• Title/Summary/Keyword: Error level

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Uncertainty Analysis of Stage-Discharge Curve Using Bayesian and Bootstrap Methods (Bayesian과 Bootstrap 방법을 이용한 수위-유량 관계곡선의 불확실성 분석)

  • Lim, Jonghun;Kwon, Hyungsoo;Joo, Hongjun;Wang, Won-joon;Lee, Jongso;You, Younghoon;Kim, Hungsoo
    • Journal of Wetlands Research
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    • v.21 no.2
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    • pp.114-124
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    • 2019
  • The objective of this study is to reduce the uncertainty of the river discharge estimation method using the stage-discharge relation curve. It is necessary to consider the quantitative and accurate estimation method because the river discharge data is essential data for hydrological interpretation and water resource management. For this purpose, the parameters estimated by Bayesian and Bootstrap methods are compared with the ones obtained by stage-discharge relation curve. In addition, the Bayesian and Bootstrap methods are applied to assess uncertainty and then those are compared with the confidence intervals of the results from standard error method which has t-distribution. From the results of this study, The estimated value of the regression analysis developed through this study is less than 1 ~ 5%. Also It is confirmed that there are some areas where the applicability is better than the existing one according to the water level at each point. Therefore, if we use more suitable method according to the river characteristics, we could obtain more reliable discharge with less uncertainty.

Reproducing Rhythmic Idioms: A Comparison Between Healthy Older Adults and Older Adults With Mild Cognitive Impairment (리듬꼴에 따른 건강 노인과 경도인지장애 노인의 리듬 재산출 수행력 비교)

  • Chong, Hyun Ju;Lee, Eun Ji
    • Journal of Music and Human Behavior
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    • v.16 no.1
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    • pp.73-88
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    • 2019
  • This research was conducted to compare the rhythm reproduction abilities between older adults with and without mild cognitive impairment (MCI) and analyze the abilities depending on the rhythm idiom. Participants between 60-85 years of age were recruited from senior community centers, dementia prevention centers, and senior welfare centers. A total of 57 participants were included in this study: 27 diagnosed with MCI and 30 healthy older adults (HOA). The experiment was conducted individually in a private room in which a participant was given random binary time rhythm idioms and instructed to reproduce the rhythmic idioms with finger tapping. Each participant's beat production was recorded with the Beat Processing Device (BPD) for iPad. BPD calculated rhythm reproduction as measured through rhythm ratio and error among beats. Results showed marginal differences between the two groups in terms of mean scores of rhythm reproduction abilities. In terms of the rhythm ratio among beats, both groups' highest rhythm reproduction rate was for <♩ ♩>, and their lowest reproduction rate was for <♩. ♪>. In conclusion, there was no significant difference in rhythm reproduction ability between the HOA and MCI groups. However, the study found an interesting result related to performance level of rhythmic idioms. This result provides therapeutic insight for formulating rhythm tasks for older adults.

A Comparative Study on Direct Instrument Methods in Open Channel for Measuring River Water Usage (하천수 사용량 계측을 위한 개수로에서의 직접 계측방법 비교 연구)

  • Baek, Jongseok;Kim, Chiyoung;Lee, Kisung;Kang, Hyunwoong;Song, Jaehyun
    • Journal of Korean Society of Disaster and Security
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    • v.13 no.4
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    • pp.65-74
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    • 2020
  • Continuous and accurate instrument of river water usage is needed for sustainable river water management. Although the instrument methods applicable to each point of use of river water are different, more precise direct instrument methods are required at the point of major open channel. Users of river water should select appropriate direct instrument methods to measure usage, but there is a lack of standards and verification research. In this study, the H-Q rating curve method, ultrasonic method, and microwave method were applied directly to the test basin in the upper basin of Mangyeong river, and the accuracy of measurement data was evaluated by comparing absolute error between discharge data calculated by instrument method. When comparing the calculated discharge of point units, the ultrasonic method showed the best results of the actual measurement. Through continuous instrument, the sum of the daily and monthly units was compared, and the ultrasonic and microwave methods were shown to be highly accurate. Based on the results of this study, it is hoped that the appropriate direct measurement method can be selected according to the importance of the river water use facility, considering that the ultrasonic method and the microwave method are relatively costly compared to the water level-flow relationship method.

Correction Algorithm of Errors by Seagrasses in Coastal Bathymetry Surveying Using Drone and HD Camera (드론과 HD 카메라를 이용한 수심측량시 잘피에 의한 오차제거 알고리즘)

  • Kim, Gyeongyeop;Choi, Gunhwan;Ahn, Kyungmo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.6
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    • pp.553-560
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    • 2020
  • This paper presents an algorithm for identifying and eliminating errors by seagrasses in coastal bathymetry surveying using drone and HD camera. Survey errors due to seagrasses were identified, segmentated and eliminated using a L∗a∗b color space model. Bathymetry survey using a drone and HD camera has many advantages over conventional survey methods such as ship-board acoustic sounder or manual level survey which are time consuming and expensive. However, errors caused by sea bed reflectance due to seagrasses habitat hamper the development of new surveying tool. Seagrasses are the flowering plants which start to grow in November and flourish to maximum density until April in Korea. We developed a new algorithm for identifying seagrasses habitat locations and eliminating errors due to seagrasses to get the accurate depth survey data. We tested our algorithm at Wolpo beach. Bathymetry survey data which were obtained using a drone with HD camera and calibrated to eliminate errors due to seagrasses, were compared with depth survey data obtained using ship-board multi-beam acoustic sounder. The abnormal bathymetry data which are defined as the excess of 1.5 times of a standard deviation of random errors, are composed of 8.6% of the test site of area of 200 m by 300 m. By applying the developed algorithm, 92% of abnnormal bathymetry data were successfully eliminated and 33% of RMS errors were reduced.

Transaction Pattern Discrimination of Malicious Supply Chain using Tariff-Structured Big Data (관세 정형 빅데이터를 활용한 우범공급망 거래패턴 선별)

  • Kim, Seongchan;Song, Sa-Kwang;Cho, Minhee;Shin, Su-Hyun
    • The Journal of the Korea Contents Association
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    • v.21 no.2
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    • pp.121-129
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    • 2021
  • In this study, we try to minimize the tariff risk by constructing a hazardous cargo screening model by applying Association Rule Mining, one of the data mining techniques. For this, the risk level between supply chains is calculated using the Apriori Algorithm, which is an association analysis algorithm, using the big data of the import declaration form of the Korea Customs Service(KCS). We perform data preprocessing and association rule mining to generate a model to be used in screening the supply chain. In the preprocessing process, we extract the attributes required for rule generation from the import declaration data after the error removing process. Then, we generate the rules by using the extracted attributes as inputs to the Apriori algorithm. The generated association rule model is loaded in the KCS screening system. When the import declaration which should be checked is received, the screening system refers to the model and returns the confidence value based on the supply chain information on the import declaration data. The result will be used to determine whether to check the import case. The 5-fold cross-validation of 16.6% precision and 33.8% recall showed that import declaration data for 2 years and 6 months were divided into learning data and test data. This is a result that is about 3.4 times higher in precision and 1.5 times higher in recall than frequency-based methods. This confirms that the proposed method is an effective way to reduce tariff risks.

Phenylketonuria: Current Treatments and Future Developments (페닐케톤뇨증의 치료: 현재와 미래)

  • Lee, Jeongho
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.20 no.2
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    • pp.37-43
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    • 2020
  • Phenylketonuria is the most prevalent disorder caused by an inborn error in aminoacid metabolism. It results from mutations in the phenylalanine hydroxylase (PAH) gene. If untreated or late treated, results in profound and irreversible mental disability. Newborn screening test identify patients with phenylketouria. The early initiation of a phenylalanine restricted diet very soon prevents most of the neuropsychiatric complications. However, the diet therapy is difficult to maintain and compliance is poor, especially in adolescents and adulthood. Since 2015, American Medical College of Medical Genetics and Genomics (ACMG) recommended more strong restrictive diet therapy for target blood level of phenylalanine (<360 umol/L). For over four decades the only treatment was a very restrictive low phenylalanine diet. This changed in 2007 with the approval of cofactor therapy (Tetrahydrobiopterin, BH4) which is effective in up to 30% of patients. Data from controlled clinical trials with sapropterin dihydrochloride indicate a similar occurrence of all-cause adverse events with this treatment and placebo. Large neutral aminoacids (LNAA) competes with phenylalanine for transport across the blood-brain-barrier and have a beneficial effect on executive functioning. A new therapy has just been approved that can be effective in most patients with PAH deficiency regardless of their degree of enzyme deficiency or the severity of their phenotype. Phenylalanine ammonia lyase (PAL-PEG) was approved in the USA by FDA in May of 2018 for adult patients with uncontrolled blood phenylalanine concentrations on current treatment. Nucleic acid therapy (therapeutic mRNA or gene therapy) is likely to provide longer term solutions with few side effects.

Application of Integrated Modelling Framework Consisted of Delft3D and HABITAT for Habitat Suitability Assessment (생물서식지 적합성 평가를 위한 Delft3D와 HABITAT 모델의 연계 적용)

  • Lim, Hyejung;Na, Eun Hye;Jeon, Hyeong Cheol;Song, Hojin;Yoo, Hojun;Hwang, Soon Hong;Ryu, Hui-Seong
    • Journal of Korean Society on Water Environment
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    • v.37 no.3
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    • pp.217-228
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    • 2021
  • This paper discusses a methodology where an integrated modelling framework is used to quantify the risk derived from anthropic activities on habitats and species. To achieve this purpose, a tool comprising the Delft3D and HABITAT model, was applied in the Yeongsan river. Delft3D effectively simulated the operational condition and flow of weirs in river. In accuracy evaluation of the Delft3D-FLOW, the Bias, Pbias, Mean Absolute Error (MAE), Nash-Sutcliffe Efficiency (NSE), and Index of Agreement (IOA) were used, and the result was evaluated as grade above 'Satisfactory'. The HABITAT calculated Habitat Suitability Value (HSV) for the following eight species: mammal, fish, aquatic plant, and benthic macroinvertebrate. An Area was defined as a suitable habitat if the HSV was larger than 0.5. HABITAT was judged accurately by measuring the Correct Classification rate (CCR) and the area under the ROC curve (AUC). For benthic macroinvertebrate, the CCR and AUC were 77% and 0.834, respectively, at thresholds of 0.017 and 4 inds/m2 for HSV and individuals per unit area. This meant that the HABITAT model accurately predicted the appearance of the benthic macroinvertebrates by approximately 77% and that the probability of false alarms was also very low. As a result of evaluating the suitability of habitats, in the Yeongsan river, if the annual "lowest level" (Seungchon weir: 2.5 EL.m/ Juksan weir: -1.35 EL.m) was maintained, the average habitat improvement effect of 6.5%P compared to the 'reference' scenario was predicted. Consequently, it was demonstrated that the integrated modelling framework for habitat suitability assessment is able to support the remedy aquatic ecological management.

Effects of Manual Therapy on Musculoskeletal Diseases : A Meta-Analysis (근육뼈대계 질환에 대한 도수치료의 효과: 메타분석)

  • Lee, Jeong-Woo;Gong, Gwang-Sik;Kim, Dong-Yeon;Koh, Un
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.1
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    • pp.203-217
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    • 2021
  • Purpose: The purpose of this meta-analysis was to examine the high-level evidence of the effects of manual therapy on musculoskeletal diseases. Methods: Domestic databases were searched for studies that conducted clinical trials associated with manual therapy on chronic musculoskeletal diseases. A total of 591 studies published between 2005 and 2018 were identified, with 18 studies satisfying the inclusion data. The studies were classified according to patient, intervention, comparison, and outcome (PICO). The search outcomes were items associated with pain and physical function. The 18 studies included in the study were evaluated by using the R meta-analysis (version 4.0). The quality of 18 randomized control trials was evaluated by using the Cochrane risk of bias (ROB). The effect sizes were computed as the corrected standardized mean difference (SMD). Subgroup and meta-regression analyses were also used. Egger's regression test was carried out in order to analyze the publication bias. Cumulative meta-analysis and sensitivity analysis were also conducted in order to analyze the data error. Results: The following factors showed the large effect size of manual therapy on chronic musculoskeletal diseases: pain (Hedges's g = 2.66; 95% CI = 1.47 ~ 3.85), and physical function (Hedges's g = 2.15; 95% CI: 1.22 ~ 3.08). The subgroup analysis only showed a statistical difference in the type of manual therapy (pain) and outcome (physical function). No statistically significant difference was found in the meta-regression analysis. Publication bias was found in the data, but the results of the trim-and-fill method showed that such bias did not largely affect the obtained data. Furthermore, there were no data errors in the cumulative meta-analysis and sensitivity analysis. Conclusion: This study provides evidence for the effectiveness of manual therapy on chronic musculoskeletal diseases in pain and physical function. Subgroup analysis suggests that only the type of manual therapy for pain and the type of outcome for physical function differed in effect size.

Estimating the Demand Function for Industrial Natural Gas Use in Korea : A Cross-sectional Analysis (횡단면 분석을 활용한 한국 산업용 도시가스 수요함수 추정)

  • Lee, Bok-Hee;Lee, Hye-Jeong;Yoo, Seung-Hoon;Huh, Sung-Yoon
    • Journal of the Korean Institute of Gas
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    • v.24 no.6
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    • pp.34-46
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    • 2020
  • In order to supply stable natural gas in the future, it is necessary to forecast the demand in advance and secure the quantity of supply. In this paper, we propose a method of estimating the demand function of industrial natural gas, which is the core of the increase of domestic natural gas demand in the future. The cross-sectional data of 304 domestic industries were used to estimate the demand function of the industrial natural gas, and the effect of industry specific characteristics such as capital investment, manufacturing cost. Finally, the least absolute deviation estimation method which is robust to outliers and does not assume the homogeneity of the error term and the normality, And the results were derived. In addition, the economic value of industrial city gas was estimated using the price elasticity of industrial city gas. Therefore, it can be seen that the continuous expansion and supply of city gas to the industrial sector is beneficial at the national level, and the government needs to promote expansion through the industrial city gas support policy.

Optimization for Decolorization and UV-Absorbility of Refined Sea Buckthorn Oil Using CCD-RSM (CCD-RSM을 이용한 시벅턴 오일의 탈색공정 최적화 및 자외선 흡수능력 평가)

  • Hong, Seheum;Zheng, Yunfei;Lee, Seung Bum
    • Applied Chemistry for Engineering
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    • v.32 no.1
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    • pp.61-67
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    • 2021
  • In this study, the adsorption decolorization process of sea buckthorn oil was carried out to verify the possibility of the sea buckthorn oil as a natural UV absorber. The optimization was carried out by using the central composite design model-response surface methodology (CCD-RSM). The response values of CCD-RSM were selected as the decolorization effect through the process, acid value after decolorization, and UV absorbance of the decolored oil at 290nm. The amount of adsorbent, temperature and time were selected as the process variables for the experiments. According to the results of CCD-RSM, the results of optimization were all consistent. The optimal conditions, which satisfy CCD-RSM statically and mathematically, were 4.32 wt.%, 134.90 ℃, and 19.8 min for the amount of adsorbent, temperature and time, respectively. The estimated response values expected under these optimal conditions values were 94.78%, 2.08 mg/g KOH, and 2.91 for the decolorization effect, acid value and UV absorbance at 290 nm, respectively. Also the average error from actual experiment for verifying the conclusions was smaller than 2%. Therefore, it was confirmed that the application of CCD-RSM to the adsorption decolorization process of sea buckthorn oil showed a very high level of acceptable results and that the sea buckthorn oil has high possibility to be used as a natural UV absorber.