Code visualization technology is rapidly popularized in the field of Android malware research once it was proposed. Aiming at the problem of insufficient representation ability of code image converted from single DEX （classes.dex） file， a new Android malware family classification method based on code image integration was proposed. Firstly， the DEX， XML （androidManifest.xml） and decompiled JAR （classes.jar） files in the Android application package were converted to three gray-scale images， and the Bilinear interpolation algorithm was used for the scaling of gray images in different sizes. Then， the three gray-scale images were integrated into a three-dimensional Red-Green-Blue （RGB） image for training and classification. In terms of classification model， the Soft Threshold （ST） Block+ResNeSt（STResNeSt） was proposed by combining the soft threshold denoising block with Split-Attention based ResNeSt. The proposed model has the strong anti-noise ability and is able to pay more attention to the important features of code image. To handle the long-tail distribution of data in the training process， Class Balance Loss （CB Loss） was introduced after data augmentation， which provided a feasible solution to the over-fitting caused by the imbalance of samples. On the Drebin dataset， the accuracy of integrated code image is 2.93 percentage points higher than that of DEX gray-scale image， the accuracy of STResNeSt is improved by 1.1 percentage points compared with the Residual Neural Network （ResNet）， the scheme of data augmentation combined with CB Loss improves the F1 score by up to 2.4 percentage points. Experimental results show that， the average classification accuracy of the proposed method reaches 98.97%， which can effectively classify the Android malware family.

Focusing on the problem of how to generate and display square Hmong language characters in computer, a dynamic construction method for square Hmong language characters was proposed. Firstly, the basic principles of the proposed method were presented. Then, the related operators for generating the square Hmong language characters were discussed. Finally, the transform operations were also explained based on the predicate rules. The proposed method realized the dynamic structure of square Hmong language characters by using up-down, left-right, half-include combination of displayed characters after storing the components and isolated characters. This technique provided an important support for glyph component extracting technology and automatic generation technology of compounds.

Petri nets simplification of property preservation is a significant approach for Petri nets analysis. Meanwhile, the computational ability of Petri nets with inhibitor arcs is equal to Turing machine. From the perspective of series transition and series places respectively, this paper proposed two simplified methods of the Petri nets with inhibitor arcs. Finally, it proved that the characteristics such as aliveness, boundedness and weak fairness of simplified Petri nets with inhibitor arcs were kept unanimous with the original Petri nets with inhibitor arcs by these methods.

For the large and complicated Petri nets, the main problem hindering the technology development is always that "too many nodes lead to station explosion". Therefore, how to simplify Petri nets effectively has always been a research focus and to simplify it to be several subnets is a very effective method. With the decomposition method of Petri nets by defining an index function on the place set, this paper gave the decomposed definition of Petri nets and proposed the related algorithms. Based on the above research, according to the dynamic feature of simplifying technology via researches of the given algorithms, the authors studied the special properties of subnet correspondingly and provided an efficient approach to analyze the Petri nets of complicated systems.