Abstract: The widely used JPEG standard algorithm for two-dimensional image compression may be adapted for compression of arrays of any dimension and data type, specifically for arrays of seismic data. Because the JPEG algorithm processes, more or less independently, small subsets (8.times.8 blocks) of larger images or arrays of data, such adaptations are particularly useful in applications that cannot maintain a large, uncompressed, multi-dimensional array in computer memory. JPEG-like methods enable compression and decompression of large arrays by iteration over sub-arrays that are small enough to reside in memory. These algorithms lead to the concept of a compressed virtual memory. Special care must be taken in JPEG-like algorithms to avoid blocking artifacts, which are discontinuities between blocks of data that are compressed and decompressed independently. Fortunately, computationally efficient methods for suppressing these artifacts are well known.

Abstract: A caisson gate valve (10) fitting within an outer casing (12) extending downwardly from a subsea wellhead below the sea floor is disclosed. The gate valve (10) includes a valve body or block (14) having an axial bore or flow passage (16) therethrough and a transverse cavity (18) in body (14) which extends through the body (14) to provide open ends (19) for cavity (18). Covers (60, 66) are mounted over the open ends (19) of cavity (18). A gate carrier (24) has an oval opening (26) which receives a gate member (28) having a gate opening (30) therein for movement between open and closed positions relative to the flow passage (16). A pair of opposed stems or pistons (32, 34) extend from gate carrier (28) for actuation of gate carrier (24) and valve member (28) between open and closed positions relative to flow passage (16). Fluid chambers (36, 38) adjacent pistons (32, 34) provide pressurized fluid for actuation of gate carrier (24) and gate member (28) therein.

Abstract: In certain offshore locations, for example off the West Coast of Africa, FPSO facilities provide an offloading facility to receive and load produced crude oil onto shuttle tankers. In such arrangements FPSO facilities use spread moored tankers with flowlines suspended in the water column to an offloading buoy or buoys which are located 1,000 to 1,500 meters away from the FPSO. Typically steel pipe flowlines as used with intermediate floatation to provide a suitable configuration that will avoid detrimental loads being imposed resulting from relative motions of the FPSO and the offloading buoy. According to the invention, a Suspended Pipe Line End Manifold (SPLEM) is connected to the end of the flowline assembly for support during towout. The SPLEM is positioned near the buoy and then connected at the sea surface to the bottom of the buoy by flexible leads such as anchor chains. The SPLEM is then flooded by selectively flooding compartments to cause it to sink to an operational position below the buoy.

Abstract: A hay bale trailer (10) for transporting and unloading cylindrical hay bales (B) having a plurality of cradle assemblies (16) supported on the trailer (10) with each cradle assembly (16) including a cradle (22) mounted for tilting movement about a horizontal axis (34) between opposed sides of the trailer (10) to permit selective unloading of cylindrical hay bales (B) from a desired side of the trailer (10). Each cradle assembly (16) includes a turntable (35) on which a cradle (22) is mounted for pivotal movement about a vertical axis (46). Upon unlocking of cradles (22) by removal of locking pins (54) from openings (36), the cradle can be manually pivoted for dumping. Springs (76) return cradle (22) to a hauling position. Cradle assemblies (16) as shown in FIG. 10 can be simultaneously unlocked for individual dumping. Actuating rod (100) unlocks levers (66).

Abstract: A high performance method and apparatus for testing a closed loop transducer is disclosed. A test bitstream signal is combined with a .SIGMA..DELTA. feedback bitstream of the transducer to produce a combined bitstream which is converted to a physical feedback to the sensor of the transducer. The .SIGMA..DELTA. bitstream output of the transducer is recorded for later analysis so as to test characteristics of the transducer. The test bitstream signal is preferably an oversampled, pulse density modulated signal. A testing arrangement is provided which is based upon the storage of short-length test patterns which are repetitively accessed to form a continuous test pattern. The test bitstream provided by the method of the invention produces very low noise and low distortion test signals where a repetitive test pattern is equivalent in length to one period of the test signal.

Abstract: A casing hanger assembly is disclosed which includes a bottom member which centralizes a casing string within a casing head and a top member of a conventional slip-type casing hanger design. The bottom member functions to rigidly centralize the casing string inside the casing head while absorbing any side bending load induced by movements of the casing string. The top member, set on top of the bottom centralizer member, supports and transfers the weight of the casing string to the casing head.

Abstract: An improved arrangement for connection of a disconnectable spider buoy to an internal turret of a floating production storage and off loading vessel is disclosed. Risers from subsea wells are connected by quick disconnect/connection devices to pipes which run through the turret and then via a product swivel to lines leading to storage tanks on the vessel. A structure is provided to create an enclosed space to enclose the connection devices at the top of the spider buoy. A ventilation shaft runs from the enclosed volume to atmosphere via the top of the turret. A forced air line is provided into the enclosed space for ventilating the space via the ventilation shaft during normal operations. If a gas leak is sensed in the enclosed space, the forced air line is closed. The small volume which surrounds the connection devices quickly fills with hydrocarbon gas to produce a high gas/air ratio in the enclosed space which greatly reduces danger of explosion.

Abstract: A fail-safe closure system for one or a plurality of springless process valve actuators is disclosed. An accumulator is provided with an urging means, such as a spring for pressurizing fluid stored therein. A source of pressurized fluid is also provided. Supply pressurized fluid is applied to an opening chamber of one or a plurality of process valve actuators while a flow path is opened to a vent from the closing chamber of the one or more actuators. For closing the actuator or actuators, a flow path is established by which pressurized fluid from the accumulator is applied to the closing chamber of the actuator or actuators while the opening chamber is vented. Control valves are arranged so that if or when they fail, they fail in a position which allows the process valve actuators to close as described.

Abstract: A pelvic support and walking assistance device is disclosed which includes a trunk support member and a thigh lifting member coupled to each other at a pivot joint positioned opposite a hip joint of a user. The device functions to prevent pelvic sway. With a spring coupled with said pivot joint, the device further provides a thigh lifting torque to partially compensate for proximal leg weakness. The spring assistance pivot device includes a winding device that can be adjusted in use for varying forward torque for varying situations.

Abstract: A method and apparatus for measuring and compensating for stray capacitance of a micro-machined sensor of an accelerometer system is disclosed. Stray capacitance differences between a top plate and a sensing element and between a bottom plate and the sensing element degrade accelerometer performance if not compensated for. Measurement of stray capacitance difference is achieved by operating the accelerometer in two calibration phases and measuring the steady-state output voltage in each of the two phases. In calibration phase 1, no force is applied to the sensor during clock intervals 1-4. In calibration phase 2, a dummy force up is applied and then a dummy force down is applied during those intervals 1-4. The difference in the output voltage of the two calibration phases is representative of the difference in stray capacitance of the sensor. Capacitance is added to the top or bottom plates in an amount proportional to the measured stray capacitance.

Abstract: A high performance method and apparatus for testing a closed loop transducer is disclosed. A test bitstream signal is combined with a .SIGMA..DELTA. feedback bitstream of the transducer to produce a combined bitstream which is converted to a physical feedback to the sensor of the transducer. The .SIGMA..DELTA. bitstream output of the transducer is recorded for later analysis so as to test characteristics of the transducer. The test bitstream signal is preferably an oversampled, pulse density modulated signal. A testing arrangement is provided which is based upon the storage of short-length test patterns which are repetitively accessed to form a continuous test pattern. The test bitstream provided by the method of the invention produces very low noise and low distortion test signals where a repetitive test pattern is equivalent in length to one period of the test signal.

Abstract: A subsea flowline (10) deployed onto the sea floor (S) has tie-in points for interfacing other subsea facilities. Mudmats (14A, 14B, 14C) support hubs (16A, 16B, 16C) at the tie-in points. One embodiment shown in FIG. 2 has a cradle (22) supporting flowline (10) for relative rotative movement. Hydraulic jacks (26) are connected to arms (24) to position and maintain hub (16) in a vertical orientation. Another embodiment, shown in FIG. 3, has an outer swivel sleeve (21A) which is mounted on mudmat (14A) and receiving flowline (10A) for relative rotation. An annular fluid chamber or toroid (25A) provides fluid communication between flowline (10) and hub (16A) connected to outer swivel sleeve (21A). Another embodiment, shown in FIG. 4, combines the features and characteristics illustrated in FIGS. 2 and 3.

Abstract: A method and apparatus for installing a metal annular seal (54) between the outer rough surface of a casing member (11) which has had a portion thereof cutaway with a remaining portion projecting upwardly from the upper end of a casing head (12). A slip installation tool (18) mounted on the upper end of the casing head (12) carries a slip assembly which includes segmented slips (42), a bushing (22), and a cam member (42). The slip installation tool (18) secures the slips (40) about the outer rough surface of the casing (11) as shown in FIGS. 7 and 8 with bushing (22) acting as a supporting base or foundation to oppose the forces from the camming action because of support from lock down screws (24). After mounting of the slip assembly about the casing (11), the installation tool (18) is removed, and the metal seal (54), formed of a relatively soft metal material, is mounted over the extending end of the casing (11). Positioning of the tubing head (50) on the casing head (12) as shown in FIGS.

Abstract: A safety relief valve (10) has a diaphragm actuator (24) including a diaphragm (26) with a dome chamber (34) on one side of the diaphragm (26) and an underdome chamber (36) on an opposed side of the diaphragm (26). A diaphragm operated pilot control valve (38) has a valve body (46) with a pilot sensing port (54), a pilot dome port (64), and a pilot underdome port (60) in fluid communication with a pilot valve chamber (52). A slidable pilot valve member (68) connected to diaphragm (42) is mounted for movement between two pairs of opposed annular seats (80, 84 and 82, 86). Actuation of pilot valve member (68) at a low set pressure permits fluid communication of inlet fluid from pressure vessel (15) to underdome chamber (36) and exhaust of fluid from dome chamber (34) to boost opening of main relief valve member (22).

Abstract: A lightweight ROV deployable tree cap (28) for deployment on a subsea production hub (10) of a subsea tree. A tree cap (28) has a lightweight body (30) with parallel planar sides and including suitable openings and slots for mounting of the various operating elements. A seal plate structure (64) includes a piston (66) connected to a seal plate (68) having a pair of downwardly projecting tubular seal members (70, 72) for fitting within the production bore (13) and annulus bore (15) of the tree hub (10) in a sealed landed position. Fluid pressure is applied to fluid line (96) to urge piston (66) and seal plate (68) downwardly into sealing landed position. For removal or retrieval of tree cap (28) from the installed position on subsea tree hub (10), fluid pressure is applied through fluid lines (108, 110) for the upward movement of seal plate (68) and tubular seal members (70, 72) from sealing relation with production bore (13) and annulus bore (15).

Abstract: A system for injecting an additive within a fuel storage tank or the fuel tank (10) of a vehicle (12) including an additive injector (22) mounted within the tubular inlet (14) of the fuel tank (10). The additive injector (22) includes an additive pump (46) driven by impeller blades (50) on an end of a pump shaft (48). The fuel discharged from the fuel nozzle (58) strikes the blades (50) to rotate the impeller (47) of pump (46) for dispensing the additive. The additive container (51) has an additive line (56) extending to a pump (46) for the supply of additive thereto for discharge from additive nozzle (54) into the flowing fuel stream. The additive is blended with the flowing fuel stream when discharged. The additive injector (22) may be utilized as a retrofit unit on an existing fuel tank by the removal of fuel tank cap (18) and the insertion of additive dispenser (22) within the tubular inlet (14).

Abstract: A device and method is disclosed to correct intonation errors and generate vibrato in solo instruments and vocal performances in real time. The device determines the pitch of a musical note produced by voice or instrument and shifts the pitch of that note to produce a very high quality, high fidelity output. The device includes a pitch detector that automatically recognizes the pitch of musical notes quickly. The detected pitch is then used as an input to a pitch corrector that converts the pitch of the input to an output with a desired pitch. The corrected musical note is then in tune with the pitch standard. The device and method employ a microprocessor that samples the signal from a musical instrument or voice at regular intervals using an analog-to-digital converter and then utilizes data derived from an auto-correlation function of the waveform to continuously determine the period of the waveform. The period of the waveform is then compared to a desired period or periods (such as found in a scale).

Abstract: A gas regulator valve (14) for maintaining a preset low gas pressure in a storage tank (10). A fluid balanced piston valve member (32) is seated in a closed position on seat (40). A diaphragm actuator (70) has a diaphragm (76). A linkage including opposed link arms (106, 108) is positioned between the diaphragm (76) and the piston valve member (32) and a roller (104) supported on link arms (106, 108) contacts the valve member (32) for controlling the movement of the valve member (32) between open and closed positions. The inner upper ends of link arms (106, 108) are pivotally mounted on bracket (94) secured to the housing and the lower outer ends of the link arms (106, 108) are pivotally mounted on opposed brackets (88, 90) secured to the diaphragm (76). An axial movement of the diaphragm (76) of about two inches results in an axial movement of roller (104) and piston valve member (32) of about 0.20 inch to provide a ratio of about ten to one.