Table 4 Comparative analysis of AiM and baseline models with accuracy and efficiency metrics.

From: AiM: urban air quality forecasting with grid-embedded recurrent MLP model

Model

Avg. Accuracy

Avg. Loss

Latency (ms)

Params (k)

Strengths

Limitations

ARIMA26

60%

0.42

0.5

5

Well-established statistical forecasting

Struggles with non-stationarity and multi-dimensional dependencies

SARIMAX27

63%

0.40

0.7

6

Incorporates exogenous variables

Limited scalability to high-frequency AQI fluctuations

SVR28

70%

0.35

2.3

20

Captures non-linear trends

No sequential modeling; poor in long-horizon forecasts

RF29

78%

0.28

1.8

50

Handles feature importance well

Weak in temporal dependency learning

XGBoost30

82%

0.22

2.1

45

Excellent tabular performance

Requires heavy tuning; lacks temporal dynamics

GRU53

84%

0.18

5.2

120

Efficient sequence modeling

Loses detail in long-term dependencies

LSTM52

85%

0.16

5.8

130

Captures long-term dependencies

Gradient vanishing/exploding under extreme fluctuations

CNN-LSTM10

86%

0.14

6.3

150

Extracts spatial + temporal features

Higher complexity; prone to overfitting on small datasets

BLSTM54

88%

0.12

8.5

220

Bi-directional learning of temporal features

Computationally expensive; still noise-sensitive

FL-BGRU11

89%

0.11

9.1

230

Federated + bi-GRU improves generalization

Dependency on distributed data quality

TinyML GRU (Edge AI)55

82%

0.22

3.1

60

Ultra-low latency; edge deployable

Accuracy trade-off due to quantization

Proposed AiM

96%

0.04

4.5

125

Grid-embedded Bi-GRU captures spatiotemporal patterns; robust to noise

Slightly higher initial training overhead