What is claimed is:
1. A method for concealing errors detected in an input audio bit stream, the digital audio bit stream configured as a series of packets, said method comprising the steps of:
detecting a first beat and a subsequent plurality of beats in the audio bit stream;
defining a first inter-beat interval extending between said first beat and a (k1)th subsequent beat;
storing at least a portion of the audio bit stream occurring within said first inter- beat interval;
detecting an erroneous audio segment occurring in a second inter-beat interval extending between said (k1)th beat and a (2k1)th subsequent beat; and
replacing at least a first part of said erroneous audio segment with a corresponding part of said stored digital audio bit stream portion.
2. A method as in claim 1 wherein k is an integer greater than or equal to 2.
3. A method as in claim 1 wherein said stored audio bit stream portion includes at least one packet positioned on at least one said beat.
4. A method as in claim 1 wherein said step of detecting a first beat comprises a step of computing the variance of the audio bit stream using decoded IMDCT coefficients.
5. A method as in claim 1 wherein said step of detecting a first beat comprises the step of utilizing a window-switching pattern.
6. A method as in claim 1 wherein said step of detecting a first beat comprises a step of computing the envelope of the audio bit stream using decoded IMDCT coefficients.
7. A method as in claim 1 wherein said step of detecting a first beat comprises the steps of computing the variance of the audio bit stream using decoded IMDCT coefficients and utilizing a window-switching pattern.
8. A method as in claim 1 wherein said step of storing at least a portion of the audio bit stream includes a step of storing said portion in a circular first-in first-out (FIFO) buffer.
9. A method for error concealment in a process of digital audio streaming, said method comprising the steps of:
providing a bitstream;
detecting at least two beats extracted from said bitstream, said beats extracted from a signal having repetitive sequences; and
determining an inter-beat interval between said at least two beats.
10. A method as in claim 9 wherein said signal having repetitive sequences comprises at least one signal from the group consisting of a music signal and an audio signal.
11. A method as in claim 9 wherein said signal having repetitive sequences includes an error pattern.
12. A method as in claim 9 wherein said signal having repetitive sequences includes a packet loss from an IP network and a burst error from a wireless channel.
13. A method as in claim 9 further comprising the step of decoding at least a portion of said signal having repetitive sequences.
14. A method as in claim 9 wherein said signal having repetitive sequences comprises at least one element from the group consisting of a rhythm element, a beat element, and a bar element.
15. A method as in claim 11 further comprising the step of replacing said error pattern with music content.
16. A method as in claim 9 further comprising the step of replacing one said beat with another said beat from a preceding bar.
17. A method for error concealment in a process of digital audio streaming in a wireless terminal, said method comprising the step of storing two consecutive inter-beat intervals of the compressed audio bitstream
18. A memory for error concealment in a process of digital audio streaming in a wireless terminal, said memory comprising:
storing means for storing a signal history of musical beats of two consecutive inter-beat intervals of the compressed audio bitstream.
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 method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of:
(a) providing a molten salt electrolyte at a temperature of less than 900\xb0 C. having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, said liner having a bottom and walls extending upwardly from said bottom;
(b) providing a plurality of substantially non-consumable anodes and cathodes disposed in a generally vertical direction in said electrolyte, said anodes comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, said cathodes having a surface, said anodes having a surface disposed opposite said surface of said cathode defining a region therebetween, said anodes containing apertures through said surface of said anode to permit flow of electrolyte through said apertures to provide alumina-enriched electrolyte to said region between said anodes and said cathodes; and
(c) passing electrical current through said anodes and through said electrolyte to said cathodes for purposes of electrolysis, depositing aluminum at said cathodes and producing gas at said anodes.
2. The method in accordance with claim 1 wherein said surfaces of said cathode and said anode are planar surfaces.
3. The method in accordance with claim 1 wherein said electrolyte is comprised of one or more alkali metal fluorides.
4. The method in accordance with claim 1 wherein said electrolyte is comprised of one or more alkali metal fluorides and aluminum fluoride.
5. The method in accordance with claim 1 including maintaining said electrolyte in a temperature range of about 660\xb0 to 860\xb0 C.
6. The method in accordance with claim 1 wherein said electrolyte has a melting point in the range of 715\xb0 to 860\xb0 C.
7. The method in accordance with claim 1 including passing an electric current through said cell at a current density in the range of 0.1 to 1.5 Acm2.
8. The method in accordance with claim 1 including maintaining said liner as an anode by passing electric current therethrough.
9. The method in accordance with claim 1 wherein said anodes are comprised of 10 to 70 wt. % Cu, 15 to 60 wt. % Ni, the remainder iron, incidental elements and impurities.
10. The method in accordance with claim 9 wherein said cathodes are selected from the group consisting of titanium diboride, zirconium diboride, titanium carbide, zirconium carbide and molybdenum.
11. The method in accordance with claim 1 wherein said anodes are cast from a melt of Cu\u2014Ni\u2014Fe and then heated to provide a single microstructutral phase.
12. The method in accordance with claim 11 wherein said cast anodes are heated to a temperature range of 950\xb0 to 1250\xb0 C. to provide the single microstructural phase.
13. The method in accordance with claim 1 wherein said anodes and cathodes have planar surfaces arranged in a vertical orientation in said electrolyte and wherein said anodes and cathodes are arranged in alternating relationship.
14. The method in accordance with claim 1 including adding alumina to said cell on a substantially continuous basis.
15. The method in accordance with claim 1 wherein said anodes are comprised of 20 to 50 wt. % Cu, 20 to 40 wt. % Ni, and 20 to 40 wt. % Fe.
16. The method in accordance with claim 1 including collecting aluminum from said cathode in the bottom of said cell.
17. The method in accordance with claim 1 wherein said anodes are hollow and have two planar surfaces, each planar surface disposed opposite a surface of said cathode, permitting flow of alumina-enriched electrolyte from said hollow through said apertures to the region between said anodes and said cathodes.
18. The method in accordance with claim 1 wherein said flow of molten electrolyte in said cell is generally in an upwardly direction between said anodes and said cathodes.
19. The method in accordance with claim 1 including maintaining alumina in said electrolyte in a range of 2 to 6 wt. %.
20. A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of:
(a) providing a molten salt electrolyte having a melting point in the range of 715\xb0 to 900\xb0 C. and having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, said liner having a bottom and walls extending upwardly from said bottom;
(b) providing a plurality of anodes and cathodes disposed in a generally vertical direction in said electrolyte, said anodes comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, said cathodes having a planar surface disposed opposite an anode planar surface, said cathodes’ and said anodes’ planar surfaces defining a region therebetween, said anodes containing apertures through said anode planar surface to permit flow of electrolyte through said apertures to provide alumina-enriched electrolyte to said region between said anodes and said cathodes; and
(c) passing electrical current through said anodes and through said electrolyte to said cathodes, depositing aluminum at said cathodes and producing gas at said anodes.
21. The method in accordance with claim 20 wherein said anodes are heated to a temperature range of 950\xb0 to 1250\xb0 C. to provide the single microstructural phase.
22. A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of:
(a) providing a molten salt electrolyte having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, said liner having a bottom and walls extending upwardly from said bottom;
(b) adding alumina to said electrolyte on a continuous basis to provide an alumina-enriched electrolyte;
(c) providing a plurality of substantially non-consumable anodes and cathodes disposed in a generally vertical direction in said electrolyte, said anodes comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, said cathodes having a surface and said anodes having a planar surface disposed opposite said surface of said cathode defining a region therebetween, said anodes containing apertures through said planar surface;
(d) flowing alumina-enriched electrolyte through said apertures to provide alumina-enriched electrolyte to said region between said anodes and said cathodes; and
(e) passing electrical current through said anodes and through said electrolyte to said cathodes, depositing aluminum at said cathodes and producing gas at said anodes.
23. An improved anode for use in an electrolytic cell for producing aluminum from alumina dissolved in a molten salt electrolyte contained in said cell wherein aluminum is deposited at the cathode, oxygen is produced at the anode when electric current is passed through the cell, said cell containing at least one cathode and one anode disposed in said electrolyte, said anodes comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, said cathode having a surface, said anode having a surface for disposing opposite said cathode surface to provide an anode-cathode distance defining a region between said anode and said cathode surfaces, said anode having apertures therein to permit flow of electrolyte through said apertures to provide alumina-enriched molten salt electrolyte in said region between said anodes and said cathodes.
24. The anode in accordance with claim 23 wherein said anode is comprised of 10 to 70 wt. % Cu, 15 to 60 wt. % Ni, the remainder iron, incidental elements and impurities.
25. The anode in accordance with claim 23 wherein said anode is a cast anode cast from a melt of Cu\u2014Ni\u2014Fe and then heated to provide a single microstructural phase.
26. The anode in accordance with claim 23 wherein said anode contains a hollow region for flowing alumina-enriched molten electrolyte to said apertures to flow electrolyte through said apertures to said region.
27. An improved anode for use in an electrolytic cell for producing aluminum from alumina dissolved in a molten salt electrolyte contained in said cell, said cell containing at least one cathode and one anode disposed in said electrolyte, said cathode having a flat surface, said improved anode comprising:
two anode panels comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, said anode panels in electrical communication and separated to define a space between said panels for flowing molten electrolyte, each of said anode panels having a flat surface for disposing opposite said cathode surface to provide a region between the anode and the cathode surface, said panels having apertures to permit flow of alumina-enriched electrolyte contained in said space to said region between said anodes and said cathodes.
28. The anode in accordance with claim 27 wherein said anode is cast anode formed from a melt of Cu\u2014Ni\u2014Fe, the cast anode heated to provide said single microstructural phase.
29. The anode in accordance with claim 27 wherein said anode is heated to a temperature range of 950\xb0 to 1250\xb0 C. to provide the single microstructural phase.
30. In an improved method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte wherein a molten salt electrolyte is maintained at a temperature of less than 900\xb0 C., the electrolyte having alumina dissolved therein, and alumina add to the electrolyte on a continuous basis to provide alumina-enriched electrolyte, and wherein a plurality of non-consumable anodes and cathodes are disposed in a vertical direction in said electrolyte, said cathodes having a flat surface, the improved method comprising:
(a) providing anodes having a planar surface disposed opposite the flat surface of the cathode to define a region between the cathode flat surface and the planar surface of the anode, said anodes comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, the anode planar surface containing apertures permitting flow of electrolyte through the apertures to provide alumina-enriched electrolyte to the region between said anodes and said cathodes;
(b) passing electrical current through said anodes and through said electrolyte to said cathodes, depositing aluminum at said cathodes and producing gas at said anodes.
31. The method in accordance with claim 30 wherein said anodes are heated to a temperature range of 950\xb0 to 1250\xb0 C. to provide the single microstructural phase.
32. An electrolytic cell for producing aluminum from alumina dissolved in an electrolyte, the cell comprised of:
(a) a liner for containing the electrolyte, the liner having a bottom and walls extending upwardly from said bottom and means for adding alumina to said cell to provide alumina-enriched electrolyte;
(b) a plurality of non-consumable anodes and cathodes disposed in said electrolyte contained in said cell, said anodes comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, said cathodes having a cathode surface, said anodes having an anode surface disposed from said cathode surface to define a region between said anode and cathode, and said anode surface containing apertures extending through said anode surface to permit flow of electrolyte therethrough to provide alumina-enriched electrolyte to said region between said anodes and said cathodes; and
(c) means for passing electrical current through said anodes and through said electrolyte to said cathodes for producing aluminum at said cathode and gas at said anodes.
33. The cell in accordance with claim 32 wherein said cathode surface is a planar surface.
34. The cell in accordance with claim 32 wherein said anode surface is a planar surface.
35. The cell in accordance with claim 32 wherein said anode and said cathode have an active area ratio anode to cathode in the range of 1.1:1 to 5:1.
36. The cell in accordance with claim 32 wherein the anodes are heated to a temperature range of 950\xb0 to 1250\xb0 C. to provide the single microstructural phase.
37. The cell in accordance with claim 32 wherein the anodes and cathodes have planar surfaces arranged in a vertical orientation in said electrolyte and wherein said anodes and cathodes are arranged in alternating relationship.
38. The cell in accordance with claim 32 wherein the anodes are hollow and have two planar surfaces, each planar surface disposed opposite a surface of said cathode, permitting flow of alumina-enriched electrolyte from said hollow through said apertures to the region between said anodes and said cathodes.
39. An anode having increased anode active surface area for use in an electrolytic cell for producing aluminum from alumina dissolved in a molten salt electrolyte contained in the cell, the cell containing at least one cathode and one anode disposed in said electrolyte, said anode comprised of a Cu\u2014Ni\u2014Fe alloy having a single microstructural phase, said cathode having a surface, the anode having a first surface for disposing opposite said cathode surface to provide a controlled anode-cathode distance defining a region between said anode and said cathode surfaces, said anode having a second surface disposed from said first surface of said anode to provide said anode with a thickness dimension, said anode having apertures extending from said first surface to said second surface, said apertures defined by a wall of said anode, said wall providing additional anode active surface area during electrolysis of said alumina in said cell.
40. The anode in accordance with claim 39 wherein said anode surface is a planar surface.
41. The anode in accordance with claim 39 wherein said first surface of said anode is a planar surface.
42. The anode in accordance with claim 39 wherein the anodes are comprised of 20 to 50 wt. % Cu, 20 to 40 wt. % Ni, and 20 to 40 wt. % Fe.
43. The anode in accordance with claim 39 wherein the anodes are cast anodes comprised of 20 to 50 wt. % Cu, 20 to 40 wt. % Ni, and 20 to 40 wt. % Fe.
44. An anode having increased anode active surface area for use in an electrolytic cell for producing aluminum from alumina dissolved in a molten salt electrolyte contained in the cell, the cell containing at least one cathode and one Cu\u2014Ni\u2014Fe anode disposed in said electrolyte, wherein said anode is a cast anode heated to a temperature range of 950\xb0 to 1250\xb0 C. to provide a single microstructural phase, said cathode having a planar surface, the anode having a planar first surface for disposing opposite said cathode planar surface to provide a controlled anode-cathode distance of \xbc to 1 inch defining a region between said anode and said cathode surfaces, said anode having a second surface disposed from said first surface to provide said anode with a thickness dimension, said anode having apertures extending from said first surface to said second surface, said apertures defined by a wall of said anode, said wall providing additional anode active surface area during electrolysis of said alumina in said cell and providing for flow of alumina-enriched electrolyte to said region between said anode and cathode, the ratio of said anode active surface area to cathode active surface area being in the range of 1:1 to 5:1.