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Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

1996

National Taiwan Ocean University

Articles 1 - 8 of 8

Full-Text Articles in Engineering

Nondestructive Testing Of The Corrosive Damage Of Reinforced Concrete Structures Using Ultrasonic Method, Ming-Te Liang, Run Huang, Chii-Ming Jiang Jun 1996

Nondestructive Testing Of The Corrosive Damage Of Reinforced Concrete Structures Using Ultrasonic Method, Ming-Te Liang, Run Huang, Chii-Ming Jiang

Journal of Marine Science and Technology

The purpose of this study is to determine the corrosive damage of reinforced concrete members using the ultrasonic technique. The ultrasonic tester (type ULCON 3) connected the touched vertical-beam dictator (frequency: 50kHz, diameter=20mm) is used to measure the velocity and scan the concrete surface for predicting the corrosive damage, When the rebars are corroded, the ultrasonic wave propagation will very due to energy decay and velocity change. Based on the ultrasonic pulse velocity and amplitude, the structural quality of reinforced concrete can be predicted. Some results obtained from this investigation are described as follows: (1) 'The amplitude of refective wave …

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Network-Integrated Ship Automatic System And Internetworking To The Internet, Li-Der Chou, Jeng Yih Juang Jun 1996

Network-Integrated Ship Automatic System And Internetworking To The Internet, Li-Der Chou, Jeng Yih Juang

Journal of Marine Science and Technology

Many automatic systems developed for the merchant ships are focused on the Unmanned Machinery Space (UMS), and therefore it is necessary to build a local area network (LAN) on the ship in order to integrate these automatic systems. By means of the Inmarsat satellite system, the shipboard LAN is interconnected with the terrestrial communication networks such as the Internet. In the paper, the shipboard LAN is designed from the view point of survivability, and three concepts to reduce the satellite communication cost for the interconnection of the shipboard LAN and the Internet are proposed. Finally, the way to implement the …

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A Modularized Software Package For Adaptive Beamforming, Shun-Hsyung Chang, Shao-Wei Leu, Hsing-Wang Liang Jun 1996

A Modularized Software Package For Adaptive Beamforming, Shun-Hsyung Chang, Shao-Wei Leu, Hsing-Wang Liang

Journal of Marine Science and Technology

This paper presents a modularized simulation software package for adaptive beamforming. In recent years, the theory and technology of adaptive beamforming have been applied extensively in many different areas such as radar, sonar, communication systems, and geophysical exploration. As many new beamforming architectures and related algorithms are being introduced, researchers find themselves repeating the laborious process of writing similar software routines in order to conduct simulations. This is largely due to the lack of well-defined and modularized supporting software. Therefore, we have implemented a collection of representative algorithms available for adaptive beamforming and constructed a simulator with menu-driven user interface. …

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Spherical Surface Vibration Identification By Spherical Holography And Acoustic Intensity, Jen-Chieh Lee Jun 1996

Spherical Surface Vibration Identification By Spherical Holography And Acoustic Intensity, Jen-Chieh Lee

Journal of Marine Science and Technology

This study presents the capabilities of spherical surface vibration identification by using spherical acoustical holography and acoustic intensity measurement. The spherical holographic technique reconstructs the surface particle velocity from the acoustic pressure on the hologram. The acoustic pressure can be calculated from acoustic intensity measurement. The results of computer simulation show that, based on one direction acoustic intensity measurement only, spherical surface vibration can be identified from spherical holographic techniques.

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Manipulation Of Transfer Function Matrix Via State-Space Approach, Jeng Yih Juang Jun 1996

Manipulation Of Transfer Function Matrix Via State-Space Approach, Jeng Yih Juang

Journal of Marine Science and Technology

Algebraic manipulations of transfer function matrix via statespace approach will be given without referring to the symbolic manipulations involving the indeterminate s, for a linear continu-ous-time system (or, z, for a linear discrete-time system). The resultant transfer function is closely related to a state-space representation, and therefore is advantageous in realization, implementation, computer simulation and stability analysis. Furthermore, the design, implementation, and analysis of linear dynamic controllers, in the forms of 2-input-1-output and 2D (two degree of freedoms), are illustrated with numerical examples via the method proposed.

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Elastic Modulus Of Concrete Affected By Elastic Moduli Of Mortar And Artificial Aggregate, Chung-Chia Yang, Yon-Yer Lin, Ran Huang Jun 1996

Elastic Modulus Of Concrete Affected By Elastic Moduli Of Mortar And Artificial Aggregate, Chung-Chia Yang, Yon-Yer Lin, Ran Huang

Journal of Marine Science and Technology

The effect of two artificial aggregate types and three kinds of mortar on the elastic modulus of concrete are reported. Bighteen batches of concrete with various volume fractions (10%, 20%, and 30%) were selected. Theoretical moduli were calculated based on micromechanics. Following recent studies of concrete as a twophase composite material, this study examines whether there is a relation between the elastic modulus of the constituents and concrete. From the examination of available experimental results, it is apparent that elastic modulus of concrete is affected by elastic modulus of constituents and volume fraction of aggregate. Test results were compared with …

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Protection Of Steel Using Aluminum Sacrificial Anodes In Artificial Seawater, Tai-Ming Tsai Jun 1996

Protection Of Steel Using Aluminum Sacrificial Anodes In Artificial Seawater, Tai-Ming Tsai

Journal of Marine Science and Technology

The performance of aluminum alloys used as sacrificial anodes for cathodic protection in seawater was investigated in this study, Results show that A1 -3.5%Zn -0.05%In sacrificial anode alloy C has the best current efficiency, most negative open circuit potential and energy characteristics among five different Al-Zn-In alloys. Polarization curve of alloy C also shows no passivation behavior in artificial seawater. The corrosion rate of mild steel in artificial seawater was determined as a function of applied cathodic potential. The cathodic protection potential determined for mild steel in seawater was -0.78 V,SCE for a corrosion rate of less than 1 mpy. …

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A Study On Fabrication Of Zinc Oxide Thin Film Acoustic Sensors, C.C. Chang, J.H. Chang Jun 1996

A Study On Fabrication Of Zinc Oxide Thin Film Acoustic Sensors, C.C. Chang, J.H. Chang

Journal of Marine Science and Technology

In this study, acoustic sensors were formed by depositing a zinc oxide (ZnO) thin film on a silicon dioxide/silicon(SiO/Si) substrate using radio frequency (RF) planar-magnetron sputtering method. The results showed higher substrate temperatures and higher RF powers enhanced C-axis oriented structure of the Zno thin film and optimized the ZnO thin film acoustic property. The frequency spectrum measurement on the acoustic sensor underwater involved three peaks at frequencies 640 KHz, 2.4 MHz and 2.9 MHz, respectively. Sensitivity reached to -132.02 dBrelv/ upa. The results indicated that under the pressure of acoustic frequencies the sensor response was directly proportional to pressure …

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