• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1996.11a
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• pp.160-164
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• 1996

Montgomery 알고리듬은 모듈라 연산을 고속으로 수행하는 방법이다. 그러나 이는 연산할 수를 n-residue로 변환하는 전처리 단계가 필요하다. 이러한 residue 변환에 필요한 오버헤드로 인해 한번의 곱셈에는 비효율적이다. 본 논문에서는 Montgomery 알고리듬을 사용하여 한번의 곱셈을 효율적으로 수행하는 방법을 제안한다.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.195-203
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• 2015

Quintozene, pentachloronitrobenzene (PCNB) is a contact fungicide for control of soilborne phytopathogenic fungi during cultivation of diverse crops. It was introduced to agricultural use around 1930's as a substitute for mercurial disinfectants. Although quintozene had been first registered in Korea on 1969. However, now it was banned to use due to its high residue levels in selected harvest products. Also, high possibility is expected that the residue may be contained in imported agricultural commodities as it is still used widely over the world. Therefore, this study was conducted to establish a determination method for quintozene residue in crops using GC/ECD/MS. Quintozene residue was extracted with acetonitrile from representative samples of five raw products which comprised hulled rice, soybean, Kimchi cabbage, green pepper, and apple. The extract was diluted with saline water, and n-hexane partition was followed to recover quintozene from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The quintozene was quantitated by GLC with ECD, using a DB-1 capillary column. The crops were fortified with quintozene at 3 levels per crop. Mean recoveries ranged from 79.9% to 102.7% in five representative agricultural commodities. The coefficients of variation were less than 4.3%. Quantitative limit of quintozene was 0.004 mg/kg in representative five crop samples. A GC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of quintozene in agricultural commodities.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.321-331
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• 2019

BACKGROUND: Pinoxaden is the phenylpyrazoline herbicide developed by Syngenta Crop Protection, Inc. and marketed on 2006. The maximum residue levels for wheat and barley were set by import tolerance. Thus, Ministry of Food and Drug Safety (MFDS) official analytical method determining Pinoxaden residue was necessary in various food matrixes. Satisfaction of international guideline of CODEX (Codex Alimentarius Commission CAC/GL 40) and National Institute of Food and Drug Safety Evaluation-MFDS (2017) are additional pre-requirements for analytical method. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was investigated to analyze residue of Pinoxaden (M4), which is defined as pesticide residue in Korea, in foods. METHODS AND RESULTS: Pinoxaden (M4) was extracted followed by acid digestion (2hr reflux with 1N HCl) and pH adjusting (pH 4-5 with 3% ammonium solution). To remove oil, additional clean-up step with hexane saturated with acetonitrile was required to high oil contained sample before purification. HLB cartridge and nylon syringe filter were used for purification. Then, samples were analyzed by LC-MS/MS using reserve phase column C₁₈. Five agricultural group representative commodities (mandarin, potato, soybean, hulled rice, and red pepper) were used to verify the method in this study. The liner matrix-matched calibration curves were confirmed with coefficient of determination (r²) > 0.99 at calibration range 0.002-0.2 mg/kg. The limits of detection and quantitation were 0.004 and 0.01 mg/kg, respectively, which were suitable to apply Positive List System (PLS). Mean average accuracies of pinoxaden (M4) were shown to be 74.0-105.7%. The precision of pinoxaden and its metabolites were also shown less than 14.5% for all five samples. CONCLUSION: The method investigated in this study was suitable to CODEX (CAC/GL 40) and National Institute of Food and Drug Safety Evaluation-MFDS (2017) guideline for residue analysis. Thus, this method can be useful for determining the residue in various food matrixes in routine analysis.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.184-192
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• 2017

BACKGROUND: This study was performed to evaluate the residue dissipation of boscalid and spinetoram on crown daisy and sweet pepper affected by the morphology of the crop. The half-lives and dissipation rate constants for boscalid and spinetoram on crown daisy and sweet pepper were calculated. And then lower limit of 95% confidence interval for dissipation rate constant could be used to propose the pre-harvest residue limit. METHODS AND RESULTS: The pesticide products diluted according to the pesticide label were applied one time on crown daisy and sweet pepper at 2 field sites, respectively. Initial concentration of boscalid and spinetoram on crown daisy after application were in the range of 72.80~117.15 mg/kg and 2.82~4.67 mg/kg, respectively. And Initial concentration of boscalid and spinetoram on sweet pepper were in the range of 1.58~1.62 mg/kg and 0.10~0.21 mg/kg, respectively. Boscalid and spinetoram for crown daisy dissipted below the maximum residue limit(MRL) at 10 and 2 days after application, respectively. All residues concentration of boscalid and spinetoram for sweet pepper below the MRL at 0 day after application. The half-lives based on dissipation rate constant for boscalid and spinetoram on crown daisy were 4.2~4.9 days and 3.0~2.4 days respectively. And the half-lives for boscalid and spinetoram on sweet pepper were 6.7~7.0 days and 2.8~4.0 days respectively. CONCLUSION: The difference in initial concentration of boscalid and spinetoram among crop commodities were due to different crop morphology with larger surface areas. This study was suggested that pre-harvest residue limit would be calculated from lower limit of 95% confidence interval for dissipation rate constant and would be useful to protect consumers by controlling the pesticide residues in crop.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.357-361
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• 1989

Wheat Doenjang was manufactured by mixing various ratio of the soymilk residue with wheat Koji. As the result, the content of reducing sugar was increased till 50 days and decreased thereafter during aging of the mash. As the combination ratio of soymilk residue was increased, the content of reducing sugar was decreased and amino nitrogen content was increased prominently till 50 days in all testing samples but thereafter the increasing ratio was slowdowned. At the beginning of the aging the content of the amino nitrogen was higher in the testing sample which had higher combination ratio of soymilk residue but at the end of the aging the result was reversed. The content of the total acids was increased prominently till 40 days but thereafter the increasing ratio was slowdowned, and in each testing samples the difference in total acid content was extremely slight. In the color of each testing samples aged 80 days as the combination ratio of soymilk residue was increased, the lightness was increased, and the redness was decreased but the yellowness was increased. From the result of sensory evaluation test of wheat Doenjang aged 90 days, soy sprout Doenjang soup showed the best taste in control and as the combination ratio of soymilk residue was increased, the taste was dropped slightly but no significant differences was obtained among the testing sample A,B and C but between control and testing sample D there was significant difference. In the original taste of Doenjang, the control was the best and as the combination ratio of soymilk residue increased, the point was dropped but there were no significant differences between control and testing sample A and testing sample B and C.

• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.349-354
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• 1999

This study was conducted to propose residue limits of organophosphorus pesticides in functional foods produced from peels of citrus fruits. For these, not only reduction factors of pesticides in cooking and processing were estimated, but factors needed in order to produce residue limits were identified and their application method was devised. The results were as follows: (1) reduction factors appeared as 0.09-1.60 by different processings of various foods, (2) residue limits of pesticides on dietary fiber and bioflavonoid products could be computed from maximum residue limit of pesticides on the raw agricultural produce, reduction factors, and the anticipated amount of consumption of the functional foods. (3) residue limits of 18 organophosphorus pesticides were proposed in the range of 0.01-3.0mg/Kg on the dietary fiber product and 0.1-80mg/Kg on the bioflavonoid product from citrus fruit peels.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.84-93
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• 2013

BACKGROUND: This study was carried out to investigate the residual characteristics of insecticides used for Oriental Tobacco Budworm control and to establish the recommended pre-harvest residue limit leading to contribution in safety of paprika production. METHODS AND RESULTS: The recommended Pre-Harvest Residue Limits (PHRLs) of insecticides during cultivation of paprika were calculated from residue analyses of insecticides in fruits 1, 3, 5, 7, 10, 12, 15, 18 and 21 days after treatment. Paprika samples were extracted with QuEChERS method and cleaned-up with amino propyl SPE cartridge and PSA, and insecticide residues were analyzed either by HPLC/DAD or GLC/ECD. The limits of detection were 0.01 mg/kg for 5 insecticides. Average recoveries were $81.3{\pm}1.62%$-$98.3{\pm}1.58%$ of 5 insecticides at fortification levels of 0.1 and 0.5 mg/kg. The biological half-lives of the insecticides were 8.5 days for bifenthrin, 11.8 days for chlorantraniliprole, 16.8 days for chlorfenapyr, 7.1 days for lamda-cyhalothrin and 31.3 days for methoxyfenozide at recommended dosage, respectively. CONCLUSION(S): The pre-harvest residue limits for 10 days before harvest were recommended 1.05 mg/kg, 1.41 mg/kg, 0.93 mg/kg, 2.06 mg/kg and 1.08 mg/kg as bifenthrin, chlorantraniliprole, chlorfenapyr, lamda-cyhalothrin and methoxyfenozide, respectively. This study can provide good practical measures to produce safe paprika fruit by prevention of products from exceeding of MRLs at pre-harvest stage.

• Applied Biological Chemistry
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• v.31 no.1
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• pp.65-78
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• 1988

This study aims effective use of soymilk residue, by-product of soymilk production, and making noodles by mixing soymilk residue with wheat flour. The results of viscosity property, cooking test of dry noodles, texture test of cooked noodles, and sensory test of cooked noodles were as follows. The color of cooked noodles were slightly shifted to yellowness according to the mixing of soymilk residue. The mixing of soymilk residue resulted in the decrease of texture and the loss of solids due to the decrease of visccelasity. Na-alginate, Na-C.M.C., guar gum, and crude gluten were added to improve the texture of noodles mixed with soymilk residue. As the results, either Na-alginate or guar gum was very effective in increasing the viscosity of composite flour and either guar gum or crude gluten was very effective in improving cooking quality. The texture of noodles supplemented by Na-alginate 1.0%, Na-C.M.C. 2.0%, guar gum 0.5%, or crude gluten 2.0% was similar to that of wheat flour noodles. Complex additives mixed with two different additives were very effective in improving noodle-making characteristics. Especially, the properties of the soymilk residue mixed noodles supplemented by crude gluten 1.0% and Na-C.M.C. 1.0% or crude gluten 1.0% and gum 0.5% were nearly the same in the texture organoleptic properties compared with those of wheat flour noodles.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.125-133
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• 2011

Ametryn is used in USA, China, and Japan, but not introduced in Korea yet. So, MRL (Maximum Residue Level), and analytical method of ametryn were not establishment in Korea. Therefore, this experiment was conducted to establish a determination method for ametryn residue in crops using HPLC-UVD/MS. Ametryn residue was extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and dichloromethane partition was followed to recover ametryn from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The ametryn was quantitated by HPLC with UVD, using a Tosoh ODS 120T ($4.6{\times}250$ mm) column. The crops were fortified with ametryn at 2 levels per crop. Mean recovery ratio were ranged from 83.7% for a 0.2 mg/kg in soybean to 91.1% for a 1.0 mg/kg in hulled rice. The coefficients of variation were ranged from 1.2% for a 1.0 mg/kg in hulled rice to 3.6% for a 1.0 mg/kg in soybean. Quantitative limit of amatryn was 0.02 mg/kg in representative 5 crop samples. A LC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of ametryne in agricultural commodities.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.230-236
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• 2009

Sewage sludge cake(SSC) is seriously concerned because ocean dumping, which is the cheapest treatment method now, will be banned in 2012. On the basis of this reason, recycling of SSC is emphasized to convert the treatment method. One of the method to recycling SSC could be carbonization process which also can be reduced greenhouse gas effectively. And carbonization residue of SSC produced by carbonization process can become a renewable energy source. However, carbonization process has not been evaluated by considering basic operating data such as heating value, yield and fuel ratio. In this study, the basic characteristics of SSC such as proximate analysis, elementary analysis and heating value are analyzed. In carbonization process, the effect of carbonization temperature and time on the residue of SSC are estimated. And the analysis is carried out to obtain basic properties of the residue of SSC. From the result of chemical composition of SSC residue, there is 27% of phosphate in SSC. Phosphate will take a role of reductant to convert from hazardous substance to non-hazardous material. As increased carbonization temperature and time, heating value and yield are decreased but fuel ratio(fixed carbon/volatile combustible) of the residue is increased. In the carbonization process, the optimum temperature and time in carbonization test for SSC can be decided by $250^{\circ}C$ and 15 min, respectively. However, the carbonization residue of SSC can not be deserved to use one of renewable energy sources because the heating value at the optimum condition is relatively low. Hence, it is desirable that SSC can be mixed with other organic waste to carbonize.