Aiming at fast establishment of a wireless network around a multi-level building in a disaster area, we propose an efficient method to determine the locations of network nodes in the air. Nodes are attached to balloons outside a building and deployed in the air so that the network can be accessed from anywhere in the building. In this paper, we introduce an original radio propagation model for predicting path loss from an outdoor position to a position inside a building. In order to address the three-dimensional deployment problem, the proposed method optimizes an objective function for satisfying two goals: (1) guarantee the coverage: the target space needs to be covered by over a certain percentage by wireless network nodes, (2) minimize the number of network nodes. For solving this problem, we propose an algorithm based on a genetic algorithm. To evaluate the proposed method, we compared our method with three benchmark methods, and the results show that the proposed method requires fewer nodes than other methods.
This talk is an overview of several species of agent-based models. The goal is to identify common aspects, and to frame questions about how statistical inference on such models might be done.
Many problems in information retrieval and related fields depend on a reliable measure of the distance or similarity between objects that, most frequently, are represented
as vectors. This paper considers vectors of bits. Such data structures implement entities as diverse as bitmaps that indicate the occurrences of terms and bitstrings indicating the presence
of edges in images. For such applications, a popular distance measure is the Hamming distance. The value of the Hamming distance for information retrieval applications is limited by the
fact that it counts only exact matches, whereas in information retrieval, corresponding bits that are close by can still be considered to be almost identical. We define a "Generalized
Hamming distance" that extends the Hamming concept to give partial credit for near misses, and suggest a dynamic programming algorithm that permits it to be computed efficiently.
We envision many uses for such a measure. In this paper we define and prove some basic properties of the :Generalized Hamming distance," and illustrate its use in the area of object
recognition. We evaluate our implementation in a series of experiments, using autonomous robots to test the measure's effectiveness in relating similar bitstrings.
Articulo Científico "Energy Flow Algorithm for the improvement of the Energy ...CARMEN IGLESIAS
This note wroten by Carmen Iglesias Escudero explains the aplication of the Energy Flow algorithm in order to improve the energy resolution of the jets reconstructe by the fast simulation package of ATLAS namely Atlfast. The results are been calculated for different values of the cone, 0,4 and 0,7 and different range of Et of the generated QCD jets, in order to compare the behaviour of the algorithm whith the variation of these parameters. We can conclude, that considering the region of Et where the momentum resolution of the inner detector is better than the energy resolution of the hadronic calorimeter, below 140 GeV, the use of the Energy Flow Method give us an improvement in the energy resolution of the jet around 45-40% and 35-30% for R=0,7.
This talk is an overview of several species of agent-based models. The goal is to identify common aspects, and to frame questions about how statistical inference on such models might be done.
Many problems in information retrieval and related fields depend on a reliable measure of the distance or similarity between objects that, most frequently, are represented
as vectors. This paper considers vectors of bits. Such data structures implement entities as diverse as bitmaps that indicate the occurrences of terms and bitstrings indicating the presence
of edges in images. For such applications, a popular distance measure is the Hamming distance. The value of the Hamming distance for information retrieval applications is limited by the
fact that it counts only exact matches, whereas in information retrieval, corresponding bits that are close by can still be considered to be almost identical. We define a "Generalized
Hamming distance" that extends the Hamming concept to give partial credit for near misses, and suggest a dynamic programming algorithm that permits it to be computed efficiently.
We envision many uses for such a measure. In this paper we define and prove some basic properties of the :Generalized Hamming distance," and illustrate its use in the area of object
recognition. We evaluate our implementation in a series of experiments, using autonomous robots to test the measure's effectiveness in relating similar bitstrings.
Articulo Científico "Energy Flow Algorithm for the improvement of the Energy ...CARMEN IGLESIAS
This note wroten by Carmen Iglesias Escudero explains the aplication of the Energy Flow algorithm in order to improve the energy resolution of the jets reconstructe by the fast simulation package of ATLAS namely Atlfast. The results are been calculated for different values of the cone, 0,4 and 0,7 and different range of Et of the generated QCD jets, in order to compare the behaviour of the algorithm whith the variation of these parameters. We can conclude, that considering the region of Et where the momentum resolution of the inner detector is better than the energy resolution of the hadronic calorimeter, below 140 GeV, the use of the Energy Flow Method give us an improvement in the energy resolution of the jet around 45-40% and 35-30% for R=0,7.
(Paper) A Method for Overlay Network Latency Estimation from Previous Observa...Naoki Shibata
Weihua Sun, Naoki Shibata, Keiichi Yasumoto, Masaaki Mori, "A Method for Overlay Network Latency Estimation from Previous Observation", in Proc. of The Twelfth International Conference on Networks (ICN2013), pp.95--100, 29 Jan. 2013.
Abstract—Estimation of the qualities of overlay links is useful for optimizing overlay networks on the Internet. Existing estimation methods requires sending large quantities of probe packets between two nodes, and the software for measurements have to be executed at both of the end nodes. Accurate measurements require many probe packets to be sent, and other communication can be disrupted by significantly increased network traffic. In this paper, we propose a link quality estimation method based on supervised learning from the previous observation of other similar links. Our method does not need to exchange probe packets, estimation can be quickly made to know qualities of many overlay links without wasting bandwidth and processing time on many nodes. We conducted evaluation of our method on PlanetLab, and our method showed better performance on path latency estimation than estimating results from geographical distance between the two end nodes.
(Paper) Efficient Evaluation Methods of Elementary Functions Suitable for SIM...Naoki Shibata
Naoki Shibata : Efficient Evaluation Methods of Elementary Functions Suitable for SIMD Computation, Journal of Computer Science on Research and Development, Proceedings of the International Supercomputing Conference ISC10., Volume 25, Numbers 1-2, pp. 25-32, DOI:10.1007/s00450-010-0108-2 (May. 2010).
http://ito-lab.naist.jp/~n-sibata/pdfs/isc10simd.pdf
http://freecode.com/projects/sleef
Data-parallel architectures like SIMD (Single Instruction Multiple Data) or SIMT (Single Instruction Multiple Thread) have been adopted in many recent CPU and GPU architectures. Although some SIMD and SIMT instruction sets include double-precision arithmetic and bitwise operations, there are no instructions dedicated to evaluating elementary functions like trigonometric functions in double precision. Thus, these functions have to be evaluated one by one using an FPU or using a software library. However, traditional algorithms for evaluating these elementary functions involve heavy use of conditional branches and/or table look-ups, which are not suitable for SIMD computation. In this paper, efficient methods are proposed for evaluating the sine, cosine, arc tangent, exponential and logarithmic functions in double precision without table look-ups, scattering from, or gathering into SIMD registers, or conditional branches. We implemented these methods using the Intel SSE2 instruction set to evaluate their accuracy and speed. The results showed that the average error was less than 0.67 ulp, and the maximum error was 6 ulps. The computation speed was faster than the FPUs on Intel Core 2 and Core i7 processors.
(Paper) MTcast: Robust and Efficient P2P-based Video Delivery for Heterogeneo...Naoki Shibata
In this paper, we propose a new video delivery method called MTcast (Multiple Transcode based video multicast) which achieves efficient simultaneous video delivery to multiple users with different quality requirements by relying on user nodes to transcode and forward video to other user nodes. In MTcast, each user specifies a quality requirement for a video consisting of bitrate, picture size and frame rate based on the user’s environmental resource limitation. All users can receive video with the specified quality (or near this quality) along a single delivery tree. The main characteristics of MTcast are in its scalability, high user satisfaction degree in received video quality, short startup latency and robustness against node failure. Through simulations, we have confirmed that MTcast can achieve much higher user satisfaction degree and robustness against node failure than the layered multicast method.
(Paper) P-Tour: A PERSONAL NAVIGATION SYSTEM FOR TOURISMNaoki Shibata
In this paper, we propose a personal navigation system for tourism called P-Tour. When a tourist specifies multiple destinations with relative importance and restrictions on arrival/staying time, P-Tour computes the nearly best schedule to visit part of those destinations. In addition to the map-based navigation, P-Tour provides temporal guidance according to the schedule, and automatically modifies the schedule when detecting the situation that the tourist cannot follow the schedule. We have developed a route search engine as a Java Servlet which can compute a semi-optimal schedule in reasonable time using techniques of genetic algorithms.
(Paper) P2P VIDEO BROADCAST BASED ON PER-PEER TRANSCODING AND ITS EVALUATION ...Naoki Shibata
Shibata, N., Yasumoto, K., and Mori, M.: P2P Video Broadcast based on Per-Peer Transcoding and its Evaluation on PlanetLab, Proc. of 19th IASTED Int'l. Conf. on Parallel and Distributed Computing and Systems (PDCS2007), pp. 478-483, (November 2007).
http://ito-lab.naist.jp/themes/pdffiles/071121.shibata.pdcs2007.pdf
We have previously proposed a P2P video broadcast method called MTcast for simultaneously delivering video to user peers with different quality requirements. In this paper, we design and implement a prototype system of MTcast and report the results of its performance evaluation in the real Internet environment. MTcast relies on each peer to transcode and forward video to other peers. We conducted experiments on 20 PlanetLab nodes, evaluated startup delay and recovery time from peer leaving/failure, and confirmed that MTcast achieves practical performance in a real environment.
GPGPU-Assisted Subpixel Tracking Method for Fiducial MarkersNaoki Shibata
With an aim to realizing highly accurate position estimation, we propose in this paper a method for efficiently and accurately detecting the 3D positions and poses of traditional fiducial markers with black frames in high resolution images taken by ordinary web cameras. Our tracking method can be efficiently executed utilizing GPGPU computation, and in order to realize this, we devised a connected-component labeling method suitable for GPGPU execution. In order to improve accuracy, we devised a method for detecting 2D positions of the corners of markers in subpixel accuracy. We implemented our method in Java and OpenCL, and we confirmed that the proposed method provides better detection and measurement accuracy, and recognizing from high-resolution images is beneficial for improving accuracy. We also confirmed that our method is more than two times as fast as the existing method with CPU computation.
(Paper) Parking Navigation for Alleviating Congestion in Multilevel Parking F...Naoki Shibata
Kenmotsu, M., Sun, W., Shibata, N., Yasumoto, K. and Ito, M. : "Parking Navigation for Alleviating Congestion in Multilevel Parking Facility," Proc. of 2012 IEEE 76th Vehicular Technology Conference (VTC2012-Fall), Sep.2012.
Abstract - Finding a vacant parking space in a large crowded parking facility takes long time. In this paper, we propose a navigation method that minimizes the parking time based on collected real-time positional information of cars. In the proposed method, a central server in the parking facility collects the information and estimates the occupancy of each parking zone. Then, the server broadcasts the occupancy data to the cars in the parking facility. Each car then computes a parking route with the shortest expected parking waiting time and shows it to the driver. We conducted simulation-based evaluations of the proposed method using a realistic model based on trace data taken from a real parking facility. We confirmed that the proposed method reduced parking waiting time by 20%–70% even with low system penetration.
(Paper) A Method for Pedestrian Position Estimation using Inter-Vehicle Comm...Naoki Shibata
Abstract—In this paper, we propose a method for detecting the positions of pedestrians by cooperation of multiple cars with directional antennas to support drivers for pedestrian safety. In the method, each pedestrian carries a device which periodically transmits a beacon with a unique ID, and each car passing near the pedestrian receives the beacon by a directional antenna and measures the distance and the angle of arrival.
We assume the distribution of the measurement errors to be a normal distribution, and the system calculates the existence probabilities of each pedestrian at each point. By exchanging information of the probabilities between cars, the area with high existence probability is narrowed down. In this paper, we first describe the situations where detecting positions of pedestrians
greatly contribute to pedestrian safety, and then we describe the probability model used in our method, the method for calculating existence probabilities from information from multiple cars, and the protocol for exchanging the probability information between cars. We evaluated our method on QualNet simulator, and
confirmed that the positions can be detected accurately enough for practical uses.
(Paper) Task scheduling algorithm for multicore processor system for minimiz...Naoki Shibata
Shohei Gotoda, Naoki Shibata and Minoru Ito : "Task scheduling algorithm for multicore processor system for minimizing recovery time in case of single node fault," Proceedings of IEEE International Symposium on Cluster Computing and the Grid (CCGrid 2012), pp.260-267, DOI:10.1109/CCGrid.2012.23, May 15, 2012.
In this paper, we propose a task scheduling al-gorithm for a multicore processor system which reduces the
recovery time in case of a single fail-stop failure of a multicore
processor. Many of the recently developed processors have
multiple cores on a single die, so that one failure of a computing
node results in failure of many processors. In the case of a failure
of a multicore processor, all tasks which have been executed
on the failed multicore processor have to be recovered at once.
The proposed algorithm is based on an existing checkpointing
technique, and we assume that the state is saved when nodes
send results to the next node. If a series of computations that
depends on former results is executed on a single die, we need
to execute all parts of the series of computations again in
the case of failure of the processor. The proposed scheduling
algorithm tries not to concentrate tasks to processors on a die.
We designed our algorithm as a parallel algorithm that achieves
O(n) speedup where n is the number of processors. We evaluated
our method using simulations and experiments with four PCs.
We compared our method with existing scheduling method, and
in the simulation, the execution time including recovery time in
the case of a node failure is reduced by up to 50% while the
overhead in the case of no failure was a few percent in typical
scenarios.
(Paper) Emergency Medical Support System for Visualizing Locations and Vital ...Naoki Shibata
The triage tag is used in Mass Casualty Incident (MCI) to check the priority of patients treatments and conditions. However, it is difficult to grasp a change in the patient’s information since it is a paper tag. In this paper, we propose a system using the electronic triage tag (eTriage) that facilitates emergency medical technicians to grasp patients locations and conditions through visualization. This system provides the following three views of the patients information: (1) Inter-site view which shows on a map an overview of the latest status in multiple first-aid stations including the number of technicians and patients of each triage category; (2) Intra-site view which shows detailed status of each first-aid station including the location, triage category, and vital signs of each patient on a 3D map created based on the environment mapping technique; and (3) Individual view which shows vital information of patients on a tablet PC according to its orientation using the augmented reality technique. In this paper, we describe the design and implementation of the proposed system with some preliminary evaluation results.
Takashima, E.,Murata, Y., Shibata, N., Ito, M.: Self Adaptive Island GA, Proceedings of 2003 Congress on Evolutionary Computation (CEC 2003), Vol.2, pp.1072-1079, DOI:10.1109/CEC.2003.1299787
http://ito-lab.naist.jp/themes/pdffiles/031209.eiichi-t.cec2003.pdf
Exploration efficiency of GAs largely depends on parameter values. But, it is hard to manually adjust these values. T o cope with this problem, several adaptive GAs which automatically adjust parameters have been proposed. However , most of the existing adaptive GAs can adapt only a few parameters at the same time. Al-though several adaptive GAs can adapt multiple param-eters simultaneously , these algorithms require extremely large computation costs. In this paper , we propose Self Adaptive Island GA(SAIGA) which adapts four param-eter values simultaneously while finding a solution to a problem. SAIGA is a kind of island GA, and it adapts parameter values using a similar mechanism to meta-GA. Throughout our evaluation experiments, we con-firmed that our algorithm outperforms a simple GA us-ing De Jong's rational parameters, and has performance close to a simple GA using manually tuned parameter values.
(Paper) An Endorsement Based Mobile Payment System for a Disaster AreaNaoki Shibata
Babatunde Ojetunde, Naoki Shibata, Juntao Gao, and Minoru Ito : An Endorsement Based Mobile Payment System for A Disaster Area, in Proc. of The 29th IEEE International Conference on Advanced Information Networking and Applications (AINA-2015) (29% acceptance rate), pp.482-489, Mar. 2015. DOI:10.1109/AINA.2015.225
A payment system in a disaster area is essential for people to buy necessities such as groceries, clothing, and medical supplies. However, existing payment systems require the needed communication infrastructures (like wired networks and cellular networks) to enable transactions, so that these systems cannot be relied on in disaster areas, where these communication infrastructures may be destroyed. In this paper, we propose a mobile payment system, adopting infrastructureless mobile adhoc networks (MANETs), which allow users to shop in disaster areas while providing secure transactions. Specifically, we propose an endorsement-based scheme to guarantee each transaction and a scheme to provide monitoring based on location information, and thus achieve transaction validity and reliability. Our mobile payment system can also prevent collusion between two parties and reset and recover attacks by any user. Security is ensured by using location-based mutual monitoring by nearby users, avoiding thereby double spending in the system.
(Paper) A Method for Sharing Traffic Jam Information using Inter-Vehicle Comm...Naoki Shibata
Shibata, N., Terauchi, T., Kitani, T., Yasumoto, K., Ito, M., Higashino, T.: A Method for Sharing Traffic Jam Information Using Inter-Vehicle Communication, The 2nd International Workshop on Vehicle-to-Vehicle Communications (V2VCOM) (Mobiquitous2006 Workshop), pp. 1-7, DOI:10.1109/MOBIQ.2006.340428 (July 2006) (invited paper).
http://ito-lab.naist.jp/themes/pdffiles/060725.shibata.v2vcom06.pdf
In this paper, we propose a method for cars to autonomously and cooperatively collect traffic jam statistics to estimate arrival time to destination for each car using inter-vehicle communication. In the method, the target geographical region is divided into areas, and each car measures time to pass through each area. Traffic information is collected by exchanging information between cars using inter-vehicle communication. In order to improve accuracy of estimation, we introduce several mechanisms to avoid same data to be repeatedly counted. Since wireless bandwidth usable for exchanging statistics information is limited, the proposed method includes a mechanism to categorize data, and send important data prior to other data. In order to evaluate effectiveness of the proposed method, we implemented the method on a traffic simulator NETSTREAM developed by Toyota Central R&D Labs, conducted some experiments and confirmed that the method achieves practical performance in sharing traffic jam information using inter-vehicle communication.
(Slides) Efficient Evaluation Methods of Elementary Functions Suitable for SI...Naoki Shibata
Naoki Shibata : Efficient Evaluation Methods of Elementary Functions Suitable for SIMD Computation, Journal of Computer Science on Research and Development, Proceedings of the International Supercomputing Conference ISC10., Volume 25, Numbers 1-2, pp. 25-32, 2010, DOI: 10.1007/s00450-010-0108-2 (May. 2010).
http://www.springerlink.com/content/340228x165742104/
http://freshmeat.net/projects/sleef
Data-parallel architectures like SIMD (Single Instruction Multiple Data) or SIMT (Single Instruction Multiple Thread) have been adopted in many recent CPU and GPU architectures. Although some SIMD and SIMT instruction sets include double-precision arithmetic and bitwise operations, there are no instructions dedicated to evaluating elementary functions like trigonometric functions in double precision. Thus, these functions have to be evaluated one by one using an FPU or using a software library. However, traditional algorithms for evaluating these elementary functions involve heavy use of conditional branches and/or table look-ups, which are not suitable for SIMD computation. In this paper, efficient methods are proposed for evaluating the sine, cosine, arc tangent, exponential and logarithmic functions in double precision without table look-ups, scattering from, or gathering into SIMD registers, or conditional branches. We implemented these methods using the Intel SSE2 instruction set to evaluate their accuracy and speed. The results showed that the average error was less than 0.67 ulp, and the maximum error was 6 ulps. The computation speed was faster than the FPUs on Intel Core 2 and Core i7 processors.
Circular barcode design resistant to linear motion blur (preliminary slides)Naoki Shibata
It is hard to recognize markers from a moving camera, because of motion blur. Our circular barcode design allows fairly stable recognition even with linear motion blur. Each circular barcode can contain 9 bits of data. We developed an algorithm that recognizes barcodes at 30 frames/sec from 1080P video, utilizing GPGPU.
(Paper) A Method for Overlay Network Latency Estimation from Previous Observa...Naoki Shibata
Weihua Sun, Naoki Shibata, Keiichi Yasumoto, Masaaki Mori, "A Method for Overlay Network Latency Estimation from Previous Observation", in Proc. of The Twelfth International Conference on Networks (ICN2013), pp.95--100, 29 Jan. 2013.
Abstract—Estimation of the qualities of overlay links is useful for optimizing overlay networks on the Internet. Existing estimation methods requires sending large quantities of probe packets between two nodes, and the software for measurements have to be executed at both of the end nodes. Accurate measurements require many probe packets to be sent, and other communication can be disrupted by significantly increased network traffic. In this paper, we propose a link quality estimation method based on supervised learning from the previous observation of other similar links. Our method does not need to exchange probe packets, estimation can be quickly made to know qualities of many overlay links without wasting bandwidth and processing time on many nodes. We conducted evaluation of our method on PlanetLab, and our method showed better performance on path latency estimation than estimating results from geographical distance between the two end nodes.
(Paper) Efficient Evaluation Methods of Elementary Functions Suitable for SIM...Naoki Shibata
Naoki Shibata : Efficient Evaluation Methods of Elementary Functions Suitable for SIMD Computation, Journal of Computer Science on Research and Development, Proceedings of the International Supercomputing Conference ISC10., Volume 25, Numbers 1-2, pp. 25-32, DOI:10.1007/s00450-010-0108-2 (May. 2010).
http://ito-lab.naist.jp/~n-sibata/pdfs/isc10simd.pdf
http://freecode.com/projects/sleef
Data-parallel architectures like SIMD (Single Instruction Multiple Data) or SIMT (Single Instruction Multiple Thread) have been adopted in many recent CPU and GPU architectures. Although some SIMD and SIMT instruction sets include double-precision arithmetic and bitwise operations, there are no instructions dedicated to evaluating elementary functions like trigonometric functions in double precision. Thus, these functions have to be evaluated one by one using an FPU or using a software library. However, traditional algorithms for evaluating these elementary functions involve heavy use of conditional branches and/or table look-ups, which are not suitable for SIMD computation. In this paper, efficient methods are proposed for evaluating the sine, cosine, arc tangent, exponential and logarithmic functions in double precision without table look-ups, scattering from, or gathering into SIMD registers, or conditional branches. We implemented these methods using the Intel SSE2 instruction set to evaluate their accuracy and speed. The results showed that the average error was less than 0.67 ulp, and the maximum error was 6 ulps. The computation speed was faster than the FPUs on Intel Core 2 and Core i7 processors.
(Paper) MTcast: Robust and Efficient P2P-based Video Delivery for Heterogeneo...Naoki Shibata
In this paper, we propose a new video delivery method called MTcast (Multiple Transcode based video multicast) which achieves efficient simultaneous video delivery to multiple users with different quality requirements by relying on user nodes to transcode and forward video to other user nodes. In MTcast, each user specifies a quality requirement for a video consisting of bitrate, picture size and frame rate based on the user’s environmental resource limitation. All users can receive video with the specified quality (or near this quality) along a single delivery tree. The main characteristics of MTcast are in its scalability, high user satisfaction degree in received video quality, short startup latency and robustness against node failure. Through simulations, we have confirmed that MTcast can achieve much higher user satisfaction degree and robustness against node failure than the layered multicast method.
(Paper) P-Tour: A PERSONAL NAVIGATION SYSTEM FOR TOURISMNaoki Shibata
In this paper, we propose a personal navigation system for tourism called P-Tour. When a tourist specifies multiple destinations with relative importance and restrictions on arrival/staying time, P-Tour computes the nearly best schedule to visit part of those destinations. In addition to the map-based navigation, P-Tour provides temporal guidance according to the schedule, and automatically modifies the schedule when detecting the situation that the tourist cannot follow the schedule. We have developed a route search engine as a Java Servlet which can compute a semi-optimal schedule in reasonable time using techniques of genetic algorithms.
(Paper) P2P VIDEO BROADCAST BASED ON PER-PEER TRANSCODING AND ITS EVALUATION ...Naoki Shibata
Shibata, N., Yasumoto, K., and Mori, M.: P2P Video Broadcast based on Per-Peer Transcoding and its Evaluation on PlanetLab, Proc. of 19th IASTED Int'l. Conf. on Parallel and Distributed Computing and Systems (PDCS2007), pp. 478-483, (November 2007).
http://ito-lab.naist.jp/themes/pdffiles/071121.shibata.pdcs2007.pdf
We have previously proposed a P2P video broadcast method called MTcast for simultaneously delivering video to user peers with different quality requirements. In this paper, we design and implement a prototype system of MTcast and report the results of its performance evaluation in the real Internet environment. MTcast relies on each peer to transcode and forward video to other peers. We conducted experiments on 20 PlanetLab nodes, evaluated startup delay and recovery time from peer leaving/failure, and confirmed that MTcast achieves practical performance in a real environment.
GPGPU-Assisted Subpixel Tracking Method for Fiducial MarkersNaoki Shibata
With an aim to realizing highly accurate position estimation, we propose in this paper a method for efficiently and accurately detecting the 3D positions and poses of traditional fiducial markers with black frames in high resolution images taken by ordinary web cameras. Our tracking method can be efficiently executed utilizing GPGPU computation, and in order to realize this, we devised a connected-component labeling method suitable for GPGPU execution. In order to improve accuracy, we devised a method for detecting 2D positions of the corners of markers in subpixel accuracy. We implemented our method in Java and OpenCL, and we confirmed that the proposed method provides better detection and measurement accuracy, and recognizing from high-resolution images is beneficial for improving accuracy. We also confirmed that our method is more than two times as fast as the existing method with CPU computation.
(Paper) Parking Navigation for Alleviating Congestion in Multilevel Parking F...Naoki Shibata
Kenmotsu, M., Sun, W., Shibata, N., Yasumoto, K. and Ito, M. : "Parking Navigation for Alleviating Congestion in Multilevel Parking Facility," Proc. of 2012 IEEE 76th Vehicular Technology Conference (VTC2012-Fall), Sep.2012.
Abstract - Finding a vacant parking space in a large crowded parking facility takes long time. In this paper, we propose a navigation method that minimizes the parking time based on collected real-time positional information of cars. In the proposed method, a central server in the parking facility collects the information and estimates the occupancy of each parking zone. Then, the server broadcasts the occupancy data to the cars in the parking facility. Each car then computes a parking route with the shortest expected parking waiting time and shows it to the driver. We conducted simulation-based evaluations of the proposed method using a realistic model based on trace data taken from a real parking facility. We confirmed that the proposed method reduced parking waiting time by 20%–70% even with low system penetration.
(Paper) A Method for Pedestrian Position Estimation using Inter-Vehicle Comm...Naoki Shibata
Abstract—In this paper, we propose a method for detecting the positions of pedestrians by cooperation of multiple cars with directional antennas to support drivers for pedestrian safety. In the method, each pedestrian carries a device which periodically transmits a beacon with a unique ID, and each car passing near the pedestrian receives the beacon by a directional antenna and measures the distance and the angle of arrival.
We assume the distribution of the measurement errors to be a normal distribution, and the system calculates the existence probabilities of each pedestrian at each point. By exchanging information of the probabilities between cars, the area with high existence probability is narrowed down. In this paper, we first describe the situations where detecting positions of pedestrians
greatly contribute to pedestrian safety, and then we describe the probability model used in our method, the method for calculating existence probabilities from information from multiple cars, and the protocol for exchanging the probability information between cars. We evaluated our method on QualNet simulator, and
confirmed that the positions can be detected accurately enough for practical uses.
(Paper) Task scheduling algorithm for multicore processor system for minimiz...Naoki Shibata
Shohei Gotoda, Naoki Shibata and Minoru Ito : "Task scheduling algorithm for multicore processor system for minimizing recovery time in case of single node fault," Proceedings of IEEE International Symposium on Cluster Computing and the Grid (CCGrid 2012), pp.260-267, DOI:10.1109/CCGrid.2012.23, May 15, 2012.
In this paper, we propose a task scheduling al-gorithm for a multicore processor system which reduces the
recovery time in case of a single fail-stop failure of a multicore
processor. Many of the recently developed processors have
multiple cores on a single die, so that one failure of a computing
node results in failure of many processors. In the case of a failure
of a multicore processor, all tasks which have been executed
on the failed multicore processor have to be recovered at once.
The proposed algorithm is based on an existing checkpointing
technique, and we assume that the state is saved when nodes
send results to the next node. If a series of computations that
depends on former results is executed on a single die, we need
to execute all parts of the series of computations again in
the case of failure of the processor. The proposed scheduling
algorithm tries not to concentrate tasks to processors on a die.
We designed our algorithm as a parallel algorithm that achieves
O(n) speedup where n is the number of processors. We evaluated
our method using simulations and experiments with four PCs.
We compared our method with existing scheduling method, and
in the simulation, the execution time including recovery time in
the case of a node failure is reduced by up to 50% while the
overhead in the case of no failure was a few percent in typical
scenarios.
(Paper) Emergency Medical Support System for Visualizing Locations and Vital ...Naoki Shibata
The triage tag is used in Mass Casualty Incident (MCI) to check the priority of patients treatments and conditions. However, it is difficult to grasp a change in the patient’s information since it is a paper tag. In this paper, we propose a system using the electronic triage tag (eTriage) that facilitates emergency medical technicians to grasp patients locations and conditions through visualization. This system provides the following three views of the patients information: (1) Inter-site view which shows on a map an overview of the latest status in multiple first-aid stations including the number of technicians and patients of each triage category; (2) Intra-site view which shows detailed status of each first-aid station including the location, triage category, and vital signs of each patient on a 3D map created based on the environment mapping technique; and (3) Individual view which shows vital information of patients on a tablet PC according to its orientation using the augmented reality technique. In this paper, we describe the design and implementation of the proposed system with some preliminary evaluation results.
Takashima, E.,Murata, Y., Shibata, N., Ito, M.: Self Adaptive Island GA, Proceedings of 2003 Congress on Evolutionary Computation (CEC 2003), Vol.2, pp.1072-1079, DOI:10.1109/CEC.2003.1299787
http://ito-lab.naist.jp/themes/pdffiles/031209.eiichi-t.cec2003.pdf
Exploration efficiency of GAs largely depends on parameter values. But, it is hard to manually adjust these values. T o cope with this problem, several adaptive GAs which automatically adjust parameters have been proposed. However , most of the existing adaptive GAs can adapt only a few parameters at the same time. Al-though several adaptive GAs can adapt multiple param-eters simultaneously , these algorithms require extremely large computation costs. In this paper , we propose Self Adaptive Island GA(SAIGA) which adapts four param-eter values simultaneously while finding a solution to a problem. SAIGA is a kind of island GA, and it adapts parameter values using a similar mechanism to meta-GA. Throughout our evaluation experiments, we con-firmed that our algorithm outperforms a simple GA us-ing De Jong's rational parameters, and has performance close to a simple GA using manually tuned parameter values.
(Paper) An Endorsement Based Mobile Payment System for a Disaster AreaNaoki Shibata
Babatunde Ojetunde, Naoki Shibata, Juntao Gao, and Minoru Ito : An Endorsement Based Mobile Payment System for A Disaster Area, in Proc. of The 29th IEEE International Conference on Advanced Information Networking and Applications (AINA-2015) (29% acceptance rate), pp.482-489, Mar. 2015. DOI:10.1109/AINA.2015.225
A payment system in a disaster area is essential for people to buy necessities such as groceries, clothing, and medical supplies. However, existing payment systems require the needed communication infrastructures (like wired networks and cellular networks) to enable transactions, so that these systems cannot be relied on in disaster areas, where these communication infrastructures may be destroyed. In this paper, we propose a mobile payment system, adopting infrastructureless mobile adhoc networks (MANETs), which allow users to shop in disaster areas while providing secure transactions. Specifically, we propose an endorsement-based scheme to guarantee each transaction and a scheme to provide monitoring based on location information, and thus achieve transaction validity and reliability. Our mobile payment system can also prevent collusion between two parties and reset and recover attacks by any user. Security is ensured by using location-based mutual monitoring by nearby users, avoiding thereby double spending in the system.
(Paper) A Method for Sharing Traffic Jam Information using Inter-Vehicle Comm...Naoki Shibata
Shibata, N., Terauchi, T., Kitani, T., Yasumoto, K., Ito, M., Higashino, T.: A Method for Sharing Traffic Jam Information Using Inter-Vehicle Communication, The 2nd International Workshop on Vehicle-to-Vehicle Communications (V2VCOM) (Mobiquitous2006 Workshop), pp. 1-7, DOI:10.1109/MOBIQ.2006.340428 (July 2006) (invited paper).
http://ito-lab.naist.jp/themes/pdffiles/060725.shibata.v2vcom06.pdf
In this paper, we propose a method for cars to autonomously and cooperatively collect traffic jam statistics to estimate arrival time to destination for each car using inter-vehicle communication. In the method, the target geographical region is divided into areas, and each car measures time to pass through each area. Traffic information is collected by exchanging information between cars using inter-vehicle communication. In order to improve accuracy of estimation, we introduce several mechanisms to avoid same data to be repeatedly counted. Since wireless bandwidth usable for exchanging statistics information is limited, the proposed method includes a mechanism to categorize data, and send important data prior to other data. In order to evaluate effectiveness of the proposed method, we implemented the method on a traffic simulator NETSTREAM developed by Toyota Central R&D Labs, conducted some experiments and confirmed that the method achieves practical performance in sharing traffic jam information using inter-vehicle communication.
(Slides) Efficient Evaluation Methods of Elementary Functions Suitable for SI...Naoki Shibata
Naoki Shibata : Efficient Evaluation Methods of Elementary Functions Suitable for SIMD Computation, Journal of Computer Science on Research and Development, Proceedings of the International Supercomputing Conference ISC10., Volume 25, Numbers 1-2, pp. 25-32, 2010, DOI: 10.1007/s00450-010-0108-2 (May. 2010).
http://www.springerlink.com/content/340228x165742104/
http://freshmeat.net/projects/sleef
Data-parallel architectures like SIMD (Single Instruction Multiple Data) or SIMT (Single Instruction Multiple Thread) have been adopted in many recent CPU and GPU architectures. Although some SIMD and SIMT instruction sets include double-precision arithmetic and bitwise operations, there are no instructions dedicated to evaluating elementary functions like trigonometric functions in double precision. Thus, these functions have to be evaluated one by one using an FPU or using a software library. However, traditional algorithms for evaluating these elementary functions involve heavy use of conditional branches and/or table look-ups, which are not suitable for SIMD computation. In this paper, efficient methods are proposed for evaluating the sine, cosine, arc tangent, exponential and logarithmic functions in double precision without table look-ups, scattering from, or gathering into SIMD registers, or conditional branches. We implemented these methods using the Intel SSE2 instruction set to evaluate their accuracy and speed. The results showed that the average error was less than 0.67 ulp, and the maximum error was 6 ulps. The computation speed was faster than the FPUs on Intel Core 2 and Core i7 processors.
Circular barcode design resistant to linear motion blur (preliminary slides)Naoki Shibata
It is hard to recognize markers from a moving camera, because of motion blur. Our circular barcode design allows fairly stable recognition even with linear motion blur. Each circular barcode can contain 9 bits of data. We developed an algorithm that recognizes barcodes at 30 frames/sec from 1080P video, utilizing GPGPU.
BalloonNet: A Deploying Method for a Three-Dimensional Wireless Network Surro...Naoki Shibata
Aiming at fast establishment of a wireless network around a multi-level building in a disaster area, we propose an efficient method to determine the locations of network nodes in the air. Nodes are attached to balloons outside a building and deployed in the air so that the network can be accessed from anywhere in the building. In this paper, we introduce an original radio propagation model for predicting path loss from an outdoor position to a position inside a building. In order to address the three-dimensional deployment problem, the proposed method optimizes an objective function for satisfying two goals: (1) guarantee the coverage: the target space needs to be covered by over a certain percentage by wireless network nodes, (2) minimize the number of network nodes. For solving this problem, we propose an algorithm based on a genetic algorithm. To evaluate the proposed method, we compared our method with three benchmark methods, and the results show that the proposed method requires fewer nodes than other methods.
Congestion Alleviation Scheduling Technique for Car Drivers Based on Predicti...Naoki Shibata
In arranging efficient touring to various areas in urban areas, taking into account potential congestion is needed in order to schedule the order of these visits it is important to on the roads used and at the places to be visited. A number of scheduling methods have been proposed for finding (1) a noncongested route by sharing route information among users, or (2) a schedule to alleviate congestion at specific places based on the latest congestion information. However, these methods do not suffice since they do not deal with, simultaneously, congestion on road and at sites visited. In this paper, we propose a method of finding schedules for thousands of users by predicting, in advance, both types of congestion. Using the predicted results, the method adjusts each user’s provisional schedule by changing visiting order of places, and reducing their number in keeping with each user’s preferences. We have implemented the proposed method and evaluated it by simulations. The results showed it to achieve higher user satisfaction than existing methods.
An Endorsement Based Mobile Payment System for A Disaster AreaNaoki Shibata
Babatunde Ojetunde, Naoki Shibata, Juntao Gao, and Minoru Ito : An Endorsement Based Mobile Payment System for A Disaster Area, to appear in Proc. of The 29th IEEE International Conference on Advanced Information Networking and Applications (AINA-2015), Mar. 2015.
A payment system in a disaster area is essential for people to buy necessities such as groceries, clothing, and medical supplies. However, existing payment systems require the needed communication infrastructures (like wired networks and cellular networks) to enable transactions, so that these systems cannot be relied on in disaster areas, where these communication infrastructures may be destroyed. In this paper, we propose a mobile payment system, adopting infrastructureless mobile adhoc networks (MANETs), which allow users to shop in disaster areas while providing secure transactions. Specifically, we propose an endorsement-based scheme to guarantee each transaction and a scheme to provide monitoring based on location information, and thus achieve transaction validity and reliability. Our mobile payment system can also prevent collusion between two parties and reset and recover attacks by any user. Security is ensured by using location-based mutual monitoring by nearby users, avoiding thereby double spending in the system.
GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing ...Naoki Shibata
Jiaxing Xu, Weihua Sun, Naoki Shibata and Minoru Ito : "GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing Traffic Congestion," in Proc. of IEEE Vehicular Networking Conference 2014 (IEEE VNC 2014), pp. 179-186.
Serious traffic congestion is a major social problem in large cities. Inefficient setting of traffic signal cycles, especially, is one of the main causes of congestion. GreenWave is a method for controlling traffic signals which allows one-way traffic to pass through a series of intersections without being stopped by a red light. GreenWave was tested in several cities around the world, but the results were not satisfactory. Two of the problems with GreenWave are that it still stops the crossing traffic, and it forms congestion in the traffic turning into or out of the crossing streets. To solve these problems, we propose a method of controlling traffic signals, GreenSwirl, in combination with a route guidance method, GreenDrive. GreenSwirl controls traffic signals to enable a smooth flow of traffic through signals times to turn green in succession and through non-stop circular routes through the city. The GreenWave technology is extended thereby. We also use navigation systems to optimize the overall control of the city's traffic. We did a simulation using the traffic simulator SUMO and the road network of Manhattan Island in New York. We confirmed that our method shortens the average travel time by 10%-60%, even when not all cars on the road are equipped to use this system.
Task Scheduling Algorithm for Multicore Processor Systems with Turbo Boost an...Naoki Shibata
Yosuke Wakisaka, Naoki Shibata, Keiichi Yasumoto, Minoru Ito, and Junji Kitamichi : Task Scheduling Algorithm for Multicore Processor Systems with Turbo Boost and Hyper-Threading, In Proc. of The 2014 International Conference on Parallel and Distributed Processing Techniques and Applications(PDPTA'14), pp. 229-235
In this paper, we propose a task scheduling algorithm for multiprocessor systems with Turbo Boost and Hyper-Threading technologies. The proposed algorithm minimizes the total computation time taking account of dynamic changes of the processing speed by the two technologies, in addition to the network contention among the processors. We constructed a clock speed model with which the changes of processing speed with Turbo Boost and Hyper-threading can be estimated for various processor usage patterns. We then constructed a new scheduling algorithm that minimizes the total execution time of a task graph considering network contention and the two technologies. We evaluated the proposed algorithm by simulations and experiments with a multiprocessor system consisting of 4 PCs. In the experiment, the proposed algorithm produced a schedule that reduces the total execution time by 36% compared to conventional methods which are straightforward extensions of an existing method.
(Slides) A Decentralized Method for Maximizing k-coverage Lifetime in WSNsNaoki Shibata
Katsuma, R., Murata, Y., Shibata, N., Yasumoto, K., Ito, M.: "A Decentralized Method for Maximizing k-coverage Lifetime in WSNs," Proc. of The Sixth International Conference on Mobile Computing and Ubiquitous Networking (ICMU 2012), pp.16-23, May.23, 2012.
http://ito-lab.naist.jp/mediawiki/images/1/17/Icmu2012.pdf
In this paper, we propose a decentralized method for maximizing lifetime of data collection wireless sensor networks (WSNs) by making minimal number of nodes operate and putting other nodes in sleep. We divide a target field into multiple grids and make nodes in each grid locally achieve k-coverage. We can reduce energy consumption of WSN by minimizing the number of active nodes required for kcoverage. However, coverage degree is likely to go to excess beyond k near border between grids when deciding active nodes in each grid independently. To solve this problem, our method decides the minimal set of active nodes for adjoined grids at different times so that k-coverage of a grid is achieved taking into account the coverage in its neighboring grids. Through computer simulations, we confirmed that the proposed method achieved distribution of WSN processing with a small decrease of k-coverage lifetime compared to the centralized algorithm.
(Slides) Task scheduling algorithm for multicore processor system for minimiz...Naoki Shibata
Shohei Gotoda, Naoki Shibata and Minoru Ito : "Task scheduling algorithm for multicore processor system for minimizing recovery time in case of single node fault," Proceedings of IEEE International Symposium on Cluster Computing and the Grid (CCGrid 2012), pp.260-267, DOI:10.1109/CCGrid.2012.23, May 15, 2012.
In this paper, we propose a task scheduling al-gorithm for a multicore processor system which reduces the
recovery time in case of a single fail-stop failure of a multicore
processor. Many of the recently developed processors have
multiple cores on a single die, so that one failure of a computing
node results in failure of many processors. In the case of a failure
of a multicore processor, all tasks which have been executed
on the failed multicore processor have to be recovered at once.
The proposed algorithm is based on an existing checkpointing
technique, and we assume that the state is saved when nodes
send results to the next node. If a series of computations that
depends on former results is executed on a single die, we need
to execute all parts of the series of computations again in
the case of failure of the processor. The proposed scheduling
algorithm tries not to concentrate tasks to processors on a die.
We designed our algorithm as a parallel algorithm that achieves
O(n) speedup where n is the number of processors. We evaluated
our method using simulations and experiments with four PCs.
We compared our method with existing scheduling method, and
in the simulation, the execution time including recovery time in
the case of a node failure is reduced by up to 50% while the
overhead in the case of no failure was a few percent in typical
scenarios.
(Slides) A Technique for Information Sharing using Inter-Vehicle Communicatio...Naoki Shibata
Shinkawa, T., Terauchi, T., Kitani, T., Shibata, N., Yasumoto, K., Ito, M. and Higashino, T.: A Technique for Information Sharing using Inter-Vehicle Communication with Message Ferrying, International Workshop on Future Mobile and Ubiquitous Information Technologies (FMUIT'06).
http://mimi.naist.jp/~yasumoto/papers/FMUIT2006-shinkawa.pdf
In this paper, we propose a method to realize traffic information
sharing among cars using inter-vehicle communication.
When traffic information on a target area is retained
by ordinary cars near the area, the information may be lost
when the density of cars becomes low. In our method, we
use the message ferrying technique together with the neighboring
broadcast to mitigate this problem. We use buses
which travel through regular routes as ferries. We let buses
maintain the traffic information statistics in each area received
from its neighboring cars. We implemented the proposed
system, and conducted performance evaluation using
traffic simulator NETSTREAM. As a result, we have confirmed
that the proposed method can achieve better performance
than using only neighboring broadcast.
(Slides) A Personal Navigation System with a Schedule Planning Facility Based...Naoki Shibata
Shiraishi, T., Nagata, M., Shibata, N., Murata, Y., Yasumoto, K. and Ito, M.: A Personal Navigation System with a Schedule Planning Facility Based on Multiobjective Criteria, Proceedings of the 2nd International Conference on Mobile Computing and Ubiquitous Networking (ICMU2005), pp.104-109, (April 2005)
http://ito-lab.naist.jp/themes/pdffiles/icmu05-takayu-s.pdf
In our previous work, we have proposed a personal navigation
system called P-Tour, which facilitates tourists to compose
a schedule to visit multiple destinations taking into account
their preferences and time restrictions. In this paper,
we extend P-Tour in the following two ways: (1) allowing
users to optimize their tour schedules under multiple conflicting
criteria such as total expenses and satisfaction degrees;
and (2) navigating users to the next destination in more efficient
way. We have implemented the above extensions and
integrated them into P-Tour. Through some experiments, we
show the effectiveness of the proposed extensions.
(Slides) A Method for Distributed Computaion of Semi-Optimal Multicast Tree i...Naoki Shibata
Takashima, E., Murata, Y., Shibata, N., Yasumoto, K. and Ito, M.: A Method for Distributed Computaion of Semi-Optimal Multicast Tree in MANET, IEEE Wireless Communications and Networking Conference (WCNC 2007), pp. 2570-2575, DOI:10.1109/WCNC.2007.478 (March 2007).
http://ito-lab.naist.jp/themes/pdffiles/070314.eiichi-t.wcnc2007.pdf
In this paper, we propose a new method to construct
a semi-optimal QoS-aware multicast tree on MANET using
distributed computation of the tree based on Genetic Algorithm
(GA). This tree is sub-optimal for a given objective (e.g.,
communication stability and power consumption), and satisfies
given QoS constraints for bandwidth and delay. In order to
increase scalability, our proposed method first divides the whole
MANET to multiple clusters, and computes a tree for each
cluster and a tree connecting all clusters. Each tree is computed
by GA in some nodes selected in the corresponding cluster.
Through experiments using network simulator, we confirmed that
our method outperforms existing on-demand multicast routing
protocol in some useful objectives.
(Slides) A demand-oriented information retrieval method on MANETNaoki Shibata
Enomoto, M., Shibata, N., Yasumoto, K., Ito, M. and Higashino, T.: A demand-oriented information retrieval method on MANET, International Workshop on Future Mobile and Ubiquitous Information Technologies (FMUIT'06).
http://ito-lab.naist.jp/themes/pdffiles/060510.makoto-e.fmuit06.pdf
In urban areas including shopping malls and stations
with many people, it is important to utilize various information
which those people have obtained. In this paper, we
propose a method for information registration and retrieval
in MANET which achieves small communication cost and
short response time. In our method, we divide the whole application
field into multiple sub-areas and classify records
into several categories so that mobile terminals in an area
holds records with a category. Each area is associated with
a category so that the number of queries for the category
becomes the largest in the area. Thus, mobile users search
records with a certain category by sending a query to nodes
in the particular area using existing protocol such as LBM
(Location-Based Multicast). Through simulations supposing
actual urban area near Osaka station, we have confirmed
that our method achieves practical communication
cost and performance for information retrieval in MANET.
(Slides) Inter-Vehicle Communication Protocol for Cooperatively Capturing and...Naoki Shibata
Kotani, K., Sun, W., Kitani, T., Shibata, N., Yasumoto, K., Ito, M.:Inter-Vehicle Communication Protocol for Cooperatively Capturing and Sharing Intersection Video, Proc. of 2nd IEEE Intelligent Vehicular Communications System Workshop (IVCS'10), (CD-ROM), Jan. 9th, 2010. DOI:10.1109/CCNC.2010.5421635 (Jan. 2010).
http://www.aist-nara.ac.jp/~sunweihua/papers-fullversion/I-10-01-02.pdf
For accident prevention at intersections, it is useful for
drivers to grasp the position of vehicles in blind spots.
This can be achieved without infrastructure if some vehicles
passing near the intersection capture and share live
video of the intersection through inter-vehicle communications.
However, such video streaming requires a congestion
control mechanism. In this paper, aiming to let a driver
grasp the situation at an intersection, we propose a method
to select vehicles that send a video in order to generate a
live bird’s-eye-view video of the intersection. In our method,
each vehicle at an intersection exchanges information with
others, such as the sub-areas of the intersection it captures,
the quality of its video, and its position and speed. Based
on the exchanged information, each vehicle autonomously
judges whether it should send its video or not. Through
simulation with a QualNet simulator, we confirm that our
method achieves a good video arrival rate and video quality
sufficient for practical use.
(Slides) UbiREMOTE: Framework for Remotely Controlling Networked Appliances t...Naoki Shibata
Kiyokawa, K., Yamamoto, S., Shibata, N., Yasumoto, K., Ito, M.: UbiREMOTE: Framework for Remotely Controlling Networked Appliances through Interaction with 3D Virtual Space, Proc. of ACM Multimedia Systems 2010 (MMSys2010), pp.271-280, DOI:10.1145/1730836.1730870 (Feb. 2010).
http://ito-lab.naist.jp/mediawiki/images/6/60/100223mmsys.pdf
In this paper, we propose a framework named “UbiREMOTE”for controlling information appliances connected to a home network with a unified and intuitive user interface from a remote place. The UbiREMOTE framework provides users with a way to control appliances in a home through a virtual space drawn on a mobile terminal screen which reflects the latest conditions of the real appliances and the rooms in the home. With UbiREMOTE, a user controls appliances by (1) moving to the front of an appliance, (2) choosing the appliance to control and (3) pushing buttons on the virtual remote controller which imitates the real remote controller for the appliance or the real console. In this paper, we propose a method to improve the drawing speed of 3D virtual space on mobile terminals and a method for automatically reflecting condition changes of the real space in the virtual space. We implemented the methods and evaluated the performance. The results showed that the proposed methods can be practically used on small mobile terminals.
(Slides) A Method for Pedestrian Position Estimation using Inter-Vehicle Comm...Naoki Shibata
http://ito-lab.naist.jp/themes/ITS/pdfs/2-1/1.pdf
Sawa, Y., Kitani, T., Shibata, N., Yasumoto, K., Ito, M.:
A Method for Pedestrian Position Estimation using Inter-Vehicle Communication, Proc. of the 3rd IEEE Workshop on Automotive Networking and Applications (AutoNet 2008), pp. 1 - 6, DOI:10.1109/GLOCOMW.2008.ECP.57 (Dec 2008).
In this paper, we propose a method for detecting the positions of pedestrians by cooperation of multiple cars with directional antennas to support drivers for pedestrian safety. In the method, each pedestrian carries a device which periodically transmits a beacon with a unique ID, and each car passing near the pedestrian receives the beacon by a directional antenna and measures the distance and the angle of arrival.
We assume the distribution of the measurement errors to be a normal distribution, and the system calculates the existence probabilities of each pedestrian at each point. By exchanging information of the probabilities between cars, the area with high existence probability is narrowed down. In this paper, we first describe the situations where detecting positions of pedestrians greatly contribute to pedestrian safety, and then we describe the probability model used in our method, the method for calculating existence probabilities from information from multiple cars, and the protocol for exchanging the probability information between cars. We evaluated our method on QualNet simulator, and confirmed that the positions can be detected accurately enough for practical uses.
(Slides) P-Tour: A Personal Navigation System for TouristNaoki Shibata
http://ito-lab.naist.jp/themes/pdffiles/041019.atsu-mar.ITSWC2004.pdf
Maruyama, A., Shibata, N., Murata, Y., Yasumoto, K. and Ito, M.: P-Tour: A Personal Navigation System for Tourism, Proceedings of 11th World Congress on ITS Nagoya, pp.18-21 (October 2004)
We propose a personal navigation system for tourism called P-Tour. When a tourist specifies multiple destinations with relative importance and restrictions on arrival/staying time, P-Tour computes the nearly best schedule to visit part of those destinations. In addition to the map-based navigation, P-Tour provides temporal guidance according to the schedule, and automatically modifies the schedule when detecting the situation that the tourist cannot follow the schedule. We have developed a route search engine as a Java Servlet which can compute a semi-optimal schedule in reasonable time using techniques of genetic algorithms.