• Mass Spectrometry Letters
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• v.12 no.2
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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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• v.18 no.5
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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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• v.17 no.2
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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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• v.10 no.4
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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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• v.14 no.5
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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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• v.14 no.4
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7C
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• pp.459-466
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• 2011

This paper addresses the problem in the acquisition of binary offset carrier (BOC) signals employed in global navigation satellite systems, which is caused by the multiple side-peaks of the BOC autocorrelation function. We first observe that the side-peaks arise due to the fact that the BOC autocorrelation is made up of the sum of the sub-correlations shaped irregularly, and then, propose a novel acquisition scheme based on a recombination of the sub-correlations with cyclostationarity. The proposed scheme is demonstrated to remove the side-peaks completely for any type of BOC signal and to provide a performance improvement over the conventional schemes in terms of the mean acquisition time.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.6
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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.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1323-1329
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• 2020

To characterize the molecular structure of PhE-gal synthesized using Escherichia coli 𝛽-gal, NMR (¹H- and ¹³C-) spectroscopy and mass spectrometry of PhE-gal were conducted. ¹H NMR spectrum of PhE-gal showed multiple peaks corresponding to the galactosyl group, which is an evidence of galactosylation on 2-phenylethanol (PhE). Downfield proton peaks at 𝛿_H 7.30~7.21 ppm showed the presence of aromatic protons of PhE as well as benzyl CH₂ protons at 𝛿_H 2.88 ppm. Up field proton peaks at 𝛿_H 4.31 ppm, 4.07 ppm and multiple peaks from 𝛿_H 3.86~3.38 ppm are indicative of galactocylation on PhE. ¹³C NMR spectrum revealed the presence of 12 carbons suggestive of PhE-gal. Among 12 carbon peaks from PhE-gal, the four peaks at 138.7, 129.0, 128.6 and 126.5 were assigned aromatic carbons in the phenyl ring. Three peaks at 129.0, 128.6 and 126.5 showed high intensities, indicating CH aromatic carbons. ¹³C NMR data of PhE-gal showed 6 monosaccharide peaks from galactose and 2 peaks from aliphatic chain of PhE, indicating that PhE-gal was galactosyl PhE. The mass value (sodium adduct ion of PhE-gal, m/z = 307.1181) from mass spectrometry analysis of PhE-gal, and ¹H and ¹³C NMR spectral data were in good agreement with the expecting structure of PhE-gal. We are expecting that through future study it will eventually be able to develop a new additive with low cytotoxicity.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.10
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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.