• Biomedical Science Letters
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• v.2 no.1
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• pp.41-48
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• 1996

The C-reactive protein(CRP) from ascitic and pleural fluid was purified using calcium dependent affinity chromatography of CNBr activated Sepharose-4B covalently coupled to p-diazonium phenylphosphorylcholine(DPPC) and hydroxylapitite chromatography. Polyclonal antibody was prepared from rabbit by immunizing the purified CRP. Specific immunoglobulin G was isolated using affinity chromatography and coupled to microparticles. A sensitive microparticle-based immunoassay was developed to measure CRP within 3 mins. The detection range was between 0.5mg/dl) and 20mg/dl in serum, showing strong response in the range of 0.7~2.9 mg/dl, weak response in 5.0~13.2 mg/dl and zone phenomenon over 28mg/dl. The average value of CRP in 74 samples was 3.8mg/dl and most of the values were lower than 10mg/dl .The CRP values of serum samples were determined by our microparticle-based immunoassay, and were compared with those obtained using the other commercial products(B Co., France and I Co., Japan). Good correlations were shown between the values obtained by our developed microparticle-based immunoassay system and those by other commercial products. All performance characteristics evaluated make our developed microparticles-based immunoassay suitable for a simple, rapid, and reliable screening of CRP in serum.

• Journal of Life Science
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• v.25 no.11
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• pp.1273-1279
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• 2015

Agarase from a novel agar-degrading bacterium isolated from seawater in Namhae at Gyeongsangnamdo province of Korea was characterized. The SH-1 strain was selected from thousands of colonies on Marine agar 2216 media. Almost full 16S rRNA gene sequence of the agarolytic SH-1 strain showed 99% similarity with that of bacteria of Simiduia genus and named as Simiduia sp. SH-1. Agarase production was growth related, and activity was declined from stationary phase. Secreted agarase was prepared from culture media and characterized. It showed maximum activity of 698.6 units/L at pH 7.0 and 30℃ in 20 mM Tris-HCl buffer. Agarase activity decreased as the temperature increased from an optimum of 30℃, with 90% and 75% activity at 40℃ and 50℃, respectively. Agarase was not heat resistant. Slightly lower agarase activity was observed at pH 6.0 than at pH 7.0, without statistical difference, and 80% and 75% activity were observed at pH 5.0 and 8.0, respectively. Neoagarotetraose and neoagarobiose were the main final products of agarose, indicating that it is β-agarase. Simiduia sp. SH-1 and its β-agarase would be useful for the industrial production of neoagarotetraose and neoagarobiose, which have a whitening effect on skin, delaying starch degradation, and inhibiting bacterial growth.

• Journal of the Mineralogical Society of Korea
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• v.29 no.4
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• pp.221-227
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• 2016

Copper is an essential transition metal involving in various biogeochemical processes. With the recent advances in analytical techniques and mass spectrometry, such as MC-ICP-MS, it is possible to measure Cu isotopes, which allows us to understand various biogeochemical processes in detail. Nonetheless, few studies have been performed in South Korea. In this study, we compared two purification methods previously reported using an anion exchange resin ($AG^{(R)}$ MP-1M), developed the best method in our lab environment, and then verified it by measuring Cu isotopic compositions in two USGS geological reference materials (BHVO-2 and BIR-1a). Although all matrix cations causing mass bias were effectively removed through both two methods with the yield of better than 95%, the method using the mixture of HCl and $H_2O_2$ only displays Cu isotopic compositions, in excellent agreement with reported values within the error. The method developed in this study is expected to be commonly applied to earth and environmental sciences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.465-473
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• 2019

This paper is meaningful as the first case where a 4 - sided hull-fixed phased array radar was installed on a mast separated from Korea and the alignment was verified. The mechanical alignment method was studied for accurately mounting two separate masts for naval ships and the 3D scanner for alignment. Hull-fixed phased array radar uses very high frequency, so the short wavelength can cause a phase difference of the device due to the small positional error. Since the array antenna is fixed with the hull, it has higher accuracy control than the rotary radar for 4 array surfaces. The study describes a method of checking the flatness of two radar masts manufactured at a factory, a method of aligning masts in a shipyard, and a method of aligning four array pad mounting surfaces. As a tool for this, a 3D laser scanner and a software-based method for comparing survey results with 3D CAD are used. This paper is meaningful as the first example of installing a four-sided hull-fixed phased array radar on a separate mast from a Korean naval ship and deriving a mechanical alignment method.

• Journal of the Korean earth science society
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• v.42 no.1
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• pp.1-10
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• 2021

Silicon (Si) is the second most abundant element in the crust and consists of three stable isotopes, 28Si (92.23%), 29Si (4.67%), and 30Si (3.10%). Si isotopes are widely studied worldwide as a proxy for the biogeochemical cycle of Si to reconstruct the paleoenvironment and paleoclimate. However, in Korea, there have been no studies on biogenic silica using Si isotopes. In this study, we carried out Si isotope measurements of giant diatoms, summarizing the previously reported alkali fusion methods and establishing the best Si separation method for biogenic silica. Samples were completely digested using alkali fusion at high temperatures, effectively separating Si using an AG® 50W-X8 cation exchange resin. To evaluate the precision and accuracy of our measurements, Si isotope standard material (NBS-28) and USGS reference materials (AGV-2, GSP-2, BHVO-2) were analyzed. The results are in excellent agreement with the reported values within the acceptable error. The Si isotope measurement method developed in this study is expected to help in understanding the paleoclimate and paleoenvironment by tracing the Si cycle.

• Composites Research
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• v.36 no.5
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• pp.303-309
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• 2023

In this paper, a Progressive Damage and Failure Analysis (PDFA) modeling method was developed using ABAQUS/EXPLICIT to predict in-plane damage and delamination for Open-Hole Compression (OHC) testing. The proposed PDFA model was constructed based on Hashin criteria and cohesive behavior. The strength and stiffness of OHC specimens with three types of stacking sequences [(45/-45/0₂)₃]_s , [(45/0/-45/90)₃]_s and [45/-45/0/45/-45/90/(45/-45)₂]_s were compared to comprehensively evaluate the validity of the Finite Element(FE) model of PDFA. The strength and stiffness of the OHC specimens were predicted relatively well, with less than a percentage error 10.0 %. For the numerical simulation case for each layup, the damage initiation/evolution of OHC specimens were evaluated for delamination and tension/compression matrix damage before and after failure.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.325-332
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• 2016

The objective of this study was to determine the growth characteristics of cool ($C_1$) and warm season grasses ($C_2$) in pastures mixed with $C_1$ and $C_2$ suitable for grazing horses and effect of pastures mixed with tall and short grasses on the intake characteristics of horses. $C_1$ used in this study was Kentucky bluegrass, Redtop (short type grass) and tall type grasses were orchardgrass and tall fescue, respectively. The short type grass used as $C_2$ was Bermudagrass. This study had the following four treatment groups: 1) Treatment 1 (Bermudagrass + Kentucky bluegrass + Redtop) 2) Treatment 2 (Bermudagrass + tall fescue + orchardgrass) 3) Treatment 3 (Kentucky bluegrass + Redtop) 4) Treatment 4 (tall fescue + orchardgrass). There was no winterkilling or lodging problem at an altitude of 200 m. Plant heights in mixed pasture of Treatment 1, 2, 3, and 4 were 53.9, 58.2, 57.5, and 78.1 cm, respectively. Plant height was the highest in Treatment 4. Dry matter yield was in the following order : Treatment 4 > Treatment 3 > Treatment 2 > Treatment 1. In the first investigation regarding vegetation distribution, Bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 70% and 66.7%, respectively. Overall, other grasses showed poor growth. In the second investigation of vegetation distribution, Bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 80% and 60.7%, respectively. Crude protein content, neutral detergent fiber content, acid detergent fiber content, digestibility value, and nutritive values were the lowest in Treatment 4, followed by those in Treatment 1, Treatment 2 and Treatment 3.

• The korean journal of orthodontics
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• v.29 no.5 s.76
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• pp.563-573
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• 1999

The purpose of this study was to evaluate the availability of computer system for the measurement of tooth size in the model analysis through the comparison of two measurements: One was to use a computer; and the other was to use vernier calipers. Twenty sets of casts were used, which showed a moderate degree of crowding and full eruption of all teeth. The mesio-distal width of 12 teeth from the left central incisor to the left first molar at each set of the casts were measured twice with vernier calipers and a computer respectively. This measurement was repeated two weeks later. First, for the reproducibility analysis, the two computer measurements were compared then the vernier calipers measurements were compared. Second, all the teeth were sepapated into the region of mesiodistal contact points and its width was measured by a micrometer to obtain standard measurements. For the accuracy analysis, these standard measurements were compared with the measurements from the dental casts using two methods. The difference between them was defined as the measurement error. To investigate the cause of measurement error, an examination was made for the presence and degree of contact point deviation on each tooth from the upper and lower occlusograms, and the mesio-distal angulation of each tooth was measured with TARG. Following results were obtained through statistical analysis. 1. In the analysis for reproducibility; the measurements with vernier calipers showed significant differences in three out of twelve teeth while the computer measurements showed significant differences in one out of twelve teeth. 2. In the analysis for accuracy; compared with the standard measurements, the measurements with vernier calipers showed significant differences in three out of twelve teeth while the computer measurements showed significant differences in two out of twelve teeth. 3. Compared with the standard measurements, the measurements with vernier calipers were apt to be larger at the upper first molar, and smaller at the lower first molar The computer measurements, however, were apt to be larger at both upper and lower first molars. 4. The measurements with vernier calipers showed the largest error at the lower first molar and the degree of error was variable according to the tooth while the difference of error was small in the computer measurements. 5. In the analysis for the correlation of the degree of measurement errors with the contact point deviation index and the mesio-distal crown angulation of each tooth, the measurements with vernier calipers did not show significant correlation while the measurements with computer showed slight Positive correlations. The results of this study indicate that a computer system may be useful for the measurement of tooth size in the model analysis.

• Korean Business Review
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• v.11
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• pp.241-253
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• 1998

One form of the anomalies of stock price changes as reaction to earnings information is believed to be caused by the so-called earnings fixation, which is the overreaction of stock prices to earnings. According to the Sloan (1996) study, stock price changes are positively associated with earnings at the time of earnings releases, but the association becomes negative after that, as the early overreaction is corrected. However, the problem in his study is to use cash flows computed by adjusting earnings with appropriate income statement and balance sheet items. As Bahnson et al. (1996) show, these cash flows substantially deviate from SFAS No. 95 cash flows and the sample used in this study is found to be subject to this substantial measurement error. Therefore, the result of Sloan might be driven by this error and the reexamination of earnings fixation is warranted. The results are generally consistent with those in Sloan. First, earnings is positively associated with stock price changes at the time of earnings releases, but the association becomes negative after that. Second, cash flows show a weak association with stock price changes at the time of earnings releases, but the association become stronger thereafter. Third, when seperated from cash flows, accruals have an incremental explanation about stock price changes beyond that of cash flows, accruals have a negative association later on. This finding is consistent with stock price overreaction to accruals, even when more cleaner cash flow data are used.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.27-38
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• 1999

The errors between track segments or at the cross-over points of shipborne gravity were successfully reduced by applying a cross-over error adjustment technique using satellite gravity. The integration of shipborne and satellite altimeter-implied free-air gravity anomalies after the cross-over error adjustment resulted in a high resolution gravity map which contains both short and long wavelength components. The successful adjustment of the cross-over errors in the shipborne gravity using the satellite gravity suggests that the shipborne gravity can be combined with the satellite anomalies characterized by a stable and long wavelength component. The resulting free-air anomaly map is evenly harmonized with both short and long wavelength anomalies. Thus the corrected anomaly map can be better used for the geological interpretation. Free-air anomalies with more than 140 mGal in total variations generally correspond to the seafloor topographic changes in their regional patterns. A series of gravity highs are aligned from the Korea Plateau to the Oki Island, which are interpreted to be caused by seamounts or volcanic topographies. The gravity minima along the western and southern shelf edge are associated not only with the local basement morphology and thick sediment fill at the continental margin, but also possibly with the crustal edge effect known for passive continental margins. Series of NE-trending linear anomalies are possibly caused by a swarm of volcanic intrusions followed the initial opening of the Ulleung Basin. The linear high anomalies in the Ulleung Plateau are terminated by the straightly NNW-trending anomalies with a sharp gradient in its western boundary which indicates a fault-line scarp. The opposite side adjoined with the fault-line scarp shows no correlation with the fault-line scarp in geometry indicating that the block might be horizontally slided from the north. A gravity high in contrast to the deepening in seafloor toward the northeastern central Ulleung Basin is probably responsible for the thin crust and shallow seated mantle. The gravity minima along the western and southern shelf edge are associated not only with the local basement morphology and thick sediment fill at the continental margin, but also possibly with the crustal edge effect known for passive continental margins. Series of NE-trending linear anomalies are possibly caused by a swarm of volcanic intrusions followed the initial opening of the Ulleung Basin. The linear high anomalies in the Ulleung Plateau are terminated by the straightly NNW-trending anomalies with a sharp gradient in its western boundary which indicates a fault-line scarp. The opposite side adjoined with the fault-line scarp shows no correlation with the fault-line scarp in geometry indicating that the block might be horizontally slided from the north. A gravity high in contrast to the deepening in seafloor toward the northeastern central Ulleung Basin is probably suggestive of a thin crust and shallow seated mantle.