• Journal of Food Hygiene and Safety
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• v.33 no.3
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• pp.168-175
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• 2018

The use of microwave-assisted extraction and an acid-base clean-up process to determine the amount of methylmercury (MeHg) in marine products was suggested in order to improve the complicated sample preparation process. The optimal conditions for microwave-assisted extraction was developed by using a 10% NaCl solution as an extraction solution, setting the extraction temperature at $50^{\circ}C$, and holding for 15 minutes to extract the MeHg in marine products. A NaOH solution was selected as a clean-up substitute instead of L-cysteine solution. Overall, 670 samples of marine products were analyzed for total mercury (Hg). Detection levels were in the range of $0.0006{\sim}0.3801{\mu}g/kg$. MeHg was analyzed and compared using the current food code and the proposed method for 49 samples which contained above 0.1 mg/kg of Hg. Detection ranges of methylmercury followed by the Korea Food Code and the proposed method were $75.25(ND{\sim}516.93){\mu}g/kg$ and $142.07(100.14{\sim}244.55){\mu}g/kg$, respectively. The total analytical time of proposed method was reduced by more than 25% compared with the current food code method.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.267-271
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• 2013

A survey of aflatoxin $B_1$ and ochratoxin A was conducted on dried red pepper and red pepper powder. Total number of 193 samples were collected from local markets in Incheon. The presence of aflatoxin $B_1$ and ochratoxin A was determined by high performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. The recovery rate of aflatoxin $B_1$ and ochratoxin A were more than 80% and the limits of quantification were 0.13 ${\mu}g/kg$ for aflatoxin $B_1$ and 0.30 ${\mu}g/kg$ for ochratoxin A. Aflatoxin $B_1$ was detected in 33 samples (17.1%) with a range of 0.14~9.67 ${\mu}g/kg$ and ochratoxin A was detected in 40 samples (20.7%) with a range of 0.31~3.31 ${\mu}g/kg$. These results show that the occurrence of aflatoxin $B_1$ and ochratoxin A in dried red pepper and red pepper powder tested in this study is low compared with the standard in Korea Food Code (10 ${\mu}g/kg$ as aflatoxin $B_1$ and 7 ${\mu}g/kg$ as ochratoxin A).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4A
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• pp.291-300
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• 2002

In this paper, a way of constituting optimized S box and G function was suggested in the block cipher whose structure is similar to SEED, which is KOREA standard of 128-bit block cipher. S box can be formed with nonlinear function and an affine transform. Nonlinear function must be strong with differential attack and linear attack, and it consists of an inverse number over GF(2$\^$8/) which has neither a fixed point, whose input and output are the same except 0 and 1, nor an opposite flexed number, whose output is one's complement of the input. Affine transform can be constituted so that the input/output correlation can be the lowest and there can be no fixed point or opposite fixed point. G function undergoes diffusive linear transform with 4 S-box outputs using the matrix of 4$\times$4 over GF(2$\^$8/). G function can be constituted so that MDS(Maximum Distance Separable) code can be formed, SAC(Strict Avalanche Criterion) can be met, there can be no weak input, where a fried point, an opposite fried point, and output can be two's complement of input, and the construction of hardware can be made easy. The S box and G function suggested in this paper can be used as a constituent of the block cipher with high security, in that they are strong with differential attack and linear attack with no weak input and they are excellent at diffusion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.612-617
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• 2009

Fresh vegetable juice is a non-heat treated product and the only step to reduce microbial growth is washing. Therefore, the materials for fresh vegetable juice including Angelica keiskei, Brassica loeracea var. acephala, and Daucus carota L. were treated by ozone after the first washing process and investigated for microbial and chemical changes. The number of the total aerobic bacteria in materials after selection step were $8.2{\times}10^5{\sim}5.0{\times}10^6\;CFU/g$, which was a higher contamination level than the limit of Korea food code ($10^5\;CFU/g$). However, after the 1st washing process and ozone treatment, the total aerobic bacterial number was reduced to $4.7{\times}10^4{\sim}6.7{\times}10^4\;CFU/g$, which showed 2 log microbial reduction. After the 2nd washing step followed by ozone treatment, there was no difference in microbial number. The number of colifroms in the materials of fresh vegetable juice were $8.0{\times}10^3{\sim}3.5{\times}10^3\;CFU/g$ initially but showed $1.5{\times}10^2{\sim}3.0{\times}10^2\;CFU/g$ after the ozone treatment (1 log reduction). On the other hand, there was no changes in the contents of ascorbic acid, flavonoids, polyphenols, minerals (cadmium and lead) during all processes. In addition, no color changes were observed during washing process. Therefore, ozone treatment in the materials of fresh vegetable juice decreased the microbial numbers. Also, chemical characteristics of ozone treated sample were not different when compared with control.

• Journal of KIISE:Software and Applications
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• v.29 no.5
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• pp.326-335
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• 2002

Recently there have been a number of researches to provide code mobility to lazy functional language (LFL) programs by translating LFL programs to Java programs. These approaches are basically baled on architectural similarities between abstract machines of LFLs and Java. The abstract machines of LFLs and Java programming language, Spineless Tagless G-Machine(STGM) and Java Virtual Machine(JVM) respectively, share important common features such as built- in garbage collector and stack machine architecture. Thus, we can provide code mobility to LFLs by translating LFLs to Java utilizing these common features. In this paper, we propose a new translation scheme which fully utilizes architectural common features between STGM and JVM. By redefining STGM as an eval-apply evaluation model, we have defined a new translation scheme which utilizes Java Virtual Machine Stack for function evaluation and totally eliminates stack simulation which causes array manipulation overhead in Java. Benchmark program translated to Java programs by our translation scheme run faster on JDK 1.3 than those translated by the previous schemes.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.4
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• pp.227-233
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• 2022

The 3D-printing technique is used for manufacturing objects by adding multiple layers, and it is relatively easy to manufacture objects with complex shapes. The 3D concrete printing technique, which incorporates 3D printing into the construction industry, does not use a formwork when placing concrete, and it requires less workload and labor, so economical construction is possible. However, 3D-printed concrete is expected to have a lower strength than that of molded concrete. In this study, the properties of 3D-printed concrete were analyzed. To fabricate the 3D-printed concrete samples, the extrusion path and shape of the samples were designed with Ultimaker Cura. Based on this, G-codes were generated to control the 3D printer. The optimal concrete mixing proportion was selected considering such factors as extrudability and buildability. Molded samples with the same dimensions were also fabricated for comparative analysis. The properties of each sample were measured through a three-point bending test and uniaxial compression test, and a comparative analysis was performed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.2
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• pp.123-130
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• 2009

This study was conducted to obtain basic data for developing a special salted mackerel. For this purpose, food quality characterization data on 11 kinds of salted commercial mackerels were gathered. Korean Industrial Standards (KSH 6029) stipulate that a salted mackerel should be less than $1.0{\times}10^6\;CFU/g$ in viable cells, negative for Escherichia coli, less than 50 mg% for volatile basic nitrogen (VBN) and less than 3% for salinity. Only one sample (code 10) among the 11 kinds of commercial salted mackerels is believed to posses acceptable limits according to KSH 6029. The others except code 2 and 4 showed less than 50 mg/kg in histamine content, a safe range for allergies. The peroxide values of 4, 5, 7, 10 and 11 in sample code were lower than 22 meq/kg, which were low compared to the other salted mackerels. The major fatty acids of all salted mackerels were 16:0 (13.2-22.1%), 18:1n-9 (11.7-23.1%), and 22:6n-3 (13.5-20.4%). The Hunter color values ranged from 31.1 to 51.0 (average 37.9) for lightness, from 0.6 to 8.1 (average 3.3) for redness, from -2.9 to 9.3 (average 5.8) for yellowness, and from 46.8 to 65.8 (average 59.5) for color difference. From these results, it was concluded that the code 10 is superior than the other salted mackerels. Thus, a new salted mackerel product should be superior or similar to the food quality characteristics of this sample.

• Journal of Sensor Science and Technology
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• v.4 no.4
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• pp.1-9
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• 1995

The ${\gamma}$-ray deposition spectra were calculated by Monte Calro method to obtain the scintillation characteristics of the ${\gamma}$-ray for BGO scintillation detector with the spherical shape of 1.25 cm radius. The code used in calculating the ${\gamma}$-ray deposition spectra was made for personal computer with qbasic language. Also the ${\gamma}$-ray energy spectra of $^{22}Na$, $^{137}Cs$ and $^{207}Bi$ were measured with the detector. The energy dependent resolution below 2000 keV for the detector was determined by estimating the standard deviation of the photopeak fitted with gaussian function, and $X^{2}$ fitting using Nardi's empirical formula. The measured spectra of $^{22}Na$ and $^{137}Cs$ were compared with the broadened spectra which were obtained by broadening the calculated ${\gamma}$-ray deposition spectra with the energy dependent resolution. The absolute efficiency and the intrinsic peak efficiency of the detector were obtained by calculating the ${\gamma}$-ray deposition spectrum with the code.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.57-67
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• 1997

The objective of present paper is to investigate elasto-plastic behaviour and estimate the resistance capacity of a beam-shear wall structural system against earthquake ground accleration exciations. Pushover analysis is adopted to estimate inttiate and post stiffnesses and yielding point for inelastic response analysis in LPM (Lumped Parameter Mass) model, and modified Clough model is used as the hysteresis rule of each story. Three earthquake waves are used in the analysis but their peak ground accelerations are changed to be 0.12g, 0.24g. It is assumed that the earthquakes act in the longigtudianl direction of a 25 Story apartment building which consists of two some unit plan. The distribution of story ratio and ductility ratio are estimated and discussed within Korean, Japanese code and UBC.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.233-238
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• 2005

In general CELP(Code Excited Linear Prediction) type vocoders provide good speech qualify around 4.8kbps. Among them, G.723.1 developed for Internet Phone and video-conferencing includes two vocoders, 5.3kbps ACELP(Algebraic-CELP) and 6.3kbps MP-MLQ(Multi-Pulse Maximum Likelihood Quantization) In order to improve the speech qualify in CELP vocoder, in this paper. we proposed a new spectrum analysis algorithm with variable window In CELP vocoder, the spectrum of the synthesised speech signal is distorted because the fixed size windows is used for spectrum analysis. So we have measured the spectral leakage and in order to minimize the spectral leakage have adjusted the window size. Applying this method G.723.1 ACELP, we can got SD(Spectral Distortion) reduction 0.084(dB), residual energy reduction 6.3$\%$ and MOS(Mean Opinion Score) improvement 0.1.