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        검색결과 604

        241.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Response spectra of a building are made with a SDOF system taking into account a first mode shape, even though higher modes may affect on the dynamic responses of a high-rise building. A soft soil layer under a building also affects on the responses of a building. In this study, seismic responses of a MDOF system were investigated to examine the effects of higher modes on the response of a tall building by comparing them with those of a SDOF system including the kinematic interaction effect. Study was performed using a pseudo 3D finite element program with seven bedrock earthquake records downloaded from the PEER database. Effects of higher modes on the seismic responses of a tall building were investigated for base shear force and base moment of a MDOF system including story shear forces and story moments. Study results show that higher modes of a MDOF system contribute to a reduction of base shear force up to 1/4-1/5 of KBC and base moment. The effect of higher modes is more significant on the base shear force than on the base moment. Maximum story shear force and moment occurred at the top part of a building rather than at a base in the cases of tall buildings differently from short buildings, and higher modes of a tall building affected on the base forces making them almost constant at the base. A soft soil layer also affects some on the base shear force of a high-rise building independently on the soft soil type, but a soft soil effect is prominent on the base moment.
        4,000원
        242.
        2015.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 기업성과에 영향을 미치는 두 가지 요인으로 제휴 포트폴리오 내의 자원(resources)과 교섭력 (bargaining power)을 지목하고, 이들이 각각, 그리고 동시에 기업성과에 미치는 영향을 분석하였다. 포트폴리 오 내의 자원을 통한 가치창출(value creation) 효과와 교섭력을 통한 가치전유(value appropriation) 효과를 구분한 선행 연구들을 확장하여, 본 연구는 두 가지 효과가 함께 시너지를 낼 수 있다는 상호보완적 관점에서 자 원과 교섭력을 함께 고려하여야 한다는 논의를 제시하였다. 글로벌 소프트웨어 산업의 196개 기업의 제휴 포트 폴리오를 분석한 결과, 제휴 포트폴리오 내의 자원만을 고려하거나 교섭력만을 고려한 경우 기업성과에 미치는 영향을 발견하지 못하거나 부분적으로만 발견할 수 있었다. 한편, 자원과 교섭력을 함께 고려한 경우 기업성과에 주는 긍정적인 영향을 확인할 수 있었다. 이를 통해 기업은 제휴 포트폴리오의 자원과 교섭력을 모두 고려할 수 있는 통합적인 관점을 가져야 하며, 한 가지 요소가 충족되더라도 다른 한 가지 요소가 충족되지 않을 경우 제휴 전략을 재고할 필요가 있다는 점을 제언하였다.
        8,300원
        243.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        식물은 유도저항성이나 천적류의 공격활동 변화를 유발하여 관련 초식성 곤충류 간 상호작용관계에 불리한 영향을 미칠 뿐만 아니라 식물 체내 영양물질 동태나 타감물질 그리고 외부 형태적 변화 등을 통하여 초식곤충류에 유리한 영향을 미치기도 한다. 본고에서는 식물이 개재되었 을 때 초식 곤충류간의 상호작용 관계와 초식성 곤충 가해에 대한 식물의 여러 가지 반응특성과의 관계나 곤충류 생활사 특성이 초식성 곤충군집 의 구조에 미치는 영향을 살펴보고 그의 군집학적 의의를 고찰하였다.
        4,000원
        244.
        2015.04 구독 인증기관·개인회원 무료
        Ticks are obligatory ectoparasites of many vertebrates and transmit pathogens causing diseases such as Heartland virus and Ehrlichiosis. The lone star tick, Ambloyomma americanum L., is the primary vector of Ehrlichia chaffeensis, which causes human monocytic Ehrlichiosis. We aimed to investigate the genomic levels of gene regulation in the processes of acquiring the pathogen and of immune to pathogen. We designed six experimental groups: E. chaffeensis positive and negative groups of males and females, and pathogen free male and female ticks. Illumine HiSeq 2500 sequenced six libraries with 100-cycle single direction. Raw sequence reads (more than 209 million) were trimmed and filtered based on minimum quality score (Q-value >30) and size (> 40nt) for de novo assembly. Assembly using Trinity pipeline produced 140,574 contigs from trimmed and filtered sequence reads (about 117 million reads, 56% of raw data). For quality control of the de novo assembly of transcripts, we filtered out the sequences for mitochondrial, E. chaffeensis, and transposable elements sequences, and tested for contig redundancy and gap separations of the assembled sequences. RSEM and edgeR analyses of 61,802 contigs for identifying differentially expressed genes were followed by Blast2GO analyses for annotations of contigs and enriched-gene ontology (GO) term analyses in pairwise comparisons of the libraries. Further investigation of major groups of genes induced by pathogen would provide better understanding of pathogen-vector interaction, which will allow us to prevent of pathogen transmission by interrupting interaction between pathogen and ticks.
        245.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the influence of probabilistic variability in stiffness and nonlinearity of soil on response of nuclear power plant (NPP) structure subjected to seismic loads considering the soil-structure interaction (SSI). Both deterministic and probabilistic methods have been employed to evaluate the dynamic responses of the structure. For the deterministic method, SRPmin method given in USNRC SRP 3.7.2(2013) (envelope of responses using three shear modulus profiles of lower bound(GLB), best estimate(GBE) and upper bound(GUB)) and SRPmax method (envelope of responses by more than three ground profiles within range of GLB≤G≤GUB) have been considered. The probabilistic method uses the Latin Hypercube Sampling (LHS) that can capture probabilistic feature of soil stiffness defined by the median and the standard deviation. These analysis results indicated that 1) number of samples shall be larger than 60 to apply the probabilistic approach in SSI analysis and 2) in-structure response spectra using equivalent linear soil profiles considering the nonlinear behavior of soil medium can be larger than those based on low-strain soil profiles.
        4,300원
        246.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerical simulations of liquid water droplets interacting with gas channel walls in a polymer electrolyte membrane fuel cell are performed with the volume of fluid (VOF) method. To investigate the effect of channel wall wettability, the contact angles of gas diffusion layer (GDL) and the side/top walls are varied as 45, 90, and 140 degrees. Two different water injection inlet locations are selected to investigate the interactions of liquid water with the different gas channel walls. As the GDL contact angle increases, the GDL surface water coverage ratio and the water volume ratio decrease. When the water injection hole is located near the side wall, the GDL surface water coverage ratio decreases and the water volume ratio increases as the contact angle of the side and top walls decreases. In conclusion, the GDL surface water coverage ratio and the water volume ratio may compete with each other to determine the fuel cell performance.
        4,000원
        247.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        LNG 선박에서 발생하는 슬로싱 충격하중은 다상유동 및 기체의 압축효과에 따라 CCS에서 발생하는 압력과 구조응답에 큰 영향을 미칠 수 있다. 본 연구에서는 슬로싱 운동 시 LNG의 유동에 의해 발생하는 슬로싱 충격을 시뮬레이션하기 위해서 다상유동을 적용한 수치해석 모델을 제시하였으며, 그 결과를 실험과 비교하여 타당성을 검토하였다. 또한 효율적인 구조응답 계산을 위해 분사모델을 이용한 유체구조 연성해석 방법에 대해서 검토하고 멤브레인형 Mark III 화물창의 강도평가에 적용하여 LNG 화물창의 강도평가를 위한 가능성을 검토하였다.
        4,000원
        248.
        2015.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents a detailed procedure for a nonlinear soil-structure interaction of a seismically isolated NPP(Nuclear Power Plant) structure using the boundary reaction method (BRM). The BRM offers a two-step method as follows: (1) the calculation of boundary reaction forces in the frequency domain on an interface of linear and nonlinear regions, (2) solving the wave radiation problem subjected to the boundary reaction forces in the time domain. For the purpose of calculating the boundary reaction forces at the base of the isolator, the KIESSI-3D program is employed in this study to solve soil-foundation interaction problem subjected to vertically incident seismic waves. Wave radiation analysis is also employed, in which the nonlinear structure and the linear soil region are modeled by finite elements and energy absorbing elements on the outer model boundary using a general purpose nonlinear FE program. In this study, the MIDAS/Civil program is employed for modeling the wave radiation problem. In order to absorb the outgoing elastic waves to the unbounded soil region, spring and viscous-damper elements are used at the outer FE boundary. The BRM technique utilizing KIESSI-3D and MIDAS/Civil programs is verified using a linear soil-structure analysis problem. Finally the method is applied to nonlinear seismic analysis of a base-isolated NPP structure. The results show that BRM can effectively be applied to nonlinear soil-structure interaction problems.
        4,000원
        249.
        2015.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The nuclear accident due to the recent earthquake in Japan has triggered awareness of the importance of safety with regard to nuclear power plants (NPPs). An earthquake is one of the most important parameters which governs the safety of NPPs among external events. Application of a base isolation system for NPPs can reduce the risk for earthquakes. At present, a soil-structure interaction (SSI) analysis is essential in the seismic design of NPPs in consideration of the ground structure interaction. In the seismic analysis of the base-isolated NPP, it is restrictive to consider the nonlinear properties of seismic isolation devices due to the linear analysis of the SSI analysis programs, such as SASSI. Thus, in this study, SSI analyses are performed using an iterative approach considering the material nonlinearity of the isolators. By performing the SSI analysis using an iterative approach, the nonlinear properties of isolators can be considered. The difference between the SSI analysis results without iteration and SSI with iteration using SASSI is noticeable. The results of the SSI analysis using an effective linear (non-iterative) approach underestimate the spectral acceleration because the effective linear model cannot consider the nonlinear properties of isolators. The results of the SSI analysis show that the horizontal response of the base-isolated NPP is significantly reduced.
        4,000원
        250.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The dynamic interaction of liquid droplets emerging from the gas diffusion layer surface is modeled to study the behavior of liquid water inside the gas channel of a polymer electrolyte membrane fuel cell with the volume of fluid (VOF) formulation. The surface contact angle of gas diffusion layer is varied as 45, 90, and 140 degrees. The air inlet velocity in the gas channel is varied as 5, 10, and 15 m/s. The water inlet velocity from micro pores is varied as 0.5, 1, and 2 m/s. As the contact angle increases, water coverage ratio increases. As the air inlet velocity and the water inlet velocity increase, water droplets move faster toward the channel exit as evidenced from the water front location plots. In summary, the hydrophobic wall contact angle and higher air/water inlet velocities provide better water removal characteristics.
        4,000원
        251.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        로봇과 인간의 상호작용에서 언어에 의한 정보 전달은 상호작용의 한계가 있으므로, 더욱 원활하고 효율적인 의사소통과 나아가 로봇의 감정 표현까지 구현하기 위해서는 비언어적 커뮤니케이션이 필요하다. 본 연구에서는 쇼핑을 지원하는 로봇을 전제로 하여 쇼핑 행태에 따른 7가지 비언어적 정보를 도출하였다. 도출된 비언어적 정보의 요소로서 표정을 선정하고, 2D 분석을 통하여 얼굴 구성요소를 코드화 하였다. 얼굴 구성요소의 코드를 조합한 3D 애니메이션을 이용하여 비언어적 정보의 표현에 대한 유의성을 분석하였 다. 분석 결과, 제안된 비언어적 정보의 표현 방법은 높은 수준의 유의성을 보여 비언어적 정보 연구의 기초자료 로서 활용 가능성이 확인되었다. 다만, '당황'의 경우 코드화된 얼굴 구성 요소의 모양 적용에 한계가 있으며 보 다 체계적 연구가 요구된다.
        4,000원
        252.
        2014.10 구독 인증기관·개인회원 무료
        Five species of the subfamily Cicadinae are found in urban areas at the center of the Korean peninsula, including Cryptotympana atrata, Hyalessa fuscata, Meimuna mongolica, Meimuna opalifera and Graptopsaltria nigrofuscata. Out of those species, the densities of C. atrata and H. fuscata are generally high in the urban area. I hypothesized that there is a vigorous acoustic interaction where two species are abundant. We tested this hypothesis by conducting the 24-h recording experiments in four localities: Gwacheon(GC), Jamsil(JS), Ewha University(EU) and Yangpyeong(YP). Based on the preliminary enumeration surveys of exuviae, GC and JS were designated as high density localities and EU and JS were as low density localities. The results of 24-h recordings and abiotic factor based on the multinomial logistic regression showed that C. atrata and H. fuscata were negatively correlated in high density area GC and JS. In JS and EU, the density of H. fuscata is close to each other. However, the probability of chorusing in JS is significantly lower than EU. This might be due to acoustic competition between two species. Moreover, we confirmed that the choruses of males of C. atrata produced loud choruses usually during the day when temperature high and males of H. fuscata produced calling song throughout the day but peaked in the morning and night. Consequently, multi-species cicada in different temporal pattern probably cannot be explained by only acoustic interaction but the combination of both abiotic and biotic factors probably constrain multi-species cicada to call together during the limited time windows.
        253.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 논문은 온도차에 따라 변화되는 이온성 액체와 낮은 밴드갭을 갖는 고분자인 poly(2-heptadecyl-4-vinylthieno[3,4-d]thiazole)(PHVTT) 간의 상호작용 및 고분자 의 거동을 조사하 였다. 이온성 액체는 methyl imidazolium chloride([MIM]Cl), butyl methyl imidazolium chloride([BMIM]Cl), tri-butyl methyl ammonium methyl sulfate([TBMA][ MeSO4])를 사용하였으며, 21, 28, 32, 37℃로 온도를 변화시키며 상호작용의 변화를 UV-vis spectroscopy, FT-IR spectroscopy, photoluminescence spectroscopy를 통해 확인한 결과 이온성 액체인 [MIM]Cl, [TBMA][MeSO4]와 PHVTT의 상호작용은 점차 약해짐을 확인할 수 있었지만, [BMIM]Cl은 온도 변화에 따른 상호작용의 변화를 보이지 않았다.
        4,000원
        254.
        2014.07 구독 인증기관·개인회원 무료
        Online advertisers use multiple channels to reach consumers on the Internet. However, little is known on the interplay between online advertising channels. To fill this gap, this study provides a comprehensive overview of interaction effects in online advertising for individual consumers, including not only site visits, but also exposures that do not directly lead to a click. Based on a large cookie-based individual-level data set the authors analyze interaction effects within and between channel groups on purchase behavior. By classifying online marketing channels along the dimensions of initiation locus and previous brand awareness, they find significant interactions between contacts within and across channel types. While clicks following contacts in customer-initiated channels that require brand awareness overall have a negative effect on purchase propensity, previous clicks in firm-initiated channels positively interact with clicks in customer-initiated channels. The results can help managers to coordinate marketing strategies, optimize campaigns, and develop individualized marketing and targeting approaches.
        255.
        2014.07 구독 인증기관·개인회원 무료
        This research examines the influence of network position, identity construction and role playing within business to business (B2B) interactions processes. The framework used as the basis for considering interaction processes developed from the AAR model (Håkansson & Snehota, 1995) and includes: accessing resources; developing actor bonds and conducting activities. There has been little research conducted into network position (Abrahamsen et al., 2012; Schepis et al., 2014); identity construction (Huemer, 2013; Schepis et al., 2014) and role playing (Abrahamsen et al., 2012; Lowe et al., 2012). This research develops a framework for incorporating all three concepts into the interaction process, rather than investigating them individually or paired, commonly undertaken in previous research. The research is conducted within an interpretive paradigm with 20 interviews conducted within the junior mining industry in Western Australia. Interviews were analysed using Leximancer™ and a comparison of the perceptions from companies playing different roles within the network examined. Results highlight that network position is influenced through accessing resources and developing actor bonds; identity construction occurs through developing actor bonds and conducting activities and role playing occurs when conducting activities and accessing resources. A theoretical framework highlights each of the above concepts within the framework of interaction processes. The value of this paper is that the each of these concepts is influenced through different aspects of the interaction process. Thus, highlighting which aspects of the interactions processes managers can adapt to improve their network position, identity construction and role perceptions.
        256.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study explores the effects of peer intimacy on Korean primary English learners' collaborative group work in terms of writing achievement and peer interaction. Fifty six elementary school students engaged in small group work on English writing tasks. They were grouped in three different types: high intimacy level group, low intimacy level group, and random group. The study results indicated no significant group differences in the students' abilities and attitudes of English writing. However, the three groups differed in the quantity and quality of peer interaction. The high intimacy group produced the largest number of utterance and the most collaborative interactions. The low intimacy group, on the other hand, produced more utterances but less collaborative interactions than did the random group. Overall, the study results suggested that peer intimacy may have no immediate effect on students' learning through small group work but it possibly has delayed effects in prolonged group work by mediating the quantity and quality of peer interactions. Limitations of the study and pedagogical suggestions are provided.
        6,100원
        257.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the collapse of historical masonry structures in Europe in the late 1990’s, the interests in understanding the long-term effect of masonry under sustained compressive stresses have increased. That requires combining the significance of time-dependent effects of creep with the effect of damage due to overstress to realize the evolution of cracks and then failure in masonry. Meanwhile, composite analysis of masonry columns was proven effective for realizing ultimate strength capacity of masonry column. In this study, a simplified mechanical model with step-by-step in time analysis was proposed to incorporate the interaction of damage and creep to estimate the maximum stress occurred in masonry. It was examined that the interaction of creep and damage in masonry can accelerate the failure of masonry.
        4,000원
        258.
        2014.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a series of dynamic centrifuge tests were performed for a soil-foundation-structural interaction system in dry sand with various embedded depths and superstructure conditions. Sinusoidal wave, sweep wave and real earthquake were used as input motion with various input acceleration and frequencies. Based on the results, a natural period and an earthquake load for soil-structure interaction system were evaluated by comparing the free-field and foundation accelerations . The natural period of free field is longer than that of the soil-foundation-structure system. In addition, it is confirmed that the earthquake load for soil-foundation-structure system is smaller than that of free-field in short period region. In contrast, the earthquake load for soil-foundation-structure interaction system is larger than that of free-field in long period region. Therefore, the current seismic design method, applying seismic loading of free-field to foundation, could overly underestimate seismic load and cause unsafe design for long period structures, such as high-rise buildings.
        4,000원
        260.
        2014.04 구독 인증기관·개인회원 무료
        톱다리개미허리노린재[Riptortus pedestris (Fabricius) (Hemiptera: Alydidae)]는 콩에서 중요한 난방제 해충이다. 톱다리개미허리노린재와 두 종의 알기생벌의 계절적 발생 패턴을 기주 식물과 연관하여 고찰하였다. 또한 천적 상호간의 상대적 발생 패턴의 차이와 이유를 분석하고 톱다리개미허리노린재의 기주 식물에 대한 적합도 검증 결과를 바탕으로 톱다리개미허리노린재의 관리 전략을 제시하였다. 톱다리개미허리노린재의 효과적인 관리를 위해서 저항성품종의 사용, 과수의 경우 주변 작물에서 콩을 배제하는 것, 기주알 공급을 통한 보존적 생물적 방제, 살충제 사용 시기의 조절 등이 고려되어야 한다.