Abstract: A calculation method reduces a bit-width of an Ising model, the Ising model being expressed in terms of a plurality of spins, interaction coefficients between the plurality of spins, and external magnetic field coefficients acting respectively on the plurality of spins. The calculation method includes: adding an auxiliary spin to the Ising model; and setting a new interaction coefficient between the auxiliary spin and at least one of the plurality of spins to obtain a new Ising model, thereby reducing a bit-width of at least one of the interaction coefficients between the plurality of spins and the external magnetic field coefficients acting respectively on the plurality of spins.

Abstract: A welding method for welding a first metal member to a second metal member, where the first metal member is plate-shaped, includes: bringing the first metal member into contact with the second metal member; and radiating a laser beam along a spiral scanning pattern straddling an interface line between the first metal member and the second metal member.

Abstract: A hard disk comb includes: a main body including a groove; and an arm joined to the main body. A part of the arm is disposed inside the groove, and an opening edge of the groove is joined to an upper surface of the arm.

Abstract: A clean-room monitoring device for monitoring the interior of a clean-room having a floor in which a removable cover such as a grating or a non-porous cover is disposed, includes: a monitoring camera which captures an image of the removable cover; a monitor which detects the existence of an opening exposed when the removable cover is removed, based on an image signal obtained from the monitoring camera, detects the presence of a workman approaching the opening if it is detected that the opening exists, and outputs a warning signal if the workman is detected; and a warning generator which receives the warning signal from monitor and issues a warning.

Abstract: A clean-room monitoring device for monitoring the interior of a clean-room having a floor in which a removable cover such as a grating or a non-porous cover is disposed, includes: a monitoring camera which captures an image of the removable cover; a monitor which detects the existence of an opening exposed when the removable cover is removed, based on an image signal obtained from the monitoring camera, detects the presence of a workman approaching the opening if it is detected that the opening exists, and outputs a warning signal if the workman is detected; and a warning generator which receives the warning signal from monitor and issues a warning.