Abstract: A circuit driving guide device includes at least one camera unit, disposed in a first vehicle, for acquiring driving information of the first vehicle driven on a driving route of a circuit and circuit information provided for each event occurring during driving on the driving route of the circuit, a communication module, disposed inside the first vehicle, for receiving, from a circuit server, map information of the driving route of the circuit and driving information of a second vehicle among one or more other vehicles driven on the driving route of the circuit, and a driving guide processor, disposed inside the first vehicle, for guiding a user in driving by analyzing the driving information of the first vehicle and the circuit information acquired from the at least one camera unit, and the map information and the driving information of the second vehicle provided from the communication module, and by applying an analyzed result value, obtained from the analyzing of the driving guide processor, to a driving

Abstract: A tripod constant velocity joint includes: a spider having a plurality of trunnions; a plurality of roller assemblies which are respectively assembled to the plurality of the trunnions; and a housing defining a plurality of track grooves which respectively receive the plurality of roller assemblies. The respective roller assembly includes: an inner roller which is coupled to the trunnion; an outer roller which is disposed to surround the inner roller; a needle roller which is interposed between the inner roller and the outer roller; and an elastic member which elastically supports the outer roller outwardly in a radial direction with respect to the inner roller.

Abstract: A constant-velocity universal joint includes: an outer joint member having a plurality of outer ball grooves; an inner joint member having a plurality of inner ball grooves; a plurality of torque transmitting balls; and a ball cage. The outer ball groove and the inner ball groove respectively have a double shape, and a ratio O/H of an offset value O which is a distance between an inflection point of the outer ball groove and a line connecting centers of the torque transmitting balls in a state that the outer joint member and the inner joint member form 0 angle and a distance H between a center line of the inner joint member and a center of the torque transmitting ball in a state that the outer joint member and the inner joint member form 0 angle is within a range of 0.07 to 0.11.

Abstract: Provided are a hollow drive shaft and a method for manufacturing the same in which a concentrated load to a weak point which may be occurred by differences of sectional thicknesses and outer diameters of the shaft is dispersed so that the strength may be uniform throughout the whole length of the drive shaft. The hollow drive shaft includes: one or more small-diameter portion having a hollow shape; and a large-diameter portion which is disposed in a vicinity of the small-diameter portion and has an outer diameter relatively greater than the small-diameter portion. A sectional thickness of the large-diameter portion is less than a sectional thickness of the small-diameter portion, and a first sectional portion from an outer surface to a point corresponding to 35% to 60% of a sectional thickness of the large-diameter portion is carburized to have a first hardness.

Abstract: A constant-velocity universal joint includes: an outer joint member having a plurality of outer ball grooves; an inner joint member having a plurality of inner ball grooves; a plurality of torque transmitting balls; and a ball cage. The outer ball groove and the inner ball groove respectively have a double shape, and a ratio O/H of an offset value O which is a distance between an inflection point of the outer ball groove and a line connecting centers of the torque transmitting balls in a state that the outer joint member and the inner joint member form 0 angle and a distance H between a center line of the inner joint member and a center of the torque transmitting ball in a state that the outer joint member and the inner joint member form 0 angle is within a range of 0.07 to 0.11.

Abstract: The present invention has been made in an effort to provide a hollow drive shaft and a method for manufacturing the same in which the concentrated load to a weak point which may be occurred by differences of sectional thicknesses and outer diameters is dispersed so that the strength may be uniform throughout the whole length. A hollow drive shaft includes: one or more small-diameter portion having a hollow shape; and a large-diameter portion which is disposed in the vicinity of the small-diameter portion and has an outer diameter relatively greater than the small-diameter portion. A sectional thickness of the large-diameter portion is less than a sectional thickness of the small-diameter portion, and a first sectional portion from an outer surface to a point corresponding to 35% to 60% of a sectional thickness of the large-diameter portion is carburized to have a first hardness.

Abstract: A recovery method for a high-dimensional index structure is disclosed, in which a reinsert operation is employed based on ARIES (algorithm for recovery and isolation exploiting semantics) and a page-oriented redo and a logical undo. Further, a recording medium on which a program for carrying out the above method is recorded is disclosed, the program being readable by a computer. The recovery method for a high-dimensional index structure employing a reinsert operation according to the present invention includes the following steps. At a first step, an entry is inserted into a node, a minimum bounding region is adjusted, an overflow is processed, and a log record is stored. At a second step, the log record thus stored is recovered.

Abstract: A recovery method for a high-dimensional index structure is disclosed, in which a reinsert operation is employed based on ARIES (algorithm for recovery and isolation exploiting semantics) and a page-oriented redo and a logical undo. Further, a recording medium on which a program for carrying out the above method is recorded is disclosed, the program being readable by a computer. The recovery method for a high-dimensional index structure employing a reinsert operation according to the present invention includes the following steps. At a first step, an entry is inserted into a node, a minimum bounding region is adjusted, an overflow is processed, and a log record is stored. At a second step, the log record thus stored is recovered.

Abstract: A concurrency control method for searching the high-dimensional index tree of a database is disclosed. The concurrency control includes: a) adding a root node to the queue and acquiring the shared lock for reinsertion node; b) determining whether the queue is empty or not, fetching a node from the queue and assigning the fetched node as a current node if queue is not empty, releasing the shared lock and terminating the search process if queue is empty; c) acquiring the shared latch in the current node, selecting the lower nodes which are within the query range and adding the selected nodes to the queue if current node is not leaf or to the result set if current node is leaf; and d) returning to the step b).

Abstract: A concurrency control method for a high dimensional index structure that provides efficient concurrency control method for a high dimensional index structure, which performs reinsertion of certain objects to cope with node overflow. The concurrency controlled searching method includes the following steps. First, an entry is obtained from a queue storing the root node and an object relating to the entry is selected. Second, whether a logic sequence number (LSN) of a lower level node is larger than an expected LSN stored in the upper node is determined. Third, the process moves to a neighbor node of the lower level node if the LSN is bigger than an expected LSN stored in the upper node in the second step, selects a relating object, and performs from the second step repeatedly.