• Journal of Radiation Protection and Research
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• v.41 no.3
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• pp.291-300
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• 2016

Background: It is necessary to assess radiation dose to workers due to inhalation of airborne particulates containing naturally occurring radioactive materials (NORM) to ensure radiological safety required by the Natural Radiation Safety Management Act. The objective of this study is to develop an internal dose assessment procedure for workers at industries using raw materials containing natural radionuclides. Materials and Methods: The dose assessment procedure was developed based on harmonization, accuracy, and proportionality. The procedure includes determination of dose assessment necessity, preliminary dose estimation, airborne particulate sampling and characterization, and detailed assessment of radiation dose. Results and Discussion: The developed dose assessment procedure is as follows. Radioactivity concentration criteria to determine dose assessment necessity are $10Bq{\cdot}g^{-1}$ for $^{40}K$ and $1Bq{\cdot}g^{-1}$ for the other natural radionuclides. The preliminary dose estimation is performed using annual limit on intake (ALI). The estimated doses are classified into 3 groups ( < 0.1 mSv, 0.1-0.3 mSv, and > 0.3 mSv). Air sampling methods are determined based on the dose estimates. Detailed dose assessment is performed using air sampling and particulate characterization. The final dose results are classified into 4 different levels ( < 0.1 mSv, 0.1-0.3 mSv, 0.3-1 mSv, and > 1 mSv). Proper radiation protection measures are suggested according to the dose level. The developed dose assessment procedure was applied for NORM industries in Korea, including coal combustion, phosphate processing, and monazite handing facilities. Conclusion: The developed procedure provides consistent dose assessment results and contributes to the establishment of optimization of radiological protection in NORM industries.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.102-109
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• 2018

This paper seeks to present a multi-control method that can contribute to effective control of the production line with multiple bottleneck processes. The multi-control method is the production system that complements shortcomings of CONWIP and DBR, and it is designed to determine the raw material input according to the WIP level of two bottleneck processes and WIP level of total process. The effectiveness of the production system developed by applying the multi-control method was verified by the following three procedures. Raw material input conditions of the multi-control method are as follows. First, raw materials are go into the production line when the number of the total process WIP is lower than established number of WIP in total process and first process is idle. Second, raw materials are introduced when the number of WIP of two bottleneck processes is lower than the established number of WIP of each bottleneck process. Third, raw materials are introduced when the first process and in front of bottleneck process are idle even if the number of WIP in the total process is less than established number of WIP of the total process. The production line with two bottleneck processes was selected as the condition for production environment, and the production process modeling of CONWIP, DBR and multi-control production method was defined according to the production condition. And the optimum limited WIP level suitable for each system was obtained by applying a genetic algorithm to determine the total limited number of WIP of CONWIP, the limited number of WIP of DBR bottleneck process, the number of WIP in the total process of multi-control method and the limited number of WIP of bottleneck process. The limited number of WIP of CONWIP, DBR and multi-control method obtained by the genetic algorithm were applied to ARENA modeling, which is simulation software, and a simulation was conducted to derive result values on the basis of three criteria such as production volume, lead time and number of goods in-progress.

• Korean Journal of Metals and Materials
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• v.50 no.11
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• pp.829-838
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• 2012

The microstructure, chemical composition, and lead isotope ratio of the Buddhist bell of Yongmoon Mountain Sangwonsa temple, which was selected as one of the three great bells of Korea by Japanese historians, were analyzed in order to estimate the origin of the material and the time of casting. The microstructure of the temple bell was composed of a copper matrix phase with ${\alpha}$, a face centered cubit lattice structure, a ${\delta}$ phase with $Cu_{41}$ $(Sn,Ag,Sb)_{11}$ as the chemical structural formula, dispersed lead and $Cu_2S$ particles, and locally agglomerated fine particles. Through analysis of the chemical composition of the bell, a criterion (Pb: 0-3.0 wt%, Sn: 10-15 wt%) for distinguishing the bells of the Shilla dynasty from the bells of the Koryo Chosun dynasty is proposed. Examining the lead isotope ratio of $^{207}Pb/^{206}Pb$ and $^{208}Pb/^{206}Pb$ of the Buddhist bell of Sangwonsa temple proved that the bell was fabricated using raw materials in South Korea, which led to the conclusion that the bell was cast in Korea and the top board of the bell has been damaged by an unknown individual. The criteria of distinguishing the bells from the Shilla dynasty from the bells of the Koryo Chosun dynasty presented for the first time in this research is expected to aid in identifying and estimating the previously unclear production years of other bells.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.145-148
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• 2014

Purpose: Serum thyroglobulin (Tg) determination has been reported to be a sensitive indicator of persistent or recurrent differentiated thyroid cancer (DTC) after total thyroidetectomy. In patients free of metastasese and recurrences after a complete thyroidectomy and radioiodine removal for DTC, the Tg is usually <1 ng/mL or can no longer be detected even with TSH stimulation. Therefore, report in low Tg levels and selecting criteria for retest is very important. The purpose of this study was to establish selecting criteria for retest which is efficient at reliability improvement and Turn around time (TAT). Materials and Methods: Sera from 137 patients with DTC were divided into two groups as first(<1.0 ng/mL or >4.0 ng/mL) and second(1.0-4.0 ng/mL). In case of group(<1.0 ng/mL) is in patient free of metastases and recurrences, >4.0 ng/ml is low coefficient of variation (CV%) at internal quality control and good linearity at standard curve. Therefore first group began with Delta/Panic check (D/P) and second group surveyed with the latest results. In that the latest results were <1.0 ng/ml, we checked the thyroxin withdrawal. Finally selected specimen retested with raw specimen. Results: In first group, we was able to reduce the retest rate(30.8% to 7.7%). and In second group, 40% to 5%. The total retest rate was 7.3%. Conclusion: If using the selecting criteria for retest, is helpful to accuracy and quickness of the result report.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.135-139
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• 2002

The standard of quality was required to promote the consumption of potato and produce the high quality processing products. It will contribute the stability for processing products and the marketability of potato. The quality was determined based on size of tuber and content of dry matter. Even though the criteria of potato quality was involved many characters of tubers, the most important things were grading and packing of potato to create the consumption. For processing of raw materials, the standard of tubers had create between producer and processor according to size of tuber and content of dry matter. The evaluation of quality was performed over the standard to enhance the control of quality. In addition, the seed potato should be taken the evaluation to disease in the field during the period of cultivation and managed under the strict regulation in storage before release to farmer. Then, the producer of seed potato will make a good relationship to farmer with high quality tubers.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.152-162
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• 2024

In this study, we investigated the levels of the natural preservatives, benzoic acid, sorbic acid, and propionic acid, in raw unprocessed vegetables. Quantitative analysis of benzoic acid and sorbic acid was performed using high-performance liquid chromatography with a diode array detector (HPLC-DAD) and confirmed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Propionic acid was analyzed using a gas chromatography-flame ionization detector (GC-FID) and confirmed using gas chromatography-mass spectrometry (GC-MS). From a total of 497 samples, benzoic acid, sorbic acid, and propionic acid were found in 50 (10%), 8 (0.2%), and 61 samples (12.3%), respectively. The highest quantity of benzoic acid, sorbic acid, and propionic acid was found in peony root (1,057 mg/kg), nut-bearing torreya seeds (27.3 mg/kg), and myrrha (175 mg/kg), respectively. The background concentration range of naturally occurring preservatives in raw vegetables determined in this study could be used as standard inspection criteria to address consumer complaints and trade disputes.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.229-233
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• 2006

Comparison of the grade of raw ginseng and that of red ginseng was investigated. The materials used in this study were Korean ginseng (Panax ginseng C. A. Meyer) and American ginseng(Panax quinquefolium L.) Coefficient of body term, length of main stem and weight of raw ginseng were used as the classifying criteria of the root size and grades. Korean ginseng distinguished the distribution of weight size from that of American ginseng. Korean ginseng distributed largely in middle and large root size, and American ginseng distributed largely in middle and small root size. American ginseng had shorter length of main root, bigger diameter of main root and more number of adventitious roots than Korean ginseng. The quality of Korean ginseng was better than that of American ginseng. In Korean ginseng, high quality of red ginseng above second grade (Jisam) was obtained, but low quality of red ginseng under third grade (Yangsam) in American ginseng. In Korean raw ginseng, the coefficients of body form of middle weight and large weight size were under 0.5, but those of American ginseng was over 0.5. So American ginseng were not adequate to produce good red ginseng. Those factors as length of main root and weight of main root were not significantly influenced on the qualify of red ginseng in both Korean ginseng and American ginseng. Coefficient of body form was leading factor affecting the quality of red ginseng. To improve the quality of red ginseng, coefficient of body form, weight of main root and length of main root were controlled adequately in both Korean ginseng and American ginseng.

• The Korean Journal of Food And Nutrition
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• v.33 no.3
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• pp.287-298
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• 2020

When producing rice products, it is very important to select suitable raw materials. Therefore, in this study, the quality characteristics of 16 rice cultivars were quantified to determine the criteria for evaluating the machinability of raw rice. The L value, which can affect the color of porridge prepared from rice, was the greatest for Hwaseonchalbyeo (84.17). The water-binding capacity, related to water interaction, was high in Hyangcheola (113.2%), and water solubility was high in Shingil (22.3%). Dodamssal (42.3%, 70.7 RVU) and Hwaseonchalbyeo (4.7%, 27.8 RVU) showed lower final viscosity compared to the cultivars in which the amylose content was medium groups (16.4~21.2%, 173.6~277.2 RVU). Specifically, cultivars with high or low amylose content had a low viscosity. The characteristics of the distribution of raw rice quality data were confirmed through 11 histograms. Furthermore, amylose content vs. water solubility, water solubility vs. peak viscosity, and peak viscosity vs. final viscosity showed high correlations (r=0.542, -0.569, and 0.836 respectively, p<0.01), and clear cultivar discrimination by the standard error of the mean (0.765~10.811). In conclusion, amylose content, water solubility, and peak viscosity were considered the most suitable characteristics for the quality evaluation of raw rice.

• Korean journal of food and cookery science
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• v.30 no.1
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• pp.51-63
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• 2014

A microbiological quality evaluation on cooked food, food materials and cooking equipment was conducted in 14 school food services in Changwon area, South Korea for Ojingeochaesomoochim (vegetable salad with blanched squid) which went through cooking process after heating treatment. Only 5 schools out of the 14 (35.7%) observed the sanitization criteria of the Korean School Meals Sanitization Management for raw vegetables (concentration of chlorine solution: 100ppm, immersion time of sanitizing: 5 min). The acceptance rates regarding the microbial standards for Korean school meals showed improvement before and after of sanitization: for onions 57.1% vs 71.4%; cucumber 42.9% vs. 78.6%. However, garlic showed adverse sanitizing effect as the acceptance rate went down from 42.9% to 35.7%. Blanched squid and red pepper paste was acceptable in all 14 schools (100%), while squid seasoned with red pepper powder was acceptable in only 42.9% of the schools. Microbial results for knives, cutting boards, mixing bowls were satisfactory, however 35.7% of sanitary gloves that were put on right before the seasoning showed poor sanitization, and this indicated high probability of cross-contamination from the gloves. We calculated that 57.1% of the cooked foods were in accordance with the microbial standards for Korean school meals. Therefore, it is strongly recommended to have verification process, especially on the effectiveness of sanitization of raw vegetables, in cooking foods through cooking process after heating treatment in HACCP system of school food service.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.321-326
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• 2022

In this study, cogeneration power plants that use biomass as a raw material to convert them into energy have recently received a lot of attention worldwide and are gradually increasing in South Korea. Therefore, in order to confirm the possibility of using the generated floor material as a fine aggregate for concrete, properties and stability evaluation experiments were performed. Compared to standard sand, the compressive strength of wood chip aggregate was improved by 11 % to 111 %, the length change rate was 89 %, and the waste processing test results met all criteria for hazardous substances. All of these are satisfied, and it is judged that the floor materials by the cogeneration power plant can be used as a fine aggregate for concrete.