• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.165-175
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• 2019

In response to elevated temperature, a shift in the rice planting period was proposed as a promising option in temperate regions. To understand the yield response of early maturing rice to different transplanting dates and to analyze the related agronomic traits in the central plain area, we performed a two-year study using different transplanting dates and six varieties in Suwon, Korea. The maximum head rice weight was achieved in the treatments transplanted between June 14 and 29, depending upon the varieties. The optimal mean temperature during the 40 days from heading stage for attaining the maximum head rice weight was $21.8^{\circ}C$ on the average of six varieties. The index of head rice weight was positively correlated with the indices of both the milled rice weight and head rice percentage, the latter showing a higher coefficient of determination. The highest milled rice weight was commonly achieved from the treatment transplanted on June 29, where the head rice weight was also the highest. The index of milled rice weight was significantly correlated with the indices of grain filling percentage and number of spikelets per area, but not correlated with the index of 1000-brown rice weight. The transplanting date with the highest milled rice yield produced the largest number of spikelets per area, greatest biomass at the heading and harvesting stages, and highest level of harvest index. We suggest that the optimal transplanting date for early maturing rice varieties in the central plain area is from June 14 to 29. High head rice yield in this study was attributed to increased spikelets owing to the increased biomass production at the heading stage, enhanced grain filling due to the high biomass production and harvest index at maturity, and improved head rice percentage.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.923-929
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• 2022

The Chuncheon Mullori area is an underprivileged area of water welfare where local water supply is not supplied, and it is supplying water to the villages with small water supply facilities using lateral flow and groundwater as water sources. This is an area with poor water supply conditions, such as relying on water trucks due to water shortages during the recent severe drought. Therefore, in order to solve the problem of water shortage during drought and to prepare for the increasing water demand, a sand dam was installed along the valley, and this facility has been operating since May 2022. In this study, repeated simulations were performed according to the hydraulic conductivity of the filler material and the storage coefficient value for the inflow condition for about two years from mid-March 2020 to mid-March 2022. For each case, the amount of discharge through the perforated drain pipe was calculated. Overall, as the hydraulic conductivity increased, the amount of discharge and its ratio increased. However, when the hydraulic conductivity of the second floor was relatively low, the amount of discharge increased and then decreased as the hydraulic conductivity of the third floor increased. This is considered to be due to the fact that the water level was kept low due to the rapid drainage compared to the net inflow into the third floor because the water permeability of the third floor and the drainage coefficient of the drain pipe were large. As a result of simulating the flow of the open channel in the upper part of the sand dam as a hypothetical groundwater layer with very high hydraulic conductivity, the decrease in discharge rate was slower than the increase in the hydraulic conductivity of the hypothetical layer, but it was clearly shown that the discharge volume decreased relatively as the hydraulic conductivity of the virtual layer increased.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.111-118
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• 2016

Acne vulgaris is a chronic inflammatory condition characterized by comedo, papule, cyst, nodule and postinflammatory hyperpigmentation. Meanwhile, it is also induced by adverse event of drugs. Among them, acneiform folliculitis is a side effect of epidermal growth factor receptor (EGFR) inhibitor, which is an anticancer agent, and its incidence may occur in upward of 75 ~ 100% of cases. The main method of acne vulgaris treatment is oral antibiotics, retinoids, topical medication and so on. However, it is limitation that teratogenicity caused by retinoids and antibiotic resistance increased by using antibiotics. In this study, we aimed to evaluate the clinical efficacy and safety of topical recombinant human (rh) EGF in treating facial acne vulgaris. Twenty three Koreans (age: 10 ~ 29 years) with mild to moderate acne vulgar participated in the study and applied topical rhEGF cream (trouble control EGF) with 3 products (trouble control clarifying cleansing foam, trouble control all-clear filling toner, redroll calming moisture) on their face twice daily for four weeks. Several assessment methods were applied: Acne lesion counts score by investigator's global assessment, efficacy and satisfaction score by subjects. Skin sebum output level, hydration level and redness level were also measured at each visit. At the final visit, skin sebum level, transepidermal water loss, skin redness statistically decreased and acne lesions (comedone, papule) were statistically reduced. No severe side effects were observed during the study. In conclusion, topical rhEGF seems to be an effective and safe adjuvant treatment option for mild acne vulgaris.

• The Korean Journal of Pain
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• v.27 no.4
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• pp.353-359
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• 2014

Background: Epidural steroid injections are an accepted procedure for the conservative management of chronic backache caused by lumbar disc pathology. The purpose of this study was to evaluate the epidurographic findings for the midline, transforaminal and parasagittal approaches in lumbar epidural steroid injections, and correlating them with the clinical improvement. Methods: Sixty chronic lower back pain patients with unilateral radiculitis from a herniated/degenerated disc were enrolled. After screening the patients according to the exclusion criteria and randomly allocating them to 3 groups of 20 patients, fluoroscopic contrast enhanced epidural steroids were injected via midline (group 1), transforaminal (group 2) and parasagittal interlaminar (group 3) approaches at the level of the pathology. The fluoroscopic patterns of the three groups were studied and correlated with the clinical improvement measured by the VAS over the next 3 months; any incidences of complications were recorded. Results: The transforaminal group presented better results in terms of VAS reduction than the midline and parasagittal approach groups (P < 0.05). The epidurography showed a better ventral spread for both the transforaminal (P < 0.001) and the paramedian approaches (P < 0.05), as compared to the midline approach. The nerve root filling was greater in the transforaminal group (P < 0.001) than in the other two groups. The ventral spread of the contrast agent was associated with improvement in the VAS score and this difference was statistically significant in group 1 (P < 0.05), and highly significant in groups 2 and 3 (P < 0.001). In all the groups, any complications observed were transient and minor. Conclusions: The midline and paramedian approaches are technically easier and statistically comparable, but clinically less efficacious than the transforaminal approach. The incidence of ventral spread and nerve root delineation show a definite correlation with clinical improvement. However, an longer follow-up period is advisable for a better evaluation of the actual outcom.

• Economic and Environmental Geology
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• v.26 no.3
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• pp.259-265
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• 1993

The variation of H/F coefficient (Hubnerite/Feberite coefficient) and the temperature of formation with depth have been studied for the hydrothermal tungsten-quartz veins from Ssangjeon, Weolag, Cheongyang, and Sannae mines. All samples were selected at the same paragenetic stage and mineral assemblege according to depth. The studied mines provide an opportunity to examine and regional variations in wolframite composition in different provinces. The formation temperature is linearly related to the depth. At the Weolag, Cheongyang and Sannae mines, the H/F ratio of wolframite and filling temperatures of fluid inclusions in quartz show a general tendency to decrease at shallow levels, in spite of different geological settings. This implies the pH of fluid will decrease vertically with falling temperature and the high H/F ratio of wolframite in deep zone result in an increase of pH with depth. The Ssangjeon mine exhibits a tendency to increase slightly upwards at shallow level. This implies a different geochemical environment (high pH environment) for the Ssangjeon mine, as compared to the other three mines. The H/F coefficient pattern suggests that it is a useful geothermometer for vein-type tungsten deposits in Korea. The H/F coefficient as an indication of depth should be examined for use in exploration.

• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.145-149
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• 2003

Manufacturing facilities of the pharmaceuticals must meet certain level of the cleanness required so that foreign substances such as dust, moisture, heat, microorganism, or virus do not contaminate the product. In case of radiopharmaceuticals for medical treatment and diagnosis, not only should the operators and environment be protected from radiation but also need to be isolated from the foreign contaminant. Therefore, manufacturing facilities for radiopharmaceuticals must satisfy the design standards of both hot cell and clean room which are specified by GMP. However, standards of maintaining negative pressure for preventing spread of radioactive contaminant in isolated facilities conflict with the standards of maintaining positive pressure for keeping cleanness. To solve this problem, air pressure of hot cell was designed lower than in the adjacent area to meet standards of the radiation safety. To keep higher cleanness in certain part of the hot cell for filling, minimal relative positive pressure allows. In order to effectively maintain the cleanness that is required for production of Tc-99m generator, which takes 70% of whole demand of radiopharmaceuticals, the rooms placed in each side of production room are used as a buffer area and three lead hot cells are installed in production room. In this research, we established the appropriate engineered design concept for Tc-99m generator manufacturing facility, which satisfies both GMP cleanness standard for preventing particles, bacteria, other contaminants and the regulations of radiation safety for supervising and controlling the amount of radiation exposure and exhausted radioactivity. And the concept of multi-barrier buffer zones is introduced to apply negative air pressure for hot cell with first priority and to continue relative positive air pressure for clean room.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.2
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• pp.139-145
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• 2012

There is a unique type of fatty acid in the hair surface. 18-methyleicosanoic acid (18-MEA) is an unusual anteiso fatty acid covalently linked to the outermost surface of hair cuticle. A layer of 18-MEA is located in the upper ${\beta}$-layer of the CMC that is responsible for the low surface energy and low friction resistance of the hair's outer surface. The high mobility of 18-MEA molecule facilitates spreading of extraneous lipid by decreasing interfacial shear strength. In this study, we introduced N-hydroxyl succinimidyl ester functional group to the one end of C10 - 40 isoalkyl acid for regenerating hair surface with covalently bound fatty acid layer. The re-hydrophobicization of hair surface has been investigated by contact angle measurement. The inner moisture content of hair at different levels of humidity (40, 55, 70 %RH) was measured by electric moisture analyzer. Treatment with Hydroxysuccinimidyl C10 - 40 Isoalkyl Acidate (HCIA) was supposed to make hair surface smoother by filling the cracks between cuticles with covalently bound fatty acid monomolecular layer like cuticle glue. This glue effect was also confirmed with line profile of AFM images. Therefore, the moisture and structural components of inner hair were not easily flown out and the optimum moisture content could be kept constantly though the outside humidity level was changed. The lateral force microscopy (LFM) by using atomic force microscope showed that the friction force of hair surface treated with HCIA was decreased. It also showed the constantly sustained friction value even after shampooing repeated 15 times.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.129-134
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• 2020

Moisture infiltration inside the solar cell module, filling of EVA sheet, melting of the frame seal, and deterioration of power generation performance in the module one year after installation are occurring. Whitening phenomenon, electrode corrosion phenomenon, and dielectric breakdown phenomenon are appearing in solar cell module installed in Korea before 5-7 years, leading to deterioration of power generation performance, and big problems for long-term reliability and long life technology are emerging. Therefore, in order to solve these problems, the development of a micro inverter (MiCrco Inverter Converter, MiC) including the function of securing the durability of the solar cell module and monitoring the aging progress and the solar cell based on the monitoring data from the MiC smart monitoring programs have been proposed to determine the aging of modules. In addition, in order to become a highly efficient solar smart monitoring system through systematic operation management through IT convergence with MiC that has enhanced monitoring function of solar cell module, SoC(System On Chip) in micro inverter is the environment for solar cell module. There is a demand for functions that can detect information in a complex manner and perform communication and control when necessary. Based on these requirements, this paper aims to develop SoC-based low-cost MiC smart photovoltaic system technology.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.161-163
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• 2002

The BNCT(Boron Neutron Capture Therapy) facility has been developed in Hanaro(High-flux Advanced Neutron Application Reactor), a research reactor of Korea Atomic Energy Research Institute. A typical tangenial beam port is utilized with this BNCT facility. Thermal neutrons can be penetrated within the limits of the possible maximum instead of being filtered fast neutrons and gamma rays as much as possible using the silicon and bismuth single crystals. In addition to, the liquid nitrogen (LN$_2$) is used to cool down the silicon and bismuth single crystals for the increase of the penetrated thermal neutron flux. Neutron beams for BNCT are shielded using the water shutter. The water shutter was designed and manufactured not to interfere with any other subsystem of Hanaro when the BNCT facility is operated. Also, it is replaced with conventional beam port plug in order to cut off helium gas leakage in the beam port. A circular collimator, composed of $\^$6/Li$_2$CO$_3$ and polyethylene compounds, is installed at the irradiation position. The measured neutron flux with 24 MW reactor power using the Au-198 activation analysis method is 8.3${\times}$10$\^$8/ n/cm$^2$ s at the collimator, exit point of neutron beams. Flatness of neutron beams is proven to ${\pm}$ 6.8% at 97 mm collimator. According to the result of acceptance tests of the water shutter, the filling time of water is about 190 seconds and drainage time of it is about 270 seconds. The radiation leakages in the irradiation room are analyzed to near the background level for neutron and 12 mSv/hr in the maximum for gamma by using BF$_3$ proportional counter and GM counter respectively. Therefore, it is verified that the neutron beams from BNCT facility in Hanaro will be enough to utilize for the purpose of clinical and pre-clinical experiment.

• Journal of the Korean Geotechnical Society
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• v.36 no.10
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• pp.33-39
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• 2020

A geological repository has been considered as an option for the disposal of high-level radioactive waste (HLW). The HLW is disposed in a host rock at a depth of 500~1,000 meters below the ground surface based on the concept of engineered barrier system (EBS). The EBS is composed of a disposal canister, buffer material, backfill material, and gap-filling material. The compacted bentonite buffer is very important since it can restrain the release of radionuclide and protect the canister from the inflow of ground water. The saturation of the buffer decreases because high temperature in a disposal canister is released into the surrounding buffer material, but saturation of the buffer increases because of the inflow of ground water. The unsaturated properties of the buffer are critical input parameters for the entire safety assessment of the engineered barrier system. In Korea, Gyeongju bentonite can be considered as a candidate buffer material, but there are few test results of the unsaturated properties considering temperature variation. Therefore, this paper conducted experiment of soil-water characteristic curve for the Gyeongju compacted bentonite considering temperature variation under a constant water content condition. The relative error showed approximately 2% between test results and modified van-Genuchten model values.