• The KIPS Transactions:PartA
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• v.12A no.5 s.95
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• pp.413-420
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• 2005

The Newton-Raphson iterative algorithm for finding a floating point reciprocal square mot calculates it by performing a fixed number of multiplications. In this paper, a variable latency Newton-Raphson's reciprocal square root algorithm is proposed that performs multiplications a variable number of times until the error becomes smaller than a given value. To find the rediprocal square root of a floating point number F, the algorithm repeats the following operations: '$X_{i+1}=\frac{{X_i}(3-e_r-{FX_i}^2)}{2}$, $i\in{0,1,2,{\ldots}n-1}$' with the initial value is '$X_0=\frac{1}{\sqrt{F}}{\pm}e_0$'. The bits to the right of p fractional bits in intermediate multiplication results are truncated and this truncation error is less than '$e_r=2^{-p}$'. The value of p is 28 for the single precision floating point, and 58 for the double precision floating point. Let '$X_i=\frac{1}{\sqrt{F}}{\pm}e_i$, there is '$X_{i+1}=\frac{1}{\sqrt{F}}-e_{i+1}$, where '$e_{i+1}{<}\frac{3{\sqrt{F}}{{e_i}^2}}{2}{\mp}\frac{{Fe_i}^3}{2}+2e_r$'. If '$|\frac{\sqrt{3-e_r-{FX_i}^2}}{2}-1|<2^{\frac{\sqrt{-p}{2}}}$' is true, '$e_{i+1}<8e_r$' is less than the smallest number which is representable by floating point number. So, $X_{i+1}$ is approximate to '$\frac{1}{\sqrt{F}}$. Since the number of multiplications performed by the proposed algorithm is dependent on the input values, the average number of multiplications Per an operation is derived from many reciprocal square root tables ($X_0=\frac{1}{\sqrt{F}}{\pm}e_0$) with varying sizes. The superiority of this algorithm is proved by comparing this average number with the fixed number of multiplications of the conventional algorithm. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a reciprocal square root unit. Also, it can be used to construct optimized approximate reciprocal square root tables. The results of this paper can be applied to many areas that utilize floating point numbers, such as digital signal processing, computer graphics, multimedia, scientific computing, etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.87-95
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• 2016

This study examined the characteristics of the hourly demand of city gas in Korea and proposed multiple regression models to obtain precise estimates of the hourly demand of city gas. Forecasting the hourly demand of city gas with accuracy is essential in terms of safety and cost. If underestimated, the pipeline pressure needs to be increased sharply to meet the demand, when safety matters. In the opposite case, unnecessary inventory and operation costs are incurred. Data analysis showed that the hourly demand of city gas has a very high autocorrelation and that the 24-hour demand pattern of a day follows the previous 24-hour demand pattern of the same day. That is, there is a weekly cycle pattern. In addition, some conditions that temperature affects the hourly demand level were found. That is, the absolute value of the correlation coefficient between the hourly demand and temperature is about 0.853 on average, while the absolute value of the correlation coefficient on a specific day improves to 0.861 at worst and 0.965 at best. Based on this analysis, this paper proposes a multiple regression model incorporating the hourly demand ahead of 24 hours and the hourly demand ahead of 168 hours, and another multiple regression model with temperature as an additional independent variable. To show the performance of the proposed models, computational experiments were carried out using real data of the domestic city gas demand from 2009 to 2013. The test results showed that the first regression model exhibits a forecasting accuracy of MAPE (Mean Absolute Percentage Error) around 4.5% over the past five years from 2009 to 2013, while the second regression model exhibits 5.13% of MAPE for the same period.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.1 no.1
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• pp.11-23
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• 2003

A study on the electrolytic dissolution of SUS-304 and Inconel-600 specimen was carried out in neutral salt electrolyte to evaluate the applicability of electrochemical decontamination process for recycle or self disposal with authorization of large amount of metallic wastes contaminated with uranium compounds generated by dismantling a retired uranium conversion plant in Korea. Although the best electrolytic dissolution performance for the specimens was observed in a Na2s04 electrolyte, a NaNO$_3$ neutral salt electrolyte, in which about 30% for SUS-304 and the same for Inconel-600 in the weight loss was shown in comparison with that in a Na$_2$SO$_4$ solution, was selected as an electrolyte for the electrochemical decontamination of metallic wastes with the consideration on the surface of system components contacted with nitric acid and the compatibility with lagoon wastes generated during the facility operation. The effects of current density, electrolytic dissolution time, and concentration of NaNO$_3$ on the electrolytic dissolution of the specimens were investigated. On the basis of the results obtained through the basic inactive experiments, electrochemical decontamination tests using the specimens contaminated with uranium compounds such as UO$_2$, AUC (ammonium uranyl carbonate) and ADU (ammonium diuranate) taken from an uranium conversion facility were performed in 1M NaNO$_3$ solution with the current density or In mA/$\textrm{cm}^2$. it was verified that the electrochemical decontamination of the metallic wastes contaminated uranium compounds was quite successful in a NaNO$_3$ neutral salt electrolyte by reducing $\alpha$ and $\beta$ radioactivities below the level of self disposal within 10 minutes regardless of the type of contaminants and the degree of contamination.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.191-198
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• 1996

Amrinone is a non-glycosidic, non-adrenergic positive inotropic agent with peripheral and coronary vasodilator effect. It inhibits phosphodiesterase F-III, the cardiac cyclic-AMP specific phosphodiesterase, selectively and potently. In this study, the effects of IV administered amrinone and dopamine were compared in 40 patients who had open heart surgery. Amrinone was administered as a bolus of 1 5~2mglkg for several minutes, followed by continuous infusion at 5~1 Oug/kg/min. The hemodynamic measurements including heart rate, systolic and diastolic pressure, cardiac index, pulmonary wedge pressure, and systemic vascular resistance were recorded immediately for 12~24 hours awl 7th day following operation. In amrinone group, cardiac index increased from 3.73$\pm$1.39 L/min/m2 to 5.44$\pm$2.65 L/min/m2 at the time of posterative 48 hours (n=20, p< 0.05). The decrease in systemic vascular resistance from 1237.5 $\pm$ 637.7 dyne/sec/cm2 to 1000.8 $\pm$ 608.5 dyne/sec/cm2(p<0.05). In Dopamine group, the heart rate increased from 92.1 $\pm$ 13.0/min to 101.0 $\pm$ 13.1/min and the cardiac index decreased from 3.40 $\pm$ 0.50 L/min/m2 to 2.53 $\pm$ 1.15 L/min/m2 at the time of postoperative 12 hours(p<0.05). Systemic vascular resistance increased from 1058.5 $\pm$ 234.6 dyne/sec/cm2 to 1979.7 $\pm$ 759.2 dynelsec/cm2 The comparison of the hemodynamic effects of amrinone and dopamine, both drugs improved cardiac performance. But the administration of amrinone results in a higher cardiac index, diastolic blood pressure and lower systemic vascular resistance than those achieved with dopamine (p<0.05). The uniqueness of the action of amrinone on the heart and its sustained hemodynamic effect suggest it has clinical promise, pos operative care of cardiac surgery

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.110-120
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• 2005

For utilizing vitrification to treat low and intermediate level waste, industrial pilot plant was designed and constructed in October 1999 at Daejon, Korea through the joint research program among NETEC, MOBIS and SGN. More than 70 tests were performed on simulated IER, DAW etc. including key nuclide surrogate(Cs, Co); this plant has been shown to vitrify the target waste effectively and safely, however, some dust are generated from the HTF(High Temperature Filter) as a secondary waste. In case of long term operation, it is also concerned that pipe plugging can be occurred due to deposited dust in cooling pipe namely, connecting pipe between CCM(Cold Crucible Melter) and HTF. In this regard, we have developed the special complementary system of the off-gas treatment system to recycle the dust from HTF to CCM and to remove the interior dust of cooling pipe. Main concept of the dust recycling is to feed the dust to the CCM as a slurry state; this system is regarded as of an important position in the viewpoint of volume reduction, waste disposal cost and glass melt control in CCM. The role of DRS(Dust Recycling System) is to recycle the major glass components and key nuclides; this system is served to lower glass viscosity and increase waste solubility by recycling B, Na, Li components into glass melt and also to re-entrain and incorporate into glass melt like Cs, Co. Therefore dust recycling is helpful to control the molten glass; it is unnecessary to consider a separate dust treatment system like a cementation equipment. The effects of Dust Cleaner are to prevent the pipe plugging due to dust and to treat the deposited dust by raking the dust into CCM. During the pilot vitrification test, overall performance assessment was successfully performed; DRS and Dust Cleaner are found to be useful and effective for recycling the dust from HTF and also removing the dust in cooling pipe. The obtained operational data and operational experiences will be used as a basis of the commercial facility.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.3
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• pp.198-206
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• 1995

Baled silage making(BS) of selected forage crops was discussed during 1991-1993, to determine the best cutting time of the plants for BS production, BS yields and silage quality. Seven species of forage crops and pasture grasses(rye, barley, spring oat, Italian ryegrass, orchardgrass, alfalfa and grass-legume pasture mixtures) were harvested at different stage of growth from young plant to physiological maturity, and baled in a self constructed square baling chamber. Each bales, measured 90cm length, 60cm width and 50cm height, were wrapped with 0.05mrn thick polyethylene plastic film, and stored in stack silo. Each bales were weighed between 15-20 kg in dry matter basis. The effects of pre wilting and formic acid addition on the silage quality of young plant materials, which contained high water concentration, was also evaluated during the experiment. Rye plant including of barley and spring oat were evaluated as a good materials for baled silage making. Fodder rye produced high quality BS with a value of silage quality point 84(Flieg's point) when the plant harvested at stage of greatest dry matter accumulation by 12.64 tonha. The best quality BS of barley was obtained at stage of hard dough to yellow stage by 11.9 ton/ha dry matter yield and 81 point silage quality. Italian ryegrass and pasture grasses including of orchardgrass, alfalfa and grass-legume pasture mixtures procuced also high quality bale silage by harvesting at stage of late blooming. However pre witting operation and formic acid addition was required for BS production of grass materials because of high water contents. Water contents of Italian ryegrass and other pasture species ranged 18.9%(Italian) to 20.8%(alfalfa). Silage quality point of Italian BS harvested at late blooing was increased from 72 to 88 by 1/2-one day pre wilting and 0.3% formic acid treatment. Silage quality of young plant materials of rye and other forage crops, barley and spring oat were also improved markedly through the pre wilting treatment and formic acid addition.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.1
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• pp.55-71
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• 2013

By aircraft from Aviation regulations and institutional regulatory framework for ensuring the safety is secured. State-of-the-art aircraft, according to the type of development and diversification, modernization and new types of aircraft are operated. In particular, light aircraft and ultralight flying device such as the gyro-plane and unmanned flying devices is introduced a new device, and the device operates at these flight in accordance with the standards of the Aviation Act regulations may not occur often. Variety of light aircraft and ultra-light aircraft assembly, can be adapted for a person engaged in the business of aviation safety management and to perform the legal basis was established. Depending on the classification of newly introduced aircraft, the biggest change is the introduction of the concept of the LSA. In Korea, the various light aircraft are operating, but these aircraft range not clearly Aviation Regulations had difficulty in ensuring safety. This study examined the differences between international rules and regulations of Korea about the classification of aircraft. The LSA are included in aircraft categories internationally, but LSA will not be included in the aircraft categories, which is one of a range of powered flight device exists in Korea Aviation Act. Limit for maximum continuous power speed in a LSA, it is a limit on the right of the people who want using the high-performance plane. Also it is an international trend does not fit in, and is consistent with the intent of LSA manufacturer. Delete the content from a range of future aviation law revisions and light aircraft-related provisions to limit the maximum continuous power speed is considered to be suitable for the purpose of introducing the light aircraft industry. The laws and regulations set up in order to ensure the safety of ultralight aircraft categories existing in ultralight aircraft that exceeds the purpose of the introduction of LSA technology development at home and abroad, and is intended to reflect. These standards complement of aircraft operation is not appropriate for the situation unless the country is difficult to ensure the safety of operations. Also developed in other countries, the introduction of aircraft operating in the country, so many problems occur early revision is required.

• Macromolecular Research
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• v.16 no.7
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• pp.575-585
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• 2008

There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.762-770
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• 2005

Adsorption and biodegradation performance of chlorinated by-products such as trihalomethanes(THMs) and haloacetic acids(HAA5) on granular activated carbon were evaluated in this study. The coconut-based activated carbon was found more effective than others in adsorption of THMs due to larger pore volume of less than $20{\AA}$. The wood-based activated carbon was less effective than coconut- and coal-based activated carbon in adsorption nevertheless having larger pore volume and specific surface area than others. The maximum adsorption capacity(X/M) of coconut-based carbon for THMS was 1.1-1.5 times larger than coal based carbon and 14.1-31.4 times larger than wood based activated carbons. Activated carbon usage rate(CUR) of coconut-, coal- and wood-based activated carbons for chloroform were 9.4, 11.2 and 38 g/day respectively. In the evaluation of adsorption isotherm of THM species for coconut-, coal- and wood-based activated carbons, k value of chloroform was the lowest in the THM species, It menas that chloroform is difficult to remove by activated carbon adsorption. and BDCM, CDBM, bromoform are in the succeeding order of adsorption. In the evaluation of biodegradation rate, mean biodegradation rate was chloroform 7%, BDCM 5%, CDBM 4% and bromoform 3%, respectively THMs are difficult materials to be biodegraded. In the evaluation of characteristics of adsorption and biodegradation for HAA5 species, HAA5 species appear to be removed effectively by activated carbon. Most of the HAA5 are adsorbed at the beginning of operation periods and HAA5 except TCAA were almost biodegraded from bed volume of 2,000 and more than 90 percent of biodegradation of TCAA was started from bed volume around 4,000 and after that biodegradation rate was increased with increasing bed volume.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1016-1023
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• 2006

The water content of dewatered cake produced from belt press dewatering equipment was about 75 wt% which was some high to handle it, so the equipment contained a limit at the economical and environmental aspect. The thermal dewatering equipment built as an alternative to overcome several problems was set up at the sludge treatment field and estimated some feasibility as comparison with the dewatering performance of belt press. First, dewatering properties of waterworks sludge was analyzed by monthly. The sludge of a water shortage season contained a high organic content which led to be difficult to dewater the cake, the other side the sludge of rainwater season was ease to dewater because of low organic content. According to the results to analysis the water content of dewatered cake produced from two equipments on the base of the seasonal dewatering properties, the water content of dewatered cake produced from thermal dewatering for sludge of water shortage season was $41.6{\sim}48.3$ wt% and $71{\sim}84$ wt% from belt press. In the case of rainwater season, the water content of dewatered cake produced from thermal dewatering was $34{\sim}37.7$ wt% and $57{\sim}70$ wt% from belt press. It was understood that thereduction of water content of cake by thermal dewatering was larger than belt press. The economical aspect for two equipments was evaluated on considering the reduction of cake treatment amount as the decrease of water content of cake. When putting the cost index of thermal dewatering into 100, belt press was 121. This meant that thermal dewater was more economical than belt press by about 20% in the side of construction and operation. In conclusion, thermal dewatering equipment was estimated by producing the low water content dewatered cake as well as being operated with low coat.