• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.450-454
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• 2003

Natural periods are usually determined by the so-called linearized finite displacement theory even for a suspension bridge. This linearized method, with formulating structural stiffness by taking dead-load tension into consideration, calculates the natural periods of the bridge. As a result, the assumed initial tensions for each cable member may affect the accuracy of calculated natural periods and some other dynamic responses. This paper mainly demonstrates the effect of initially introduced tension accuracy on the evaluation of dynamic characteristics for a suspension bridge.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.118-125
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• 2012

In this paper, an approach to designing controllers for the tension/movement control of working robot to install a stringing wire cable is presented. To design a controller, when the robot moves a certain distance maintaining constant tension, the dynamic model of a stringing wire cable which considers effects of weights according to changing lengths is presented. Also the tension at startup of the working robot is studied by numerical analysis which is based on the equation of the dynamic wire model. From the dynamic model for a stringing wire cable, working robot for tension/movement control is suggested and designed a feedforward controller with a accelerator gain to suppress a mutual interference of the both tasks of tension/movement control. Depending on the operating conditions of the working robot, the effectiveness of the suggested system has been verified by the simulation and experimental results.

• Ocean Systems Engineering
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• v.7 no.3
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• pp.225-246
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• 2017

Excessive dynamic-tension variations on the top-tensioned risers (TTRs) deteriorate the structural integrity and cause potential safety hazards. This phenomenon has become more remarkable in the development of deep-water fields with harsher environmental loads. The conventional prediction method of tension variations in hydro-pneumatic tensioner (HPT) has the disadvantage to underestimate the magnitude of cyclic loads. The actual excessive dynamic tension variations are larger when considering the viscous frictional fluid effects. In this paper, a suppression method of tension variations in HPT is modeled by incorporating the magneto-rheological (MR) damper and linear-force actuator. The mathematical models of the combined HPT and MR damper are developed and a force-control scheme is introduced to compensate the excessive tension variations on the riser tensioner ring. Numerical simulations and analyses are conducted to evaluate the suppression of tension variations in HPT under both regular- and irregular-wave conditions for a drilling riser of a tensioned-leg platform (TLP). The results show that significant reduction of tension variations can be achieved by introducing the proposed system. This research has provided a theoretical foundation for the HPT tension control and related structural protection.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.381-386
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• 2002

The objective of this study was to link conformational changes of proteins at a water/methylene chloride interface to their destabilization upon emulsification. When 4 aqueous protein solutions (bovine serum albumin, $\beta$-lactoglobulin, ovalbumin, or ribonuclease) were emulsified in methylene chloride, considerable proportions of all the proteins became water insoluble aggregates. There were also noticeable changes in the compositions of their water-soluble species. A series of water/methylene chloride interfacial reactions upon the proteins was considered a major cause of the phenomena observed. Based on this supposition, the interfacial tension was determined by a Kruss DVT-10 drop volume tensiometer under various experimental conditions. It substantiated that the interfacial tension was high enough to cause the adsorption of all the proteins. Under our experimental conditions, their presence in the aqueous phase resulted in reductions of the interfacial tension by the degrees of 8.5 - 17.1 mN $m^{-1}$. In addition, dynamic changes in the interfacial tension were monitored to compare relative rates at which the adsorbed proteins underwent conformational, structural rearrangements at the interface. Such information helped make a prediction about how easily proteins would denature and aggregate during emulsification. Our study indicated that emulsifying aqueous protein solutions in organic solvents should be handled with care, due to adverse interfacial effects.

• Journal of Power System Engineering
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• v.2 no.2
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• pp.81-86
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• 1998

The dynamic response characteristics of Tension Leg Platforms(TLPs) in waves are examined for presenting the basic data for design of TLPs. The numerical approach is based on a combination of the three dimensional source distribution method and the dynamic response analysis method, in which the superstructure of TLP is assumed to be flexible instead of rigid. Restoring forces by hydrostatic pressure on the submerged surface of a TLP have been accurately calculated by excluding the assumption of the slender body theory. The hydrodynamic interactions among TLP members, such as columns and pontoons, and the structural damping are included in the motion and structural analysis. Numerical results are compared with the experimental ones, which are obtained in the literature, concerning the motion and tension responses of a TLP in waves. The results of comparison confirmed the validity of the proposed approach.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.316-316
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• 2000

SPM dynamic model was developed by using Bland & Ford formulas considered elastic zone in roll gap, gauge meter equation, tension equation, speed equation and actuator models. And SPM controllers of the field were done model ing. It was shown the efficiency of constant tension, rol1ing force and elongation controllers by the simulation program and it was recommended the proper gain to the controllers of the field.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.5 s.98
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• pp.595-603
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• 2005

In this work, the multiple dynamic absorber( MDA ) is introduced to reduce several vibration modes of shadow mask simultaneously and its design method is developed from the theory of the simple dynamic absorber. When designing the dynamic absorber, there are three significant design parameters such as mass, damping ratio and tuning frequency. Therefore the sensitivity analysis for those parameters has been executed in order to find out the design criteria of multiple dynamic absorber using the finite element model of shadow mask. The multiple dynamic absorber(MDA) designed by the proposed method is tested theoretically and experimentally to estimate the efficiency of vibration reduction. From the results, it is verified that the method is feasible to apply the system having the multiple nitration modes and more efficient than the thin wire-type damper used commercially to reduce the vibration of shadow mask.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1193-1199
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• 2003

Maintaining track tension in tracked vehicles minimizes the excessive load on the tracks and prevents the peal-off of tracks from the road-wheel, and adequately guarantees the stable and improved driving of the tracked vehicles. However, the track tension cannot be easily measured due to the limitation in the sensor technology, harsh environment, etc. In this study, the track tension is estimated in realtime from the measurable signals of tracked vehicles and controlled based on a fuzzy logic controller. The proposed control system is implemented on tracked vehicles and its performance is evaluated under various driving conditions.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.780-785
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• 2003

Maintaining track tension in tracked vehicles minimizes the excessive load on the tracks and prevents the peal-off of tracks from the road-wheel, and adequately guarantees the stable and improved driving of the tracked vehicles. However, the track tension cannot be easily measured due to the limitation in the sensor technology, harsh environment, etc. In this study, the track tension is estimated in real-time from the measurable signals of tracked vehicles and controlled based on a fuzzy logic controller. The proposed control system is implemented on tracked vehicles and its performance is evaluated under various driving conditions.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.137-140
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• 1996

This study investigated the length-tension and velocity-force relations of the torso erectors. A myoelectric based approach was used wherein a dynamic biomechanical model incorporating active and passive tissue charactreistics provided music kinematic estimates during controlled sagittal plan extension motions. A double linear optimization formulation from the literatured provided muscle tension estimates. The data supported a linear length-tension relation toward full flexion for both the erector spinae and latissimus muscles. Velocity trends agreed with that predicted by Hill's exponential relation. The results have implications for muscle tension estimation in biomechanical torso modeling, and suggest a possible low back pain injury mechanism.