Abstract: A pseudo crank rotational speed determining unit for a bicycle includes a speed determining unit which determines a speed of the bicycle and a pseudo crank rotational speed determining unit. The pseudo crank rotational speed determining unit operatively communicates with the speed determining unit and determines a pseudo crank rotational speed from the determined speed of the bicycle. In a more specific embodiment, a front gear identifying unit identifies a front gear of the bicycle, and a rear gear identifying unit identifies a rear gear of the bicycle. The pseudo crank rotational speed determining unit determines a gear ratio from the identified front gear and the identified rear gear, and then the pseudo crank rotational speed is determined from the determined speed of the bicycle and from the determined gear ratio.

Abstract: A bicycle shift control device includes a pedaling force determining unit for determining a pedaling force exerted on a pedaling member and a shift stage determining unit which determines an optimum shift stage of a bicycle transmission from the pedaling force. In a more specific embodiment, the shift control device includes a memory that stores first and second pedaling force values for a shift stage of the bicycle transmission, wherein the second pedaling force value is greater than the first pedaling force value, and first and second traveling speed values for the shift stage of the bicycle transmission, wherein the second traveling speed value is greater than the first traveling speed value.

Abstract: A shift control device for a bicycle transmission having a plurality of transmission paths includes a hub shaft, a driver rotatably mounted around the hub shaft for rotating in first and second directions, wherein the first direction is opposite the second direction, a transmission path selecting member for selecting among the plurality of transmission paths, and a reverse motion mechanism coupled to the driver for converting rotation of the driver in the first direction into motion in the second direction. An operation mechanism operates the transmission path selecting member, wherein the operation mechanism includes a first drive force takeoff component which moves between a first state and a second state.

Abstract: A bicycle transmission includes a shaft, a driving part supported about the shaft for coupling to the input part, a driven part supported about the shaft for coupling to the output part, and a planetary gear mechanism disposed between the driving part and the driven part for changing the transmission ratio of the motive force applied from the driving part to the driven part. The planetary gear mechanism comprises a sun gear installed about the shaft, an output gear for transmitting motive force to the driven part, a frame part installed about the shaft and coupled to the driving part, and a planetary gear rotatably coupled to the frame part and disposed between the sun gear and the output gear for engaging the sun gear and the output gear. A clutch comprising a roller is disposed at an intermediate point along the transmission path between the driving part and the driven part for transmitting the motive force from the driving part to the driven part in one direction only.

Abstract: A system is provided for improving the speed for writing data in a disk array system. The disk array system includes a solid state disk storage device configured with semiconductor flash memory to sequentially store the parity for the disk array. The solid state disk storage device allows data sectors to be assigned sequentially in a cluster consisting of a set of blocks. Each block is a physical unit of erasure. Write operations for a plurality of sectors are written across the set of blocks in the cluster.

Abstract: A method and system are provided for improving the speed for writing data in a disk array system (RAID). Disks are divided into the ones for reading old data and the other ones for writing new data. An external semiconductor storage device is used as a parity device which significantly enhances performance in writing.A disk array system is used for storing data for which a parity group comprises N data units stored in sectors of N magnetic disk drives with parity stored in the parity device. At least N+1 data-storing magnetic disk drives are provided, where sectors of at least one magnetic disk drive are used as redundant sectors.

Abstract: A bicycle transmission includes a shaft, a driving part supported about the shaft for coupling to the input part, a driven part supported about the shaft for coupling to the output part, and a planetary gear mechanism disposed between the driving part and the driven part for changing the transmission ratio of the motive force applied from the driving part to the driven part. The planetary gear mechanism comprises a sun gear installed about the shaft, an output gear for transmitting motive force to the driven part, a frame part installed about the shaft and coupled to the driving part, and a planetary gear rotatably coupled to the frame part and disposed between the sun gear and the output gear for engaging the sun gear and the output gear. A clutch comprising a roller is disposed at an intermediate point along the transmission path between the driving part and the driven part for transmitting the motive force from the driving part to the driven part in one direction only.

Abstract: A motor-driven hub for a bicycle includes a hub shaft, a hub body rotatably mounted about the hub shaft, a drive member coaxially mounted with the hub shaft, a motor coupled to the drive member for rotating the drive member, and a one-way clutch disposed in a transmission path between the drive member and the hub body for transmitting rotation of the drive member to the hub body only in one direction. A gear reduction mechanism in the form of a planetary gear unit may be mounted in the transmission path between the drive member and the hub body so that the hub body rotates slower than the drive member. The motor may be mounted outside the hub or inside the hub. When mounted inside the hub, the motor may be mounted coaxially about the hub shaft so that the center of gravity of the motor lies within the hub along the axis of the hub.

Abstract: A method and system are provided for improving the speed for writing data in a disk array system (RAID). Sectors of the disks are divided into the ones for reading old data and the other ones for writing new data. An external semiconductor storage device is used as a parity device which significantly enhances performance in writing. Preferably, a disk array system is used for storing data for which a parity group comprises N data units stored in sectors of N magnetic disk drives with parity stored in the parity device. At least N+1 magnetic disk drives are provided, where sectors of at least one magnetic disk drive are used as redundant sectors.