검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 462

        1.
        2025.03 구독 인증기관·개인회원 무료
        지표면의 불투수층 증가는 빗물의 토양침투를 감소시키고 우수 침투를 제한하여 표면 유출에 의한 피해를 야기하였으며, 홍수 도달시간이 단축됨에 따라 첨두 유출량이 증가하므로 배수 시스템의 용량 부족 및 침수 피해를 초래하였다. 이에, 환 경부에서는 생태면적률 제도를 도입하여 저영향 개발(Low Impact Development, LID) 기술 도입의 활성화를 도모하고 있 으며, 이 중 투수블록포장이 약 40%를 차지하고 있다. 그러나, 주로 표층 콘크리트 블록의 품질기준 마련 및 성능 개선 연 구가 수행되었으며, 하부구조의 우수 침투 능력을 평가한 연구는 미흡한 실정이다. 특히, 투수성능이 증가할수록 구조적 지 지력이 감소하므로 내구성을 만족하는 범위에서 투수계수를 충족하는 입도분포를 실험적 연구를 통해 제시할 필요가 있다. 따라서, 시험체 내 수두를 일정하게 유지시켜 일정 시간동안 유입되는 하부 유출량을 측정하였으며, 같은 입도분포일 때 잔 골재 함량이 증가할수록 투수계수가 감소하는 것으로 나타났다. 이처럼 골재 입도분포 특성에 의해 물이 하부로 침투되는 유출량이 상이하므로 정량적인 평가를 통해 투수계수를 만족하는 적정 입도 기준의 제시가 가능할 것으로 판단된다.
        2.
        2025.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 다목적 선박(MPV)의 공기역학적 구조물 설계, 분석 및 향상을 통해 그린 워터 압력에 의한 구조적 안전을 보장하고, 탈탄소화 및 에너지 효율성에 이바지하는 방법을 기술하였다. 유한 요소 분석(FEA)을 통한 초기 평가에서 좌굴 발생에 대한 잠재적인 취약점 이 있음을 확인하였다. 이러한 문제를 해결하기 위해 보강재(Carling stiffener)와 두께 증가를 통하여 응력을 재분배하고 국부적인 좌굴 발생의 위험을 최소화하였다. 보강 후 분석 결과, 한국선급(KR)의 안전 기준인 항복 강도, 미국 선급(ABS) 좌굴 강도 및 노르웨이 표준(NORSOK) 변 위 기준을 모두 충족하는 것이 확인되었다. 결과적으로 고유치 좌굴 해석 결과가 안전 기준을 초과하고 최대 변위가 허용 한계 내에 있는 등 중요한 개선이 이루어졌다. 이러한 개선은 극한의 해양 조건에서 운영 신뢰성을 보장할 수 있다. 이 연구는 공기역학적 항력 감소와 구조적 안전성의 이중적인 이점을 강조하며, 국제 해사 기구(IMO)의 2050 탈탄소화 목표에 부합하는 연료 효율성 및 온실가스 배출 감소에 이바지할 수 있다. 연구 결과는 다양한 선박 유형에 걸쳐 항력 감소 기술을 확장하기 위한 기초 자료를 제공하며, 지속 가능하고 탄력적인 해양 운영을 위한 대안을 제시하였다. 향후 연구는 구조적 안전 평가를 가속할 수 있는 단순화된 모델링 기술 개발에 집중할 것이다.
        4,200원
        3.
        2025.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Proper Orthogonal Decomposition (POD) is applied to analyze the coherent structure of three-dimensional cylinder wake flow. The flow field data, such as velocity and pressure as functions of time, was obtained by the incompressible CFD analysis. The resulting CFD data was then used to determine eigenvalues, POD modes, and time coefficients through POD process. The flow field was approximately reconstructed using some of lower POD modes. The three-dimensional field reconstructed using the low-order model was found to be in good agreement with the original. This verifies that low-dimensional modeling of complex flow fields is fully possible.
        4,000원
        4.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 캐릭터 아크(Character Arc)와 트랜스 아이덴티티(Trans Identity) 이론을 결합하여 영화 <사바하> 주요 인물들의 내적 변화와 정 체성 전환 과정을 분석하였다. 연구 목적은 캐릭터 중심 서사 중 다중 캐릭터 간 상호작용이 서사의 복합성과 입체성을 증진하는지를 규명하는 데 있다. 연구 결과, 첫째, 박웅재는 종교적 회의와 세속적 욕망을 극복 하며 진정한 신앙으로 귀환하는 긍정적 변화 아크를 완성하였다. 둘째, 정나한은 거짓된 신념에서 벗어나 자신의 정체성을 재정립하였다. 셋째, 김제석은 거짓된 신념에 집착한 끝에 자멸하며 부정적 변화 아크의 전형 을 보여준다. 넷째, 세 캐릭터 간의 상호작용은 각자의 정체성 전환을 촉 진하며 서사의 주요 동력으로 작용하였다. 인물 간 상호작용이 정체성 변화와 서사 구조의 복합성을 심화시키는 과정을 구체적으로 규명했으 며, 창작 실무에서 설득력 있는 캐릭터 구축을 위한 가이드를 제공한다. 나아가 후속 연구로 캐릭터 아크와 트랜스 아이덴티티의 적용을 다양한 장르와 서사체로 확장할 필요성을 제안한다.
        6,000원
        5.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The dome structure is suitable as a roof for large spatial structures because it can maintain the shape without installing columns in the internal space. However, the structure characteristics of the lower and upper structures of the dome structure are different, and damage may occur when an earthquake occurs. Therefore, in this study, mid-story isolation system was applied to the ribbed dome and geodesic dome structures to analyze the seismic response of the lower and upper structures according to the dome shape. As a result of the analysis, the displacement of the ribbed dome increased, but the deformation of the ribbed dome and the response of the lower structure decreased, and the seismic response of the geodesic dome decreased overall. From this result, the effect of the isolator according to the shape of the dome structure was confirmed, and the mid-story isolation is considered effective in reducing the seismic response of the upper and lower structures.
        4,000원
        6.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study determined the minimum size of a representative molecular structure for use in future dynamic analyses of asphalt binders. The minimum representative size, considering factors such as aging, additive types, and temperature variations, was established using density and radial distribution functions. This approach ensures that the structure reflects temperature-dependent property changes, which are critical characteristics of asphalt binders. In this study, the structure of asphalt-binder molecules was generated using the composition proposed by Li and Greenfield (2014) for AAA1. To assess the appropriateness of the molecular structure size, we generated additional structures, X2 and X3, maintaining the same composition as X1, but with two and three times the number of molecules, respectively, as suggested by Li and Greenfield (2014). Silica and lignin were considered as additives, and the aging conditions examined included unaged, short-term aging, and long-term aging. In addition, 11 temperature conditions were investigated. The density and radial distribution functions were plotted and analyzed. The variables influencing the density and radial distribution functions were set as the aging degree of the asphalt binder (unaged, short-term aging, long-term aging), 11 temperature conditions ranging from 233 to 433 K in 20 K intervals, structure size (X1, X2, and X3), and the presence of additives (no additives, silica, and lignin). For density, clear differences were observed based on the degree of aging, temperature conditions, and presence of additives, whereas the structure size did not significantly affect the density. In terms of radial distribution functions, the X1 structure reflected differences based on the degree of aging and the presence of additives but was limited in exhibiting temperature-dependent variations. In contrast, the X3 structure effectively captured temperature-dependent trends, indicating that the size of the molecular structure is crucial when evaluating energy calculations or physical tensile strength, necessitating careful assessment.
        4,000원
        8.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although concerns about overheating of the franchise industry's market structure continue to be raised, there are few studies that analyze the market structure of the franchise industry and suggest practical use. Most existing studies mainly analyze the market structure of other industries using industrial concentration(HHI) as an indicator of market competition intensity from the perspective of industrial organization theory. This study seeks to present a market structure analysis method that is different from existing methods. Considering practical application, this study presented a method to analyze the market structure that combines industry concentration(HHI) analysis and matrix analysis of the franchise industry. First, the industry concentration(HHI) and operating profit ratio(SMR) of 15 major industries in the franchise industry were analyzed in a time series manner (2014-2019). Second, using industrial concentration and operating profit ratio(SMR) as two variables on the x-axis and y-axis, a two-stage matrix analysis was used to understand the market structure characteristics of 15 industries at a glance. Third, a method of utilizing the matrix analysis results for practical decision-making was presented.
        4,500원
        9.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Vertical takeoff and landing (VTOL) is a core feature of unmanned aerial vehicles (UAVs), which are commonly referred to as drones. In emerging smart logistics, drones are expected to play an increasingly important role as mobile platforms. Therefore, research on last-mile delivery using drones is on the rise. There is a growing trend toward providing drone delivery services, particularly among retailers that handle small and lightweight items. However, there is still a lack of research on a structural definition of the VTOL drone flight model for multi-point delivery service. This paper describes a VTOL drone flight route structure for a multi-drone delivery service using rotary-wing type VTOL drones. First, we briefly explore the factors to be considered when providing drone delivery services. Second, a VTOL drone flight route model is introduced using the idea of the nested graph. Based on the proposed model, we describe various time-related attributes for delivery services using drones and present corresponding calculation methods. Additionally, as an application of the drone route model and the time attributes, we comprehensively describe a simple example of the multi-drone delivery for first-come-first-served (FCFS) services.
        4,600원
        10.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: As the number of households raising companion dogs increases, the pet genetic analysis market also continues to grow. However, most studies have focused on specific purposes or native breeds. This study aimed to collect genomic data through single nucleotide polymorphism (SNP) chip analysis of companion dogs in South Korea and perform genetic diversity analysis and SNP annotation. Methods: We collected samples from 95 dogs belonging to 26 breeds, including mixed breeds, in South Korea. The SNP genotypes were obtained for each sample using an Axiom™ Canine HD Array. Quality control (QC) was performed to enhance the accuracy of the analysis. A genetic diversity analysis was performed for each SNP. Results: QC initially selected SNPs, and after excluding non-diverse ones, 621,672 SNPs were identified. Genetic diversity analysis revealed minor allele frequencies, polymorphism information content, expected heterozygosity, and observed heterozygosity values of 0.220, 0.244, 0.301, and 0.261, respectively. The SNP annotation indicated that most variations had an uncertain or minimal impact on gene function. However, approximately 16,000 non-synonymous SNPs (nsSNPs) have been found to significantly alter gene function or affect exons by changing translated amino acids. Conclusions: This study obtained data on SNP genetic diversity and functional SNPs in companion dogs raised in South Korea. The results suggest that establishing an SNP set for individual identification could enable a gene-based registration system. Furthermore, identifying and researching nsSNPs related to behavior and diseases could improve dog care and prevent abandonment.
        4,000원
        11.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        강원도 가리왕산, 발왕산, 방태산, 함백산의 아고산대에서 출현하는 사스래나무군락 25개 조사구를 대상으로 식생조 사를 실시하고 분석하였다. TWINSPAN 및 DCA 분석 결과, 사스래나무-신갈나무군락(GroupⅠ), 사스래나무-당단풍 나무군락(GroupⅡ), 사스래나무군락(GroupⅢ)의 총 3개 군락으로 분류되었다. 사스래나무-신갈나무군락(GroupⅠ)은 해발 1,082~1,192m 방태산 등산로 주변에 위치하고, 사스래나무-당단풍나무군락(GroupⅡ)은 해발 1,230~1,373m 방 태산, 가리왕산, 함백산의 능선과 사면에 위치한다. 사스래나무-신갈나무군락과 사스래나무-당단풍나무군락은 현재 교목층에 사스래나무가 우점하고 있으나 장기적으로는 경쟁 관계인 신갈나무가 우점할 것으로 예상된다. 사스래나무군 락(GroupⅢ)은 해발 1,428~1,464m 함백산과 발왕산 정상부 전석지에 위치한다. 현재 사스래나무 세력이 매우 우세하 고 차세대 형성도 활발하여 앞으로도 사스래나무가 우점할 것으로 예상된다. 사스래나무군락은 일반적으로 해발 1,000m 이상에서 출현하며, 해발고도가 높을수록 사스래나무의 세력이 우세한 것으로 나타났다. 토양 분석 결과, 설악산 대청봉 및 지리산 반야봉 아고산대 지역과 비슷한 양상을 보였다. 군락별 종다양도는 1.210~1.293, 균재도는 0.698~0.795, 우점도는 0.208~0.302로 나타났다.
        4,500원
        12.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper introduces a study on measuring the 3D vibration displacement of plate structure using Digital Image Correlation (DIC) applied to stereo digital continuous camera images. The proposed method is a non-contact 3D displacement measurement method that does not require physical sensors to be attached to the structure, and it has the advantage of simultaneously measuring dynamic displacements at multiple points on the structure. Theoretically, multiple cameras can be used, but in this study, two cameras were used to capture continuous images of the vibrating structure, and the image coordinates of multiple tracking points at arbitrary positions on the structure were measured using correlation matching. Using these image coordinates as input data, the dynamic 3D positions were calculated through Space intersection, successfully determining the 3D dynamic displacements. The measured dynamic displacements were validated for accuracy by comparing them with values measured by laser displacement sensors. And frequencies of measured data were validated by comparing with computational modal analysis by Finite Element Model (FEM).
        4,000원
        13.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유체-구조물-지반 상호작용을 고려한 액체저장탱크의 유한요소 모형을 제시하고, 비선형 지진응답 해석기법을 정식화한다. 탱크 구조물은 기하 및 재료 비선형 거동을 고려할 수 있는 쉘 요소로 모델링한다. 유체의 거동은 acoustic 요소로 구현하고, interface 요소 를 사용하여 구조물과 결합한다. 지반-구조물 상호작용을 고려하기 위해 지반의 근역과 원역을 각각 solid 요소와 perfectly matched discrete layer로 모델링한다. 예제 20만 kl급 액체저장탱크의 지진취약도 해석에 적용하여, 유연한 지반에 구조물이 놓인 경우 부지에 서의 암반노두운동의 증폭 및 필터링으로 인해 지진취약도의 중앙값과 대수 표준편차가 감소하는 것을 관찰할 수 있다.
        4,000원
        17.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oxygen-rich porous carbon is of great interest for energy storage applications due to its improved local electronic structures compared with unmodified porous carbon. However, a tunable method for the preparation of oxygen-rich porous carbon with a special microstructure is still worth developing. Herein, a novel modification of porous carbon with different microstructures is facilely prepared via low-temperature solvothermal and KOH activation methods that employ the coal tar and eight substances, such as cellulose as carbon source and modifier, respectively. By testing the yield, surface group structure, lattice structures, morphology, thermal weight loss, and specific capacitance of carbonaceous mesophase, cellulose–hydrochloric acid is identified as the additive for the preparation of oxygen-rich coal tar-based porous carbon. The obtained porous carbon displays a specific surface area of up to 859.49 m2 g− 1 and an average pore diameter of 2.39 nm. More importantly, the material delivers a high capacity of 275.95 F g− 1 at 0.3 A g− 1 and maintains a high capacitance of 220 F g− 1 even at 10 A g− 1. When in a neutral electrolyte, it can still retain a reversible capacity of 236.72 F g− 1 at 0.3 A g− 1 and 136.79 F g− 1 at 10 A g− 1. This work may provide insight into the design of carbon anode materials with high specific capacity.
        4,500원
        18.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study performed the seismic response analysis of an LNG storage tank supported by a disconnected piled raft foundation (DPRF) with a load transfer platform (LTP). For this purpose, a precise analytical model with simultaneous consideration of Fluid-Structure Interaction (FSI) and Soil-Structure Interaction (SSI) was used. The effect of the LTP characteristics (thickness, stiffness) of the DPRF system on the seismic response of the superstructure (inner and outer tanks) and piles was analyzed. The analytical results were compared with the response of the piled raft foundation (PRF) system. The following conclusions can be drawn from the numerical results: (1) The DPRF system has a smaller bending moment and axial force at the head of the pile than the PRF system, even if the thickness and stiffness of the LTP change; (2) The DPRF system has a slight stiffness of the LTP and the superstructure member force can increase with increasing thickness. This is because as the stiffness of the LTP decreases and the thickness increases, the natural frequency of the LTP becomes closer to the natural frequency of the superstructure, which may affect the response of the superstructure. Therefore, when applying the DPRF system, it is recommended that the sensitivity analysis of the seismic response to the thickness and stiffness of the LTP must be performed.
        4,300원
        19.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Application areas of floating marine structure systems have been increased with the development of power generation systems using renewable energy. Hence it is necessary to analyze the behavior of these floating systems for efficient design and operation. In this study, a computational analysis was performed to predict the characteristics of mooring lines load variation connected to a floating marine structure with waves. Pressure on the floating body and mooring lines load were analyzed with wave direction and height. The floating body stability severely decreased for 90° of the wave incident direction, and maximum load of the mooring lines increased with the height. These results are expected to be applicable for optimal design of the marine floating system.
        4,000원
        20.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Special equipment used for snow removal is only used in the winter and must be moved into storage during non-winter seasons. However, when moving heavy equipment using a forklift within a limited space, safety accidents may occur due to deformation and damage due to the worker's limited visibility and excessive loading of heavy objects. In this study, the scissors boom of the developed heavy load transporter was conducted in two cases: link structural analysis and position-based structural analysis. In detail, the link structural analysis covers four cases of stress and safety factor according to material and thickness to optimize the specifications of the material selected during development, and the structural analysis according to position covers two cases before and after the lift, when maximum stress concentration is achieved. Safety was evaluated through finite element analysis. As a result of the study, when manufacturing a scissors boom type heavy load transporter that can withstand a load of 10 tons, the link showed safety at SS400 4.5mm or higher, and reinforcement is needed in the upper and lower structures, so it is judged to be useful in applying materials according to the load.
        4,000원
        1 2 3 4 5