Multi-Layered Blockchain Governance Game

The research designs a new integrated system for the security enhancement of a decentralized network by preventing damages from attackers, particularly for the 51 percent attack. The concept of multiple layered design based on Blockchain Governance Games frameworks could handle multiple number of networks analytically. The Multi-Layered Blockchain Governance Game is an innovative analytical model to find the best strategies for executing a safety operation to protect whole multiple layered network systems from attackers. This research fully analyzes a complex network with the compact mathematical forms and theoretically tractable results for predicting the moment of a safety operation execution are fully obtained. Additionally, simulation results are demonstrated to obtain the optimal values of configuring parameters of a blockchain-based security network. The Matlab codes for the simulations are publicly available to help those whom are constructing an enhanced decentralized security network architecture through this proposed integrated theoretical framework.

A REAL TIME SPEED MODULATION SYSTEM TO IMPROVE OPERATIONAL ABILITY OF AUTONOMOUS PLANING CRAFT IN A SEAWAY

This study focuses on developing a control system to enhance the seaworthiness of Autonomous high-speed Planing Crafts (APCs). APCs operating at high-speed in a seaway encounter very high vertical accelerations which pose a hazard to payload and crafts' structural integrity. Therefore, for safety operation of APCs in a seaway it is proposed to employ a system termed vision-aided speed modulation system (VSMS). The proposed VSMS employs an embedded analytical tool termed Motion Assessment of Planing Craft in a Seaway (MAPCS) for the prediction of vertical accelerations and angular velocities, the APC might encounter in the incoming waves. As a response to the MAPCS predicted values the VSMS speed setting module modulates the craft's forward speed. All modules of the VSMS are presented together with their validation and system's preliminary operational results. It is concluded that VSMS might be an essential tool to considerably enhance the operational ability of APCs.

Seepage behavior assessment of earth-rock dams based on Bayesian network

Seepage behavior assessment is an important part of the safety operation assessment of earth-rock dams, because of insufficient intelligent analysis of monitoring information, abnormal phenomena or measured values are often ignored or improperly processed. To improve the intelligent performance of the monitoring system, this article has established an assessment framework covering project quality, maintenance status, monitoring data analysis, and on-site inspection based on the relevant norms of seepage safety assessment of earth-rock dams and the expert survey scoring method, and the Leaky Noisy-OR Gate extended model were used to determine the probability of events, and the dynamic and static Bayesian networks used to assess the possibility of seepage failure of earth-rock dams and diagnose the most likely cause of failure. The function of static and dynamic Bayesian networks to assess the seepage behavior of earth-rock dams, abnormal measured values, and causes of anomalies can make up for the limitations of reservoir management personnel and monitoring system in seepage failure experience and seepage knowledge of earth-rock dams and enable better handling of abnormal phenomena and monitoring information, making the monitoring system more intelligent.

Transient DC Over-Voltage Protection for ITER PF AC/DC Converter

The International Thermonuclear Experimental Reactor (ITER) poloidal field (PF) AC/DC converters are composed by thyristor-based phase controlled converter modules. As the core component of ITER PF AC/DC converter, the thyristor is very sensitive to over-voltage and damaged in microseconds, therefore, the transient over-voltage protection strategy is desperately essential to ensure the converter safety operation. In this paper, a nanosecond respond and high reliability protection strategy which combined by Metal Oxide Varistor (MOV) and external bypass is proposed to protect the ITER PF AC/DC converter from transient DC over-voltage. The MOV is designed to certify the fast respond in nanosecond. Moreover, a bidirectional BreakOver Diode (BOD) circuit board is designed to activate external bypass to ensure the reliability of the transient DC over-voltage protection strategy. The performance-testing platform is built to study its performance. The experiments on ITER PF AC/DC converter test facility are carried out. According to the experiment results, the external bypass is triggered by BOD board effectively and the load current is transferred to the external bypass in 2 us when BOD suffers from an over-voltage. The effectiveness of the proposed transient DC over-voltage protection strategy is verified.

Hybrid Architectural Network Implementation to Realize a Fire Evacuation Path with 2.4 GHz Zigbee and LoRa

The Internet of Things (IoT) is playing a significant role in realizing real monitoring. In fire safety and evacuation, early fire event detection using IoT-enabled sensors may help to control and minimize further consequences of the fire accident. In this study, we propose a hybrid architecture based on 2.4 GHz Zigbee and long-range (LoRa) for real-time fire detection, monitoring, and assisting in the safe evacuation of the building. The architecture comprises five different components, namely: end device, evacuation path display controller, safety operation controller, vision node, and gateway. The end device and vision node provide real-time sensory data and visuals that provide details of fire occurrence. The evacuation path display controller and the safety operation controller based on the 2.4 GHz Zigbee receive data from the end device and make the decision accordingly. In addition, a Zigbee simulation is performed on the OPNET simulator to analyze the network parameters such as throughput, retransmission attempts, medium access (MAC) queue size and queue delay, and packet delivery ratio (PDR). The evaluation metrics of link budget and ToA of LoRa are also calculated by varying the code rate and spreading factor. To realize the proposed architecture, customization of hardware is carried out with the development of hardware prototypes. Dijkstra’s shortest path algorithm is implemented in the evacuation path display controller to provide the shortest evacuation path during a fire incident. The hardware of the system is implemented in real-time, and the system provides real-time sensor data along with the evacuation path.

A Fault Diagnosis Method Based on EEMD and Statistical Distance Analysis

Serious vibration or wear with large friction usually appear when faults occur, which leads to more serious faults such as the destruction of the oil film, bringing great damages to both the society and economic sector. Therefore, the accurate diagnosis of a fault in the early stage is important for the safety operation of machinery. To effectively extract the fault features for diagnosis, EMD-based methods are widely used. However, these methods spend lots of efforts diagnosing faults and require plenty of professional knowledge of diagnosis. Although many intelligent classifiers can be used to automatically diagnose faults such as wear, a broken tooth and imbalance, the combing EMD-based method, the scarcity of samplings with labels hinder the application of these methods to engineering. It is because the model of the intelligent classifier must be constructed based on sufficient samplings with a label. To solve this problem, we propose a novel fault diagnosis method, which is performed based on the EEMD and statistical distance analysis. In this method, the EEMD is used to decompose one original signal into several IMFs and then the probability density distribution of each IMF is calculated. To diagnose the fault of the machinery, the Euclidean distance between the signal acquired under an unknown fault with the other referenced signals acquired previously under various fault types is calculated. At last, the fault of the signal is the same with the referenced signal when the distance is the smallest. To verify the effectiveness of our proposed method, a dataset of bearings with different faults, and a dataset of 2009 Prognostics and Health Management (PHM) data challenge, including gear, bearing and shaft faults are used. The result shows that the proposed method can not only automatically diagnose faults effectively, but also fewer samplings with a label are used compared with the intelligent methods.

UAS Safety Operation – Legal Issues on Reporting UAS Incidents

Introduction. This paper examines regulations which govern procedures for reporting incidents other than accidents or serious incidents related to unmanned aircraft system (UAS) operations. The regulations are discussed in the context of available data and the paper included an analysis of them from both a European and national perspective. The goal of the paper is to provide a series of recommendations with regard to the procedures for reporting and analyzing UAS incidents in order to improve the safe integration of unmanned and manned aviation. This article also explores the legal consequences that arise from the midair collision between a UAS and a manned aircraft. Material and methods: The method of study comprises a content analysis of existing legislations. The current doctrine was confronted with existing regulations, documents and materials. Results: The results of the study show that there is a practical problem of objectively identifying operators of a UAS as well as in defining what exactly constitutes an “incident”. It can be reasonably concluded that reporting and analyzing UAS-related incidents allows for the assessment and development of strategies for integrating manned and unmanned aviation. It is worth mentioning that drones and UAS technology requires refinement, especially in technological terms. It is reasonable to take action aimed at raising awareness amongst UAS users of the need to report incidents, as well as engaging UAS users in the investigative process which follows such occurrences.

Heuristic Feature Selection for Wind Power Anomaly Events Study

Wind power ramp events are typical harmful anomaly events in wind engineering, which bring new threat to the safety operation of power systems. To in-depth understand ramps and mitigate their harms, suitable ramp characteristics are crucial in many studies, e.g., ramp definition, classification, prediction and so on. However, due to ramps’ specificity on event feature, more profound characteristics are needed besides basic ramp morphological characteristics. In this paper, an approach for extracting and selecting ramp characteristics is proposed for ramp study. First, according to ramps’ causation on energy change, wavelet transformation is introduced to analyze ramp categories, and used to extract ramp energy characteristics. Then, heuristic feature selection methods are proposed to select ramp characteristics based on specific ramp application contexts. The objective of feature selection is to remove redundant characteristics, and to improve ramp studies’ performance. Finally, combining basic ramp characteristics and wavelet characteristics, ramp studies on category classification and prediction of appointed characteristics are implemented on industrial data. The computational results validate the usefulness of wavelet characteristics, the feasibility of the proposed approach, and that performance of ramp study could be improved by using ramp characteristics in this paper.

Radiation Safety Exploration Using Radio-photoluminescence Dosimeter for Crookes Tubes in Junior and Senior High School in Japan

Background: Crookes tube is utilized in junior high and high schools in Japan to study the character of electrons and current, and not for radiological education. There is no official guideline or regulation for these radiation source to the public. Therefore, most teachers have no information about the leakage of X-rays from Crookes tube. The peak energy of X-rays is approximately 20 keV, and it is impossible to measure using conventional survey meters.Materials and Methods: Each leakage dose of low energy X-rays from 38 Crookes tube in the education field, such as junior and senior high schools in Japan, was explored by the teachers in the school using radio-photoluminescence (RPL) dosimeters. Before and after the measurements, the dosimeters were sent by postal mails.Results and Discussion: At the exploration in this study, it was estimated that the 70 μm dose equivalent, Hp(0.07) of X-rays from 31 Crookes tubes were smaller than 100 μSv in 10 minutes, at the distance of 1 m, where the Crookes tube was usually observed. However, the highest dose was estimated as 0.69 mSv by an equipment with the full power. Furthermore, one Crookes tube exhibited 0.62 mSv with minimum output power of the induction coil. This relatively large dose was reduced by the shorter distance of discharge electrodes of the induction coil.Conclusion: The leakage dose of low energy X-rays from 38 Crookes tube was explored using RPL dosimeters. It was estimated that the Hp(0.07) of X-rays from 31 Crookes tubes were smaller than 100 μSv in 10 minutes at the distance of 1 m, while some equipment radiated a higher dose. With this study, the provisional guideline for the safety operation of Crookes tube is established.

Brazil Deepwater BC-10 ESP Operation without Downhole ESP Gauges

The paper reports on the integrated approach for the Brazil Deepwater BC-10 Electrical Submersible Pump (ESP) Operation without Downhole ESP gauges to safety operate the system and surveillance on light to heavy viscosity fluids and two phases, liquid – gas flow. The Electrical Submersible Pumping (ESP) system uses in Brazil are multistage centrifugal pumps for high rate and high boost applications inside a vessel system (caisson) powered with Pressure and Temperature gauges in each caisson, Venturi flowmeter at the discharge of the pump and a Motor POD located at the bottom of the motor that provides internal motor winding temperature (MWT), ESP vibration and Motor External Pressure for safety operation and to help predict ESP performance. To operate Brazil ESP systems without downhole gauges, an integrated analysis was performed to understand the more important and minimum acceptable variables required to operate the system, substitutions for the essential gauges and bypassed for non-critical gauges for ESP operations. Extended study and analysis were performed to cover in detail each of the alarms to allow running the ESP but maintaining the capacity to protect the system which will be the focus for this paper. All possible scenarios were considering and modelled for TRIP alarms such as out of range MWT, vibration, boost pressure, flow, pressure and temperature at the discharge to ensure capability functions for the critical variables were still available for the safety operation of the system. Low/High flow is a condition that may lead to ESP performance problems, in case of prolonged operation, a correlation from Gasmer Testing (1) based on ESP Boost and VFD current is proposed to calculate pump flowrate for safety operation to avoid ESP failures. The main technical contributions of this work are the detail approach, modeling and analysis for safety field operation without downhole gauges for predicting pump and motor performance. This study determines the minimum number of acceptance variables required and substitutions, as well variables that can be bypasses for non-critical gauges for ESP operations.