Y S Chen

Publications (11)14 Total impact

• Article: Dielectric, magnetic and magnetoelectric properties of multiferroic BiFe0.5Cr0.5O3–NiFe2O4 composites

  S. Narendra Babu, Jen-Hwa Hsu, Y. S. Chen, J. G. Lin
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  ABSTRACT: Multiferroic composites of NiFe ₂ O ₄ (NFO) and BiFe _0.5 Cr _0.5 O ₃ (BFCO) are synthesized and their dielectric, magnetic, and magnetoelectric (ME) properties are measured at room temperature. NFO-BFCO forms a two-phase composite. The composite has a larger magnetization and dielectric constant than those of both parent compounds, due to the effects of interfacial strain on BFCO. Furthermore, the ME response in NFO-BFCO is about one time larger than that of BFCO, revealing the success of magnetic control of the dielectric response via the mechanical coupling, which can be exploited in the future applications of multiferroic composites.
  Journal of Applied Physics 06/2010; · 2.17 Impact Factor
• Article: Correlation of magnetic ordering and electric polarization in multiferroic LuMn1-xFexO3 (0≤x≤0.2)

  J. G. Lin, Y. S. Chen, T. C. Han
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  ABSTRACT: We have synthesized a series of LuMn _{1- x} Fe _x O ₃ (0≤ x ≤0.2) samples and study the effect of Fe-doping on their magnetic and dielectric properties. The magnetic characterization indicates that with increasing Fe-content up to 0.2, the antiferromagnetic (AFM) transition temperature increases from 90 to 105 K. A corresponding shift in the peak-positions of specific heat and dielectric anomaly is observed, indicating a strong correlation between the magnetic ordering and the electric polarization. Further analysis suggests that the rising of AFM transition temperature with increasing Fe-content should be from the structural origin, in which the strength of AFM interaction as well as the electrical polarization is dependent on the in-plane lattice parameters.
  Journal of Applied Physics 06/2010; · 2.17 Impact Factor
• Source

  Available from: edu.tw

  Article: Investigation of Jahn–Teller splitting with O 1s x-ray absorption spectroscopy in strained Nd1-xCaxMnO3 thin films

  Daniel Hsu, Y. S. Chen, M. Y. Song, C. H. Chuang, Minn-Tsong Lin, W. F. Wu, J. G. Lin
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  ABSTRACT: Electronic structures of strained Nd _1-x Ca _x MnO ₃ (NCMO) thin films with x=0 to 0.8 are investigated via x-ray absorption spectroscopy (XAS). The obtained O 1s spectra within the photon energy 529–535 eV can be decomposed into e_g↑¹ , e_g↑² , t_2g↓ , and e_g↓ bands. Based on the assigned energy levels of these band states, the energies of magnetic exchange, crystal field and Jahn–Teller (JT) splitting are determined. Particularly, the JT splitting is around 0.8 eV, which is observed with O 1s XAS for the first time in NCMO thin films.
  Applied Physics Letters 02/2010; · 3.84 Impact Factor
• Conference Proceeding: Real-time approaching vehicle detection in blind-spot area

  C.T. Chen, Y.S. Chen
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  ABSTRACT: Detecting objects (including all kinds of vehicles, bicycles, and pedestrians) accurately and efficiently is an essential issue in blind-spot information system (BLIS). To meet these requirements, this paper presents an image-based method to detect approaching objects in blind-spot area and proposes a verification method by using the recorded video database from real traffic environment. By taking video frames and converting the images into one dimensional information, the image entropy of the road scene in the near lane are estimated. Thus, by analysis the lane information, an object will be detected and located in a constant time. This idea has been realized and implemented on low-cost DSP platform developed by Automotive Research and Testing Center (ARTC, Taiwan). The accurate rate of this blind-spot detection system (BDS) is 91% and the frame rate is more than 20 frames per sec (fps), in day and night and all weather conditions. The BDS has been applied for general vehicles and heavy truck vehicles nowadays.
  Intelligent Transportation Systems, 2009. ITSC '09. 12th International IEEE Conference on; 11/2009
• Article: Origin of R-Dependent Dielectric Anomalies in RMnO3 with R = Y, Ho, Er, Tm, Yb and Lu

  M. C. Lin, Y. S. Chen, T. C. Han, J. G. Lin, C. H. Chen
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  ABSTRACT: A series of hexagonal polycrystalline RMnO3 (R = Y, Ho, Er, Tm, Lu and Yb) samples are systematically prepared, and their temperature-dependent magnetic susceptibility, specific heat and dielectric properties are measured, in order to investigate the origin of R-dependent dielectric behavior. The dielectric anomalies are found to be strongly correlated with the antiferromagnetic transitions. Both occur near the same temperatures (70100 K) and have a very similar R-dependency. Further analysis suggests that the origin of R-dependent dielectric anomalies in the ferroelectric phases could be the variation of strength of antiferromagnetic interaction via the change of in-plane lattice parameters.
  Ferroelectrics. 01/2009; 380(1):38-47.
• Article: Ginsenoside Rb1 enhances peripheral nerve regeneration across wide gaps in silicone rubber chambers.

  Y S Chen, C H Wu, C H Yao, C T Chen
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  ABSTRACT: Silicone rubber chambers filled with collagen containing ginsenoside Rb1 (GRb1) were used to repair lesioned rat sciatic nerves with 15-mm gaps between stumps. Six weeks after implantation, histology of the nerve regenerated in the chambers filled with GRb1 and collagen contained larger axons than those in the chambers with collagen only. This study showed that the GRb1 could exert a positive influence on nerve regeneration when using silicone rubber tubes.
  The International journal of artificial organs 12/2002; 25(11):1103-8. · 1.86 Impact Factor
• Article: Effects of percutaneous electrical stimulation on peripheral nerve regeneration using silicone rubber chambers.

  Y S Chen, C L Hu, C L Hsieh, J G Lin, C C Tsai, T H Chen, C H Yao
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  ABSTRACT: The purpose of this study was to determine whether 0.8-1 mA, 2 Hz of percutaneous electrical stimulation could affect the regeneration of a 10-mm gap of rat sciatic nerve created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes. Six weeks after implantation, though the group receiving the electrical stimulation had a lower success percentage of regeneration (57%) compared with the controls receiving no stimulation (70%), quantitative histology of the successfully regenerated nerves revealed that the mean values of the axon density, blood vessel number, blood vessel area, and percentage of blood vessel area in total nerve area in the group with the electrical stimulation were all significantly larger than those in the controls (p < 0.05). These results showed that the electrical stimulation could elicit rehabilitating effects on the regenerated nerves.
  Journal of Biomedical Materials Research 12/2001; 57(4):541-9.
• Article: Effect of acupuncture stimulation on peripheral nerve regeneration using silicone rubber chambers.

  Y S Chen, C H Yao, T H Chen, J G Lin, C L Hsieh, C C Lin, C J Lao, C C Tsai
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  ABSTRACT: The purpose of this study was to determine whether acupuncture could affect the regeneration of a 10-mm gap of rat sciatic nerve created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes. Empty silicone rubber tubes with no further treatment were used as controls. Six weeks after implantation, the animals received the acupuncture or the electroneedling treatment exhibited a more mature ultrastructural nerve organization with significantly higher numbers in the axon density, the blood vessel area, and the percentage of blood vessel area occupied in total nerve area than the controls. In addition, the electroneedling could combine both the needling and the electrical stimulation to potentiate the nerve-growth promoting effect of the acupuncture treatment. These results showed that acupuncture treatment could elicit positive effects on regenerated peripheral nerves.
  The American Journal of Chinese Medicine 02/2001; 29(3-4):377-85. · 1.98 Impact Factor
• Article: Analgesic effect of electric stimulation of peripheral nerves with different electric frequencies using the formalin test.

  C L Hsieh, C C Kuo, Y S Chen, T C Li, C T Hsieh, C J Lao, C J Lee, J G Li
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  ABSTRACT: Although electroacupuncture (EA) has been widely used to treat pain, the optimal frequency of EA therapy remains unclear. The study sought to determine the effect of different EA frequencies in a Sprague-Dawley (SD) rat model of pain. Electric stimulation (ES) at frequencies of 2 Hz, 15 Hz or 100 Hz was applied to the ipsilateral or contralateral sciatic nerve of the injected hindpaw of SD rats. Formalin (50 microl, 5%) was subcutaneously injected into the plantar surface of the left hindpaw to induce a nociceptive response. Behavior, including licking and biting, was observed to have two distinct periods, an early phase during the first 5 mins and a late phase from 21-35 mins after injection. The total biting or licking count served as an Indicator of nociceptive response. Our results indicate that ES of the ipsilateral sciatic nerve at a frequency of 2 Hz or 15 Hz reduced the nociceptive responses in both the early and the late phases of the formalin test, whereas ES at 2 Hz had greater antinociceptive effect than ES at 15 Hz in the early phase. No similar analgesic effect in the early phase was observed for ES at 100 Hz. Both pretreatment with ES at 2 Hz and naloxone (3 mg/kg, s.c.) produced a greater antinociceptive response in the late phase than when ES at 2 Hz was delivered immediately after formalin administration. In addition, ES of the neck muscle or contralateral sciatic nerve at a frequency of 2 Hz also decreased licking and biting activity in both phases. The results of this study indicate that different analgesic mechanisms are involved in the response to ES at frequencies of 2 Hz, 15 Hz and 100 Hz, and that ES at 2 Hz has a greater analgesic effect on formalin-induced nociceptive response, especially when it is delivered prior to the onset of pain. The analgesic effect of ES may be mediated via a central origin in the supraspinal level. These findings suggest that 2 Hz may be a good frequency selection for clinical EA applications in analgesia, and that pretreatment with EA at 2 Hz may be an effective method to treat post-operative pain.
  The American Journal of Chinese Medicine 02/2000; 28(2):291-9. · 1.98 Impact Factor
• Conference Proceeding: Peripheral nerve regeneration in silicone rubber chambers filledwith collagen, laminin and fibronectin

  Y S Chen, C.I. Hsieh, C H Yao
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  ABSTRACT: A 10-mm gap of rat sciatic nerve was created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes filled with an extracellular gel containing collagen, laminin and fibronectin. Empty silicone rubber tubes were used as controls. Six weeks after implantation, all extracellular elements were completely degraded and absorbed, and 90% of the animals from the extracellular gel group exhibited regeneration across the nerve gaps, whereas only 60% in the control group. Histology of the regenerated nerves revealed that a more mature ultrastructural organization with 28% larger cross sectional area and 28% higher number of myelinated axons in the extracellular gel group than the controls. These results showed that the gel mixture of collagen, laminin and fibronectin could offer a suitable growth medium for the regeneration of axons
  Engineering in Medicine and Biology Society, 2000. Proceedings of the 22nd Annual International Conference of the IEEE; 02/2000
• Article: Scanning electron microscopic observations of rat sciatic nerve fiber regeneration through silicone rubber nerve cuffs

  Y. S. Chen, C. L. Hsieh, J. G. Lin, C. C. Tsai, H. C. Hsu, T. W. Lu
  China Medical College Journal. 01/1999; 8(3):75-82.