scholarly journals Constructing program animations using a pattern based approach

2007 ◽  
Vol 4 (2) ◽  
pp. 97-114 ◽  
Author(s):  
da Cruz ◽  
Rangel Henriques ◽  
João Varanda
Keyword(s):  
Source Code ◽  
Program Comprehension ◽  
Control Flow ◽  
Rule Base ◽  
Program Execution ◽  
Source Program ◽  
Visualization Of Data ◽  
And Control ◽  
Compiler Techniques ◽  
Rewriting Rules

The aim of this paper is to discuss how our pattern-based strategy for the visualization of data and control flow can effectively be used to animate the program and exhibit its behavior. That result allows us to propose its use for Program Comprehension. The animator uses well known compiler techniques to inspect the source code in order to extract the necessary information to visualize it and understand program execution. We convert the source program into an internal decorated (or attributed) abstract syntax tree and then we visualize the structure by traversing it, and applying visualization rules at each node according to a pre-defined rule-base. In order to calculate the next step in the program execution, a set of rewriting rules are applied to the tree. The visualization of this new tree is shown and the program animation is constructed using an iterative process. No changes are made in the source code, and the execution is simulated step by step. Several examples of visualization are shown to illustrate the approach and support our idea of applying it in the context of a Program Comprehension environment.

scholarly journals Control Flow Treatment in a Simple: Semantics-Directed Compiler Generator

1981 ◽  
Vol 10 (137) ◽  
Author(s):  
Neil D. Jones ◽  
Henning Christiansen
Keyword(s):  
Simple Algebra ◽  
Control Flow ◽  
Program Execution ◽  
Correctness Proofs ◽  
Compiler Generation ◽  
Source Program ◽  
Target Program ◽  
Definition Of ◽  
Flow Treatment ◽  
Semantic Definition

<p>A simple algebra-based algorithm for compiler generation is described. Its input is a semantic definition of a programming language, and its output is a ''compiling semantics'' which maps each source program into a sequence of compile-time actions whose net effect on execution is the production of a semantically equivalent target program. The method does not require individual compiler correctness proofs or the construction of specialized target algebras.</p><p>Source program execution is assumed to proceed by performing a series of elementary actions on a runtime state. A semantic algebra is introduced to represent and manipulate possible execution sequences. A source semantic definition has two parts: A set of semantic equations mapping source programs into terms of the algebra, and an interpretation which gives concrete definitions of the state and the elementary actions on it.</p>

scholarly journals An Android Inline Hooking Framework for the Securing Transmitted Data

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4201
Author(s):  
Yu-an Tan ◽  
Shuo Feng ◽  
Xiaochun Cheng ◽  
Yuanzhang Li ◽  
Jun Zheng
Keyword(s):  
Source Code ◽  
Control Flow ◽  
Security Policies ◽  
Unauthorized Access ◽  
Shared Objects ◽  
Android Applications ◽  
Runtime Performance ◽  
And Control

Information leaks can occur through many Android applications, including unauthorized access to sensors data. Hooking is an important technique for protecting Android applications and add security features to them even without its source code. Various hooking frameworks are developed to intercept events and process their own specific events. The hooking tools for Java methods are varied, however, the native hook has few methods. Besides, the commonly used Android hook frameworks cannot meet the requirement of hooking the native methods in shared libraries on non-root devices. Even though some approaches are able to hook these methods, they have limitations or are complicated to implement. In the paper, a feasible hooking approach for Android native methods is proposed and implemented, which does not need any modifications to both the Android framework and app’s code. In this approach, the method’s reference address is modified and control flow is redirected. Beyond that, this study combines this approach with VirtualXposed which aims to run it without root privileges. This hooking framework can be used to enforce security policies and monitor sensitive methods in shared objects. The evaluation of the scheme demonstrates its capability to perform hook operation without a significant runtime performance overhead on real devices and it is compatible and functional for the native hook.

Study on Novel Automatic Steel Bundling Machine Pneumatic Control System

2012 ◽  
Vol 490-495 ◽  
pp. 594-597
Author(s):  
Cheng Qun Li ◽  
Liang Gao
Keyword(s):  
Control System ◽  
Control Program ◽  
Control Flow ◽  
Pneumatic Control ◽  
The Core ◽  
New Type ◽  
Action Process ◽  
And Control

This paper introduces a new type of automatic steel bundling machine for bundling process, which includes a pneumatic action process, mainly do some researches on the pneumatic control system. The system chooses PLC as the core control component, puts forward the hardware of control system and control flow. Eventually we have been designed the control program.

scholarly journals Development of a Hybrid Electric Vehicle Simulation Tool with a Rule-Based Topology

2021 ◽  
Vol 11 (23) ◽  
pp. 11319
Author(s):  
Hyun Woo Won
Keyword(s):  
Hybrid Electric Vehicle ◽  
Hybrid Simulation ◽  
Rule Base ◽  
Simulation Tool ◽  
Control Logic ◽  
Rule Based ◽  
Vehicle Simulation ◽  
Wide Range ◽  
Hybrid Electric ◽  
And Control

The performance of hybrid electric vehicles (HEVs) greatly depends on the various sub-system components and their architecture, and designers need comprehensive reviews of HEVs before vehicle investigation and manufacturing. Simulations facilitate development of virtual prototypes that make it possible to rapidly see the effects of design modifications, avoiding the need to manufacture multiple expensive physical prototypes. To achieve the required levels of emissions and hardware costs, designers must use control strategies and tools such as computational modeling and optimization. However, most hybrid simulation tools do not share their principles and control logic algorithms in the open literature. With this motivation, the author developed a hybrid simulation tool with a rule-based topology. The major advantage of this tool is enhanced flexibility to choose different control and energy management strategies, enabling the user to explore a wide range of hybrid topologies. The tool provides the user with the ability to modify any sub-system according to one’s own requirements. In addition, the author introduces a simple logic control for a rule-base strategy as an example to show the flexibility of the tool in allowing the adaptation of any logic algorithm by the user. The results match the experimental data quite well. Details regarding modeling principle and control logic are provided for the user’s benefit.

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