Sound source localization is carried out based on TDOA (Time-Difference-Of-Arrival) between microphones. When the TDOA is detected from a phase difference between two microphones, an ambiguity of phase difference often occurs under a high resolution situation and thus the estimation accuracy degrades significantly. In this paper, a propagation delay characteristic is approximated directly using FIR (Finite Impulse Response) filter, in which an impulse response is described by sinc function and an adjustable parameter is just a TDOA. Although there is not the ambiguity of phase difference in this procedure, an appropriate TDOA has to be searched using any optimization because the TDOA takes a real value. This falls into a non-linear optimization problem and there are many local minima in the search space therefore, a local minimum stagnation often occurs when applying a normal steepest decent algorithm for the search. In the proposed method, TDOA is estimated by introduction an avoidance method of local minimum stagnation. The validity of the proposed method is shown from several experimental results.

光導波路型の1入力多出力光スイッチとして、アレイ光導波路を用いた構成がある。この構成では、入力光を入力側スラブ光導波路で各アレイ光導波路に分配した後、アレイ光導波路間の位相差を線形に変えることによって出力側スラブ光導波路内で結像される波面に偏向を与え、出力ポートを選択することができる。これまで、各アレイ光導波路への光パワー分配比は入力側スラブ光導波路内のフラウンホーファー回折によるガウス分布が前提とされていたが、各アレイ光導波路への光パワー分配比を適切に設定することによって、光スイッチのクロストークを低減できることを解析により示す。

This paper proposes a numerical method to estimate track lateral alignment. The estimation of the track lateral alignmentisformulatedastheproblemoffindinganapproximatesolutiontoafunctionalequation, andtheSincfunction approximation, which has been studied in the field of numerical analysis, and the Fourier transform approximation based on numerical integration methods are utilized to construct the approximate solution. In particular, our newly proposed method directly deals with the singularity in the frequency transfer function involved in the estimation.

概要. 本論文では，端点特異性をもつ解析関数の成す関数空間に対して，Ganelius 標本点を用いた関数近似公式を提案する．そして，この公式がSE-

In this paper, a novel method for solving multiple sound source localization problem using two microphone system. In this problem, it is assumed that the number of sound sources is more than 2 and is unknown in advance. That is, this problem is one of underdetermined problems having unknown number of measurement targets. For solving such a problem, a method based on swarm intelligence is applied, in which estimation of the number of sound sources and multiple source directions in the same framework. The effectiveness of the method is shown from several experimental results in the actual room.

In recent years, research and development of highly accurate position detection indoors have attracted attention. In this paper, we propose a new scheme to improve accuracy of position detection indoors, identifying the direct wave between BLE transmitter (TX) and BLE receiver (RX), applying RD-CUBA-MUSIC⁽¹⁾ to indoor multi-path environment. In the proposed scheme, the direction of radio wave arrival is estimated in both directions of TX→RX and RX→TX. Estimation accuracy is improved by collating the arrival directions of the pair of two-way direct wave candidates. This Direction-Of-Arrival (DOA) estimation for direct wave is sequentially executed with a plurality of RXs and indoor position of TX is detected using the DOAs and the corresponding RX positions. In RD-CUBA-MUSIC, we select a beam pattern with high correlation with the sinc function beam pattern as a beam pattern of the ESPAR antenna. Computer simulation shows that the proposed scheme can achieve a detection accuracy within 1 m in error at a 91% probability. It also shows within 0.5 m in error at 67% even though it is in an indoor multi-path environment.