Browsing by Author "Chen, Y-C"

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Almost disturbance decoupling and tracking control for multi-input multi-output non-linear uncertain systems: application to a half-car active suspension system
(2009-03-01)
Chien, T-L
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Chen, C-C
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Tsai, M-C
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Chen, Y-C
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材料科學與工程學系
This study presents a novel feedback linearization control of non-linear multi-input multi-output uncertain systems for the tracking and almost disturbance decoupling performances. The main contribution of this study is to construct a controller, under appropriate conditions, such that the resulting closed-loop system is valid for any initial condition and bounded tracking signal with the following characteristics: input-to-state stability with respect to disturbance inputs and almost disturbance decoupling. In addition, a new theorem on robust stability is proposed in this study to provide a new criterion for closed-loop stability. A typical case, which cannot be solved by any previous study on the almost disturbance decoupling problem, is proposed in this study to exploit the fact that the tracking and the almost disturbance decoupling performances can be easily achieved by the proposed approach. Finally, the proposed control law is simulated in a half-car active suspension system on which the effectiveness of the design is verified.
An RFID-Based Software Agent Framework on Pervasive Health Service
(2009)
Yeh, Kun-Chieh
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Chen, Y-C
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Chen, C-C
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Chen, Ruey-Shun
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資訊管理與財務金融系註：原資管所+財金所
Due to the aging population society coming, more and more families need the in-time service of medical care for the elderly. For creating a healthy and safety living environment, this study is applied to the radio frequency identification (RFID) and the software agent technology to develop the Pervasive Health Service Grid. This framework is based on the grid architecture to provide patients health service at home environment. Furthermore, we also construct a platform with mobile mechanism to fulfill the requirements of personal health care. This study will be helpful to establish the personal medical treatment environment, and enhance the service quality of health care.
Controlling magnetoelectric coupling by nanoscale phase transformation in strain engineered bismuth ferrite
(2012)
Liu, Y. Y.
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Vasudevan, R. K.
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Pan, K.
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Xie, S. H.
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Liang, W-I
The magnetoelectric coupling in multiferroic materials is promising for a wide range of applications, yet manipulating magnetic ordering by electric field proves elusive to obtain and difficult to control. In this paper, we explore the prospect of controlling magnetic ordering in misfit strained bismuth ferrite (BiFeO3, BFO) films, combining theoretical analysis, numerical simulations, and experimental characterizations. Electric field induced transformation from a tetragonal phase to a distorted rhombohedral one in strain engineered BFO films has been identified by thermodynamic analysis, and realized by scanning probe microscopy (SPM) experiment. By breaking the rotational symmetry of a tip-induced electric field as suggested by phase field simulation, the morphology of distorted rhombohedral variants has been delicately controlled and regulated. Such capabilities enable nanoscale control of magnetoelectric coupling in strain engineered BFO films that is difficult to achieve otherwise, as demonstrated by phase field simulations.
Energy-efficient and reliable multicasting for WiMAX multi-hop relay networks
(2012-09-25)
Chen, C-Y
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Jia, W-K
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Chen, Y-C
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資訊工程學系
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Department of Computer Science
Orthogonal frequency division multiplexing (OFDM)-based wireless transmission technologies such as WiMAX are now widely deployed, and the frame check sequence (FCS) scheme is used to enhance the reliability of OFDM-based systems. As the padding overhead cannot be completely avoided in such systems when variable-length medium access control (MAC) frames are encapsulated, the authors propose a novel cyclic redundancy check (CRC)-based error-correction scheme that utilises the frame padding overhead to carry as much extra segmented FCS information as possible. In a multi-hop relay environment, a mobile station might receive a multicast frame more than once, so the error bit correction scheme could be triggered in the first transmission. In the IEEE's work, the original CRC scheme is optional and only has limited error-detection capability in upper MAC layer. FCS requires a few bits in a frame, but in our work, CRC is compulsory and all sub-FCSs are carried by padding space without using any extra bit. For the best error-correction capability, all transmissions must be padded as many sub-FCSs are possible in cross layer. The proposed approach achieves a significant performance improvement over the legacy FCS scheme in terms of error detection and correction of multicast frames in a transparent mode multi-hop relay network, and it is redundancy-free as well as energy efficient. The authors assess the performance improvement via both mathematical analysis and simulations. The results show that the mobile stations get significant improvement of goodput and utilisation in an error-prone WiMAX multi-hop relay network.
Resistin facilitates breast cancer progression via TLR4-mediated induction of mesenchymal phenotypes and stemness properties
(2018-02-01)
Wang, C-H
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Wang, P-J
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Hsieh, Y-C
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Lo, S.
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Lee, Y-C
Growing evidence indicates that resistin-an obesity-related cytokine-is upregulated in breast cancer patients, yet its impact on breast cancer behavior remains to be ascertained. Similarly, Toll-like receptor 4 (TLR4) has been implicated in breast cancer progression, however, its clinically relevant endogenous ligand remains elusive. In this study, we observed that high serum resistin levels in breast cancer patients positively correlated with tumor stage, size and lymph node metastasis. These findings were replicated in animal models of breast cancer tumorigenesis and metastasis. Resistin was found to promote epithelial-mesenchymal transition and stemness in breast cancer cells-mechanisms critical to tumorigenesis and metastasis-through a TLR4/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappa B)/signal transducer and activator of transcription 3 (STAT3) signaling pathway and negated by TLR4-specific antibody and antagonist. These findings provide clear evidence that resistin is a clinically relevant endogenous ligand for TLR4, which promotes tumor progression via TLR4/NF-kappa B/STAT3 signaling, providing insights into a novel therapeutic target in breast cancer.