Taiwan Association of Engineering and Technology Innovation: E-Journals
Not a member yet
887 research outputs found
Sort by
Flexible Macroblock Ordering Scramble Encryption Techniques for H.264/AVC Videos
Get PDFIn this paper, a new video encryption method through scrambling the compressed videos is presented, which is targeted for H.264/AVC video encryptionin order to provide the greatest content protection in the compressed domain.The proposed algorithm uses a macroblock switching mechanism to scramble the video contentfor the compressed video sequences. Only the instantaneous decoded reference (IDR) pictures are scrambled to take the advantage of drift error propagation from all the inter-prediction frames. The proposed encryption technique is designed to perform after the encoding process on the compressed bitstream such that bitstream is modified by the parser directly. Finally,the scrambled video is still format-compliant to a general H.264/AVC decoder and can only be recovered by the authorized user that owns private key. Based on experimental results, the scene in the scrambled video can be effectively protected by the proposed scheme with low computational complexity and negligiblebitrate overhead
Using Unsupervised Machine Learning to Detect Peer-to-Peer Botnet Flows
Get PDFThe war against botnet infection is fought every day by users that want to feel safe against any threat of compromise hosts. In this paper we are going to focus on the behavior of Peer 2 Peer (P2P) botnets, which along with hybrid botnets is a growing trend among attackers. The main approach will consist of a behavior comparison among features extracted from network flows, focusing only in the flows from P2P applications including P2P botnets
System Dynamics Approach for Bridge Deterioration Monitoring System
Get PDFBridge monitoring plays an important role in reducing catastrophic failure. Structural Health Monitoring (SHM) has been performed on one of the bridge components such as decks, girders, abutments/piers independently. However, the failure can be attributed either a component defect or combination among them. Bridge deterioration model requires the analysis of complex and dynamic variables. The system dynamic (SD) is a powerful simulation method to study the dynamic and complex systems. This paper aims to discuss the concept of bridge deterioration monitoring using SD approach. The proposed model utilized variables from the previous studies to represent the bridge component interrelationship, while SD will be used to simulate the probability of bridge failure and to find the dominant bridge component that influences the failure. The model can also be used as guidance for bridge deterioration mitigation and repair program
A Low-cost Design of Earthquake Detector with Rescue Message Deliver using Mobile Device
Get PDFThe earthquake detector is a complex and expensive device. It is necessary to design a simpler and cheaper earthquake detector for common use. Our research employs the ability of Android-based mobile device to design a minimal cost detector for sensing the earthquake. Therefore, as the earthquake occurring, the mobile device can detect the earthquake and issue a warning alarm to the phone owner. At the same time, a rescue messages including disaster location, earthquake level, and related information to the disaster center. Experimental results show that the proposed method can achieve the usage of disaster rescue
Combustion Synthesis of Mullite/Metal Boride Composites
Get PDFFormation of composite materials composed of mullite (3Al2O3×2SiO2) and transition metal borides (NbB2 and TaB2) was studied by self-propagating high-temperature synthesis (SHS). Starting materials included not only metal oxides (Nb2O5 and Ta2O5) and boron oxide (B2O3) as the sources of metallic elements and boron, but also Al and Si powders as the reducing agents. The evolution of mullite from in situ formed SiO2 and Al2O3 and synthesis of NbB2 and TaB2 were investigated. The effect of excess Si addition was studied on the combustion temperature, flame-front propagation velocity, and phase composition of the final product. For formation of the NbB2/mullite composites, the combustion velocity about 2.5 mm/s and reaction temperature around 1500 oC decreased slightly as the Si content increased. However, a considerable decrease in combustion front velocity from 2.74 to 1.43 mm/s and in reaction temperature from 1600 to 1250 oC was observed for the production of the TaB2/mullite composites. The XRD patterns of the final products confirmed the role of excess Si in the improvement of silicothermic reduction of B2O3 and subsequent evolution of NbB2, TaB2, and mullite. The EDS analysis indicated an atomic proportion close to that of 3Al2O3×2SiO2 for the mullite grains synthesized in this study
Optimization of Coupler inlet for Planar Solar Concentrator
Get PDFIn this study, we implemented optimization for the coupler inlets of the planar solar concentrator, which was proposed in our prior work. The planar solar concentrator had a waveguide slab to carry an array of light-collecting elements thereon. The light entering the elements is focused on the coupler inlets and guided into the slab with propagating therein through total internal reflection (TIR). Thus, all the light from the elements is guided to the ends of the slab and highly concentrated. Because the coupler inlets couple light into the slab and also decouple the light propagating in the slab in subsequent interactions, they must be optimized to balance between coupling efficiency and decoupling loss. The optimized arrangements of coupler inlets included three types here: uniform-thickness platform, stepped-thickness platform, and stepped-width platform. In the simulation, the three types have the same area of the inlet to keep the concentrator with the same tolerance of the incident angle of light. We analyzed both the optical efficiency and range of the vertical angular distribution of the light reaching the outlet end of the slab; then made a comparison for the three inlet arrangements. The simulation results demonstrate the stepped-thickness and stepped-width platforms provide higher efficiency and concentrated irradiance
A Circuit Device of Detecting the Bearing Deflection
Get PDFThis paper investigates the operation of the motor caused by the bearing deflection, we will design detection circuit to detect bearing deflection, the circuit includes coil, rectifier circuit and voltage measuring device. In the interior of the motor, coil has been designed in gap between the stator silicon steel, and then connect a rectifier circuit to an external motor, the rectifier circuit is connected to the voltage measurement terminal. When bearings close to stator silicon steel in the operation of the motor, the induced voltage of the coil will rise and transmit the voltage to rectifier circuit instantly. In this case, the voltage rectifier circuit will convert the DC voltage, the voltage delivered to the voltage measurement terminal, at this time, users can know the motor bearings have deflected phenomenon based on the DC voltage , and can immediately improve motor and maintenance operations
Nostril in RGB Imaginary by Using NI Vision LabVIEW
Get PDFMonitoring of breath function is needed for medical science to evaluate condition of patient for some diseases. The patient will be observed continuously on face (nostril). Face recognition is the most important stage to localize the measurement. Because of that need, thermal image is used to record changing temperature on patient face. Thermal image has two type image, gray and RGB image. In this paper, we used RGB image as the raw data and trying to find face, eye and, nostril as breathing indicator. We divided the nostril recognition in three main steps: eyes detection, calculate the center of mass between two eyes, measured the center of mass distance to nose, get nostril location. We applied image processing algorithm such as gray image, binary image and template matching. All those algorithm are programmed in NI Vision LabVIEW. The distance between subject and camera is fixed in 1 meter. The experimental result showed that nostril always detected even though the subjects have some movements during measurement. 
The Effect of the Curvature-Rate on the Response of Local Sharp-Notched SUS304 Stainless Steel Tubes under Cyclic Bending
Get PDFIn this study, the response of local sharp-notched SUS304 stainless steel tubes with different notch depths of 0.2, 0.4, 0.6, 0.8 and 1.0 mm subjected to cyclic bending at different curvature-rates of 0.0035, 0.035 and 0.35 m-1s-1 were experimentally investigated. The tube bending machine and curvature-ovalization measurement apparatus, which was designed by Pan et al. [1], were used for conducting the curvature-controlled cyclic bending. For a constant curvature-rate, the moment-curvature curve revealed that the cyclic hardening and became a steady loop after a few bending cycles; the notch depth had almost no influence on the curves. Moreover, the ovalization-curvature curve increased in an increasing and ratcheting manner with the number of bending cycles. Large notch depths resulted in larger ovalization of the tube cross-section. In addition, for a constant notch depth, higher curvature-rates led to larger cyclic hardening and faster increasing of ovalization
Composite Elements for Biomimetic Aerospace Structures with Progressive Shape Variation Capabilities
Get PDFThe paper presents some engineering solutions for the development of innovative aerodynamic surfaces with the capability of progressive shape variation. A brief introduction of the most significant issues related to the design of such morphing structures is provided. Thereafter, two types of structural solutions are presented for the design of internal compliant structures and flexible external skins. The proposed solutions exploit the properties and the manufacturing techniques of long fibre reinforced plastic in order to fulfil the severe and contradictory requirements related to the trade-off between morphing performance and load carrying capabilities