著者
田中 大輔
出版者
公益社団法人 日本薬学会
雑誌
YAKUGAKU ZASSHI (ISSN:00316903)
巻号頁・発行日
vol.130, no.3, pp.315-323, 2010 (Released:2010-03-01)
参考文献数
19
被引用文献数
4 3

Fragment-Based Drug Discovery (FBDD) has been recognized as a newly emerging lead discovery methodology that involves biophysical fragment screening and chemistry-driven fragment-to-lead stages. Although fragments, defined as structurally simple and small compounds (typically <300 Da), have not been employed in conventional high-throughput screening (HTS), the recent significant progress in the biophysical screening methods enables fragment screening at a practical level. The intention of FBDD primarily turns our attention to weakly but specifically binding fragments (hit fragments) as the starting point of medicinal chemistry. Hit fragments are then promoted to more potent lead compounds through linking or merging with another hit fragment and/or attaching functional groups. Another positive aspect of FBDD is ligand efficiency. Ligand efficiency is a useful guide in screening hit selection and hit-to-lead phases to achieve lead-likeness. Owing to these features, a number of successful applications of FBDD to “undruggable targets” (where HTS and other lead identification methods failed to identify useful lead compounds) have been reported. As a result, FBDD is now expected to complement more conventional methodologies. This review, as an introduction of the following articles, will summarize the fundamental concepts of FBDD and will discuss its advantages over other conventional drug discovery approaches.
著者
田中 大輔 石光 俊介
出版者
一般社団法人 日本機械学会
雑誌
Dynamics & Design Conference
巻号頁・発行日
vol.2016, 2016

<p>Every year the City of Hiroshima holds the Peace Memorial Ceremony to console the souls of those who were lost due to the atomic bombing as well as pray for the realization of everlasting world peace. Since the ambient noise of this ceremony is very loud, these noise was tried to reduce using a passive method and Active Noise Control (ANC). There are some problems that audiences or TV crews cannot catch the meanings of presenter's messages such as the Prime Minister's, because of ambient noise. To reduce these noises, tents were prepared in the venue. There were also useful for protect people from the strong suns. The difference between the sounds near the loudest place in the park and those in the venue was measured to confirm the effectiveness of each countermeasure. The one of the loudest noise came from an opposite bank of the river. Though the noise was detected at the river side, it was not detected in the venue. As a result, the noise in the venue was reduced by 15 dB owing to each countermeasure. As most of the noise are speech, a 6-second young woman's voice was used as the noise source and reference signal in the ANC test of this study. Noise source includes the high frequency components up to 4000Hz. High-speed signal processing was required to reduce the noise that has high frequency components and changes its amplitudes rapidly. FPGA with a clock of 40MHz was selected for the fast signal processing. Filtered-x LMS algorithm was used in the ANC, and sampling frequency was 15 kHz and adaptive filter coefficients were set to 3000 tap. As the results of control, the noise was reduced by 10dB in 500Hz to 5000Hz.</p>
著者
伊東 淳一 藤井 崇史 星野 哲馬 小高 章弘 佐藤 以久也 田中 大輔
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society (ISSN:09136339)
巻号頁・発行日
vol.128, no.8, pp.1005-1012, 2008-08-01
参考文献数
12
被引用文献数
4 3

This paper proposes analysis a dead-time error voltage compensation method with a disturbance observer for vector control, and analyses the proposed method. The dead-time compensation is very important to improve performances in the low speed region. The proposed compensation method is composed in the d-q rotational frame with the disturbance observer. As a result, a disturbance transmission characteristic becomes same as a high-pass filter. Then a stability of the proposed controller is hardly affected by controller parameters. In this paper, the validity of analysis is confirmed by experimental results under some conditions. The experimental results are similar to analyzed characteristics and indicate a validity of the analysis results.
著者
田中 大輔 大鐘 武雄 小川 恭孝
出版者
一般社団法人電子情報通信学会
雑誌
電子情報通信学会論文誌. B, 通信 (ISSN:13444697)
巻号頁・発行日
vol.82, no.11, pp.2133-2141, 1999-11-25
被引用文献数
39

同一チャネル干渉除去技術として基地局にアダプティブアレーを用いたSDMA方式を検討した.SDMA方式においては,所要の誤り率特性を得られない場合も起こりうるので,チャネルの割当可否を事前に,かつ容易に判断する手法が必要となる.ユーザからの信号が特定の到来方向を有する場合には,アレーの応答ベクトルによって与えられる空間相関を用いる手法が考えられる.本論文では,2ユーザ及び3ユーザにおけるチャネル割当基準を検討した.このとき空間相関値はそれぞれ一つまたは三つ与えられるが,2ユーザの場合は各ユーザの平均SNRと相関値が割当基準となり,3ユーザの場合は各ユーザの平均SNRと三つの相関値の積と2乗和の関係が割当基準となることが明らかとなった.また,3ユーザの場合に孤立セルにおいて呼損率特性を評価した結果,SDMAを用いない場合と比較して収容トラヒックはおよそ3.5倍まで上昇することが明らかとなった.