An Ant Colony Algorithm Based on Cross-Layer Design for Routing and Wavelength Assignment in Optical Satellite Networks

This paper introduces an ant colony routing and wavelength assignment algorithm based on cross-layer design(CL-ACRWA),which can overcome the adverse effects of Doppler wavelength shift on data transmission in optical satellite networks. Firstly, a cross-layer optimization model is built, which considers the Doppler wavelength shift, the transmission delay as well as wavelength-continuity constraint. Then an ant colony algorithm is utilized to solve the cross-layer optimization model, resulting in finding an optimal light path satisfying the above constraints for every connection request. The performance of CL-ACRWA is measured by the communication success probability, the convergence property and the transmission delay. Simulation results show that CL-ACRWA performs well in communication success probability and has good global search ability as well as fast convergence speed. Meanwhile, the transmission delay can meet the basic requirement of real-time transmission of business.

A Pole Assignment Design Method of Process Control System for Tubular Heat Exchanger

This Paper has first studied the simplified model of tubular heat exchanger which is widely used in the industry and other field.On the basis of reference 2,a new pole assignment design method of pro-cess control system with derivative control action is found.For the above system,the method and the for-mation which calculate the feedback matrix K and gain matrix L is given,and the simulation of the system is made.

Dynamic routing and wavelength assignment algorithm of optical satellite networks based on cross-layer design

In order to overcome the adverse effects of Doppler wavelength shift on data transmission in the optical satellite networks,a dynamic routing and wavelength assignment algorithm based on crosslayer design( CL-DRWA) is introduced which can improve robustness of the network. Above all,a cross-layer optimization model is designed,which considers transmission delay and wavelength-continuity constraint,as well as Doppler wavelength shift. Then CL-DRWA is applied to solve this model,resulting in finding an optimal light path satisfying the above constraints for every connection request. In CL-DRWA,Bellman-Ford method is used to find an optimal route and a distributed relative capacity loss method is implemented to get an optimal wavelength assignment result on the optimal route. Moreover,compared with the dynamic routing and wavelength assignment algorithm based on minimum delay strategy( MD-DRWA),CL-DRWA can make an improvement of 5. 3% on the communication success probability. Meanwhile,CL-DRWA can meet the requirement of transmission delay for real-time services.

Strategies for Designing Online Course Assignments: Based on “XuetangX” Course Samples

Assignments are an important tool to evaluate learners’learning effectiveness in online courses.Clarifying assignment design strategies is of great significance for promoting the quality construction of online education courses.This paper uses Bloom’s taxonomy framework revised by Anderson and Krathwohl(2001)as a reference to label the knowledge types and cognitive dimensions in the assignment context of eight courses.Combined with a literature review,a discipline–objective–schedule(DOS)three-dimensional analysis framework based on the achievement of curriculum objectives,the design of chapter schedule,and the heterogeneity of disciplines is constructed to conduct an in-depth analysis of online course assignment design strategies.The research findings show that the online course assignment design strategy has an obvious curriculum objective orientation,follows the gradual learning rule,and presents typical disciplinary differences.The study finds that the current assignment design of online courses has three issues:first,a mismatch between assignment design and curriculum objectives;second,a lack of diversity in assignment formats;and third,insufficient comprehensiveness of some subject assignments.Based on the above discussions,corresponding suggestions are provided.

Strategies for Improving the Teaching Quality in Middle Schools Under the Double Reduction Policy

The meaning of the term“reduction”in Double Reduction Policy implores teachers to reflect on their teaching process and improve teaching efficiency.Not only should the quantity be reduced,but so should the behavior.Having a comprehensive understanding of the students’learning process is actually a form of science.Therefore,we need to study and enhance its development[1].In order to reduce the learning burden and increase the efficiency of classroom teaching,we must clearly identify the inefficient and ineffective behaviors in classroom teaching,so as to avoid the following situations:a lack of deep thinking,a lack of ability in lesson preparation,fragmentation of questions and answers,a lack of questions that highlight the key points,anticlimax teaching process,and the habit of running over time in class[2,3].On this basis,this paper elaborates the current education state and clarifies the basic requirements of effective classroom teaching.Meanwhile,to reduce students’workload and increase the efficiency in carrying out assignments,much attention should be paid to optimizing assignment design and refining homework review and feedback.The purpose is to assign homework with an appropriate amount(achievable),precision(targeted),and suitability(personalized).Putting an end to the repetitious and unified training is not enough to improve the effect.