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        검색결과 1,072

        824.
        2017.09 서비스 종료(열람 제한)
        This study is an analytical research on the size effect of concrete flexural-compressive strength. The meso-scale finite element method was used to analyze various sizes of specimens. As a result of the analysis, the size effect that the flexural-compressive strength becomes smaller as the size of specimen becomes bigger is analytically confirmed.
        825.
        2017.08 KCI 등재 서비스 종료(열람 제한)
        조영제의 혈관외유출을 한번이라도 경험한 방사선사들은 혈관외유출의 발생에 대한 두려움으로 검사하 는 동안 정신적 고통을 수반하게 된다. 환자의 경우 심한 신체적, 정신적 고통과 의료진 및 의료에 대한 불 신을 갖게 되므로 미연에 예방할 수 있는 방안의 마련이 무엇보다 필요하다. 따라서 본 연구에서는 조영제 주입 시 압력인 PSI를 낮추어 혈관외유출을 예방하고자 하며 그 방안으로 자동주입기와 환자의 정맥주사 바늘에 연결되는 Y자 형태의 연결관(connecting tube)의 직경에 따른 조영제 주입 시 PSI의 변화를 비교 분 석하고자 하였다. Y형태의 연결관 직경이 약 2 mm 정도인 A제품의 경우 전체 평균 연령의 PSI는 98.5, 표 준편차 9.72로 나타났다. 연결관 직경 약 3 mm 정도인 B제품의 경우 전체 연령의 평균 PSI는 62.0, 표준편 차 8.59로 나타났다. 이것은 직경이 더 넓은 B제품의 경우 A제품과 비교했을 때 평균압력이 37.05% 감소한 결과이다.
        826.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        Soybean [Glycine max (L.) Merr.] is an important source for protein, oil, carbohydrates, isoflavones, and many other nutrients to humans and animals. Lipoxygenase protein is the main antinutritional factor in mature soybean seed. Soybean cultivar, "Choseon" with yellow medium seed size and free of lipoxygenase 2,3 protein was developed. "Choseon" was selected from the population derived from the cross between cultivar, "Jinpum 2" and germplasm, PI408155. "Choseon" has purple flowers, tawny pubescence, a determinate growth habit, and light yellow pods at maturity. The seed of "Choseon" has yellow hilum and yellow seed coat color. Seed protein and oil content on a dry weight basis were 34.2 and 16.9%, respectively. "Choseon" has shown a resistant reaction to soybean necrosis, soybean mosaic virus, Cercospora leaf spot and blight, black root rot, pod and stem blight, and bacterial pustule. "Choseon" matured in 5 October with plant height of 51 cm and a 100-seed weight of 15.1 g. Average yield of "Choseon" was 2.66 (Ton/ha) on the regional yield trials of 2013 at 4 locations. "Choseon" has been registered as a soybean cultivar (registration number: 5985, registration date: April 11, 2016) by Korea Seed & Variety Service, Republic of Korea.
        827.
        2017.04 서비스 종료(열람 제한)
        This study was aimed to investigate the effect of aggregate size on the tensile behavior of highly ductile fiber-reinforced cementitious composites. Partial applying 5.6mm coarse aggregate instead of micro silica sand was considered. It was revealed that the fiber-reinforced cementitous composites with 5.6 mm coarse aggregate as well as micro silica sand still showed enough tensile strain capacity more than 5% and limited crack width less than 150 ㎛.
        828.
        2017.04 서비스 종료(열람 제한)
        This study was aimed to investigate the effect of aggregate size on the tensile behavior of highly ductile fiber-reinforced cementitious composites. Partial applying 5.6mm coarse aggregate instead of micro silica sand was considered. It was revealed that the fiber-reinforced cementitous composites with 5.6 mm coarse aggregate as well as micro silica sand still showed enough tensile strain capacity more than 5% and limited crack width less than 150 ㎛.
        829.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        To understand the changes in physical parameters and phytoplankton size structure caused by tides, a fixed station in the Youngsan River estuary was monitored at 2-h intervals, on April 28, 2012 and August 12, 2012. No clear relationship was observed between the temperature and salinity changes and tidal levels in April. However, in August, temperature decreased during the ebb tide and increased during the flood tide, while salinity showed the opposite trend. In addition, there was no specific change in the phytoplankton biomass corresponding to tidal levels in April. In August, the total chlorophyll a and the biomass of net phytoplankton (>20μm ) increased almost 20 times during the ebb tide and decreased during the flood tide. The biomass of nanophytoplankton (<20μm ) showed a similar variation in response to tidal level changes. In April, the relationship between percent contributions of phytoplankton size structure and tidal levels was not clear. In August, the net phytoplankton was dominant in the early stage and nanophytoplankton was dominant in the later stage, while contribution of nanophytoplankton and net phytoplankton increased at high tide and low tide, respectively. Therefore, in April, other factors such as freshwater discharge were more important than the tide, whereas in August, when no freshwater discharge was recorded, the changes in semidiurnal tides influenced the physical parameters and phytoplankton dynamics. These results could contribute to the understanding of phytoplankton dynamics in the Youngsan River estuary.
        830.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        This study is an experimental program developed to estimate the effect of size on the shear performance of reinforced concrete (RC) beams with stirrups made from recycled coarse aggregates (RCA). The test was conducted on eight RC beams with shear reinforcement, and the main variables were section size and RCA replacement ratio (Rr = 0% or 30%). The tension reinforcement ratio (ρ = 0.012), shear span-to-depth ratio (a/d = 1.5), and width-to-depth ratio (h/b = 1.5) were fixed. Empirical test results, theoretical results, and code calculations were compared for each specimen. The results demonstrated that the empirical test results of each sample compared favorably with the theoretical calculations within a sufficient safety margin (1.32-2.61). Also, a comparison between RCA-RC beams with Rr = 30% and RC beams containing natural coarse aggregates (NCAs) showed that the two beams exhibited similar load-displacement curves and shear strengths. Consequently, RCA-RC beams made using a RCA replacement ratio of up to 30% do not cause safety or serviceability problems.
        831.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        In this study, we investigated variations in particle size distribution in the process flow from a fluff-SRF manufacturing process in Y city via particle size analysis of waste. About 110 kg of MSW was analyzed in accordance with the process flows for the analysis of the particle size distribution by separating from 300 mm to 10 mm. The first tranche of waste was crushed with a primary crusher such that 100% of particles were smaller than 200 mm. A secondary crusher was used to ensure that 90% of particles were smaller than 10 mm. The crushing function and disintegration effect resulted in waste that contained 30% particles smaller than 10 mm. The primary multistage bulk selection process separated the first non-combustibles from waste passed by the secondary crusher. It produced 19.24% non-combustibles. Secondary multistage bulk selection discharges the final set of non-combustibles from the first non-combustibles after recovering any remaining combustibles. The combustible recovery ratio was 28.24%, and the final non-combustible discharge ratio was about 71.76%. The regular and high-speed disintegrators exhibited 85% and 97% efficiency in producing waste smaller than then 50 mm, respectively. This is thought to improve the yield and quality of SRF in the context of a reasonable management plan via characteristic analysis of residues from the disintegration process.
        832.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        Stability of labor market in rural areas was analyzed in this paper with categories of industrial group, employment scale, surviving period, and founder group. The stability of each classified labor market was compared with each other to figure out the stable business class and the unstable class in rural areas. The results of rural areas were compared with those of urban areas. The stability was analyzed with average and coefficient of variation (C.V.) of annual total employees’ change rates. It was revealed that labor market of ‘primary industry’, including agriculture, is unstable. Especially, labor market of ‘mid-size’ and ‘primary industry’ businesses founded as ‘incorporated company’ in rural areas is vulnerable. While labor market of ‘large-size’ is proved to be unstable, it is confirmed that ‘small-size’ or ‘mid-size’, and ‘over-ten-year survived’ businesses have positive contribution to the stable labor market in rural and urban areas. The results show that the stability of labor market is different in each category of business and in each region of rural or urban area. It is expected that the results can be utilized for the regional development policies, of labor and industry part.
        833.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        Cyclic loading tests for a total of nine test specimens were performed to evaluate the seismic performance of the exposed steel column-base plate connections. From the tests, flexural strength, deformation capacity, energy dissipation, and initial stiffness were investigated. The primary test parameters were the thickness of base-plate, embedment length of anchor bolt, the presence of hook, and rib plates. Test results showed that flexural behavior of column base-plate connection was substantially affected by the base-plate thickness, embedment length and the number of anchor bolts. On the other hand, the effect of rib plates on the increase of the flexural performance was not observed. The initial stiffness of the test specimens was about 15% of the flexural stiffness obtained by assuming that the support is fixed. As a result, even if the exposed column base-plate is designed in accordance with current design recommendations, in case that bond strength between concrete and the anchor bolts is not sufficient, the base-plate connection showed an unaccceptable load-displacement behavior.
        834.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        This study was aimed to investigate the effect of aggregate size on the tensile behavior of highly ductile fiber-reinforced cementitious composites. Partial applying 5.6mm coarse aggregate instead of micro silica sand was considered. It was revealed that the fiber-reinforced cementitous composites with 5.6 mm coarse aggregate as well as micro silica sand still showed enough tensile strain capacity more than 5% and limited crack width less than 150 ㎛.
        835.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        Aerosol mass size distributions were investigated at 865 m high the of Jirisan national park. A nanosampler cascade impactor was used to collect aerosols. The atmospheric aerosol particles had a unimodal mass size distribution, which peaked at 0.5–1.0 μm, and a mass aerodynamic diameter of 1.13 μm. The annual average concentrations of TSP, PM10, PM2.5, PM1, PM0.5 and PM0.1 were 20.9 μg/m3, 19.3 μg/m3, 14.9 μg/m3, 10.7 μg/m3, 5.3 μg/m3, 1.2 μg/m3, respectively. TSP concentrations were below 30 μg/m3 during the sampling period. On average PM10, PM2.5, PM1, PM0.5 and PM0.1 made up 0.91, 0.70, 0.41, 0.19 and 0.07 of TSP, respectively. The annual average of PM2.5/PM10 ratio was 0.77.
        836.
        2016.11 KCI 등재 서비스 종료(열람 제한)
        소아는 방사선 감수성이 어른에 비해 높고 몸의 크기가 작아 어른과 같은 양의 방사선에 노출 되더라도 유효선량은 어른에 비해 더 높기 때문에 불필요한 피폭 방사선량을 줄이는 것이 매우 중요하다. 따라서 본 연구에서는 소아 두부 CT 검사에 있어서 피폭 방사선량을 경감할 수 있는 방법을 모색하고자 부산지역 병원들에서 시행된 년 간소아 두부 CT 검사에 대한 CT 선량지표(CTDI)를 국내 진단참고준위와 비교하여 분석함으로써 제안점을 도출하고자 하였다. 이를 위하여 부산시내에 설치된 CT 장비 중 소아 두부 CT 검사를 시행하며, 선량보고서를 PACS로 전송하는 24개 병원 28대 CT 장비를 대상으로 하여 소아 두부 CT 검사를 의뢰받은 10세 미만의 소아 2,043명을 후향적으로 조사하였다. 결과적으로 전체병원의 소아 두부 CT의 선량지표 CTDIvol의 평균값은 31.18 mGy, DLP는 444.73 mGy·cm로 나타나 진단참고준위를 초과하는 것으로 나타났다. 연령이 낮을수록 방사선에 대한 관리가 더욱 필요하다고 할 수 있는데 연구결과 6-10세 이하의 연령에 비해 더 낮은 다른 두 연령별에서 진단참고준위를 초과하는 환자수와 초과되는 비율이 높게 나타났다. 따라서 불필요한 방사선 노출을 줄이고 선량관리를 위한 노력들이 필요하다. 이를 위해 본 연구에서는 진단참고준위를 벗어나는 선량의 정도를 파악하고 초과되는 선량지표의 원인을 분석하여 선량감소를 위한 방안을 마련하고자 한다.
        837.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        Investigation of the plant growth affected by plug cell volume/pot size and plant age in herbaceous native plants belonging to 11 family and 24 species showed that growth of aerial part was different according to both plant age and plug cell volume/pot size. Among them, especially Iris dichotoma, Iris ensata var. spontanea, Iris pseudoacorus Lysimachia vulgaris var. davurica, Campanula glomerata var. dahurica and Solidago virgaurea subsp. asiatica showed more prominent difference depending on plug cell volume compared to other species. Regarding growth of subterranean part, as decrease plug cell volume/pot size root quality index became high while root weight became low, indicating that growth restriction was happened by exceed increase of root density due to limited root zone area. As increase cell volume/pot size, root development became active in bigger than 150 ㎖ of cell volume. Plant quality got better as increase cell volume/pot size, and 60 days old plants (DOP) revealed higher quality than 90 DOP revealed, indicating that marketing is possible from 60 DOP. Considering both plant age and cell volume (pot size), plant quality was better in smaller cell volume when cultivate plants in short time, while better in bigger cell volume when cultivate plants long time. Accordingly, when extend cultivation periods in small volume of plug cell, plant quality became bad. Therefore, this study showed that in order to produce high quality of plants, plants should be grown in proper plug cell volume depending on cultivation periods. Among plants tested Hosta longipes, Aquilegia buergeriana var. oxysepala, Aquilegia japonica, Veronica linariifolia, Hemerocallis fulva, Iris ensata var. spontanea, Iris pseudoacorus, Allium senescens, Hypericum ascyron, Caltha palustris var. palustris, Gentiana scabra, Campanula glomerata var. dahurica, Dendranthema boreale, Dendranthema zawadskii var. latilobum, Aster spathulifolius, Aster maackii, Aster koraiensis and Solidago virgaurea subsp. asiatica were determined to be able to produce standard size nursery plants using plug tray, and proper plug cell volume was bigger than 150 ㎖ (32 cell tray).
        838.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This study investigated the family size effect on English word processing via visual lexical decision task with three different groups of speakers, i.e., L1 English speakers, Korean L2 English learners, and English bilinguals. For English simple nouns, verbs, and adjectives, we examined the effects of the type count of morphologically related members and the surface base-frequency on lexical processing. First, results showed that the family size effect emerged in Korean L2 learners, but it was mostly inhibitory. To be specific, words with a large family size elicited slower response latencies than those with a small family size. However, the facilitatory effect arose for bilinguals and native speakers of English. Second, it was exhibited that high-frequency base words were recognized more quickly than low-frequency counterparts, confirming that token frequency as well as type frequency codetermines their recognition latency. These findings suggest that L1, bilinguals, and L2 learners' mental lexicons are organized by morphologically related words along with surface frequency although their effect size differs depending on the amount of language exposure. Finally, building on the results in the current experimental study, we propose a formal account for the processing advantages of words with a large family size under a psycholinguistic model and processing constraints.
        839.
        2016.05 서비스 종료(열람 제한)
        Background : Jiwhang (Rehmannia glutinosa L.) cultivation area of chungnam province was 62ha(219 farms, 53.9% of domestic cultivation area, M.A.F.R.A. 20142)). Recently, jiwhang is rapidly spread to 150ha ( Geumsan administration statistics, 2015) as taking place of income crop in Chungnam. High quality jiwhang GAP production and improvement of the distribution system including magnus customers, producer association fosterage and conventional market Vitalization were the reason of rapid cultivation area increase of Rehmannia glutinosa L. in Geumsan. This study was performed to set up the standard Rhizome size for planting in Rehmannia glutinosa L. Materials and Methods ○ Experiment variety : Togang ○ Treatment(rhizome length) : ① 1cm ② 2cm ③ 3cm ④ 4cm ⑤ 6cm(control) ○ Planting date : May 6, 2015 ○ Planting distance : 30×15cm ○ Experiment place : Ginseng and Medicinal Plant Research Institute (Geumsan-gun, Chungcheongnam-do) Conclusion : In the aboveground growth was no significant difference among treatments. In the root characteristics, there was no significant difference among treatments. Take a 1∼2cm rhizome planting saved rhizome amount and planting time to 73.8%∼64.3% and 68.4%∼ 57.8% respectively than 6cm(control).
        840.
        2016.04 서비스 종료(열람 제한)
        In Korea, Small-size buildings are not performed structural calculation. Also it does not assess the safety about lateral loads such like earthquake. In this study, We proposed the steel column bases that can be applied to small buildings. And We analyzed the Steel Column Bases flexural behavior.