• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.32 no.6
• /
• pp.481-495
• /
• 2020

After the resonator on the basis of the wave-filter theory was designed to control the waves with a specific frequency range surging into the harbor, the several case with the use of resonator have been reported in some part of sea, including the port of Long Beach, USA, and yacht harbor at Rome, Italy in order to control the long-period wave motion from the vessels. Recently, the utility and applicability of the resonator has been sufficiently verified in respect of the control of tsunami approximated as the solitary wave and/or the super long-period waves. However, the case with the application of tsunami in the real sea have not been reported yet. In this research, the respective case with the use of existing resonator at the port of Mukho and Imwon located in the eastern coast of South Korea were studied by using the numerical analysis through the COMCOT model adapting the reduction rate of 1983 Central East Sea tsunami and 1993 Hokkaido Southwest off tsunami. Consequently, the effectiveness of resonator against tsunami in the real sea was confirmed through the reduction rate of maximum 40~50% at the port of Mukho, and maximum 21% at the port of Imwom, respectively. In addition, it was concluded that it is necessary to study about the various case with application of different shape, arrangement, and size of resonator in order to design the optimal resonator considering the site condition.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.32 no.6
• /
• pp.575-586
• /
• 2020

In this study, a two-dimensional hydraulic model test was conducted to examine the hydraulic phenomena that occur around the seawall when wave and wind coexist. Based on recent seawall repair and reinforcement examples, the experimental section was constructed under the condition of installing wave dissipation blocks on the safety surface of four different representative seawalls. Water level fluctuation, reflection, overtopping and wave pressure characteristics according to external force change were reviewed. It was confirmed that the top concrete shape of the seawall is the most important factor of the hydraulic characteristics that appear in front of the seawall, and the tendency is more pronounced when wind acts. Even in the case of vertical type seawall, when wind of 3 m/s~5 m/s occurs, the amount of overtopping increases to about 5%~12%. In the case of wave pressure, it was confirmed from the experimental results that the value increased from about 1.5 to 2.2 times in front of the top of concrete block. In addition, it was confirmed that when the shape of the seawall was different, the range of change in the hydraulic characteristics appeared larger. Therefore, when designing a seawall of a new shape, a more detailed review of the hydraulic characteristics should be accompanied based on these experimental results.

• Journal of Life Science
• /
• v.31 no.1
• /
• pp.47-51
• /
• 2021

In today's society, functional whitening cosmetics are important to beauty. Fungi are known to produce a variety of whitening-related metabolites. In this study, we searched for tyrosinase inhibitors with metabolic products derived from Trichoderma atroviride supernatant in order to apply a material for whitening functional cosmetics. In addition, the inhibitory effect was compared to arbutin, which has already been approved as a whitening raw material by the Korea Ministry of Food and Drug Safety (KMFDS). The metabolites from the T. atroviride supernatant showed higher tyrosinase inhibitory activity than that of arbutin. Some of the tyrosinase inhibitors were stable to heat, whereas some were unstable. The heat unstable material was exhibited in the case of samples treated with little amounts, such as 0.02~0.2%. They were very unstable in acidic and alkali pHs, especially under acidic conditions. However, it was found that a weakly-acidic to neutral pH range was the optimal working pH, especially neutral pH. Since the activity of the inhibitory substances in the T. atroviride supernatant was maintained regardless of proteinase K treatment, it was assumed that the metabolites, but not the bioactive peptides, were involved in the activity. In summary, we propose that the metabolites derived from T. atroviride supernatant have strong potential as whitening raw material.

• Journal of the Korean Society of Radiology
• /
• v.15 no.1
• /
• pp.85-91
• /
• 2021

The purpose of this study is to derive an equation to verify the accuracy of the dose rate for each component calculated at the measurement point outside the maze door when designing the maze door of 6 MV X-ray beam. Based on the component-specific dose rate calculation formula for the measurement point outside the maze door described in NCRP Report 151 and IAEA Safety Report Series 47, the dose rate calculation formula for each component when applying the values of the drawing-based parameters and the dose rate calculation formula for each component when applying the values of conservative parameters are derived. From the two dose rate calculation formulas for each component, the dose rate verification formula for each component at the measurement point outside the maze door was derived. The resulting dose rate verification formula for each component at the measurement point outside the maze door can be compared and analyzed whether the dose rate for each component at the measurement point outside the maze door calculated by the designer falls within the range of the dose rate obtained from the derived dose rate verification formula for each component. This verification formula is considered to be practically useful in verifying the accuracy of the dose rate for each component calculated by the designer.

• Journal of Korean Neurosurgical Society
• /
• v.64 no.2
• /
• pp.271-281
• /
• 2021

Objective : Immune checkpoint inhibitors (ICIs) are approved for treating non-small-cell lung cancer (NSCLC); however, the safety and efficacy of combined ICI and Gamma Knife radiosurgery (GKS) treatment remain undefined. In this study, we retrospectively analyzed patients treated with ICIs with or without GKS at our institute to manage patients with brain metastases from NSCLC. Methods : We retrospectively reviewed medical records of patients with brain metastases from NSCLC treated with ICIs between January 2015 and December 2017. Of 134 patients, 77 were assessable for brain responses and categorized into three groups as follows : group A, ICI alone (n=26); group B, ICI with concurrent GKS within 14 days (n=24); and group C, ICI with non-concurrent GKS (n=27). Results : The median follow-up duration after brain metastasis diagnosis was 19.1 months (range, 1-77). At the last follow-up, 53 patients (68.8%) died, 20 were alive, and four were lost to follow-up. The estimated median overall survival (OS) of all patients from the date of brain metastasis diagnosis was 20.0 months (95% confidence interval, 12.5-27.7) (10.0, 22.5, and 42.1 months in groups A, B, and C, respectively). The OS was shorter in group A than in group C (p=0.001). The intracranial disease progression-free survival (p=0.569), local progression-free survival (p=0.457), and complication rates did not significantly differ among the groups. Twelve patients showed leptomeningeal seeding (LMS) during follow-up. The 1-year LMS-free rate in treated with ICI alone group (69.1%) was significantly lower than that in treated with GKS before ICI treatment or within 14 days group (93.2%) (p=0.004). Conclusion : GKS with ICI showed no favorable OS outcome in treating brain metastasis from NSCLC. However, GKS with ICI did not increase the risk of complications. Furthermore, compared with ICI alone, GKS with ICI may be associated with a reduced incidence of LMS. Further understanding of the mechanism, which remains unknown, may help improve the quality of life of patients with brain metastasis.

• Journal of the Korean Society of Radiology
• /
• v.15 no.3
• /
• pp.307-312
• /
• 2021

In nuclear medicine, radioactive isotope tracers are administered to the human body to obtain and evaluate disease morphological information and biological function information. Dose calibrator is a device used to measure the radioactivity of a single nuclide in medical institutions. Administration of the correct dose to the human body acts as an important factor in diagnosis and treatment, and measurement through a dose calibrator before administration is the most important factor. Dose calibrator performs daily quality control after installation in each medical institution. Quality control is a means of guaranteeing quality control after installation, and is essential for improving the quality of treatment and promoting patient safety. Therefore, accurate and standardized performance evaluation methods should be established. In this study, 3D printing was used for quantitative evaluation of quality control by increasing the accuracy and standardization of quality control. When the 3D printer was installed and reproducibility was tested, the error range of the expected value and reading value decreased by 0.302% in the F-18 nuclide and 0.09% in the ^99mTc-pertechnate nuclide than when the 3D printer was installed. The error rate for other nuclides was also found to have a low error rate for reproducibility tests when 3D printing was installed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.200-210
• /
• 2020

The maintenance of educational facilities was assembled in 12 project classifications of the Educational Improvement Program. The priorities were decided by the evaluation scores derived from the condition investigation, and maintenance works were budgeted in the order of priorities. These priorities were a schedule for conducting maintenance and an important criterion for obtaining a construction order. Several restrictions in the condition investigation exist, which derives budgets and conducts maintenance separately based on the priorities. An educational facility manager has a restriction in quantity take-off, which results in an incorrect budget. Discomfort would occur in an educational environment, and a period of infringing safety would increase. This study proposes applying a BIM in the condition investigation and the planning framework for work-type packaging. A BIM supports a budget calculation and derives evaluation scores by linking a repair and an inspection result. The work-type packaging algorithm divides a budget allocation range and derives the result of a grouped work-types applied in an equivalent space and element. As a result of applying cases, it could shorten the duration by approximately 37.4%. Its usability in selecting a grouped work-type was evaluated through an assessment with workers.

• Clean Technology
• /
• v.26 no.4
• /
• pp.304-310
• /
• 2020

In order to apply a photocatalyst (TiO2) to various building materials, TiO2-mayenite was prepared in this study. The TiO2 was synthesized using the sol-gel method by fixing titanium isopropoxide (TTIP) and urea at a ratio of 1 : 1. Later, they were calcined in a temperature range of 400-700 ℃ to analyze the properties according to temperature. BET, TGA, and XRD were used to analyze the physical and chemical properties of TiO2. The nitrogen oxide removal test was confirmed by measuring the change in the concentration of NO for 1 h according to KS L ISO 22197-1. The prepared TiO2 samples exhibited an anatase crystal structure below 600 ℃, and TiO2 (urea)-400 showed the highest nitrogen oxide removal rate at 2.35 µmol h-1. TiO2-mayenite was prepared using two methods: spraying TiO2 dispersion solution (s/s) and sol-gel solution (g/s). Through BET and XRD analysis, it was found that 5-TiO2 (g/s) prepared by spraying a sol-gel solution has maintained its crystallinity even after heat treatment. Also, 5-TiO2 (g/s)-500 showed the highest removal rate of 0.55 µmol h-1 in the nitrogen oxide removal test. To prepare TiO2-mayenite, it was confirmed that mayenite should be blended with TiO2 in a sol-gel state to maintain the crystal structure and exhibit a high nitrogen oxide removal rate.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.27 no.1
• /
• pp.45-51
• /
• 2021

Purpose: Problems related to the elderly's daily life, such as social isolation and absence of a place to go, are already widely recognized, but there are few domestic studies or support policies for this, and the elderly leisure welfare facilities provided by the state do not fully support the elderly's daily life. There are studies related to the elderly's neighborhood environment and facilities, which can be seen as the third place for the elderly in Korea, but these are mostly quantitative studies. In order to talk about the third place for daily support for the elderly in Korea, a detailed study of the use cases of the third place in Korea is needed. This study analyzes the third place of the elderly in Korea and discovers the characteristics and components. Based on the detailed analysis of the third place of the elderly, the characteristics of the third place of the elderly in Korea and the elements constituting it are found to be able to represent the specific necessary environment of the third place of the elderly. Methods: The research targets include 'A Mill' (located in Jungnang-gu, Seoul), and 'Roadside in front of Villa B'(located in Dongdaemun-gu, Seoul), 'C-dong roadside park'(located in Dobong-gu, Seoul) within the range of repeated observations and meetings among the places used as a third place for the elderly was selected. The site survey consisted of in-depth interviews, observational surveys, and participatory observations. In-depth interviews were held for a total of 5 months, from October to December 2019 and from April to May 2020. Results: As a result, a total of 11 characteristics (adjacent to the residence, an open place, an independent space, a comfortable place to stay, a pleasant space, safety is guaranteed, a place that has been operated for a long time, a place that can be used autonomously, a place where social exchange occurs, No financial burden, fun activities) was discovered. Implications: This study is significant in that unlike the existing studies focusing on the use behavior of established institutions or facilities, the elderly identified the necessary environment through their own created places.

• Informatization Policy
• /
• v.28 no.4
• /
• pp.76-92
• /
• 2021

The value of personal information is increasing with the digital transformation of the 4th Industrial Revolution. The purpose of this study is to analyze the efficiency of personal information protection efforts of 2,000 private companies. It uses a stochastic frontier approach (SFA), a parametric estimation method that measures the absolute efficiency of protective activities. In particular, the personal information activity index is used as an output variable for efficiency analysis, with the personal information protection budget and number of personnel utilized as input variables. As a result of the analysis, efficiency is found to range from a minimum of 0.466 to a maximum of 0.949, and overall average efficiency is 0.818 (81.8%). The main causes of inefficiency include non-fulfillment of personal information management measures, lack of system for promoting personal information protection education, and non-fulfillment of obligations related to CCTV. Policy support is needed to implement safety measures and perform personal information encryption, especially customized support for small and medium-sized enterprises.