• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.4
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• pp.182-193
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• 1997

The interaction of monochromatic incident waves with a horizontal flexible membrane is investigated in the context of two-dimensional linear hydro-elastic theory. First, analytic diffraction and radiation solutions for a submerged impermeable horizontal membrane are obtained. Second, the theoretical prediction was compared with a series of experiments conducted in a two-dimensional wave tank at Texas A & M University. The measured reflection and transmission coefficients reasonably follow the trend of predicted values. Using the developed computer program, the performance of surface-mounted or submerged horizontal membrane wave barriers is tested with various system parameters and wave characteristics. It is found that the properly designed horizontal flexible membrane can be an effective wave barrier.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.418-430
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• 2017

The objective of this study was to understand the combined effect of shading treatment and harvest time on pungency, ascorbic acid content, market-quality pepper yield, and photosynthetic activity in a yellow 'Star Flame' and 'Fire Flame' F1 hybrid pepper cultivar (Capsicum annuum). Plants were cultivated in a greenhouse under white, red, and green shading nets and compared to those grown under unshaded control conditions. The ascorbic acid and pungency parameters were analyzed by high-performance liquid chromatographic methods. Ascorbic acid, a compound of high nutritive value in pepper, was highest in fruits gathered during the first summer harvest in both hybrids. The ascorbic acid content was found to be further increased in fruits from plants grown under white net shading in both 'Star Flame' and 'Fire Flame'. Total capsaicinoid contents in 'Star Flame' were influenced by the interaction of shading treatment and harvest time (p = 0.004), with the lowest amounts ($241.2-251.5mg{\cdot}kg^{-1}$ fresh weight) resulting from white and red shading treatments at the early autumn harvest. In 'Fire Flame', both shading treatment (p = 0.009) and harvest time (p < 0.001) affected total capsaicinoid contents. We observed significantly higher total capsaicinoid contents in control fruits compared to that resulting from red and green shading treatments at the second harvest, and that resulting from red shading treatment at the third harvest. Analysis of photosynthetic activity revealed a significant and negative correlation between Fv/Fm values and total capsaicinoid contents in both hybrids (p < 0.001). Based on the obtained results, the harvest of peppers during summer should be promoted to produce fruits with high pungency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1738-1756
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• 2020

To improve the accuracy and realism of the virtual surgical simulation system, this paper proposes an optimized mass-spring model with shape restoration ability based on volume conservation to simulate soft tissue deformation. The proposed method constructs a soft tissue surface model that adopts a new flexion spring for resisting bending and incorporates it into the mass-spring model (MSM) to restore the original shape. Then, we employ the particle swarm optimization algorithm to achieve the optimal solution of the model parameters. Besides, the volume conservation constraint is applied to the position-based dynamics (PBD) approach to maintain the volume of the deformable object for constructing the soft tissue volumetric model base on tetrahedrons. Finally, we built a simulation system on the PHANTOM OMNI force tactile interaction device to realize the deformation simulation of the virtual liver. Experimental results show that the proposed model has a good shape restoration ability and incompressibility, which can enhance the deformation accuracy and interactive realism.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.7
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• pp.601-608
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• 2015

The static aeroelastic analysis and optimization of flexible wings are conducted for steady state conditions while both aerodynamic and structural parameters can be used as optimization variables. The system of multidisciplinary design optimization as a robust methodology to couple commercial codes for a static aeroelastic optimization purpose to yield a convenient adaptation to engineering applications is developed. Aspect ratio, taper ratio, sweepback angle are chosen as optimization variables and the skin thickness of the wing. The real-coded adaptive range multi-objective genetic algorithm code, which represents the global multi-objective optimization algorithm, was used to control the optimization process. The support vector regression(SVR) is applied for optimization, in order to reduce the time of computation. For this multi-objective design optimization problem, numerical results show that several useful Pareto optimal designs exist for the flexible wing.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_1
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• pp.439-446
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• 2013

This paper is about assessment of soil loss in irrigation reservoir based on GIS. Natural disaster caused by soil loss whose natural incidence has been rapidly reduced due to successful tree planting campaign shows high potential risk, since the latest localized heavy rain resulted from extreme weather event and artificial land development acts as direct factors for land disaster. To prevent it, various techniques and technologies have been used to predict effect of soil loss. However, reliability of techniques and technologies to predict its effect precisely is relatively low so far because the natural disaster by soil loss is taken place by complicated interaction between possible factors and direct factors. Geospatial approach is essential to examine these interactions. In this regard, this study will provide detailed plan to improve prediction reliability for soil loss of irrigation reservoir, using GIS that has Hydrologic -Topographical parameter and digital map as its input parameters.

• Journal of Information Technology Services
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• v.19 no.1
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• pp.89-102
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• 2020

With the technology of the 4th Industrial Revolution integrated into the industry as a whole, digital transformation (DT) is becoming an innovative and essential element of corporate survival in the fashion industry, and it is expected that the paradigm shift in shopping will become an unavoidable reality, especially based on the AR. Therefore, in this study, the characteristics of augmented reality were presented separately as perceived realism, interaction, pleasure, and usability, and the influence of augmented reality by immersion parameters on the user's satisfaction and intended to reveal the relationship between satisfaction and usage through the characteristics of augmented reality. For the purpose of this study, a structured questionnaire was conducted, and the available 209 responses were collected and used for empirical analysis. The results of the empirical analysis are as follows. First, while immersion has the greatest effect on satisfaction, the effect on use intention has a stronger effect on satisfaction than immersion. This indicates that purchase occurs when the user's immersion leads to satisfaction, and when the satisfaction falls, the intention to use is also lowered. Second, interactivity, enjoyment, and ease of use among the various characteristics of fashion applications have a positive effect on immersion. Among them, ease of use had a strong effect on immersion. In light of this, it can be seen that ease of use should be considered first when creating an application based on augmented reality in the future fashion industry. However, the perceived reality is low in the degree of immersion, and the effect on satisfaction is also lowered, so it is difficult to be connected to intention. Considering that this study was conducted through indirect experience through video viewing, this study expects the development of research through a more practical research model in the future, as the impact is considered to be a relatively low measurement.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.2
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• pp.264-274
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• 1997

A numerical analysis on condensation and coagulation of the metallic species with fly ash particles pre-existing in an incinerator was performed. Waste was simplified as a mixture of methane, chlorine, and small amounts of Pb and Sn. Vapor-phase amounts of Pb- and Sn -compounds were first calculated assuming a thermodynamic equilibrium state. Then theories on vapor-to-particle conversion, vapor condensation onto the fly ash particles, and particle-particle interaction were examined and incorporated into equations of aerosol dynamics and vapor continuity. It was assumed that the particles followed a log-normal size distribution and thus a moment model was developed in order to predict the particle concentration and the particle size distribution simultaneously. Distributions of metallic vapor concentration (or vapor pressure) were also obtained. Temperature drop rate of combustion gas, fly ash concentration and its size were selected as parameters influencing the discharged amount of metallic species. In general, the coagulation between the newly formed metal particles and the fly ash particles was much greater than that between the metal particles themselves or between the fly ash particles themselves. It was also found that the amount of metallic species discharged into the atmosphere was increased due to coagulation. While most of PbO vapors produced from the combustion were eliminated due to combined effect of condensation and coagulation, the highly volatile species, PbCl$_{2}$ and SnCl$_{4}$ vapors tended to discharge into the atmosphere without experiencing either the condensation or the coagulation. For Sn vapors the tendency was between that of PbO vapors and that of PbCl$_{2}$ or SnCl$_{4}$. To restrain the discharged amount of hazardous metallic species, the coagulation should be restrained, the number concentration and the size of pre-existing fly ash particles should be increased, and the temperature drop rate of combustion gas should be kept low.

• Toxicological Research
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• v.32 no.2
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• pp.123-132
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• 2016

The impact of mobile phone (MP) radiation on the brain is of specific interest to the scientific community and warrants investigations, as MP is held close to the head. Studies on humans and rodents revealed hazards MP radiation associated such as brain tumors, impairment in cognition, hearing etc. Melatonin (MT) is an important modulator of CNS functioning and is a neural antioxidant hormone. Zebrafish has emerged as a popular model organism for CNS studies. Herein, we evaluated the impact of GSM900MP (GSM900MP) radiation exposure daily for 1 hr for 14 days with the SAR of 1.34W/Kg on neurobehavioral and oxidative stress parameters in zebrafish. Our study revealed that, GSM900MP radiation exposure, significantly decreased time spent near social stimulus zone and increased total distance travelled, in social interaction test. In the novel tank dive test, the GSM900MP radiation exposure elicited anxiety as revealed by significantly increased time spent in bottom half; freezing bouts and duration and decreased distance travelled, average velocity, and number of entries to upper half of the tank. Exposed zebrafish spent less time in the novel arm of the Y-Maze, corroborating significant impairment in learning as compared to the control group. Exposure decreased superoxide dismutase (SOD), catalase (CAT) activities whereas, increased levels of reduced glutathione (GSH) and lipid peroxidation (LPO) was encountered showing compromised antioxidant defense. Treatment with MT significantly reversed the above neurobehavioral and oxidative derangements induced by GSM900MP radiation exposure. This study traced GSM900MP radiation exposure induced neurobehavioral aberrations and alterations in brain oxidative status. Furthermore, MT proved to be a promising therapeutic candidate in ameliorating such outcomes in zebrafish.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.1
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• pp.30-36
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• 2020

This study aimed to investigate heart rate variability (HRV) characteristics of cold pattern with repeated measurement data. Participants were taken from a Daejeon University cohort study from 2015 to 2018. Forty-seven of the participants studied displayed cold pattern while 23 showed signs of non-cold pattern. HRV was measured in supine position for 5 minutes at each year, and an 8-item cold pattern questionnaire was used for the diagnosis of cold pattern. SDNN (standard deviation of the NN intervals) and RMSSD (the square root of the mean squared differences of successive NN intervals) were used as time domain analysis, and TP (total power), VLF (power in very low frequency range), LF (power in low frequency range), HF (power in high frequency range), LF norm (LF power in normalized units), HF norm (HF power in normalized units) and LF/HF were used as frequency domain analysis. In the Mann-Whitney U test, LF norm, HF norm, and LF/HF showed differences between the cold pattern group and non-cold pattern group at every measurement, and in the independent t-test, the differences were also observed at three points except for the baseline (2015). In the repeated measures ANOVA, the interaction effects were not observed in all HRV parameters, but the time period effects were observed in SDNN, RMSSD, TP, VLF, LF and HF. There were significant differences between those two groups in LF norm, HF norm and LF/HF. This study suggests that LF norm, HF norm and LF/HF might be a useful indicator of cold pattern properties.

• Biomolecules & Therapeutics
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• v.18 no.3
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• pp.343-349
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• 2010

This study was designed to investigate the effects of ticlopidine on the pharmacokinetics of carvedilol after oral or intravenous administration of carvedilol in rats. Carvedilol was administered orally (3 mg/kg) or intravenously (1 mg/kg) without or with oral administration of ticlopidine (4, 12 mg/kg) to rats. The effects of ticlopidine on P-glycoprotein (P-gp) and cytochrome P450 (CYP) 2C9 activity were also evaluated. Ticlopidine inhibited CYP2C9 activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of $25.2\;{\mu}M$. In addition, ticlopidine could not significantly enhance the cellular accumulation of rhodamine 123 in MCF-7/ADR cells overexpressing P-gp. Compared with the control group (given carvedilol alone), the area under the plasma concentration-time curve (AUC) was significantly (12 mg/kg, p<0.05) increased by 14-41%, and the peak concentration ($C_{max}$) was significantly (12 mg/kg, p<0.05) increased by 10.7-73.3% in the presence of ticlopidine after oral administration of carvedilol. Consequently, the relative bioavailability (R.B.) of carvedilol was increased by 1.14- to 1.41-fold and the absolute bioavailability (A.B.) of carvedilol in the presence of ticlopidine was increased by 36.2-38.5%. Compared to the i.v. control, ticlopidine could not significantly change the pharmacokinetic parameters of i.v. administered carvedilol. The enhanced oral bioavailability of carvedilol may result from inhibition of CYP2C9-mediated metabolism rather than P-gpmediated efflux of carvedilol in the intestinal and/or in liver and renal eliminatin of carvedilol by ticlopidine.