• Title/Summary/Keyword: Interquartile range

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The study of comparisons of standardization methods (원점수 순위와 표준점수 순위 비교를 통한 표준화 방법비교)

  • Min, Dae-Kee;Jung, Ji-Hyeon
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.1
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    • pp.113-120
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    • 2012
  • When we evaluate prospective students in the interview process, we have to implement a system in which each student can be fairly judged. This process, the standardization of the scores which the interviewers have produced based on a student's performance, is implemented to ensure that each student receives a score that objectively translates one's performance. Although we don't know exactly how effective the standardization is in many different cases, we have researched which standardization methods are most stable and have minimum risks among the four methods such as STD, Range, MAD and IQR. These methods use scales such as standard deviation, range, maximum median and interquartile range.

Diabetes prediction mechanism using machine learning model based on patient IQR outlier and correlation coefficient (환자 IQR 이상치와 상관계수 기반의 머신러닝 모델을 이용한 당뇨병 예측 메커니즘)

  • Jung, Juho;Lee, Naeun;Kim, Sumin;Seo, Gaeun;Oh, Hayoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.10
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    • pp.1296-1301
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    • 2021
  • With the recent increase in diabetes incidence worldwide, research has been conducted to predict diabetes through various machine learning and deep learning technologies. In this work, we present a model for predicting diabetes using machine learning techniques with German Frankfurt Hospital data. We apply outlier handling using Interquartile Range (IQR) techniques and Pearson correlation and compare model-specific diabetes prediction performance with Decision Tree, Random Forest, Knn (k-nearest neighbor), SVM (support vector machine), Bayesian Network, ensemble techniques XGBoost, Voting, and Stacking. As a result of the study, the XGBoost technique showed the best performance with 97% accuracy on top of the various scenarios. Therefore, this study is meaningful in that the model can be used to accurately predict and prevent diabetes prevalent in modern society.

Comparison of the Efficacy of Diluted Polyethylene Glycol and Low-Density (0.1% w/v) Barium Sulfate Suspension for CT Enterography (전산화단층촬영 소장조영술을 위한 희석된 폴리에틸렌 글리콜과 저밀도(0.1% w/v) 바륨 현탁액의 유용성 비교)

  • Yeon Jung Kim;Seung Ho Kim;Tae Wook Baek;Hyungin Park
    • Journal of the Korean Society of Radiology
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    • v.84 no.4
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    • pp.911-922
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    • 2023
  • Purpose To compare small bowel distension and side effects between a diluted polyethylene glycol (PEG) solution and a low-density (0.1% w/v) barium sulfate suspension (LDBSS) for CT enterography (CTE) preparation. Materials and Methods Total 173 consecutive patients who underwent CTE were enrolled in this study. The LDBSS (1 L) was used in 50 patients, and the diluted iso-osmotic PEG solution (1 L) was used in 123 patients. Two blinded radiologists independently scored jejunal and ileal distensions on a 5-point scale. To compare side effects between the two groups, the patients reported whether they had immediate complications after the administration of the oral contrast media. Results For ileal and jejunal distension, the diluted PEG solution showed no difference from the LDBSS for either reader (ileum: reader 1, median, 4; 4, interquartile range, 3-4; 3-4, p = 0.997; reader 2, median, 4; 4, interquartile range, 3.3-4.0; 3-4, p = 0.064; jejunum: reader 1, median, 2; 2, interquartile range, 2-3; 2-3, p = 0.560; reader 2, median, 3; 2, interquartile range, 2-3; 2-3, p = 0.192). None of the patients complained of immediate complications following administration of either of the oral contrast media. Conclusion The diluted PEG solution showed comparable bowel distension compared to LDBSS and no immediate side effects; thus, it can be a useful alternative.

Using the Sample IQR for Calculating Sample Size (표본크기 결정을 위한 IQR의 활용방법)

  • 홍종선;김현태;윤상호;정민정
    • The Korean Journal of Applied Statistics
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    • v.16 no.1
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    • pp.181-193
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    • 2003
  • Without a sample standard deviation for an estimator of the population standard deviation u in a sample size computations, we often use some functions of a sample range (R) or interquartile range (IQR) by an estimator of $\sigma$. In order to avoid under-powered studies, these estimates must have a high probability of being greater than or equal to $\sigma$. In this paper, these probabilities of being greater than or equal to $\sigma$ are estimated for IQR for various parents distributions, and are compared with the probabilities for R/4 (Browne 2001). Alternative divisors (K) are explored and discussed for which the probabilities of R/K and IQR/K being greater than or equal to $\sigma$ is at least 95%.

Robust Image Fusion Using Stationary Wavelet Transform (정상 웨이블렛 변환을 이용한 로버스트 영상 융합)

  • Kim, Hee-Hoon;Kang, Seung-Hyo;Park, Jea-Hyun;Ha, Hyun-Ho;Lim, Jin-Soo;Lim, Dong-Hoon
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1181-1196
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    • 2011
  • Image fusion is the process of combining information from two or more source images of a scene into a single composite image with application to many fields, such as remote sensing, computer vision, robotics, medical imaging and defense. The most common wavelet-based fusion is discrete wavelet transform fusion in which the high frequency sub-bands and low frequency sub-bands are combined on activity measures of local windows such standard deviation and mean, respectively. However, discrete wavelet transform is not translation-invariant and it often yields block artifacts in a fused image. In this paper, we propose a robust image fusion based on the stationary wavelet transform to overcome the drawback of discrete wavelet transform. We use the activity measure of interquartile range as the robust estimator of variance in high frequency sub-bands and combine the low frequency sub-band based on the interquartile range information present in the high frequency sub-bands. We evaluate our proposed method quantitatively and qualitatively for image fusion, and compare it to some existing fusion methods. Experimental results indicate that the proposed method is more effective and can provide satisfactory fusion results.

Outlier detection in dental research (치의학 연구에서 이상치의 처리)

  • Kim, Ki-Yeol
    • The Journal of the Korean dental association
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    • v.55 no.9
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    • pp.604-616
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    • 2017
  • In clinical dental research, errors occur in spite of careful study design and conduct. Data cleaning procedures intend to identify and correct these errors or at least to minimize their influence on study. Outlier is the one of these errors. Outlier detection is the first step in data analysis process which has a serious effect in the field of dental research. Hence, this paper aims to introduce the methods to detect the outliers and to examine their influences in statistical data analysis.

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Outlier Detection and Replacement for Vertical Wind Speed in the Measurement of Actual Evapotranspiration (실제증발산 측정 시 연직 풍속 이상치 탐색 및 대체)

  • Park, Chun Gun;Rim, Chang-Soo;Lim, Kwang-Suop;Chae, Hyo-Sok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.5
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    • pp.1455-1461
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    • 2014
  • In this study, using flux data measured in Deokgokje reservoir watershed near Deokyu mountain in May, June, and July 2011, statistical analysis was conducted for outlier detection and replacement for vertical wind speed in the measurement of evapotranspiration based on eddy covariance method. To statistically analyze the outliers of vertical wind speed, the outlier detection method based on interquartile range (IQR) in boxplot was employed and the detected outliers were deleted or replaced with mean. The comparison was conducted for the measured evapotranspiration before and after the outlier replacement. The study results showed that there is a difference between evapotranspiration before outlier replacement and evapotranspiration after outlier replacement, especially during the rainy day. Therefore, based on the study results, the outliers should be deleted or replaced in the measurement of evapotranspiration.

Ultrasound-guided needle decompression and steroid injection for calcific tendinitis of the shoulder: risk factors for repeat procedures and outcome analysis

  • Kim, Su Cheol;Lee, Sang Min;Park, Gun Tae;Jang, Min Chang;Yoo, Jae Chul
    • Clinics in Shoulder and Elbow
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    • v.24 no.2
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    • pp.55-65
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    • 2021
  • Background: Although ultrasound-guided needle decompression (US-GND) can treat calcific tendinitis of the shoulder effectively, repeat procedures might be required for unresolved symptoms. We evaluated the overall clinical outcomes of US-GND with subacromial steroid injection and the final results and factors predisposing toward repeat procedures. Methods: Ninety-eight patients who underwent US-GND for calcific tendinitis of the supraspinatus/infraspinatus were analyzed between March 2017 and December 2018. The clinical outcomes (pain visual analog scale, functional visual analog scale [FVAS], and American Shoulder and Elbow Surgeons [ASES] score) and final subjective satisfaction were compared between groups A (single US-GND) and B (repeat US-GND). The factors predisposing toward repeated US-GNDs were analyzed. Results: We found that 59.3% (58/98) of patient ASES scores were ≥80, and 73.5% of patients (72/98) were satisfied with the outcome. Group B (n=14) demonstrated a significantly higher rate of dominant-arm involvement compared to group A (78.6% vs. 48.8%, p=0.046). However, initial calcification size, shape, number, density, subscapularis involvement, lavage, and procedure time did not differ significantly between the groups. Group B showed poorer final FVAS (7 [interquartile range, 6-8] vs. 8 [interquartile range, 7-9], p=0.036) and subjective satisfaction compared to group A (satisfied: 5 [35.7%] vs. 67 [79.8%], p<0.001]. Conclusions: US-GND with subacromial steroid injection is a viable treatment option for calcific tendinitis of the shoulder. Dominant-arm involvement was the only independent factor for repeated US-GND. Final outcome of repeated US-GND for unimproved patients was promising; however, these outcomes were poor compared to those of the patients who improved after the first procedure.

A Survey on Procedural Sedation and Analgesia for Pediatric Facial Laceration Repair in Korea

  • Dongkyu Lee;Hyeonjung Yeo;Yunjae Lee;Hyochun Park;Hannara Park
    • Archives of Plastic Surgery
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    • v.50 no.1
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    • pp.30-36
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    • 2023
  • Background Most children with facial lacerations require sedation for primary sutures. However, sedation guidelines for invasive treatment are lacking. This study evaluated the current status of the sedation methods used for pediatric facial laceration repair in Korea. Methods We surveyed one resident in each included plastic surgery training hospital using face-to-face interviews or e-mail correspondence. The health care center types (secondary or tertiary hospitals), sedation drug types, usage, and dosage, procedure sequence, monitoring methods, drug effects, adverse events, and operator and guardian satisfaction were investigated. Results We included 45/67 hospitals (67%) that used a single drug, ketamine in 31 hospitals and chloral hydrate in 14 hospitals. All health care center used similar sedatives. The most used drug administered was 5 mg/kg intramuscular ketamine (10 hospitals; 32%). The most common chloral hydrate administration approach was oral 50 mg/kg (seven hospitals; 50%). Twenty-two hospitals (71%) using ketamine followed this sequence: administration of sedatives, local anesthesia, primary repair, and imaging work-up. The most common sequence used for chloral hydrate (eight hospitals; 57%) was local anesthesia, administration of sedatives, imaging work-up, and primary repair. All hospitals that used ketamine and seven (50%) of those using chloral hydrate monitored oxygen saturation. Median operator satisfaction differed significantly between ketamine and chloral hydrate (4.0 [interquartile range, 4.0-4.0] vs. 3.0 [interquartile range, 3.0-4.0]; p <0.001). Conclusion The hospitals used various procedural sedation methods for children with facial lacerations. Guidelines that consider the patient's condition and drug characteristics are needed for safe and effective sedation.

Why Is a b-value Range of 1500-2000 s/mm2 Optimal for Evaluating Prostatic Index Lesions on Synthetic Diffusion-Weighted Imaging?

  • So Yeon Cha;EunJu Kim;Sung Yoon Park
    • Korean Journal of Radiology
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    • v.22 no.6
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    • pp.922-930
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    • 2021
  • Objective: It is uncertain why a b-value range of 1500-2000 s/mm2 is optimal. This study was aimed at qualitatively and quantitatively analyzing the optimal b-value range of synthetic diffusion-weighted imaging (sDWI) for evaluating prostatic index lesions. Materials and Methods: This retrospective study included 92 patients who underwent DWI and targeted biopsy for magnetic resonance imaging (MRI)-suggested index lesions. We generated sDWI at a b-value range of 1000-3000 s/mm2 using dedicated software and true DWI data at b-values of 0, 100, and 1000 s/mm2. We hypothesized that lesion conspicuity would be best when the background (i.e., MRI-suggested benign prostatic [bP] and periprostatic [pP] regions) signal intensity (SI) is suppressed and becomes homogeneous. To prove this hypothesis, we performed both qualitative and quantitative analyses. For qualitative analysis, two independent readers analyzed the b-value showing the best visual conspicuity of an MRI-suggested index lesion. For quantitative analysis, the readers assessed the b-value showing the same bP and pP region SI. The 95% confidence interval (CI) or interquartile range of qualitatively and quantitatively selected optimal b-values was assessed, and the mean difference between qualitatively and quantitatively selected b-values was investigated. Results: The 95% CIs of optimal b-values from qualitative and quantitative analyses were 1761-1805 s/mm2 and 1640-1771 s/mm2 (median, 1790 s/mm2 vs. 1705 s/mm2; p = 0.003) for reader 1, and 1835-1895 s/mm2 and 1705-1841 s/mm2 (median, 1872 s/mm2 vs. 1763 s/mm2; p = 0.022) for reader 2, respectively. Interquartile ranges of qualitatively and quantitatively selected optimal b-values were 1735-1873 s/mm2 and 1573-1867 s/mm2 for reader 1, and 1775-1945 s/mm2 and 1591-1955 s/mm2 for reader 2, respectively. Bland-Altman plots consistently demonstrated a mean difference of less than 100 s/mm2 between qualitatively and quantitatively selected optimal b-values. Conclusion: b-value range showing a homogeneous background signal may be optimal for evaluating prostatic index lesions on sDWI. Our qualitative and quantitative data consistently recommend b-values of 1500-2000 s/mm2.