Thumwarin, Pitak

Preferred name

Thumwarin, Pitak

Alternative Name

Thumwarin, P.

Main Affiliation

Music Science and Engineering

pitak.th@kmitl.ac.th

Now showing 1 - 10 of 15

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Audio forensics from gunshot for firearm identification
(2014-01-01)
Thumwarin, P.
;
Wakayaphattaramanus, N.
;
Matsuura, T.
;
Yakoompai, K.
The gunshot blast is one of the evidences used to identify the criminal gun in the shooting scene. We proposed a method of using the gunshot blast to identify the firearm caliber in terms of audio forensics. The experiments were performed on the database consisting of 80 audio files of gunshot sounds fired from 8 different guns. At first, the autocorrelation functions of the gunshot sounds were calculated and normalized in the preprocessing stage. Then the Fourier cosine coefficients could be used to reduce the fluctuation and to extract the features of gunshot sounds. In addition, the gun sounds could also be verified by evaluating the difference among the Fourier cosine coefficients of the reference, and then the gun caliber could be identified. © 2014 IEEE.
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On-line writer dependent character recognition for khmer based on FIR system characterizing handwriting motion
(2008-10-06)
Thumwarin, P.
;
Khem, S.
;
Janchitraponvej, K.
;
Matsuura, T.
We proposed an on-line writer dependent Khmer recognition method based on FIR system characterizing handwriting motion. The handwriting motion can be described by two features, barycenter trajectory and its velocity. The barycenter is determined from the center point of the script and the two adjacent pen-point positions with respect to time in handwriting process. Then the barycenter and its velocity are expanded into wavelet series to extract the time-frequency characteristics of handwriting motion. In this paper, the FIR(finite impulse response) system characterizing the handwriting motion is introduced. In this case, the wavelet coefficients of the velocity and trajectory of the barycenter are used as the input and output of the FIR system, respectively. The obtained impulse response of the FIR system is considered as the individual feature for a particular character. Finally, Khmer alphabets can be recognized by using the Euclidean distance between the impulse responses obtained from the reference alphabets and those of the alphabets to be recognized. Khmer character recognition experiments were performed on a database consisting of 4770 of numerals and alphabets written by 15 people. As the results, the average of the recognition rate was 97.05%. ©2008 IEEE.
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Iris recognition based on dynamic radius matching of iris image
(2012-10-02)
Thumwarin, P.
;
Chitanont, N.
;
Matsuura, T.
This paper presents iris recognition method based on dynamic radius matching of iris image. First, the iris images are segmented to remove the eyelashes and eyelids. Then the individual feature of the iris image can be extracted by expanding their polar images into Fourier series. The obtained Fourier coefficient is used as the individual features for iris recognition. Moreover, in order to reduce the fluctuation caused by size of pupil and iris, the dynamic radius matching is introduced to calculate the similarity between the iris images. Experimental results were performed on CASIA V1.0 [6] public iris database having 756 iris images from 108 persons. The obtained accuracy rate was 94.8%. © 2012 IEEE.
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An adaptive generalized RAKE CDMA receiver for layered space time coded systems in multipath fading channels
(2010-07-30)
Keovkolyan, T.
;
Nugrahani, D.
;
Thumwarin, P.
;
Teekapakvisit, C.
;
Matsuura, T.
An adaptive generalized RAKE receiver for Layered Space Time Coded CDMA (LSTC-CDMA) system has been proposed in this paper. The proposed Generalized RAKE receiver, based on a joint adaptive iterative detection and decoding algorithm, adaptively mitigates the effect of multipath fading and cancels the system interferences such as Co-Channel Interference (CCI) and Multiple Access Interference (MAI). The Partially Filtered Gradient Least Means Square (PFGLMS) algorithm is used for both feed-forward filter and feedback filter in the adaptive detection in order to determine the weight coefficient of each finger element. The performance of the system is evaluated by simulation results for the various numbers of RAKE fingers in multipath Rayleigh fading channels.
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On-line writer recognition for Thai numeral
(2002-01-01)
Thumwarin, P.
;
Tangtisanon, P.
;
Murata, S.
;
Matsuura, T.
This paper discusses an on-line writer recognition for Thai numerals. First, a center point of a Thai numeral is determined after normalization. Then the center point is shifted to an origin. Secondly, the distance from the origin to the pen-point position in the handwriting process is measured and the area of a triangle determined from the origin and the two adjacent points of the pen-point position is calculated. Thirdly, the features of pen-point movement in the process are extracted by expanding the time sequence of the above distance and area into Fourier series. Then the features of pen-point movement are represented in terms of Fourier coefficients. Fourthly, in order to describe the handwriting process features, the FIR system with the above coefficients as input and output of the system is introduced. Then the impulse response of the FIR system is used as the feature of handwriting process. Furthermore in order to recognize the writer, K-L expansion (J.T. Tou and R.C. Gonzalez "Pattern Recognition Principles", Addison-Wesley, pp. 269, 1974) of the obtained impulse response is used. In the experiments, the average rates of type I (false rejection) and type II (false acceptance) error were 17.14% and 9.26%, respectively.
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FIR firearm identification system
(2009-01-01)
Thumwarin, P.
;
Prasit, C.
;
Suwanvesh, T.
;
Matsuura, T.
We propose a FIR(Finite impulse response) firearm identification system. The firearm can be identified by using the impulse response of the FIR system characterizing the rotation invariant feature of the cartridge case image. In this case, the rotation invariant feature can be extracted by the magnitude of Fourier coefficients of polar image of the cartridge. Then the obtained Fourier coefficients are used as the input and the output of the FIR system. The impulse response of the FIR system is used as the unique feature for firearm identification. Finally, the firearm can be identified by the Fisher's linear discriminant function. The experimental results are taken to show the effectiveness of the proposed method.
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Firearm identification based on FIR system characterizing rotation invariant feature of cartridge case image
(2008-12-01)
Thumwarin, P.
;
Prasit, C.
;
Boonbumroong, P.
;
Matsuura, T.
We propose firearm identification method based on FIR system characterizing rotation invariant feature of cartridge case image. The rotation invariant feature is represented by the absolute value of Fourier coefficients of polar image on circles with different radii of the cartridge case's primer. Then the FIR(Finite impulse response) system characterizing the rotation invariant feature of cartridge case's primer image is introduced. The absolute value of Fourier coefficients obtained from the polar image on the circles with different radii are used as the input and output of the FIR system, respectively. The obtained impulse response of the FIR system is considered as the unique feature of the individual gun. Finally, a firearm can be identified by using the Fisher's linear discriminant function of the obtained impulse response of the FIR system. The firearm identification experiments are conducted to show the effectiveness of the proposed method. © 2008 IEEE.
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Firearm identification system with rotation invariance
(2010-01-01)
Thumwarin, P.
;
Prasit, C.
;
Yakoompai, K.
;
Matsuura, T.
This paper presents a firearm identification method with rotation invariance. The rotation invariant feature can be extracted by the magnitude of Fourier coefficients of polar image of the cartridge on circles with different radii. Then the fluctuation of the obtained magnitude of Fourier coefficients can be reduced by the FIR(Finite impulse response) Wiener filter. And they are used as the input and the output of the FIR system characterizing the rotation invariant feature of cartridge image. The impulse response of the FIR system is used as the unique feature for firearm identification. Finally, the firearm can be identified by the Fisher's linear discriminant function. The experimental results are given to show the effectiveness of the proposed method. ©ICROS.
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Firearm identification based on rotation invariant feature of cartridge case
(2008-12-01)
Thumwarin, P.
;
Prasit, C.
;
Matsuura, T.
This paper, proposes firearm identification method based on rotation invariant feature of cartridge case image. The rotation invariance feature is represented by the absolute value of Fourier coefficients of polar image of cartridge case on circles with different radii. The absolute value of Fourier coefficients is considered as the individual feature of the particular gun. Finally, the firearm can be identified by the distance between the absolute value of Fourier coefficients obtained from the reference cartridge case and the cartridge case to be identified. The firearm identification experiments are given to show the effectiveness of the proposed method. © 2008 SICE.
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On-line signature verification based on FIR system characterizing velocity and direction change of barycenter trajectory
(2010-12-01)
Thumwarin, P.
;
Pernwong, J.
;
Wakayaphattaramanus, N.
;
Matsuura, T.
We propose an on-line signature verification method based on finite impulse response(FIR) system characterizing velocity and direction change of barycenter trajectory. First, the discrete cosine transforms (DCTs) of the characteristics are used to reduce fluctuation and extract the feature of handwriting in signing process. Then the signature verification system is realized by the three FIR subsystems. The obtained impulse responses of the three FIR subsystems are used as the individual feature for signature verification. Signature can be verified by evaluating the difference between the impulse responses of the FIR subsystems for a reference signature and the signature to be verified. The signature verification experiments were performed on the SUBCORPUS-100 MCYT signature database[6] consisting of 5,000 signatures from 100 signers. ©2010 IEEE.

Thumwarin, Pitak

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