Abstract: The present disclosure provides a privacy computing method based on homomorphic encryption, which includes steps as follows. The ciphertext data is received, where the ciphertext data has a floating-point homomorphic encryption data structure, and the floating-point homomorphic encryption data structure of the ciphertext data includes the ciphertext mantissa, exponent parameter and gain parameter. The gain parameter sets the precision of the floating point corresponding to the ciphertext mantissa. The exponent parameter is adapted to multiplication or division. The artificial intelligence model performs operations on the ciphertext data to return the ciphertext result.

Abstract: The federated learning system includes a moderator and client devices. Each client device performs a method for verifying model update as follows: receiving a hash function and a general model; training a client model according to the general model and raw data; calculating a difference as an update parameter between the general model and the client model, sending the update parameter to the moderator; inputting the update parameter to the hash function to generate a hash value; sending the hash value to other client devices, and receiving other hash values; summing all the hash values to generate a trust value; receiving an aggregation parameter calculated according to the update parameters; inputting the aggregation parameter to the hash function to generate a to-be-verified value; and updating the client model according to the aggregation parameter when the to-be-verified value equals the trust value.

Abstract: An anti-pullout and low-resistance screw includes a shank, a screw-in portion, a head portion, and a thread. The thread is helically formed around both the screw-in portion and the shank and includes a plurality of thread convolutions. Each thread convolution includes an upper tooth surface facing the head portion and a lower tooth surface facing the screw-in portion. At least one tapered pressing structure is designed on the screw-in portion and/or the shank to define at least one section with its outer diameter tapering towards the screw-in portion gradually. The tapered pressing structure extends from a bottom edge of the lower tooth surface along a longitudinal axis of the shank. The lower tooth surface has a lower tooth surface height that is greater than the thread height. An annular anti-pullout plane is formed on the shank between two adjacent thread convolutions to enhance the anti-pullout strength of the screw.

Abstract: A screw includes a head and a shank extending from the head, and a hole-enlarging portion formed on the shank. The hole-enlarging portion features no thread and a substantially triangular transverse section. The hole-enlarging portion includes three inclined edges spaced from one another in the circumferential direction of the shank, and a guiding slope is formed between two adjacent inclined edges. The shank defines a longitudinal axis and is provided with a thread. Each inclined edge extends toward the head in an inclined direction relative to a horizontal axis perpendicular to the longitudinal axis. The inclined direction of each inclined edge is identical to a direction in which the thread extends toward the head.

Abstract: A wood screw is disclosed herein. It comprises a screw head and a rod body integrally extended from the screw head and having a shank part and a screwing part, wherein the screwing part comprises a straight surface surrounded with a threaded section and a cutting section on which a cutting unit is formed, and wherein a root diameter of the shank part is larger than root diameters of the threaded section and the cutting section respectively, and larger than or equal to a maximum outer diameter of the cutting section defined by the cutting unit.

Abstract: A concrete screw is adapted to be driven into a hole predrilled in a concrete structure and includes a head, a shank extending from the head, a thread formed on the shank, and a plurality of bump units. The shank includes front and rear segments spaced along a longitudinal axis. The bump units are distributed on at least the front segment of the shank and staggered along the longitudinal axis. Each bump unit includes a plurality of bumps constitute an inclined pattern relative to the longitudinal axis. Each bump protrudes from the periphery of the shank. In the course of the screw being driven into the hole, the bumps pulverize concrete debris in the hole, and waste debris accumulates at a segment of the shank on which the bump units are distributed for development of a pressing segment and promotion of anti-pullout strength of the screw.

Abstract: A screw includes a head and a shank extending from the head and defining a longitudinal axis. A thread is provided on the shank. The head includes a top portion and a cone portion located between the top portion and the shank. A plurality of recesses is provided in a peripheral surface of the cone portion and spaced in a circumferential direction of the cone portion. Each recess includes first and second side edges opposite to each other in the circumferential direction and an upper edge connecting the first and second side edges. The first side edge features a maximum recess depth greater than a maximum recess depth of the second side edge. The top edge extending in the circumferential direction of the cone portion is partially arranged between the top portion and the first side edge of an adjacent recess in the longitudinal axis direction.

Abstract: An anti-pullout and low-resistance screw includes a shank, a screw-in portion, a head portion, and a thread. The thread is helically formed around both the screw-in portion and the shank and includes a plurality of thread convolutions. Each thread convolution includes an upper tooth surface facing the head portion and a lower tooth surface facing the screw-in portion. At least one tapered pressing structure is designed on the screw-in portion and/or the shank to define at least one section with its outer diameter tapering towards the screw-in portion gradually. The tapered pressing structure extends from a bottom edge of the lower tooth surface along a longitudinal axis of the shank. The lower tooth surface has a lower tooth surface height that is greater than the thread height.

Abstract: A wood screw that includes a head and a shank is revealed. The shank is formed by a main shank portion and a tapered portion whose diameter is smaller than that of the main shank portion, both provided with a locking thread. A plurality of drilling units, whose outside diameter of the drilling unit is smaller than that of the locking thread, is disposed on the tapered portion. The drilling units first destroy workpiece material corresponding to the main shank portion so that the workpiece material becomes loose and the resistance of the locking thread of the main shank portion is reduced. Thereby the wood screw is screwed into the workpiece more smoothly. Moreover, an internal thread segment whose thread depth matches that of the locking thread of the main shank portion is formed so that the wood screw and the workpiece are fastened more firmly.

Abstract: A screw includes a head and a shank extending from the head and defining a longitudinal axis. A thread is provided on the shank. The head includes a top portion and a cone portion located between the top portion and the shank. A plurality of recesses is provided in a peripheral surface of the cone portion and spaced in a circumferential direction of the cone portion. Each recess includes first and second side edges opposite to each other in the circumferential direction and an upper edge connecting the first and second side edges. The first side edge features a maximum recess depth greater than a maximum recess depth of the second side edge. The top edge extending in the circumferential direction of the cone portion is partially arranged between the top portion and the first side edge of an adjacent recess in the longitudinal axis direction.

Abstract: A screw includes a head and a shank extending from the head, and a hole-enlarging portion formed on the shank. The hole-enlarging portion features no thread and a substantially triangular transverse section. The hole-enlarging portion includes three inclined edges spaced from one another in the circumferential direction of the shank, and a guiding slope is formed between two adjacent inclined edges. The shank defines a longitudinal axis and is provided with a thread. Each inclined edge extends toward the head in an inclined direction relative to a horizontal axis perpendicular to the longitudinal axis. The inclined direction of each inclined edge is identical to a direction in which the thread extends toward the head.

Abstract: A threaded fastener includes a head, a shank extending from the head, and a. cone portion. The head includes a top portion and an annular side wall extending downwardly from a periphery of the top portion. The cone portion is formed between the shank and the top portion and has a peripheral surface tapering from the top portion to the shank. An annular groove is created between the annular side wall and the cone portion for development of an accommodating space with an opening downward in a bottom of the head. The annular groove is surrounded by an inner surface of the annular side wall, the peripheral surface of the cone portion, and a bottom wall of the top portion connected between the annular side wall and the cone portion.

Abstract: A wood screw is disclosed herein. It comprises a screw head and a rod body integrally extended from the screw head and having a shank part and a screwing part, wherein the screwing part comprises a straight surface surrounded with a threaded section and a cutting section on which a cutting unit is formed, and wherein a root diameter of the shank part is larger than root diameters of the threaded section and the cutting section respectively, and larger than or equal to a maximum outer diameter of the cutting section defined by the cutting unit.

Abstract: A wood screw that includes a head and a shank is revealed. The shank is formed by a main shank portion and a tapered portion whose diameter is smaller than that of the main shank portion, both provided with a locking thread. A plurality of drilling units, whose outside diameter of the drilling unit is smaller than that of the locking thread, is disposed on the tapered portion. The drilling units first destroy workpiece material corresponding to the main shank portion so that the workpiece material becomes loose and the resistance of the locking thread of the main shank portion is reduced. Thereby the wood screw is screwed into the workpiece more smoothly. Moreover, an internal thread segment whose thread depth matches that of the locking thread of the main shank portion is formed so that the wood screw and the workpiece are fastened more firmly.

Abstract: A wood screw is disclosed herein. It comprises a screw head and a rod integrally connected to a bottom of the screw head and having a first section and a second section, wherein the first section has a straight surface surrounded with a screw thread and the second section is connected to a bottom of the first section and has a tapered straight surface, on which at least one cutting unit is formed, each of the at least one cutting unit enabling to form a state of a concave, a convex or combination thereof.

Abstract: A screw for thin iron sheets includes a shank, a first thread, and a second thread. The shank includes a tapered screw-in portion, a head, and a straight rod portion between the screw-in portion and the head. The straight rod portion features non-circular cross sections. The first and second threads are spirally developed on the outer circumference of the shank and extend to the straight rod portion from a tip of the screw-in portion, respectively. The first thread includes a plurality of first thread convolutions, and the second thread includes a plurality of second thread convolutions spaced from the first thread convolutions of the first thread. Each of the first and second thread convolutions features a crest angle between 48 and 52 degrees.