Patents Assigned to DDI Corporation
  • Patent number: 7212972
    Abstract: A feature description method capable of high-speed, efficiently searching audio data or grasping a summary of the audio data by giving considerations to elements and characteristics peculiar to the audio data, is provided. Also, an audio video data feature description collection construction method for collecting feature descriptions from multiple pieces of audio video data based on a specific feature type makes it possible to efficiently, clearly describe a feature description collection.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: May 1, 2007
    Assignee: DDI Corporation
    Inventors: Masaru Sugano, Yasuyuki Nakajima, Hiromasa Yanagihara, Akio Yoneyama, Haruhisa Kato
  • Patent number: 7152063
    Abstract: A document filtering scheme capable of reducing the number of erroneously selected non-relevant documents without reducing the number of correctly selected relevant documents is disclosed. a non-relevant profile expressing non-relevant documents that are judged as having high similarities with respect to a relevant profile expressing a user's request but not matching with the user's request is utilized in addition to the relevant profile, such that each search target document for which the similarity with respect to the relevant profile is higher than a prescribed threshold for the relevant profile and the similarity with respect to the non-relevant profile is higher than a prescribed threshold for the non-relevant profile is removed as a non-relevant document.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: December 19, 2006
    Assignee: DDI Corporation
    Inventors: Keiichirou Hoashi, Naomi Inoue, Kazunori Matsumoto, Kazuo Hashimoto
  • Patent number: 7010504
    Abstract: There is proposed a competitive buying and selling system that avoids unnatural bidding prices and exclusive possession of resources, stabilizes bidding prices, and provides such an environment that participants can bid easily. There are included a first step in which a server opens a subject of buying and selling and a successful bid evaluation function thereof to a plurality of clients, a second step in which each of the clients makes a participant determine the subject of buying and selling and a bidding price thereof by using the successful bid evaluation function, and notifies a determined result to the server, and a third step in which the server selects a bidding price of a participant who has indicated a highest evaluation value based on the successful bid evaluation function among all bidding prices notified from the clients and designates the participant as a successful bidder.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: March 7, 2006
    Assignee: DDI Corporation
    Inventors: Akio Ishikawa, Satoshi Konishi, Hajime Nakamura
  • Patent number: 7010585
    Abstract: The object of the present invention is to provide a DNS server and terminals both of which are capable of sending and receiving communication by means of a small number of IP addresses. In the case where a firewall is not provided, when the DNS server receives an inquiry of a FQDN, it sends a broad cast frame for searching a terminal to which an IP address is assigned via all the network devices. When a terminal monitors the broad cast frame and finds the FQDN to be its own FQDN, it returns the uni-cast frame to the DNS server. When the DNS server receives the uni-cast frame, it makes a look-up table and a reverse look-up table. As a result, the terminal can receive the communication by an ordinary method. In the case where the firewall is provided, by processing an IP address conversion between the external IP address and the internal address by the use of an IP address conversion means NAT in addition to making the look-up table and the reverse look-up table, the terminal can receive communication.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: March 7, 2006
    Assignee: DDI Corporation
    Inventor: Tohru Asami
  • Patent number: 7010592
    Abstract: As shown in FIG. 2, when the SYN segment is detected, the amount of transmitted segment from the side which sent the detected SYN segment is obtained by counting the continuously detected DATA segments for collecting the traffic in a certain direction where it is impossible to directly capture the traffic. Further, the amount [ini_sdt] of the transmitted bytes from the side which sent the detected SYN segment is obtained by calculating the equation [ini_sdt]=[SEQn+LENn]?[SEQ1]. Wherein, [SEQ1] is the sequence number of the first detected DATA segment, [SEQn] is the sequence number of the last detected DATA segment and [LENn] is the user data length of the last detected DATA segment.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: March 7, 2006
    Assignee: DDI Corporation
    Inventors: Tomohiko Ogishi, Akira Idoue, Toru Hasegawa, Toshihiko Kato
  • Patent number: 6961316
    Abstract: In a mobile communication system having a plurality of radio packet channels of different transmission rate with each other between a base station and a mobile station, undesirable interference to adjacent cells of adjacent base stations is decreased. Signal quality of a receive signal at a mobile station is measured, and the better said signal quality is, the higher packet channel is assigned. Thus, although signal quality is poor because of long distance between a base station and a mobile station, no increase of transmission power of a base station is requested. Thus, interference to adjacent cells is decreased. When high rate packet channel is selected, short packet transmission time may be assigned so that amount of data transmission is kept uniform in spite of said signal quality.
    Type: Grant
    Filed: January 16, 2001
    Date of Patent: November 1, 2005
    Assignee: DDI Corporation
    Inventors: Akira Yamaguchi, Yoshio Takeuchi
  • Patent number: 6898423
    Abstract: A group communication system includes a plurality of mobile terminals with member-attribute information, and a center component for collecting location information of the mobile terminals. The center component includes a group generation device for generating a group based on a group-area information and a group-attribute information which are specified, and a group member management device for always monitoring joining and leaving of the mobile terminals with the location information and the member-attribute information which correspond to the group-area information and the group-attribute information of the group, respectively.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: May 24, 2005
    Assignee: DDI Corporation
    Inventors: Shinji Motegi, Hiroki Horiuchi, Masaru Enomoto, Toshikane Oda
  • Patent number: 6836484
    Abstract: A wireless packet communication system includes at least one radio terminal station, and a base station for multiplexing packets to be transmitted using a plurality of subcarriers and for sending the multiplexed packets to the at least one radio terminal station. The system has a unit provided in the base station for simultaneously sending reference signals on the subcarriers with the same level to the at least one radio terminal station, a report unit provided in the at least one radio terminal station for reporting to the base station received conditions of the reference signal of each subcarrier or of each subband corresponding to a frequency band occupied by a plurality of subcarriers, and a unit provided in the base station for allocating the subcarrier or the subband to each of the packets to be transmitted depending upon the reported received conditions of the subcarrier or the subband, the allocation being performed in a transmission order of the packets.
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: December 28, 2004
    Assignee: DDI Corporation
    Inventor: Toshinori Suzuki
  • Publication number: 20040249744
    Abstract: There is proposed a competitive buying and selling system that avoids unnatural bidding prices and exclusive possession of resources, stabilizes bidding prices, and provides such an environment that participants can bid easily. There are included a first step in which a server opens a subject of buying and selling and a successful bid evaluation function thereof to a plurality of clients, a second step in which each of the clients makes a participant determine the subject of buying and selling and a bidding price thereof by using the successful bid evaluation function, and notifies a determined result to the server, and a third step in which the server selects a bidding price of a participant who has indicated a highest evaluation value based on the successful bid evaluation function among all bidding prices notified from the clients and designates the participant as a successful bidder.
    Type: Application
    Filed: June 10, 2004
    Publication date: December 9, 2004
    Applicant: DDI CORPORATION
    Inventors: Akio Ishikawa, Satoshi Konishi, Hajime Nakamura
  • Patent number: 6782201
    Abstract: A four fiber ring network optical switching circuit capable of realizing the bridge function at times of the span switching and the ring switching economically by a very compact structure is disclosed. A four fiber ring network optical switching circuit is formed by a 10×8 optical matrix switch having ten input ports and eight output ports, and two branching elements adapted to branch each one of two optical signals among eight optical signals that are inputs of the four fiber ring network optical switching circuit, into two identical optical signals, and to enter the two identical optical signals into two input ports of the 10×8 optical matrix switch such that the eight optical signals are entered into the ten input ports of the 10×8 optical matrix switch as ten optical signals.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: August 24, 2004
    Assignees: DDI Corporation, KDD Submarine Cable Systems, Inc.
    Inventors: Shu Yamamoto, Tetsuya Miyazaki, Yasuyuki Nagao, Tomohiro Otani
  • Patent number: 6775478
    Abstract: An optical TDM multiplexing apparatus to multiplex a plurality of input signals in the optical stage in the time domain according to the invention comprise a plurality of signal light sources to generate optical signals each having a wavelength different from the others to carry each of the plurality of the input signals, a timing adjuster to adjust timings between the respective optical signals so that each optical signal output from the plurality of the signal light sources is disposed on a time slot different from the others in the time domain, an optical multiplexer to multiplex each optical signal output from the timing adjuster in the wavelength domain and a wavelength converter to convert each wavelength of the output light from the optical multiplexer into a predetermined wavelength.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: August 10, 2004
    Assignees: DDI Corporation, KDD Submarine Cable Systems Inc.
    Inventors: Masatoshi Suzuki, Noboru Edagawa
  • Patent number: 6763059
    Abstract: This invention provides a spread spectrum signal demodulator in which a noise component included in respective demodulation symbols is reduced and an effect of interference removal is further improved. Symbol decorrelating means detect correlations between spread codes allocated to spread spectrum signals to be removed and a receiving signal. A symbol deciding means 121 synthesizes one or the plurality of one symbol correlation values b1 to bk in common phase, namely, diversity-synthesizes them so as to decide a symbol. As the symbol decision, hard decision or soft decision can be used. Correlation modification means input the one symbol correlation values b1 to bk output from the symbol decorrelating means and the symbol decided result output from the symbol deciding means 121 thereinto, and modify the symbol correlation values b1 to bk. The modified symbol correlation values d1 to dk are transmitted into interference replicating means so as to be spectrum-spread by corresponding spread codes.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: July 13, 2004
    Assignee: DDI Corporation
    Inventors: Toshinori Suzuki, Yoshio Takeuchi
  • Patent number: 6748178
    Abstract: An optical fiber (12a) with a large effective core area and a large chromatic dispersion value is disposed on an input side of signal light, and an optical fiber (12b) with a small effective core area and a small chromatic dispersion value or a chromatic dispersion value of negative polarity is disposed on an output side of the signal light. A pumping light source (14) generates pumping light of 1450 nm to cause Raman amplification of 1550 nm in the optical fiber (12b). The output light from the pumping light source (14) enters the optical fiber (12b) from the back through a WDM optical coupler (16). Provided that y=(Pin−&agr;)/(Pp·10 Log L) where input power of the optical fiber (12a) (i.e.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: June 8, 2004
    Assignees: DDI Corporation, KDD Submarine Cable Systems, Inc.
    Inventors: Takayuki Miyakawa, Masatoshi Suzuki, Noboru Edagawa
  • Patent number: 6741810
    Abstract: In a signal demultiplexing device formed by a probe light source, a wavelength converter, and a wavelength demultiplexer, the probe light source is formed by a plurality of sub-probe light sources configured to respectively generate the sub-probe lights with the prescribed different wavelengths for respective time-slots, a multiplexer configured to multiplex the sub-probe lights generated by the plurality of sub-probe light sources, and a phase different giving unit configured to give phase differences corresponding to time-slot positions to the sub-probe lights multiplexed by the multiplexer, and to sequentially output the sub-probe lights with the phase differences in correspondence to respective time-slots.
    Type: Grant
    Filed: February 15, 2001
    Date of Patent: May 25, 2004
    Assignees: DDI Corporation, KDD Submarine Cable Systems, Inc.
    Inventors: Tomohiro Otani, Tetsuya Miyazaki, Shu Yamamoto
  • Patent number: 6690928
    Abstract: A mobile communication system has exchange units for exchanging communication-traffic among mobile terminals, a transportation-traffic monitor for detecting transportation-traffic of the mobile terminals, and a traffic forecast unit including at least a communication-traffic forecast unit for forecasting future communication-traffic based on the detected communication-traffic and on the detected transportation-traffic.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: February 10, 2004
    Assignee: DDI Corporation
    Inventors: Satoshi Konishi, Hiroyuki Fukuoka
  • Patent number: 6690732
    Abstract: A scene characteristics detection type motion video encoding apparatus is provided for minimizing the degradation of picture quality derived from the point of scene change. The filtering characteristic (namely a filter factor) of a spatiotemporal filter is updated in response to the scene attribute data (a) received from a scene change point detector and the encoding difficulty data (b) received from an encoding difficulty estimator. Accordingly, when the encoding difficulty is high, high frequency components of the input video signal are eliminated. A rate controller determines the target amount of data to be encoded using scene attribute data (a) and the encoding difficulty data (b). When the point of scene change is detected, the target amount of data to be encoded for the input video signal which is distanced by a given distance from the point of scene change is weighted for matching with the encoding difficulty by a weighting factor Wsc (>1.0).
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: February 10, 2004
    Assignee: DDI Corporation
    Inventors: Sei Naito, Shuichi Matsumoto
  • Patent number: 6615030
    Abstract: In order to prevent decrease of channel efficiency and to effectuate high quality communication while moderating increase of apparatus scale of an interference canceler part and cutting down costs, in a mobile communication and radio base station apparatus according to the present invention, an interference cancel processing part within the base station apparatus is provided with reverse spread processing/respread processing parts for performing reverse spread processing and respread processing on received signals, synthesizing processing parts for synthesizing signals that have been subjected to the respread processing, and subtraction processing parts for subtracting the synthesized signal from received signal, in multiple stages. The interference cancel processing part processes received signals of users #1-#k.
    Type: Grant
    Filed: September 6, 2000
    Date of Patent: September 2, 2003
    Assignees: Hitachi, Ltd., DDI Corporation
    Inventors: Joichi Saito, Naruhito Nakahara, Yuuji Ishida, Naoki Tsubaki, Toshinori Suzuki, Yoshio Takeuchi, Sumaru Niida
  • Patent number: 6515793
    Abstract: An optical waveform shaper comprising a probe light source for generating probe light with a constant amplitude, a signal copier to which input signal light of a signal wavelength and the probe light output from the probe light source is applied and which copies the signal of the input signal light onto the probe light, and an extinction ratio improver for improving the extinction ratio of output light from the signal copier is described.
    Type: Grant
    Filed: December 26, 2000
    Date of Patent: February 4, 2003
    Assignees: DDI Corporation, KDD Submarine Cable Systems, Inc.
    Inventors: Noboru Edagawa, Masatoshi Suzuki
  • Patent number: 6377388
    Abstract: An optical signal processor is disclosed comprising a first optical path having a first electroabsorption optical modulator to be applied with a constant voltage and to absorb light of a signal wavelength, a second optical path having a fixed phase relation with the first optical path relative to a probe wavelength, a probe light introducer for dividing probe light of the probe wavelength into two portions and feeding them respectively into the first and second optical paths, an original signal light introducer for introducing original signal light of the signal wavelength into the first electroabsorption optical modulator, and a combiner for combining both light of the probe wavelength passed through the first and second paths.
    Type: Grant
    Filed: November 20, 2000
    Date of Patent: April 23, 2002
    Assignees: DDI Corporation, KDD Submarine Cable Systems Inc.
    Inventors: Haruhisa Sakata, Kosuke Nishimura, Masashi Usami, Munefumi Tsurusawa
  • Publication number: 20010032204
    Abstract: A document filtering scheme capable of reducing the number of erroneously selected non-relevant documents without reducing the number of correctly selected relevant documents is disclosed. a non-relevant profile expressing non-relevant documents that are judged as having high similarities with respect to a relevant profile expressing a user's request but not matching with the user's request is utilized in addition to the relevant profile, such that each search target document for which the similarity with respect to the relevant profile is higher than a prescribed threshold for the relevant profile and the similarity with respect to the non-relevant profile is higher than a prescribed threshold for the non-relevant profile is removed as a non-relevant document.
    Type: Application
    Filed: February 28, 2001
    Publication date: October 18, 2001
    Applicant: DDI Corporation.
    Inventors: Keiichirou Hoashi, Naomi Inoue, Kazunori Matsumoto, Kazuo Hashimoto