• Journal of Soil and Groundwater Environment
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• v.26 no.3
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• pp.37-49
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• 2021

There is domestic Soil Contamination Warning Standard (SCWS) as remediation standard concentration of contaminated soils. No risk should be observed at soil concentration less than SCWS. Therefore, SCWS was evaluated to confirm the risk assessment. Background Concentration of Soil (BGC) and target remediation concentration were also assessed. The results show that Excess Cancer Risk (ECR) of SCWS was the highest in the groundwater intake pathway (Adult: 6.27E-04, Child: 2.81E-04). Total Cancer Risk (TCR) was 7.76E-04 and 4.30E-04 for adult and child, exceeding reference value (10^-6). Hazard Quotient (Non-Carcinogenic Risk, HQ) was the highest in the indoor air inhalation pathway (Adult: 3.64E+03, Child: 8.74E+02). Hazard Index (Total Non-Carcinogenic Risk, HI) exceeded reference value 1. ECR of the BGC was the highest in the groundwater intake pathway (Adult: 1.71E-04, Child: 7.67E-05). TCR was 2.12E-04 for adults and 1.17E-04 for children, exceeding the reference value (10^-6). HQ was the highest in groundwater intake pathway (Adult: 4.10E-01, Child: 1.84E-01). HI was lower than reference value 1 (Adult: 4.78E-01, Child: 2.50E-01). The heavy metal affecting ECR was Arsenic (As). The remediation-concentration of As was 7.14 mg/kg which is higher than BGC (6.83 mg/kg). TCR of As should be less than reference value (10^-6), but it was higher for all of SCWS, BGC and target remediation concentration. Therefore, it is suggested that risk assessment factors should be re-evaluated to fit domestic environmental settings and SCWS should be induced to satisfy the risk assessment.

• Tuberculosis and Respiratory Diseases
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• v.86 no.2
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• pp.133-141
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• 2023

Background: The present study evaluated the association between participation in a rehabilitation program during a hospital stay and 1-year survival of patients requiring at least 21 days of mechanical ventilation (prolonged mechanical ventilation [PMV]) with various respiratory diseases as their main diagnoses that led to mechanical ventilation. Methods: Retrospective data of 105 patients (71.4% male, mean age 70.1±11.3 years) who received PMV in the past 5 years were analyzed. Rehabilitation included physiotherapy, physical rehabilitation, and dysphagia treatment program that was individually provided by physiatrists. Results: The main diagnosis leading to mechanical ventilation was pneumonia (n=101, 96.2%) and the 1-year survival rate was 33.3% (n=35). One-year survivors had lower Acute Physiology and Chronic Health Evaluation (APACHE) II score (20.2±5.8 vs. 24.2±7.5, p=0.006) and Sequential Organ Failure Assessment score (6.7±5.6 vs. 8.5±2.7, p=0.001) on the day of intubation than non-survivors. More survivors participated in a rehabilitation program during their hospital stays (88.6% vs. 57.1%, p=0.001). The rehabilitation program was an independent factor for 1-year survival based on the Cox proportional hazard model (hazard ratio, 3.513; 95% confidence interval, 1.785 to 6.930; p<0.001) in patients with APACHE II scores ≤23 (a cutoff value based on Youden's index). Conclusion: Our study showed that participation in a rehabilitation program during hospital stay was associated with an improvement of 1-year survival of PMV patients who had less severe illness on the day of intubation.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.175-190
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• 1994

In order to get fundamental information for prediction of landslide hazard, both forest and site factors affecting slope stability were investigated in many areas of active landslides. Twelve descriptors were identified and quantified to develop the prediction model by multivariate statistical analysis. The main results obtained could be summarized as follows : The main factors influencing a large scale of landslide were shown in order of precipitation, age group of forest trees, altitude, soil texture, slope gradient, position of slope, vegetation, stream order, vertical slope, bed rock, soil depth and aspect. According to partial correlation coefficient, it was shown in order of age group of forest trees, precipitation, soil texture, bed rock, slope gradient, position of slope, altitude, vertical slope, stream order, vegetation, soil depth and aspect. The main factors influencing a landslide occurrence were shown in order of age group of forest trees, altitude, soil texture, slope gradient, precipitation, vertical slope, stream order, bed rock and soil depth. Two prediction models were developed by magnitude and frequency of landslide. Particularly, a prediction method by magnitude of landslide was changed the score for the convenience of use. If the total store of the various factors mark over 9.1636, it is evaluated as a very dangerous area. The mean score of landslide and non-landslide group was 0.1977 and -0.1977, and variance was 0.1100 and 0.1250, respectively. The boundary value between the two groups related to slope stability was -0.02, and its predicted rate of discrimination was 73%. In the score range of the degree of landslide hazard based on the boundary value of discrimination, class A was 0.3132 over, class B was 0.3132 to -0.1050, class C was -0.1050 to -0.4196, class D was -0.4195 below. The rank of landslide hazard could be divided into classes A, B, C and D by the boundary value. In the number of slope, class A was 68, class B was 115, class C was 65, and class D was 52. The rate of landslide occurrence in class A and class B was shown at the hige prediction of 83%. Therefore, dangerous areas selected by the prediction method of landslide could be mapped for land-use planning and criterion of disaster district. And also, it could be applied to an administration index for disaster prevention.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.6 s.52
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• pp.47-56
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• 2006

A method is presented for evaluating the economic efficiency of a semi-active magneto-rheological (MR) damper system for cable-stayed bridges under earthquake loadings. An optimal MR damper capacity maximizing the cost-effectiveness is estimated for various seismic characteristics of ground motion. The economic efficiency of MR damper system is addressed by introducing the life-cycle cost concept. To evaluate the expected damage cost, the probability of failure is estimated. The cost-effectiveness index is defined as the ratio of the sums of the expected damage costs and each device cost between a bridge structure with the MR damper system and a bridge structure with elastic bearings. In the evaluation of cost-effectiveness, the scale of damage cost is adopted as parametric variables. The results of the evaluation show that the MR damper system can be a cost-effective design alternative. The optical capacity of MR damper is increased as the seismic hazard becomes severe.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4B
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• pp.261-266
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• 2012

In this study, soil environmental impact assessment using risk-based approach was compared with that using concentration-based approach. For this, heavy metal contaminant exposure was characterized in an abandoned mine area. According to the estimated carcinogenic and non-carcinogenic risks, soil ingestion was identified as the most dominant exposure pathway. When contaminant concentrations exceeded the Korean Soil Contamination Warning Standards, their corresponding risk values also exceeded the Total Soil Risk Standard. Even the cases of satisfying the Korean Soil Contamination Warning Standards mostly showed higher risk levels than the Total Soil Risk Standard, re-confirming a more sensitivity of the risk-based assessment than concentration-based assessment. However, the in-depth analysis of the estimated non-carcinogenic risk values revealed a few cases for soil contact pathway showing contaminant concentrations higher than the Korean Soil Contamination Warning Standards although their non-carcinogenic risk values satisfied the level of Hazard Index Standard. The findings from this study support a necessity of shifting policy paradigm from concentration-based approach into risk-based approach for reliable risk assessment in abandoned mine areas, and also suggest a necessity of further fundamental studies regarding risk factors and standards.

• Journal of Environmental Impact Assessment
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• v.8 no.2
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• pp.1-8
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• 1999

The research centers on the concentration profile and risk assessment of toxic metals for ambient air in Taejon industrial complex. Airborne concentrations of each toxic metal for risk assessment were obtained from 2-year sampling by high volume air sampler and analysis by ICP-MS and ICP-AES in the complex. The long-term arithmetic mean of human carcinogen, arsenic, hexavalent chromium and nickel subsulfide was 5.53, 2.16 and $3.46ng/m^3$ while the mean of probable human carcinogen, beryllium, cadmium and lead was 0.08, 2.35, $293.29ng/m^3$, respectively. And the long-term arithmetic mean concentration of non-carcinogenic metal, manganese was $55.91ng/m^3$. The point risk estimate for the inhalation of carcinogenic metals was $3.6{\times}10^{-5}$, which was higher than a risk standard of $10^{-5}$. About 75% of the cancer risk was to the inhalation of human carcinogen, arsenic. Thus, it is necessary to properly manage arsenic risk in Taejon industrial complex. The point hazard index by the inhalation of manganese was 1.1. Therefore, an investigation into Taejon industrial complex is needed to obtain more fine long-term concentration data for airborne non-carcinogenic metals including manganese.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2225-2229
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• 2013

Background: As data on the relation between obesity and lymph node ratio are missing in the literature, we here aimed to assess the impact of obesity on this parameter and other clinicopathological features of breast cancer cases and patient survival. Materials and Methods: Medical data of 646 patients, all referred to two centers in Tehran, Iran, were reviewed. Factors that showed significant association on univariate analysis were entered in a regression model. Kaplan-Meier and Cox-regression were employed for survival analysis. Results: Obesity was correlated with the expression of estrogen and progesterone receptor (p=0.004 and p=0.039, respectively), metastasis to axillary lymph nodes (p=0.017), higher lymph node rate (p<0.001) and larger tumor size (p<0.001). The effect of obesity was stronger in premenopausal women. There was no association between obesity and expression of human epidermal growth factor receptor. Three factors showed independent association with BMI on multivariate analysis; tumor size, estrogen receptor and lymph node ratio. Obesity was predictive of shorter disease-free survival with a hazard ratio of 3.324 (95%CI: 1.225-9.017) after controlling for the above-mentioned variables. Conclusions: The findings of this study support the idea that obese women experience more advanced disease with higher axillary lymph node ratio, and therefore higher stage at the time of diagnosis. Furthermore, obesity was associated with poorer survival independent of lymph node rate.

• Asian Journal of Atmospheric Environment
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• v.5 no.4
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• pp.247-262
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• 2011

This study assessed the health risks of childhood exposure to PBDEs via different possible pathways in children's facilities and indoor playgrounds. When PBDE contamination was measured, it was determined through multiple routes, including inhalation of indoor dust, dermal contact with product surfaces and children's hands, and incidental dust ingestion. Samples were collected from various children's facilities (playrooms, daycare centers, kindergartens, and indoor playgrounds) during summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). The hazard index (HI) was estimated for non-carcinogens, and PBDEs, such as TeBDE, PeBDE, HxBDE, and DeBDE, were examined. The sensitivity to the compounds did not exceed 1.0 (HI) for any of the subjects in any facility. However, current data about toxicity does not reflect effects that were fully sensitive in children, so there is uncertainty in the dose-response data. The contribution rates of PBDEs were 71.4 to 96.1% and 3.7 to 28.2% for intake and inhalation exposure, respectively, indicating that intake of floor dust and inhalation are the primary routes.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.17-28
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• 2011

This study proposed a speed management strategy for the enhancement of traffic safety on freeways. A novel feature of the proposed strategy is to provide desirable speed information to individual vehicles. A microscopic traffic simulator, VISSIM, was used for the performance evaluation. Vehicle trajectory data were used to evaluate the various speed management scenarios including the different levels of proportions of heavy vehicles. The proposed speed management strategy would be a useful precursor for developing an effective traffic control and operations system to prevent traffic accidents on freeways.

• Journal of Gastric Cancer
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• v.20 no.3
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• pp.256-266
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• 2020

Purpose: This study aimed to examine the early postprandial changes in gastrointestinal (GI) hormones and hemodynamics in terms of early dumping syndrome after gastrectomy for gastric cancer. Materials and Methods: Forty patients who underwent gastrectomy for gastric cancer and 18 controls without previous abdominal surgery were enrolled. Before and 20 minutes after liquid meal ingestion, blood glucose, glucagon-like peptide-1 (GLP-1), and GLP-2 concentrations and superior mesenteric artery (SMA) and renal blood flow were measured. The patients' heart rates were recorded at 5-minute intervals. All subjects were examined for dumping syndrome using a questionnaire based on Sigstad's clinical diagnostic index. Results: The postprandial increases in blood glucose, GLP-1, and GLP-2 levels as well as SMA blood flow and heart rate were greater in patients who underwent gastrectomy than in controls (all P<0.010). Patients who underwent gastrectomy showed a significantly decreased renal blood flow (P<0.001). Among patients who underwent gastrectomy, distal gastrectomy was a significant clinical factor associated with a lower risk of early dumping syndrome than total gastrectomy (hazard ratio, 0.092; 95% confidence interval, 0.013-0.649; P=0.017). Patients who underwent total gastrectomy showed a greater postprandial increase in blood glucose (P<0.001), GLP-1 (P=0.030), and GLP-2 (P=0.002) levels as well as and heart rate (P=0.013) compared to those who underwent distal gastrectomy. Conclusions: Early postprandial changes in GI hormones and hemodynamics were greater in patients who underwent gastrectomy than in controls, especially after total gastrectomy, suggesting that these changes play a crucial role in the pathophysiology of early dumping syndrome.