Abstract: A non-transitory computer-readable recording medium stores a data management program for performing a zero knowledge proof of a credential owned by a user causing a computer to execute: disclosing a commitment of a digital signature of the credential to a verifier server; requesting the verifier server to verify a knowledge proof of the digital signature using the commitment; transmitting, to the verifier server, a plurality of digital signatures including the digital signature of the credential; and requesting the verifier server to verify a set membership proof in which one of the plurality of digital signatures is owned by the user.

Abstract: An object is to provide a cage silicate that can be industrially safely and simply produced by using an alkali silicate solution that does not generate alcohol as a Si raw material and using non-toxic quaternary ammonium, and a method for producing the same. The problem is solved by the following cage silicate: A cage silicate consisting of anion component 1 represented by following formula (1), anion component 2 which is a mineral acid ion, cation component 1 represented by following formula (2), and cation component 2 which is an alkali ion, in which, to the mole number in terms of SiO2, a ratio of the mole number of water, (H2O/SiO2), is 0.7 to 30, a ratio of the mole number of alkali ions, (alkali ions/SiO2), is 1.0×10?7 to 1.0×10?2, and a ratio of the mole number of the mineral acid ions, (mineral acid ions/SiO2), is 1.0×10?7 to 1.0×10?3. In formula (2), R represents an alkyl group having 2 to 20 carbon atoms.

Abstract: A method for producing a silica sol containing a small amount of metal impurities and in which colloidal silica having an elongated particle shape dispersed in a solvent, includes: preparing a raw material liquid by adding a compound as an anion source selected from inorganic acids, organic acids, and their ammonium salts, and ammonia to a colloidal aqueous solution of activated silica having an SiO2 concentration of 1 to 6% by mass and a pH of 2 to 5 so that the mass ratio of the compound to SiO2 is 3.0 to 7.0%; and heating the raw material liquid at 80 to 200° C. for 0.5 to 20 hours. The elongated colloidal silica particles exhibit a DL/DB ratio of 2.5 or more. DL is an average particle diameter as measured by the dynamic light scattering method. DB is a primary particle diameter as measured by the nitrogen gas adsorption method.

Abstract: A method for producing a silica sol containing a small amount of metal impurities and wherein colloidal silica having an elongated particle shape is dispersed in a solvent, by addition of a compound as an anion source and ammonia as an alkali source and heating of the resultant mixture at a predetermined temperature, includes the following steps: (a) preparing a raw material liquid by adding at least one compound as an anion source selected from the group of inorganic acids, organic acids, and ammonium salts of these acids, and ammonia to a silica sol as a raw material having SiO2 of 1% by mass to 30% by mass and a pH of 2 to 5 so the mass ratio of the compound to SiO2 is 0.5% to 1.9%; and (b) heating the raw material liquid prepared in step (a) at 80° C. to 200° C. for 0.5 hours to 20 hours.

Abstract: A vibration damping device including a supporting member rotating with a rotation element around a rotation center of the rotation element; a restoring force generation member coupled to the supporting member to transfer torque to and from the supporting member and configured to swing with rotation of the supporting member; and an inertia mass body coupled to the supporting member via the restoring force generation member and swinging around the rotation center with the restoring force generation member with rotation of the supporting member, in which the restoring force generation member swings around a swing center so that a relative position with respect to the inertia mass body does not change, and a distance between a center of gravity of the restoring force generation member and the swing center changes with a change in a swing angle of the restoring force generation member with respect to the inertia mass body.

Abstract: A vibration damping device includes: a supporting member that rotates integrally with a rotation element, to which torque from an engine is transmitted, around a rotation center of the rotation element; a restoring force generation member that is coupled to the supporting member so as to transmit and receive torque to and from the supporting member and that is configured to swing in accordance with rotation of the supporting member; and an inertia mass body that is coupled to the supporting member via the restoring force generation member and that swings around the rotation center in conjunction with the restoring force generation member in accordance with rotation of the supporting member, in which the restoring force generation member swings around a swing center that is set so that a relative position with respect to the inertia mass body does not change, and a distance between a center of gravity of the restoring force generation member and the swing center changes in accordance with a change in a swing a

Abstract: A method for producing a silica sol containing a small amount of metal impurities and in which colloidal silica having an elongated particle shape dispersed in a solvent, includes: preparing a raw material liquid by adding a compound as an anion source selected from inorganic acids, organic acids, and their ammonium salts, and ammonia to a colloidal aqueous solution of activated silica having an SiO2 concentration of 1 to 6% by mass and a pH of 2 to 5 so that the mass ratio of the compound to SiO2 is 3.0 to 7.0%; and heating the raw material liquid at 80 to 200° C. for 0.5 to 20 hours. The elongated colloidal silica particles exhibit a DL/DB ratio of 2.5 or more. DL is an average particle diameter as measured by the dynamic light scattering method. DB is a primary particle diameter as measured by the nitrogen gas adsorption method.

Abstract: A method for producing a silica sol containing a small amount of metal impurities and wherein colloidal silica having an elongated particle shape is dispersed in a solvent, by addition of a compound as an anion source and ammonia as an alkali source and heating of the resultant mixture at a predetermined temperature, includes the following steps: (a) preparing a raw material liquid by adding at least one compound as an anion source selected from the group of inorganic acids, organic acids, and ammonium salts of these acids, and ammonia to a silica sol as a raw material having SiO2 of 1% by mass to 30% by mass and a pH of 2 to 5 so the mass ratio of the compound to SiO2 is 0.5% to 1.9%; and (b) heating the raw material liquid prepared in step (a) at 80° C. to 200° C. for 0.5 hours to 20 hours.

Abstract: A vibration damping device including a support member rotabable about the center of rotation of a rotary element; a restoring force generation member coupled to the support member; an inertial mass body coupled to the support member via the restoring force generation member; and a guided portion and a guide portion provided alternately on one of the restoring force generation member or the inertial mass body. The guide portion guides the guided portion so the restoring force generation member swings along the radial direction of the center of rotation and the inertial mass body swings about the center of rotation when the support member is rotated. A component of a centrifugal force acting on the restoring force generation member is transferred from the guided portion to the guide portion. The restoring force generation member includes two mass bodies facing each other and disposed on sides of the inertial mass body.

Abstract: A vibration damping device includes a supporting member rotatable about a rotation center of a rotating element, a restoring-force generating member coupled to the supporting member, and an inertial mass body coupled to the supporting member via the restoring-force generating member. The restoring-force generating member includes two guidable portions disposed with a clearance therebetween in a circumferential direction of the rotating element, and a torque transmission portion between the two guidable portions to transmit torque to and from the supporting member. The inertial mass body includes multiple guide portions for guiding corresponding guidable portions.

Abstract: A vibration damping device 20 includes: a crank member 22 that is swingable along with rotation of a driven member 15 to which torque from an engine EG is transferred; and an inertial mass body 23 coupled to the driven member 15 via the crank member 22 and swung about a center of rotation RC in conjunction with the crank member 22 along with rotation of the driven member 15. The vibration damping device 20 is designed such that an effective order qeff becomes higher as the amplitude of vibration of input torque transferred from the engine EG to the driven member 15 becomes larger.