• Journal of Korean Neurosurgical Society
• /
• v.65 no.3
• /
• pp.449-456
• /
• 2022

Objective : The aim of this study was to evaluate the clinical outcome of sphenoid wing meningioma with periorbital invasion (PI) after operation. Methods : Sixty one patients with sphenoid wing meningioma were enrolled in this study. Their clinical conditions were monitored after the operation and followed up more than 5 years at the outpatient clinic of a single institution. Clinical and radiologic information of the patients were all recorded including the following parameters : presence of PI, presence of peri-tumor structure invasion, pathologic grade, extents of resection, presence of hyperostosis, exophthalmos index (EI), and surgical complications. We compared the above clinical parameters of the patients with sphenoid wing meningioma in the presence or absence of PI (non-PI), then linked the analyzed data with the clinical outcome of the patients. Results : Of 61 cases, there were 14 PI and 47 non-PI patients. PI group showed a significantly higher score of EI (1.37±0.24 vs. 1.00±0.01, p<0.001), more frequent presence of hyperostosis (85.7% vs. 14.3%, p<0.001), and lower rate of gross total resection (GTR) (35.7% vs. 68.1%, p=0.032). The lower score of pre-operative EI, the absence of both PI and hyperostosis, smaller tumor size, and the performance of GTR were associated with lower recurrence rates in the univariate analysis. However, in the multivariate analysis, the performance of GTR was the only significant factor to determine the recurrence rate (p=0.043). The incidences of surgical complications were not statistically different between the subtotal resection (STR) and GTR groups, but it was strongly associated tumor size (p=0.017). Conclusion : The GTR group showed lower recurrence rate than the STR group without differences in the surgical complications. Therefore, the GTR is strongly recommended to treat sphenoid wing meningioma with PI for the better clinical outcome.

• Korean Chemical Engineering Research
• /
• v.55 no.5
• /
• pp.600-608
• /
• 2017

Hazard risk of explosion on pharmaceutical raw materials dust in pharmaceutical industry often exists when it is handled or processed in the industrial sites, and explosion accident is caused by this. In this study, the dust explosion characteristics of the three pharmaceutical raw materials samples were measured. The main explosion characteristics are as follows: $P_{max}$, MIE and MIT of loxoprofen acid having $5.31^{\circ}C$ of median diameter are obtained 8.4 bar, 1 mJ < MIE < 3 mJ and $550^{\circ}C$. $P_{max}$, MIE and MIT of camphorsulfonate having $95.63^{\circ}C$ of median diameter are obtained 7.9 bar, 30 mJ < MIE < 100 mJ and $510^{\circ}C$. $P_{max}$, MIE and MIT of rifampicine having $26.48^{\circ}C$ of median diameter are obtained 7.9 bar and 1 mJ < MIE < 3 mJ and $470^{\circ}C$. The deflagration index ($K_{st}$) and the explosion index (EI) were obtained by using these data. The explosion hazard assessment of pharmaceutical raw materials dust was compared and examined. As a result, the explosion hazard assessment according to deflagration index and explosion index were the explosion class with St 2 and the explosion hazard rating of severe for loxoprofen acid & rifampicine and St 1 and strong for clopidogrel camphorsulfonate, respectively.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.51 no.1
• /
• pp.1-9
• /
• 2009

The objective of this paper was to evaluate the auto-calibration with multi-objective optimization method to calibrate the parameters of the Soil and Water Assessment Tool (SWAT) model. The model was calibrated and validated by using nine years (1996-2004) of measured data for the 384-ha Baran reservoir subwatershed located in central Korea. Multi-objective optimization was performed for sixteen parameters related to runoff. The parameters were modified by the replacement or addition of an absolute change. The root mean square error (RMSE), relative mean absolute error (RMAE), Nash-Sutcliffe efficiency index (EI), determination coefficient ($R^2$) were used to evaluate the results of calibration and validation. The statistics of RMSE, RMAE, EI, and $R^2$ were 4.66 mm/day, 0.53 mm/day 0.86, and 0.89 for the calibration period and 3.98 mm/day, 0.51 mm/day, 0.83, and 0.84 for the validation period respectively. The statistical parameters indicated that the model provided a reasonable estimation of the runoff at the study watershed. This result was illustrated with a multi-objective optimization for the flow at an observation site within the Baran reservoir watershed.

• International Journal of Reliability and Applications
• /
• v.8 no.1
• /
• pp.111-124
• /
• 2007

In this paper, we apply insightful statistical reliability tools to manage and seek improvements in the strengths of Oriented Strand Board (OSB). As a part of the OSB manufacturing process, the product undergoes destructive testing at various intervals to determine compliance with customers' specifications. Workers perform these tests on sampled cross sections of the OSB panel to measure the tensile strength, also called internal bond (IB), in pounds per square inches until failure. Additional stiffness strength tests include parallel and perpendicular elasticity indices (EI), which are taken from cross sectional samples of the OSB panel in the parallel and perpendicular directions with respect to the orientation of the wood strands. We explore both graphically and statistically these "pressure-to-failures" of OSB. Also, we briefly comment on reducing sources of variability in the IB and EI of OSB.

• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.1
• /
• pp.81-86
• /
• 2016

Heavy metal pollution in agricultural fields at the abandoned metal mines has been serious problems in Korea. In order to manage heavy metal pollution in surface water and soil, numerous remediation strategies have been established. Therefore, main purpose of this research was to examine feasibility of ecological toxicity assessment for establishing management strategy in heavy metal polluted agricultural fields. Heavy metal concentration in surface water and soil was monitored along with ecotoxicity experiment with Daphnia magna and Eisenia fetida. Result showed that high toxicity was observed in heavily polluted agricultural field with heavy metals. In case of mortality of Daphnia magna (85%) and Eisenia fetida (6.7%), the highest ratio was observed when heavy metal concentration in surface and soil was high. Calculated ecotoxicity index (EI) ranged 0.06-0.30 and the highest EI was observed in heavily polluted sites among 5 abandoned metal mines. Overall, ecological toxicity assessment is necessary to evaluate heavy metal pollution in agricultural fields near at the abandoned metal mines along with chemical concentration analysis.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.54 no.6
• /
• pp.53-63
• /
• 2012

The objectives of this study were to develop a linked watershed-waterbody modeling system and to assess the impacts of indirect wastewater reuse on irrigation water quality. The Osan stream watershed within Gyeonggi-do of South Korea was selected for this study. The linked modeling system was composed of the SWAT (Soil and water assessment tool) and QUALKO2 models. The SWAT model was calibrated and validated using the stream discharge and water quality data from 2010 to 2011. Runoff and non-point source pollutants from each subbasin and stream discharge from 1980 to 2009 were simulated by the SWAT model and applied to the QUALKO2 model. The QUALKO2 model was calibrated and validated under the conditions of low water and normal discharges, respectively. Finally, The 10-day irrigation water quality from April to September was simulated. The statistical measures of coefficient of determination ($R^2$), reliability index (RI), and efficiency index (EI) were used to evaluate the system performance. The $R^2$, RI and EI values ranged from 0.5 to 1.0, 1.03 to 1.92, and -35.03 to 0.95, respectively. The 10-day irrigation water quality showed the concentrations of BOD and coliform exceeded the water quality guidelines for wastewater reuse. The linked modeling system can be a useful tool to estimate non-point source pollutant loads in watershed and to control the water quality of effluent from a wastewater treatment plant and irrigation water in the downstream waterbody.

• Journal of Korean Neurosurgical Society
• /
• v.37 no.1
• /
• pp.1-7
• /
• 2005

Objective: Peritumoral brain edema(PTBE) accounts for approximately 60% of meningiomas. It has not been identified why vasogenic edema, frequently shown in intra-axial tumors is also developed in extra-axial tumor such as meningiomas. Therefore, the authors assess the peritumoral brain edema of meningiomas with a focus on the angiographic pattern and expression of MIB-1 to clarify their correlation. Methods: A total 32 cases of meningioma was studied. The authors attempted to identify 1) the location of PTBE and the edema index (EI), 2) the location and dominancy of pial supply compared with meningeal supply, 3) the biological activity of meningiomas indicated by the MIB-1 LI (labeling index), 4) their interaction. Results: No PTBE was observed in the meningiomas without pial arterial supplement from internal carotid artery (ICA) and vertebral artery (VA). The PTBE of meningiomas with pial supply was developed intensely along the pial arterial supplement, and increased statistically in proportion to the extent of pial supply from ICA or VA rather than meningeal supply. Also, the MIB-1 LI in meningiomas tended to be larger in the tumors of the larger EI and the dominancy of pial supply. Conclusion: A strong correlation is found between the extent of PTBE in meningiomas and the dominancy of pial supply. The MIB-1 LI also tend to be associated with the PTBE. Therefore, the MIB-1 LI in benign meningiomas may represent not only the proliferative potential of the tumor, but also the biological activity like angiogenesis.

• Journal of Korean Academy of Nursing Administration
• /
• v.11 no.3
• /
• pp.265-273
• /
• 2005

Purpose: This study was to investigate the degree and pattern of learning organization and MBTI personality type in clinical nurses. Methods: The participants were 685 nurses working in the 8 general hospitals located in Seoul and Incheon. The data were collected by self-reporting questionnaires from April 1 to August 30, 2004. The data were analyzed using SAS program for descriptive statistics and Pearson's correlation coefficient. Results: The most frequent identified personality type was ISTJ and the least identified personal types was ENFJ. In 4 preference patterns, Extroversion, Sensing, Thinking and Judgement were identified a dominant index in each categories. The mean score of learning organization was 3.47 and the mental model was got the highest score. The EI index had a significant positive correlation with personal mastery. However the TF index had a negative correlation with personal mastery, systems thinking, and mental models, and also the JP index had a negative correlation with 5 learning organization sub categories. Conclusion: With these results, it was identified that the preference patterns on MBTI had the significant correlation with learning organization. So these results will be used to develop the more effective strategies to increase learning organization based on nurse's personality types.

• 한국연소학회:학술대회논문집
• /
• 2014.11a
• /
• pp.233-234
• /
• 2014

Lean-rich combustion system was composed both fuel-lean and fuel-rich flame at once. Each of fuel-lean and fuel-rich combustion types to reduce Thermal $NO_x$ and obtain flame stability. This study was confirmed a stability of flame through variation of flame shape that EGR was applied and compared the emission characteristics of EGR lean-rich combustion system to normal premixed combustion system at real condition to review a utility of the system. As a result, emission index of $NO_x$ and CO generated from EGR lean-rich combustion system at global equivalence ratio is 0.85 just half level($NO_x$ 0.31 g/kg, CO 0.08g/kg) compared to the amount generated from normal premixed combustion system at equivalence ratio is 0.78.

• Korean Journal of Radiology
• /
• v.20 no.4
• /
• pp.683-692
• /
• 2019

Objective: We aimed to evaluate correlations between computed tomography (CT) parameters and pulmonary function test (PFT) parameters according to disease severity in patients with chronic obstructive pulmonary disease (COPD), and to determine whether CT parameters can be used to predict PFT indices. Materials and Methods: A total of 370 patients with COPD were grouped based on disease severity according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) I-IV criteria. Emphysema index (EI), air-trapping index, and airway parameters such as the square root of wall area of a hypothetical airway with an internal perimeter of 10 mm (Pi10) were measured using automatic segmentation software. Clinical characteristics including PFT results and quantitative CT parameters according to GOLD criteria were compared using ANOVA. The correlations between CT parameters and PFT indices, including the ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC) and FEV₁, were assessed. To evaluate whether CT parameters can be used to predict PFT indices, multiple linear regression analyses were performed for all patients, Group 1 (GOLD I and II), and Group 2 (GOLD III and IV). Results: Pulmonary function deteriorated with increase in disease severity according to the GOLD criteria (p < 0.001). Parenchymal attenuation parameters were significantly worse in patients with higher GOLD stages (P < 0.001), and Pi10 was highest for patients with GOLD III (4.41 ± 0.94 mm). Airway parameters were nonlinearly correlated with PFT results, and Pi10 demonstrated mild correlation with FEV1/FVC in patients with GOLD II and III (r = 0.16, p = 0.06 and r = 0.21, p = 0.04, respectively). Parenchymal attenuation parameters, airway parameters, EI, and Pi10 were identified as predictors of FEV₁/FVC for the entire study sample and for Group 1 (R² = 0.38 and 0.22, respectively; p < 0.001). However, only parenchymal attenuation parameter, EI, was identified as a predictor of FEV₁/FVC for Group 2 (R² = 0.37, p < 0.001). Similar results were obtained for FEV₁. Conclusion: Airway and parenchymal attenuation parameters are independent predictors of pulmonary function in patients with mild COPD, whereas parenchymal attenuation parameters are dominant independent predictors of pulmonary function in patients with severe COPD.