• Journal of Distribution Science
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• v.20 no.4
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• pp.95-100
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• 2022

Purpose: This study aimed to investigate whether distribution and service companies maintained their accounting information quality and provided reliable information despite the economic changes occurring after the outbreak of the COVID-19 pandemic in Korea. The distribution industry has enjoyed increased demand as many companies expanded their untact distribution channels, including to online sales. However, as the pandemic drags on, their future prospects remain uncertain. Research design, data, and methodology: In this study, we define 2018-2019 as the "pre COVID-19 period" and 2020 as the "post COVID-19 period." An empirical analysis was performed using a regression model that includes POST, the independent variable, indicating the post COVID-19 period, and discretionary accruals(DA), a proxy for earnings management, as a dependent variable. Results: The analysis shows that the coefficient of POST is significantly positive (+) for the dependent variable DA. This finding suggests that distribution and service companies engaged in more earnings management during the post COVID-19 period than during the pre COVID-19 period, indicating their awareness of the uncertainty of future business performance as the pandemic persists. An additional analysis confirmed that smaller companies with fewer stakeholders and higher information asymmetry tend to engage more in earnings management than larger companies.

• Analytical Science and Technology
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• v.15 no.5
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• pp.417-426
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• 2002

Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry (ICP-DRC-QMS) was characterized for the detection of the six naturally occurring calcium isotopes. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio. This experiment shows that the potentially interfering ions such as $Ar^+$, ${CO_2}^+$, ${NO_2}^+$, $CNO^+$ at the calcium masses m/z 40, 42, 43, 44 and 48 were removed by flowing $NH_3$ gas at the rate of 0.7 mL/min $NH_3$ as reactive cell gas in the DRC with a RPq value (rejection parameter) of 0.6. The limits of detection for $^{40}Ca$, $^{42}Ca$, $^{43}Ca$, $^{44}Ca$, and $^{48}Ca$ were 1, 29, 169, 34, and 15 pg/mL, respectively. This method was applied to the determination of calcium in synthetic food digest samples (CCQM-P13) provided by LGC for international comparison. The isotope dilution method was used for the determination of calcium in the samples. The uncertainty evaluation was performed according to the ISO/GUM and EURACHEM guidelines. The determined mean concentration and its expanded uncertainty of calcium was ($66.4{\pm}1.2$) mg/kg. In order to assess our method, two reference samples, Riverine Water reference sample (NRCC SLRS-3) and Trace Elements in Water reference sample (NIST SRM 1643d), were analyzed.

• Analytical Science and Technology
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• v.28 no.6
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• pp.460-466
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• 2015

An isotope dilution liquid chromatography tandem mass spectrometry was developed as a primary method for the quantitative analysis of cholesterol in infant formula. Cholesterol-d₄ was used as an internal standard and spiked into the infant formula sample. In order to release cholesterol out of cholesteryl ester, which is cholesterol bound to fatty acids in infant formula, saponification was carried out. Saponification conditions were optimized with heating temperature, reaction time and the concentration of KOH. The optimum conditions were as follows; heating temperature was 70 ℃, reaction time was 180 min and the concentration of KOH was 0.8 mL of 8 M KOH for about 0.1 g infant formula sample. Extraction of cholesterol out of sample solution was carried out with hexane uisng liquid-liquid extraction. Chromatographic analysis was carried out using Phenomenex Kinetex C₁₈ column. Mobile phase was 0.1% acetic acid in methanol/water (v/v, 99/1) and flow rate was 0.3 mL/min. Cholesterol and cholesterol-d₄ were monitored at mass transfer m/z 369/259 and 373/263 respectively. Reproducibility of the method was evaluated to be 0.23% of the measurement result. The expanded uncertainty of the measurement result of cholesterol in infant formula was approximately 1.9% at a 95% confidence level. NIST standard reference material having certified values of cholesterol in infant formula, was analyzed in order to verify this method. The ID-LC/MS/MS results were well agreed with the certified values of NIST SRM within the uncertainty.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.535-542
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• 2016

As one of the most cost-effective methods for surface emission measurements, flux chamber method has been used worldwide. It can be classified into two types: SFC (with slope method) and DFC (with steady-state method). SFC (static flux chamber) type needs only simple equipment and is easy to handle. However, the value of flux might vary with SFC method, because it assumes that the change of concentration in chamber is linear with time. Although more specific equipments are required for DFC (dynamic flux chamber) method, it can lead to a constant result without any ambiguity. We made a self-designed DFC using a small and compact kit, which recorded good sample homogeneity (RSD < 5%) and recovery ( > 90%). Relative expanded measurement uncertainty of this improved DFC method was 7.37%, which mainly came from uncontrolled sweep air. The study shows that the improved DFC method can be used to collect highly reliable emission data from large landfill area.

• Analytical Science and Technology
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• v.23 no.3
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• pp.247-254
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• 2010

This study was carried out to produce Reference Materials (RMs) for Proficiency Testing (PT) of PCBs in waste analytical laboratories. Two RMs were prepared from used transformer oil samples and PCB free transformer oil by spiking PCBs standard solutions. The spiked PCB RMs were homogenized by mixing and settling up to 90 days. Homogenized concentration of PCBs with Arochlor 1254 (6 ppm), 1254:1260 (1:1) (5 ppm) were observed in 60 days stationary phase but Arochlor 1260 (3.5 mg/L) were observed in 90 days stationary phase. One-way ANOVA test were carried out and showed that the RMs were suitably homogenized, which can be used for proficiency testing. The Relative Standard Deviations (RSDs) of analytical results were 3.51~5.01% for the PCBs RMs in 10 replicates. The expanded uncertainty of PCBs analytical procedure were 0.26~0.49.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.297-305
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• 2022

Antioxidants are food additives that extend the shelf life of food products by preventing lipid rancidity caused by active oxygen. They can either be naturally-derived or manufactured synthetically via chemical synthesis. In this study, method validation of five synthetic antioxidants, namely butylated hydroxyanisole, butylated hydroxytoluene, tertiary butylhydroquinone, propyl gallate, and disodium ethylenediaminetetraacetic acid, was performed using a high performance liquid chromatography-ultraviolet visible detector, and the method applicability was evaluated by analyzing foods containing antioxidants. The coefficient of determination (R²) average was 0.9997, while the limit of detection and limit of quantification were 0.02-0.53 and 0.07-1.61 mg/kg, respectively. The intra and inter-day accuracies and precisions were 83.2±0.7%-98.7±2.1% and 0.1%-5.7% RSD, respectively. Inter-laboratory validation for accuracy and precision was conducted using the Food Analysis Performance Assessment Scheme quality control material. The results satisfied the guidelines presented by the AOAC International. In addition, the expanded uncertainty was less than 16%, as recommended by CODEX. Consequently, to enhance public health safety, the results of this study can be used as basis data for evaluating the intake of synthetic antioxidants and assessing their risks in Korea.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.188-194
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• 2023

This study aimed to derive the basic wood density, one of several carbon emission factors, for carbon accounting of bamboo forests in Korea. Bamboo is mainly distributed in Jeollanam-do and Gyeongsangnam-do provinces, and 101 sample trees were selected for each of the three species (Phyllostachys nigra var. henonis, P. bambusoides, and P. pubescens). The basic wood density derivation used the KS F 2098 method. The measurements showed that the basic wood density was 0.83 g/cm³ for P. nigra var. henonis, 0.81 g/cm³ for P. bambusoides, and 0.72 g/cm³ for P. pubescens. However, the bamboo distribution area in Korea is not very large, and P. pubescens grows in one area only. Therefore, the basic wood density that can be applied to bamboo was 0.79 g/cm³. Evaluation of the uncertainty of the extracted basic wood density showed a very low value of 1.61%, which confirmed the reliability of the basic wood density derived from this analysis. The basic wood density, biomass expansion factor, and root-to-shoot ratio were used to calculate the carbon storage capacity of one bamboo plant and expanded to calculate the capacity for a hectare of bamboo. Carbon storage and absorption of bamboo were calculated by applying a carbon-emission factor, such as the basic wood density. These study results are expected to contribute to the carbon-neutral policy and forest management direction in Korea.

• The Journal of the Acoustical Society of Korea
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• v.33 no.1
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• pp.31-39
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• 2014

In this paper, two calibration methods for angular vibration pickups using a precision rotary encoder are proposed. The KRISS (Korea Research Institute of Standards and Science) primary angular vibration calibration system and the calibration procedures are briefly explained. The rotary encoder is shown to be calibrated in two methods: The one is to use the laser interferometer to calibrate the rotary encoder under test and the other is to exploit the certificate of the encoder supplied. Complex sensitivities measured from the first are shown to be less than 0.1 % difference in magnitude and $0.01^{\circ}$ difference in phase shift in reference to those of the primary calibration system. Their expanded uncertainties were observed to be less than 0.6 % in magnitude and $0.4^{\circ}$ in phase shift over the range of 0.4 to 200 Hz. Under the same calibration conditions, complex sensitivities evaluated by the second method are shown be 0.1 % difference in magnitude and $0.6^{\circ}$ difference in phase shift in reference to those of the primary calibration system. Their expanded uncertainties were seen to be less than 4.8 % in magnitude and $2.8^{\circ}$ in phase shift.

• International Commerce and Information Review
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• v.14 no.1
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• pp.345-366
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• 2012

The country using factoring actively today is England. The history of factoring could throw back to the Middle Ages, but modern factoring was developed in colonial age of the United States and it was known throughout England in 1960s. At the beginning, it performed mercantile agent who works in local area in order to get rid of uncertainty and inconvenience of a distant trade, but it was getting developed into a today's factoring system which focusing more on financial function. The factoring is called 'account receivable financing' in the United States and it is started out as sales agent and getting developed to 'del credere agent' who guarantee the payment. The activities of factors have been expanded to not only consignment sale and payment guarantees but also advance financing service. However, at the end of the 19th century, the direct sales(direct marketing) was expanded by the development of telecommunication and transportation technology, and then the marketing service by factor was degraded, but the collection of payment and advance finance had been maintained until now and developed into today's factoring system. Especially, the establishment of Uniform Commercial Code in 1931 had formed the basis for activating factoring in the United States through preparing a legal basis of factoring. Due to changes of international trade environment, most of commercial bank in Korea have to deal with export factoring as a trade finance service and it is desirable to specialize as a financing for small and medium company.

• Journal of Radiation Protection and Research
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• v.44 no.3
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• pp.103-109
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• 2019

Background: Four-dimensional computed tomographic (4DCT) images are increasingly used in clinic with the growing need to account for the respiratory motion of the patient during radiation treatment. One of the reason s that makes the dose evaluation using 4DCT inaccurate is a change of the patient respiration during the treatment session, i.e., intrafractional uncertainty. Especially, when the amplitude of the patient respiration is greater than the respiration range during the 4DCT acquisition, such an organ motion from the larger respiration is difficult to be represented with the 4DCT. In this paper, the method to generate images expecting the organ motion from a respiration with extended amplitude was proposed and examined. Materials and Methods: We propose a method to generate extra-phase images from a given set of the 4DCT images using deformable image registration (DIR) and linear extrapolation. Deformation vector fields (DVF) are calculated from the given set of images, then extrapolated according to respiratory surrogate. The extra-phase images are generated by applying the extrapolated DVFs to the existing 4DCT images. The proposed method was tested with the 4DCT of a physical 4D phantom. Results and Discussion: The tumor position in the generated extra-phase image was in a good agreement with that in the gold-standard image which is separately acquired, using the same 4DCT machine, with a larger range of respiration. It was also found that we can generate the best quality extra-phase image by using the maximum inhalation phase (T0) and maximum exhalation phase (T50) images for extrapolation. Conclusion: In the present study, a method to construct extra-phase images that represent expanded respiratory motion of the patient has been proposed and tested. The movement of organs from a larger respiration amplitude can be predicted by the proposed method. We believe the method may be utilized for realistic simulation of radiation therapy.