=Paper= {{Paper |id=Vol-2882/MediaEval_20_paper_39 |storemode=property |title=Personal Air Quality Index Prediction Using Inverse Distance Weighting Method |pdfUrl=https://ceur-ws.org/Vol-2882/paper39.pdf |volume=Vol-2882 |authors=Trung-Quan Nguyen,Dang-Hieu Nguyen,Loc Tai Tan Nguyen |dblpUrl=https://dblp.org/rec/conf/mediaeval/NguyenNN20 }} ==Personal Air Quality Index Prediction Using Inverse Distance Weighting Method== https://ceur-ws.org/Vol-2882/paper39.pdf
                               Personal Air Quality Index Prediction
                             Using Inverse Distance Weighting Method
                               Trung-Quan Nguyen1 , Dang-Hieu Nguyen2 , Loc Tai Tan Nguyen3
                                    1, 2, 3 University of Information Technology, Ho Chi Minh City, Vietnam
                                          1, 2, 3 Vietnam National University, Ho Chi Minh City, Vietnam

                             quannt.13@grad.uit.edu.vn,hieund.12@grad.uit.edu.vn,locntt.12@grad.uit.edu.vn

ABSTRACT
                                                                                                                          1
In this paper, we propose a method to predict the personal air                                                  𝑀𝑖 =                                    (1)
quality index in an area by only using the levels of the following                                                   𝑑 (π‘₯, π‘₯𝑖 ) 𝑝
pollutants: PM2.5, NO2, O3. All of them are measured from the                           with 𝑝 is the power value that is used to control the value of the
nearby weather stations of that area. Our approach uses one of                       weight. It should be noticed that the Haversine method is used to
the most well-known interpolation methods in spatial analysis,                       calculate the distance between the two coordinates.
the Inverse Distance Weighted (IDW) technique, to estimate the                          The value 𝑦 of an unknown point π‘₯ is calculated as:
missing air pollutant levels. After that, we can use those levels to                                                 Í𝑛
calculate the Air Quality Index (AQI). The results show that the                                                      𝑖=1 𝑀𝑖 𝑋𝑖
                                                                                                              𝑦 (π‘₯) = Í 𝑛 𝑀                              (2)
proposed method is suitable for the prediction of those air pollutant                                                   𝑖=1 𝑖
levels.                                                                                  with 𝑀𝑖 is the weight, 𝑋𝑖 is the value of the known point π‘–π‘‘β„Ž .

                                                                                     3.1     Prediction
1    INTRODUCTION
                                                                                     At first, all possible time frame in hour-interval is listed by grouping
The need to know the personal air pollution data is vital because it                 the training data. Then, we start to loop through the training data
is better to provide each individual with regional air quality data,                 per time frame.
which seems to be more accurate than the global data measured                           In each loop, we get the coordinates of all unknown points that
from far away weather stations. The problem is finding a suitable                    need to be predicted. After that, we get the values of the known
method to predict air quality data in a local area from the global                   points and their respective coordinates from the public air pollution
data. This paper reports our solution to tackle this challenge.                      data provided by 26 weather stations surrounding the Tokyo area
   To know more about this challenge and the dataset that we will                    also in that time frame.
use, you can refer to the overview paper of MediaEval 2020 - Insight                    With all the necessary data gathered, we can use the IDW for-
for Wellbeing: Multimodal personal health lifelog data analysis [1].                 mula to make the prediction. Please note that the initial power
                                                                                     value 𝑝 of the IDW formula is 2.
2    RELATED WORK                                                                       After repeating those steps for each air pollutant data (PM2.5,
The inverse distance weighting method [4] is used commonly in                        NO2, O3), we have the final results.
spatial interpolation [3]. This paper will apply the basic form of
IDW without any modification.                                                        3.2     Optimization
                                                                                     To have the best performance, we could find the optimal value
3    APPROACH                                                                        of power value p by trying different values of 𝑝 until the IDW
Due to the limited time available for experimenting with algorithms                  produces acceptable values of SMAPE/RMSE/MAE.
requiring more time to train data, such as neural network-related                       After evaluating the 𝑝-value ranges from 0 to 5, we find that
algorithms, we choose the IDW. Moreover, because there are no                        the best power values for PM2.5, NO2, and O3 are 1.5, 3.5, and 0,
statistical assumptions involved [2], it is simpler than Kriging or                  respectively.
other statistical interpolation methods. The way it works is easy to
understand. Based on the assumption that closer points will have                     4     RESULTS AND ANALYSIS
similar values than further points, it will use the measured values                  The evaluation of PM2.5, NO2, O3, and AQI prediction provided by
surrounding the unknown point to predict the value. By giving                        MediaEval task organizers are shown in Table 1, Table 2, Table 3,
each known point a weight, the predicted value will be the average                   and Table 4, respectively.
of those points.                                                                        In general, PM2.5 prediction is acceptable, but there is a big gap
   The weight 𝑀𝑖 for a known point 𝑖 is the inverse of the distance                  in NO2 and O3 prediction results. It is mainly because the IDW
𝑑 from that point to the unknown point π‘₯, which is computed as:                      formula does not have any offset parameters to compensate for the
                                                                                     big difference between weather stations’ public weather data and
Copyright 2020 for this paper by its authors. Use permitted under Creative Commons
License Attribution 4.0 International (CC BY 4.0).
                                                                                     the one carried out by personal equipment used by volunteers. This
MediaEval’20, December 14-15 2020, Online                                            could be because of some differences in methods and devices of
                                                                                     those two data providers.
MediaEval’20, December 14-15 2020, Online                                                                                      Quan N.T. et al.

        Table 1: Evaluation of the PM2.5 prediction                 data, such as wind direction, wind speed, temperature, to improve
                                                                    accuracy.
       Sensor    MAE              RMSE           SMAPE
                                                                    REFERENCES
       100001    5.190319201      8.732748788    0.45931373
                                                                     [1] Zhao P. J Nguyen N.T. Nguyen T.B. Dang-Nguyen D. T. Gurrin C. Dao,
       100002    3.720370835      5.511739014    0.406428735
                                                                         M. S. 2020. Overview of MediaEval 2020: Insights for Wellbeing Task
       100003    1.619832154      2.095919331    0.133032135             - Multimodal Personal Health Lifelog Data Analysis. In MediaEval
       100005    2.874009812      4.055352722    0.35371517              Benchmarking Initiative for Multimedia Evaluation, CEUR Workshop
       100006    3.233921439      4.341966928    0.468214919             Proceedings.
       100007    1.695290448      1.707219278    0.625317245         [2] Leonardo Ramos Emmendorfer and GraΓ§aliz Pereira Dimuro. 2020. A
       200003    6.465190052      9.724716828    0.444137991             Novel Formulation for Inverse Distance Weighting from Weighted
       200004    4.815504659      7.436923815    0.400557289             Linear Regression. In Computational Science – ICCS 2020, Valeria V.
                                                                         Krzhizhanovskaya, GΓ‘bor ZΓ‘vodszky, Michael H. Lees, Jack J. Don-
                                                                         garra, Peter M. A. Sloot, SΓ©rgio Brissos, and JoΓ£o Teixeira (Eds.).
         Table 2: Evaluation of the NO2 prediction                       Springer International Publishing, Cham, 576–589.
                                                                     [3] Jin Li and Andrew D. Heap. 2011. A review of comparative studies of
            Sensor     MAE         RMSE         SMAPE                    spatial interpolation methods in environmental sciences: Performance
                                                                         and impact factors. Ecological Informatics 6, 3 (2011), 228 – 241. https:
            100001     30.15104    34.62797     0.729989                 //doi.org/10.1016/j.ecoinf.2010.12.003
            100002     13.80071    18.2614      0.399087             [4] Donald Shepard. 1968. A Two-Dimensional Interpolation Function for
            100003     18.85267    20.40416     1.218212                 Irregularly-Spaced Data. In Proceedings of the 1968 23rd ACM National
            100005     12.69285    16.3694      0.411915                 Conference (ACM ’68). Association for Computing Machinery, New
            100006     11.92978    14.12164     0.452494                 York, NY, USA, 517–524. https://doi.org/10.1145/800186.810616
            100007     14.99076    15.85102     0.562354
            200003     12.27167    15.1809      0.364154
            200004     7.664357    9.571268     0.257642

          Table 3: Evaluation of the O3 prediction

       Sensor    MAE              RMSE            SMAPE
       100001    11.14697072      16.74763774     0.474838877
      β€˜ 100002   13.71316126      18.17918429     0.595873229
       100003    12.15603603      14.13207772     0.554840783
       100005    12.91552723      15.99672071     0.53328839
       100006    15.72452576      19.40818331     0.728461886
       100007    30.3013034       31.07255621     1.600495059
       200003    14.62686484      18.79131409     0.490170718
       200004    22.0919231       31.69232972     0.58440423

          Table 4: Evaluation of the AQI prediction

       Sensor    MAE              RMSE           SMAPE
       100001    18.21506046      34.20371647    0.496721967
       100002    18.10474466      38.8695944     0.49921946
       100003    30.32401094      78.4465017     0.311432437
       100005    10.79848535      19.6665506     0.389208159
       100006    14.29939129      34.48844262    0.44466795
       100007    23.5094483       60.19537217    0.521219253
       200003    16.31585216      22.42326978    0.4097449
       200004    12.93598111      19.188617      0.378573048


5   DISCUSSION AND OUTLOOK
We intend to explore more advanced algorithms in our future work,
such as the advanced form of IDW [4], the combination of IDW
with multiple regression. Also, we plan to utilize more weather