• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.239-245
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• 2010

There are 11,811 LWR spent fuels stored at reactor sites, as of 2009. Source terms based on reference spent fuel which represents entire spent fuels with bounding values in the aspect of source term has been applied to a design of nuclear installations, instead of those which are generated by weighting respective source term for each spent fuel. Simplified regression models to estimate total decay heat, radioactivity, and ingestion hazard index for spent fuel from Westinghouse-type reactors were developed in this study, because it can be used as a fundamental model for weighting source term for respective spent fuel to exclude conservativeness in source terms. It was found that the estimated source terms agreed with calculated value from ORIGEN-ARP within 5%. It was also found that the conservativeness could be excluded if the weight source terms were used as reference source term in the design. Therefore, it is expected that the developed regression model could be widely used in the conceptual design process of nuclear facilities related with storage and disposal of spent nuclear fuel.

• Resources Recycling
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• v.16 no.4
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• pp.27-32
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• 2007

The characteristics of fluorine removal from wastewater have been investigated by precipitation method using calcium as a precipitant for the purpose of the reuse of treated wastewater. In the conditions of 10 mM of the initial concentration of fluorine and pH 4, the precipitation of fluorine was rapidly progressed within a few minutes after the precipitant was added and the precipitation of fluorine was observed to follow a second order reaction. Also, as the addition of precipitant was increased, the reaction rate constant of fluorine precipitation was found to rise. Postulating that the maximum fluorine removal was attained at pH 4, about 70% of fluorine was precipitated compared with the maximum removal when 10 times of equivalent amount of calcium was employed at pH 2 and the fluorine removal was about 96% compared with its maximum value at pH 3 under the same addition of precipitant. The fluorine precipitation reaction was found to be endothermic and the coexistence of $SiF_6{^{2-}}$ with fluorine resulted in its less removal. Finally, the isoelectric point of the precipitate was examined to be ca. pH 5.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.627-639
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• 2014

Accurate correction of surface effect from back scattered solar radiance is one of key issue to retrieve aerosol information from satellite measurements. In this study, two different methods are applied to retrieve surface reflectance by using single visible channel measurement from meteorological imager onboard COMS. The first one is minimum reflectance method, which composes the minimum value among previously measured reflectances at each pixel over a certain search window length. This method assumes that the darkest pixel corresponds to the aerosol-free condition, and deduces surface reflectance by correcting atmospheric scattering from the measured visible reflectance. The second method, named as the "atmospheric correction method" in this study, estimates the result by correcting aerosol and atmospheric scattering with ground-based observation of aerosol optical properties. The purpose of this study is to investigate the retrieval accuracy of the widelyused minimum reflectance method. Also, the retrieval error caused by the loading of background aerosol is mainly estimated. The comparison between surface reflectances retrieved from the two methods shows good agreement with the correlation coefficient of 0.87. However, the results from the minimum reflectance method are slightly overestimated than the values from the atmospheric correction method when surface reflectance is lower than 0.2. The average difference between the two results is 0.012 without the background aerosol correction. By considering the background aerosol effect, however, the difference is reduced to 0.010.

• Journal of Korea Water Resources Association
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• v.43 no.8
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• pp.733-745
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• 2010

Seasonality of hydrologic extreme variable is a significant element from a water resources managemental point of view. It is closely related with various fields such as dam operation, flood control, irrigation water management, and so on. Hydrological frequency analysis conjunction with partial duration series rather than block maxima, offers benefits that include data expansion, analysis of seasonality and occurrence. In this study, nonstationary frequency analysis based on the Bayesian model has been suggested which effectively linked with advantage of POT (peaks over threshold) analysis that contains seasonality information. A selected threshold that the value of upper 98% among the 24 hours duration rainfall was applied to extract POT series at Seoul station, and goodness-fit-test of selected GEV distribution has been examined through graphical representation. Seasonal variation of location and scale parameter ($\mu$ and $\sigma$) of GEV distribution were represented by Fourier series, and the posterior distributions were estimated by Bayesian Markov Chain Monte Carlo simulation. The design rainfall estimated by GEV quantile function and derived posterior distribution for the Fourier coefficients, were illustrated with a wide range of return periods. The nonstationary frequency analysis considering seasonality can reasonably reproduce underlying extreme distribution and simultaneously provide a full annual cycle of the design rainfall as well.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.65-75
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• 2010

When the cost-benefit analysis is applied for social discount rate(SDR), the choice of SDR to be used in analysis is critical. One of the important issues when public investment project evaluate what is the SDR theory, so there have studied about SDR and no exact answer it so far. In this study, there are three of SDR theories that be estimated social time preference rate, social investment returns and the weighted average method from 1990s, 2000 to 2003 and 2004 to 2008.. First, social time preference method computes consumer's interest rate and the model of Pearce and Ulph(1999). Second, social investment returns method computes private returns of capital. Third, the weighted average method computes the model of Squire, L., Herman G. van der Tak(1975) and private consumption expense and the private investment expense. SDR is estimated in the rage between 2.4% and 3.9% from 2004 to 2008. It is not appropriate that the interest rate was unstable. But it is consider for social equity from present to future generations. Considering this things, downward need to the value of current SDR 5.5%.

• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.71-78
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• 2013

This paper investigated the influences of ramp traffic flow on the lane utilization for signalized intersection approaches which are adjacent to an off-ramp-street junction. The statistical test showed a correlation between lane utilization and the ramp traffic flow. As the ramp traffic flow increases, the left lanes are less utilized and the right lanes are more utilized. The lane utilization factors are calculated by applying traffic data collected from the Seoul Metropolitan area. The utilization factors are 1.113 for 2 lanes, 1.124 for 3 lanes, and 1.131 for 4 lanes. The lane utilization factors proposed in the paper show higher values than those in current Korea Highway Capacity Manual (KHCM) under the conditions that the number of lanes is 2 or 3. However, the lane utilization factor for 4 lanes in the paper shows lower value than in KHCM. The ramp traffic flow causes more utilization of the right lanes than at normal signalized intersections and the extent gets larger as the number of lanes decreases. Based on the results of the paper, the lane utilization factors at signalized intersection approaches should be revised and reasonable capacity should be recalculated if the signalized intersection is adjacent to an off-ramp-street junction.

• Journal of Preventive Medicine and Public Health
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• v.29 no.4 s.55
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• pp.831-842
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• 1996

Demand for high quality medical care has recently been increasing in step with high level of income and education. Patients prefer the use of large general hospitals to small community hospitals. Large hospitals, usually located at urban area, expand their capacities to cope with the increasing demand, therefore, they easily secure revenue necessary for growth and development of hospitals. However, small community hospitals are facing with serious financial difficulties caused from the reduction of patients in one hand and the inflation of cost in another. If small rural hospitals were closed, the closure would have negative impacts on local economies in addition to the decrease in access to medical care. Community leaders should have an insight on the contribution of community hospitals to local economies. They could make a rational decision on the hospital closure only with the understanding of hospital's contribution to the community. This study is designed to develop an economic model to estimate the contribution of rural hospital to local economies, and also to apply this model with a specific hospital. The contribution of a hospital to local economies consists of two elements, direct effect and multiplier effects. The direct impacts include hospital's local purchasing power, employee's local purchasing power, and the consumption of patients coming from outside the community. The direct impact induces multiplication effect in the local economy. The seed money invested to other industries grows through economic activities in the region. This study estimated the direct effect with the data of expenditure of the case hospital. The total effect was calculated by multiplied the direct effect with a multiplier. The multiplier was drown from the ratio of marginal propensity of income and expenditure. Beside the estimation of the total impacts, the economic effect from the external resources was also analyzed by the use of the ratio of patients coming outside the region. The results are as follows. 1. The direct economic contribution of the hospital to the local economy is 1,104 million won. 2. The value of multiplier in the region is 2.976. 3. The total economic effect is 3,286 million won, and the multiplication effect is 2,182 million won. 4. The economic contribution from the external resources is 245 million won which is 7.5% of the total economic effect.

• The Journal of Korean Medical History
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• v.25 no.2
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• pp.63-96
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• 2012

The PingMaiFa chapter, which is the second chapter of SongBon ShangHanLun, is the scholarly description(專論) of the pulse and pathological mechanism but has not been studied and published yet. This study is about article 1-13 which is the first part of The PingMaiFa chapter. We compared the original texts within the editions, comparing and analyzing the annotations of successive dynastic medical group. The articles of The SongBon ShangHanLun PingMaiFa chapter 1-13 is consisted as is shown: article 1 states about the general features of normal pulse (平脈) and its physiological mechanism and the morbid pulses (病脈) caused by wind, cold, retained fluid, pain and heat vexation, article 1,10 state about the normal pulses of Five viscera (lung, heart, spleen, liver and kidney) and their manipulations in pulse taking, article 2 states about the differentiations of deficiency and excess syndrome according to pulse conditions, article 3, 4 state about the estimation of good prognoses and a factitious disorder by the combination of pulses and symptoms, article 6 states about Latent qi (伏氣) and its diagnostic features, article 5 states about inspection and listening examination as co-diagnostic methods of the pulse diagnosis, article 7, 8, 9 state that the emotions, such as fear and shame, and the dietary are important factors to consider for making diagnosis, article 11 states about the overwhelming pulse (相乘脈) which indicates the abnormal correlations between five phases and appears in four patterns as the dissolute(縱), the unrighteous(橫), the unfavorable(逆) and the favorable(順), article 12 states about 6 harmful pulses(殘賊脈), which are string-like pulse(弦脈), tight pulse(緊脈), floating pulse(浮脈), slippery pulse(滑脈), sunken pulse(沈脈), rough pulse(澁脈), article 13 states about "JaeGoe"(災怪) which is an unexpected response after treatment and it comes because of the formulas that had before. Throughout all these articles, The PingMaiFa chapter not only offers great value for Pulse-taking diagnosis, but also leads to a better understanding of clinical applications.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.2
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• pp.97-107
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• 2017

This study is the second investigation on the steady flow characteristics of an SI engine with a semi-edge combustion chamber as a function of the port shape with varying evaluation positions. For this purpose, the planar velocity profiles were measured from 1.75B, 1.75 times of bore position apart from the bottom of head, to 6.00B positions using particle - image velocimetry. The flow patterns were examined with both a straight and a helical port. The velocity profiles, streamlines, and centers of swirl were almost the same at the same valve lift regardless of the measuring position, which is quite different from the case of the pent-roof combustion chamber. All the eccentricity values of the straight port were out of distortion criterion 0.15 through the lifts and the position. However, the values of the helical port exceeded the distortion criterion by up to 4 mm lift, but decreased rapidly above the 3.00B position and the 5 mm lift. There always existed a relative offset effect in the evaluation of the swirl coefficient using the PIV method due to the difference of the ideal impulse swirl meter velocity profile assumption, except for the cylinder-center-base estimation that was below 4 mm of the straight port. Finally, it was concluded that taking the center as an evaluation basis and the assumption about the axial velocity profile did not have any qualitative effect on swirl evaluation, but affected the value owing to the detailed profile.

• Journal of Korea Multimedia Society
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• v.5 no.4
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• pp.458-467
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• 2002

There has been proposed many simplification algorithms for effectively decreasing large-volumed polygonal surface data. These algorithms apply their own cost function for collapse to one of fundamental simplification unit, such as vertex, edge and triangle, and minimize the simplification error occurred in each simplification steps. Most of cost functions adopted in existing works use the error estimation method based on distance optimization. Unfortunately, it is hard to define the local characteristics of surface data using distance factor alone, which is basically scalar component. Therefore, the algorithms cannot preserve the characteristic features in surface areas with high curvature and, consequently, loss the detailed shape of original mesh in high simplification ratio. In this paper, we consider the vector component, such as surface orientation, as one of factors for cost function. The surface orientation is independent upon scalar component, distance value. This means that we can reconsider whether or not to preserve them as the amount of vector component, although they are elements with low scalar values. In addition, we develop a simplification algorithm based on half-edge collapse manner, which use the proposed cost function as the criterion for removing elements. In half-edge collapse, using one of endpoints in the edge represents a new vertex after collapse operation. The approach is memory efficient and effectively applicable to the rendering system requiring real-time transmission of large-volumed surface data.