• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2452-2457
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• 2024

To obtain site-specific values of the Derived Concentration Guideline Levels (DCGLs) for decommissioning of KRR-1&2, the soil density and distribution coefficient values for Cs-137, a major contaminant radionuclide, were determined. The soil density was evaluated according to the test method established by the Korean Agency for Technology and Standards of the Ministry of Trade, Industry, and Energy (KATS). The distribution coefficient was evaluated using a batch test. The validity of using the evaluated soil density and distribution coefficient as site-specific values was assessed through radiation dose assessment reflecting these values. Average soil density value obtained was 1.738 g/cm³, which was within the typical range of normal soil density, 1.0-1.8 g/cm³. The average distribution coefficient value was 7,754 mL/g. Applying the maximum, average, and minimum values of the evaluated soil density and distribution coefficient showed similar radiation dose results, thus suggesting that it is reasonable to use the average values of each parameter as site-specific values. Findings of this study can help determine DCGLs that reflect the characteristics of the research reactor site.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.69-75
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• 2013

During the magnetic abrasive polishing of a curved surface, the improvement in surface roughness varies with the maximum value and distribution of magnetic flux density. Thus, in this study, the magnetic flux density on the curved surface was simulated according to curvature radii of magnetic tool. As a result of the simulation, the 14.5mm of the magnetic tool had a higher maximum magnetic flux density and it showed a large weighted magnetic flux density. The weighted magnetic flux density means the highest value for the magnetic flux density in the curvature of the magnetic tool. From the experimental verification, the better improvement in surface roughness was observed on wider area at the 14.5mm radius of the magnetic tool than other radii.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.357-364
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• 1999

The purpose of this study is to analysis the grain distribution and compaction characteristics of structural backfill with reclaimed soil. Five(5) reclaimed soil samples which passed #200 sieve have been used in the test. The study showed that the maximum dry density and the bearing value rate turned out to be becoming smaller when the more the quantity passed #200 sieve, the smaller the soil grain. The maximum dry density value calculated from the compaction md relative density test showed wet method > compaction method > dry method. The correlation coefficient between Rc and Dr based on the grain distribution and the compaction characteristics showed that the maximum dry density value by the wet method is little higher than the compaction method and dry method.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.1015-1020
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• 2021

This study retrospectively analyzed the test results of 113 healthy postmenopausal women without special diseases among patients who visited a medical institution in Busan from January 2020 to June 2021. The purpose of the study was to investigate the effect of BMI (Body Mass Index) on bone density in menopause women, the analysis of the lumbar and femur of patients with low weight (BMI<18.5) showed a significant probability (p-value) of 0.000, and the normal weight (18.5≦BMI<23.0) of the femur. In overweight (23.0≦BMI<25.0), the significance probability (p-value) of the lumbar region was 0.021 and the significance probability (p-value) of the femur was 0.034, confirming the correlation. However, in patients with high obesity (30.0≦BMI<40.0), the p-value of the lumbar region was 0.127, and the p-value of the femur was 0.093, indicating that there was no correlation between BMI and bone density.

• Journal of Korean Neurosurgical Society
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• v.54 no.5
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• pp.384-389
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• 2013

Objective : Use of quantitative computed tomography (CT) to evaluate bone mineral density was suggested in the 1970s. Despite its reliability and accuracy, technical shortcomings restricted its usage, and dual-energy X-ray absorptiometry (DXA) became the gold standard evaluation method. Advances in CT technology have reduced its previous limitations, and CT evaluation of bone quality may now be applicable in clinical practice. The aim of this study was to determine if the Hounsfield unit (HU) values obtained from CT correlate with patient age and bone mineral density. Methods : A total of 128 female patients who underwent lumbar CT for back pain were enrolled in the study. Their mean age was 66.4 years. Among them, 70 patients also underwent DXA. The patients were stratified by decade of life, forming five age groups. Lumbar vertebrae L1-4 were analyzed. The HU value of each vertebra was determined by averaging three measurements of the vertebra's trabecular portion, as shown in consecutive axial CT images. The HU values were compared between age groups, and correlations of HU value with bone mineral density and T-scores were determined. Results : The HU values consistently decreased with increasing age with significant differences between age groups (p<0.001). There were significant positive correlations (p<0.001) of HU value with bone mineral density and T-score. Conclusion : The trabecular area HU value consistently decreases with age. Based on the strong positive correlation between HU value and bone mineral density, CT-based HU values might be useful in detecting bone mineral diseases, such as osteoporosis.

• Journal of Animal Environmental Science
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• v.7 no.3
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• pp.177-182
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• 2001

This study was conducted to find out the coefficient relationships between intensity values image processing and pollution density of slurries. Slurry images were obtained from the image processing system using personnel computer and CCD-camera. Software, written in Visual $c^{++}$, combined the functions of the image capture, image processing and image analysis. The data of image processing for slurries were analyzed by the method of regression analysis. The results are as follows. 1. Red(R)-values among image processing data were obtained the highest correlation coefficient 0.9213 for detecting COD. Also, green(G)-value were obtained the highest correlation coefficient 0.9019 fur detecting BOD. Blue(B)-value could not find significant values to detect the pollution resources density. 2. Hue(H)-values among image processing data were obtained the highest correlation coefficient 0.9466 for detecting BOD. This fact could be used in detecting BOD 3. Green(G)-value, GRAY-value, Hue(H)-value, Saturation(5)-value and Intensity(I)-value were the correlation coefficient more than 0.8 for BOD. Hue(H)-value was higher correlation coefficient than any other value. It was possible to detect pollution density of slurries by using the image processing system. 4. Red(R)-value, GRAY-value and Saturation(5)-value were obtained the correlation coefficient more than 0.8 for detecting COD. a-value had the highest correlation coefficient Among these values. It was possible to detect density indirectly by using the image processing system. 5. SS-density were obtained the correlation coefficient less than 0.8 by using the image processing system. The density of $NH_4$-N and $NO_3$-N were obtained correlation coefficient less than 0.2.

• Journal of the Korean Wood Science and Technology
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• v.52 no.3
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• pp.234-242
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• 2024

In this study, the effect of carbonization temperature and mixing ratio of ceramics manufactured from sawdust, chaff and charcoal on sound absorption performance and density profile was investigated. The density profile of ceramics prepared by the addition rates of sawdust, chaff and charcoal showed the highest value at 91.00% when the ratio of sawdust, chaff and charcoal was 50:25:15. However, the difference in density profile according to the addition rate was insignificant. The density profile of ceramics manufactured according to the carbonization temperature showed the highest value of 88.06% when manufactured at 800℃. However, it does not show any particular trend, so it is understood that the effect of the carbonization temperature on the density gradient is small. On the other hand, the sound absorption coefficients of ceramics prepared by the addition rates of sawdust, chaff and charcoal is between 0.3 and 0.4 at almost all frequencies when the addition rates of sawdust, chaff and charcoal are 50:30:10 and 50:35:5, respectively. Therefore, as the chaff particles increased, the sound absorption performance was improved. In addition, the sound absorption coefficients of the ceramics manufactured at each carbonization temperature showed the highest value in the ceramics manufactured at 1,200℃.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.57.1-57.1
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• 2013

We investigate the method to measure both the present value of the matter energy density contrast and the Hubble parameter directly from the measurement of the linear growth rate which is obtained from the large scale structure of the Universe. From this method, one can obtain the value of the nuisance cosmological parameter $\Omo$ (the present value of the matter energy density contrast) within 3% error if the growth rate measurement can be reached $z >3.5$. One can also investigate the evolution of the Hubble parameter without any prior on the value of $H_0$ (the current value of the Hubble parameter). Especially, estimating the Hubble parameter are insensitive to the errors on the measurement of the normalized growth rate $f \sigma_8$. However, this method requires the high $z$ ($z >3.5$) measurement of the growth rate in order to get the less than 5% errors on the measurements of $H(z)$ at $z \leq 1.2$ with the redshift bin $\Delta z = 0.2$. Thus, this will be suitable for the next generation large scale structure galaxy surveys like WFMOS and LSST.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.799-803
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• 1997

Smell and sound are closely connected with our life. But there is no way to represent the exact numerical value of smell. On the contary, there is a method of represent the exact numerical value of sound. In this thesis, using and adapting this method about sound, a new method of expressing the numercal value of smell is going to be derived. These two methods are similar, but there are so many substances which emit smells and the methods of measuring the density of the substances are various according to kinds of the substances. So the new method about smell will be derived by a new idea.

• Korean Institute of Interior Design Journal
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• v.20 no.6
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• pp.272-281
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• 2011

The purpose of this study is to analyze the correlation between spatial space structure and visitors' behavior and interpret visitors' behavior concretely from the aspect of exhibition environments. So, this study intends to qualify spatial space structure with integration, connectivity and control value by utilizing space syntax, limit to tracking score among the analysis index and reinterpret with exhibition density and extend of eyesight among the exhibition environments. The results of this study are as follows; First, in case of museums, tracking score shows plus correlation with connectivity and control value among the space syntax variables and very low correlation with integration. In case of art museums, tracking score shows plus correlation with integration and wide variable is judged to more useful to analyze visitor's behavior than minor variable. Second, museums doesn't make a great effect on visitors' behavior from the aspect of extent of eyesight, but from the aspect of exhibition density, visitors relatively watched evenly without short cut at the early stage of exhibition in spite of high exhibition density. And, they conducted short cut as they went to the middle stage of exhibition on the course of watching although the numerical value of exhibition density is low. Third, in case of art museums, visitors' behavior was relatively influenced by exhibition density, not extent of eyesight. But, as they went to the high level on the course of watching, watching speed became rapid and watching length became short in the place the value of extent of eyesight was high. Its reason is judged to be easy to grasp position or space structure of the next exhibition room visually. Therefore, when the concentration of watching is necessary from the aspect of exhibition, to control exhibition density properly before the space is useful to draw visiting to exhibition space afterward.