Complex problem solving is the ability to solve increasingly complex problems through research, analysis, and feedback. Due to the redundancy and complexity of information from different fields such as digital technologies, it is very important to integrate environmental changes flexibly to achieve the best solution. Usually, simple problem solving only involves the evaluation process, while complex problem solving involves multiple variables and potential solutions to complex problems. Complex systems cover at least three different aspects: a complex system can be described at different levels of abstraction; a complex system develops over time, with the historical state, current state, and future state; a complex system has a rich knowledge system, which can activate a large semantic network and a list of potential strategies. Complex problem solving is a dynamic process unfolding over time with different stages, and there are obvious differences between simple knowledge acquisition and knowledge application.

In particular, Digital Technology (DT) is widely used for complex problem solving and has achieved remarkable results. DT includes all electronic tools, automatic systems, technical equipment, and resources that generate, process, and store information. DT is also called digital-coded technology and computer DT because it relies on the computer to encode, compress, and decode information in data operation and storage. DT is different from analog technology. Data are converted into electrical signals with various amplitudes in analog technology, while DT converts data into a binary system that has high noise robustness. Additionally, the DT system can increase the number of binary bits to improve information accuracy. The main impact of DT on the industrial world includes the improvement of performance or productivity and the large-scale reorganization and customization of the supply chain. In today's intelligent virtual era, DT will see a deeper influence in industrial innovation and applications. Macroscopically, the development of digital design is the process of the application of modern information technology in the field of product design from point to line, and then from line to surface. The wide application of digital simulation is becoming the trendy development of DT. With the advent of virtual prototype ideas, the application of DT simulation tends to be more collaborative and systematic. The research on virtual prototypes and their key technologies will improve the enterprise's ability to independently design and develop, thereby promoting enterprise informatization.

This Special Issue aims to collect the latest research progress and application fields of DT in complex problem solving, to provide a platform for scholars to discuss and exchange theories and experiences, to jointly expand the application scope of DT, and realize complex problem solving with lower cost and higher efficiency. Original research and review articles are welcome.

Potential topics include but are not limited to the following:

• Application of digital technology to integrate intelligent devices and applications
• Technical equipment running through binary computing code in complex problems solving
• Audio/video and information communication technology-based on cyberspace
• Application of recording, processing, receiving, transmitting, and displaying information in digital form
• Optimization scheme of digital technology creativity and information dissemination efficiency
• Innovation of online tools, new algorithms, and applications in complex problems solving
• Digital technology in blockchain and cryptocurrency
• Mathematical algorithms based on blockchain to establish digital trust
• Application of digital technology based on artificial intelligence in complex problems solving
• Application of digital technology in big data processing in cloud computing environment
• Construction of three-dimensional, folding, and interactive architecture based on digital technology