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        검색결과 22

        3.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리나라는 기상 악화 속에서 감항성이 확보된 선박만이 항해할 수 있도록 선박출항을 해사안전법에 근거하여 통제하고 있으 나 통제 대상선박 지정에 대한 과학적 평가 결과 및 정량적 근거가 미비하여, 항행안전의 확보와 합리적 출항통제 운영을 위한 개선 의견 이 제기되고 있다. 본 연구는 풍랑 주의보 발효 시 주요 통제대상 선종인 예인선의 실선계측을 통해, 현행 출항통제 기준의 적정성을 평 가하고 현실성 있게 개선될 수 있도록 정량적 근거를 제시하는 것에 연구 목적이 있다. 이를 위해 예인선에 선박의 3축 운동과 선체가속 도를 측정하는 Sensor를 설치하여 유의파고 3m인 해역 내에서 운항하여 선체운동 성능을 계측하였고, 계측된 수치를 내항성능 평가요소 및 한계 값 기준을 바탕으로 비교 분석하였다. 실측 선박은 톤수에 따른 현행 통제기준에서 제외되었으나, 분석 결과 Pitch 값이 Operation 기준을 넘어 항행안전에 위험성이 존재하였다. 본 연구 결과는 선박 출항통제 대상에 대한 검토와 다양한 선종 및 제원을 대표할 수 있는 추가적 실측연구가 필요함을 시사한다.
        4,000원
        4.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Because magnets fabricated using Nd-Fe-B exhibit excellent magnetic properties, this novel material is used in various high-tech industries. However, because of the brittleness and low formability of Nd-Fe-B magnets, the design freedom of shapes for improving the performance is limited based on conventional tooling and postprocessing. Laserpowder bed fusion (L-PBF), the most famous additive manufacturing (AM) technique, has recently emerged as a novel process for producing geometrically complex shapes of Nd-Fe-B parts owing to its high precision and good spatial resolution. However, because of the repeated thermal shock applied to the materials during L-PBF, it is difficult to fabricate a dense Nd-Fe-B magnet. In this study, a high-density (>96%) Nd-Fe-B magnet is successfully fabricated by minimizing the thermal residual stress caused by substrate heating during L-PBF.
        4,000원
        8.
        2019.03 구독 인증기관 무료, 개인회원 유료
        Recently, the importance of on-site detection of pathogens has drawn attention in the field of molecular diagnostics. Unlike in a laboratory environment, on-site detection of pathogens is performed under limited resources. In this study, we tried to optimize the experimental conditions for on-site detection of pathogens using a combination of ultra-fast convection polymerase chain reaction (cPCR), which does not require regular electricity, and nucleic acid lateral flow (NALF) immunoassay. Salmonella species was used as the model pathogen. DNA was amplified within 21 minutes (equivalent to 30 cycles of polymerase chain reaction) using ultra-fast cPCR, and the amplified DNA was detected within approximately 5 minutes using NALF immunoassay with nucleic acid detection (NAD) cassettes. In order to avoid false-positive results with NAD cassettes, we reduced the primer concentration or ultra-fast cPCR run time. For singleplex ultra-fast cPCR, the primer concentration needed to be lowered to 3 μM or the run time needed to be reduced to 14 minutes. For duplex ultra-fast cPCR, 2 μM of each primer set needed to be used or the run time needed to be reduced to 14 minutes. Under the conditions optimized in this study, the combination of ultra-fast cPCR and NALF immunoassay can be applied to on-site detection of pathogens. The combination can be easily applied to the detection of oral pathogens.
        4,000원
        10.
        2017.06 구독 인증기관 무료, 개인회원 유료
        Metformin (1,1-dimethylbiguanide hydrochloride), derived from French lilac (Galega officinalis), is a first-line anti-diabetic drug prescribed for patients with type 2 diabetes. However, the role of metformin in odontoblastic cell differentiation is still unclear. This study therefore undertook to examine the effect of metformin on regulating odontoblast differentiation in MDPC-23 mouse odontoblastic cells derived from mouse dental papilla cells. As compared to controls, metformin significantly accelerated the mineralization, significantly increased and accelerated the expressions of ALP and Col I mRNAs, and significantly increased the accelerated expressions of DSPP and DMP-1 mRNAs, during differentiation of MDPC-23 cells. There was no alteration in cell proliferation of MDPC-23 cells, on exposure to metformin. These results suggest that the effect of metformin on MDPC-23 mouse odontoblastic cells derived from mouse dental papilla cells, facilitates the odontoblast differentiation and mineralization, without altering the cell proliferation.
        4,000원
        12.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigates the analysis algorithm for developing an optimum hull form with minimum wave resistance by using the practical application of one minus prismatic. In this algorithm the potential-based panel method was adopted to get the wave resistance coefficient as the objective function and SQP method was applied as an optimizer to get the optimum hull form. As an target ship, the series 60(CB=0.6) was taken into account and LBP(length between perpendiculars) of the ship was changed in the direction including a central parallel portion. To verity the validity of this study, the results of the numerical analyses were compared with experimental data.
        4,000원
        14.
        2016.02 KCI 등재 구독 인증기관·개인회원 무료
        A numerical investigation was performed based on the Reynolds-Averaged Navier-Stokes(RANS) equations for the two-dimensional unsteady incompressible flow around a vertical axis turbine(VAT) with NACA0012 and NACA0018 wing sections. FLUENT was used as a numerical tool to predict the flow filed around the VATs and the performance of the VATs. CFD analysis using FLUENT was carried out at several angles of attack for NACA0012 and NACA0018 wing sections and the results were compared with the corresponding experimental data for validation and calibration of the numerical analysis results. The VATs with 3, 4 wings were adopted to determine the characteristics of the change in the number of wings. The results of the numerical analysis were compared each other to determine the characteristics of the VATs according to the thickness variation of the wing section.
        15.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구에서는 물량저감 철근상세를 갖는 중공 철근콘크리트 교각 시스템의 전용 설계프로그램과 소성설계 적용 결과를 제시하였다. 개발된 물량저감 철근상세는 경제성과 합리성을 갖으며 공사기간의 단축을 가져올 수 있다. 물량저감 중공 철근콘크리트 교각의 적용을 통해 경제성 평가를 수행하였다. 평가 결과 개발상세가 기존상세에 비해 구조적 합리성, 시공성, 그리고 경제성 등이 우수함을 확인하였다.
        4,000원
        16.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pathologic chronic inflammation, such as that seen with microbial infection and autoimmune diseases, creates microenvironmental conditions that promote cancer. Therefore, if chronic inflammation can be alleviated, the risk of carcinoge- nesis may decrease. Turmeric is a dried rhizome powder from Curcuma longa. Curcumin, the major constituent of turmeric, presents anti-inflammatory, antioxidant, antimicrobial and chemopreventive activities. In the present study, we investigated immune responses to dietary turmeric in ICR mice to determine the effects of turmeric when used as a dietary chemoprevention agent. After dietary turmeric was given for three or six weeks to ICR male mice, the immune responses were characterized. The methods of characterization involved; the determination of the T cell subpopulation in the spleen, relative mRNA expression levels of IFN-γ and TNF-α and serum lysozyme activity. Dietary turmeric was found to decrease spleen weight, decrease the proportion of CD4-CD8+ T cells, and decrease phagocytic activity. These results suggest that turmeric might alleviate abnormal chronic inflammation by the action of immune suppression.
        4,000원
        17.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon nanomaterials in organic photovoltaic (OPV) cells have attracted a great deal of interest for the development of high-efficiency, flexible, and low-cost solar cells. Due to the complicated structure of OPV devices, the electrical properties and dispersion behavior of the carbon nanomaterials should be controlled carefully in order for them to be used as materials in OPV devices. In this paper, a fundamental theory of the electrical properties and dispersion behavior of carbon nanomaterials is reviewed. Based on this review, a state-of-the-art OPV device composed of carbon nanomaterials, along with issues related to such devices, are discussed.
        4,500원
        19.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
          By the early 20 century, “workman” introduced by SONY was the leading portable analog sounder. However, at the same century, workman was pushed out from the portable sounder by iRiver developed by MPMAN.COM. This portable digital sounder is called MP3-P
        4,000원
        20.
        2022.12 KCI 등재 서비스 종료(열람 제한)
        The present study aimed to examine the effect of dietary Ptecticu tenebrifer powder mixtures as pet dogfeed ingredients on crude fat and ash digestibility. Three groups of feeds Feed A, Feed B, and Feed C supplied from three farms were fed to a total of 45 dogs. The dietary Ptecticu tenebrifer powder mixture were prepared by mixing 25 g of Ptecticu tenebrifer powder with 100 g of canned food. Feed A, Feed B, and Feed C containing dietary Ptecticu tenebrifer powder mixtures were fed to 15 dogs of each breed of bichon, poodle, and chihuahua that were divided into three groups following a completely randomized design. For measuring the crude fat and crude ash digestibility, manure of each dog breed from each group were collected. Crude fat digestibility was not statistically significant among the dog breeds fed with feed C (p>0.05), but overall there was a statistical difference between the feed and the group by dog breed (p<0.05). In terms of crude ash digestibility, the three types of feed showed differences with respect to dog breeds (p<0.05). However, the group with no significant difference was observed in Feed B by dog breed (p>0.05). In conclusion, feeding Ptecticu tenebrifer powder mixture to dog breeds had no positive effect on the crude fat and ash digestibility and can be used as pet dogfeed ingredients.
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