Possibilistic Nested Logic Programs

We introduce the class of possibilistic nested logic programs. These possibilistic logic programs allow us to use nested expressions in the bodies and the heads of their rules. By considering a possibilistic nested logic program as a possibilistic theory, a construction of a possibilistic logic programing semantics based on answer sets for nested logic programs and the proof theory of possibilistic logic is defined. We show that this new semantics for possibilistic logic programs is computable by means of transforming possibilistic nested logic programs into possibilistic disjunctive logic programs. The expressiveness of the possibilistic nested logic programs is illustrated by scenarios from the medical domain. In particular, we exemplify how possibilistic nested logic programs are expressive enough for capturing medical guidelines which are pervaded of vagueness and qualitative information

A formal semantics of PLC programs in Coq

International audienceProgrammable logic Controllers (PLC) are embedded systems that are widely used in industry. We propose a formal semantics of the Instruction List (IL) language, one of the five programing languages defined in the IEC 61131-3 standard for PLC programing. This semantics support a significant subset of the IL language that includes on-delay timers. We formalized this semantics in the proof assistant Coq and used it to prove some safety properties on an example of PLC program.Programmable logic Controllers (PLC) sont des systèmes embarqués qui sont largement utilisés dans l'industrie. Nous proposons dans ce papier une sémantique formelle du langage Instruction List (IL), l'un des cinq langages de programmation défini dans la norme IEC 61131-3 pour la programmation des PLC. Cette sémantique prend en charge un sous-ensemble important du langage IL qui comprend les timers on-delay. Nous avons formalisé cette sémantique dans le système Coq et nous l'avons utilisé pour prouver certaines propriétés de sûreté sur un exemple de programme PLC

A Survey of Digital Systems Curriculum and Pedagogy in Electrical and Computer Engineering Programs

Digital Systems is one of the basic foundational courses in Electrical and Computer Engineering. One of the challenges in designing and modifying the curriculum for the course is the fast pace of technology change in the area. TTL chips that were in vogue with students building physical circuits, have given way to new paradigms like FPGA based synthesis with hardware description languages such as VHDL. However, updating a course is not as simple as just changing the book, and changing the syllabus. A large amount of work needs to be done in terms of selecting the book that will accommodate the course, the device that should be used, the laboratory content, and even how much time needs to be dedicated for every topic. All these issues, and many more makes it hard to take the decision of updating the course. For that reason, this paper surveys the pedagogy and methodology that is used to teach the digital systems curriculum at different universities. The goal is that it will serve as a resource for faculty looking to update or revamp their digital systems curricula. Within the document they will find a comparative study by electrical and computer engineering program, a list of textbooks, and the devices most commonly used.Cockrell School of Engineerin

Metalevel programming in robotics: Some issues

Computing in robotics has two important requirements: efficiency and flexibility. Algorithms for robot actions are implemented usually in procedural languages such as VAL and AL. But, since their excessive bindings create inflexible structures of computation, it is proposed that Logic Programming is a more suitable language for robot programming due to its non-determinism, declarative nature, and provision for metalevel programming. Logic Programming, however, results in inefficient computations. As a solution to this problem, researchers discuss a framework in which controls can be described to improve efficiency. They have divided controls into: (1) in-code and (2) metalevel and discussed them with reference to selection of rules and dataflow. Researchers illustrated the merit of Logic Programming by modelling the motion of a robot from one point to another avoiding obstacles

Real-time Motion Planning For Autonomous Car in Multiple Situations Under Simulated Urban Environment

Advanced autonomous cars have revolutionary meaning for the automobile industry. While more and more companies have already started to build their own autonomous cars, no one has yet brought a practical autonomous car into the market. One key problem of their cars is lacking a reliable active real-time motion planning system for the urban environment. A real-time motion planning system makes cars can safely and stably drive under the urban environment. The final goal for this project is to design and implement a reliable real-time motion planning system to reduce accident rates in autonomous cars instead of human drivers. The real-time motion planning system includes lane-keeping, obstacle avoidance, moving car avoidance, adaptive cruise control, and accident avoidance function. In the research, EGO vehicles will be built and equipped with an image processing unit, a LIDAR, and two ultrasonic sensors to detect the environment. These environment data make it possible to implement a full control program in the real-time motion planning system. The control program will be implemented and tested in a scaled-down EGO vehicle with a scaled-down urban environment. The project has been divided into three phases: build EGO vehicles, implement the control program of the real-time motion planning system, and improve the control program by testing under the scale-down urban environment. In the first phase, each EGO vehicle will be built by an EGO vehicle chassis kit, a Raspberry Pi, a LIDAR, two ultrasonic sensors, a battery, and a power board. In the second phase, the control program of the real-time motion planning system will be implemented under the lane-keeping program in Raspberry Pi. Python is the programming language that will be used to implement the program. Lane-keeping, obstacle avoidance, moving car avoidance, adaptive cruise control functions will be built in this control program. In the last phase, testing and improvement works will be finished. Reliability tests will be designed and fulfilled. The more data grab from tests, the more stability of the real-time motion planning system can be implemented. Finally, one reliable motion planning system will be built, which will be used in normal scale EGO vehicles to reduce accident rates significantly under the urban environment.No embargoAcademic Major: Electrical and Computer Engineerin