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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>DTESI</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Optimizing construction site management through YOLOv5-based object detection: a comprehensive analysis of resource utilization and safety enhancement</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Serhii Dolhopolov</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tetyana Honcharenko</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Igor Achkasov</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Vladyslav Hots</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Kyiv National University of Construction and Architecture</institution>
          ,
          <addr-line>31, Air Force Avenue, Kyiv, 03037</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2024</year>
      </pub-date>
      <volume>9</volume>
      <fpage>16</fpage>
      <lpage>17</lpage>
      <abstract>
        <p>This study introduces a YOLOv5-based object detection system for optimizing construction site management, addressing critical challenges in resource utilization and safety. We developed a custom YOLOv5 model to identify and track construction resources, equipment, and vehicles in real-time using CCTV footage. The model was trained on a dataset of 1,897 images over 30 epochs, achieving a final precision of 0.852, recall of 0.723, and mean Average Precision (mAP_0.5) of 0.792. Performance evaluation using Intersection over Union (IoU) and confusion matrix analyses demonstrated high accuracy across different object categories, with an overall precision of 88%, recall of 79%, and mAP at the 50 IoU threshold of 85% on the validation dataset. These results indicate the model's robust capability in accurately detecting and classifying various construction-related objects. The proposed system offers a comprehensive framework for integrating AI-driven object detection into construction management, potentially enhancing operational efficiency through optimized resource allocation and improving site safety via real-time monitoring. Future research will focus on refining the model's performance in diverse environmental conditions and exploring its integration with other emerging construction technologies.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Construction site</kwd>
        <kwd>YOLOv5</kwd>
        <kwd>recognition systems</kwd>
        <kwd>real-time object classification</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        The construction industry is undergoing a significant transformation driven by AI and ML
technologies, particularly YOLOv5-based object detection, to address challenges in resource
management and safety. This advanced technology offers real-time detection and classification of
construction assets, enhancing operational efficiency and safety protocols [
        <xref ref-type="bibr" rid="ref1 ref2">1,2</xref>
        ].
      </p>
      <p>
        Recent studies have demonstrated YOLOv5's efficacy in construction settings. Xue et al.
developed an improved YOLOv5 algorithm for track construction safety [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ], while Zhou et al.
proposed a YOLOv5 model for sorting construction waste [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. Cai et al. showcased a
YOLOv4based framework applicable to construction site management [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], and Peng et al. introduced
CORY-Net, a YOLOv5 variant for power grid construction site monitoring [
        <xref ref-type="bibr" rid="ref4">4,8</xref>
        ].
      </p>
      <p>
        YOLOv5's applications extend beyond basic object detection to analyzing equipment usage
patterns, real-time monitoring of tool locations, and identifying potential safety hazards. Yang et al.
demonstrated its effectiveness in monitoring safety protocol compliance [
        <xref ref-type="bibr" rid="ref5">5,9</xref>
        ], while Zeng et al.
highlighted the importance of adapting these models to the unique challenges of construction sites
[
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>The integration of YOLOv5 into construction management systems represents a paradigm shift
towards data-driven decision-making and operational efficiency. Wan et al.'s work on YOLOv5 for
object detection in high-resolution images underscores the model's robustness across various
conditions [7], a crucial attribute for the dynamic environment of construction sites.</p>
      <p>The purpose of this research can be summarized as follows:





</p>
      <p>Evaluate YOLOv5's effectiveness in improving construction site efficiency.</p>
      <p>Assess YOLOv5's impact on construction site safety.</p>
      <p>Explore customization of YOLOv5 models for specific construction environments.
Investigate integration with other technologies (e.g., drones, IoT).</p>
      <p>Identify challenges and limitations in deploying YOLOv5-based systems.</p>
      <p>Provide recommendations for future research and development.</p>
      <p>By addressing these objectives, this study seeks to contribute to the knowledge base on
advanced object detection technologies in construction site management, paving the way for a
more efficient, safe, and technologically advanced construction industry.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Main research</title>
      <p>The proposed study aims to enhance construction site efficiency and safety through the
implementation of a YOLOv5-based object detection model. This section outlines the materials and
methods used to develop, train, and deploy the model for resource and equipment management on
construction sites.</p>
      <p>This comprehensive framework leverages YOLOv5 for object detection to manage resources and
equipment on construction sites effectively and is represented as a model in Figure 1. By
emphasizing the detection and classification of resources and integrating this information into
actionable insights for site managers, the system ensures resources are used efficiently and
effectively, enhancing overall site safety and operational efficiency.</p>
      <sec id="sec-2-1">
        <title>2.1. Dataset of the study</title>
        <p>The success of the YOLOv5 object detection model for construction site management relies heavily
on a comprehensive and representative dataset [11]. This study employed a meticulous data
collection process to ensure the model's effectiveness across various construction site scenarios.</p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Data collection</title>
        <p>The dataset encompasses three main categories:
1. Equipment Utilization. Images of bulldozers, concrete mixers, and generators in both idle
and active states.
2. Tool and Machinery Tracking. Images of hand drills, power saws, jackhammers, and
welding machines in various usage states.
3. Vehicle Recognition. Images of cranes, dump trucks, excavators, and cement trucks in
operational and idle states.</p>
      </sec>
      <sec id="sec-2-3">
        <title>2.3. Activity detection methodology</title>
        <p>The fundamental idea is to analyze a sequence of images to identify whether an object, such as a
concrete mixer, remains in the same state (indicating inactivity) or transitions between states
(indicating activity). This determination is made by observing changes in the object's features or
position across the image sequence.</p>
        <p>Object Does Not Change Its State – Not Active. When a sequence of images is fed into a
detection system where the object does not change its state, the object is classified as not active.
For a concrete mixer, this would mean that across multiple frames, there is no visible change in its
position, orientation, or any operational components (e.g., the mixing drum remains stationary).
The lack of change suggests that the concrete mixer is idle. Detecting inactivity involves analyzing
the object's features across the sequence and noting the absence of significant variation.</p>
        <p>Object Changes Its State – Active. Conversely, if the object changes its state across the
sequence of images, it is classified as active. For the concrete mixer example, this would be
indicated by visible changes such as the rotation of the mixing drum, movement of the mixer from
one location to another, or other signs of operation. Detecting activity involves identifying
variations in the object's features, such as changes in texture (rotation patterns of the drum),
position, or other operational indicators that signify the mixer is in use. An example of an active
equipment recognition system is shown in Figure 2.</p>
        <p>The detection of object activity typically involves the following steps:



</p>
        <p>Feature Extraction. Identifying relevant features indicative of the object's state.</p>
        <p>Temporal Analysis. Comparing features across image sequences to detect changes over
time.</p>
        <p>State Classification. Classifying objects as active or inactive based on detected feature
changes.</p>
        <p>Contextual Information Integration. Enhancing accuracy by incorporating knowledge of
typical operational cycles.</p>
        <p>This principle of object activity detection is not limited to concrete mixers but can be applied to
a wide range of objects and scenarios where understanding the operational state is crucial.
Implementing such a system requires careful consideration of the features to be extracted, the
method for temporal analysis, and the criteria for classifying the state of the object.</p>
      </sec>
      <sec id="sec-2-4">
        <title>2.4. Data cleaning</title>
        <p>Data cleaning is crucial for preparing an optimal dataset for training the YOLOv5-based object
detection model [12]. The process involved:
1. Removing irrelevant images not depicting construction equipment, tools, or vehicles in
specified states.
2. Eliminating duplicate images to prevent overfitting.
3. Correcting mislabelled images to ensure accurate representation of classes and states.
4. Implementing quality control measures to remove blurry, poorly lit, or obstructed images.</p>
        <p>This meticulous process ensures a dataset optimized for training an effective and accurate
YOLOv5 model, focusing on relevance, diversity, accuracy, and quality.</p>
      </sec>
      <sec id="sec-2-5">
        <title>2.5. Image preprocessing</title>
        <p>Image preprocessing is pivotal in enhancing the dataset's suitability for model training [13]. Key
steps included:
1. Resizing all images to a uniform dimension for YOLOv5 training.
2. Adjusting brightness and contrast to simulate various lighting conditions.
3. Applying image normalization to scale pixel values.
4. Employing data augmentation techniques (rotations, translations, flipping, scaling).
5. Converting some images to different color spaces (e.g., HSV, LAB) to enhance object
detection capabilities [14-15].</p>
        <p>The preprocessed dataset was then organized into training, validation, and test sets, ensuring
comprehensive model evaluation.</p>
      </sec>
      <sec id="sec-2-6">
        <title>2.6. Splitting data</title>
        <p>The dataset was divided into three subsets:


</p>
        <p>Training set (70%): 1,897 images (1,610 machinery, 287 tool tracking)
Validation set (20%): 542 images (460 equipment/vehicle, 82 tool tracking)
Test set (10%): 271 images (230 equipment/vehicle, 41 tool tracking)</p>
        <p>This structured approach ensures balanced representation across all classes and states.</p>
      </sec>
      <sec id="sec-2-7">
        <title>2.7. Testing and evaluation</title>
        <p>The model's performance was evaluated using CCTV imagery from a local construction site,
focusing on accuracy and reliability in object detection and classification.</p>
      </sec>
      <sec id="sec-2-8">
        <title>2.7.1. Intersection over Union (IoU)</title>
        <p>IoU quantifies the accuracy of predicted bounding boxes against ground truth. The equation for IoU
is given by:
(1)
(2)
IoU = area of overlap</p>
        <p>area of ∪¿ , ¿
where area of overlap is the area where the predicted bounding box and the actual (ground truth)
bounding box overlap; area of ∪¿ is the total area covered by both the predicted bounding box and
the actual bounding box, minus the area of overlap. It represents the combined area of both boxes
where either box has coverage.</p>
      </sec>
      <sec id="sec-2-9">
        <title>2.7.2. Confusion matrix</title>
        <p>Precision measures the model's accuracy in predicting positive observations. The equation for
Precision is given by:</p>
        <p>Precision=</p>
        <p>TP
TP + FP
=</p>
        <p>TP
all detections
,
where TP are the true positive predictions; FP are the false positive predictions.</p>
        <p>Recall assesses the model's sensitivity. The equation for Recall is given by:
where FN are the false negative predictions.</p>
        <p>Mean Average Precision (mAP) evaluates the model's accuracy across all classes. The equation
for mAP is given by:
where n is the total number of classes in the dataset; AP is calculated for each class and represents
the precision at different recall levels. It takes into account the order of the predictions, rewarding
models that return true positives earlier. The equation of AP is given by:</p>
        <p>n−1
AP=∑ [ Recall ( k )− Recall ( k +1 )] ∙ Precision( k ) ,
k=0
(5)
where k is the index used to sum over a sorted list of objects, thresholds, or intervals.</p>
        <p>The model was evaluated using these metrics on the dataset split into training, validation, and
test sets, with an IoU threshold of 0.5. This comprehensive assessment ensures the model's
accuracy and reliability in real-world construction site scenarios, contributing to improved safety
and efficiency.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Results</title>
      <p>The model underwent training for 30 epochs on the dataset comprising construction equipment,
tools, and vehicles, with a batch size set at 16. The training process was completed in
approximately 23 minutes utilizing a Google Colab GPU. Figure 3 illustrates the model's
performance across the training phase for the construction equipment and tools dataset,
showcasing the metrics of precision, recall, and mAP at the 50 IoU threshold.
The performance of YOLOv5 on the validation dataset, which included images of classes, is
summarized in Table 2. The model achieved an overall precision of approximately 88%, a recall of
79%, and a mAP at the 50 IoU threshold of 85%.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Conclusion</title>
      <p>Thus, the implementation of the YOLOv5-based object detection model for enhancing construction
site efficiency and safety has demonstrated significant potential in revolutionizing the management
of resources and equipment. Through meticulous training, validation, and testing processes, the
model has shown high accuracy in detecting and classifying various construction-related objects,
including equipment in idle and active states, tools, and vehicles, directly contributing to improved
operational efficiency and safety measures on construction sites.</p>
      <p>The model's training over 30 epochs, utilizing a dataset meticulously prepared with images of
construction equipment, tools, and vehicles, resulted in a final precision of 0.852, a recall of 0.723,
and a mAP_0.5 of 0.792. These metrics underscore the model's capability to accurately identify and
classify objects, which is crucial for real-time monitoring and management applications. The high
performance across different classes, particularly in vehicle recognition and equipment utilization,
highlights the model's versatility and effectiveness in addressing the dynamic needs of construction
site management. The validation and testing phases further affirmed the model's reliability, with
precision and recall rates consistently above 85% and 79%, respectively, across various object
categories. This level of accuracy ensures that the model can serve as a dependable tool for
construction site managers, enabling them to make informed decisions based on real-time data
regarding the status and location of tools, machinery, and vehicles.</p>
      <p>In conclusion, the YOLOv5-based object detection model represents a significant advancement
in leveraging computer vision and deep learning technologies for construction site management.
By providing a robust solution for real-time detection and classification of construction resources
and equipment, the model paves the way for smarter, safer, and more efficient construction site
operations. Future work will focus on further refining the model's accuracy, exploring its
integration with other technological solutions, and expanding its application to a broader range of
construction site scenarios, ultimately contributing to the ongoing digital transformation of the
construction industry.</p>
    </sec>
    <sec id="sec-5">
      <title>Declaration on Generative AI</title>
      <p>The authors have not employed any Generative AI tools.
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