Speed tracking servo control system incorporatingtraveling-wave-type ultrasonic motor and feasible evaluations

A variety of ultrasonic motors (USMs) have attracted special interest as a new type of actuator in servo motion control systems. For practical applications, the speed servo control system incorporating the ultrasonic motor developed in Japan has some special unique features. However, this system has several significant problems, such as the inherent speed ripple characteristics, the speed regulation characteristics under the condition of applied disturbance load torque, and the speed tracking characteristics. In order to solve these practical problems, some control schemes of ultrasonic-actuated motor systems have been proposed and discussed theoretically, which include fuzzy reasoning control, adaptive control, repetitive learning control, and neural-network-based learning control. However, it is considered that these control strategies mentioned above have not been sufficiently substantiated from a feasible experimental point of view. This paper presents a newly proposed precise speed tracking servo control system using the compact traveling-wave-type ultrasonic motor. Its proposed control scheme is composed of both the driving frequency control loop with the variable-gain strategy and the applied voltage control loop with the speed ripple reduction strategy of the USM. The improved speed characteristics realized by this proposed control system are demonstrated and evaluated in experiments     

A constant DC voltage control‐based strategy for an active power quality compensator in electrified railways with improved response

This paper proposes a constant DC voltage control‐based strategy for an active power quality compensator (APQC) used in electrified railways. The proposed strategy consists of only an I‐PD‐based constant DC capacitor voltage control with an added moving‐average type low‐pass filter (LPF). The added LPF improves the response of the constant DC capacitor voltage control for the APQC. Thus we offer the simplest control method for the APQC used in electrified railways with improved response. The basic principle of the proposed control strategy is discussed in detail, and then confirmed by digital computer simulation using the PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with unity power factor are obtained on the primary side of the Scott transformer in the traction substation systems, improving the response by one‐fourth as compared to that of the previously proposed control method. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A starting method of the harmonic current compensator using a hybrid active filter for wind power generation systems with soft starters

This paper proposes a starting method of the harmonic current compensator using a hybrid active filter for wind power generation systems. The active filter (AF) in the proposed method of the hybrid power filter behaves as a resistor and reactive power compensator to suppress the inrush current and leading currents for the passive filter (PF) under the starting condition. The basic principle of the proposed starting method is discussed, and then confirmed by digital computer simulation using PSCAD/EMTDC. Simulation results demonstrate that the proposed starting method can overcome the inrush and leading currents for the PF, building up the DC capacitor voltage of the AF. IEEJ Trans 2011 DOI: 10.1002/tee.21815     

Studies on possibility for alleviation of lifestyle diseases by low-dose irradiation or radon inhalation

Our previous studies showed the possibility that activation of the antioxidative function alleviates various oxidative damages, which are related to lifestyle diseases. Results showed that, low-dose X-ray irradiation activated superoxide dismutase and inhibits oedema following ischaemia-reperfusion. To alleviate ischaemia-reperfusion injury with transplantation, the changes of the antioxidative function in liver graft using low-dose X-ray irradiation immediately after exenteration were examined. Results showed that liver grafts activate the antioxidative function as a result of irradiation. In addition, radon inhalation enhances the antioxidative function in some organs, and alleviates alcohol-induced oxidative damage of mouse liver. Moreover, in order to determine the most effective condition of radon inhalation, mice inhaled radon before or after carbon tetrachloride (CCl(4)) administration. Results showed that radon inhalation alleviates CCl(4)-induced hepatopathy, especially prior inhalation. It is highly possible that adequate activation of antioxidative functions induced by low-dose irradiation can contribute to preventing or reducing oxidative damages, which are related to lifestyle diseases.     

A novel active power quality compensator topology with DC voltage balancer for electrified railways

This paper proposes a novel active power quality compensator (APQC) topology with a DC voltage balancer for electrified railways. The APQC is composed of a three‐leg structure with two common DC capacitors. Two legs perform as two half‐bridge inverters, which compensate the unbalanced active, reactive, and harmonic currents on the source side in the traction substation. The third leg controls two common DC capacitor voltages with a small amount of the output currents. Therefore, the current rating of the third leg can be reduced as compared to that of the already proposed three‐leg structured APQC. In the control algorithm of the two half‐bridge inverters, a strategy based on constant DC capacitor voltage control is used, which does not need any calculation blocks of the unbalanced active, reactive, and harmonic components of the load current to perform the APQC operation. Thus we offer the simplest algorithm for the proposed APQC. The basic principle of the proposed APQC topology with the DC voltage balancer is discussed in detail, and then confirmed by digital computer simulation using the PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that the proposed APQC can achieve balanced and sinusoidal source currents on the primary side of the Scott transformer in traction substations for electrified railways. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A new current control strategy based on the internal model principle for a current balancer in single‐phase three‐wire distribution systems

This paper proposes a new current control strategy that is based on the internal model principle for a current balancer in single‐phase three‐wire distribution systems. The proposed current control strategy includes a sinusoidal reference input model to achieve the zero steady‐state error tracking. The appropriate control gains of this control strategy can be systematically determined by using a state‐feedback controller design method via linear matrix inequalities. The basic principle of the proposed control strategy is discussed in detail, and then confirmed by digital computer simulation using the PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that zero steady‐state error tracking is achieved by the proposed control strategy. Also, balanced source currents are obtained on the secondary side of a pole‐mounted distribution transformer while the load conditions are unbalanced. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Radon inhalation suppresses nephropathy in streptozotocin-induced type-1 diabetic mice

In this study, we investigated the suppressive effects of radon inhalation against nephropathy in C57BL/6J mice with type-1 diabetes induced by intraperitoneal injection of streptozotocin (50 mg/kg weight, given five times). Four weeks after diabetes induction, the diabetic mice were continuously treated with inhaled radon-222 of 2000 Bq/m³ or air only (sham) for four weeks. The results showed that radon inhalation did not affect type-1 diabetic symptoms such as body weight loss, hyperglycemia, and hypoinsulinemia. However, diabetic mice treated with radon showed lower urinary albumin excretion and fibrotic change in renal glomeruli compared with diabetic mice not treated with radon. Furthermore, renal superoxide dismutase activity and glutathione content were significantly higher in diabetic mice treated with radon than in diabetic mice not treated with radon. These findings suggested that radon inhalation enhanced renal antioxidants activities, resulting in the suppression of diabetic nephropathy. This study may contribute to the development of a novel approach in the treatment of nephropathy for diabetic patients.     

Technetium-99m-DTPA-galactosyl human serum albumin liver scintigraphy evaluation of regional CT/MRI attenuation/signal intensity differences

Terbinafine is an allylamine antifungal agent widely used to treat dermatophyte onychomycosis and dermatomycoses. We report 10 severe cutaneous adverse reactions associated with terbinafine therapy which required discontinuation of the antifungal agent: erythema multiforme (five patients), erythroderma (one), severe urticaria (one), pityriasis rosea (one) and worsening of pre-existing psoriasis (two patients). The spectrum of cutaneous adverse effects associated with terbinafine therapy is reviewed. Patients should be counselled about discontinuing terbinafine at the onset of a cutaneous eruption and about seeking medical advice about further management.     

An approximate solution to a jit-based ordering system

In this paper we consider a multi-stage multi-product production, inventory and transportation system including lot production processes and develop a goal programming model for a pull type ordering system based on the concept of a Just-In-Time(JIT) production system. We also present a pragmatic approach which reduces the required computational time for the formulated mixed integer goal programming problem using a mathematical programming modeling language. The proposed solution procedure is realized utilizing the post-optimal analysis which can be performed by the modeling language.     

Anatomic variants of the cystic duct and cysticohepatic junction: diagnosis with MR cholangiography

The cystic duct are variable in length, course and site of termination. A knowledge of the variable anatomy of the cystic duct and cysticohepatic junction is important in biliary surgery, because failure to recognize anatomic variations may result in a significant ductal injury. Magnetic resonance cholangiography (MRC) is a recently developed technique that demonstrates the biliary tree noninvasively and without injection of contrast material. Anatomic variants of the cystic duct and cysticohepatic junction that may increase the risk of bile duct injury in biliary surgery are frequently identified with MRC. MRC will be a noninvasive and a useful technique in the diagnosis of anatomic variants of the cystic duct and cysticohepatic junction.