• Title/Summary/Keyword: large deviations

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Performance Evaluation of WWTP Based on Reliability Concept (신뢰성에 기초한 하수처리장 운전효율 평가)

  • Lee, Doo-Jin;Sun, Sang-Woon
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.3
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    • pp.348-356
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    • 2007
  • Statistical and probabilistic method was used in the analysis of data, which is the most effective one in describing the various natures, and the methodology relating the results with the design was developed. Influents and effluents of three treatment plants were analyzed and the focus was made on BOD, COD, SS, IN, TP The fluctuations of influent such as BOD, COD, SS were extremely large and their standard deviations(st.dev) were more than 10 mg/L. but those of TN, TP were small; the st.dev was 6.6 mg/L for TN, 0.6 mg/L for TP, respectively. But, effluent concentration showed consistent pattern regardless of the influent fluctuations, the st.dev was ranged between 0.28 and 4.48 mg/L. Effluent distributional characteristics were as follows; BOD, COD were distributed normally, but SS, TN, and TP, log-normally; unsymmetric and skewed to the right. The coefficient of reliability(COR) based on the results of statistics of data was introduced to evaluate the process performance an4 to reflect the process performance to the process design. The coefficient of reliability relates the design value(the goal) with the standards and it can be used in operating treatment facilities under a certain reliability level and/or in evaluating the reliability of the treatment facilities on operation. Each treated water quality of effluent showed the half of water quality standards in the level of 50% percentile and all treatment plant was achieved 100% probability of water quality standards. It was concluded that the variability of the process performance should be reflected to the design procedure and the standards through the analysis based on the statistics and the probability.

Factors Analysis Related to Health Administration Students' Satisfaction on Hospital Practice (보건행정 전공 대학생들의 병원실습 만족도에 영향을 미치는 요인분석)

  • Park, Eun-Young;Jang, Young-Jin;Hong, Jong-Pil
    • Journal of Korean Clinical Health Science
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    • v.5 no.1
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    • pp.825-833
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    • 2017
  • Purpose .This study aims to assess the influence factors on the level of satisfaction with hospital training and to provide basic data for more efficient hospital practice of students' public health administration . Methods . We have conducted a survey on students satisfaction with their hands on practice against 200 students in Busan, Kyeongnam and Kyungbook area, who have completed their practice in public health administration. We have identified the general characteristics of the target respondents, the current training status of the department for the hospital practice and training venue; also analyzed the characteristics composed of the apprentice student's attitude before the practice, satisfaction with the department training program and hospital for practice, as well as their practice at hospital. The general characteristics of the target respondents and clinic practice status at the hospital were measured in percentage and frequency analysis; the average and standard deviations of hospital size were also measured; and the correlations between satisfaction with the department, attitude towards the practice and satisfaction with the hospital were analyzed. Results . Most public health administration students experienced their practice at the hospital after the first semester on the $2^{nd}$year and they have received the foundation training for the practice. The survey allowed multiple responses and the results are as follows: medical terminology 49.5%, medical coordinator 36.7%, Hospital administration 26.5%, Health insurance 17.3%, and medical recording and practice 13.8% respectively. In terms of each individual student's attitude towards the practice at the hospital, the respondents answered as follows: I have completed the obligatory subjects for the practice before the practice 89.5%; I have been fully informed on the hospital for my practice. 74.5%; I responsibly practiced and worked with professionalism and sense of belonging to the hospital as a member of staff 90%; I have actively learned and adopted 95%; My knowledge and skills from the practice was relevant to the theory and practice from my course 83.5%. The findings of satisfaction by size of hospital were in order of a small clinic($3.24{\pm}0.63$), medium sized clinic($3.27{\pm}0.65$), hospital ($3.20{\pm}0.61$), and large sized comprehensive hospital ($2.93{\pm}0.74$). Consequently the satisfaction rate shows no significant difference by size of hospital. In relations between practice attitude and satisfaction with subject, the matter of acquiring information and fully understanding of the hospital for practice before practice(p=0.04), the matter of a sense of belonging and responsibility at hospital during practice(p=0.33). the matter of active adaptation attitude during practice (p=0.42), and the matter of correlations with school curriculum during practice(p=0.00) showed significant results. In relations between practice attitude and satisfaction with the hospital for practice, the matter of acquiring information and fully understanding of the hospital for practice before practice(p=0.01), the matter of a sense of belonging and responsibility at hospital during practice(p=0.04), and the matter of correlations with school curriculum during practice(p=0.00) showed significant results. Conclusion . The most essential subject for the practice in public health administration is medical terminology and there is no significance in satisfaction with the practice by size of hospital. Students were content with the hospital where they can experience as much as possible. Students content with their major show positive attitude towards the practice and so do those content with the hospital. Those with the positive attitude towards the practice show the high correlation of satisfaction with both the major and hospital. As a result, the satisfaction with the major is the significant attribute to the practice in the hospital.

Estimation of the Lowest and Highest Astronomical Tides along the west and south coast of Korea from 1999 to 2017 (서해안과 남해안에서 1999년부터 2017년까지 최저와 최고 천문조위 계산)

  • BYUN, DO-SEONG;CHOI, BYOUNG-JU;KIM, HYOWON
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.24 no.4
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    • pp.495-508
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    • 2019
  • Tidal datums are key and basic information used in fields of navigation, coastal structures' design, maritime boundary delimitation and inundation warning. In Korea, the Approximate Lowest Low Water (ALLW) and the Approximate Highest High Water (AHHW) have been used as levels of tidal datums for depth, coastline and vertical clearances in hydrography and coastal engineering fields. However, recently the major maritime countries including USA, Australia and UK have adopted the Lowest Astronomical Tide (LAT) and the Highest Astronomical Tide (HAT) as the tidal datums. In this study, 1-hr interval 19-year sea level records (1999-2017) observed at 9 tidal observation stations along the west and south coasts of Korea were used to calculate LAT and HAT for each station using 1-minute interval 19-year tidal prediction data yielded through three tidal harmonic methods: 19 year vector average of tidal harmonic constants (Vector Average Method, VA), tidal harmonic analysis on 19 years of continuous data (19-year Method, 19Y) and tidal harmonic analysis on one year of data (1-year Method, 1Y). The calculated LAT and HAT values were quantitatively compared with the ALLW and AHHW values, respectively. The main causes of the difference between them were explored. In this study, we used the UTide, which is capable of conducting 19-year record tidal harmonic analysis and 19 year tidal prediction. Application of the three harmonic methods showed that there were relatively small differences (mostly less than ±1 cm) of the values of LAT and HAT calculated from the VA and 19Y methods, revealing that each method can be mutually and effectively used. In contrast, the standard deviations between LATs and HATs calculated from the 1Y and 19Y methods were 3~7 cm. The LAT (HAT) differences between the 1Y and 19Y methods range from -16.4 to 10.7 cm (-8.2 to 14.3 cm), which are relatively large compared to the LAT and HAT differences between the VA and 19Y methods. The LAT (HAT) values are, on average, 33.6 (46.2) cm lower (higher) than those of ALLW (AHHW) along the west and south coast of Korea. It was found that the Sa and N2 tides significantly contribute to these differences. In the shallow water constituents dominated area, the M4 and MS4 tides also remarkably contribute to them. Differences between the LAT and the ALLW are larger than those between the HAT and the AHHW. The asymmetry occurs because the LAT and HAT are calculated from the amplitudes and phase-lags of 67 harmonic constituents whereas the ALLW and AHHW are based only on the amplitudes of the 4 major harmonic constituents.

A study on the present situation of the treatment services provided by alcohol addiction specialized hospitals (알코올중독전문병원의 서비스 제공 현황에 관한 연구)

  • Cho, Hyun;Yoo, Jin-Yeong;Lee, Ji-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3547-3554
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    • 2011
  • The aim of this study is to take hold of the present situation as well as the perspective of the domestic alcohol specialized hospitals. The structured questionnaire was prepared to understand the type of services, manpower and systematic programs. Among eight hospitals that stand for the alcohol addiction specialized hospitals, six hospitals agreed to participate in the survey, which was made from Jun. 17 to July 15, 2010. The average number of beds of the surveyed hospitals was 208. They were mostly private ones(66.7%), located in urban area(50%), and had experiences of alcohol treatment less than five years(50%). While all of them practiced both the inpatient and outpatient services, only 33% provided the systematic outpatient program that was at least 2 or 3 hours per week. All hospitals practiced the physical and individual psychological evaluations, but only 16.1% had the daytime programs. The beds of protective ward were 72% of all beds, and the beds of night and day occupied 7.6% and 2.6% respectively. It was found that although the average number of mental health social worker and mental health nurse was larger than that required in the regulation of mental health law there are significant deviations between hospitals. However, the manpower of psychiatrists and nurses were comparatively large. The first problem indicated by clinical experts was the patient's refusal of care, which results in an inefficiency in the treatment. The next problem was the lack of local health care institutions that can attend on the discharged patients were important issues. Also the low reimbursement and indifferences to the alcohol abuse were considered as important issues.

Calibration of Hargreaves Equation Coefficient for Estimating Reference Evapotranspiration in Korea (우리나라 기준증발산량 추정을 위한 Hargreaves 공식의 계수 보정)

  • Hwang, Seon-ah;Han, Kyung-hwa;Zhang, Yong-seon;Cho, Hee-rae;Ok, Jung-hun;Kim, Dong-Jin;Kim, Gi-sun;Jung, Kang-ho
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.21 no.4
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    • pp.238-249
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    • 2019
  • The evapotranspiration is estimated based on weather factors such as temperature, wind speed and humidity, and the Hargreaves equation is a simple equation for calculating evapotranspiration using temperature data. However, the Hargreaves equation tends to be underestimated in areas with wind speeds above 3 m s-1 and overestimated in areas with high relative humidity. The study was conducted to determine Hargreaves equation coefficient in 82 regions in Korea by comparing evapotranspiration determined by modified Hargreaves equation and the Penman-Monteith equation for the time period of 2008~2018. The modified Hargreaves coefficients for 50 inland areas were estimated to be 0.00173~0.00232(average 0.00196), which is similar to or lower than the default value 0.0023. On the other hand, there are 32 coastal areas, and the modified coefficients ranged from 0.00185 to 0.00303(average 0.00234). The east coastal area was estimated to be similar to or higher than the default value, while the west and south coastal areas showed large deviations by area. As results of estimating the evapotranspiration by the modified Hargreaves coefficient, root mean square error(RMSE) is reduced from 0.634~1.394(average 0.857) to 0.466~1.328(average 0.701), and Nash-Sutcliffe Coefficient(NSC) increased from -0.159~0.837(average 0.647) to -0.053~0.910(average 0.755) compared with original Hargreaves equation. Therefore, we confirmed that the Hargreaves equation can be overestimated or underestimated compared to the Penman-Monteith equation, and expected that it will be able to calculate the high accuracy evapotranspiration using the modified Hargreaves equation. This study will contribute to water resources planning, irrigation schedule, and environmental management.

Effects of Local Climatic Conditions on the Early Growth in Korean White Pine (Pinus koraiensis Sieb. et Zucc.) Stands -Relation between Annual Increment and Local Climatic Conditions- (지역별 잣나무 초기생장에 미치는 미기후의 영향 - 연년생장과 미기후와의 관계-)

  • Chon Sang- Keun;Shin Man Yong
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.1 no.1
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    • pp.41-51
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    • 1999
  • This study was conducted to investigate the effects of local climatic conditions on the annual increment of Korean white pine planted in Gapyung and Yaungdong. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age were measured and summarized for each locality. Based on these statistics, annual increments for 8 years from stand age 10 to 18 were calculated for each of stand variables. A topoclimatological technique which makes use of empirical relationships between the topography and the weather in study sites was applied to produce normal estimates of monthly mean, maximum, minimum temperatures, relative humidity, precipitation, and hours of sunshine. Then, the yearly climatic variables from 1990 to 1997 for each study site were derived from the spatial interpolation procedures based on inverse- distance weighting of the observed deviation from the climatic normals at the nearest 11 standard weather stations. From these estimates, 17 weather variables such as warmth index, coldness index, index of aridity etc., which affect the tree growth, were computed on yearly base for each locality. The deviations of measured annual increments from the expected annual increments for 8 years based on yield table of Korean white pine were then correlated with and regressed on the yearly weather variables to examine effects of local climatic conditions on the growth. Gapyung area provides better conditions for the growth of Korean white pine in the early stage than Youngdong area. This indicates that the conditions such as low temperature, high relative humidity, and large amount of precipitation provide favor environment for the early growth of Korean white pine. A ccording to the correlation and regression an analysis using local climatic conditions and annual increments, the growth pattern of Gapyung area corresponds to this tendency. However, it was found that the relationship between annual increments and local climatic conditions in Youngdong area shows different tendency from Gapyung. These results mean that the yearly growth pattern could not sufficiently be explained by climatic conditions with high variance in yearly weather variables. In addition, the poor growth in Youngdong area might not only be affected by climatic conditions, but also by other environmental factors such as site quality.

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Selection Model of System Trading Strategies using SVM (SVM을 이용한 시스템트레이딩전략의 선택모형)

  • Park, Sungcheol;Kim, Sun Woong;Choi, Heung Sik
    • Journal of Intelligence and Information Systems
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    • v.20 no.2
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    • pp.59-71
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    • 2014
  • System trading is becoming more popular among Korean traders recently. System traders use automatic order systems based on the system generated buy and sell signals. These signals are generated from the predetermined entry and exit rules that were coded by system traders. Most researches on system trading have focused on designing profitable entry and exit rules using technical indicators. However, market conditions, strategy characteristics, and money management also have influences on the profitability of the system trading. Unexpected price deviations from the predetermined trading rules can incur large losses to system traders. Therefore, most professional traders use strategy portfolios rather than only one strategy. Building a good strategy portfolio is important because trading performance depends on strategy portfolios. Despite of the importance of designing strategy portfolio, rule of thumb methods have been used to select trading strategies. In this study, we propose a SVM-based strategy portfolio management system. SVM were introduced by Vapnik and is known to be effective for data mining area. It can build good portfolios within a very short period of time. Since SVM minimizes structural risks, it is best suitable for the futures trading market in which prices do not move exactly the same as the past. Our system trading strategies include moving-average cross system, MACD cross system, trend-following system, buy dips and sell rallies system, DMI system, Keltner channel system, Bollinger Bands system, and Fibonacci system. These strategies are well known and frequently being used by many professional traders. We program these strategies for generating automated system signals for entry and exit. We propose SVM-based strategies selection system and portfolio construction and order routing system. Strategies selection system is a portfolio training system. It generates training data and makes SVM model using optimal portfolio. We make $m{\times}n$ data matrix by dividing KOSPI 200 index futures data with a same period. Optimal strategy portfolio is derived from analyzing each strategy performance. SVM model is generated based on this data and optimal strategy portfolio. We use 80% of the data for training and the remaining 20% is used for testing the strategy. For training, we select two strategies which show the highest profit in the next day. Selection method 1 selects two strategies and method 2 selects maximum two strategies which show profit more than 0.1 point. We use one-against-all method which has fast processing time. We analyse the daily data of KOSPI 200 index futures contracts from January 1990 to November 2011. Price change rates for 50 days are used as SVM input data. The training period is from January 1990 to March 2007 and the test period is from March 2007 to November 2011. We suggest three benchmark strategies portfolio. BM1 holds two contracts of KOSPI 200 index futures for testing period. BM2 is constructed as two strategies which show the largest cumulative profit during 30 days before testing starts. BM3 has two strategies which show best profits during testing period. Trading cost include brokerage commission cost and slippage cost. The proposed strategy portfolio management system shows profit more than double of the benchmark portfolios. BM1 shows 103.44 point profit, BM2 shows 488.61 point profit, and BM3 shows 502.41 point profit after deducting trading cost. The best benchmark is the portfolio of the two best profit strategies during the test period. The proposed system 1 shows 706.22 point profit and proposed system 2 shows 768.95 point profit after deducting trading cost. The equity curves for the entire period show stable pattern. With higher profit, this suggests a good trading direction for system traders. We can make more stable and more profitable portfolios if we add money management module to the system.

Availability Assessment of Single Frequency Multi-GNSS Real Time Positioning with the RTCM-State Space Representation Parameters (RTCM-SSR 보정요소 기반 1주파 Multi-GNSS 실시간 측위의 효용성 평가)

  • Lee, Yong-Chang;Oh, Seong-Jong
    • Journal of Cadastre & Land InformatiX
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    • v.50 no.1
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    • pp.107-123
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    • 2020
  • With stabilization of the recent multi-GNSS infrastructure, and as multi-GNSS has been proven to be effective in improving the accuracy of the positioning performance in various industrial sectors. In this study, in view that SF(Single frequency) GNSS receivers are widely used due to the low costs, evaluate effectiveness of SF Real Time Point Positioning(SF-RT-PP) based on four multi-GNSS surveying methods with RTCM-SSR correction streams in static and kinematic modes, and also derive response challenges. Results of applying SSR correction streams, CNES presented good results compared to other SSR streams in 2D coordinate. Looking at the results of the SF-RT-PP surveying using SF signals from multi-GNSS, were able to identify the common cause of large deviations in the altitude components, as well as confirm the importance of signal bias correction according to combinations of different types of satellite signals and ionospheric delay compensation algorithm using undifferenced and uncombined observations. In addition, confirmed that the improvement of the infrastructure of Multi-GNSS allows SF-RT-SPP surveying with only one of the four GNSS satellites. In particular, in the case of code-based SF-RT-SPP measurements using SF signals from GPS satellites only, the difference in the application effect between broadcast ephemeris and SSR correction for satellite orbits/clocks was small, but in the case of ionospheric delay compensation, the use of SBAS correction information provided more than twice the accuracy compared to result of the Klobuchar model. With GPS and GLONASS, both the BDS and GALILEO constellations will be fully deployed in the end of 2020, and the greater benefits from the multi-GNSS integration can be expected. Specially, If RT-ionospheric correction services reflecting regional characteristics and SSR correction information reflecting atmospheric characteristics are carried out in real-time, expected that the utilization of SF-RT-PPP survey technology by multi-GNSS and various demands will be created in various industrial sectors.

Production Increase of Milk in Dairy Cow by Metabolic Profile Test (대사판정시험을 이용한 젖소의 우유증산)

  • Lee Chang-Woo;Kim Bonn-Won;Ra Jeong-Chan;Shin Sang-Tae;Kim Doo;Kim Jong-Taik;Hong Soon-Il
    • Journal of Veterinary Clinics
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    • v.10 no.1
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    • pp.65-94
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    • 1993
  • This study examined metabolic profiles of 1349 Holstein cows from 91 commercial herds. Thirteen parameters which are consisted of twelve blood components and body condition score were examined and their mean values. standard deviations and standard limits, which are 80% confidential limits, in each lactational stage were reported. The variations of each parameter affected by season, individual milk yield, adjusted corrected milk yield of herd. and lactation number were also reported. A model of metabolic profile test applicable to this country where the average number of cows in a herd is small as to be fifteen is designed. Metabolic profiles as reflected in each parameter were discussed in relation to adequacy of dietary intake for production, milk production, reproductive performance, and diseases, and the possible measure to improve productivity of dairy cows were proposed. Much of the variation in parameters was due to differences between herds, and less to differences between seasons, differences between individual milk yield, and differences between lactational stages. As the average herd size in this country is small, it is believed that all the cows in a herd must be sampled, and the individual result of each parameter was compared with the standard limit for each lactational stage, and the percentage of cows which are outside the standard limits in a herd was calculated to use as a criteria for evaluation of the herd. Data outside the 99% confidential limits were to be deleted at first, but when the trends of the data outside the 99% confidential limits are same as the trends of the data within 99% confidential limits, the deleted data must be reviewed again, otherwise some important informations would be missed. The mean concentration of blood urea nitrogen in this study was much higher than that was reported in England, U.S.A. and Japan, and it was similar to the upper limits reported in England, U.S.A. and Japan. So it was thought that the concentration of blood urea nitrogen is improper as a criteria for protein intake. The increase of serum total protein cocentration beyond standard limits was due to increase of serum globulin concentration in most of the cows. The correlation coefficient between serum and protein and serum globulin concentration was 0.83. Serum globulin concentration was negatively related to adjusted corrected milk of herd. Serum albumin, calcium and magnessium concentrations were negatively related to adjusted corrected milk of herd, which indicate that high-producing individual or high-producing herd have not taken sufficient protein/amino acids, calcium and magnessium. Packed cell volume was negatively related to adjusted corrected milk of the herd, and the trend was same In each lactational stage. The correlation coefficient between serum and packed cell volume was 0.16 and the correlation was very weak. Blood glucose concentration was lowest in early lactational stage, which indicates negative energy balance in early lactational stage. Blood glucose concentration was negatively related to adjusted corrected milk of herd from peak to late lactational stage, which indicates negative energy balance during the period in high-producing individuals or high-producing herds. Correlation coefficient between serum aspartate aminotransferase activity and serum ${\gamma}$-glutamyltransferase activity was 0.41, and this indicates that serum ${\gamma}$-glutamyltransferase should be included as a parameter of metabolic profile test to evaluate liver function. Body condition score of dairy cows in this country was lower than that of Japan in every lactational stages, and the magnitude of increase in body condition score during middle and late lactational stages was small. Metabolic profile can not be evaluated with solely nutritional intake. When an individual or large percentage of cows in a herd have adnormal values In parameters of metabolic profile test, veterinary clinician and nutritionist should cooperate so as to diagnose diseases and to calculate the e of no운ents simultaneously.

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Contents of vitamin B9 (folate) and B12 (cobalamins) in commonly consumed seafood menus in Korea (한국인 상용 수산물 식단의 비타민 B9과 B12 함량)

  • Park, Eun-Young;Jeong, Bomi;Chun, Jiyeon
    • Journal of Nutrition and Health
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    • v.54 no.2
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    • pp.211-223
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    • 2021
  • Purpose: A total of 39 seafood menus were prepared according to the Korean standard recipe, and analyzed for vitamin B9 (folate) and B12 (cobalamins) contents, using validated applied analytical methods. The menus included Guk/Tang/Jjigae (boiled or stewed dishes, n = 10), Bokkeum (stir-fried dishes, n = 10), Jjim/Jorim (braised or steamed dishes, n = 7), Gui (baked or grilled dishes, n = 7), Twigim (deep-fried dishes, n = 2) and Muchim (dried or blanched-seasoned dishes, n = 3). Methods: The contents of vitamin B9 and B12 in all food samples were determined by the trienzyme extraction-Lactobacillus casei and immunoaffinity-high-performance liquid chromatography/photodiode array detection methods. Analytical quality control was performed in order to assure reliability of the analysis. Results: Accuracy (97.4-100.6% recoveries) and precision (< 6% relative standard deviations for repeatability and reproducibility) of vitamin B9 and B12 analyses were determined to be excellent. The vitamin B9 and B12 contents of the 39 seafood menus evaluated, varied in the range of 1.83-523.08 ㎍/100 g and 0.11-38.30 ㎍/100 g, respectively, depending on the ingredients and cooking methods. The vitamin B9 content was highest in Jomi-gim (523.08 ㎍/100 g), followed by Geonsaeu-bokkeum (128.34 ㎍/100 g) and Janmyeolchi-bokkeum (121.53 ㎍/100 g). Vitamin B12 was detected in all seafood menus, with highest level obtained in Kkomack-jjim (41.58 ㎍/100 g). The seaweed dish was found to have high levels of both vitamin B9 and B12. All assays were performed under strict quality control. Conclusion: Guk and Tang menus, which contain a large amount of water, were relatively lower in the vitamin B9 and B12 contents than the other menus. Bokkeum menus containing various vegetables were high in the vitamin B9 content, but the vitamin B12 content was dependent on the type of seafood used in the menu.