著者
IWAMOTO Chuzo MATSUI Yuta
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)
巻号頁・発行日
vol.99, no.6, pp.1145-1148, 2016
被引用文献数
1

The Building puzzle is played on an N×N grid of cells. Initially, some numbers are given around the border of the grid. The object of the puzzle is to fill out blank cells such that every row and column contains the numbers 1 through N. The number written in each cell represents the height of the building. The numbers around the border indicate the number of buildings which a person can see from that direction. A shorter building behind a taller one cannot be seen by him. It is shown that deciding whether the Building puzzle has a solution is NP-complete.
著者
S. S. Gupta R. Senani
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Electronics Express (ISSN:13492543)
巻号頁・発行日
vol.1, no.16, pp.507-512, 2004 (Released:2004-11-25)
参考文献数
15
被引用文献数
10 14

Recently, the authors introduced two new second-order single-resistance-controlled oscillators (SRCO) employing four/three unity-gain cells (unity-gain voltage followers and unity-gain current followers). In this communication, a novel family of SRCOs has been presented which employ a reduced number of (only two) unity-gain cells as active elements. The workability of the new circuits has been confirmed by the SPICE simulations of their CMOS-implementable versions.
著者
Kazunori AKABANE Nobuaki MOCHIZUKI Shigeru TERUHI Mamoru KOBAYASHI Shuichi YOSHINO Masashi SHIMIZU Kazuhiro UEHARA
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.E99.B, no.9, pp.1920-1929, 2016-09-01 (Released:2016-09-01)
参考文献数
27
被引用文献数
4

In the near future, many sensors and terminals will be connected to the public network to provide various convenient IoT/M2M services. In order to connect many sensors to the network efficiently, wireless communication systems in the 920MHz band are seen as attractive solutions. We are focusing on the 920MHz band to research and develop high-capacity protocols that can accommodate many terminals, and low power consumption technologies for battery-driven terminals. In this paper, we describe the following three concrete wireless systems that use our proposals. (1) A physical distribution pallet management system that can handle thousands of pallet-embedded sensors and a wireless module with a battery lifetime of about ten years. (2) Water leakage monitoring system for underground pipes by using sensors and a wireless module in each valve box. (3) A wide-area and high-capacity radio relay system for smart metering services like the reading of gas meters. The radio relay system can accommodate various sensors and terminals and has large potential for providing various IoT/M2M services in conjunction with smart metering services.
著者
Takaaki DEGUCHI Yoshiaki TANIGUCHI Go HASEGAWA Yutaka NAKAMURA Norimichi UKITA Kazuhiro MATSUDA Morito MATSUOKA
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.E99.B, no.2, pp.347-355, 2016-02-01 (Released:2016-02-01)
参考文献数
17
被引用文献数
1 1

In this paper, we propose a workload assignment policy for reducing power consumption by air conditioners in data centers. In the proposed policy, to reduce the air conditioner power consumption by raising the temperature set points of the air conditioners, the temperatures of all server back-planes are equalized by moving workload from the servers with the highest temperatures to the servers with the lowest temperatures. To evaluate the proposed policy, we use a computational fluid dynamics simulator for obtaining airflow and air temperature in data centers, and an air conditioner model based on experimental results from actual data center. Through evaluation, we show that the air conditioners' power consumption is reduced by 10.4% in a conventional data center. In addition, in a tandem data center proposed in our research group, the air conditioners' power consumption is reduced by 53%, and the total power consumption of the whole data center is exhibited to be reduced by 23% by reusing the exhaust heat from the servers.
著者
Manuel CEDILLO HERNANDEZ Antonio CEDILLO HERNANDEZ Francisco GARCIA UGALDE Mariko NAKANO MIYATAKE Hector PEREZ MEANA
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Information and Systems (ISSN:09168532)
巻号頁・発行日
vol.E98.D, no.9, pp.1702-1705, 2015-09-01 (Released:2015-09-01)
参考文献数
8
被引用文献数
2

In this letter we present an imperceptible and robust watermarking algorithm that uses a cryptographic hash function in the authentication application of digital medical imaging. In the proposed scheme we combine discrete Fourier transform (DFT) and local image masking to detect the watermark after a geometrical distortion and improve its imperceptibility. The image quality is measured by metrics currently used in digital image processing, such as VSNR, SSIM and PSNR.
著者
眞田 克
出版者
一般社団法人 電子情報通信学会
雑誌
電子情報通信学会 基礎・境界ソサイエティ Fundamentals Review (ISSN:18820875)
巻号頁・発行日
vol.5, no.4, pp.293-301, 2012-04-01 (Released:2012-04-01)
参考文献数
16

水道管からの水漏れと同じくLSIも欠陥箇所を介して電流が漏れ出し故障に至らしめる.この漏れ電流現象はLSIを評価する重要なパラメータの一つである.しかしながらDSM(Deep Sub-Micron)化に伴うデバイス技術の進展は電流値を用いた評価を困難とした.この問題を克服すべく,テスト技術は統計処理による正常/異常値間の差分の顕在化による識別法更には電源電流の波形の相関比較やフーリエ変換による数理処理により異常の有/無を顕在化する技術が開発されている.故障診断技術は漏れ電流の特徴を用い,論理情報と組み合わせることで簡易で高精度に故障候補を特定する技術の開発で評価技術の向上が図られている.
著者
韓 太舜 小林 欣吾
出版者
一般社団法人 電子情報通信学会
雑誌
電子情報通信学会 基礎・境界ソサイエティ Fundamentals Review (ISSN:18820875)
巻号頁・発行日
vol.8, no.4, pp.229-243, 2015-04-01 (Released:2015-04-01)
参考文献数
45

マルチユーザ通信路符号化問題,なかんずく,干渉通信路の符号化問題は,その重要な基本的特質のゆえに近年多くの通信理論研究者が多大の関心を持って精力的に研究に取り組んでいる.特に,問題の本質的な性格を把握するために,2 組の送信者・受信者の場合がよく研究されてきた.韓と小林によって1981 年に提示された一般の干渉通信路に対する達成可能な領域,すなわち,HK 領域の表現は現在に至るまで最良であり続けてきた.本稿では,HK 領域の解説を中心に据えて,その領域の表現を簡略化する研究や,既に容量域の決定されている干渉通信路の部分クラスに関する解説を与える.また,Han-Kobayashi スキームのごく簡単な適用でも,ガウス干渉通信路の容量域に対してSNR(SN 比, 信号対雑音比)とINR(干渉対雑音比)を大きくした漸近的な状況では最適であることを示したEtkin, Tse, Wang による研究を解説する.更に,その出現以来35 年後の今年になって,Han-Kobayashi 領域をしのぐ伝送レート対の存在することがNairらによって明らかにされてHan-Kobayashi 領域の最適性が否定されたという話題にも触れ,干渉通信路研究に新しい転機が訪れたことを伝える.
著者
Shinji Nakaoka
出版者
一般社団法人 電子情報通信学会
雑誌
Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)
巻号頁・発行日
vol.6, no.1, pp.54-70, 2015 (Released:2015-01-01)
参考文献数
34
被引用文献数
1 3 3

Immunotherapy for cancer is a forthcoming therapeutic option in cancer treatment. A variety of approaches, including adoptive cell transfer, adjuvant therapy, and monoclonal antibody therapy, are currently used as complementary or alternative cancer treatments. Since immunity against tumors is established as a result of complex interactions among tumors and immune cells, a theoretical framework to elucidate the dynamics of tumor killing by immune cells initiated by clinical intervention needs to be developed. We construct a simple mathematical model that describes the killing of tumors by T cells. We focus on a mathematical characterization of the effect of adoptive cell transfer therapy, the injection of a patient's own ex vivo activated T cells to initiate tumor immunity. On the basis of rigorous mathematical analyses and numerical computations, we provide biological interpretations for the possible outcomes of adoptive cell transfer under three different scenarios in terms of proliferation. In our modeling framework, adoptive cell transfer therapy can be understood as a driving force that potentially operates to shift the state of an immune response from inactive to active. On the other hand, our modeling framework suggests the possibility that a tumor can exploit a self-augmenting proliferation of T cells mediated by autocrine/paracrine signaling as an escape strategy from an immune response.
著者
中村 健太郎
出版者
一般社団法人 電子情報通信学会
雑誌
電子情報通信学会 基礎・境界ソサイエティ Fundamentals Review (ISSN:18820875)
巻号頁・発行日
vol.7, no.3, pp.249-255, 2014-01-01 (Released:2014-01-01)
参考文献数
16
被引用文献数
1

超音波振動から直線運動や回転運動を得る超音波アクチュエータについて,摩擦駆動の超音波モータを中心に,その原理と構成例,得られる特性について解説する.圧電セラミックス素子で発生した往復運動である振動から一方向運動を得るための原理として,複合振動形と進行波形に分けて説明し,複合振動形を例に得られるべき性能を論じる.また,それぞれの方式で直線運動を得る構成方法,回転運動を得る構成方法を具体的に紹介する.また,効率や寿命を改善する最近の試みについても述べる.