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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>CONTINUOUS HAPTIC INFORMATION IN TARGET TRACKING FROM A MOVING PLATFORM</title>
      <link>https://trid.trb.org/View/539884</link>
      <description><![CDATA[This study was conducted to gain insight into the effects of different forms of continuous haptic information (CHI) on operator performance with a moving unmanned platform.  In a simulator experiment, participants tracked a moving target with a disturbed viewfinder (moving platform).  While the participants performed this combined pursuit and compensatory tracking task, haptic information was provided to them concerning translatory disturbances of the platform.  Two steering variables were manipulated between participants presence or absence of CHI provided at the control device and automated or manual stabilization of the platform.  The other factors were image degradation, motor task load, and visual task load.  Haptic information was generated by movements of an active joystick that was used for steering the platform.  It was shown that both CHI and platform stabilization substantially reduced tracking error. These effects were not additive; CHI improved tracking performance only when the platform was not stabilized, and it did not significantly degrade pursuit tracking performed with a stabilized viewfinder.  The magnitude of the CHI effect was independent of image degradation, motor load, and visual load. CHI at the joystick improves tracking performance when it involves relevant control information; when it provides other information, tracking performance is only marginally degraded. Actual or potential applications of this research include performance of missions in environments that are difficult to access, potentially harmful to humans, or both.]]></description>
      <pubDate>Wed, 21 Oct 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/539884</guid>
    </item>
    <item>
      <title>REPLACEMENT OF OPERATIONAL STATION NON-VITAL AUTOMATIC TRAIN OPERATION (ATO) EQUIPMENT WITH A COMMERCIAL OFF-THE-SHELF MICROPROCESSOR</title>
      <link>https://trid.trb.org/View/477399</link>
      <description><![CDATA[The philosophy of no impact to revenue service, when replacing operating equipment is challenging but achievable.  Careful work with estblished proven equipment, proven design, and proven test techniques has resulted in a process where new equipment replaces old operating equipment with no surprises.  The process can be summarized as follows: perform engineering design using proven techniques; use proven and established equipment that has the inherent flexibility of a software-based system; package the installation and test activities to fit in appropriate time windows, use proven software development methods to develop and test software; when possible operate new equipment in parallel with old in service equipment to prove the new equipment; and, test.]]></description>
      <pubDate>Thu, 23 Apr 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/477399</guid>
    </item>
    <item>
      <title>RESPONSES OF A SPAR PLATFORM IN RANDOM WAVES AND CURRENTS (EXPERIMENT VS. THEORY)</title>
      <link>https://trid.trb.org/View/480287</link>
      <description><![CDATA[The response characteristics of a large slack-moored floating spar in regular waves, bichromatic waves, and unidirectional irregular waves with or without sheared currents are investigated by experimentation and numerical analysis.  A time domain nonlinear motion analysis computer program was developed to numerically to simulate the performance of the spar for various wave and current conditions.  It was found that the linear wave-body interaction theory alone was not adequate and the second-order wave-body interaction theory including the effects of viscous and wave drift dampings had to be used for the reliable motion prediction of a spar.  The complete first- and second-order diffraction/radiation programs for bichromatic, bi-directional waves were developed using the higher order boundary element method, and the viscous drag forces were computed from the Morison drag formula based on the relative velocity squared. The wave drift damping was computed using the modified drift gradient method.  The two-term Volterra series were used to calculate the time series of nonlinear potential excitations in random seas.  The resulting numerical results agreed well with the measured data.  It was seen that the low-frequency surge and pitch responses were in general greater than the wave-frequency responses and the slowly-varying responses were appreciably reduced in the presence of currents.  The total response amplitudes were found to be practically acceptable in the survival condition characterized by an 100-year storm sea.]]></description>
      <pubDate>Thu, 27 Mar 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/480287</guid>
    </item>
    <item>
      <title>TRANSIENT SURVIVAL ANALYSIS OF A MOORED FLOATING OFFSHORE PLATFORM: UNBIASED</title>
      <link>https://trid.trb.org/View/480288</link>
      <description><![CDATA[This paper investigates the very large amplitude roll motions of a capsized mobile offshore drilling unit.  The dynamical systems approach is utilised to analyze all possible motions for fixed vessel and environmental conditions.  The effects of wind bias and an equivalent mooring system are included.  As expected, it was found that the effects of wind bias dramatically effects the systems safe basin, a measure of the vessel's resistance to capsizing.  The mooring system was found to have a limited effect on the roll due to it's small size relative to the hydrostatic roll restoring moment.]]></description>
      <pubDate>Thu, 27 Mar 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/480288</guid>
    </item>
    <item>
      <title>DYNAMIC RESPONSE OF MOORED SEMI-SUBMERSIBLE PLATFORMS TO NON- COLLINEAR WAVE, WIND AND CURRENT LOADING</title>
      <link>https://trid.trb.org/View/480299</link>
      <description><![CDATA[The authors developed a non-linear time domain analysis procedure and calculation tools based on these procedures to predict the motion response of moored semisubmersibles under wave, wind and current loading.  These tools have been validated with published results.  In the first part of the paper a brief summary of the nonlinear analysis procedures is given, together with some results obtained from predictions and published experimental and theoretical results. In the second part of the paper the results of parametric studies investigating the effects of variations in external wave, wind and current force magnitudes and directions on the dynamic motion response of semisubmersible platforms are illustrated.  These results show the sensitivity of certain types of response values as the external forces vary in magnitude and in direction.  Such results provide essential information for probability based design procedures. In the last part of the paper, time domain models are used to simulate incidents which occurred in the North Sea in 1990, in which mooring lines of some semi-submersibles failed.]]></description>
      <pubDate>Thu, 27 Mar 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/480299</guid>
    </item>
    <item>
      <title>ANALYSIS OF JACK-UP UNITS DURING TRANSIT WITH LEGS LOWERED</title>
      <link>https://trid.trb.org/View/467286</link>
      <description><![CDATA[Conventionally jack-up units are transported from one location to another with the majority of their legs extended above the hull. On certain occasions, due to possible storm conditions, they must lower their legs below the hull significantly to maintain expected vessel motions within an acceptable level.  During a storm, the unit will respond with six degrees of motion while afloat.  The extended portion of the legs below the hull will be subjected to drag loads. Unlike the condition with legs extended in air, analysis of a jack-up with its legs lowered below the hull has not been widely reported in published literature.  This paper reports the motion analysis of a jack- up for different leg drafts and indicates the safe limits up to which the leg can be extended below the hull without overstressing it.]]></description>
      <pubDate>Mon, 04 Nov 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/467286</guid>
    </item>
    <item>
      <title>ACTIVE AND SEMI-ACTIVE CONTROL METHODS IN WAVE-STRUCTURE INTERACTION</title>
      <link>https://trid.trb.org/View/456290</link>
      <description><![CDATA[There are a variety of proposed passive, active, and semi-active motion reduction systems for floating platforms.  All these methods can be classified according to the energy requirements, the energy absorption, and the energy storages.  The theoretical and experimental results for a semi-active method with open bottom chambers and air valves is presented.  Even a quite coarse model leads to a fourth order bilinear equation system to which the classical design methods for linear controllers cannot be applied.  The numerically computed optimal trajectories can be used as a reference, but because of the computing time, they are still away from real-time applications.  A control law determined by minimizing the time derivative of the Lyapunov function yields a very poor system behaviour.  A heuristic control which is much more efficient is proposed and investigated.  This control law is based on the physical insight and can be expressed by the very simple equations. For the levelling of initial states a comparison with the optimal trajectories and the optimal control signals is carried out.  The performance index with the heuristic control law is 150% of the optimal index which is quite low compared with 420% for the Lyapunov type controller.]]></description>
      <pubDate>Wed, 27 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/456290</guid>
    </item>
    <item>
      <title>TRANSIENT SURVIVAL ANALYSIS OF A MOORED FLOATING OFFSHORE PLATFORM: WIND BIASED</title>
      <link>https://trid.trb.org/View/456515</link>
      <description><![CDATA[In this paper, the very large amplitude roll motions of the capsized MODU OCEAN RANGER is investigated.  The dynamical systems approach is utilized to analyze all possible motions for fixed vessel and environmental conditions.  The effects of wind bias and an equivalent mooring system is included.  As expected, it was found that the effects of wind bias dramatically effected the system's safe basin, a measure of the vessel's resistance to capsizing. Surprisingly, the mooring system was found to have a limited effect on the roll due to it's small size relative to the hydrostatic roll restoring moment.]]></description>
      <pubDate>Wed, 27 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/456515</guid>
    </item>
    <item>
      <title>HIGH RESOLUTION SEMI-ANALYTICAL THREE DIMENSIONAL LINEAR MOTIONS FOR TENSION LEG PLATFORMS</title>
      <link>https://trid.trb.org/View/456516</link>
      <description><![CDATA[Previous work by the authors has resulted in very accurate semi-analytical solutions for the three-dimensional linear hydrodynamics of submerged pontoons, floating columns and combinations of these solutions for the analysis of structures such as the ISSC TLP.  This paper is an extension of the semi-analytic approach to establishing the linear motions of the ISSC TLP including the effects of the tethers.  A major advantage of the approach is that response functions may be computed accurately at an arbitrarily high resolution due to the inherent geometric and computational simplicity of the semi-analytical solution scheme. Therefore, the solution serves as a benchmark for the evaluation of results generated using panel methods, and this is illustrated by comparisons with the scatter obtained with available results in the literature]]></description>
      <pubDate>Wed, 27 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/456516</guid>
    </item>
    <item>
      <title>INTERPRETATION OF NONLINEAR EFFECTS ON THE DYNAMIC RESPONSE OF A TLP</title>
      <link>https://trid.trb.org/View/456517</link>
      <description><![CDATA[To determine the nature and importance of various nonlinear effects on the dynamic response of a TLP, a number of parametric studies have been conducted determining the dynamic response of a simplified model to wave and current action.  The results of these analyses were then used to compute linear, quadratic and cubic transfer functions, based on Volterra series, to assess the type of nonlinearity which controls the response over the different frequency ranges.  The nonlinearities result in the existence of response amplitudes and energy at frequencies which are outside of the range of the excitation frequencies but which correspond to the natural frequencies of the TLP in surge, heave and pitch.  They are of different order (quadratic or cubic) over the different frequency ranges (below or above the wave frequency range).]]></description>
      <pubDate>Wed, 27 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/456517</guid>
    </item>
    <item>
      <title>RESPONSES OF ARTICULATED LOADING PLATFORM IN IRREGULAR WAVES</title>
      <link>https://trid.trb.org/View/456528</link>
      <description><![CDATA[The wave frequency and slowly varying responses of an articulated loading platform (ALP) in unidirectional irregular waves are investigated both in frequency and time domain.  The first- and second-order wave diffraction/radiation problems are solved by the ring-source boundary integral equation method, and the viscous drag forces are computed from the Morison drag formula based on the relative velocity squared.  The two-term Volterra series are used to calculate the time series of nonlinear potential excitations in random seas.  The linearized drag force model is used for the spectral analysis in the frequency domain, while a direct time-stepping integration method is used in the time domain to include the nonlinear drag.  The relative importance of various excitation and damping sources for different size ALPs is discussed.  The second- order low-frequency responses can be comparable to or even greater than the wave-frequency responses, depending on the available damping; hence, they need to be included for the reliable motion analysis of an ALP.  Finally it is show that the computation agrees well with Sincock's experiment.]]></description>
      <pubDate>Wed, 27 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/456528</guid>
    </item>
    <item>
      <title>TIME-DOMAIN SIMULATION OF LARGE-AMPLITUDE RESPONSE OF FLOATING PLATFORMS</title>
      <link>https://trid.trb.org/View/455629</link>
      <description><![CDATA[Two numerical simulation models to predict large-amplitude motions of floating platforms are presented.  The first method is based on the application of the relative-velocity formulation of Morison's equation for force calculations.  The second method developed in this work uses the three-dimensional potential theory in time domain.  In this method, both the Froude-Krylov and scattering forces are calculated by considering finite wave amplitude effects in random waves.  The effect of various nonlinearities on the low-frequency motions and high-frequency tether-tension response of a tension leg platform are studies using these simulation models in conjunction with power spectral methods.  The presence of current and the nonlinear drag force are observed to have a significant effect on the low frequency motions and tether tensions.]]></description>
      <pubDate>Mon, 04 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/455629</guid>
    </item>
    <item>
      <title>MOORING-INDUCED DAMPING</title>
      <link>https://trid.trb.org/View/455844</link>
      <description><![CDATA[The research reported in this paper is aimed specifically at the determination of the absorption of energy by a mooring system from an offshore platform as a result of its motion.  This transfer of energy represents a "mooring-induced damping" and can be important for ship-like platforms in two situations, where the inherent damping from other sources is slight.  These are roll motions during operations and surge motions of single-point moored platforms in survival conditions. Results of parametric studies based on non-linear mooring dynamics simulation are presented for damping induced by horizontal motions (surge, sway and yaw) and vertical motions (heave, roll and pitch). The results include variations in pretension, amplitude, frequency, scope, stiffness, drag coefficient and current.]]></description>
      <pubDate>Mon, 04 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/455844</guid>
    </item>
    <item>
      <title>A STUDY ON THE UNSTABLE MOTIONS OF A SEMISUBMERSIBLE PLATFORM WITH A LARGE LIST ANGLE IN WAVES</title>
      <link>https://trid.trb.org/View/432623</link>
      <description><![CDATA[In this paper, the authors deal with the property of the dynamic response of a semisubmersible platform with a large list angle in beam sea condition.  In previous experimental tests, it was observed that a significant subharmonic motion appeared in the response of certain wave frequencies.  In order to elucidate the mechanism of the unstable motion, a numerical simulation of the response in regular waves was carried out.  It is concluded that the subharmonic motion is mainly caused by the nonlinear coupling moment due to the difference of hydrodynamic forces acting on both sides of lowerhulls.  The calculated results agreed qualitatively with experimental results.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/432623</guid>
    </item>
    <item>
      <title>COMBINED EFFECT OF WAVES AND CURRENT ON THE MOTION BEHAVIOUR AND TETHER FORCES OF A DEEPWATER TENSION LEG PLATFORM</title>
      <link>https://trid.trb.org/View/434330</link>
      <description><![CDATA[In this paper results are discussed of model experiments and computations of the wavecurrent interaction effects on the motions of a tension leg platform in deep water with waves and current coming in from ahead. the model experiments were performed in the deep water testing facility, recently installed in the Wave and Current Basin of the Maritime Research Institute Netherlands (MARIN). It is shown that the neglect of wave-current interaction in both computations as well as in model test experiments will lead to substantially higher motion amplitudes. See also the following Abstract.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/434330</guid>
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