• Journal of Energy Engineering
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• v.29 no.1
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• pp.63-74
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• 2020

The Kori-Unit 1 nuclear power plant, which is scheduled for decommissioning after permanent shutdown, is expected to generate a large amount of various types of radioactive waste during decommissioning process. For concrete radioactive waste, which is expected to occupy the most amount, it is important to analyze the current waste disposal status and legal limitations and to prepare an appropriate and efficient disposal method. Concrete radioactive waste is waste of various levels, of which the clearance level is bioshield concrete. In this paper, clearance radioactive waste safety evaluation was performed using the RESRAD code, which is a safety evaluation code, based on the activation evaluation results for the wastes with the clearance level. The clearance scenario of the target radioactive waste was selected and the individual's exposure dose was calculated at the time of clearance to determine whether the clearance criteria limit prescribed by the Nuclear Safety Act was satisfied. As a result of the evaluation, the results showed significantly lower results and satisfied the criteria value. Based on the results of this clearance safety assessment, the appropriate disposal method for bioshield concrete, which are the clearance wastes of subject of deregulation, was suggested.

• YAKHAK HOEJI
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• v.29 no.6
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• pp.362-366
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• 1985

These paper was attempted to investigate the mechanism of increased blood level of sulfisomidine by cimetidine pretreatment pharmacokinetically. Especially, effect of cimetidine pretreatment on both renal clearance and biliary clearance of sulfisomidine was studied in rabbits. The results are as follows. The blood level of sulfisomidine administered intravenously in dose of 25mg/kg was elevated significantly by cimetidine pretreatment. Relative bioavailability and biological half-life were increased significantly by cimetidine pretreatment. Overall elimination rate constant ($betha$) and distribution rate constant ($K_{13}$) of sulfisomidine were decreased significantly by cimetidine pretreatment. The renal and biliary clearance of sulfisomidine were decreased significantly compared with those of control rabbits by cimetidine pretreatment. The results may be also related to the inhibition of sulfisomidine metabolism enzyme activity or reduction of blood flow in the liver.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.395-398
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• 2009

Currently, a new generation of ducted fan UAVs (Unmanned Aerial Vehicles) is under development for a wide range of inspection, investigation and combat missions as well as for a variety of civil roles like traffic monitoring, meteorological studies, hazard mitigation etc. The current study presents extensive results obtained experimentally in order to investigate the tip clearance effects on performance characteristics of a ducted fan for small UAV systems. Three ducted fans having different tip clearance gap and with same rotor size were examined under three different yawed conditions of calibrated slanted hot-wire probe. Three dimensional velocity flow fields were measured from hub to tip at outlet of the ducted fan. The analysis of data were done by PLEAT (Phase locked Ensemble Averaging Technique) and three non-linear differential equations were solved simultaneously by using Newton -Rhapson numerical method. Flow field characteristics such as tip vortex and secondary flow were confirmed through axial, radial and tangential velocity contour plots. At the same time, the effects of tip clearance on axial thrust and input power were also investigated by using wind tunnel measurement system. For enhancing the performance of ducted fan, tip clearance level should be as small as possible.

• The Korean Journal of Nuclear Medicine
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• v.3 no.2
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• pp.49-54
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• 1969

The present study has been undertaken to analyze scan manifestations in obstructive jaundice. Scan changes were cprrelated with the duration of jaundice. In addition, clearance rates of trace dose of colloidal radiogold were assessed in each case. The materials were consisted of 19 cases with surgically and/or histopathlogically verified obstructive jaundice from various causes including common duct stone, empyema of the gall bladder and carcinoma of the pancreas head etc. Blood clearance rates of colloidal $^{198}Au$ were determined after the injection of 8 uCi by simple geometrical drawing of recorded strip charts. Scan was performed following additional injection of the same radiogold. In 16 out of 19 cases, the scan revealed rather typical "arborifrom" mottlings around the porta hepatis. The intensity and appearance of such mottlings on the scan was related with the duration of jaundice and level of serum bilirubin and alkaline phosphatase. The blood clearance rates remained to be within normal range in 74 percent of the patients. In the remaining 26 percent, clearance rates ranged between 4.1 and 6 minutes. It is concluded that the association of "arboriform" mottlings and normal or mildly delayed clearance rates in the patients with jaundice is characteristic of obstructive changes in the biliary system.

• Industrial Engineering and Management Systems
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• v.11 no.1
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• pp.30-38
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• 2012

This paper discusses a clearance pricing on daily perishable products considering a reference price of consumers. The daily perishable products are sometimes sold at a discount price before closing time to stimulate demand when the number of unsold products is more than initially envisioned. The discount pricing results both in an increase of the revenue of the day and in a decrease of the disposal cost. The discounting, however, also declines a reference price of consumers which is a mental price and serves as an anchor price to judge if a current sales price is loss or gain for the consumers. An excess discounting decreases the demand for the products sold at a regular price in the future and diminishes long-term profit. This study conducts a mathematical analysis on the clearance pricing problem for a single period with stochastic variations both on demand and on the inventory level at clearance time. The expected profit function especially depends on the response of consumers to the clearing price against their reference prices. A procedure is proposed to derive an optimal clearance price when consumers are loss-neutral. A sufficient condition is shown to obtain an optimal price for loss-averse and loss-seeking consumers by an analogous procedure.

• Nuclear industry
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• v.20 no.6 s.208
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• pp.55-59
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• 2000

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.381-386
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• 2010

This study examined the changes in the walking pattern during level walking under low illumination conditions. Fourteen male subjects ($22.1{\pm}2.21$ years, $174{\pm}3.74\;cm$, $68.86{\pm}10.81\;kg$) with normal vision and no disabilities were enrolled in this study. All experiments were performed on a level walkway with three conditions: normal walking (preferred & low speed) and walking with low illumination. 3D motion capturing system was used for acquisition and analysis of the walking motion data with a sampling frequency of 120Hz. The walking speed, normalized jerk(NJ) at the center of mass(COM), wrist and heel, knee and elbow joint angle, ratio of the knee joint angle to elbow joint angle and the toe clearance on stance phase were used to compare the differences in walking pattern between the two illumination conditions, The results showed that the walking speed and joint angles decreased in low illumination, whereas the NJ and toe minimum clearance increased. In low illumination, most variables were similar to effects of low speed walking, but toe clearance was different from the effects of low speed. These results can be used as primary data for examining the changes in the level walking pattern of young adults under low illumination. Further study will be needed to compare these results in young adults with those in the elderly.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.60-67
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• 2004

The exposure dose form recycling of a large amount of the steel scrap from the KRR-1＆2 decommissioning activities was evaluated, and also the clearance level(draft) was derived. The maximum individual dose and collective dose were evaluated by modifying internal dose conversion factor which was based on the concept of effective dose in ICRP 60, applied to the RESRAD-RECYCLE ver 3.06 computing code, IAEA Safety Series 111-P-1.1 and NUREG-1640 as the assessment tool. The result of assessment for individual dose and collective dose is 23.9 $\mu$Sv per year and 0.11 man$.$Sv per year respectively. The clearance levels were ultimately determined by extracting the most conservative value form the results of the generic assessment and specific assessment methodologies. The result of clearance level for radionuclides( $Co^{60}$ , C $s^{l37}$) is less than 1.14${\times}$10$^{-1}$ Bq/g to comply with the clearance criterion(maximum individual dose : 10 $\mu$Sv per year, collective dose : 1 man$.$Sv per year) provided for Korea Atomic Energy Act and relevant regulations.s.

• Tuberculosis and Respiratory Diseases
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• v.45 no.3
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• pp.546-552
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• 1998

Background: Up to 90% of a theophylline dose is biotransformed, by interaction with one or more the variants of the cytochrome P-450 drug metabolism system. Macrolides affect the elimination of theophylline by influencing on the microsomal enzyme systems. We evaluate the effect of erythromycin and new macrolides on the serum theophylline level and clearance. Method : Subjects consisted of moderate asthmatic patients with normal renal and hepatic functions. All subjects were non-smokers and treated with oral theophylline 400 mg per day. We randomly assigned 53 patients into four groups. Each group was treated with one macrolides, the first group erythromycin(n:19, 500 mg bid), second roxithromycin (n:14. 150 mg bid), third clarithromycin (n:10, 250 mg bid) and fourth azithromycin(n:10, 250 mg bid). We measured the serum theophylline level and clearance at three intervals, at pretreatment, after the first and fourth week after receiving the following macrolides, erythromycin, roxithromycin and clarithromycin. When azithromycin was administered, the serum theophylline level was measured at pretreatment and after one week of treatment They were measured by a computerized program of Bayesian method. Results : When compared with control, erythromycin and roxithromycin-treated groups had a significantly elevated serum theophylline level and decreased clearance. However, there were no significant changes of the serum theophylline level and clearance in clarithromycin and azithromycin-treated groups. Conclusion : These results suggest that theophylline dose may need to be readjusted and have periodic drug monitoring when erythromycin or roxithromycin is administered concurrently.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.123-133
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• 2010

A statistical evaluation methodology was developed to determine the compliance of candidate waste stream with clearance criteria based upon distribution of radionuclide in a waste stream at a certain confidence level. For the cases where any information on the radionuclide distribution is not available, the relation between arithmetic mean of radioactivity concentration and its acceptable maximum standard deviation was demonstrated by applying widely-known Markov Inequality and One-side Chebyshev Inequality. The relations between arithmetic mean and its acceptable maximum standard deviation were newly derived for normally or lognormally distributed radionuclide in a waste stream, using probability density function, cumulative density function, and other statistical relations. The evaluation methodology was tested for a representative case at 95% of confidence level and 100 Bq/g of clearance level of radioactivity concentration, and then the acceptable range of standard deviation at a given arithmetic mean was quantitatively shown and compared, by varying the type of radionuclide distribution. Furthermore, it was statistically demonstrated that the allowable range of clearance can be expanded, even at the same confidence level, if information on the radionuclide distribution is available.