• 방사선산업학회지
• /
• 제11권1호
• /
• pp.13-18
• /
• 2017

Recently, the number of PET cyclotrons has increased in Korea. A cyclotron mainly produces $^{18}F$, which is used for the production of [$^{18}F$]FDG, a cancer diagnostic radiopharmaceutical. For radiation protection, the discharge control standard under the Nuclear Safety Act limits the radioactive concentration of $^{18}F$ in the exhaust discharged from a nuclear power utilization facility to below $2,000Bq\;m^{-3}$. However, the radioactive concentration of $^{18}F$ discharged during [$^{18}F$]FDG production at the cyclotron facility at Chosun University is maintained at about $1,500Bq\;m^{-3}$ on average, which is 75% of the concentration limit of the discharge control standard, and temporarily exceeds the standard as per the real-time monitoring results. This study evaluated the performance of the exhaust filter unit of the cyclotron facility at Chosun University by assessing the concentration of $^{18}F$ in the exhaust, and an experiment was conducted on the discharge reduction, where $^{18}F$ is discharged without reacting with the FDG precursors during [$^{18}F$]FDG synthesis and is immediately captured by the [$^{18}F$]FDG automatic synthesis unit. Based on the performance evaluation results of the exhaust filter at the cyclotron facility of Chosun University, the measured capture efficiency before and after the filter was found to be 92%. Furthermore, the results of the discharge reduction experiment, where the exhaust $^{18}F$ was immediately captured by the [$^{18}F$]FDG synthesizer, showed a very satisfactory 94.3% reduction in the concentration of discharge compared to the existing discharge concentration.

• 한국가족복지학
• /
• 제54호
• /
• pp.225-262
• /
• 2016

본 연구의 목적은 아동보호서비스 개입사례의 재학대 특성을 확인하는 것이다. 이를 위해 국가아동학대정보시스템에 접근하여 2012년에 신고 접수된 전수를 추출하였고 이들 사례 중 아동학대로 판정된 사례를 중심으로 2014년까지 총 3년간의 데이터를 수집하여 해당기간 내 재학대가 발생한 사례들의 특성을 확인하였다. 재학대 특성은 생존분석을 통해 재학대 발생 시점 및 빈도를 중심으로 살펴보았다. 분석결과, 2012년에 학대판정을 받은 5,542사례 중 323사례가 이후 3년 이내에 재학대를 기록하였다. 대부분의 사례(93.5%)가 1회의 재학대를 기록하였지만 2회의 재학대를 기록한 사례도 21사례로 확인되었다. 또한 학대로 판정된 이후 1개월 이내에 가장 많은 재학대가 발생하였고, 이전 아동보호서비스 연루 유무, 중복학대 유무, 신체학대 포함 여부, 서비스 제공 유형 등에 따라 재학대 발생 시기 및 빈도가 다르게 나타났다. 아동의 연령 및 문제행동 수, 학대행위자의 스트레스 및 사회적 고립, 가족구성원인 학대행위자, 이전 아동보호서비스 연루 기록, 재신고 총 횟수 증가 등은 이후의 재학대 발생과 관련되었다. 본 연구는 이러한 분석결과를 토대로 아동학대의 재학대 예방을 위한 정책적, 실천적 함의를 논하고 관련 제언을 제시하였다.

• 디지털융복합연구
• /
• 제17권11호
• /
• pp.195-200
• /
• 2019

4차 산업혁명시대에 사물인터넷의 역할은 엔드단에서 데이터를 수집하여 빅데이터를 기술을 통하여 분석하여 미래나 행동을 분석하는 시대에 있다. 따라서 사물인터넷의 특성상 보안에 취약하여 경량화된 보안 프로토콜이 필요한 실정이다. 또한 사물인터넷의 보급은 우리 생활을 많이 변화시키고 있다. 전 세계 IT 기업들은 이미 사물인터넷 기반의 제품과 서비스에 주력하고 있으며 전자기기를 통한 통신 뿐 아니라 일반 사물과의 통신이 가능한 만물인터넷 시대로 가고 있다. 사람과 사람, 사람과 사물, 사물과 사물이 시간과 공간의 제약을 받지 않고 상호작용하면서 정보를 수집하고 분석해서 적용하고 있다. 생활은 점점 스마트해 지지만 이에 반해 개인정보 유출의 가능성은 더욱 커져서 이를 악용할 경우 사생활 침해를 넘어 생명을 위협하는 경우도 생길 것이다. 따라서 본 연구에서는 개인정보 보호를 위협하는 보안 위협과 이에 대응하는 방안을 제안하여 4차산업혁명시대에 걸맞는 안전한 사물인터넷 환경을 구축하는데 필요한 대응책을 제시하였다.

• Computers and Concrete
• /
• 제17권6호
• /
• pp.787-799
• /
• 2016

Climate anomalies in recent years, numerous natural disasters caused by landslides and a large amount of entrained sands and stones in Taiwan have created significant disasters and greater difficulties in subsequent reconstruction. How to respond to these problems efficaciously is an important issue. In this study, the sands and stones were doped with recycled materials (waste LCD glass sand, slag powder), and material was mixed for recycled ready-mixed soil. The study is based on security and economic principles, using flowability test to determine the water-binder ratio (W/B=2.4, 2.6, and 2.8), a fixed soil: sand ratio of 6:4 and a soil: sand: glass ratio of 6:2:2 as fine aggregate. Slag (at concentrations of 0%, 20%, and 40%) replaced the cement. The following tests were conducted: flowability, initial setting time, unit weight, drop-weight and compressive strength. The results show that the slump values are 220 -290 mm, the slump flow values are 460 -1030 mm, and the tube flow values are 240-590 mm, all conforming to the objectives of the design. The initial setting times are 945-1695 min. The unit weight deviations are 0.1-0.6%. The three groups of mixtures conform to the specification, being below 7.6 cm in the drop-weight test. In the compressive strength test, the water-binder ratios for 2.4 are optimal ($13.78-17.84kgf/cm^2$). The results show that Recycled ready-mixed soil materials (RRMSM) possesses excellent flowability. The other properties, applied to backfill engineering, can effectively save costs and are conducive to environmental protection.

• 고려인삼학회:학술대회논문집
• /
• 고려인삼학회 2002년도 학술대회지
• /
• pp.351-365
• /
• 2002

Earlier studies have demonstrated that chromium (Cr) VI compounds have been shown to be more toxic and carcinogenic than other chromium compounds. The aim of the present work was to evaluate the antioxidant effects of red ginseng against chromium VI -induced toxicity and free radical generation. Sixty adult male rats were divided into six equal groups include: control group, group received Cr VI alone (50 mg/kg b.w.), group treated with Korean ginseng (K. ginseng) alone (20 mg/kg b.w), group treated with Cr VI for 15 days then received K. ginseng for other 15 days, group treated with Cr VI and K. ginseng at the same time for 15 days, and group treated with K. ginseng for 15 days then Cr VI for other 15 days. The results revealed that Cr VI caused significant increase in ALT, AST, ALP, G-GT, urea, creatinine, and acid phosphatase. Whereas, it caused significant decrease in TP, albumin, testosterone, GPX, and SOD indicating a stress for liver, kidney and testes. K. ginseng alone caused significant increase in GPX and SOD activities in healthy animals and this result suggests a prophylactic role for this herb in protection against the damaging impact induced by free radical species. Furthermore, the other biochemical parameters measured after K. ginseng administration were comparable to the control values. Treatment with Cr VI followed by K. ginseng, Cr VI and K. ginseng or K. ginseng followed by Cr VI resulted in significant improvement in all tested parameters towards the normal values of the controls. However, this improvement was pronounced in the group pre-treated with K. ginseng for 15 days before Cr VI administration. It could be concluded that K. ginseng exhibited a protective action against the toxic effects of Cr VI and it had the ability to scavenge free radicals resulted from Cr VI intoxication.

• 산업경영시스템학회지
• /
• 제38권4호
• /
• pp.30-38
• /
• 2015

IT security service provides customers with the capability of protecting the networked information asset and infrastructures, and the scope of security service is expanding from a technology-intensive task to a comprehensive protection system for IT environment. To improve the quality of this service, a research model which help assess the quality is required. Several research models have been proposed and used in various service areas, but few cases are found for IT security service. In this work, a research model for the IT security quality has been proposed, based on research models such as SERVQUAL and E-S-QUAL. With the proposed model, factors which affect the service quality and the best quality measure have been identified. And the feasibility of using quantitative measures for quality has been examined. For analysis, structural equation modeling and various statistical methods such as principal component analysis were used. The result shows that satisfaction is the most significant measure affected by the proposed quality factors. Two quality factors, fulfillment and empathy, are the main determinants of the service quality. This leads to a strategy of quality improvement based on factors of emotion and perception, not of technology. The quantitative measures are considered as promising alternative measures, when combined with other measures. In order to design reliable quantitative measures, more work should be done on target processing time and users' expectation. It is hoped that work of this research will provide efficient tools and methods to improve the quality of IT security service and help future research works for other IT service areas.

• 수산해양교육연구
• /
• 제12권1호
• /
• pp.83-97
• /
• 2000

This article refers to the processions and the improvement of the 7th revised curriculum development for the Fisheries and Merchant Marine High School, published at Dec. 30, 1997. The general point of the 7th revised curriculum development was to cultivate creative Korean who will lead the epoch of globalization and information and to perform the learner-centered curriculum. Moreover, it defines the nature of Business High School not as completive but as continuing education. Based on this view, the improvment of 7th revised curriculum has been searched in varous sides. The group of general researchers and cooperators consisted of 12 members who were of university professors, teachers, related business men and executives in the administration branches, and the total researchers of 7th revised curriculum development were 90 members. The basic orientation of the research for the revised curriculum development was as following : The improvement of basic ability, job-analysis ability, integrity of theory and practice, acquisition of the certificate of national qualification, interrelation and cooperative role division between school and industrial fields, extension of self-decision ability of school and local society, protection of learner-selection right and maintaining close relations with the business-educational organization under life-long education system. Thus on the whole, the research for educational goals and contents, instructions, learning theory and evaluation is being processed with a high activity, based on the above mentioned plan of 7th revised curriculum development. At the same time, the methods and the models are being investigated. At last, it is to be noted that, in such as the 7th revised curriculum development research in this case, the effort should not be spared to harmonize the basic technological knowledge of the specialists in the Fisheries and Merchant Marine field and the cultural, liberal arts of personality education.

• 한국안전학회지
• /
• 제34권5호
• /
• pp.15-21
• /
• 2019

A rack-type warehouse has the advantage of storing a large amount in a small area by loading goods vertically. But in terms of fire risk, the fire load is very high, which can cause massive damage in the event of a fire. In the United States, research has been actively conducted to minimize the spread of vertical fires, and relevant standards have been established and operated. In Korea, research and related standards are insufficient to prevent the vertical spread of rack-type warehouse fires. In this study, an experimental study was conducted to prevent the vertical spread of a rack-type warehouse fire using a horizontal barrier and in-rack sprinklers. As a result of the test, the horizontal barrier considering the continuous flame prevented the vertical spread of the flame for a certain time. However, the horizontal barrier with continuous flame did not show the effect of preventing continuous flame. The combination of the horizontal barrier and the in-rack sprinkler prevented the vertical spread of fire effectively. In addition, the heat collecting effect through the horizontal barrier was shown and helped the early operation of the in-rack sprinklers.

• Journal of Animal Science and Technology
• /
• 제63권4호
• /
• pp.766-777
• /
• 2021

Bezafibrate, a fibrate drug used as a lipid-lowering agent to treat hyperlipidemia, is a pan-agonist of peroxisome proliferator-activated receptor alpha. It can enhance mitochondrial fatty acid oxidation, oxidative phosphorylation, and mitochondrial biogenesis. After ovulation, oocytes may get arrested at the metaphase II (MII) stage until fertilization beyond optimal timing, which is termed as post-ovulatory aging. Post-ovulatory aging is a disease that degrades DNA, mitochondria, and oxidative system, and has a negative impact on embryo development and quality; however, the impact of bezafibrate during post-ovulatory aging has not been fully defined. In the present study, we assessed the ability of bezafibrate to prevent the progression of aging in in vitro conditions as well as the underlying mechanisms in pigs. An appropriate concentration of this drug (50 µM) was added, and then oxidative stress, reactive oxygen species downstream, mitochondrial biogenesis, and mitochondrial function were analyzed via immunofluorescence staining and real-time polymerase chain reaction. Bezafibrate significantly alleviated reactive oxygen species and ameliorated glutathione production simultaneously in oocytes and embryos. Moreover, it diminished H2A.X and attenuated CASPASE 3 expression produced by oxidative stress in oocytes and embryos. Furthermore, bezafibrate remarkably improved the mitochondrial function and blastocyst quality as well as markedly reduced the mitochondria/TOM20 ratio and mtDNA copy number. The elevated PARKIN level indicated that mitophagy was induced by bezafibrate treatment after post-ovulatory aging. Collectively, these results suggest that bezafibrate beneficially affects against porcine post-ovulatory oocyte aging in porcine by its antioxidant property and mitochondrial protection.

• 한국농공학회논문집
• /
• 제63권5호
• /
• pp.1-11
• /
• 2021

Soil moisture plays a critical role in hydrological processes, land-atmosphere interactions and climate variability. It can limit vegetation growth as well as infiltration of rainfall and therefore very important for agriculture sector and food protection. Recently, due to the increased damage from drought caused by climate change, there is a frequent occurrence of shortage of agricultural water, making it difficult to supply and manage stable agricultural water. Efficient water management is necessary to reduce drought damage, and soil moisture management is important in case of upland crops. In this study, soil moisture was calculated based on the water balance model, and the suitability of soil moisture data was verified through the application. The regional soil moisture was calculated based on the meteorological data collected by the meteorological station, and applied the Runs theory. We analyzed the spatiotemporal variability of soil moisture and drought impacts, and analyzed the correlation between actual drought impacts and drought damage through correlation analysis of Standardized Precipitation Index (SPI). The soil moisture steadily decreased and increased until the rainy season, while the drought size steadily increased and decreased until the rainy season. The regional magnitude of the drought was large in Gyeonggi-do and Gyeongsang-do, and in winter, severe drought occurred in areas of Gangwon-do. As a result of comparative analysis with actual drought events, it was confirmed that there is a high correlation with SPI by each time scale drought events with a correlation coefficient.