General Track 3: Geometric Modeling, Graphics and Visualization -- Automatic User Testing and Emotion Detection in Interactive Urban Devices -- Robust Seeded Image Segmentation using Adaptive Label Propagation and Deep Learning-Based Contour Orientation -- Siamese Network with Gabor Filter for Recognizing Handwritten Digits -- Semi-Supervised Time Series Classification through Image Representations -- Construction of Torus of Revolution generated from Epicycloids -- General Track 4: Advanced and Emerging Applications -- AutoML Framework for labor potential modeling -- Seismic inversion for fracture model reconstruction: from 1D inversion to machine learning -- "Fat" rays in three dimensional media to approximate a broadband signal propagation -- Visualization, Analysis and Collaborative Discussion of Severe Weather Events -- General Track 6: Urban and Regional Planning -- Investigating alternative clustering algorithms for a cluster-first, route-second truck and drone scheduling algorithm -- Strategic Directions of Ensuring the Financial Stability of the Transport Enterprise -- New Geographies of Fuel Purchase during the Covid-19 Pandemic: Evidence from the Italian Northeastern Border Zone -- Local budget revenue formation reality, obstacles and prospects in Georgia: an empirical examination and creative approach -- Design principles for platform-based innovation in smart cities -- Analysis of an Enterprise's Compliance with the Authorized Economic Operator Status in the Context of the Customs Policy of Ukraine -- A Usage and Analysis measured CO2 Levels in Japanese Community Buses with IoT Sensors -- Assessment of spatial inequality in agglomeration planning -- Assessment of spatial inequality through the accessibility of urban services -- PHD Showcase Papers: -- Topic Modelling for Characterizing COVID-19 Misinformation on Twitter: A South African Case Study -- Investigating the Use of Topic Modeling for Social Media Market Research: a South African Case Study -- Mitigating Traffic Congestion in Smart and Sustainable Cities Using Machine Learning: A Review -- Urban Resilience Key Metrics Thinking and Computing Using 3D Spatio-Temporal Forecasting Algorithms -- A framework for the analysis of metaheuristics for the travelling salesman problem with drone with interceptions -- Value-oriented management of city development programs based on data from social networks -- Short Papers: -- OdeShell: an interactive tool and a specific domain language to develop models based on Ordinary Differential Equations -- Multiple Integer Divisions with an Invariant Dividend and Monotonically Increasing or Decreasing Divisors -- Large Scale Study of Binary Galaxy Image Classification and the Impact of Image Augmentation Techniques -- A Prediction Model of Pixel Shrinkage Failure using Multi-Physics in OLED Manufacturing Process -- Wavelength computation from RGB -- A Close-up on the AI Radiologist Software -- Thematic modeling of professional communication practices of helping specialists -- Mobility networks as a predictor of socioeconomic status in urban systems -- Forecasting in shipments: comparison of Machine Learning Regression algorithms on industrial applications for supply chain -- An Unseen Features-Enriched Lifelong Machine Learning Framework -- Urban zoning using intraday mobile phone-based commuter patterns in the city of Brno -- Management qualification and responsible management in local government -- The issue of small municipalities - the possibility of applying the principles of socially responsible management.

The two-volume set LNCS 13956 and 13957 constitutes the refereed proceedings of the 23rd International Conference on Computational Science and Its Applications, ICCSA 2023, held at Lesvos Island, Greece, during July 3-6, 2023. The 67 full papers and 13 short papers and 6 PHD showcase papers included in this volume were carefully reviewed and selected from a total of 283 submissions. The contributions are grouped in topics which deal with General Track 1: Computational Methods, Algorithms and Scientific Applications; General Track 2: High Performance Computing and Networks; General Track 3: Geometric Modeling, Graphics and Visualization; General Track 4: Advanced and Emerging Applications; General Track 5: Information Systems and Technologies; General Track 6: Urban and Regional Planning; and PHD Showcase Papers.