• Title/Summary/Keyword: interval criteria

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On the Origin of Visibility Degradation in Seoul (서울지역의 시정 장애 요인에 관한 연구)

  • 윤순창;이강웅
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.3
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    • pp.229-236
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    • 1998
  • Visibility is a good indicator of comprehensive alto quality. The prevailing visibility in Seoul is no better than the past although the average concentration of SO2 and TSP (total suspended particulate) has decreased quite significantly in the past decade, owing to the government efforts to reduce the emission. Then, a question arises why visibility has not been improved. In order to answer this question we have investigated which components of air pollutants are most responsible for the visibility degradation in Seoul. Analysis on the visibility vs the aerosol sixte distribution measured by an optical particle counter shows that the particles of the size interval between 0.5mm and 2.5mm are most responsible for the visibility degradation. Among the criteria air Pollutants, NOB concentration is found to be moot responsible, rather than PM10. ton analysis of the particulate collected by a high volume sampler shows that the nitrate component increases more significantly than other ions when visibility becomes very poor. Therefore, we conclude that the major causes of visibility degradation in Seoul are the increase of NOB, nitrates and the particles of the size range between 0.5mm and 2.5mm.

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Effect of the Freshwater Discharge on Seawater and Sediment Environment in a Coastal Area in Goheung County, South Korea

  • Nguyen, Hoang Lam;Jang, Min-Seok;Cho, Hyeon-Seo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.3
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    • pp.270-276
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    • 2014
  • Seasonal characteristics of water and sediment qualities and potential effects of the freshwater discharge from a small tide embankment interior in a coastal area in Goheung county were investigated from May to September in 2012. Chemical oxygen demand values (COD) were mostly higher than 2 mg/L in summer ebb tide, which exceed the standard value of water quality criteria II of acceptable level for aquaculture activities. Nitrogen and phosphorus were found as the limiting nutrients for algae growth in summer and fall and in spring, respectively. Nitrogen was the limiting nutrient for diatom growth in the whole studied period. The sudden high values of COD, ammonia, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) were found in water sample collected from station 5 which located in front of the tide embankment sluice gate during spring ebb tide. The freshwater discharge form the tide embankment interior maybe affected the survey areas during a short time interval. Mean values of eutrophication index of the surveyed coastal region in spring, summer and fall were all bigger than 1. Water quality was mostly considered at level II which acceptable for aquaculture activities. Sediment quality in this study was generally in the range of standard for fisheries environment.

Characteristics and Control of Nonpoint Pollutants in Railway Station (철로 역사에서 발생 가능한 비점오염물질의 특성 및 관리방안)

  • Oa Seong Wook;Kim Lee-Hyung
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1695-1700
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    • 2004
  • Nonpoint pollutants were monitored on railway station land use. Lots of pollutant mass were washed-off in a first hour. The 95$\%$ confidence interval of pollutant concentrations ranges from 61.6 to 115.4 mg/L for TSS(mean= 88.50 mg/L). 103.8$\∼$244.1 mg/L for COD(mean= 174 mg/L) and 7.68$\∼$17.32 mg/L for Oil & Grease(mean= 12.5 mg/L). The various metals were also washed-off during storm runoff from railway station. The ranges of 95$\%$ confidence intervals were 39.2$\∼$84.0 ug/L for total Cu(mean= 61.6 ug/L), 14.0 $\∼$ 25.8 ug/L for total Pb(mean= 19.9 ug/L) and 182.2 $\∼$ 376.1 ug/L for total Zn(mean= 279.2 ug/L). As a result of this research, we concluded that up to 50$\%$ of the total pollutant mass can be removed when first 30$\%$ of the total flow are treating, and it can be a first flush criteria for best management practices.

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Decision Variable Design of Discrete Systems using Simulation Optimization (시뮬레이션 최적화를 이용한 이산형 시스템의 결정변수 설계)

  • 박경종
    • Proceedings of the Korea Society for Simulation Conference
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    • 1999.10a
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    • pp.63-69
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    • 1999
  • The research trend of the simulation optimization has been focused on exploring continuous decision variables. Yet, the research in discrete decision variable area has not been fully studied. A new research trend for optimizing discrete decision variables ha just appeared recently. This study, therefore, deals with a discrete simulation method to get the system evaluation criteria required for designing a complex probabilistic discrete event system and to search the effective and reliable alternatives to satisfy the objective values of the given system through a on-line, single run with the short time period. Finding the alternative, we construct an algorithm which changes values of decision variables and a design alternative by using the stopping algorithm which ends the simulation in a steady state of system. To avoid the loss of data while analyzing the acquired design alternative in the steady state, we provide background for estimation of an auto-regressive model and mean and confidence interval for evaluating correctly the objective function obtained by small amount of output data through simulation with the short time period. In numerical experiment we applied the proposed algorithm to (s, S) inventory system problem with varying Δt value. In case of the (s, S) inventory system, we obtained good design alternative when Δt value is larger than 100.

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Ventilator-associated Pneumonia with Circuit Changes Every 7 Days versus Every 14 Days (회로 교환주기에 따른 인공호흡기 관련 폐렴발생률 차이)

  • Choi, Jeong-Sil;Yeon, Jeong-Haw
    • Journal of Korean Academy of Nursing
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    • v.40 no.6
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    • pp.799-807
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    • 2010
  • Purpose: To determine whether the practice of not routinely changing ventilator circuits in patients who require prolonged mechanical ventilation is associated with ventilator-associated pneumonia (VAP). Methods: Patients were divided into two groups, ventilator circuits were routinely changed every 7 days for the control group (39) and every 14 days for the experimental group (40) over a period of 1 yr (April 1, 2009-March 31, 2010). Pediatric patients (age 17 yr or less) were not included. VAP was diagnosed by the criteria of the Centers of Disease Control and Prevention (CDC). Incidence of VAP and characteristics of infection were evaluated. Results: In the experimental group, 2 episodes of pneumonia were observed in 40 patients and 1,322 ventilator days. The rate of VAP was 1.5 per 1,000 ventilator days. There was 1 episode of pneumonia in 39 patients and 481 ventilator days for the control group. The rate of VAP was 2.1 per 1,000 ventilator days. The difference between both groups was not significant (p=.695). Conclusion: Extending ventilator circuit change interval from 7 days to 14 days does not increase the risk for VAP.

Effectiveness of Exercise Therapy on Physical Function in Patients With Ankylosing Spondylitis: Systemic Review and Meta-Analysis (강직성 척추염 환자의 신체기능에 대한 운동치료의 효과: 체계적 고찰과 메타분석)

  • Shim, Jae-Hun
    • Physical Therapy Korea
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    • v.16 no.3
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    • pp.50-59
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    • 2009
  • The aim of the study was to evaluate the effectiveness of exercise therapy on physical function of patients with anklyosing spondylitis (AS) through the systemic review and meta-analysis. The 54 studies were identified from computerized search of published researches on PubMed, Embase, CINAHL, PEDro, KISS, KERIS database until February, 2008 and review of reference lists. The main search terms were the combination "ankylosing spondylitis", "exercise", "spondyloarthropathy and exercise", "ankylosing spondylitis and physical therapy". The subgroup analysis was performed by the publication year, quality score, type of disease, content of intervention, intervention provider, type of intervention, method of intervention, intervention period and the point of outcome measured. Two reviewers independently selected trials for inclusion, assessed the quality and extracted the data. The result was as follows: The 10 trials were eligible for inclusion criteria, then the systematic review and meta-analysis was assessed on effectiveness of exercise therapy. The meta-analysis of 10 studies based on the random effect model showed that the exercise therapy was beneficial in treating the diseases (effect size .55; 95% confidence interval -.3.75~.61). The findings suggest that the exercise therapy would be appropriate to manage the physical function of AS with evidence based on Meta-analysis. Therefore, the exercise therapy supervised by physical therapist should be recognized as the essential approach to manage the AS and necessarily recommended to improve physical function.

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Effect of premedication on postoperative pain after root canal therapy in patients with irreversible pulpitis: a systematic review and meta-analysis

  • Kumar, Gaurav;Sangwan, Pankaj;Tewari, Sanjay
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.21 no.5
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    • pp.397-411
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    • 2021
  • This systematic review aimed to assess the effect of premedication on postoperative pain after root canal treatment in vital teeth. Five electronic databases were searched for randomized clinical trials, and two independent reviewers selected eligible studies, extracted data, and assessed the quality of studies using the Cochrane Risk of Bias tool. Meta-analysis was conducted using the random-effects model, and the pooled effect estimate of the standardized mean difference (SMD) between premedication and placebo was calculated. Subgroup analysis was conducted based on the class and route of the drug. Studies with a high risk of bias were excluded from the sensitivity analysis. Ten trials satisfied the inclusion criteria, of which eight were included in the meta-analysis. Premedication was more effective in reducing postoperative pain than placebo at 6 hours (SMD = -1.00; 95% confidence interval [CI] = -1.33 to -0.66), 12 hours (SMD = -0.80; 95% CI = -1.05 to -0.56), and 24 hours (SMD = -0.72; 95% CI = -1.02 to -0.43). The results of the sensitivity analysis confirmed the findings of the primary analysis. Based on these results, it can be concluded that premedication is effective in reducing postoperative pain in teeth with irreversible pulpitis. However, additional quality studies are required for further validation.

Effects of nonpharmacological interventions on the psychological health of high-risk pregnant women: a systematic review and meta-analysis

  • Yoo, Hyeji;Ahn, Sukhee
    • Women's Health Nursing
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    • v.27 no.3
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    • pp.180-195
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    • 2021
  • Purpose: This study aimed to summarize the current evidence on the effects of nonpharmacological interventions on psychological health outcomes for women with high-risk pregnancies due to conditions such as preeclampsia, gestational diabetes, or preterm labor. Methods: The following databases were searched from January 2000 to December 2020: PubMed, Ovid Embase, CINAHL, Web of Science, DBpia, RISS, and KISS. Two investigators independently reviewed and selected articles according to the inclusion/exclusion criteria. RoB 2 and the ROBINS-I checklist were used to evaluate study quality. Results: Twenty-nine studies with a combined total of 1,806 pregnant women were included in the systematic review and meta-analysis. Psychological health improvements were found in women with preeclampsia (Hedges' g=-0.67; 95% confidence interval [CI], -0.91 to -0.44), gestational diabetes (Hedges' g=-0.38; 95% CI, -0.54 to -0.12), and preterm labor (Hedges' g=-0.73; 95% CI, -1.00 to -0.46). The funnel plot was slightly asymmetrical, but the fail-safe N value and the trim-and-fill method showed no publication bias. Conclusion: Nonpharmacological interventions for women with high-risk pregnancies due to conditions such as preeclampsia, gestational diabetes, and preterm labor can improve psychological parameters such as anxiety, stress, and depression. Nurses can play a pivotal role in the nursing management of pregnant women with high-risk conditions and apply various types of nonpharmacological interventions to meet their needs in uncertain and anxious times during pregnancy.

Prevalence, Subtypes and Risk Factors of Irritable Bowel Syndrome among Male Adolescents (남자 고등학생의 과민대장증후군 유병률, 증상 유형 및 위험요인)

  • Yang, Yun-Yi
    • Journal of the Korean Society of School Health
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    • v.32 no.1
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    • pp.1-9
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    • 2019
  • Purpose: The purpose of this study was to identify the prevalence, subtypes and risk factors of Irritable Bowel Syndrome (IBS) among male adolescents. Methods: The survey was conducted on male adolescents (n=441) attending a high school. Rome IV criteria was used to diagnose IBS. Data on health promoting behaviors, psychological distress, sleep hygiene practices were collected using self-administered structured questionnaires. Results: The prevalence of IBS was 11.1% and the subtypes were mixed (77.5%), unclassified (10.2%), diarrhea-predominant (8.2%), and constipation-predominant (4.1%). Risk factors influencing IBS were sleeping time (Odds Ratio [OR]=1.00, 95% Confidence Interval [CI]: 0.99~1.00), anxiety, a subfactor under psychological distress (OR=1.12, 95% CI: 1.02~1.22), and arousal-related behaviors, a subfactor under sleep hygiene practices (OR=1.10, 95% CI: 1.03~1.17). Conclusion: Our findings indicated that IBS is a common problem in male adolescents. It is necessary to develop school-based intervention strategies addressing sleeping time, anxiety and arousal-related behaviors in order to prevent and improve IBS in male adolescents.

Evaluation of the Humpty Dumpty Falls Scale: An Analysis of Electronic Medical Records (소아 낙상위험 측정도구 (Humpty Dumpty Falls Scale) 평가: 전자의무기록을 이용하여)

  • Cho, Yun Hee;Kim, Young Ju
    • Journal of Korean Clinical Nursing Research
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    • v.25 no.2
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    • pp.142-150
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    • 2019
  • Purpose: The aim of this study was to evaluate the efficiency of the Humpty Dumpty Falls Scale as one of the falls risk assessment tools, and also to evaluate risk factors as predictors of falls in pediatric patient populations. Methods: In a retrospective, case-control design with data from the electronic medical records of 13 pediatric patients who fell and 1,941 who did not fall before matching and 429 who did not fall after matching by gender, age, diagnosis, and length of stay. Results: All the variables showed no significant differences after matching. At the cutoff score of 13, sensitivity, specificity, negative and positive predictive values were 92.3%, 37.1%, 99.9%, and 0.01%, respectively. The area under the Receiver Operating Characteristics was 0.597. The results from the logistic regression showed that the pediatric inpatient population who had higher risk scores was significantly associated with falls. The odds ratios ranged from 1.31 to 4.71 with 90% confidence interval. Conclusion: The saturation impairments criterion as one of the diagnostic parameter was negatively associated with falls, but the relative risk score was higher than the other criteria. Therefore, it seems that the diagnostic parameter seems to be required to verify results through large sample studies.