• Title/Summary/Keyword: DMT

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Evaluation of Engineering Properties of Clays Through Flat Dilatometer Tests (Flat Dilatometer 현장시험을 통한 점토 지반의 공학적 성질 추정)

  • Lee, Seung-Rae;Kim, Yun-Tae;Kim, Jun-Seok
    • Geotechnical Engineering
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    • v.8 no.3
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    • pp.23-36
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    • 1992
  • The flat dilatometer(DMT) has been practically used as an in-situ test equipment. It is a simple, rapid and cost-effective tool to characterize the in-situ stress-strain-strength properties of various types of ground materials. However, the results of flat DMT should be validated with considerable data with respect to the known reference values for a specific site. In this study, the applicability of existing relationships which were established for other local deposits is verified by performing the tests in several clay deposits. To compare with the DMT results, field vane tests and cone penetration tests were also carried out in the same field as reference tests, and unconsolidated undrained tests, oedometer tests, and other fundamental material properties tests were conducted on the thin-walled tube samples in the laboratory. The results of the flat DMT combined with empirical correlations are used to estimate soil types, unit weights, coefficients of lateral earth pressure at rest, overconsolidation ratios, constrained moduli and undrained shear strengths of three clay local deposits. It was found that various geotechnical properties estimated from the flat DMT generally well agree with those from the reference tests.

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Synchronization for VDSL system using DMT (DMT 방식을 이용한 VDSL시스템의 동기)

  • 최병익;우정수;임기홍
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.10C
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    • pp.951-962
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    • 2002
  • A DMT transceiver recovers the sampling time from reserved sub-carriers, the pilots. Since the pilots are available after the FFT, the symbol synchronization must be done before sample synchronization. In DMT VDSL system, symbol synchronization is handled separately from sample synchronization, although the two processes are intimately related. The DMT symbol itself contains sufficient information, the cyclic extension, for symbol synchronization. Using only the sign bit of received signal, the Maximum Likelihood Estimation solution is derived. The Tx windowing in the transmitter of DMT VDSL system results in the blurring of MLE peaks. We propose the weighted summing MLE method using the sign bit which produces the clearly sharp top of MLE peaks. The stability of symbol synchronization is improved significantly by averaging over a few symbols. This paper presents the study of the original MLE and the weighted summing MLE using sign bit. A clock difference between transmitter and receiver destroys the oahogonality of the carriers. Therefore, a receiver using asynchronous sampling must perform timing correction in the discrete-time domain. We introduce an efficient digital sample synchronization method which is based on temporal and frequency domain digital signal processing.

Plasma Membrane Transporters for Lead and Cadmium

  • Bressler Joseph P.;Olivi Luisa;Cheong Jae Hoon;Kim Yongbae;Bannon Desmond
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2004.11a
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    • pp.50-61
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    • 2004
  • Lead and cadmium are potent environmental toxicants that affect populations living in Europe, Americas, and Asia. Identifying transporters for lead and cadmium could potentially 1 help us better understand possible risk factors. The iron transporter divalent metal transporter 1(DMT1) mediates intestinal transport of cadmium, and lead in yeast and fibroblasts overexpressing DMT1. In human intestinal cells knocking down expression of DMT1 attenuated uptake of cadmium and iron but not lead. A possible explanation is the expression of a second transporter for lead in intestine. In astrocytes, however, DMT1 appears to transport lead in an extracellular buffer at pH value. At neutral pH, transport was not mediated by DMT1 but rather by a transporter that is stimulated by bicarbonate and inhibited by 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonic acid. The identity of this lead transporter is under study.

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A Study on the Evaluation of Overconsolidation Ratio of Marine Clay by Flat DMT (DMT를 이용한 해성점토의 과압밀비 추정에 관한 연구)

  • Jeong, Hyeok;Kim, Jong-Kook;Chae, Young-Su;Yoon, Won-Sub
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.979-986
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    • 2008
  • In this study, it enforced DMT test, CPTu test, laboratory consolidation test, because it estimated stress history of Gwangyang port marine clay. Through DMT test obtained Horizontal stress index($K_D$), predicted overconsolidation ratio by $K_D$. To compare empirical equation with laboratory consolidation test and CPTu test calculated OCR examined application. The result, Powell & Uglow(1988) method underestimated OCR value in comparison with Suggestion. Comparatively Byeon wi yong(2004) and Chang(1991) method seem to exactly predict in-situ stress states. Sugawara(1988) method of CPTu test seems to underestimate OCR.

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Design and Performance Evaluation of Equalizer for the S-DMT Cable Modem (S-DMT 케이블 모뎀의 등화기 설계 및 성능평가)

  • Cho, Byung-Hak
    • Journal of Digital Contents Society
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    • v.7 no.2
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    • pp.109-115
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    • 2006
  • In this paper, we design and performance evaluate the equalizer for S-DMT table modem, which supports more channels and better quality symmetric mutimedia services over HFC network. We verified that both of the designed equalizers show good convergence characteristics and that the performance of the time domain equalizer is 1 dB better than that of the frequency domain equalizer overall range of Eb/No.

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DMT Transport System Analysis for Rail Logistics Efficiency (철도물류 효율화를 위한 DMT수송시스템 현황분석)

  • Shin, Seung-Kwon;Kim, Seog-Won;Seo, Sung-Il
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1668-1673
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    • 2007
  • In light of the growing traffic congestion problem and congestion cost, the container transport by railway has to be increased. The freight transport by railway can have decided advantages over trucks in terms of energy efficiency, emissions and cost for certain freight movements, just as transportation in the metropolitan region can have great advantages over driving truck. But the freight transport by truck should gain significant mobility benefits from a freight railway system. Thus, the DMT(Dual Mode Trailer) transport system which is coupled railway transport advantages with load transport advantages has been developed and used in the european countries. The DMT transport will therefore serve the areas required by transport organizers. This paper describes the various DMT transport systems and its strength and weakness.

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Novel Driving Mechanism of the Next Generation Transportation Systems for Revival of Railroad Logistics (철도물류 활성화를 위한 차세대 물류운송 시스템의 새로운 구동방식에 관한 연구)

  • Lee, K.S.;Lee, Y.J.;Lee, J.W.;Cho, H.C.;Han, D.S.;Han, G.J.
    • Journal of Power System Engineering
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    • v.12 no.6
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    • pp.56-63
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    • 2008
  • Many advanced nations have been developing the next generation logistic systems to effectively deal with gradually increased logistic flows over the world. Particularly, dual mode trailer(DMT) systems are significantly focused as a new alternative transportation which basically provides integrating of the land and railroad services. This paper presents new driving mechanism for DMT systems using the hydraulic pressure cylinder systems. Such is mechanically composed of supporting and rotating parts independently, which are mostly important for whole system performance. We analyze feasible operational problem occurred in driving mechanism from the conventional DMT systems and compare our proposed deign specification with the Modalohr DMT system to demonstrate its reliability and practicability.

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A Study on DMT Synthesis Using Crude TPA Sludge Generated from PET Alkaline Waste Water as Raw Materials (PET 감량폐약으로부터 발생되는 crude TPA sludge를 원료로 한 DMT 합성에 관한 연구)

  • Cho, Hwan;Kim, Jong Bo;Jeong, Hee Cheon;Jeon, Byung Dae
    • Textile Coloration and Finishing
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    • v.7 no.2
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    • pp.9-16
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    • 1995
  • When alkaline waste water of PET fabric is treated with sulfuric acid, undegradable material, crude TPA sludge is generated, so that treatment has a serious problem. The result of DMT synthesis using crude TPA sludge generated from PET alkaline waste water were as follows: 1. When crude TPA generated from alkaline waste water is reactioned with methanol under catalyst of sulfuric acid, pure DMT can be obtained. 2. In DMT synthesis from crude TPA, addition of copper sulfate can increase yield, and increasing the amount of sulfuric acid can shorten reaction time.

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A Study on the Economical Feasibility Analysis For Development of Dual Mode Trailer System

  • Kim, Kwang-Hee
    • Journal of Navigation and Port Research
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    • v.34 no.2
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    • pp.137-144
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    • 2010
  • In light of the growing traffic congestion problem and congestion cost, the container transport by railway has to be increased. The freight transport by railway can have decided advantages over trucks in terms of energy efficiency, emissions and cost for certain freight movements, just as transportation in the metropolitan region can have great advantages over driving truck. But the freight transport by truck should gain significant mobility benefits from a freight railway system. Thus, the DMT(Dual Mode Trailer) transport system which is coupled railway transport advantages with load transport advantages has been developed and used in the european countries. The DMT transport will therefore serve the areas required by transport organizers. The purpose of this paper is to estimate economical feasibility analysis for development of DMT transport system. Consequently, this study analyzed the characteristics of the DMT system. The horizontal load.unload system is being considered as an adoptable DMT system in consideration of the situation in Korea.