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One of the typical problems in the precise vibration is resonance characteristics at low frequency disturbance due to a heavy mass. An electro-magnetic(EM) air spring is a kind of vibration control unit and active isolator. The EM air spring in this study aims at removing the low frequency resonance for semiconductor manufacturing. The mechanical and electronic parts in the active isolator are designed to operate under a weight of 2.5 tons. The EM spring is floated using air pressure in a pneumatic elastic chamber and actuated by EM levitation force. The actuator consists of a EM coil and a permanent magnetic plate which are installed inside of the chamber. An air mount was constructed for the experiment with a stone surface plate, 4 active air springs, 4 gap sensors, a DSP controller, and a multi-channel power amp. A PD control method and operating logic was applied to the DSP. Simulation using 1/4 model was carried out and compared with the experiments. The time duration and maximum peak at resonance frequency can be reduced sharply by the proposed system. The results show that the active system can avoid the resonance caused by the natural frequency of the passive system.

In this paper, a numerical study is carried out for super-pipe, flat plate and axisymmetric body flows to investigate a validity of using wall function and high    in calculation of high Reynolds number flow. The velocity profiles in boundary layer agree well with the law of the wall. And it is found that the range of   which validated the logarithmic law of the wall grows with increasing Reynolds number. From the result, an equation is suggested that can be used to estimate a maximum   value of validity of the log law. And the slope(1/κ) of the log region of the numerical result is larger than that of experimental data.On the other hand, as    is increasing, both the friction and the pressure resistances tend to increase finely. When using    value beyond the range of log law, the surface shear stress shows a significant error and the pressure resistance increases rapidly. However, when using    value in the range, the computational result is reasonable.

Background/Aims: Kidney transplantation (KT) is the best treatment for end-stage renal disease patients. Although previous studies have demonstrated that the clinical outcome following living related (LR) KT is better than that following unrelated (LUR) KT in ABO-compatible KT recipients, recent studies showed no differences in clinical outcomes between the two treatments. In this study, we compared the clinical outcomes of LR and LUR KT in ABO-incompatible KT recipients. Methods: From January 2011 to August 2013, 19 cases of ABO-incompatible KT were analyzed retrospectively. Eight kidneys (7 cases of parent-offspring and 1 case of siblings, Group 1) were donated from living-related donors and 11 (all spousal donors, Group 2) from living-unrelated donors. We investigated patient survival, graft survival, acute rejection, graft function, and complications. Results: On Kaplan-Meier analysis, patient and graft survival during follow-up were 87.5% and 87.5% in Group 1; both were 100% in Group 2. Acute rejection, graft function, and medical and surgical complications were not significantly different between the two groups. Conclusions: The short-term clinical outcomes between LR and LUR KT in ABO-incompatible KT recipients were equivalent. Most domestic cases of LUR KT are from spousal donors and the spousal donor will be a major donor in ABO-incompatible KT patients.

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