著者

Hajime Taira Yuki Inoue Akihiko Torii Masatoshi Okutomi

出版者

Information Processing Society of Japan

雑誌

IPSJ Transactions on Computer Vision and Applications (ISSN:18826695)

巻号頁・発行日

vol.7, pp.84-88, 2015 (Released:2015-07-27)

参考文献数

18

被引用文献数

1 15

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In this work, we proposes a simple yet effective method for improving performance of local feature matching among equirectangular cylindrical images, which brings more stable and complete 3D reconstruction by incremental SfM. The key idea is to exiplictly generate synthesized images by rotating the spherical panoramic images and to detect and describe features only from the less distroted area in the rectified panoramic images. We demonstrate that the proposed method is advantageous for both rotational and translational camera motions compared with the standard methods on the synthetic data. We also demonstrate that the proposed feature matching is beneficial for incremental SfM through the experiments on the Pittsburgh Reserach dataset.

著者

Eiko Takaoka Takayuki Yonezu Takafumi Namekawa

出版者

Information Processing Society of Japan

雑誌

IPSJ Online Transactions (ISSN:18826660)

巻号頁・発行日

vol.8, pp.1-8, 2015 (Released:2015-01-27)

参考文献数

25

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We designed, developed, and evaluated computer programming education at high schools and universities in 2012 and 2013 to offer students an opportunity to experience practical programming. We provided a programming course to a high school, preparing content-rich materials. In order to generate motivation for learning in students, we set “to create practical applications” as a goal of the course. In 2012, only a few students could create practical applications; however, in 2013, we improved the teaching methods and by the end of the course, almost half of the participants were able to produce practical applications. In addition, some students applied their programs for the Live E! science contest and they received prizes in 2012 and two students applied and one of them received a prize in 2013. An additional notable outcome of the course that we provided was the extent to which first-year students became interested in programming.

著者

Takuya Kuwahara Yukino Baba Hisashi Kashima Takeshi Kishikawa Junichi Tsurumi Tomoyuki Haga Yoshihiro Ujiie Takamitsu Sasaki Hideki Matsushima

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.26, pp.306-313, 2018 (Released:2018-03-15)

参考文献数

17

被引用文献数

18

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Modern vehicles are equipped with Electronic Control Units (ECUs) and external communication devices. The Controller Area Network (CAN), a widely used communication protocol for ECUs, does not have a security mechanism to detect improper packets; if attackers exploit the vulnerability of an ECU and manage to inject a malicious message, they are able to control other ECUs to cause improper operation of the vehicle. With the increasing popularity of connected cars, it has become an urgent matter to protect in-vehicle networks against security threats. In this paper, we study the applicability of statistical anomaly detection methods for identifying malicious CAN messages in in-vehicle networks. We focus on intrusion attacks of malicious messages. Because the occurrence of an intrusion attack certainly influences the message traffic, we focus on the number of messages observed in a fixed time window to detect intrusion attacks. We formalize features to represent a message sequence that incorporates the number of messages associated with each receiver ID. We collected CAN message data from an actual vehicle and conducted a quantitative analysis of the methods and the features in practical situations. The results of our experiments demonstrated our proposed methods provide fast and accurate detection in various cases.

著者

Tatsuya Abe Toshiyuki Maeda

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.25, pp.244-255, 2017 (Released:2017-02-15)

参考文献数

49

被引用文献数

5

---

Relaxed memory consistency models specify effects of executions of statements among threads, which may or may not be reordered. Such reorderings may cross loop iterations. To the best of our knowledge, however, there exists no concurrent program logic which explicitly handles the reorderings across loop iterations. This paper provides concurrent program logic for relaxed memory consistency models that can represent, for example, total store ordering, partial store ordering, relaxed memory ordering, and acquire and release consistency. There are two novel aspects to our approach. First, we translate a concurrent program into a family of directed acyclic graphs with finite nodes and transitive edges called program graphs according to a memory consistency model that we adopt. These represent dependencies among statements which represent reorderings of not only statements but also visibility of their effects. Second, we introduce auxiliary variables that temporarily buffer the effects of write operations on shared memory, and explicitly describe the reflections of the buffered effects to shared memory. Specifically, we define a small-step operational semantics for the program graphs with the introduced auxiliary variables, then define sound and relatively complete logic to the semantics.

著者

EricS.Fukuda Hiroaki Inoue Takashi Takenaka Dahoo Kim Tsunaki Sadahisa Tetsuya Asai Masato Motomura

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.23, no.2, pp.143-152, 2015-03-15

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Memcached has been widely accepted as a technology to improve the response speed of web servers by caching data on DRAMs in distributed servers. Because of its importance, the acceleration of memcached has been studied on various platforms. Among them, FPGA looks the most attractive platform to run memcached, and several research groups have tried to obtain a much higher performance than that of CPU out of it. The difficulty encountered there, however, is how to manage large-sized memory (gigabytes of DRAMs) from memcached hardware built in an FPGA. Some groups are trying to solve this problem by using an embedded CPU for memory allocation and another group is employing an SSD. Unlike other approaches that try to replace memcached itself on FPGAs, our approach augments the software memcached running on the host CPU by caching its data and some operations at the FPGA-equipped network interface card (NIC) mounted on the server. The locality of memcached data enables the FPGA NIC to have a fairly high hit rate with a smaller memory. In this paper, we describe the architecture of the proposed NIC cache, and evaluate the effectiveness with a standard key-value store (KVS) benchmarking tool. Our evaluation shows that our system is effective if the workload has temporal locality but does not handle workloads well without such a characteristic. We further propose methods to overcome this problem and evaluate them. As a result, we estimate that the latency improved by up to 3.5 times over software memcached running on a high performance CPU.Memcached has been widely accepted as a technology to improve the response speed of web servers by caching data on DRAMs in distributed servers. Because of its importance, the acceleration of memcached has been studied on various platforms. Among them, FPGA looks the most attractive platform to run memcached, and several research groups have tried to obtain a much higher performance than that of CPU out of it. The difficulty encountered there, however, is how to manage large-sized memory (gigabytes of DRAMs) from memcached hardware built in an FPGA. Some groups are trying to solve this problem by using an embedded CPU for memory allocation and another group is employing an SSD. Unlike other approaches that try to replace memcached itself on FPGAs, our approach augments the software memcached running on the host CPU by caching its data and some operations at the FPGA-equipped network interface card (NIC) mounted on the server. The locality of memcached data enables the FPGA NIC to have a fairly high hit rate with a smaller memory. In this paper, we describe the architecture of the proposed NIC cache, and evaluate the effectiveness with a standard key-value store (KVS) benchmarking tool. Our evaluation shows that our system is effective if the workload has temporal locality but does not handle workloads well without such a characteristic. We further propose methods to overcome this problem and evaluate them. As a result, we estimate that the latency improved by up to 3.5 times over software memcached running on a high performance CPU.

著者

Jun Liu Kensuke Fukuda

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.26, pp.148-157, 2018 (Released:2018-02-15)

参考文献数

35

被引用文献数

1

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To enhance Internet security, researchers have largely emphasized diverse cyberspace monitoring approaches to observe cyber attacks and anomalies. Among them darknet provides an effective passive monitoring one. Darknets refer to the globally routable but still unused IP address spaces. They are often used to monitor unexpected incoming network traffic, and serve as an effective network traffic measurement approach for viewing certain remote network security activities. Previous works in this field discussed possible causes (i.e., anomalies) of darknet traffic and applied their classification schemes on short-term traces. Our interest lies, however, in how darknet traffic has evolved and the effectiveness of a darknet traffic taxonomy for longitudinal data. To reach these goals, we propose a simple darknet traffic taxonomy based on network traffic rules, and evaluate it with two darknet traces: one covering 12 years since 2006, while the other covering 11 years since 2007. The evaluation results reveal the effectiveness of this taxonomy: we are able to label over 94% of all source IPs with anomalies defined by the taxonomy, leaving the unlabeled source ratio low. We also examine the evolution of different anomalies since 2006 (especially in recent years), analyze the temporal and spatial dependency and parameter dependency of darknet traffic, and conclude that most sources in the datasets are characterized by just one or two anamalies with simple attack mechanisms. Moreover, we compare the taxonomy with a one-way traffic analysis tool (i.e., iatmon) to better understand their differences.

著者

Xuan Thien Phan Kensuke Fukuda

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.25, pp.182-190, 2017 (Released:2017-02-15)

参考文献数

29

被引用文献数

16

---

Fine-grained network traffic monitoring is important for efficient network management in software-defined networking (SDN). The current SDN architecture, i.e., OpenFlow, relies on counters in the flow entries of forwarding tables for such monitoring tasks. This is not efficient nor flexible since the packet-header fields that users aim for monitoring are not always the same or overlap with those in OpenFlow match fields, which is designed for forwarding as a higher priority. This inflexibility may result in unnecessary flow entries added to switches for monitoring and controller-switch monitoring-based communication overhead, which may cause the communication channel to become a bottleneck, especially when the network includes a large number of switches. We propose SDN-Mon, a SDN-based monitoring framework that decouples monitoring from existing forwarding tables, and allows more fine-grained and flexible monitoring to serve a variety of network-management applications. SDN-Mon allows the controller to define the arbitrary sets of monitoring match fields based on the requirements of controller applications to flexibly monitor traffic. In SDN-Mon, some monitoring processes are selectively delegated to SDN switches to leverage the computing processor of the switch and avoid an unnecessary overhead in the controller-switch communication for monitoring. We implemented SDN-Mon and evaluated its performance on Lagopus switch, a high-performance software switch.

著者

Toyoda Kentaroh Sasase Iwao

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.23, no.1, pp.81-92, 2015

被引用文献数

5

---

VoIP/SIP is taking place of conventional telephony because of very low call charge but it is also attractive for SPITters who advertise or spread phishing calls toward many callees. Although there exist many feature-based SPIT detection methods, none of them provides the flexibility against multiple features and thus complex threshold settings and training phases cannot be avoided. In this paper, we propose an unsupervised and threshold-free SPITters detection scheme based on a clustering algorithm. Our scheme does not use multiple features directly to trap SPITters but uses them to find the dissimilarity among each caller pair and tries to separate the callers into a SPITters cluster and a legitimate one based on the dissimilarity. By computer simulation, we show that the combination of Random Forests dissimilarity and PAM clustering brings the best classification accuracy and our scheme works well when the SPITters account for more than 20% of the entire caller.

著者

Hajime Fujita Yutaka Ishikawa

出版者

Information Processing Society of Japan

雑誌

IPSJ Online Transactions (ISSN:18826660)

巻号頁・発行日

vol.4, pp.73-83, 2011 (Released:2011-03-18)

参考文献数

22

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In this paper we propose DTS (Distributed TCP Splicing), a new mechanism for performing content-aware TCP connection switching in a broadcast-based single IP address cluster. Broadcast-based design enables each cluster node to continue to provide services to clients even when other nodes in the cluster fail. Each connection request from a client is first distributed among the cluster using the consistent hashing method, in order to share the request inspection workload. Then the connection is transferred to an appropriate node according to the content of the request. DTS is implemented on the Linux kernel module and does not require any modification to the main kernel code, server applications, or client applications. With an 8-node server configuration, a DTS cluster with multiple request inspectors achieves about 3.4 times higher connection throughput compared to the single inspector configuration. A SPECweb 2005 Support benchmark is also conducted with a four node cluster, where DTS reduces the total amount of disk accesses with a locality-aware request distribution and almost halves the number of file downloads that fail to meet the speed requirement.

著者

Stephen Marsh Pamela Briggs Khalil El-Khatib Babak Esfandiari John A. Stewart

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.19, pp.231-252, 2011 (Released:2011-07-06)

参考文献数

40

被引用文献数

1 8

---

Device Comfort is a concept that uses an enhanced notion of trust to allow a personal (likely mobile) device to better reason about the state of interactions and actions between it, its owner, and the environment. This includes allowing a better understanding of how to manage information in fine-grained context as well as addressing the personal security of the user. To do this, it forms a unique relationship with the user, focusing on the device's judgment of user in context. This paper introduces and defines Device Comfort, including an examination of what makes up the comfort of a device in terms of trust and other considerations, and discusses the uses of such an approach. It also presents some ongoing developmental work in the concept, and an initial formal model of Device Comfort, its makeup and behaviour.

著者

Hajime Tazaki Rodney Van Meter Ryuji Wakikawa Keisuke Uehara Jun Murai

出版者

Information Processing Society of Japan

雑誌

Journal of Information Processing (ISSN:18826652)

巻号頁・発行日

vol.19, pp.118-128, 2011 (Released:2011-03-09)

参考文献数

26

---

MANET for NEMO (MANEMO) is a new type of network that integrates multi-hop mobile wireless networks with global connectivity provided by Network Mobility (NEMO). Two factors limit the scalability of MANEMO: the volatility of topologically correct global addresses, and excessive traffic load caused by inefficient use of nested tunnels and the consequent redundant routing of packets. We propose NAT-MANEMO, which solves both problems by applying NAT for some mobile router addresses, bypassing tunnel nesting. This approach retains global addresses for mobile end nodes, preserving application transparency, and requires only minimal modification to existing specifications. Our ideas are evaluated using simulation and a proof of concept implementation. The simulation shows the additional signaling overhead for the route optimization introduced by our proposal is negligible compare to the bandwidth of an IEEE 802.11 link. The implementation confirms that route optimization reduces latency and improves throughput.

著者

Yuichi Yaguchi Kenta Iseki Ryuichi Oka

出版者

Information Processing Society of Japan

雑誌

IPSJ Transactions on Computer Vision and Applications (ISSN:18826695)

巻号頁・発行日

vol.2, pp.1-14, 2010 (Released:2010-02-04)

参考文献数

39

被引用文献数

1 5

---

A two-dimensional continuous dynamic programming (2DCDP) method is proposed for two-dimensional (2D) spotting recognition of images. Spotting recognition is the simultaneous segmentation and recognition of an image by optimal pixel matching between a reference image and an input image. The proposed method performs optimal pixel-wise image matching and 2D pixel alignment, which are not available in conventional algorithms. Experimental results show that 2DCDP precisely matches the pixels of nonlinearly deformed images.

著者

Hiroshi Uehara Kenichi Yoshida

出版者

Information Processing Society of Japan

雑誌

IPSJ Digital Courier (ISSN:13497456)

巻号頁・発行日

vol.2, pp.145-154, 2006 (Released:2006-03-08)

参考文献数

15

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This paper proposes a method for creating the viewers' side annotations that reflect viewers' attentions on TV dramas. Internet bulletin boards are filled with large amount of viewers' dialogues concerning TV programs. Our approach is to extract the viewers' attention embedded in these dialogues and express them in the form of the graphical structures called attention graphs. The attention graphs act as viewers' side annotations. Viewers' side annotations assist in providing viewers with hints to locate their favorite scenes in full-length TV programs. In general, Internet bulletin boards are described without any particular order and are expressed in a poor grammatical manner. Our approach is to statistically recognize the notable frequencies of the words which represent viewers' attentions out from such unstructured documents. Attention graphs are the outcome of this approach. Attention graphs are evaluated by three types of tests. The test results demonstrate that attention graphs sufficiently act as viewers' side annotations, in terms of pointing out which scene the viewers pay attention to and clarifying how deeply viewers are impressed by the scenes.