An extended interval temporal logic and a framing technique for temporal logic programming

PhD ThesisTemporal logic programming is a paradigm for specification and verification of concurrent programs in which a program can be written, and the properties of the program can be described and verified in a same notation. However, there are many aspects of programming in temporal logics that are not well-understood. One such an aspect is concurrent programming, another is framing and the third is synchronous communication for parallel processes. This thesis extends the original Interval Temporal Logic (ITL) to include infinite models, past operators, and a new projection operator for dealing with concurrent computation, synchronous communication, and framing in the context of temporal logic programming. The thesis generalizes the original ITL to include past operators such as previous and past chop, and extends the model to include infinite intervals. A considerable collection of logic laws regarding both propositional and first order logics is formalized and proved within model theory. After that, a subset of the extended ITL is formalized as a programming language, called extended Tempura. These extensions, as in their logic basis, include infinite models, the previous operator, projection and framing constructs. A normal form for programs within the extended Tempura is demonstrated. Next, a new projection operator is introduced. In the new construct, the sub-processes are autonomous; each process has the right to specify its own interval over which it is executed. The thesis presents a framing technique for temporal logic programming, which includes the definitions of new assignments, the assignment flag and the framing operator, the formalization of algebraic properties of the framing operator, the minimal model semantics of framed programs, as well as an executable framed interpreter. The synchronous communication operator await is based directly on the proposed framing technique. It enables us to deal with concurrent computation. Based on EITL and await operator, a framed concurrent temporal logic programming language, FTLL, is formally defined within EITL. Finally, the thesis describes a framed interpreter for the extended Tempura which has been developed in SICSTUS prolog. In the new interpreter, the implementation of new assignments, the frame operator, the await operator, and the new projection operator are all included

A review of 3D printed concrete : performance requirements, testing measurements and mix design

As one of the ways contributing to the progress of the industrialization of the construction industry, 3D printed concrete (3DPC) has attracted more and more attention in recent years. The utilization of 3DPC can accelerate the construction speed, save the labor and raw materials, as well as improve the design freedom of construction without formworks. However, one of the most significant challenges for the application of 3DPC is the printing materials. These is a significant difference in the mixtures and performance between 3DPC and normal concrete. In order to provide an intensive reference for future studies to satisfy the performance requirements of 3DPC structures, this study firstly reviews the performance requirements of 3DPC, including the printability, fresh and hardened mechanical properties, and durability. Based on this, the specialized test methods for 3DPC are reviewed for the effective quality evaluation of 3DPC. The last part presents a review of mix design from the point of view of different materials and mix design approaches. The results show that 3DPC needs to meet the printability that it has higher requirements for rheology, hydration, and green strength than normal concrete. The interlayer bond is the key to study the anisotropic strength and durability degradation. More accurate test methods and testing standards should be developed. Besides, coarse aggregates and recycled materials need to be considered in the mix design of 3DPC