あらまし 人間の聴覚機能を計算機で実現しようという試みが活発に進められており、その枠組を総称して計算論的 聴覚情景分析 (Computational Auditory Scene Analysis: CASA)と呼ぶ。近年この研究分野における興味の対象は、 Bregmanが指摘した分凝要件 [1]に基づく混合音分離法の実現にある。CASAにおける多くの従来手法の間で共通す るのは、各時刻で独立に調波成分を見つけ出すための処理 (周波数方向の群化)と、抽出された調波成分特徴量の時系 列を時間方向にスムージングする処理 (時間方向の群化)を多段処理的に行っている点である。しかしながら、より良 い群化プロセスの実践のためには、これらは本来協調し合いながら行われるべきであり、個々の音源の時間周波数全 域に渡ったスペクトル構造を一挙に推定できる方法論が不可欠であると我々は考える。本稿では、この...

We propose a computational auditory scene analysis (CASA) model for monaural speech segregation. It deals with low-frequency and high-frequency signals differently. For high-frequency signals, it generates segments based on common amplitude modulation (AM) and groups them according to AM repetition rates. This model performs substantially better than previous CASA systems.

Parsing of sound sources in the auditory environment or 'auditory scene analysis' is a computationally demanding cognitive operation that is likely to be vulnerable to the neurodegenerative process in Alzheimer's disease. However, little information is available concerning auditory scene analysis in Alzheimer's disease. Here we undertook a detailed neuropsychological and neuroanatomical charact...

Spectrum agility (SA) is a novel way of improving spectrum utilization efficiency and making greater bandwidth available to network applications. Despite its advantages, the fundamental operations (e.g., periodic spectrum sensing) involved in realizing SA can also adversely affect application performance. We propose Context-Aware Spectrum Agility (CASA), which uses application hints together wi...

Sound source localization and separation with permutation resolution are essential for achieving a computational auditory scene analysis system that can extract useful information from a mixture of various sounds. Because existing methods cope separately with these problems despite their mutual dependence, the overall result with these approaches can be degraded by any failure in one of these c...

1 Special Lab Non-Invasive Brain Imaging, Leibniz Institute for Neurobiology, Magdeburg, Germany 2 Cognition Institute, University of Plymouth, Plymouth, UK 3 School of Psychology, University of Plymouth, Plymouth, UK 4 Department of Neuroscience, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, USA 5 Department of Otorhinolaryngology-Head and Neck Surgery, Albert Einstein ...

Evolution and entropy in the organization of urban street patterns Nahid Mohajeri a , Jon R. French b & Michael Batty c a Department of Geography, University College London, London, UK b Environmental Modelling Group, Department of Geography, University College London, London, UK c Centre for Advanced Spatial Analysis (CASA), University College London, London, UK Version of record first publish...