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        검색결과 38

        2.
        2022.12 구독 인증기관 무료, 개인회원 유료
        This study investigated changes in psychological stress levels of 60 firefighters after participation in an eight-week Equine-Assisted Learning (EAL) program consisting of 16 sessions. The Korean versions of the Posttraumatic Diagnosis Scale (PDS-K), the Center for Epidemiological Studies Depression Scale (K-CESD), and the Difficulties in Emotional Regulation Scale (K-DERS) were used for measurements. Participants were divided into two groups according to level of posttraumatic stress symptoms (PTSS): the PTSS risk group and the PTSS non-risk group. Results showed that PDS-K, K-CESD, and K-DERS scores were significantly reduced after the program in the PTSS risk group. Significant reduction was also found in all sub-scales of PDS-K: re-experiencing, avoidance/emotional numbing, and hyperarousal. Moreover, in the PTSS risk group, there were greater improvements with significant group x time interactions. These findings suggest that EAL is effective in relieving PTSD and PTSD-related symptoms of firefighters with subsyndromal or more severe levels of PTSD.
        4,500원
        3.
        2022.10 구독 인증기관·개인회원 무료
        Organic scintillator is easy to manufacture a large size and the fluorescence decay time is short. However, it is not suitable for gamma measurement because it is composed of a low atomic number material. Organic scintillation detectors are widely used to check the presence or absence of radiation. The fluorescence of organic scintillators is produced by transitions between the energy levels of single molecules. In this study, an organic scintillator development study was conducted for use in gamma measurement, alternative materials for secondary solute used in basic organic scintillators were investigated, and the availability of alternative materials, detection characteristics, and neutron/gamma identification tests were performed. In other words, a secondary solute showing an improved energy transfer rate than the existing material was reported, and the performance was evaluated. 7-Diethylamino -4-methylcoumarin (DMC), selected as an alternative material, is a benzopyrone derivative in the form of colorless crystals, has high fluorescence and high quantum yield in the visible region, and has excellent light stability. In addition, it has a large Stokes shift characteristic, and solubility in solvent is good. Through this study, it was analyzed that the absorption wavelength range of DMC coincided with the emission wavelength range of PPO, which is the primary solute. Through this study, it was confirmed that the optimal concentration of DMC was 0.04wt%. As a result of performing gamma and neutron measurement tests using a DMC-based liquid scintillator, it showed good performance (FOM=1.42) compared to a commercial liquid scintillator. Therefore, the possibility of use as a secondary solute was demonstrated. Based on this, if studies on changes in the composition of secondary solute or the use of nanoparticles are conducted, it will be possible to manufacture and utilize a scintillator with improved efficiency compared to the existing scintillator.
        4.
        2022.10 구독 인증기관·개인회원 무료
        The safe, efficient and cost-effective decommissioning and dismantling of radioactive facilities requires the accurate characterization of the radionuclide activities and dose rate environment. And it is critical across many nuclear industries to identify and locate sources of radiation accurately and quickly. One of the more challenging aspects of dealing with radiation is that you cannot see it directly, which can result in potential exposure when working in those environments. Generally, semiconductor detectors have better energy resolution than scintillation detectors, but the maximum achievable count rates are limited by long pulse signals. Whereas some high pure germanium detectors have been developed to operate at high count rates, and these HPGe detectors could obtain gamma-ray spectra at high count rates exceeding 1 Mcps. However, HPGe detectors require cooling devices to reduce the leak currents, which becomes disadvantageous when developing portable radiation detectors. Furthermore, chemicalcompound semiconductor detectors made of cadmium telluride and cadmium zinc telluride are popular, because they have good energy resolution and are available at room temperature. However, CdTe and CZT detectors develop irradiation-induced defects under intense gamma-ray fields. In this Review, we start with the fundamentals of gamma rays detection and review the recent developments in scintillators gamma-ray detectors. The key factors affecting the detector performance are summarized. We also give an outlook on the field, with emphasis on the challenges to be overcome.
        5.
        2022.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Polarimetric measurements of the lunar surface from lunar orbit soon will be available via Wide-Field Polarimetric Camera (PolCam) onboard the Korea Pathfinder Lunar Orbiter (KPLO), which is planned to be launched in mid 2022. To provide calibration data for the PolCam, we are conducting speckle polarimetric measurements of the nearside of the Moon from the Earth’s ground. It appears that speckle imaging of the Moon for scientific purposes has not been attempted before, and there is need for a procedure to create a “lucky image” from a number of observed speckle images. As a first step of obtaining calibration data for the PolCam from the ground, we search for the best sharpness measure for lunar surfaces. We then calculate the minimum number of speckle images and the number of images to be shift-and-added for higher resolution (sharpness) and signal-to-noise ratio.
        4,200원
        9.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 게임 동영상의 고화질 변환이 가능한 초해상화 알고리즘을 제시한다. 본 알고리즘은 오픈 소 스 형태의 GPU에서 제공하는 MMU에서 구현될 수 있도록 희소 행렬 연산을 이용해서 설게된다. 이를 위해 서 일반적인 영상 해상도 향상 방법인 이중 일차 및 이중 삼차 보간 법과 심층 학습에 기반한 초해상화 모 델에서 사용하는 컨볼루션 연산을 희소 행렬 연산으로 변환하는 방법을 제시한다. 이는 각 픽셀에 적용되는 필터를 행렬 곱 형태로 표현하고, 이 행렬을 희소 행렬로 표현함으로써 수행되는데, 이러한 과정을 통해서 연산의 효율성을 추구함으로써 안정적인 초해상화 알고리즘을 제공한다. 이러한 희소행렬 연산 형태로 표현 되는 초해상화 알고리즘은 기존의 라이브러리를 이용해서 구현된 초해상화 알고리즘과 유사한 PSNR과 FPS 를 보인다.
        4,000원
        11.
        2018.10 구독 인증기관·개인회원 무료
        Whitefly (Hemiptera: Aleyrodidae) pests, including the tobacco whitefly, Bemisia tabaci, and the greenhouse whitefly, Trialeurodes vaporariorum, are economically important in agriculture. With the annual growth of the domestic fresh fruit export market, various quarantine treatment methods are being used to export strawberries of better quality. The objective of the present study was to evaluate the effects of gamma rays on the development and reproductive sterility of B. tabaci and T. vaporariorum. In both species, the eggs were completely inhibited from hatching at 50 Gy, and the emergence of 3rd instar nymphs was completely suppressed at 150 Gy. Some adult B. tabaci and T. vaporariorum spawning occurred at 100 Gy and 70 Gy, respectively; however, at these irradiation levels, F1 hatchability was completely inhibited. Dosimetry results showed that the penetrating power of gamma ray in the strawberry-filled box was the lowest at the mid-box position. Therefore, B. tabaci and T. vaporariorum were placed in the middle of the strawberry-filled box and irradiated. A gamma-ray irradiation of 100 Gy suppressed the development and reproduction of eggs and adults in both B. tabaci and T. vaporariorum. However, the development of 3rd instar nymphs was inhibited at 300 Gy for B. tabaci and 200 Gy for T. vaporariorum. Our data suggest that at least 300 Gy should be used for the control of these two types of whitefly for strawberry export.
        13.
        2012.09 구독 인증기관 무료, 개인회원 유료
        MicroRNAs (miRNAs, miRs) are about 21-25 nucleotides in length and regulate mRNA translation by base pairing to partially complementary sites, predominantly in the 3’-untranslated region (3’-UTR) of the target mRNA. In this study, the expression profile of miRNAs was compared and analyzed for the establishment of miRNA-related odontoblast differentiation using MDPC-23 cells derived from mouse dental papilla cells. To determine the expression profile of miRNAs during the differentiation of MDPC-23 cells, we employed miRNA microarray analysis, quantitative real-time PCR (qRT-PCR) and Alizaline red-S staining. In the miRNA microarray analysis, 11 miRNAs were found to be up- or down-regulated more than 3-fold between day 0 (control) and day 5 of MDPC-23 cell differentiation among the 1,769 miRNAs examined. In qRT-PCR analysis, the expression levels of two of these molecules, miR-194 and miR-126, were increased and decreased in the control MDPC-23 cells compared with the MDPC-23 cells at day 5 of differentiation, respectively. Importantly, the overexpression of miR-194 significantly accelerated mineralization compared with the control cultures during the differentiation of MDPC-23 cells. These results suggest that the miR-194 augments MDPC-23 cell differentiation, and potently accelerates the mineralization process. Moreover, these in vitro results show that different miRNAs are deregulated during the differentiation of MDPC-23 cells, suggesting the involvement of these genes in the differentiation and mineralization of odontoblasts.
        4,000원
        15.
        1981.12 구독 인증기관·개인회원 무료
        17.
        2017.05 서비스 종료(열람 제한)
        Background : Panax ginseng C.A. Meyer is a perennial herb belongs to the family Araliaceae. Wild-cultivated ginseng (WCG) is a specific type of ginseng in Korea which cultivated on artificial forest cultivation method. To obtain a WCG which is similar to wild ginseng (WG), this method usually performed in a mountain using seeds or seedlings of cultivated ginseng (CG) and WG. WCG is very expensive because it is difficult to cultivate. However, systematic cultivation method have not yet been developed compared to high added value. Furthermore, very high price of WCG caused the problem that Panax notoginseng or Panax quinquefolium are sold as WCG in Korean market. In this study, we analyzed the genetic diversity of WCG collected from five areas in Korea using SSR markers. Methods and Results : WCG samples were collected from five areas in Korea (Bucheon, Cheongju, Hoengseong, Judeok and Ulsan). DNA extraction was performed using CTAB method. SSR markers were collected from the published papers. After test PCR using the markers, one of the primer pair was labeled with fluorescence dye (FAM, NED, PET, or VIC) and GeneScan analysis were performed. DNA amplification was conducted using T-100 Thermal Cycler (Bio-Rad). PCR products were separated by capillary electrophoresis on the ABI 3730 DNA analyzer (Applied Biosystems). Conclusion : Eight SSR markers were collected from the published literature and used for the analysis. From the 8 tested SSR markers, 7 SSR markers showed polymorphism between varieties. GenScan analysis were performed using the selected SSR markers to analyze the phylogenetic relationship of WCG. From the results, WCG cultivated in Korea showed that they have a very diverse genetic background.
        18.
        2017.05 서비스 종료(열람 제한)
        Background : Wild-cultivated ginseng (WCG) prices are very different according to root ages. Generally, two methods are used to discriminate the root ages of Panax ginseng C.A. Meyer. The first method is the yearly determination method by the ring dyeing method, and the second method is the confirmation the number of stem vestiges in the rhizome. In this study, we analyzed the agronomic and growth characteristics of the WCG cultivated in Korea. In this study, to determine the appropriate root ages discrimination method for the determination of the root ages of WCG, the root ages of WCG and cultivated ginseng was examined. Methods and Results : We examined the cultivated ginseng (CG) and WCG that was collected and sold by regional groups at the Korean market. WCG does not form annual rings, which are clear and regular in wild ginseng. Therefore, it is impossible to identify the age of WCG by using the annual growth rings staining method. However, the age can be estimated by determining the number of stem vestiges in the rhizome. Conclusion : From the results of the Study on identification of root age for quality evealuation in WCG in Korea. Appropriate root ages discrimination method of WCG was confirmation the number of stem vestiges in the rhizome.
        19.
        2017.05 서비스 종료(열람 제한)
        Background : Panax ginseng C.A. Meyer is a representative medicinal plants and it has been used in traditional medicine because the plant have many effective component such as saponins. To obtain a wild-cultivated ginseng (WCG) which is similar to wild ginseng (WG), this method usually performed in a mountain using seeds or seedlings of cultivated ginseng (CG) and WG. WCG is very expensive because it is difficult to cultivate. However, systematic cultivation method have not been developed compared to their high added value. Furthermore, very high price of WCG caused the problem that Panax notoginseng or Panax quinquefolium are sold as WCG in Korean market. This is concerned as a serious problem to consumers. In this study, we analyzed the agronomic and growth characteristics of the WCG cultivated in Korea. Methods and Results : We examined the WCG that was collected and sold by regional groups at the Korean market. The root age, growth conditions, and quality level of the cultivated WCG were confirmed. WCG samples were collected from five areas in Korea (Bucheon, Cheongju, Hoengseong, Judeok and Ulsan). The main root diameter, root shape index, rhizome length, and root weight showed high level of variation and they did not form annual rings. Conclusion : Agronomic and growth characteristics of WCG showed high variations according to cultivating regions.
        20.
        2017.05 서비스 종료(열람 제한)
        Background : Undulatum Rhubarb, commonly produced in domestic, is rhizome of Rheum undulatum L. that belongs to the family Polygonaceae. It also can be used as a substitute of R. palmatum L., R. tanguticum Maximowicz ex Balf., and R. officinale Baillon which completely depend on import system. However, there should be clear clarification among Undulatum Rhubarb and Rhubarb, because Undulatum Rhubarb contains rhaponticin as marker compound that is not indicated at Rhubarb. Some of the recently imported Undulatum Rhubarbs have been found to be Rhubarb. Also, it is known that only Undulatum Rhubarb is cultivated at domestic environment. But some plant origins of Rhubarb are grown in Korea, too. Further study are needed to clarify clear origin between Undulatum Rhubarb and Rhubarb. Thus, we collected some domestically cultivated samples and identified them. Methods and Reseults : Rheum undulatum L., Rhubarb, Rheum tanguticum Maximowicz ex Balf. which were cultivated in Gangwondo Agricultural Research and Extension Services in Cheorwon were collected and anayzed the DNA sequences. We also compared DNA sequences in Rhubarb collected from England and R. rhabarbarum L., R. undulatum L., and R. franzenbachii on NCBI. As a result, two kinds of rhubarb cultivated in the test plantation were identified as R. rhabarbarum and R. officinale. In addition, R. undulatum (plant origin of Undulatum Rhubarb) was identified as Rhubarb (Rheum rhabarbarum) in England with 99 - 100% identical in nuclear ITS gene region. Conclusion : R. undulatum, plant origin of Undulatum Rhubarb, is reported as synonym of R. rhabarbarum, R. franzenbachii. Rheum speices which are cultivated as tester in Gangwondo Agricultural Research and Extension Services in Cheorwon are estimated as R. undulatum and R. officinale. Therefore, not only Undulatum Rhubarb but Rhubarb could be grown in Korea.
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