• Journal of Plant Biotechnology
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• v.37 no.1
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• pp.102-109
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• 2010

Fructan has been found to accumulate in various tissues during periods when light levels increased carbon fixation where low temperatures reduced growth rates while photosynthesis continued. In this study, we have cloned 1-sucrose:sucrose fructosyl transferase(1-sst) and 1-fructan: fructan fructosyl transferase (1-fft, a key enzyme for the synthesis of fuctan) from Jerusalem Artichoke (Helianthus tuberosus L.). The recombinant vector with 1-sst and 1-fft has been constructed under the control of 35S promoter of KJGV-B2 vector and transgenic plants obtained by Agrobacterium tumefaciens LBA4404. PCR analysis carried out on the putative transgenic plants for amplification of the coding region of specific gene (1-sst, 1-fft), and HPT genes. Transgenic lines carrying of 1-sst and 1-fft were confirmed for integration into the rice genome using Southern blot hybridization and RT-PCR. The transgenic plants in $T_2$ generation were selected and expression pattern analysis revealed that 1-sst and 1-fft were stable. This analysis confirmed the presence of low-molecular-weight fructan in the seedling of the transgenic rices. Therefore, cold tolerance and carbohydrate metabolism will be possible to develop resistant plants using the transgenic rice.

• Journal of the Korean Society for Nondestructive Testing
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• v.12 no.3
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• pp.12-19
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• 1992

This paper shows that the identified and unidentified components of surface roughness in NC turning lathe which can not be analyzed in time domain such as $R_{max},\;R_a$ can be isolated in frequency domain by FFT analyzer. By interfacing FFT analyzer with stylus surface roughness instrument, surface roughness on change of working condition, especially tool feed, such as 0.1, 0.15, 0.2, 0.25, 0.3(mm/rev) can be analyzed in frequency domain as follows. 1. By frequency analysis of surface roughness profile, the basic wave length of surface roughness can be obtained to isolate the identified and unidentified components of surface roughness. 2. With increase of tool feed, the unidentified components of surface roughness increase. 3. Since $R_{max}$, which can be obtained by stylus surface roughness is proportion to the output voltage of FFT analyzer, FFT analyzer also can be used to measure surface roughness in time domain such $R_a,\;R_{max}$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.359-360
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• 2008

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1071-1074
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• 2002

In this paper, power quality analysis system is proposed where voltage or current waveforms are nonsinusoidal. The proposed system relies on the FFT algorithm to compute real and reactive power. The advantage of system is that harmonic analysis is carried out on a period of the input signal. The proposed system is based on FFT processor which is designed using VHDL(Very high-speed integrated circuit Hardware Description Language). In the design of FFT processor, radix- $2^2$ is adopted to reduce several complex multipliers for twiddle factor. Complex multiplier is implemented as only shifters and adders. Therefore, the system is able to have both high hardware efficiency and high performance.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.13-18
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• 2001

In this paper, FFT(Fast Fourier Transform) analysis of friction was suggested as a method to interpret the contact conditions. Micro-grooves with various dimensions were fabricated on the silicon surface to investigate the frictional behavior with respect to the change in geometrical contact condition. Frictional forces between micro-grooved surfaces and spheres modeled as surface asperities were measured using a micro-tribotester which was built inside a SEM(Scanning Electron Microscope). The experimental results show that the relative dimensions and distributions of contact asperities between two surfaces can be predicted by the power spectrum and the main frequency in FFT-based analysis of friction coefficient. Also, it was shown that the friction coefficient for multi-asperities was the result of the superposition of that for each asperity.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.3-9
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• 1999

This paper concerns performance of a parallel digital signal processing system. The performance of the system is analyzed in terms of CPU cycles required for 1024-point FFT computation. The number of cycles is estimated in three different approaches; FFT algorithm-based, assembly level source code-based, and probability-based. The results of analysis indicate that on a bus-based system the best performance for FFT is achieved with a single board. Because in some applications like FFT, where frequent data exchanges among processors occur, the number of communication cycles increases as the number of boards. It is observed that inter-board communication degrades overall system performance for the FFT computation. Also shown is that linear increase in performance can be obtained if multiple buses are employed.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.261-269
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• 2004

In this paper, an efficient algorithm for computing in the MPEG/audio Layer Ⅲ (MP3) encoder is proposed. The proposed algerian performs a full-band 1024-point FFT by computing 32-point FFT's of 32 subband outputs. To reduce the aliasing caused by the analysis filter bank, an aliasing cancellation butterfly is developed. A major benefit of the proposed algorithm is the computational saving. By using the proposed algorithm, it is possible to save 40~50% of computations for FFT, which results in about 20% reduction of the PAM-2 complexity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.393-396
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• 2009

This paper describes a design of variable-length FFT/IFFT processor for OFDM-based communication systems. The designed FFT/IFFT processor adopts the in-place single-memory architecture, and uses a hybrid structure of radix-4 and radix-2 DIF algorithms to accommodate FFT lengths of $N=64{\times}2^k$ ($0{\leq}k{\leq}7$). To achieve both memory size reduction and the improved SQNR, a two-step conditional scaling technique is devised, which conditionally scales the intermediate results of each computational stage. The performance analysis results show that the average SQNR's of 64~8,192-point FFT's are over 60-dB. The processor synthesized with a $0.35-{\mu}m$ CMOS cell library can operate with 75-MHz@3.3-V clock, and 64-point and 8,192-point FFT's can be computed in $2.55-{\mu}s$ and $762.7-{\mu}s$, respectively, thus it satisfies the specifications of wireless LAN, DMB, and DVB systems.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.4
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• pp.53-60
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• 2011

In order to augment the robustness of OFDM system to Rayleigh multipath fading, there exist two smart antenna algorithms, namely, Pre-FFT smart antenna and Post-FFT smart antenna. After the mathematical modeling of both smart antenna algorithms, computer simulations have been carried to compare and analyze the performance of generalized eigen problem based Pre-FFT algorithm and the performance of Wiener solution based Post-FFT algorithm. It has been shown that the Post-FFT smart antenna far outperforms the Pre-FFT smart antenna due to the computational complexities. Especially it is so when the multipath signal arrives at beyond the guard interval and a rich co-channel interferer is introduced. Performance of a subcarrier clustering method proposed to lessen the computing load has been compared to that of a typical Wiener solution based Post-FFT smart antenna. Performance comparison between MRC(Maximum Ratio Combining) diversity based Post-FFT algorithm and typical Post-FFT algorithm has also been carried.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.50-58
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• 2009

Periodic variation of local paper structure was evaluated using two-dimensional fast Fourier transform (FFT) and spectral analysis. Since the periodic variation could originate from various sources and have different magnitudes and patterns depending on the origins, a complete analysis of local paper structure properties such as local grammage, local thickness, local apparent density and surface topography was proposed in this study. For a commercial copy paper, the individual periodic patterns for each local structural property were identified by using inverse FFT spectrums of the filtered spectrum. The spectral analysis of newsprint sample provided the period of variation quantitatively, which was useful in comparing the origins of the individual periodic patterns of the local structural properties.