Sensor placement optimization in structural health monitoring using distributed monkey algorithm

Yi, Ting-Hua,Li, Hong-Nan,Zhang, Xu-Dong Techno-Press 2015 Smart Structures and Systems, An International Jou Vol.15 No.1

Proper placement of sensors plays a key role in construction and implementation of an effective structural health monitoring (SHM) system. This paper proposes a novel methodology called the distributed monkey algorithm (DMA) for the optimum design of SHM system sensor arrays. Different from the existing algorithms, the dual-structure coding method is adopted for the representation of design variables and the single large population is partitioned into subsets and each subpopulation searches the space in different directions separately, leading to quicker convergence and higher searching capability. After the personal areas of all subpopulations have been finished, the initial optimal solutions in every subpopulation are extracted and reordered into a new subpopulation, and the harmony search algorithm (HSA) is incorporated to find the final optimal solution. A computational case of a high-rise building has been implemented to demonstrate the effectiveness of the proposed method. Investigations have clearly suggested that the proposed DMA is simple in concept, few in parameters, easy in implementation, and could generate sensor configurations superior to other conventional algorithms both in terms of generating optimal solutions as well as faster convergence.

Cadmium stress inhibits the growth of primary roots by interfering auxin homeostasis in Sorghum bicolor seedlings

Yi-hua Zhan,Cheng-hao Zhang,Qiu-xun Zheng,Zong-an Huang,Chen-liang Yu 한국식물학회 2017 Journal of Plant Biology Vol.60 No.6

Phytotoxic effects of cadmium (Cd), a heavy metalpollutant, on plants have been extensively examined. Auxinplays vital roles in many aspects of plant development. Theassociation between root growth and auxin signaling in CdstressedSorghum bicolor was analyzed in our study. Rootelongation, shoot length and the maximal photochemicalefficiency (Fv/Fm) in S. bicolor seedlings were dramaticallyreduced after Cd stress treatment. Cd was found to bepredominantly confined in the meristematic zone using a Cdstainingmethod. Cd stress remarkably influenced the cellcycle progression at the root tip as shown by EdU (ethynyldeoxyuridine) assay. The content of IAA was markedlydiminished in the roots of Cd-stressed S. bicolor, which wasalong with the increase of IAA oxidase activity. Auxintransport inhibitors, 1-naphthoxyacetic acid (1-NOA) or 1-naphthylphthalamic acid (NPA), greatly reduced plant toleranceto Cd stress, whereas exogenous application of 1-naphthaleneacetic acid (NAA) improved Cd tolerance in S. bicolor seedlings. Cd stress altered the transcript level ofsome putative auxin biosynthetic genes. In addition, NAAinterfered with the homeostasis of Cd-induced reactiveoxygen species (ROS). These results revealed that Cd stressdisturbed the growth of S. bicolor seedlings by affecting thehomeostasis of auxin and ROS.

Past and Future development of Electronic Dictionary in China

(Yi Hua Zhang) 연세대학교 언어정보연구원 2001 제 2 차 아시아 사전학회 국제 학술대회 Vol.- No.-

N/A

Outlier detection of GPS monitoring data using relational analysis and negative selection algorithm

Yi, Ting-Hua,Ye, X.W.,Li, Hong-Nan,Guo, Qing Techno-Press 2017 Smart Structures and Systems, An International Jou Vol.20 No.2

Outlier detection is an imperative task to identify the occurrence of abnormal events before the structures are suffered from sudden failure during their service lives. This paper proposes a two-phase method for the outlier detection of Global Positioning System (GPS) monitoring data. Prompt judgment of the occurrence of abnormal data is firstly carried out by use of the relational analysis as the relationship among the data obtained from the adjacent locations following a certain rule. Then, a negative selection algorithm (NSA) is adopted for further accurate localization of the abnormal data. To reduce the computation cost in the NSA, an improved scheme by integrating the adjustable radius into the training stage is designed and implemented. Numerical simulations and experimental verifications demonstrate that the proposed method is encouraging compared with the original method in the aspects of efficiency and reliability. This method is only based on the monitoring data without the requirement of the engineer expertise on the structural operational characteristics, which can be easily embedded in a software system for the continuous and reliable monitoring of civil infrastructure.

Optimal sensor placement for health monitoring of high-rise structure based on collaborative-climb monkey algorithm

Yi, Ting-Hua,Zhou, Guang-Dong,Li, Hong-Nan,Zhang, Xu-Dong Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.2

Optimal sensor placement (OSP) is an integral component in the design of an effective structural health monitoring (SHM) system. This paper describes the implementation of a novel collaborative-climb monkey algorithm (CMA), which combines the artificial fish swarm algorithm (AFSA) with the monkey algorithm (MA), as a strategy for the optimal placement of a predefined number of sensors. Different from the original MA, the dual-structure coding method is adopted for the representation of design variables. The collaborative-climb process that can make the full use of the monkeys' experiences to guide the movement is proposed and incorporated in the CMA to speed up the search efficiency of the algorithm. The effectiveness of the proposed algorithm is demonstrated by a numerical example with a high-rise structure. The results show that the proposed CMA algorithm can provide a robust design for sensor networks, which exhibits superior convergence characteristics when compared to the original MA using the dual-structure coding method.

Wavelet based multi-step filtering method for bridge health monitoring using GPS and accelerometer

Yi, Ting-Hua,Li, Hong-Nan,Gu, Ming Techno-Press 2013 Smart Structures and Systems, An International Jou Vol.11 No.4

Effective monitoring, reliable data analysis, and rational data interpretations are challenges for engineers who are specialized in bridge health monitoring. This paper demonstrates how to use the Global Positioning System (GPS) and accelerometer data to accurately extract static and quasi-static displacements of the bridge induced by ambient effects. To eliminate the disadvantages of the two separate units, based on the characteristics of the bias terms derived from the GPS and accelerometer respectively, a wavelet based multi-step filtering method by combining the merits of the continuous wavelet transform (CWT) with the discrete stationary wavelet transform (SWT) is proposed so as to address the GPS deformation monitoring application more efficiently. The field measurements are carried out on an existing suspension bridge under the normal operation without any traffic interference. Experimental results showed that the frequencies and absolute displacements of the bridge can be accurate extracted by the proposed method. The integration of GPS and accelerometer can be used as a reliable tool to characterize the dynamic behavior of large structures such as suspension bridges undergoing environmental loads.

A new method for optimal selection of sensor location on a high-rise building using simplified finite element model

Yi, Ting-Hua,Li, Hong-Nan,Gu, Ming Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.6

Deciding on an optimal sensor placement (OSP) is a common problem encountered in many engineering applications and is also a critical issue in the construction and implementation of an effective structural health monitoring (SHM) system. The present study focuses with techniques for selecting optimal sensor locations in a sensor network designed to monitor the health condition of Dalian World Trade Building which is the tallest in the northeast of China. Since the number of degree-of-freedom (DOF) of the building structure is too large, multi-modes should be selected to describe the dynamic behavior of a structural system with sufficient accuracy to allow its health state to be determined effectively. However, it's difficult to accurately distinguish the translational and rotational modes for the flexible structures with closely spaced modes by the modal participation mass ratios. In this paper, a new method of the OSP that computing the mode shape matrix in the weak axis of structure by the simplified multi-DOF system was presented based on the equivalent rigidity parameter identification method. The initial sensor assignment was obtained by the QR-factorization of the structural mode shape matrix. Taking the maximum off-diagonal element of the modal assurance criterion (MAC) matrix as a target function, one more sensor was added each time until the maximum off-diagonal element of the MAC reaches the threshold. Considering the economic factors, the final plan of sensor placement was determined. The numerical example demonstrated the feasibility and effectiveness of the proposed scheme.

Lifetime Prediction and Aging Behaviors of Nitrile Rubber Under Operating Environment of Transformer

Yi-Hua Qian,Hong-zhao Xiao,Ming-hao Nie,Yao-hong Zhao,Yunbai Luo,Shu-ling Gong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

Based on the actual operating environment of transformer, the aging tests of nitrile butadiene rubber (NBR) were conducted systematically under four conditions: in air, in transform oil, under compression in air and under compression in transform oil to studythe effect of high temperature, transform oil and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber and predict the lifetime. The effects of liquid media and compression stress simultaneously on the thermal aging behaviors of nitrile butadiene rubber were studied by using characterization methods such as IR spectrosc-opy, thermogravimetric measurements, Differential Scanning Calorimetry (DSC) measurements and mechanical property measurements. The changes in physical properties during the aging process were analyzed and compared. Different aging conditions yielded materials with different properties. Aging at 70°C under compression stress in oil, the change in elongation at break was lower than that aging in oil, but larger than that aging under compression in air. The compression set or elongation at break as evaluation indexes, 50% as critical value, the lifetime of NBR at 25°C was predicted and compared. When aging under compression in oil, the prediction lifetime was lower than in air and under compression in air, and in oil. It was clear that when predicting the service lifetime of NBR in oil sealing application, compression and media liquid should be involved simultaneously. Under compression in oil, compression set as the evaluation index, the prediction lifetime of NBR was shorter than that of elongation at break as the evaluation index. For the life prediction of NBR, we should take into account of the performance trends of NBR under actual operating conditions to select the appropriate evaluation index.

A Rapid and Efficient Pre-deployment Key Scheme for Secure Data Transmissions in Sensor Networks Using Lagrange Interpolation Polynomial

Hua-Yi Lin,De-Jun Pan,Xin-Xiang Zhao,Zhi-Ren Qiu 보안공학연구지원센터 2008 International Journal of Security and Its Applicat Vol.2 No.3

This study proposes a pre-deployment key management scheme that requires a few memory capacities and CPU computations to address secure data transmissions in Wireless Sensor Networks (WSNs). The proposed scheme exploits threshold key management mechanisms by Lagrange Interpolation polynomial generating a key set for sensor nodes, and uses symmetric and irreversible cryptography schemes to encrypt transmitted data by the generated keys with Message Authentication Code (MAC). The sensor nodes merely have to aggregate and encrypt received data without complicated cryptography operations. The proposed approach can achieve rapid and efficient secure data transmissions with low communications, and is proper to be implemented on large-scale sensor networks.

Quality Characteristics of Songpyeon Containing Different Fillings during Storage

Yi-Hua Wen,은종방 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.1

Songpyeon is a Korean traditional food made of rice with different fillings. The fillings may affect the qualities of songpyeon, such as shelf-life. Therefore, quality characteristics of songpyeon filled with chopped black eyed peas (CBP) and unchopped black eyed peas (UCBP)were investigated during storage at room temperature. As a result, all samples had moisture content and pH values favorable for microbial growth. Hardness, gumminess, and chewiness were increased during storage. All sensory parameters values decreased steadily in stored songpyeon. The shelf-life of songpyeon was suggested to be only 2days by the panelists. UCBP had higher number of total microbial loads, yeasts, and molds than those of CBP. Coliforms were not detected in songpyeon during storage. These results suggested that songpyeon filled with UCBP had a shorter shelf-life than songpyeon filled with CBP.