http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
10 mm급 원형 마이크로스피커의 가상 스피커 TS 매개변수 규명
박석태(Park, Seok-Tae) 한국소음진동공학회 2007 한국소음진동공학회 논문집 Vol.17 No.11
It was discussed to identify Thiele Small Parameters for Pseudo loudspeaker within 10mm grade microspeaker attached to closed-box using known dynamic mass of moving parts. Also, enhanced circuit model for vented-box micro speaker system was used to more accurately simulate electrical impedance curves for real vented-box microspeaker system and compared to test results. Consequently, it showed that micro speaker could be modeled by pseudo loudspeaker TS parameters similar to general loudspeaker. Vented-box microspeaker model with pseudo loudspeaker TS parameters was well suited to describe real microspeaker. Also, it was proposed to estimate volume of rear closed-box of microspeaker without design specifications.
밀폐박스 상태의 가상 라우드스피커 매개변수 규명법 및 개선된 밀폐박스 모델링
박석태(Park, Seok-Tae) 한국소음진동공학회 2007 한국소음진동공학회 논문집 Vol.17 No.10
It was proposed to identify Thiele Small Parameters for loudspeaker attached to closed-box using known dynamic mass of moving parts. Also, enhanced PSPICE circuit model for closed-box loudspeaker system was proposed to more accurately simulate real closed-box loudspeaker system. Frequency dependent parameters were used to model voice coil inductor. Acoustic pressure response curves and electrical impedance curves were simulated and investigated by PSPICE circuit model according to compensation filter's parameters. Finally, proposed method is expected to be utilized for identification of pseudo Thiele Small parameters of microspeaker.
Seok-Tae Park(박석태) 한국소음진동공학회 2019 한국소음진동공학회 논문집 Vol.29 No.3
This paper presents physical coordinate-based 3-node triangular, 4-node rectangular, and 4-node quadrilateral FE codes on the Kirchhoff thin plate theory. Isoparametric 4-node quadrilateral and 4-node plate shell FE codes based on natural coordinates are also presented. The calculation time needed to solve a system equation was compared using direct, iterative, and full matrix and sparse matrix solvers including Gauss elimination method, CG, DGESV, DSGESV, SOR, PCG, GMRES, FGMRES, MGMRES, PARDISO, etc. The full matrix and the sparse matrix were applied to compare the computing time of the system equation using OCTAVE or the MATLAB intrinsic operator ‘\’. The computation times for PCG methods using four types of preconditioners were also compared. The computation time of the finite element method is compared with that of the PCG method after processing the system matrix with the full matrix and sparse matrix forms. We showed that PARDISO and sparse MATLAB or OCTAVE operator ‘\’ could be useful and effective methods for conducting large-scale finite element analyses using personal computers.
Seok-Tae Park(박석태) 한국소음진동공학회 2024 한국소음진동공학회 논문집 Vol.34 No.2
The sound pressure measured at the near field exhibits significant fluctuation depending on the size and frequency of the sound source. Therefore, it is necessary to use the sound pressure measured or numerically calculated at a sufficient distance from a radiator to estimate the actual sound power of the source. In this study, we investigated the appropriate distance for measuring or numerically calculating the sound pressure to validly estimate the sound power of a radiator, which depends on the frequency. A theoretical estimation of the starting position of the far-field acoustic characteristics for rigid disk vibrations was conducted, and the results were numerically compared and reviewed using the Rayleigh integral method (RIM) and lumped parameter method (LPM). The analysis using these methods, with modeling based on the 1/3 wavelength rule, demonstrated accurate predictions of the near-field acoustic characteristics. It was shown that the near sound field could be accurately predicted by modeling and analyzing under the condition of the 1/3 wavelength rule using the RIM and LPM. It was found that even when elements were modeled at a larger size than the 1/3 wavelength rule, the far-field sound pressure result could effectively depict the theoretical far-field sound pressure in the case of the RIM. It was also shown that the sound pressure due to the vibration of a flexible circular disk modeled with an element size based on the 1/3 wavelength rule was well predicted by both the LPM and RIM.
Seok-Tae Park(박석태) 한국소음진동공학회 2019 한국소음진동공학회 논문집 Vol.29 No.3
Various techniques have been proposed to shorten the analysis time of the traditional acoustic direct boundary element method. The overall analysis time can be reduced by vector operations and parallel operations. When constructing the system equation, unnecessary repetitions were reduced and modified separately to increase the analysis speed. To solve the system equations, computation speeds for each case to run on a CPU were compared using LINPACK-, LAPACK-, and MKL-dedicated libraries. Furthermore, when the system equations were solved by hybrid programming using the CPU and GPU, results that were hundreds of times faster could be achieved than when using multiple CPUs. The system matrix had a complex, asymmetric, dense matrix form; thus, direct solution methods were used. A system matrix equation solver code written by the hybrid method using Fortran and C languages was executed in the CUDA core of the GPU, enabling high-speed operations. The prediction results of the input acoustic impedance of a cone horn using the developed direct boundary element method code were in good agreement with the test results. It was possible to perform an acoustic analysis of several thousand degrees of freedom using the developed acoustic direct boundary element method codes at the time of a cup of tea. When using the acoustic boundary element method codes for calculations over 20 000 degrees of freedom and at 200 frequency points, results could be obtained within a few hours.
박석태(Park, Seok-Tae) 인천대학교 인천학연구원 2004 인천학연구 Vol.3 No.-
After Japan occupied Korea(1910) and really came to build colony. It put up assimilation policy for the civilizing of the East Asia aimed at the rule of colonies on the surface. However, in reality, it is understood by everybody that the above policy was the one aimed at discriminating colonial region as inferior people. And since here lies intentional making self internal (domination) , or making internal stranger (discrimination) consciousness together, I think it played a great role for highlighting the form of a colony. The local color or the color of a native town came to stress the thematic factor through the request of Japanese judging committee members, the request of Japanese judging committee members, as Joseon Art Exhibition began to be held, This request as Joseon Art Exhibition began to be held. We cannot doubt that the above is a part the policy of the colonization of the culture by Japanese government. And it reveals Japanese colonialism by means of the government-sponsored art exhibition and shows that it discriminates the interior land from the exterior land nakedly. We can see that by merely looking at the works of the painters of the corresponding colony which displayed the consciousness of native land by using female as a theme, the orientalism getting out of political thing and stressing noncivilization was applied as it is. Consequently, the consciousness of a native land which appeared to the painters of Joseon Art Exhibition grew up in the local color that is a product of Japanese colonialism. And this consciousness entered another way seeking the disposition of nationalism brings about the making of main land and the color of a native. The common trait which appeared to the art community of Korea is the fact that the Japanese influence criticizing the western modernization and crying out for returning to oriental spirit came to be further stressed through local color. This makes a dual stranger what is non-western and pre-modern aspect, so that Joseon color showed oriental image as non-western and pre-modern view. In particular, this oriental nature shows its characteristic as primitive theme which accepted the fauvism of the western modernism. The local color in government-sponsored art exhibition also makes the interpretation of the dominated. And I think that the deep-seated interpretation of the problem will be accompanied, depending how the local color demanded from the colonial ruler is accepted and developed. Consequently, through this study I compared the local color made by the sponsors of colonialism with the paintings shown at Joseon Art Exhibition, and examined the position of accepting them. However, as the method of the study has a limit in which all-out and multilateral groping, I am going to wait for more advanced study.