Note: high capacity digital laser beam steering system

The combination of liquid crystal cells with polarizing cube beam splitters has been used to direct a beam of light to multiple directions. The polarization at each beam splitter is controlled by applying a signal to a corresponding liquid crystal cell. Ten cascaded stages have deflected a HeNe laser beam to 1024 digitally selectable angles.     

Network intrusion detection based on deep learning model optimized with rule-based hybrid feature selection

ABSTRACT

Network Intrusion Detection System (NIDS) is often used to classify network traffic in an attempt to protect computer systems from various network attacks. A major component for building an efficient intrusion detection system is the preprocessing of network traffic and identification of essential features which is essential for building robust classifier. In this study, a NIDS based on deep learning model optimized with rule-based hybrid feature selection is proposed. The architecture is divided into three phases namely: hybrid feature selection, rule evaluation and detection. Several search methods and attribute evaluators were combined for features selection to enhance experimentation and comparison. The results obtained showed that the number of selected features will not affect the detection accuracy of the feature selection algorithms, but directly proportional to the performance of the base classifier. Results from the performance comparison proved that the proposed method outperforms other related methods with reduction of false alarm rate, high accuracy rate, reduced training and testing time of 1.2%, 98.8%, 7.17s and 3.11s, respectively. Finally, the simulation experiments on standard evaluation metrics showed that the proposed method is suitable for attack classification in NIDS.     

Moving average control charts for the rayleigh and inverse rayleigh distributions under time truncated life test

In this paper, the moving average control chart is developed under time truncated test to monitor the number of failures when the lifetime of an item follows the Rayleigh and inverse Rayleigh distributions. The number of failures is detected when a planned number of items has been placed on a time truncated testing experiment. The average run lengths (ARL) for various parameter settings are used to evaluate the performance of the proposed control chart. Also, the control chart parameters such as test time multiplier ($a$) and chart coefficient (k) are obtained by contemplating the in-control ARL for various sample sizes. The study revealed that the proposed control chart outperform the existing time truncated attribute control chart in the quick detection of shifts in process parameters. The application of the proposed chart methodology is also demonstrated using simulated data.     

QUACS: Routing Data Packets in Ad Hoc Networks on Buffer-Constrained Load Balancing Conditions During Emergency Rescue Crisis

Mobile wireless networks have been gaining popularity since the turn of the new millennium as they enable communication to take place without fixed communication infrastructure. This form of communication, which has been made possible by radio links proved its usefulness during emergency medical rescues such as an Ebola pandemic, battlefield communications or other emergency situations, where quick communication is of paramount importance. Nature-inspired algorithms such as AntHocNet, AntSense, among other ant inspired techniques, have been mimicked in solving the communication challenges in wireless networks, but they focus mostly on the ‘next-hop’ in determining routing of data packets from the source to the destination, which tends to suffer from congestion-related problems. Ant routing methods focus more on next-hop neighbours when choosing the shortest path which might have many data packets and are prone to congestion. Focusing on the next-hop neighbours poses a challenge of having other nodes that end up being congested. This problem of routes being heavily used, often decreases throughput rates, leading to the proposed Queuing Ant Colony System (QUACS) which is a bio-inspired, complementing the queuing optimisation approach in routing of data packets across the network. The results of simulations show that QUACS performs better in throughput, packet delivery ratio, end-to-end delay and communication overhead than other ant routing algorithms. This study is particularly beneficial in the ad hoc networks where the QUACS routing method can greatly assist in faster communication and evacuation in emergency for treatment of patients during emergency medical rescue operations.     

Impacts of Ignored Evaporation and Sedimentation Fluxes at Planning on Reservoir Performance in Operation

Inevitable evaporation and sedimentation will influence reservoir operational performance if the two fluxes have been ignored when sizing reservoir systems. While this is to be expected, very few studies have quantified this influence. This study has analysed the effects of evaporation and sedimentation on reservoirs operational performance. It used seven reservoirs in Yesilirmak Basin, Turkey as case studies. The Dams serve a variety of purposes including irrigation, domestic and industrial, hydropower generation and flood control. Performance with regard to meeting these needs was characterized using reliability (time-based and volume-based), resilience, vulnerability and sustainability. The results showed that while ignoring both the evaporation and sedimentation during planning does affect subsequent operational performance, the influence of evaporation was more significant. Possible reasons are provided for the outcome and ways by which both can be accommodated during planning analyses thus mitigating the operational effects are suggested.