• Title/Summary/Keyword: z-score

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A Scoring System for the Originality in Evaluation of Mathematical Creativity (수학 창의성 평가에서 독창성의 점수화 방법)

  • Lee, Kang-Sup
    • The Mathematical Education
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    • v.49 no.1
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    • pp.111-118
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    • 2010
  • This paper attempts to establish a scoring system for the originality in evaluation of mathematical creativity. The scoring system is composed of three categories; fluency, flexibility and originality. In this paper, we proposed an evaluation method for originality as following based on relative frequency and standard normal distribution. (1) Fluency: It is judged on the basis of the number of correct answers a student made. If several correct answers are given for a single category, then its maximum score is set to 5 points. (2) Flexibility: We examined how many categories the students' responses can be classified into. If at most 15 answers are allowed for each question, the maximum score of flexibility is 15 points. (3) Originality: Originality score is given if a student made some original response that other students did not show. That is, it reflects relative rarity. The originality is measured according to the following steps: Step 1: Analyze the frequency of how many students made an answer to the response type categorized at low level, and calculate the relative frequency p of each category. Step 2: Find the originality point os for each response, that is, os = max{0,z} where z satisfies P(Z > z) = p with standard normal distributed random variable Z. For example, - p is greater than 0.5: 0 point - p is 0.1587: 1 point - p is 0.0228: 2 points - p is 0.0013: 3 points Step 3: Assign the one's originality score to the sum of originality point for each response. Remark. There is no upper limit of originality score.

Bone Mineral Density, Biochemical Bone Turnover Markers and Factors associated with Bone Health in Young Korean Women (성인초기 여성의 골밀도, 생화학적 골표지자 및 골건강 관련 요인)

  • Park, Young-Joo;Lee, Sook Ja;Shin, Nah-Mee;Shin, Hyunjeong;Kim, Yoo-Kyung;Cho, Yunjung;Jeon, Songi;Cho, Inhae
    • Journal of Korean Academy of Nursing
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    • v.44 no.5
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    • pp.504-514
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    • 2014
  • Purpose: This study was done to assess the bone mineral density (BMD), biochemical bone turnover markers (BTMs), and factors associated with bone health in young Korean women. Methods: Participants were 1,298 women, ages 18-29, recruited in Korea. Measurements were BMD by calcaneus quantitative ultrasound, BTMs for Calcium, Phosphorus, Osteocalcin, and C-telopeptide cross-links (CTX), body composition by physical measurements, nutrients by food frequency questionnaire and psychosocial factors associated with bone health by self-report. Results: The mean BMD (Z-score) was -0.94. 8.7% women had lower BMD ($Z-score{\leq}-2$) and 14.3% women had higher BMD ($Z-score{\geq}0$) than women of same age. BTMs were not significantly different between high-BMD ($Z-score{\geq}0$) and low-BMD (Z-score<0) women. However, Osteocalcin and CTX were higher in women preferring caffeine intake, sedentary lifestyle and alcoholic drinks. Body composition and Calcium intake were significantly higher in high-BMD. Low-BMD women reported significantly higher susceptibility and barriers to exercise in health beliefs, lower bone health self-efficacy and promoting behaviors. Conclusion: Results of this study indicate that bone health of young Korean women is not good. Development of diverse strategies to intervene in factors such as exercise, nutrients, self-efficacy, health beliefs and behaviors, shown to be important, are needed to improve bone health.

Association between body mass index and hepatitis B antibody seropositivity in children

  • Kwon, Yoowon;Jeong, Su Jin
    • Clinical and Experimental Pediatrics
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    • v.62 no.11
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    • pp.416-421
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    • 2019
  • Background: The seropositivity rate of hepatitis B surface antigen (anti-HBs) antibodies is known to be ≥95% after hepatitis B virus vaccination during infancy. However, a low level or absence of anti-HBs in healthy children is discovered in many cases. Recent studies in adults reported that a reduced anti-HBs production rate is related to obesity. Purpose: To investigate whether body mass index (BMI) affects anti-HBs levels in healthy children following 3 serial dose vaccinations in infancy. Methods: We recruited 1,200 healthy volunteers aged 3, 5, 7, or 10 years from 4-day care centers and 4 elementary schools. All subjects completed a questionnaire including body weight, height, and vaccine type received. Levels of serum hepatitis B surface antigen (HBsAg) and anti-HBs in all subjects were analyzed using electrochemiluminescence immunoassay. The standardized scores (z score) for each sex and age were obtained using the lambda-mu-sigma method in the 2017 Korean National Growth Charts for children and adolescents. Results: Our subjects (n=1,200) comprised 750 males (62.5%) and 450 females (37.5%). The overall anti-HBs seropositivity rate was 57.9% (695 of 1,200). We identified significant differences in mean BMI values between seronegative and seropositive groups (17.45 vs. 16.62, respectively; P<0.001). The anti-HBs titer was significantly decreased as the BMI z score increased adjusting for age and sex (B=-15.725; standard error=5.494; P=0.004). The probability of anti-HBs seropositivity based on BMI z score was decreased to an OR of 0.820 after the control for confounding variables (95% confidence interval, 0.728-0.923; P=0.001). Conclusion: There was a significant association between anti-HBs titer and BMI z score after adjustment for age and sex. Our results indicate that BMI is a potential factor affecting anti-HBs titer in healthy children.

Effectiveness after Designation of a Trauma Center: Experience with Operating a Trauma Team at a Private Hospital

  • Kim, Kyoung Hwan;Han, Sung Ho;Chon, Soon-Ho;Kim, Joongsuck;Kwon, Oh Sang;Lee, Min Koo;Lee, Hohyoung
    • Journal of Trauma and Injury
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    • v.32 no.1
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    • pp.1-7
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    • 2019
  • Purpose: The present study aimed to evaluate the influence of how the trauma care system applied on the management of trauma patient within the region. Methods: We divided the patients in a pre-trauma system group and a post-trauma system group according to the time when we began to apply the trauma care system in the Halla Hospital after designation of a trauma center. We compared annual general characteristics, injury severity score, the average numbers of the major trauma patients, clinical outcomes of the emergency department, and mortality rates between the two groups. Results: No significant differences were found in the annual patients' average age ($54.1{\pm}20.0$ vs. $52.8{\pm}18.2$, p=0.201), transportation pathways (p=0.462), injury mechanism (p=0.486), injury severity score (22.93 vs. 23.96, p=0.877), emergency room (ER) stay in minutes (199.17 vs. 194.29, p=0.935), time to operation or procedure in minutes (154.07 vs. 142.1, p=0.767), time interval to intensive care unit (ICU) in minutes (219.54 vs. 237.13, p=0.662). The W score and Z score indicated better outcomes in post-trauma system group than in pre-trauma system group (W scores, 2.186 vs. 2.027; Z scores, 2.189 vs. 1.928). However, when analyzing survival rates for each department, in the neurosurgery department, in comparison with W score and Z score, both W score were positive and Z core was higher than +1.96. (pre-trauma group: 3.426, 2.335 vs. post-trauma group: 4.17, 1.967). In other than the neurosurgery department, W score was positive after selection, but Z score was less than +1.96, which is not a meaningful outcome of treatment (pre-trauma group: -0.358, -0.271 vs. post-trauma group: 1.071, 0.958). Conclusions: There were significant increases in patient numbers and improvement in survival rate after the introduction of the trauma system. However, there were no remarkable change in ER stay, time to ICU admission, time interval to emergent procedure or operation, and survival rates except neurosurgery. To achieve meaningful survival rates and the result of the rise of the trauma index, we will need to secure sufficient manpower, including specialists in various surgical area as well as rapid establishment of the trauma center.

A statistical model for interview score based on projection (사영에 근거한 면접 점수의 통계적 모형)

  • Park, Cheol-Yong;Kim, Hyun-Wook
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.3
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    • pp.495-504
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    • 2012
  • In this study, we propose a statistical model based on projection that generates interview scores. In this model, each interviewee's true score and its related variable are viewed as X, Y values respectively in the two dimensional plane, and each interviewer's score is the projected score of true score X to the axis rotated by some angle, which reflects the interviewer's perspective. Each interviewer's observed interview score is obtained by adding personal bias and observed error to this projected score. We compared commonly used standardizing methods of interview scores such as trimmed mean method, rank method, and z-score method based on the proposed statistical model. In this simulation, two types of interview methods, two numbers of interviewers, two degrees of interviewers' expertise and two distributions and three correlations between actual score and its related variable are all considered.

A Study on the Determination Information of Cash holdings in Korean Export-Oriented Companies (한국의 수출지향형 기업에서 현금유동성 결정정보에 관한 연구)

  • Kim, Jong-Taek;Shin, Yeon-Soo;Shin, Yong-Jae
    • International Commerce and Information Review
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    • v.11 no.1
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    • pp.157-176
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    • 2009
  • This study analyzed the information factors which determine cash liquidity in Korean export-oriented companies. In this paper, cash liquidity means the ratio of the value of cash or cash equivalent to the asset value subtracted marketable securities value from total asset value. The empirical test shows that main information factors are the size of company, the growth opportunity of company, the volatility of operating cash flows and free cash flows, the credit yield spread of company, the debt ratio, the turnover ratio of cash flows and free cash flows, and the estimate of bankruptcy that amounts to the inverse number of Z score. In summary, the size of company, debt ratio, turnover ratio of cash flows and free cash flows, and Z-score have negative influence on the cash liquidity of Korean export-oriented companies. but the volatility of operating cash flows affect the cash liquidity positively.

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Effect of Enzyme Replacement Therapy on Growth in Korean Patients with Mucopolysaccharidosis Type I (I형 뮤코다당증 환자들에서 효소 보충 요법이 성장에 미치는 영향)

  • Huh, Rimm;Cho, Sung Yoon;Chang, Mi Sun;Lee, Jieun;Kwun, Younghee;Kim, Su Jin;Sohn, Young Bae;Park, Sung Won;Maeng, Se Hyun;Kwon, Eun-Kyung;Han, Sun Ju;Jung, Jooyoun;Jin, Dong-Kyu
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.13 no.2
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    • pp.111-119
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    • 2013
  • Purpose: Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder caused by deficiency of the enzyme ${\alpha}$-L-iduronidase, which leads to a broad spectrum of multisystemic manifestations. Short stature and decreased growth velocity are prominent features of MPS I. The aim of the present study was to evaluate the effect of enzyme replacement therapy (ERT) on growth of Korean MPS I patients from a single center. Methods: Height data were obtained by retrospective chart review of 10 Korean patients with MPS I who had received ERT for a minimum of 3 years. Height was expressed as standard deviation scores (SDS) based on normative data. Annual growth rates were calculated before and during ERT. A piecewise regression model was used to analyze height z-scores before and after treatment. Individual analysis was performed for impact of phenotype [(severe (Hurler) versus attenuated (Hurler-Scheie, Scheie)] on growth. Results: Annual growth was 3.3 cm (z-score= -0.21) in the year before ERT and 6.2 cm (z-score= 0.17), 5.8 cm (z-score= 0.07), and 3.8 cm (z-score= -0.4) in the first, second, and third years of ERT, respectively. Regression analysis showed improvement in the slope after ERT (difference= 0.04; P=0.022). Estimated slope differences between severe and attenuated phenotypes were statistically significant before (P=0.001) and after treatment (P<0.0001), although no significant difference was noted when stratified by phenotype. Conclusion: ERT with aldurazyme appears to have a positive impact on linear growth in patients with MPS I.

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Evaluation of Growth between Breast-Fed and Formula-Fed Korean Infants from 1 to 3 Postpartum Months -Compared with the Korean Standard and NCHS Reference- (모유영양아와 인공영양아의 1~3개월의 성장발육 상태 평가-한국 표준치와 NCHS Reference간의 비교-)

  • 최경숙;구재옥
    • Korean Journal of Community Nutrition
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    • v.3 no.4
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    • pp.533-541
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    • 1998
  • This study compares the growth performance(weight-for-age Z-score, height-for-age Z-score, weight-for-height Z-score) of one- to three- month-old Korean infants(n=232) with the Korean standard(1994) and NCHS reference(1983). The weight-for-age Z-scores(WAZ) by the Korean standard were -2∼1,5 for males and -3∼1 for females. The NCHS reference, WAZ results were -1∼2.5 and -2.5∼3.5 for males and females, respectively. The WAZ compared Korean standard showed no subjects with overnutrition. But 1.3% of the infants showed signs of malnutrition. Comparison with NCHS reference revealed that 0.4% of the infants were malnourished and 7.0% of the infants were overnourished. The WAZ of formula-fed infants were distributed higher than breast-fed infants, but that was not significant. The height-for-age Z-score(HAZ) by the Korean standard were -4.5%∼1.5% for males and -4∼1.5% for females. According to the NCHS reference, HAZ were -2.5%∼2.5% and -3∼3 for males and females, respectively. When the WAZ was compared with the Korean standard, there was no overnutrition but 16% of the infants showed signs of malnutrition. The NCHS reference, revealed that 6.9% of the infants were malnourished and 1.8% of the infants were ovemourished. The weight-for-height Z-scores(WHZ) by the Korean standard were -2∼5 for males and -2.5∼5 for females. The NCHS reference WAZ scores were -1∼4 and -1.5∼4.5 for males and females, respectively. When the WHZ was compared with the Korean standard, 2.2% of infants were malnourished and 19.5% were overnourished. There were no malnourished subjects according to the NCHS reference and 19.1% of the infants were overnourished. When the three Z-scores are considered together, 92.0% of the infants should a normal growth status, there was no malnutrition, and 8.0% of the infants were overnourished. The growth performance was evaluated differently according to the type of standards. Thus, it is necessary to set proper growth standards for infants, according to which classification of feeding methods is chosen. A longterm and careful assessment of infants's growth performances to develop any group of standards.

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The Correlation of Psychopathology and Suicide in North Korean Refugee Adolescents (탈북 청소년의 정신병리와 자살과의 관련성)

  • Im, Donggyun;Park, Subin;Kim, Seung Hyun;Im, Woo Young;Jun, Jin Yong
    • Korean Journal of Psychosomatic Medicine
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    • v.25 no.2
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    • pp.95-100
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    • 2017
  • Objectives : This study was designed for the purpose of the relationship between psychopathology and suicide in North Korean Refugee Adolescents. Methods : The subjects were 104 North Korean Refugee Adolescents. We investigated the The Korean version of the Center for Epidemiologic Studies for Depression, Revised Children's Manifest Anxiety Scale and Rosenberg Self-Esteem Scale. We also investigated the suicide ideation, planning and attempt. The self-report was taken to the North Korean Refugee Adolescents. Results : The Center for Epidemiologic Studies for Depression Score(Z=-4.050, p<0.001), Revised Children's Manifest Anxiety Score(t=-2.757, p<0.01), Rosenberg Self-Seteem Score(Z=-2.328, p<0.05) were significantly associated with the suicide ideation in North Korean Refugee Adolescents. In logistic regression analysis, only The Center for Epidemiologic Studies for Depression Score(p<0.005) expected the suicidal ideation. Conclusions : The management of depression would be helpful to reduce the suicide in North Korean Refugee Adolescents.

Use of Dual-Energy X-ray Absorptiometry in Children with Inflammatory Bowel Disease: A Large Single Centre Study

  • Jois, Asha;Perera, Sajini;Simm, Peter;Alex, George
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.25 no.6
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    • pp.473-480
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    • 2022
  • Purpose: Low bone mineral density (BMD) is a complication in children with inflammatory bowel disease (IBD). There are limited data evaluating dual-energy x-ray absorptiometry (DXA) as a screening tool for low BMD in children with IBD. We performed a single site retrospective analysis of DXA use. Methods: Children aged 5-18 years with IBD diagnosed between 2013 to 2017 at the Royal Children's Hospital, Australia, were included. Patient demographics, measures of disease activity, DXA scores, and factors related to BMD were collected. Results: Over a median follow up of 5.1 (4-6.4) years, 72/239 (30.1%) children underwent DXA, and 28/239 (11.7%) children had a second DXA. Our DXA practice differed to consensus guidelines regarding initial screening based on height and/or body mass index (BMI) z-score (8/17 [47.1%]), and repeat surveillance (13/42 [31.0%]). Children had a median lumbar spine (LS) z-score -0.80 (-1.65-0.075). Children with LS z-score≤-2.0 (n=14) had lower weight (6.57 [1.78-23.7] vs. 51.1 [26.5-68.7], p=0.0002) and height centiles (3.62 [1.17-17.1] vs. 42 [16.9-67.1], p=0.0001), and higher faecal calprotectin (FCP) (3041 [1182-4192] vs. 585 [139-2419], p=0.009) compared to children with LS z-score>-2.0. No fractures were reported. Of 28 children who underwent a second DXA 1.6 (1.1-2.2) years following initial DXA, no significant change in z-scores occurred. Conclusion: Children with IBD had low BMD. In addition to height centile and weight centile, FCP was associated with lower BMD, and should be considered in DXA screening guidelines. Greater clinician awareness of DXA consensus guidelines is required. Future prospective studies are required.