Identification of Distributed Denial of Services Anomalies by Using Combination of Entropy and Sequential Probabilities Ratio Test Methods.

One of the most dangerous kinds of attacks affecting computers is a distributed denial of services (DDoS) attack. The main goal of this attack is to bring the targeted machine down and make their services unavailable to legal users. This can be accomplished mainly by directing many machines to send a very large number of packets toward the specified machine to consume its resources and stop it from working. We implemented a method using Java based on entropy and sequential probabilities ratio test (ESPRT) methods to identify malicious flows and their switch interfaces that aid them in passing through. Entropy (E) is the first technique, and the sequential probabilities ratio test (SPRT) is the second technique. The entropy method alone compares its results with a certain threshold in order to make a decision. The accuracy and F-scores for entropy results thus changed when the threshold values changed. Using both entropy and SPRT removed the uncertainty associated with the entropy threshold. The false positive rate was also reduced when combining both techniques. Entropy-based detection methods divide incoming traffic into groups of traffic that have the same size. The size of these groups is determined by a parameter called window size. The Defense Advanced Research Projects Agency (DARPA) 1998, DARPA2000, and Canadian Institute for Cybersecurity (CIC-DDoS2019) databases were used to evaluate the implementation of this method. The metric of a confusion matrix was used to compare the ESPRT results with the results of other methods. The accuracy and f-scores for the DARPA 1998 dataset were 0.995 and 0.997, respectively, for the ESPRT method when the window size was set at 50 and 75 packets. The detection rate of ESPRT for the same dataset was 0.995 when the window size was set to 10 packets. The average accuracy for the DARPA 2000 dataset for ESPRT was 0.905, and the detection rate was 0.929. Finally, ESPRT was scalable to a multiple domain topology application.

Quaternion Model of Higher-Order Rotating Polarization Wave Modulation for High Data Rate M2M LPWAN Communication.

With growing interest in Industry 4.0, machine-to-machine communication (M2M) will become the key enabler for low-power wide area networks (LPWANs) in connecting machines and sensor nodes distributed across a distance in the industrial environment. The choice of modulation and diversity techniques, and the selection of spectrum (licensed/unlicensed) will impact and influence the requirements of wireless M2M systems. Link reliability is one of the most important requirements for LPWAN deployment in industrial scenarios. Rotating Polarization Wave (RPW) system has been recently proposed as an LPWAN solution for reliable M2M communication in high clutter environment and it deploys BPSK modulation with polarization diversity (PD). This paper proposes a new multi-level Rotating Polarization Phase-Shift Keying (RP-MPSK) modulation to provide high data rate and energy efficiency. A novel quaternion model for RPW system (Q-RPW) is also proposed to reduce the complexity in modeling, simulation, and implementation. Results using Q-RPW model show that RP-MPSK modulation offers a high diversity gain over BPSK with second-order diversity. Bit error rate (BER) performance of RP-MPSK modulation compared against other LPWAN modulation like MPSK, FSK and QAM has shown high reliability and substantial improvement in SNR. To overcome the degradation in error performance caused by the proposed higher-order modulation, sampling rates are recommended based on BER performance. BER performance of RP-MPSK under multipath and interference conditions is also investigated.

Methods and Challenges in Shot Boundary Detection: A Review.

The recent increase in the number of videos available in cyberspace is due to the availability of multimedia devices, highly developed communication technologies, and low-cost storage devices. These videos are simply stored in databases through text annotation. Content-based video browsing and retrieval are inefficient due to the method used to store videos in databases. Video databases are large in size and contain voluminous information, and these characteristics emphasize the need for automated video structure analyses. Shot boundary detection (SBD) is considered a substantial process of video browsing and retrieval. SBD aims to detect transition and their boundaries between consecutive shots; hence, shots with rich information are used in the content-based video indexing and retrieval. This paper presents a review of an extensive set for SBD approaches and their development. The advantages and disadvantages of each approach are comprehensively explored. The developed algorithms are discussed, and challenges and recommendations are presented.

Extradural haemorrhage: is there a role for endovascular treatment?

The middle meningeal artery (MMA) is the most proximal and largest branch of the internal maxillary artery (IMA). It courses superiorly to the foramen spinosum making a sharp right angle bend entering the skull. The MMA has frontal, parietal and petrosal branches, the frontal branch being identified by its anterior convex curve along the greater wing of sphenoid. Trauma and a resultant extradural haematoma (EDH) demands urgent neurosurgical intervention to prevent imminent foramen magnum herniation and rapid demise. The seriousness of EDHs cannot be overstated and is a clear neurosurgical emergency requiring immediate definitive management. Historically craniotomy is the gold standard. But recent advances propose angiography and subsequent embolization as an alternative to craniotomy. We employed embolization to manage EDHs in two cases whose original clinical presentation did not demand urgent surgery. We discuss their subsequent management focusing on treatment choices and the potential role of endovascular techniques. We describe an alternative diagnostic protocol and embolic agents using Onyx and coils.

Phenotype versus genotype in gliomas displaying inter- or intratumoral histological heterogeneity.

PURPOSE: Molecular classification of gliomas is becoming increasingly important clinically as an adjunct to histopathological diagnosis. Whereas histological heterogeneity of gliomas is well recognized, less is known of the relationship between histological heterogeneity and genetic alterations. Our objective was to investigate the relationship between genotype and phenotype for markers of potential clinical utility in histologically heterogeneous gliomas. EXPERIMENTAL DESIGN: We have used laser capture microdissection to sample the various histological phenotypes present in 42 tumors from 25 glioma cases with either inter- or intratumoral histological heterogeneity, and multiple simultaneous PCR amplification of microsatellite markers and capillary electrophoresis to determine allelic imbalance in chromosomes 1p, 19q, 17p, 10p, and 10q. RESULTS: Loss of 1p36 and 19q13 was seen only in oligodendroglial histology in 7 of 13 oligodendrogliomas. 17p13 loss was found in 14 of 41 tumors in astrocytic, oligoastrocytic, oligodendroglial, and glioblastomatous histologies. Chromosome 10 loss was seen in all of the high-grade histologies in 7 of 7 glioblastomas with an oligodendroglial component and in 1 of 5 low-grade oligodendroglial regions present within high-grade tumors. Seven tumors from 5 cases had no detectable losses of any markers investigated. In 13 tumors with intratumoral heterogeneity, identical genetic losses were present in all areas of histological differentiation. Additional losses were seen in some but not all of the histologies within 2 tumors and were associated with progression in 3 cases. CONCLUSIONS: The gliomas in this study were more homogeneous in their genotype than their histological phenotype with regions of differing histological subtype indistinguishable by the genetic markers investigated, supporting a monoclonal origin of these tumors.

A 5-year study of the outcome of surgically treated depressed skull fractures.

BACKGROUND: Many changes and improvement have taken place in the management of head injured patients in the last 20 years. There have been few recent studies analysing the overall outcomes including early complications of depressed skull fractures. The aim of our study was, therefore, to examine the factors influencing the surgical outcome of patients with depressed skull fractures. METHODS: We reviewed case notes of 73 consecutive surgically treated depressed skull fractures during the period from 1 January 1994 to 31 December 1998 admitted to the Walton Centre for Neurology and Neurosurgery, Liverpool. RESULTS: There was a male preponderance of 9:1. Alleged assault was the most common cause of depressed skull fractures followed by road traffic accidents. Postoperative infection rate was 8.2%. More than 80% of patients received prophylactic antibiotics. We failed to show any statistically significant association between the use of antibiotics and reduction of the rate of infection. However, prevalence of infection was significantly associated with brain contusion, low GCS score and dural tear (P < 0.05). Prevalence of early post-traumatic epilepsy was 12.3%. No patients received prophylactic anticonvulsants. There was no significant association between dural tear and prevalence of post-traumatic epilepsy. Mortality rate was 1.4%. CONCLUSIONS: Paediatric populations have better outcome; 7 out of 10 patients in this series progressed to full recovery. Use of prophylactic antibiotics did not reduce the infection rate. Presence of dural tear was not associated with an increase risk of post-traumatic epilepsy.