Abstract: A matrix calculation method and system for calculating funny matrix multiplication (FMM) of a matrix A and a matrix B, including: sequentially calculating a permutation of indices {ai} in which values are arranged in a non-decreasing order with respect to each i-th row where i=1 to the number of rows of the matrix A; storing a value, which is greater than expected as a value of a matrix, for C[i, j] with respect to each j-th column where j=1 to the number of columns of the matrix A in the i-th row; sequentially calculating a permutation of indices {bj} in which values are arranged in a non-decreasing order with respect to each j-th column where j=1 to the number of columns of the matrix B; and setting the values of C[i, j], which are i and j components of the matrix C.

Abstract: A plurality of landmarks selected from a source weighed graph on which a path search is performed; and the shortest path lengths between landmarks, and the shortest path lengths from vertices to landmarks adjacent to the respective vertices are calculated, and are stored in a memory device so as to be later referable. Routines for calculating upper and lower limits of the shortest path length corresponding to two vertices v and w are prepared by using expressions derived from quadrangle inequalities formed of the two vertices v and w as well as two landmarks adjacent to the respective vertices v and w. In response to a call from an A* search program, these routines return the upper limit or the lower limit of the shortest path length corresponding to v and w by referring to the shortest path lengths between landmarks, and the shortest path lengths from vertices to landmarks adjacent to the respective vertices, which have been previously stored in the memory device.

Abstract: An analysis system, information processing apparatus, activity analysis method, and program for analyzing activities of an information source on a network. The system and apparatus include an attribute extraction block for extracting, an information propagation graph acquisition block for searching action history data, and a characteristic user calculation block for calculating an amount characteristic. The method and program product include the steps of extracting an information characteristic value, searching action history data, registering the information, calculating an amount characteristic, and integrating the amount characteristic.

Abstract: A method and system for solving shortest paths from multiple sources to multiple destinations faster. A method of solving the multiple-pairs shortest path problem is provided using processing by a computer having storage means. The method includes the steps of: (A) reading graph data S on multiple vertices as search starting points from a storage area of the computer; (B) reading graph data T on multiple vertices as search targets from the storage area of the computer; (C) selecting k vertices s1, s2, . . . , sk from the graph data S; (D) deleting the k vertices from the graph data S; (E) finding and storing, in the storage area, shortest path lengths from each of the selected k vertices to the graph data T; and (F) repeating the steps from (C) to (E) until the graph data S becomes empty.

Abstract: An information processor and method for classifying user attributes of a plurality of nodes connected to a network. The information processor includes: an action history obtaining unit for generating a spammer-reporting action history set; a related node obtaining unit for generating a node set and a link set related to the spammer-reporting actions; an undirected graph generation unit for generating an undirected graph from the node set and the link set; and a max-cut computation unit classifying the nodes constituting the undirected graph into two exclusive sets that do not commonly include any element so as to maximize an indicator value defined by links bridging the two sets.

Abstract: An analysis system, information processing apparatus, activity analysis method, and program for analyzing activities of an information source on a network. The system and apparatus include an attribute extraction block for extracting, an information propagation graph acquisition block for searching action history data, and a characteristic user calculation block for calculating an amount characteristic. The method and program product include the steps of extracting an information characteristic value, searching action history data, registering the information, calculating an amount characteristic, and integrating the amount characteristic.

Abstract: A plurality of landmarks selected from a source weighed graph on which a path search is performed; and the shortest path lengths between landmarks, and the shortest path lengths from vertices to landmarks adjacent to the respective vertices are calculated, and are stored in a memory device so as to be later referable. Routines for calculating upper and lower limits of the shortest path length corresponding to two vertices v and w are prepared by using expressions derived from quadrangle inequalities formed of the two vertices v and w as well as two landmarks adjacent to the respective vertices v and w. In response to a call from an A* search program, these routines return the upper limit or the lower limit of the shortest path length corresponding to v and w by referring to the shortest path lengths between landmarks, and the shortest path lengths from vertices to landmarks adjacent to the respective vertices, which have been previously stored in the memory device.

Abstract: A method for producing expanded polypropylene resin particles wherein polypropylene resin particles impregnated with a physical blowing agent are heated along with an aqueous medium and a dispersant and are released and expanded at reduced pressure from the interior of a pressure-tight vessel, wherein the aforementioned aqueous medium has an electrical conductivity of from not less than 0.00 ms/m to not more than 20.00 mS/m. The resulting particles obtained are without inconsistencies caused by differences in the amount of dispersant adhering to the particles or the amount of dispersant added to prevent the particles from fusing together during the heat treatment step of the method.

Abstract: A method for producing expanded polypropylene resin particles wherein polypropylene resin particles impregnated with a physical blowing agent are heated along with an aqueous medium and a dispersant and are released and expanded at reduced pressure from the interior of a pressure-tight vessel, wherein the aforementioned aqueous medium has an electrical conductivity of from not less than 0.00 ms/m to not more than 20.00 mS/m. The resulting particles obtained are without inconsistencies caused by differences in the amount of dispersant adhering to the particles or the amount of dispersant added to prevent the particles from fusing together during the heat treatment step of the method.

Abstract: An optical output shutoff detecting circuit of the present invention includes a flip-flop. The flip-flop has a D terminal to which a signal representative of a result of comparison between the output level of an optical signal output from a laser diode and a reference signal is input, and a C terminal to which a signal produced by delaying a data signal is input. The output signal of the flip-flop is used to detect the output level of the optical signal.

Abstract: An optical receiver having a photodiode and a preamplifier includes a charge controller which charges a capacitor depending on an received voltage signal at each burst timing of the burst-mode signal and then discharges the capacitor with a predetermined time constant to produce an amplitude-varying offset component. The current signal of the photodiode is controlled so that the amplitude-varying offset component is canceled out.

Abstract: A voltage controlled oscillator includes transistors Q1, Q2 and Q3 constituting a differential amplifier circuit. The differential amplifier circuit performs switching operations in accordance with input pulse signals. A current amplitude determined by the emitter current of the transistor Q3 drives a laser diode. An operational amplifier 6 has an output connected to the base of the transistor Q3 via an emitter follower Q7. A control terminal 7 is connected to the non-inverting input of the operational amplifier 6. A voltage applied to the control terminal 7 controls the base potential of the transistor Q3, thereby changing the emitter current of the transistor Q3. The current for driving the laser diode is controlled by the voltage signal via the emitter follower. Therefore, the ON/OFF control of the drive current can be executed surely and stably without being influenced by noise, wiring pattern capacity or the like and even from the outside of the laser diode drive circuit.