• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.56-60
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• 2009

Purpose: The various studies and efforts to develop program are in progress in the field of nuclear medicine for the purpose of reducing scan time. The Oncoflash is one of the programs used in whole body bone scan which allows to maintain the image quality while to reduce scan time. When Those applications are used in clinical setting, both the image quality and reduction of scan time should be considered, therefore, the purpose of this study was to determine the criteria for proper scan speed. Materials and Methods: The subjects of this study were the patients who underwent whole body bone scan at the departments of nuclear medicine in the Asan Medical Center located in Seoul from 1st to 10th, July, 2008. The whole body bone images obtained in the scan speed of 30cm/min were classified by the total counts into under 800 K, and over 800 K, 900 K, 1,000 K, 1,500 K, and 2,000 K. The image quality were assessed qualitatively and the percentages of those of 1,000K and under of total counts were calculated. The FWHM before and after applying the Oncoflash were analyzed using images obtained in $^{99m}Tc$ Flood and 4-Quadrant bar phantom in order to compare the resolution according to the amount of total counts by the application of the Oncoflash. Considering the counts of the whole body bone scan, the dosed 2~5 mCi were used. 152 patients underwent the measurement in which the counts of Patient Postioning Monitor (PPM) were measured with including head and the parts of chest which the starting point of whole body bone scan from 7th to 26th, August, 2008. The correlations with total counts obtained in the scan speed of 30cm/min among them were analyzed (The exclusion criteria were after over six hours of applying isotopes or low amount of doses). Results: The percentage of the whole body bone image which has the geometric average of total counts of under 1,000K among them obtained in the scan speed of 30cm/min were 17.6%(n=58) of 329 patients. The qualitative analysis of the image groups according to the whole body counts showed that the images of under 1,000K were assessed to have coarse particles and increased noises. The analysis on the FWHM of the images before and after applying the Oncoflash showed that, in the case of PPM counts of under 3.6 K, FWHM values after applying the Oncoflash were higher than that before applying the Oncoflash, whereas, in the case of that of over 3.6 K, the FWHM after applying the Oncoflash were not higher than that before applying the Oncoflash. The average of total counts at 2.5~3.0 K, 3.1~3.5 K, 3.6~4.0 k, 4.1~4.5 K, 4.6~5.0 K, 5.1~6.0 K, 6.1~7.0 K, and 7.1 K over (in PPM) were $965{\pm}173\;K$, $1084{\pm}154\;K$, $1242{\pm}186\;K$, $1359{\pm}170\;K$, $1405{\pm}184\;K$, $1640{\pm}376\;K$, $1,771{\pm}324\;K$, and $1,972{\pm}385\;K$, respectively and the correlations between the counts in PPM and the total counts of image obtained in the scan speed of 30 cm/min demonstrated strong correlation (r=.775, p<.01). Conclusions: In the case of PPM coefficient over 3.6 K, the image quality obtained in the scan speed of 30cm/min and after applying the Oncoflash was similar to that obtained in the scan speed of 15 cm/min. In the case of total counts over 1,000 K, it is expected to reduce scan time without any damage on the image quality. In the case of total counts under 1,000 K, however, the image quality were decreased even though the Oncoflash is applied, so it is recommended to perform the re-image in the scan speed of 15 cm/min.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.111-124
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• 2010

To monitor the environment of land surface change is considered as an important research field since those parameters are related with land use, climate change, meteorological study, agriculture modulation, surface energy balance, and surface environment system. For the change detection, many different methods have been presented for distributing more detailed information with various tools from ground based measurement to satellite multi-spectral sensor. Recently, using high resolution satellite data is considered the most efficient way to monitor extensive land environmental system especially for higher spatial and temporal resolution. In this study, we use two different spatial resolution satellites; the one is SPOT/VEGETATION with 1 km spatial resolution to detect coarse resolution of the area change and determine objective threshold. The other is Landsat satellite having high resolution to figure out detailed land environmental change. According to their spatial resolution, they show different observation characteristics such as repeat cycle, and the global coverage. By correlating two kinds of satellites, we can detect land surface change from mid resolution to high resolution. The K-mean clustering algorithm is applied to detect changed area with two different temporal images. When using solar spectral band, there are complicate surface reflectance scattering characteristics which make surface change detection difficult. That effect would be leading serious problems when interpreting surface characteristics. For example, in spite of constant their own surface reflectance value, it could be changed according to solar, and sensor relative observation location. To reduce those affects, in this study, long-term Normalized Difference Vegetation Index (NDVI) with solar spectral channels performed for atmospheric and bi-directional correction from SPOT/VEGETATION data are utilized to offer objective threshold value for detecting land surface change, since that NDVI has less sensitivity for solar geometry than solar channel. The surface change detection based on long-term NDVI shows improved results than when only using Landsat.

• Journal of the Korean earth science society
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• v.38 no.1
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• pp.64-79
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• 2017

We have reported the petrographic properties on the soda straw primarily based on the field measurements and discussed the causes of their traits. 156 soda straws in district B of the Baeg-nyong Cave nominated with the natural monument No. 260 have been investigated to estimate physical, sedimentological and textural characteristics. The soda straws have an average length of 3.05 cm with a standard deviation of 1.7 cm and a mean diameter of 6.0 mm. This result shows that the average diameter of the soda straws measured in this study is thicker than previous reports by 20%. Although the drip rates of cave water from 85.3% of all the soda straws are exceedingly lower than 1 drop per 10 minutes, almost all soda straws have a dripping water. We firstly report growth lamina in the Korean soda straw from 85.3% of all samples, and this textural dominance indicates that the growth lamina are one of the common features of the soda straws at least in the study area. Secondary precipitations inside the soda straw were identified from 68.6%. Notably, the strong inverse correlation between growth lamina and secondary precipitates was represented from 70.5% of all samples. This finding might be explained by the seasonality of cave drip water supplied into the soda straws or the increased opacity caused by secondary precipitates. Based on petrograhic characteristics, the soda straws in the study area can be classified into normal and erratic types. Hopefully our results on the soda straws in Baeg-nyong Cave would provide a basis for the descriptions of soda straws from other caves and paleoclimatic applications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.519-525
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• 2012

Effects of cultivated conditions on antioxidant compounds and antioxidant activities of sweet potatoes (Ipomoea batatas (L.) Lam) were determined. The cultivated variety was Shinyulmi, and they were cultivated in a conventional culture, successful cropped hairy vetch culture, successful cropped barley cultivation, successful cropped rye cultivation, successful cropped mix-seeding of hairy vetch and barley, successful cropped mix-seeding of hairy vetch and rye, and not fertilizer. The brix degree, moisture, protein, and ash content of the sweet potatoes did not significantly change with the cultivated conditions. However amylose, total dietary fiber, and mineral content had significant changes. The total polyphenol, flavonoid, and tannin content of the methanolic extracts of the sweet potato's pericarp showed significant differences from cultivated conditions, however, the sweet potato's sarcocarp did not significantly change. The highest DPPH and ABTS radical scavenging activities of the methanolic extracts of the sweet potatoes were 958.81 and 663.53 mg TE/100 g in the sweet potato's pericarp on the successful cropped hairy vetch culture. Generally, there was a difference in antioxidant compound content and radical scavenging activity on the methanolic extract of sweet potato with cultivated conditions.

• Korean Journal of Hospice Care
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• v.8 no.1
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• pp.1-12
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• 2008

Perpose: The purpose of this study was to investigate the perception of death between Korean and Chinese nursing students. And it will help develop curriculum for preparing death, the quality of hospice care, as well as nursing education and practice. Methods: Data was collected from 492 nursing students participated(248 Korean and 244 Chinese) by questionnaire designed for examining Death Orientation (Thorson & Powell, 1988). They were analyzed using Cronbach's Alpha coefficients, factor analysis, t-test, ANOVA and regression analysis (SPSS; win 12.0 version) Results: More than half of the Korean nursing students followed a religion (58.5%) while the majority of Chinese nursing students did not follow a religion (93.9%). In the view of the afterlife, nursing students in China had two views. 'I really don't know what happens after a person dies (30.3%)' and ‘There is no afterlife and death is the end (29.5%)’. On the other hand the Korean nursing students’ answer were, 'After dying, a person goes to heaven or hell (27.3%)' and 'I really don't know what happens after a person dies. (22.9%)' The study also found that the average of 25 items in Death Orientation is 2.36points of nursing students in Korea and 2.50points of nursing students in China. This means that the concern, anxiety and fear were of the middle level for the Chinese Students and were higher than Korean students (t=3.51, p=.000). In the low factor of death orientation, those in Korea had higher 'anxiety of burden to family' than those in China (t=-3.50, p=.001). The nursing students in China had higher 'anxiety of the unknown (t=4.96, p=.000)', 'fear of suffering (t=6.88, p=.000), 'fear of extinction body and life (t=5.20, p=.000), 'fear of lost self-control(t=2.12, p=.034)', and 'anxiety of future existence and nonexistence (t=2.33, p=.020)' than those in Korea. There was no statistically significant difference for the 'concern of body and fear of identity lost' category. The death orientation of Korean nursing students had statistically significant differences according to age (t=3.20, p=.002), religion (t=2.56, p=.011), and afterlife (F=4.64, p=.000). The contribution of Death Orientation had a statistically significant difference, the afterlife variable (0.735, p=0.001). The death orientation of Chinese nursing students did not have any statistically significant differences. Conclusion: In conclusion, there were differences in death orientation between Korean and Chinese nursing students. In particular, those who believed in afterlife showed acceptance of death. The results of this study suggest that nursing curricula should include education program on death and spiritual nursing. Additional studies are needed to establish death education in China with careful considerations on Chinese policies, cultures and social systems.

• The Journal of Engineering Geology
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• v.30 no.4
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• pp.457-468
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• 2020

Problems arising during pile design works for plant construction, civil and architecture work are mostly come from uncertainty of geotechnical characteristics. In particular, obtaining the N-value measured through the Standard Penetration Test (SPT) is the most important data. However, it is difficult to obtain N-value by drilling investigation throughout the all target area. There are many constraints such as licensing, time, cost, equipment access and residential complaints etc. it is impossible to obtain geotechnical characteristics through drilling investigation within a short bidding period in overseas. The geotechnical characteristics at non-drilling investigation points are usually determined by the engineer's empirical judgment, which can leads to errors in pile design and quantity calculation causing construction delay and cost increase. It would be possible to overcome this problem if N-value could be predicted at the non-drilling investigation points using limited minimum drilling investigation data. This study was conducted to predicted the N-value using an Artificial Neural Network (ANN) which one of the Artificial intelligence (AI) method. An Artificial Neural Network treats a limited amount of geotechnical characteristics as a biological logic process, providing more reliable results for input variables. The purpose of this study is to predict N-value at the non-drilling investigation points through patterns which is studied by multi-layer perceptron and error back-propagation algorithms using the minimum geotechnical data. It has been reviewed the reliability of the values that predicted by AI method compared to the measured values, and we were able to confirm the high reliability as a result. To solving geotechnical uncertainty, we will perform sensitivity analysis of input variables to increase learning effect in next steps and it may need some technical update of program. We hope that our study will be helpful to design works in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.103-111
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• 1988

This study was carried out with two cultivars under two levels of pH and four levels of nitrogen fertilization in a field and nutri-culture experiments to obtain the information about the effects of pH and nitrogen fertilization on the growth and yield of soybean. Acidic condition suppressed the growth of soybean plants, and thus yield and yield components of soybean decreased under acidic condition. But they increased with increased nitrogen fertilization. Especially, these respones were more remarkable under acidic condition and in the variety Jangbaegkong. Grain yield of soybean were highly correlated with the content of allantoin and total nitrogen of soybean plants in the variety Jangbaegkong, but this was not in the variety Danyeobkong. The content of protein and fat of soybean seeds decreased under acidic condition, and more nitrogen fertilization increased the protein content, but decreased the fat content.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.1
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• pp.1-9
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• 2006

Regardless of the recent observed warmer winters in Korea, more freeze injuries and associated economic losses are reported in fruit industry than ever before. Existing freeze-frost forecasting systems employ only daily minimum temperature for judging the potential damage on dormant flowering buds but cannot accommodate potential biological responses such as short-term acclimation of plants to severe weather episodes as well as annual variation in climate. We introduce 'dormancy depth', in addition to daily minimum temperature, as a complementary criterion for judging the potential damage of freezing temperatures on dormant flowering buds of grape vines. Dormancy depth can be estimated by a phonology model driven by daily maximum and minimum temperature and is expected to make a reasonable proxy for physiological tolerance of buds to low temperature. Dormancy depth at a selected site was estimated for a climatological normal year by this model, and we found a close similarity in time course change pattern between the estimated dormancy depth and the known cold tolerance of fruit trees. Inter-annual and spatial variation in dormancy depth were identified by this method, showing the feasibility of using dormancy depth as a proxy indicator for tolerance to low temperature during the winter season. The model was applied to 10 vineyards which were recently damaged by a cold spell, and a temperature-dormancy depth-freeze injury relationship was formulated into an exponential-saturation model which can be used for judging freeze risk under a given set of temperature and dormancy depth. Based on this model and the expected lowest temperature with a 10-year recurrence interval, a freeze risk probability map was produced for Hwaseong County, Korea. The results seemed to explain why the vineyards in the warmer part of Hwaseong County have been hit by more freeBe damage than those in the cooler part of the county. A dormancy depth-minimum temperature dual engine freeze warning system was designed for vineyards in major production counties in Korea by combining the site-specific dormancy depth and minimum temperature forecasts with the freeze risk model. In this system, daily accumulation of thermal time since last fall leads to the dormancy state (depth) for today. The regional minimum temperature forecast for tomorrow by the Korea Meteorological Administration is converted to the site specific forecast at a 30m resolution. These data are input to the freeze risk model and the percent damage probability is calculated for each grid cell and mapped for the entire county. Similar approaches may be used to develop freeze warning systems for other deciduous fruit trees.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.34-40
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• 2021

Purpose If a new test is introduced or reagents are changed in the laboratory of a medical institution, the characteristics of the test should be analyzed according to the procedure and the assessment of reagents should be made. However, several necessary conditions must be met to perform all required comparative evaluations, first enough samples should be prepared for each test, and secondly, various reagents applicable to the comparative evaluations must be supplied. Even if enough comparative evaluations have been done, there is a limit to the fact that the data variation for the new reagent represents the overall patient data variation, The fact puts a burden on the laboratory to the change the reagent. Due to these various difficulties, reagent changes in the laboratory are limited. In order to introduce a competitive bid, the institute conducted a full investigation of Radioimmunoassay(RIA) reagents for each test and established the range of reagents available in the laboratory through comparative evaluations. We wanted to share this process. Materials and Methods There are 20 items of tests conducted in our laboratory except for consignment tests. For each test, RIA reagents that can be used were fully investigated with the reference to external quality control report. and the manuals for each reagent were obtained. Each reagent was checked for the manual to check the test method, Incubation time, sample volume needed for the test. After that, the primary selection was made according to whether it was available in this laboratory. The primary selected reagents were supplied with 2kits based on 100tests, and the data correlation test, sensitivity measurement, recovery rate measurement, and dilution test were conducted. The secondary selection was performed according to the results of the comparative evaluation. The reagents that passed the primary and secondary selections were submitted to the competitive bidding list. In the case of reagent is designated as a singular, we submitted a explanatory statement with the data obtained during the primary and secondary selection processes. Results Excluded from the primary selection was the case where TAT was expected to be delayed at the moment, and it was impossible to apply to our equipment due to the large volume of reagents used during the test. In the primary selection, there were five items which only one reagent was available.(squamous cell carcinoma Ag(SCC Ag), β-human chorionic gonadotropin(β-HCG), vitamin B12, folate, free testosterone), two reagents were available(CA19-9, CA125, CA72-4, ferritin, thyroglobulin antibody(TG Ab), microsomal antibody(Mic Ab), thyroid stimulating hormone-receptor-antibody(TSH-R-Ab), calcitonin), three reagents were available (triiodothyronine(T3), Tree T3, Free T4, TSH, intact parathyroid hormone(intact PTH)) and four reagents were available are carcinoembryonic antigen(CEA), TG. In the secondary selection, there were eight items which only one reagent was available.(ferritin, TG, CA19-9, SCC, β-HCG, vitaminB12, folate, free testosterone), two reagents were available(TG Ab, Mic Ab, TSH-R-Ab, CA125, CA72-4, intact PTH, calcitonin), three reagents were available(T3, Tree T3, Free T4, TSH, CEA). Reasons excluded from the secondary selection were the lack of reagent supply for comparative evaluations, the problems with data reproducibility, and the inability to accept data variations. The most problematic part of comparative evaluations was sample collection. It didn't matter if the number of samples requested was large and the capacity needed for the test was small. It was difficult to collect various concentration samples in the case of a small number of tests(100 cases per month or less), and it was difficult to conduct a recovery rate test in the case of a relatively large volume of samples required for a single test(more than 100 uL). In addition, the lack of dilution solution or standard zero material for sensitivity measurement or dilution tests was one of the problems. Conclusion Comparative evaluation for changing test reagents require appropriate preparation time to collect diverse and sufficient samples. In addition, setting the total sample volume and reagent volume range required for comparative evaluations, depending on the sample volume and reagent volume required for one test, will reduce the burden of sample collection and planning for each comparative evaluation.