Abstract: According to one embodiment, a memory system includes a frequency value update unit, a first intra-group rearranging unit, a second intra-group rearranging unit, and a routing unit. The frequency value update unit adds a first value to each of one or more first frequency values that are associated with one or more first symbols, respectively, in one or more entries in a table. The first intra-group rearranging unit rearranges first entries, which belong to a first group, using frequency values in the first entries. The second intra-group rearranging unit rearranges second entries, which belong to a second group lower than the first group, using frequency values. The routing unit rearranges at least one of the first entries and at least one of the second entries.

Abstract: A multi-pass welding method is provided for minimizing bead sagging and forming a welded joint having a good weld metal surface, even during multi-pass welding in a horizontal orientation, and a multi-pass butt welded joint and a lamination pattern calculation method for a multi-pass weld formed by the method. The weld metal has a plurality of layers from the rear surface of a base material to the front surface thereof. The plurality of layers include a finishing layer having at least two layers including an end layer; and a ground layer for forming the finishing layer. A boundary layer, which is the layer of the ground layer adjacent to the finishing layer, is formed such that the position of an upper plate-side weld is closer to the front surface of the base material than the position of a lower plate-side weld.

Abstract: A welding device for gas shielded arc welding includes: a portable welding robot mounted with a welding torch including a nozzle that guides jetting of shielding gas and a contact tip that performs energization on a consumable electrode; a feeding device that supplies the consumable electrode to the welding torch; a welding power source that supplies electric power to the consumable electrode via the contact tip; a gas supply source that supplies the shielding gas to be jetted from a nozzle end; and a control device that controls the portable welding robot. When the welding torch is seen from a side of jetting of the shielding gas, the contact tip is placed in an inside of an opening of the nozzle, the nozzle and the contact tip have a relatively movable structure, and an inner diameter of the nozzle end is within a range of 10-20 mm.

Abstract: A method controls a portable welding robot to ensure good bead appearance even where a workpiece corner and a curved section of a guide rail are not located on a concentric circle and where there is a large difference in curvature between the workpiece corner and the curved section of the guide rail. A portable welding robot sets a guide rail with respect to a workpiece having a corner and performs arc welding on the workpiece while moving on the guide rail and a welding control device controls the portable welding robot. The control method includes determining a torch position on the workpiece via a torch position determination unit, calculating a torch angle at the torch position via a torch angle calculation unit, and controlling the torch angle via a movable part based on the calculated torch angle.

Abstract: A gas shield arc welding method that reduces the number of joints, which are the sites where defects occur more readily, and that enables automatic welding with a welding robot. A gas shield arc welding method in which a steel pipe Wo is welded by multi-pass welding with a steel frame erection adjusting tool attached to an erection piece on the steel pipe Wo to immobilize an open end section of the steel pipe. An initial single or several layers are welded to the open end section, after welding, the steel frame erection adjusting tool is removed; and remaining layers are welded with a welding robot such that two bead joints are formed at no more than two sites.

Abstract: A flux-cored wire comprising a flux which is a core and a hoop which is an outer skin or sheath is described. The flux includes a strong deoxidizing metal element containing Mg and Al, and a fluoride powder. At least 60 mass % of a strong deoxidizing metal powder related to the strong deoxidizing metal element has a grain size of at most 150 ?m. At least 60 mass % of the fluoride powder has a grain size of at most 75 ?m. The flux is present at a concentration of 10-30 mass % relative to a total mass of the flux-cored wire. The flux-cored wire also requires a specific composition of elements.

Abstract: In this welding control method for a portable welding robot that moves along a guide rail, for using the portable welding robot to weld a workpiece including a groove: a groove shape detection position is established in at least one location in a welding sector extending from a welding starting point to a welding end point; the groove shape at a groove shape detection position Pn is sensed by means of a detecting means of the portable welding robot, which is moving along the guide rail; groove shape information is calculated from detection data obtained by the sensing; and a welding condition is acquired on the basis of the groove shape information.

Abstract: The present invention relates to a flux-cored wire for positive polarity gas-shielded arc welding use, in which a flux contains a metal powder and also contains BaF2 and SrF2 and AlF3 and/or CaF2 as fluorides wherein the content of BaF2 is 1.0 to 4.5%, the content of SrF2 is 2.0% or less, the content of CaF2 is 0.45% or less and the content of AlF3 is 0.70% or less, at least one of metal elements constituting the flux and the fluorides is a strong deoxidizing metal element having a specified standard formation Gibbs energy, and the content of each of an oxide and a carbonate in the flux is 0.5% or less.

Abstract: A welding device for gas shielded arc welding includes: a portable welding robot mounted with a welding torch including a nozzle that guides jetting of shielding gas and a contact tip that performs energization on a consumable electrode; a feeding device that supplies the consumable electrode to the welding torch; a welding power source that supplies electric power to the consumable electrode via the contact tip; a gas supply source that supplies the shielding gas to be jetted from a nozzle end; and a control device that controls the portable welding robot. When the welding torch is seen from a side of jetting of the shielding gas, the contact tip is placed in an inside of an opening of the nozzle, the nozzle and the contact tip have a relatively movable structure, and an inner diameter of the nozzle end is within a range of 10-20 mm.

Abstract: The Cu core ball contains a Cu ball and a solder layer for covering a surface of the Cu ball. The Cu ball contains at least one element selected from Fe, Ag, and Ni in a total amount of 5.0 or more to 50.0 ppm by mass or lower, S in an amount of 0 or more to 1.0 ppm by mass or lower, P in an amount of 0 or more to less than 3.0 ppm by mass, and remainder of Cu and inevitable impurities. The Cu ball contains purity which is 99.995% or higher and 99.9995% by mass or lower, and sphericity which is 0.95 or higher. The solder layer includes Ag in an amount of more than 0 to 4.0% by mass or less, Cu in an amount of more than 0 to 3.0% by mass or less, and remainder of Sn.

Abstract: The present invention pertains to: a method for arc spot welding a steel plate having a carbon equivalent CeqBM of 0.35 or more (the carbon equivalent CeqBM is defined in the specification), the method being characterized in that a welding wire containing 98.5 mass % or more of Fe is used, and the ratio between the carbon equivalent CeqWM of a weld metal formed by the method (the carbon equivalent CeqWM of the weld metal is defined in the specification) and the carbon equivalent CeqBM of the steel plate, CeqWM/CeqBM is 0.2-1.0. According to the arc spot welding method, brittle fracture can be prevented and high joint strength can be obtained even when the C content in the steel plate is high.

Abstract: The Cu core ball contains a Cu ball and one or more metal layer for covering a surface of the Cu ball, each layer including one or more element selected from Ni, Co, Fe and Pd. The Cu ball contains at least one element selected from Fe, Ag, and Ni in a total amount of 5.0 or more to 50.0 ppm by mass or lower, S in an amount of 0 ppm by mass or more to 1.0 ppm by mass or lower, P in an amount of 0 ppm by mass or more to less than 3.0 ppm by mass, and remainder of Cu and inevitable impurities. The Cu ball contains purity which is 99.995% by mass or higher and 99.9995% or lower, sphericity which is 0.95 or higher and a diameter of 1 ?m or more to 1000 ?m or lower.

Abstract: The present invention relates to a method for arc-welding a steel plate having a C content of 0.08-0.30% by mass, wherein the arc welding method comprises welding under a condition whereby X represented by formula (1) is 200 or less using a welding wire in which the total content of Cr and Ni thereof is 1.00% by mass or greater. (1): X=0.8×(300-279[C]W-25[Si]W-35[Mn]W-49[Ni]W-47[Cr]W-61[Mo]W) +0.2×(300-279[C]BM-25[Si]BM-35[Mn]BM-49[Ni]BM-47[Cr]BM-61[Mo]BM) (where [C]W, [Si]W, [Mn]W, [Ni]W, [Cr]W, [Mo]W, [C]BM, [Si]BM, [Mn]BM, [Ni]BM, [Cr]BM, and [Mo]BM are defined in the specification).

Abstract: The Cu core ball contains a Cu ball and one or more metal layer for covering a surface of the Cu ball, each layer including one or more element selected from Ni, Co, Fe and Pd. The Cu ball contains at least one element selected from Fe, Ag, and Ni in a total amount of 5.0 or more to 50.0 ppm by mass or lower, S in an amount of 0 ppm by mass or more to 1.0 ppm by mass or lower, P in an amount of 0 ppm by mass or more to less than 3.0 ppm by mass, and remainder of Cu and inevitable impurities. The Cu ball contains purity which is 99.995% by mass or higher and 99.9995% or lower, sphericity which is 0.95 or higher and a diameter of 1 ?m or more to 1000 ?m or lower.

Abstract: A Cu core ball contains a Cu ball and at least one metal layer for covering a surface of the Cu ball. The metal layer is made of at least one element selected from the group of Ni, Co, Fe and Pd. The Cu ball contains at least one element selected from a group of Fe, Ag and Ni in a total amount of 5.0 ppm by mass or more to 50.0 ppm by mass or lower, S in an amount of 0 ppm by mass or more to 1.0 ppm by mass or lower, P in an amount of 0 ppm by mass or more to less than 3.0 ppm by mass, and remainder of Cu and inevitable impurities. The Cu ball contains purity which is 99.995% by mass or higher to 99.9995% by mass or lower, and sphericity which is 0.95 or higher.

Abstract: The Cu core ball contains a Cu ball and a solder layer for covering a surface of the Cu ball. The Cu ball contains at least one element selected from Fe, Ag, and Ni in a total amount of 5.0 or more to 50.0 ppm by mass or lower, S in an amount of 0 or more to 1.0 ppm by mass or lower, P in an amount of 0 or more to less than 3.0 ppm by mass, and remainder of Cu and inevitable impurities. The Cu ball contains purity which is 99.995% or higher and 99.9995% by mass or lower, and sphericity which is 0.95 or higher. The solder layer includes Ag in an amount of more than 0 to 4.0% by mass or less, Cu in an amount of more than 0 to 3.0% by mass or less, and remainder of Sn.

Abstract: The present invention pertains to: a method for arc spot welding a steel plate having a carbon equivalent CeqBM of 0.35 or more (the carbon equivalent CeqBM is defined in the specification) and containing 0.35 mass % or more of C, the method being characterized by forming a weld metal having a structure in which the proportion of an austenitic structure exceeds 80%; and a welding wire suitable for being used therefor. According to the arc spot welding method, brittle fracture can be prevented and high joint strength can be obtained even when the C content in the steel plate is high.

Abstract: An arc welding device is provided with including: a wire feed motor; a rocker arm attached freely rotatably to an output shaft of the wire feed motor; a pair of wire feed rollers attached to the rocker arm; a rotation transmitting mechanism for transmitting the rotation of the wire feed motor to the wire feed roller; a rocker drive unit; and a welding power supply unit. The wire feed roller has inserted therein welding wire disposed along the rocking direction of the rocker arm. The welding wire is fed towards a torch tip by the wire feed roller, and arcing and shorting can be repeated with forward and backward movement by the rocker arm in the direction of the wire feed.

Abstract: In an arc welding method of performing welding by employing CO2 gas as shield gas, supplying a welding current to flow between a welding wire and a workpiece to be welded while feeding the welding wire toward the workpiece, and generating an arc with the welding current, the arc welding method includes a welding step of performing the welding of the workpiece while executing control to adjust the welding current, and a welding termination step of executing control to apply the welding current having a trapezoidal waveform when the welding of the workpiece is terminated.

Abstract: In an arc welding method of performing welding by employing CO2 gas as shield gas, supplying a welding current to flow between a welding wire and a workpiece to be welded while feeding the welding wire toward the workpiece, and generating an arc with the welding current, the arc welding method includes a welding step of performing the welding of the workpiece while executing control to adjust the welding current, and a welding termination step of executing control to apply the welding current having a trapezoidal waveform when the welding of the workpiece is terminated.