著者
Hisashi Kada Hiromasa Hojyo Isao T. Tokuda
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.5, no.4, pp.466-475, 2014 (Released:2014-10-01)
参考文献数
24
被引用文献数
3

Because of an increasing demand on electric power and limited resources for conventional fuels, highly efficient engine that is capable of converting energy resource to electric power with a small loss is awaited. In this respect, Stirling engine provides a strong potential because of its efficient thermodynamic cycle, which is ideally close to the theoretical limit of the Carnot cycle. Practical use of the Stirling engine, however, has been limited because of its low output power. Towards its wider applicability, simultaneous operation of many individual Stirling engines is indispensable to increase the output power. This paper presents an experimental study of synchronized dynamics of two coupled Stirling engines. It is shown that the synchronized operation of the population of engines provides a key technology to extend the system size so as to produce a large-scale electric energy.
著者
Naoki Shinohara
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.10, no.21, pp.20132009-20132009, 2013-11-10 (Released:2013-11-10)
参考文献数
53
被引用文献数
2 39 1

Microwave power transmission (MPT) has had a long history before the more recent movement toward wireless power transmission (WPT). MPT can be applied not only to beam-type point-to-point WPT but also to an energy harvesting system fed from distributed or broadcasting radio waves. The key technology is the use of a rectenna, or rectifying antenna, to convert a microwave signal to a DC signal with high efficiency. In this paper, various rectennas suitable for MPT are discussed, including various rectifying circuits, frequency rectennas, and power rectennas.
著者
Jung-Dong Park
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.11, no.18, pp.20140806-20140806, 2014 (Released:2014-09-25)
参考文献数
6
被引用文献数
1

Switching mode CMOS frequency multipliers are studied in sub-Terahertz regime. Analysis on the multiplier architectures and optimal gate bias at CMOS switch are investigated to maximize output power at designated harmonics. Utilizing a differential pair, a 195 GHz tripler having a hair-pin filter is designed to maximize 3rd harmonics with −14.8 dB of conversion gain (CG) from Pin = +13 dBm of the balanced input, while the 260 GHz quadrupler utilizes quadruple-push pairs which achieves CG = −16 dB from two +13 dBm of the balanced I/Q driving signals in a 65 nm digital CMOS process.
著者
Jung-Dong Park
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
pp.11.20140806, (Released:2014-09-03)
参考文献数
6
被引用文献数
1

Switching mode CMOS frequency multipliers are studied in sub-Terahertz regime. Analysis on the multiplier architectures and optimal gate bias at CMOS switch are investigated to maximize output power at designated harmonics. Utilizing a differential pair, a 195GHz tripler having a hair-pin filter is designed to maximize 3rd harmonics with -14.8dB of conversion gain (CG) from Pin=+13dBm of the balanced input, while the 260GHz quadrupler utilizes quadruple-push pairs which achieves CG=-16dB from two +13dBm of the balanced I/Q driving signals in a 65nm digital CMOS process.
著者
三浦 道子
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.3, no.1, pp.1_57-1_65, 2009-07-01 (Released:2011-07-01)
参考文献数
17

これまで産業界をけん引してきたMOSFET の微細化を推進することが難しくなってきている.これは,微細化によって達成された高性能化を有効に利用する用途が限られてきたことのほかに,微細化によって応用を難しくするMOSFET の特性が顕著になってきたことが挙げられる.一方,エコ社会の実現には,低消費電力回路設計への要求が高い.これを実現するには,MOSFET の微細化は避けて通れない.1970 年代に回路シミュレータが開発されて,たくさんのトランジスタを複雑に組み合わせて様々な性能を持った回路が設計できるようになった.このとき以来長く用いられてきたのが,Meyer モデルで,様々の近似を用いてトランジスタ特性を簡潔な式で記述している.しかし複雑な特性を呈する微細MOSFET にはモデルの精度が不十分になってきた.そこでトランジスタ特性を物理原理に基づいて記述する,表面ポテンシャルモデルが開発され,モデルの主流になりつつある.この変遷をMOSFET特性に基づいて解説する.
著者
Meiqin WANG Xiaoyun WANG Kam Pui CHOW Lucas Chi Kwong HUI
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.E93.A, no.12, pp.2744-2754, 2010-12-01 (Released:2010-12-01)
参考文献数
10
被引用文献数
3

CAST-128 is a block cipher used in a number of products, notably as the default cipher in some versions of GPG and PGP. It has been approved for Canadian government use by the Communications Security Establishment. Haruki Seki et al. found 2-round differential characteristics and they can attack 5-round CAST-128. In this paper, we studied the properties of round functions F1 and F3 in CAST-128, and identified differential characteristics for F1 round function and F3 round function. So we identified a 6-round differential characteristic with probability 2-53 under 2-23.8 of the total key space. Then based on 6-round differential characteristic, we can attack 8-round CAST-128 with key sizes greater than or equal to 72bits and 9-round CAST-128 with key sizes greater than or equal to 104bits. We give the summary of attacks on reduced-round CAST-128 in Table 10.
著者
木村 康則 Matthew DEPETRO 谷岡 秀昭
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.4, no.4, pp.311-317, 2011-04-01 (Released:2011-04-01)
参考文献数
27

米国で医療制度改革法案が成立したことにより,医療現場の効率化や健康保険制度の改革などが進んでいる.本稿では,これらを推進するための有効な手段と考えるmHealthと呼ばれる考えを紹介し,それを実現するための生体情報を取得するためのセンサ技術特に血圧と血糖値の測定手法に関して現状を紹介する.また,このアプローチが真に実現されるための課題も述べる.
著者
Xuan Zhu Chunqing Wu Yuhua Tang Junjie Wu Xun Yi
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.10, no.5, pp.20130013-20130013, 2013-03-05 (Released:2013-03-05)
参考文献数
8
被引用文献数
4

Utilizing memristor to obtain multi-level memory in nano-crossbar is a promising approach to enhance the memory density. In this paper, we proposed a solution for multi-level programming of memristor in nanocrossbar, which can be implemented on nanocrossbar without the need for extra selective devices. Meanwhile, using a general device model, this solution is demonstrated to be adaptive to a wide range of memristors that have been experimentally fabricated through HSPICE simulation.
著者
Md. Mottaleb HOSSAIN Md. Abdullah-AL HUMAYUN Md. Tanvir HASAN Ashraful Ghani BHUIYAN Akihiro HASHIMOTO Akio YAMAMOTO
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Electronics (ISSN:09168524)
巻号頁・発行日
vol.E95.C, no.2, pp.255-261, 2012-02-01 (Released:2012-02-01)
参考文献数
26
被引用文献数
2 9

This paper reports on a theoretical study and modeling of a 1.55µm quantum dot heterostructure laser using InN as a promising candidate for the first time. Details of design and theoretical analysis of probability distribution of the optical transition energy, threshold current density, modal gain, and differential quantum efficiency are presented considering a single layer of quantum dots. Dependence of threshold current density on the RMS value of quantum dot size fluctuations and the cavity length is studied. A low threshold current density of ∼51Acm-2 is achieved at room temperature for a cavity length of 640µm. An external differential efficiency of ∼65% and a modal gain of ∼12.5cm-1 are obtained for the proposed structure. The results indicate that the InN based quantum dot laser is a promising one for the optical communication system.
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
Nitin SINGHAL Jin Woo YOO Ho Yeol CHOI In Kyu PARK
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.E95.D, no.5, pp.1475-1484, 2012-05-01 (Released:2012-05-01)
参考文献数
18
被引用文献数
6 13

In this paper, we analyze the key factors underlying the implementation, evaluation, and optimization of image processing and computer vision algorithms on embedded GPU using OpenGL ES 2.0 shader model. First, we present the characteristics of the embedded GPU and its inherent advantage when compared to embedded CPU. Additionally, we propose techniques to achieve increased performance with optimized shader design. To show the effectiveness of the proposed techniques, we employ cartoon-style non-photorealistic rendering (NPR), speeded-up robust feature (SURF) detection, and stereo matching as our example algorithms. Performance is evaluated in terms of the execution time and speed-up achieved in comparison with the implementation on embedded CPU.
著者
Son Trinh-Van Gina Kwon Keum Cheol Hwang Yong Bae Park
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.10, no.17, pp.20130596-20130596, 2013-09-10 (Released:2013-09-10)
参考文献数
9
被引用文献数
1

A uniplanar, compact electromagnetic band-gap (UC-EBG) structure based on modified semi-Spidron fractal and meander-line strip (SFM-EBG) patterning is proposed. The semi-Spidron fractal geometry significantly increases the equivalent capacitance, whereas meander-line strips increase the equivalent inductance; as a result, the proposed design can be used to successfully miniaturize an EBG structure having a wide operating bandwidth. The measurement results show that a center frequency reduction of 32.14% as compared to that achieved by a conventional UC-EBG structure can be achieved by utilizing this proposed structure. The SFM-EBG structure has a measured operating bandwidth of 39.7% (3.33-4.98GHz), which is wider than that of a conventional UC-EBG (31%).
著者
小野 定康 藤井 哲郎 藤井 竜也
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.3, no.2, pp.2_10-2_33, 2009-10-01 (Released:2011-07-01)
参考文献数
13
被引用文献数
1 1

本稿では, 日本発の超高精細4K ディジタルシネマの開発とハリウッドをはじめとする映像専門家の間で高い評価を得るに至った歴史について述べる. それは決して平たんな道ではなかったし, これからも様々な問題に遭遇するであろと予想している. しかしそれらがあっても, この超高精細画像を使う究極のコンテンツと呼ばれるディジタルシネマが最終段階に入ってきたことは確実になって現在に至っている.