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    Method and apparatus for pulse width modulation in a switching amplifier
    11.
    发明授权
    Method and apparatus for pulse width modulation in a switching amplifier 有权
    开关放大器中的脉宽调制方法和装置

    公开(公告)号：US07724082B2

    公开(公告)日：2010-05-25

    申请号：US11913113

    申请日：2006-05-04

    Applicant: Sang Jin Park ,  Yong Hun Cho ,  Yun Do Kim

    Inventor： Sang Jin Park ,  Yong Hun Cho ,  Yun Do Kim

    IPC: H03F3/38

    CPC classification number: H04L25/4902 ,  H03F3/217 ,  H03K7/08

    Abstract: There is provided a method and apparatus for output pulse width modulation in a digital amplifier including: a determining step of adding or subtracting a value corresponding to a predetermined offset to or from an input audio signal alternately according to a period of the input audio signal, thereby determining a sign of a resulting value of adding or subtracting; a switching step of outputting the input audio signal to a first port based on the determined sign, or outputting the input audio signal to a second port after inverting the input audio signal into a positive number; an adjusting step of adding a value of a predetermined switching time to the audio signals output from the first port and the second port, and outputting a resulting value of adding; and a modulating step of performing pulse width modulation on the audio signals output from the adjusting step and outputting a first modulation signal and a second modulation signal.

    Abstract translation: 提供了一种数字放大器输出脉冲宽度调制方法和装置，包括：根据输入音频信号的周期交替地向输入音频信号输入或从输入音频信号中减去与预定偏移相对应的值的确定步骤， 从而确定加法或减法的结果值的符号; 切换步骤，基于所确定的符号将输入音频信号输出到第一端口，或者在将输入音频信号反转为正数之后将输入音频信号输出到第二端口; 调整步骤，对从所述第一端口和所述第二端口输出的音频信号添加预定切换时间的值，并输出所得到的加法值; 以及对从调整步骤输出的音频信号进行脉宽调制并输出第一调制信号和第二调制信号的调制步骤。

    Bipolar plate and direct liquid feed fuel cell stack
    15.
    发明申请
    Bipolar plate and direct liquid feed fuel cell stack 有权
    双极板和直接液体进料燃料电池堆

    公开(公告)号：US20060115705A1

    公开(公告)日：2006-06-01

    申请号：US11287443

    申请日：2005-11-28

    Applicant: Kyoung Choi ,  Jong-koo Lim ,  Yong-hun Cho ,  Il Moon

    Inventor： Kyoung Choi ,  Jong-koo Lim ,  Yong-hun Cho ,  Il Moon

    IPC: H01M8/02 ,  H01M8/10 ,  H01M8/24

    CPC classification number: H01M8/2455 ,  H01M8/0258 ,  H01M8/0263 ,  H01M8/1009 ,  H01M8/241

    Abstract: A bipolar plate and a direct liquid feed fuel cell stack are provided. The bipolar plate includes a manifold that is coupled with the fuel/oxidant path holes and a plurality of flow channels that are coupled with the manifold. The flow channels are divided into a plurality of groups, where the flow channel of each group forms a serpentine flow path and a length of each flow channel is substantially the same.

    Abstract translation: 提供了双极板和直接液体进料燃料电池堆。 双极板包括与燃料/氧化剂通道孔耦合的歧管和与歧管联接的多个流动通道。 流动通道被分成多个组，其中每组的流动通道形成蛇形流动路径，并且每个流动通道的长度基本相同。

    METHOD OF PREPARING NANO-SIZED CATALYST ON CARBON SUPPORT
    16.
    发明申请
    METHOD OF PREPARING NANO-SIZED CATALYST ON CARBON SUPPORT 有权
    制备纳米尺寸催化剂对碳支持的方法

    公开(公告)号：US20110104588A1

    公开(公告)日：2011-05-05

    申请号：US12775062

    申请日：2010-05-06

    Applicant: Nak Hyun Kwon ,  Inchul Hwang ,  Jae Seung Lee ,  Yung-Eun Sung ,  Tae-Yeol Jeon ,  Sung Jong Yoo ,  Kug-Seung Lee ,  Yong-Hun Cho

    Inventor： Nak Hyun Kwon ,  Inchul Hwang ,  Jae Seung Lee ,  Yung-Eun Sung ,  Tae-Yeol Jeon ,  Sung Jong Yoo ,  Kug-Seung Lee ,  Yong-Hun Cho

    IPC: H01M4/92 ,  B01J21/18 ,  B01J23/40

    CPC classification number: H01M4/92 ,  H01M4/8663 ,  H01M4/885 ,  H01M4/926 ,  Y02E60/50

    Abstract: The present invention provides a method of synthesizing a nano-sized transition metal catalyst on a carbon support, including dissolving a stabilizer in ethanol thus preparing a mixture solution, adding a support to the mixture solution thus preparing a dispersion solution, dissolving a transition metal precursor in ethanol thus preparing a precursor solution, mixing the precursor solution with the dispersion solution with stirring, and then performing reduction, thus preparing the nano-sized transition metal catalyst. This method enables the synthesis of transition metal nanoparticles supported on carbon powder having a narrow particle size distribution and a wide degree of dispersion through a simple process, and is thus usefully applied to the formation of an electrode material or the like of a fuel cell.

    Abstract translation: 本发明提供了一种在碳载体上合成纳米尺寸的过渡金属催化剂的方法，包括将稳定剂溶解在乙醇中，从而制备混合溶液，向混合溶液中加入载体，从而制备分散液，将过渡金属前体 在乙醇中制备前体溶液，在搅拌下将前体溶液与分散液混合，然后进行还原，从而制备纳米尺寸的过渡金属催化剂。 该方法能够通过简单的工艺合成负载在碳粉末上的过渡金属纳米粒子，其具有窄的粒度分布和宽的分散度，因此有利地用于燃料电池的电极材料等的形成。

    Method for preparing the mixed electrode catalyst materials for a PEM fuel cell
    17.
    发明申请
    Method for preparing the mixed electrode catalyst materials for a PEM fuel cell 有权
    制备PEM燃料电池用混合电极催化剂材料的方法

    公开(公告)号：US20090005237A1

    公开(公告)日：2009-01-01

    申请号：US11985810

    申请日：2007-11-16

    Applicant: Nak Hyun Kwon ,  Yung Eun Sung ,  In Su Park ,  Yong Hun Cho ,  In Chul Hwang ,  Il Hee Cho

    Inventor： Nak Hyun Kwon ,  Yung Eun Sung ,  In Su Park ,  Yong Hun Cho ,  In Chul Hwang ,  Il Hee Cho

    IPC: H01M4/88

    CPC classification number: H01M4/921 ,  H01M4/926 ,  H01M2008/1095

    Abstract: The present invention relates to a process for preparing electrode catalyst materials for a polymer electrolyte membrane fuel cell (PEMFC), and particularly to a high-performance platinum-non-platinum mixed electrode catalyst (Pt—RuOs/C) having a physically mixed structure of RuOs alloy and platinum materials, which is prepared by adding a small amount of platinum (Pt) to RuOs alloy materials highly dispersed on a carbon support, where the amount of platinum used is drastically reduced as compared to the conventional platinum materials, thus lowering the manufacturing cost.

    Abstract translation: 本发明涉及一种制备聚合物电解质膜燃料电池（PEMFC）的电极催化剂材料的方法，特别涉及具有物理混合结构的高性能铂 - 非铂混合电极催化剂（Pt-RuO / C） 的RuO合金和铂材料，其通过向高度分散在碳载体上的RuO合金材料添加少量铂（Pt）而制备，其中与常规铂材料相比，所使用的铂的量显着降低，因此降低 制造成本。

    Pulse width modulation type audio amplifier having variable average switching frequency
    18.
    发明授权
    Pulse width modulation type audio amplifier having variable average switching frequency 失效
    具有可变平均开关频率的脉宽调制型音频放大器

    公开(公告)号：US06888403B2

    公开(公告)日：2005-05-03

    申请号：US10222400

    申请日：2002-08-16

    Applicant: Yong Hun Cho ,  Bong Joo Kim

    Inventor： Yong Hun Cho ,  Bong Joo Kim

    IPC: H03G1/00 ,  H03F3/217 ,  H03F3/38

    CPC classification number: H03F3/217

    Abstract: The present invention relates to an audio amplifier using a pulse width modulation, and more particularly, to a pulse width modulation type audio amplifier which an average switching frequency or a cutoff frequency of a low pass filter is variable in accordance with frequency of input signal. The present invention has a method for using average switching frequency of an output pulse by lowering the average switching frequency in accordance with the bandwidth of the input audio signal for relative narrow bandwidth than that of an input audio signal having a usual bandwidth of 20 kHz like as a pulse width modulation type radio signal and a low bandwidth signal for a subwoofer, a method for lowering a cutoff frequency of a low pass filter for restoring an output pulse to a continuous time signal together an average switching frequency of the output pulse, and a method for using respective average switching frequencies different to each other for each channel having respective different bandwidths in a multi-channel amplifier. By using the average switching frequency as lower as possible in accordance with the bandwidth of the input audio signal, the power efficiency is enhanced and the electromagnetic interference affecting peripheral devices can be minimized.

    Abstract translation: 本发明涉及一种使用脉冲宽度调制的音频放大器，更具体地说，涉及一种根据输入信号的频率可变的低通滤波器的平均切换频率或截止频率可变的脉宽调制型音频放大器。 本发明具有通过相对于具有20kHz的通常带宽的输入音频信号的带宽相对于相对窄带宽的输入音频信号的带宽来降低平均切换频率的方法来使用输出脉冲的平均切换频率， 作为用于低音炮的脉冲宽度调制型无线电信号和低带宽信号，一种降低低通滤波器的截止频率的方法，用于将输出脉冲恢复为连续时间信号，一起输出脉冲的平均切换频率，以及 一种在多声道放大器中对于具有各自不同带宽的每个声道使用彼此不同的各个平均切换频率的方法。 通过根据输入音频信号的带宽尽可能地使用平均切换频率，提高了功率效率，并且能够使影响周边设备的电磁干扰最小化。

    Image format converting method and apparatus
    19.
    发明授权
    Image format converting method and apparatus 失效
    图像格式转换方法和装置

    公开(公告)号：US06606423B2

    公开(公告)日：2003-08-12

    申请号：US08961944

    申请日：1997-10-31

    Applicant: Yong-hun Cho

    Inventor： Yong-hun Cho

    IPC: G06K932

    CPC classification number: G06T3/4007

    Abstract: An image format converting method and apparatus are provided. The image format converter includes a pre-filter for pre-filtering the input image and for outputting a pre-filtered signal, and a format converter for bi-linear interpolating the pre-filtered signal, according to a predetermined aspect ratio, and for outputting a format converted signal. Therefore, the image format converter can have simple structure by adding the pre-filter, before the format converter using simple bi-linear interpolation, so that the image can be enlarged or reduced while remaining distinct and without aliasing.

    Abstract translation: 提供了一种图像格式转换方法和装置。 图像格式转换器包括用于对输入图像进行预滤波和用于输出预滤波信号的预滤波器，以及用于根据预定宽高比双向线性内插预滤波信号的格式转换器，并用于输出 格式转换信号。 因此，在格式转换器使用简单的双线性插值之前，图像格式转换器可以通过添加预滤波器具有简单的结构，使得图像可以被放大或缩小，同时保持不同且没有混叠。

    Motion picture detecting method
    20.
    发明授权
    Motion picture detecting method 失效
    电影检测方法

    公开(公告)号：US5959681A

    公开(公告)日：1999-09-28

    申请号：US774493

    申请日：1996-12-30

    Applicant: Yong-Hun Cho

    Inventor： Yong-Hun Cho

    IPC: H04N9/78 ,  H04B7/26 ,  H04N5/14 ,  H04N5/44 ,  H04N7/01 ,  H04N11/20

    CPC classification number: H04N5/144 ,  H04N7/012

    Abstract: A method of accurately detecting rapid motion as well as slow motion using two field memories in an interlaced-progressive scanning converter for changing an interlaced-scanned signal into a progressive-scanned signal. A threshold coefficient, which is used for comparison to a difference between temporal interpolation and spatial interpolation values to determine whether a picture is in motion, is determined dynamically in the disclosed method, rather than being a fixed, predetermined value. The threshold coefficient is determined based upon a degree of correlation between data of pixels above and below a pixel to be interpolated. Detection of whether the picture is stationary is based upon the difference between the data of pixels above and below the pixel to be interpolated is greater than a stationary coefficient. The threshold coefficient is maintained as being no less than the value of the stationary coefficient.

    Abstract translation: 使用隔行逐行扫描转换器中的两个场存储器精确地检测快速运动以及慢动作的方法，用于将隔行扫描信号改变为逐行扫描信号。 在所公开的方法中动态地确定用于与时间插值和空间内插值之间的差异进行比较以确定图像是否在运动中的阈值系数，而不是固定的预定值。 基于要插值的像素的上方和下方的像素的数据之间的相关度来确定阈值系数。 检测图像是否静止是基于要插值的像素的上下像素的数据之间的差大于平稳系数。 阈值系数保持为不小于平稳系数的值。

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