• Korean Journal of Ichthyology
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• v.32 no.1
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• pp.8-13
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• 2020

The feeding habits of oriental bonito (Sarda orientalis) were studied using 288 specimens collected in the coastal waters of Jeju Island, Korea from January to December 2015. Oriental bonito is pelagic piscivore that consumes mainly fishes especially Engraulis japonicus and Scomber japonicus. Its diet also includes small quantities euphausiids, amphipods and cephalopods. Oriental bonito showed ontogenetic changes in feeding habits. Although fishes were the primary food consumed by all size groups, the ratio of fishes was slightly increased as body size increase. There also was a significant relationships between mean prey number and weight according to size class and season.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.116-116
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• 2013

(Ni-22Cr-10Al-1Y)와 ($ZrO_2-25CeO_2-2.5Y_2O_3$)로 구성되는 금속/세라믹 복합코팅을 대기용사(ASP; air plasma spay)으로 철 기판위에 1:3, 2:2, 3:1의 무게비로 혼합하여 제조하였다. 용사된 코팅은 금속이영지역과 세라믹잉여지역으로 구별되고, 용사중에 NiCrAlY중의 Al이 선택적으로 산화되어 Al2O3가 계면에 존재하였다. 복합코팅은 $NaCl-Na_2SO_4$ 용융염에서 $800{\sim}900^{\circ}C$, 50시간 동안 부식실험을 실시하였다. 부식생성물은 NiO, $Cr_2O_3$, ${\alpha}-Al_2O_3$가 생성되는데, 부식이 진행되면서 용해되었다. 용융염 부식이 진행되는 동안에 Cr, Al이 외방확산하였고, Na, Cl, S는 내부로 확산되었다. 시간 및 온도뿐만 아니라 금속의 양이 증가할수록 코팅의 내식성은 저하되었다.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.331-335
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• 1997

'인체공학적 학생용 책상과 의자 개발(김정용, 1996)'에 관한 연구에서 제작된 1차 시제품을 면밀히 재평가한 결과, 책상 상판의 상하 탄력으로 인한 안전성, 파이프 처리 기술과 높이 조절의 용이성, 한 호수의 의자로 초등 학생부터 고등 학생까지 만족시키지 못하는 신체 적합도 등의 보완점이 제기되었 다. 이를 해결하기 위해 1차 시제품에서 추구하고자 했던 인체공학적 설계 요소를 유지하면서 재료역 학적인 요소와 파이프 가공 기술 등을 고려하여 개선안을 제시하였다. 책상의 무게중심이 중앙에 위치 하도록 다리를 안쪽으로 이동시켜 상판의 흔들림을 방지하였고, 파이프 사이에 삽입된 PVC와 열쇠 모 양의 조립 구멍, 특수 설계된 나사로 조절이 용이하고 고정성과 안전성이 향상되었으며, 파이프 용접 방식으로 넓은 범위의 신체 특성을 포함할 수 있게 되었다. 의자는 초등 학생용과 중.고등 학생용으로 나누어 2호로 설계하였고, 좌판의 곡면을 보다 완만하게 디자인하여 Lumbar와 오금 부위의 압박을 최 소화하였다. 이 외에도 좌판 밑부분에 보조 서랍을 두어 수납 공간의 부족 문제를 해결하였으며, 등받 이에 손잡이용 구멍을 뚫어 이동 시 편의를 제공하였다. 다양하고 세심한 평가 결과를 바탕으로 세부 설계를 완성하였고, 개선된 2차 시제품은 신체 적합도가 더욱 향상되고, 기능성과 편이도가 증대되어 초.중.고등 학생용 교구로서 학생들의 건강한 신체 발달과 학습 의욕 증가 및 중소기업의 이윤 향상 이 기대된다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9C
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• pp.683-690
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• 2008

By using inherent stopping criteria of LDPC codes, the average number of iterations can be substantially reduced at high signal to noise ratio (SNR). However, we encounter a problem when hybrid automatic repeat request (H-ARQ) systems are applied. Frequent failures of decoding at low SNR region imply that the decoder leaches the maximum number of iterations frequently and thus the decoding complexity increases. In this paper, we propose a combination of stopping criteria using the syndrome weight of tentative codeword. By numerical analysis, it is shown that the decoding complexity of given H-ARQ system is reduced by 70-80% with the proposed algorithms.

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.17-25
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• 1999

The feasibility of using waste lime, which is produced as a byproduct during the manufacture of sodium carbonate in Inchon, Korea. as a stabilization admixture with weathered granite soil was investigated. Laboratory tests were conducted to determine the chemical composition, pH, compaction characteristics, unconfined compression strength. X-ray diffraction analysis of waste lime and weathered granite soil admixtures. Based on the present tests, it appears that the admixtures are environmentally safe and can be used as landfill material.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.251-253
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• 2010

In the leakage test of a Main Oxidizer shut-off valve, gas leakage was found on the middle flange with a metal conical seal. The structural analysis was performed for three models with different numbers of bolts and flange shapes and then one model was selected in consideration of the minimum axial gap deformation as well as the weight increment due to the change of flange shapes. Experimental leakage tests for the simulated flanges of the selected model has resulted in no gas leakage, and consequently the structural analysis method for the design of the middle flanges has proved feasible.

• Polymer(Korea)
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• v.32 no.1
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• pp.90-93
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• 2008

We developed a variety of polymeric jelly phantoms that can be used in hyperthermia using an electromagnetic wave as an auxiliary cancer therapy. Particularly, using an appropriate material composed of polyethylene, deionized water, and sodium chloride, jelly phantoms for brain was prepared. Also, their electrical properties were characterized by measuring the dielectric constant and conductivity. As the results, overall electrical values of the phantoms decreased with increasing the amount of the components of the materials, excepted for sodium chloride. Additionally, storage characteristics of the phantoms showed a sustainable stability up to 6 months. Based on the experimental results, it can be proposed that jelly phantoms containing a ferro-magnetic particle could be a potential material for cancer therapy following the further study on the temperature elevation effect and the evaluation of electromagnetic properties of the materials.

• Journal of the Korean Wood Science and Technology
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• v.32 no.2
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• pp.1-8
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• 2004

Heavy metals were removed from CCA- and CCFZ- treated wood using a brown-rot fungi Tyromyces palustris. The amount of effective elements extracted from treated woods was compared for different treatment methods. The relationship between the amount of heavy metals removed and concentrations of oxalic acid for treated wood was examined. Also, the relationship between mycelia weight and removal rate was examined. The removed quantity of heavy metal from treated wood according to fermentation methods was examined. The extraction amount of chromium and arsenic components increased with increasing oxalic acid concentration, but the extraction amount of copper did not improved much. A 287 mg of mycelia weight can remove chromium and arsenic over 60% in 3 g CCA chips and copper was also removed over 50%. The chromium, copper and arsenic were removed over 60% by shaking fermentation, the removal rate of copper by static cultivation was higher than that of shaking fermentation. The removal rate of chromium, copper and arsenic were 72%, 61% and 59% with air-lift bioreactor, respectively.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.104-111
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• 1993

Background: Gram-negative bacterial endotoxin induced septicemia is known to be a leading cause in the development of adult respiratory distress syndrome(ARDS). The mechanism of endotoxin induced lung injury is mainly due to the activated neutrophils which injure the capillary endothelial cells by releasing oxidant radical and resulted in pulmonary edema. We studied the change of antioxidant enzyme in the case of large or small, intermittant dose of endotoxin infused rat lungs. Methods: Endotoxin was given to the rat through the peritoneal cavity in the dose of 7 mg/kg body weight in the large dose group and 1 mg/kg for 10 days in the small dose group. Bronchoalveolar lavage (BAL) was done and rats were killed at 6, 12, 24 hours after single endotoxin injection in the large dose group and 3, 7, 10 days after daily endotoxin injection for 10 days in the small dose group. The lungs were perfused with normal saline through the pulmonary artery to remove the blood and were homogenized in 5 volume of 50 mM potassium phosphate buffer containing 0.1 mM EDTA. After centrifuging at 100,000 g for 60 minute, the supernatent was removed and stored at $-70^{\circ}C$ until measuring for superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and protein. Results: We observed the following results. 1) The lung wet/dry weight ratio and albumin concentration in the BAL fluids were increased to peak at 12 hours and neutrophil number in the BAL fluids were peak at 6 hours after endotoxin injection in the large dose group. 2) Cu, Zn SOD (IU/mg protein) was significantly decreased after 6, 12 hours after endotoxin injection in the large dose group. 3) There were no singnificant change in the level of Mn SOD, catalase, GSH-Px after endotoxin injection in both groups. Conclusion: Endotoxin in the large dose group produced the acute pulmonary edema and decreased the Cu, Zn SOD in the lung tissue after injecting endotoxin at 6 and 12 hours. These phenomenon may be due to the cell membrane damage by endotoxin. Further research would be necessary whther giving SOD by intratracheal route or method to increase the synthesis of SOD may lessen the acute lung injury by endotoxin.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.152-158
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• 2010

Biosorption is considered to be an alternative method to replace the present adsorbent systems for the treatment of metal contaminated wastewater. In this study, by-product which was abandoned from brewing factory was used to remove metal component in aqueous solution. The experimental results showed that the range of the removal efficiency is 60~91% and adsorption equilibrium was reached in about 3 hr. FT-IR and stereo microscope has been used to observe the surface conditions and changes in functional groups by calcination. At the end of elution, the amount of nitrogen and phosphorus in water was increased 11 and 7 times compare raw sample to calcinated samples. The Langmuir isotherm adequately described the adsorption of waste materials and the maximum adsorption capacity was 28.17 mg/g for Cd. The overall results suggested that waste material might can be used for biosorption of Cd.