• Title/Summary/Keyword: Yeon Ju Hwan

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Investigation of Prohibited Seed-Borne Plant Pathogenic Bacteria in Korea (국내 종자전염 규제 식물병원세균 조사)

  • Hong, Yeon-Seok;Choi, Hyun Ju;Lee, Ingyeong;Lim, Yeon-Jeong;Park, Sung Woo;Nam, Bong Woo;Lee, Bu Ja;Park, Duck Hwan
    • Research in Plant Disease
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    • v.26 no.3
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    • pp.134-143
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    • 2020
  • The goal of this manuscript is to determine seed-borne plant pathogenic bacteria and phytoplasmas among quarantine pests in Korea. Four and two prohibited bacteria and phytoplasmas, respectively, and 35 and 17 restricted bacteria and phytoplasmas, respectively, were assessed whether they are seed-borne or not based on preliminary reports. As results, two species of prohibited bacteria, eighteen species of restricted bacteria, and one species of restricted phytoplasma have been determined as being seed-borne plant pathogenic bacteria. Thus, quarantine fields must account for these lists once inspection has been conducted on imported seeds and also use of these lists can help to reduce the production of new diseases that can spread from infected imported seeds.

Protection of NMDA-Induced Neuronal Cell Damage by Methanol Extract of Myristica Fragrans Seeds in Cultured Rat Cerebellar Granule Cells

  • Ban, Ju-Yeon;Cho, Soon-Ock;Kim, Ji-Ye;Bang, Kyong-Hwan;Seong, Nak-Sul;Song, Kyung-Sik;Bae, Ki-Whan;Seong, Yeon-Hee
    • Natural Product Sciences
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    • v.10 no.6
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    • pp.289-295
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    • 2004
  • Myristica fragrans seed from Myristica fragrans Houtt (Myristicaceae) has various pharmacological activities peripherally and centrally. The present study aims to investigate the effect of the methanol extract of Myristica fragrans seed (MF) on N-methyl-D-aspartate (NMDA)-induced neurotoxicity in primary cultured rat cerebellar granule neuron. MF, over a concentration range of 0.05 to $5\;{\mu}g/ml$, inhibited NMDA (1 mM)- induced neuronal cell death, which was measured by trypan blue exclusion test and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. MF $(0.5\;{\mu}g/ml)$ inhibited glutamate release into medium induced by NMDA (1 mM), which was measured by HPLC. Pretreatrnent of MF $(0.5\;{\mu}g/ml)$ inhibited NMDA (1 mM)-induced elevation of cytosolic calcium concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that MF prevents NMDA-induced neuronal cell damage in vitro.

A Review Study and Proposal of Facial Palsy Sequelae Evaluating Scale (안면마비 후유증 평가법에 대한 고찰 및 제언)

  • Suk, Kyung Hwan;Ryu, Hee Kyoung;Goo, Bon Hyuk;Lee, Ju Hyeon;Ryu, Soo Hyeong;Lee, Su Yeon;Kim, Min Jeong;Park, Yeon Cheol;Seo, Byung Kwan;Park, Dong Suk;Baek, Yong Hyeon
    • Journal of Acupuncture Research
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    • v.31 no.4
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    • pp.99-108
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    • 2014
  • Objectives : This study was performed to review articles referring to facial palsy sequelae evaluating scale and propose how to assess facial palsy sequelae. Methods : We searched for the medical literature to find out method of evaluating facial palsy sequelae. Then, we researched strengths and weaknesses of the scale and considered the way to appraise the facial palsy sequelae. Results : There were subjective and objective scale for evaluating facial palsy sequelae. Subjective scale could offer detailed assessment but had low objectivity and reproducibility. Objective scale had consistency and detachment but needed for specific equipments with time for measuring and calculating. Conclusions : We should evaluate the facial palsy sequelae with the strengths of subjective and objective scale and assess facial nerve function, symptoms of facial palsy sequelae and quality of life entirely. Moreover, the scale has to contain the reliability with static and dynamic assessment.

Compared Anti-inflammatory Activity of Euonymus alatus and Euonymus alatus for. ciliatodentatus (Franch. & Sav.) Hiyama Extract on Macrophages (화살나무(Euonymus alatus)와 회잎나무(Euonymus alatus for. ciliatodentatus (Franch. & Sav.) Hiyama) 추출물의 대식세포에 대한 항염증 활성비교)

  • Kim, Jeong Hwa;Oh, Su-Yeon;Han, Ju Hwan;Lee, Gooi Yong;An, Chan Ki;Hwang, Bang Yeon;Lee, Jae Kwon
    • YAKHAK HOEJI
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    • v.58 no.6
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    • pp.357-363
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    • 2014
  • Euonymus alatus (EAE) and Euonymus alatus for. ciliatodentatus (Franch. & Sav.) Hiyama (EACHE) belong to the Celastraceae family and are one of the medicinal herbs used in traditional medicine as a therapeutic agent for blood circulation diseases. In this study, we prepared leaves methanolic extract of EAE (L-EAE), twigs methanolic extract of EAE (T-EAE), leaves methanolic extract of EACHE (L-EACHE) and twigs methanolic extract of EACHE (T-EACHE), and compared their anti-inflammatory activities. To analyze the anti-inflammatory activities, Raw 264.7 cells were used, since they are immature-macrophages and easily matured by lipopolysaccharide (LPS) stimulation. All extracts showed anti-inflammatory activities in the activated Raw 264.7 cells. That is, we showed that L-EACHE and T-EACHE are potent inhibitors of the production of nitric oxide and pro-inflammatory cytokines. These results are expected to serve as a guide for future studies on the ability of Celastraceae family to inhibit acute and chronic inflammatory diseases.

Study on Mechanism of Combustion Instability in a Dump Gas Turbine Combustor (모형가스터빈 연소기내 연소불안정성에 대한 연구)

  • Lee, Jong-Ho;Lee, Yeon-Ju;Jeon, Chung-Hwan;Jang, Yeong-Jun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.9
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    • pp.1284-1291
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    • 2002
  • Combustion instabilities are an important concern associated with lean premixed combustion. Laboratory-scale dump combustor was used to understand the underlying mechanisms causing combustion instabilities. Experiments were conducted at atmospheric pressure and sound level meter was used to track the pressure fluctuations inside the combustor. Instability maps and phase-resolved OH chemiluminescence images were obtained at several conditions to investigate the mechanism of combustion instability and relations between pressure wave and heat release rate. It showed that combustion instability was susceptible to occur at higher value of equivalence ratio (>0.6) as the mean velocity was decreased. Instabilities exhibited a longitudinal mode with a dominant frequency of ∼341.8 Hz, which corresponded to a quarter wave mode of combustor. Heat release and pressure waves were in-phase when instabilities occurred. Rayleigh index distribution gave a hint about the location where the strong coherence of pressure and heat release existed. These results also give an insight to the control scheme of combustion instabilities. Emission test revealed that NOx emissions were affected by not only equivalence ratio but also combustion instability.

Diagnostic Tool for Cold Sensation of Hands: A Preliminary Study (수부냉증 진단방법에 관한 기초연구)

  • Ko, Seung-woo;Park, Jong-ju;Kong, Kyung-hwan;Go, Ho-yeon
    • The Journal of Internal Korean Medicine
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    • v.36 no.3
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    • pp.228-235
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    • 2015
  • Objectives: The aim of this study was to find an effective medical device to detect cold sensation of hands. Methods: Patients with cold sensation of hands (N=42) were recruited in July 2013. We surveyed patients’ general characteristics, severity of cold sensation, body temperature in Nogung (PC8) and Hyeopbaek (LU4) measured with a digital thermometer, digital infrared thermal imaging, and pulse wave velocity. Results: The relation between severity of cold sensation and temperature in Nogung (PC8) and Hyeopbaek (LU4) was statistically significant. The results showed a higher correlation of severity of cold sensation with Nogung (PC9) than with Hyeopback (LU4) temperature. No other indices were statistical significant. Conclusions: Measuring the Nogung (PC9) temperature is most reasonable for assessing the severity of cold sensation of hands. To generalize this result, however, a large-scale study is warranted.

Microstructure and Hardness Changes of the CVD-ZrC Film with Different Deposition Temperature (증착온도 변화에 따른 화학증착 ZrC의 미세구조와 경도 변화)

  • Park, Jong-Hoon;Jung, Choong-Hwan;Kim, Weon-Ju;Kim, Do-Jin;Park, Ji-Yeon
    • Journal of the Korean Ceramic Society
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    • v.45 no.9
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    • pp.567-571
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    • 2008
  • The properties of a grown film by the chemical vapor deposition process depend on the deposition temperature because the deposition mechanism of the CVD film is controlled by the deposition temperature. The preferred orientation of the zrC film changed from (111) to (220) or (200) with an increase of the deposition temperature. The grain size of the ZrC film changes from $0.8{\mu}m$ to $2.5{\mu}m$ in the range of 1350 to $1500^{\circ}C$. The hardness of the deposited ZrC film depended on the preferred orientation and the grain size. The hardness of the ZrC film deposited at $1400^{\circ}C$ was 31 GPa.

Current Revision Control according to Temperature of IPMSM in Electric Scooter (전기 스쿠터용 매입형 영구자석 동기전동기의 온도보상에 의한 전류 보정 제어)

  • Im, Jong-Bin;Ham, Sang-Hwan;Cho, Su-Yeon;Oh, Se-Young;Ryu, Gwang-Hyeon;Ahn, Han-Woong;Lee, Ju
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.802-803
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    • 2011
  • 매입형 영구자석 동기전동기는 강건한 회전자 구조와 릴럭턴스 토크를 사용할 수 있다는 점, 악계자 제어를 하기 쉽다는 점에서 넓은 속도와 토크를 필요로하는 하이브리드 차량이나 전기 차량에 적합한 전동기이다. 영구자석의 감자곡선은 온도에도 의존하기 때문에 온도에 따라 전동기의 자속과 토크가 변하게 된다. 이 논문은 전기 스쿠터에 사용되는 매입형 영구자석 동기전동기의 온도에 따른 지령 전류 보정에 의한 제어법에 대해 연구하였다. 토크 리플을 줄이기 위해서 속도-토크 곡선과 감자곡선을 이용하여 구하였으며, 보정된 지령 전류를 구하기 위해 Lagrange 보간법과 재귀 최소자승(Recursive Least Square : RLS) 법을사용하여 전류맵을 만들었다.이 지령 전류는 토크와 인버터 출력 전류값을 계산하는데 사용된다. 전류맵을 만들기 위해서 측정한 온도는 20, 80, 100도이다. 본 논문에서 제안한 제어법을 이용하여 토크 리플이 줄어듬을 시뮬레이션과 실험을 통해서 확인할 수 있었다.

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Study on Thermal analysis of the single phase Line Start Permanent Magnet Motor for Refrigerator Compressor (냉장고 컴프레서용 단상 유도형 동기 전동기의 열 해석에 관한 연구)

  • Ahn, Han-Woong;Ham, Sang-Hwan;Cho, Su-Yeon;Ryu, Gwang-Hyeon;Oh, Se-Young;Um, Suk-Kee;Lee, Ju
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.993-994
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    • 2011
  • This paper presents the characteristic analysis of thermal behavior of a single-phase line-start permanent magnet motor(LSPM) for high-efficiency design. By analyzing of thermal behavior, it can consider demagnetization characteristics of permanent magnets. In addition, by calculating the allowable current density it will be able to reduce the size of the stator. For this reason single-phase LSPM is necessary to examine the thermal analysis. Thermal analysis was performed using heat source mapping, and it is verified by finite element method.

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Design of Linear Synchronous Motor for Thrust Force Ripple Reduction using Module Phase Set Shift (Module Phase Set Shift를 이용한 선형 동기 전동기의 추력 리플 저감 설계)

  • Ryu, Gwang-Hyeon;Lee, Hyung-Woo;Cho, Su-Yeon;Oh, Se-Young;Ham, Sang-Hwan;Im, Jong-Bin;Ahn, Han-Woong;Lee, Ju
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.848-849
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    • 2011
  • Rotating machines are using gears to change the rotary motion into the linear motion, on the other hand, linear motors have a accurate position control and excellent dynamic characteristics because of generating a thrust force directly. But the important problem, one of the linear motor is a high thrust force ripple. Thrust force ripple has a bad effect on the position accuracy and the dynamic characteristics, so it is necessary to reduce the thrust force ripple. Cogging is one of the cause that affect thrust force ripple. Cogging has some connection with the GCD between pole pitch and teeth pitch It is proposed method to reduce a thrust ripple of the linear motor that chamfering, skew, and so on. In this paper, the module phase set shift(MPSS) is used to reduce a thrust force ripple that has a similar effect to skew. And propose a method that reduce a thrust force ripple more by use of chamfering.

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