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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>September</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>From Pixels to Generalization: Ensuring Information Security and Model Performance with Design Principles for Synthetic Image Data in Deep Learning</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Martin Böhmer</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Martin Luther University Halle-Wittenberg</institution>
          ,
          <addr-line>Universitätsring 3, 06108 Halle (Saale)</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2023</year>
      </pub-date>
      <volume>18</volume>
      <issue>2023</issue>
      <fpage>0000</fpage>
      <lpage>0002</lpage>
      <abstract>
        <p>This paper explores the ethical and effective utilization of synthetic image data in computer vision deep learning. It addresses the challenges of acquiring real-world training data and proposes design principles for selecting, generating, and integrating synthetic images. These principles cover aspects such as ethical compliance, privacy protection, scene diversity, and complexity management. By adopting a design science research approach and using a multi-method research design, the study provides actionable guidance for researchers and practitioners, as these design principles ensure responsible use of synthetic image data while improving model performance and privacy protection. The paper contributes to design knowledge in the general IS, deep learning, and IS ethics field, highlighting the theoretical and practical relevance of the proposed principles. The reusability of the design principles promotes the efficient use of synthetic image data in computer vision and has been positively evaluated.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Design Principles</kwd>
        <kwd>Deep Learning</kwd>
        <kwd>Synthetic Image Data</kwd>
        <kwd>Information Security</kwd>
        <kwd>AI Ethics</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Since computer vision deep learning models often consist of millions or even billions of
parameters, they rely on large amounts of training data to achieve high performance and
generalization [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. However, acquiring real-world training data for artificial intelligence (AI)
applications can be costly, error-prone, limited, or imbalanced [
        <xref ref-type="bibr" rid="ref2 ref3 ref4">2, 3, 4</xref>
        ]. Synthetic image data (e.g.
in the form of video game engine generated scenes) has emerged as a promising alternative,
offering scalability, precision, and potentially more robust and accurate models [
        <xref ref-type="bibr" rid="ref2 ref5 ref6">5, 2, 6</xref>
        ].
Nonetheless, guiding design knowledge on how to utilize synthetically generated image data in
deep learning remains scarce. Moreover, the synthetic illustration of humans, including their
separate or related characteristics such as body parts, raises ethical considerations regarding
privacy, consent, and the potential for misrepresentation or discrimination. In addition, the
usecase context of synthetic image data often revolves around human-related domains [
        <xref ref-type="bibr" rid="ref7 ref8 ref9">7, 8, 9</xref>
        ], such
as medicine or surveillance. These domains inherently involve sensitive information and human
interactions, making it crucial to design technologies that align with ethical standards and user
values. Given the nascent state of the synthetic imagery domain, this paper therefore defines the
following guiding research question:
RQ: How to ethically, effectively, and robustly utilize synthetic image data in computer vision deep
learning environments?
      </p>
      <p>
        To answer this question and to contribute prescriptive knowledge, the design science research
paradigm [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] and design science process model [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] are adopted, with a focus on the value
sensitive design theory [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ] as the guiding theoretical lens. The research approach employs a
multi-method research design, combining qualitative methods such as moderated focus groups
and think aloud sessions to ensure the validity and comprehensiveness of the study design.
Therefore, the research aims to fill the aforementioned research gap by deriving design principles
based on kernel theories, the literature, and practical insights. The design principles address key
aspects such as ethical compliance, privacy protection, data governance, scene diversity,
controlled composition, complexity management, and data augmentation, providing actionable
guidance for researchers and practitioners in the selection, generation, and integration of
synthetic image data for training deep learning models. By adopting these design principles,
practitioners can ensure ethical and responsible use of synthetic image data while enhancing
model performance, privacy protection, and generalization. The reusability of these principles in
similar contexts contributes to their wider application and adoption, addressing the current lack
of design knowledge and promoting efficient utilization of synthetic image data in computer
vision deep learning environments.
      </p>
      <p>The following sections present the research design, theoretical and practical foundations,
design principles, and the evaluation of the proposed principles. The conclusion highlights the
contributions of this study to the design knowledge in the field of utilizing synthetic image data
in computer vision and identifies potential areas for future research.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Research Design</title>
      <p>
        In order to contribute prescriptive rather than descriptive knowledge [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ], the design science
research paradigm [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ] was used for the purpose of this study. In addition, value sensitive design
theory [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ] was used as the guiding theoretical lens (see Section 3.1), which served as the
theoretical framework for the methodological techniques and design of the approach undertaken
in this paper. Therefore, a multi-method research approach [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ] consisting of different qualitative
methods was chosen to address the shortcomings of single methods and to ensure the validity of
the design. The methods used for this study are based on value sensitive design [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ] and include
a moderated focus group for data collection and a think aloud session for evaluating the design
principles.
      </p>
      <p>
        Since the design science research paradigm can be operationalized through various
methodological approaches [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ], this study utilized the framework proposed by Vaishnavi and
Kuechler [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] due to its explicit focus on theoretically grounded design principles. As shown in
Figure 1, the approach includes the five steps: awareness of problem, suggestion, development,
evaluation, and conclusion. Furthermore, and particularly with respect to the ethical and
information security scope of this paper, the ethical design science framework proposed by
Durani et al. [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ] was used to derive ethical and, in addition, negative design principles (discussed
in detail in Section 4), addressing the disruptive nature of recent advancements in technology and
especially deep learning. In this paper, we delve into the intricacies of design principles, because
they form the foundation of design knowledge and play a pivotal role in solving the problem at
hand [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ], which in this case is the theoretical void of guiding design knowledge on how to use
synthetic image data in deep learning.
      </p>
    </sec>
    <sec id="sec-3">
      <title>3. Theoretical and Practical Foundations</title>
      <p>
        Given that state-of-the-art deep learning models for computer vision comprise millions, if not
billions, of parameters, the training process for these models necessitates an immense quantity
of training data, which is frequently absent or imbalanced [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Therefore, the impulse for the
underlying research stems from a genuine real-world circumstance, namely, the provision of
scalable, precise, and ethical computer vision deep learning models and their respective training
data. The highlighted problem originates from several prior studies that found synthetically
trained computer vision models to be more robust, accurate, and less error-prone [
        <xref ref-type="bibr" rid="ref2 ref5 ref6">5, 2, 6</xref>
        ]. In
addition, synthetic image data achieves photorealism and can be generated and scaled infinitely,
making it a genuine alternative to conventional real imagery approaches [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Therefore, a
thorough analysis of the scientific literature was conducted in the scope of this study to identify
relevant research streams and kernel theories. In addition, the theoretical foundations are further
supported by the results of a moderated focus group, which serve as practical foundations for the
development of the design principles.
      </p>
      <sec id="sec-3-1">
        <title>3.1. Kernel Theory</title>
        <p>
          To ensure scientific rigor and stringency, design science research endeavors can use kernel
theories to derive design principles. Broadly speaking, kernel theory functions as a form of
justificatory knowledge within the realm of design knowledge development, as indicated by the
work of Gregor and Hevner [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ], such as in the form of design principles [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ]. Henceforth, this
study adopts the analyze with lens-mechanism proposed by Möller et al. [
          <xref ref-type="bibr" rid="ref19">19</xref>
          ], drawing upon the
theoretical foundations of employing kernel theories as a means of analysis. The use of a
theoretical lens allows researchers to derive concepts indirectly, guiding the analysis or framing
of data within the conceptual borders of a specific theory. This approach aligns with the
perspective of Niederman and March [
          <xref ref-type="bibr" rid="ref20">20</xref>
          ] on the theoretical lens, which emphasizes its role in
aiding the theorization process, leading to the formulation of design principles or
metarequirements based on a data foundation. Thus, by adopting the analyze with lens-mechanism
proposed by Möller et al. [
          <xref ref-type="bibr" rid="ref19">19</xref>
          ], this study aims to analyze the data through a theoretical lens,
allowing for a more robust and informed exploration of the underlying concepts and patterns. As
the most appropriate kernel theory for the scope of this study, the value sensitive design theory
[
          <xref ref-type="bibr" rid="ref12">12</xref>
          ] was chosen as it epitomizes a theoretically grounded approach that considers human values
in a principled and comprehensive manner throughout the design process, which aligns perfectly
with the research goal of developing technology that respects and incorporates user values while
ensuring ethically responsible and user-centered design decisions. In the specific use-case of
synthetic image data utilization for deep learning tasks, this especially connects to the synthetic
illustration of humans (including separate or related characteristics, e.g. body parts), the use-case
context in which the synthetically generated image data is used (often human-related, e.g.
medicine or surveillance), and the potential ethical implications that arise from the creation and
utilization of synthetic images. The theoretical lens of value sensitive design [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ] thus helps not
only to derive design principles, but also to establish a robust elicitation and evaluation (e.g., think
aloud sessions) of these principles. Moreover, the theory recognizes that technology is not neutral
as it can influence behavior, perception, and societal structures, and thus should be designed in a
way that reflects positive human values and respects ethical principles, promoting a holistic
approach to technology design that goes beyond functionality in order to consider the broader
impact on individuals, society, and the environment.
        </p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Theoretical Foundations</title>
        <p>
          To establish the objectives for addressing the aforementioned problem, a comprehensive
analysis of the scientific literature focused on the research area of synthetic image data
generation in deep learning, in line with our DSR methodology, was conducted. As
aforementioned, training deep learning models in computer vision requires large amounts of data
to achieve a fairly high degree of generalization, which is often costly, missing, or unbalanced [
          <xref ref-type="bibr" rid="ref1">1</xref>
          ].
Several studies have highlighted the effectiveness of synthetic data for training deep learning
models in various computer vision tasks. Lee et al. [
          <xref ref-type="bibr" rid="ref21">21</xref>
          ] and Krump et al. [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ] utilized synthetic
datasets for deep learning-based object detection, specifically in underwater sonar imaging and
vehicle detection on UAV platforms, respectively. Body et al. [
          <xref ref-type="bibr" rid="ref22">22</xref>
          ] and Condrea et al. [
          <xref ref-type="bibr" rid="ref23">23</xref>
          ]
demonstrated the value of artificial augmented textual data and purely synthetic training data,
respectively, for sentiment analysis models and vital signs detection in videos. Similarly, Liu et al.
[
          <xref ref-type="bibr" rid="ref8">8</xref>
          ] and Zaki et al. [
          <xref ref-type="bibr" rid="ref24">24</xref>
          ] employed synthetic data for pose estimation and semantic object/scene
categorization. Hence, these studies collectively highlight the effectiveness of synthetic data in
various computer vision domains.
        </p>
        <p>
          Additionally, domain adaptation, which is a technique that involves adapting a model trained
on one domain (synthetic) of data to perform well on a different but related domain (real), and
transfer learning have been extensively explored in the context of synthetic data. Lahiri et al. [
          <xref ref-type="bibr" rid="ref25">25</xref>
          ],
Venkateswara et al. [
          <xref ref-type="bibr" rid="ref26">26</xref>
          ], and Kuhnke and Ostermann [
          <xref ref-type="bibr" rid="ref7">7</xref>
          ] focused on unsupervised domain
adaptation for synthetic data, learning transferable feature representations, and domain
adaptation for pose estimation, respectively. Seib et al. [
          <xref ref-type="bibr" rid="ref3">3</xref>
          ] conducted a comprehensive review of
current approaches that combine real and synthetic data to enhance neural network training,
supporting the argument for a combination of training data and data augmentation. Aranjuelo et
al. [
          <xref ref-type="bibr" rid="ref27">27</xref>
          ] discussed key strategies for synthetic data generation in people detection from
omnidirectional cameras, emphasizing the effective use of both real and synthetic data. Valtchev
and Wu [
          <xref ref-type="bibr" rid="ref28">28</xref>
          ] demonstrated the utility of domain randomization for neural network classification,
showcasing the effectiveness of synthetic data in training robust models. These studies provide
insights into the adaptation of synthetic data to real-world scenarios.
        </p>
        <p>
          Moreover, the combination of synthetic and real training data has been investigated by several
researchers. Wan et al. [
          <xref ref-type="bibr" rid="ref29">29</xref>
          ], Bird et al. [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ], and Abu Alhaija et al. [
          <xref ref-type="bibr" rid="ref30">30</xref>
          ] utilized mixed datasets,
comprising both synthetic and real data, for document layout analysis, scene classification, and
object detection in augmented reality, respectively. Thereby, these studies highlight the benefits
of leveraging both synthetic and real data for training computer vision models.
        </p>
        <p>
          Furthermore, the use of synthetic data generation techniques and simulators has been
explored. Müller et al. [
          <xref ref-type="bibr" rid="ref31">31</xref>
          ] introduced a photorealistic simulator for generating synthetic data for
computer vision applications, whereas Zhang et al. [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ] proposed a stacked multichannel
autoencoder framework for efficient learning from synthetic data. Valerio Giuffrida et al. [
          <xref ref-type="bibr" rid="ref32">32</xref>
          ]
generated synthetic training data for the detection of synthetic Arabidopsis plants using
generative adversarial networks. Scheck et al. [
          <xref ref-type="bibr" rid="ref33">33</xref>
          ] introduced a synthetic dataset that serves as
a valuable resource for training and evaluating deep learning models. These works provide
insights into the generation and utilization of synthetic data for training deep learning models.
        </p>
        <p>Despite the considerable research on utilizing synthetic image data for computer vision deep
learning models, there remains a notable research gap in terms of a comprehensive framework
or guidelines that provide design knowledge to effectively and systematically utilize synthetic
data in this context. While individual studies have demonstrated the benefits and effectiveness of
synthetic data in specific tasks, there is a lack of unified principles or guidelines that guide
researchers and practitioners in the selection, generation, and integration of synthetic image data
for training deep learning models. Hereby, the absence of such design knowledge hinders the
widespread adoption and consistent utilization of synthetic data, leading to potential
inefficiencies, suboptimal performance, and challenges in real-world deployment.</p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Practical Foundations</title>
        <p>
          To ensure scientific rigor, and after analyzing the aforementioned research streams and kernel
theory, it seemed reasonable to conduct a moderated focus group with AI experts to rigorously
derive design knowledge, compare it to the literature findings, and incorporate it into the design
principles. Moderated focus groups are especially predestined for extensive qualitative insights
into a subject [
          <xref ref-type="bibr" rid="ref34">34</xref>
          ] and align with the kernel theory of value sensitive design [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ].
        </p>
        <p>
          The conducted focus group consisted of n=11 participants, including three AI senior scholars,
two AI research associates, two computer vision project leads, and four IS researchers, all with
professional experience ranging from 3-17 years. The goal of the moderated focus group was to
develop design knowledge (e.g., user-specific requirements, characteristics, process steps), but
without incorporating the literature findings to avoid any bias. To ensure qualitative rigor during
and after this session, the well-established methodology outlined by Gioia et al. [
          <xref ref-type="bibr" rid="ref35">35</xref>
          ] was followed
throughout, which involved formulating first order concepts, second order themes, and aggregate
dimensions (AD) based on the subjects' expressed statements. The focus group findings are shown
in Figure 2. The focus group findings revealed key insights regarding the utilization of synthetic
image data in computer vision deep learning settings. Participants emphasized the importance of
adhering to ethical guidelines and privacy regulations throughout the data generation process.
They also stressed the need to remove personally identifiable information and conduct privacy
impact assessments regularly to mitigate privacy risks - resulting in AD1 (Privacy and Ethical
Compliance). The subjects also highlighted the significance of implementing mechanisms for
generation control and data governance to prevent unauthorized access or misuse which was
epitomized by AD2 (Data Governance). Additionally, the focus group emphasized the need for
synthetic scene diversity, recommending the incorporation of various elements and
crossdomain scene randomization to enhance generalization. While promoting scene diversity, they
emphasized the importance of maintaining control over scene composition to ensure proper
representation of intended features and factors of interest. This resulted in AD3 (Synthetic Scene
Generation). The participants further suggested gradually increasing the complexity of synthetic
scenes to prevent overfitting and promote robust learning and generalization. They also
recommended data augmentation techniques, such as geometric transformations and color
modifications, to diversify synthetic scenes and enable the learning of robust representations
invariant to real-world variations – illustrated by AD4 (Robust Learning and Generalization).
        </p>
        <p>Overall, these focus group findings provided valuable insights for the proposed design
principles, which aim to guide the ethical and effective utilization of synthetic image data in
computer vision research and applications.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Design Principles for Using Synthetic Image Data</title>
      <p>
        As aforementioned, the performed design cycle was dedicated to creating design knowledge and
developing theoretically sound design principles as the main artifact. As design principles
embody a general design solution for a class of problems [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ], they are of prescriptive and
universal nature, specifying how a solution should be designed to achieve the desired objective
[36]. In this context, the DPs were derived from a supportive approach and the conceptual schema
of Gregor et al. [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ], whose a priori specification suggests prescriptive wording [36], thereby
allowing us to formulate accessible, precise, and expressive design knowledge, as elucidated by
the framework [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ]. In addition to utilizing the anatomy of a design principle [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ] and the kernel
theory of value sensitive design [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ], the development and wording of the design principles were
guided by the ethical design science research framework proposed by Durani et al. [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ], resulting
in more prescriptive guidance for leveraging the positive impact of the artifact and minimizing
its adverse effects.
      </p>
      <p>The design principles were rigorously derived from the literature and the aggregate
dimensions from the qualitatively analyzed focus group results. As shown in Figure 3, seven
specific design principles were developed to address the identified problem of lacking design
knowledge on how to utilize synthetic image data in computer vision deep learning
environments.</p>
      <p>
        DP1 draws from AD1 and states that ethical guidelines and principles should be followed when
generating and utilizing synthetic image data. Incorporating value sensitive design [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ], it is
important to align data generation processes with privacy regulations and to show respect for
individual privacy rights. Therefore, care should be taken to employ suitable data generation
techniques (e.g. via Unity3D) and to refrain from incorporating sensitive information or biases
that could potentially compromise the privacy or security of individuals.
      </p>
      <p>
        DP2 also builds on AD1 and addresses the need for the synthetic image data to contain no
personally identifiable information (PII) or sensitive data. It's necessary to anonymize or
obfuscate any elements that could potentially reveal an individual's identity. Throughout the
process of using synthetic imagery, regular privacy impact assessments should be conducted to
assess the privacy risks associated with the generation, storage, transmission, and use of the data.
Appropriate measures should then be implemented to mitigate the identified risks and ensure
ongoing compliance with privacy regulations, thus aligning with value sensitive design [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. In
this regard, it is recommended that differential privacy mechanisms be incorporated into the
generation and use of synthetic image data, where controlled noise or perturbations are
introduced during data generation to prevent individual data points from being distinguished
with a high degree of certainty [
        <xref ref-type="bibr" rid="ref3 ref4">3, 4</xref>
        ]. This approach can protect the privacy of individuals even in
the presence of external information.
      </p>
      <p>
        Based on AD2, DP3 states that mechanisms should be implemented to control and regulate the
generation of synthetic image data, such as process frameworks, toolkits, virtual environments,
or guidelines. Hence, policies and procedures need to be established to govern the creation, usage,
and distribution of synthetic data in order to prevent unauthorized access or misuse, ensuring
value sensitive design [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ].
      </p>
      <p>
        DP4 stems from AD3 and specifies that a wide range of diverse and random elements should
be incorporated into synthetic scenes, including textures, backgrounds, and objects. By varying
these factors, the model will be encouraged to learn relevant object characteristics instead of
relying on color or other irrelevant cues [
        <xref ref-type="bibr" rid="ref3 ref33">33, 3</xref>
        ]. To further improve generalization, cross-domain
scene randomization should be used, which involves incorporating scene elements from different
domains or contexts (e.g., non-healthcare elements in healthcare settings). Introducing
unconventional backgrounds, objects, or textures that are not typically associated with the
objects of interest can push the model to learn their intrinsic properties, thereby promoting
adaptability to real-world scenarios [
        <xref ref-type="bibr" rid="ref28 ref3">3, 28</xref>
        ].
      </p>
      <p>
        DP5 closely connects to DP4 and further relates to AD3, stating that while aiming to promote
scene diversity (and randomness), it is important to maintain a level of control over the
composition of synthetic scenes. This ensures that the intended features and factors of interest
are properly represented where factors such as object scale, orientation, and spatial relationships
should be considered to enhance generalization [
        <xref ref-type="bibr" rid="ref33 ref6">6, 33</xref>
        ]. Rather than relying solely on changing
the appearance of objects, the focus should be on varying their key features, and changing
attributes such as shape, size, material properties, and structural characteristics will challenge
the model to learn object representations based on these relevant factors rather than superficial
visual cues.
      </p>
      <p>
        DP6 draws from AD4 and addresses the gradual introduction of synthetic scenes with
increasing complexity. Training the deep learning model should begin with simpler scenes that
highlight objects and factors of interest more prominently, and gradually incorporate additional
elements to prevent overwhelming the model [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] . This approach helps prevent overfitting and
encourages the model to learn robust and generalizable representations, which is highly relevant
when working with synthetic rather than real data [
        <xref ref-type="bibr" rid="ref29 ref3 ref5">5, 3, 29</xref>
        ].
      </p>
      <p>
        DP7 also stems from AD4 and states that augmentation techniques, such as geometric
transformations, color modifications, and noise addition, should be utilized to enhance the
diversity of synthetic scenes [
        <xref ref-type="bibr" rid="ref3 ref31 ref4">31, 3, 4</xref>
        ]. These techniques simulate real-world variations and assist
the model in learning robust representations that remain invariant to such transformations,
which further mitigates the risk of model overfitting [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] .
      </p>
    </sec>
    <sec id="sec-5">
      <title>5. Evaluation</title>
      <p>
        To ensure scientific rigor in the evaluation of this design cycle, the well-established FEDS
framework proposed by Venable et al. [37] was used. the evaluation phase is highly relevant in
design science research [
        <xref ref-type="bibr" rid="ref11">11, 37</xref>
        ], it is necessary to select an appropriate strategic process and
determine the constructs to be evaluated. Given the small and rather simple design of the main
artifact, embodied in a set of design principles that result in low social and technical risk and
uncertainty, the evaluation strategy of quick &amp; simple [37] was chosen. Thus, the goal was to
conduct an evaluation episode to complete the design cycle and to move quickly to a summative
evaluation. The evaluation schema employed in this study takes into account the roles of key
stakeholders involved the formulation of design principles. This schema allows design science
researchers to assess the usability of generated design principles for different user groups. Two
critical questions arise from this perspective: first, whether the design principles are
understandable and useful to implementers, and second, whether they effectively serve the goals
of users who implement the resulting instantiations [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ]. Therefore, evaluation activity 2 [38] was
used, which describes an artificial activity, since the artifact has not yet been properly
instantiated (note that Figure 4 serves only as an exemplary visualization). This activity aims to
validate the principles of form and function, which have been developed during the design cycle
[38].
      </p>
      <sec id="sec-5-1">
        <title>Reusability Category</title>
        <p>Accessibility
Importance
Novelty and
Insightfulness
Actability and</p>
        <p>Guidance
Effectiveness</p>
      </sec>
      <sec id="sec-5-2">
        <title>Verbalized Think Aloud Results</title>
        <p>The participants stated that they found the design principles to be highly
accessible, emphasizing the clarity and understandability of the language used.</p>
        <p>Particularly in terms of privacy and data protection (DP1, DP2, DP3), the
participants recognized the importance of practitioners being able to
comprehend and implement these principles effectively, ensuring ethical and
privacy-compliant use of synthetic image data.</p>
        <p>However, participants noted that while the design principles presented were
well constructed, there was a suggestion to consider including explanations for
technical terms such as "differential privacy mechanisms". They mentioned
that providing brief definitions for such terms could help readers who may not
be deeply familiar with the field to better understand the content.</p>
        <p>The participants also highlighted the significant importance of the design
principles. They acknowledged that these principles addressed crucial concerns
related to privacy, data anonymization, information security, and regulatory
compliance (DP1, DP2, DP3). By incorporating these principles into deep
learning environments, the participants emphasized the practical relevance
and significance of adhering to them, fostering trust and responsible use of
synthetic image data.</p>
        <p>The participants expressed their appreciation for the design principles, stating
that they introduced fresh perspectives to the generation and utilization of
synthetic image data.</p>
        <p>The emphasis on diversity and randomness in scene composition, the
incorporation of unconventional elements, and cross-domain randomization
were noted as innovative approaches (DP4, DP5). According to the participants,
these principles challenged traditional methods and encouraged thinking
beyond the conventional, promoting adaptability to real-world scenarios.</p>
        <p>The participants commended the actability and appropriate guidance provided
by the design principles. They highlighted the clear frameworks, policies, and
mechanisms suggested to regulate the generation and usage of synthetic image
data (DP3). The participants found the gradual introduction of complexity
during training and the utilization of augmentation techniques as practical
suggestions aligned with their deep learning workflows (DP6, DP7). The
guidance provided struck a balance between providing direction and allowing
for creative application of the principles.</p>
        <p>The effectiveness of the design principles was evident to the participants. They
recognized the emphasis on preventing privacy risks (DP1, DP2), mitigating
overfitting, and enhancing model generalization (DP4, DP5, DP6, DP7). By
adhering to these principles, the participants noted that robust deep learning
models could be developed, yielding high performance on real-world data.</p>
        <p>They found the strategies of gradually introducing complexity (DP6) and using
augmentation techniques (DP7) to be effective in optimizing performance and
ensuring the practical utility of synthetic image data.</p>
        <p>However, participants expressed that while the concepts of DP6 and DP7 were
intriguing, they suggested that a comparative analysis be included which could
contrast the proposed principles with existing methodologies and highlight the
unique advantages and improvements.</p>
        <p>
          To ensure the objectives of feasibility, accessibility, completeness, and applicability, it seems
reasonable to apply the framework of design principle reusability proposed by Iivari et al. [39].
This framework provides a systematic approach to evaluating the design principles generated
during the design cycle and, by assessing the reusability of these principles, researchers can
determine their potential for wider application and adoption in similar contexts [39]. For this
purpose, and in accordance to the kernel theory of value sensitive design [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ], a qualitative think
aloud session addressing the reusability of the proposed design principles was conducted.
Therefore, the method of concurrent think-aloud [40] was employed with n=9 AI experts, where
the sample size was decided based on the “10±2 rule” for think aloud sessions [41]. The
participants were asked to verbalize their thoughts about the design principles in terms of the
reusability categories proposed by Iivari et al. [39]. The experts were provided with a detailed
textual description of the design principles, along with visual examples of synthetic image data.
Table 1 presents the qualitative think aloud results, including the categories of the reusability
framework and the clustered verbalized thoughts of the participants.
        </p>
        <p>Overall, the participants of the think aloud session positively evaluated the design principles,
emphasizing their accessibility, importance, novelty and insightfulness, actability with
appropriate guidance, and overall effectiveness in enhancing the use of synthetic image data in
deep learning environments. Their feedback underscored the value and especially the reusability
of these principles in guiding practices and ensuring responsible and efficient utilization of
synthetic image data in deep learning. Nonetheless, a few areas for improvement have been
identified by the participants. However, a number of potential areas for refinement emerged from
their constructive feedback. Participants noted that while the structure of the design principles
was commendable, they suggested that clarifications of technical terms such as "Differential
Privacy Mechanisms" could be included. It was suggested that providing concise definitions for
these terms could serve to help readers or researchers less familiar with the field to better
understand the content. In addition, participants expressed the notion that despite the appeal of
DP6 (Gradual Complexity Increase) and DP7 (Data Augmentation), it might be prudent to
introduce a comparative analysis that could compare the proposed principles with existing
methodologies, thereby highlighting their particular merits and improvements. These
suggestions for refinement, which come from the participants and should be picked up in
subsequent design science cycles, are intended to increase the accessibility and effectiveness of
the design principles, serve a wider range of readers, and further substantiate their utility.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>6. Conclusion</title>
      <p>
        The paper proposes general design principles for the use of synthetic image data in computer
vision deep learning environments to ensure more ethical, robust, traceable, and effective
development and implementation of such models. Consequently, to answer the initially
formulated research question of this paper, the results of a completed design science research
cycle have been presented. Hereby, the positive evaluation of the design principles substantiates
the theoretical and practical relevance of the design principles and researchers can adapt these
to develop, utilize, or modify deep learning models based on synthetic image data. By using the
DSR paradigm [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ], the study moves beyond descriptive knowledge and aims to provide
prescriptive knowledge, focusing on the design principles for utilizing synthetic image data in
deep learning. This integration of the design science research paradigm contributes to the
advancement of design knowledge in the field along with the IS design science knowledge base
according to Woo et al. [42]. The paper also contributes theoretically by employing the value
sensitive design theory, as proposed by Friedman et al. [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ], which enhances the understanding
of the ethical implications and user values in the context of synthetic image data utilization. The
practical implications of these design principles include improved performance, enhanced
privacy protection, and responsible and efficient utilization of synthetic image data in real-world
applications, while the reusability of these principles in similar contexts contributes to their
wider application and adoption, promoting responsible and efficient utilization of synthetic
image data in computer vision.
      </p>
      <p>
        Meanwhile, in the context of the positive evaluation episode, the following limitations should
be considered: First, design principles and their development are tied to the subjective creativity
of the researcher, even after various data collection episodes and literature reviews. However,
not all design decisions can or should be derived from behavioral or mathematical theories, as
some degree of creativity is essential to developing an innovative design artifact [43, 44], whereas
a certain degree of rigor can be implemented such as the utilized methodological approaches of
Gregor et al. [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ], Möller et al. [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ], or Fu et al. [36]. Second, as with any other evaluation, the
results describe only one sample, meaning that different results could be expected if a different
sample were chosen. Therefore, this particular limitation could be addressed in future research,
while the application of the design principles (in various domains such as digital health, etc.) as
part of a case study or framing guideline seems highly interesting. It would be presumptuous to
assume that the design principles contain all the necessary information that will need to be either
refined, adapted, or expanded in future research efforts. Moreover, the highlighted areas for
improvement of the design principles based on the reusability framework could be addressed in
a subsequent design science cycle and future research.
[36] K.K. Fu, M.C. Yang, K.L. Wood, Design principles: Literature review, analysis, and future
directions. Journal of Mechanical Design, 138(10), 2016, 101103.
[37] J. Venable, J. Pries-Heje, R. Baskerville, FEDS: a framework for evaluation in design science
research. European Journal of Information Systems, 25 (2016), 77-89.
[38] C. Sonnenberg, J. Vom Brocke, Evaluation patterns for design science research artefacts, in
Practical Aspects of Design Science: European Design Science Symposium (2012), Leixlip,
Ireland, 71-83.
[39] J. Iivari, M.R.P. Hansen, A. Haj-Bolouri, A framework for light reusability evaluation of design
principles in design science research, in 13th International Conference on Design Science
Research and Information Systems and Technology: Designing for a Digital and Globalized
World, 2018.
[40] M. Van Den Haak, M. De Jong, P. Jan Schellens, Retrospective vs. concurrent think-aloud
protocols: testing the usability of an online library catalogue. Behaviour &amp; Information
Technology (2003), 22(5):339-351.
[41] W. Hwang, G. Salvendy, Number of people required for usability evaluation: the 10±2 rule.
      </p>
      <p>Communications of the ACM (2010) 53(5):130-133.
[42] C. Woo, A. Saghafi, A. Rosales, What is a Contribution to IS Design Science Knowledge?, in</p>
      <p>Thirty Fifth International Conference on Information Systems, 2014, Auckland.
[43] A. Hevner, S. Chatterjee, Design science research in information systems, Design research in
information systems, 2010, Springer, Boston, 9-22.
[44] R. Baskerville, M. Kaul, J. Pries-Heje, V.C. Storey, E. Kristiansen, Bounded creativity in design
science research, in ICIS 2016 Proceedings.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>L.</given-names>
            <surname>Alzubaidi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Zhang</surname>
          </string-name>
          , et al.,
          <article-title>Review of deep learning: Concepts, CNN architectures, challenges, applications, future directions</article-title>
          ,
          <source>Journal of Big Data</source>
          <volume>8</volume>
          (
          <year>2021</year>
          ),
          <fpage>1</fpage>
          -
          <lpage>74</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <given-names>S.</given-names>
            <surname>Hinterstoisser</surname>
          </string-name>
          ,
          <string-name>
            <given-names>O.</given-names>
            <surname>Pauly</surname>
          </string-name>
          et al.,
          <article-title>An annotation saved is an annotation earned: Using fully synthetic training for object detection in 'Proceedings of</article-title>
          the IEEE/CVF'(
          <year>2019</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>V.</given-names>
            <surname>Seib</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Lange</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Wirtz</surname>
          </string-name>
          , Mixing Real and
          <article-title>Synthetic Data to Enhance Neural Net-work Training -</article-title>
          A
          <source>Review of Current Approaches</source>
          ,
          <year>2020</year>
          , arXiv:
          <year>2007</year>
          .08781.
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>X.</given-names>
            <surname>Zhang</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Y.</given-names>
            <surname>Fu</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Jiang</surname>
          </string-name>
          ,
          <string-name>
            <given-names>X.</given-names>
            <surname>Xue</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Y.G.</given-names>
            <surname>Jiang</surname>
          </string-name>
          , G. Agam,
          <article-title>Stacked multichannel autoencoder-an efficient way of learning from synthetic data</article-title>
          .
          <source>Multimedia Tools and Applications</source>
          <volume>77</volume>
          (
          <year>2018</year>
          ),
          <fpage>26563</fpage>
          -
          <lpage>26580</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>J.J.</given-names>
            <surname>Bird</surname>
          </string-name>
          ,
          <string-name>
            <given-names>D.R.</given-names>
            <surname>Faria</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Ekárt</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.P.</given-names>
            <surname>Ayrosa</surname>
          </string-name>
          ,
          <article-title>From simulation to reality: CNN transfer learning for scene classification</article-title>
          ,
          <source>in 2020 IEEE 10th International Conference on Intelligent Systems</source>
          (
          <year>2020</year>
          ), IEEE,
          <fpage>619</fpage>
          -
          <lpage>625</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <given-names>M.</given-names>
            <surname>Krump</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.</given-names>
            <surname>Ruß</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Stütz</surname>
          </string-name>
          ,
          <article-title>Deep learning algorithms for vehicle detection on UAV platforms: first investigations on the effects of synthetic training</article-title>
          ,
          <source>in Modelling and Simulation for Autonomous Systems: 6th International Conference, MESAS</source>
          <year>2020</year>
          , Palermo, Italy,
          <fpage>50</fpage>
          -
          <lpage>70</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>F.</given-names>
            <surname>Kuhnke</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Ostermann</surname>
          </string-name>
          ,
          <article-title>Deep head pose estimation using synthetic images and partial adversarial domain adaption for continuous label spaces</article-title>
          ,
          <source>in Proceedings of the IEEE/CVF International Conference on computer vision</source>
          (
          <year>2019</year>
          ),
          <fpage>10164</fpage>
          -
          <lpage>10173</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [8]
          <string-name>
            <given-names>J.</given-names>
            <surname>Liu</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Rahmani</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Akhtar</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Mian</surname>
          </string-name>
          ,
          <article-title>Learning human pose models from synthesized data for robust RGB-D action recognition</article-title>
          .
          <source>International Journal of Computer Vision</source>
          <volume>127</volume>
          (
          <year>2019</year>
          ),
          <fpage>1545</fpage>
          -
          <lpage>1564</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [9]
          <string-name>
            <given-names>C.</given-names>
            <surname>Taleb</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Likforman-Sulem</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Mokbel</surname>
          </string-name>
          ,
          <article-title>Improving deep learning Parkinson's disease detection through data augmentation training</article-title>
          ,
          <source>in Pattern Recognition and Artificial Intelligence: Third Mediterranean Conference, MedPRAI</source>
          ,
          <year>2020</year>
          , Istanbul, Turkey,
          <fpage>79</fpage>
          -
          <lpage>93</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [10]
          <string-name>
            <given-names>A.</given-names>
            <surname>Hevner</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>March</surname>
          </string-name>
          , J. Park, S. Ram,
          <article-title>Design science in information systems re-search</article-title>
          ,
          <source>MIS Quarterly 28(1)</source>
          (
          <year>2004</year>
          ),
          <fpage>75</fpage>
          -
          <lpage>105</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [11]
          <string-name>
            <given-names>V.K.</given-names>
            <surname>Vaishnavi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>W.</given-names>
            <surname>Kuechler</surname>
          </string-name>
          ,
          <article-title>Design science research methods and patterns: innovating information</article-title>
          and communication technology,
          <year>2015</year>
          , Crc Press.
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          [12]
          <string-name>
            <given-names>B.</given-names>
            <surname>Friedman</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.H.</given-names>
            <surname>Kahn</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Borning</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Huldtgren</surname>
          </string-name>
          ,
          <article-title>Value sensitive design and information systems. Early engagement and new technologies: Opening up the laboratory</article-title>
          ,
          <year>2013</year>
          ,
          <fpage>55</fpage>
          -
          <lpage>95</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [13]
          <string-name>
            <given-names>S.</given-names>
            <surname>Gregor</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.R.</given-names>
            <surname>Hevner</surname>
          </string-name>
          ,
          <article-title>Positioning and presenting design science research for maximum impact</article-title>
          .
          <source>MIS Quarterly</source>
          (
          <year>2013</year>
          ),
          <fpage>337</fpage>
          -
          <lpage>355</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [14]
          <string-name>
            <given-names>J.</given-names>
            <surname>Mingers</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Brocklesby</surname>
          </string-name>
          , Multimethodology:
          <article-title>Towards a framework for mixing methodologies</article-title>
          .
          <source>Omega</source>
          ,
          <volume>25</volume>
          (
          <issue>5</issue>
          ),
          <year>1997</year>
          ,
          <fpage>489</fpage>
          -
          <lpage>509</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          [15]
          <string-name>
            <given-names>J.R.</given-names>
            <surname>Venable</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Pries-Heje</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.L.</given-names>
            <surname>Baskerville</surname>
          </string-name>
          ,
          <article-title>Choosing a design science research methodology in ACIS 2017 Proceedings</article-title>
          ,
          <year>2017</year>
          ,
          <volume>112</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          [16]
          <string-name>
            <given-names>K.</given-names>
            <surname>Durani</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Eckhardt</surname>
          </string-name>
          , T. Kollmer,
          <source>Towards ethical design science research in ICIS 2021 Proceedings</source>
          ,
          <year>2021</year>
          ,
          <volume>3</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          [17]
          <string-name>
            <given-names>R.</given-names>
            <surname>Baskerville</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Pries-Heje</surname>
          </string-name>
          ,
          <article-title>Explanatory design theory</article-title>
          .
          <source>Business &amp; Information Systems Engineering</source>
          ,
          <volume>2</volume>
          (
          <year>2010</year>
          ),
          <fpage>271</fpage>
          -
          <lpage>282</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          [18]
          <string-name>
            <given-names>S.</given-names>
            <surname>Gregor</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L. Chandra</given-names>
            <surname>Kruse</surname>
          </string-name>
          , S. Seidel,
          <article-title>Research perspectives: the anatomy of a design principle</article-title>
          .
          <source>Journal of the Association for Information Systems</source>
          ,
          <year>2020</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          [19]
          <string-name>
            <given-names>F.</given-names>
            <surname>Möller</surname>
          </string-name>
          ,
          <string-name>
            <given-names>T.</given-names>
            <surname>Schoormann</surname>
          </string-name>
          , G. Strobel,
          <string-name>
            <given-names>M.R.P.</given-names>
            <surname>Hansen</surname>
          </string-name>
          , Unveiling the Cloak:
          <source>Kernel Theory Use in Design Science Research in ICIS 2022 Proceedings</source>
          ,
          <year>2022</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          [20]
          <string-name>
            <given-names>F.</given-names>
            <surname>Niederman</surname>
          </string-name>
          ,
          <string-name>
            <surname>S. March,</surname>
          </string-name>
          <article-title>The “theoretical lens” concept: We all know what it means, but do we all know the same thing? Communications of the Association for Information Systems</article-title>
          ,
          <volume>44</volume>
          (
          <issue>1</issue>
          ),
          <year>2019</year>
          ,
          <volume>1</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation>
          [21]
          <string-name>
            <given-names>S.</given-names>
            <surname>Lee</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Park</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Kim</surname>
          </string-name>
          ,
          <article-title>Deep learning based object detection via style-transferred underwater sonar images</article-title>
          .
          <source>IFAC-PapersOnLine</source>
          ,
          <volume>52</volume>
          (
          <issue>21</issue>
          ),
          <year>2019</year>
          ,
          <fpage>152</fpage>
          -
          <lpage>155</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation>
          [22]
          <string-name>
            <given-names>T.</given-names>
            <surname>Body</surname>
          </string-name>
          ,
          <string-name>
            <given-names>X.</given-names>
            <surname>Tao</surname>
          </string-name>
          ,
          <string-name>
            <given-names>Y.</given-names>
            <surname>Li</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Li</surname>
          </string-name>
          ,,
          <string-name>
            <given-names>N.</given-names>
            <surname>Zhong</surname>
          </string-name>
          ,
          <article-title>Using back-and-forth translation to create artificial augmented textual data for sentiment analysis models</article-title>
          .
          <source>Expert Systems with Applications</source>
          ,
          <volume>178</volume>
          ,
          <year>2021</year>
          ,
          <volume>115033</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation>
          [23]
          <string-name>
            <given-names>F.</given-names>
            <surname>Condrea</surname>
          </string-name>
          ,
          <string-name>
            <given-names>V.A.</given-names>
            <surname>Ivan</surname>
          </string-name>
          ,
          <string-name>
            <surname>M.</surname>
          </string-name>
          <article-title>Leordeanu, In search of life: Learning from synthetic data to detect vital signs in videos</article-title>
          ,
          <source>in Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops</source>
          ,
          <year>2020</year>
          ,
          <fpage>298</fpage>
          -
          <lpage>299</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation>
          [24]
          <string-name>
            <given-names>H.F.</given-names>
            <surname>Zaki</surname>
          </string-name>
          ,
          <string-name>
            <given-names>F.</given-names>
            <surname>Shafait</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Mian</surname>
          </string-name>
          ,
          <article-title>Viewpoint invariant semantic object and scene categorization with RGB-D sensors</article-title>
          . Autonomous Robots,
          <volume>43</volume>
          (
          <year>2019</year>
          ),
          <fpage>1005</fpage>
          -
          <lpage>1022</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation>
          [25]
          <string-name>
            <given-names>A.</given-names>
            <surname>Lahiri</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Agarwalla</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.K.</given-names>
            <surname>Biswas</surname>
          </string-name>
          ,
          <article-title>Unsupervised domain adaptation for learning eye gaze from a million synthetic images: An adversarial approach</article-title>
          ,
          <source>in Proceedings of the 11th Indian Conference on Computer Vision</source>
          (
          <year>2018</year>
          ),
          <source>Graphics and Image Processing</source>
          ,
          <fpage>1</fpage>
          -
          <lpage>9</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation>
          [26]
          <string-name>
            <given-names>H.</given-names>
            <surname>Venkateswara</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Chakraborty</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>Panchanathan</surname>
          </string-name>
          ,
          <article-title>Deep-learning systems for domain adaptation in computer vision: Learning transferable feature representations</article-title>
          .
          <source>IEEE Signal Processing Magazine</source>
          ,
          <volume>34</volume>
          (
          <issue>6</issue>
          ),
          <year>2017</year>
          ,
          <fpage>117</fpage>
          -
          <lpage>129</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref27">
        <mixed-citation>
          [27]
          <string-name>
            <given-names>N.</given-names>
            <surname>Aranjuelo</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.</given-names>
            <surname>García</surname>
          </string-name>
          ,
          <string-name>
            <given-names>E.</given-names>
            <surname>Loyo</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Unzueta</surname>
          </string-name>
          ,
          <string-name>
            <given-names>O.</given-names>
            <surname>Otaegui</surname>
          </string-name>
          ,
          <article-title>Key strategies for synthetic data generation for training intelligent systems based on people detection from omnidirectional cameras</article-title>
          .
          <source>Computers &amp; Electrical Engineering</source>
          ,
          <volume>92</volume>
          (
          <year>2021</year>
          ),
          <fpage>107105</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref28">
        <mixed-citation>
          [28]
          <string-name>
            <given-names>S.Z.</given-names>
            <surname>Valtchev</surname>
          </string-name>
          , J. Wu,
          <article-title>Domain randomization for neural network classification</article-title>
          .
          <source>Journal of big Data</source>
          ,
          <volume>8</volume>
          (
          <issue>1</issue>
          ),
          <year>2021</year>
          ,
          <volume>94</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref29">
        <mixed-citation>
          [29]
          <string-name>
            <given-names>L.</given-names>
            <surname>Wan</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Zhou</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Zhang</surname>
          </string-name>
          ,
          <article-title>Data Synthesis for Document Layout Analysis</article-title>
          ,
          <source>in International Symposium on Emerging Technologies for Education</source>
          ,
          <year>2020</year>
          ,
          <fpage>244</fpage>
          -
          <lpage>252</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref30">
        <mixed-citation>
          [30]
          <string-name>
            <given-names>H.</given-names>
            <surname>Abu Alhaija</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.K.</given-names>
            <surname>Mustikovela</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Mescheder</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Geiger</surname>
          </string-name>
          ,
          <string-name>
            <given-names>C.</given-names>
            <surname>Rother</surname>
          </string-name>
          ,
          <article-title>Augmented reality meets computer vision: Efficient data generation for urban driving scenes</article-title>
          .
          <source>International Journal of Computer Vision</source>
          ,
          <volume>126</volume>
          ,
          <year>2018</year>
          ,
          <fpage>961</fpage>
          -
          <lpage>972</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref31">
        <mixed-citation>
          [31]
          <string-name>
            <given-names>M.</given-names>
            <surname>Müller</surname>
          </string-name>
          ,
          <string-name>
            <given-names>V.</given-names>
            <surname>Casser</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J.</given-names>
            <surname>Lahoud</surname>
          </string-name>
          ,
          <string-name>
            <given-names>N.</given-names>
            <surname>Smith</surname>
          </string-name>
          ,
          <string-name>
            <surname>B. Ghanem,</surname>
          </string-name>
          <article-title>Sim4cv: A photo-realistic simulator for computer vision applications</article-title>
          .
          <source>International Journal of Computer Vision</source>
          ,
          <volume>126</volume>
          ,
          <year>2018</year>
          ,
          <fpage>902</fpage>
          -
          <lpage>919</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref32">
        <mixed-citation>
          [32]
          <string-name>
            <given-names>M.</given-names>
            <surname>Valerio Giuffrida</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Scharr</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S.A.</given-names>
            <surname>Tsaftaris</surname>
          </string-name>
          , Arigan:
          <article-title>Synthetic arabidopsis plants using generative adversarial network</article-title>
          ,
          <source>in Proceedings of the IEEE international conference on computer vision workshops</source>
          ,
          <year>2017</year>
          ,
          <fpage>2064</fpage>
          -
          <lpage>2071</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref33">
        <mixed-citation>
          [33]
          <string-name>
            <given-names>T.</given-names>
            <surname>Scheck</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.</given-names>
            <surname>Seidel</surname>
          </string-name>
          ,
          <string-name>
            <surname>G.</surname>
          </string-name>
          <article-title>Hirtz, Learning from theodore: A synthetic omnidirectional top-view indoor dataset for deep transfer learning</article-title>
          ,
          <source>in Proceedings of the IEEE/CVF Winter conference on applications of computer vision</source>
          (
          <year>2020</year>
          ),
          <fpage>943</fpage>
          -
          <lpage>952</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref34">
        <mixed-citation>
          [34]
          <string-name>
            <given-names>D.L.</given-names>
            <surname>Morgan</surname>
          </string-name>
          , Qualitative Research Methods:
          <article-title>Focus groups as qualitative research (2</article-title>
          ),
          <year>1997</year>
          , Thousand Oaks SAGE Publications, Inc.
        </mixed-citation>
      </ref>
      <ref id="ref35">
        <mixed-citation>
          [35]
          <string-name>
            <given-names>D.A.</given-names>
            <surname>Gioia</surname>
          </string-name>
          ,
          <string-name>
            <given-names>K.G.</given-names>
            <surname>Corley</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.L.</given-names>
            <surname>Hamilton</surname>
          </string-name>
          ,
          <article-title>Seeking qualitative rigor in inductive research: Notes on the Gioia methodology</article-title>
          .
          <source>Organizational research methods</source>
          ,
          <volume>16</volume>
          (
          <issue>1</issue>
          ),
          <year>2012</year>
          ,
          <fpage>15</fpage>
          -
          <lpage>31</lpage>
          .
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>