• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.1
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• pp.20-26
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• 2013

Objectives: This study was conducted to evaluate the health risk of workers exposed to butyl glycidyl ether to prevent them from developing occupational diseases. Methods: The workplaces that coat floor with epoxy were selected and the samples were collected and analyzed with NIOSH 1616 Method. We calculate workplace reference concentration using with NOAEL estimated by the study of Anderson et al. in 1978. Risk was calculated by the ratio of exposure to workplace reference concentration. Monte-Carlo simulation was performed to derivate the median, cumulative 90%, and cumulative 95% value by using Crystal Ball. Results: Butyl glycidyl ether is a skin, eye irritator and can result in central nervous system depression, allergic reaction. NOAEL was 38 ppm and workplace reference concentration was calculated as 0.73 ppm corrected with uncertainty factors. Geometric mean was 1.152 ppm and geometric standard deviation was 1.522 by the workplace environment measurement. The median, cumulative 90%, and cumulative 95% value of risk were calculated as 1.617, 1.934, and 2.092, respectively. Conclusions: Not only cumulative 90% and cumulative 95% value but also the median of risk is higher than 1.0 by the risk characterization, so it can do a lot of harm to workers. Therefore, the process of derivating workplace reference concentration and the appropriacy of the uncertainty factors should be re-examined.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.15 no.25
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• pp.11-14
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• 1992

This paper presents a method for establishing an initial value of redundancy optimization problem to maximize system reliability of multiconstraint mixed parallel-series system. The constraints not be linear. This paper proposes a new initial value which is near to optimal solution by considering the relative median rate of the unreliability and amount of consumed resources for each subsystem. To show the efficiency of this model. numerical example and comparison with Narasimhalu is illustrated in chapter 4.

• Journal of Korean Neurosurgical Society
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• v.54 no.3
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• pp.232-235
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• 2013

Objective : Major complaints of carpal tunnel syndrome (CTS) are sensory components. However, motor deficit also impedes functional status of hand. Contrary to evaluation of sensory function, the objective, quantitative evaluation of median nerve motor function is not easy. The motor function of median was evaluated quantitatively using load cell and its correlation with findings of electrodiagnostic study (EDS) was evaluated. Methods : Objective motor function of median nerve was evaluated by load cell and personal computer-based measurement system. All of the measurement was done in patients diagnosed as having idiopathic CTS by clinical features and EDS findings. The strength of thumb abduction and index finger flexion was measured in each hand three times, and the average value was used to calculate thumb index ratio (TIR). The correlation of TIR with clinical, EDS, and ultrasonographic findings were evaluated. Results : The TIR was evaluated in 67 patients (119 hands). There were 14 males and 53 females, mean age were 57.6 years (range 28 to 81). The higher preoperative nerve conductive studies grade of the patients, the lower TIR was observed [p<0.001, analysis of variance (ANOVA)]. TIR of cases with thenar atrophy were significantly lower than those without (p<0.001, t-test). TIR were significantly lower in patients with severe median nerve swelling in ultrasonography (p=0.042, ANOVA). Conclusion : Measurements of median nerve motor function using load cell is a valuable evaluation tool in CTS. It might be helpful in detecting subclinical motor dysfunction before muscle atrophy develops.

• Health Policy and Management
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• v.33 no.2
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• pp.203-213
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• 2023

This study examined the trend of healthcare status and compared the status of South Korea and other member of the Organization for Economic Cooperation and Development (OECD) using the OECD health statistics 2022. We used the OECD health statistics from 2022 and a position value for relative comparison (PARC) index to compare the five elements of the healthcare system. The study also used a Mann-Kendall test to analyze the trend of the PARC values from 2000 to the present year. The findings of the study indicate that many South Korea's PARC values were higher than the OECD median. But practicing physician in supply part and medical cost were lower than OECD median but the trend significantly increased. Medical accessibility part and quality of care part except primary care, and mental health had a high relative position but the trend did not increased significantly. After outbreak of coronavirus disease 2019, there were changes in medical accessibility. Health screening and vaccinations showed an overall decline in 2020 compared to 2019. These results suggest that policymakers need to take necessary steps for a sustainable healthcare system in the country.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.82-92
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• 2013

This study has investigated naturally occurring radioactive materials (N.O.R.M; $^{238}U$, $^{222}Rn$) for 353 drinking groundwater wells in metamorphic rock areas in Korea. Uranium concentrations ranged from N.D (not detected) to 563.56 ${\mu}g/L$ (median value, 0.68 ${\mu}g/L$) and radon concentrations ranged from 108 to 11,612 pCi/L (median value, 1,400 pCi/L). Uranium and radon concentrations in the groundwater generally are similar to USA with similar geological setting. Uranium concentrations in 9 wells (2.6%) exceeded 30 ${\mu}g/L$, which is the maximum contaminant level (MCL) by the US environmental protection agency (EPA), radon concentrations in 46 wells (13%) exceeded 4,000 pCi/L, which is the Alternative MCL (AMCL) by the US.EPA. The log-log correlation coefficient between uranium and radon was 0.32. The correlation coefficient between uranium and pH was 0.12 and the correlation coefficient between radon and temperature was -0.01. The correlation coefficient between uranium and $HCO_3$ was 0.09 and the correlation coefficient between uranium and Ca was 0.11. The median value of uranium was high Chung-Buk (1.78 ${\mu}g/L$), Gyeong-Buk (1.37 ${\mu}g/L$), In-Cheon (1.06 ${\mu}g/L$) for each province. On the other hand, the median value of radon was high In-Cheon (2,962 pCi/L), Chung-Buk (2,339 pCi/L), Jeon-Buk (2,165 pCi/L) for each province. Jeon-Buk for log-log correlation coefficient is the highest (0.63) among provinces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.141-146
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• 2018

Recently, location recognition technology has attracted much attention, especially for locating people or objects in an indoor environment without being influenced by the surrounding environment GPS technology is widely used as a method of recognizing the position of an object or a person. GPS is a very efficient, but it does not allow the positions of objects or people indoors to be determined. RFID is a technology that identifies the location information of a tagged object or person using radio frequency information. In this study, an RFID system is constructed and the position is measured using tags. At this time, an error occurs between the actual and measured positions. To overcome this problem, a neural network is trained using the measured and actual position data to reduce the error. In this case, since the number of read tags is not constant, they are not suitable as input values for training the neural network, so the neural network is trained by converting them into center-of-gravity inputs and median value inputs. This allows the position error to be reduce by the neural network. In addition, different numbers of trained data are used, viz. 50, 100, 200 and 300, and the correlation between the number of data input values and the error is checked. When the training is performed using the neural network, the errors of the center-of-gravity input and median value input are compared. It was found that the greater the number of trained data, the lower the error, and that the error is lower when the median value input is used than when the center-of-gravity input is used.

• Korean Journal of Clinical Pharmacy
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• v.25 no.3
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• pp.151-158
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• 2015

Objective: This study was designed to compare pegfilgrastim and filgrastim in diffuse large B-cell lymphoma (DLBCL) patients treated with a rituximab with cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone (R-CHOP) regimen in terms of clinical efficacy and cost-effectiveness. Method: Clinical efficacy was measured by trough level of absolute neutrophil count (ANC), days of ANC under 50% of baseline value, days of ANC under 90% of baseline value, duration of ANC recovery to baseline value, days of ANC less than $0.5{\times}10^9cells/L$, and difference of peak and trough level of ANC during 1 cycle of R-CHOP regimen. To evaluate cost-effectiveness, total prices of used filgrastim and pegfilgrastim within 1 cycle of R-CHOP were analyzed. Results: In terms of clinical efficacy, trough level of ANC and days to ANC recovery showed statistical significance. The median trough levels of ANC with administration of filgrastim and pegfilgrastim were 0.18 and 1.94 (p = 0.021), respectively, and the median durations of ANC recovery to baseline value were 5.5 days and 2 days (p = 0.023), respectively. For the median days of ANC under 50% of baseline value, days of ANC under 90% of baseline value, days of ANC less than $0.5{\times}10^9cells/L$, and difference of peak and trough level of ANC during 1 cycle of R-CHOP, the pegfilgrastim group performed better than the filgrastim group. However the difference was not statistically significant. In terms of overall expense during 1 cycle of R-CHOP, pegfilgrastim is about 3.43 times more expensive than filgrastim. Conclusion: Pegfilgrastim is more efficient than filgrastim in terms of clinical efficacy. In terms of prices, pegfilgrastim is more expensive than filgrastim for patients, but it is more convenient in clinical use. Therefore, pegfilgrastim should be the preferred choice of G-CSF for neutropenic patients. Further comparative study of pegfilgrastim and filgrastim is needed.

• Progress in Medical Physics
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• v.26 no.4
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• pp.229-233
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• 2015

We retrospectively reviewed lung cancer patients who were treated with stereotactic ablative radiotherapy (SABR). We investigated the value of response evaluation after treatment by measuring the volume change of tumors on serial chest computed tomography (CT) examinations. The study included 11 consecutive patients with early-stage (T1-T2aN0M0) non-small cell lung cancer (NSCLC) who were treated with SABR. The median dose of SABR was 6,000 cGy (range 5,000~6,400) in five fractions. Sequential follow-up was performed with chest CT scans. Median follow-up time was 28 months. Radiologic measurement was performed on 51 CT scans with a median of 3 CT scans per patient. The median time to partial response ($T_{PR}$) was 3 months and median time to complete remission ($T_{CR}$) was 5 months. Overall response rate was 90.9% (10/11). Five patients had complete remission, five had partial response, and one patient developed progressive disease without response. On follow-up, three patients (27.2%) developed progressive disease after treatment. We evaluated the the response after SABR. Our data also showed the timing of response after SABR.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.981-984
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• 2005

Recently, filtering methods for attenuating noise while preserving image details are in progress actively. And SM(standard median) fille. showed a great performance for noise removal in impulse noise environment but, it caused edge cancellation error So, variable methods that modified SM(standard median)filter have been proposed, and CWM(center weighted median) filter is representative. Also, there are several methods to improve the efficiency based on min/max operation in term of preserving detail and filtering speed. In this paper, we managed a pixel corrupted by impulsive noise using min/max value of the surrounding band enclosing a pixel, and compared the efficiency with exiting methods in the simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.798-801
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• 2014

Nowadays, the demand for multimedia services has grown with the rapid evolution in the digital era. But due to external causes in the process of processing, transmitting and storing image data, the images are damaged. One of the major causes of such damage is known to be noise. Some of the most commonly used methods for removing noise are CWMF(center weighted median filter), A-TMF(alpha-trimmed mean filter) and AWMF(adaptive weighted median filter). However, these filters all leave a bit to be desired in removing noise in a complex noise environment. Therefore this paper suggest an image restoration filter algorithm that first judges the noise and sets a adjustment weight based on the median value and distance of the mask to remove the complex noise. For an objective analysis, the results were compared against existing methods and the PSNR(peak signal to noise ratio) was used as a reference.