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        검색결과 40

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As a means to activate eco pastoral system in alpine grassland, the government can consider public pastures, which are currently unused, to scale them up into public ranches. Depending on ownership and operation, four management models proposed as follows: 1) Government-Owned and Operated with Balanced Profit and Loss 2) Government-Owned and Operated with Revenue Generation 3) Government-Owned but Privately Operated by Outsourced to Professional Manager 4) Full Privatization (Ownership and Operation by Private Individuals). The study outlined above proposes four management models for the activation of eco pastoral system in alpine grassland. It also suggests methods for the selection and performance evaluation of manager to establish a profitable structure. Additionally, the research provides management methods for the conservation of grazing ecology in pastoral ecosystems. Particularly, the adaptation of tools commonly used in South Korean business sector for the selection and performance evaluation of manager within the system of the proposed management models. This aspect is deemed valuable as it aligns these tools with the specific characteristics of eco pastoral system in alpine grassland, contributing not only to the effective implementation of the models but also to the enhancement of the revenue structure.
        4,000원
        4.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        제주도 북서부인 애월 해안에는 평탄하게 흐른(판상) 용암류와 둥근 모양(원통)의 용암류가 관찰된다. 원통형 용암류의 치밀한 내부에는 동심원 구조와 방사상 절리가 발달한다. 구엄리 돌염전 주변의 판상 용암류 내부에는 상하부의 굵기가 다른 주상절리가 발달한다. 주상절리 상부는 다각형의 형태가 고르지 않으며 직경은 120-150 cm이다. 주상절리 하부는 육각형과 오각형으로 형태가 일정하고, 크기도 60 cm 내외이다. 원통형 로브는 크기와 형태에 따라 두 그룹으로 나눌 수 있다. 하나는 메가로브인데, 최대 직경이 30 m인 반원형이다. 또 하나는 원형의 로브로 직경이 10 m 이하이다. 원통형 용암류의 방사상 절리의 기둥 단면은 육각형과 오각형이며, 기둥의 직경은 중심에서 바깥쪽으로 증가하는데 바깥쪽 경계부에서는 80-120 cm 정도이다. 원통형 용암에서 관찰되는 동심원 구조는 4가지 요인이 복합된 것이다. 첫째는 원형의 균열로, 원통형 용암류 내에서 안쪽과 바깥쪽 사이의 온도차와 밀도차로 발생한 수축으로 생긴 틈새이다. 둘째는 방사상 절리의 마디층이 동심원을 이룬 것으로, 이 마디층은 방사상 절리와 동시에 만들어진 것이다. 셋째는 유동 띠로서, 용암이 흐를 때 둥근 통로에 남긴 흔적이다. 네 번째는 용암에서 빠져나온 가스가 동굴에 형성된 기공 띠이다.
        4,000원
        6.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 인공신경망을 이용해 건물 구조물의 가속도계 설치 위치 및 개수를 선정하는 방법을 제안한다. 인공신경망의 입력 층에는 층에 설치되는 가속도계로부터 얻는 가속도이력데이터가 입력되며, 출력층에는 구조물을 정의하는 각 층의 질량과 강성 값을 출력하도록 신경망을 구성한다. 가속도계의 설치 위치 및 개수를 선정하기 위해 여러 설치 시나리오를 가정하고 훈련을 통해 인공신경망을 구한다. 훈련에 사용되지 않은 예제를 이용해 예측 성능을 비교하였다. 센서 개수 및 위치에 따른 예측 성능을 비교하여 설치위치 및 개수를 선정한다. 6층과 10층 예제 적용을 통해 제안하는 방법을 검증하였다.
        4,000원
        7.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we developed a learning progression for the structure of the solar system using multi-tier supply form items and validated its appropriateness. To this end, by applying Wilson’s (2005) construct modeling approach, we set up ‘solar system components,’ ‘size and distance pattern of solar system planets,’ and ‘solar system modeling’ as the progress variables of the learning progression and constructed multi-tier supply form items for each of these variables. The items were applied to 150 fifth graders before and after the classes that dealt with the ‘solar system and star’ unit. To describe the results of the assessment, the students’ responses to each item were categorized into five levels. By analyzing the Wright map that was created by applying the partial credit Rasch model, we validated the appropriateness of the learning progression based on the students’ responses. In addition, the validity of the hypothetical pathway that was established in the learning progression was verified by tracking changes in the developmental level of students before and after the classes. The results of the research are as follows. The bottom-up research method that used multi-tier supply form items was able to elaborately set the empirical learning progression for the conceptualization of the structure of the solar system that is taught in elementary school. In addition, the validity of the learning progression was high, and the development of students was found to change with the learning progression.
        4,900원
        8.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Seismic responses due to the dynamic coupling between a primary structure and secondary system connected to a structure are analyzed in this study. The seismic responses are compared based on dynamic coupling criteria and according to the error level in the natural frequency, with the recent criteria being reliant on the error level in the spectral displacement response. The acceleration responses and relative displacement responses of a primary structure and a secondary system for a coupled model and two different decoupled models of two degrees-of-freedom system are calculated by means of the time integration method. Errors in seismic responses of the uncoupled models are reduced with the recent criteria. As the natural frequency of the secondary system increases, error in the natural frequency decreases, but seismic responses of uncoupled models can be underestimated compared to that of coupled model. Results in this paper can help determine dynamic coupling and predict uncoupled models’ response conservatism.
        4,000원
        9.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A hybrid mid-story seismic isolation system with a smart damper has been proposed to mitigate seismic responses of tall buildings. Based on previous research, a hybrid mid-story seismic isolation system can provide effective control performance for reduction of seismic responses of tall buildings. Structural design of the hybrid mid-story seismic isolation system is generally performed after completion of structural design of a building structure. This design concept is called as an iterative design which is a general design process for structures and control devices. In the iterative design process, optimal design solution for the structure and control system is changed at each design stage. To solve this problem, the integrated optimal design method for the hybrid mid-story seismic isolation system and building structure was proposed in this study. An existing building with mid-story isolation system, i.e. Shiodome Sumitomo Building, was selected as an example structure for more realistic study. The hybrid mid-story isolation system in this study was composed of MR (magnetorheological) dampers. The stiffnessess and damping coefficients of the example building, maximum capacity of MR damper, and stiffness of isolation bearing were simultaneously optimized. Multi-objective genetic optimization method was employed for the simultaneous optimization of the example structure and the mid-story seismic isolation system. The optimization results show that the simultaneous optimization method can provide better control performance than the passive mid-story isolation system with reduction of structural materials.
        4,000원
        10.
        2016.11 구독 인증기관·개인회원 무료
        The hollow fiber membranes were prepared via hybrid process of the thermally induced phase separation(TIPS) and the non-solvent induced phase separation(NIPS). The spinning dope solution consisted of poly(vinylidene fluoride) (PVDF) / dibutyl phthalate (DBP) / 1-methyl-2-pyrrolidone (NMP), where DBP was used as a diluent and NMP as a solvent for PVDF. Various bore fluids were tested different ratio solvent/diluent mixture. Depending on the miscibility of dope solution and internal coagulant the samples underwent the different phase separation mechanisms and rates. Phase separation mechanism study for various combinations were performed to support the interpretation of the membrane structure. Membrane characterizations were performed such as water flux, porosity, pore size, and mechanical strength.
        11.
        2016.05 구독 인증기관·개인회원 무료
        The hollow fiber membranes were prepared via hybrid process of the thermally induced phase separation(TIPS) and the non-solvent induced phase separation(NIPS). The spinning dope solution consisted of poly(vinylidene fluoride) (PVDF) / dibutyl phthalate (DBP) / 1-methyl-2-pyrrolidone (NMP), where DBP was used as a diluent and NMP as a solvent for PVDF. Bore fluids were tested different ratio solvent/ethanol and diluent/ethanol mixture. The membrane structure was analyzed by SEM and FT-IR to confirm phase separation mechanisms. Various structures were obtained due to the different phase separation mechanism. Membrane characterizations were performed such as water flux, pore size, rejection efficiencies and mechanical strength.
        12.
        2015.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, shaking table test has been carried out for the dual frame passive control system for seismic performance verification of the proposed system. The proposed system was separated into two independent frameworks that are strength resistant core and frame structure by connecting to the damper. Moreover, the seismic performance improvement of the proposed system has been verified by comparing and analyzing the experimental results of the proposed system with an existing core system. As a result of the shaking table test, acceleration and displacement responses of dual-frame vibration control system are decreased than those of the existing strength resistant type core system. In the case of the core system, while the damage was concentrated on the column of first floor, the damage of the dual system was dispersed in each layer. The damage also was concentrated on the damper, almost no damage occurs to the structural members. It has been emphasized that installed dampers in the proposed dual system reduce the input energy of whole structure by absorbing seismic input energy, which leads overall system damage to be reduced.
        4,000원
        13.
        2014.11 구독 인증기관 무료, 개인회원 유료
        백제는 한강유역에서 건국하고 금강유역에서 멸망했다. 왕이 살던 곳을 기준으로 구분하면, 한강유역에서는 慰禮城과 漢城, 금강유역에서는 熊津城과 泗沘都城으로 나뉜다. 흔히 위례성을 백제 전기의 왕성, 한성을 백제 전기의 도성․왕도라고 부른다. 기록에 따르면 한성은 北城과 南城 2개의 성으로 이루어졌는데, 북성은 기존의 위례성을 재편한 것이며 남성은 새로 쌓은 산성으로서 유사시를 대비한 군사적 목적의 왕성이다. 남성은 한산 자락에 쌓았으므로 漢山城으로도 불렸다. 북성은 지금의 풍납토성, 남성은 지금의 몽촌토성에 비정된다. 백제 왕도의 방위체계에 대해서는 한강유역의 고대 성곽을 유기적으로 연결하는 방식을 흔히 사용하지만, 유적 편년을 충분히 검토하지 못한 상태에서 지도상으로만 상정한 것이어서 한계가 있다. 백제 한성도읍기의 방위체계는 왕성 부근에 촘촘한 그물망 형태로 산성을 배치하는 것이 아니라 오히려 변경 쪽에 치중했다. 왕도는 한강을 통제하면서 유사시에 옹성할 수 있는 군사적 목적의 배후산성을 대비해놓는 정도였으며, 군사요새는 한강보다 임진강․예성강 등 고구려와 전투를 자주 벌인 북방지역에 훨씬 더 많이 축조하였다. 고대의 방위체계 연구에는 유적의 정확한 편년에 기초하여 역사적 배경을 귀납적이며 거시적으로 통찰하려는 자세가 필요하다.
        4,800원
        14.
        2014.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Metal films (i.e., Ti, Al and SUH310S) were prepared in a magnetron sputtering apparatus, and their cross-sectional structures were investigated using scanning electron microscopy. The apparatus used consisted of a cylindrical metal target which was electrically grounded, and two anode rings attached to the top and to the bottom of the target. A wire was placed along the center-line of the cylindrical target to provide a substrate. When the electrical potential of the substrate was varied, the metal-film formation rate depended on both the discharge voltage and the electrical potential of the substrate. As we made the magnetic field stronger, the plasma which appeared near the target collected on the plasma wall surface and thereby decreased the bias current. The bias current on the conducting wire was different from that for cation collection. The bias current decreased because the collection of cations decreased when we increased the magnetic-coil current. When the substrate was electrically isolated, the films deposited showed a slightly coarse columnar structure with thin voids between adjacent columns. In contrast, in the case of the grounded substrate, the deposited film did not show any clear columns but instead, showed a densely-packed granular structure. No peeling region was observed between the film and substrate, indicating good adhesion.
        4,000원
        15.
        2014.05 구독 인증기관 무료, 개인회원 유료
        본 연구는 불탑 중 백제 말기 건립된 익산 미륵사지 석탑과 조선 중기 보은 법주사팔상 전과의 계통사적 구조체계의 상관성을 고찰한 것으로 다음과 같은 결론을 도출하였다. 첫째, 익산 미륵사지 구층석탑은 내부에 심초석(心礎石)이 설치된 것으로 보아 심주와 사천주가 코어구조체계(core structure system)인 누각형 탑파로 상층기둥의 위치에 따른 체감율이 큰 것으로 보아 퇴칸은 칸물림방식의 전각형이 채택된 절충형식이라는 추정이 가능하다. 둘째, 보은 법주사 팔상전은 목탑의 기본적인 구성요소인 옥심주와 사천주가 코어 구조 체계로 채용되고, 주변 협칸과 퇴칸은 전각형 칸물림방식의 중층구조기법을 부차적으로 채택하여 익산 미륵사지 석탑과 같은 계통의 체감율이 큰 특징의 절충형 목탑이라고 할 수 있다. 셋째, 백제시대 불탑구조는 누각형(평좌층식, 포구조식)과 누각형에 전각형을 채택한 절충형으로 대별된다. 불탑은 필요에 따라 탑신의 높낮이를 비례적으로 조절하여 완성미를 높였으며, 처마길이를 충분히 확보함으로써 건축물의 볼륨감(massing)이 풍부한 기능성이 강한 건축물을 축조하였다. 넷째, 백제시대에 창안된 새로운 불탑형식으로서의 절충양식은 백제 말기에 시원하여 문화통치기인 통일신라시대와 지방문화를 정책적으로 장려한 고려시대를 거쳐 조선 중기 보은 법주사 팔상전으로 끊임없이 이어져 계승된 백제 고유의 불탑양식이라고 할 수 있다.
        4,000원
        16.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 금강 지류인 충남 청양군 지천의 어류군집 및 멸종위기종 미호종개와 흰수마자의 서식현황을 파악 하기 위하여 2011년 조사를 실시하였다. 지천 상류(St. 1~St. 4)는 하천형이 Aa-Bb형 또는 Bb형이고 하상구조 는 자갈과 돌의 비율이 높았으며 10~23종의 어류가 서식하였고, 중류(St. 5~St. 7)는 하천형이 Bb형이고 하상 구조는 돌과 큰돌의 비율이 높았으며 16~23종의 어류가 서식하였으며, 하류(St. 8~St. 10)는 하천형이 Bb-Bc형이 고 하상구조는 모래의 비율이 높았으며 20~29종의 어류 가 서식하였다. 전체 출현한 어종은 모두 9과 44종이었고, 우점종은 피라미 Zacco platypus (37.2%), 아우점종은 돌 고기 Pungtungia herzi (5.8%)와 모래무지 Pseudogobio esocinus (5.5%)였으며, 그 다음으로 납자루 Acheilognathus lanceolatus (5.3%)와 참갈겨니 Z. koreanus (5.2%), 참마자 Hemibarbus longirostris (4.9%), 긴몰개 Squalidus gracilis majimae (3.5%) 등의 순으로 우세하게 출현하였 다. 출현종 중 고유종은 16종(36.4%)으로 비교적 높게 나 타났고, 멸종위기종은 미호종개와 흰수마자 2종이, 외래어 종은 배스 Micropterus salmoides 1종이 출현하였다. 지점 들 간의 군집유사도를 분석한 결과 상류(St. 1~St. 4)와 중류(St. 5~St. 7), 하류(St. 8~St. 10)로 나누어지고, 우 점도는 하류로 갈수록 대체로 낮아지는 반면, 다양도와 균등도, 종풍부도 하류로 갈수록 대체로 높아지는 경향을 보였다. 하류에서 출현한 멸종위기종 미호종개와 흰수마 자의 서식현황을 정밀조사한 결과, 두 종 모두 하상이 모 래인 곳에 집단을 형성하여 서식하고 있어 주목되었다.
        4,300원
        17.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the realm of missiology got extended and the subjects of missiological research differs varies, the understanding of culture in mission field is crucial before doing mission there. In terms of definition of mission as crossing over the cultural boundary, I investigate the system of the Chinese government and power structure in relation to religious laws and regulations. I argue that if the Korean Christianity do mission for China and cooperate with Chinese church in official ways, this step is necessary. According to the Chinese Constitution, the People’s Republic of China (PRC) is organized of political party, government, and military authority. The people’s democratic dictatorship and socialism are the basic Chinese system, which cannot be inflicted by any individual person and group. The Chinese government widely accomplishes religious freedom, but this is on the base of socialistic perspectives. The United Front Work Department of the Chinese Communist Party(CCP) Central Committee, which is a substructure organization of CCP, forms the basic direction of the religious policy. Then the State Administration for Religious Affairs of PRC overall controls the policy of religion. In this kind of structure, China not only allows religious freedom, but also seeks to gradually dissolve religion through anti-religious propaganda. Religion is just one of tools, which formulates firm foundation of socialism in China. With this type of limitation, the Chinese Christianity has been existed until now under the control of National Committee of Three-Self Patriotic Movement of the Protestant churches in China, National TSPM. In fact, this agrees with United Front Strategy(UFS) and then becomes a ‘Socialization of Christianity.’ The Chinese government always emphasizes that only legal interchanges of Chinese Christianity can be allowed, which means the government wants to get absolute control. In this situation, I seek the appropriate models of religious interchanges between Chinese and Korean church. Most of all, I claim that the Korean Christianity should understand a system of Government and Power Structure in China before doing mission there. The friendly foreign interchanges, which are stressed by the Chinese government, can be promoted through China Religious Culture Communication Association (CRCCA). Secondly, based on ecumenical principles, Korean churches should develop official relationship with Chinese churches. Regarding to the organization of National TSPM and China Christian Council (CCC), Korean churches should find the subject of religious interchanges. In final, both positive and negative part of Chinese UFS should be acknowledged and then establish strategies. UFS interchanges with foreign religions based on dissolving them, but we should take advantage of their policy and use it for spread the gospel.
        6,700원
        18.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The research proposes seven elimination rules of redundant gates and blocks in Fault Tree Analysis (FTA) and Reliability Block Diagram (RBD). The computational complexity of cut sets and path sets is NP-hard. In order to reduce the complexity of Minimal Cut Set (MCS) and Minimal Path Set (MPS), the paper classifies generation algorithms. Moreover, the study develops six implementation steps which reflect structural importance (SI) and reliability importance (RI) from Reliability Centered Maintenance (RCM) that a priority of using the functional logic among components is to reduce (improve) the system unavailability (or availability). The proposed steps include efficient generation of state structure function by Rare Event Enumeration (REA). Effective use of importance measures, such as SI and ill measures, is presented based on the number and the size of MCS and MPS which is generated from the reference[5] of this paper. In addition, numerical examples are presented for practitioners to obtain the comprehensive understanding of six steps that is proposed in this research.
        4,000원
        20.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        구조시스템은 역사적으로 발달해온 기술적 배경에 따라 건축에 사용되었고, 구조의 역할도 변화되어 왔다. 그러므로 다양한 구법으로 이루어지는 연성구조시스템의 건립사례와 시기에 따라 건립된 규모를 조사함으로써 여러 연성구조형식의 a성을 고찰하고 연성구조의 전개방향을 모색하였다. 그 결과, 연성구조시스템은 초기에 여러 케이블구조로 발달하기 시작하였으나 1970년대 이후부터는 막구조가 주로 사용되고 있는 것으로 나타났다 또한 초기의 케이블 구조시스템들은 대공간 건축에 주로 사용되었으나, 1970년 이후에는 중소규모의 건축물에 사용되는 경향이 있으며, 격자형 케이블구조나 공기막구조 그리고 돔 형식의 들림형 하이브리드 막구조가 대형공간으로 발달하는 경향을 보이는 것으로 나타났다.
        4,000원
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