Abstract: A method and apparatus for synchronizing multimedia content with a client device which supports a multi-server environment are provided. The server includes a synchronization policy management unit which acquires a synchronization policy; a synchronization information collector which collects log information of a previously performed synchronization and of a change occurring after the previously performed synchronization; a synchronization processor which performs synchronization in accordance with the collected log information; a change log management unit which stores a result of the synchronization; an interface unit which transmits the log information; and a storage unit which stores the multimedia content and the meta data of the multimedia content.

Abstract: A method of synchronizing broadcast contents between a broadcast recorder and a portable content player and an apparatus for the same are disclosed. The broadcast content synchronizing method includes obtaining metadata about broadcast contents stored in a portable content player from the portable content player; confirming a broadcast content that has already been reproduced among the broadcast contents stored in the portable content player by the obtained metadata; retrieving a broadcast content corresponding to the next installment of the confirmed broadcast content from recorded broadcast contents; and storing the retrieved broadcast content in the portable content player.

Abstract: A method of measuring shear friction factor between a workpiece material and a forming tool through a backward extrusion process. The method includes steps of: positioning the workpiece material at a groove previously manufactured on the forming die by turning; pressurizing the workpiece material to form an extruded product by pressure of a downwardly moving punch; forming tip on the extruded end of the extruded product; measuring an external diameter of the extruded product and a diameter of the tip, and obtaining a perpendicular distance by subtracting the diameter of the tip from the external diameter and dividing the subtracting result by two; and acquiring shear friction factor by calculating predetermined coefficients and a normalized perpendicular distance non-dimensionalized by thickness value of the extruded product. The thickness is defined as an interval between the external diameter of the extruded product and an external diameter of the punch.

Abstract: A method of measuring the representative shear friction factor at the interface between a workpiece material and forming die during bulk forming processes through a backward extrusion process is disclosed. In this measuring method, the workpiece material is primarily positioned at a predetermined groove location within the forming die of the extrusion tool-set and is pressurized by a punch. This process forms an apex at the backward extruded end of the extruded product. Thereafter, the perpendicular distance “d” from the external side surface of the extruded product to the apex is measured and used to calculate the representative shear friction factor “mf”. In the above method, the diameter of the workpiece material is equal to the average of the outer diameter of the punch and the inner diameter of the forming die. It is also positioned such that its central axis is aligned with the central axes of both the punch and the forming die.

Abstract: An audio listening device includes a circuit for amplifying sound source signals and a mechanism including a bone conduction vibrator transforming an output signal of the amplifying circuit into a vibration. A vibration source transforms the output of the amplifying circuit into a first magnetic field and vibration. A vibration generating unit generates a second magnetic field for the vibration source to vibrate upwards and downwards due to attraction and repulsion processes of the first and second magnetic fields. A damper is connected to the vibration source to arouse air conduction hearing due to the vibration of the vibration source. A vibration plate is connected to the vibration source to arouse a bone conduction hearing due to the vibration of the vibration source. A vibration transmission unit transmits the bone conduction hearing and air conduction hearing to the hearing impaired.