• Title/Summary/Keyword: Percentile Method

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Study on Estimation Method of Water Cycle Goal in Waterfront City (수변도시의 물순환 목표 산정 방안 연구)

  • Kim, Jae-Moon;Baek, Jong-Seok;Shin, Hyun-Suk;Park, Kyoung-Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.475-487
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    • 2020
  • The current water-management paradigm is changing from the expansion of reservoirs and facilities for simple outflows and non-point source management to the building of a sound water circulation system throughout the watershed. Based on this, water management for the watershed as a whole is establishing standards through local ordinances. The purpose of this study is to establish water cycle targets that are resilient to water management even after the development of cities in watersheds where water management is highly needed. This was done by referring to research and ordinances related to water circulation by local governments. A method is proposed based on a storage and infiltration method for rainfall. Through a comparison of percentiles, it was found that the water circulation target of a planned waterside city can be treated with 52% of total rainfall and 80% of rainfall of 17 mm per day. To quantitatively improve the quality results of these calculation procedures, it is estimated that the calculation of water cycle targets will be more reliable if other various variables such as the safety of low impact development factors or the selection of appropriate specifications are considered later.

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.

Gastro-esophageal Reflux in Asthmatic Patients (기관지 천식환자에서 위식도 역류에 관한 연구)

  • Suh, Jung-Kyung;In, Kwang-Ho;Lee, So-Ra;Lee, Sang-Yeub;Cho, Jae-Youn;Shim, Jae-Jeong;Kang, Kyung-Ho;Yoo, Se-Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.4
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    • pp.836-843
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    • 1997
  • Background : The prevalence of Gastro-esophageal reflux(GER) in patients with asthma is estimated to be 50~60% and treatment of GER has been shown to improve asthma symptoms in Western. But GER has been known to be less common in Eastern and GER prevalence rates in asthmatics are not available in Korea. Method : We compared the prevalence rate of GER in 42 patients with asthma to that in 20 healthy normal controls and examed the efficacy of new prokinetic drug, cisapride(40mg/day, 8weeks) in patients with GER and asthma. For acid GER to be considered pathological, 24 hour esophageal pH monitoring should reveal values exceeding upper limit of 95 percentile for at least one of 6 parameter of DeMesseter's table. Result : The results showed GER was more common in patients with asthma(11/42, 26.2%) than normal controls(3/20, 15%) and asthmatics group showed a significant longer supine time pH<4(%) and total time pH<4(%), and more reflux episodes as compared with normal control group. After 4 asthmatics with GER were treated with cisapride, their asthma symtom scores, FEV1 and composite scores of pH monitoring were improved. Conclusion : GER is more common in asthmatics than in normal controls in Korea and prepulsid reduces asthma symptoms in patients with GER and asthma.

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Correlation between Body Fat Percent Estimated by Bioelectrical Impedance Analysis and Other Variable Methods (생체전기 저항법에 의한 체지방율과 다른 계측치간의 상관성 연구)

  • Yom, Hye Won;Kim, Su Jung;Whang, Il Tae;Hong, Young Mi
    • Clinical and Experimental Pediatrics
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    • v.46 no.8
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    • pp.751-757
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    • 2003
  • Purpose : Obesity is a significant health problem with medical and psychological consequences for children and adolescents. The purpose of this study was to assess the correlation between body fat percent using bioelectrical impedance(BI) and other variable methods. Methods : We measured height, weight, body mass index(BMI) and body fat percent by skinfold thickness(ST) and BI in 1,035(496 male; 539 female) children from seven to 18 years of age. The correlation coefficients between BI and each of the other different methods were obtained. The sensitivity and specificity to predict obesity by these several methods were studied. Results : Fat percent estimated by BI analysis and BMI showed a strong correlation(r=0.749). Fat percent estimated by BI analysis and ST showed a very strong correlation(r=0.835). At the 95th percentile cut-off point for BI, ST showed a sensitivity of 57.7%, and a specificity of 97.6% for estimating body fat. At the 95th percentile cut-off point for BI, BMI showed a sensitivity of 84.9%, and a specificity of 99.3% for estimating body fat. Conclusion : The fat percent estimated by BI analysis correlated strongly with ST or BMI. BI analysis is an objective and accurate method for estimating body fat in childhood obesity.

Operator Exposure to Indoxacarb Wettable Powder and Water Dispersible Granule during Mixing/loading and Risk Assessment (Indoxacarb의 수화제 및 입상수화제 살포액 조제 시 농작업자의 노출량 측정 및 위해성 평가)

  • Kim, Eunhye;Hwang, Yon-Jin;Kim, Suhee;Lee, Hyeri;Hong, Soonsung;Park, Kyung-Hun;Kim, Jeong-Han
    • The Korean Journal of Pesticide Science
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    • v.16 no.4
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    • pp.343-349
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    • 2012
  • Exposure and risk assessments were conducted to evaluate the relative safety of mixing/loading work of indoxacarb between wettable powder (WP) and water dispersible granule (WG). Hand exposure was monitored using cotton gloves while inhalation exposure was measured using personal air monitor. Method validation for the exposure monitoring was established successfully through several experiments. Limit of determination and limit of quantitation were 0.25 and 1 ng, respectively. $R^2$ of calibration curve linearity was more than 0.9999 and reproducibility was 0.7-6. Recovery of indoxacarb from gloves, solid sorbent and glass fiber filter at three different levels was 81.5-108.8%. Trapping efficiency and breakthrough tests gave 981.5-108.8% of recovery. During mixing/loading procedure, hand exposure amount (75 percentile of 30 repetitions) for indoxacarb WP was 6 folds (459.8 mg/kg a.i) than that of WG (81.4 mg/kg a.i). This result indicates that WG has less drift than WP thanks to its granular type of formulation. Inhalation amount was $10^{-8}-10^{-7}%$ of spray mixture prepared and $10^{-4}-10^{-3}%$ of hand exposure. In inhalation case, no significant differences were observed between two formulations. Margin of safety was calculated for risk assessment using male Korean average body weight and acceptable operator exposure level as the important exposure factors. Mixing/loading procedures for both of the formulations were considered to be of least risk because calculated MOS values were more than 1.

Food Group and Dietary Nutrient Intakes by Sugar-Sweetened Beverage Intake Level in Korean High School Students Using the Data from 2007~2015 Korea National Health and Nutrition Examination Survey (2007~2015 국민건강영양조사를 이용한 고등학생의 가당음료 섭취 수준에 따른 식품군 및 영양 섭취 실태)

  • Kim, Sun Hyo
    • Journal of Korean Home Economics Education Association
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    • v.33 no.2
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    • pp.95-113
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    • 2021
  • This study examined the food group and dietary nutrient intakes by sugar-sweetened beverage(SSB) intake level in high school students aged 15~18 years(n=2,377) using the 2007~2015 Korea National Health and Nutrition Examination Survey. Subjects were classified into three groups by SSB(included carbonated drinks, sports drinks, and caffeinated drinks that contained added sugars) intake level obtained from 24-hour recall method: SSB 1(SSB intake 0 g/d), SSB 2(0 g/d < SSB intake < 50th percentile) and SSB 3(SSB intake ≥ 50th percentile). Result of daily intakes of SSB were 160.6±10.5 g/d for boys and 98.6±7.1 g/d for girls and it increased for boys(p<0.0001) and girls(p=0.0280) by year. The highest intakes were carbonated drinks followed by fruit juices for boys and girls. Intakes of carbonated drinks increased as 2.7 times for boys(p<0.0001) and 1.6 times for girls between 2007 and 2015 year. Daily intakes of vegetables were the lowest in SSB 3 of three groups for boys and girls(p<0.0001), and those of fruits were lower in SSB 2 and SSB 3 than SSB 1 for boys(p=0.0013). Daily intakes of milk & milk products decreased toward SSB 3 group for boys(p<0.0001) while those were the lowest in SSB 3 of three groups for girls. Daily intakes of dietary fiber(21.3~25.3%) and calcium(49.6~59.8%) were very low compared to the dietary reference intakes. Percentage of daily intakes compared to the dietary reference intakes increased for energy for boys and girls(p<0.0001) while decreased for vitamin C toward SSB 3 group for boys(p<0.0001) and girls(p=0.0382). Those of calcium were the lowest in SSB 3 of three groups for boys(p<0.0001) and girls(p=0.0008). Ratio of excess intakes of energy/fat increased toward SSB 3 group for boys and girls(p=0.0002). Ratio of calcium deficiency was not different among groups but that was very high(85.9~92.5%). Therefore, it should be emphasized to reduce SSB intakes in order to improve diversity in food group and dietary nutrient intakes among high school students through dietary education and government support.

Yearly Trend of Sugar-Sweetened Beverage(SSB) Intake and Nutritional Status by SSB Intake Level in Korean Middle School Students Using the 2007~2015 Korea National Health and Nutrition Examination Survey (중학생의 가당음료 섭취량 변화 추이와 가당음료 섭취 수준에 따른 영양상태 평가: 2007~2015 국민건강영양조사를 이용하여)

  • Kim, Sun Hyo
    • Journal of Korean Home Economics Education Association
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    • v.33 no.1
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    • pp.63-79
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    • 2021
  • This study examined yearly trend of sugar-sweetened beverage(SSB) intake and compared nutritional status by SSB intake level in middle school students aged 12~14 years(n=2,543) using the data from 2007~2015 Korea National Health and Nutrition Examination Survey. SSB included carbonated drinks, sports drinks, and caffeinated drinks contained added sugar. Subjects were classified into three groups by SSB intake level obtained from 24-hour recall method: SSB 1(SSB intake 0 g/d), SSB 2(0 g/d < SSB intake < 50th percentile) and SSB 3(SSB intake ≥ 50th percentile). Result of daily intake of SSB was 76.1±6.2 g/d for boys and 59.5±4.7 g/d for girls and it was increased significantly for boys(p-trend 0.0004) and girls(p-trend 0.0038) by year. The most intakes were carbonated drinks followed by fruit juices and sports drinks for boys and girls. Percentage of daily intake compared to the dietary reference was increased for energy and iron while was decreased for calcium and vitamin C toward SSB 3 group. Ratio of excess intake of energy/fat was increased significantly for boys(p=0.0091) and girls(p<0.0001) toward SSB 3 group. Ratio of calcium deficiency was 86.8~94.9% for boys and girls and it was very high. Therefore, it should be emphasized to reduce SSB intake and drink plain water without added sugar, etc. and milk as a source of calcium for improving nutritional status of middle school students through dietary education and social support.

Application of Rainfall Runoff Model with Rainfall Uncertainty (강우자료의 불확실성을 고려한 강우 유출 모형의 적용)

  • Lee, Hyo-Sang;Jeon, Min-Woo;Balin, Daniela;Rode, Michael
    • Journal of Korea Water Resources Association
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    • v.42 no.10
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    • pp.773-783
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    • 2009
  • The effects of rainfall input uncertainty on predictions of stream flow are studied based extended GLUE (Generalized Likelihood Uncertainty Estimation) approach. The uncertainty in the rainfall data is implemented by systematic/non-systematic rainfall measurement analysis in Weida catchment, Germany. PDM (Probability Distribution Model) rainfall runoff model is selected for hydrological representation of the catchment. Using general correction procedure and DUE(Data Uncertainty Engine), feasible rainfall time series are generated. These series are applied to PDM in MC(Monte Carlo) and GLUE method; Posterior distributions of the model parameters are examined and behavioural model parameters are selected for simplified GLUE prediction of stream flow. All predictions are combined to develop ensemble prediction and 90 percentile of ensemble prediction, which are used to show the effects of uncertainty sources of input data and model parameters. The results show acceptable performances in all flow regime, except underestimation of the peak flows. These results are not definite proof of the effects of rainfall uncertainty on parameter estimation; however, extended GLUE approach in this study is a potential method which can include major uncertainty in the rainfall-runoff modelling.

The Efficient Anchorage Management of VTS through Analysis of Domain Watch (영역감시 분석을 통한 VTS의 효율적 정박지 관리 방안에 관한 연구)

  • Lee, Jin-Suk;Song, Chae-Uk
    • Journal of Navigation and Port Research
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    • v.42 no.3
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    • pp.201-206
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    • 2018
  • The purpose of this study is to estimate a proper Domain Watch between anchored vessels in order to propose a method for the efficient management of VTS(Vessel Traffic Service) of the N-anchorage in Busan harbor, which is the largest port in Korea. For this purpose, we proposed the calculation method of Domain Watch and investigated the ship length(L), the distance between anchored vessels ($D_{ij}$), the domain radius(R), and the domain radius vs L(R/L) during the peak time of the vessels in the latest usage of anchorage. As a result of technical analysis for the surveyed data, the minimum R/L for securing the safety distance between anchored vessels was selected based on 2.85 corresponding to the 70th percentile of the total data. This result was applied to the N-anchorage of Busan and compared with the 'Guidelines of Port and Harbor Design(2014)', and we have confirmed that it is reasonable to set the Domain radius with the minimum 2.85L or more in VTS. This study considers the safety management of anchorage for VTS. This study could contribute to the safety of vessels using anchorage and the safety management plan of VTS when it is applied to other ports in operation such as it was in Busan.

A Study on Knowledge, Educational Needs and Educational Experience for Indwelling Catheter Management in the Families of Home Care Clients (유치도뇨관 삽입 가정간호대상자 가족의 유치도뇨관 관리에 관한 지식, 교육요구 및 교육경험)

  • Kim, Jung-Soon;Lee, Sang-Ju;Kang, In-Soon
    • Journal of Home Health Care Nursing
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    • v.12 no.1
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    • pp.92-116
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    • 2005
  • Purpose: This study was a predicative survey to provide home care clients with indwelling urinary catheters for furnishing basic educational material to their families by analyzing the family members' knowledge, educational needs and educational experience about indwelling catheter management. Method : The subjects consisted of 108 family members who cared for home care clients with indwelling catheters. Data were collected by home care nurses in nine hospitals in Pusan, who directly interviewed with them through questionnaires from Sep. 6th to 30th in 2004. The questionnaires for data collection were developed through pre-survey and reference review. The collected data was analyzed by using frequency, percentile, mean, variation, t-test, ANOVA on SPSS 10.1 package. Results : There were characters of home care clients with indwelling catheters: women(67.6%) were more than men; the average age of them was $69.60{\pm}14.99$ years old; neurogenic and cerebrovascular diseases(80.0%) were the most common disease group; 81.5% of them were totally dependent on others in terms of level of activity. Home care clients' families had these characters: women(76.9%) were more than men; the average age was $54.5{\pm}13.70$ years old; 46.3% of them were parents or sons or daughters in terms of relation with patient; tl1e average care period was $39.8{pm}34.20$ months. Level of knowledge about indwelling catheter management of the family members were 69.8% and its mean were $20.24{\pm}4.53$. Educational needs were 90.9% and its mean were $14.55{\pm}3.56$. Educational experience were 53.3% and its mean were $8.53{\pm}4.30$. 'Complications in using an indwelling catheter', 'Symptoms to call for a home care nurse' and 'Method to attach an indwelling catheter' were high ranked in both educational needs and educational experience. 'Anatomy of urinary tract', 'Functions of urinary tract' and 'Catheter placement' were low ranked in both educational needs and educational experience Level of knowledge about indwelling catheter management of the families showed a significant difference according to their age(F=5.35, p=0.01). Educational needs showed a significant difference according to care period(F=3.06, p=0.04). Conclusion: the family members' level of knowledge and educational experience about indwelling catheter management and their educational were not sufficient while their educational needs were high. In other words although the family members were acknowledged education needs, but the care for the patients with indwelling catheter weren't performed well because of their lack of related knowledge. Therefore systematic educational programs about indwelling catheter management for home care clients and their families should be made on the base of this study.

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