Yuedan Liu
Pusan National University
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Publication
Featured researches published by Yuedan Liu.
Modern Physics Letters B | 2011
Yuedan Liu; Tae-Soo Chon; Hunki Baek; Younghae Do; Jinhee Choi; Yun Doo Chung
Movement of different strains in Drosophila melanogaster was continuously observed by using computer interfacing techniques and was analyzed by permutation entropy (PE) after exposure to toxic chemicals, toluene (0.1 mg/m3) and formaldehyde (0.01 mg/m3). The PE values based on one-dimensional time series position (vertical) data were variable according to internal constraint (i.e. strains) and accordingly increased in response to external constraint (i.e. chemicals) by reflecting diversity in movement patterns from both normal and intoxicated states. Cross-correlation function revealed temporal associations between the PE values and between the component movement patterns in different chemicals and strains through the period of intoxication. The entropy based on the order of position data could be a useful means for complexity measure in behavioral changes and for monitoring the impact of stressors in environment.
Modern Physics Letters B | 2011
Tuyen Van Nguyen; Yuedan Liu; Il-Hyo Jung; Tae-Soo Chon; Sang-Hee Lee
Revealing biological responses of organisms in responding to environmental stressors is the critical issue in contemporary ecological sciences. Markov processes in behavioral data were unraveled by utilizing the hidden Markov model (HMM). Individual organisms of daphnia (Daphnia magna) and zebrafish (Danio rerio) were exposed to diazinon at low concentrations. The transition probability matrix (TPM) and the emission probability matrix (EPM) were accordingly estimated by training with the HMM and were verified before and after the treatments with 10-6 tolerance in 103 iterations. Structured property in behavioral changes was accordingly revealed to characterize dynamic processes in movement patterns. Parameters and sequences produced through the HMM training could be a suitable means of monitoring toxic chemicals in environment.
Modern Physics Letters B | 2013
Yan Li; Jang-Myung Lee; Tae-Soo Chon; Yuedan Liu; Hungsoo Kim; Mi-Jung Bae; Young-Seuk Park
Based on computer vision techniques, the movement tracks of an indicator species (zebrafish) were continuously observed in two dimensions before and after the treatments with a toxic chemical (formaldehyde, 2.5 ppm). Behavioral patterns based on the shape of movement segments were regarded as states, while linear and angular speeds measured from the movement segments were used as observed events for training with a hidden Markov model (HMM). The state sequences were estimated by HMM based on transition and emission probability matrices, and observed events. The movement tracks were further reconstructed based on behavior state sequences generated by HMM. Subsequently, permutation entropy and fractal dimension were calculated to monitor behavioral changes before and after the treatments. Both parameters based on the real and reconstructed data significantly decreased after the treatments, and individual variability was minimized with the parameters obtained from the reconstructed tracks. The parameter extraction based on optimal state sequence by HMM was suitable for resolving the problem of variability in behavioral data, and would be an effective means of monitoring chemical stress in the environment.
Scientific Reports | 2017
Hyun-Jeong Eom; Yuedan Liu; Gyu-Suk Kwak; Muyoung Heo; Kyung Seuk Song; Yun Doo Chung; Tae-Soo Chon; Jinhee Choi
We conducted an inhalation toxicity test on the alternative animal model, Drosophila melanogaster, to investigate potential hazards of indoor air pollution. The inhalation toxicity of toluene and formaldehyde was investigated using comprehensive transcriptomics and computational behavior analyses. The ingenuity pathway analysis (IPA) based on microarray data suggests the involvement of pathways related to immune response, stress response, and metabolism in formaldehyde and toluene exposure based on hub molecules. We conducted a toxicity test using mutants of the representative genes in these pathways to explore the toxicological consequences of alterations of these pathways. Furthermore, extensive computational behavior analysis showed that exposure to either toluene or formaldehyde reduced most of the behavioral parameters of both wild-type and mutants. Interestingly, behavioral alteration caused by toluene or formaldehyde exposure was most severe in the p38b mutant, suggesting that the defects in the p38 pathway underlie behavioral alteration. Overall, the results indicate that exposure to toluene and formaldehyde via inhalation causes severe toxicity in Drosophila, by inducing significant alterations in gene expression and behavior, suggesting that Drosophila can be used as a potential alternative model in inhalation toxicity screening.
Water Science and Technology | 2011
Gaosheng Zhang; Linlin Chen; Yuedan Liu; Tae-Soo Chon; Zongming Ren; Zijian Wang; Jianping Zhao; Yangyong Zhao
Due to urgency of the accidental pollution events (APE) on one side and the variability in water quality data on the other side, a new online monitoring and management system (OMMS) was developed for the purpose of sustainable water quality management and human health protection as well. The Biological Early Warning System (BEWS) based on the behavioral responses (behavior strength) of medaka (Oryzias latipes) were built in combination with the physico-chemical factor monitoring system (PFMS) in OMMS. OMMS included a monitoring center and six monitoring stations. Communication between the center and the peripheral stations was conducted by the General Packet Radio Service (GPRS) network transmission complemented by a dial-up connection for use when GPRS was unavailable. OMMS could monitor water quality continuously for at least 30 days. Once APEs occurred, OMMS would promptly notify the administrator to make some follow up decisions based on the Emergency Treatment of APE. Meanwhile, complex behavioral data were analyzed by Self-Organizing Map to properly classify behavior response data before and after contamination. By utilizing BEWS, PFMS and the modern data transmission in combination, OMMS was efficient in monitoring the water quality more realistically.
Ecological Informatics | 2016
Chunlei Xia; Tae-Soo Chon; Yuedan Liu; Jing Chi; Jang-Myung Lee
A novel scheme for the behavioral monitoring of multiple fish is presented based on measurements of the fish posture. Image identification of the fish head and tail is proposed by examining the gray level appearance features. A simplified posture of fish was calculated from its head and centroid. Multiple individual tracking was developed by incorporating the fish posture and global nearest neighbor. The proposed tracking scheme was tested with 2-5 individual Zebra fish (Cyprinidae, Danio rerio) under laboratory conditions. The experimental results confirmed the stability of the identification of a fish head and tail and a robust tracking performance was achieved. The proposed method could accurately record the movement trajectories and posture information of each individual. The tracking errors were only 0.278%-1.572% for 2-5 individual fish while the posture measurement error rates were less than 0.16%. Furthermore, the movement patterns of the fish, e.g., angular variations and distribution of the movement angle, were investigated from the behavioral data, which revealed the advantages of the proposed posture measurement for behavioral studies. The aggregation behavior of multiple fish was also analyzed to reveal the interaction patterns of the individuals in response to the spatial formation of the neighbors
Ecological Modelling | 2011
Yuedan Liu; Sang-Hee Lee; Tae-Soo Chon
Journal of the Korean Physical Society | 2010
Yuedan Liu; Tae-Soo Chon; Sang-Hee Lee
Ecological Informatics | 2013
Tae-Soo Chon; Xiaodong Qu; Woon-Seok Cho; Hyun Ju Hwang; Hongqu Tang; Yuedan Liu; Jung-Hye Choi; Myounghwa Jung; Bok Sil Chung; Hak Young Lee; Young Ryun Chung; Sung-Cheol Koh
Procedia environmental sciences | 2012
Yuedan Liu; F.C. Wu; Chang Woo Ji; Tae-Soo Chon