Abstract: A fault monitoring method is executed by a monitoring device in a fault monitoring system that includes a terminal used by a user, an appliance to be operated by the user, the monitoring device, and a plurality of authentication servers each including a distributed ledger, and includes: obtaining event information stored in the plurality of authentication servers and indicating an event generated in response to a request that includes a processing instruction for the user operating the appliance; obtaining state information indicating whether the appliance is faulty, from the appliance; generating first transaction data including the state information obtained and transmitting the first transaction data to the plurality of authentication servers; and transmitting the processing instruction included in the event information to the appliance, when the appliance is determined to be not faulty from the state information.

Abstract: A control method includes: receiving first information pertaining to a first contract from a first terminal used by a first user who is one of two parties who have agreed to the first contract; when consent of a party aside from the two parties is required to validate the first contract, identifying a second user as the party aside from the two parties with reference to a ledger storing information pertaining to a past contract, and transmitting the first information to a second terminal operated by the second user; obtaining second information in which a confirmation result indicating whether the second user consents to the first contract and a digital signature of the second user are added to the first information; and confirming the second information, and when the confirmation result indicates consent, setting the first contract as a valid contract and storing the second information in the ledger.

Abstract: An electronic device includes: a housing; a display provided at a front side thereof; and a stand provided at a back side thereof. The housing has a transition wall between back and bottom walls, which extends further to the front as further downwardly separated from the back wall. The transition wall has a recessed part and a ventilation hole communicated with the recessed part. The stand is attached to the housing so that the stand can move between a closed state where the stand approaches the back wall and an open state where a bottom end part of the stand is separated away from the back wall so that the stand can support the housing at an angle from a placement surface. The stand is configured so that the bottom end part of the stand covers part of the recessed part when the stand is in the closed state.

Abstract: A synthetic quartz glass substrate having a controlled hydrogen molecule concentration is prepared by (a) hot shaping a synthetic quartz glass ingot into a glass block, (b) slicing the glass block into a glass plate, (c) annealing the glass plate at 500-1,250° C. for 15-60 hours, (d) hydrogen doping treatment of the glass plate in a hydrogen gas atmosphere at 300-450° C. for 20-40 hours, and (e) dehydrogenation treatment of the glass plate at 200-400° C. for 5-10 hours.

Abstract: A synthetic quartz glass substrate having a controlled hydrogen molecule concentration is prepared by (a) hot shaping a synthetic quartz glass ingot into a glass block, (b) slicing the glass block into a glass plate, (c) annealing the glass plate at 500-1,250° C. for 15-60 hours, (d) hydrogen doping treatment of the glass plate in a hydrogen gas atmosphere at 300-450° C. for 20-40 hours, and (e) dehydrogenation treatment of the glass plate at 200-400° C. for 5-10 hours.