Ryoichi KAWAHARA


Workflow Extraction for Service Operation Using Multiple Unstructured Trouble Tickets
Akio WATANABE Keisuke ISHIBASHI Tsuyoshi TOYONO Keishiro WATANABE Tatsuaki KIMURA Yoichi MATSUO Kohei SHIOMOTO Ryoichi KAWAHARA 
Publication:   
Publication Date: 2018/04/01
Vol. E101-D  No. 4  pp. 1030-1041
Type of Manuscript:  Special Section PAPER (Special Section on Data Engineering and Information Management)
Category: 
Keyword: 
system managementoperationtrouble ticketworkflowmultiple sequence alignmenthidden markov model
 Summary | Full Text:PDF(1.4MB)

Name Resolution Based on Set of Attribute-Value Pairs of Real-World Information
Ryoichi KAWAHARA Hiroshi SAITO 
Publication:   
Publication Date: 2017/01/01
Vol. E100-B  No. 1  pp. 110-121
Type of Manuscript:  PAPER
Category: Network
Keyword: 
real world informationname resolutioncurse of dimensionalitysearching algorithm
 Summary | Full Text:PDF(792KB)

An Online Framework for Flow Round Trip Time Measurement
Xinjie GUAN Xili WAN Ryoichi KAWAHARA Hiroshi SAITO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2014/10/01
Vol. E97-B  No. 10  pp. 2145-2156
Type of Manuscript:  PAPER
Category: Network
Keyword: 
flow measurementround trip timebloom filterdata stream computation
 Summary | Full Text:PDF(1.8MB)

Optimally Identifying Worm-Infected Hosts
Noriaki KAMIYAMA Tatsuya MORI Ryoichi KAWAHARA Shigeaki HARADA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/08/01
Vol. E96-B  No. 8  pp. 2084-2094
Type of Manuscript:  PAPER
Category: Network Management/Operation
Keyword: 
wormdetectionsamplingoptimum design
 Summary | Full Text:PDF(1.3MB)

Multicast Pre-Distribution VoD System
Noriaki KAMIYAMA Ryoichi KAWAHARA Tatsuya MORI Haruhisa HASEGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/06/01
Vol. E96-B  No. 6  pp. 1459-1471
Type of Manuscript:  PAPER
Category: Network
Keyword: 
rich contentCDNISP
 Summary | Full Text:PDF(1.4MB)

Optimally Designing ISP-Operated CDN
Noriaki KAMIYAMA Tatsuya MORI Ryoichi KAWAHARA Haruhisa HASEGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/03/01
Vol. E96-B  No. 3  pp. 790-801
Type of Manuscript:  PAPER
Category: Network
Keyword: 
content deliveryCDNISP
 Summary | Full Text:PDF(1.5MB)

Analyzing Characteristics of TCP Quality Metrics with Respect to Type of Connection through Measured Traffic Data
Yasuhiro IKEDA Ryoichi KAWAHARA Noriaki KAMIYAMA Tatsuaki KIMURA Tatsuya MORI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/02/01
Vol. E96-B  No. 2  pp. 533-542
Type of Manuscript:  PAPER
Category: Internet
Keyword: 
QoStraffic measurementTCP
 Summary | Full Text:PDF(2.8MB)

Effect of Limiting Pre-Distribution and Clustering Users on Multicast Pre-Distribution VoD
Noriaki KAMIYAMA Ryoichi KAWAHARA Tatsuya MORI Haruhisa HASEGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/01/01
Vol. E96-B  No. 1  pp. 143-154
Type of Manuscript:  PAPER
Category: Network
Keyword: 
VoDcontent distributionmulticast
 Summary | Full Text:PDF(1.8MB)

Traffic Engineering of Peer-Assisted Content Delivery Network with Content-Oriented Incentive Mechanism
Naoya MAKI Takayuki NISHIO Ryoichi SHINKUMA Tatsuya MORI Noriaki KAMIYAMA Ryoichi KAWAHARA Tatsuro TAKAHASHI 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2012/12/01
Vol. E95-D  No. 12  pp. 2860-2869
Type of Manuscript:  Special Section PAPER (Special Section on Parallel and Distributed Computing and Networking)
Category: Network and Communication
Keyword: 
content delivery networkpeer-assisted networkcontents combinationscombining contentstraffic localization
 Summary | Full Text:PDF(845KB)

Analyzing and Reducing the Impact of Traffic on Large-Scale NAT
Ryoichi KAWAHARA Tatsuya MORI Takeshi YADA Noriaki KAMIYAMA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2012/09/01
Vol. E95-B  No. 9  pp. 2815-2827
Type of Manuscript:  PAPER
Category: Network
Keyword: 
large scale NATnumber of active flowstraffic measurement
 Summary | Full Text:PDF(1.6MB)

Effects of Sampling and Spatio/Temporal Granularity in Traffic Monitoring on Anomaly Detectability
Keisuke ISHIBASHI Ryoichi KAWAHARA Tatsuya MORI Tsuyoshi KONDOH Shoichiro ASANO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2012/02/01
Vol. E95-B  No. 2  pp. 466-476
Type of Manuscript:  PAPER
Category: Internet
Keyword: 
anomaly detectionsamplingspatio/temporal granularityhurst parameter
 Summary | Full Text:PDF(1.8MB)

Packet Sampling TCP Flow Rate Estimation and Performance Degradation Detection Method
Ryoichi KAWAHARA Tatsuya MORI Keisuke ISHIBASHI Noriaki KAMIYAMA Hideaki YOSHINO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/05/01
Vol. E91-B  No. 5  pp. 1309-1319
Type of Manuscript:  Special Section PAPER (Special Section on Communication Quality)
Category: Measurement Methodology for Network Quality Such as IP, TCP and Routing
Keyword: 
packet samplingTCP performanceflow measurement
 Summary | Full Text:PDF(1.9MB)

Finding Cardinality Heavy-Hitters in Massive Traffic Data and Its Application to Anomaly Detection
Keisuke ISHIBASHI Tatsuya MORI Ryoichi KAWAHARA Yutaka HIROKAWA Atsushi KOBAYASHI Kimihiro YAMAMOTO Hitoaki SAKAMOTO Shoichiro ASANO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/05/01
Vol. E91-B  No. 5  pp. 1331-1339
Type of Manuscript:  Special Section PAPER (Special Section on Communication Quality)
Category: Measurement Methodology for Network Quality Such as IP, TCP and Routing
Keyword: 
cardinalityanomaly detectiondata stream
 Summary | Full Text:PDF(1.5MB)

Identifying Heavy-Hitter Flows from Sampled Flow Statistics
Tatsuya MORI Tetsuya TAKINE Jianping PAN Ryoichi KAWAHARA Masato UCHIDA Shigeki GOTO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/11/01
Vol. E90-B  No. 11  pp. 3061-3072
Type of Manuscript:  Special Section PAPER (Special Section on Next Generation Network Management)
Category: 
Keyword: 
network measurementpacket samplingflow statisticsa priori distributionBayes' theorem
 Summary | Full Text:PDF(1MB)

QoS-Aware Overlay Routing with Limited Number of Alternative Route Candidates and Its Evaluation
Masato UCHIDA Satoshi KAMEI Ryoichi KAWAHARA Takeo ABE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/09/01
Vol. E89-B  No. 9  pp. 2361-2374
Type of Manuscript:  Special Section PAPER (Special Section on Networking Technologies for Overlay Networks)
Category: 
Keyword: 
overlay routingQoSoverlay network
 Summary | Full Text:PDF(2MB)

Detection of TCP Performance Degradation Using Link Utilization Statistics
Keisuke ISHIBASHI Ryoichi KAWAHARA Takuya ASAKA Masaki AIDA Satoshi ONO Shoichiro ASANO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/01/01
Vol. E89-B  No. 1  pp. 47-56
Type of Manuscript:  PAPER
Category: Network
Keyword: 
TCPperformancelink utilizationmeasurement
 Summary | Full Text:PDF(616.5KB)

Method of Bandwidth Dimensioning and Management for Aggregated TCP Flows with Heterogeneous Access Links
Ryoichi KAWAHARA Keisuke ISHIBASHI Tatsuya MORI Toshihisa OZAWA Takeo ABE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/12/01
Vol. E88-B  No. 12  pp. 4605-4615
Type of Manuscript:  PAPER
Category: Internet
Keyword: 
TCP performanceprocessor-sharing modelheterogeneous access linksbandwidth dimensioning and management
 Summary | Full Text:PDF(1.3MB)

A Method of Bandwidth Dimensioning and Management Using Flow Statistics
Ryoichi KAWAHARA Keisuke ISHIBASHI Takuya ASAKA Shuichi SUMITA Takeo ABE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/02/01
Vol. E88-B  No. 2  pp. 643-653
Type of Manuscript:  PAPER
Category: Network Management/Operation
Keyword: 
TCP performancebandwidth dimensioning and managementnumber of active flows
 Summary | Full Text:PDF(888KB)

On the Characteristics of Internet Traffic Variability: Spikes and Elephants
Tatsuya MORI Ryoichi KAWAHARA Shozo NAITO Shigeki GOTO 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2004/12/01
Vol. E87-D  No. 12  pp. 2644-2653
Type of Manuscript:  Special Section PAPER (Special Section on New Technologies and their Applications of the Internet)
Category: Traffic Measurement and Analysis
Keyword: 
measurementanalysistrafficspikeselephant flow
 Summary | Full Text:PDF(1MB)

An Adaptive Load Balancing Method for Multiple Paths Using Flow Statistics and Its Performance Analysis
Ryoichi KAWAHARA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/07/01
Vol. E87-B  No. 7  pp. 1993-2003
Type of Manuscript:  PAPER
Category: Network
Keyword: 
load balancingTCPMPLS
 Summary | Full Text:PDF(1.9MB)

A Method of IP Traffic Management Using the Relationship between TCP Flow Behavior and Link Utilization
Ryoichi KAWAHARA Keisuke ISHIBASHI Takuya ASAKA Katsunori ORI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2003/11/01
Vol. E86-B  No. 11  pp. 3244-3256
Type of Manuscript:  PAPER
Category: Network Management/Operation
Keyword: 
TCP performanceIPtraffic managementnumber of active flows
 Summary | Full Text:PDF(1.5MB)

A Scalable IP Traffic Control Method for Weighted Bandwidth Allocation per Flow
Ryoichi KAWAHARA Naohisa KOMATSU 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/10/01
Vol. E84-B  No. 10  pp. 2815-2829
Type of Manuscript:  PAPER
Category: Internet
Keyword: 
weighted bandwidth allocationdifferentiated services architectureestimated number of flows
 Summary | Full Text:PDF(911.5KB)

Performance of TCP/IP over ATM over an ADSL
Ryoichi KAWAHARA Hiroshi SAITO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2000/02/25
Vol. E83-B  No. 2  pp. 140-154
Type of Manuscript:  Special Section PAPER (IEICE/IEEE Joint Special Issue on Recent Progress in ATM Technologies)
Category: IP/ATM
Keyword: 
ADSLATMTCPbandwidth variationsABRABR switch algorithmGFC
 Summary | Full Text:PDF(1.6MB)

Method of Implementing GFR Service in Large-Scale Networks Using ABR Control Mechanism and Its Performance Analysis
Ryoichi KAWAHARA Yuki KAMADO Masaaki OMOTANI Shunsaku NAGATA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1999/12/25
Vol. E82-B  No. 12  pp. 2081-2094
Type of Manuscript:  PAPER
Category: Communication Networks and Services
Keyword: 
ATMGFRABRlarge-scale networksVS/VDexplicit rate controlWRR
 Summary | Full Text:PDF(1.3MB)

Overload Control for the Intelligent Network and Its Analysis by Simulation
Ryoichi KAWAHARA Takuya ASAKA Shuichi SUMITA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1995/04/25
Vol. E78-B  No. 4  pp. 494-503
Type of Manuscript:  Special Section PAPER (Special Issue on Traffic and Quality Control for Communication Networks)
Category: 
Keyword: 
overload controlIntelligent Networkoverloaded SCPacceptable number of callsvarious types of services
 Summary | Full Text:PDF(770.1KB)