leukemia increased from 109 to 322, 1186, and 6637 with increases in cumulative benzene exposure from less than 40 parts per million-years (ppm-years), to 40 to 199, 200 to 399, and 400 or more. respectively. A cumulative benzene exposure of 400 ppm years is equivalent to a mean annual exposure of 10 ppm over a 40-year working lifetime; 10 ppm is the currently enforceable standard in the United States for occupational exposure to benzene. To examine the shape of the exposure-response relation, we performed a conditional logistic-regression analysis, in which 10 controls were matched to each cohort member with leukemia. From this model, it can be calculated that protection from benzene induced leukemia would increase exponentially with any reduction in the permissible exposure limit.

• Journal of Embryo Transfer
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• v.10 no.1
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• pp.33-44
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• 1995

Genetic changes from improving female's reproductive rate through in vitro fertilization of large number of oocytes were studied. The breeding scheme employed was multiple ovulation and embryo transfer of juveniles and adults. Both balanced and unbalanced matings were examined for the four closed progeny population sizes, 10$^3$, 10$^4$, 105, 106. In balanced matings, all selected sires and dams were mated to each other(cross-classified mating) while unbalanced matings allowed selected dams and sires mated partially, eg. unbalanced matings allowed averages of .5 and .25 progeny per each mating. Various numbers of selected sires and dams were also examined in both balanced and unbalanced matings. In all mating schemes, selection of males and females was restricted to he one from each fullsib family to reduce the rate of inbreeding. The model calculations were deterministic and accounted for the effects of selection and inbreeding on loss of the genetic variation in succeeding generations. Balanced rectangular mating schemes, where more donors were selected than sires, resulted in larger selection responses than balanced square mating schemes, where equal numbers of sires and donors were selected, and unbalanced rectangular mating. The first round selection responses from the balanced rectangular matings of juvenile MOET, eg. number of progeny per mating equals 2 with 10 sires selected, were 1.192, 1.406, 1.580 and 1.735 times larger than the first round selection responses from the balanced square mating schemes for the given four progeny population sizes, 10$^3$, 10$^4$, 105 and 106, respectively. Similar results were obtained in adult MOET breeding schemes. However, balanced square matings gave greater selection responses than the unbalanced rectangular matings.