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This paper proposes an automatic design method of typical parameters such as number of phases, number of poles, stack thickness, stator outer diameter, rotor outer diameter, and number of turns of a switched reluctance motor from the requirement of the N‐T characteristic. In particular, a specific parameter related to the magnetic saturation is defined in order to arbitrarily determine how much to use the magnetic properties of the iron core material. In the proposed method, the typical motor parameters in order to realize a miniaturized volume which satisfies an input N‐T characteristic are obtained by setting the parameter related to magnetic saturation, maximum electrical frequency, maximum current density, maximum copper loss, conductor slot fill factor, magnetic properties of material, and input voltage. The designed motor is analyzed using the Finite Element Method (FEM) in order to validate the proposed method. [ABSTRACT FROM AUTHOR]

Abstract: A novel circuit topology for a single‐phase inverter with a power decoupling capability operated in discontinuous current mode (DCM) is proposed in this paper. An inverter connected to a single‐phase grid requires a power decoupling capability to compensate for a power ripple with twice the grid frequency. Bulky capacitors are used as DC‐link capacitors in conventional systems. In contrast, the proposed circuit topology can use ceramic capacitors instead of electrolytic capacitors by reducing the required capacitance based on the active buffer concept. Moreover, this active buffer requires no additional inductor because it uses DCM for the power decoupling capability. In this paper, a control method for the active buffer circuit operated in DCM is introduced. An experimental verification of a 1‐kW prototype shows that the proposed circuit reduces the input current ripple at twice the grid frequency by 96.8%, with a maximum efficiency of 95.2%. In addition, the Pareto optimization of power density and efficiency is used to clarify the maximum power density points. It is found that the maximum power density of the proposed circuit is 1.6 times higher than that of a conventional boost‐type active buffer. [ABSTRACT FROM AUTHOR]

SUMMARY In this study, the lowest loss point is calculated using the permeance method when the machine parameters of the interior permanent magnet synchronous motor are changed. Using the proposed method, the motor loss is easily calculated compared to the conventional method. The periodic change in the magnetic resistance in the air-gap according to the rotation of the rotor does not need to be considered because the magnetic equivalent circuits of the rotor and stator are separated. In this study, the motor loss is calculated by the proposed method and a finite element method (FEM). As a result, the error in the calculation results between the permeance method and the FEM is 2.9%. On the other hand, the motor losses are calculated by the permeance method when some machine parameters are changed. As a result, these results agree in principle with those of the FEM. Therefore, the validity of the proposed method is confirmed. In addition, the method for motor design is considered in terms of the loss. [ABSTRACT FROM AUTHOR]

SUMMARY This paper proposes a fault ride through (FRT) method for a matrix converter in a grid-connected system to control the grid reactive current and generator torque during a three-phase short voltage sag. In the proposed method, the control period of the system is divided into three modes. In the first mode, all switches are turned off, and in the second mode, a zero vector is obtained at the output of the matrix converter. By using these two modes along with a snubber circuit in the matrix converter, the generator torque is controlled during the three-phase voltage sag. Further, in the third mode, a nonzero vector is selected to connect the generator to the grid for providing the reactive current to the grid. In addition, the paper proposes a feedback control to obtain a stable ride through operation. From the experimental results, it is confirmed that grid reactive current of 0.86 p.u. and generator torque of 1.07 p.u. are achieved by the proposed FRT method during the three-phase voltage sag. [ABSTRACT FROM AUTHOR]

This paper discusses pulse density modulation (PDM) control methods for a single-phase to three-phase matrix converter (MC) in high-frequency applications. The proposed circuit is used as an interface converter for a wireless power transfer system. This converter can input a frequency of several hundred kilohertz and output a low frequency, that is, 50 Hz or 60 Hz, for a commercial power grid. The proposed circuit implements zero voltage switching (ZVS) operation by using PDM control methods and obtains high efficiency. In this paper, two PDM control strategies are compared: delta-sigma conversion and the PDM pattern generation method based on space vector modulation (SVM), which is proposed here. Also, the experimental results obtained with the proposed system will be presented and discussed. The total harmonic distortions (THDs) of the output voltage with delta-sigma conversion and the PDM pattern generation method based on SVM are found to be 5.96% and 2.15%, respectively. In addition, the maximum efficiencies with delta-sigma conversion and the PDM control based on SVM are 93.4% and 97.3%, respectively. From the results, the validity of the PDM control based on SVM has been confirmed for improvement of the output waveforms and reduction of the switching loss. [ABSTRACT FROM AUTHOR]

SUMMARY This paper provides a fundamental analysis of a power supply and rectifiers for wireless power transfer using magnetic resonant coupling (MRC). MRC enables efficient wireless power transfer over middle-range transfer distances. MRC for wireless power transfer should operate at a high frequency in the industry science medical band, such as 13.56 MHz, because the size of the transfer device decreases at higher transfer frequencies. Therefore, the output frequency of the power supply on the transmitting side should be 13.56 MHz. In addition, the rectifier on the receiving side is operated at a high frequency. This paper focuses on the reflected power in the power supply and rectifiers. Thus, the parametric design method is clarified for the power supply, including a low-pass filter to match the output, the impedance of the power supply with the characteristic impedance of the transmission line. In addition, the effects on the rectifiers of silicon carbide and gallium nitride diodes are confirmed by performing an experiment and a loss analysis. [ABSTRACT FROM AUTHOR]

This paper proposes a three‐phase wireless power transfer (WPT) system with a three‐phase‐to‐three‐phase matrix converter. The proposed system directly converts power from an AC grid to high‐frequency AC for WPT. The three‐phase WPT system with the matrix converter is effectively expands the lifetime of the WPT system. A novel hybrid commutation method, which is suitable for the WPT system with a resonant characteristic, is proposed to avoid the commutation failure of the matrix converter. The strategy of the proposed hybrid commutation is based on an estimation of the current direction considering the resonant characteristics and elimination of commutation in the critical area. The proposed commutation method achieves an AC input‐current total harmonic distortion (THD) of 4.7% with the resonant three‐phase load without a current sensor on the high‐frequency side. Furthermore, the proposed WPT system achieves a system efficiency of 88.2% at a load of 4 kW. [ABSTRACT FROM AUTHOR]

This paper proposes a new circuit topology for a high-efficiency isolated DC/DC converter using series compensation. The proposed converter consists of a high-efficiency resonance half-bridge converter and a series con-verter. The series converter regulates the output voltage and provides only the differential voltage between the input voltage and output voltage. Therefore, the circuit achieves high efficiency when the input voltage is almost equal to the output voltage, because then only the resonance con-verter will operate. In this paper, the approach employed to achieve high efficiency by using the proposed series com-pensation method is introduced. In addition, the fundamen-tal operation and the method of designing the proposed circuit are described. The suitability of the proposed circuit was confirmed by performing experiment and loss analysis, and the maximum efficiency achieved was 96.2%. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(2): 42-52, 2013; Published online in Wiley Online Library (wileyon-linelibrary.com). [ABSTRACT FROM AUTHOR]

Phyllotaxy is defined as the spatial arrangement of leaves on the stem. The mechanism responsible for this extremely regular pattern is one of the most fascinating enigmas in plant biology. In this study, we identified a gene regulating the phyllotactic pattern in rice. Loss-of-function mutants of the DECUSSATE [DEO gene displayed a phyllotactic conversion from normal distichous pattern to decussate. The dec mutants had an enlarged shoot apical meristem with enhanced cell division activity. In contrast to the shoot apical meristem, the size of the root apical meristem in the dec mutants was reduced, and cell division activity was suppressed. These phenotypes indicate that DEC has opposite functions in the shoot apical meristem and root apical meristem. Map-based cloning revealed that DEC encodes a plant-specific protein containing a glutamine-rich region and a conserved motif. Although its molecular function is unclear, the conserved domain is shared with fungi and animals. Expression analysis showed that several type A response regulator genes that act in the cytokinin signaling pathway were down-regulated in the dec mutant. In addition, dec seedlings showed a reduced responsiveness to exogenous cytokinin. Our results suggest that DEC controls the phyllotactic pattern by affecting cytokinin signaling in rice. [ABSTRACT FROM AUTHOR]

This paper describes a three-phase power converter which utilizes the neutral point of an induction motor and demonstrates the performance of the motor using the proposed method under various operating conditions. Several motor test results, such as the speed-torque characteristic, the torque impact, and the acceleration-deceleration characteristic, are included to confirm the performance of the induction motor. The structure of the proposed circuit consists primarily of an AC/AC converter [indirect matrix converter (IMC)] and a boost converter connected to the neutral point of the induction motor. In addition, this paper also proposes a method to reduce the ripple found in the battery current. Several experimental results show that the motor works well, and even the leakage inductance is utilized in the boost converter. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Summary Leaf veins have a complex network pattern. Formation of this vein pattern has been widely studied as a model of tissue pattern formation in plants. To understand the molecular mechanism governing the vascular patterning process, we isolated the rice mutant, commissural vein excessive1 ( coe1). The coe1 mutants had short commissural vein (CV) intervals and produced clustered CVs. Application of 1- N-naphthylphthalamic acid and brefeldin A decreased CV intervals, and application of 1-naphthaleneacetic acid increased CV intervals in wild-type rice; however, coe1 mutants were insensitive to these chemicals. COE1 encodes a leucine-rich repeat receptor-like kinase, whose amino acid sequence is similar to that of brassinosteroid-insensitive 1-associated receptor kinase 1 (BAK1), and which is localized at the plasma membrane. Because of the sequence similarity of COE1 to BAK1, we also examined the involvement of brassinosteroids in CV formation. Brassinolide, an active brassinosteroid, decreased the CV intervals of wild-type rice, and brassinazole, an inhibitor of brassinosteroid biosynthesis, increased the CV intervals of wild-type rice, but coe1 mutants showed insensitivity to these chemicals. These results suggest that auxin and brassinosteroids regulate CV intervals in opposite directions, and COE1 may regulate CV intervals downstream of auxin and brassinosteroid signals. [ABSTRACT FROM AUTHOR]

Recently, renewable resource supplies, such as fuel cells, photovoltaic cells, wind power, and engine generators for distributed power systems have been studied intensely. Conventional compensators with switching devices are constructed based on a voltage source inverter using six arms. Therefore, conventional power quality compensators require a large electrolytic capacitor in the DC link part of the equipment. The use of a large capacitor hinders downsizing efforts and the lowering of equipment costs. Direct converters, which do not have a large electrolytic capacitor and an initial charge circuit, can be used to realize downsizing and lowering of equipment costs, when compared with conventional converters. This paper proposes a new application of a matrix converter to a PM generator for power quality compensation, such as reactive power compensation, harmonic current, and power interruption. The novel point of this work is that the matrix converter provides reactive power with harmonic current. Simulated and experimental results confirm that the matrix converter can maintain high performance the same as a conventional active filter and an uninterruptible power supply (UPS). © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(4): 37–44, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20972 [ABSTRACT FROM AUTHOR]

This paper proposes the safest novel commutation method for a matrix converter. There are two conventional commutation methods which depend on the polarity of the input line voltage (it is called “voltage commutation”) and depend on the polarity of the output current (it is called “current commutation”). However, problem of the voltage commutation is that commutation failure occurs around zero of the input line voltage. It is difficult to detect its polarity due to depending on offset and delay of the sensor. Similarly, the current commutation failure occurs around zero of the load current. A cause of these detection errors are a detection delay and an offset of a sensor. The proposed commutation method combines the input voltage commutation and the load current commutation. Therefore, the proposed commutation method can decrease the commutation failure without high accuracy sensor. In addition, a voltage error compensation based on the proposed commutation method is proposed in this paper. The proposed method can simply compensate for the commutation error of the output voltage and the input current at the same time. The effects of the proposed method are confirmed by experimental results with a 750 W induction motor and a R-L load. Those results confirm that the proposed commutation can decrease commutation failure. Moreover, the total harmonics distortion of the input current and the output current are 2.6 point and 0.9 point lower than that of the condition without the compensation at 100% output power. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(4): 49–57, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20826 [ABSTRACT FROM AUTHOR]

Cleistogamy is an efficient strategy for preventing gene flow from genetically modified (GM) crops. We identified a cleistogamous mutant of rice harbouring a missense mutation (the 45th residue isoleucine to threonine; I45T) in the class-B MADS-box gene SUPERWOMAN1 ( SPW1), which specifies the identities of lodicules (equivalent to petals) and stamens. In the mutant, spw1-cls, the stamens are normal, but the lodicules are transformed homeotically to lodicule–glume mosaic organs, thereby engendering cleistogamy. Since this mutation does not affect other agronomic traits, it can be used in crosses to produce transgenic lines that do not cause environmental perturbation. Molecular analysis revealed that the reduced heterodimerization ability of SPW1I45T with its counterpart class-B proteins OsMADS2 and OsMADS4 caused altered lodicule identity. spw1-cls is the first useful mutant for practical gene containment in GM rice. Cleistogamy is possible in many cereals by engineering class-B floral homeotic genes and thereby inducing lodicule identity changes. [ABSTRACT FROM AUTHOR]

This paper proposes a novel control method based on the virtual AC/DC/AC conversion for the matrix converter. The virtual AC/DC/AC conversion method is a very simple strategy to control the input current and the output voltage for the matrix converter. There are two new topics proposed in this paper. First, this paper proposes the minimum switching loss modulation on the virtual rectifier. In our proposed modulation, only two arms switching in the virtual rectifier using DC link current control by the virtual inverter can obtain clean sinusoidal input current. Second, a novel lean controlled carrier modulation on the virtual inverter is proposed. The leans of the triangle carrier are controlled by the duty ratio of the rectifier side pulse. The lean controlled carrier reduces harmonic distortion of the input current by avoiding interference between the rectifier control and the inverter control. These new proposals are confirmed by simulation and experimental results. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(3): 65–73, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20144 [ABSTRACT FROM AUTHOR]

This paper proposes a multi‐port DC‐AC converter with high efficiency and high‐power density. The proposed circuit consists of a full bridge converter, a series active filter, and an unfolder circuit. The proposed circuit reduces the low switching losses owing to the square waveform operation with low switching frequency. In addition, the proposed converter improves the power density because the number of inductors is significantly reduced compared to the conventional multi‐port converter. As the experimental result, the maximum efficiency of the proposed circuit reached 99.3%. Finally, the power density of the proposed converter is evaluated by the Pareto front curve. As the result, the power density of the proposed circuit was increased by 1.6 times in comparison with the conventional circuit. [ABSTRACT FROM AUTHOR]

The proposed inverter combines two methods which can significantly decrease the on-state and switching losses. The first method, using a current transformer and a single transistor, makes possible the reduction of the on-state loss to less than one-third of the usual Darlington transistor. The second method, using an auxiliary commutation IGBT in parallel with the transistor, makes possible zero-voltage switching, resulting in no switching loss. To realize higher inverter efficiency, a snubber and its loss recovery circuit are employed. Three-phase inverters were fabricated experimentally to evaluate our idea. Device volume and weight can be decreased to one-third those of a conventional three-phase inverter, and an efficiency of 98.0% from 5 kW to 20 kW is obtained at a switching frequency of 16 kHz. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(1): 62–69, 1997 [ABSTRACT FROM AUTHOR]

This article proposes a novel method of improving the overall coupling coefficient of a wireless power transfer system by using a four‐winding transformer of which two pairs of windings each are connected in parallel in the primary side and secondary side. By weakening the coupling coefficients kc between the parallel windings, the overall magnetic coupling between the primary side and secondary side of the transformer is improved. In order to confirm the validity of the proposed method, a conventional high‐kc four‐winding transmission coil and the proposed low‐kc four‐winding transmission coil are experimentally assessed. Then, the coils are introduced into a nonresonant inductive power transfer system utilizing a dual active bridge converter in order to confirm the correction of the input power factor. As a result, the overall magnetic coupling of the proposed four‐winding coils was found to be improved by 17% compared with the overall magnetic coupling of the conventional coil. Moreover, the input power factor for the entire load is corrected with the proposed four‐winding coil. Therefore, a low kc is effective in improving the overall magnetic coupling. [ABSTRACT FROM AUTHOR]

SUMMARY This paper proposes a configuration of a single-phase voltage source inverter that features power decoupling capability. Generally, the converter connected to a single-phase grid employs bulky dc link capacitors such as electrolytic capacitors in order to decouple the power ripple with twice the frequency of the power supply. The power ripple in the proposed circuit is compensated by an active buffer with small capacitors. In this paper, the fundamental operations of the proposed converter are confirmed by experimental results. From the experimental results, the output current total harmonic distortion (THD) is 3.51%, the ratio of the input current is 14.3%, and the output power factor is over 99%. In addition, the volume of the proposed circuit is reduced by 61% when the carrier frequency is 64 kHz compared to that with a carrier frequency of 16 kHz. Finally, from an evaluation of the power density using Pareto front curves, the proposed circuit achieves high power density in comparison with the conventional circuit. [ABSTRACT FROM AUTHOR]

It has been brought to the attention of the publisher that an error appeared in the title of the above article. The title as it appears here is correct. We apologize for any inconvenience this error may have caused the author. [ABSTRACT FROM AUTHOR]

Most aerial parts of the plant body are products of the continuous activity of the shoot apical meristem (SAM). Leaves are the major component of the aerial plant body, and their temporal and spatial distribution mainly determines shoot architecture. Here we report the identification of the rice gene PLASTOCHRON3 ( PLA3)/ GOLIATH ( GO) that regulates various developmental processes including the rate of leaf initiation (the plastochron). PLA3/ GO encodes a glutamate carboxypeptidase, which is thought to catabolize small acidic peptides and produce small signaling molecules. pla3 exhibits similar phenotypes to pla1 and pla2– a shortened plastochron, precocious leaf maturation and rachis branch-to-shoot conversion in the reproductive phase. However, in contrast to pla1 and pla2, pla3 showed pleiotropic phenotypes including enlarged embryo, seed vivipary, defects in SAM maintenance and aberrant leaf morphology. Consistent with these pleiotropic phenotypes, PLA3 is expressed in the whole plant body, and is involved in plant hormone homeostasis. Double mutant analysis revealed that PLA1, PLA2 and PLA3 are regulated independently but function redundantly. Our results suggest that PLA3 modulates various signaling pathways associated with a number of developmental processes. [ABSTRACT FROM AUTHOR]

This paper proposes a control method for a dual active bridge (DAB) converter, which achieves both a reduction in the nonlinear transmission power error due to the dead‐time and a reduction in the inductor current with a three‐level operation. The nonlinear transmission power error is compensated by designing a zero current period in the inductor current with the three‐level operation. In addition, an inductor current reduction method for the three‐level operation is also proposed. In the nonlinear transmission power error compensation method, the inductor current is reduced by suppressing the circulating current by considering the zero‐current period to be the dead‐time. The validity of the proposed method is confirmed using a 2.0‐kW prototype. The experimental results show that the transmission power error is reduced by up to 85.1%. In addition, the inductor current is reduced by up to 64.1% and the loss is reduced by up to 58.6%. Moreover, the DC offset is eliminated by utilizing the voltage polarity reverse phenomenon in the voltage control. [ABSTRACT FROM AUTHOR]

Summary: Floods impede gas (O2 and CO2) exchange between plants and the environment. A mechanism to enhance plant gas exchange under water comprises gas films on hydrophobic leaves, but the genetic regulation of this mechanism is unknown. We used a rice mutant (dripping wet leaf 7, drp7) which does not retain gas films on leaves, and its wild‐type (Kinmaze), in gene discovery for this trait. Gene complementation was tested in transgenic lines. Functional properties of leaves as related to gas film retention and underwater photosynthesis were evaluated. Leaf Gas Film 1 (LGF1) was identified as the gene determining leaf gas films. LGF1 regulates C30 primary alcohol synthesis, which is necessary for abundant epicuticular wax platelets, leaf hydrophobicity and gas films on submerged leaves. This trait enhanced underwater photosynthesis 8.2‐fold and contributes to submergence tolerance. Gene function was verified by a complementation test of LGF1 expressed in the drp7 mutant background, which restored C30 primary alcohol synthesis, wax platelet abundance, leaf hydrophobicity, gas film retention, and underwater photosynthesis. The discovery of LGF1 provides an opportunity to better understand variation amongst rice genotypes for gas film retention ability and to target various alleles in breeding for improved submergence tolerance for yield stability in flood‐prone areas. [ABSTRACT FROM AUTHOR]

Auxin is a fundamental plant hormone and its localization within organs plays pivotal roles in plant growth and development. Analysis of many Arabidopsis mutants that were defective in auxin biosynthesis revealed that the indole-3-pyruvic acid ( IPA) pathway, catalyzed by the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS ( TAA) and YUCCA ( YUC) families, is the major biosynthetic pathway of indole-3-acetic acid ( IAA). In contrast, little information is known about the molecular mechanisms of auxin biosynthesis in rice. In this study, we identified a auxin-related rice mutant, fish bone ( fib). FIB encodes an orthologue of TAA genes and loss of FIB function resulted in pleiotropic abnormal phenotypes, such as small leaves with large lamina joint angles, abnormal vascular development, small panicles, abnormal organ identity and defects in root development, together with a reduction in internal IAA levels. Moreover, we found that auxin sensitivity and polar transport activity were altered in the fib mutant. From these results, we suggest that FIB plays a pivotal role in IAA biosynthesis in rice and that auxin biosynthesis, transport and sensitivity are closely interrelated. [ABSTRACT FROM AUTHOR]

Summary The temporal and spatial control of meristem identity is a key element in plant development. To better understand the molecular mechanisms that regulate inflorescence and flower architecture, we characterized the rice aberrant panicle organization 2 ( apo2) mutant which exhibits small panicles with reduced number of primary branches due to the precocious formation of spikelet meristems. The apo2 mutants also display a shortened plastochron in the vegetative phase, late flowering, aberrant floral organ identities and loss of floral meristem determinacy. Map-based cloning revealed that APO2 is identical to previously reported RFL gene, the rice ortholog of the Arabidopsis LEAFY ( LFY) gene. Further analysis indicated that APO2/RFL and APO1, the rice ortholog of Arabidopsis UNUSUAL FLORAL ORGANS, act cooperatively to control inflorescence and flower development. The present study revealed functional differences between APO2/RFL and LFY. In particular, APO2/RFL and LFY act oppositely on inflorescence development. Therefore, the genetic mechanisms for controlling inflorescence architecture have evolutionarily diverged between rice (monocots) and Arabidopsis (eudicots). [ABSTRACT FROM AUTHOR]

This paper proposes a control strategy for matrix converters to reduce the torque ripple in the overmodulation range. In the overmodulation range, motor drive performance of matrix converters is deteriorated because of the output voltage saturation. In particular, the torque ripple which has lower frequency components than the input voltage frequency is remarkable. This paper presents a theoretical analysis of the causes of the torque ripple and the effect of the proposed control strategy. Experimental examinations including performance comparison with a trapezoidal wave modulation are carried out using a 400-V, 22-kW experimental system. The experimental results verify the validity of the theoretical analysis and confirm the effectiveness of the proposed control strategy for reducing the torque ripple. Furthermore, the harmonic distortion of the output current is also reduced compared with the trapezoidal wave modulation. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(4): 40–48, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20829 [ABSTRACT FROM AUTHOR]

Numerous genes are involved in the regulation of plant development, including those that regulate floral homeotic genes, We identified two recessive allelic rice mutants, open beak-1 ( opb-1) and opb-2, which exhibited pleiotropic defects in leaf morphogenesis, inflorescence architecture, and floral organ identity. Abnormal cell proliferation was observed in the leaves and spikelets, and ectopic or overexpression of several class 1 knox genes was detected; thus, the abnormal cell proliferation in opb mutants is probably caused by ectopic class 1 knox gene expression. The opb mutants also had defects in floral organ identity, resulting in the development of mosaic organs, including gluminous lodicules, staminoid lodicules, and pistiloid stamens. These results, together with the reduced expression of a class B gene, indicate that OPB positively regulates the expression of class B genes. Map-based cloning revealed that OPB encodes a transcription factor that is orthologous to the Arabidopsis JAGGED gene and is expressed in leaf primordia, inflorescence meristem, rachis branch meristems, floral meristem, and floral organ primordia. Taken together, our data suggest that the OPB gene affects cellular proliferation and floral organ identity through the regulation of class 1 knox genes and floral homeotic genes. [ABSTRACT FROM AUTHOR]

In this paper, a novel control method for a matrix converter is proposed. The proposed method is a PAM (Pulse Amplitude Modulation) control method based on a virtual AC/DC/AC conversion method. Output voltage amplitude is controlled by controlling a virtual DC link voltage with a virtual rectifier. Output frequency is controlled by a virtual inverter. First, the proposed method is explained. Next, the validity of the proposed method is confirmed through simulation and experiment using a 750-W prototype matrix converter. Moreover, various characteristics of the proposed method and conventional virtual AC/DC/AC method are compared through experiment. As a result of the experiment, it has been understood that total harmonic distortion of output current and common-mode voltage can be reduced compared with the case of using a conventional virtual AC/DC/AC conversion method. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(4): 88–96, 2009; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20601 [ABSTRACT FROM AUTHOR]