• Title/Summary/Keyword: 풍선

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What Scientific Model Should We Use to Teach Cosmic Expansion to Students? (우주 팽창 교수.학습을 위해 어떤 모형을 사용해야 할까?)

  • Hyunjung Lee;Dayeon Yoo;Byeongmin Kong;Junyeon Won;Hyunjin Shim
    • Journal of Science Education
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    • v.48 no.2
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    • pp.101-110
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    • 2024
  • This study compares two analogical models employed in the instruction of cosmic expansion to assess their impact on the comprehension of middle and high school students. Among the most frequently used models, the balloon model, in which the surface of a balloon represents the Universe, and the bread model, in which the bread itself symbolizes the Universe, were chosen. Using the balloon model, students are required to conceptualize the 2-dimensional surface as representing a higher-dimensional space. Using the bread model, students need to visualize the Universe as the interior of the bread prior to slicing it. For middle school students who had not yet studied cosmic expansion, the balloon model proved more effective in conveying the fundamental scientific concept that the expanding Universe has no center. High school students, who were already familiar with the concept of expansion without a center from previous lessons, found it easier to map the analogy onto the target using the bread model. Based on these results, we conclude that employing multiple models is necessary to complement any single analogy, given its inherent limitations.

Ozone Concentration Measurement and Atmospheric Scale Height Analysis Using Helium Balloon in the Troposphere and the Lower Stratosphere Over the Southern Korean Peninsula (헬륨풍선을 이용한 대기 중 오존 밀도 측정 및 대기 높이 척도 분석: 한반도 남부 지역의 대류권 및 성층권 하부)

  • Seungwoo Yoo;Min Jun Kim;Byeong-Hyeon Han;Eojin Kim;Ki-nam Kim;Jong-Kyun Chung
    • Journal of Space Technology and Applications
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    • v.4 no.3
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    • pp.220-231
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    • 2024
  • This study deals with an experiment to measure ozone concentration in the atmosphere over the Korean Peninsula, Jeollabuk-do, using a helium balloon and analyze the change in atmospheric density based on the scale height. In the experiment, Arduino Uno was used to collect data and ozone concentration was measured using the MQ131 sensor. In addition, the BMP280 sensor was used to measure temperature and atmospheric pressure at various altitudes. The experimental results showed that the scale height of the atmosphere over the Korean Peninsula was 6,828.30 m, and the decreasing pattern of atmospheric density was confirmed based on this. In addition, by analyzing the graph of the measured ozone level, a phenomenon of a rapid decrease in the ozone level was observed between 8 km and 9 km altitude. These results can provide important information for understanding the atmospheric environment and ozone concentration changes and for environmental monitoring.

Antioxidant Effect and Component Analysis of Cardiospermum halicacabum Leaf Extracts (풍선덩굴 잎 추출물의 항산화 효과 및 성분 분석)

  • Jeong, Hyo Jin;Kim, A Rang;Lee, Keon Soo;Park, So Hyun;Shin, Hyuk Soo;Lee, Sang Rae;Song, Ba Reum;Lee, Yun Ju;An, Hyun Jin;Lee, Jae Duk;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.2
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    • pp.175-187
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    • 2017
  • In this study, the antioxidant effect and component analysis for extract and fractions of Cardiospermum halicacabum leaf were investigated. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from dried C. halicacabum leaf. The yields of extract and fractions were 16.4, 0.9 and 0.3% per dried powder, respectively. DPPH (1,1-phenyl-2-picrylhydrazyl) radical scavenging activity ($FSC_{50}$) of ethyl acetate fraction ($92.5{\mu}g/mL$) was the greatest radical scavenging activity, but lower than (+)-${\alpha}$-tocopherol ($8.9{\mu}g/mL$). In reactive oxygen species (ROS) scavenging activity (total antioxidant capacity, $OSC_{50}$) on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system, aglycone fraction ($4.2{\mu}g/mL$) was the highest total antioxidant capacity and similar to L-ascorbic acid ($1.5{\mu}g/mL$). The cellular protective effects of C. halicacabum leaf extract and fractions on the $^1O_2$-induced cellular damage of human erythrocytes were exhibited at all concentration-dependent ($5.0-25.0{\mu}g/mL$). Especially, aglycone fraction (${\tau}_{50}$, 76.4 min) in $25.0{\mu}g/mL$ showed the most protective effect among extracts. Components of the ethyl acetate fraction obtained from C. halicacabum extracts were analyzed by TLC, HPLC chromatogram and LC/ESI-MS. Results showed that the ethyl acetate fraction contained some flavonoids, such as apigenin-7-O-glucuronide, apigenin-7-glucosdie and quercitrin hydrate. These results suggest that the extracts and fractions of C. halicacabum leaf may be applied as antioxidant functional cosmetic raw materials.

Prognostic Analysis of Drug-Eluting Balloon Catheter and Drug-Eluting Stent for In-Stent Restenosis of Drug-Eluting Stent (스텐트 재협착 병변에서 약물코팅 풍선카테터과 약물용출 스텐트의 예후 분석)

  • Lee, Doo Hwan;Song, Jong Nam;Park, Sin eui;Choi, Nam Gil;Han, Jae Bok;Kim, In Soo
    • Journal of the Korean Society of Radiology
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    • v.13 no.3
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    • pp.381-389
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    • 2019
  • Although the development of Drug-eluting stent (DES) improved the ISR significantly more than the Bare metal stent (BMS), the coronary stent restenosis (ISR) treatment still has a high recurrence rate. This study is compared the efficacy of DEB with that of DES implantation in patients with ISR. Among 4,316 patients who underwent coronary stent implantation at the Chonnam National University Hospital between November 2012 and December 2016, 187 patients developed ISR on follow-up coronary angiography ($66.3{\pm}11.0years$, 123 males) were enrolled and divided into two groups according to revascularization method as group I (DEB group; n=127) and group II (DES group; n=60). Primary end point was defined as major adverse cardiac events (MACEs), composite of cardiac death (CD), myocardial infaction (MI), target lesion revascularization (TLR) and stent thrombosis (ST) during two-year follow-up between the two groups. There were no differences in the baseline characteristics and angiographic findings except that prevalence of device length was shorter ($21.1{\pm}5.3$ vs. $25.3{\pm}9.6 mm$, p<0.002) in group I.Two-year MACE were not different in the two groups (8.7%vs.10.0%, p=0.789). The incidences of cardiac death (0%vs.0%, p=1.000), MI (1.6%vs.6.7%, p=0.085), TLR(8.7% vs. 10.0%, p=0.789) and ST (0% vs. 0%, p=1000). DEB demonstrated comparable risk reduction for MACEs compared with DES in patients with ISR during two-year follow-up. DEB might be good alternative for the treatment of ISR in patients with ISR.

Fresh Water Flume Analysis Using an Unstructured Grid Ocean Circulation Model (비정규격자계 해양순환 모델을 이용한 하구에서의 담수 유출분석)

  • Hwang, Jin-Hwan;Park, Young-Gyu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.4
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    • pp.227-234
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    • 2009
  • Using a finite volume ocean circulation model based on an unstructured grid (FVCOM), we studied the structure of a fresh water bulge that influences on the Region Of Freshwater Influence. Fresh water discharged a river forms a coastal boundary current to the righthand side and a cyclonically circulation freshwater bulge that grows with time. In the middle of the bulge, vertical motions bring fresh water to the bottom. When tidal motions are included, the bulge disappears while the boundary currents becomes wider. Through a simple comparison of areas occupied low salinity water we quantified vertical and horizontal mixing due to the tide and showed that the tidal motion enhances the vertical mixing. During the first few tidal cycles right after the onset of the river discharge, due to tidal excursion the horizontal mixing becomes stronger. The vertical mixing by the tide mixes the fresh water After a certain time the water around the river mouth is well mixed and the horizontal excursion of the fresh water near the river mouth does not have much effect on the horizontal mixing. When there is no tidal motion horizontal mixing is mainly by the inertial instability at the surface and the horizontal mixing becomes stronger over time.

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Assessment of Cerebral Collateral Circulation Using $^{99m}Tc$-Hexamethyleneamine Oxime (HMPAO) SPECT During Internal Carotid Artery Balloon Test Occlusion (내경동맥 풍선 시험 결찰술(BTO)시 $^{99m}Tc$-HMPAO 뇌 SPECT를 이용한 대뇌 측부 순환의 평가)

  • Ryu, Young-Hoon;Yun, Mi-Jin;Chung, Tae-Sub;Lee, Jong-Doo;Park, Chang-Yun
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.1
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    • pp.22-30
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    • 1995
  • To predict preoperatively the safety of permanent occlusion of an internal carotid artery with $^{99m}Tc$-HMPAO brain single photon emission computed tomography(SPECT) from an objective point of view, Twenty-four patients underwent balloon test occlusion (BTO) of the internal carotid arteries because of neck and skull base tumors. The authors assessed the uptake of both middle cerebral artery territories before and during BTO with $^{99m}Tc$-HMPAO brain SPECT using semiquantitative analysis method and compared the results with other factors(neurologic examination, arterial stump pressure and electroenceph-alogram). Nineteen patients had not experienced neurological deteriorating or any problem during BTO. Their comparative uptakes of the middle cerebral artery territories were 95 to 101% of the pre-BTO state. The remaining five patients showed severe neurologic symptoms such as transient hemiplegia and unconsciousness. Their comparative uptake of the middle cerebral artery territories were 77 to 85% of the pre-BTO state, and were well matched with other factors. $^{99m}Tc$-HMPAO brain SPECT before and during BTO seems to be a simple and objective method for prediction of permanent neurologic deficits when the comparative uptake of middle cerebral artery territories during BTO is lower than 85% of that before BTO.

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The Developing Trend of Cardiovacular Drug Coated Balloon Catheter (심장혈관용 약물코팅풍선카테터의 개발 동향)

  • Park, Junghun;Jo, Won-Il;Byeon, Dae-Heung;Kang, So Young;Nam, Choong-hyun;Seo, Kyoung-Woo;Park, Jun-Kyu
    • Applied Chemistry for Engineering
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    • v.33 no.5
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    • pp.545-550
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    • 2022
  • As a result of the rapid entry into an aging society and westernized eating habits, the number of heart disease patients caused by angina pectoris, myocardial infarction, and high blood pressure has increased by more than 100,000 over five years. Heart disease has consistently ranked second in the cause of death in Korea over the past eight years, and medical expenses consumed annually reach 6 trillion won. While various treatments are being proposed for more patients, drug-coated balloon catheters have been developed and gradually commercialized to solve the disadvantages of stent implantation such as restenosis and increased risk of bleeding due to long-term double antiplatelet medication. In Korea, it began to use a drug-coated balloon catheter with the first release of it called "SeQuent Please (Bibrown Korea)" in 2010. Its demand increased gradually as insurance benefits were applied in 2012. Drug-coated balloon angioplasty is increasing in use not only in Korea but also around the world, especially in the Asia-Pacific region, including Japan. Until now, the demand for domestic products is increasing, and if the efficiency in vivo and clinical trials is proven in the future, it is expected to be an effective procedure compared to high-risk stent implantation.

나의 국제표준화회의 참가기 - 온몸으로 체득한 표준채택 노하우

  • Lee, Hyeon-U
    • TTA Journal
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    • s.137
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    • pp.132-133
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    • 2011
  • 구슬이 서말이라도 꽤어야 보배라는 말이 있다. 아무리 앞선 아이디어로 포장되고 좋은 특허로 뒷받침 되어도 표준에 반영되지 못한 기술은 바람 빠진 풍선만도 못한 신세일 뿐이다. 그러나 세계 굴지의 회사들이 표준확보에 혈안이 되어 있는 정글 같은 국제표준무대에서 표준채택은 결코 녹녹한 일이 아니다. 하지만 장기적 전략을 가지고 치밀한 전술로 접근하면 의외로 표준확보는 가까이 와 있음을 발견하게 될 것이다.

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노블리스 오블리주-세상에서 가장 아름다운 월급봉투

  • Jeon, Heung-Yun
    • Venture DIGEST
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    • s.45
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    • pp.17-17
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    • 2004
  • 2월 19일 종로에 있는 제일은행 본점 1층 로비는 때 아닌 행사로 시끌벅적 했다. 색색의 풍선으로 장식된 무대와 가지런히 놓여진 의자들이 따사로운 아침 햇살에 유난히 더 깨끗하고 환하게 보였다. 단정한 양복에 사랑의 열매를 달거나, 와이셔츠 차림으로 2층, 3층 난간으로 얼굴을 내민 은행원들은 ‘무슨 일인가?’하는 표정으로 하나 둘 행사장 앞으로 모여들었다.

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