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Unmanned Ground Vehicle for Autonomous Non‐Destructive Testing of FRP Bridge Decks

AIP Conference Proceedings 2007年第1期894卷 1723-1730页

作者： P. Klinkhachorn A. Scott Mercer Udaya B. Halabe Hota V. S. GangaRao 1Lane Department of Computer Science and Electrical Engineering West Virginia University Morgantown WV 26505‐6109 2Department of Civil and Environmental Engineering Constructed Facilities Center West Virginia University Morgantown WV 26505‐6103

Current non‐destructive techniques for defect analysis of FRP bridge decks have a narrow scope. These techniques are very good at detecting certain types of defects but are not robust enough to detect all defects by themselves. For example, infrared thermography (IRT) can detect air filled defects and Ground Penetrating Radar (GPR) is good at detecting water filled ones. These technologies can be combined to create a more robust defect detection scheme. To accomplish this, an Unmanned Ground Vehicle (UGV) has been designed that incorporates both IR and GPR analysis to create a comprehensive defect map of a bridge deck. The UGV autonomously surveys the deck surface and acquires data. The UGV has two 1.5 GHz ground coupled GPR antennas that are mounted on the front of the UGV to collect GPR data. It also incorporates an active heating source and a radiometric IR camera to capture IR images of the deck, even in less than ideal weather scenarios such as cold cloudy days. The UGV is designed so that it can collect data in an assembly line fashion. It moves in 1 foot increments. When moving, it collects GPR data from the two antennas. When it stops it heats a section of the deck. The next time it stops to heat a section, the IR camera is analyzing the preheated deck section while preparing for the next section. Because the data is being continually collected using this method, the UGV can survey the entire deck in an efficient and timely manner.

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The Effects of Heating Methods on Infrared Thermography

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AIP Conference Proceedings 2007年第1期894卷 1593-1599页

作者： A. Scott Mercer P. Klinkhachorn Udaya B. Halabe Hota V. S. GangaRao 1Lane Department of Computer Science and Electrical Engineering West Virginia University Morgantown WV 26505‐6109 2Department of Civil and Environmental Engineering Constructed Facilities Center West Virginia University Morgantown WV 26505‐6103

Infrared (IR) Thermography is a good way of detecting air filled defects in FRP decks. When heat is applied to the deck surface, the material over the air void heats up faster and becomes hotter than the surrounding area and an IR camera can distinguish this defective area from a sound area in the deck based on surface temperature measurements. Since this technique requires application of heat in order to produce results, it seems only logical that one should research the effects of different heating types on the defect analysis. For this study, various heat sources; such as the sun, a 5000 BTU quartz electric heater, a 9000 BTU propane convection heater, and a 35000 BTU forced air propane heater, were used to heat up an FRP deck specimen with built‐in defects for IR analysis. Different heating times were used to determine the effects on the accuracy and the total elapsed time involved in seeing a defect in the resultant IR images. A few methods, such as CO2 cooling, for decreasing the time it takes to see the defect in the image were also explored.

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Active Thermography for the Detection of Defects in Powder Metallurgy Compacts

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AIP Conference Proceedings 2007年第1期894卷 1312-1319页

作者： Souheil Benzerrouk Reinhold Ludwig Diran Apelian 1Powder Metallurgy Research Center METAL PROCESSING INSTITUTE Worcester Polytechnic Institute Worcester MA 01609 2Department of Electrical and Computer Engineering Worcester Polytechnic Institute Worcester MA 01609

Active thermography is an established NDE technique that has become the method of choice in many industrial applications which require non‐contact access to the parts under test. Unfortunately, when conducting on‐line infrared (IR) inspection of powder metallic compacts, complications can arise due the generally low emissivity of metals and the thermally noisy environment typically encountered in manufacturing plants. In this paper we present results of an investigation that explores the suitability of active IR imaging of powder metallurgy compacts for the detection of surface and sub‐surface defects in the pre‐sinter state and in an on‐line manufacturing setting to ensure complete quality assurance. Additional off‐line tests can be carried out for statistical quality analyses. In this research, the IR imaging of sub‐surface defects is based on a transient instrumentation approach that relies on an electric control system which synchronizes and monitors the thermal response due to an electrically generated heat source. Preliminary testing reveals that this newly developed pulsed thermography system can be employed for the detection of subsurface defects in green‐state parts. Practical measurements agree well with theoretical predictions. The inspection approach being developed can be used for the testing of green‐state compacts as they exit the compaction press at speeds of up to 1,000 parts per hour.

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Estimation of Fatigue Damage for an Austenitic Stainless Steel (SUS304) Using Magnetic Methods

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AIP Conference Proceedings 2007年第1期894卷 1290-1297页

作者： M. Oka T. Yakushiji Y. Tsuchida M. Enokizono 1Department of Computer and Control Engineering Oita National College of Technology 1666 Maki Oita 870‐0152 Japan 2Department of Mechanical Engineering Oita National College of Technology 1666 Maki Oita 870‐0152 Japan 3Department of Electrical and Electronic Engineering Faculty of Engineering Oita University 700 Dannoharu Oita 870‐1192 Japan

There are some fatigue damage estimation methods of the austenitic stainless steel that uses the martensitic transformation. For instance, they are the remanent magnetization method, the excitation method, and so on. Those two methods are being researched also in our laboratory now. In the remanent magnetization method, it is well known that the relation between fatigue damage and the remanent magnetization is simple, clear, and reproducible. However, this method has the disadvantage to need a special magnetizer. This method cannot be easily used on the site such as the factory. On the other hand, because the special magnetizer is unnecessary, the excitation method can use easily on the site. The output signal of this method is small. In this paper, two fatigue evaluation methods such as the remanent magnetization method and the excitation method are introduced. In addition, we report on the result of comparing the fatigue evaluation performances of two methods.

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Fabrication and Electrical Characterization of Lambda DNA Field Effect Transistors

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AIP Conference Proceedings 2007年第1期893卷 359-360页

作者： Jong‐Seung Hwang Maeng Ho Son Sung Woo Hwang Doyeol Ahn 1Institute of Quantum Information Processing and Systems University of Seoul Jeonnong Dongdaemoon Seoul 130‐743 Korea 2Department of Electronics and Computer Engineering Korea University Anam Sungbuk Seoul 136‐075 Korea

We report fabrication and characterization of lambda DNA field effect transistors. Our transistor is basically a DNA network formed in between the source and the drain electrode on a SiO2/Si substrate. Measured source‐drain current (ISD) as a function of the source‐drain bias shows nonlinear characteristics. Such non‐linearity is typically a manifestation of the semiconducting behavior and is believed to be caused by the energy gap of the DNA molecules. Our sample shows a field effect behavior and we observe that ISD increases as the gate bias becomes more negative. It suggests that the lambda DNA used in our experiment is a p‐type molecule.

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An Interactive HIFU Therapy Planning Using Simulation & Visualization

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AIP Conference Proceedings 2007年第1期911卷 150-156页

作者： Liangshou Wu Viren Amin Ron Roberts Timothy Ryken 1Center for Nondestructive Evaluation Iowa State University Ames Iowa 2Department of Electrical and Computer Engineering Iowa State University Ames Iowa 3Departments of Neurosurgery and Radiation Oncology University of Iowa Iowa City Iowa

Planning of HIFU therapy using patient‐specific data is crucial for successful results. We are developing integrated tools for HIFU therapy planning using pre‐treatment imaging, HIFU simulation, and interactive visualization. We employ techniques for 2D/3D image segmentation to generate layered surface model; ultrasound simulation of beam intensity distribution and HIFU temperature profiles; visualization of integrated 3D anatomy and US beam simulation; and interactive strategy planning for studying the approaches of HIFU delivery. We present a systematic approach for developing and integrating these tools in interactive software using C++, OpenGL, C♯.Net, and ITK. With interactive visualization of the HIFU simulation parameters and the tissue effects, a range of scenario could be studied for an optimal HIFU delivery for a given patient. This continuing work has potential to aid development of optimized high‐precision HIFU dosimetry and patient‐specific planning strategies by reducing the guess work on dosage parameters and thereby reducing the overall treatment duration and reduced exposure to non‐target tissues.

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A MEMS‐Based Micro Biopsy Actuator for the Capsular Endoscope Using LiGA Process

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AIP Conference Proceedings 2007年第1期879卷 1443-1446页

作者： Sunkil Park Kyo‐in Koo Gil‐sub Kim Seoung Min Bang Si Young Song Chong Nam Chu Doyoung Jeon Dongil “Dan” Cho 1School of Electrical Engineering and Computer Science ASRI NBSRC ISRC NAVRC Seoul National University Korea 2Department of Internal Medicine Yonsei University College of Medicine Korea 3School of Mechanical and Aerospace Engineering Seoul National University Seoul Korea 4Department of Mechanical Engineering Sogang University Seoul Korea

This paper presents a LiGA (German acronym for LIthografie, Galvanoformung, Abformung) based micro biopsy actuator for the capsular endoscope. The proposed fabricated actuator aims to extract sample tissues inside small gastric intestines, that cannot be reached by conventional biopsy. The actuator size is 10 mm in diameter and 1.8 mm in length. The mechanism is of a slider‐crank type. The actuator consists of trigger, rotational module, and micro biopsy tool. The core components are fabricated using the LiGA process, for overcoming the limitations in accuracy of conventional precision machining.

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Fusion of Microwave and Eddy Current Data for a Multi‐Modal Approach in Evaluating Corrosion Under Paint and in Lap Joints

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AIP Conference Proceedings 2007年第1期894卷 611-618页

作者： K. Gupta M. T. Ghasr S. Kharkovsky R. Zoughi R. J. Stanley A. Padwal M. O’Keefe D. Palmer J. Blackshire G. Steffes N. Wood 1Electrical and Computer Engineering Department University of Missouri‐Rolla Rolla MO 65409 2Department of Material Science and Engineering University of Missouri‐Rolla Rolla MO 65409 3The Boeing Company Boeing Phantom Works St. Louis MO 63166 4Air Force Research Laboratory (AFRL) Wright Patterson OH 45433

Critical aircraft structures are susceptible to hidden corrosion. Find‐it and fix‐it approaches are inefficient as it relates to managing the problems associated with corrosion. More comprehensive corrosion information may be obtained using data fusion from several detection and evaluation methods. To this end, microwave, conventional and pulsed eddy current data from a multi‐layer corroded panel, representing an aircraft lap joint, are fused and used as inputs to a structural analysis model to obtain a comprehensive snapshot of the corroded environment. This paper presents the data fusion algorithm and the structural analysis model along with a discussion of the results.

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An Experimental Study of Effects of Overlaying Tissues on HIFU Lesion

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AIP Conference Proceedings 2007年第1期911卷 237-241页

作者： Tao Long Viren Amin Ronald Roberts R. B. Thompson Scott McClure Timothy Ryken 1Center for Nondestructive Evaluation Iowa State University Ames Iowa 2Department of Electrical and Computer Engineering Iowa State University Ames Iowa 3Department of Veterinary Clinical Sciences Iowa State University Ames Iowa 4Department of Neurosurgery and Radiation Oncology University of Iowa Iowa City Iowa

Understanding the effect of overlaying tissues on HIFU lesion is crucial for estimating HIFU dose distribution at a target tissue. We have run a series of experiments to systematically observe the effects of the overlaying tissues on the HIFU beam and ultimately the lesion created in the target tissue. First, we mapped out the HIFU transducer beam (in low power) under water without and with different overlaying tissue layers. Then, we performed a series of experiments in high power to create lesions in target tissues (e.g., liver) without and with overlaying tissues (e.g. muscle). The lesions are characterized by slicing the tissues and reconstructing the 3D lesion from calibrated pictures of the target tissue slices. The low power beam measurements show significant effects in terms of severe beam wave‐field amplitude distortion due to phase aberration introduced by velocity inhomogeneity in the overlaying tissues. These results compare well qualitatively with the computational models. The results from the high power HIFU lesions in a similar setup using various tissues, including liver and muscle, provide understanding of the significance of phase aberration in overlaying tissues and could prove useful towards high precision HIFU therapy.

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Further Development of the Simulation of Sonic IR Imaging of Cracks in Metals with Finite‐Element Models

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AIP Conference Proceedings 2007年第1期894卷 471-477页

作者： Xiaoyan Han Md. Sarwar Islam G. M. Newaz L. D. Favro R. L. Thomas 1Department of Electrical and Computer Engineering Wayne State University Detroit MI 48202 2Department of Mechanical Engineering Wayne State University Detroit MI 48202 3Institute for Manufacturing Research Wayne State University Detroit MI 48202 4Physics Department Wayne State University Detroit MI 48202 4aCollege of Science Wayne State University Detroit MI 48202

Sonic IR imaging, which combines infrared imaging and ultrasound excitation, as a relative new member of the NDE family, has been drawing wider and wider attention due to its fast, wide area inspection capability. In our previous presentations and publications, we have described the application of acoustic chaos to Sonic IR imaging and have provided experimental illustrations as well. In addition, we have described realistic finite‐element models that simulate the heating of cracks in metals by both chaotic and non‐chaotic sound. These models allow for both friction and plastic deformation as sources of heating. In this paper, we present our further study on the physical mechanisms that are responsible for the advantages of chaotic sound for Sonic IR crack detection. Using finite‐element analysis, here we will present theoretical explanations, both for the origin of the chaos, and for the mechanisms responsible for the chaotic enhancement of crack detection.

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