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Author

Takayoshi Yokota

Bio: Takayoshi Yokota is an academic researcher from Hitachi. The author has contributed to research in topics: Floating car data & Traffic flow. The author has an hindex of 22, co-authored 102 publications receiving 1938 citations.


Papers
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Patent
02 Sep 2004
TL;DR: In this paper, a traffic information providing system externally acquires traffic information including information relating to the travel time of a link, calculates a travel time for a non-provision link to which no travel time is provided through estimate/complement operation.
Abstract: A traffic information providing system externally acquires traffic information including information relating to the travel time of a link, calculates a travel time for a non-provision link to which no travel time is provided through estimate/complement operation. The estimate/complement operation is carried out with use of travel times, emergencies, travel times of links in the vicinity of the non-provision link, and so on, obtained in the near past. The system stores and statistically processes the externally-acquired traffic information, and also estimates a travel time in the near future. When there is an abnormality in the acquired traffic information, the system deletes the abnormality, regards the information as a non-provision link, calculates a probability distribution of travel times of links, calculates a probability distribution of travel times of the entire route made up of a plurality of links, and also calculates a probability for a specific travel time range.

199 citations

Patent
13 Aug 2001
TL;DR: In this article, a means for receiving the spot or area information being transmitted, and receiving information that has been linked to the spot/area information was presented. And a storage media for retaining the received information that the above-mentioned judgment means has judged to be included in the spot and area information corresponding to the traveling route of the mobile body.
Abstract: To ensure that of all information transmitted through broadcast communications, only the information corresponding to the traveling route of a mobile body will be efficiently displayed at the information terminal of a car navigation system or the like, the information terminal is provided with: a means for receiving the spot or area information being transmitted, and receiving information that has been linked to the spot or area information being transmitted, a means for judging whether the spot or area information that has been received above is included in part of the spot or area information corresponding to the traveling route of the mobile body, and storage media for retaining the received spot or area information that the above-mentioned judgment means has judged to be included in the spot or area information corresponding to the traveling route of the mobile body.

146 citations

Patent
23 Jan 2008
TL;DR: In this paper, a traffic information system including a travel history database retaining the data on the travel history of vehicle measured at a constant temporal or running interval; a link cost weighting pattern database for storing patterns for weighting the link costs of road links, used in the determination of the travel paths of vehicles; a vehicle ID/link cost weighted pattern set database retaining data representing the matching of the vehicle IDs with their associated link cost weightsing patterns used to determine the travel path of the vehicles; and a link-cost weighting patterns selection unit selecting the patterns to weighting
Abstract: A traffic information system including a travel history database retaining the data on the travel history of vehicle measured at a constant temporal or running interval; a link cost weighting pattern database for storing patterns for weighting the link costs of road links, used in the determination of the travel paths of vehicles; a vehicle ID/link cost weighting pattern set database retaining the data representing the matching of the vehicle IDs with their associated link cost weighting patterns used to determine the travel paths of the vehicles; a link cost weighting pattern selection unit selecting the patterns for weighting the link costs used to determine the travel paths of the vehicles on the basis of the vehicle IDs; and a vehicle ID/link cost weighting pattern matching unit recording the data representing the matching of the vehicle IDs with their associated link cost weighting patterns.

135 citations

Patent
20 Sep 2001
TL;DR: In this paper, a method of presuming traffic conditions for implementing a forecast and a presumption of traffic jam situation in an area where probe cars are not traveling currently, in which the probe cars send floating car data that is times and positions of traveled areas to center facilities, and the center accumulates the floating cars data in a floating car database by traffic conditions presumption means.
Abstract: A method of presuming traffic conditions for implementing a forecast and a presumption of traffic jam situation in an area where probe cars are not traveling currently, in which the probe cars send floating car data that is times and positions of traveled areas to center facilities, and the center accumulates the floating car data in a floating car data database by traffic conditions presumption means and also presumes forecast traffic jam information in the forward areas of the probe cars and presumed traffic jam information in the backward areas thereof by using the current floating car data and the floating car data database accumulated from the past to the present.

83 citations

Patent
19 Aug 2005
TL;DR: In this article, a regression analysis is performed with day factors as independent variables, with congestion length from each bottleneck point selected as the target, in which the day factors refer to factors such as day of the week, national holiday/etc.
Abstract: In a congestion prediction using measurement data which is acquired by an on-road sensor or a probe car, and which includes none of explicit information about bottleneck points, with respect to time-sequence data on congestion ranges accumulated in the past, data on congestion front-end positions are summarized into plural clusters by the clustering. Representative value in each cluster is assumed as position of each bottleneck. A regression analysis, in which day factors are defined as independent variables, is performed with congestion length from each bottleneck point selected as the target. Here, the day factors refer to factors such as day of the week, national holiday/etc. It then becomes possible to precisely predict a future congestion length.

76 citations


Cited by
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Patent
01 Feb 1999
TL;DR: An adaptive interface for a programmable system, for predicting a desired user function, based on user history, as well as machine internal status and context, is presented for confirmation by the user, and the predictive mechanism is updated based on this feedback as mentioned in this paper.
Abstract: An adaptive interface for a programmable system, for predicting a desired user function, based on user history, as well as machine internal status and context. The apparatus receives an input from the user and other data. A predicted input is presented for confirmation by the user, and the predictive mechanism is updated based on this feedback. Also provided is a pattern recognition system for a multimedia device, wherein a user input is matched to a video stream on a conceptual basis, allowing inexact programming of a multimedia device. The system analyzes a data stream for correspondence with a data pattern for processing and storage. The data stream is subjected to adaptive pattern recognition to extract features of interest to provide a highly compressed representation that may be efficiently processed to determine correspondence. Applications of the interface and system include a video cassette recorder (VCR), medical device, vehicle control system, audio device, environmental control system, securities trading terminal, and smart house. The system optionally includes an actuator for effecting the environment of operation, allowing closed-loop feedback operation and automated learning.

1,182 citations

Patent
11 Mar 2010
TL;DR: In this paper, the authors proposed a system for preventing vehicle accidents in which GPS ranging signals relating to a host vehicle's position on a roadway on a surface of the earth are received on a first communication link from a network of satellites and DGPS auxiliary range correction signals for correcting propagation delay errors in the GPS ranging signal from a station or satellite.
Abstract: System and method for preventing vehicle accidents in which GPS ranging signals relating to a host vehicle's position on a roadway on a surface of the earth are received on a first communication link from a network of satellites and DGPS auxiliary range correction signals for correcting propagation delay errors in the GPS ranging signals are received on a second communication link from a station or satellite. The host vehicle's position on a roadway on a surface of the earth is determined from the GPS, DGPS, and accurate map database signals with centimeter accuracy and communicated to other vehicles. The host vehicle receives position information from other vehicles and determines whether any other vehicle from which position information is received represents a collision threat to the host vehicle based on the position of the other vehicle relative to the roadway and the host vehicle. If so, a warning or vehicle control signal response to control the host vehicle's motion is generated to prevent a collision with the other vehicle.

1,020 citations

Patent
29 Mar 2001
TL;DR: In this article, integrated imaging and GPS network monitors remote object movement and displays objects and detectors in web browser interface, and provides selectable connection between system controller and various cameras according to object positions.
Abstract: Integrated imaging and GPS network monitors remote object movement. Browser interface displays objects and detectors. Database stores object position movement. Cameras detect objects and generate image signal. Internet provides selectable connection between system controller and various cameras according to object positions.

646 citations

Patent
28 Aug 2006
TL;DR: In this paper, an Internet appliance, comprising, within a single housing, packet data network interfaces, adapted for communicating with the Internet and a local area network, at least one data interface selected from the group consisting of a universal serial bus, an IEEE-1394 interface, a voice telephony interface, an audio program interface, video program interfaces, an audiovisual program interface and a camera interface.
Abstract: An Internet appliance, comprising, within a single housing, packet data network interfaces, adapted for communicating with the Internet and a local area network, at least one data interface selected from the group consisting of a universal serial bus, an IEEE-1394 interface, a voice telephony interface, an audio program interface, a video program interface, an audiovisual program interface, a camera interface, a physical security system interface, a wireless networking interface; a device control interface, smart home interface, an environmental sensing interface, and an environmental control interface, and a processor, for controlling a data transfer between the local area network and the Internet, and defining a markup language interface communicated through a packet data network interface, to control a data transfer or control a remote device.

616 citations