Abstract:
A system and method for controlling an interior permanent magnet synchronous motor (IPMSM) are presented. In an exemplary implementation, phase current ripple estimation techniques are utilized for variable frequency switching pulse-width modulation control of the IPMSM. In one implementation, the method includes controlling a three-phase inverter based on an initial switching frequency to generate a three-phase alternating current (AC) voltage for the IPMSM. Transformed voltages are determined in a rotating reference frame based on the three-phase AC voltage in the stationary reference frame. Current ripples are determined in the rotating reference frame based on the transformed voltages. Phase current ripples are determined in the stationary reference frame based on the current ripples in the rotating reference frame. A modified switching frequency for the three-phase inverter is determined based on the initial switching frequency and the phase current ripples. The three-phase inverter is then controlled based on the modified switching frequency.
Abstract:
The present invention relates to a rotary powder container with a brush, wherein powder is discharged through a brush of a powder discharge case by rotating an internal case containing powder in an external case. The internal case is able to be rotated in the external case, wherein powder is discharged into a brush when a plurality of discharge holes of a powder discharge case are in line with a plurality of discharge member holes of a powder discharge member if the internal case is rotated in the external case, and powder is not discharged into a brush when the plurality of discharge holes of the powder discharge case are not in line with the plurality of discharge member holes of the powder discharge member if the internal case is rotated in the external case. The present invention is convenient to use and has an elegant look.
Abstract:
Single nucleotide polymorphisms (SNP) for predicting prognosis of hepatocellular carcinoma after curative surgical resection are provided. The SNPs have a significant correlation with an over-expression of MTA1 which is useful prognostic factor for prediction of prognosis or poor survival after curative surgical resection of hepatocellular carcinoma. Therefore, the SNPs can be used in developing micro-arrays or test kits for prediction of the prognosis of hepatocellular carcinoma, and in screening drugs to improve poor prognosis of hepatocellular carcinoma after curative surgical resection.
Abstract:
Disclosed is a method for producing a propylene polymer using an alkoxysilane compound comprising a trialkylsilyl group in its molecular structure, specifically a method for easily producing an isotactic propylene polymer with dramatically improved melt flowability, owing to the improved reactivity of hydrogen that is provided as a molecular weight regulator, by specifically using an alkoxysilane compound comprising a trialkylsilyl group in the molecular structure thereof as an external electron donor in propylene polymerization.
Abstract:
Provided is a method for preparing a support for olefin polymerization catalysts used in polyolefin preparation processes. Particularly, provided is a novel method for preparing a support for olefin polymerization catalysts comprising the reaction of metal magnesium with an alcohol in the presence of an additive for initiating the reaction, characterized in that halogenated nitrogen compound is used as the additive for initiating the reaction, resulting in a spherical dialkoxy magnesium support.The spherical support for olefin polymerization catalysts obtained from the method of the present invention has a spherical particle shape with a smooth surface, uniform particle size distribution and 0.25 g/cc or more of bulk density, which makes it suitable for preparing a catalyst that is enough to meet the particle properties required by commercial olefin polymerization processes including, for example slurry polymerization, bulk polymerization, gas phase polymerization and the like.
Abstract:
The present invention relates to a method for producing a propylene polymer having a very high melt flowability, specifically to a method for producing an isotactic propylene polymer having a dramatically improved melt flowability with a relatively high production yield in convenient way, by improving the reactivity of hydrogen that is served as a molecular weight controlling agent in propylene polymerization.
Abstract:
In an apparatus for automatically filling a pipette according to the present invention, only a predetermined air is supplied to a pipette assembly to which a substance is discharged, even if an excessive operation force is applied by a user, so it is possible to prevent a waste of the substance being unnecessarily discharged.
Abstract:
A semiconductor device including a PLL providing candidate clocks of different phases in response to a first clock received from a reader via an antenna, a phase difference detector detecting a phase difference between the first clock and a clock from the candidate clocks, a phase difference controller that selects another clock from the candidate clocks, and a driver that provides transmission data synchronously with the another clock to the reader.
Abstract:
A method and apparatus for changing a page when an e-book terminal is inclined is provided. The method includes sensing that the e-book terminal is inclined to a left or right side, then changing a current page to a next page when the e-book terminal is inclined to the left side or changing the current page to a previous page when the e-book terminal is inclined to the right side.
Abstract:
A system and method for controlling an interior permanent magnet synchronous motor (IPMSM) are presented. In an exemplary implementation, phase current ripple estimation techniques are utilized for variable frequency switching pulse-width modulation control of the IPMSM. In one implementation, the method includes controlling a three-phase inverter based on an initial switching frequency to generate a three-phase alternating current (AC) voltage for the IPMSM. Transformed voltages are determined in a rotating reference frame based on the three-phase AC voltage in the stationary reference frame. Current ripples are determined in the rotating reference frame based on the transformed voltages. Phase current ripples are determined in the stationary reference frame based on the current ripples in the rotating reference frame. A modified switching frequency for the three-phase inverter is determined based on the initial switching frequency and the phase current ripples. The three-phase inverter is then controlled based on the modified switching frequency.