著者
大槻知史 齋藤 直樹 中井 満 下平 博 嵯峨山 茂樹
出版者
一般社団法人情報処理学会
雑誌
情報処理学会論文誌 (ISSN:18827764)
巻号頁・発行日
vol.43, no.2, pp.245-255, 2002-02-15
被引用文献数
12

本稿では,隠れマルコフモデル(HMM)を用いて,人間が鍵盤入力した演奏情報(標準MIDIファイル)の発音時刻の間隔から,意図された音価列を復元推定する手法を提案し,実験によりその効果を実証する.人間が音楽演奏する際の物理的音長は,音価に対応する正規の長さから意識的・無意識的に揺らぐため,楽譜入力や自動採譜などでは,楽譜として意図された各音符の音価を正しく推定するのは容易ではない.そこで,連続音声認識の定式化にならって,音楽的な演奏を学習・認識する原理をHMMの手法を用いてモデル化する.さらに,同様の原理により小節線・拍子推定,テンポ変化推定も可能となることを示す.This paper proposes the use of Hidden Markov Model (HMM) for rhythmrecognition from musical performance recorded in the standard MIDIfile format. Intentionally or unintentionally, physical durations ofmusical notes in human performances often fluctuate from nominallengths of the intended notes. Estimating intended note sequences is,therefore, not trivial for computers. In this paper, we formulate theprocess of understanding and recognizing musical rhythm patterns usingHMM similarly to continuous speech recognition (CSR). It is shownthat the same principle enables bar line allocation, beat recognition,and tempo estimation.
著者
大槻 知史 愛須 英之 田中 俊明
出版者
公益社団法人日本オペレーションズ・リサーチ学会
雑誌
日本オペレーションズ・リサーチ学会和文論文誌 (ISSN:04534514)
巻号頁・発行日
vol.53, pp.30-55, 2010-12
参考文献数
13
被引用文献数
2

現在多くの鉄道事業者では,経験豊富な熟練者が膨大な時間を割いて一定期間の車両運用の基本計画を作成し,またダイヤ乱れが発生する度に計画修正している.本稿ではこの車両運用計画作成の自動化を目的とする制約充足解法を提案し,実問題に基づく評価では汎用ソルバーCPLEXよりも高速に求解できることを確認した.また提案解法は基本計画作成・修正計画作成のいずれにも利用可能であり,かつ評価関数の設計の自由度が高いため,多くの鉄道事業者に対し適用可能な汎用解法となる可能性がある.
著者
中里 裕美 大槻 知史 鐘ヶ江 秀彦
出版者
日本地域学会
雑誌
地域学研究 (ISSN:02876256)
巻号頁・発行日
vol.35, no.3, pp.719-736, 2005 (Released:2007-06-01)
参考文献数
19
被引用文献数
1 1

Historically, Local Currency Systems (LCS) were founded in 1930s when economic depression spread widely around the world to support the local economy. However, currently, LCS are seen as a tool to strengthen solidarity in the local community by solving social welfare issues and environmental issues uncovered by the state.This study aims to clarify the social functions for participants in LCS through a case study of Local Exchange Trading Systems (LETS) in Sweden. The focus will be on the role of personal relationship networks. This study examines an in-depth interview with the organizers of seven LETS associations in three cities in Sweden (Stockholm, Göteborg, and Lund) to reveal their purpose. A questionnaire survey was done in BYTS, the oldest and largest LETS to date in Sweden, to test the realization of the previous revealed purposes. Additionally, we use the methods of Social Network analysis to grasp the characteristics of personal relationship networks in LCS. The study can show that one of the main aims of these LETS—to develop social networks—is indeed accomplished. Not only was the social functions of the LETS a motivation for the effective participants to join BYTS, but they also could establish personal relationships. The opportunity to make friends was especially attractive for low-income, low-educated and retired persons. Furthermore, we identify four characteristics of LCS networks ; such as expanding peer to peer networks without mediation of the office (a network center) and creating the system for evaluation of goods and services which are hard to evaluate in the national currency system of our dehumanized society.The result suggests that LCS can contribute to visualize various potential needs embedded in the participants' mundane lives which usually are ignored by the public policy and the market through promoting peer to peer reciprocal exchanges, and therefore we can conclude that personal relationship networks created by using LCS has the important function to revitalize local community.