• Journal of radiological science and technology
• /
• v.16 no.1
• /
• pp.67-80
• /
• 1993

Recently, a large number of new screen-film systems have become available for use in diagnostic radiology. These new screens are made of materials generally known as rare-earth phosphors which have high x-ray absorption and high x-ray to light conversion efficiency compared to calcium tungstate phosphors. The major advantage of these new systesms is reduction of patient exposure due to their high speed or high sensitivity. However, a system with excessively high speed can result in a significant degradation of radiographic image quality. Therefore, th speed is important parameters for users of these system. Our aim of in this was to determine accurately and precisely the absolute speed and relative speeds of both new and conventional screen-film system. We determined the absolute speed in condition of BRH phantom beam qulity and the relative speed were measured by a split-screen technique in condition of BRH and ANSI phantom beam qulity. The absolute and the relative speed were determined for 8 kinds of screen-4 kinds of film in regular system and 7 kinds of screen-7 kinds of film in ortho system. In this study we could know the New Rx, T-MAT G has the highest film speed, also know Green system's stndard deviation of relative speed larger than blue system. It was realized that there were no relationship between the absolute speed and the blue system. It was realized that there were no relationship between the absolute speed and the relative speed in ortho or regular system.

• 제어로봇시스템학회:학술대회논문집
• /
• 1987.10b
• /
• pp.150-154
• /
• 1987

A new mixed approximation method is proposed for the model reduction of high order linear and time-invariant dynamic systems. This method makes allowance for stability and feature retention simultaneously. After defining dominant frequency range which affects relative stability of systems, a part of denominator is obtained using the energy dispersion method and tests are obtained using dominant frequency response matching method. The proposed method reflects the characteristic of the original system more faithfully and guarantees absolute stability of the reduction model.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.45 no.1
• /
• pp.33-44
• /
• 2003

This study was conducted to estimate the design flood by the determination of best fitting order for LH-moments of the annual maximum series at fifteen watersheds. Using the LH-moment ratios and Kolmogorov-Smirnov test, the optimal regional probability distribution was identified to be the Generalized Extreme Value (GEV) in the first report of this project. Parameters of GEV distribution and flood flows of return period n years were derived by the methods of L, L1, L2, L3 and L4-moments. Frequency analysis of flood flow data generated by Monte Carlo simulation was performed by the methods of L, L1, L2, L3 and L4-moments using GEV distribution. Relative Root Mean Square Error. (RRMSE), Relative Bias (RBIAS) and Relative Efficiency (RE.) using methods of L, Ll , L2, L3 and L4-moments for GEV distribution were computed and compared with those resulting from Monte Carlo simulation. At almost all of the watersheds, the more the order of LH-moments and the return periods increased, the more RE became, while the less RRMSE and RBIAS became. The Absolute Relative Reduction (ARR) for the design flood was computed. The more the order of LH-moments increased, the less ARR of all applied watershed became It was confirmed that confidence efficiency of estimated design flood was increased as the order of LH-moments increased. Consequently, design floods for the appled watersheds were derived by the methods of L3 and L4-moments among LH-moments in view of high confidence efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.1
• /
• pp.385-405
• /
• 2019

High Efficiency Video Coding (HEVC) enables significantly improved compression performance relative to existing standards. However, the advance also requires high computational complexity. To accelerate the intra prediction mode decision, a minimum risk Bayesian classification framework is introduced. The classifier selects a small number of candidate modes to be evaluated by a rate-distortion optimization process using the sum of absolute Hadamard transformed difference (SATD). Moreover, the proposed method provides a loss factor that is a good trade-off model between computational complexity and coding efficiency. Experimental results show that the proposed method achieves a 31.54% average reduction in the encoding run time with a negligible coding loss of 0.93% BD-rate relative to HEVC test model 16.6 for the Intra_Main common test condition.

• Journal of Society of Preventive Korean Medicine
• /
• v.3 no.1
• /
• pp.157-172
• /
• 1999

This treatise, after review recent data on Oriental Medical toxicity, gets a conclusion on toxic concept of Oriental Medicine. 1. In the oriental medicine, the concept of toxic character contains propensity which disposition is inclined, and general meaning covered with the effect of a medicine, a side effect, formation of a medicine Besides, the concept diversely is used in the cause of a disease, names, symptoms, how to treat, medicines, prevention name, etc. 2. Every herbal drugs has toxic character. Levels of toxicity are nonexistence(無毒), existence(有毒), a little(小毒), always(常毒), serious(大毒), fatal toxic(劇毒), whose concepts in the Oriental Medicine are divided relative and absolute at the same time. 3. The examples of the fatal events by poisoning up to now are more than 400 cases(in China). 4. The factors of toxicity are the amount used unsuitably, the combination, directions, and interactions between western and oriental medicine, etc. The reduction of toxicity and how to detoxicate is several methods. The toxic science in Oriental Medicine based on the formation of oriental medicine present principles which use herbal drugs safely and availablely, utilizing th dispositions and efficiencies. It has positive, learning spirits which prevent abuse of oriental medicine, and which exactly diagnose and use the herbal drugs in the treatment with absolute toxic medicine. However, I think that scientific, positive experimental research is necessary to setup dose-response relation, be in relative quantity of toxic character, operate on the reactive mechanism exactly.

• Journal of Preventive Medicine and Public Health
• /
• v.55 no.4
• /
• pp.389-397
• /
• 2022

Objectives: This study examined the effect of out-of-pocket (OOP) payment reduction on the potential utilization of low-value magnetic resonance imaging (MRI) across income groups. Methods: We conducted an experimental vignette survey using a proportional quota-based sample of individuals in Korea (n=1229). In two hypothetical vignettes, participants were asked whether they would be willing to use MRI if they had uncomplicated headache and non-specific low back pain, each before and after OOP payment reduction. To account for the possible role of physician inducement, half of the participants were initially presented with vignettes that included a physician recommendation for low-value care. The predicted probability, slope index of inequality (SII), and relative index of inequality (RII) were calculated using logistic regression. Results: Before OOP payment reduction, the lowest income quintile was least likely to use low-value MRI regardless of physician inducement (36.7-49.6% for low back pain; 30.5-39.3% for headache). After OOP payment reduction, almost all individuals in each income quintile were willing to use low-value MRI (89.8-98.0% for low back pain; 78.1-90.3% for headache). Absolute and relative inequalities concerning potential low-value MRI utilization decreased after OOP payments were reduced, even without physician inducement (SII: from 8.15 to 5.37%, RII: from 1.20 to 1.06 for low back pain; SII: from 6.99 to 0.83%, RII: from 1.20 to 1.01 for headache). Conclusions: OOP payment reduction for MRI has the potential to increase low-value care utilization among all income groups while decreasing inequality in low-value care utilization.

• Nuclear Engineering and Technology
• /
• v.50 no.3
• /
• pp.462-469
• /
• 2018

The background spectrum of a $3^{{\prime}{\prime}}{\times}3^{{\prime}{\prime}}$ NaI(Tl) well-type scintillation SILENA detector was measured without shielding, in 6 cm thick lead shielding, and with 2 mm thick electrolytic copper covering the detector inside the lead shielding. The relative remaining background of the lead shield lined with copper was found to be ideal for low-level environmental radioactive spectroscopy. The background total count rate in the (20-2160 KeV) was reduced 28.7 times by the lead and 29 times by the Cu + Pb shielding. The effective reduction of background (1.04) by the copper mainly appeared in the energy range from X-ray up to 500 KeV, while for the total energy range the ratio is 1.01 relative to the lead only. In addition, a strong relation between the full-energy peak absolute efficiency and the detector well height was found using gamma-ray isotropic radiation point sources placed inside the detector well. The full-energy peak efficiency at a midpoint of the well (at 2.5 cm) is three times greater than that on the detector surface. The energy calibrations and the resolution of any single energy line are independent of the locations of the gamma source inside or outside of the well.

• Journal of Wellbeing Management and Applied Psychology
• /
• v.6 no.3
• /
• pp.13-18
• /
• 2023

Purpose: The small-scale environmental impact assessment has been in operation since its implementation in August 2000, and is a system that meets the purpose of sustainable development in consideration of the environment in areas requiring conservation. However, when preparing a small environmental impact assessment report, the contents of the reduction measures are too qualitative, or reports are prepared to simply list the compliance stipulated by individual laws, and the contents of consultations prepared by consultative agencies and review agencies are not much different. In addition, the direction of consultation on development projects for similar locations of the same project type is frequently changed by reflecting the subjective judgment of the consultative officer of the Ministry of Environment (Environment Agency). Therefore, this study attempted to improve the establishment of measures to reduce the existing simple listing of qualitative contents and the inconsistent presentation of review opinions by consultative agencies and review agencies. Research design, data and methodology: The research method extracted absolute evaluation items and relative evaluation items among small environmental impact assessment items, analyzed and presented detailed items, and prepared a distribution table for each section according to the details of the relative evaluation items, and presented them as a table. Results: This study was conducted to derive uniform results with objective indicators in the preparation and consultation process of a small-scale environmental impact assessment. Conclusions: Once a quantitative evaluation is established, the consultant can objectively determine and process the environmental impact.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.5B
• /
• pp.267-272
• /
• 2012

To reduce the flood risk caused by unexpected heavy rainfall, many prediction methods for flood have been developed. A major constituent of flood prediction is an accurate rainfall estimation which is an input of hydrologic models. In this study, a regional-scale weather model which can provide relatively longer lead time for flood mitigation compared to the Nowcasting based on radar system will be introduced and applied to the Chongmi river basin located in central part of South Korea. The duration of application of a regional weather model is from July 11 to July 23 in 2006. The estimated rainfall amounts were compared with observations from rain gauges (Sangkeuk, Samjook, and Sulsung). For this rainfall event at Chongmi river basin, Thomson and Kain-Frisch Schemes for microphysics and cumulus parameterization, respectively, were selected as optimal physical conditions to present rainfall fall amount in terms of Mean Absolute Relative Errors (MARE>0.45).

• Korean Journal of Social Welfare
• /
• v.56 no.4
• /
• pp.57-78
• /
• 2004

The economic crisis in $1997{\sim}1998$ caused massive unemployment and unprecedentedly increased the number of the poor in Korea. As many unemployed families fell into poverty, the poverty rate skyrocketed to higher than 10 percent. Not later than 2000, unemployment late got back to normal and real average income among urban households approached to the income level prior to the economic crisis. Although the economic crisis has been passed through, poverty was not decreased to the low level prior to the crisis by 2000. Why does it remain high? This study attempts to provide an answer to this question by analysing the poverty trend over the 1990s. Data come from the National Survey of Household Income and Expenditures 1991, 1996, and 20001. Results show that poverty was rapidly reduced in the first half period of the 1990s. This reduction in poverty is largely explained by steady and rapid economic growth. Modest improvement in income inequality also contributed. In contrast, the poverty rate considerably increased in the latter half of the 1990s. Average income was not fully recovered to its prior level, which reflected the economic crisis and the subsequent economic stagnation. Worsened income inequality led to higher poverty rate too. In addition, demographic changes increased the share of economically vulnerable types of families, such as families headed by single parents and the elderly. The most significant factor in explaining the higher poverty rate was extended income differential among non-elderly adults, while the next was the increased number of the elderly families. Yet, findings a little differ depending on which concepts of poverty to adopt. In the analyses based on the concept of absolute poverty, economic growth the most significantly affected the poverty trends in the 1999s. Changes in income inequality played the most important role in explaining the trend in relative poverty. Adopting the concepts of quasi-absolute poverty, which is preferred in this study, results show that rapid economic growth significantly reduced poverty in the first half of the 1990s and both worsened income inequality and stagnated economic growth increased poverty in the latter 1990s.