• Applied Biological Chemistry
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• v.15 no.2
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• pp.143-162
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• 1972

Based on the concentration of $^{40}K$ naturally occurring radioisotope of potassium, a method for the determination of total potassium in soils and plants was developed. The method was extended to evaluate the potassium supplying power of soils by taking the ratio of exchangeable potassium to total potassium $(K_{ex}/K_t)$, termed the potassium buffering capacity. Using this as index, it was observed that the release of potassium from soil fellows the from order reaction. A linear relationship was found between the potassium buffering capacity and the release constant of potassium or mica content of the clay. Similarly the potassium buffering capacity was also closely correlated with total uptake of potassium by rice plant. Hence it is concluded that the method for determining of the potassium buffering capacity could be veil applied to characterize the potassium availability of soils. The method for the determination of potassium is characterized by (1) The efficient measurement of the weak beta activity emissions from the samples, (2) identification of $^{40}K$, (3) calculation of total potassium content using the proportional constant of $^{40}K$ of samples to that of the standard. Difference in the potassium supplying power of soils due to soil types was also evaluated with the use of this technique. The degree of the potassium supplying power was in the order of soil types as red-yellow podzolic and lateric soils, basaltic materials(Rvd)> low-humic gley and alluvial soils, alluvial plains and food plains(Apa)> low-humic gley soils, nearly level to sloping local alluvial plains and slopes(Afb)> low-humic gley and alluvial soils, fluvio-marine plains (Fma).

• Economic and Environmental Geology
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• v.18 no.3
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• pp.239-246
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• 1985

Uranium-thorium separation technique from shallow sediment and ${\alpha}$-source electrodeposition technique are established in the present work, and uranium series disequilibrium dating method is applied to the quaternary piston core from Sangback-do, South Sea of Korean Peninsula. The age of the piston core (depth 200~300cm) sampled from Latitude $34^{\circ}06^{\prime}37^{{\prime}{\prime}}$, Longitude $127^{\circ}37^{\prime}37^{{\prime}{\prime}}$ was determined as ranging from $9.0{\pm}2.2$ to $22.9{\pm}3.3$ Ky B.P, i.e., Later Pleistocene, older than Holocene which was stratigraphically known in the previous study. The sedimentation rate in the area is regularly increased according to the depth of the sedimentation layer. Except a few split sections of the piston core the sedimentation rates are avarage 7.2cm/1,000 years. Where sedimentation layer is deeper, then sedimentation rate tend to be slower. It must be pointed in age calculation that initial $^{230}Th/^{234}U$ radioactivity ratio is much influenced when detrital material was introduced in the sample. The $^{230}Th/^{234}U$ activity ratio measured in the present work is 0.06 at $^{232}Th=0$, and this value shows higher analytical errors because of the low· radioactivity of $^{230}Th$ in the samples.

• Nuclear Engineering and Technology
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• v.39 no.5
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• pp.673-682
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• 2007

The contents of transuranic elements in high-burnup spent fuel samples were determined. The activity amounts of $^{238}Pu,\;^{239}Pu,\;^{240}Pu,\;^{241}Am,\;^{244}Cm\;and\;^{242}Cm$ were measured by alpha spectrometry using $^{242}Pu\;and\;^{243}Am$ as tracers, respectively. A spike addition method for $^{237}Np$ was established by an alpha and gamma spectrometry using $^{239}Np$ as a spike after the optimum conditions for the measurements of $^{237}Np\;and\;^{239}Np$, respectively, were obtained. A separation system using anion exchange chromatography and diethylhexylphosphoric acid extraction chromatography was applied for the separation of these elements. This method was applied to high-burnup spent nuclear fuel samples $(40{\sim}60GWD/MTU)$. The contents of the transuranic elements were compared with those by ORIGEN-2 code. Measurements and the calculations of the contents of the plutonium isotopes $^{238}Pu,\;^{239}Pu\;and\;^{240}Pu$ agreed to within 10% on average. The contents of $^{237}Np$ agreed to within approximately 5% except for one instance of a calculation, while those of $^{241}Am,\;^{244}Cm\;and\;^{242}Cm$ showed higher values by approximately 19%, 35% and 14% on average, respectively, compared to the calculations according to the burnup.

• Korean Journal of Clinical Pharmacy
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• v.18 no.1
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• pp.45-49
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• 2008

The goal of this research was to identify problems associated with the management of nutrition support team (NST) in hospitals in Korea. Management status of NST in the hospitals was surveyed over the phone or interviewed by visit during August 2007. NST in foreign countries was collected by reference search and websites in the internet. Survey analysis also was performed during March, 2007 with forty-one medical staff in a university hospital located in Jinju, Kyungsangnamdo. Korean Society for Parenteral and Enteral Nutrition (KSPEN) was organized in 2001 and currently has thirty-three member hospitals with on-site NST as of August, 2007. Most of the member hospitals were big hospitals with more than 500 beds and were organized within five years. The most significant problem identified was the shortage of nutrition specialists exclusively involved in the NST. Survey analysis revealed that more than half of medical staff prescribed parenteral nutrition based on their own nutrition requirement calculation rather than consultation with NST. It appears that status of NST management of hospitals in Korea are considered to be at beginner stage and therefore, needs more aggressive advertising activity to increase consultation usage by medical staff.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.293-299
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• 2004

Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence, numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristics of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends is towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a model of vehicle emission calculation by using real-time traffic data was studied. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It is possible that characteristics of hourly air pollutants emission rates is obtained from hourly traffic volume and speed. An emission rates model is allocated with a high resolution space by using geographic information system (GIS). Vehicle emission model was developed with a high resolution spatial, gridded and hourly emission rates.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.477-484
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• 2014

Caldera is a large depression commonly formed by collapse of the ground following explosive eruption of a large body of stored magma. On earth, calderas and caldera complexes range in size from kilometers to tens of kilometers. Historical eruptions associated with caldera collapse have led to huge fatalities in Indonesia as well as left global impacts. This study presents case study on calderas in Indonesia which resembles to Mount Baekdu located at the border of China and North Korea; in the perspectives of similar characteristics, principal hazard, recent symptom of volcanic activity and the threat if eruption occurs in the near future. Calculation by using weighted evaluation matrix for Mount Krakatau, Mount Tambora, Mount Ijen, Tengger Caldera, Mount Rinjani and Ranau Caldera were taken for the selection of a site for future case study.

• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.140-146
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• 2013

PURPOSE. The aim of this study was to investigate the destructive effects of biofilm formation and/or biocorrosive activity of 6 different oral microorganisms. MATERIALS AND METHODS. Three different heat polymerized acrylic resins (Ivocap Plus, Lucitone 550, QC 20) were used to prepare three different types of samples. Type "A" samples with "V" type notch was used to measure the fracture strength, "B" type to evaluate the surfaces with scanning electron microscopy and "C" type for quantitative biofilm assay. Development and calculation of biofilm covered surfaces on denture base materials were accomplished by SEM and quantitative biofilm assay. According to normality assumptions ANOVA or Kruskal-Wallis was selected for statistical analysis (${\alpha}$=0.05). RESULTS. Significant differences were obtained among the adhesion potential of 6 different microorganisms and there were significant differences among their adhesion onto 3 different denture base materials. Compared to the control groups after contamination with the microorganisms, the three point bending test values of denture base materials decreased significantly (P<.05); microorganisms diffused at least 52% of the denture base surface. The highest median quantitative biofilm value within all the denture base materials was obtained with P. aeruginosa on Lucitone 550. The type of denture base material did not alter the diffusion potential of the microorganisms significantly (P>.05). CONCLUSION. All the tested microorganisms had destructive effect over the structure and composition of the denture base materials.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3138-3147
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• 2000

EC(Electronic Commerce) which is cone the virtual space through Internet, has the advantage of time and space. On the contrary, it also has weak point like security probelm because anybody can easily access to the system due to open network attribute of Internet. Theretore, we need the solutions that protect the EC security problem for safe and useful EC activity. One of these solution is the implemonlation of a strong cipher algorithm. YK2(YoungKu Kang) cipher algorithm proposed in this paper is advantage for the EC security and it overcomes the limit of the current 6/1 bits block cipher algorithm using 128 bits key length for input, output, encryption key and 32 rounds. Moreover, it is degigned for the increase of time complexity and probability calculation by adapting more complex design for key scheduling regarded as one of the important element effected to enciyption.

• Korean Journal of Community Nutrition
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• v.8 no.1
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• pp.91-101
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• 2003

The purpose of this study was to investigate the compliance and need for diet therapy among diabetics and their caregivers. A total of 625 respondents participated in this survey. Appropriate management for long-term blood glucose control and difficult-to-manage cases appeared to be diet therapy, physical activity, medical treatment and folk remedies, in that order. The most important educational avenues for diet therapy were books, magazines and TV, Most respondents were educated in diet therapy within a year after diagnosis and had practiced diet therapy for over four years. The most common diet therapy Practices were food selection and Quantity control. Of the specific problems in practicing diet therapy, time and labor, taste, and meal planning appeared to be equally difficult factors. The prevailing diet therapy skills were controlling food amounts at breakfast and supper, and selecting food for lunch and refreshments. Respondents practicing both skills were about 20% of the participants; this shows the need to improve the current situation. The nutrients most frequently considered in diet therapy practice were simple sugars (sugar and sweet goods) , total fats and cholesterol. Since the perception of the role of dietary fiber among respondents was very low, nutrition education about the importance of dietary fiber and food sources of dietary fiber was needed. Diabetics seemed to be concerned about diabetic menus. Three difficult problems in planning diabetic menus were daily menu planning, patient's preferences, and the calculation of calories. As a means of nutrition counseling, they preferred interviews. The higher the educational status and the lower the age, the higher the preference was for internet or PC counseling. Therefore, it is necessary to develop nutrition educational programs so that diabetics can obtain practical knowledge of diet therapy. Furthermore, it is also necessary to develop additional means of informing diabetics about menu planning, while still considering Korean dietary behavior.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.445-452
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• 2018

The field of agriculture, forestry, and other land-use (AFOLU) is concerned with greenhouse emissions of agriculture (crop and livestock), as is the field of land-use, land-use change, and forestry (LULUCF). The 1996 IPCC guideline and the 2006 IPCC guideline are used in combination for calculation of greenhouse gas emission from the agricultural sector, and the 2003 IPCC guideline is used for that from the land-use sector. In this research, we analyzed GHG emissions of the cropland sector in AFOLU based on the 2006 IPCC guideline. The results showed that GHG emissions of 1990 was $-504Gg{\cdot}CO_2-eq$, while that of the last year was $2,871Gg{\cdot}CO_2-eq$. Compared with the 2003 methodology, total emissions according to the 2006 IPCC was lower except in 1997 and 2003. This trend is due to difference of analyzed emission sources, lower default values, and global warming potential by the 2006 IPCC. The results are estimated using limited data at the Tier 1 level and the first issue to be solved is the activity data from the land-use change matrix. Although this result should be improved, it can be used as the basis for calculating GHG emissions of the AFOLU sector.