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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Exchange Rates Prediction for Time-series Data using Advanced Q-sensing Model</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>T. Soni Madhulatha</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Md. Atheeq Sultan Ghori</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="editor">
          <string-name>Universidad Camilo José Cela, Madrid, Spain</string-name>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Computer Science Telangana Social Welfare Residential Degree College for Women</institution>
          ,
          <addr-line>Telangana</addr-line>
          ,
          <country country="IN">India</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Department of Computer Science and Engineering,Telangana University</institution>
          ,
          <addr-line>Telangana</addr-line>
          ,
          <country country="IN">India</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2022</year>
      </pub-date>
      <abstract>
        <p>Financial market is afected by non-linearity with severe market fluctuations. The foreign exchange (forex) is a superior financial market that involves risks as well as profits for the investors. There are several models developed in literature to forecast the forex rates but none of the models considered the major influential factors involved in the market. Deep learning-based advanced Q-sensing (AQS) prediction model used to accurately predict the future forex rates by considering diferent market factors. Initially, the multivariate time-series data are gathered and pre-processed to treat the missing and null values. Then, the data are provided to the AQS model for predictions where, the reinforcement learning (RL) strategy is utilized to take optimal decisions. The overall simulations illustrated the efectiveness and eficiency of the proposed method and the average accuracy of the model in predicting the forex KGSWC-2022: Second International Workshop on Deep Learning for Question Answering, November 21-23, 2022, ⋆You can use this document as the template for preparing your publication. We recommend using the latest version of the ceurart style. ∗Corresponding author. †These authors contributed equally.</p>
      </abstract>
      <kwd-group>
        <kwd>Foreign exchange rates prediction„ time-series data</kwd>
        <kwd>reinforcement learning</kwd>
        <kwd>Q-learning</kwd>
        <kwd>deep learning</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Foreign exchange (forex) market is known to be the world’s biggest currency exchange market
accounting for over 5.1 trillion volume trade/day [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Forecasting, the forex rates is one of
the hot topics in recent times but, due to the high fluctuations in the currency rates, it is very
complex to obtain accurate prediction results [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. To make trading and investment decisions,
the government and companies evaluate the currency rates of one country with respect to other
one. Accurate prediction of forex rates is helpful for the investors and traders to achieve high
returns with reduced risk factors [
        <xref ref-type="bibr" rid="ref3 ref4">3, 4</xref>
        ]. Since the market is influenced by the political and
economic factors, the data are collected as time-series to understand the impacts in currency
rates. Therefore, constructing a model that can efectively handle the irregular data to accurately
predict the forex rates is a challenging task [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ].
      </p>
      <p>
        The dynamic changes in the market provide information about the past and future events
and a prediction model is capable of identifying these events based on time series [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. There
are diferent models in literature that are formulated for forex rates prediction. Diverse steps
are taken by the research community to construct accurate models to deal with the financial
time-series data[
        <xref ref-type="bibr" rid="ref7 ref8">7, 8</xref>
        ]. These models can be either statistical or soft computing-based where,
the soft computing models are more accurate and efective in prediction [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. The popular
statistical models in literature for financial time-series prediction include autoregressive moving
average (ARMA) [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ], autoregressive integrated moving average (ARIMA) [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] etc. These
models use the past events extracted from the time-series data to predict the future events.
The soft computing-based techniques are more efective in predicting the forex rates as these
techniques are stable and can handle any type of non-linear data. The common soft computing
techniques in literature include fuzzy set theory [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ] artificial neural network (ANN)[
        <xref ref-type="bibr" rid="ref13">13, 14, 15</xref>
        ],
support vector machine (SVM) [16, 17, 18] etc.
      </p>
      <p>These models take appropriate decisions on the exchange rates by considering the influential
factors to maximize the returns. In case of soft computing techniques, the neural network
models provide higher performance rates compared to other techniques [19]. Due to this reason,
researchers formulated various hybrid models by integrating neural network architectures with
another neural network [20], statistical model like ARIMA [21], optimization algorithms [22]
etc. The hybrid models are observed to provide higher performance rates than the non-hybrid
models. Hybridization of deep learning models for prediction handles the non-linear data
without losing its stability in processing diverse large datasets.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Proposed methodology</title>
      <p>Prediction of forex rates is a challenging task as there are periodic market fluctuations that
afects the forex rates. This induces changes in the currency rates while making investment
leading to loss for any one party involved in the investment plan. To deal with the market
lfuctuations, prediction of forex rates based on the historical multivariate time-series data is
important. An eficient framework to predict the forex rates for diferent countries based on
Indian rupees (INR) is proposed in this paper that considers several influential parameters of
the exchange rate. The proposed work includes two main phases such as pre-processing and
prediction.</p>
      <p>Initially, the time-series datasets collected for simulations are pre-processed to remove the null
values. This reduces the computational complexity of the prediction process. After this step, the
data values are provided to the prediction model for training. The proposed model is developed
to forecast the exchange rates of United States dollar (USD), British pound sterling (GBP),
euro (EUR), Emirati dirham (AED) and Japanese yen (JPY). Apart from these exchange rates,
the proposed approach also considers several influential parameters that afect the exchange
rates such as BOP, inflation rate, gold price, crude oil price and GDP. To eficiently predict the
exchange rates, this approach introduces a hybrid approach known as advanced Q-sensing (AQS)
that is robust on the time-series data. This model is not afected with the market fluctuations
and can provide reliable prediction results on the considered time-series data.</p>
      <sec id="sec-2-1">
        <title>2.1. Data pre-processing</title>
        <p>Data pre-processing is a process of evaluating the dataset and extracting the missing or
inaccurate data to improve the quality of data for prediction. The time-series datasets considered in
this work are evaluated manually to detect the null values. The steps of pre-processing include
the following:
• Evaluating the dataset for null values
• Removal of unnecessary columns
The time-series datasets included null values in certain columns and these are manually detected
and removed. Since the required columns in the datasets are filled with values, the null values
are directly discarded. Similarly, the columns that are unnecessary are also evaluated and
discarded.</p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Deep-Q network</title>
        <p>Generally, the values of state and action obtained by the RL agent after analyzing the
environment are updated in a Q-table to find the mappings between the states and actions.When the
Q-values are initialized to zero, the probability for the agent to choose random actions for the
state is high. Random mapping of action values may result in decreased reward value and this
problem worsens with time. Also, the problem to be solved by the proposed approach depends
on the time-series data where there is a higher probability of choosing random actions for the
input states.</p>
        <p>To restrict the imperfections of updating a Q-table, deep Q-learning has been introduced
where the Q-table is replaced by a neural network for accurate mapping. The neural network
used in place of Q-table known as the deep-Q network (DQN) learns the weight values that
can approximate the Q-function. After the training phase, the neural network gets of the
environment as an input and selects with highest Q-value. In the training process, the neural
network learns the optimal weight values that can ultimately predict the highest Q-values for
the input states. The process is repeated in an iterative manner where the network predicts the
best actions for all the input states until the target function is approximated for the target state.</p>
        <p>Moreover, the DQN is capable of learning from the experience gained from the older states.
This property makes the proposed approach eficient as the future forex rates prediction can
be improved by determining the previous rates predicted.Thus, the DQN can be prepared for
training with the time-series data by minimizing the mean squared error (MSE) in the bellman
equation.</p>
        <p>This loss value is reduced in the proposed model using the back-propagation algorithm that
optimally chooses the weight value for prediction.
2.2.1. Proposed AQS model for forex rate prediction
In the proposed approach, the Q-learning is combined with the DQN for predicting the future
forex rates of diferent countries with respect to INR. The influential factors such as gold rate,
crude oil rate, inflation rate, BOP and GDP are also considered to view the fluctuations in the
currency rates. The proposed prediction model introduces a deep sensing network in place of
DQN to make predictions on the Q-values.</p>
        <p>Initially, a forecasting environment is built with the feature combinations and certain
thresholds that results in future forex rates. Every combination of the feature comprises the samples
with their labels. Sequential actions are performed by the agent by maximizing the reward to
determine the forex rates. The agent achieves a positive reward when the predicted value is
close to the target otherwise, the reward is negative.</p>
        <p>Since the forex rate prediction is a complex task with a requirement of a huge amount of
samples for prediction, the DQN concept is utilized in this paper. The multi-directional recurrent
neural network (M-RNN) model is utilized in this work to predict the future forex rates based
on diferent parameters. The proposed model is named as advanced Q-sensing (AQS) model
which is actually built with M-RNN over the DQN framework. The M-RNN model is efective
in making accurate observations of the environment. Also, the training of this model is eficient
as this model makes predictions based on the cost metrics (i.e. penalty issued for incorrect
predictions). The M-RNN model predicts the Q-values through training with input states where
the objective of training is to maximize the rewards and to minimize the cost function. The
main advantage of M-RNN is that the model ensures that there are no missing observations
that requires prediction of Q-values.</p>
        <p>For prediction of Q-values using the M-RNN model, we train four blocks in the training
stage such as interpolation, imputation, prediction and error estimation blocks. The traditional
M-RNN model discussed in uses an additional block known as adaptive sampling block for
multiple presentations. In this work, we discard this block to reduce the computational time
of the training phase. Moreover, the q-value prediction requires no sampling as the missing
measurements are already treated and there can be no loss of information. The interpolation
and imputation blocks focuses on reducing the loss function defined while dealing with the
missing measurements.</p>
        <p>• Interpolation block</p>
        <p>This block gets the feature combinations as the input and constructs an interpolation
function . While training a network for prediction, there is a possibility that some of the
data are missed leading to error in prediction. Thus, the interpolation block considers
only the samples within a particular feature combination at a time.</p>
        <p>The basic units of this block is the bi-directional recurrent neural network (Bi-RNN) with
a gated recurrent unit (GRU). A slight modification in the inputs to the hidden units of
forward (lagged) and backward (advanced) layers is done in Bi-RNN for proper training
of time-series data.
• Imputation block</p>
        <p>This block constructs an imputation function and it considers only the feature combination
at a particular time-step whereas, the feature combinations at the other time-steps are
not taken into account. The basic units of this block are the fully connected (FC) layers
that are independent of the time-steps.</p>
        <p>The model uses several FC layers in this block with linear activations. The stacked unit
of Bi-RNN and FC is known as M-RNN
• Prediction block</p>
        <p>The prediction process is carried out in this block where the feature samples are
reconstructed and appropriate labels are predicted to determine the Q-values. A mask vector is
used in this block as the input along with the data to ensure that the required sample to
be labelled is available or not.</p>
        <p>Initially, the M-RNN model is pre-trained and then the DQN model is trained with the
state and action spaces in the environment. The action space selection is enumerated
based on a greedy policy where defines the probability of selecting the appropriate action.
The action value with the highest Q-value is selected by the probability The weights in
the M-RNN model are iteratively updated using the back-propagation algorithm.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Results and discussion</title>
      <p>The proposed AQS model for forex rate prediction has been tested using diferent datasets to
prove its excellence in accurately identifying the exchange rates. The datasets are initially
pre-processed through manual evaluation by checking each of its rows and columns.Then the
pre-processed datasets are provided to the proposed AQS model for prediction. The proposed
model has been evaluated under five diferent foreign currencies (USD, GBP, AED, EUR and JPY)
with respect to INR. Apart from this, the major influential factors considered are gold rate, crude
oil price, GDP, BOP and inflation rate. Four major inflation rates such as transport, food, health
and education are taken to estimate the forex rates. The proposed model has been evaluated in
terms of performance metrics, model performance and time complexity on all the datasets.</p>
      <p>From Table 1 it is clear that the proposed model provided stable results on all the datasets. The
maximum accuracy rate reached by the AQS model is on the EUR/INR dataset with the accuracy
value of 96.98. This explains that the model is capable of accurately determining the exchange
rate of EUR/INR and is able to deal with the market fluctuations. The minimum accuracy of the
model is attained for the USD/INR dataset with an overall accuracy value of 89.53. The overall
performance results suggest that the proposed AQS model is suitable for predicting the forex
rates of diferent countries by considering most of the influential parameters.</p>
      <p>The performance comparison of the proposed and existing models are graphically depicted
in Figure 2. The values of accuracy, precision, recall and f-measure are taken on average. From
the graph, it is clear that the proposed model secured the highest performance values compared
to the other models. The average accuracy scored by the proposed model is 94.36 whereas, the
compared AlexNet, ResNet, LSTM, M-RNN and GRU models scored 88.76, 84.02, 78.93, 84.38
and 77.98 respectively.</p>
      <p>The actual vs. prediction plot obtained from all the prediction models on the USD/INR dataset
for 100 weeks is depicted in Figure 3. From the figure, it is clear that the proposed model
provided better prediction results than the other models compared with it. For all the weeks,
the AQS model outperformed the other models and provided better prediction results. Thus,
the AQS model is capable of accurately predicting the exchange rates of USD/INR under several
market factors.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Conclusion</title>
      <p>In this paper, a novel deep-learning-based prediction model is introduced to accurately predict
the future forex rates with the consideration of major influential factors. The proposed model
combined Q-learning with the M-RNN sensing network to attain higher results in prediction.
Multiple currency rates along with the influential parameters are considered for predictions.</p>
      <p>The proposed model has been trained and tested with five currency rates such as USD/INR,
GBP/INR, EUR/INR, AED/INR and JPY/INR and with certain market factors such as gold rate,
crude oil price, inflation, BOP and GDP.The evaluations of the model has been extended in terms
of diferent metrics to identify the suitability of the model in predicting the market fluctuations
and future exchange rates.</p>
      <p>The deep sensing capability of the proposed AQS model helped it to gather more features
to provide reliable results. The overall accuracy rate of prediction has been improved and the
processing time of the model has been reduced. The proposed model outperformed the existing
learning models in predicting the weekly forex rates of diferent currencies.
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