<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Topic and Sentiment Analysis for Understanding Territorial Identity: A Case Study of the Lower Aosta Valley</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Consuelo Rubina Nava</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Alessandro Riccardo Novallet</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Stefano Tedeschi</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Università della Valle d'Aosta - Université de la Vallée d'Aoste</institution>
          ,
          <addr-line>Aosta</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>This paper investigates how natural language processing and machine learning techniques can shed light on the evolving identity of marginal territories. Focusing on the case study of the Lower Aosta Valley (Italy), a mountain region shifting from an industrial to a tourism-based economy, we propose a methodology to analyze two complementary sources of qualitative data: stakeholder interviews and user-generated accommodation reviews. By leveraging topic modeling and sentiment analysis, we uncover not only the main thematic narratives linked to the area but also a clear emotional divide between internal and external perspectives. Local stakeholders often voice concern and skepticism, while visitors express high levels of satisfaction and appreciation. By quantifying these divergences, the study highlights how AI-enabled textual analysis can reveal structured insights from unstructured data, capturing the multi-actor, dynamic nature of place identity. Beyond the case study, the work demonstrates the potential of computational methods to inform inclusive, data-driven approaches to regional development. Future research will involve expanding and diversifying the dataset to support more robust territorial monitoring over time.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Sentiment analysis</kwd>
        <kwd>Topic analysis</kwd>
        <kwd>Qualitative data</kwd>
        <kwd>Lower Aosta Valley</kwd>
        <kwd>Mountain region</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        In geographical and territorial studies, identity is often defined as the set of human, institutional,
economic, and socio-cultural elements that characterize a specific area and support its development
potential [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Traditionally considered a static attribute linked to tangible resources, identity is
increasingly understood as a dynamic and evolving process, co-constructed through the continuous
interaction between local communities and their environment [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. Within this evolving framework, the
role of data-driven approaches is becoming increasingly relevant for capturing complex, multi-actor
perspectives on territorial transformation [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>
        Mainstream literature still relies on traditional models, often overlooking the impact of co-creation
and digital technologies [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. Therefore there is an urgency for a renewed framework that integrates data
analytics into the brand-building process [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] to reconceptualize brand identity as a dynamic, co-created
construct shaped by multiple stakeholders [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>This study advances the debate by stressing the strategic role of data-driven approaches in identifying
and building a brand identity, leveraging digital insights to understand and guide stakeholder interactions
and enhance territorial uniqueness. To this aim, we apply computational tools to a case study related
to the identity of the Lower Aosta Valley (LAV), a peripheral area in northwestern Italy. This area is
particularly interesting as a case study given that it is currently transitioning from an industrial past
toward a more tourism-oriented future. Despite its vulnerabilities, the LAV features a unique blend of
cultural, natural, and historical resources. However, its identity remains fragmented and still in the
process of being defined, particularly in light of its recent economic and functional transformations.</p>
      <p>
        To address this complexity, we analyze two text-based data sources - interviews with local stakeholders
and user-generated accommodation reviews - using topic modeling [
        <xref ref-type="bibr" rid="ref7 ref8">7, 8</xref>
        ] and sentiment analysis [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ].
2nd Workshop “New frontiers in Big Data and Artificial Intelligence” (BDAI 2025), May 29-30, 2025, Aosta, Italy
* Corresponding author.
†These authors contributed equally.
$ c.nava@univda.it (C. R. Nava); a.novallet@univda.it (A. R. Novallet); s.tedeschi@univda.it (S. Tedeschi)
0000-0002-8046-8185 (C. R. Nava); 0009-0002-1068-9270 (A. R. Novallet); 0000-0002-9861-390X (S. Tedeschi)
© 2025 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
      </p>
      <p>These methods, grounded in machine learning and statistical inference, enable the extraction of latent
themes and emotional tones at scale. By applying these AI-driven techniques to a geographically
contextualized problem, we aim to ofer new methodological insights into how territorial identity can
be empirically investigated through unstructured textual data.</p>
      <p>The paper is organized as follows. Section 2 introduces the adopted computational methodology, with
an emphasis on topic and sentiment analysis. Section 3 outlines the socio-spatial context of the LAV
while Section 4 presents the data sources. Section 5 discusses the main results, highlighting perception
gaps and thematic patterns. Section 6 concludes by summarizing key insights and outlining directions
for future interdisciplinary research at the intersection of AI and territorial studies.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Methodology</title>
      <p>The methodology adopted in this study, summarized in Figure 1, is grounded in the analysis of qualitative
data, drawing on two complementary sources: in-depth interviews with residents and textual reviews
posted by visitors on hospitality platforms such as Booking.com. This dual approach, originally
conceived by the authors, allows us to capture both the internal perspective of those who inhabit the
territory daily and the external gaze of those who experience it temporarily. In doing so, we are able to
explore the multifaceted and often contrasting ways in which place identity is constructed, perceived,
and narrated.</p>
      <p>Qualitative data ofers a privileged lens through which to examine the symbolic and emotional
dimensions of place attachment, revealing expectations, memories, criticisms, and aspirations that
are not easily measurable through quantitative indicators. To process these rich and unstructured
narratives, we apply computational methods designed for textual analysis, namely topic modeling and
sentiment analysis. These techniques enable us to detect underlying thematic patterns and emotional
tones across large corpora of text, providing both a structured representation of prevalent discourses
and a nuanced reading of how individuals relate to the territory.</p>
      <p>By combining human interpretation with automated analysis, this methodology ofers a robust
and flexible tool for investigating territorial identity in contexts marked by complexity, diversity, and
evolving perceptions. It proves especially useful in uncovering tensions, shared values, and latent
opportunities that might otherwise remain invisible in traditional branding or policy approaches. To
this aim, we propose two diferent approaches resting on topic and sentiment analysis of these type of
data.</p>
      <sec id="sec-2-1">
        <title>2.1. Topic analysis</title>
        <p>
          To uncover dominant themes, we applied topic modeling techniques, which enable the extraction of
latent semantic structures from large collections of text. We began by transforming the textual data
using the Term Frequency–Inverse Document Frequency (TF-IDF) method, a statistical measure that
evaluates the importance of words relative to the entire corpus [
          <xref ref-type="bibr" rid="ref7">7</xref>
          ]. Given a document collection , a
word  and a document  ∈ :
        </p>
        <p>TF-IDF (, , ) = , · log
︂(
|| )︂
,</p>
        <p>(1)
(2)
where , represents the term frequency of  in the document , || is the cardinality of the corpus and
, the number of documents in which  appears. This representation allows for a more informative
weighting of terms by downplaying frequently occurring but less meaningful words.</p>
        <p>
          Following this, we employed Non-negative Matrix Factorization (NMF), a dimensionality reduction
algorithm well-suited for topic modeling [
          <xref ref-type="bibr" rid="ref8">8</xref>
          ]. NMF factorizes the term-document matrix into two
lower-dimensional matrices:
        </p>
        <p>≈  
where  is the TF-IDF matrix,  represents the term-topic associations, and  captures the
topicdocument relationships. Each topic is thus represented by a distribution over terms that frequently
co-occur, allowing us to interpret key semantic clusters in the data. Rather than assigning topics to
individual documents, our analysis focused on interpreting the most salient topics overall, with the aim
of identifying central themes and recurring narratives that characterize the discourse on the LAV area.</p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Sentiment analysis</title>
        <p>To complement the structural insights provided by topic analysis, we conducted sentiment analysis to
assess the emotional tone of the textual data. This technique, grounded in natural language processing,
allows us to determine whether a given text expresses a positive, negative, or neutral sentiment - thereby
shedding light on public attitudes, perceptions, and afective orientations.</p>
        <p>
          To carry out the analysis, we employed the bert-base-multilingual-uncased-sentiment model [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ],
a pre-trained variant of the BERT architecture that has been fine-tuned for multilingual sentiment
classification. The model processes text in a context-aware manner, using 12 transformer layers
and attention mechanisms to capture subtle emotional cues and linguistic nuances. Text inputs are
automatically lowercased to reduce variability linked to capitalization [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ]. The output consists of five
sentiment scores, ranging from very negative to very positive, which allows for a detailed mapping of
the emotional tone across diferent contributions. This makes it possible to detect patterns in how the
LAV area is discussed, revealing prevailing moods, emotional contrasts, and potential tensions or points
of appreciation.
        </p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. The case study</title>
      <p>We choose as a case study for our methodological proposal the LAV which is a small but distinct area
within the Aosta Valley, an autonomous alpine region located in northwestern Italy.</p>
      <p>The interest behind the LAV rests on the fact that it is undergoing an economic transition. Compared
to the rest of the region, largely oriented toward tourism, the LAV has traditionally been the most
industrialized area of the Aosta Valley. While the industrial sector has declined, the area is starting
to look toward tourism as a potential driver of development, building on its rich natural, historical,
and cultural heritage. What makes the LAV particularly interesting is the combination of several
distinctive features: its strategic position as a gateway to the region, the presence of both alpine and
Mediterranean landscapes supported by a mild microclimate, and remarkable biodiversity. The area
also ofers year-round accessibility and is well-suited for outdoor activities. Cultural and historical
elements, such as Roman roads, medieval castles, and the Bard Fortress, further enrich its character.
All these elements suggest a promising potential for tourism. However, this transformation from an
industrial hub to a touristic destination is still ongoing, and the region currently lacks a clearly defined
identity. Understanding and defining this identity remains a key issue for its future development.</p>
      <p>According to the National Strategy for Inner Areas (SNAI)1, starting with the 2014–2020 programming
period, the LAV - made up of 23 municipalities at low, mid, and high altitude - has been classified as
one of the three Inner Areas of the Aosta Valley. This classification is mainly due to its distance from
major service centers and its geographical marginality. The present study focuses on a subset of 17
of these 23 municipalities, specifically excluding the high-altitude ones with a strong tourist vocation.
Instead, attention is placed on low- and mid-altitude municipalities located at the eastern edge of the
region, near the Bard Fortress and along the Dora Baltea River. This selection presents both a crucial
opportunity and a methodological challenge: the municipalities under investigation display significant
heterogeneity in terms of size, population density, local economic and hospitality activities, cultural
identities, and political governance models. Such diversity makes the case of the LAV particularly rich
for analysis, allowing for a nuanced understanding of how place-based dynamics shape brand identity.
At the same time, it requires careful methodological attention to capture the complexity and multiplicity
of perspectives involved.</p>
      <p>Finally, the industrialization of the LAV is another key aspect of this case study. From the late 19th
century, the area developed a strong industrial base thanks to water resources for energy production
and suitable land for setting up factories on the valley floor. Key examples of this industrial past include
the Brambilla cotton mill in Verrès and the I.L.L.S.A. Viola steelworks in Pont-Saint-Martin, both closed
in the late 1990s. While some industrial activity remains, it no longer defines the area’s identity. Many
abandoned production sites mark a clear shift from its industrial roots, adding complexity to the analysis
of territorial identity and future development. These spaces are not neutral: they are imbued with
historical meaning, socio-economic memory, and often conflicting narratives about decline, resilience,
and regeneration. Their symbolic and material presence can generate ambiguity in how local actors
perceive and represent the area’s identity - oscillating between nostalgia for a lost industrial prosperity
and aspiration for new forms of territorial valorization. This ambivalence poses a challenge when
attempting to define coherent place-based branding strategies or to identify unifying development
trajectories. It requires nuanced interpretation and context-sensitive analysis capable of capturing how
these post-industrial legacies shape both current perceptions and future imaginaries of the territory.</p>
    </sec>
    <sec id="sec-4">
      <title>4. Data</title>
      <p>This study adopts a qualitative approach to explore the perceptions surrounding the LAV. Qualitative
methods were selected to capture the complexity of personal experiences, narratives, and attitudes
that are not easily reducible to numerical indicators. Two main sources of data were considered: (i)
in-depth interviews with key stakeholders and (ii) user-generated accommodation reviews. Together,
these sources ofer a multifaceted understanding of how the LAV is experienced and represented, both
by those who work in the area and by those who visit it.
4.1. In-depth interviews
15 targeted interviews were conducted with key stakeholders, including 7 political representatives and
8 business operators, who engage with the LAV on a daily basis through their work. The interview
questions were shared in advance, and the interviews were recorded, transcribed, and analyzed
qualitatively. The transcripts underwent preprocessing steps such as text cleaning, lemmatization, and
1https://www.agenziacoesione.gov.it/strategia-nazionale-aree-interne/
(a) Interviews.
(b) Reviews.
phrase standardization. To improve the accuracy of the topic analysis, irrelevant terms (e.g., adverbs,
conjunctions) were added to the stop-word list to refine the results.</p>
      <sec id="sec-4-1">
        <title>4.2. Accommodation reviews</title>
        <p>To capture the perspectives of both tourists and visitors, which are more dificult to access directly, the
reviews left for the LAV accommodation facilities on Booking.com were analyzed. While these reviews
primarily focus on the quality of the accommodations rather than the broader region, they ofered
valuable insights into how the LAV is perceived by tourists. The reviews analyzed were collected from
January 2022 to February 2024, and included both hotel and non-hotel accommodations within the
territory.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Preliminary results</title>
      <p>The results of our analysis reveal a striking contrast between how the territory is perceived by those who
live and work in it, and by those who experience it as visitors. On one hand, local stakeholders -primarily
administrators and entrepreneurs - tend to emphasize limitations, challenges, and untapped potential.
On the other hand, tourists and guests express a predominantly positive perception, highlighting the
value of the area’s features, atmosphere, and overall experience.</p>
      <sec id="sec-5-1">
        <title>5.1. In-depth interviews</title>
        <p>Interviews consistently reveal a shared perception of LAV as a territory rich in untapped tourism
opportunities. However, the topic analysis brings to light a rich variety of perspectives, reflecting the
multifaceted nature of LAV as perceived by the interviewees. These nuances are closely tied to the
backgrounds of the speakers, who were primarily either local administrators or entrepreneurs. These
difering standpoints contribute to a layered interpretation of LAV’s potential and limitations.</p>
        <p>As for sentiment analysis, the overall emotional tone conveyed in the interviews leans toward the
negative. This is clearly illustrated in Figure 2a, where the ‘negative’ and ‘neutral’ categories dominate
in terms of mean scores (0.302 and 0.340 respectively) and interquartile ranges. The ‘very_negative’
category (mean score of 0.101), while lower in absolute values, also shows consistent presence,
underscoring a recurrent sense of frustration or skepticism. On the other hand, positive sentiments (‘positive’,
0.176, and ‘very_positive’, 0.080) are markedly less represented, suggesting that while some hopeful or
optimistic views exist, critical or cautious attitudes dominate the discourse.</p>
      </sec>
      <sec id="sec-5-2">
        <title>5.2. Accommodation reviews</title>
        <p>Reviews of local accommodation facilities portray a markedly more positive image of the LAV area,
highlighting a diferent dimension of its perceived value. From the topic analysis, two recurring
themes stand out: the strategic and convenient location of LAV, appreciated for its proximity to key
destinations, and its overall peacefulness, which contributes to a relaxing experience for visitors.
Alongside these territorial features, reviews often focus on the quality of the accommodation itself,
praising the cleanliness, services ofered, and professionalism of the staf. While these comments
primarily address the hospitality experience, it is important to acknowledge that the perception of
accommodation quality inevitably shapes the overall impression of the destination. In this sense,
the visitor’s satisfaction with lodging facilities contributes—directly and indirectly—to constructing a
positive image of the LAV region as a whole.</p>
        <p>Sentiment analysis further supports this positive portrayal. As shown in Figure 2b, the majority of
sentiment scores are concentrated in the ‘positive’ and ‘very_positive’ categories, both of which display
high mean values - 0.309 and 0.574. In contrast, negative and neutral sentiments are nearly negligible,
indicating that most guests had rewarding and enjoyable stays. This contrasts sharply with the more
critical tones seen in institutional or entrepreneurial interviews, suggesting a gap between perceived
potential and actual visitor experience.</p>
        <p>An even more nuanced picture emerges when we compare diferent types of accommodations. As
shown in Table 1, non-hotel accommodations (e.g., B&amp;Bs, agritourisms, short rentals) received higher
average scores in the ‘very_positive’ category (0.642) compared to hotels (0.475), while also registering
lower averages in all negative sentiment categories. This diference is statistically significant across
the board, as indicated by extremely low p-values. These findings suggest that guests may perceive
non-hotel accommodations as more authentic, personalized, or better integrated with the surrounding
environment, further enhancing the positive experience of staying in LAV.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>6. Conclusion</title>
      <p>This study has demonstrated how advanced computational techniques can enrich our understanding of
territorial identity, particularly in regions undergoing socio-economic transition. By applying topic
modeling and sentiment analysis to qualitative datasets - interviews and user-generated reviews - we
were able to capture the nuanced, often contrasting perceptions that define the Lower Aosta Valley.
These methods, rooted in machine learning and natural language processing, allowed us to extract
latent semantic structures and emotional signals that would be dificult to identify through traditional
analysis alone.</p>
      <p>The results highlight a striking divergence: local stakeholders tend to focus on constraints and
unrealized potential, while external visitors express overwhelmingly positive sentiments. These findings
do not merely reflect subjective opinion, they illustrate measurable emotional and thematic patterns
across large, heterogeneous corpora. Moreover, the statistically significant diferences observed between
types of accommodation reviews underscore the capacity of AI-driven sentiment analysis to detect
ifne-grained distinctions in user experience.</p>
      <p>This perception gap has important implications. First, it suggests that the LAV already possesses a
set of appreciated qualities that could serve as the foundation for a renewed, tourism-oriented identity.
Second, it underscores the need for inclusive, community-driven strategies that not only promote the
area externally but also help rebuild local confidence and alignment around shared values and goals.</p>
      <p>From a methodological standpoint, the study contributes to the emerging field of computational
territorial studies by demonstrating how AI and data science techniques - particularly NLP and statistical
modeling - can be mobilized to investigate identity as a dynamic, multi-actor construct. These tools
open up new possibilities for large-scale, reproducible, and data-rich analyses of place-based narratives.</p>
      <p>Future research could build on this foundation by expanding both the interview base and the volume
of user-generated reviews to improve the robustness and representativeness of findings. Enlarging
the dataset would enable more granular analyses across time, stakeholder groups, and sub-regions,
deepening our understanding of how territorial identity evolves and is perceived from within and
beyond. Ultimately, this study encourages a closer integration between territorial thinking and computer
science, where computational methods do not merely support traditional approaches but actively shape
new ways of seeing and engaging with place.</p>
    </sec>
    <sec id="sec-7">
      <title>Acknowledgments</title>
      <p>Funded by the European Union – NextGenerationEU, Mission 4 Component 1.5 – ECS00000036 – CUP
B63B22000010001.</p>
    </sec>
    <sec id="sec-8">
      <title>Declaration on Generative AI</title>
      <p>During the preparation of this work, the authors used ChatGPT in order to: grammar and spelling
check, paraphrase and reword. After using this tool, the authors reviewed and edited the content as
needed and take full responsibility for the publication’s content.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>W.</given-names>
            <surname>Stohr</surname>
          </string-name>
          ,
          <article-title>Selective Self-Reliance and Endogenous Regional Development-Preconditions and Constraints</article-title>
          ,
          <source>Technical Report</source>
          , WU Vienna University of Economics and Business,
          <year>1984</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <given-names>F.</given-names>
            <surname>Pollice</surname>
          </string-name>
          , et al.,
          <article-title>Il ruolo dell'identità territoriale nei processi di sviluppo locale</article-title>
          ,
          <source>Bollettino della Società geografica italiana 10</source>
          (
          <year>2005</year>
          )
          <fpage>75</fpage>
          -
          <lpage>92</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>C.</given-names>
            <surname>Költringer</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Dickinger</surname>
          </string-name>
          ,
          <article-title>Analyzing destination branding and image from online sources: A web content mining approach</article-title>
          ,
          <source>Journal of Business Research</source>
          <volume>68</volume>
          (
          <year>2015</year>
          )
          <fpage>1836</fpage>
          -
          <lpage>1843</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>F.</given-names>
            <surname>Conte</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P.</given-names>
            <surname>Piciocchi</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Siano</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Bertolini</surname>
          </string-name>
          , et al.,
          <article-title>Data-driven strategic communication for brand identity building: the case study of capital one</article-title>
          ,
          <source>SINERGIE</source>
          <volume>42</volume>
          (
          <year>2024</year>
          )
          <fpage>83</fpage>
          -
          <lpage>105</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>L. E.</given-names>
            <surname>Olsen</surname>
          </string-name>
          ,
          <article-title>Chapter 5: future of branding in the digital age</article-title>
          , in: At the Forefront, Looking Ahead:
          <article-title>Research-Based Answers to Contemporary Uncertainties of Management</article-title>
          , Universitetsforlaget Oslo,
          <year>2018</year>
          , pp.
          <fpage>73</fpage>
          -
          <lpage>84</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <given-names>S. M. F.</given-names>
            <surname>Padela</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Wooliscroft</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A.</given-names>
            <surname>Ganglmair-Wooliscroft</surname>
          </string-name>
          ,
          <article-title>Brand systems: Integrating branding research perspectives</article-title>
          ,
          <source>European Journal of Marketing</source>
          <volume>57</volume>
          (
          <year>2022</year>
          )
          <fpage>387</fpage>
          -
          <lpage>425</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>J.</given-names>
            <surname>Ramos</surname>
          </string-name>
          , et al.,
          <article-title>Using tf-idf to determine word relevance in document queries</article-title>
          ,
          <source>in: Proceedings of the first instructional conference on machine learning</source>
          , volume
          <volume>242</volume>
          ,
          <string-name>
            <surname>Citeseer</surname>
          </string-name>
          ,
          <year>2003</year>
          , pp.
          <fpage>29</fpage>
          -
          <lpage>48</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [8]
          <string-name>
            <given-names>D.</given-names>
            <surname>Lee</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H. S.</given-names>
            <surname>Seung</surname>
          </string-name>
          ,
          <article-title>Algorithms for non-negative matrix factorization</article-title>
          ,
          <source>Advances in neural information processing systems</source>
          <volume>13</volume>
          (
          <year>2000</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [9]
          <string-name>
            <given-names>A.</given-names>
            <surname>Sahoo</surname>
          </string-name>
          ,
          <string-name>
            <given-names>R.</given-names>
            <surname>Chanda</surname>
          </string-name>
          ,
          <string-name>
            <surname>N. Das</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          <string-name>
            <surname>Sadhukhan</surname>
          </string-name>
          ,
          <article-title>Comparative analysis of bert models for sentiment analysis on twitter data</article-title>
          ,
          <source>in: 2023 9th International Conference on Smart Computing and Communications (ICSCC)</source>
          , IEEE,
          <year>2023</year>
          , pp.
          <fpage>658</fpage>
          -
          <lpage>663</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [10]
          <string-name>
            <given-names>C.</given-names>
            <surname>Sun</surname>
          </string-name>
          ,
          <string-name>
            <given-names>L.</given-names>
            <surname>Huang</surname>
          </string-name>
          ,
          <string-name>
            <given-names>X.</given-names>
            <surname>Qiu</surname>
          </string-name>
          ,
          <article-title>Utilizing BERT for aspect-based sentiment analysis via constructing auxiliary sentence</article-title>
          ,
          <source>in: Proc. of the 2019 Conf. of the North American Chapter of the ACL</source>
          , Vol.
          <volume>1</volume>
          ,
          <string-name>
            <surname>ACL</surname>
          </string-name>
          ,
          <year>2019</year>
          , pp.
          <fpage>380</fpage>
          -
          <lpage>385</lpage>
          . URL: https://aclanthology.org/N19-1035/.
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>