• Mass Spectrometry Letters
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• 제12권2호
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• pp.41-46
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• 2021

Collision-induced dissociation (CID) and higher-energy collisional dissociation (HCD) are the widely used fragmentation technique in mass spectrometry-based proteomics studies. Understanding the fragmentation pattern from the tandem mass spectra using statistical methods helps to implement efficient spectrum analysis algorithms. The study characterizes the frequency of occurrence of multi-charged fragment ions and their neutral loss events of doubly and triply charged peptides in the CID and HCD spectrum. The dependency of the length of the fragment ion on the occurrence of multi-charged fragment ion is characterized here. Study shows that the singly charged fragment ions are generally dominated in the doubly charged peptide spectrum. However, as the length of the product ion increases, the frequency of occurrence of charge 2 fragment ions increases. The y- ions have more tendencies to generate charge 2 fragment ions than b- ions, both in CID and HCD spectrum. The frequency of occurrence of charge 2 fragment ion peaks is prominent upon the dissociation of the triply charged peptides. For triply charged peptides, product ion of higher length occurred in multiple charge states in CID spectrum. The neutral loss peaks mostly exist in charge 2 states in the triply charged peptide spectrum. The b-ions peaks are observed in much less frequency than y-ions in HCD spectrum as the length of the fragment increases. Isotopic peaks are occurred in charge 2 state both in doubly and triply charged peptide's HCD spectrum.

• Archives of Pharmacal Research
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• 제18권5호
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• pp.340-345
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• 1995

A nebumetone tablet in development $(Navuton^R)$ was tested for its bioequivalence to the erference tablet $(Uniton^R)$. Seventeen healthy Korean male subjects participated in this study. Each subject received a 1-g dose of nabumetone (2tables each) in an unbalanced, randomized, two-way crossover investigation. Serum concentrations of 6-methoxy-2-na-phthylacetic acid (6-MNA), a major metabolite of nebumetone, were measured over 120 hr interval by a high-performance liquid chromatography. The maximum serum concentration $(C_{max})$ and time to reach the maximum concentration$(T_{max})$ were read directly, but area under the serum concentration time curve from time 0 to 120 hr (AUC) and mean residence time serum curves showed multiple peaks of 6-MNA in most subjects, and the $C_{max}$ and $T_{max}$ were read from the highest serum peaks. calculated bioavailability parameters for test and reference tablets were 148.6 : 1377.9 $\mug \cdot hr/ml$ for AUC; 25.2:23.1 $\mu/ml$ for $C_{max}$; 11.8:16.4 hr for $T_{max}$, and 42.6 : 43.8 hr for MRT, respectively. The paired t-test revealed no significant differences in all the parameters between the two tablets. Analysis ofl variance (ANOVA) revealed no significant differences between groups and formulations in all the parameters ($C_{max}$ and $T_{max}$, AUC and MRT) indicating the crossover design of the experiment was properly performed. But significant differences (p<0.05) between subject/groups and periods were found for all the parameters indicating substantial intersubject and interperiodic variations for these parameters.

• Journal of Power Electronics
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• 제17권2호
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• pp.514-521
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• 2017

This paper proposes a shadowing compensation method for the solar modules of grid-connected photovoltaic generation systems. The shadowing compensator (SC) implemented by the proposed shadowing compensation method is used only for the solar modules that can be shaded by predictable sources of shading. The proposed SC can simplify both the power circuit and the control circuit as well as improve power efficiency and utilizes a voltage equalizer configured by a modified multi-winding fly-back converter. The proposed SC harvests energy from the entire solar cell array to compensate for the shaded sub-modules of the solar cell array, producing near-identical voltages of all shaded and un-shaded sub-modules in the solar cell array. This setup prevents the formation of multiple peaks in the P-V curve under shaded conditions. Hardware prototypes are developed for the SCs implemented by the conventional and modified multi-winding fly-back converters, and their performance is verified through testing. The experimental results show that both SCs can overcome the multiple peaks in the P-V curve. The proposed SC is superior to the SC implemented by the conventional multi-winding fly-back converter.

• Journal of Crop Science and Biotechnology
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• 제10권4호
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• pp.237-242
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• 2007

Genome duplication(i.e. polyploidy) is a common phenomenon in the evolution of plants. The objective of this study was to achieve a comprehensive understanding of genome duplication for SNP discovery by Thymine/Adenine(TA) cloning for confirmation. Primer pairs were designed from 793 EST contigs expressed in the roots of a supernodulating soybean mutant and screened between 'Pureunkong' and 'Jinpumkong 2' by direct sequencing. Almost 27% of the primer sets were failed to obtain sequence data due to multiple bands on agarose gel or poor quality sequence data from a single band. TA cloning was able to identify duplicate genes and the paralogous sequences were coincident with the nonspecific peaks in direct sequencing. Our study confirmed that heterogeneous products by the co-amplification of a gene family member were the main cause of obtaining multiple bands or poor quality sequence data in direct sequencing. Counts of amplified bands on agarose gel and peaks of sequencing trace suggested that almost 27% of nonrepetitive soybean sequences were present in as many as four copies with an average of 2.33 duplications per segment. Copy numbers would be underestimated because of the presence of long intron between primer binding sites or mutation on priming site. Also, the copy numbers were not accurately estimated due to deletion or tandem duplication in the entire soybean genome.

• Food Science and Biotechnology
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• 제14권5호
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• pp.656-660
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• 2005

The relationship between the gas chromatographic (GC) patterns of sauce made of barley bran and ranked order in sensory analysis was investigated by multiple regression analysis (MRA). Most of the 42 barley bran sauce samples comprised about 34 peaks, in which the content of 9, 12-octadecanoic acid methyl ester was the highest, followed by those of 2-furanmethanol and 2-furancarboxaldehyde. It is difficult to estimate the aroma quality of barley bran sauce samples on the basis of only one peak. The 34 aroma compounds of the 42 samples were analyzed by an MRA model featuring six transformations. The most precise fit was calculated from the absolute value transformed with the root square of each peak, and the multiple determination coefficient showed that 91.6% of the variation in the sensory score could be explained on the basis of GC data.

• International Journal of Contents
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• 제14권4호
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• pp.57-64
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• 2018

Among many UNESCO world heritage sites in Korea, "Historic Village: Hahoe" is adjacent to Nakdong River and it is imperative to monitor the water level near the village in a bid to forecast floods and prevent disasters resulting from floods.. In this paper, we propose a recurrent neural network with multiple hidden layers to predict the water level near the village. For training purposes on the proposed model, we adopt the sixth-order error function to improve learning for rare events as well as to prevent overspecialization to abundant events. Multiple hidden layers with recurrent and crosstalk links are helpful in acquiring the time dynamics of the relationship between rainfalls and water levels. In addition, we chose hidden nodes with linear rectifier activation functions for training on multiple hidden layers. Through simulations, we verified that the proposed model precisely predicts the water level with high peaks during the rainy season and attains better performance than the conventional multi-layer perceptron.

• 한국통신학회논문지
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• 제36권7C호
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• pp.459-466
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• 2011

본 논문에서는 위성항법 시스템에서 (global navigation satellite system: GNSS) 사용되는 이진 옵셋 반송파(binary offset carrier: BOC) 신호 상관함수의 주변 첨두 때문에 발생하는 신호 획득 문제에 대해 소개한다. 우선 BOC 신호의 상관함수를 분석하여 상관함수의 주변 첨두가 불규칙한 형태를 갖는 부 상관함수들의 결합을 통해 형성된다는 점을 관찰하며, 관찰 결과를 바탕으로 cyclostationarity를 지니는 부 상관함수들의 재조합에 기반을 둔 신호 획득 기법을 제안한다. 제안한 기법은 모든 BOC 신호에 적용되어 주변 첨두를 완벽히 제거할 수 있으며, 모의실험을 통해 제안한 기법이 기존의 기법들에 비해 더 나은 평균 신호 획득 시간 (mean acquisition time: MAT) 성능을 제공함을 보인다.

• 비파괴검사학회지
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• 제34권6호
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• pp.419-427
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• 2014

Nonlinear features of ultrasonic waves are more sensitive to the presence of a fatigue crack than their linear counterparts are. For this reason, the use of nonlinear ultrasonic techniques to detect a fatigue crack at its early stage has been widely investigated. Of the different proposed techniques, laser nonlinear wave modulation spectroscopy (LNWMS) is unique because a pulse laser is used to exert a single broadband input and a noncontact measurement can be performed. Broadband excitation causes a nonlinear source to exhibit modulation at multiple spectral peaks owing to interactions among various input frequency components. A feature called maximum sideband peak count difference (MSPCD), which is extracted from the spectral plot, measures the degree of crack-induced material nonlinearity. First, the ratios of spectral peaks whose amplitudes are above a moving threshold to the total number of peaks are computed for spectral signals obtained from the pristine and the current state of a target structure. Then, the difference of these ratios are computed as a function of the moving threshold. Finally, the MSPCD is defined as the maximum difference between these ratios. The basic premise is that the MSPCD will increase as the nonlinearity of the material increases. This technique has been used successfully for localizing fatigue cracks in metallic plates.

• 한국응용과학기술학회지
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• 제37권5호
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• pp.1323-1329
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• 2020

대장균 효소 𝛽-gal를 이용하여 합성된 phenylethanol galactoside (PhE-gal)의 분자구조를 NMR (¹H-와 ¹³C-)과 고성능 mass spectrometry를 이용하여 분석하였다. 그 결과 PhE-gal은 ¹H NMR에서 2-phenylethanol (PhE)에 갈락토실기가 도입되었음을 나타내는 피크가 나타났다. 방향족 고리에서 오는 𝛿_H 7.30~7.21 ppm의 피크와 𝛿_H 2.88 ppm에 나타난 벤질기 위치의 CH₂에서 오는 피크는 PhE가 존재함을 나타낸다. 지방족 사슬 영역인 𝛿_H 4.31 ppm, 4.07 ppm과 𝛿_H 3.86~3.38 ppm에서 나타나는 7개의 proton 피크로부터 단당류가 도입되었음을 확인할 수 있었다. ¹³C NMR 스펙트럼에서 나타난 12개의 탄소 피크 중 4개의 피크는 방향족 고리인 페닐기로부터, 또한 단당류에서 기인한 6개의 탄소피크가 존재하므로 PhE에 단당이 도입되었음을 알 수 있다. PhE-gal의 분자량을 확인하기 위하여 질량분석기로 분석한 결과 m/z가 307.1181인 PhE-gal의 sodium adduct ion ([M+Na]⁺)이 나타나 생성물이 PhE-gal임을 알 수 있었다. 따라서 본 연구결과 E. coli 𝛽-galactosidase에 의한 촉매반응으로 PhE에 갈락토즈가 첨가된 생성물인 PhE-gal이 성공적으로 생합성 되었음을 확인하였다.

• 전자공학회논문지A
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• 제32A권10호
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• pp.51-63
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• 1995

In this paper, a new real-time optical image switching system based on the phase-typed BPEJTC is suggested. The phase filter mask which has the arbitrary position mapping function between input and output planes is constructed by using the modified JTPS of the BPEJTC. Then, the input image is convolved with this phase filter mask in the spatial frequency domain and through further Fourier transform the input image is switched to the new positions in the output correlation plane where the correlation peaks are occurred. And, based on the computer simulation results, the practical optical switched to the new positions in the output correlation plane where the correlation peaks are occurred. And, based on the computer simulation results, the practical optical switching system is opto-digitally constructed and through some experiments on image switching the possiblity of real-time implementation of the multiple optical image switching system by using the BPEJTC is suggeste.