Ant-based evidence distribution with periodic broadcast in attacked wireless network

In order to establish trust among nodes in large wireless networks, the trust certicates need to be distributed and be readily accessible. However, even so, searching for trust certicates will still become highly cost and delay especially when wireless network is suering CTS jamming attack. We believe the individual solution can lead us to solve this combination problems in the future. Therefore, in this work, we investigate the delay and cost of searching a distributed certicate and the adverse eects of fabiricated control packet attacks on channel throughput and delivery ratio respectively, and propose two techniques that can improve the eciency of searching for such certicates in the network and mitigate the CTS jamming attack's eect. Evidence Distribution based on Periodic Broadcast (EDPB) is the rst solution we presented to help node to quickly locate trust certicates in a large wireless sensor network. In this solution, we not only take advantages from swarm intelligence alogrithm, but also allow nodes that carrying certicates to periodically announce their existence. Such announcements, together with a swarm-intelligence pheromone pdate procedure, will leave traces on the nodes to lead query packets toward the certicate nodes. We then investigate the salient features of this schema and evaluate its performance in both static and mobile networks. This schema can also be used for other essential information dissemination in mobile ad hoc networks. The second technqiue, address inspection schema (AIS) xes vulnerabilities exist in distribution coordinating function (DCF) dened in IEEE 802.11 standard so that each node has the ability to beat the impact of CTS jamming attack and furthermore, benets network throughput. We then perform ns-2 simulations to evaluate the benet of AIS

HiHGNN: Accelerating HGNNs through Parallelism and Data Reusability Exploitation

Heterogeneous graph neural networks (HGNNs) have emerged as powerful algorithms for processing heterogeneous graphs (HetGs), widely used in many critical fields. To capture both structural and semantic information in HetGs, HGNNs first aggregate the neighboring feature vectors for each vertex in each semantic graph and then fuse the aggregated results across all semantic graphs for each vertex. Unfortunately, existing graph neural network accelerators are ill-suited to accelerate HGNNs. This is because they fail to efficiently tackle the specific execution patterns and exploit the high-degree parallelism as well as data reusability inside and across the processing of semantic graphs in HGNNs. In this work, we first quantitatively characterize a set of representative HGNN models on GPU to disclose the execution bound of each stage, inter-semantic-graph parallelism, and inter-semantic-graph data reusability in HGNNs. Guided by our findings, we propose a high-performance HGNN accelerator, HiHGNN, to alleviate the execution bound and exploit the newfound parallelism and data reusability in HGNNs. Specifically, we first propose a bound-aware stage-fusion methodology that tailors to HGNN acceleration, to fuse and pipeline the execution stages being aware of their execution bounds. Second, we design an independency-aware parallel execution design to exploit the inter-semantic-graph parallelism. Finally, we present a similarity-aware execution scheduling to exploit the inter-semantic-graph data reusability. Compared to the state-of-the-art software framework running on NVIDIA GPU T4 and GPU A100, HiHGNN respectively achieves an average 41.5$\times$ and 8.6$\times$ speedup as well as 106$\times$ and 73$\times$ energy efficiency with quarter the memory bandwidth of GPU A100

Ant-Based Evidence Distribution with Periodic Broadcast in Attacked Wireless Network

In order to establish trust among nodes in large wireless networks, the trust certificates need to be distributed and be readily accessible. However, even so, searching for trust certificates can be delayed and costly especially when wireless network is under CTS jamming attack, in which the attacker jams the reception of a control packet termed clear-to-send, CTS. We believe the individual solution can lead us to solve the combined problem. Therefore, in this work, we investigate the delay and cost of searching a distributed certificate and the adverse effects of fabricated control packet attacks on channel throughput and delivery ratio respectively, and propose two techniques that can improve the efficiency of searching for such certificates in the network and mitigate the CTS jamming attack's effect. Evidence Distribution based on Periodic Broadcast (EDPB) is the first solution we present to help node to quickly locate trust certificates in a large wireless sensor network. In this solution, nodes carrying certificates periodically announce their existence. Such announcements, together with a swarm-intelligence pheromone update procedure, will leave traces on the nodes to lead query packets toward the certificate nodes. We then investigate the salient features of this schema and evaluate its performance in both static and mobile networks. This schema can also be used for other essential information dissemination in mobile ad hoc networks. The second technique, address inspection schema (AIS) addresses vulnerabilities in distribution coordinating function (DCF) defined in IEEE 802.11 standard. The AIS scheme allows nodes to detect the CTS jamming attack and mitigates its adverse effect. We then perform ns-2 simulations to evaluate the benefit of AIS

PeB: Periodic Broadcast for Information Distribution in Large Wireless Networks

Abstract—Large wireless networks are envisioned to play increasingly important roles as more and more mobile wireless devices are available to use. In these networks, it is often the case that some critical information needs to be readily accessible by the regular nodes, requiring a careful design of the information distribution technique. In this work, we propose PeB, Periodic Broadcast, that takes advantage of periodic broadcast from the information server(s) to leave traces for nodes requesting for the information. One salient feature of the PeB scheme is its periodic broadcast schedule that maintains the freshness of the trace toward the information servers. We present our extensive investigation of the PeB scheme on cost and network dynamics. I

Semantic resolution for e-commerce

Abstract. We describe a research project on resolving semantic differences for multi-agent systems (MAS) in electronic commerce. The approach can be characterized as follows: (1) agents in a MAS may have their own specific ontologies defined on top of a shared base ontology; (2) concepts in these ontologies are represented as frame-like structures based on DAML+OIL language; (3) the semantic differences between agents are resolved at runtime through inter-agent communication; and (4) the resolution is viewed as an abductive inference process, and thus necessarily involves approximation reasoning.

Significance of Prehistoric Liquefaction Features in the Xilinhot District, Inner Mongolia, Northern China

Paleo-ground ruptures, fissures, liquefaction and geomorphic features in the Xilinhot district, Inner Mongolia, northern China, are documented and seismic intensity for the meizoseismal areas and magnitudes of paleoearthquakes are estimated. Trenching investigations revealed a huge paleoseismic ground rupture and fissure zone with a width of more than 200 m. Field investigations and interpretation of remote sensing images demonstrate that active faults related to paleoearthquakes appear to be about 200 km long. Geologic and geomorphic evidences indicate that one large earthquake with a magnitude of about 7.5 at about 13 ka BP or multiple paleoseismic events of M ¡_ 6.0 have occurred in the studied area since 53 ka BP. One of the paleo-meizoseismal areas is determined to be near Xilinhot. Seismic intensity in Modified Mercalli scale (MM) is estimated to be larger than VI in the vicinity of the study area and at least VIII in the epicentral region. This is consistent with seismic activities in and around the Xilinhot district in recent years, but higher than anything yet reported. The results provide important data for design engineering and regional planning in order to resist damage from potentially large earthquakes in the future

Rhegmatogenous retinal detachment surgery in elderly people over 70 years old: visual acuity, quality of life, and cost-utility values.

BACKGROUND AND PURPOSE: To evaluate the influence of rhegmatogenous retinal detachment (RRD) surgery on elderly patients in terms of visual acuity, vision-related quality of life and its cost-effectiveness. METHODS: Elderly patients over 70 years old, who were diagnosed and underwent RRD surgery at Shanghai First People's Hospital, Shanghai Jiao Tong University, China, from January 1, 2009, through January 1, 2013. The participants received scleral buckling surgery and vitreous surgery with or without scleral buckling under retrobulbar anesthesia. We followed the patients for 1 year and collected best-corrected visual acuity (BCVA), vision-related quality of life, and direct medical costs data. Utility values elicited by time-trade-off were analyzed to determine the quality of life. Quality-adjusted life years (QALYs) gained in life expectancy were calculated and discounted at 3% annually. Costs per QALY gained were reported using the bootstrap method. Further analyses were made for two age groups, age 70-79 and age over 80 years. Sensitivity analyses were performed to test stability of the results. RESULTS: 98 patients were included in the study. The BCVA significantly improved by 0.53±0.44 (Logarithm of the Minimum Angle of Resolution (logMAR)) at the 1-year postoperative time point (p<0.001). Utility values increased from 0.77 to 0.84 (p<0.001), and an average of 0.4 QALYs were gained in the life expectancy. Costs per QALY gained from the RRD surgery were 33,186 Chinese Yuan (CNY) (5,276 US dollars (USD))/QALY; 24,535 CNY (3,901 USD)/QALY for the age group of 70-79 years and 71,240 CNY (11,326 USD)/QALY for the age group over 80 years. CONCLUSIONS: RRD surgery improved the visual acuity and quality of life in the elderly patients over 70 years old. According to the World Health Organization's recommendation, at a threshold of willingness to pay of 115,062 CNY (18,293 USD)/QALY, RRD surgery is cost effective in the elderly patients