• Structural Engineering and Mechanics
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• v.85 no.1
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• pp.65-80
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• 2023

To explore the effect of Engineered Cementitious Composite (ECC) on improving the progressive collapse resistance of reinforced concrete frames under a middle column removal scenario, six beam-column substructures were tested by quasistatic vertical loading. Among the six specimens, four were ECC-concrete composite specimens consisting of different depth of ECC at the bottom or top of the beam and concrete in the rest of the beam, while the other two are ordinary reinforced concrete specimens with different concrete strength grades for comparison. The experimental results demonstrated that ECC-concrete composite specimens can improve the bearing capacity of a beam-column substructure at the stages of compressive arch action (CAA) and catenary action in comparison with ordinary concrete specimen. Under the same depth of ECC, the progressive collapse resistance of a specimen with ECC at the beam bottom was superior to that at the beam top. With the increase of the proportion of ECC arranged at the beam bottom, the bearing capacity of a composite substructure was increased, but the increase rate slows down with the proportion. Meanwhile, the nonlinear numerical analysis software MSC Marc was used to simulate the whole loading process of the six specimens. Theoretical formulas to calculate the capacities of ECC-concrete composite specimens at the stages of flexural action, CAA and catenary action are proposed. Based on the research results, this study suggests that ECC should be laid out at the beam bottom and the layout depth should be within 25% of the total beam depth.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.713-722
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• 2022

In this paper, the flow performance and aero-acoustic noise generated by the target centrifugal fan system were investigated numerically and experimentally. Also, the numerical method for Computational Aero-Acoustics were evaluated by comparing each method. To analyze the performance of the centrifugal fan experimentally, the acoustic power level was measured in the semi-anechoic chamber using microphones, and the active frequency range for the noise performance was identified and that frequency range was applied for Computational Aero-Acoustics (CAA) techniques as sampling frequency. Then, Navier-Stokes equation and the Ffowcs Williams&Hawking equations were used to analyze the flow and sound power numerically, respectively, and a virtual acoustic radiation plane was designed and used for the implementation of the sound field. The accuracy and numerical characteristics of the numerical methods were validated by comparing simulated acoustic power levels with acoustic power levels measured.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1140-1145
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• 2023

Cerebral amyloid angiopathy-related inflammation (CAA-RI) is an encephalopathy caused by inflammation of β-amyloid peptide deposition in cerebrovascular vessels. It is a rare disease that mainly occurs in the elderly and is characterized by rapidly progressive dementia, headache, seizures, and focal neurologic deficits. CAA-RI can demonstrate characteristic brain MRI findings and can be reversed by steroids or other immunosuppressive therapies. Here, we report a case of CAA-RI, which was initially misdiagnosed as a subacute infarction but was diagnosed while reviewing follow-up brain MRI images, and spontaneous remission was achieved.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.456-462
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• 2010

Baseline sensitivity to benthiavalicarb, iprovalicarb and dimethomorph included into carboxylic acid amide (CAA) group was evaluated in 180 isolates of Phytophthora capsici over 4 years from 2005 to 2008. $EC_{50}$ (effective concentration inhibiting mycelial growth by 50%) value of benthiavalicarb ranged from $0.015{\mu}g\;mL^{-1}$ to $0.049{\mu}g\;mL^{-1}$ with a mean of $0.033{\mu}g\;mL^{-1}$. The mean values of $EC_{50}$ of iprovalicarb and dimethomorph were 0.411 (0.197 - 0.556) ${\mu}g\;mL^{-1}$ and 0.271 (0.101 - 0.798) ${\mu}g\;mL^{-1}$, respectively. Although there was no increasing tendency in $EC_{50}$of benthiavalicarb and iprovalicarb during 4 years, $EC_{50}$ of dimethomorph was increased gradually by laps of time. There was no cross-resistance between each fungicide used in this study and metalaxyl. Among fungicides included into CAA group, there was a positive correlation between benthiavalicarb and iprovalicarb, and between dimethomorp and mandipropamid.

• Korean Journal of Agricultural Science
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• v.26 no.2
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• pp.33-38
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• 1999

This study was carried out to analyze the genetic polymorphisms of genomic DNA of blood and meat for conservation of the genetic resources and genetic improvement of Korean Native goat. The genetic identification between Korean Native goat and imported goat was examined using RAPD(random amplified polymorphisms DNAs) analysis with 30 Korean Native goat, 10 hybrid, 10 imported goat. 10 Korean native goat meat and 10 imported goat meat. The results obtained from this study were summarized as follows: 1. Genomic DNA from Korean native goat, hybrid and imported goat could be obtained above about 23kb size using 0.5% agarose gel electrophoresis and the ratio of optical density at 260nm to that at 280nm was between 1.7 and 2.0 using UV spectrophtometer instrument. 2. In the results of the gene identification between Korean Native goat and hybrid, and imported goat using RAPD methods with random primer of 110 kinds, only Korean native goat showed a specific band at about 369bp using a random primer OPO-19 (5'-CAA ACG TCG G-3'), but imported goat and hybrid not showed. 3. Also, in the results of the gene identification between Korean Native goat meat and imported goat meat using RAPD methods with random primer, Korean native goat only showed a specific band at about 369bp using a random primer No. 19(5'-CAA ACG TCG G-3'), but imported goat not showed.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.170-171
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• 2003

• Journal of the korean Society of Automotive Engineers
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• v.8 no.4
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• pp.24-35
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• 1986

현재 주요 가스상물질은 미국의 경우 규제전보다 일산화탄소가 96%, 탄화수소 96%, 질소산화물 76%가 개선되어 어느정도 안정단계에 들어 갔다고 볼 수 있다. 그러나, 입자상물질규제는 디이 젤자동차의 증가와 더불어 1986-1994기간동안 대폭적으로 강화되고 있다. 그러나 자동차 배출 가스중에는 수백가지의 화학물질이 존재하고 인체에 유독한 물질은 규제물질외에도 엄청나게 많다. 따라서 1977년 8월에 개정된 미국의 대기정정법(CAA, clean air act)에는 "신규 제작자동 차나 엔진에 사용되는 어떠한 방지장치, 시스템 또는 부품도 공중보건, 복지 및 안전에 부당한 위험을 일으키거나 일으키는 요인이 될 수 없다"(참조, CAA 202 (a) 및 CFR 86.084-5)고 규 정하고 있다. 이에 따라 미국환경청에서는 회람 등을 통하여 가능한 독성물질에 대하여 경우에 따라 측정할 것을 요구하고 있다. 국내 환경보전법에도 자동차연료첨가제 사용할 때 현저하게 유해한 물질이 배출된다고 인정하는 때에는 그 사용을 규제할 수 있게 되어있고 새로 제정될 자동차 배출가스 시험검사방법 및 절차에 관한 규정에 이에 관한 사항을 추가할 움직임이 있다. 물론 미규제물질의 규제하는 인체에 대한 피해정도나 측정방법 등의 여러 가지 문제가 수반되나 장기적인 국민보건과 환경보전 측면에서 신중하게 다루어져야 되리라 봐서 여러 가지 오염물질의 현황이나 분석방법 등에 대하여 기술코자 한다.여 기술코자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.800-811
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• 2014

Recent developments in the prediction of the contribution of windnoise to the interior SPL have opened a realm of new possibilities in terms of i) how the convective and acoustic sources terms can be identified, ii) how the interaction between the source terms and the side glass can be described and finally iii) how the transfer path from the sources to the interior of the vehicle can be modelled. This work discusses in details these three aspects of wind noise simulation and recommends appropriate methods to deliver required results at the right time based on i) simulation and experimental data availability, ii) design stage at which a decision must be made and iii) time available to deliver these results. Several simulation methods are used to represent the physical phenomena involved such as CFD, FEM, BEM, FE/SEA Coupled and SEA. Furthermore, a 1D and 2D wavenumber transformation is used to extract key parameters such as the convective and the acoustic component of the turbulent flow from CFD and/or experimental data whenever available. This work focuses on the validation of the wind noise source characterization method and the vibro-acoustic models on which the wind noise sources are applied.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.227-234
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• 1993

A serological survey for antibody to chicken anemia agent(CAA) was carried out by virus neutralization test. Antibody to CAA was detected in broilers and layers at different age groups. The results obtained were summarized as follows ; 1. Of a total of 1,035 chicken sera from 1.16 flocks 617 samples of sera were detected as positive(59.6%) and 95 flocks of a total flocks as positive(81.9%). 2. Proportion of positive sera by age were 92.3 %(88.9~100%) at 1 to 2 weeks of age, 56.4%(16.7~77.8%) at 3 to 9 weeks of age, 85.0%(50.0~100%) at 10 to 14 weeks of age and all tested sera were positive at over the 15 weeks age. 3. In each broiler and layer chicken 63.6% and 68.4% chicks possessed positive sera respectively. 4. Neutralizing antibody titer in age group was various from 1:10 to 1:6,400 and mean titer was 1:400 to 1:800.

• Journal of Cardiovascular Imaging
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• v.26 no.4
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• pp.238-246
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• 2018

BACKGROUND: Kawasaki disease (KD) sometimes presents with only fever and cervical lymphadenopathy before other clinical signs materialize. This lymphadenopathy-first-presenting Kawasaki disease (LKD) may be misdiagnosed as bacterial cervical lymphadenitis (BCL). We investigated characteristic imaging and clinical data for factors differentiating LKD from BCL. METHODS: We compared imaging, clinical, and laboratory data of patients with KD and BCL. We included patients admitted to a single tertiary center between January 2015 and July 2018. RESULTS: We evaluated data from 51 patients with LKD, 63 with BCL, and 218 with typical KD. Ultrasound imaging revealed multiple enlarged lymph nodes in both LKD and BCL patients. On the other hand, computed tomography (CT) showed more abscesses in patients with BCL. Patients with LKD were younger and showed higher systemic and hepatobiliary inflammatory markers and pyuria than BCL patients. In multivariable logistic regression, younger age and higher C-reactive protein (CRP) retained independent associations with LKD. A comparison of the echocardiographic findings in LKD and typical KD showed that patients with LKD did not have a higher incidence of coronary artery abnormalities (CAA). CONCLUSIONS: LKD patients tend to have no abscesses on CT and more elevated systemic hepatobiliary inflammatory markers and pyuria compared to BCL patients. The absence of abscess on CT, younger age, and elevated CRP were the most significant variables differentiating LKD from BCL. There was no difference in CAA between LKD and typical KD.