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        검색결과 882

        261.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As buildings are becoming larger, demand for mega-sized composite columns (over 1-meter diameter) is increased. We have developed and commercialized welded built-up CFT column (ACT Column I) since 2005 which are structurally stable and economical using cold-formed steel with rib. However, there has a limit in size of cross section (618˟618mm) by a fabrication facilities. And due to characteristics of closed cross section, there has a limit to construction of connection of moment frame. Composite mega column (ACT Column II) has same concept of forming closed cross section. But in order to enlarge cross sectional size, thick plate is inserted between cold-formed steels. Since composite mega column can control thickness and width of thick plate, steel or composite beams can be directly attached to the connection. In this study, we propose strength formula of composite mega column to beam connections with T-shaped stiffener as internal diaphragm and verified through finite element analysis and simple tensile experiment.
        4,000원
        262.
        2018.01 구독 인증기관 무료, 개인회원 유료
        초기 통계에 따르면 용문석굴 당대 기년관음보살상은 53구가 있으며, 기년이 없는 상은 140여구가 있다. 필자는 현장조사에 의거해 기년관음 상에 대해 구체적 기록 및 분석을 진행하고, 역사문헌과 비석의 내용들 을 참고하여 용문석굴 당대 관음상의 특징 및 형상변천 규율에 대해 정리하였다. 또한 당대 관음상에 관한 다른 문제들에 대해서도 검토하여 당대 용문을 비롯하여 낙양지역의 정토신앙 및 관음신앙에 대해 살펴보 고자 한다.
        10,100원
        263.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, uniaxial tensile tests of ETFE films with three kinds of thicknesses(100, 200, 250μm) and two kinds of directions(machine direction & transverse direction) are performed and the tensile strength, the tensile strain at break and the Young’s modulus of ETFE films are compared for two kinds of specimen types(2 & 5). It could be figured out that there are no significant difference between tensile strengths of two specimen types but the tensile strain at break and the Young’s modulus of ETFE films are affected by the specimen types. And it is concluded that the uniaxial tensile test of specimen type 2 are more reliable than that of specimen type 5.
        4,000원
        265.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The proportion of software in the automotive industry is steadily increasing due to the rapid technological development of automobile E/E parts. Because the automotive E/E technology is now on the basis of intelligent automobile and advanced safety automobile technology. The purpose of this study is to investigate the effect of organizational capability (organizational resource capability and management capability), process capability (process capability, customer Requirement management capability), performance dimension (motivation, participation level). In this study, we conducted questionnaires and statistical analysis on engineers (members of the Korea Advanced Automotive Technology Association) who perform research and development activities in the R&D organization of the automotive E/E part in South Korea. ANOVA is applied for the verification of the difference in performance measured by organizational capability, process maturity, and motivation participation level according to company characteristics (level of processing : supply chain configuration, annual sales, total SW development ratio). According to the results of this study, in order to improve the performance of ASPICE or ISO 26262-related consulting project, a different consulting approach strategy considering the characteristics of organization and personnel is needed. In summary, the analysis results for the three main treatment levels are as follows. The difference in organizational capacity, process capability and performance was found to be statistically significant according to supply chain configuration and annual sales, but it was found that the difference of response according to the proportion of total SW was not significant.
        4,200원
        266.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, single layer latticed domes have attracted many designers and researchers’s attention all over the world, because single layer latticed domes as space structure are of great advantage in not only mechanical rationality but also function, fabrication, construction and economic aspect. Yamada developed the shape factor S which represents the shape of spherical latticed dome from a structural perspective as well as a geometric perspective. According to a prior study, the structural behavior and the buckling characteristics of the latticed dome were mostly noticeable when the shape factor of latticed dome was in the range of 1.5 to 5. That is, S, in the range of 1.5 to 5, are able to estimate not only overall buckling, but also member buckling and nodal buckling. In this study, we developed shape models using various size of members with the fixed rise-span ratio. One particular characteristic of the latticed dome is that it is not only light in weight but also high in strength. But the aiming at the use of light-weight materials and at the minimized section of members may result in buckling to cause an unstable state of the overall structure when the external force reaches a limitation. Especially, the structural strength is disadvantageous to the snow loads than the earthquake loads because of light-weight, and is greatly affected by the conditions of loading. This paper is to develop the structural stability according to the shapes and load conditions for single-layer latticed spherical dome with 300m span.
        4,000원
        267.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research is to numerically perform the optimal design of the shutter valves in the two-stroke engine by analyzing flow resistance with four different design shapes. Shutter valves were numerically analysed for four different industry-design based cases using ANSYS FLUENT V.14. At the result, it was found that the most design-effective case was case 4 with dimensions of 4.5 cm radius and 26 cm length of cylinder with a sphere of 6 cm radius in the valve. Pressure loss of three cases is between 0.70% and 6.48% when compared to case 1. However, 0.16% of pressure loss increased as the rotational speed of valve increased with 1 rad/s. Thus, at lower rotational speed, the case 4 was possibly optimal shape design due to the lowest pressure loss.
        4,000원
        268.
        2017.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        SiAlON-based ceramics are some of the most typical ceramic materials used as cutting tools for HRSA(Heat Resistant Super-Alloys). SiAlON can be fabricated using ceramic processing, such as mixing, granulation, compaction, and sintering. Spray drying is a widely-used method for producing a granular powder of controlled morphology and size with flowability. In this study, we report a systematic investigation aimed at optimizing spherical granule morphology by controlling spray-drying parameters such as gas flow and feed rate. Before spray drying, the viscosities of the raw material slurries were also optimized with the amount of dispersant added.
        4,000원
        272.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the size of the wind turbine tower becomes larger and larger, research on assembled wind turbine tower that is advantageous for transportation and installation is continuing. Large wind turbine tower require door openings for maintenance. The opening of the tower has an irregular cross section, and an excessive stress is generated due to the door opening. The result is structural damage to the tower and many accidents. In this research, stress analysis was performed on a model with internal stiffener to prevent excessive stress. The stress was investigated around the openings where the tower was resonant and excessive stressed, and the shape of the openings was optimized. Through optimization, we confirmed that the maximum stress was reduced by about 6% with respect to the initial value.
        4,000원
        273.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The object of research is based on 1.5 MW wind turbine blade. This paper has carried out the aerodynamic shape optimization design of wind turbine blade. Based on the aerodynamic basic theory of wind turbine blade design and combined with particle swarm optimization algorithm(PSO), the design optimization model of the aerodynamic shape of blade is established. Through this study, the optimization results of the angle inducing ′ and tangential inducing  were obtained. The calculation programs are written and calculated chord length and torsion angle of the blade used by ′ and . The calculation result for the optimized wind turbine was 1.38 MW when the wind speed was 16 m/s. The 8 % error could be considered as an engineering acceptable error and the calculated values can be proved the correctness of the design value.
        4,000원
        274.
        2017.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Gd2O3:Eu3+ red phosphors were prepared by template method from crystalline cellulose impregnated by metal salt. The crystallite size and photoluminescence(PL) property of Gd2O3:Eu3+ red phosphors were controlled by varying the calcination temperature and Eu3+ mol ratio. The nano dispersion of Gd2O3:Eu3+ was also conducted with a bead mill wet process. Dependent on the time of bead milling, Gd2O3:Eu3+ nanosol of around 100 nm (median particle size : D50) was produced. As the bead milling process proceeded, the luminescent efficiency decreased due to the low crystallinity of the Gd2O3:Eu3+ nanoparticles. In spite of the low PL property of Gd2O3:Eu3+ nanosol, it was observed that the photoluminescent property was recovered after re-calcination. In addition, in the dispersed nanosol treated at 85 oC, a self assembly phenomenon between particles appeared, and the particles changed from spherical to rod-shaped. These results indicate that particle growth occurs due to mutual assembly of Gd(OH)3 particles, which is the hydration of Gd2O3 particles, in aqueous solvent at 85 oC.
        4,000원
        275.
        2017.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Surface morphology and optical properties such as transmittance and haze effect of glass etched by physical and chemical etching processes were investigated. The physical etching process was carried out by pen type sandblasting process with 15~20 μm dia. of Al2O3 media; the chemical etching process was conducted using HF-based mixed etchant. Sandblasting was performed in terms of variables such as the distance of 8 cm between the gun nozzle and the glass substrate, the fixed air pressure of 0.5bar, and the constant speed control of the specimen stage. The chemical etching process was conducted with mixed etching solution prepared by combination of BHF (Buffered Hydrofluoric Acid), HCl, and distilled water. The morphology of the glass surface after sandblasting process displayed sharp collision vestiges with nonuniform shapes that could initiate fractures. The haze values of the sandblasted glass were quantitatively acceptable. However, based on visual observation, the desirable Anti-Glare effect was not achieved. On the other hand, irregularly shaped and sharp vestiges transformed into enlarged and smooth micro-spherical craters with the subsequent chemical etching process. The curvature of the spherical crater increased distinctly by 60 minutes and decreased gradually with increasing etching time. Further, the spherical craters with reduced curvature were uniformly distributed over the etched glass surface. The haze value increased sharply up to 55 % and the transmittance decreased by 90 % at 60 minutes of etching time. The ideal haze value range of 3~7 % and transmittance value range of above 90 % were achieved in the period of 240 to 720 minutes of etching time for the selected concentration of the chemical etchant.
        4,000원
        276.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        마음에 품은 理想이 현실의 어려움으로 좌절되었을 때 이러한 마음은 광적인 분노와 현실 에 대한 부정으로 표출된다. 명말청초 시기 격변기를 살았던 지식인들은 부패한 현실과 이민 족의 침입으로 나라를 잃게 되자 시문과 술에 마음을 기탁하거나 광기 어린 행동들로 자신의 내면세계를 표출하였다. 광적인 행동, 냉소적인 웃음과 애통한 울음 속에는 당시 지배계층에 대한 멸시와 조롱, 자신의 처지에 대한 절망감과 울분이 내재되어 있다. 명말 청초 문학가이 자 출판가였던 張潮의 虞初新志는 명말청초 시기 문인들의 작품 150편을 수록한 작품집이 다. 우초신지는 인물을 대상으로 한 작품이 100여 편에 달하는데, 작품 속 인물들은 개성과 패기가 넘치고 거침이 없으며 세상과 타협하지 않는 호탕함을 보여준다. 우초신지의 작품 속에 그려진 狂人 형상을 살펴보면 크게 세 부류로 나눠볼 수 있다. 첫째, 호탕하고 자유분방 한 인물, 둘째, 봉건적 예법을 거부하고 권력에 저항하는 인물, 셋째는 혼란한 사회 환경 속 에서 기예를 통해 자신의 삶의 가치를 추구했던 인물들이다. 수록된 작품을 통해 당시 지식 인들의 심리세계도 엿볼 수 있다. 명청 왕조 교체기라는 정치적 격변기에 고민하던 지식인들 의 복잡한 처세심리를 드러내기도 하고, 새로운 정권의 희생양이 될까 두려워서 자연에 은거 하며 술과 사물에 마음을 의탁하며 정신적인 시름을 잊고자 하는 마음도 드러나 있다. 또한 자신의 처한 현실을 부정하기 위해 미치광이처럼 행동하며 마음속의 울분을 표출해내기도 하 였다.
        4,600원
        277.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고속 활주선에서 차인은 활주자세 변화 뿐 아니라 선체의 균형을 잡아주는 역할을 하며, 저항성능에 큰 영향을 미친다. 그러나 이러한 차인의 설계는 배수량, 선저경사각, 흘수, 선폭 등 다양한 설계 인자들에 영향을 받는 변수로 많은 경험을 필요로 한다. 본 연구에 서는 경험식이 아닌 계산을 통해 차인에 대한 설계 시 형상에 대한 기본적인 지침 마련을 목적으로 고속 활주선의 차인의 형상에 따른 저항성능에 대해 계산하였다. 설계는 상용 설계 프로그램인 Yacht-one을 이용하였으며, 유동해석은 상용 해석프로그램인 STAR-CCM+으로 DFBI(Dynamic Fluid Body Interaction)방법을 적용하여 수행하였다. 초기 설계 차인 각도인 17도를 기준으로 차인 15도, 차인 16도, 차인 19도 로 변경하여 설계 속도인 30노트에서 해석을 수행하였다. 그 결과, trim은 4개의 차인 중 16도가 가장 컸으며, heave는 차인 15도에서 가장 우수하였다. 해석 결과를 봤을 때 저항 측면에서 초기 설계 각도인 차인 17도 보다 차인 16도가 우수함을 보이고 있어 실제 설계 시 초기 설계 각도에서 +2도, -2도의 범위로 계산을 통해 저항 성능과 자세에서 우수한 차인을 선택해야 함을 알 수 있다.
        4,000원
        278.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The heat transfer characteristics of forced convection according to the geometric shapes with four rectangular blocks in a horizontal PCB channel was analyzed numerically using SST (Shear Stress Transport) turbulence model. As the boundary condition for CFD (Computational Fluid Dynamics) analysis, the inlet temperature and air velocity were respectively 300 K and 3.84 m/s and the heat flux of the block surface was 358 W/㎡. The shape factors of block were width, height, spacing and channel entrance height. As the results, the heat transfer rate was decreased as the width ratio (x/h) was increased, while it was increased as the height ratio (h/x) is increased. Also as the block spacing ratio (s/x) was increased, the heat transfer effects was not significantly affected. And as the channel entrance height ratio (H/x) was increased, the heat transfer performance was decreased.
        4,000원
        279.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the present study, FE analysis was performed for characterising structural strength of a seat frame w.r.t. varying sectional shapes as well as different materials of the seat back frame based on the FMVSS 207 regulation in order to obtain the design outline of a lightweight seat frane structure. Four types of materials, i.e., SAPH440, Al7021, Al6082 and carbon/epoxy composites were applied to the seat back frame type beams and their bending behaviours were compared by three point bending FE analysis. Consequently, the lightweight structure of seat back frame with the equivalent strength characteristics of conventional frame was suggested.
        4,000원
        280.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        『조각상』 에서 예이츠는 고대 그리스에서 중세 인도를 거쳐 현대 아일랜 드에 이르는 예술의 역사를 형상과 무형상의 변증법이라는 관점에서 추적한다. 그는 피타고라스적인 수, 피디아스의 형상, 불상의 무형상의 형상 그리고 아일랜드의 형상 을 통해 예술의 역사적 변천을 제시한다. 『조각상』 은 형상과 무형상 간의 경쟁의 역사 뿐만 아니라 예술에서 형상의 의미에 대한 예이츠의 사색을 잘 보여준다. 그리스의 조 각상에 걸 맞는 아일랜드의 영웅적 행위를 형상화함으로써 그는 아일랜드인의 꿈을 밝게 비추기를 고대한다.
        4,800원