Hierarchical Colored Timed Petri Nets for Maintenance Process Modeling of Civil Aircraft

Civil aircraft maintenance process simulation model is an effective method for analyzing the maintainability of a civil aircraft. First, we present the Hierarchical Colored Timed Petri Nets for maintenance process modeling of civil aircraft. Then, we expound a general method of civil aircraft maintenance activities, determine the maintenance level for decomposition, and propose the methods of describing logic of relations between the maintenance activities based on Petri Net. Finally, a time Colored Petri multi-level network modeling and simulation procedures and steps are given with the maintenance example of the landing gear burst tire of a certain type of aircraft. The feasibility of the method is proved by the example.

Real- Time Color Enhancement Method Used for Intelligent Mobile Terminals

In certain environments and under some conditions, the video images taken by the intelligent mobile video phones seem dark, and the colors are not bright or saturated enough.This paper presents an adaptive method to enhance the video image brightness visualization and the color performance depending on the certain hardware property and function parameters. The experimental results prove that this method can enhance the colors and the contrast of the video images, based on the estimated quality feature values of each frame, without using the extra Digital Signal Processor (DSP).

Verification of Session Initiation Protocol Using Timed Colored Petri Net

In this work, Session Initiation Protocol model is established by using Timed Colored Petri Nets (TCPN). SIP (Session Initiation Protocol) is a protocol developed to assist in providing advanced telephony services across the Internet. The Session Initiation Protocol (SIP) has become the quasi-standard for Voiceover-Internet Protocol (VoIP) communications. SIP is based on a client–server infrastructure in which user agents represent the end-terminals as clients, proxy servers handle SIP message routing between the user agents, and registrar servers store the client’s contact information into a location service. By use of timed color set and useful time attributes in tokens defined in CPN tools, timer and time-related problems of SIP are modeled and analyzed. Timer is an important part for SIP, especially the INVITE transaction.

Content Determination of Total Flavonoids from Paulownia fortunei Flower

[Objectives]The research aimed to explore the determination method for content of total flavonoids from Paulownia fortunei flower.[Methods]Rutin was taken as control.By comparing absorption characteristics of total flavonoids in NaNO_(2)-Al(NO_(3))_(3)-NaOH and AlCl_(3) chromogenic system,an appropriate method for the determination of total flavonoids from P.fortunei flower was screened,and the method was verified by methodology.On the basis of single factor experiment,the coloration time of the method was optimized by orthogonal experiment.[Results]NaNO_(2)-Al(NO_(3))_(3)-NaOH chromogenic system was more suitable for the determination of total flavonoids from P.fortunei flower,and the adding standard recovery was between 99.2%and 105.5%,and RSD was 2.18%,with better repeatability,precision,stability and accuracy.The optimized coloration time of NaNO_(2),Al(NO_(3))_(3) and NaOH was 6,6,and 10 min.Under the condition,average content of total flavonoids from P.fortunei flower was 3.78%,and RSD was 2.05%.[Conclusions]The optimized NaNO_(2)-Al(NO_(3))_(3)-NaOH chromogenic method is simple,rapid,and accurate,and could be used as a method for the determination of total flavonoids from P.fortunei flower.

Solving Resource-constrained Multiple Project Scheduling Problem Using Timed Colored Petri Nets

To solve the resource-constrained multiple project scheduling problem(RCMPSP) more effectively,a method based on timed colored Petri net(TCPN) was proposed.In this methodology,firstly a novel mapping mechanism between traditional network diagram such as CPM(critical path method)/PERT(program evaluation and review technique) and TCPN was presented.Then a primary TCPN(PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism.Meanwhile,the object PTCPN was used to simulate the multiple projects scheduling and to find the approximately optimal value of RCMPSP.Finally,the performance of the proposed approach for solving RCMPSP was validated by executing a mould manufacturing example.