• 제목/요약/키워드: college of science-engineering

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Real-time Measurements of Water Level and Temperature using Fiber-optic Sensors Based on an OTDR (광섬유와 OTDR을 이용한 실시간 수위 및 온도 측정)

  • Sim, Hyeok In;Yoo, Wook Jae;Shin, Sang Hun;Jang, Jaeseok;Kim, Jae Seok;Jang, Kyoung Won;Cho, Seunghyun;Moon, Joo Hyun;Lee, Bongsoo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.9
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    • pp.1239-1244
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    • 2014
  • In this study, two fiber-optic sensors were fabricated to measure water level and temperature using optical fibers, a coupler, a Lophine and an OTDR (optical time-domain reflectometer). First, using Fresnel's reflection generated at the distal-ends of each optical fiber, which was installed at different depth, we measured the water level according to the variation of water level. Next, we also measured the temperature of water using a temperature sensing probe based on the Lophine, whose absorbance changes with the temperature. The measurable temperature range of the fiber-optic sensor is from $5^{\circ}C$ to $65^{\circ}C$ because the maximum operation temperature of the optical fiber without a physical deterioration is up to $80^{\circ}C$.

Modulation of Nrf2/ARE and Inflammatory Signaling Pathways by Hericium erinaceus Mycelia Extract

  • Jin, Kyong-Suk;Park, Ji-Young;Cho, Mi-Kyung;Jang, Ji-Hyun;Jeong, Jae-Han;Ok, Seon;Bak, Min-Ji;Song, Young-Sun;Kim, Myo-Jeong;Cho, Chung-Won;Jeong, Woo-Sik
    • Food Science and Biotechnology
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    • v.18 no.5
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    • pp.1204-1211
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    • 2009
  • Hericium erinaceus is an edible mushroom used as a medicinal food in Asian countries. In this study, the chemopreventive effects of H. erinaceus mycelia hot water extract (HEW) were evaluated. HEW remarkably induced the luciferase activity of the antioxidant response element (ARE), located in the promoter region of phase 2 and antioxidant genes and regulated by nuclear factor E2-related factor 2 (Nrf2). The up-regulation of ARE activity by HEW corresponded with the induction of Nrf2 and the antioxidant enzyme, hemeoxygenase-1. The inhibition of cyclooxygenase-2 (COX-2) activity is a promising effective approach in cancer chemoprevention, and HEW prominently suppressed COX-2 protein expression in HepG2 cells. Furthermore, HEW showed anti-inflammatory activity by modulating inflammatory mediators such as nitric oxide (NO), inducible NO synthase, tumor necrosis factor-${\alpha}$, interleukin-$1{\beta}$, and the transcription factor, nuclear factor-${\kappa}B$, in lipopolysaccharide-stimulated RAW 264.7 cells. These results suggest that H. erinaceus possessed anti-tumor and anti-inflammatory effects via the modulation of Nrf2/ARE and inflammatory signaling pathways, and may therefore have potential use as a natural chemopreventive agent.

Antiplatelet Effects of Cordycepin-Enriched WIB-801CE from Cordyceps militaris: Involvement of Thromboxane A2, Serotonin, Cyclooxygenase-1, Thromboxane A2 Synthase, Cytosolic Phospholipase A2

  • Ok, Woo Jeong;Nam, Gi Suk;Kim, Min Ji;Kwon, Hyuk-Woo;Kim, Hyun-Hong;Shin, Jung-Hae;Lim, Deok Hwi;Kwon, Ho-Kyun;Lee, Chang-Hwan;Chung, Soo-Hak;Kim, Jong-Lae;Park, Hwa-Jin
    • Biomedical Science Letters
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    • v.22 no.4
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    • pp.127-139
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    • 2016
  • A species of the fungal genus Cordyceps has been used as an ingredient of traditional Chinese medicine. In this study, we prepared cordycepin-enriched WIB-801CE, an ethanol extract from culture solution of Cordyceps militaris-hypha, and evaluated its antiplatelet effects on human platelet aggregation. WIB-801CE dose-dependently inhibited ADP-, collagen-, and thrombin-induced platelet aggregation. These antiplatelet effects by WIB-801CE were associated with the attenuation of thromboxane $A_2$ ($TXA_2$) production and serotonin release by ADP, collagen, and thrombin. The inhibition of $TXA_2$ production by WIB-801CE was due to the inhibition of cyclooxygenase-1, $TXA_2$ synthase, and cytosolic phospholipase $A_2$ activity. Therefore, these data suggest that WIB-801CE may be a beneficial component against protection from platelet aggregation-mediated thrombotic disease.

A Study on the Quality Evaluation of BI fused to SOA (SOA와 융합된 BI의 품질 평가에 대한 연구)

  • Kang, Dong-Woo;Lee, S.H.;Park, H.K.;Na, H.J.;Choi, J.M.;Yoo, H.Y.
    • Proceedings of the Korean Information Science Society Conference
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    • 2010.06b
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    • pp.107-111
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    • 2010
  • 급변화하는 비즈니스 환경에 가장 빠르게 대응할 수 있고, IT 자원의 상호운용성 및 재활용성을 증대할 수 있는 SOA 기반 소프트웨어 시장이 급격히 증가함에 따라 SOA 기반 시스템 품질 평가 방법들이 연구되고 있다. 그러나, SOA에 융합된 BI 관점의 평가 방법은 연구가 부족하다. 본 연구에서는 ISO/IEC 9126국제 표준을 참조하여 SOA와 융합된 BI의 품질 평가 특성을 제시하고, 사례 연구를 통해 품질 평가 방법을 제안 및 검증한다. 본 연구를 통해, BI를 SOA와 융합하는 과정에 품질 특성을 고려하여 구현 및 융합함으로써 소프트웨어의 품질 향상을 유도하고 완성된 소프트웨어의 품질 평가에 활용될 것으로 기대한다.

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Detection of Color Information Using Optical Method (광학적 방법을 이용한 색 정보 검출)

  • Kim, Ji-Sun;Jung, Gu-In;Lee, Tae-Hee;Choi, Ju-Hyeon;Oh, Han-Byeol;Kim, A-Hee;Jung, Hyon-Chel;Jun, Jae-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.159-164
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    • 2015
  • Color is distinguished due to the light in which natural light is reflected by object and made with combination of RGB(red, green, blue; three colors). This study proposes color analysis system with optical method to be used conveniently. Color information of sample is determined with the optical sensor. By using the CIE diagram in particular, it detects purity value and wavelength. The method to distinguish color is very economical, simple, and convenient. The result can be used to confirm accurate information of color for various applications.

Fabrication and Characterization of a Fiber-Optic Alpha/Beta Detector for Nuclear Medicine Application (핵의학 적용을 위한 광섬유 기반의 알파/베타 검출기의 제작 및 특성분석)

  • Hong, Seung-Han;Yoo, Wook-Jae;Shin, Sang-Hun;Seo, Jeong-Ki;Han, Ki-Tek;Jeon, Da-Yeong;Cho, Seung-Hyun;Lee, Bong-Soo
    • Journal of Sensor Science and Technology
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    • v.21 no.5
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    • pp.367-373
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    • 2012
  • We fabricated a fiber-optic alpha/beta detector, which is composed of a sensing probe, a plastic optical fiber, a photomultiplier tube, and a multichannel analyzer, to obtain the energy spectra of radioactive isotopes. As inorganic scintillators of a sensing probe, a ZnS(Ag) film was coupled with a $CaF_2$(Eu) crystal for alpha and beta spectroscopy. In this study, $^{210}Po$ and $^{90}Sr$ were used as alpha and beta sources, respectively, and we measured the radiation energy spectra using a fiber-optic alpha/beta detector to identify alpha and beta emitting radionuclides for nuclear medicine application. Also, the variations of energy spectrum were obtained according to the length of plastic optical fiber.

Basic Research of Robot Arm Bending Angle Measuring System Using by PSD Sensor (PSD센서를 이용한 로봇팔 굽힘각 측정 시스템 기초 연구)

  • Goh, Bong-Jun;Kim, Ji-Sun;Oh, Han-Byeol;Kim, A-Hee;Kim, Jun-Sik;Lee, Eun-Suk;Baek, Jin-Young;Jun, Jae-Hoon
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1409-1410
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    • 2015
  • 현대기술의 발달로 인해 인간의 삶 중 많은 부분을 기계가 차지하고 있다. 특히 로봇공학 분야는 위험하거나 혹은 매우 정밀함을 요하는 일, 단순반복 등 인간이 기피하거나 하기 어려운 일을 대신 해줌으로서 많은 관심을 받고 있다. 이에 우리는 우리 생활에 가장 깊숙히 들어와 있는 로봇팔분야에 대해 말하고자 한다. 현재 로봇팔은 산업용은 물론, 의료용, 재해용 등 다양한 분야에서 사용되고 있다. 하지만 매우 정밀하고 정확한 작업을 위해 만들어져 있음에도 불구하고, 약간의 충격에도 이상이 생긴다거나, 기기의 이음세 부분의 잦은 회전으로 마모가 발생하게 되고 그에 따라 미세한 오차가 발생한다. 그런 상황을 방지하고자, 우리는 PSD(Position Sensitive Detecter)센서를 이용해 실시간으로 굽힘각을 측정 및 감시하여 보다 정확한 구동을 유도하려 한다. 이는 단순한 로봇팔만이 아닌 휴머노이드나 다른 회전을 이용하는 기기라면 어디든 쉽게 적용 할 수 있을 것이다.

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The Study about Angle Measuring Technique According to Optical Fiber Tip Angle (광섬유 종단 각에 따른 각도 측정 기술에 대한 연구)

  • Kim, Jun-Sik;Kim, Ji-Sun;Oh, Han-Byeol;Kim, A-Hee;Goh, Bong-Jun;Lee, Eun-Suk;Shin, Ye-Ji;Jun, Jae-Hoon
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1405-1406
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    • 2015
  • 본 논문에서는 비교적 가격이 저렴하면서 전자기장의 영향을 적게 받는 광학 소자를 이용하여 각도를 측정하는 연구에 대해 다루고 있다. 보다 측정 범위를 넓히기 위해 빛을 수광하는 포토트랜지스터를 3개 사용하였고, 발광부의 빛을 효과적으로 전달하기 위해 광섬유를 사용하였으며, 이 광섬유의 끝을 여러 각도로 가공하였다. 그 결과 포토트랜지스터를 1개 사용한 경우보다 측정 범위가 넓어지고, 광섬유의 끝을 가공함으로써 측정 신호의 비대칭성과 피크점이 이동하는 것을 확인하였다. 본 연구는 각도 측정을 요하는 다양한 분야에서 활용될 수 있는 측정 기술에 기반이 될 것으로 판단된다.

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Influence of Reaction Conditions on the Grafting Pattern of 3-Glycidoxypropyl trimethoxysilane on Montmorillonite

  • He, Wentao;Yao, Yong;He, Min;Kai, Zhang;Long, Lijuan;Zhang, Minmin;Qin, Shuhao;Yu, Jie
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.112-116
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    • 2013
  • Surface modification of montmorillonite (MMT) with 3-glycidoxypropyl trimethoxysilane (3GTO) in mild methanol/water mixture has been investigated in detail. The influence of reaction conditions (including silane concentration in feed, reaction time and reaction temperature) on the grafting amount and yield of silane, and further on the grafting pattern of silanes was studied by thermogravimetric analysis, elemental analysis, X-ray diffraction (XRD) and BET. Higher silane concentration, longer reaction time and higher reaction temperature are all benefit to higher grafting amount. When the grafting reaction was performed with 3 mmol/g silane concentration, at $90^{\circ}C$ for 24 h, the grafted amount and yield of silane reached 1.4443 mmol/g and 30%, respectively. Based on the XRD and BET data analysis, a speculation that the grafting pattern of silanes was concentration dependence was proposed.

Transcriptome and proteome analysis of pregnancy and postpartum anoestrus ovaries in yak

  • Chen, Zhou;Wang, Jine;Ma, Junyuan;Li, Shuyuan;Huo, Shengdong;Yang, Yanmei;Zhaxi, Yingpai;Zhao, Yongqing;Zhang, Derong
    • Journal of Veterinary Science
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    • v.23 no.1
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    • pp.3.1-3.12
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    • 2022
  • Background: Domestic yaks are the most important livestock species on the Qinghai-Tibetan Plateau. Adult female yaks normally breed in the warm season (July to September) and enter anestrous in the cold season (November to April). Nevertheless, it is unclear how ovarian activity is regulated at the molecular level. Objectives: The peculiarities of yak reproduction were assessed to explore the molecular mechanism of postpartum anestrus ovaries in yaks after pregnancy and parturition. Methods: Sixty female yaks with calves were observed under natural grazing in Haiyan County, Qinghai Province. Three yak ovaries in pregnancy and postpartum anestrus were collected. RNA sequencing and quantitative proteomics were employed to analyze the pregnancy and postpartum ovaries after hypothermia to identify the genes and proteins related to the postpartum ovarian cycle. Results: The results revealed 841 differentially expressed genes during the postpartum hypoestrus cycle; 347 were up-regulated and 494 genes were down-regulated. Fifty-seven differential proteins were screened: 38 were up-regulated and 19 were down-regulated. The differential genes and proteins were related to the yak reproduction process, rhythm process, progesterone-mediated oocyte maturation, PI3K/AKT signaling pathway, and MAPK signaling pathway categories. Conclusions: Transcriptome and proteomic sequencing approaches were used to investigate postpartum anestrus and pregnancy ovaries in yaks. The results confirmed that BHLHE40, SF1IX1, FBPX1, HSPCA, LHCGR, BMP15, and ET-1R could affect postpartum hypoestrus and control the state of estrus.