• Title/Summary/Keyword: statistical confidence

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An exploration of the relationship between crime/victim characteristics and the victim's criminal damages: Variable selection based on random forest algorithm (범죄 및 피해자 특성과 범죄피해 내용의 관계 탐색: 랜덤포레스트 알고리즘에 기초한 변인선택)

  • Han, Yuhwa;Lee, Wooyeol
    • Korean Journal of Forensic Psychology
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    • v.13 no.2
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    • pp.121-145
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    • 2022
  • The current study applied the random forest algorithm to Korean crime victim survey data collected biennially between 2010 and 2018 to explore the relationship between crime/victim characteristics and the victim's criminal damages. A total of 3,080 cases including gender, age (life cycle stage), type of crime, perpetrator acquisition, repeated victimization, psychological damage (depression, isolation, extreme fear, somatic symptoms, interpersonal problems, moving out to avoid people, suicidal impulses, suicide attempts), and emotional changes after victimization (changes in self-protection confidence, self-esteem, confidence in others, confidence in legal institutions, and respect for Korean legal system/law) were analyzed. Considering the features of data that are difficult to apply traditional statistical techniques, this study implemented random forest algorithms to predict crime and victim characteristics using the victim's criminal damages (psychological damage and emotional change) and selected good predictors using VSURF function in VSURF package for R. As a result of the analysis, it was confirmed that the relationship between the type of crime and depression, extreme fear, somatic symptoms, and interpersonal problems, between perpetrator acquisition and somatic symptoms and interpersonal problems, and between repeated victimization and changes in respect for Korean legal system/law. Gender and life cycle stage (youth/adult/elderly) were found to be related to extreme fear and changes in self-protection confidence, respectively. However, more empirical evidence should be aggregated to explain the results as meaningful. The results of this study suggest that it is necessary to enhance the experts' knowledge and educate them on cases about the relationship between crime/victim characteristics and criminal damage. Strengthening their interview strategy and knowledge about law/rules were also needed to increase the effectiveness of the Korean victim assessment system.

Features of sample concepts in the probability and statistics chapters of Korean mathematics textbooks of grades 1-12 (초.중.고등학교 확률과 통계 단원에 나타난 표본개념에 대한 분석)

  • Lee, Young-Ha;Shin, Sou-Yeong
    • Journal of Educational Research in Mathematics
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    • v.21 no.4
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    • pp.327-344
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    • 2011
  • This study is the first step for us toward improving high school students' capability of statistical inferences, such as obtaining and interpreting the confidence interval on the population mean that is currently learned in high school. We suggest 5 underlying concepts of 'discretion of contingency and inevitability', 'discretion of induction and deduction', 'likelihood principle', 'variability of a statistic' and 'statistical model', those are necessary to appreciate statistical inferences as a reliable arguing tools in spite of its occasional erroneous conclusions. We assume those 5 concepts above are to be gradually developing in their school periods and Korean mathematics textbooks of grades 1-12 were analyzed. Followings were found. For the right choice of solving methodology of the given problem, no elementary textbook but a few high school textbooks describe its difference between the contingent circumstance and the inevitable one. Formal definitions of population and sample are not introduced until high school grades, so that the developments of critical thoughts on the reliability of inductive reasoning could not be observed. On the contrary of it, strong emphasis lies on the calculation stuff of the sample data without any inference on the population prospective based upon the sample. Instead of the representative properties of a random sample, more emphasis lies on how to get a random sample. As a result of it, the fact that 'the random variability of the value of a statistic which is calculated from the sample ought to be inherited from the randomness of the sample' could neither be noticed nor be explained as well. No comparative descriptions on the statistical inferences against the mathematical(deductive) reasoning were found. Few explanations on the likelihood principle and its probabilistic applications in accordance with students' cognitive developmental growth were found. It was hard to find the explanation of a random variability of statistics and on the existence of its sampling distribution. It is worthwhile to explain it because, nevertheless obtaining the sampling distribution of a particular statistic, like a sample mean, is a very difficult job, mere noticing its existence may cause a drastic change of understanding in a statistical inference.

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The Effect of Life Style on Eco-Friendly Clothing Practices and Efficacy in Middle School Students (중학생의 라이프스타일이 친환경적인 의생활 실천 및 효능감에 미치는 영향)

  • Kim, Yunhwa
    • Journal of Korean Home Economics Education Association
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    • v.27 no.4
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    • pp.141-154
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    • 2015
  • The world has been demanding a green growing world in order to solve serious environmental pollution and resource depletion. This study aims to identify life style factors that drive eco-friendly clothing practices and efficacy in middle school students. Data was collected from 215 middle school students in Daegu, using a self-administered questionnaire in December 2013. Statistical analyses to determine frequency, average, ANOVA, factor analysis, reliability analysis, and regression analysis were performed using SPSS 21 program. The results of factor analysis indicated that eco-friendly clothing practices were classified into purchasing and management, reuse, washing, and recycle, and eco-friendly clothing practices efficacy was sub-grouped into practice confidence, purchasing and management efficacy, and washing and sharing efficacy, and life style consisted of fashion pursuit, environment pursuit, planned purchasing, and economy. Eco-friendly clothing practices and efficacy were significant differences in sex and grade (p<0.05). Eco-friendly clothing practices were significantly affected by the factors of environment pursuit, planned purchasing, economy of life style, and the factors of practice confidence, purchasing and management efficacy, and washing and sharing efficacy of eco-friendly clothing practices efficacy (p<0.05). The planned purchasing factor of life style significantly affected all the factors of eco-friendly clothing practices efficacy. This study suggests that eco-friendly clothing practices education program could account for the life style factors such as fashion pursuit, environment pursuit, planned purchasing, and economy with gender and grade to be effective for middle school students.

Estimation of the Daily Human Intake of Acrylamide (AA) Based on Urinary N-acetyl-S-(2-carbamoylethyl)-cysteine (AAMA) and the Contribution of Dietary Habits in South Korean Adults (요중 AAMA에 의한 한국 성인 아크릴아마이드(AA)의 하루섭취량 추정 및 기여 식습관에 대한 분석)

  • LEE, Jin-Heon;LEE, Kee-Jae;KANG, Hee-Sook
    • Journal of Environmental Health Sciences
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    • v.42 no.4
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    • pp.235-245
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    • 2016
  • Objectives: This study estimated the adult Korean daily intake of acrylamide (AA) and investigated its relationship with demographic, lifestyle and dietary habits by using urinary concentrations of N-acetyl-S-(2-carbamoylethyl)-cysteine (AAMA). Methods: Human data (n=1870) was collected in a nationwide cross-sectional biomonitoring program representing the population (18-69 years) residing in South Korea. Urinary AAMA was analyzed with a LC-MS/MS system. Daily intakes of AA were estimated using mass daily AAMA, which was calculated through urinary AAMA concentration and daily creatinine excretion. Statistical analysis was performed with SAS procedures for calculating geometric means, confidence intervals and the exponentiated beta coefficient of multiple linear regressions. Results: Daily intake of AA was estimated at $0.475{\mu}g/kg$ body weight (BW) per day (95% confidence interval (CI): 0.447-0.503). In the case of current smokers, AA intake was $0.957{\mu}g/kg$ BW per day (95% CI: 0.847-1.067), which was significantly higher than that of former smokers and never smoked (p<0.0001). The strong affecting factors were age (95% CI: 0.68-1.14; p=0.0180), education level (95% CI: 1.05-1.42; p=0.0163), body mass index (BMI) (95% CI: 1.00-1.82; p<0.0001), and smoking status (95% CI: 0.97-3.05; p<0.0001). Korean dietary habits increasing AA intake were coffee (p=0.0005), cup noodles (p=0.0010) and canned foods (p=0.0005). Meanwhile, foods decreasing AA intake were fresh fruit (p=0.0076), cooked beef (p=0.0335) and cooked pork (p=0.0147). Conclusion: The Korean daily intake of AA in adults was estimated to be similar with those found in developed countries. The factors increasing daily AA intake were coffee, cup noodles and canned foods, and decreasing factors were fresh fruit, cooked beef and cooked pork.

The Relationship between Learning Motivation and Task Commitment of Science-Gifted (과학영재학생의 학습동기와 과제집착력과의 관계)

  • Park, Mi-Jin;Lee, Yong-Seob
    • Journal of Gifted/Talented Education
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    • v.21 no.4
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    • pp.961-977
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    • 2011
  • The purpose of this study was to investigate the relationship between learning motivation and task commitment and find sub factors of learning motivation that affect task commitment. For this study 30 science gifted student (4th and 5th grade in elementary school) participated. The survey instruments used for this study were Academic Motivation Scale and Task Commitment Scale. The statistical methods employed for data analysis were the correlation analysis and multiple regression analysis. The result of this study were as follows: First, the learning motivation and task commitment of science gifted students showed similar levels. But there was differences of strength each sub factors of learning motivation and task commitment. Second, there was a significant positive correlation between learning motivation and task commitment. Also, learning motivation has the explanatory power of predictive variable for the task commitment approximately 49.3%. Expecially learning motivation has significant positive correlation with responsibility and self-control that sub factors of task commitment. Among the sub factor of learning motivation, confidence has most correlations with sub factors of task commitment and significant impact on task commitment. This result indicate that we need to develop learning motivation to improve task commitment and especially develop learning motivation program to grow up confidence of science-gifted.

Bioequivalence of Broadcef Capsule to Cefradine Yuhan Capsule (Cephradine 500 mg) (유한세프라딘 캅셀(세프라딘 500 mg)에 대한 브로드세프 캅셀의 생물학적 동등성)

  • Cho, Hea-Young;Lee, Suk;Kang, Hyun-Ah;Oh, In-Joon;Lim, Dong-Koo;Moon, Jai-Dong;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.32 no.3
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    • pp.215-221
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    • 2002
  • Cephradine is a first generation cephalosporin and has broad spectrum antibacterial activity against gram-positive and gram-negative microorganisms, through inhibition of bacterial cell wall synthesis. Cephradine is useful for treatment of infections of the urinary and respiratory tract, skin and soft tissues. The purpose of the present study was to evaluate the bioequivalence of two cephradine capsules, Cefradine Yuhan (YuHan Corporation) and Broadcef (Ilsung Pharmaceuticals Co. Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The cephradine release from the two cephradine capsules in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty normal male volunteers, $23.10{\pm}2.90$ years in age and $67.69{\pm}8.04\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one capsule containing 500 mg as cephradine was orally administered, blood was taken at predetermined time intervals and the concentrations of cephradine in serum were determined using HPLC method with UV detector. The dissolution profiles of two cephradine capsules were very similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AVC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AVC_t\;and\;C_{max}$ and untransformed $T_{max}$. The results showed that the differences in $AVC_t,\;C_{max}\;and\;T_{max}$ between two capsules based on the Cefradine Yuhan were -2.87%, -0.96% and -4.85%, respectively. There were no sequence effects between two capsules in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of 1og(0.8) to log(1.25) $(e.g.,\;log(0.93){\sim}log(1.02)\;and\;log(0.88){\sim}log(1.13)\;for \;AVC_t\;and\;C_{max},\;respectively)$. The 90% confidence interval using untransformed data was within ${\pm}20%$ $(e.g., \;-17.54{\sim}7.78\;for\;T_{max})$. All parameters met the criteria of KFDA guideline for bioequivalence, indicating that Broadcef capsule is bioequivalent to Cefradine Yuhan capsule.

A Systematic Review of Risk Factors for Brain Metastases and Value of Prophylactic Cranial Irradiation in Non-Small Cell Lung Cancer

  • Sun, Dian-Shui;Hu, Li-Kuan;Cai, Ying;Li, Xiao-Mei;Ye, Lan;Hou, Hua-Ying;Wang, Cui-Hong;Jiang, Yu-Hua
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1233-1239
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    • 2014
  • Background: The incidence of brain metastases (BM) varies in patients with non-small cell lung cancer (NSCLC), calls into question the value of prophylactic cranial irradiation (PCI). It is possible that clinicopathologic characteristics are associated with the development of BM, but these have yet to be identified in detail. Thus, we conducted the present meta-analysis on risk factors for BM and the value of PCI in patients with NSCLC. Methods: Eligible data were extracted and the risk factors for BM and the value of PCI in patients with NSCLC were analyzed by calculating the pooled odds ratio (OR). Heterogeneity was detected using Q and I-squared statistics, and publication bias was tested by funnel plots and Egger's test. Results: Six randomized controlled trials with a focus on the value of PCI and 13 eligible studies with a focus on risk factors for BM were included. PCI significantly reduced the incidence of BM in patients with NSCLC (p=0.000, pooled OR=0.34, 95% confidence interval = 0.37-0.59). Compared with non-squamous cell carcinoma, squamous cell carcinoma was associated with a low incidence of BM in patients with NSCLC (p=0.000, pooled OR=0.47, 95% confidence interval =0.34-0.65). The funnel plot and Egger's test suggested that there was no publication bias in the current meta-analysis. Conclusions: This meta-analysis provides statistical evidence that compared with non-squamous cell carcinoma, squamous cell carcinoma can be used as a predictor for BM in patients with NSCLC, and PCI might reduce the incidence of BM in patients with NSCLC, but does not provide a survival benefit.

Bioequivalence of Levopid Tablet to Levopride Tablet (Levosulpiride 25 mg) (레보프라이드 정(레보설피리드 25 mg)에 대한 레보피드 정의 생물학적 동등성)

  • Cho, Hea-Young;Kang, Hyun-Ah;Moon, Jai-Dong;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.32 no.2
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    • pp.127-133
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    • 2002
  • Levosulpiride is the 1evo-enantiomer form of racemic sulpiride, a benzamide derivative selectively inhibiting dopaminergic $D_2$ receptors at the trigger zone both in the central nervous system and in the gastrointestinal tract. The purpose of the present study was to evaluate the bioequiva1ence of two levosulpiride tablets, Levopride (SK Pharmaceutical Co., Ltd.) and Levopid (Dae Won Pharmaceutical Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The levosulpiride release from the two levosulpiride tablets in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty eight normal male volunteers, $23.82{\pm}3.26$ years in age and $69.13{\pm}8.58$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 25 mg of levosulpiride was orally administered, blood was taken at predetermined time intervals and the concentrations of levosulpiride in serum were determined using HPLC method with fluorescence detector. The dissolution profiles of two levosulpiride tablets were very similar at all dissolution media. Besides, the pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t\;and\;C_{max}$ and untransformed $T_{max}$. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two tablets based on the Levopride were -1.17%, 1.20% and -1.09%, respectively. There were no sequence effects between two tablets in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) $(e.g.,\;log(0.93){\sim}log(1.07)\;and\;log(0.90){\sim}log(1.14)\;for\;AUC_t\;and\;C_{max}$, respectively). The 90% confidence interval using untransformed data was within ${\pm}20%$ $(e.g.,\;-19.47{\sim}16.20\;for\;T_{max})$. All parameters met the criteria of KFDA guideline for bioequivalence, indicating that Levopid tablet is bioequivalent to Levopride tablet.

Bioequivalence of Hanacef Capsule to Duricef Capsule (Cefadroxil 500 mg) (듀리세프 캅셀(세파드록실 500 mg)에 대한 하나세프 캅셀의 생물학적 동등성)

  • Cho, Hea-Young;Lee, Suk;Moon, Jai-Dong;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.32 no.2
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    • pp.135-140
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    • 2002
  • Cefadroxil is a semi-synthetic cephalosporin active against many Gram-positive and Gram-negative bacteria. The drug has been used for the treatment of the urinary and respiratory tract infections when caused by susceptible strains of the designated microorganism. The purpose of the present study was to evaluate the bioequivalence of two cefadroxil capsules, Duricef (Bo Ryung Pharmaceutical Co. Ltd.) and Hanacef (Korean Pharmaceutical Co. Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The cefadroxil release from the two cefadroxil capsules in vitro was tested using KP VII Apparatus II method with various different kinds of dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty four normal male volunteers, $21.58{\pm}2.43$ years in age and $70.74{\pm}10.29$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one capsule containing 500 mg as cefadroxil was orally administered, blood was taken at predetermined time intervals and the concentrations of cefadroxil in serum were determined using HPLC with UV detector. The dissolution profiles of two cefadroxil capsules were very similar at all dissolution media. The pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t\;and\;C_{max}$ and untransformed $T_{max}$. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two capsules based on the Duricef were 0.05%, -5.29% and 4.53%. There were no sequence effects between two capsules in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) $(e.g.,\;log(0.95){\sim}log(1.05)\;and\;log(0.87){\sim}log(1.02)$ for $AUC_t\;and\;C_{max}$, respectively). The 90% confidence interval using untransformed data was within ${pm}20%$ $(e.g.,\;-6.75{\sim}15.74\;for\;T_{max})$. All parameters met the criteria of KFDA guideline for bioequivalence, indicating that Hanacef capsule is bioequivalent to Duricef capsule.

The Analysis of the Number of Donations Based on a Mixture of Poisson Regression Model (포아송 분포의 혼합모형을 이용한 기부 횟수 자료 분석)

  • Kim In-Young;Park Su-Bum;Kim Byung-Soo;Park Tae-Kyu
    • The Korean Journal of Applied Statistics
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    • v.19 no.1
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    • pp.1-12
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    • 2006
  • The aim of this study is to analyse a survey data on the number of charitable donations using a mixture of two Poisson regression models. The survey was conducted in 2002 by Volunteer 21, an nonprofit organization, based on Koreans, who were older than 20. The mixture of two Poisson distributions is used to model the number of donations based on the empirical distribution of the data. The mixture of two Poisson distributions implies the whole population is subdivided into two groups, one with lesser number of donations and the other with larger number of donations. We fit the mixture of Poisson regression models on the number of donations to identify significant covariates. The expectation-maximization algorithm is employed to estimate the parameters. We computed 95% bootstrap confidence interval based on bias-corrected and accelerated method and used then for selecting significant explanatory variables. As a result, the income variable with four categories and the volunteering variable (1: experience of volunteering, 0: otherwise) turned out to be significant with the positive regression coefficients both in the lesser and the larger donation groups. However, the regression coefficients in the lesser donation group were larger than those in larger donation group.