• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권8호
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• pp.413-424
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• 2002

Recently, in the linear motion system, high performances are required In dynamic characteristics. Vector control method is capable of instantaneous thrust control can meet these high performance requirements. Linear induction motor(LIM) have static and dynamic end effects due to its finite core length, so that per-phase impedances are asymmetric and an air gap flux distribution is distorted. These points of the d-q axis equivalent circuit model considering both end effects is more complicated. This paper proposes the d-q axis equivalent circuit and the vector control method considering both static and dynamic end effects of the LIM. As a result, it is shown that the results of the equivalent circuit method(ECM) have a good agreement with those of the finite element method(FEM).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.345-348
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• 1988

In this paper, the dynamic characteristics of asymmetrical two-phase induction motors are investigated for improving its dynamic performances. The equations which describe the dynamic performance of asymmetrical two-phase induction motors are established and analyzed dynamic characteristics by digital computer simulation. The differential equation is solved by the algorithm of predictor-corrector method. The effects due to machine parameters are analyzed.

• Journal of Plant Biology
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• 제32권4호
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• pp.313-322
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• 1989

A system was established for induction of multi-shoots and plant regeneration from mesophyll protoplasts of alfalfa, Medicago sativa L. cv. Vernal. Different hormonal effects were tested at each step of protoplast culture, i.e. cell division in modified Kao's liquid medium (K566-7). calli formation on SH semi solid medium, and multi-shoot regeneration from calli on SHa and SHb solid media. Frequency of multi-shoots and plant regeneration was affected by various combinations of phytohormones in final step. The evaluation of multi-shoots induction systems via protoplast culture was discused.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.612-615
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• 1997

In this paper, a robust speed controller considering the effect of uncertainty (plant parameter variation. external load disturbance. unmodeled and nonlinear dynamics etc..) for induction motor is proposed. Firstly. the dynamic model at nominal case of induction motor is estimated. Based on the estimated model. the IPSC ( Integral - Proportional Speed Controller) is designed. Then a DTRC (Dead-time Robust Controller) combining DTC ( Dead-time Compensator) & SRC (Simple Robust Controller) is designed to reduce the effects of parameter variation and external disturbance. Some simulated results are provided to demonstrate the effectiveness of the proposed controller.

• 대한안전경영과학회지
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• 제5권2호
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• pp.199-214
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• 2003

With the progress of industrial technology, industrial machinery and home appliances have multi-function and high performances by the electronic control technology. Various results are given from the measuring switching induction noise according to environmental condition and its effects cannot be predicted accurately. Therefore, the output results should be analyzed and applied to practical work. To minimize the false operation, Taguchi Method used to solve the quality problem is adopted to analyze the characteristics within the constrained measuring level.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.31-33
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• 1998

The sensitivity of induction watthour meter was reviewed by characteristic tests under the effects of each input harmonics and the variation of power factor of inverter input/output terminal. This paper presents experimental data on the characteristics of induction watthour meter under the effect of harmonics.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5455-5461
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• 2014

Background: Saponins are a major active component for the traditional Chinese medicine, Rubus parvifolius L., which has shown clear antitumor activities. However, the specific effects and mechanisms of saponins of Rubus parvifolius L. (SRP) remain unclear with regard to human chronic myeloid leukemia cells. The aim of this study was to investigate inhibition of proliferation and apoptosis induction effects of SRP in K562 cells and further elucidate its regulatory mechanisms. Materials and Methods: K562 cells were treated with different concentrations of SRP and MTT assays were performed to determine cell viability. Apoptosis induction by SRP was determined with FACS and DAPI staining analysis. Western blotting was used to detect expression of apoptosis and survival related genes. Specific inhibitors were added to confirm roles of STAT3 and AMPK pathways in SRP induction of apoptosis. Results: Our results indicated that SRP exhibited obvious inhibitory effects on the growth of K562 cells, and significantly induced apoptosis. Cleavage of pro-apoptotic proteins was dramatically increased after SRP exposure. SRP treatment also increased the activities of AMPK and JNK pathways, and inhibited the phosphorylation expression level of STAT3 in K562 cells. Inhibition of the AMPK pathway blocked the activation of JNK by SRP, indicating that SRP regulated the expression of JNK dependent oon the AMPK pathway. Furthermore, inhibition of the latter significantly conferred resistance to SRP pro-apoptotic activity, suggesting involvement of the AMPK pathway in induction of apoptosis. Pretreatment with a STAT3 inhibitor also augmented SRP induced growth inhibition and cell apoptosis, further confirming roles of the STAT3 pathway after SRP treatment. Conclusions: Our results demonstrated that SRP induce cell apoptosis through AMPK activation and STAT3 inhibition in K562 cells. This suggests the possibility of further developing SRP as an alternative treatment option, or perhaps using it as adjuvant chemotherapeutic agent for chronic myeloid leukemia therapy.

• 한국안전학회지
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• 제36권2호
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• pp.10-17
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• 2021

This paper presents the robust design of each component used in the development of an induction bolt heating system for dismantling the high-temperature high-pressure casing heating bolts of turbines in power plants. The induction bolt heating system comprises seven assemblies, namely AC breaker, AC filter, inverter, transformer, work coil, cable, and CT/PT. For each of these assemblies, the various failure modes are identified by the failure mode and effects analysis (FMEA) method, and the causes and effects of these failure modes are presented. In addition, the risk priority numbers are deduced for the individual parts. To ensure robust design, the insulated-gate bipolar transistor (IGBT), switched-mode power supply (SMPS), C/T (adjusting current), capacitor, and coupling are selected. The IGBT is changed to a field-effect transistor (FET) to enhance the voltage applied to the induction heating system, and a dual-safety device is added to the SMPS. For C/T (adjusting current), the turns ratio is adjusted to ensure an appropriate amount of induced current. The capacitor is replaced by a product with heat resistance and durability; further, coupling with a water-resistant structure is improved such that the connecting parts are not easily destroyed. The ground connection is chosen for management priority.

• 전기학회논문지P
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• 제54권3호
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• pp.134-140
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• 2005

Most of the loads in industrial power distribution systems are usually balanced and connected to three power systems. However, in the user power distribution systems, partial loads are single & three phase and unbalanced, generating voltage unbalance by the impedance mismatching. Voltage unbalance has detrimental effects on three-phase induction motors, including over heating, line-current unbalance, derating, torque pulsation, low efficiency, etc. This paper presents a scheme on operation states of a three-phase induction motor under the unbalanced voltages with harmonics components. Three-phase voltages applied to the stator winding of the studied induction motor are controlled by respectively adjusting not only fundamental but also harmonics components. Harmonic components at the voltage unbalanced factor(VUF) of the three-phase source voltages can then be examined the different values of VUF on machine's operation characteristics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2113-2116
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• 1997

The speed sensorless vector control of induction motor using the rotor speed and flux estimation is widely used. In practice, these schemes depend on the accurate parameters of the machine. If in the vector control scheme an inaccurate parameter of induction motor due to skin effects and to temperature variations is used. it is difficult to achieve correct field orientation. From this reason. we propose robust speed sensorless vector control of induction motor against the variations of parameter and disturbance by using extended Kalman filter. For speed and rotor flux estimation. conventional adaptive flux observer is applied. extended Kalman filter which is correctly capable of estimating rotor flux and load by eliminating virtually influences of structural noises is proposed. Simulation results show the effectiveness of the control strategy proposed here for the induction motor drives.