Browsing by Author "Hung, Shih-Lin"

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A Computer-Aided Approach to Pozzolanic Concrete Mix Design
(2018-01-01)
Kao, Ching-Yun
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Shen, Chin-Hung
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Jan, Jing-Chi
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Hung, Shih-Lin
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土木工程學系
Pozzolanic concrete has superior properties, such as high strength and workability. The precise proportioning and modeling of the concrete mixture are important when considering its applications. There have been many efforts to develop computer-aided approaches for pozzolanic concrete mix design, such as artificial neural network- (ANN-) based approaches, but these approaches have proven to be somewhat difficult in practical engineering applications. This study develops a two-step computer-aided approach for pozzolanic concrete mix design. The first step is establishing a dataset of pozzolanic concrete mixture proportioning which conforms to American Concrete Institute code, consisting of experimental data collected from the literature as well as numerical data generated by computer program. In this step, ANNs are employed to establish the prediction models of compressive strength and the slump of the concrete. Sensitivity analysis of the ANN is used to evaluate the effect of inputs on the output of the ANN. The two ANN models are tested using data of experimental specimens made in laboratory for twelve different mixtures. The second step is classifying the dataset of pozzolanic concrete mixture proportioning. A classification method is utilized to categorize the dataset into 360 classes based on compressive strength, pozzolanic admixture replacement rate, and material cost. Thus, one can easily obtain mix solutions based on these factors. The results show that the proposed computer-aided approach is convenient for pozzolanic concrete mix design and practical for engineering applications.
A Displacement Frequency Response Function-Based Approach for Locating Damage to Building Structures
(2020-03-17)
Kao, Ching-Yun
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Chen, Xuan-Zhi
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Hung, Shih-Lin
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土木工程學系
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Department of Civil Engineering
Frequency response function (FRF) data can provide considerably more information on damage in the desired frequency range as compared to modal data extracted from a very limited range around resonances. Among structural health monitoring techniques, FRF-based methods have the potential to locate structural damage. Conventional structural damage detection technology collects structural response data using contact systems, such as displacement or acceleration transducers. However, installing these contact systems can be costly in terms of labor, cost, and time. Several noncontact measurement technologies, such as optical, laser, radar, and GPS, have been developed to overcome these obstacles. Given the rapid advances in optical imaging hardware technology, the use of digital photography in structural monitoring systems has attracted considerable attention. This study develops a displacement FRF-based approach to locate damage to building structures. The proposed damage location index, CurveFRFDI, improves the sensitivity of SubFRFDI, which is a substructure FRF-based damage location index proposed by Lin et al. (2012). Moreover, the feasibility of applying the proposed approach to locate damage to building structures using displacement measured by a digital camera combined with digital image correlation techniques is also investigated in this study. A numerical example and an experimental example are presented to demonstrate the feasibility of using the proposed approach to locate damage to building structures for single and multiple nonadjacent damage locations.
Active 433 MHz-W UHF RF-powered chip integrated with a nanocomposite m-MWCNT/polypyrrole sensor for wireless monitoring of volatile anesthetic agent sevoflurane
(2008-01-15)
Chavali, Murthy
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Lin, Tzu-Hsuan
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Wu, Ren-Jang
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Luk, Hsiang-Ning
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Hung, Shih-Lin
Tiny remote sensors capable of monitoring gases and vapors are having greatest demand due to their potential applications in diverse research fields. In the present work, design and fabrication of an active wireless UHF (433 MHz) RF-powered sensing system for monitoring volatile organic compounds is presented. The developed sensor chip consists of a thin film of gas-responsive composite material, based on modified multiwalled carbon nanotubes (m-MWCNTs) and polypyrrole (Ppy), coated over two comb-like interdigitated gold electrodes. Wireless modules have been integrated with the chemical sensor chip (composite m-MWCNTs/Ppy) and RF components to detect volatile anesthetic agent, fluoromethyl 2,2,2,-trifluoro-1-(trifluoromethyl) ethyl ether (sevoflurane) is demonstrated. (c) 2007 Elsevier B.V. All rights reserved.
Application of m-CNTs/NaClO4/Ppy to a fast response, room working temperature ethanol sensor
(2008-08-28)
Wu, Ren-Jang
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Huang, Yu-Ching
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Yu, Ming-Ru
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Lin, Tzu Hsuan
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Hung, Shih-Lin
A new blended material, m-CNTs/NaClO4/Ppy, was developed as a gas sensor to detect ethanol concentrations at room temperature. The sensing material polypyrrole (Ppy) was synthesized in situ by UV-photo-polymerization. The multiwall carbon nanotubes (m-CNTs) added enhanced the short-term repeatability of the Ppy-sensing material. The relative resistance variation (R-ethanol/R-air) of mCNTs/NaClO4/Ppy was 1.193 when exposed to ethanol of 30,000 ppm. The sensor response and recovery times (both 20s) were very short to this concentration. An unstable baseline of the sensor was explained by theoretical calculation of molecular dynamics made for ethanol adsorption on polypyrrole, which revealed formation of a new bond, N-H center dot center dot center dot O. Adsorption energy decreased with increasing the number of ethanol molecules adsorbed and was 0.8 kcal/mol at eight adsorbed molecules. Sensor responses of three different Ppy samples were measured to ethanol concentrations of 18,000-40,000 ppm. (C) 2008 Elsevier B.V. All rights reserved.
DEVELOPMENT OF WIRELESS SENSORS FOR RAPID DEPLOYMENT IN CIVIL INFRASTRUCTURES
(2007)
Lin, Tzu-Hsuan
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Hung, Shih-Lin
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Wen, Chun-Ming
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交大名義發表
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National Chiao Tung University
Buildings and civil infrastructures are frequently subjected to natural hazards such as earthquakes, typhoons, hurricanes and fires. Therefore, developing an efficient and robust monitoring system has become a most significant research area. Wireless Sensor Network (WSN) is a novel and attractive technology and has been an energetic research area in recent years. Furthermore, wireless sensor networks have developed several applications mainly to monitor hazardous environments. The bolt is ubiquitous in our life environment, such as buildings, bridges, railways and pipelines. Therefore, the new inspiration for developing a wireless sensor device, which is named "smart bolt", is proposed in this paper, which is to develop a wireless sensor device for rapid deploying. The prototype device is capable of wireless sensing via embedding the wireless sensor into a bolt, consisting of sensing and wireless communication modules. This paper introduces wireless technology and applications; moreover, it presents the prototype device design that includes hardware design and sensor integration. Experimental study was designed to investigate the benefit and efficiency of the proposed prototype and is finally shown in the paper to confirm the feasibility of a wireless sensor network in buildings and civil infrastructure.
Improved MS_CMAC neural networks by integrating a simplified UFN model
(2008-04-01)
Jan, Jiun-Chi
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Hung, Shih-Lin
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土木工程學系
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Department of Civil Engineering
Macro_Structure_CMAC (MS_CMAC) is a variational CMAC neural network that is designed for modeling smooth functional mappings. The MS_CMAC learning strategy involves constructing virtual grid-distributed data points from random-distributed training data points, and then using the virtual data points to train a tree structure network that is composed of one-dimensional CMAC nodes. A disadvantage of the MS_CMAC is that the prediction errors near the boundary area might sometimes be unexpectedly large. Another disadvantage of the MS_CMAC is that generating virtual grid-distributed data points generally takes a long computational time. Therefore, this study develops an improved model by integrating an unsupervised fuzzy neural network (UFN) into the MS_CMAC to initialize systematically the virtual grid-distributed data points. Additionally, a new error feedback ratio function is adopted to speed up the MS_CMAC training. Several numerical problems are considered to test the improved MS_CMAC. The computed results indicate that a simplified UFN model can produce good initial values of the virtual grid-distributed data points to aggrandize MS_CMAC training. The MS_CMAC prediction is also improved by using the initialized virtual grid-distributed data points.
Integrating a Hive Triangle Pattern with Subpixel Analysis for Noncontact Measurement of Structural Dynamic Response by Using a Novel Image Processing Scheme
(2014)
Lu, Yung-Chi
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Hung, Shih-Lin
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Lin, Tzu-Hsuan
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土木工程學系
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Department of Civil Engineering
This work presents a digital image processing approach with a unique hive triangle pattern by integrating subpixel analysis for noncontact measurement of structural dynamic response data. Feasibility of proposed approach is demonstrated based on numerical simulation of a photography experiment. According to those results, the measured time-history displacement of simulated image correlates well with the numerical solution. A small three-story frame is then mounted on a small shaker table, and a linear variation differential transformation (LVDT) is set on the second floor. Experimental results indicate that the relative error between data from LVDT and analyzed data from digital image correlation is below 0.007%, 0.0205 in terms of frequency and displacement, respectively. Additionally, the appropriate image block affects the estimation accuracy of the measurement system. Importantly, the proposed approach for evaluating pattern center and size is highly promising for use in assigning the adaptive block for a digital image correlation method.
Locating Damage Using Integrated Global-Local Approach with Wireless Sensing System and Single-Chip Impedance Measurement Device
(2014)
Lin, Tzu-Hsuan
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Lu, Yung-Chi
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Hung, Shih-Lin
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土木工程學系
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Department of Civil Engineering
This study developed an integrated global-local approach for locating damage on building structures. A damage detection approach with a novel embedded frequency response function damage index (NEFDI) was proposed and embedded in the Imote2.NET-based wireless structural health monitoring (SHM) system to locate global damage. Local damage is then identified using an electromechanical impedance-(EMI-) based damage detection method. The electromechanical impedance was measured using a single-chip impedance measurement device which has the advantages of small size, low cost, and portability. The feasibility of the proposed damage detection scheme was studied with reference to a numerical example of a six-storey shear plane frame structure and a small-scale experimental steel frame. Numerical and experimental analysis using the integrated global-local SHM approach reveals that, after NEFDI indicates the approximate location of a damaged area, the EMI-based damage detection approach can then identify the detailed damage location in the structure of the building.
New sensing technology for detection of the common inhalational anesthetic agent sevoflurane using conducting polypyrrole films
(2007-10-01)
Wu, Ren-Jang
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Huang, Yu-Ching
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Chavali, Murthy
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Lin, Tzu Hsuan
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Hung, Shih-Lin
A new type of gas sensor to measure resistance was developed to detect sevoflurane concentrations at room temperature. The measured FTIR spectrum of sevoflurane vapor was given. The sensing material polypyrrole was synthesized in situ by UV-photopolymerization. The relative resistance variation was 3.9 for a sevoflurane concentration of 1.2%. The sensor response time (60 s) and recovery time (20 s) were very short. Molecular dynamic calculations made for sevoflurane adsorption on polypyrrole revealed formation of a new bond, N-H-F. The bond length was predicted to be in the range of 0.2-0.4 nm. The bond energy was about 7.2 kcal/mol. Sensor responses to the concentrations 0. 1-10% were 1.57-5.9, respectively. (C) 2007 Elsevier B.V. All rights reserved.
Towards Development of Wireless Sensor System for Monitoring Anesthetic Agents
(2010-12-01)
Lin, Tzu-Hsuan
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Hung, Shih-Lin
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Chavali, Murthy
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Wu, Ren-Jang
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Luk, Hsiang-Ning
In this paper, the design and development of sensing system for volatile anesthetic agent based on wireless sensor network is proposed. The proposed system include smart sensor chip fabricated by dip coating conducting polymer for sensing sevoflurane, the most commonly used inhalational anesthetic agent. This paper also discusses the total sensor system design including hardware design, software design and sensor integration. Present sensor system consists of both wireless sensing unit and a wireless receiving unit. The wireless sensing unit includes, sensing module, data acquisition module and wireless microprocessor module. The design of the wireless receiving unit includes two functional modules, a wireless microprocessor module and gateway. The experimental study was conducted to investigate the proposed prototype wireless sensor system. Results indicate the response of the sensor is rapid, and while returning to the initial level immediately after removal of the analyte. The response time T(90) (represents the time to 90% signal with the equilibrium signal) of 5.77% sevoflurane sensing curve is less than 60 s, and recovery time is also less than 60 S. This system has good potential application in monitoring indoor environments in hospitals and being anesthetic agent it is a challenge subject to study as well.
Two Strategies to Improve the Differential Evolution Algorithm for Optimizing Design of Truss Structures
(2020-07-20)
Kao, Ching-Yun
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Hung, Shih-Lin
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Setiawan, Budy
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土木工程學系
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Department of Civil Engineering
The performance of differential evolution (DE) mostly depends on mutation operator. Inappropriate configurations of mutation strategies and control parameters can cause stagnation due to over exploration or premature convergence due to over exploitation. Balancing exploration and exploitation is crucial for an effective DE algorithm. This work presents an enhanced DE (EDE) for truss design that utilizes two new strategies, namely,integrated mutationandadaptive mutation factorstrategies, to obtain a good balance between the exploration and exploitation of DE. Three mutation strategies (DE/rand/1,DE/best/2, andDE/rand-to-best/1) are combined in theintegrated mutationstrategy to increase the diversity of random search and avoid premature convergence to a local minimum. Theadaptive mutation factorstrategy systematically adapts the mutation factor from a large value to a small value to avoid premature convergence in the early searching period and to increase convergence to the global optimum solution in the later searching period. The outstanding performance of the proposed EDE is demonstrated through optimization of five truss structures.