Keiji Yamada

dblp:27/109 · DBLP profile ↗
← Back
31ranked-venue papers
6as first author
0since 2021 · last 2012
0000-0002-3954-0317ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 18 · 6 first-authorDatabases, data management, data science and information retrieval · 12 · 3 first-authorGraphics, computer vision, multimedia, augmented reality and games · 8 · 3 first-authorComputer networks · 6Human-computer interaction and ubiquitous computing · 3Applied, interdisciplinary, general and emerging computing · 2

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Human-computer interaction and pervasive computing
2 papers
Human-robot interaction · 54% Haptics and multimodal interaction · 27% Interaction techniques and input · 9%
Databases, data mining, and information retrieval
2 papers
Data mining · 61% Web and social media mining · 30% Information retrieval · 9%
Artificial intelligence
2 papers
Probabilistic and Bayesian machine learning · 55% Representation and self-supervised learning · 46%

Topics — the 10 heaviest of 13, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Haptics and multimodal interaction
multimodal interaction
0.112012
Interactive multimodal social robot for improving quality of care of elderly in Australian nursing homes · ACM Multimedia 2012
Human-robot interaction › assistive robotics
socially assistive robotics
0.112012
Interactive multimodal social robot for improving quality of care of elderly in Australian nursing homes · ACM Multimedia 2012
Human-robot interaction
social robot
0.112012
Interactive multimodal social robot for improving quality of care of elderly in Australian nursing homes · ACM Multimedia 2012
Data mining
anomaly detection
0.112010
Exponential Family Tensor Factorization for Missing-Values Prediction and Anomaly Detection · ICDM 2010
Data mining › multidimensional data analysis › multiway data analysis › tensor analysis
tensor factorization
0.112010
Exponential Family Tensor Factorization for Missing-Values Prediction and Anomaly Detection · ICDM 2010
Interaction techniques and input › text entry
camera-based text input
0.012004
Camera-Typing Interface for Ubiquitous Information Services · PerCom 2004
Health and well-being technologies
elderly care
0.012012
Interactive multimodal social robot for improving quality of care of elderly in Australian nursing homes · ACM Multimedia 2012
Machine learning › Probabilistic and Bayesian machine learning › statistical inference
exponential family
0.012010
Exponential Family Tensor Factorization for Missing-Values Prediction and Anomaly Detection · ICDM 2010
Machine learning › Representation and self-supervised learning › prototype learning
learning vector quantization
0.011995
Generalized Learning Vector Quantization · NIPS 1995
Machine learning › Representation and self-supervised learning
prototype learning
0.011995
Generalized Learning Vector Quantization · NIPS 1995

Methods — techniques the papers use, named apart from their topics

laplace approximation · 0.2gaussian process · 0.2EM algorithm · 0.2exploratory analysis · 0.1automatic error correction · 0.0automatic concatenation · 0.0generalized learning vector quantization · 0.0
YearPublicationVenuePosition
2012 Analysis of the correlation between the regularity of work behavior and stress indices based on longitudinal behavioral data
abstract
Increasingly, longitudinal behavioral data captured by various sensors are being analyzed to improve workplace performance. In this paper, we analyze the correlation between the regularity of workers' behavior and their levels of stress. We used a 23-month behavioral dataset for 18 workers that recorded their use of PCs and their locations in the office. We found that the principal eigenbehaviors extracted from the dataset with PCA represented typical work behaviors such as overwork using a PC and routine times for meetings. We found that more than 80% of each of the 18 workers' individual behaviors could be reconstructed using nine principal eigenbehaviors. In addition, the deviation ranges for the reconstruction accuracies were significantly different for workers in different positions. We conducted the correlation analysis between work behaviors of the workers and their stress level. Our results show a significant negative correlation (r > 0.69, p < 0.01) between the accuracy of reconstructed work behaviors and physical stress levels; and a significant positive correlation between the accuracy of reconstructed behavior and stress dissolution abilities. Our results suggest that the correlation between the stress level of workers and the regularity of their work behavior exists. This correlation will be useful for occupational healthcare.
Shogo Okada, Yusaku Sato, Yuki Kamiya, Keiji Yamada, Katsumi Nitta
ICMI4
2012 Interactive multimodal social robot for improving quality of care of elderly in Australian nursing homes
abstract
This paper describes the design of multimodal robotic system, embodiment of multimodal interaction (voice, gestures, emotion, touch panel and dance) in assistive social robot (Matilda) for modeling group based and one-to-one interactions with technology adverse elderly in nursing homes. It describes the human-centered evaluation of Matilda based on quality, naturalness, user satisfaction and predictive accuracy based on first ever field trials in Australia. The multimodal social robots have facilitated breaking the technology barriers with the elderly leading to several aged care facilities and community centers showing interest in future trials.
Rajiv Khosla, Mei-Tai Chu, Reza Kachouie, Keiji Yamada, Yoshihiro Fujita, Tomoharu Yamaguchi
ACM Multimedia4
2011 Toward Future Network Systems Boosting Interactions between People in Social Networks
abstract
This paper discusses the modeling, the observation, and the analysis of a social experiment, in which we built an online social network to observe interactions between people. We try to model the problem from the micro-economics aspect; we use the concept of utility to model people's behaviors in this experiment. Furthermore, we consider incentive reward as an external factor and observed how people's behavior would change based on how we give incentive reward. We assumed the scenario of content recommendation in an online social network and compared the two reward assignment rules: i) a user gets reward if she or he informs her/his friend of the pointer to the content and ii) a user gets reward if her/his friend she or he informed of the content pointer reacts to the content. We expect that, in the former, the social network is not activated because the information flow is unidirectional, while, in the latter, the social network can be activated because it stimulates people to react to the information they have received.
Ryoichi Shinkuma, Yoshinori Takata, Naoki Yoshinaga 0002, Satoko Itaya, Shinichi Doi, Tatsuro Takahashi, Keiji Yamada
ICCCN7
2011 Node-First Causal Network Extraction for Trend Analysis Based on Web Mining
Hideki Kawai, Katsumi Tanaka, Kazuo Kunieda, Keiji Yamada
KES (2)4
2011 Proposal of ride-sharing system using harmonic aggregation of user demands
abstract
In this paper, we propose a ride-sharing system with harmonic aggregation of user demands to support both human satisfaction and resource efficiency, and report results of the simulation of our proposed system showing the efficiency of our method. Our proposed ride-sharing system alters user action time and harmonically aggregates user transfer by using flexible parts of users' demands toward their actions. We built a demonstration system visualizing our future vision in which the proposed ride-sharing method was represented as one scenario. In this system, the ride-sharing will be implemented as the joining of several small personal vehicles. We performed our simulations with basic scenarios including part of the proposed method and obtained results showing that the ride-sharing system with our proposed method has four-times higher efficiency than that without the method.
Satoko Itaya, Rie Tanaka, Naoki Yoshinaga 0002, Taku Konishi, Shinichi Doi, Keiji Yamada
LCN6
2011 Exponential family tensor factorization: an online extension and applications
Kohei Hayashi, Takashi Takenouchi, Tomohiro Shibata, Yuki Kamiya, Daishi Kato, Kazuo Kunieda, Keiji Yamada, Kazushi Ikeda
Knowl. Inf. Syst.7
2011 A scalable interest-oriented peer-to-peer pub/sub network
Daishi Kato, Kaoutar Elkhiyaoui, Kazuo Kunieda, Keiji Yamada, Pietro Michiardi
Peer-to-Peer Netw. Appl.4
2010 Exponential Family Tensor Factorization for Missing-Values Prediction and Anomaly Detection
abstract
In this paper, we study probabilistic modeling of heterogeneously attributed multi-dimensional arrays. The model can manage the heterogeneity by employing an individual exponential-family distribution for each attribute of the tensor array. These entries are connected by latent variables and are shared information across the different attributes. Because a Bayesian inference for our model is intractable, we cast the EM algorithm approximated by using the Lap lace method and Gaussian process. This approximation enables us to derive a predictive distribution for missing values in a consistent manner. Simulation experiments show that our method outperforms other methods such as PARAFAC and Tucker decomposition in missing-values prediction for cross-national statistics and is also applicable to discover anomalies in heterogeneous office-logging data.
Kohei Hayashi, Takashi Takenouchi, Tomohiro Shibata, Yuki Kamiya, Daishi Kato, Kazuo Kunieda, Keiji Yamada, Kazushi Ikeda
ICDM7
2010 Proposal of user-collaborative mobile object assignment system
abstract
Recently, mobile object sharing systems including car-sharing systems have been gathering more attention as an ecological activity. In this paper, we propose a user-collaborative mobile object assignment system using location information of users. The optimal mobile object assignment is to minimize travel distances of mobile objects in the existing mobile object assignment system, and the system controls allocation of mobile objects. The system recommends the two users to hand over the mobile object to each other if it is the optimal way for users, for example, one user gets off the car and another user rides on the same car continuously. Our proposed system uses the location information of both current and next users to find the optimal way for both users, and informs them the information. Then, the system can trigger the independent collaboration of users by leaving a final decision up to them. Firstly our system calculates optimal mobile object assignment for both current and next users. Secondly, if it is efficient for both current and next users to change the destination of the current user, the system recommends the current user to change the current destination to the calculated one. Thereafter, the system gets an extra fee from the next user, and gives a part of that to the current user as incentive for change of destination when it is needed. Our system can achieve a more friendly system for both user and environment than the current system and solve the distribution problem of mobile objects. Also, we did multi-agent simulations with basic scenarios including a part of proposed method, and got results showing that the system was effective at increasing the number of people who were collaborate with each other.
Satoko Itaya, Naoki Yoshinaga 0002, Hirohiko Ito, Rie Tanaka, Taku Konishi, Shinichi Doi, Keiji Yamada
LCN7
2010 Analyzing collective view of future, time-referenced events on the web
abstract
Humans have always desired to guess the future in order to adapt their behavior and maximize chances of success. In this paper, we conduct exploratory analysis of future-related information on the web. We focus on the future-related information which is grounded in time, that is, the information on forthcoming events whose expected occurrence dates are already known. We collect data by crawling search engine index and analyze collective view of future time-referenced events discussed on the web.
Adam Jatowt, Hideki Kawai, Kensuke Kanazawa, Katsumi Tanaka, Kazuo Kunieda, Keiji Yamada
WWW6
2009 A Scalable Interest-oriented Peer-to-Peer Pub/Sub Network
abstract
Publish/subscribe represents a new paradigm for distributed content delivery. It provides an alternative to address-based communication due to its ability to decouple communication between the source and the destination. However, it has remained a challenge to devise a scalable overlay supporting expressive content-filtering while satisfying the desirable requirements large distributed systems should fulfill. Our goal is to build an efficient P2P publish/subscribe network where only interested nodes are involved in event dissemination, and the amount of overhead generated by network discovery and membership management is small. In order to do so, we use a Bloom filter based mapping scheme to map IDs to nodes' interests, in addition to a new interest proximity metric to forward events and to build nodes' routing tables. As for network discovery we propose a new approach we call ldquoshared interest approachrdquo. Our scheme ensures an upper bound of routing tables size that only depends on the size of the ID digest. To evaluate the algorithms proposed in this work we conducted simulations in both static and dynamic settings.
Kaoutar Elkhiyaoui, Daishi Kato, Kazuo Kunieda, Keiji Yamada, Pietro Michiardi
Peer-to-Peer Computing4
2009 Adaptive Embodied Entrainment Control and Interaction Design of the First Meeting Introducer Robot
abstract
This paper describes a robotic agent that can promote communication when people first meet. When two people meet for the first time, a communication mediator can be important because people often feel stressed and cannot talk comfortably. Our agent reduces their stress by using embodied entrainment and thus promotes communication. In the research field of embodied entrainment, suitable timing of a nod or back-channel feedback has been discussed, but situations to communicate in are limited. We have developed an embodied entrainment control system that recognizes communication states and adapts to them accordingly. For this, we focus on effective non-verbal information for communication. Using this information, our agent helps a talker and a listener to alternate their roles appropriately. We conducted communication experiments with the agent and confirmed its effectiveness. In the experiments, we used and compared different representation of the agent: an embodied robot agent, a computer graphics agent, and no agent. We report the comparison results and discuss representations for communication agents.
Kenzaburo Miyawaki, Mutsuo Sano, Ryohei Sasama, Tomoharu Yamaguchi, Keiji Yamada
SMC5
2009 ChronoSeeker: Future Opinion Extraction
abstract
In this paper, we will propose a novel technique for Future Opinion Extraction, a new task of Information Extraction. The system we built can extract automatically future opinions, building automatic queries for the Search API. We obtained an F-Measure of 81.8% for the filtering of future opinion candidates. Our method provides future opinions allowing us to identify future problems and future goals of our society in the forty next years. The total system, called ChronoSeeker, contains +20,000 future opinions.
Pierre Brun, Hideki Kawai, Kazuo Kunieda, Keiji Yamada
Web Intelligence4
2009 An emulator for peer-to-peer distributed hash tables
Daishi Kato, Kazuo Kunieda, Keiji Yamada
Comput. Commun.3
2004 Camera-Typing Interface for Ubiquitous Information Services
abstract
We propose a new technology called the camera-typing interface, which can read printed characters such as URLs with a low-resolution camera. It realizes a type of ubiquitous information service using smart phones with cameras. This method includes two main advantages: automatic concatenation of sequential shots and automatic error correction by re-shooting. The automatic concatenation enables a user to take segmented images of a character string, thus a low-resolution camera can be used as the interface device. The automatic error correction enables the user to correct misrecognized characters just by retaking images around them, providing an easy and natural way of error correction. We present two experimental results to prove effectiveness of our method. Both results indicate that our proposed method is helpful.
Shuji Senda, Kyosuke Nishiyama, Toshiyuki Asahi, Keiji Yamada
PerCom4
2001 A Stochastic Model for Handwritten Word Recognition Using Context Dependency Between Character Patterns
abstract
In a handwritten word or sentence, deformation of each character pattern often depends on that of other character patterns due to their cursiveness or the writer's characteristic. In this paper, a new word recognition method is proposed, that takes into consideration the dependency of deformation between characters. The stochastic model used in our method, which is to say a bigram model of character patterns, is constructed on the assumption that there is a Markovian property underlying in the deformation of a character string, and has a learning algorithm based on the EM algorithm. Experimental results in ZIP code recognition show the effectiveness of our method.
Takafumi Koshinaka, Daisuke Nishiwaki, Keiji Yamada
ICDAR3
2001 A Maximum-Likelihood Approach to Segmentation-Based Recognition of Unconstrained Handwriting Text
abstract
We propose a maximum-likelihood approach to segmentation-based recognition of unconstrained handwriting text. The segmentation scores and recognition scores are transformed into posterior probabilities, and the likelihood function which is composed of both these probabilities and character n-gram probabilities is derived from the Bayesian theorem. The recognition result which maximizes the function can be obtained by Viterbi search. Experiments have shown that the proposed likelihood function is effective in the recognition of online Japanese text.
Shuji Senda, Keiji Yamada
ICDAR2
2000 A Method of Analyzing the Handling of Paper Documents in Motion Images
abstract
In this paper, we describe a new system for analyzing the motions involved in handling documents on a desk. Video images are captured by a camera mounted above the desk and the motion which occurs when someone handles the document is classified as movement of the document, turning of the pages, or finger pointing. Furthermore, the system can detect the appearance of fresh regions as a result of movement of the document and the turning of its pages and it can also detect the positions of fingers in the image to realize a natural pointing function. We evaluated implementations of some components of the system and found that they provide sufficient performance to act as parts of a user interface for an interactive document management system.
Keiji Yamada, Koji Ishikawa, Noboru Nakajima
ICPR1
1998 Document Layout and Reading Sequence Analysis by Extended Split Detection Method
Noboru Nakajima, Keiji Yamada, Jun Tsukumo
Document Analysis Systems2
1998 Document reconstruction and recognition from an image sequence
abstract
A new method for reconstructing a document from an image sequence and recognizing contents of the document is described. In this method frame images in the image sequence are acquired as partial sub-images by a moving camera. The reconstruction includes a rather expensive registration process. To make its use practical, the proposed method registers sub-images hierarchically by sub-tree matching of the layout structure. Images of a corresponding character pair are piled using sub-pixel precision displacement and interpolated to restore image quality and resolution. The proposed method increased the character recognition rate by 6.8 points to 93.1% when resolution was 133 dpi. The computational cost was reduced to 1/23 that of registration by conventional matching.
Noboru Nakajima, Naoya Tanaka, Keiji Yamada
ICPR3
1998 A formulation of learning vector quantization using a new misclassification measure
abstract
This paper reports a formulation of learning vector quantization (LVQ) using a new misclassification measure based on minimum classification error (MCE). We show that the convergence property of reference vectors depends on the definition of the misclassification measure, and show that our definition guarantees the convergence, unlike LVQ1.1 or Juan and Katagiri's formulation based on MCE (1992). Experimental results for handwritten digit recognition reveal that the proposed method is superior to LVQ algorithms in recognition capability.
Atsushi Sato, Keiji Yamada
ICPR2
1998 Handwritten text retrieval using two-stage pattern matching with handwritten query
abstract
Describes a method of retrieving handwritten text with handwritten queries. The properties of handwritten Japanese texts have prevented conventional handwritten European text retrieval methods from being applied to Japanese. To address this problem, the proposed method was devised to segment texts into blocks and search stored texts by using a two-stage flexible matching method. At the first stage, the features used for flexibly matching block series were designed to reduce the amount of the processing which produces features of combined blocks. In the second stage, flexible matching between corresponding blocks was employed to exclude erroneous candidates. Experiments demonstrated 99.5% recall and 20% precision in the case of queries with four characters.
Keiji Yamada
ICPR1
1997 Unconstrained Japanese Address Recognition Using a Combination of Spatial Information and Word Knowledge
abstract
We describe a new handwritten address recognition method which can correct the errors occurring in line extraction, character segmentation, and character recognition as a possible means of avoiding the error accumulation which occurs during the recognition sequence in conventional methods. We formulate the address recognition method as a minimum cost search problem. We define the character recognition cost which estimates the reliability of the character recognition result, the arrangement cost which estimates the plausibility of the character string's spatial arrangement, and the word knowledge cost which estimates the plausibility of the linguistic conditions. By using a combination of these costs, the proposed method can recognize an address which has not been extracted as a single line from input images by a conventional method. The efficiency of the proposed method is evaluated through an experiment using 600 Japanese mail images. An address recognition rate of 79.38% was obtained.
Eiki Ishidera, Daisuke Nishiwaki, Keiji Yamada
ICDAR3
1997 Non-uniformly Sampled Feature Extraction Method for Kanji Character Recognition
abstract
Describes a non-uniform sampling method for obtaining local orientation features to be used in the recognition of Japanese kanji characters, the proposed method determines feature extraction by sampling features one-dimensionally in a direction perpendicular to a given line orientation. Furthermore, it samples features at non-uniform intervals so as to avoid misidentifying two lines in close proximity as a single line. It has been tested with handwritten kanji characters, and the results show a good ability to distinguish such characters, a task which can easily confuse conventional recognition methods that rely on uniform sampling of local orientation features.
Keiji Yamada
ICDAR1
1996 Analysis of address layout on Japanese handwritten mail-a hierarchical process of hypothesis verification
abstract
This paper describes a new method for analyzing Japanese mail layout. We first classify the many kinds of variations in Japanese mail layout into format variations, extraneous object variations, and arrangement variations of destination address characters. These variations are cyclically dependent on one another, but have insufficient information to fix other variations. To solve these problems, we developed an address layout analysis method using a hierarchical hypothesis verification process, which consists of a format determination process and a destination address character line detection process, hierarchically. This method increased the correct address format determination rate by 5.8% to 86.6% and the correct destination address character line detection rate by 10.2% to 92.8% for 1482 test pieces of mail. This method is practically applied to Japanese mail sorting machine.
Noboru Nakajima, Tetsuo Tsuchiya, Takeshi Kamimura, Keiji Yamada
ICPR4
1995 Optimal sampling intervals for Gabor features and printed Japanese character recognition
abstract
This paper discusses sampling intervals of two-dimensional Gabor features in the two-dimensional pattern, orientation angle, and logarithmic frequency domains. The discussion on the feature stabilities for basic image transformations clarifies the stable range for translation, rotation and scaling. These stable ranges directly lead to sampling intervals for the individual feature domains. Multi-resolution features are constructed in terms of the combination of elements optimally sampled in the feature domains. The features of the optimal sampling intervals are examined in printed Japanese character recognition. The optimal sampling intervals maximize recognition rates at the same time as keeping computational cost low.
Keiji Yamada
ICDAR1
1995 Generalized Learning Vector Quantization
Atsushi Sato, Keiji Yamada
NIPS2
1994 Gabor Feature Stabilities for Basic Image Transformations
abstract
This paper describes the feature stabilities for four basic image transforma-tions, while examining an image feature extraction method using 2D Gabor filters, as an exmple. The basic transformations are intensity change, scaling, translation, and rotation. Based on the consideration about intensity change and scaling, feature normalization methods were proposed. Moreover, opti-mal sampling resolutions are determined according to the discussions. Scal-ing is related with the sampling resolution in the frequency domain and the filter wavelength should be y/2-fold of the smallest filter wavelength, where j is an integer number. The sampling interval in an image domain is a half of a filter wavelength. The sampling interval in a rotation angle domain is TT/10. The Gabor feature extraction method, whose sampling resolutions were determined based on the stability considerations, were examined on printed Japanese character recognition. When sufficient sampling resolu-tion was not attained, the recognition rate became lower. This method can achieve a maximally 96.8 % recognition rate, when every sampling resolution is satisfied. 1
Keiji Yamada
BMVC1
1993 On-line Japanese character recognition experiments by an off-line method based on normalization-cooperated feature extraction
abstract
It is shown that an offline character recognition method is effective for use in an online Japanese character recognition. Major conventional online recognition methods have restricted the number and the order of strokes. The offline method removes these restrictions, based on pattern matching of orientation feature patterns. It has been improved with developments in nonlinear shape normalization, nonlinear pattern matching, and the normalization-cooperated feature extraction method. It was used to examine 52,944 online Kanji characters in 1,064 categories. The recognition rate achieved 95.1%, and the cumulation recognition rate within the best five candidates was 99.3%.>
M. Hamanaka, Keiji Yamada, Jun Tsukumo
ICDAR2
1993 Feedback pattern recognition by inverse recall neural network model
abstract
A feedback pattern recognition method based on an inverse recall neural network model is proposed. The model is a kind of multi-layer feedforward model. This model has three functional components. First is a recognition result generation according to a feedforward process in a multi-layer model. Another component calculates an uncertainty score from the output values. If the uncertainty score is greater than a threshold value, the last component, that is an inverse recall, operates. The inverse recall function produces changes in input values, in order to reduce the uncertainty score. The changes show input parts which are important for more certain recognition but are missed in the input pattern. The feedback method can adjust feature extraction parameters so as to detect the important features shown by the inverse recall network model. Then, features are extracted again by using the modified feature extraction parameter values. These feedforward and feedback processings are repeated until a certain recognition result is obtained. This method was examined for handwritten alpha-numeric recognition and it was found that a rejection ratio can be reduced at the same substitution error ratio.>
Keiji Yamada
ICDAR1
1992 A segmentation method for handwritten Japanese character lines based on transitional information
abstract
The authors propose a method to segment a character line image into individual character images and recognize them. To segment Japanese handwriting accurately, it is necessary to use character recognition results and contexts. However, recognition results might be wrong, or recognition confidence scores might be inaccurate. Dictionary consulting is not sufficient to deal with such ambiguous character recognition results. The paper reports on a method which hierarchically uses transitional information and a word dictionary for recognition results for all possible characters. Experimental results show that, for character line samples written roughly, 91.7% recognition rate is achieved while the recognition rate for a method without transitional information is 78.3%.>
Yayoi Kobayashi, Keiji Yamada, Jun Tsukumo
ICPR (2)2