著者

鈴木 拓弥 小林 真 長嶋 祐二

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J101-D, no.3, pp.560-568, 2018-03-01

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聴覚障害学生を対象とした授業では,聴覚の代行として視覚情報による支援が中心となる.しかし,実技演習時の細かな操作を教示する場合やタイミングが重要とされる場面では,視覚情報を中心とした手法では不十分な教示状態があることが分かってきた.本論文では,視覚によって提示される情報保障の一部を触覚によって伝達する手法を考案し,教員の実演内容を触覚情報によって提示する教示支援システムSZCAT (SynchroniZed Click Action Transmitter)を開発した.そして,開発したシステムの効果に関する基礎的研究として,従来からの手法と,触覚情報を追加した手法とを比較し,触覚情報提示の有効性を検証した.その結果,触覚情報を追加したことによる視線移動の減少効果や,教示内容の見逃しや誤認識を軽減させる効果について確認できた.

著者

瀧田 愼 大熊 浩也 森井 昌克

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J103-D, no.4, pp.291-300, 2020-04-01

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キャッシュレス決済の手段としてQRコードの利用が進められている.QRコードは高い認識率を誇るものの,人は保存された情報をデコーダなしで知ることができない.悪意のあるものが偽装したQRコードを作成し,利用者の不用意な操作により悪性サイトに誘導することや不正送金させることが問題となっている.QRコードを利用した決済が広まりつつある中で,その安全性を十分に検証する必要がある.本研究では誤り訂正符号の性質を用いて,二つの情報を出力するQRコードを開発している.提案QRコードを悪用すると,通常は正常なサイトに誘導するが,稀に悪意のあるサイトに誘導する偽装QRコードを作成することができる.悪意のあるイベントの再現性が低いため,偽装QRコードの存在を検知することは困難である.本論文では,消失訂正を用いて二つの情報を出力するQRコードの構成方法を与える.提案手法により,正規のQRコードとの差異が小さい偽装QRコードを構成可能である.更に,偽装QRコードの具体的な対策について述べる.

著者

Aren Shinozaki Takaya Miyano Yoshihiko Horio

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.11, no.4, pp.466-479, 2020 (Released:2020-10-01)

参考文献数

20

被引用文献数

1

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We have applied noisy echo state networks to the short-term forecasting of hyperchaotic and chaotic time series. The hyperchaotic time series were generated using the augmented Lorenz equations as a star network of Q nonidentical Lorenz systems and a four-dimensional Lorenz system. The echo state networks were used mainly in the recursive forecasting mode, wherein the output value of the network, i.e., the predicted value, at the current time step was recursively fed back to the input node at the next time step of prediction. The addition of external noise to the reservoir network has been found to considerably improve the fidelity of the geometrical structures of the chaotic attractors reconstructed from the predicted time series. We discuss these observations on the basis of Ueda's theory of chaos.

著者

Masataka Motoyama Ken Umeno

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Electronics Express (ISSN:13492543)

巻号頁・発行日

pp.18.20210011, (Released:2021-02-10)

参考文献数

32

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This letter aims to demonstrate the concept of wireless power coloring (WPC), i.e., frequency division multiplexing of wireless power transfer (WPT). Currently, to obtain significant received power in WPT, the power is generated from a single transmission source. Herein, we propose a method of transmitting wireless power through more than one (N ≧ 2) multiplexed coloring source. To achieve this, we use power transmitting sources with different resonance frequencies in magnetic resonance-type WPT to selectively send power to a designated receiver.

著者

Sho KANAMARU Kazushi KAWAMURA Shu TANAKA Yoshinori TOMITA Nozomu TOGAWA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E104-D, no.2, pp.226-236, 2021-02-01

被引用文献数

4

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Ising machines have attracted attention, which is expected to obtain better solutions of various combinatorial optimization problems at high speed by mapping the problems to natural phenomena. A slot-placement problem is one of the combinatorial optimization problems, regarded as a quadratic assignment problem, which relates to the optimal logic-block placement in a digital circuit as well as optimal delivery planning. Here, we propose a mapping to the Ising model for solving a slot-placement problem with additional constraints, called a constrained slot-placement problem, where several item pairs must be placed within a given distance. Since the behavior of Ising machines is stochastic and we map the problem to the Ising model which uses the penalty method, the obtained solution does not always satisfy the slot-placement constraint, which is different from the conventional methods such as the conventional simulated annealing. To resolve the problem, we propose an interpretation method in which a feasible solution is generated by post-processing procedures. We measured the execution time of an Ising machine and compared the execution time of the simulated annealing in which solutions with almost the same accuracy are obtained. As a result, we found that the Ising machine is faster than the simulated annealing that we implemented.

著者

Kouji SHIBATA

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.E104-C, no.2, pp.93-101, 2021-02-01

被引用文献数

4

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A method for the calibration of S11 at the front surface of a material for a coaxial-feed type cut-off circular waveguide with three reference materials inserted and no short termination condition was proposed as a preliminary step for dielectric measurement in liquids. The equations for jig calibration of S11 with these reference materials were first defined, and the electrostatic capacitance for the analytical model unique to the jig was quantified by substituting the reflection constant (calculated at frequencies of 0.50, 1.5 and 3.0 GHz using the mode-matching (MM) technique) into the equivalent circuit, assuming the sample liquid in the jig. The accuracy of S11 measured using the proposed method was then verified. S11 for the front surface of the sample material was also measured with various liquids in the jig after calibration, and the dielectric constants of the liquids were estimated as an inverse problem based on comparison of S11 calculated from an analytical model using EM analysis via the MM technique with the measured S11 values described above. The effectiveness of the proposed S11 calibration method was verified by comparison with dielectric constants estimated after S11 SOM (short, open and reference material) calibration and similar, with results showing favorable agreement with each method.

著者

後安 謙吾 谷口 義明 井口 信和

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J104-D, no.2, pp.159-163, 2021-02-01

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本論文では,MR技術を用い実空間上に仮想ネットワーク環境を構築するシステムを開発する.本システムにより,実ネットワーク機器を用いることなく,ネットワーク機器の配置や配線などの物理的な構成を確認しながら,ネットワークの検証や構築学習を実施できる.

著者

Koji KAMMA Toshikazu WADA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E104-D, no.1, pp.194-202, 2021-01-01

被引用文献数

2

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This paper presents a pruning method, Reconstruction Error Aware Pruning (REAP), to reduce the redundancy of convolutional neural network models for accelerating their inference. In REAP, we have the following steps: 1) Prune the channels whose outputs are redundant and can be reconstructed from the outputs of other channels in each convolutional layer; 2) Update the weights of the remaining channels by least squares method so as to compensate the error caused by pruning. This is how we compress and accelerate the models that are initially large and slow with little degradation. The ability of REAP to maintain the model performances saves us lots of time and labors for retraining the pruned models. The challenge of REAP is the computational cost for selecting the channels to be pruned. For selecting the channels, we need to solve a huge number of least squares problems. We have developed an efficient algorithm based on biorthogonal system to obtain the solutions of those least squares problems. In the experiments, we show that REAP can conduct pruning with smaller sacrifice of the model performances than several existing methods including the previously state-of-the-art one.

著者

Hwanhee KIM Teasung HAHN Sookyun KIM Shinjin KANG

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E103.D, no.8, pp.1901-1910, 2020-08-01 (Released:2020-08-01)

参考文献数

36

被引用文献数

1

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This paper describes graph-based Wave Function Collapse algorithm for procedural content generation. The goal of this system is to enable a game designer to procedurally create key content elements in the game level through simple association rule input. To do this, we propose a graph-based data structure that can be easily integrated with a navigation mesh data structure in a three-dimensional world. With our system, if the user inputs the minimum association rule, it is possible to effectively perform procedural content generation in the three-dimensional world. The experimental results show that the Wave Function Collapse algorithm, which is a texture synthesis algorithm, can be extended to non-grid shape content with high controllability and scalability.

著者

Yuki NOYORI Hironori WASHIZAKI Yoshiaki FUKAZAWA Hideyuki KANUKA Keishi OOSHIMA Shuhei NOJIRI Ryosuke TSUCHIYA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E104.D, no.1, pp.106-116, 2021-01-01 (Released:2021-01-01)

参考文献数

30

被引用文献数

4

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Resource limitations require that bugs be resolved efficiently. The bug modification process uses bug reports, which are generated from service user reports. Developers read these reports and fix bugs. Developers discuss bugs by posting comments directly in bug reports. Although several studies have investigated the initial report in bug reports, few have researched the comments. Our research focuses on bug reports. Currently, everyone is free to comment, but the bug fixing time may be affected by how to comment. Herein we investigate the topic of comments in bug reports. Mixed topics do not affect the bug fixing time. However, the bug fixing time tends to be shorter when the discussion length of the phenomenon is short.

著者

Zhonghao ZHANG Chongbin XU Li PING

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.E95-B, no.12, pp.3663-3670, 2012-12-01

被引用文献数

1

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In this paper, we present a transmission scheme for a multiple-input multiple-output (MIMO) quasi-static fading channel with imperfect channel state information at the transmitter (CSIT). In this scheme, we develop a precoder structure to exploit the available CSIT and apply spatial coupling for further performance enhancement. We derive an analytical evaluation method based on extrinsic information transfer (EXIT) functions, which provides convenience for our precoder design. Furthermore, we observe an area property indicating that, for a spatially coupled system, the iterative receiver can perform error-free decoding even the original uncoupled system has multiple fixed points in its EXIT chart. This observation implies that spatial coupling is useful to alleviate the uncertainty in CSIT which causes difficulty in designing LDPC code based on the EXIT curve matching technique. Numerical results are presented, showing an excellent performance of the proposed scheme in MIMO fading channels with imperfect CSIT.

著者

Takuya Hoshi Norihide Kashio Yuta Shiratori Kenji Kurishima Minoru Ida Hideaki Matsuzaki

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Electronics Express (ISSN:13492543)

巻号頁・発行日

vol.16, no.3, pp.20181125, 2019 (Released:2019-02-10)

参考文献数

12

被引用文献数

2 6

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This letter presents the current-gain and high-frequency characteristics of double heterojunction bipolar transistors (DHBTs) consisting of an n-InGaP emitter, a p-GaAsSb/p-InGaAsSb base, and an n-InP collector. The impact of the thickness of the first base metal (Pt) on the base contact resistivity is investigated in a p-GaAsSb/p-InGaAsSb test structure for the purpose of improving fmax. A low base contact resistivity (4.8 Ωµm2) is obtained when the Pt layer is thinner than the p-GaAsSb layer. A fabricated InGaP/GaAsSb/InGaAsSb DHBT with a 0.25-µm emitter exhibits a high current gain of 33 even though the base sheet resistance is as low as 1025 Ω/sq. The DHBT also exhibits an fmax of 703 GHz and a breakdown voltage of 5.4 V. These results demonstrate that this DHBT technology is useful for fabricating high-speed integrated circuits with high output voltages.

著者

Ushio JIMBO Junji YAMADA Ryota SHIOYA Masahiro GOSHIMA

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.E100-C, no.3, pp.245-258, 2017-03-01

被引用文献数

1

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Timing fault detection techniques address the problems caused by increased variations on a chip, especially with dynamic voltage and frequency scaling (DVFS). The Razor flip-flop (FF) is a timing fault detection technique that employs double sampling by the main and shadow FFs. In order for the Razor FF to correctly detect a timing fault, not the main FF but the shadow FF must sample the correct value. The application of Razor FFs to static logic relaxes the timing constraints; however, the naive application of Razor FFs to dynamic precharged logic such as SRAM read circuits is not effective. This is because the SRAM precharge cannot start before the shadow FF samples the value; otherwise, the transition of the bitline of the SRAM stops and the value sampled by the shadow FF will be incorrect. Therefore, the detect period cannot overlap the precharge period. This paper proposes a novel application of Razor FFs to SRAM read circuits. Our proposal employs a conditional precharge according to the value of a bitline sampled by the main FF. This enables the detect period to overlap the precharge period, thereby relaxing the timing constraints. The additional circuit required by this method is simple and only needed around the sense amplifier, and there is no need for a clock delayed from the system clock. Consequently, the area overhead of the proposed circuit is negligible. This paper presents SPICE simulations of the proposed circuit. Our proposal reduces the minimum cycle time by 51.5% at a supply voltage of 1.1 V and the minimum voltage by 31.8% at cycle time of 412.5 ps.

著者

Kuniyasu SUZAKI Kengo IIJIMA Toshiki YAGI Cyrille ARTHO

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E96-A, no.1, pp.215-224, 2013-01-01

被引用文献数

10

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Memory deduplication improves the utilization of physical memory by sharing identical blocks of data. Although memory deduplication is most effective when many virtual machines with same operating systems run on a CPU, cross-user memory deduplication is a covert channel and causes serious memory disclosure attack. It reveals the existence of an application or file on another virtual machine. The covert channel is a difference in write access time on deduplicated memory pages that are re-created by Copy-On-Write, but it has some interferences caused by execution environments. This paper indicates that the attack includes implementation issues caused by memory alignment, self-reflection between page cache and heap, and run-time modification (swap-out, anonymous pages, ASLR, preloading mechanism, and self-modification code). However, these problems are avoidable with some techniques. In our experience on KSM (kernel samepage merging) with the KVM virtual machine, the attack could detect the security level of attacked operating systems, find vulnerable applications, and confirm the status of attacked applications.

著者

中島 淑貴 柏岡 秀紀 キャンベル ニック 鹿野 清宏

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:09151923)

巻号頁・発行日

vol.J87-D2, no.9, pp.1757-1764, 2004-09-01

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「非可聴つぶやき認識」という,新しいスタイルの実用的な入力インタフェースを提案する.これは音声認識の雑音に対する脆弱性,情報の周囲への漏えい性を克服するため,声帯の振動を伴う通常音声の空気伝搬ではなく,「非可聴つぶやき(Non-Audible Murmur: NAM)」,つまり第三者に聴取不能な声帯の振動を伴わない調音呼気音の体内伝導を,体表からサンプリングし,HMMを用いて認識するものである.これを実現するための基礎として,第一に医療用膜型聴診器の原理を応用した体表接着型マイクロホンを開発した.第二として体内を伝導するNAMを採取して認識するために最適な接着位置を発見した.第三としてNAMの音響学的性質を検討した.第四として,この部位から採取されたサンプルを用い,HMM音響モデルに追加学習してNAM音響モデルを作成した.これらをもとに,日本語ディクテーション基本ソフトウェアを評価に用い,認識エンジンJuliusを使用して大語い連続認識実験を行い,NAM認識の実用可能性を検討した.

著者

田中 和樹 キム ビョンゴン 小林 嵩 ベッカリ アブデルモウラ 難波 忍 西村 公佐 キム フーン チャン ユン 鈴木 正敏

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 C (ISSN:13452827)

巻号頁・発行日

vol.J101-C, no.2, pp.107-118, 2018-02-01

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現在の1000倍以上のトラヒックが見込まれる5G以降の無線通信システムでは,ミリ波等の高い周波数帯の小セル局を多数設置して大容量トラヒックを収容する必要がある.小セル一局あたりの通信速度は数十Gbpsと想定され,光アクセス回線の大容量化は喫緊の課題である.更に,既に商用展開が進んでいるC-RAN構成は5G以降も有望なアーキテクチャーと考えられるものの,従来の光アクセス回線の伝送方式は通信速度の十数倍の伝送容量を必要とするため,代替技術が望まれる.光を搬送波として無線信号をアナログ波形のまま伝送するアナログRoF (A-RoF)伝送方式は,伝送帯域を大幅に低減可能で,有望な技術の一つである.本論文では,最初にA-RoF技術の既存適用例として,CATV伝送システムに用いられているIF-over-Fiber (IFoF)伝送方式を紹介する.更に,IFoF・A-RoF方式を無線基地局収容光回線へ適用した場合のシステム構成例を示す.続いて,数値シミュレーションによりIFoF伝送方式が適用可能な伝送条件の範囲を明らかにする.商用のLTE無線基地局及び実フィールドに設置された光ファイバを用いた実験を行い,数値シミュレーション結果との比較を行うとともに,IFoF伝送方式の商用システムへの適用可能性を示す.

著者

龍 梓 木村 龍一郎 飯田 頌平 宇津呂 武仁 三橋 朋晴 山本 幹雄

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J102-D, no.3, pp.104-117, 2019-03-01

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ニューラル機械翻訳(NMT)の弱点の一つとして,扱える語彙に限りがある点が知られている.NMTにおいては,語彙辞書に含まれていない単語は未知語トークンとして出力されるため,これが誤訳となる.従来法では,出力文に含まれた未知語トークンが対応する原言語の単語を推定しその訳語に置き換えることによって,NMTにおいて出力可能となる語彙の規模を拡大した.しかし,この方式は,単語単位での語彙規模の拡大にとどまる点が弱点であった.本論文においては,ニューラル翻訳において,大規模フレーズ語彙に対応する方式を提案する.具体的には,訓練用対訳文においてフレーズ間の二言語対応の情報を収集し,二言語間で対応済みのフレーズ対訳対を同一のトークンに置き換えた後,NMTモデルの訓練を行う.翻訳時には,NMTモデルの語彙集合中の語彙部分に対しては,NMTモデルによる訳文生成がなされ,一方,その他のフレーズまたは単語語彙部分に対しては,SMTモデルによる翻訳がなされる.日中,中日,日英,英日の各方向の翻訳において評価を行い,提案手法の有効性を検証した.

著者

Nitish RAJORIA Yuki IGARASHI Jin MITSUGI Yusuke KAWAKITA Haruhisa ICHIKAWA

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

pp.2016EBP3472, (Released:2017-06-13)

被引用文献数

3 11

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This paper proposes a novel multiple access method that enables concurrent sensor data streaming from multiple batteryless, wireless sensor tags. The access method is a pseudo-FDMA scheme based on the subcarrier backscatter communication principle, which is widely employed in passive RFID and radar systems. Concurrency is realized by assigning a dedicated subcarrier to each sensor tag and letting all sensor tags backscatter simultaneously. Because of the nature of the subcarrier, which is produced by constant rate switching of antenna impedance without any channel filter in the sensor tag, the tag-to-reader link always exhibits harmonics. Thus, it is important to reject harmonics when concurrent data streaming is required. This paper proposes a harmonics rejecting receiver to allow simultaneous multiple subcarrier usage. This paper particularly focuses on analog sensor data streaming which minimizes the functional requirements on the sensor tag and frequency bandwidth. The harmonics rejection receiver is realized by carefully handling group delay and phase delay of the subcarrier envelope and the carrier signal to accurately produce replica of the harmonics by introducing Hilbert and inverse Hilbert transformations. A numerical simulator with Simulink and a hardware implementation with USRP and LabVIEW have been developed. Simulations and experiments reveal that even if the CIR before harmonics rejection is 0dB, the proposed receiver recovers the original sensor data with over 0.98 cross-correlation.

著者

末永 貴俊 飯野 恵秋 黒田 知宏 大城 理 千原 國宏

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:09151923)

巻号頁・発行日

vol.J83-D2, no.1, pp.324-332, 2000-01-25

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超音波診断装置を用いて実時間で遠隔医療を行うためには,超音波診断動画像の伝送及び,計測用の超音波プローブを患者にあてる位置・角度などが リアルタイムで指示できる環境が必要である.特にプローブ操作については空間情報を直感的に伝える必要があり,既存の音声・画像通信技術だけでは伝達が困難である.そこで本論文では計測側の計測風景の上に超音波診断に用いられるプローブと同じ形のCG(CGプローブ)を重ね合わせ,診断側の専門医が遠隔地から計測者にプローブをあてる位置・角度などを教示するシステムを提案する.

著者

山口 高弘 坂野 寿和 藤井 竜也 安藤 裕 北村 正幸

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:09151923)

巻号頁・発行日

vol.J84-D2, no.6, pp.1203-1212, 2001-06-01

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遠隔医療コンサルテーションは,地方の診療所と中央の病院を結び,遠隔の医師に対して中央の専門医が診断支援を行うサービスである.本研究は,そうしたサービスを実現するために必要な機能を明らかにし,そうしたシステムを具現化することを目標としている.我々は,高速ネットワーク,医用画像データベース,超高精細画像読影ステーション,IPテレビ会議システムをベースとした遠隔医療システムを構築し,それをベースとして遠隔医療コンサルテーションシステムを開発した.開発したシステムを用いて,遠隔の2人の医師が同じ画像を参照しながら放射線治療に関して相談する遠隔医療コンサルテーション実験を行った.ネットワーク速度に依存しない高速な画像表示切換を実現する画像プリロード機能や,画像表示連携機能,共有ポインタ表示機能などシステム上に実装した連携機能の有効性を実験的に明らかにした.