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        검색결과 1,571

        361.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, nonlinear finite element analysis based on the Modified Compression Field Theory has been conducted to evaluate shear strength of RC walls with opening. On the analysis, reinforcement ratio within development length of rebars nearby the opening was reduced in the model in order to investigate the effect of opening on shear strength of RC shear walls. The nonlinear finite element analysis has been verified through comparison with the test result in literature. Through the verification, it was investigated that the analysis considering the development length of rebars well reflected the effect of an opening on shear strength of RC shear walls while current design provisions did not reasonably consider one.
        4,000원
        362.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The boundary reaction method(BRM) is a substructure time domain method, it removes global iterations between frequency and time domain analyses commonly required in the hybrid approaches, so that it operates as a two-step uncoupled method. 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. In the time domain analysis, the near-field soil is modeled to simulate the wave radiation problem. This paper evaluates the performance of the BRM according to modeling extent of near-field soil for the nonlinear SSI analysis of base-isolated NPP structure. For this purpose, parametric studies are performed using equivalent linear SSI problems. The accuracy of the BRM solution is evaluated by comparing the BRM solution with that of conventional SSI seismic technique. The numerical results show that the soil condition affects the modeling range of near-field soil for the BRM analysis as well as the size of the basemat. Finally, the BRM is applied for the nonlinear SSI analysis of a base-isolated NPP structure to demonstrate the accuracy and effectiveness of the method.
        4,600원
        363.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        OBJECTIVES : The objective of this research is to determine the integrity of pavement structures for areas where voids exist. Furthermore, we conducted the study of voided-area analysis and remaining life prediction for pavement structures using finite element method. METHODS : To determine the remaining life of the existing voided areas under asphalt concrete pavements, field and falling weight deflectometer (FWD) tests were conducted. Comparison methods were used to have better accuracy in the finite element method (FEM) analysis compared to the measured surface displacements due to the loaded trucks. In addition, the modeled FEM used in this study was compared with well-known software programs. RESULTS : The results show that a good agreement on the analyzed and measured displacements can be obtained through comparisons of the surface displacement due to loaded trucks. Furthermore, the modeled FEM program was compared with the available pavement-structure software programs, resulting in the same values of tensile strains in terms of the thickness of asphalt concrete layers. CONCLUSIONS: The study, which is related to voided-area analysis and remaining life prediction using FEM for pavement structures, was successfully conducted based on the comparison between our methods and the sinkhole grade used in Japan.
        4,000원
        364.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to inquire original design and character of dancheong in Yeongnamnu Pavilion which features unusual portraits of twisting dragons and four heavenly creatures. Its artistic value and originality can be found in the portraits of four heavenly creatures which are painted on the interior seonjayeon(fan shape rafter) and in the unique design of crossbeam meoricho(flower decorations on each side of pillars). Yeongnamnu’s crossbeam meoricho is janggu-meoricho type(meoricho with hourglass figure) with full-shape lotus and half-shape flower decorations. And it can be said that, dragon portrait painted on the border of lotus and flower decorations in green and yellow is a very unique style of dancheong, for the reason that it has scarcely been used before and ever since. The portrait of four heavenly creatures painted on each corner of seonjayeon is also found to be unique in design, for the reason that the design has rarely been used throughout history, with only two exceptions in mural tombs of Goguryeo and folding screen in Injeongjeon Hall of Changdeokgung Palace . With its unique and authentic feature along with its rarity in number, the portrait of four heavenly creatures painted on Yeongnamnu can be considered as quite symbolic and important.
        4,000원
        365.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, application content which is applied by gamification elements has been enhanced. However, gamification elements has not been strongly applied in the life-logging application. Because, this application is not focused on fun, but on the visualization of the data and the records of the user's external or internal information. Therefore, the purpose of this paper is to establish the gamification elements for 'life-logging' service. To do this, the gamification elements were extracted and classified by surveys, exploratory factor analysis and confirmatory factor analysis. As a result, the gamification elements for life-logging applications are formed by three factors; ‘Acting’, ‘Achievement’, and ‘Social’. As the established gamification elements are effectively applied to life-logging applications, it is expected to be a basis for helping to provide enjoyable behavior and usability beyond the common function of user record.
        4,000원
        366.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There were lots of changes of the wooden structure in the middle of Joseon Dynasty. It was the time of replacement from Jusimpo (simple bracket system) to Ikgong (wing-like bracket system) and each bracket had shown mutual variation as well as itself. The aspects of change were discovered that the decorative elements of Ikgong and Dapo (multi-bracket system) had accepted from each other. It was clearly shown that not only the Ungung (carved cloud-shape) and Chotgaji (shape of the acuminate leaf) of Ikgong had affected to Dapo, but also Gaang (pseudo-pointing cantilever) of Dapo had affected to Ikgong. It was mostly found in the Buddhist architecture because there was the conservatization of ruling hierarchy as well as the active growth of Buddhist society.
        4,000원
        367.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The mobile device users have been increasing significantly because of the development of social network system. Mobile educational serious games are occupying a large portion of the serious game market but there is a lack of the quality evaluation elements for providing useful quality evaluation information about educational serious game to user or developer. This study conducted prioritizing the quality elements of mobile educational serious game contents. Then, these elements are decomposed into sub-elements and resulted into a hierarchical model with three levels. To evaluate the priorities among elements, AHP(Analytic Hierarchy Process) is adopted. Additionally, if the evaluation element of this study would be applied into other game contents, it can provide the fundamental information for quality improvement of total mobile educational serious game contents.
        4,000원
        368.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to survey current chicken industry and the status of technology based on the KAFACI project on the promotion of good management for increased productivity of market oriented small scale chicken producers in Nigeria. The agricultural sector has been identified as a virile sector with varieties of opportunities for the much sought diversification of revenue base and employment generation in Nigeria despite the dominance of smallholder farmers. The chicken enterprise has being a component of the livestock industry showing increasing importance. Growing entrepreneurships for sustainable growth of the industry requires investigating the prevailing environment in market-oriented chicken production in Southwest Nigeria. This study investigated the production practices, constraints of market oriented smallholder chicken farmers. Data were generated through farm survey of 240 farmers selected by multi-stage sampling techniques from 5 out of 6 states in the Southwest. Data were analyzed using descriptive statistics. The study shows a population of famers dominated by male 76.7% and average year of education of 13.88years. Foundation stock of birds are prominently sourced from commercial hatcheries (75.8%) and reared under intensive management system (87.8%). Majority of the farmers (46.7%) are into rearing of layers, broilers and cockerels with an average stock size of 449, 157 and 158 birds respectively. Birds are fed twice daily (74.8%) on compounded ration by 95.4% of the farmers. Major production constraints are high feed cost (32.1%), shortage of capital (30.0%) and poor access to market (25.4%). However, 96.7% of the farmers considered the enterprise profitable.
        4,000원
        369.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, refined finite element (FE) analyses intended to evaluate the capacity of the existing water purification plant structures against seismic force are conducted with an aim to predict possibility generating tension crack and compression crushing. The FE models for three types of main plant structures were constructed to take ground condition, boundary condition, and water interaction into consideration for advanced simulation. The nonlinear dynamic analyses were performed by using ground motion data which have been used for seismic design. Both compression crushing and tention crack, which are distributed over concrete plant structures during peak ground acceleration (PGA), are investigated by analyzing failure possibility controlled with the strain limits. After observing FE analysis results, it is possible to predict tenstion cracking which can be found at some parts of the main structure.
        4,000원
        370.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study mainly evaluate the aseismic performance of the existing intake tower structure, which is one of the national important infra structures, on the basis of the refined finite element (FE) analysis results. The realistic evaluation for structural damage was conducted by using the nonlinear material model that takes tension and compression strength of deteriorate concrete into consideration during FE modeling. In addition, not only tension crack but also compression crushing was analyzed by utilizing field contour functions provided in the program during nonlinear dynamic analyses when peak ground acceleration (PGA) occurred. After observing FE analysis results, it can be shown that the damage of the intake tower is the most likely to occur at the water level and the base support.
        4,000원
        378.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구에서는 p-version 동적무한요소법을 도입함으로써 FE-IE 기법에 기반한 KIESSI-3D 프로그램의 속도향상에 역점 을 두었다. KIESSI-3D의 성능을 평가하기 위해 8가지 실규모 SSI 문제에 대한 수치해석을 수행하였다. 이를 위해 근역지반 모델의 반경( r0 )이 구조물기초 반경(R)의 1.2배, 1.5배, 3.0배인 KIESSI-3D 해석모델을 고려하였다. 또한 SASSI2010 프로그 램을 이용한 SSI 해석을 수행하였으며, 이 결과를 KIESI-3D에 의한 결과와 정확성 및 계산속도를 비교하였다. 수치해석 결 과, 인 KIESI-3D 모델을 사용하면 정확한 해석을 수행할 수 있음을 알 수 있었다. 계산속도 측면을 보면, 새로운 KIESSI-3D의 해석속도는 기존 KIESSI-3D에 비해 최대 25배 빠른 것으로 나타났다.
        4,300원
        379.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Road subsidence occurs owing to road cavities, which cause many social and environmental problems, especially in cities. Recently, road cavities were detected by various ground radars and repair works were carried out against the detected cavities. The condition assessments related to the road cavities are necessary to understand the potential risk of the cavities. Therefore, in this study, a numerical study was performed to assess the various conditions of road cavities. METHODS : The numerical method adopted in this study is the discrete element approach, and it is suitable for analyzing the condition because it can consider the movement of the soil particles in the surrounded cavity areas. In addition, the triaxial test was modeled and performed under various cavity conditions inside the specimens. RESULTS: The conditions of different cavity locations and shapes were analyzed to identify the effect of cavity state. Three general cases of particle size distributions were formulated to identify the effect of surrounding ground conditions. As a result, the degree of decrement and volumetric strain were varied depending on the locations and shapes of the cavity. Only minor changes were observed when the particle size distributions were altered. CONCLUSIONS: The strength reduction was higher when the cavity formed was larger and located in the upper zone. Similar to the cavity shape, strength reduction and volume deformation are more influenced by the width than the length of the cavities. There is an influence from ground conditions such as the particle size distribution, especially on the wide cavity.
        4,000원