1. A tensioner system for a riser in a floating platform having a deck, comprising:
a riser support conductor surrounding the riser and having an upper end coupled to an upper portion of the riser; and
a hydro-pneumatic tensioner assembly coupled between the deck and a lower end of the riser support conductor so as to exert a pull-type tensional force on the riser support conductor, whereby the riser support conductor conveys the pull-type tensional force to the upper portion of the riser.
2. The tensioner system of claim 1, further comprising a reactive load assembly mounted to the floating platform and configured to receive the riser support conductor so as to react to a two-point dynamic bending moment imposed on the riser support conductor.
3. The tensioner system of claim 2, wherein the riser support conductor includes a plurality of radially-extending stabilizer elements operatively engaged by the reactive load assembly so as to resist rotational forces.
4. The tensioner system of claim 1, further comprising a support conductor coupling assembly operatively connecting the hydro-pneumatic tensioner assembly to the support conductor so as to transfer a tension load from the hydro-pneumatic tensioner assembly to the riser support conductor.
5. The tensioner system of claim 1, wherein the hydro-pneumatic tensioner assembly comprises a plurality of hydro-pneumatic tensioners, each of which comprises:
a cylinder coupled to a source of pneumatically-pressurized hydraulic fluid;
a hydraulically-actuated piston disposed for axial reciprocation within the cylinder; and
a piston rod having a first end connected to the piston and a second end operatively coupled to the riser support conductor.
6. The tensioner system of claim 1, wherein the riser has an upper end connected to a riser tension joint, wherein the riser support conductor has an upper end, and wherein the tensioner system further comprises a riser tension joint support assembly that comprises:
a plurality of load shoulder elements connected to the upper end of the riser support conductor; and
a tension joint donut circumferentially engaging the riser tension joint and having an outer periphery engaging the load shoulder elements so as to convey a tensional force from the riser support conductor to the riser through the load shoulder elements and the donut.
7. The tensioner system of claim 6, wherein the load shoulder elements are pivotably connected to the upper end of the riser support conductor so as to be pivotable between a retracted position allowing access to the interior of the riser support conductor, and a landed position engaging the donut.
8. The tensioner system of claim 3, wherein the reactive load assembly comprises:
a support element secured to the platform and having a central opening through which the riser support conductor passes; and
a stabilizer engagement assembly mounted on the support element and configured to engage the stabilizer elements.
9. The tensioner system of claim 8, wherein the stabilizer engagement assembly is positionally adjustable relative to stabilizer elements.
10. The tensioner system of claim 9, wherein the stabilizer engagement assembly comprises a plurality of roller pairs, wherein the rollers in each pair are configured and located so as to engage the stabilizer elements.
11. The tensioner system of claim 9, wherein the stabilizer engagement assembly comprises a plurality of bearing pad arrangements, each configured and located so as to engage the stabilizer elements.
12. A hydro-pneumatic tensioner system for a top-tensioned riser in a floating platform comprising:
a riser support conductor coaxially surrounding the riser and having an upper end and a lower end;
a riser tension joint support assembly operatively coupling the upper end of the riser support conductor to an upper end of the riser so as to convey an axial tension load thereto from the riser support conductor;
a hydro-pneumatic tensioner assembly mounted to the floating platform; and
a support conductor coupling assembly operatively coupling the tensioner assembly to the lower end of the riser support conductor so as to convey an axial tension load from the tensioner assembly to the riser support conductor;
wherein the tensioner assembly the support conductor coupling assembly and the riser tension joint assembly cooperate with the riser support conductor to exert a pull-type tensional force upon the top-tensioned riser, responsive to motion induced in the floating platform.
13. The tensioner system of claim 12, wherein the hydro-pneumatic tensioner assembly comprises a plurality of pull-type hydro-pneumatic tensioners configured to provide a long-stroke, pull-type tensional force applied to the riser support conductor.
14. The tensioner system of claim 12, further comprising:
a reactive load assembly mounted to the floating platform and configured to receive the riser support conductor, wherein the reactive load assembly reacts with a two-point dynamic bending moment imposed on at least one of the top-tensioned riser and the riser support conductor.
15. The tensioner system of claim 12, wherein the tensioner assembly comprises a plurality of hydro-pneumatic tensioners, each of which comprises:
a cylinder coupled to a source of pneumatically-pressurized hydraulic fluid;
a hydraulically-actuated piston disposed for axial reciprocation within the cylinder; and
a piston rod having a first end connected to the piston and a second end operatively connected to the support conductor coupling assembly.
16. The tensioner system of claim 15, wherein the support conductor coupling assembly comprises:
a conductor tension ring having an interior surface operatively engaging the riser support conductor; and
a plurality of tension ring arms extending radially from the conductor tension ring each of the tension ring arms being operatively connected to the second end of one of the piston rods.
17. The tensioner system of claim 14, wherein the reactive load assembly comprises at least two lateral reaction assemblies, and wherein the riser support conductor includes a plurality of radially-extending stabilizer elements operatively engaged by the lateral reaction assemblies so as to resist rotational forces on the support conductor.
18. The tensioner system of claim 12, wherein the riser has an upper end connected to a riser tension joint, and wherein the tensioner system further comprises a riser tension joint support assembly that comprises:
a plurality of load shoulder elements connected to the upper end of the riser support conductor; and
a tension joint donut circumferentially engaging the riser tension joint and having an outer periphery engaging the load shoulder elements so as to convey a tensional force from the riser support conductor to the riser through the load shoulder elements and the donut.
19. The tensioner system of claim 18, wherein the load shoulder elements are pivotably connected to the upper end of the riser support conductor so as to be pivotable between a retracted position allowing access to the interior of the riser support conductor, and a landed position engaging the donut.
20. The tensioner system of claim 17, wherein each of the lateral reaction assemblies comprises:
a support element secured to the platform and having a central opening through which the riser support conductor passes; and
a stabilizer engagement assembly mounted on the support element and configured to engage the stabilizer elements.
21. The tensioner system of claim 20, wherein the stabilizer engagement assembly is positionally adjustable relative to the stabilizer elements.
22. The tensioner system of claim 21, wherein the stabilizer engagement assembly comprises a plurality of roller pairs, wherein the rollers in each pair are configured and located so as to engage the stabilizer elements.
23. The tensioner system of claim 21 wherein the stabilizer engagement assembly comprises a plurality of bearing pad arrangements, each configured and located so as to engage the stabilizer elements.
24. In a floating platform including a top-tensioned riser, a pull-type tensioner for applying tensile forces axially to the riser through a riser support conductor coaxially surrounding the riser and operatively coupled to an upper portion of the riser, the tensioner comprising:
a hydraulic cylinder mounted vertically in the platform;
a piston disposed within the cylinder for axial reciprocation therein;
a piston rod having a first end attached to one side of the piston and a second end operatively coupled to the riser support conductor;
a hydraulic fluid source fluidly coupled to the cylinder so as to deliver hydraulic fluid to the cylinder on the one side of the piston; and
a source of pneumatic pressure operatively coupled to the source of hydraulic fluid so as to pressurize the hydraulic fluid.
25. The tensioner of claim 24, wherein the hydraulic fluid source is a first fluid source, and wherein the tensioner further comprises a second fluid source fluidly coupled to the cylinder so as to deliver fluid to the cylinder on a second side of the piston opposite the first side.
26. The tensioner of claim 25, wherein the first fluid source delivers fluid at a substantially higher pressure than does the second fluid source.
27. The tensioner of claim 24, wherein the second end of the piston rod is operatively coupled to the riser support conductor through a support conductor coupling assembly.
28. The tensioner of claim 27, wherein the support conductor coupling assembly comprises:
a conductor tension ring having an interior surface operatively engaging the riser support conductor; and
a plurality of tension ring arms extending radially from the conductor tension ring, each of the tension ring arms being operatively connected to the second end of the piston rod.
29. A riser tension joint support assembly for use in a floating platform including a top-tensioned riser having an upper end connected to a riser tension joint, and a riser support conductor coaxially surrounding the riser, the riser tension joint support assembly comprising:
a plurality of load shoulder elements connected to the upper end of the riser support conductor; and
a tension joint donut circumferentially engaging the riser tension joint and having an outer periphery engaging the load shoulder elements so as to convey a tensional force from the riser support conductor to the riser through the load shoulder elements and the donut.
30. The tensioner system of claim 29, wherein the load shoulder elements are pivotably connected to the upper end of the riser support conductor so as to be pivotable between a retracted position allowing access to the interior of the riser support conductor, and a landed position engaging the donut.
31. In a floating platform, of the type having a top-tensioned riser coaxially surrounded by and operatively coupled to a riser support conductor, and a pull-type tensioning assembly operatively coupled between the platform and the riser support conductor, the improvement comprising:
a reactive load assembly mounted to the floating platform and configured to receive the riser support conductor, wherein the reactive load assembly reacts with a two-point dynamic bending moment imposed on at least one of the top-tensioned riser and the riser support conductor.
32. The platform of claim 31, wherein the reactive load assembly comprises at least two lateral reaction assemblies, and wherein the riser support conductor includes a plurality of radially-extending stabilizer elements operatively engaged by the lateral reaction assemblies so as to resist rotational forces on the support conductor.
33. The platform of claim 32, wherein each of the lateral reaction assemblies comprises:
a support element secured to the platform and having a central opening through which the riser support conductor passes; and
a stabilizer engagement assembly mounted on the support element and configured to engage the stabilizer elements.
34. The platform of claim 33, wherein the stabilizer engagement assembly is positionally adjustable relative to the stabilizer elements.
35. The platform of claim 34, wherein the stabilizer engagement assembly comprises a plurality of roller pairs, wherein the rollers in each pair are configured and located so as to engage the stabilizer elements.
36. The platform of claim 34, wherein the stabilizer engagement assembly comprises a plurality of bearing pad arrangements, each configured and located so as to engage the stabilizer elements.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A feature calculation device comprising:
an obtaining unit configured to obtain a point sequence group comprising a set of point sequences in which a sequence of a plurality of points is fixed;
a first calculator configured to, for each of the point sequences in the point sequence group, calculate a plurality of values related to a curvature of a shape of the point sequence, with a reference point with respect to the point sequence as a reference, and calculate feature quantities based on the plurality of calculated values; and
a second calculator configured to calculate a histogram representing a distribution of the feature quantities of each of the point sequences, wherein
for each of the point sequences, the first calculator is configured to calculate each feature quantity of one to C (where C\u22671), and
as the histogram, the second calculator is configured to calculate a co-occurrence histogram that represents a co-occurrence distribution of the first feature quantity to the C-th feature quantity of each of the point sequences,
wherein the obtaining unit is one of a touch-sensitive panel, a touch-pad, a mouse or an electronic pen, and
wherein the point sequences constituting the point sequence group represent a plurality of strokes entered when a stylus pen or a finger makes contact with an input screen.
2. The device according to claim 1, wherein, for each of the point sequences, the second calculator is configured to poll a value weighted with the length of the point sequence, to bins in which feature quantities from the first feature quantity to the C-th feature quantity of the point sequence co-occur, to thereby calculate the co-occurrence histogram.
3. The device according to claim 1, further comprising a normalizing unit configured to normalize the calculated histogram.
4. The device according to claim 1, wherein the first calculator is configured to set the reference point to any one of points in each of the point sequences.
5. The device according to claim 1, wherein the first calculator is configured to set the reference point to a point other than points in the point sequences.
6. A feature calculation method comprising:
obtaining, by an obtaining unit, a point sequence group comprising a set of point sequences in which a sequence of a plurality of points is fixed;
calculating, by a first calculator, for each of the point sequences in the point sequence group, a plurality of values related to a curvature of a shape of the point sequence, with a reference point with respect to the point sequence as a reference, and calculating feature quantities based on the plurality of calculated values; and
calculating, by a second calculating unit, a histogram representing a distribution of the feature quantities of each of the point sequences, wherein
for each of the point sequences, each feature quantity of one to C (where C\u22671) is calculated by the first calculator, and
as the histogram, a co-occurrence histogram is calculated by the second calculator, the co-occurrence histogram representing a co-occurrence distribution of the first feature quantity to the C-th feature quantity of each of the point sequences,
wherein the obtaining unit is one of a touch-sensitive panel, a touch-pad, a mouse or an electronic pen, and
wherein the point sequences constituting the point sequence group represent a plurality of strokes entered when a stylus pen or a finger makes contact with an input screen.
7. A computer program product comprising a non-transitory computer readable medium including program instructions, wherein the instructions, when executed by a computer, cause the computer to:
obtain a point sequence group comprising a set of point sequences in which a sequence of a plurality of points is fixed;
calculate, for each of the point sequences in the point sequence group, a plurality of values related to a curvature of a shape of the point sequence, with a reference point with respect to the point sequence as a reference, and calculating feature quantities based on the plurality of calculated values; and
calculate a histogram which representing a distribution of the feature quantities of each of the point sequences, wherein
for each of the point sequences, each feature quantity of one to C (where C\u22671) is calculated, and
as the histogram, a co-occurrence histogram is calculated, the co-occurrence histogram representing a co-occurrence distribution of the first feature quantity to the C-th feature quantity of each of the point sequences,
wherein the point sequences constituting the point sequence group represent a plurality of strokes entered when a stylus pen or a finger makes contact with a touch input screen.