Abstract: The first memory of a control unit has a control program stored therein, and an update of the control program is performed at a predetermined timing. After the update of the control program, the second memory in the control unit is referred to, and an event code stored in the second memory is extracted if the event code does not correspond to any one of event code group respectively associated with events that can possibly be generated by the updated control program. Due to the decreased necessity for use as reference data, the extracted event code may be considered as un-necessary and may be deleted, for example, from the memory.

Abstract: An engine ECU compares an acceleration value with a reference value, which corresponds to an accelerator operation value inputted in response to a user operation on an accelerator pedal, and stores vehicle behavior data when the acceleration value exceeds the reference value. After determining that the acceleration value is larger than the reference value and storing the vehicle behavior data, the reference value is changed to a larger value. After determining that the acceleration value is smaller than the reference value and, for example, a period in which the acceleration value remains lower than the reference value, reaches a set period, the reference value is changed to a smaller value. Thus, the number of times of storing the vehicle behavior data is equalized among vehicle users.

Abstract: An apparatus includes a first memory device, a second memory device and a controller. The first memory device stores vehicular data in accident. The second memory device has control data area for storing control data in nonvolatile manner. The controller records the vehicular data stored in the first memory device into the control data area of the second memory device by overwriting the control data in response to vehicular accident. It is possible to increase a recordable amount of vehicular data in vehicular accident without increasing recording capacity exclusively preserved to vehicular data.

Abstract: An engine ECU compares an acceleration value with a reference value, which corresponds to an accelerator operation value inputted in response to a user operation on an accelerator pedal, and stores vehicle behavior data when the acceleration value exceeds the reference value. After determining that the acceleration value is larger than the reference value and storing the vehicle behavior data, the reference value is changed to a larger value. After determining that the acceleration value is smaller than the reference value and, for example, a period in which the acceleration value remains lower than the reference value, reaches a set period, the reference value is changed to a smaller value. Thus, the number of times of storing the vehicle behavior data is equalized among vehicle users.

Abstract: An apparatus includes a first memory device, a second memory device and a controller. The first memory device stores vehicular data in accident. The second memory device has control data area for storing control data in nonvolatile manner. The controller records the vehicular data stored in the first memory device into the control data area of the second memory device by overwriting the control data in response to vehicular accident. It is possible to increase a recordable amount of vehicular data in vehicular accident without increasing recording capacity exclusively preserved to vehicular data.

Abstract: The first memory of a control unit has a control program stored therein, and an update of the control program is performed at a predetermined timing. After the update of the control program, the second memory in the control unit is referred to, and an event code stored in the second memory is extracted if the event code does not correspond to any one of event code group respectively associated with events that can possibly be generated by the updated control program. Due to the decreased necessity for use as reference data, the extracted event code may be considered as un-necessary and may be deleted, for example, from the memory.

Abstract: A small-scale wireless communication system offering advanced security level. An encryption key memory of an access point stores an encryption key list of a plurality of different encryption keys. A change information transmitter periodically transmits change information to a terminal by radio, the change information requesting the change of encryption key. An encryption key selector selects an encryption key from the encryption key list under a rule when the change information transmitter transmits the change information. A terminal-side encryption key memory of the terminal stores a terminal-side encryption key list which is the same as the encryption key list. A change information receiver receives the change information from the access point. Upon reception of the change information, a terminal-side encryption key selector selects an encryption key from the terminal-side encryption key list under a rule which is the same as the rule which the encryption key selector used to select the encryption key.

Abstract: A radio communication system for leveling off the processing loads of radio stations (access points) to which mobile terminals are connected, to improve the quality of service in radio communication. A mobile terminal searches for a beacon signal and transmits a connection request to a radio station which has sent the beacon signal captured. In the access point, a beacon-signal transmission section transmits the beacon signal, a connection-count management section manages, according to a connection-completion message, a local-station connection count and an other-station connection count, and a connection processing section receives the connection request, performs comparison processing for the local-station connection count and the other-station connection count, applies, when the local-station connection count is smaller than the other-station connection count, connection processing to the mobile terminal and generates a connection-completion message when a connection to the mobile terminal is completed.

Abstract: A wireless communication apparatus capable of preventing data leakage in wireless communication. A transmitted data frame receiver receives a transmitted data frame which is transmitted from a terminal to the wireless communication apparatus. An address information converter converts the address information of the terminal included in the transmitted data frame, into the address information of the own wireless communication apparatus. A radio transmitter transmits the transmitted data frame by radio. An address information comparator compares the address information included in a received data frame received by a radio receiver, with the address information of wireless communication apparatuses being stored in an address information memory. A received data frame destruction unit destructs the received data frame depending on the comparison result.

Abstract: A communication control device constitutes an access point of a wireless LAN system. The communication control device includes a unit receiving a movement advance notification of a terminal into a wireless zone under control; and a unit transmitting a transmission standby instruction so that a terminal transmitting data is brought into a wait state and a movement target terminal moving into the wireless zone under the control is allowed to transmit data by priority upon reception of the movement advance notification.

Abstract: A radio communication system for leveling off the processing loads of radio stations (access points) to which mobile terminals are connected, to improve the quality of service in radio communication. A mobile terminal searches for a beacon signal and transmits a connection request to a radio station which has sent the beacon signal captured. In the access point, a beacon-signal transmission section transmits the beacon signal, a connection-count management section manages, according to a connection-completion message, a local-station connection count and an other-station connection count, and a connection processing section receives the connection request, performs comparison processing for the local-station connection count and the other-station connection count, applies, when the local-station connection count is smaller than the other-station connection count, connection processing to the mobile terminal and generates a connection-completion message when a connection to the mobile terminal is completed.

Abstract: A small-scale wireless communication system offering advanced security level. An encryption key memory of an access point stores an encryption key list of a plurality of different encryption keys. A change information transmitter periodically transmits change information to a terminal by radio, the change information requesting the change of encryption key. An encryption key selector selects an encryption key from the encryption key list under a rule when the change information transmitter transmits the change information. A terminal-side encryption key memory of the terminal stores a terminal-side encryption key list which is the same as the encryption key list. A change information receiver receives the change information from the access point. Upon reception of the change information, a terminal-side encryption key selector selects an encryption key from the terminal-side encryption key list under a rule which is the same as the rule which the encryption key selector used to select the encryption key.

Abstract: A wireless communication apparatus capable of preventing data leakage in wireless communication. A transmitted data frame receiver receives a transmitted data frame which is transmitted from a terminal to the wireless communication apparatus. An address information converter converts the address information of the terminal included in the transmitted data frame, into the address information of the own wireless communication apparatus. A radio transmitter transmits the transmitted data frame by radio. An address information comparator compares the address information included in a received data frame received by a radio receiver, with the address information of wireless communication apparatuses being stored in an address information memory. A received data frame destruction unit destructs the received data frame depending on the comparison result.

Abstract: Disclosed is a preferable method for producing an avalanche photo diode in which an impurity-doped region having a relatively high concentration and a step-like distribution has a step portion in another impurity-doped region having a relatively low concentration and a gradational distribution so that the circumferential portion of the high concentration region is made shallow in comparison with the central portion of the same, the step portion having a shape so that the radius of curvature thereof varies continuously.