Authors make a change because the modification is required to ensure the accuracy of a result. An advertent typo appears in
Table 3, corresponding to LOAWA, where the first value mentioned should be –3.75 (and not –0.375 as it appears now).
The authors wish to make the following corrections to their published paper. In summary, on page 11,
Table 3 should be changed from
to the following correct version:
The authors would like to apologize for any inconvenience caused to the readers by these changes. The changes do not affect the scientific results reported in Tables 1 and 2 and Figures 2 and 3. The manuscript will be updated and the original will remain online on the article webpage, with a reference to this Correction.
Reference
- Balasubramanian, P.; Maskell, D.L. Hardware Optimized and Error Reduced Approximate Adder. Electronics 2019, 8, 1212. [Google Scholar] [CrossRef]
Table 3.
Error metrics of the approximate adders shown in Figure 1b–g. Average error (AE), mean average error (MAE), and root mean square error (RMSE) were calculated by considering a 4-bit and an 8-bit inaccurate sub-adder (i.e., K = 4 and K = 8) in the approximate adders. The generalized error range of the approximate adders using a K-bit inaccurate sub-adder is also specified.
Table 3.
Error metrics of the approximate adders shown in Figure 1b–g. Average error (AE), mean average error (MAE), and root mean square error (RMSE) were calculated by considering a 4-bit and an 8-bit inaccurate sub-adder (i.e., K = 4 and K = 8) in the approximate adders. The generalized error range of the approximate adders using a K-bit inaccurate sub-adder is also specified.
| Type of Adder | Error Characteristics |
|---|
| AE | MAE | RMSE | Error Range |
|---|
| K = 4 | K = 8 | K = 4 | K = 8 | K = 4 | K = 8 |
|---|
| Accurate | Nil | Nil | Nil | Nil |
| LOA | 0.25 | 0.25 | 2.875 | 47.875 | 4 | 64 | – (2K–1–1) to 2K–1 |
| LOAWA | –0.375 | –63.75 | 3.75 | 63.75 | 5.477 | 90.33 | – (2K–1) to 0 |
| APPROX5 | 0.5 | 0.5 | 4 | 64 | 4.637 | 73.9 | – (2K–1–1) to 2K–1 |
| HEAA | –1.75 | –31.75 | 1.75 | 31.75 | 2.646 | 45.08 | – (2K–1–1) to 0 |
| OLOCA | 1 | 16 | 3.203 | 51.997 | 4.301 | 69.13 | – (2K–1–1) to (2K–1+2K–2–1) |
| HOERAA | –0.5 | –8 | 1.938 | 31.996 | 2.550 | 41.31 | – (2K–1–1) to (2K–1–1) |
Table 3.
Error metrics of the approximate adders shown in Figure 1b to 1g. Average error (AE), mean average error (MAE), and root mean square error (RMSE) were calculated by considering a 4-bit and an 8-bit inaccurate sub-adder (i.e., K = 4 and K = 8) in the approximate adders. The generalized error range of the approximate adders using a K-bit inaccurate sub-adder is also specified.
Table 3.
Error metrics of the approximate adders shown in Figure 1b to 1g. Average error (AE), mean average error (MAE), and root mean square error (RMSE) were calculated by considering a 4-bit and an 8-bit inaccurate sub-adder (i.e., K = 4 and K = 8) in the approximate adders. The generalized error range of the approximate adders using a K-bit inaccurate sub-adder is also specified.
| Type of Adder | Error Characteristics |
|---|
| AE | MAE | RMSE | Error Range |
|---|
| K = 4 | K = 8 | K = 4 | K = 8 | K = 4 | K = 8 |
|---|
| Accurate | Nil | Nil | Nil | Nil |
| LOA | 0.25 | 0.25 | 2.875 | 47.875 | 4 | 64 | – (2K–1–1) to 2K–1 |
| LOAWA | –3.75 | –63.75 | 3.75 | 63.75 | 5.477 | 90.33 | – (2K–1) to 0 |
| APPROX5 | 0.5 | 0.5 | 4 | 64 | 4.637 | 73.9 | – (2K–1–1) to 2K–1 |
| HEAA | –1.75 | –31.75 | 1.75 | 31.75 | 2.646 | 45.08 | – (2K–1–1) to 0 |
| OLOCA | 1 | 16 | 3.203 | 51.997 | 4.301 | 69.13 | – (2K–1–1) to (2K–1+2K–2–1) |
| HOERAA | –0.5 | –8 | 1.938 | 31.996 | 2.550 | 41.31 | – (2K–1–1) to (2K–1–1) |
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