• Journal of the Korean Magnetics Society
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• v.21 no.6
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• pp.204-207
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• 2011

We developed a time-resolved magneto-optical Kerr effect microscope system to investigate ultrafast magnetization dynamics. Based on the pump-probe method, 0.1-ps time resolution was achieved by use of a fs Ti:Sapphire laser. The magnetization dynamics was then measured on Pt/Co/Pt thin films with various Co thicknesses. All the samples exhibited ultrafast demagnetization within a few ps by direct heating of pump laser. Some thicker samples showed precessional motion of magnetization, from which the Gilbert damping constant was determined based on the Landau-Lifshitz-Gilbert equation.

• Korean Journal of Optics and Photonics
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• v.2 no.4
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• pp.209-213
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• 1991

Recently, the developments in generating and amplifying ultrashort optical pulses $(ps=10^{-12}s or fs=10^{-15}s)$ have imposed on great advances in the time-resolved laser spectroscopy. Especially, the transient absorption spectroscopy has a wide application range and the main idea of this technique is pump & probe method. After the pump pulse makes the material an excited or a transient states, the probe pulse is sent through the material to measure the absorbance change due to the transient states. Here, if the absorbance change was measured by the time delay between pump & probe pulses, the dynamic information of the excited or the transient states (the transient abnsorption changes by time & wavelength) can be obtained. At our laboratory, the ultrashort optic1 pulse (

• Journal of Korea Trade
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• v.24 no.8
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• pp.81-100
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• 2020

Purpose - Based on complexity theory, this study develops a configurational model to predict the profitability of Halal cosmetics firms in the Indonesian and Malaysian markets. The proposed research model involves two level configurations-industry context and selling strategies-to predict high and low scores of a firm's profitability. The industry context configuration model comprises industry stability, product homogeneity, price sensitivity, and switching cost. Selling strategies include customer-focused, competitor-focused, and margin-focused approaches. Design/methodology - This is the first empirical study that calculates causal models using a combination of industry context and selling strategy factors to predict profitability. Data obtained from the marketing managers of cosmetics firms are used to test the proposed configurational model using fuzzy-set qualitative comparative analysis (fsQCA). It contributes to the current knowledge of business marketing by identifying the factors necessary to achieve profitability using analysis of condition (ANC). Findings - The results revealed that unique and distinct models explain the conditions for high and low profitability in the Indonesian and Malaysian halal cosmetic markets. While customer-focused selling strategy is necessary to attain a higher profit in both the markets, margin-focused selling strategy appears to be an essential factor only in Malaysia. Complexity of the interactions of selling strategies with industry factors and differences between across two study markets confirmed that complexity theory can support the research configurational model. The theoretical and practical implications are also illustrated. Originality/value - Despite the rapid growth of the global halal industry, there is little knowledge about the halal cosmetic market. This study contributes to the current literature of the halal market by performing a set of asymmetric analytical approaches using a complex theoretical model. It also deepens our understating of how the Korean firms can approach the Muslim consumer's needs to generate more beneficial turnover/revenue.

• Journal of the Korean Geotechnical Society
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• v.37 no.7
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• pp.5-12
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• 2021

When drilling investigations for Rock Slopes are not possible, it is often difficult to calculate the Ground Design Constants required for the Limit Equilibrium Analysis. Therefore, the outcrops or partially cutted Rock Slopes were analysed using JRC and JCS that can be easily and conveniently measured. In particular, the effect of the JRC on the Safety Factor or the Rock Slopes was analyzed intensively, and the results were presented as a relationship formula and Table. When the Rock slope was stable, the JRC increased by an average of 9.0% as the slope height increased, and increased by an average of 29.8% as the slope angle increased. JRC was more sensitive to slope angle changes. The Cohesion corresponding to JRC was calculated from JRC-Fs formula. JRC and Cohesion showed a nonlinear relationship, and the Cohesion was about 8.0% more sensitive to slope height changes than slope angle changes.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.35-45
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• 2018

Motion Estimation(ME) has been developed to reduce the redundant data in digital video signal. ME is an important part of video encoding system, However, it requires huge computational complexity of the encoder part, and fast motion search methods have been proposed to reduce huge complexity. Multi- view video is obtained by capturing on a three-dimensional scene with many cameras at different positions and its complexity increases in proportion to the number of cameras. In this paper, we proposed an efficient motion method which chooses a search pattern adaptively by using the temporal-spatial correlation of the block and the characteristics of the block. Experiment results show that the computational complexity reduction of the proposed method over TZ search method and FS method can be up to 70~75% and 99% respectively while keeping similar image quality and bit rates.

• Journal of Veterinary Clinics
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• v.36 no.3
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• pp.159-165
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• 2019

Pimobendan is an inodilator used to treat canine heart failure, and pentoxifylline is reported to be beneficial for microcirculation and heart disease. The purpose of this study was to evaluate the pharmacokinetic and pharmacodynamic profiles of a novel pimobendan-pentoxifylline liquid mixture after oral administration to dogs. Eight healthy Beagle dogs were included in the study. The dogs were divided into the control group (orally administered water; n = 4) and experimental group (orally administered pimobendan-pentoxifylline liquid mixture [pimobendan 0.25 mg/kg, pentoxifylline 15 mg/kg]; n = 4). Plasma samples were obtained and echocardiographic indices were measured for 24 hours after administration. The concentrations of pimobendan and pentoxifylline were quantified by using a liquid chromatography-mass spectrometer (LC-MS). The elimination half-life ($T_{1/2}$) was $32.96{\pm}9.80mins$ for pimobendan and $29.49{\pm}6.67mins$ for pentoxifylline. The time to reach maximum concentration ($T_{max}$) were $52.50{\pm}31.22mins$ for pimobendan and $41.25{\pm}18.87mins$ for pentoxifylline. The maximum blood concentration ($C_{max}$) was $96.92{\pm}75.64ng/mL$ for pimobendan and $7074.07{\pm}3261.1ng/mL$ for pentoxifylline. Of the echocardiographic indices, fractional shortening (FS) and left ventricular internal diameter at end systole (LVIDs) were significantly altered at 1-3 hours after the administration of pimobendan-pentoxifylline liquid mixture. The pimobendan-pentoxifylline liquid mixture was well tolerated by the dogs, with no adverse effects observed during the study.

• Journal of Forest and Environmental Science
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• v.36 no.4
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• pp.281-289
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• 2020

The study was conducted to observe the effects of compost of faecal sludge (FSC) and food waste (FWC) on seed germination and initial growth performance of Acacia auriculiformis and Swietenia mahagoni seedlings at the nursery of Chittagong University, Bangladesh. Before sowing the seeds, different combinations of FSC and FWC were incorporated with nutrient-deficient natural forest soils. Seed germination and growth parameters of seedlings were recorded after two, three and four month of seed sowing. We observed that seed germination (%) and seedlings growth parameters varied significantly (p<0.05) in the soil added with FSC and FWC in comparison to control. The highest germination was observed 88.89% for A. auriculiformis in combination of soil and FSC at 3:1 and 92.59% for S. mahagoni where soil combined with FWC at 4:1. The seedling biomass and other growth parameters of A. auriculiformis and S. mahagoni was also observed with combinations of soil with FSC 3:1 and soil with FWC 4:1. Therefore, the study revealed that the compost of both FS and FW can be a good soil conditioner for the initial growth of forest seedlings and the proven combinations can help to grow quality seedlings in the nursery.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2256-2268
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• 2018

Hydrophilic and hydrophobic polyethersulfone (PES)-zinc oxide (ZnO) sublayers were prepared by loading of ZnO nanoparticles into PES matrix. Both porosity and hydrophilicity of the hydrophilic sublayer were increased upon addition of hydrophilic ZnO, while these were decreased for the hydrophobic sublayer. In addition, the results demonstrated that the hydrophilic membrane exhibited smaller structural parameter (S value or S parameter or S), which is beneficial for improving pure water permeability and decreasing mass transfer resistance. In contrast, a higher S parameter was obtained for the hydrophobic membrane. With a 2 M NaCl as DS and DI water as FS, the pure water flux of hydrophilic TFN0.5 membrane was increased from $21.02L/m^2h$ to $30.06L/m^2h$ and decreased for hydrophobic TFN0.5 membrane to $14.98L/m^2h$, while the salt flux of hydrophilic membrane increased from $10.12g/m^2h$ to $17.31g/m^2h$ and decreased for hydrophobic TFN0.5 membrane to $3.12g/m^2h$. The increment in pure water permeability can be ascribed to reduction in S parameter, which resulted in reduced internal concentration polarization (ICP). The current study provides a feasible and low cost procedure to decrease the ICP in FO processes.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.59-70
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• 2021

A method for simultaneous detection of fipronil (F) and its metabolites fipronil desulfinyl (FD), fipronil sulfide (FS), fipronil sulfone (FSO) in chicken eggs was applied and validated. It includes single-step, cheap, effective, rugged, safe-based method (SinChERS) for sample preparation and ultra high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS/MS) for chemical analysis. Results suggested that formic acid enhanced the recovery of 4 target residues and 1% supplementation to acetonitrile gained higher recoveries than that of 5%. SinChERS integrated extraction and clean-up steps into one, with shorter time (1.5 h) to operate and higher recoveries (97%-100%) than HLB, Envi-Carb-NH2 and quik-easy-cheap-effective-rugged-safe method (QuEChERS), and it consumed the smallest volume of extracting solvent (10 mL) as QuEChERS. Quantitative analyses using external standard method suggested the linear ranges of 4 target compounds were 1-20 ㎍/L with R2 >0.9947. The limit of detection (S/N>3) and quantification (S/N>10) were 0.3 ㎍/kg and 1 ㎍/kg. Recoveries ranged from 89.0% to 104.4%, and the relative standard deviations (n=6) at 1, 10, and 20 ㎍/kg were lower than 6.03%. Thirty batches of domestic eggs (500 g each) were detected by the established SinChERS-based UHPLC-MS/MS and no target residues were detected in all samples. The method developed in this study is a rapid, sensitive, accurate and economic way for multi-residue analysis of fipronil and its metabolites in eggs.

• Journal of Korean Society on Water Environment
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• v.38 no.2
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• pp.72-81
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• 2022

Numerous studies have investigated the occurrence and fate of microplastics in the environment; however, only limited effort has been devoted to exploring the characteristics of dissolved organic matter (DOM) leached from microplastics. In microplastic (MP)-contaminated environment, MPs are typically mixed with naturally-occurring particles, which interferes with their detection in the environment. Thus, it is necessary to distinguish between the DOM leached from MPs and those leached from natural particles and also to characterize their properties. This study investigated DOM leaching behavior from MPs (polystyrene: PS, polyvinylchloride: PVC) and natural particulates (forest soil: FS, litter leaves: LL) under light, which is considered one of the main weathering processes that affect MPs in the environment. The leached DOM concentrations and fluorescence characteristics were compared under dark versus light conditions. Regardless of the origins, UV light promoted DOM release from all the particulates. More DOM was released from natural particles than from MPs under both conditions. However, the effect of promoting DOM release by UV was more pronounced for MPs than for natural particles. It was observed from fluorescence spectra that the intensity of the humic-like region was substantially reduced when MP-derived DOM was exposed to UV light, whereas the change of intensity was very little for natural particles. Under light conditions, the ratio of protein-like to humic-like fluorescence of MP-derived DOM was higher than that of DOM from natural particles. This study implies that a substantial amount of DOM could be leached from MPs even in MP-polluted environment under UV irradiation. Protein/humic fluorescence ratio could be utilized as a fast probing indicator to separate the two sources of particles under light.