• Title/Summary/Keyword: T. B. Lee

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Inductor-less 6~18 GHz 7-Bit 28 dB Variable Attenuator Using 0.18 μm CMOS Technology (0.18 μm CMOS 기반 인덕터를 사용하지 않는 6~18 GHz 7-Bit 28 dB 가변 신호 감쇠기)

  • Na, Yun-Sik;Lee, Sanghoon;Kim, Jaeduk;Lee, Wangyoung;Lee, Changhoon;Lee, Sungho;Seo, Munkyo;Lee, Sung Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.1
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    • pp.60-68
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    • 2016
  • This paper presents a 6~18 GHz 7-bit digital-controlled attenuator. The proposed attenuator is based on switched-T architecture, but no inductor is used for minimum chip size. The designed attenuator was fabricated using $0.18{\mu}m$ CMOS process, and characterized using on-wafer testing setup. The resolution(minimum attenuation step) and the maximum attenuation range of the attenuator were measured to be 0.22 dB and 28 dB, respectively. The measured RMS attenuation error and the RMS phase error for 6~18 GHz were less than 0.26 dB and $3.2^{\circ}$, respectively. The reference state insertion loss was less than 12.4 dB at 6~18 GHz. The measured input and output return losses were better than 9.4 dB over all frequencies and attenuation states. The chip size is $0.11mm^2$ excluding pads.

무기담채를 이용한 폐수처리

  • Cha, Wol-Seok;Gwon, Gyu-Hyeok;Choe, Hyeong-Il;Jeong, Gyeong-Hun;Lee, Dong-Byeong;Jeong, Gil-Rok
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.343-347
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    • 2003
  • Power of loess ball on nitrogen and phosphorous removal in wastewater treatment were investigated. flow line A ( anaerobic${\rightarrow}$oxic${\rightarrow}$anoxic(organic source methanol)${\rightarrow}$p-absorption) showed the results of T-P 0.5, T-N 1.0, and COD 10ppm bellow, and flow line B ( oxic${\rightarrow}$anoxic, organic source: methanol${\rightarrow}$p-absorption) showed the results of T-P 0.3, T-N 5.0, and COD 15 ppm bellow. flow line C ( anaerobic${\rightarrow}$oxic${\rightarrow}$anoxic, organic source: wastewater ${\rightarrow}$ p-absorption) showed the results of T-P 0.6, T-N 10, and COD 15 ppm bellow, and flow line D ( oxic${\rightarrow}$anoxic, organic source: methanol${\rightarrow}$p-absorption) showed the results of T-P 1, T-N 8m, and COD 20 ppm bellow. So the results of these experiments showed the probability of loess ball in wastewater treatment.

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Effect of SLCO1B1 T521C on Statin-induced Myotoxicity: A Systematic Review and Meta-analysis (SLCO1B1 T521C가 스타틴에 의한 근육독성 발생에 미치는 영향: 체계적 문헌고찰 및 메타분석)

  • Lee, Young Sook;Chun, Pusoon
    • Korean Journal of Clinical Pharmacy
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    • v.28 no.4
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    • pp.320-332
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    • 2018
  • Background: This study was performed to clarify the effect of SLCO1B1 T521C on statin-induced myotoxicity. Methods: The PubMed, Embase, Ovid, and Cochrane Library databases were searched for all published studies between database inception and April 2018. Using Review Manager 5, the pooled odds ratio (OR) and corresponding 95% confidence interval (CI) were determined to assess the effect of SLCO1B1 T521C on statin-induced myotoxicity by using different genetic models. Results: Eleven observational studies and one randomized controlled trial were included in the meta-analysis. The pooled analysis showed that the incidence of statin-induced myotoxicity was significantly associated with the SLCO1B1 521C variant allele. Among patients using statins, the incidence of myotoxicity was higher in those carrying the 521TC or 521CC variant than in those carrying the 521TT variant in the dominant model (TC + CC vs TT, OR: 1.57; 95% CI: 1.20, 2.05; p = 0.001). The 521TC genotype was associated with a higher risk of myotoxicity than the 521TT genotype (OR: 1.42; 95% CI: 1.09, 1.86; p = 0.009). Furthermore, the incidence of myotoxicity was higher in 521CC carriers than in 521TC carriers (OR: 1.40; 95% CI: 1.06, 1.83; p = 0.02) and noticeably higher in 521CC carriers than in 521TT carriers (OR: 2.26; 95% CI: 1.23, 4.17; p = 0.009). Conclusion: The identification of individuals with the SLCO1B1 521C variant allele prior to the initiation of statin therapy might be useful to predict the risk of toxicity development, determine the individual dose, and prevent myotoxicity.

A Study on Position and Induced Voltage of ADSS Using CSM (CSM을 이용한 ADSS유도전압 해석 및 위치선정에 관한 연구)

  • Myung, S.H.;Lee, B.Y.;Lee, G.C.;Lee, J.B.;Ha, T.H.;Joo, M.N.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1654-1656
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    • 1997
  • Tracking currents related to field exposure for ADSS in T/L is of importance. At phase-ta-phase voltage in excess of 100 kV self-supporting aerial cables with solid insulation tend to suffer damage in regions close to the tower. The damage can be put down to surface tracking currents resulting from different degrees of surface contamination and moisture. Main characteristic of this exposure is the induced voltage analysis and position of ADSS. For complicated calculation of induced voltage on ADSS, this paper described an effective numerical calculation method based on CSM. The proposed methods are applied to 275 kV T/L of Malaysia.

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Activation of toll-like receptor signaling by polysaccharide isolated from cell culture of Acantopanax senticosus

  • Ahn, H-J;Han, S-B;Yoon, Y-D;Lee, H-S;Moon, J-S;Lee, C-W;Lee, K-H;Park, S-K;Kim, H-C
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.11b
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    • pp.182-182
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    • 2002
  • We investigated the mechanism of immunomodulatory action of polysaccharide isolated from cell culture of Acanthopanax senticosus (ASP). ASP was found to increase directly proliferation and differentiation of B cells, and cytokine production of macrophages, but not proliferation and cytokine production of T cells.(omitted)

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($^{11}$B NMR study of vortex dynamics in LuNi$_2$B$_2$C

  • Lee, K.H.;Seo, S.W.;Kim, D.H.;Khang, K.H.;Seo, H.S.;Hwang, C.S.;Cho, B.K.;Lee, Moo-Hee
    • 한국초전도학회:학술대회논문집
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    • v.10
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    • pp.107-110
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    • 2000
  • ($^{11}$B NMR measurements have been performed on single crystals of LuNi$_2$B$_2$C superconductor to investigate vortex lattice structures and dynamical behavior. The spectrum in the superconducting state is significantly broadened by local field inhomogeneity due to the vortex lattice and the peak point of the spectrum shifts toward low magnetic field due to the imperfect field penetration. The linewidth of the spectrum reflecting local field variation is much smaller than expected for conventional vortex lattices and shows peculiar increase at low temperature. Furthermore, the transverse relaxation rate, 1/T$_2$, probing the slow motion of vortices, exhibits a single peak as temperature decreases. These prominent results highlight significant fluctuation of vortices even for this low T$_c$, and nearly isotropic 3D superconductor.

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A Study on the Container Charges of Pusan Container Terminal (부산 콘테이너 부두의 하역료에 관한 연구 - 공영기업 차원의 요금산정을 중심으로 -)

  • Lee, Cheol-Yeong;Lee, Kwang-Hee
    • Journal of Korean Port Research
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    • v.3 no.1
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    • pp.3-33
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    • 1989
  • The amount of the Korean export & import in 1987 reached $88.3 billion which was 1.75% of the total world trade and the proportion of foreign dependence to G.N.P was 74.5%. From these facts, we can infer that the development of national economy is largely dependent upon trade. Therefore the role of transportation, especially Ocean transportation, as a basis of economic development through trade is one of the main factors that can not be passed over. Here, We can define that a port as a subsystem of transportation determines the efficiency of the total transportation system. Thus, the purpose of this paper is to contribute in improvement of the efficiency in port, reinforcement of the international competitiveness for exporting goods by the analysis of the cargo handling charges. In order to do this, this paper deals the case of B.C.T.O.C. Furthermore, this study gives some important informations related to the level of tariffs for establishing an autonomous port administration. The Summary of the conclusions of this paper is as follows ; 1) The object of port administration in Korea has been emphasized on the maximization of efficiency in using the port facilities. Nowadays, however, it should be moved to a direction that port is operated under the compound aims considering the public interests and economy. 2) For a criterian of tariff calculation, A tariff system based on the cost accounting is desirable. In general it is recommended that the cost for construction, management, and operation of port is compensated by the revenue from port operation. Therefore, it is necessary for the administration bodies of each port to establish a tariff system on the basis of the independent profit system. 3) For the investigation of actors of tariff adjustment by the Break-even point analysis, (1) When we conducted the B.E.P analysis using total cost as cost term, we got 3.8% discount in tariff at 12% of target profit rate and 1.5% discount at 15% of rate. when we set the target profit rate as 17% we could have the proper tariff level. (2) When using operating cost as cost term, we got 13.1% discount in tariff at 12% of target profit rate and 10.9% discount at 15% of rate. When setting the target profit rat as 28%, we could have the proper tariff level. 4) Comparing with the tariffs of foreign ports for the basic terminal rate, The tariff level of B.C.T.O.C showed 33% of stevedoring charge and 80% of marshalling charge incurred at Kobe port. The comparison with Singapore port gave 50% of transhipment charge and 17% - 20 % of stevedoring charge. 5) We found that the financial structure of B.C.T.O.C was better than those of other companies and the worth fixed assets ratio was too low. The fact of low worth fixed assets ratio implies that the cargo handling facilities should be increased. Moreover, The return of assets for B.T.T.O.C was good but non-operating expenses were still contained too much in. Therefore, we think that it is necessary for B.C.T.O.C. to rationalize business management. Although the present cargo handing charge for B.C.T.O.C is a proper level in terms of a public corporation, for the final recommendation in connection to the results, It is required to take the rationalization process for business management.

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T-Shaped DGS for CPW (CPW에 삽입된 T자형 DGS)

  • Kim Hyung-Mi;Lee Bom-Son
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.10 s.89
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    • pp.938-943
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    • 2004
  • In this paper, we propose a T-shaped DGS for CPW and provide the closed-form solutions for power loss rate, and bandwidth of the DGS. The proposed T-shaped DGS structure has a range of capacitance(C) 5.5 times wider than the dumbbell-shaped DGS structure. In addition we also analyze relations between R, L, C values of the DGS equivalent circuit and total loss rate, BW, $\omega_0$ of the DGS.