• Title/Summary/Keyword: statistical confidence

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Summertime Heat Waves and Ozone : an Interaction on Cardiopulmonary Mortality? - Based on the 1994 Heat Wave in Korea - (1994년 하절기의 심혈관계 및 호흡기계 초과사망 - 이상고온 및 대기오염의 영향을 중심으로 -)

  • Sung, Joo-Hon;Kim, Ho;Cho, Soo-Hun
    • Journal of Preventive Medicine and Public Health
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    • v.34 no.4
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    • pp.316-322
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    • 2001
  • Objectives : To explore the possible effect of an interaction between summertime heat waves and ozone on cardiopulmonary mortality during the 1994 heat wave in Korea. Methods : The unusually hot summer of 1994 in Korea was defined as the heat wave in this study. We examined the associations of air pollutants with daily cardiopulmonary deaths between 1991-1995, considering the product term of the heat wave and each pollutant, weather and time trends. Results : During the heat wave, while temperatures were uniformly higher than those of other summers, the within-heat-wave difference in mortality paralleled that in the regional ozone levels. In terms of the influence of the heat wave, the results of ozone were different to those of total suspended particles (TSP) and sulfur dioxide $(SO_2)$. The ozone association (relative risk (RR) : 1.036; 95% confidence interval (CI) = 1.018-1.054) was observed only under heat wave conditions, while the TSP (RR : 1.006, 95% CI = 0.999-1.012) and the $SO_2$ (RR = 1.018, 95% CI : 1.011-1.024) associations were found under normal weather conditions (per interquartile increase of each pollutant; results of three pollutants model). The ozone association under heat wave was attributable to the statistical interaction between the heat wave and ozone. Conclusions : These results support the possibility of a biological synergy between the heat wave and ozone, one that is not evident between the heat wave and other major pollutants like particles or $SO_2$.

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A Study on Weight Concerns and Their Control on Behavior in Female University Students Living in Jeonju (전주 지역 여대생의 체중 조절에 대한 관심도 및 실행 행태에 관한 연구)

  • Rho, Jeong-Ok
    • The Korean Journal of Food And Nutrition
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    • v.20 no.3
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    • pp.325-333
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    • 2007
  • This study was conducted to investigate the weight concerns of female university students living in Jeonju, as well as their control on behavior. Self-administered questionnaires were collected from 285 students. Statistical data analysis was completed using the SPSS v. 11.0 program. The results are summarized as follows: The average weight, height, and BMI of the subjects were 21.43 kg, 161.93 cm, and 19.8, respectively. With regard to body image, most were dissatisfied with their figures, especially the hips and thighs. About 42% of the students estimated their figures as 'slightly fat', while 5.4% stated 'very fat', even though their BMI classified as 'normal'. Four percent of the underweight students described themselves as being 'fatty'. Approximately 93% of the students had strongly pursued weight control, and 45.3% reported wanting to lose about $2{\sim}5$ kg. Almost 73% of the respondents had weight loss experience. The primary reason for weight control was to improve self-confidence. Only 19.6% had succeeded in losing weight, while nearly 48% had stopped dieting. To reduce weight, about two thirds of the students ate less(e.g. no snacks, no sweets). Fifty percent tried to reduce weight by more physical activity(e.g. sports). Television(50.9%), friends(48.4%), and newspapers/magazines(40.4%) were essential sources of pertinent information. In conclusion, the results show that female students in Jeonju have a great interest in weight reduction. Thus, the majority are willing to try several methods for weight reduction, which however, are not promising and not based on a lasting nutritional change. Therefore, it's necessary to increase cooperation among those concerned(e.g. dietitians, teachers, parents, media) and to develop weight-control programs that take into consideration lifestyle and daily habits, as well as combine physical activity, nutrition, and behavioral and personality training.

Modified Arachnoid Plasty Reduces Chronic Subdural Hematoma after Unruptured Aneurysm Clipping : Technical Note

  • Lee, Won Jae;Nam, Taek Min;Jo, Kyung-Il;Yeon, Je Young;Hong, Seung-Chyul;Kim, Jong-Soo
    • Journal of Korean Neurosurgical Society
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    • v.61 no.6
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    • pp.761-766
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    • 2018
  • Objective : Chronic subdural hematoma (CSDH) is a rare complication of unruptured intracranial aneurysm (UIA) clipping surgery. To prevent postoperative CSDH by reducing subdural fluid collection, we applied the modified arachnoid plasty (MAP) during the UIA clipping surgery to seal the dissected arachnoid plane. Methods : This retrospective study included 286 patients enrolled from July 2012 to May 2015. We performed arachnoid plasty in all patients, with MAP used after June 17, 2014. Patients were divided into two groups (non-MAP vs. MAP), and by using uni- and multivariate analyses, baseline characteristics, and relationships with postoperative CSDH between the two groups were analyzed. The degree of preoperative brain atrophy was estimated using the bicaudate ratio (BCR) index. Results : Ten patients (3.5%) among 286 patients had postoperative CSDH after clipping. Nine (3.1%) were in the non-MAP group, and one (0.9%) was in the MAP group. The higher BCR index showed statistical significance with occurrence of postoperative CSDH in both uni- (p=0.018) and multivariate (p=0.012; odds ratio [OR], 8.547; 95% confidence interval [CI], 1.616-45.455) analyses. MAP was associated with a lower risk of postoperative CSDH (p=0.022; OR, 0.068; 95% CI, 0.007-0.683). Conclusion : This study shows that the degree of preoperative brain atrophy is associated with an increased occurrence of CSDH after clipping and that MAP could help reduce the risk of postoperative CSDH after unruptured aneurysm clipping via a lateral supraorbital approach.

Effects of Trust and Cognitive Absorption on Smart Phone Use and User Satisfaction (신뢰와 인지적 몰입 매개변수가 스마트폰의 사용과 만족도에 미치는 영향 분석)

  • Lee, Bong-Gyou;Yeo, Yoon-Ki;Kim, Ki-Youn;Lee, Jong-Hoon
    • The KIPS Transactions:PartD
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    • v.17D no.6
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    • pp.471-480
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    • 2010
  • The purpose of this study is to explore determinants which affect the significant increase in the user acceptance of smart phone. This study also analyzes the effect of each variable on the actual acceptance by empirical methods. In this study, first, the system quality and the service quality are defined as independent variables based on developed IS success model of DeLone & McLean(2003). Second, we proposed the research model by providing trust and perceptual immersion as intermediate variables, and user satisfaction and actual use as dependent variables by the proceeding research for accepting information technology and new service. Third, the statistical analysis is conducted by surveying to 200 smart phone users for verifying a validity of research models and hypotheses. As a result, almost hypotheses are accepted in confidence interval except for the hypothesis between security and trust variable.

Bioequivalence of Mycosil Tablet to Lamisil Tablet (Terbinafine 125 mg) (라미실 정(테르비나핀 125 mg)에 대한 미코실 정의 생물학적 동등성)

  • Cho, Hea Young;Park, Hyun Jin;Jeong, Kyung Hee;Cho, Haeng Nam;Moon, Jai Dong;Lee, Yong Bok
    • Korean Journal of Clinical Pharmacy
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    • v.10 no.2
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    • pp.62-67
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    • 2000
  • Terbinafine has a primary fungicidal action mediated by squalene epoxidase inhibition. Treated fungi accumulate squalene while becoming deficient in ergosterol, an essential component of fungal cell membranes. Bioequivalence of two terbinafine tablets, $Lamisil^{TM}$ (Novartis Korea Ltd., Seoul, Korea) and $Mycosil^{TM}$ (Daewon Pharmaceutical Co., Ltd., Seoul, Korea), was evaluated according to the guidelines of Korea Food and Drug Administration (KFDA). Sixteen normal male volunteers ($20\sim29$ years old) were randomly divided into two groups and a randomized $2\times2$ cross-over study was employed. After oral administration of $Mycosil^{TM}\;or\;Lamisil^{TM}$ (125 mg terbinafine), blood samples were taken at predetermined time intervals and the serum terbinafine concentrations were determined using an HPLC method with UV/VIS detector. The pharmacokinetic parameters $(AUC_t,\;C_{max}\;and\;T_{max})$ were calculated and ANOVA was utilized for the statistical analysis. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two tablets based on the $Lamisil^{TM}$ tablet were $-2.24\%,\;-7.68\%\;and\;2.92\%$, respectively. The powers %(1-\beta)\;for\;AVC_t,\;C_{max}\;and\;T_{max}\;were\;87.11\%,\;95.36\%\;and\;99.99\%$, respectively. Minimum detectable differences $(\Delta)\;and\;90\%$ confidence intervals were all less than $\pm20\%$. All these parameters met the criteria of KFDA for bioequivalence, indicating that $Mycosil^{TM}$ tablet is bioequivalent to $Lamisil^{TM}$ tablet.

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The Recency Period for Estimation of Human Immunodeficiency Virus Incidence by the AxSYM Avidity Assay and BED-Capture Enzyme Immunoassay in the Republic of Korea

  • Yu, Hye-Kyung;Heo, Tae-Young;Kim, Na-Young;Wang, Jin-Sook;Lee, Jae-Kyeong;Kim, Sung Soon;Kee, Mee-Kyung
    • Osong Public Health and Research Perspectives
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    • v.5 no.4
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    • pp.187-192
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    • 2014
  • Objectives: Measurement of the incidence of the human immunodeficiency virus (HIV) is very important for epidemiological studies. Here, we determined the recency period with the AxSYM avidity assay and the BED-capture enzyme immunoassay (BED-CEIA) in Korean seroconverters. Methods: Two hundred longitudinal specimens from 81 seroconverters with incident HIV infections that had been collected at the Korea National Institute of Health were subjected to the AxSYM avidity assay (cutoff = 0.8) and BED-CEIA (cutoff = 0.8). The statistical method used to estimate the recency period in recent HIV infections was nonparametric survival analyses. Sensitivity and specificity were calculated for 10-day increments from 120 days to 230 days to determine the recency period. Results: The mean recency period of the avidity assay and BED-CEIA using a survival method was 158 days [95% confidence interval (CI), 135-181 days] and 189 days (95% CI, 170-208 days), respectively. Based on the use of sensitivity and specificity, the mean recency period for the avidity assay and BED-CEIA was 150 days and 200 days, respectively. Conclusion: We determined the recency period to estimate HIV incidence in Korea. These data showed that the nonparametric survival analysis often led to shorter recency periods than analysis of sensitivity and specificity as a new method. These findings suggest that more data from seroconverters and other methodologies are needed to determine the recency period for estimating HIV incidence.

Relation between Multiple Markers of Work-Related Fatigue

  • Volker, Ina;Kirchner, Christine;Bock, Otmar L.
    • Safety and Health at Work
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    • v.7 no.2
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    • pp.124-129
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    • 2016
  • Background: Work-related fatigue has a strong impact on performance and safety but so far, no agreed upon method exists to detect and quantify it. It has been suggested that work-related fatigue cannot be quantified with just one test alone, possibly because fatigue is not a uniform construct. The purpose of this study is therefore to measure work-related fatigue with multiple tests and then to determine the underlying factorial structure. Methods: Twenty-eight employees (mean: 36.11; standard deviation 13.17) participated in five common fatigue tests, namely, posturography, heart rate variability, distributed attention, simple reaction time, and subjective fatigue before and after work. To evaluate changes from morning to afternoon, t tests were conducted. For further data analysis, the differences between afternoon and morning scores for each outcome measure and participant (${\Delta}$ scores) were submitted to factor analysis with varimax rotation and each factor with the highest-loading outcome measure was selected. The ${\Delta}$ scores from tests with single and multiple outcome measures were submitted for a further factor analysis with varimax rotation. Results: The statistical analysis of the multiple tests determine a factorial structure with three factors: The first factor is best represented by center of pressure (COP) path length, COP confidence area, and simple reaction time. The second factor is associated with root mean square of successive difference and useful field of view (UFOV). The third factor is represented by the single ${\Delta}$ score of subjective fatigue. Conclusion: Work-related fatigue is a multidimensional phenomenon that should be assessed by multiple tests. Based on data structure and practicability, we recommend carrying out further studies to assess work-related fatigue with manual reaction time and UFOV Subtest 2.

Spectrophotometric Determination of Nizatidine and Ranitidine Through Charge Transfer Complex Formation

  • Walash, M.;Din, M.-Sharaf-EI;Metwalli, M.E.S.;RedaShabana, M.
    • Archives of Pharmacal Research
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    • v.27 no.7
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    • pp.720-726
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    • 2004
  • Two Spectrophotometric procedures are presented for the determination of two commonly used H2-receptor antagonists, nizatidine (I) and ranitidine hydrochloride (II). The methods are based mainly on charge transfer complexation reaction of these drugs with either ${\rho}-chloranilic$ acid (${\rho}-CA$) or 2, 3 dichloro-5, 6-dicyanoquinone (DDQ). The produced colored products are quantified spectrophotometrically at 515 and 467 nm in chloranilic acid and 000 methods, respectively. The molar ratios for the reaction products and the optimum assay conditions were studied. The methods determine the cited drugs in concentration ranges of 20-200 and $20-160\;\mu\textrm{g}/mL$ for nizatidine and ranges of 20-240 and $20-140\;\mu\textrm{g}/mL$ for ranitidine with chloranilic acid and DDQ methods, respectively. A more detailed investigation of the complexes formed was made with respect to their composition, association constant, molar absorptivity and free energy change. The proposed procedures were successfully utilized in the determination of the drugs in pharmaceutical preparations. The standard addition method was applied by adding nizatidine and ranitidine to the previously analyzed tablets or capsules. The recovery of each drug was calculated by comparing the concentration obtained from the spiked mixtures with those of the pure drug. The results of analysis of commercial tablets and the recovery study (standard addition method) of the cited drugs suggested that there is no interference from any excipients, which are present in tablets or capsules. Statistical comparison of the results was performed with regard to accuracy and precision using student's t-test and F-ratio at 95% confidence level. There is no significant difference between the reported and proposed methods with regard to accuracy and precision.

Effect of dietary quality on periodontal diseases in Korean adults: the Korea National Health and Nutrition Examination Survey (2016-2018) (한국 성인의 식생활의 질이 치주질환에 미치는 영향: 국민건강영양조사 제7기(2016-2018) 자료 활용)

  • Park, Jung-Eun
    • Journal of Korean society of Dental Hygiene
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    • v.21 no.5
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    • pp.535-543
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    • 2021
  • Objectives: This study investigated the relationship between the Korean healthy eating index (KHEI) and periodontal disease in the Korean adult population. Methods: The data used in the analyses were obtained from the seventh Korean National Health and Nutrition Examination Survey (2016-2018). Data were analyzed by chi-square tests and t-test. Multiple regression analysis was also performed to assess the association between KHEI and periodontal disease. Statistical significance was set at p<0.05. Results: Multiple logistic regression analysis adjusted for socioeconomic variables showed that medical and health behavior variables were significantly related to the KHEI 1 (<63.7, odds ratio [OR]: 1.23, 95% confidence interval [CI]: 1.03-1.46), KHEI 2 (63.7-79.9, OR: 1.14, 95% CI: 0.97-1.34), and risk for periodontal disease. Conclusions: The results showed a significant association between the KHEI and periodontal disease in the Korean adult population.

The Effects of Favorable Responses to the Municipal Police System on the Private Security Confidence of the Police (자치경찰제에 대한 호의적 반응이 경찰의 민간경비 신뢰에 미치는 영향)

  • Shin, Jae-Hun;Kim, Sang-Woon
    • The Journal of the Korea Contents Association
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    • v.19 no.7
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    • pp.281-290
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    • 2019
  • With the goal of enforcing a municipal police system in a national scale starting from 2021, the proposal for introducing municipal police system is promoted and the private security is spotlighted as the measure for supplementing the issues for municipal police system. To solve this issue, the method of promoting and actively utilizing the private security which served as an assistant for security service into the cooperator for security service is suggested as a practical method. To analyze how police's favorable attitude toward introduction of municipal police system influence on the favorable trust toward private security system, this study conducted a survey on front line police officers and analyzed the collected data through statistical technique. As a result, the police officers favorable to introduction of municipal police system also showed positive attitude toward private security and machine security. However, the survey didn't provide significant result on labor expense. In order for the private security service to be accepted as the cooperator for security service, it is necessary to solve the labor expense issue and strengthen trust on machine security.