• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.35-40
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• 2018

Purpose : The range of force differs from the size of proton energy used in our hospital. The compensator enables to change energy size based on distal thickness which also makes changes in dose rate. Therefore, the purpose of this study is to evaluate the effect of changing the thickness of compensator distal on dose range and beam on time. Subject and Methodology : Five low energy patients who have received proton therapy were selected as subjects for this study. Beam on was checked for the selected patients during the existing therapy. After then, the thickness of distal of compensator was increased by 2 cm up to 14 cm through proton therapy plan system(TPS) for comparative analysis. For the evaluation of dose range, the value of the target's conformity index(CI) and the maximum dose of rear side target's organ at risk(OAR) were compared. Furthermore, to evaluate the effect of therapy time, beam on time was compared by making compensator distal in each thickness. Result : The result of homogeneity index and conformity index of the increased compensator distal showed the same level in all patients. The comparison results of OAR of target rear side showed 7 cGy at spine cord of abdomen at maximum, 88 cGy at eyeball's RT lens, 391 cGy at RT lens of nasal cavity 51 cGy at trachea of the mediastinum, and 661 cGy at a small bowl of the pelvis. The comparison results of the beam on time showed a reduction from 126 seconds to 62 seconds for the abdomen, from 105 seconds to 37 seconds for the eyeball, from 187 seconds to 134 seconds for nasal cavity, from 100 seconds to 40 seconds for mediastinum, from 440 seconds to 118 seconds for the pelvis. Conclusion : The research result showed that as the distal thickness of compensator increased, the size of energy increased. In addition, beam on decreased due to the increase of dose rate. It is expected that the result would help reduce the treatment time and increase the convenience of patients if it is applied to liver patients who need respiratorygated therapy and pediatric patients. However, distal penumbra increased as the size energy increased. Therefore, in treating cases where OAR is in the vicinity of the target rear side, the influence of penumbra should be taken into account in adjusting thickness level of the compensator in proton therapy plan.

• Food Science and Preservation
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• v.19 no.6
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• pp.825-832
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• 2012

In this study, the quality characteristics and antioxidant activity of mulberry salad dressing prepared with yam juice during storage at $5^{\circ}C$ for four weeks were evaluated. The salad dressing was prepared with a salad base, mulberry, omija, and yam (4:4:6:1 or 4:4:6:3). Fresh yam juice was added to the salad dressing at 0, 7, and 18% levels. After four weeks storage, the pH increased whereas the acidity decreased. As the yam concentration increased, the pH increased to 3.84 and the acidity decreased to 0.14%. The Hunter color L (lightness), b (yellowness), and a (redness) values decreased over the storage period. After four weeks storage, the viscosity increased from 83.2 to 158.5 cp according to the amount of yam juice that was added. The antioxidant activity, such as the DPPH radical scavenging activity, and the total polyphenol content of the salad dressing improved as the yam concentration increased. Moreover, according to the storage time, the peroxide value did not increase. These results show that the mulberry salad dressing to which omija and fresh yam juice were added maintained its freshness with high antioxidative activity during storage.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.273-278
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• 2019

The multi-layer insulating curtains used in the experiment was produced in six combinations using non-woven fabric containing aerogel and compared and analyzed by measuring heat flux and heat perfusion rates due to weight, thickness and temperature changes. Using silica aerogel, which have recently been noted as new material insulation, this study tries to produce a new combination of multi-layer insulating curtains that can complement the shortcomings of the multi-layer insulating curtains currently in use and maintain and improve its warmth, and analyze the thermal properties. The heat flux means the amount of heat passing per unit time per unit area, and the higher the value, the more heat passing through the multi-layer insulating curtain, and it can be judged that the heat retention is low. The weight and thickness of multi-layer insulation curtains were found to be highly correlated with thermal insulation. In particular, insulation curtains combined with aerogel meltblown non-woven fabric had relatively higher thermal insulation than insulation curtains with the same number of insulation materials. However, the aerogel meltblown non-woven fabric is weak in light resistance and durability, and there is a problem that the production process and aerogel are scattering. In order to solve this problems, the combination of expanded aerogel non-woven fabric and hollow fiber non-woven fabric, which are relatively simple manufacturing processes and excellent warmth, are suitable for use in real farms.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.43-49
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• 2019

Purpose : We apply the Layered Rescanning PBS designed to complement the Pencil Beam Scanning(PBS), which is vulnerable to moving organs with the Moving Phantom, and compare the homogeneity with the single scan PBS. Methods and materials: Matrix X (IBA, Belgium) and Moving Phantom (standard imaging, USA) were used. A dose of 200 cGy was measured in the AP direction on a hypothetical tumor $10{\times}10{\times}5cm$. The plan type was planned as 4 kinds of sinlge scan PBS, rescan number 4, 8, 12 times. Were measured three times for each types. During the measurement, the respiratory cycle of the Moving Phantom was generally set to 4 seconds per cycle, and the movement radius in the S-I direction was set to 2 cm. In addition, beam on time was measured. Results : The mean values of $D_{max}$ in the PTV were $246.47{\pm}18.8cGy$, $223.43{\pm}8.92cGy$, and $222.47{\pm}7.7cGy$, $213.9{\pm}6.11cGy$ and the mean values of $D_{min}$ were $165.53{\pm}4.32cGy$, $173.13{\pm}11.94cGy$, $184.13{\pm}8.04cGy$, $182.67{\pm}4.38cGy$ and the mean values of $D_{mean}$ $192.77{\pm}6.98cGy$, $196.7{\pm}4.01cGy$, $198.17{\pm}4.96cGy$, $195.77{\pm}3.15cGy$ respectively. As the number of rescanning increased, the Homogeneity Index converged to 1. The beam on time was measured as 2:15, 3:15, 4:30, 5:37 on average. In the measurement process, in the low dose layer of the MU, the problem was found that it was not rescanned as many times as the set number of rescan. Conclusions : In the treatment of tumors with long-term movements, the application of layered rescanning PBS showed a more uniform dose distribution than single scan PBS. And as the number of rescan increase, the distribution of homogeneity is uniform. Compared with single scan plan and 12 rescan plan, HI value was improved by 0.32. Further studies are expected to be applicable to patients who can not be treated with respiratory synchronous radiation therapy.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.2
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• pp.85-96
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• 2019

Solar radiation is an important variable for estimation of energy balance and water cycle in natural and agricultural ecosystems. A deep neural network (DNN) model has been developed in order to estimate the daily global solar radiation. Temperature and precipitation, which would have wider availability from weather stations than other variables such as sunshine duration, were used as inputs to the DNN model. Five-fold cross-validation was applied to train and test the DNN models. Meteorological data at 15 weather stations were collected for a long term period, e.g., > 30 years in Korea. The DNN model obtained from the cross-validation had relatively small value of RMSE ($3.75MJ\;m^{-2}\;d^{-1}$) for estimates of the daily solar radiation at the weather station in Suwon. The DNN model explained about 68% of variation in observed solar radiation at the Suwon weather station. It was found that the measurements of solar radiation in 1985 and 1998 were considerably low for a small period of time compared with sunshine duration. This suggested that assessment of the quality for the observation data for solar radiation would be needed in further studies. When data for those years were excluded from the data analysis, the DNN model had slightly greater degree of agreement statistics. For example, the values of $R^2$ and RMSE were 0.72 and $3.55MJ\;m^{-2}\;d^{-1}$, respectively. Our results indicate that a DNN would be useful for the development a solar radiation estimation model using temperature and precipitation, which are usually available for downscaled scenario data for future climate conditions. Thus, such a DNN model would be useful for the impact assessment of climate change on crop production where solar radiation is used as a required input variable to a crop model.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.137-144
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• 2021

Purpose : The usability of X-Jaw split VMAT was evaluated by comparative analysis of the dose distribution between the treatment plan divided by X-Jaw and Full field VMAT treatment plan in left breast cancer treatment including supraclavicular lymph nodes. Materials and Methods : 10 patients with left breast cancer, including supraclavicular lymph nodes, were simulated using vacuum cushion, and 2 Full field Arc VMAT and 4 X-Jaw split Arc VMAT were planned The treatment plan was designed to include more than 95% of the Planning Target Volume (PTV) and to be minimally irradiated in the surrounding Organ at risk (OAR). Dose analysis of PTV and OAR was performed through dose volume histogram (DVH). Results : The Full field VMAT treatment plan and the X-Jaw split VMAT treatment plan of 10 patients were expressed as average values and compared. The difference between the two treatment plans was not large, with a Conformity index (CI) of 1.05±0.04, 1.04±0.03, and a Homogeneity index (HI) of 1.07±0.008, 1.07±0.009. For OAR, V5 in the left lung is 56.1±6.50%, 50.4±6.30%, and V20 is 20.0±4.15%, 13.52±3.61%. Compared to Full field VMAT, V5 decreased by 10.0% V20 by 32.6% in X-Jaw split VMAT. The V30 of the heart is 3.68±1.85%, 2.23±1.52%, and the Mean dose is 8.93±1.65 Gy, 7.67±1.52 Gy. In the X-Jaw split VMAT, V30 decreased by 39.3% and the Mean dose decreased by 14.1%. The left lung and heart, which are normal tissues, were found to have a statistical significance of that p-value is less than 0.05. Conclusion : In the case of left breast cancer treatment, which includes Supraclavicular lymph nodes with a large PTV volume and a length of X Jaw of 15 cm or more, the X-Jaw split VMAT shows improved dose distribution, which can reduce radiation dose of OAR such as lungs and heart, while maintaining similar PTV coverage with HI and CI equivalent to Full field VMAT. It is thought to be effective in reducing radiation complications.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.343-355
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• 2022

Customized cosmetics are continuously mentioned as cosmetics in response to changes in the social environment and trends that emphasize individuality. Therefore, in this study, four types of nanoemulsion ampoules corresponding to skin types were prepared by different ratios of nanoemulsion formulation and ampoule formulation, and the applicability as a customized cosmetic base was checked. Particle size, polydispersity index, zeta potential, and viscosity according to time for 90 d were measured for four nanoemulsion ampoules with different volatile residues, and turbiscan was measured as a method for evaluating the stability of a colloidal dispersion system. Finally, human usability satisfaction was evaluated. As a result, it was confirmed that four kinds of nanoemulsion ampoules had a higher amount of volatile residue in the dry skin test product than in the oily skin test product. The pH was in the range of 6.41 to 6.88, and the particle size was in the range of 170 to 174 nm, and the change after 90 d was within 1.2% of the maximum, and there was no specificity in particle size stability. It was confirmed that the polydispersity index was almost constant, and showed a particle size distribution close to monodispersity by showing a change within a value smaller than 0.21 in all test products. The zeta potential was initially -63 mV or more for all four types of test products, and although it showed a slight decrease with time, there was little change to the extent of a maximum decrease of 2.5%. Viscosity was initially in the range of 4,100 to 5,100 cps and showed a decreasing trend with time, showing a maximum decrease of 37.7%. In the turbiscan measurement, the turbiscan stability index, a measure of stability, was all below 1.0, indicating dispersion stability. In the usability satisfaction evaluation (6 points) of 4 nanoemulsion ampoules corresponding to skin type, oily skin product (5.42 ± 0.67 points) > neutral oily skin product (5.36 ± 0.67 points) > neutral dry skin product (5.15 ± 0.69 point) > dry skin product (4.75 ± 0.75 points) in the order of evaluation. Four types of nanoemulsion ampoules are physically stable and have confirmed their applicability as a customized cosmetic base according to skin type, and are expected to expand in various ways.

• Journal of the Korean earth science society
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• v.44 no.1
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• pp.13-35
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• 2023

Ocean currents play the most important role in causing and controlling global climate change. The water depth of the Yellow Sea is very shallow compared to the East Sea, and the circulation and currents of seawater are quite complicated owing to the influence of various wind fields, ocean currents, and river discharge with low-salinity seawater. The Yellow Sea Warm Current (YSWC) is one of the most representative currents of the Yellow Sea in winter and is closely related to the weather of the southwest coast of the Korean Peninsula, so it needs to be treated as important in secondary-school textbooks. Based on the 2015 revised national educational curriculum, secondary-school science and earth science textbooks were analyzed for content related to the YSWC. In addition, a questionnaire survey of secondary-school science teachers was conducted to investigate their perceptions of the temporal variability of ocean currents. Most teachers appeared to have the incorrect knowledge that the YSWC moves north all year round to the west coast of the Korean Peninsula and is strong in the summer like a general warm current. The YSWC does not have strong seasonal variability in current strength, unlike the North Korean Cold Current (NKCC), but does not exist all year round and appears only in winter. These errors in teachers' subject knowledge had a background similar to why they had a misconception that the NKCC was strong in winter. Therefore, errors in textbook contents on the YSWC were analyzed and presented. In addition, to develop students' and teachers' data literacy, class materials on the YSWC that can be used in inquiry activities were developed. A graphical user interface (GUI) program that can visualize the sea surface temperature of the Yellow Sea was introduced, and a program displaying the spatial distribution of water temperature and salinity was developed using World Ocean Atlas (WOA) 2018 oceanic in-situ measurements of water temperature and salinity data and ocean numerical model reanalysis field data. This data visualization materials using oceanic data is expected to improve teachers' misunderstandings and serve as an opportunity to cultivate both students and teachers' ocean and data literacy.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.4
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• pp.51-58
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• 2023

In this study, anaerobic co-digestion was carried out using desulfurization sludge and sewage sludge (primary sludge) to evaluate the effects of sulfur compounds in anaerobic digestion. The experiment was carried out in the form of a batch test using 500 mL duran bottle, and the mixing ratio of the feedstock was selected based on the ratio of COD/SO₄. As a result of the experiment, it was confirmed that the amount of biogas generated and the yield decreased at the mixing ratio of COD/SO₄ 20 or less. In particular, below COD/SO₄ 10, it was lower than seed (283.5 mL) which was set without feedstock to correct biogas generated by itself from seed sludge. Methane yield tended to decrease from a ratio of COD/SO₄ 20 or less to 0.135 m³/kg VS compared to 0.396 m³/kg VS of COD/SO₄ 50. In addition, compared to 0.0097 m³/kg VS of hydrogen sulfide yield from COD/SO₄ 50, the ratio of COD/SO₄ 20 increased sharply to 0.0223 m³/kg VS, and in particular, the highest result was 0.0855 m³/kg VS in COD/SO₄ 10. Based on these results, it is judged that the effect of sulfide in anaerobic digestion can have an adverse effect if the COD/SO₄ ratio decreases to less than 20.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.156-163
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• 2009

Statement of problem: Recently, there have been increased esthetic needs for posterior dental restorations. The failure of posterior dental ceramic restoration are possible not only by the characters of the component materials but also by the type of food. Purpose: The research aim was to compare the in vitro fracture resistance of simulated first molar crowns fabricated using 4 dental ceramic systems, full-porcelain-occlusal-surfaced PFG, half-porcelain-occlusal-surfaced PFG, Empress 2, Ice Zirkon and selected Korean foods. Material and methods: Eighty axisymmetric crowns of each system were fabricated to fit a preparation with 1.5- to 2.0-mm occlusal reduction. The center of the occlusal surface on each of 15 specimens per ceramic system was axially loaded to fracture in a Instron 4465, and the maximum load(N) was recorded. Afterwards, selected Korean foods specimens(boiled crab, boiled chicken with bone, boiled beef rib, dried squid, dried anchovy, round candy, walnut shell) were prepared. 15 specimens per each food were placed under the Instron and the maximum fracture loads for them were recorded. The 95% confidence intervals of the characteristic failure load were compared between dental ceramic systems and Korean foods. Afterwards, on the basis of previous results, 14Hz cyclic load was applied on the 4 systems of dental ceramic restorations in MTS. The reults were analyzed by analysis of variance and Post Hoc tests. Results: 95% confidence intervals for mean of fracture load 1. full porcelain occlusal surfaced PFG Crown: 2599.3 to 2809.1 N 2. half porcelain occlusal surfaced PFG Crown: 3689.4 to 3819.8 N 3. Ice Zirkon Crown: 1501.2 to 1867.9 N 4. Empress 2 Crown: 803.2 to 1188.5 N 5. boiled crab: 294.1 to 367.9 N 6. boiled chicken with bone: 357.1 to 408.6 N 7. boiled beef rib: 4077.7 to 4356.0 N 8. dried squid: 147.5 to 190.5 N 9. dried anchovy: 35.6 to 46.5 N 10. round candy: 1900.5 to 2615.8 N 11. walnut shell: 85.7 to 373.1 N under cyclic load(14Hz) in MTS, fracture load and masticatory cycles are: 1. full porcelain occlusal surfaced PFG Crown fractured at 95% confidence intervals of 4796.8-9321.2 cycles under 2224.8 N(round candy)load, no fracture under smaller loads. 2. half porcelain occlusal surfaced PFG Crown fractured at 95% confidence intervals of 881705.1-1143565.7 cycles under 2224.8 N(round candy). no fracture under smaller loads. 3. Ice Zirkon Crown fractured at 95% confidence intervlas of 979993.0-1145773.4 cycles under 382.9 N(boiled chicken with bone). no fracture under smaller loads. 4. Empress 2 Crown fractured at 95% confidence intervals of 564.1-954.7 cycles under 382.9 N(boiled chicken with bone). no fracture under smaller loads. Conclusion: There was a significant difference in fracture resistance between experimental groups. Under single load, Korean foods than can cause fracture to the dental ceramic restorations are boiled beef rib and round candy. Even if there is no fracture under single load, cyclic dynamic load can fracture dental posterior ceramic crowns. Experimental data with 14 Hz dynamic cyclic load are obtained as follows. 1. PFG crown(full porcelain occlusion) was failed after mean 0.03 years under fracture load for round candy(2224.8 N). 2. PFG crown(half porcelain occlusion) was failed after mean 4.1 years under fracture load for round candy(2224.8 N). 3. Ice Zirkon crown was failed after mean 4.3 years under fracture load for boiled chicken with bone(382.9 N). 4. Empress 2 crown was failed after mean 0.003 years under fracture load for boiled chicken with bone(382.9 N).