Binary time-frequency masks are powerful tools for the separation of sources from a single mixture. Perfect demixing via binary time-frequency masks is possible provided the time-frequency representations of the sources do not overlap: a condition we call W-disjoint orthogonality. We introduce here the concept of approximate W-disjoint orthogonality and present experimental results demonstrating the level of approximate W-disjoint orthogonality of speech in mixtures of various orders. The results demonstrate that there exist ideal binary time-frequency masks that can separate several speech signals from one mixture. While determining these masks blindly from just one mixture is an open problem, we show that we can approximate the ideal masks in the case where two anechoic mixtures are provided. Motivated by the maximum likelihood mixing parameter estimators, we define a power weighted two-dimensional (2-D) histogram constructed from the ratio of the time-frequency representations of the mixtures that is shown to have one peak for each source with peak location corresponding to the relative attenuation and delay mixing parameters. The histogram is used to create time-frequency masks that partition one of the mixtures into the original sources. Experimental results on speech mixtures verify the technique. Example demixing results can be found online at http://alum.mit.edu/www/rickard/bss.html.

Blind separation of speech mixtures via time-frequency masking

An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

This paper presents a blind source separation method for convolutive mixtures of speech/audio sources. The method can even be applied to an underdetermined case where there are fewer microphones than sources. The separation operation is performed in the frequency domain and consists of two stages. In the first stage, frequency-domain mixture samples are clustered into each source by an expectation-maximization (EM) algorithm. Since the clustering is performed in a frequency bin-wise manner, the permutation ambiguities of the bin-wise clustered samples should be aligned. This is solved in the second stage by using the probability on how likely each sample belongs to the assigned class. This two-stage structure makes it possible to attain a good separation even under reverberant conditions. Experimental results for separating four speech signals with three microphones under reverberant conditions show the superiority of the new method over existing methods. We also report separation results for a benchmark data set and live recordings of speech mixtures.

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Underdetermined Convolutive Blind Source Separation via Frequency Bin-Wise Clustering and Permutation Alignment

An object is to provide a method for manufacturing a semiconductor device, in which the number of photolithography steps can be reduced, the manufacturing process can be simplified, and manufacturing can be performed with high yield at low cost A method for manufacturing a semiconductor device includes the following steps: forming a semiconductor film; irradiating a laser beam by passing the laser beam through a photomask including a shield for shielding the laser beam; subliming a region which has been irradiated with the laser beam through a region in which the shield is not formed in the photomask in the semiconductor film; forming an island-shaped semiconductor film in such a way that a region which is not irradiated with the laser beam is not sublimed because it is a region in which the shield is formed in the photomask; forming a first electrode which is one of a source electrode and a drain electrode and a second electrode which is the other one of the source electrode and the drain electrode; forming a gate insulating film; and forming a gate electrode over the gate insulating film

Method for Manufacturing Semiconductor Device

A time-frequency blind signal separation method applicable to underdetermined mixtures of dependent sources

We have developed a method of segregating desired speech from concurrent sounds received by two microphones. In this method, which we call SAFIA, signals received by two microphones are analyzed by discrete Fourier transformation. For each frequency component, differences in the amplitude and phase between channels are calculated. These differences are used to select frequency components of the signal that come from the desired direction and to reconstruct these components as the desired source signal. To clarify the effect of frequency resolution on the proposed method, we conducted three experiments. First, we analyzed the relationship between frequency resolition and the power spectrum’s cumulative distribution. We found that the speech-signal power was concentrated on specific frequency components when the frequency resolution was about 10-Hz. Second, we determined whether a given frequency resolution decreased the overlap between the frequency components of two speech signals. A 10-Hz frequency resolution minimized the overlap. Third, we analyzed the relationship between sound quality and frequency resolution through subjective tests. The best frequency resolution in terms of sound quality corresponded to the frequency resolutions that concentrated the speech signal power on specific frequency components and that minimized the degree of overlap. Finally, we demonstrated that this method improved the signal-to-noise ratio by over 18dB.

Sound source segregation based on estimating incident angle of each frequency component of input signals acquired by multiple microphones

There are provided a chamber having openings which are opened to an outer air and through which a solder-adhered object w is passed and having a heating/melting area and carrying areas arranged adjacent to the heating/melting area, a carrying mechanism for carrying the solder-adhered object w into the heating/melting area, a formic-acid supplying means for supplying a formic acid into the heating/melting area, an exhausting means for exhausting a gas from the heating/melting area and its neighboring area to lower a pressure in the heating/melting area rather than an outer air, heating means for heating directly or indirectly the solder-adhered object w in the heating/melting area, and air-stream suppressing means for disturbing a gas flow between the heating/melting area and the carrying areas. Accordingly, there can be provided a solder jointing system for jointing solder layers of the semiconductor device, the electronic device, or the like to the wirings or the pads, which is capable of having a high processing ability and preventing re-oxidation.

Solder jointing system, solder jointing method, semiconductor device manufacturing method, and semiconductor device manufacturing system

A semiconductor device manufacturing method comprises the steps of forming solder bumps on an underlying metal film of a semiconductor device, and placing the semiconductor device and the solder layer in a reduced pressure atmosphere containing formic acid to form the solder bumps Accordingly, the solder bumps can be formed without flux generating voids in the solder layer Furthermore, the cleaning required after the solder bumps are formed can be omitted

Method of manufacturing solder bumps and solder joints using formic acid

PROBLEM TO BE SOLVED: To separate sound accurately into respective components and to attain real time processing. SOLUTION: A difference Δτ in time required for a sound signal to travel from a sound source to microphones 1, 2 is detected from output channel signals L, R of the microphones 1, 2, where the signals L, R are divided into frequency bands L(f1 )-L(fn ), R(f1 )-R(fn ) by Fourier transform, and an arrival time difference Δτi (i=1, 2,...n) to the microphones 1, 2 of a corresponding frequency band of the L(f1 )-L(fn ), R(f1 )-R(fn ) and a signal level difference ΔLi are detected. Then L(f1 )-L(fn ), R(f1 )-R(fn ) are divided into low frequencies f1 1/Δτ, and it is determined from which sound source the L(fi ), R(fi ) arrive, based on Δτi , in the case of low frequencies, on ΔLi , Δτi in the case of medium frequencies, and on ΔLi in the case of high frequencies, and the result is outputted for each sound source and the output is subject to inverse Fourier transform by each sound source and the results are synthesized.

Sound source separation method, system and recording medium

PROBLEM TO BE SOLVED: To improve a treating capacity and to prevent re-oxidation with respect to a solder joining device for joining solder layers of a semiconductor device and electronic parts to wiring and a pad. SOLUTION: The device is comprised of a chamber 1 which has openings 2 and 3 which are opened in the air and make a solder mounting object pass and moreover has a heating and melting area 5 and carrying areas 4, 6 and 7 adjacent to the area 5, a carrying mechanism 15 which carries the solder mounting object w in the inside of the heating and melting area 5, a formic acid feeding means 16 which feeds formic acid in the inside of the heating and melting area 5, an evacuating mechanism 17 which evacuates gas in the heating and melting area 5 or its vicinity and makes a pressure the heating and melting area 5 lower than that of the air, heating means 11b and 12b which directly or indirectly heat the solder mounting object w in the inside of the heating and melting area 5,and air flow control means 8b and 8c which disturb the flow of gas between the heating and melting area 5 and each of the carrying areas 4, 6 and 7. COPYRIGHT: (C)2002,JPO

Hiroyuki Matsui

Papers

Sound source segregation based on estimating incident angle of each frequency component of input signals acquired by multiple microphones

Solder jointing system, solder jointing method, semiconductor device manufacturing method, and semiconductor device manufacturing system

Method of manufacturing solder bumps and solder joints using formic acid

Sound source separation method, system and recording medium

Solder joining device