• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1577-1583
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• 2012

Penetrator with enhanced lateral effect (PELE) is a novel projectile that does not require dynamite and a fuse. It comprises a high-density jacket that is closed at its rear end and filled with a low-density filling material. To study the explosion characteristics of PELE using AUTODYN-3D code, the calculation models of the projectile body and the bullet target were developed and the process of penetrating an aluminum-2024 alloy target using PELE was simulated. The scattering characteristics after PELE penetrated the aluminum-2024 alloy target were studied for different filling materials. The explicit finite element analysis of PELE fragmentation was implemented with the stochastic failure criterion in AUTODYN-3D code. As the filling expanded, the fragments gained velocity and dispersed laterally, increasing the damage area considerably. The number and shape of PELE fragments differed depending on the impact pressure of the filling that fragmented during the penetration and lateral dispersion processes.

• Journal of The Korean Dental Society of Anesthesiology
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• v.13 no.3
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• pp.89-94
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• 2013

Background: Various strategies have been studied to reduce the propofol injection pain. This study was designed to find out effect-site target concentration (Ce) of remifentanil at which there was a 50% probability of preventing the propofol injection pain (EC50). Methods: Anesthesia was induced with a remifentanil TCI (Minto model). The Ce of remifentanil for the first patient started from 2.0 ng/ml. The Ce of remifentanil for each subsequent patient was determined by the response of the previous patient by Dixon up-and-down method with the interval of 0.5 ng/ml. After the remifentanil reached target concentrations, propofol was administered via a target-controlled infusion system based on a Marsh pharmacokinetic model using a TCI device (Orchestra$^{(R)}$; Fresenius-Vial, Brezins, France). The dose of propofol was effect site target-controlled infusion (TCI) of $3{\mu}g/ml$. Results: The EC50 of remifentanil to prevent the propofol injection pain was $1.80{\pm}0.35ng/ml$ by Dixon's up and down method. Conclusions: The EC50 of remifentanil to blunt the pain responses to propofol injection was $1.80{\pm}0.35ng/ml$ for propofol TCI anesthesia.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.4
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• pp.217-226
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• 2019

Background: We aimed to assess the dose needed to achieve the propofol effect-site concentration using target-controlled infusion in intellectually disabled patients and to detail the most effective method for achieving a safe level of consciousness without hemodynamic changes as well as detail any resulting adverse effects. Methods: We performed a retrospective review of sedation service records of 138 intellectually disabled patients (51, mental retardation; 36, autism; 30, brain lesion, 12 genetic diseases, 9 dementia) aged over 15 years and weighing over 30 kg. These patients had received propofol via target-controlled infusion in the special care dental clinic of Seoul National University Dental Hospital from May 2008 to September 2018 for restorative treatment (112), minor surgery (13), prosthodontics (7), periodontics treatment (5), and implant (1). Results: For all groups, the duration of dental treatments was $43{\pm}18$ minutes, total sedation time was $73{\pm}23$ minutes, and total BIS values was $57{\pm}12$. The propofol maintenance dosage values for each group were: mental retardation, $3{\pm}0.5(2-4){\mu}g/ml$; autism, $3.1{\pm}0.7(2-5){\mu}g/ml;$; brain lesion, $2.8{\pm}0.7(1.5-5){\mu}g/ml;$; genetic disease, $2.9{\pm}0.9(1-4){\mu}g/ml;$ and dementia $2.3{\pm}0.7(1-3.4){\mu}g/ml;$. Conclusions: The dementia group needed a lower dosage to reach a safe, effective propofol effect-site concentration than the other groups. Since there were no complications, deep sedation is a great alternative to general anesthesia for dental treatment of intellectually disabled patients.

• Earthquakes and Structures
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• v.16 no.5
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• pp.563-573
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• 2019

When generating spectrum-compatible artificial ground motion in engineering practices, the effect of the variation in fitting parameters on the distribution of the peak ground displacement (PGD) has not yet drawn enough attention. In this study, a method for simulating ground motion matching for multiple targets is developed. In this method, a frequency-dependent amplitude envelope function with statistical parameters is introduced to simulate the nonstationarity of the frequency in earthquake ground motion. Then, several groups of time-history acceleration with different temporal and spectral nonstationarities were generated to analyze the effect of nonstationary parameter variations on the distribution of PGD. The following conclusions are drawn from the results: (1) In the simulation of spectrum-compatible artificial ground motion, if the acceleration time-history is generated with random initial phases, the corresponding PGD distribution is quite discrete and an uncertain number of PGD values lower than the limit value are observed. Nevertheless, the mean values of PGD always meet the requirement in every group. (2) If the nonstationary frequencies of the ground motion are taken into account when fitting the target spectrum, the corresponding PGD values will increase. A correlation analysis shows that the change in the mean and the dispersion values, from before the frequencies are controlled to after, correlates with the modal parameters of the predominant frequencies. (3) Extending the maximum period of the target spectrum will increase the corresponding PGD value and, simultaneously, decrease the PGD dispersion. Finally, in order to control the PGD effectively, the ground motion simulation method suggested in this study was revised to target a specified PGD. This novel method can generate ground motion that satisfies not only the required precision of the target spectrum, peak ground acceleration (PGA), and nonstationarity characteristics of the ground motion but also meets the required limit of the PGD, improving engineering practices.

• Journal of Korea Trade
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• v.26 no.6
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• pp.83-95
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• 2022

Purpose - With the recent spread of COVID-19, U.S. consumers' consumption pattern is changing towards purchasing large-capacity products, as they stay at home longer. Thus, the current research investigates the effects of box shape and component diversity for large-sized products on product evaluation in logistic business. Moreover, this research examines that information-processing fluency mediates the moderating effects of box shape and product components on target evaluations to confirm psychological mechanism for generating this effect. Design/methodology - In order to examine the hypotheses, the current research conducts two online experiments. The 184 participants (Study 1), and 205 participants (Study 2) of U.S. nationality were recruited through Amazon Mechanical Turk. This research analyzes the data by using SPSS 25 and PROCESS macro 4.0. Findings - Study 1 demonstrates that when the height of a box is greater than its width, products with single components promote positive target evaluations, while when the width of box is greater than its height, products with a variety of components lead to positive target evaluations. Study 2 shows that the same results are replicated in other product categories and with different box shape ratios. Moreover, Study 2 also finds that the ease of information processing mediates the interaction effects of box shape and component diversity on U.S. consumers' target evaluations. Originality/value - The current research has originality in that it investigates the effect of box shape and product composition diversity on U.S. consumer product evaluation from the perspective of information-processing theory Moreover, this research has practical implications for global traders who prepare for entering the U.S. market.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.198-198
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• 2005

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.05a
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• pp.413-414
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• 2018

• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.286-293
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• 2012

Korean government is enforcing 'Greenhouse gas target management' in order to achieve Greenhouse gas reduction target. To attain Greenhouse gas reduction target, companies in Korea must establish their GHG inventory system and analysis their GHG emissions characteristics for deduction of mitigation measures. LMDI(Log Mean Divisia Index) decomposition analysis is widely used to understand characteristics of GHG emission and energy consumption. In this paper, the characteristics of GHG emission from the line of railroad in Korea is respectively analyzed in terms of conversion effect, intensity effect, production effect and distance effect. Data of railroad GHG emission from 2000 to 2007 are used. As a result, total effect of railroad's GHG emission is $96,813tCO_2eq$. Production effect ($39,865tCO_2eq$) and distance effect ($327,923tCO_2eq$) affect increase of railroad GHG emissions while Conversion effect ($-158,161tCO_2eq$) and intensity effect ($-112,814tCO_2eq$) influence decrease of the emissions.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.73-88
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• 2018

The present study examined how processing features of visual information near the hand would affect task switching. Recent studies reported enhanced cognitive control of visual information presented the near hands. To investigate the enhancement of cognitive control based on the relationship between hand proximity and attention, we implemented 2 experiments. In the task switching performance experiment, the hand proximity effect depended on modality of cue and target. The first experiment showed that stimuli near the hand received greater cognitive control than stimuli far from the hand, resulting in smaller switch cost. The result could rule out the feature-binding problem, which identifies reduced switch cost as the cause instead of hand proximity. Our results show that hand proximity actually reduced switch cost. In the second experiment, we examined the effects of hand nearness, modality, and their interaction on switch cost. In task switching, the target was always visual, and the cue was presented either visually or auditorily. In addition, we manipulated the cue-target interval to observe the preparation effect of cue. The results showed that a visual cue near the hand reduced switch cost by shortening task preparation time. Also, modality switching between an auditory cue and visual target was remarkable in a hand-near condition. The results for the visual cue could be interpreted as a benefit of rapid visual attention orienting. On the other hand, the results for the auditory cue could be interpreted as the cost of interference of modality switching by slower attentional disengagement of stimuli near the hands. Finally, modulation of switch cost by attention induced by hand nearness was discussed.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.22 no.1
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• pp.29-62
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• 2018

We investigate a class of HIV infection models with two kinds of target cells: $CD4^+$ T cells and macrophages. We incorporate three distributed time delays into the models. Moreover, we consider the effect of humoral immunity on the dynamical behavior of the HIV. The viruses are produced from four types of infected cells: short-lived infected $CD4^+$T cells, long-lived chronically infected $CD4^+$T cells, short-lived infected macrophages and long-lived chronically infected macrophages. The drug efficacy is assumed to be different for the two types of target cells. The HIV-target incidence rate is given by bilinear and saturation functional response while, for the third model, both HIV-target incidence rate and neutralization rate of viruses are given by nonlinear general functions. We show that the solutions of the proposed models are nonnegative and ultimately bounded. We derive two threshold parameters which fully determine the positivity and stability of the three steady states of the models. Using Lyapunov functionals, we established the global stability of the steady states of the models. The theoretical results are confirmed by numerical simulations.