• Title/Summary/Keyword: unwinding

Search Result 46, Processing Time 0.04 seconds

Experimental Verification of Unwinding Behavior of Fiber-Optic Cable and Prediction of High-Speed Unwinding (광 케이블 풀림 거동의 실험적 검증 및 고속 풀림 거동 예측)

  • Kim, Kun Woo;Lee, Jae Wook;Kim, Hyung Ryul;Yoo, Wan Suk
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.38 no.3
    • /
    • pp.243-250
    • /
    • 2014
  • Fiber-optic cables towed by underwater vehicles have an important role in enhancing the mission capability of a mother ship. In general, fiber optic cables are unwound in water for securing unwinding stability and preventing unwinding-related problems. Therefore, in this study, the numerically simulated result is verified against the experimental result in water, and the cable-unwinding motion is predicted based on the increase in unwinding velocity. The experimental apparatus is composed of a water tank and a winder, and a high-speed camera is used for photographing the cable-unwinding motion. The numerical result defined in the Cartesian coordinate system is solved using a transient-state unwinding equation of motion. The numerical result agrees well with the experimental result, and it can predict cable-unwinding behaviors in according to an increase in the unwinding velocity.

Relative Motion Control Methodology Using the Minimum Relative Error Between Two Systems (두 시스템간의 편차 최소화를 적용한 상대적 동작제어 방법)

  • 김성권
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.9 no.12
    • /
    • pp.994-1000
    • /
    • 2003
  • A new relative motion control methodology for a following system to an independent leading system is proposed for controlling relative position, velocity, and tension etc. It is based on maintaining minimum relative error between two independent systems. The control command of the following system to a leading system is generated by adding the current command and the output of the relative error compensation. The proposed control method is implemented on the experimental equipment which is a wire winding-unwinding system to control the tension of the line. The results show the unwinding system(follower) following the independent motion of the winding system(leader) to control the constant tension of the line in order to keep the roller dancer in reference position. The relative motion control method proposed in this paper can be applied to high precision equipment for unwinding and winding fine wire, fine fiber, and tape etc.

Unwinding Behavior of and Load Prediction for Protective Tube Around Fiber-Optic Cable (보호 튜브의 풀림 거동 및 하중 예측)

  • Kim, Kun Woo;Lee, Jae Wook;Kim, Hyung Ryul;Yoo, Wan Suk
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.38 no.3
    • /
    • pp.235-241
    • /
    • 2014
  • As a fiber-optic cable is being unwound, it is protected by a tube that is designed to prevent unwinding problems such as tangling and unintentional cutting. In addition, a guide body is separated from the protective tube if a shear pin breaks when the maximum allowable load is exceeded. Therefore, it is important to analyze and predict the unwinding behavior of the protective tube, as well as the load on the shear pin, to enhance the likelihood of a successful operation when laying cables at extreme depths. In this study, the protective tube and the guide body are modeled with particles and are constrained with a constant-length constraint. The load on the shear pin was verified against experimental data, and the unwinding behavior was predicted from the load prediction results.

Prediction of the Unwinding Performance of Optical Fiber Cables by Nonlinear Dynamics Analysis (비선형 동적 거동 해석을 통한 광섬유 케이블의 풀림 성능 예측 연구)

  • Lee, Jae-Wook;Kim, Kun-Woo;Kim, Hyung-Ryul;Yoo, Wan-Suk;An, Deuk-Man
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.34 no.3
    • /
    • pp.347-352
    • /
    • 2010
  • Under harsh environments in which remote control is impossible, wire-guided control technology is effective for controlling distant underwater vehicles that serve mother ships in missions, such as exploration and installation. When the fiber is unwound from the spool, tension fluctuations occur in the fiber because of the relative velocity of the moving vehicles and unwinding velocity of the fiber. As a result, fiber cables exhibit complicated behaviors, become entangled, and may get cut. In this study, a spool-like design for winding tens of kilometers of fiber cables is proposed by analyzing cable winding. The unwinding performance of the designed spool is estimated by performing nonlinear dynamics analysis of the nonlinear behavior and tension fluctuations observed during the unwinding of the fiber.

Identification of a Novel Small Molecule Inhibitor Against SARS Coronavirus Helicase

  • Cho, Jin-Beom;Lee, Jin-Moo;Ahn, Hee-Chul;Jeong, Yong-Joo
    • Journal of Microbiology and Biotechnology
    • /
    • v.25 no.12
    • /
    • pp.2007-2010
    • /
    • 2015
  • A new chemical inhibitor against severe acute respiratory syndrome (SARS) coronavirus helicase, 7-ethyl-8-mercapto-3-methyl-3,7-dihydro-1H-purine-2,6-dione, was identified. We investigated the inhibitory effect of the compound by conducting colorimetry-based ATP hydrolysis assay and fluorescence resonance energy transfer-based double-stranded DNA unwinding assay. The compound suppressed both ATP hydrolysis and double-stranded DNA unwinding activities of helicase with IC50 values of 8.66 ± 0.26 μM and 41.6 ± 2.3 μM, respectively. Moreover, we observed that the compound did not show cytotoxicity up to 80 μM concentration. Our results suggest that the compound might serve as a SARS coronavirus inhibitor.

A Novel Chemical Compound for Inhibition of SARS Coronavirus Helicase

  • Lee, Jin-Moo;Cho, Jin-Beom;Ahn, Hee-Chul;Jung, Woong;Jeong, Yong-Joo
    • Journal of Microbiology and Biotechnology
    • /
    • v.27 no.11
    • /
    • pp.2070-2073
    • /
    • 2017
  • We have discovered a novel chemical compound, (E)-3-(furan-2-yl)-N-(4-sulfamoylphenyl) acrylamide, that suppresses the enzymatic activities of SARS coronavirus helicase. To determine the inhibitory effect, ATP hydrolysis and double-stranded DNA unwinding assays were performed in the presence of various concentrations of the compound. Through these assays, we obtained $IC_{50}$ values of $2.09{\pm}0.30{\mu}M$ (ATP hydrolysis) and $13.2{\pm}0.9{\mu}M$ (DNA unwinding), respectively. Moreover, we found that the compound did not have any significant cytotoxicity when $40{\mu}M$ of it was used. Our results showed that the compound might be useful to be developed as an inhibitor against SARS coronavirus.

Kinetic Measurement of the Step Size of DNA Unwinding by Bacteriophage T7 DNA Helicase gp4 (T7 박테리오파지 gp4 DNA helicase에 의한 DNA unwinding에서 step size의 반응속도론적 측정)

  • Kim, Dong-Eun
    • Journal of Life Science
    • /
    • v.14 no.1
    • /
    • pp.131-140
    • /
    • 2004
  • T7 bacteriophage gp4 is the replicative DNA helicase that unwinds double-stranded DNA by utilizing dTTP hydrolysis energy. The quaternary structure of the active form of T7 helicase is a hexameric ring with a central channel. Single-stranded DNA passes through the central channel of the hexameric ring as the helicase translocates $5'\rightarrow3'$ along the single-stranded DNA. The DNA unwinding was measured by rapid kinetic methods and showed a lag before the single-stranded DNA started to accumulate exponentially. This behavior was analyzed by a kinetic stepping model for the unwinding process. The observed lag phase increased as predicted by the model with increasing double-stranded DNA length. Trap DNA added in the reaction had no effect on the amplitudes of double-stranded DNA unwound, indicating that the $\tau7$ helicase is a highly processive helicase. Global fitting of the kinetic data to the stepping model provided a kinetic step size of 10-11 bp/step with a rate of $3.7 s^{-1}$ per step. Both the mechanism of DNA unwinding and dTTP hydrolysis and the coupling between the two are unaffected by temperature from $4∼37^{\circ}C$. Thus, the kinetic stepping for dsDNA unwinding is an inherent property of tile replicative DNA helicase.

Modeling and Simulation of the Linear Density Variation by Repetitive MD-Impacts in a Winding/Unwinding Control Process (Winding/Unwinding 제어공정에서 반복 충격에 기인한 MD-밀도 변동의 모델링과 시뮬레이션)

  • Huh You;Kim Hyung-J.;Kim Jong-S.;Chun Doo-H.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2006.05a
    • /
    • pp.321-322
    • /
    • 2006
  • In many manufacturing processes such as web formation, manufacturing of paper and nonwoven, fabric weaving, etc., planar sheets are transported and at the same time appropriate tension is imposed. The input material rolled up on beams is fed by unwinding the beam and the processed is then taken up on beams by winding it. While processed, the planar sheets are thrown under the processing load of impulse form, which causes irregular thickness of the processed sheet. To improve the quality of the product, a dynamic model is needed and the dynamic characteristics is to be analyzed by simulation. This study shows that density variation dynamics of the in-process-sheet in the machine direction can be described at each moment of disturbing impacts in forms of difference equations, while the impacts and tension, the time-dependency of the material properties were taken into account. Simulation showed the most serious variation of the density occurred in the process starting phase. The starting velocity curve with step form showed the least variation of the density. As the time order of the function of the starting velocity cure becomes higher, the density variation gets greater.

  • PDF

Effect of adaptive movement on durability and working time of twisted file (Adaptive movement가 twisted file의 내구성과 작업 시간에 미치는 영향)

  • Lee, Sang-Ho;Park, So-Ra;Cho, Kyung-Mo;Park, Se-Hee;Kim, Jin-Woo
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.35 no.1
    • /
    • pp.20-26
    • /
    • 2019
  • Purpose: Recently TF-adaptive movement is developed in order to increase the durability of TF files. The purpose of this study was to assess the effects of adaptive movement on durability and performance of twisted files. Materials and Methods: Resin blocks simulating artificial J-shape canals were used for this study. In TFC group, TF-adaptive ML-1 (25/.08 size) files were used to prepare the canals under continuous rotation 500 rpm/4.0 Ncm. In TFA group, TF-adaptive ML-1 (25/.08 size) files were used to prepare the canals under adaptive movement. After preparing each artificial canal, TF files were observed under dental microscope for assessing existence of unwinding, distortion, and fracture. If unwinding of flute was observed, the number of artificial canals until unwinding of flute occurs was recorded. Required time until instruments reach working length and distance of unwinded portion of files from D0 were measured. All test results were conducted by Mann-Whitney U test at a 0.05 level of significance. Results: No Ni-Ti instrument's separation was observed. Number of resin blocks until file unwinding happens and working time was significantly high in TFA group compared to TF group. Distance of distortion from D0 didn't show significant difference between TFA, TF groups. Conclusion: The number of resin blocks prepared until unwinding happens and working time were significantly high in TFA group. The location of unwinding showed no significant difference between 2 groups. Adaptive movement increased the number of canals prepared until unwinding occurs and working time of twisted files.