Deadlock-Free Multi-Path Routing for Torus-Based NoCs

In our previous work, a multi-path routing (MPR) scheme was proposed to maximize the data throughput for torus-based NoCs by utilizing multiple paths for concurrent data transmission. In this paper, a deadlock-free virtual channel model is proposed for the MPR scheme. In this virtual channel model, every physical channel on the network is split into about 3.5 virtual channels on average. It is proved that any minimal routing algorithm (including the MPR scheme) using this model is deadlock-free. The MPR scheme employing this new virtual channel model is still a fully adaptive one. The performance of the MPR scheme using the proposed virtual channel model is evaluated through simulations and compared with the fully adaptive single-path minimal routing (SPR) scheme with the same virtual channel model. Simulation results show that MPR achieves better average message latency and normalized accepted traffic than SPR under both uniform and nonuniform traffic in general

Application of D-S Evidence Fusion Method in the Fault Detection of Temperature Sensor

Due to the complexity and dangerousness of drying process, the fault detection of temperature sensor is very difficult and dangerous in actual working practice and the detection effectiveness is not satisfying. For this problem, in this paper, based on the idea of information fusion and the requirements of D-S evidence method, a D-S evidence fusion structure with two layers was introduced to detect the temperature sensor fault in drying process. The first layer was data layer to establish the basic belief assignment function of evidence which could be realized by BP Neural Network. The second layer was decision layer to detect and locate the sensor fault which could be realized by D-S evidence fusion method. According to the numerical simulation results, the working conditions of sensors could be described effectively and accurately by this method, so that it could be used to detect and locate the sensor fault

A method based on hierarchical spatiotemporal features for trojan traffic detection

Trojans are one of the most threatening network attacks currently. HTTP-based Trojan, in particular, accounts for a considerable proportion of them. Moreover, as the network environment becomes more complex, HTTP-based Trojan is more concealed than others. At present, many intrusion detection systems (IDSs) are increasingly difficult to effectively detect such Trojan traffic due to the inherent shortcomings of the methods used and the backwardness of training data. Classical anomaly detection and traditional machine learning-based (TML-based) anomaly detection are highly dependent on expert knowledge to extract features artificially, which is difficult to implement in HTTP-based Trojan traffic detection. Deep learning-based (DL-based) anomaly detection has been locally applied to IDSs, but it cannot be transplanted to HTTP-based Trojan traffic detection directly. To solve this problem, in this paper, we propose a neural network detection model (HSTF-Model) based on hierarchical spatiotemporal features of traffic. Meanwhile, we combine deep learning algorithms with expert knowledge through feature encoders and statistical characteristics to improve the self-learning ability of the model. Experiments indicate that F1 of HSTF-Model can reach 99.4% in real traffic. In addition, we present a dataset BTHT consisting of HTTP-based benign and Trojan traffic to facilitate related research in the field.Comment: 8 pages, 7 figure

Influence mechanism of contact surface mechanical properties on mechanical behavior of coal rock combination

The uniaxial compression test of coal and rock combination was carried out in order to clarify the influence mechanism of the contact surface mechanical properties on the rock-burst tendency of the coal rock combination, and the contact surfaces with four different mechanical properties were considered. The variation laws of strength, elastic modulus, strain softening phenomenon, acoustic emission characteristic signal, energy accumulation and dissipation characteristics, and impact tendency of coal rock combination were analyzed. The influence mechanism of end face effect caused by the bonding properties and failure of contact surface on local deformation characteristics and strength of coal and rock was studied. The results show that the mechanical properties of the contact surface have a certain influence on the mechanical properties of the coal rock combination. The complete contact surface enhances the strength and elastic modulus of the coal rock combination, improves the elastic energy accumulation ability, inhibits the sample fracture in the pre-peak stage, and weakens the strain softening stage after the peak. The failure of the contact surface reduces the influence of the end-face effect, improves the failure degree of the coal rock combination, prolongs the post-peak strain softening process, and the strain energy density in the pre-peak stage is mainly plastic dissipation. The mechanical indexes of unbonded coal rock combination samples are lower than that of others. The constitutive relationship of coal rock combination is established, and the strength estimation method considering the contact surface failure, and the determination method of contact surface fracture are proposed. The theoretical calculation results are consistent with the experimental results. With the improvement of mechanical properties of rock coal interface, the proportion of elastic energy of combined coal increases, and the proportion of plastic property decreases. The influence law of the mechanical properties of rock coal contact surface on the rock burst tendency of coal rock combination is clarified. It is considered that the relative mechanical properties between the contact surface and coal is an important factor which causes the conflict of various indexes of coal rock combination rock burst tendency

Numerical study on anti-impact characteristics of energy absorbing column with multicellular square tube filled with aluminum foam

Aiming at the insufficient anti-impact performance of existing components of the energy-absorbing anti-impact support, a foam aluminum filled multicellular square tube structure is proposed. According to the axial energy absorption theory of thin-walled structures filled with foam materials, the formula of average crushing load is obtained. The axial impact simulation of square tube, multicellular square tube and foam aluminum filled multicellular square tube are completed by using ABAQUS/Explicit. On this basis, the impact resistance of ordinary hydraulic column and energy absorbing hydraulic column is analyzed. The results showed that compared with the square tube and multicellular square tube, the foam aluminum filled multicellular square tube has an ideal axisymmetric progressive deformation. The initial load peak value, load bearing-mean and energy absorption are greatly improved, the effective deformation distance is reduced, the load fluctuation is reduced, and the load carrying efficiency is improved. With the increase of foam aluminum filling ratio, the effective deformation distance and energy absorption of the component are reduced. As the porosity of aluminum foam decreases, the force variance decreases, and energy absorption and the load carrying efficiency increase. Aluminum foam-filled multicellular square tube with 60% porosity at 25% filling rate is an ideal energy absorption component. Ordinary column surges after impact load, bending deformation is serious, column relies on its own deformation to absorb energy, supporting effect is poor. After the energy-absorbing column is impacted, the energy absorption component begins to deform and absorb energy. Greatly reduce the load of the column, absorb most of the outside impact energy, avoid the column bending deformation, improve the impact resistance of the support

Fertility Enhancement but Premature Ovarian Failure in esr1-Deficient Female Zebrafish

It is well established that estrogens regulate female reproduction through estrogen receptors (ERs) in the ovary. However, the precise physiological role of estrogen/ER signaling in reproduction processes remains poorly defined in zebrafish. In this study, we successfully generated an ERα (esr1) mutant line in zebrafish via transcription activator-like effectors nucleases (TALENs). It was found in the mutant females that the fertility was enhanced and the ovarian histology was normal at 90 days post-fertilization (dpf). However, the number of fertile females decreased with age. By 180 dpf, esr1 mutant females were infertile with degenerated ovaries, while the age-matched wild-type females were still fertile. Additionally, few large vitellogenic granules can be found in full grown (FG) follicles at 90 dpf and the expression of vtg genes were down-regulated at both 90 and 180 dpf in esr1 mutant zebrafish. Moreover, steroidogenesis pathway and mTOR signaling pathway were over-activated at 90 dpf, but declined prematurely in esr1 mutant zebrafish by 180 dpf. Collectively, the present study provides evidence that esr1 is fundamental for ovarian maintenance in zebrafish

A semantics aware approach to automated reverse engineering unknown protocols

Abstract—Extracting the protocol message format specifica-tions of unknown applications from network traces is important for a variety of applications such as application protocol parsing, vulnerability discovery, and system integration. In this paper, we propose ProDecoder, a network trace based protocol message format inference system that exploits the semantics of protocol messages without the executable code of application protocols. ProDecoder is based on the key insight that the n-grams of protocol traces exhibit highly skewed frequency distribution that can be leveraged for accurate protocol message format inference. In ProDecoder, we first discover the latent relationship among n-grams by first grouping protocol messages with the same semantics and then inferring message formats by keyword based clustering and cluster sequence alignment. We implemented and evaluated ProDecoder to infer message format specifications of SMB (a binary protocol) and SMTP (a textual protocol). Our experimental results show that ProDecoder accurately parses and infers SMB protocol with 100 % precision and recall. For SMTP, ProDecoder achieves approximately 95 % precision and recall