• Title/Summary/Keyword: Lee Taeho

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Characteristics of Several Korean Native Herbaceous Plants for Cut Slope Revegetation (몇 가지 자생 초화류의 사면녹화 특성)

  • Song, Jeong-Seob;Chang, Young-Deug;Lee, Sang-Jeong;Bang, Chang-Seok;Huh, Kun-Yang;Chung, Meyong-Il;Chung, Hyun-Hwan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.1
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    • pp.10-16
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    • 2005
  • This experiment was conducted to study on application of several Korean native plants by seed spray methods for cut slope revegetation, and possibility of replacement almost imported tall fescue seeds by native herbaceous plants. So, we investigated growth and covering rate after sowing native plants seeds at the artificial slope plots in Suwon and the rock exposed cut-slopes in Wonju city. Emergence rate after seed spray at artificial slopes were higher Elsholtzia splendens and Dianthus superbus var. longicalycinus, showing the highest in E. splendens. Also, E. splendens, D. superbus var. longicalycinus, and Agrostemma coronaria were possible to use for seed spray at the rock exposed cut-slopes. The plots of mixed native plants show more seasonal scenery than that of tall fescue. Soil surface run-off by Typhoon was less in plot sown native plants than those of lawn grass, resulting fresh weight of roots was heavier. Thus, we found that the mixed seed spray of several native herbaceous plants, E. splendens, D. superbus var. longicalycinus, and Agrostemma coronaria, were well covered the slopes as tall fescue.

Characterization of $HfO_2 /SiON$ stack structure for gate dielectrics (ALD를 이용한 극박막 $HfO_2 /SiON$ stack structure의 특성 평가)

  • Kim, Youngsoon;Lee, Taeho;Jaemin Oh;Jinho Ahn;Jaehak Jung
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.11a
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    • pp.115-121
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    • 2002
  • In this research we have investigated the characteristics of ultra thin $HfO_2 /SiON$stack structure films using several analytical techniques. SiON layer was thermally grown on standard SCI cleaned silicon wafer at $825^{\circ}C$ for 12sec under $N_2$O ambient. $HfO_2 /SiON$$_4$/$H_2O$ as precursors and $N_2$as a carrier/purge gas. Solid HfCl$_4$was volatilized in a canister kept at $200^{\circ}C$ and carried into the reaction chamber with pure $N_2$carrier gas. $H_2O$ canister was kept at $12^{\circ}C$ and carrier gas was not used. The films were grown on 8-inch (100) p-type Silicon wafer at the $300^{\circ}C$ temperature after standard SCI cleaning, Spectroscopic ellipsometer and TEM were used to investigate the initial growth mechanism, microstructure and thickness. The electrical properties of the film were measured and compared with the physical/chemical properties. The effects of heat treatment was discussed.

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Metal Phone MIMO Antenna Using the Auxiliary Letter Slot (보조 문자슬롯을 이용한 메탈폰 MIMO 안테나)

  • Lee, Won-hee;Son, Taeho;Jo, Youngmin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.4
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    • pp.395-398
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    • 2016
  • In this paper, a hybrid MIMO antenna for the mobile communication metal phone with auxiliary letter slot is designed and implemented. Auxiliary letter slot locates on the rear metal cover of the phone, and operates on LTE class 40 band. The slots of two letters are designed and operated with monopole+IFA hybrid antenna. Antenna satisfies under VSWR 3: 1 for LTE class 13 / LTE class 14 / CDMA / GSM / DCS / PCS / W-CDMA / LTE class 40 bands. Average gains and antenna efficiencies measured by the anechoic chamber were -5.57~-1.45 dBi and 27.75~71.6 %, respectively.

A Study on Setting Methods of Economic Level of Leakage in Water Pipe Networks (상수도 관망에서의 경제적인 누수관리목표 산정 방안 연구)

  • Hwang, Jinsoo;Choi, Taeho;Lee, Doojin;Koo, Jayong
    • Journal of Korean Society of Water and Wastewater
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    • v.31 no.3
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    • pp.237-248
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    • 2017
  • The estimation method of economical leakage management target utilized upon planning business for improvement of revenue water ratio in South Korea is presented and applicability of methods developed in this study is assessed through application on site. With a consideration of revenue water ratio in application target area, estimation method of long-term economical leakage management target is applied. Three leakage reduction methods such as replacement of residual aged pipe, leakage investigation and restoration and water pressure management are applied with a consideration of characteristics of site. Due to difficulty of obtaining data, analysis of cost/benefit by leakage reduction methods is performed by applying method of leakages estimation equation among statistical methods. As a result of application, revenue water ratio corresponding to long-term economical leakage management target is 91.6 %.

Evaluation for conjunctive operation of multi-regional water supply system through risk analysis (위기대응 취약성 분석을 통한 광역상수도 연계운영 평가)

  • Hwang, Jinsoo;Choi, Taeho;Hong, Gonghyun;Lee, Doojin;Koo, Jayong
    • Journal of Korean Society of Water and Wastewater
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    • v.33 no.4
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    • pp.269-279
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    • 2019
  • This study would present a risk analysis method to evaluate stable tap water supply in a multi-regional water supply system and propose a measure for the evaluation of the effect of the conjunctive operation of the multi-regional water supply system using this. Judging from the vulnerability for the crisis response of the entire N. multi-regional water supply system, as compared to the result of Scenario 1 in which no conjunctive pipes were operated, it was found that in Scenario 2, in which conjunctive pipes were partially operated, the vulnerability of crisis response decreased by about 30.6%, and as compared to Scenario 3, the vulnerability of crisis response decreased by 86.2%. In setting a plan for stable tap water supply in N multi-regional water supply system, using the estimated value and the method for the evaluation of the vulnerability of crisis response by pipe, by interval and by line, it is judged that this can be utilized as a basis for the judgment of the evaluation of the operation or the additional installation of conjunctive pipes.

Design of 0.6~6 GHz Ultra Wideband Quad-ridge Horn Antenna (0.6~6 GHz 초 광대역 쿼드릿지 혼 안테나 설계)

  • Choi, Cheoljin;Lee, Moonhee;Son, Taeho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.68 no.1
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    • pp.77-82
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    • 2019
  • In this paper, a 0.6~6GHz quad-ridge horn antenna which can be used for the antenna measurement of 5.8GHz WiFi system from lowest frequency band of mobile LTE (Long Term Evolution) is designed and implemented. The quad-ridge horn antenna has quadruple ridges of exponential function, a back-short and a cavity. Based on this structure, we design the cavity size, ridge gap and feed gap to have broadband characteristics. For implementation, the plates material of aluminum and copper are used for the horn and four ridges, respectively. And the insulator supports are used to maintain the gap between ridges. By measurement, antenna has the gain of 6.2~13.35dBi with the return loss of less than -6dB (under VSWR 3 : 1) in the entire design band. The results of this study can be widely used to the antenna studies on the mobile communication including low frequency band of LTE, the EMI measurement and the standard calibration measurement.

Streptozotocin-Induced Pro-Inflammatory Response in Rat Blood and its Attenuation by External Albumin Administration

  • Bae, Chun-Sik;Lee, Chang-Min;Kim, Dong-il;Ahn, Taeho
    • Journal of Veterinary Clinics
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    • v.36 no.3
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    • pp.145-149
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    • 2019
  • Previous report has suggested that the albumin levels were reduced in the peripheral blood mononuclear cells (PBMCs) and consequently oxidative stress was elevated in streptozotocin (STZ)-induced diabetic rats as albumin is the predominant antioxidant in plasma. In this study, we suggest that the levels of pro-inflammatory cytokine such as interleukin-6 (IL-6) and tumor necrosis factor-${\alpha}$ ($TNF-{\alpha}$) were increased by approximately 3.4- and 2.9-fold, respectively, in the serum of STZ-diabetic rats, compared to those of normal rat. In addition to the cytokines, the levels of C-reactive protein (CRP) were also about 3.6-fold higher, indicating that STZ induced a pro-inflammatory response in rat blood. However, when purified rat albumin was externally co-administrated with STZ through the tail vein, the serum levels of IL-6, $TNF-{\alpha}$, and CRP were markedly reduced, although the values were still higher than those of normal (non-diabetic) rats. Albumin administration also decreased STZ-induced oxidative stress in serum and PBMCs. Moreover, the decrease in cytokine and CRP levels was dependent on the dose of injected albumin. These results suggest that STZ-induced pro-inflammation and oxidative stress in rat blood might be attenuated by treatment with exogenous albumin.

Bibliographic Study on the Book Dongeuisasangjinryoeuijeon (동의사상진료의전(東醫四象診療醫典)에 대한 서지학적 고찰)

  • Yu, Jun-Sang
    • Journal of Sasang Constitutional Medicine
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    • v.32 no.4
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    • pp.1-10
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    • 2020
  • Objective The purpose of this study was to examine the composition, bibliographic characteristics, and contents of the book, Dongeuisasangjinryoeuijeon(東醫四象診療醫典). Method The images of this book published in 1941 at Haenglim publishing company, stored in the National Library of Korea were acquired and used as basic data, and books related to Sasang constitutional medicine such as Dongeuisasangshinpyun (東醫四象新編), Dongmuyugo(東武遺稿), and Sasanggeumgyebibang(四象金匱秘方) were compared. Result Many of the data were based on the Dongeuisasangshinpyun(東醫四象新編), and were made with reference to Dongmuyugo(東武遺稿) and Sasanggeumgyebibang(四象金匱秘方) partly. This book is thought to be made to be used conveniently for clinicians at the time when data on Sasang Constitutional Medicine was insufficient. In particular, it can be said that the mention of well-established diagnostic method, drugs that cause adverse reactions when a patient of a different constitution takes them and the quatrains of prescriptions using seven Chinese characters in each line are very unique. Conclusion Although most of the books, including Dongeuisasangshinpyun(東醫四象新編), were cited, it is thought that the book was well-organized in order to provide good information to the clinicians practicing Sasang Constitutional Medicine at the time. For the original part of this book, further research should be conducted.

Effect of Steady-State Oxidation on Tensile Failure of Zircaloy Cladding

  • Kim, Taeho;Choi, Kyoung Joon;Yoo, Seung Chang;Lee, Yunju;Kim, Ji Hyun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.2
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    • pp.161-170
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    • 2022
  • The effect of oxidation time on the characteristics and mechanical properties of spent nuclear fuel cladding was investigated using Raman spectroscopy, tube rupture test, and tensile test. As oxidation time increased, the Raman peak associated with the tetragonal zirconium oxide phase diminished and merged with the Raman peak associated with the monoclinic zirconium oxide phase near 333 cm-1. Additionally, the other tetragonal zirconium oxide phase peak at 380 cm-1 decreased after 100 d of oxidation, whereas the zirconium monoclinic oxide peak became the dominant peak. The oxidation time had no effect on the tube rupture pressure of the oxidized zirconium alloy tube. However, the yield and tensile stresses of the oxidized nuclear fuel cladding tube decreased after 100 d of oxidation. The results of the scanning electron microscopy and transmission electron microscopy were represented with the in-situ Raman analysis result for the oxide characteristics generated on the cladding of spent nuclear fuel.

Anti-Jamming and Time Delay Performance Analysis of Future SATURN Upgraded Military Aerial Communication Tactical Systems

  • Yang, Taeho;Lee, Kwangyull;Han, Chulhee;An, Kyeongsoo;Jang, Indong;Ahn, Seungbeom
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.9
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    • pp.3029-3042
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    • 2022
  • For over half a century, the United States (US) and its coalition military aircrafts have been using Ultra High Frequency (UHF) band analog modulation (AM) radios in ground-to-air communication and short-range air-to-air communications. Evolving from this, since 2007, the US military and the North Atlantic Treaty Organization (NATO) adopted HAVE QUICK to be used by almost all aircrafts, because it had been revealed that intercepting and jamming of former aircraft communication signals was possible, which placed a serious threat to defense systems. The second-generation Anti-jam Tactical UHF Radio for NATO (SATURN) was developed to replace HAVE QUICK systems by 2023. The NATO Standardization Agreement (STANAG) 4372 is a classified document that defines the SATURN technical and operational specifications. In preparation of this future upgrade to SATURN systems, in this paper, the SATURN technical and operational specifications are reviewed, and the network synchronization, frequency hopping, and communication setup parameters that are controlled by the Network (NET) Time, Time Of Day (TOD), Word Of Day (WOD), and Multiple Word of Day (MWOD) are described in addition to SATURN Edition 3 (ED3) and future Edition 4 (ED4) basic features. In addition, an anti-jamming performance analysis (in reference to partial band jamming and pulse jamming) and the time delay queueing model analysis are conducted based on a SATURN transmitter and receiver assumed model.