검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 6,698

        1621.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Benthic macroinvertebrates were investigated in thermal discharge that flows Buso stream region from December 2015 to February 2016, Korea. Study site was selected for the upstream, downstream relative to the mixing station and mixing station which thermal effluent flows, water quality analysis and benthic macroinvertebrates composition, taxa of EPT-group individuals, analysis of biological water quality. As a result, a total of 4,015 individuals including 50 species, 30 families, 11 orders, 4 classes, and 3 phyla were recognized. Taxa of species is Ephemeroptera 16 species (32.0%) including 6 families, the density composition was highest in 1,848 individuals (46.03%) Diptera. EPT-group occupied during the study period were a total of 1,876 individuals (46.72%) including 32 species and 17 family, lowest in the mixing station for study period. As a results of community analysis, mixing station in the Limnodrilus gotoi and Chironomidae sp.2, which is dominated by the analysis was Ecdyonurus levis, Cincticostella levanidovae, Nemoura KUa. The dominant species showed a difference in the upstream and downstream. In the functional feeding groups, in the upstream and mixing station Gathering-Collectors, downstream it was analyzed that the ratio of the highest Filtering-Collectors and decreased the ratio of Shredders increasing from upstream to downstream. Habitat orientation group is analyzed that accounted for most of the Clingers and Burrowers, from upstream to downstream toward the higher the ratio of Clingers. Biological water quality assessment results were analyzed the worst state in the mixing station with an average 2.73 (±0.41). Correspondence analysis, correlation analysis results of water temperature and the cold-water species, as the water temperature increases were analyzed by reducing cold-water species and EPT-group.
        4,300원
        1622.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A behavior of FRP(Fiber Reinforced Polymer) panel in a steel frame structure was evaluated through the finite element analysis in this study. In order to numerical analysis, a experimental test results was used to develop a three dimensional finite element model of steel frame specimen. Numerical results of the steel frame specimen was well predicted the experimental behavior of steel frame specimen. Based on the developed three dimensional finite element model of steel frame specimen, the behavior of FRP panel in the steel frame specimen was evaluated. From the numerical analysis results, strength of the steel frame specimen with FRP panel was governed by FRP panel. Also, diagonal compression behavior governed the FRP panel in the steel frame specimen in the numerical analysis results.
        4,000원
        1623.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The result of the previous work leads to the idea that the inner area of the hyperbolic shell generator should be minimized for the cooling tower with higher first natural frequency. In this study the inner area of the hyperbolic shell generator was graphically established under varying height of the throat and angle of the base lintel. From the graph, several shell geometries were selected and analysed in the aspect of the natural frequency. Three representative towers reinforced differently due to different first natural frequencies were analysed non-linearly and evaluated using a damage indicator based on the change of natural frequencies. The results demonstrated that the damage behaviour of the tower reinforced higher due to a lower first natural frequency was not necessarily advantageous than the others
        4,000원
        1624.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, a study on noise reduction characteristics of the precast floating track system, being developed as measures to mitigate noise and vibration of existing as well as constructing elevated railroad stations, is presented using numerical analysis. One of the most prominent sound analysis program, Virtual Lab., is utilized in investigating noise reduction performance of the precast floating track system, and structural velocity data, obtained from vibration analysis on a model-updated elevated railroad station considering vehicle-track-structure interaction, are used for the input of the sound analysis. The sound analysis is performed using the finite element method, and noise reduction performance before and after installing the precast floating track system is compared at three enclosed areas in the Daecheon Station, selected as a representative of elevated railroad stations in this nation. From the comparison result, it is seen that the precast floating track system can decrease noise by average of 5dB∼8dB when the Saemaeul train passing through the station and 10dB∼15dB when the KTX train passing through. Also, the noise reduction characteristics is different depending on the type of train and the distance from the track.
        4,000원
        1625.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        When reinforcing an existing reinforced concrete beam-column building with a precast concrete panel, special connection between the PC member and the RC member is required to solve the time dependent deformation of the RC member and to receive the large shear forces. The aim of this study is to obtain the shear strength of upper connection between the existing RC beam-column and infilled PC wall panels in experimentally and theoretically. Thus, the static shear loading tests were conducted on the 6 specimens with the plate connection. Shear failure was resulted from the weakest portion of interior PC panel, exterior RC, and the connection, when the PC portion which located at the center of specimen was pulled upward from the bottom. T he experimental result was compared with analytical result from ACI 318M-14 Chapter 17 for the shear strength of post-installed anchor and PCI Handbook 7th edition 6.8 Structural Steel Corbel (PCI Design Handbook 7th edition, 2010) for the strength of cast-in H-beam. The analytical and experimental results show final failure at the same location. The failure loading of experiment showed larger than average 6% to that of the analysis.
        4,500원
        1626.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The findings were summarized as follows. The safety check by manufacturer showed that 6 of 13 companies are over the average occurrence of defects. It was expected that there would be a difference between manufacturing technology capability and production system of each manufacturer. Consequently, manufacturers should institutionally improve and strengthen certification items for the upward standardization of safety certification before factory. Second, the safety check by year showed that the results of this study accord with those of previous studies on defect time. Consequently, manufacturers should classify the 3-year-old equipment for vehicle-mounted MEWP into a special check subject to do a nondestructive test according to proven results, and also reflect the test in a safety test system to do regular preventive activities of equipment defects. Third, the safety check by part showed that the boom and outrigger parts of vehicle-mounted MEWP have the most defects. Stress concentration resulted in defects as the boom part was most frequently operated in the structural parts for a real work. To prevent this, it is suitable to improve the hardness of boom materials. The outrigger part needs improvement in safety devices with materials. As an outrigger supports the overturning moment of equipment, it is most affected by its load based on the operating radius, resulting in fatigue crack.
        4,200원
        1628.
        2017.03 구독 인증기관 무료, 개인회원 유료
        The knock-in efficiency in the fibroblast is very important to produce transgenic domestic animal using nuclear transfer. In this research, we constructed three kinds of different knock-in vectors to study the efficiency of knock-in depending on structure of knock-in vector with different size of homologous arm on the β-casein gene locus in the somatic cells; DT-A_cEndo Knock-in vector, DT-A_tEndo Knock-in vector I, and DT-A_tEndo Knock-in vector II. The knock-in vector consists of 4.8 kb or 1.06 kb of 5’ arm region and 1.8 kb or 0.64 kb of 3’ arm region, and neomycin resistance gene(neor) as a positive selection marker gene. The cEndo Knock-in vector had 4.8 kb and 1.8 kb homologous arm. The tEndo Knock-in vector I had 1.06 kb and 0.64 kb homologous arm and tEndo Knock-in vector II had 1.06 kb and 1.8 kb homologous arm. To express endostatin gene as transgene, the F2A sequence was fused to the 5’ terminal of endostatin gene and inserted into exon 7 of the β-casein gene. The knock-in vector and TALEN were introduced into the bovine fibroblast by electroporation. The knock-in efficiencies of cEndo, tEndo I, and tEndo II vector were 4.6%, 2.2% and 4.8%, respectively. These results indicated that size of 3’ arm in the knock-in vector is important for TALEN-mediated homologous recombination in the fibroblast. In conclusion, our knock-in system may help to create transgenic dairy cattle expressing human endostatin protein via the endogenous expression system of the bovine β-casein gene in the mammary gland.
        4,000원
        1630.
        2017.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        사용후핵연료 파이로프로세싱에서는 방사성 희토류 염화물(RECl3)을 함유한 LiCl-KCl 공융염폐기물이 발생되며, 핫셀시설에서 운영을 목적으로 단순한 형태의 공융염폐기물 처리공정을 개발하는 것이 필요하다. 본 연구에서는, LiCl-KCl 공융염폐기물 내 희토류 핵종 분리/고화공정의 단순화를 목적으로 Li2O-Al2O3-SiO2-B2O3계의 무기합성매질을 이용하여 LiCl-KCl 공융 염 내 희토류 핵종(Nd)을 분리한 후 분리생성물을 바로 고화하는 시험을 실시하였다. 공융염 내 희토류 염화물(NdCl3) 대비 0.67의 무게비에 해당하는 무기합성매질의 양으로도 Nd 핵종을 98wt% 이상 분리할 수 있었고, 이 때 얻은 희토류 핵종 포집생성물은 약 50wt% 수준의 희토류 산화물 함량을 보유하고 있었으며, 이 포집생성물을 화학적 내구성이 우수한 단일상의 균질한 유리고화체로 제조할 수 있었다. 이 결과들은 LiCl-KCl 공융염폐기물 내 희토류 핵종의 분리/고화공정을 단순화하기 위한 방안수립에 활용될 수 있을 것이다.
        4,000원
        1633.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to modeling seismic isolation system such as lead-rubber bearing (LRB), bilinear model is widely used by many researchers. In general, an actual force-displacement relationship for LRB has a smooth hysteretic shape. So, Bouc-Wen model with smooth hysteretic shape represents more accurately actual hysteretic shape than bilinear model. In this study, seismic responses for seismically isolated nuclear power plant (NPP) with LRB modelled by Bouc-Wen and bilinear models are compared with those of NPP without seismic isolation system. To evaluate effect of earthquake characteristics for seismic responses of NPP isolated by LRB, 5 different site class earthquakes distinguished by Geomatrix 3rd Letter Site Classification and artificially generated earthquakes corresponding to standard design spectrum by Reg. Guide 1.60 are used as input earthquakes. From the seismic response results of seismically isolated NPP, it can be observed that maximum displacements of seismic isolation modelled by Bouc-Wen model are larger than those by bilinear model. Seismic responses of NPP with LRB is significantly reduced than those without LRB. This reduction effect for seismic responses of NPP subjected to Site A (rock) earthquakes is larger than that to Site E (soft soil) earthquakes.
        4,000원
        1634.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The brake systems are composed of brake disc, brake pad and caliper and, these three parts play an important role for braking. In this study, heat fluid analysis is conducted for five different ventilated disc models, and two piece brake disc model separated in rotor and housing is used. In this case, each model has a different number of holes and vent shape. The basic heat flux and braking power equations are applied for the heat fluid analysis. The cooling performance with/without the braking operation is also analyzed for given five models where the material properties and boundary conditions are set to be identical. From our analysis results, it is found that the number of disc holes and ventilated pins strongly influences on the cooling performance.
        4,000원
        1635.
        2017.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Natural and expandable graphites were chemically treated in acidic aqueous solutions such as acetic acid or mixtures of acetic acid and nitric acid. Structures and thermal conductivities of the as-treated graphites were characterized in detail. Both graphites were significantly oxidized in the mixed acidic solution of H2SO4 and HNO3, which condition was generally used for the oxidation of carbon nanotubes. This considerable oxidation of graphites caused a depression of their thermal conductivity. The structural characteristics, obtained by XRD and XPS, show that the graphites treated in the relatively weak acidic conditions (acetic acid or mixture of acetic acid and nitric acid) were quite similar to the untreated graphites. However, the thermal conductivities of both acidic-treated graphites were remarkably increased.
        4,000원
        1636.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to comprehend the change of the terms and the structure of the Pungpanbu in the T-shaped wooden shrines in the later Joseon period through the Salleung-dogamuigwes. Following conclusions have been reached through the study. First, the terms in the Salleung-dogamuigwes were similar to Yeonggeon-dogamuigwes but timing difference was verified. The word about the frame of Pungpanbu was different from the current. Second, in accordance with the extended of Pungpanbu, the members of frame of Pungpanbu had been increased and it had been changed to the lattice. The members of Pungpanbu used as plan dimensions and the size of the members had been gradually increased. Third, the Pungpanbu had been extended to protect the side of T-shaped wooden shrines. At the same time, the range of Chukjungbang had been extended. This was the result of the efforts of the era to reduce the range of plaster. This affected the overall elevation change of T-shaped wooden shrines.
        4,300원
        1637.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        FEM 수치해석을 위한 사면체격자 생성을 위해서는 물체의 볼륨정보를 표현할 수 있는 Boundary Representation (B-Rep) 모델이 필요하다. 공학분야에서는 파라메트릭 솔리드 모델링(Parametric Solid Modeling) 방법을 사용하여 BRep 모델을 정의한다. 반면 지질모델링은 메쉬 기반의 불연속(discrete) 모델링 방법을 사용하는데 이를 지질솔리드모델 (Sealed Geological Model)이라 부르며 지층, 단층, 관입암, 모델 경계면과 같은 지질학적 인터페이스들을 이용해 지질 도메인을 정의한다. 공학분야의 파라메트릭 모델링과 불연속 모델링 방식의 자료구조의 차이로 인해 불연속 B-Rep 모 델은 공학분야에서 사용하는 다양한 오픈소스, 상용 메쉬제작 소프트웨어와 쉽게 호환되지 않는다. 이 논문에서는 공학 용 메쉬 제작 소프트웨어와의 호환성을 가지도록 지질솔리드모델을 대표적인 오픈소스인 Gmsh와 상용 FEM 해석 소 프트웨어인 COMSOL로 변환하는 프로그램을 제작하였다. 지질모델링 소프트웨어를 통해 제작한 복잡한 지질구조모델 을 사용자 편의성을 갖춘 다수의 상용 소프트웨어서 쉽게 활용할 수 있어 지열, 암석역학 등 다양한 지구과학 시뮬레 이션 연구에 도움이 될 것으로 생각된다.
        4,200원
        1638.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2015년 6월부터 9월까지 보길도 일대의 소하천의 12개 조사지점에서 담수어류상 및 어류 군집구조를 분석하였다. 조사기간 동안 9과 17속 21종의 어류가 채집되었다. 망둑어과(10종, 1,157개체; 상대풍부도 (RA), 40.9%)가 우점과로 나타났고, 아우점과는 잉어과 (3종, 500개체), 숭어과(2종, 168개체)순으로 나타났다. 버들치(RA 20.7%, 397개체)가 우점종으로 나타났으며, 아우점종은 꾹저구(19.5%, 373개체), 사백어(17.2%, 330개체), 가숭어(8.5%, 163개체) 순으로 나타났다. 보길도에서 채집된 담수어류 중 생활형 구분으로 일차담수어가 9종(42.9%), 주연성 어종 11종(52.4%), 양측회유성 어종 1종(4.8%)으로 나타났다. 한반도 고유종 및 외래어종은 보길도에서 한종도 출현하지 않았다. 군집분석 결과에 따르면, 종 풍부도 지수 및 종 다양도 지수는 다른 지점에 비해 많은 종이 출현한 부황천 최하류 구간(S8)에서 각각 1.831, 1.957로 높게 나타났으며, 중류구간 (S4)에서 0으로 가장 낮게 나타났다. 반면, 우점도 지수는 중류구간 (S4) 1로 높게 나타났으며, 최하류 구간(S8)에서 0.17로 낮게 나타났다.
        4,000원
        1639.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        남부지역 덜꿩나무 집단 중 우점도가 높은 6개 지역을 대상으로 식생구조 및 토양특성을 분석하여 조 경용으로서 가치가 높은 덜꿩나무 자생지의 생육환경을 파악하여 생육 적지는 선정하는데 기초자료를 제공하고자 수행하였다. 자생지 내의 목본식물은 교목층 13수종, 아교목층 38수종, 관목층 48수종으로 총 68수종이 분포하였다. 평균상대우점치(MIV)가 높은 수종은 소나무, 굴참나무, 생강나무, 산벚나무, 땅비싸리, 당단풍나무, 진달래, 정금나무, 작살나무 등이었으며, 전 조사지역에서 공통적으로 출현한 수 종은 졸참나무와 때죽나무 2수종이었다. 덜꿩나무와 유사한 생태적 지위를 갖는 정의 상관관계를 나타 내는 수종들은 자귀나무와 노린재나무 2수종으로 나타난 반면 굴피나무는 부의 상관관계가 있어 서로 생태적 지위가 이질적인 것으로 나타났다. 자생지의 종다양도(H’), 최대종다양도(H’max), 균재도(J’) 및 우점도(1-J’)는 각각 0.887, 1.102, 0.803, 0.196으로 나타났다. 자생지의 토양특성은 pH 4.3, 유 기물함량 10.6%, 전질소함량 0.34% 및 유효인산 0.68㎎ ㎏-1로 나타났으며, 치환성양이온은 Ca2+ (16.84 cmolc ㎏-1) > K+(6.41 cmolc ㎏-1) > Mg2+(4.26 cmolc ㎏-1) 순으로 높은 함량을 나타냈다. 남 부지역 덜꿩나무 집단은 유기물 함량이 풍부하고 양이온 치환용량이 높은 강산성 토양으로 질소의 함량 에 비해 인산의 함량이 다소 높은 곳에서 자라는 경향이 있었다.
        4,200원
        1640.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This transport cask for radioactive materials will be used in the Gijang reactor. It will transport the Ir-192 10,000 Ci or I-131 80 Ci. In this case, the safety evaluation, such as protection of leakage of radioactive material, and radiation shield should be carried out before it is used in the research reactor. The safety regulation requires various tests, such as water spray, free drop, penetration, and water immersion. But this paper considers only the regulations related with thermal-stress and drop impact under the normal conditions because it will be used only in the research reactor building. In this paper, coupled numerical analysis was performed using finite element simulation to investigate the effect of position of tungsten and lead to enhance the safety of transport cask. As a result of simulation, it was verified that the Tungsten-Lead structure is the most durable among the cases considered in the study with a viewpoint of thermal-stress and drop impact.
        4,000원