A W-EAP Algorithm for IEC 61850 Protocol against DoS/Replay Attack

Substation automation system uses IEC 61850 protocol for the data transmission between different equipment manufacturers. However, the IEC 61850 protocol lacks an authentication security mechanism, which will make the communication face four threats: eavesdropping, interception, forgery, and alteration. In order to verify the IEC 61850 protocol communication problems, we used the simulation software to build the main operating equipment in the IEC 61850 network environment of the communication system. We verified IEC 61850 transmission protocol security defects, under DoS attack and Reply attack. In order to enhance security agreement, an improved algorithm was proposed based on identity authentication (W-EAP, Whitelist Based ECC & AES Protocol). Experimental results showed that the method can enhance the ability to resist attacks.

Generative Mechanisms of Classroom Silence and the Path of Avoidance

Classroom silence is complex and discrete problem.It affects the overall teaching and learning quality as well as the high-quality development of both teachers and students.Avoiding classroom silence is a highly dynamic and valuable learning process.This study explores the ecological logic of classroom silence of both teachers and students based on the connotation of classroom silence and deconstructs the endogenous and exogenous mechanisms of classroom silence from the perspectives of escape culture and the continuity theory.Following that,we construct a new model of interaction for elementary school classroom,which includes optimizing the teaching evaluation tools,creating a multidimensional physical technology environment,and fostering an interactive culture of returning to the classroom,so as to promote the overall classroom effectiveness.

Bone metastasis is a late-onset and unfavorable event in survivors of gastric cancer after radical gastrectomy:Results from a clinical observational cohort

Background The timing and incidence of recurrent bone metastasis(BM)after radical gastrectomy in patients with gastric cancer(GC)as well as the survival of these patients were not fully understood.The aim of this study was to analyze the data of an observational GC cohort and identify patients who underwent curative gastrectomy and had recurrent BM to describe and clarify the pattern and profile of BM evolution after surgery.Methods Data were retrieved from a hospital-based GC cohort,and patients who underwent upfront radical gastrectomy were selected.The time points of specific organ metastatic events were recorded,and the person-year incidence rate of metastatic events was calculated.The latency period of BM events after gastrectomy was measured and compared with that of the other two most common metastatic events,liver metastasis(LM)and distant lymph node metastasis(LNM),using analysis of variance.Propensity score matching and subgroup analysis were used for sensitivity analysis.Results A total of 1324 GC cases underwent radical gastrectomy between January 2011 and December 2021.Of these,67 BM,218 LM,and 248 LNM occurred before the last follow-up.The incidence of BM events was 1.7/100 person-years,which was approximately 3-fold lower than that of LM and distant LNM events(5.5 and 6.3 per 100 person-years,respectively).BM events had a significantly longer latency(median time,16.5 months)than LM and LNM events(11.1 and 12.0 months,respectively).Recurrent BM led to a worse prognosis(median survival,4.5 months)than those of LM and LNM events(median survival,7.7 and 7.1 months,respectively).However,no difference in overall survival after gastrectomy was observed among the groups.Conclusions Compared with other common metastatic events,BM in GC after gastrectomy is a late-onset event indicating poor survival.