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        검색결과 23

        1.
        2023.11 구독 인증기관·개인회원 무료
        The dismantling nuclear power plant is expected to continue to change the radiation working environment compared to the operating nuclear power plant. Contamination monitors and survey meters currently in use have limitations in accurate analysis source term and dose rates for continuous changes in radiation fields at dismantling sites. Due to these limitations, the use of semiconductor detectors such as HPGe and CZT detectors with excellent energy resolution and portability is increasing. The CZT detector performs as well as the HPGe detector, but there is no proven calibration procedure yet. Therefore, in this study, the HPGe calibration method was reviewed to derive implications for the CZT detector calibration method. The operating principle of a semiconductor detector that measures gamma emission energy converts them into electrical signals is the same. Two calibrations of HPGe detectors are performed according to the standard calibration procedure for semiconductor detectors for gamma-ray measurement issued by the Korea Association of Standards & Testing Organizations. The first is an energy calibration that calculates gamma-ray peak position measurements and relational expressions using standard source term that emit gamma-rays. The channel values for energy are measured using certified reference source term to determine radionuclides by identifying channels corresponding to the measured peak energy values. The second is the measurement efficiency of measuring the coefficient calibration device, which measures gamma rays emitted from the standard source term. The detector efficiency by sample or distance is measured in consideration of the shape, size, volume, and density of the calibration device. The HPGe detector performs calibration once every six months through a verified calibration method and is being used as a source term analyzer at the power plant. The CZT detector may also establish a procedure for identifying peak positions through energy calibration and calculating radioactivity through efficiency calibration. This will be a way to expand the usability of semiconductor detectors and further monitor radiation in a more effective way.
        2.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 근적외선 차단렌즈의 색 왜곡을 평가하기 위하여 객관적 및 주관적 측색 결과를 분석하였다. 방법 : Colorchecker Classic의 15번(Red), 16번(Yellow) 및 14번(Green) 색표를 가상신호등으로 설정하여 객관적 측색을 실시하였다. 객관적 평가를 위하여 디지털 카메라에 각 렌즈를 장착한 후 가상신호등을 촬영하였 다. 본래 색상과 렌즈 장착 후 측정된 색을 CIE 1976 L*a*b* 색도좌표로 표시하였고, 좌표간 거리 값인 ΔE* ab를 산출하여 색 왜곡도를 비교 분석하였다. 32명을 대상으로 주관적 평가를 실시하였다. 교통신호등의 관찰된 색을 한국 색채 표준 디지털팔레트에서 선택하도록 하여 본래 색상과 비교하였다. 결과 : 객관적 평가에서, 황색 및 녹색 가상신호등의 색왜곡은 근적외선 차단렌즈 착용 시 가장 작은 것으로 나 타났다. 근적외선 차단렌즈에 의한 적색 가상신호등의 색왜곡은 녹색렌즈보다 크지만 갈색, 회색 및 청색렌즈에 비교하여 더 적은 것으로 나타났다. 주관적 평가에서, 적색 신호등을 주시했을 때 근적외선 차단렌즈에 의한 색왜곡은 갈색렌즈와 비교하여 더 많았으며, 청색 및 녹색렌즈 착용과 유사하였고, 회색렌즈 착용보다 적은 것으로 나타났다. 결론 : 근적외선 차단렌즈의 색왜곡은 다른 렌즈와 비교하여 객관적 평가에서 가장 낮았으나, 주관적 평가에서는 유의한 차이가 없었다. 근적외선 차단렌즈의 주관적 색 재현성을 정량적으로 조사할 수 있는 추가적인 연구가 필요할 것으로 생각된다.
        4,000원
        4.
        2018.04 구독 인증기관·개인회원 무료
        2016년도에 조사를 수행한 경상북도 내 위치한 산림유전자원보호구역 3개 지역(봉화・영주・울진)의 곤충 군집 변화를 확인하기 위하여 5월에서 9월까지 함정 트랩(pitfall trap)을 이용하여 5회씩 3반복하여 각각 상대적으로 비교 하였다. 채집된 딱정벌레류는 딱정벌레과 등 22과 141종 2,415개체가 확인 되었으며, MRPP (Multi-response Permutation procedures)분석 결과 서식지간의 군집구조차이가 있음을 확인 하였고(p < 0.001), Bray-cutis 분석결과 군집간의 차이와 함께 신갈나무 군락이 보행성 딱정벌레류의 종 풍부도에 큰 영향을 주는 것으로 나타났고 소나무군락 은 비교적 낮은 영향을 받았다. 식생유형에 대한 지표종 분석결과 신갈나무 군락에서 붉은칠납작먼지벌레(Synuchus cycloderus Bates, 1873)를 포함한 4종, 자작나무 군락에서는 노랑털검정반날개(Ocypus weisei Harold, 1877)를 포함한 3종, 소나무 군락에서는 홍딱지반날개(Platydracus brevicornis Motschulsky, 1862)를 포함한 3종의 지표종 변화를 확인 하였다.
        5.
        2015.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        방선균증(actinomycosis)은 실 모양의 혐기성 세균인 방선 균에 의한 감염 질환으로, 유황과립이 특징적인 화농성 병변 을 초래한다. 방선균증은 종괴처럼 보이는 병변으로 발현할 수 있는데, 이런 이유로 방선균증은 종종 악성 종양으로 오인됐고, 많은 환자들이 정확한 진단이 내려지기 전에 수술적 절제를 받았다. 저자들은 만성췌장염 환자에게 발생한, 악성 종양과 감별이 어려웠던 췌장에 국한된 방선균증 증례를 보고하는 바이 다. 환자는 감염의 증상 및 징후를 전혀 보이지 않았고, 다른 장기의 동반 감염도 없었다. 모든 영상 소견은 염증성 종괴 보다는 췌장암을 더 시사했다. 그는 내시경초음파 유도 가는 바늘 생검을 통해서 수술 없이 방선균증을 진단 받았다. 한 달 동안의 항생제 치료 이후에 췌장의 종괴는 완전히 사라졌다.
        4,000원
        6.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Korea had experienced second epidemic highly pathogenic avian influenza (HPAI), and there were the seven affected farms, including two breeder duck farms, from 22nd November 2006 to 6th March 2007. Here, we reported the clinico-pathological characteristics of domestic breeder ducks farms naturally infected with HPAI virus (H5N1). Clinically, the most ducks showed various signs from depression, decreased egg production and feed consumption to even, death. The most commonly gross changes were hepatomegaly, splenomegaly, petechial and ecchymotic hemorrhage on the liver surface, a white stripe on the cardiac muscle, and severely hemorrhagic and deformed eggs. The most significant histopathological changes were necrosis of various cells such as neuron, lymphocytes, cardiac myocytes, hepatocytes, blood vessels and pancreatic acinar epithelium. The viral antigen was mainly detected in the endothelium of blood vessels of various organs and tissues, peripheral nerves and neuronal cells. Based on the above results, we identified that HPAI H5N1 induced systemic infection in the adult breeder ducks.
        4,000원
        8.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The soybean Kunitz trypsin inhibitor (KTI) protein is responsible for the inferior nutritional quality of unheated or incompletely heated soybean meal. Ti locus controls presence or absence of Kunitz trypsin inhibitor protein. Genetic recombination or tight linkage between Ti locus and Satt228 marker that has been identified to be tightly linked to the Ti locus was detected for marker assisted selection (MAS) using two F2 populations of titi genotype in this study. Two F2 populations were developed from the cross of A29 (KTI protein present, TiTi genotype, AA genotype in Satt228 marker) x Gaechuck#1 and Gaechuck#2 (KTI protein absent, titi genotype, BB genotype in Satt228 marker). Among 31 F2 plants derived from A29 x Gaechuck#1, twenty nine F2 plants show BB genotype that indicates no recombination between Satt228 marker and Ti locus. Only 2 F2 plants show AA genotype that indicates recombination between Satt228 marker and Ti locus. Twenty eight F2 plants derived from A29 x Gaechuck#2 show BB genotype that indicates no recombination between Satt228 marker and Ti locus. Expected genetic ratio between Satt228 marker and Ti locus was 3.6 cM in F2 population.
        4,000원
        9.
        2019.12 KCI 등재 서비스 종료(열람 제한)
        We used numerical models to reliably analyze the groundwater flow and hydraulic conductivity on Jeju Island. To increase reliability, improvements were made to model application factors such as hydraulic watershed classification, groundwater recharge calculation by precipitation, hydraulic conduction calculation using the pilot point method, and expansion of the observed groundwater level. Analysis of groundwater flow showed that the model-calculated water level was similar to the observed value. However, the Seogwi and West Jeju watersheds showed large differences in groundwater level. These areas need to be analyzed by segmenting the distribution of the hydraulic conductivity. Analyzing the groundwater flow in a sub watershed showed that groundwater flow was similar to values from equipotential lines; therefore, the reliability of the analysis results could be improved. Estimation of hydraulic conductivity distribution according to the results of the groundwater flow simulation for all areas of Jeju Island showed hydraulic conductivity > 100 m/d in the coastal area and 1 45 m/d in the upstream area. Notably, hydraulic conductivity was 500 m/d or above in the lowlands of the eastern area, and it was relatively high in some northern and southern areas. Such characteristics were found to be related to distribution of the equipotential lines and type of groundwater occurrence.
        10.
        2019.04 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to identify the problems of the underground watersheds on Jeju Island, and to establish the hydraulic groundwater basin to be used as basis for the analysis of the groundwater model. In order to evaluate the adequacy of the groundwater basin on Jeju Island, a correlation analysis between elevation and groundwater level was conducted using data from 125 observation wells. The analysis, conducted with an elevation step of 100 m, exhibited values of R2 in the range 0.1653-0.8011. No clear correlation was observed between elevation and groundwater level. In particular, the eastern and western areas showed an inverse proportionality between elevation and groundwater level. The Kriging technique was used to analyze the underground water level data and to define the equipotential lines for all areas of Jeju Island. Eight groundwater watersheds were delineated by considering the direction of groundwater flow, the positions of the observation wells, and the long and short axes of the watersheds.
        11.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        This study reviewed the applicability of the existing flood discharge calculation method on Jeju Island Han Stream and compared this method with observation results by improving the mediating variables for the Han Stream. The results were as follows. First, when the rain-discharge status of the Han Stream was analyzed using the flood discharge calculation method of the existing design (2012), the result was smaller than the observed flood discharge and the flood hydrograph differed. The result of the flood discharge calculation corrected for the curve number based on the terrain gradient showed an improvement of 1.47 - 6.47% from the existing flood discharge, and flood discharge was improved by 4.39 - 16.67% after applying the new reached time. In addition, the sub-basin was set separately to calculate the flood discharge, which yielded an improvement of 9.92 - 32.96% from the existing method. In particular, the steepness and rainfall-discharge characteristics of Han Stream were considered in the reaching time, and the sub-basin was separated to calculate the flood discharge, which resulted in an error rate of –8.77 to 8.71%, showing a large improvement of 7.31 - 28.79% from the existing method. The flood hydrograph also showed a similar tendency.
        12.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        In this study, groundwater flow was analyzed targeting Dae-jeong watershed, which exhibited the largest variations of groundwater levels at the identical elevation points among the 16 watersheds of Jeju Island. The issues of the methods applied in practice were identified and improvement plans were suggested. This groundwater-flow estimates derived by applying hydraulic conductivity values onto zones of equal topographic ground level were found to be quite different from actual measured groundwater flow. Conversely, groundwater-flow estimates that utilized hydraulic conductivity values applied onto groundwater-level equipotential lines indicated relatively lesser divergences from actual measured groundwater flow. The reliabilities of the two approaches were assessed for 60 randomly selected points on DEM (digital elevation model) maps, The method using hydraulic conductivity values applied onto groundwater-level contours turned out to be the more reliable approach for the Dae-jeong watershed in Jeju Island.
        13.
        2016.11 KCI 등재 서비스 종료(열람 제한)
        Jeju Island relies on subterranean water for over 98% of its water resources, and it is therefore necessary to continue to perform studies on drought due to climate changes. In this study, the representative standardized precipitation index (SPI) is classified by various criteria, and the spatial characteristics and applicability of drought in Jeju Island are evaluated from the results. As the result of calculating SPI of 4 weather stations (SPI 3, 6, 9, 12), SPI 12 was found to be relatively simple compared to SPI 6. Also, it was verified that the fluctuation of SPI was greater fot short-term data, and that long-term data was relatively more useful for judging extreme drought. Cluster analysis was performed using the K-means technique, with two variables extracted as the result of factor analysis, and the clustering was terminated with seven-time repeated calculations, and eventually two clusters were formed.
        14.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        This study analyzed fluctuations of ground water level of ground water wells developed in Seongsan watershed of Jeju Island until 2013 using MODFLOW, a numerical analysis model. Ground water level shows greater fluctuations from increase of pump capacity compared to the number of ground water wells. The development of ground water at the top of watershed was found to have direct influence on ground water level. Ground water wells developed until 2013 were used to continue pumping for 50 days, and ground water level of coastal region was reduced below 50% compared to the standard water level. In addition, the range of fluctuation of water level was large in the east coast region, which represents the direction of flow of ground water.
        15.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        Jeju Island is the highest rain-prone area in Korea that possesses affluent water resources, but future climate changes are predicted to further increase vulnerabilities as resultant of increasing of extreme events and creating spatial-temporal imbalance in water resources. Therefore, this study aimed to provide basic information to establish a proper water resources management plan by evaluating the effects of climate change on water resources using climate change scenario. Direct runoff ratio for 15 years (2000~2014) was analyzed to be 11∼32% (average of 23%), and average direct runoff ratio for the next 86 years (2015∼2100) was found as 28%, showing an increase of about 22% compared to the present average direct runoff ratio (23%). To assess the effects of climate change on long-term runoff, monthly runoff variation of future Gangjeong watershed was analyzed by dividing three time periods as follows: Present (2000∼2030), Future 1 (2031∼2070) and Future 2 (2071∼ 2100). The estimated results showed that average monthly runoff increases in the future and the highest runoff is shown by Future 2. Extreme values has been expected to occur more frequently in the future as compared to the present.
        16.
        2015.07 서비스 종료(열람 제한)
        Soybean is a short-day plant, which means short day length promotes flowering. So far nine major loci, E1 to E8 and J, affecting the timing of flowering and maturity have been genetically identified in soybean. To understand the roles of soybean flowering genes in photoperiod-dependent flowering time control in soybean, we analyzed not only expression patterns of E1, E2, E3 and E4 genes as well as soybean FT homologs, including GmFT2a, GmFT5a and GmFT4, but also structural variation of E1, E2, E3, and E4 genes in various soybean accessions exhibiting a broad range of flowering time. The mRNA level of GmFT2a and GmFT5a was low in late flowering accessions, but high in late flowering accessions. In contrast, GmFT4 exhibited opposite expression pattern to those of GmFT2a and GmFT5a. Structural variation of E1, E2, E3 and E4 gene in these accessions revealed that early and moderate flowering accessions contained non-functional alleles of E1, E2, E3 and E4 genes in their genome. These results suggested that expression patterns of GmFT2a GmFT5a and GmFT4 would be important factor determining flowering time in soybean and allelic variation and genetic combination of upstream E1, E2, E3, and E4 genes would be more important in soybean flowering time control than their gene expression patterns.
        17.
        2015.07 서비스 종료(열람 제한)
        FT is one of the major floral activator in photoperiod-dependent flowering pathway. To understand the role of FT homologs in flowering time control of short-day plant soybean, we identified ten soybean FT genes and named GmFTs. Phylogenetic analysis revealed that ten GmFT genes were further categorized into three subclades. Gene expression analysis showed that the most GmFT genes are mainly expressed in leaves. The expression of GmFT2a, GmFT2b, GmFT5a, and GmFT6 was strongly induced under the floral inductive short-day condition, but GmFT4 exhibited opposite expression pattern compared to those of GmFT2a, GmFT2b, GmFT5a, and GmFT6. To understand roles of GmFT genes in flowering, we generated Arabidopsis transgenic plant overexpressing GmFT genes. Both 35S:GmFT2a and 35S:GmFT5a transgenic plants showed extremely early flowering. In contrast, overexpression of GmFT4 delayed flowering of transgenic plants compared to wild type Arabidopsis. The results indicated that GmFT2a and GmFT5a might function as floral activators, while GmFT4 has an opposite function in soybean flowering. Moreover, domain swapping approaches between GmFT2a and GmFT4 revealed that the substitution of the segment B region alone, which is located in 4th exon, was sufficient to change the function of GmFT2a to floral repressor and GmFT4 to floral activator. The results suggested that soybean FT homologs have been functionally diversified during evolution and might play different roles in photoperiod-dependent flowering of soybean.
        18.
        2015.04 KCI 등재 서비스 종료(열람 제한)
        The depth of low permeable layer in Jeju Island was analyzed using the geologic columnar section data. The highest low permeable layer was found in center of Mt. Halla and the deepest area was in eastern part of Jeju Island. The study area, Seongsan watershed, is located in the eastern part of Jeju where the low permeable layer showing deep in a northward direction. Based on this analysis, the MODFLOW modeling was performed for groundwater flow of Seongsan watershed. The boundary of Seongsan watershed was set up as a no-flow and the modeling result showed the difference -0.26~0.62 m compared to the observed groundwater level. Meanwhile, MODFLOW model results considering low permeable layer showed -0.26~0.36 m differences compared to groundwater level and indicated more accurate than no-flow method result. Therefore, to interpret the groundwater flow over Seongsan watershed, comprehensive consideration including the low permeable layer distribution below the basalt layer is needed.
        19.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 부모의 자녀 양육태도와 청소년이 가진 주관적 계층감의 차이에 따라 청소년의 중독적 게임이용이 어떠한 차이를 나타내는지를 살펴보았다. 16세에서 24세 사이의 총 177명의 게임이용연령층을 대상으로 한 온라인 서베이 분석 결과, 전체 집단의 경우 부모의 양육태도 중 과잉기대 요인과 청소년 개인이 가진 높은 자기통제 수준이 게임중독이 낮은 것으로 나타났다. 주관적 계층감에 따라 전체 집단을 나누어 다시 살펴본 결과, 주관적 계층감이 낮은 집단(주관적 빈곤감이 높은 그룹)에서는 부모의 양육태도 중 과잉기대 요인이 높고, 자기통제 수준이 높을수록 게임중독이 낮아지는 것으로 밝혀졌다. 반면, 주관적 계층감이 높은 집단(주관적 빈곤감이 낮은 그룹)에서는 부모의 양육태도 중 간섭 요인만이 게임중독을 낮추는 유일한 요인으로 드러났다. 이는 부모의 양육태도 중 특정 요인과 청소년이 가진 주관적 계층감이 게임을 비롯한 다양한 미디어의 중독적 사용과 중요한 관련을 가지고 있음을 시사하는 결과라 할 수 있다.
        20.
        2013.07 서비스 종료(열람 제한)
        Phosphorus is one of the macronutrients essential for plant growth and development, as well as crop productivity. Many soils around the world are deficient in phosphate (Pi) that plants can utilize. To cope with the stress of Pi starvation, plants have evolved many adaptive strategies, such as changes of root architecture and enhanced Pi acquisition form soil. To understand molecular mechanism underlying Pi starvation stress signaling, we characterized the activation-tagged mutant showing altered responses to Pi deficiency compared to wild type Arabidopsis and named hsp3 (hypersensitive to Pi starvation3). hsp3 mutant exhibits enhanced phosphate transporter activity, resulting in higher Pi content than wild type. However, in root architectural change under Pi starvation, hsp3 shows hyposensitive responses than wild type, such as longer primary root elongation, lower lateral root density. Histochemical analysis using hsp3 mutant expressing auxin-responsive DR5::GUS reporter gene, indicated that auxin allocation from primary to lateral roots under Pi starvation is aborted in hsp3 mutant. Molecular genetic analysis of hsp3 mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’ end processing. Here, we propose that mRNA processing plays a crucial role in Pi homeostasis in Arabidopsis.
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