• Korean Journal of Mineralogy and Petrology
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• v.34 no.1
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• pp.31-40
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• 2021

The hydrogen in nominally anhydrous mineral is known to be associated with lattice defects, but it also can exist in the form of water and hydroxyl groups on the large surface of the nanoscale particles. In this study, we investigate the effectiveness of 1H solid-state nuclear magnetic resonance (NMR) spectroscopy as a robust experimental method to quantify the hydrogen atomic environments of amorphous silica nanoparticles with varying relative humidity. Amorphous silica nanoparticles were packed into NMR rotors in a temperature-humidity controlled glove box, then stored in different atmospheric conditions with 25% and 70% relative humidity for 2~10 days until 1H NMR experiments, and a slight difference was observed in 1H NMR spectra. These results indicate that amount of hydrous species in the sample packed in the NMR rotor is rarely changed by the external atmosphere. The amount of hydrogen atom, especially the amount of physisorbed water may vary in the range of ~10% due to the temporal and spatial inhomogeneity of relative humidity in the glove box. The quantitative analysis of 1H NMR spectra shows that the amount of hydrogen atom in amorphous silica nanoparticles linearly increases as the relative humidity increases. These results imply that the sample sealing capability of the NMR rotor is sufficient to preserve the hydrous environments of samples, and is suitable for the quantitative measurement of water content of ultrafine nominally anhydrous minerals depending on the atmospheric relative humidity. We expect that 1H solid-state NMR method is suitable to investigate systematically the effect of surface area and crystallinity on the water content of diverse nano-sized nominally anhydrous minerals with varying relative humidity.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.225-237
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• 1998

Purpose: We investigated the statistical methods to compose the functional brain map of human working memory and the principal factors that have an effect on the methods for localization. Materials and Methods: Repeated PET scans with successive four tasks, which consist of one control and three different activation tasks, were performed on six right-handed normal volunteers for 2 minutes after bolus injections of 925 MBq $H_2^{15}O$ at the intervals of 30 minutes. Image data were analyzed using SPM96 (Statistical Parametric Mapping) implemented with Matlab (Mathworks Inc., U.S.A.). Images from the same subject were spatially registered and were normalized using linear and nonlinear transformation methods. Significant difference between control and each activation state was estimated at every voxel based on the general linear model. Differences of global counts were removed using analysis of covariance (ANCOVA) with global activity as covariate. Using the mean and variance for each condition which was adjusted using ANCOVA, t-statistics was performed on every voxel To interpret the results more easily, t-values were transformed to the standard Gaussian distribution (Z-score). Results: All the subjects carried out the activation and control tests successfully. Average rate of correct answers was 95%. The numbers of activated blobs were 4 for verbal memory I, 9 for verbal memory II, 9 for visual memory, and 6 for conjunctive activation of these three tasks. The verbal working memory activates predominantly left-sided structures, and the visual memory activates the right hemisphere. Conclusion: We conclude that rCBF PET imaging and statistical parametric mapping method were useful in the localization of the brain regions for verbal and visual working memory.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.695-703
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• 2018

This study was conducted to suggest a sustainable farming practice forresource recycling in vegetable gardens of North Korea. In North Korea, farmers are allowed to own private vegetable gardens less than $100m^2$. However, usage of fertilizers in private vegetable gardens is very limited due to economic sanctions by UN security council. If North and South Korea initiated the cooperative action in the near future, agricultural sector would be the highest priority cooperation area. Considering the current North Korean situation in agriculture, we would like to suggest a method for producing organic fertilizer manure. For raw materials for producing manure, we selected corn byproduct, which is the most abundant material, and rabbits' feces, which are easily obtained from individual private farms in North Korea. As we cannot get corn byproducts and rabbits' feces from North Korea, we prepared samples of corn byproducts and rabbits; feces from many places in South Korea. After statistical analysis of variance, there was no significant difference in the T-N contents of corn byproducts from Gyeonggi, Gangwon, Chungnam, Chungbuk, Jeollabuk and Gyeongsangnam-dos, which indicates that the fertilizing quality of corn byproducts does not vary significantly in the spatial scale of South. Korea. In this sense, if we use corn samples from Gyeonggi province, they would not be very different from those of North Korean regions. Physicochemical properties of rabbits' feces were different between those eating feed grains and those eating plants only. Hence, we used rabbits' feces of the rabbits from Yeonchun area, which were fed by plants only. Using three different mixing ratios of corn byproducts and rabbits' feces, composting was conducted for 60 days. The mixing ratio of 1:1 produced the manure with % T-N of 1.98% and OM/N ratio of 31.7 after 30 days of composting, which is comparable to the quality of commercial manure.

• Analytical Science and Technology
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• v.28 no.6
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• pp.417-424
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• 2015

In this study, the relationship between selenoprotein concentrations in blood and stomach cancer have been searched for Korean. The concentration of each selenoprotein in blood serum was analyzed and the correlation between the concentration and stomach cancer was studied to find a potential for using Selenium as a biomarker. In concentration determination, a simple calibration curve method was used with the monitoring of m/z 78 without the use of solid phase extraction. This is a lot more simple than the method using SPE with post column isotope dilution. The result obtained from the analysis of CRM BCR-637, 72.20±3.35 ng·g⁻¹, showed similar value of reference value (81±7 ng·g⁻¹). The total concentration of Se for the controlled group, cardiovascular patients group, was 105.70±21.20 ng·g⁻¹. This value was the same as normal healthy person reported earlier. Each selenoprotein concentration of GPx, SelP and SeAlb was 26.12±7.84, 65.15±14.50, 14.43±6.99 ng·g⁻¹, respectively. The distribution of each selenoprotein was 24.7%, 61.6%, and 13.7%, which was similar to the normal person. The result of stomach cancer patients, the total concentration of Se was 76.11±28.12 ng·g⁻¹ and each concentration of GPx, SelP and SeAlb was 15.41±9.01, 50.83±17.91, and 9.87±5.21 ng·g⁻¹, respectively. The total and each selenoprotein concentration level showed significant decrease for the stomach cancer patients. The level of decrease was 41.0% for GPx, 22.0% for SelP, and 31.6% for SeAlb. However, the distribution of each selenoprotein was not much different. Either total Selenium or each selenoprotein could be used as a possible index for the diagnosis of cancer. However, in age group study, it is shown that young age group (30's-40's) did not show much difference.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.206-216
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• 2000

Predictional study for lateral change between pre- and post-orthognathic surgery has been emphasized mainly on anterior area of lateral profile; upper lip, lower lip and chin et al. So interest for lateral profile change has been less in posterior area of lateral profile and literature analyzing gonial angle change is rare. The purpose of this study is to make prediction for gonial angle change possible and to offer somewhat treatment guidance for gonial angle to be improved by investigating overall gonial angle change between pre- and post-orthognathic surgery and inquiring into factors influencing on pattern of genial angle change. For this study 35 patients were selected retrospectively. Lateral cephalometric radiographs were taken in just pre-op time, pod 1 day, pod 1 year. They were analyzed and genial angles were measured. The results were as follows : 1. Gonial angle at pod 1 day was decreased about $9.3^{\circ}$ than pre-op and gonial angle at pod 1 year was increased about $4.0^{\circ}$ than pod 1 day. So genial angle at pod 1 year was decreased about $5.3^{\circ}$ than pre-op genial angle(p<0.01). 2. Mean pre-op gonial angle was $129.4^{\circ}$, showing significantly high value than normal and mean gonial angle at pod 1 year was $124.1^{\circ}$, showing value near to normal. 3. Mean gonial angle change between pre-op and pod 1 year was decreased about $5.4^{\circ}$ in female and $5.3^{\circ}$ in male. There was no statistically significant difference between male and female(p>0.05). 4. Principal factor influencing on decreased gonial angle in gonial angle change between pre-op and pod 1 year was amount of mandibular setback. 5. Principal factor influencing on increased gonial angle in gonial angle change between pod 1 day and pod 1 year was % horizontal relapse, and it was thought that resorption and bone remodelling on posterior area in mandibular distal segment also were related to increased gonial angle. 6. It is thought that sagittal split ramus osteotomy in mandibular prognathic patients with high value of gonial angle is effective to improvement of gonial angle, and In patients who have normal range of gonial angle and are required with excessive mandibular setback, short lingual cut method, additional resection of posterior margin of distal segment, Obwegeser II method will be considerd. 7. More prudent operation and careful post-op management will be responsible for maintenance of postoperative stable gonial angle.

• Archives of design research
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• v.12 no.2
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• pp.157-168
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• 1999

Stone in the Cho Sun Dynasty has been used as the material of industry arts, widely building materials and an important material for the artistic design. But it has been generally used as an use of practical living Product like, suban, a metal printing type, a fire place, a pillowcase, a pencil case, etc, and ornament with the quality of stone material and the aesthetic view. There are several problems as like size, quantity, delivery and processing method with the stne material according to its variety and selection. Accordingly it has been studied through the whole process of shape, a material selection of design and processing method as well as studying about small stone crafts which were manufactured in the Cho Sun Dynasty, considering these problems. Stone crafts in Cho Sun Dynasty has been widely used as a living tool. There was some what difference on manufacturing purpose on its technique of folk crafts of stone crafts, but, through the research of collected crafts, they were almost the same that social need, user's taste and hobby in those days were reflected in. In the result of analysis as dividing the stone crafts into daily living product, stationery and tool, the major of daily products have been manufactured with emphasis of practicability. And they have been manufactured from agalmatolite for the propose of use. further, kitchen product had no design due to the function and living products which has been used in the main living room has been carved with the decorative expression of the various form by using intaglic, relieve, inlaid technique, etc. For the stationery, it has been characterized with aesthetic point considering the decorative effects & selection of material in accordance with use. A material for manufacturing has been used in the range of agalmtolite, atopaz, a sapphire, white stone etc. As the result of this research, It was noticeable that there was the spleudidness on the expression of design and carving. It was also noticeable that black stone and guanite have been widely esed because it didn't need the delicacy as a tool.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.347-355
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• 2021

During the earthquake, for multi-story structure, if the first floor is soft, the deformation will concentrate on that floor causing a serious damage to the column members which might leads to the collapse of the whole structure like Piloti structure during the Pohang earthquake in Korea. According to the 2016 National Disaster Management Research Institute's "Investigation of Seismic Reinforcement and Cost Analysis of Domestic Non-seismic Buildings", the rate of seismic resistance of private reinforced concrete buildings was 38.3 %. Among them, it was reported that the seismic-resistance ratio of the two to five-story structures was less than 50 %. Accordingly, the government is trying to improve the seismic rate through support projects, but the conventional seismic reinforcement methods are still expensive, and emergency construction is difficult. Therefore, in this study, the field applicability was evaluated by improving the reinforcement method using Velcro, which was developed through the research project of the Ministry of Land, Transport and Maritime Affairs in 2014. In order to improve the performance of the Velcro reinforcement method, introducing the initial tension of Velcro using high foaming rigid urethane filling between the Velcro and concrete of the columns was applied. Additionally, an experiment was conducted to evaluate the ductility of Velcro specimen from the concrete confinement effect. As a result, the ductility of the Velcro specimen was improved compare to Normal specimen. However, the energy dissipation capacity of VELCRO2 is better than VELCRO1, yet the maximum ductility of those two specimens did not show a significant difference. Therefore, the improvement of the internal filler material is still needed to have a better maximum ductility.

• The Journal of Korean Society for Radiation Therapy
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• v.32
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• pp.53-59
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• 2020

Purpose: The purpose of this study is to compare and analyze the difference between the MLC log file-based software (Mobius) and the conventional phantom-ionization chamber (ArcCheck) dose verification method according to the change of target volume. Material and method: Radius 0.25cm, 0.5cm, 1cm, 2cm, 3cm, 4cm, 5cm, 6cm, 7cm, 8cm, 9cm, 10cm with a Sphere-shaped target Twelve plans were created and dose verification using Mobius and ArcCheck was conducted three times each. The irradiated data were compared and analyzed using the point dose error value and the gamma passing rate (3%/3mm) as evaluation indicators. Result: Mobius point dose error values were -9.87% at a radius of 0.25cm and -4.39% at 0.5cm, and the error value was within 3% at the remaining target volume. The gamma passing rate was 95% at a radius of 9cm and 93.9% at 10cm, and a passing rate of more than 95% was shown in the remaining target volume. In ArcCheck, the average error value of the point dose was about 2% in all target volumes. The gamma passing rate also showed a pass rate of 98% or more in all target volumes. Conclusion: For small targets with a radius of 0.5cm or less or a large target with a radius of 9cm or more, considering the uncertainty of DQA based on MLC log files, phantom-ionized DQA is used in complementary ways to include point dose, gamma index, DVH, and target coverage. It is believed that it is desirable to verify the dose delivery through a comprehensive analysis.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.41-47
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• 2016

Background: For the accurate dose assessment in radiation therapy, energy spectrum of the photon beam generated from the linac head is essential. The aim of this study is to develop the technique to accurately unfolding the energy spectrum with the transmission analysis method. Materials and Methods: Clinical linear accelerator and Monet Carlo method was employed to evaluate the transmission signals according to the thickness of the observer material, and then the response function of the ion chamber response was determined with the mono energy beam. Finally the energy spectrum was unfolded with HEPROW program. Elekta Synergy Flatform and Geant4 tool kits was used in this study. Results and Discussion: In the comparison between calculated and measured transmission signals using aluminum alloy as an attenuator, root mean squared error was 0.43%. In the comparison between unfolded spectrum using HEPROW program and calculated spectrum using Geant4, the difference of peak and mean energy were 0.066 and 0.03 MeV, respectively. However, for the accurate prediction of the energy spectrum, additional experiment with various type of material and improvement of the unfolding program is required. Conclusion: In this research, it is demonstrated that unfolding spectra technique could be used in megavoltage photon beam with aluminum alloy and HEPROW program.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.76-79
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• 2013

Purpose: It is very important to establish the appropriate reference range in the laboratory for preventing mistakes like false positive or false negative. Because the reference range in the laboratory is standard of patient test results interpretation. Proinsulin is precursor hormone of insulin, and the importance is increasing for diagnosing diabetes or insulinoma. Proinsulin reagent used in our laboratory is produced in the USA, and the reference range provided by manufacturer was adapted to our reference range after the validation test. But, it is generally recommend for the every laboratory to establish the their own reference range. So, we decided to re-evaluate the reference range with our patients' test results. Materials and Methods: Among 737 patients who had been to health promotion center in our hospital between Dec. $8^{th}$ 2011 and Dec. $21^{st}$ 2011, 563 patients are chosen with exception of diabetics patients and patients showing abnormal test results in Fasting Glucose, HbA1c, Insulin, and C-peptide. The 563 test results (275 males and 288 females) were classified with three groups(entire, male, female), and analysis of normal distribution was performed with aid of SPSS(version 19.0). Because Each group didn't show normal distribution, the reference range was set from the lowest limit of 2.5% to the highest limit of 97.5% with Percentile method used in non-normal distribution. Results: When evaluation values are sorted in ascending order, the entire range is 4.5~52.0 pM and 5.3~51.9 pM for male and 4.5~52.0 pM for female. The calculated reference range with percentile method shows 6.7~26.5 pM for entire group, 6.8~26.5 pM for male and 6.7~26.5 pM for female, respectively. Conclusion: The reference range provided by reagent manufacturer is 6.4~9.4 pM and the one established in this study is 6.7~26.5 pM. This difference might be caused by racial characteristics between Western people and Koreans. So an ideal reference range can be gotten with normal population visiting to every hospital. Our hospital has been using the newly re-establishing reference range under consultation with the department of endocrinology since Aug. $1^{st}$ 2012.