著者

LONG Teng LIU Yongxu YANG Xiaopeng

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.95, no.1, pp.97-105, 2012-01-01

被引用文献数

3

---

The range-dependence of clutter spectrum for forward-looking airborne radar strongly affects the accuracy of the estimation of clutter covariance matrix at the range under test, which results in poor clutter suppression performance if the conventional space-time adaptive processing (STAP) algorithms were applied, especially in the short range cells. Therefore, a new STAP algorithm with clutter spectrum compensation by utilizing knowledge-aided subspace projection is proposed to suppress clutter for forward-looking airborne radar in this paper. In the proposed method, the clutter covariance matrix of the range under test is firstly constructed based on the prior knowledge of antenna array configuration, and then by decomposing the corresponding space-time covariance matrix to calculate the clutter subspace projection matrix which is applied to transform the secondary range samples so that the compensation of clutter spectrum for forward-looking airborne radar is accomplished. After that the conventional STAP algorithm can be applied to suppress clutter in the range under test. The proposed method is compared with the sample matrix inversion (SMI) and the Doppler Warping (DW) methods. The simulation results show that the proposed STAP method can effectively compensate the clutter spectrum and mitigate the range-dependence significantly.

著者

CHEN Chien-Ming KU Wei-Chi

出版者

一般社団法人電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.85, no.11, pp.2519-2521, 2002-11-01

被引用文献数

26

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Recently, Lin et al. addressed two weaknesses of a new strong-password authentication scheme, the SAS protocol, and then proposed an improved one called the OSPA (Optimal Strong-Password Authentication) protocol. However, we find that both the OSPA protocol and the SAS protocol are vulnerable to the stolen-verifier attack.

著者

Makoto NARUSE Masashi AONO Song-Ju KIM

出版者

一般社団法人 電子情報通信学会

雑誌

IEICE Transactions on Communications (ISSN:09168516)

巻号頁・発行日

vol.E96.B, no.11, pp.2724-2732, 2013-11-01 (Released:2013-11-01)

参考文献数

34

被引用文献数

1 5

---

Nature-inspired devices and architectures are attracting considerable attention for various purposes, including the development of novel computing techniques based on spatiotemporal dynamics, exploiting stochastic processes for computing, and reducing energy dissipation. This paper demonstrates that networks of optical energy transfers between quantum nanostructures mediated by optical near-field interactions occurring at scales far below the wavelength of light could be utilized for solving a constraint satisfaction problem (CSP), the satisfiability problem (SAT), and a decision making problem. The optical energy transfer from smaller quantum dots to larger ones, which is a quantum stochastic process, depends on the existence of resonant energy levels between the quantum dots or a state-filling effect occurring at the larger quantum dots. Such a spatiotemporal mechanism yields different evolutions of energy transfer patterns in multi-quantum-dot systems. We numerically demonstrate that networks of optical energy transfers can be used for solution searching and decision making. We consider that such an approach paves the way to a novel physical informatics in which both coherent and dissipative processes are exploited, with low energy consumption.

著者

HUANG Min Li LEE Jin SETIAWAN Hendra OCHI Hiroshi PARK Sin-Chong

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.93, no.4, pp.948-960, 2010-04-01

参考文献数

15

被引用文献数

1 2

---

With the growing demand for high-performance multimedia applications over wireless channels, we need to develop a Medium Access Control (MAC) system that supports high throughput and quality of service enhancements. This paper presents the standard analysis, design architecture and design issues leading to the implementation of an IEEE 802.11e based MAC system that supports MAC throughput of over 100Mbps. In order to meet the MAC layer timing constraints, a hardware/software co-design approach is adopted. The proposed MAC architecture is implemented on the Xilinx Virtex-II Pro Field-Programmable Gate Array (FPGA) (XC2VP70-5FF1704C) prototype, and connected to a host computer through an external Universal Serial Bus (USB) interface. The total FPGA resource utilization is 11, 508 out of 33, 088 (34%) available slices. The measured MAC throughput is 100.7Mbps and 109.2Mbps for voice and video access categories, transmitted at a data rate of 260Mbps based on IEEE 802.11n Physical Layer (PHY), using the contention-based hybrid coordination function channel access mechanism.

著者

Hitoshi OHNISHI Kaname MOCHIZUKI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Communications (ISSN:09168516)

巻号頁・発行日

vol.E90-B, no.1, pp.12-20, 2007-01-01

被引用文献数

33

---

The performance of a force feedback system is disturbed by delay that arises from the time required for transmission and processing of data. We used a psychophysical method to measure how much a user's subjective impression of elasticity associated with delays of feedback force deviated from the original physical elasticity. The results show that users' point of subjective equality (PSE) for their subjective impression of elasticity decreased as the delay of feedback force increased. We proposed a model that estimates the PSE of elasticity from the variables that can be physically measured. Another experiment was conducted to examine the model's prediction, which the results supported.

著者

YASUI Tadahiko NAKANO Yoshiaki

出版者

一般社団法人電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.82, no.2, pp.306-316, 1999-02-25

被引用文献数

24

---

By adopting a network architecture in which not only a calling but also a called terminal can select a wavelength, a novel WDM network becomes possible. This we call Wavelength Assignment Photonic Network (WAPN). In this network wavelengths are a kind of network resources and according to requests from terminals, wavelengths are allocated or assigned to calls. In the system a wavelength used for a call is to be used for another call after the call is terminated. By supplying wavelengths to the home, a bitrate-free, protocol free or even transmission method free network can be realized. In this paper, from a viewpoint of S/N or Q factor, WAPN is evaluated with special focus on the node architecture -i.e., from the viewpoint of node size, number of switching stages, crosstalk level, and losses, because the allowable node size is the crucial issue to decide the whole network capacity. After brief explanations of this proposed system, the model for system evaluations will be established and a node system is to be evaluated for some practical parameter values considering especially traffic characteristics of a node. As a result of this study a node system with capacity more than 100 thousands erl (about 20 Tbps throughput) can be constructed using present available technologies, which will enable us to construct large WAPN network with radius of 2,000 km and subscribers of about 50 millions.

著者

Sang-Keun HAN KeeChan PARK Young-Hyun JUN Bai-Sun KONG

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Electronics (ISSN:09168516)

巻号頁・発行日

vol.E95-C, no.11, pp.1824-1826, 2012-11-01

---

This paper introduces novel high-speed and low-power boosted level converters for use in dual-supply systems. The proposed level converters adopt a voltage boosting at the gate of pull-down transistors to improve driving speed and reduce contention problem. Comparison results in a 0.13-µm CMOS process indicated that the proposed level converters provided up to 70% delay reduction with up to 57% power-delay product (PDP) reduction as compared to conventional level converters.

著者

Komain PIBULYAROJANA KIMURA Shigetomo EBIHARA Yoshihiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E80.B, no.1, pp.116-126, 1997-01

---

Banyan networks are used in multiprocessor computer applications for an ATM switching. In this paper, we study the continuous blocking of the the first n-stage which makes the performance of the banyan networks decrease. We use the 2-dilated banyan networks into the banyan networks to remove the the continuous blocking of the the first n-stage. We call the new networks as the hybrid dilated banyan networks. We explain how to analyze the throughput of this networks at each stage. Based on the analysis of input rate and output rate at each stage, we can design the hybrid dilated banyan networks with the desirable output rate. The result of analysis shows the hybrid dilated banyan networks have higher performance and feasibility than the banyan networks.

著者

PIBULYAROJANA Komain KIMURA Shigetomo EBIHARA Yoshihiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E80.B, no.12, pp.1816-1818, 1997-12

---

Many switching networks are currently designed to support ATM architectures. In this letter, we propose the performance improvement of a network called hybrid dilated banyan network with bypasses at the stage of 4×2 re-arrangeable output switch. Our letter also includes the performance analysis of the improved hybrid dilated banyan network.

著者

CHEN Hongbing KIMURA Shigetomo EBIHARA Yoshihiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E81.B, no.1, pp.45-57, 1998-01

---

The Optimal Packet Length (OPL) in packet-switched communication systems has been studied in the literature from various aspects. In this paper, we consider the trade-off between packet length and data transmission delay in a high-speed communication system. To simplify the analysis of the mean data transmission de[ay, the model is limited to a point-to-point communication system, in which each node complies with the OSI reference model. In order to study the relationship between the OPL and the number of modules performing each protocol, two model communication systems are discussed. In one each node contains two layered protocol modules, and in the other three. Moreover, for both models, the mean data transmission delay is analyzed for two cases depending on whether or not the DLC layer or the network layer performs retransmissions. After studying the OPL which minimizes the mean data transmission delay in each case, we discuss the relationships between the OPLs and the various protocol parameters.

著者

SUN Zhenqiang KIMURA Shigetomo EBIHARA Yoshihiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E82.B, no.9, pp.1432-1438, 1999-09

---

This paper presents the generator polynomial matrices and the upper bound on the constraint length of punctured convolutional codes (PCCs), respectively. By virtue of these properties, we provide the puncturing realizations of the good known nonsystematic and systematic high rate CCs.

著者

PIBULYAROJANA Komain KIMURA Shigetomo EBIHARA Yoshihiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E83.B, no.7, pp.1474-1487, 2000-07

---

Banyan networks and their improved switches such as 2-dilated banyan networks are usually constructed by a self-routing mechanism, and provide a high multiplexing transmission capacity to ATM networks.Due to cell blocking in the switching elements in these banyan networks, however, cell loss is occurred and then the throughput of each network is decreased.To improve this problem, we have introduced bypasses to the original and the 2-dilated banyan networks.This paper focuses on the position of the bypasses in these banyan networks and proposes the one-bypass-connection methods in order to minimize cell transfer delay caused by the bypasses.We also analyze output rate of each network and show that the bypass method gives network designers flexible selections for network performance and transfer delay.

著者

OHZAHATA Satoshi KIMURA Shigetomo EBIHARA Yoshihiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E84.B, no.4, pp.752-759, 2001-04

---

Mobile IP can provide macro mobility for a mobile node (MN) instead of the original IP communication. Since the orignal Mobile IP does not consider micro mobility, it can not avoid handoff latency. The latency causes packets loss or large variations of the delivery times. To prevent it, several methods are proposed to improve the orignal Mobile IP handoff method. In our previous work, we proposed the fast registration method which enabled an MN to have two communication routes from the home agent (HA), and realized lower latency in the handoff procedures by the doublecasting on the two communication routes. But, the simulation results also show that the proposed method still has large overhead. This paper presents a seamless handoff method, which improves the fast registration method. In the method, the MN can know the first and second suitable base stations for the communications through information from the MAC media. The control helps for seamless handoff in case that the MN must frequently change its current base station (BS). The computer simulations for Constant Bit Rate (CBR) over real-time transport protocol (RTP) flow shows that the proposed method provides no handoff latency with low overhead even if the MN must occur frequcnt handoffs in a second.

著者

SUN Zhenqiang KIMURA Shigetomo EBIHARA Yoshihiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E84.B, no.5, pp.1319-1327, 2001-05

---

In the wireless asynchronous transfer mode (ATM) networks, a custom data link control (DLC) layer protocol with stronger error correction ability is needed for mitigating the affect of radio channel errors. This paper applies punctured turbo code schemes to the protection of the header and various payloads in wireless ATM cell, which are realized by the combination of programmable interleaving and puncturing. Their performance is analyzed for Rayleigh fading channel, which shows more significant reduction in cell loss rate (CLR) than the previous systems. Our proposal also provides good balance designs for CLR and the payload bit error rate (BER), and offers potential for future evolutionary improvement of the wireless ATM codingscheme.

著者

OHZAHATA Satoshi KIMURA Shigetomo EBIHARA Yoshihiko KAWASHIMA Konosuke

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E90.B, no.8, pp.2070-2080, 2007-08

被引用文献数

1 2

---

In this paper we propose a cross-layer retransmission control for TCP communication over a wireless link. With our proposed control, a retransmission delay for lost packet is reduced, packet losses in the wireless link are eliminated and all packets are delivered in the correct order. No change is required to TCP itself or to the sender. Our proposed method is implemented in a queue between the media access control (MAC) layer and logical link layer in a base station, and is designed to assist local retransmission control in the MAC layer. Computer simulations show that our proposed method can maximally use the bandwidth of the wireless link under high bit error rates conditions with conventional TCP control. The fairness problem of TCP communication between connections with different bit error rates in a wireless link is also improved, and MAC level fairness is also controllable.

著者

SHOMURA Yusuke WATANABE Yoshinori YOSHIDA Kenichi

出版者

Institute of Electronics, Information and Communication Engineers

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E91.B, no.6, pp.1896-1905, 2008

被引用文献数

12 11

---

Abnormal traffic that causes various problems on the Internet, such as P2P flows, DDoS attacks, and Internet worms, is increasing; therefore, the importance of methods that identify and control abnormal traffic is also increasing. Though the application of frequent-itemset-mining techniques is a promising way to analyze Internet traffic, the huge amount of data on the Internet prevents such techniques from being effective. To overcome this problem, we have developed a simple frequent-itemset-mining method that uses only a small amount of memory but is effective even with the large volumes of data associated with broadband Internet traffic. Using our method also involves analyzing the number of distinct elements in the itemsets found, which helps identify abnormal traffic. We used a cache-based implementation of our method to analyze actual data on the Internet and demonstrated that such an implementation can be used to provide on-line analysis of data while using only a small amount of memory.

著者

SUZUKI Kazuya JIBIKI Masahiro YOSHIDA Kenichi

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E93.B, no.5, pp.1085-1094, 2010-05

被引用文献数

2

---

The availability of IP networks has increased its importance due to the evolving use of real-time and mission-critical applications on IP networks. Methods for preparing alternate routing tables that can be used for fast restoration from link failures have been investigated. In such methods, each node has to compute a number of alternate routing tables in advance since they have to prepare for each potential failure. The resulting huge number of alternate routing tables has prevented these methods from being deployed. In this paper, we propose a method for reducing the number of alternate routing tables for link failure. It analyzes three types of shortest path trees on the basis of link-state information. We show that the number of alternate routing tables can be reduced to 1/100, on average, from that with the conventional method, and that they are small enough to be stored in the memory of IP routers.

著者

ROMANOV Anton OKAMOTO Eiji

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E93.B, no.6, pp.1411-1421, 2010-06

---

With the increasing demand for services provided by communication networks, quality and reliability of such services as well as confidentiality of data transfer are becoming ones of the highest concerns. At the same time, because of growing hacker's activities, quality of provided content and reliability of its continuous delivery strongly depend on integrity of data transmission and availability of communication infrastructure, thus on information security of a given IT landscape. But, the amount of resources allocated to provide information security (like security staff, technical countermeasures and etc.) must be reasonable from the economic point of view. This fact, in turn, leads to the need to employ a forecasting technique in order to make planning of IT budget and short-term planning of potential bottlenecks. In this paper we present an approach to make such a forecasting for a wide class of information security related incidents (ISRI) — unambiguously detectable ISRI. This approach is based on different auto regression models which are widely used in financial time series analysis but can not be directly applied to ISRI time series due to specifics related to information security. We investigate and address this specifics by proposing rules (special conditions) of collection and storage of ISRI time series, adherence to which improves forecasting in this subject field. We present an application of our approach to one type of unambiguously detectable ISRI — amount of spam messages which, if not mitigated properly, could create additional load on communication infrastructure and consume significant amounts of network capacity. Finally we evaluate our approach by simulation and actual measurement.

著者

YAMADA Takeshi KASUYA Yuki SHINOHARA Yuki KITAWAKI Nobuhiko

出版者

電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.E93.B, no.6, pp.1367-1372, 2010-06

被引用文献数

1 4

---

This paper describes non-reference objective quality evaluation for noise-reduced speech. First, a subjective test is conducted in accordance with ITU-T Rec. P.835 to obtain the speech quality, the noise quality, and the overall quality of noise-reduced speech. Based on the results, we then propose an overall quality estimation model. The unique point of the proposed model is that the estimation of the overall quality is done only using the previously estimated speech quality and noise quality, in contrast to conventional models, which utilize the acoustical features extracted. Finally, we propose a non-reference objective quality evaluation method using the proposed model. The results of an experiment with different noise reduction algorithms and noise types confirmed that the proposed method gives more accurate estimates of the overall quality compared with the method described in ITU-T Rec. P.563.

著者

VIXIE Paul

出版者

一般社団法人電子情報通信学会

雑誌

IEICE transactions on communications (ISSN:09168516)

巻号頁・発行日

vol.89, no.4, pp.1144-1149, 2006-04-01

---

Authority zones in the Domain Name System must be declared to have one or more authoritative name servers, usually consisting of one primary name server and several secondary name servers. These name servers are expected to synchronize zone data using DNS's zone transfer protocols, but the configuration of these synchronization relationships depends upon out of band information and manual processes. This paper describes a way to create name service federations such that a varying set of zones offered by a primary name server can be automatically configured for synchronization by secondary name servers. A sample implementation based on ISC BIND and Perl is described.