• 제목/요약/키워드: bivariate mean

검색결과 84건 처리시간 0.022초

이변량 지역빈도해석을 이용한 우리나라 극한 강우 분석 (Bivariate regional frequency analysis of extreme rainfalls in Korea)

  • 신주영;정창삼;안현준;허준행
    • 한국수자원학회논문집
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    • 제51권9호
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    • pp.747-759
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    • 2018
  • 다변량 빈도해석과 지역빈도해석의 장점을 동시에 가지는 다변량 지역빈도해석은 다양한 변수를 고려함으로써 수문 현상에 대하여 많은 정보를 얻을 수 있고 많은 가용 자료 수로 인하여 높은 정확도의 분석결과를 도출할 수 있다. 현재까지는 우리나라의 강우 자료를 이용하여 다변량 지역빈도해석이 시도된 적이 없어 국내의 강우 자료를 대상으로 다변량 지역빈도해석의 적용성을 검토할 필요가 있다. 본 연구에서는 다변량 지역빈도해석의 매개변수 추정, 최적 분포형 선정, 확률수문량 성장곡선 추정 등에 집중하여 이변량 수문자료인 연 최대 강우량-지속기간 자료에 대하여 이변량 지역빈도해석의 적용성을 평가하였다. 기상청 71개 지점에 대하여 분석을 실시하였다. 본 연구를 통해 적용된 지역강우자료의 최적 copula 모형으로는 Frank와 Gumbel copula 모형이 선택되었고 주변분포형에 대해서는 지역별로 Gumbel과 대수정규분포와 같은 다양한 분포형이 최적 분포형으로 선택되었다. 상대제곱근오차(relative root mean square error)를 기준으로 지역빈도해석이 지점빈도해석보다 안정적이고 정확한 확률수문량 곡선 추정을 하였다. 이변량 강우분석에서 지역빈도해석을 적용하면 안정적인 수공구조물 설계기준 제시와 강우-지속기간 관계를 모형화 할 수 있을 것으로 기대된다.

허약아클리닉에 내원한 환아들에 대한 임상적 연구 (Clinical Study on Weak Children)

  • 이훈;이진용;김덕곤
    • 대한한방소아과학회지
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    • 제14권1호
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    • pp.127-136
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    • 2000
  • The frequency of weak children, derived from constitutional and functional factors, has increased recently, but their symptoms have never been observed and analysed. A survey was conducted to evaluate and understand the characteristics of weak children. 311 children who had visited in the weak child clinic of Kyunghee Oriental Medical Hospital from January, 1999 to August, 1999, were the respondents of the Weak Child Questionnaire. They were divided into 4 groups by age and birth weight, and statistical significances were tested by one way analysis of variances and bivariate correlation analysis among groups. The results obtained were as follows: 1. Distribution of sex : male 191 cases, female 120 cases 2. The distribution of age showed the highest in $2{\sim}6$ years(45.3%), followed by $7{\sim}12$ years(31.8%), $0{\sim}1$ years(18.0%), over 13 years(4.8%) in order. There was a statistical difference of all symptoms' mean, except respiratory symptoms, among groups(p<0.01). 3. The distribution of birth weight showed the highest in $2.5{\sim}3.3kg(43.4%)$, followed by $3.3{\sim}4.1kg(39.5%)$, under 2.5kg(5.1%), over 4.lkg(2.1%) in order. There was a statistical difference of digestive symptoms' and total score mean among groups(p<0.01, p<0.05 respectively). 4. The correlation coefficient between general symptoms' mean and other symptoms´ is the highest(p<0.01). From the above results, it was suggested that general symptoms are representative of weak children's characteristics.

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Association between immunoglobulin G1 against Tannerella forsythia and reduction in the loss of attachment tissue

  • Ardila, Carlos Martin;Olarte-Sossa, Mariana;Guzman, Isabel Cristina
    • Journal of Periodontal and Implant Science
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    • 제44권6호
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    • pp.274-279
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    • 2014
  • Purpose: To evaluate whether the levels of immunoglobulin G (IgG) antibody to Tanerella forsythia are associated with periodontal status. Methods: Patients with a diagnosis of chronic periodontitis were considered candidates for the study; thus 80 chronic periodontitis patients and 28 healthy persons (control group) were invited to participate in this investigation. The presence of T. forsythia was detected by polymerase chain reaction (PCR) analysis using primers designed to target the respective 16S rRNA gene sequences. Peripheral blood was collected from each subject to identify the IgG1 and IgG2 serum antibodies against T. forsythia. All microbiological and immunological laboratory processes were completed blindly, without awareness of the clinical status of the study patients or of the periodontal sites tested. Results: The bivariate analysis showed that lower mean levels of clinical attachment level (CAL) and probing depth were found in the presence of the IgG1 antibody titers against whole-cell T. forsythia; however, only the difference in CAL was statistically significant. In the presence of the IgG2 antibody titers against whole-cell T. forsythia, the periodontal parameters evaluated were higher but they did not show statistical differences, except for plaque. The unadjusted linear regression model showed that the IgG1 antibody against whole-cell T. forsythia in periodontitis patients was associated with a lower mean CAL (${\beta}=-0.654$; 95% confidence interval [CI], -1.27 to -0.28; P<0.05). This statistically significant association remained after adjusting for possible confounders (${\beta}=-0.655$; 95% CI, -1.28 to -0.29; P<0.05). On the other hand, smoking was a statistically significant risk factor in the model (${\beta}=0.704$; 95% CI, 0.24 to 1.38; P<0.05). Conclusions: Significantly lower mean levels of CAL were shown in the presence of the IgG1 antibody titers against whole-cell T. forsythia in periodontitis patients. Thus, the results of this study suggest that IgG1 antibody to T. forsythia may have been a protective factor from periodontitis in this sample.

Factors affecting the health-related quality of life of children with cerebral palsy in Indonesia: a cross-sectional study

  • Ade Febrina Lestari;Mei Neni Sitaresmi;Retno Sutomo;Firda Ridhayani
    • Child Health Nursing Research
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    • 제30권1호
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    • pp.7-16
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    • 2024
  • Purpose: Children with cerebral palsy (CP) and their parents experience various problems that can affect their quality of life. This study examined factors affecting the quality of life of children with CP. Methods: A cross-sectional study was conducted in Yogyakarta, Indonesia, from January to August 2019. The participants were consecutively recruited children with CP aged 2 to 18 years and their parents. Ninety-eight children with CP and their parents, specifically their mothers, were recruited. Children's health-related quality of life (HRQoL) was measured using the Pediatrics Quality of Life Cerebral Palsy. Parental HRQoL and stress were measured using the WHOQOL-BREF and Parenting Stress Index (PSI). Results: Functional level V was the most common category for both Gross Motor Function Classification System (GMFCS) and Bimanual Fine Motor Function (BFMF) (35% and 28%, respectively). Children's mean HRQoL was medium (49.81±20.35). The mean total PSI score was high (94.93±17.02), and 64% of parents experienced severe stress. Bivariate analysis showed that GMFCS, BFMF, number of comorbidities, presence of pain, and parental stress were significantly correlated with the total score for children's HRQoL (p<.05). Multiple linear regression analysis (p<.05) demonstrated that more severe GMFCS and parental stress were associated with lower mean HRQoL scores in children. Conclusion: Factors including the level of GMFCS and parental stress affected the HRQoL of children with CP. Parental stress management should be included in the comprehensive management of these children.

Superparamagnetic Iron Oxide-Enhanced MRI를 이용한 간섬유화의 평가: 영상의학적 비침습적 간섬유화 지표가 AST/혈소판 비와 상관 관계가 있는가? (Evaluation of Fibrosis in Liver Cirrhosis by Superparamagnetic Iron Oxide (SPIO)-Enhanced MR Imaging: Does the Radiological Non-Invasive Fibrosis Index Correlate with the Laboratory Non-Invasive Fibrosis Index?)

  • 김신기;이창희;김경아;최재웅;이종미;박철민
    • Investigative Magnetic Resonance Imaging
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    • 제12권2호
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    • pp.115-122
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    • 2008
  • 목적: SPIO-enhanced MRI상에서 얻은 radiological non-invasive hepatic fibrosis index (RNHFI)와 AST/혈소판 비(AST to platelet ratio index, APRI)간의 상관관계를 알아보고자 하였다. 대상 및 방법: 5년동안 SPIO-enhanced MRI를 시행받은 환자들을 대상으로 하였다. 환자들을 간경변 집단과 비(非)간경변 집단으로 분류했다. PACS를 이용, 각 환자의 SPIO-enhanced MRI에서 RNHFI (간실질 신호강도 표준편차의 평균(SD), 잡음교정 변이계수(CV))를 산출했고, 각 환자의 실험실 검사 결과를 이용, APRI를 산출했다. Student's t-test를 이용하여 두 집단간의 RNHFI와 APRI의 차이를 비교했다. 각 집단에서, RNHFI와 APRI간의 이변량 상관분석을 시행했다. 결과: 간경변 집단에서, SD, CV의 평균은 각각 $10.3{\pm}3.7$, $0.19{\pm}0.08$였다. 비간경변 집단에서, SD, CV의 평균은 각각 $6.5{\pm}1.6$, $0.08{\pm}0.05$였다. 두 집단의 평균 APRI는 각각 $2.04{\pm}1.7$, $0.32{\pm}0.32$였다. RNHFI와 APRI는 두 집단 사이에서 의미 있는 차이를 보였다 (p<0.05). 간경변 집단에서, SD와 APRI는 양의 상관관계를 보였다 (r=0.5, p<0.001). 결론: SD값이 간섬유화의 간단하고 유용한 예측 인자가 될 수 있을 것으로 기대된다.

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중환자실 경장영양 환자의 영양지원, 위 잔여량 및 영양상태 (Nutritional Support, Gastric Residual Volume and Nutritional Status during Enteral Nutrition in Intensive Care Unit Patients)

  • 이민주;강지연
    • 성인간호학회지
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    • 제26권6호
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    • pp.621-629
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    • 2014
  • Purpose: The purpose of this study was to investigate the nutritional support, gastric residual volume, and nutritional status of the intensive care unit (ICU) patients on enteral feeding. Methods: A descriptive longitudinal design was used to collect 5 day data on enteral nutrition of 52 ICU patients in an university hospital. Nutritional support was calculated with actual caloric intake compared to individual caloric requirement. Residual volumes were measured prior to routine feedings, and the serum albumin levels and the total lymphocyte counts were checked to evaluate nutritional status. The data were analyzed using one group repeated measures ANOVA, paired t-test, and Spearman's bivariate correlation analysis. Results: The subjects received their first enteral feeding on the $5.75^{th}$ day of ICU admission. The mean nutritional support rate was 49.1% of the requirement, however prescription rate and support rate were increased as time goes by. Gastric residual volumes were less than 10 cc in 95% cases. A significant negative correlation was found between nutritional support and nutritional status. Conclusion: The nutritional support for ICU patient was low compared to the requirement, and their nutritional status was worse than at the time of ICU admission. Further studies are necessary to develop nursing interventions for improving nutritional support for ICU patients.

다변량 통계 분석 및 질량 균형법을 이용한 제주도 지하수의 수질 요소 분리

  • 고동찬;고경석;김용제;이승구
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.450-452
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    • 2004
  • Using factor analysis and bivariate comparisons of major components in ground water, three geochemical processes were identified as controlling factors of ground water chemistry; 1) natural mineralization by water rock interactions, 2) effect of seawater which includes salinization by seawater near seashores and deposition of sea salt, and 3) nitrate contamination by N fertilization. Contribution of rainfall was also estimated from the measured composition of wet deposition. The geochemical processes were separated using total alkalinity as an indicator for natural mineralization, Cl for effect of seawater, and nitrate for N fertilization. Relatively high correlation of major components with nitrate suggests that nitrification of nitrogenous fertilizers significantly affects ground water chemistry. Total cations derived from nitrate sources have good linearity for nitrate in equivalent basis with a slope of 1.8, which is a mean of proton production coefficients in nitrification of two major compounds in nitrogenous fertilizers, ammonium and urea. Contribution of nitrate sources to base cations, Cl, and SO$_4$ in ground water was determined considering maximum contribution of natural mineralization to estimate a threshold of the effect of N fertilization for ground water chemistry, which shows W fertilization has a greatest effect than any other processes in ground water with nitrate concentration greater than 50 mg/L for Ca, Mg, Na and with concentration greater than 30 mg/L for Cl and SO$_4$.

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Breast Cancer Prevention Information Seeking Behavior and Interest on Cell Phone and Text Use: a Cross-sectional Study in Malaysia

  • Akhtari-Zavare, Mehrnoosh;Ghanbari-Baghestan, Abbas;Latiff, Latiffah A.;Khaniki, Hadi
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권4호
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    • pp.1337-1341
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    • 2015
  • Background: Breast cancer is the most common cancer and the second principal cause of cancer deaths among women worldwide, including Malaysia. This study focused on media choice and attempted to determine the communication channels mostly used and preferred by women in seeking information and knowledge about breast cancer. Materials and Methods: A cross sectional study was carried out to examine the breast cancer prevention information seeking behavior among 450 students at one private university in Malaysia. Results: The mean age of respondents was $25{\pm}4.3years$. Common interpersonal information sources were doctors, friends, and nurses and common channel information sources were television, brochure, and internet. Overall, 89.9% used cell phones, 46.1% had an interest in receiving cell phone breast cancer prevention messages, 73.9% used text messaging, and 36.7% had an interest in receiving text breast cancer prevention messages. Bivariate analysis revealed significant differences among age, eduation, nationality and use of cell phones. Conclusions: Assessment of health information seeking behavior is important for community health educators to target populations for program development.

로지스틱 회귀모형에서 이변량 정규분포에 근거한 로그-밀도비 (Log-density Ratio with Two Predictors in a Logistic Regression Model)

  • 강명욱;윤재은
    • 응용통계연구
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    • 제26권1호
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    • pp.141-149
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    • 2013
  • 로지스틱회귀모형에서 두 설명변수의 조건부 분포가 모두 이변량 정규분포라고 할 수 있다면 설명변수들의 함수로 표현되는 로그-밀도비를 통해 모형에 포함시켜야하는 항을 알 수 있다. 두개의 이변량 정규분포에서 분산-공분산행렬이 같은 경우에는 이차항과 교차항 없이 일차항만으로 충분하다. 상관계수가 모두 0이면 교차항은 설명변수의 분산과 관계없이 필요하지 않다. 또한 로지스틱회귀모형에서 로그-밀도비를 통해 이차항과 교차항이 필요하지 않게 되는 다른 조건들도 알아본다.

Empathy, cyberbullying, and cybervictimization among Filipino adolescents

  • Shannen, Tadena;Kim, Shin-Jeong;Lee, Jungmin
    • Child Health Nursing Research
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    • 제27권1호
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    • pp.65-74
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    • 2021
  • Purpose: The purpose of this study was to gain insights into empathy, cyberbullying, and cybervictimization among Filipino adolescents. Methods: The participants were 168 junior high school students in the 7th to 10th grades at a public high school in Cavite Province, Philippines. Data were collected on demographic characteristics, the Basic Empathy Scale, and Revised Cyber Bullying Inventory-II scores. The data were analyzed in SPSS using descriptive statistics (frequency and mean), the independent t-test, bivariate correlation, and one-way analysis of variance. Results: The degree of empathy did not show a statistically significant relationship with cyberbullying (r=-.07, p=.359) but did show a significant relationship with cybervictimization (r=.18, p=.025). Furthermore, cyberbullying had a statistically significant association with cybervictimization (r=.60, p<.001). Conclusion: Although empathy does not necessarily affect cyberbullying, higher levels of empathy were found among cyberbullying victims. However, an alarming result of this study is the possibility that victims may become cyberbullies. Therefore, we should highlight empathy as part of efforts to prevent cyberbullying and to solve various cyber-related problems. Since cyberbullying and cybervictimization are closely related, it is important to focus on this relationship and to make multilateral efforts to ensure that cyberbullying does not lead to other negative issues.