Taiwan Association of Engineering and Technology Innovation: E-Journals
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On the Behavior of Lateral Pipe-Soil Interaction in Ultra-Soft Clayey Soil Using Large Scale-Laboratory Tests
Get PDFOne of the most essential challenges in the deep offshore environments is the lateral pipe-soil interaction movement in very soft soils. Thus, several comprehensive large-scale physical models with dimensions of (2.4 m*2.4 m*1.8 m) have been constructed to examine the behaviour of lateral pipe-soil interaction on a simulated seabed. In this study, large-scale model tests were performed through a special loading frame, using instrumented pipes placed on ultra-soft clayey soil to quantify the lateral pipe-soil interaction by using a precise remote gridding system. The effects of several real field conditions such as pipe end conditions, pipeline material, soft soil shear strength, rate of loading, and pipe size were inspected extensively. It was shown that the fixed-end boundaries developed more resistance up to 50% against lateral displacement in comparison to the free-end boundaries. Moreover, the maximum resistance of the plastic pipe was 64% more than the steel pipe
Enhanced Multi-factor Out-of-Band Authentication En Route to Securing SMS-based OTP Ariel
Get PDFValidation of user’s authenticity through authentication played a crucial role to address risks and security issues in today's connected world. Among different authentication methods, OTP sent via SMS was identified as the most commonly used multi-factor authentication mechanism. However, studies have shown that it has not remained attack-proof. It has been branded to be vulnerable to SMiShing, a technique comparable to Internet phishing, and Eavesdropping accomplished through keylogging, screens capturing, shoulder surfing and other social engineering practices. This study introduced an innovative approach to secure SMS-based OTP against its threats through OTP encryption using modified Blowfish algorithm. A mobile application was also employed for capturing and processing encrypted SMS-based OTP to produce new OTP for verification, thus performing end-to-end OTP. Experimentation results and analysis revealed that the proposed architecture was free against the said vulnerabilities and promote tighter security, making it a good alternative for SMS-based OTP multi-factor authentication
Complex Independent Laboratory Tests to Signify Fuel Economy and Emissions under Real World Driving
Get PDFWe discuss the shortcomings of the current European Union emission rules, which are not likely to produce any improvement of fuel economy and emissions during real-world driving vs. the pre-Diesel gate rules, because of flaws in the prescribed laboratory and on-the-road tests. The present chassis dynamometer emissions certification test is oversimplified, not representative, and not properly performed. The simple addition of generic on-the-road real-world driving tests does not help, because these tests have poor accuracy and repeatability. Therefore, we suggest the use of a more realistic, complicated, suite of driving cycles, to be rigorously performed with chassis dynamometer equipment by independent bodies, rather than the Original Equipment Manufacturers (OEMs). Additionally, we suggest that emission limits be revised, to permit the optimal mix between different engine technologies and different fuels
Application of Rotating Arms Type Permanent Magnet Motor
Get PDFThe present application related to a rotating arm type permanent magnet motor, in particular to a permanent magnet motor that was actuated by the action of the magnetic forces of a permanent magnet stator of a stator module and two thin ring permanent magnets of a rotor module. The purpose of present permanent magnet motor was to provide the torque produced by a magnetic force of the magnetic energy of a stator to drive the rotation of the rotor. The rotating arm type permanent magnet motor comprised an external support frame base, a stator module and a rotor module. The external support frame base included an upper frame, a lower frame and two side frames. The stator module included an elastic metal plate cantilever arm and a permanent magnet stator. The rotor module included a rotating shaft, a double arc shaped rotating arms type support frame, and two thin ring permanent magnets. Magnet material N45H (sintered Nd–Fe–B) was used for the permanent magnets of stator and rotor. The values of magnetic forces (attraction force and exclusion force) were inverse proportional to the position distances of poles (N pole and S pole) above the top level of thin ring permanent magnets, e.g. c= 12mm. The greater value of magnetic forces got the faster rotation speed. The values of magnetic forces could produce the good enough torque for the thin ring permanent magnets to rotate the shaft when position b= 8mm better than that when position b= 17mm. In the future, with the help of using an external swing motion of electrical controlled swing-type device to produce complete rotation, the present permanent magnet motor might save electricity and power sources. Some preliminary rotation speed data of rotating shaft in a permanent magnet motor were obtained and presented with manually controlled
Consensus via Adaptive Gain Controllers Considering Relative Distances for Multi-Agent Systems
Get PDFIn this paper, for multi-agent systems (MASs) with leader-follower structures, we present a linear matrix inequality (LMI)-based design method of an adaptive gain controller considering relative distances between agents. The proposed adaptive gain controller consists of fixed gains and variable ones tuned by time-varying adjustable parameters. The objective of this paper is to derive enough conditions for the existence of the proposed adaptive gain controller which achieves consensus for each agent. The advantages of the proposed adaptive gain controller are as follows; The proposed controller can be obtained by solving LMI, and the proposed control system can achieve consensus and formation control, even if uncertainties are included in the information for relative distances. In this paper, we show that the design problem of the proposed adaptive gain controller can be reduced to the solvability of LMI. Finally, simple numerical examples are included to illustrate the effectiveness of the proposed adaptive gain controller for MASs
Enhancing Security Levels at ISP Server Using Multiple Security Techniques with Proposed Crypo Application
Get PDFThe internet is widely used in computing. Security is an important aspect when the quality of service is evaluated and current security possesses high level encryption techniques. However, due to high data saturation and complexity, it is not enough for, only to rely on the common security techniques. In this paper, proposed application named Crypo is installed at both ends, including user and Internet Service Provider (ISP). User can connect to the public internet through providing credentials. Both ends work with same cryptographic techniques and logics. Crypo includes the existing security techniques with proposed logics. Attribute Based Encryption (ABE) is applied to user credentials. Cipher policy applies to data exchange between user and Internet Service Provider (ISP) to form a combined cipher data. Proposed logic is further applied to the binary formatted cipher data. According to proposed logic, the final encrypted binary formatted data are further applied with Advanced Encryption Standard (AES) to deliver it to the ISP. Decryption is done by the same logic applied to the sender side or vice versa. When data is retrieved by ISP from its end user, it is decrypted by the ISP after which is delivered to the public network in normal format. Four level security keeps the data and user credentials confidential. Intruders or hackers can’t reach to the end user without decrypting the secured data at ISP. While delivering encrypted data, applied logic name is also delivered so that end users can decrypt data using the same logic. By using proposed application Crypo, a secure connection is established between the end user and the ISP. An outsider cannot cause threat to the ISP’s users. Proposed multilevel cryptographic approach enhances the security
Prediction of Pressure Gradient in Two and Three-phase Flows in Horizontal Pipes Using an Artificial Neural Network Model
Get PDFConcurrent flow of gas with a mixture of oil and water in production equipment is common necessitating the need for additional investigations to gain more insight and development of more accurate correlations for prediction of flow characteristics including pressure drop. In this study, an experimental study was conducted using air-water and air-water-oil mixtures in a 0.075-m diameter pipe. Superficial gas and liquid velocities ranged from 0.03 to 0.13 m/s and 1.26 to 41.58 m/s respectively. Slug flow was the main flow pattern observed. In addition, transition to annular and annular flow were also observed. Due to the homogeneous nature of the oil-water-air mixture, the three-phase flow was evaluated as a pseudo-two-phase mixture. An Artificial Neural Network (ANN) model developed for the prediction of two- and three- phase pressure drop performed better than all models considered during the evaluation. Generally, it is found that the accuracies for pressure drop were considered adequate
Design and Testing of a Remote Deployable Water Purification System Powered by Solar Energy
Get PDFThe design of an all-inclusive, self-sufficient, sustainable water purification system for application in developing regions of the world can improve living conditions for people world-wide, especially in regions where access to clean drinking water is limited or unavailable. According to the World Health Organization, the 2015 global census estimated that 663 million people worldwide live without access to safe drinking water sources [1]. An estimated 315,000 children die each year from diarrheal diseases caused by lack of clean water and poor sanitation [2]. Based on these statistics, an all-inclusive, self-sufficient, remote-deployable water purification system has been designed, constructed, and tested to validate the concept of a renewable energy system.The system is integrated into a standard 20-foot shipping container for ease of deployment worldwide. Once situated in the operating area, the shipping container is used as the system shelter and solar panels are mounted to the roof at a location-dependent fixed angle. The solar panels are connected to a battery bank which operates the system. The water purification process utilizes a five-step progression which filters the contaminated freshwater, removing suspended particles and bacteria from the water and purifying the water to the standards of the EPA Safe Drinking Act [3].Testing verifies the capability of the solar panels to generate enough electricity to power the system and recharge the battery bank. The solar panel array has the rated power output of 2,320 Watts. The water purification operates on a maximum of 97.9 Watts of available power. With the fully charged battery bank, the water purification system can operate for 24-hours without additional solar input. With a freshwater source, the purification system can yield up to 440 liters of water per hour
A Study on Heading and Attitude Estimation of Underwater Track Vehicle
Get PDFIn this paper, we studied the designing and manufacturing of an underwater track vehicle (UTV) that can be operated in the underwater environment. We designed the electrical and control system for precise operation of the UTV and conduct test operation by using the UTV. We developed an attitude reference system (ARS) that was composed of the ring laser gyro (RLG) sensor, a geomagnetic sensor, and USBL sensor to estimate precise heading and attitude of the UTV. An inertial navigation system (INS) is developed to be combined with the developed ARS. Also, the INS navigation is configured by supplementing the USBL sensor information. We design a controller for a precise trajectory and attitude tracking by installing the ARS on the UTV. In this paper, we used an extended Kalman filter in the INS to estimate the position and attitude of the UTV. The ARS is studied to obtain more precise sensor information in an uncertain environment underwater. Performance tests of the developed INS using the UTV are conducted and the results show that the system has the best performance
Performance Evaluation of MQTT as a Communication Protocol for IoT and Prototyping
Get PDFThe hypertext transfer protocol (HTTP) has been widely used as a communication protocol for Internet access. However, for Internet of things (IoT) communication, which is expected to grow in the future, HTTP requires a large overhead and cannot provide efficiency. In order to solve this problem, lightweight communication protocols for IoT have been discussed. In this paper, we clarify some problems of HTTP for IoT and propose MQ telemetry transport (MQTT), which is a promising candidate for the IoT protocol, after conducting a performance comparison with HTTP