• Title/Summary/Keyword: 기장

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Experimental study on flow characteristics for the high efficiency transporting of the dredged soil (준설토 이송고효율화를 위한 유동특성의 실험적 분석)

  • Kim, Yu-Seung;Lee, Myung-Han;Lee, Su-Yeon
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.1
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    • pp.71-81
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    • 2016
  • To evaluate the effects of magnetic force for transporting the dredged soil, magnetic energy inducing device was installed at the dredger. The whole length of transporting pipeline reaches more than 8.5km and the efficiency of the system and the characteristics of the flow are critical factors. The main parameters which govern the flow are flow-rate, velocity, concentration and slip-layer's condition, so in the field test monitoring system was applied to check the real time conditions of the closed circuit flow and the main parameters. From analyzing the relation between the dredged soil amounts and the pump power, it can be concluded that the magnetic forces effect on the transporting system, increase the transporting quantities of dredged soil and decrease power consumption of the pump.

Variation of Dynamic Characteristics of Composite Plates Subjected to Electromagnetic and Thermal Fields via Piezoelectric Control (전자기장과 열하중을 받는 복합재료 평판의 압전제어에 따른 동특성 변화)

  • Park, Sang-Yun;Song, Ohseop
    • Composites Research
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    • v.29 no.6
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    • pp.379-387
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    • 2016
  • Structural model of laminated composite plate based on the first order shear deformation theory and subjected to a combination of piezoelectric, electromagnetic and thermal fields is established. Coupled equations of motion are derived via Hamilton's principle on the basis of electromagnetic and piezoelectric equations which are involved in constitutive equations. Proportional control and velocity feedback control logics are applied via boundary control moments and forces. Variations of dynamic chasracteristics of composite plate with collocated piezoelectric sensor and actuators, electromagnetic field and temperature gradient are investigated and it reveals that dynamic characteristics of structure can be effectively controlled by utilizing the piezoelectric effect and ply angles of fiber reinforced composites.

Growth and Yield Characteristics of Foxtail Millet, Proso Millet and Sorghum According to Sowing Date in Middle Area in Korea (중부지방에서 파종기에 따른 조, 기장, 수수의 생육 및 수량 특성)

  • Yoon, Seong-Tak;Jae, Eun-Kyeong;Kim, Young-Jung;Jeong, In-Ho;Han, Tae-Kyu;Kim, Tae-Yun;Cho, Young-Son;Kang, Hang-Won
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.60 no.2
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    • pp.197-211
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    • 2015
  • In order to investigate optimum and marginal sowing date of foxtail millet, proso millet and sorghum in middle area (Anseong, Gyeonggi province) of korea, four levels of sowing date [(May 15(1st), June 6(2th), June 26(3th), July 13(4th)] with mulching and non-mulching were treated in this experiment. We used three crops of foxtail millet, proso millet and sorghum with four varieties of Samdachal, Samdamae, Kyeongkwan1, Hwanggeumjo in foxtail millet, Leebaekchal, Manhongchal, Hwangsilchal, Hwanggeumgijang in proso millet and Nampungchal, Hwanggeumchal, DS202, Moktaksusu in sorghum achieved from RDA. In culm length, sowing date of June 26 was the highest in all varieties of foxtail millet, proso millet and sorghum. Sowing date of May 15 showed the highest ear length in foxtail and proso millet, whereas the highest ear length was obtained from sowing date of June 26 in sorghum. In numbers of leaf, sowing date of May 15 showed the highest in all three crops of foxtail millet, proso millet and sorghum. Days from sowing to heading date were reduced in Samdamae, Kyeongkwan1 and Samdachal as sowing date was late. In Hwanggeumjo it was reduced from the sowing date from May 15 to June 26, but it was same days was taken between June 26 and July 13 sowing date. Days from sowing to heading date of four varieties in proso millet were reduced as sowing date was late. Days from sowing to heading date in sorghum were reduced as sowing date was late, whereas it was increased the $4^{th}$ sowing date of July 13. There were no significant differences in growth and yield characteristics between mulching and non-mulching in four varieties of foxtail millet, proso millet and sorghum with four varieties. The highest grain numbers per panicle, 1000 grain weight and yield per 10a were obtained from sowing date of June 26 in four varieties of foxtail millet, proso millet and sorghum. In sowing date of July 13, all varieties of foxtail millet, proso millet and sorghum were not able to be ripened because of late sowing except Hwnaggeumjo, Manhongchal and Hwanggeumgijang.

Effects of the Cultivated Areas on Antioxidant Compounds and Activities of Proso Millet (Panicum miliaceum L.) (재배지역이 기장(Panicum miliaceum L.)의 항산화성분 및 활성에 미치는 영향)

  • Lee, Jae-Saeng;Song, Seuk-Bo;Ko, Jee-Yeon;Kang, Jong-Rae;Oh, Byeong-Geun;Seo, Myung-Chul;Kwak, Do-Yeon;Nam, Min-Hee;Woo, Koan-Sik
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.4
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    • pp.315-321
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    • 2011
  • Effects of antioxidant compounds and antioxidant activities of proso millet cultivated in different areas were determined. The cultivated areas were Milyang (plain area of interior), Wonju (mountainous territory) and Sinan (coastal area), and cultivated varieties were Hwanggeumgijang (HGG), Byeoruk-gijang (BRG), Norangchal-gijang (NRG), Bulgeun-gijang (BGG), Whin-gijang (WG). The highest total polyphenol contents of methanolic extracts were 2.54 and 2.65 mg/g in BGG and BRG produced in Sinan, respectively. The highest total flavonoid content were 2.66 and 2.59 mg/g in BGG and BRG produced in Sinan, respectively. The highest total tannin contents were 1.87 and 1.42 mg/g in BRG and NRG produced in Sinan. The DPPH radical-scavenging activity was the highest value of BGG (8.54 mg TE/g) and BRG (8.53 mg TE/g) produced in Sinan. The ABTS radical-scavenging activity was the highest value of BGG and BRG of 19.48 and 19.29 mg TE/g in the grains produced in Sinan, respectively. Generally, there was difference in antioxidant compound contents on the methanolic extracts of proso millet between the cultivated areas and varieties.

Field Strength Standards in 30~ 1000MHz Frequency Range (30~1000MHz 주파수 범위에서의 전자기장의 세기 표준)

  • 김정환;강찬구
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.12
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    • pp.1893-1901
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    • 1993
  • This paper presents the field strength standard established using a standard antenna method in the frequency range of 30~1000MHz at KRISS(Korea Research Institute of Standards and Science). Designs on antenna elements and a balun, and the characteristics of an antenna voltmeter are described. The uncertainties in generation the standard fields are analzed and estimated to be 5~14%.

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유도 결합형 플라즈마 공정조건 변화에 따른 플라즈마 방전과 전자기장 시뮬레이션의 비교

  • Kim, U-Jae;Jo, Tae-Hun;Park, Hye-Jin;Choe, Jin-U;Lee, Ye-Seul;Hwang, Sang-Hyeok;Yun, Myeong-Su;Gwon, Gi-Cheong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.214.2-214.2
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    • 2016
  • 플라즈마 공정은 공정의 미세화, 저온화의 필요성 때문에 반도체 및 태양전지 분야 등 여러 분야에서 널리 쓰이고 있으며 그 중요성은 점점 더 커져가고 있다. 그러나 플라즈마를 사용하는 공정에서 공정조건의 미세한 변화에 따라서 플라즈마 특성이 크게 바뀌어 공정조건에 따른 공정 결과의 예측을 어렵게 한다. 따라서 플라즈마를 이용하는 공정에 있어서 다양한 변수의 복합적인 상호작용을 고려하여 공정 결과를 예상 할 수 있는 시뮬레이션에 대한 연구가 요구되고 있다. 본 연구에서는 유도 결합형 플라즈마 발생 장치에서 공정조건에 따른 플라즈마 밀도 분포 변화를 전자기장 시뮬레이션을 통해 예상해보았으며, 시뮬레이션 결과를 실제 방전 상황에서 DLP(Double Langmuir Probe)로 측정한 값과 비교하여 플라즈마 밀도 분포와 전자기장 시뮬레이션의 정확성을 검토하였다.

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Structural Design of Angola Stadium (앙골라 주경기장 구조설계)

  • Kim, Jong-Soo;Shin, Chang-Hoon;Kim, Jeong-Hyeon
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.212-217
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    • 2008
  • This paper is concerned with the structural design of Angola Stadium. The Angola stadium is composed of a Steel moment frame system and a Cantilever steel truss roof. Whole structural analysis is necessary to ensure the stability. Considered FEM analysis, Design of Wind load & Seismic, Stand diaphragm, interaction between stand and Roof, Serviceability.

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The Analysis of Indoor Thermal Environment for Air Condition System in Dome Stadium (돔경기장의 공조방식에 따른 겨울철 열환경 분석)

  • Seok, Ho-Tae;Yang, Jeong-Hoon;Chae, Mun-Byoung
    • Journal of Korean Association for Spatial Structures
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    • v.9 no.2
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    • pp.53-63
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    • 2009
  • In this study selected the domestic dome stadium, and analyzed the indoor airflow and temperature distribution application to existing or abroad air condition system in winterabWe examined the appropriateness of flow guiding fans installed to mitigate the high-temperature.

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Field Uniformity Analysis of Reverberation Chamber with Asymmetric Structure (비대칭적 구조 전자파 잔향실 전자기장 균일도 해석)

  • 정삼영;이중근;이황재
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.5
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    • pp.837-843
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    • 2001
  • Conventional reverberation chamber has a rectangular structure including mode stirrers or mode-turned stirrers to obtain the field uniformity inside the chamber. This paper explained the way to improve the field uniformity in an asymmetric structure instead of conventional rectangular structure with right-angled planes. Two types of asymmetric structure were considered. One was an asymmetric reverberation chamber using Quadratic Residue Diffuser and the other was an asymmetric chamber with oblique enclosure including fixed Randomly Made Diffusers. The FDTD simulation method was used to analyze the field homogeneous characteristics of these asymmetric reverberation chambers.

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The Calculation of Two Dimensional Spatial Profile of Electromagnetic Field for Capacitively Coupled Plasma Source (축전 결합형 플라즈마원에 대한 전자기장의 2차원 공간 의존성 계산)

  • Kim, Y.I.;Yoon, N.S.
    • Journal of the Korean Vacuum Society
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    • v.17 no.5
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    • pp.400-407
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    • 2008
  • In this study, Two dimensional spatial profile of electromagnetic field for capacitively coupled plasma source is calculated. Based on one dimensional fluid equation, spatial profile for the axial direction of electric field and conduction current density is firstly calculated. The two dimensional spatial profile for the electromagnetic field is calculated from solution of Maxwell equation that is expanded to power series for ${\omega}r/c$ into the radial direction.