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        검색결과 596

        21.
        2023.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the fluid-structure interaction analysis, the finite element formulation is performed for the wave equation for dynamic fluid pressure, and the dynamic pressure is defined as a degree of freedom at the fluid nodes. Therefore, to connect the fluid to the structure, it is necessary to connect the degree of freedom of fluid dynamic pressure and the degree of freedom of structure displacement through an interface element derived from the relationship between dynamic pressure and displacement. The previously proposed fluid-structure interface elements use conformal finite element meshes in which the fluid and structure match. However, it is challenging to construct conformal meshes when complex models, such as water purification plants and wastewater treatment facilities, are models. Therefore, to increase modeling convenience, a method is required to model the fluid and structure domains by independent finite element meshes and then connect them. In this study, two fluid-structure interface elements, one based on constraints and the other based on the integration of nonsmooth functions, are proposed in nonconformal finite element meshes for structures and fluids, and their accuracy is verified.
        4,000원
        22.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 의미 있는 대상의 선호도 판단에 영향을 미치는 것으로 알려진 원리인 내적 편향 원리와 규범적 관점 간의 상호작용 양상을 연구하는 데에 있다. 개별 개체의 친숙도가 규범적 관점에 영향을 미친다는 점 또한 고려 하여 친숙도 수준에 따른 두 선호도 원리의 작용 양상을 검증하고자 하였다. 이를 위하여 이중 대안 선택 과제를 활용한 행동 반응 실험을 진행하였으며, 친숙도 수준(높음/낮음)에 따라 각 8개의 단일 개체를 실험 재료로 하여 내 적 편향 원리 준수 여부와 규범적 관점 준수 여부를 조작하였다. 실험 결과, 내적 편향 원리를 준수한 상태에서 개체 가 제시된 경우가 내적 편향 원리가 위배된 상태로 개체가 제시된 경우보다 더 선호되었다. 선호 판단에 걸리는 반응 시간 또한 더 짧은 것으로 나타났다. 그러나 규범적 관점 준수 여부는 선택 빈도 및 반응 시간에 영향을 미치지 않는 것으로 나타났다. 더불어, 개체의 친숙도는 선호도 판단과 관련된 의사 결정에 간섭 요인으로 작용하는 것으로 나타났다. 이와 같은 결과는 개체 선호도 원리 중 내적 편향의 강도가 규범적 관점에 비해 더 우세하며, 단일 개체가 제시될 때 그에 대한 선호 판단에 있어서 그 개체가 가진 속성보다 시각적 문맥과의 상호작용이 중요하게 작용한다 는 것을 시사한다.
        4,600원
        23.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 노년기 정서지능을 나타내는 대표적인 요인인 정서인식명확성이 노인들의 낮은 사회적 상호작 용 불안을 예측하는지를 확인하고, 그 경로에서 자존감과 자기효능감이 매개하는지를 검증하는 것이다. 대한민국 노 인 217명을 대상으로 정서인식명확성, 사회적 상호작용 불안, 자존감, 자기효능감을 측정하는 설문을 온라인으로 실 시하였다. 분석 결과, 노인의 정서인식명확성은 사회적 상호작용 불안을 부적으로 예측하였다. 또한 매개분석 결과, 자존감은 정서인식명확성과 사회적 상호작용 불안의 관계를 매개한 반면, 자기효능감은 결과가 일관되지 않았다. 즉, 자신의 정서를 명확하게 인식하는 것은 개인의 자존감을 높여 사회적 상호작용 불안을 줄이지만, 이러한 매개효과는 자기효능감을 통해서는 명확하게 확인할 수 없었다. 이 결과는 노년기에 타인과의 상호작용을 원활하게 하기 위해서 는 명확한 정서인식이 필요하다는 점을 강조하면서, 이것이 특히 건강한 자기 개념 중 자신에 대한 존중감을 높이기 때문이라는 점을 보여주고 있다. 끝으로 본 연구의 함의와 추후 연구에 대한 방향을 논의하였다.
        5,200원
        26.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To investigate the effect of the catalyst and metal–support interaction on the methane decomposition behavior and physical properties of the produced carbon, catalytic decomposition of methane (CDM) was studied using Ni/SiO2 catalysts with different metal–support interactions (synthesized based on the presence or absence of urea). During catalyst synthesis, the addition of urea led to uniform and stable precipitation of the Ni metal precursor on the SiO2 support to produce Ni-phyllosilicates that enhanced the metal–support interaction. The resulting catalyst upon reduction showed the formation of uniform Ni0 particles (< 10 nm) that were smaller than those of a catalyst prepared using a conventional impregnation method (~ 80 nm). The growth mechanisms of methane-decomposition-derived carbon nanotubes was base growth or tip growth according to the metal–support interaction of the catalysts synthesized with and without urea, respectively. As a result, the catalyst with Ni-phyllosilicates resulting from the addition of urea induced highly dispersed and strongly interacting Ni0 active sites and produced carbon nanotubes with a small and uniform diameter via the base-growth mechanism. Considering the results, such a Ni-phyllosilicate-based catalyst are expected to be suitable for industrial base grown carbon nanotube production and application since as-synthesized carbon nanotubes can be easily harvested and the catalyst can be regenerated without being consumed during carbon nanotube extraction process.
        4,300원
        27.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Interactional modification is important in SLA research because it involves correcting problematic L2 use. However, not all modifications will lead to pedagogical changes. Participants in conversational interactions are not always oriented to linguistic forms or functions. One way to address this dilemma is to examine the process by which participants come to terms with problematic L2 use in interactional exchanges. “Language moments” refer to cases in which L2 forms and functions are objects of interactive exchanges in L2 interactions. Through conversation analysis, the present study uncovered four different types in which participants in L2 interaction discovered and acted on language moments in terms of the degree of explicitness in recognizing and addressing problematic L2 use. This study used data from ESL classroom interactions that featured native teachers of English and L2 learners in an US context. This descriptive account of interactional processes might complement prior research studies that have focused on effects of interactional modification.
        6,100원
        28.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper proposes a method to evaluate the structural safety of a large wide-width greenhouse structure against wind load caused by a typhoon through a fluid structure interaction analysis technique. The conventional method consisted of roughly estimating the wind load based on the relevant laws and regulations, and determining safety through structural analysis. However, since the wind load changes nonlinearly according to the wind speed distribution and wind direction around the greenhouse and the external shape of the structure, there are many uncertainties in the existing structural safety evaluation method, and it is difficult to accurately determine the design margin. In this study, a systematic method was developed to accurately calculate the wind load acting on a greenhouse structure and evaluate structural safety by considering the characteristics of wind through a fluid structure interaction analysis using coupled computational fluid dynamics and computational structural mechanics. Using the proposed method, it is possible to significantly reduce the manufacturing cost because it is possible to obtain an optimal design that reduces the over-conservative design margin while securing the structural strength of the greenhouse.
        4,000원
        29.
        2023.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Considering the non-linear behavior of structure and soil when evaluating a nuclear power plant's seismic safety under a beyond-design basis earthquake is essential. In order to obtain the nonlinear response of a nuclear power plant structure, a time-domain SSI analysis method that considers the nonlinearity of soil and structure and the nonlinear Soil-Structure Interaction (SSI) effect is necessary. The Boundary Reaction Method (BRM) is a time-domain SSI analysis method. The BRM can be applied effectively with a Perfectly Matched Layer (PML), which is an effective energy absorbing boundary condition. The BRM has a characteristic that the magnitude of the response in far-field soil increases as the boundary interface of the effective seismic load moves outward. In addition, the PML has poor absorption performance of low-frequency waves. For this reason, the accuracy of the low-frequency response may be degraded when analyzing the combination of the BRM and the PML. In this study, the accuracy of the analysis response was improved by adjusting the PML input parameters to improve this problem. The accuracy of the response was evaluated by using the analysis response using KIESSI-3D, a frequency domain SSI analysis program, as a reference solution. As a result of the analysis applying the optimal PML parameter, the average error rate of the acceleration response spectrum for 9 degrees of freedom of the structure was 3.40%, which was highly similar to the reference result. In addition, time-domain nonlinear SSI analysis was performed with the soil's nonlinearity to show this study's applicability. As a result of nonlinear SSI analysis, plastic deformation was concentrated in the soil around the foundation. The analysis results found that the analysis method combining BRM and PML can be effectively applied to the seismic response analysis of nuclear power plant structures.
        4,200원
        30.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to determine if animal-assisted therapy could enhance language and social interactions in autistic children. It is a single case study of a 6.7-year-old child diagnosed with second-rate autism disorder with a program of twelve sessions in total, a session per week, and fifty minutes per session. The program was constructed to increase the frequency of using words and to improve interpersonal relationships through contact with peers or strangers. To do this, SCAR and E-CLAC scales went through a pretest and posttest and the changes in main behaviors observed during the twelves sessions were analyzed, obtaining the following results: First, the animal-assisted therapy program allowed the autistic child to use daily words about twice more frequently than usual. Second, the animal-assisted therapy program was effective in allowing the autistic child to improve social interactions with peers or strangers around the dog. Therefore, the animal-assisted therapy program was effective in helping the autistic child enhance language and social interactions.
        4,000원
        33.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전 세계 각국은 탄소 배출량을 줄이기 위한 다양한 노력을 하고 있다. 지난 수십 년간 몇몇 연구자들은 탄소배출량 을 줄이기 위해서 철근콘크리트 구조에서 철근을 FRP로 대체하기 위한 연구를 수행해 왔다. FRP보강근을 휨부재로 사용하기 위한 연구는 많이 수행되어 왔으나, FRP 보강근 기둥의 성능을 평가하고 설계하기 위한 연구는 거의 이루어지지 않았다. 본 연 구는 FRP보강근 콘크리트 구조 기둥과 철근콘크리트 기둥의 P-M 상관도를 비교하고, 철근콘크리트 기둥에서 철근의 대체재로 서 FRP보강근의 활용 가능성을 제시하였고, 변수는 콘크리트의 압축강도, FRP보강근의 종류, 보강근비이다.철근을 GFRP로 대체 할 경우, 요구 GFRP 보강근의 양은 철근의 4배이며, 철근비가 4% 이상이면 동일한 단면으로는 설계할 수 없다. 편심거리비가 1.0보다 크거나 철근비가 4%보다 작은 철근콘크리트 기둥의 철근을 CFRP로 대체할 경우, 보강근의양을 1/2수준으로 줄이거나 단면 크기를 줄일 수 있다.
        4,000원
        34.
        2022.10 구독 인증기관·개인회원 무료
        Time-resolved laser fluorescence spectroscopy (TRLFS) and excitation-emission matrix (EEM) spectroscopy were used to study the interaction of U(VI) and natural organic matters (NOMs) in groundwater. Various types of groundwaters (DB-1, DB-3 from KURT site and OB-1, OB-3 from a U deposit in Ogcheon metamorphic belt) were used as samples. Pulsed Nd-YAG laser at 266 nm (Continuum Minilite) was used as the light source of TRLFS. The laser pulse energy of 1.0 mJ was fixed for all measurements. The luminescence spectrum was recorded using a gated intensified chargecoupled device (Andor, DH-720/18U03 iStar 720D) attached to the spectrograph (Andor, SR-303i). EEM spectra were measured using a spectrofluorometer (Horiba Scientific, Aqualog) equipped with a 150 W ozone-free xenon arc lamp. Excitation spectra were recorded by scanning the excitation wavelength from 200 to 500 nm. Emission spectra were measured using a CCD in the wavelength range of 242–823 nm. In the case of the recently collected DB-1 samples, it was observed that the U and NOM quantities decreased compared to the samples collected before 2016. For some DB-1 samples, the amount of dissolved organic carbon indicating the presence of NOM was significantly reduced, and changes consistent with this phenomenon were observed in the EEM spectrum. The time-resolved luminescence characteristics (peak wavelengths and lifetime) of U(VI) in the DB-1 samples agree well with those of Ca2UO2(CO3)3(aq). This U(VI) species remains stable, even in samples taken five years ago. The estimated amounts of U and NOM from the spectroscopic data of DB-3, OB-1, and OB-3 samples are relatively low compared to DB-1 samples. When a known amount of U(VI) was mixed in each groundwater, the time-resolved luminescence spectrum exhibited a characteristic spectral shape different from the expected luminescence intensity. This phenomenon is presumed to be due to the interaction between U(VI) and NOM in groundwater. The results of this study suggest that the chemical speciation of NOM as well as U(VI) is required to understand U behavior in groundwater.
        37.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In a rapidly changing environment, it is essential for companies to develop their capabilities for sustainable growth. To this end, informal learning at work plays an important role for small and medium-sized enterprises that are having difficulties in human resource development. If the GRIT of workers and the spiritual leadership of leaders are maintained at an appropriate level, the effect of informal learning will increase. This study derived the following results through a survey of workers participating in the Work-learning Dual System in Korea. First, experience and feedback among informal learning activities have a significant positive effect on competency development. Second, the higher the level of the GRIT of workers, the greater the magnitude of the positive effect of experience and feedback on competency development, showing a positive moderating effect. Third, in the case of workers with high GRIT, capacity development is strengthened as experience or feedback increases, and the higher the level of spiritual leadership, the greater the scope of reinforcement. On the other hand, it can be seen that in the case of workers with low GRIT, competency development weakens as experience or feedback increases, and the higher the level of spiritual leadership, the greater the extent of the weakening.
        4,600원
        38.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A simplified method for earthquake response analysis of a rectangular liquid storage tank is proposed with fluid-structure interaction considered. In order to simplify the complex three-dimensional structural behavior of a rectangular liquid storage tank, it is assumed that structural deformation does not occur in the plane parallel to the direction in which the earthquake ground motion is applied but in the plane perpendicular to the direction. The structural deformation is approximated by combining the natural modes of the simple beam and the cantilever beam. The hydrodynamic pressure, the structure’s mass and stiffness, and the hydrodynamic pressure’s added mass are derived by applying the Rayleigh-Ritz method. The natural frequency, structural deformation, pressure, effective mode mass, and effective mode height of the rectangular liquid storage tank are obtained. The structural displacement, hydrodynamic pressure, base shear, and overturning moment are calculated. The seismic response analysis of an example rectangular liquid storage tank is performed using the proposed simplified approach, and its accuracy is verified by comparing the results with the reference solution by the finite element method. Existing seismic design codes based on the hydrodynamic pressure in rigid liquid storage tanks are observed to produce results with significant errors that cannot be ignored.
        4,000원
        39.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        디지털 정보 기술의 급속한 발전에 따라 사람들은 점점 더 자연스럽고 편리한 방식으로 인간과 컴퓨터의 상호작용을 실현하는 경향이 있습니다. 본고에서는 Leap Motion 센서를 하드웨어 플랫폼으로 하고 Unity3D 와 Leap Motion 플러그인을 소프트웨어 플랫폼으로 하여 가상 거문고의 상호작용 설계를 개발합니다. 또한 Leap Motion 장치의 개발과 연구를 통해 Leap Motion 센서에서 수집된 제스처 정보의 처리와 인식을 알고리 즘으로 구현하고, 제스처 인식 알고리즘을 이용하여 서로 다른 제스처를 분리하여 서로 다른 응답을 가능하 게 합니다.
        4,000원
        40.
        2022.06 구독 인증기관 무료, 개인회원 유료
        현재 대한민국의 가족 규모가 축소됨에 따라 반려동물에 대한 관심 및 양육 가구 수가 급증하면서 반려동물과의 상호작용도 활발하게 이루어지고 있는 추세이다. 그러나 이러 한 현실과는 달리 국내에서는 인간-동물 상호작용(Human-Animal Interactions, HAI), 반려동물과 인간의 상호작용에 관한 연구가 많이 이루어지고 있지 않는 실정이다. 본 연 구에서는 반려동물과 인간의 상호작용에 관한 국내 연구들을 살펴보고 정리하여 관련 연 구에 필요한 자료를 제공하는데 목적이 있다.
        4,000원
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