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        검색결과 391

        1.
        2026.03 구독 인증기관 무료, 개인회원 유료
        Pavement surface texture plays an essential role in skid resistance, tire–pavement interaction, and wet-weather driving safety. Conventional evaluations of pavement texture are primarily based on two-dimensional (2D) profile measurements, such as Mean Texture Depth (MTD) and Mean Profile Depth (MPD), which cannot fully represent the complex three-dimensional (3D) characteristics of pavement surfaces. As a result, the relationship between surface texture and wet pavement friction is often insufficiently described. Recent advances in high-resolution optical scanning enable detailed acquisition of surface topography and provide opportunities for more accurate texture quantification. This study proposes a comprehensive framework for characterizing micro- and macro-surface textures using high-resolution 3D scanning combined with both 2D and 3D analytical methods. Dense point-cloud data were collected from concrete pavement surfaces, and multiple longitudinal and transverse profiles were extracted. Fast Fourier Transform (FFT)-based filtering was applied to separate micro- and macro-texture components, and representative texture parameters were calculated from both profile-based and surface-based analyses. Wet pavement friction was evaluated using the British Pendulum Number (BPN), and statistical relationships between texture parameters and friction were examined. The results demonstrate that the proposed approach effectively captures multi-scale texture features and provides improved correlation with wet friction compared with traditional 2D methods. The developed methodology offers a practical basis for texture-based friction evaluation and pavement safety assessment.
        3,000원
        2.
        2026.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzes the usage behavior and travel characteristics of shared micro-electric vehicle (micro-EV) mobility services using large-scale empirical data collected over three years (2023-2025) from three pilot regions in Korea: Daejeon, Mokpo, and Jeju Island. By integrating the location-based driving records, user information, trip surveys, and weather data, 66,843 valid trips were extracted, including 49,264 trips matched with user attributes. Usage behavior was first examined through statistical analyses of user demographics and surveybased information on trip purposes, multimodal connections, and user satisfaction. The results indicate that micro-EV services support diverse usage behaviors, ranging from commuting and campus travel to leisure, with distinct regional differences in user composition and service roles. A travel pattern analysis further revealed clear temporal and environmental characteristics, including pronounced seasonal peaks between July and October, higher weekday utilization associated with commuting demand, high concentration of trips during daytime hours, and a nonlinear response to weather conditions, in which usage increased under moderate temperatures but declined during extreme heat, cold, or precipitation. A distance-based analysis showed that micro-EV trips were generally short-distance in nature, while substantial regional variations existed. Daejeon was dominated by ultra-short campus-oriented trips, Mokpo exhibited a broader distribution of short urban trips linked to daily activities and tourism, and Jeju Island demonstrated a higher share of mid-distance trips reflecting industrial park commuting and inter-destination travel. A spatial origin-destination (OD) analysis further highlighted region-specific network structures, with Daejeon forming a compact hub-based network, Mokpo displaying a dispersed pattern centered on major transit facilities, and Jeju Island exhibiting a multipurpose network shaped by commuting and tourism mobility. These findings provide empirical evidence that shared micro-EV services function as flexible region-dependent mobility solutions, underscoring the need for differentiated operational strategies, station-based service planning, and integration with local transport systems to support sustainable urban mobility.
        4,300원
        3.
        2025.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Cryopreserved semen and embryos are essential tools in livestock reproduction, enabling genetic improvement and herd management. Although these materials are theoretically stable in liquid nitrogen (LN2), viability often decreases over time, particularly in farm settings. Micro-ice crystals (MICs) are hypothesized to form under poor LN2 handling conditions, potentially compromising the survival of frozen genetic resources. However, the extent and impact of MIC accumulation have not been thoroughly quantified. Methods: This study evaluated MIC accumulation and its effects on the viability of cryopreserved bovine semen and embryos under different LN2 storage environments and conditions. MIC content was measured by filtering 10 L of LN2 through nonwoven fabric and weighing the retained crystals and debris. The viability of sperm and embryos were assessed using a computer-assisted semen analysis (CASA) and blastocoel re-expansion. Results: MIC content was 3.5 times higher in farm-stored LN2 than in laboratory LN2, with significantly more debris also detected. Progressive motility and velocity parameters (VCL, VAP, VSL) were similarly reduced. Blastocyst survival dropped significantly under farm conditions after six months (42.4%) compared to laboratory storage (84.4%, p < 0.05). These findings suggest a strong correlation between MIC accumulation and decreased post-thaw viability of cryopreserved materials. Conclusions: MICs formed in LN2 due to environmental exposure and poor handling can severely impair the viability of cryopreserved sperm and embryos. Regular filtration and improved LN2 management, especially in farm environments, are essential to reduce MIC-related damage. These practices may enhance the long-term usability and reliability of genetic resources in livestock breeding programs.
        4,000원
        5.
        2025.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        경량 골재 콘크리트는 높은 다공성을 지닌 골재를 사용하여 제작되며, 이는 재료의 역학적 성질 및 내구성에 중대한 영향을 미친 다. 최근 콘크리트 분야에서는 내부 공극 구조를 비파괴적으로 분석할 수 있는 기술로서 micro-computed tomography(micro-CT)의 활 용이 활발히 이루어지고 있으며, 특히 경량 골재 콘크리트의 공극 구조를 정밀하게 포착하는 데 효과적인 것으로 나타났다. 그러나 경 량골재는 이질적인 밀도 분포와 내부 다공성으로 인해 영상 내 분할 과정에서 어려움을 유발하며, 이로 인해 골재가 공극으로 잘못 인 식되거나 경계가 명확히 구분되지 않는 문제가 발생할 수 있다. 이러한 한계를 극복하기 위해 본 연구에서는 경량 골재 콘크리트의 micro-CT 영상에서 골재를 정밀하게 식별할 수 있도록 고안된 향상된 분할 알고리즘을 제안하였다. 제안된 알고리즘의 성능은 기존 의 세분화 방법과의 비교 분석을 통해 평가되었으며, 더불어 제안 방식과 기존 방식 각각으로 생성된 3차원 micro-CT 데이터를 활용 하여 열전도도 시뮬레이션을 수행하였다. 그 결과, 제안된 알고리즘은 공극 및 골재 경계의 정확한 식별에 있어 기존 기법보다 향상된 정확도를 보였으며, 이는 LWAC의 미세구조 분석 및 거동 예측 모델링의 정밀도를 높이는 데 기여할 수 있는 가능성을 보여준다.
        4,000원
        6.
        2025.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 고온기에 배추(Brassica rapa L. ssp. pekinensis) 의 안정생산을 위해 미세살수와 저온성필름의 고온 스트레스 저감 효과를 평가하였다. 실험1에서는 ‘춘광’과 ‘청명가을’ 배추를 대상으로 관수장치(임팩트 스프링클러, 미세살수)와 피복자재(흑색필름, 저온성필름)의 요인배치 실험을 수행하 였다. 실험2에서는 ‘춘광’ 배추를 대상으로 관수 시점에 따른 미세살수의 냉각 효과를 비교하기 위해 오전(9-11시), 오후 (13-15시), 또는 야간(19-21시)에 각각 처리하여 비교하 였다. 실험1의 결과, 저온성필름은 일중 최고 지온을 흑색필 름 대비 평균 4.5-6.9°C 하강시켰다. 미세살수는 즉각적으 로 기온을 약 5°C 하강시켰고, 상대습도를 70%까지 증가시 켰다. 엽록소 지수(SPAD)는 ‘춘광’ 배추에서는 저온성 필름 피복 시, ‘청명가을’ 배추에서는 미세살수 적용 시 가장 높았 다. 최대 광화학 효율(Fv/Fm)은 생육초기에 흑색필름과 임팩 트 스프링클러를 처리한 ‘청명가을’ 배추에서 가장 낮았으나 2주 후 0.7 이상으로 회복했다. 생육 지표는 두 품종 모두 미세 살수 처리에서 개선되었다. 실험2의 결과, 오후 관수 시 가장 기온하강 효과가 높았고, 특히 일사량과 기온이 높은 날일수 록 그 효과가 증대되었다. 야간 관수 시 미세살수에 의한 온도 변화는 없었다. 본 연구 결과를 통해 미세살수와 저온성필름 이 배추의 고온 스트레스를 저감하고 재배환경을 개선에 효과 적임을 확인하였다. 향후에는 온도조절뿐만 아니라 물 이용 효율을 함께 높일 수 있는 정밀 제어 기술 개발이 필요하다.
        4,000원
        7.
        2025.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the Autonomous Mobility Living Lab, traffic situations with both autonomous vehicles (AVs) and ordinary vehicles driven by humans (HDVs) are explored. Research on countermeasures and efficient transportation management plans has emerged from this context. In this study, we analyzed the effect of AVs with different speeds on signal intersections and road networks to derive efficient traffic operation plans for roads on which various AVs and HDVs with different driving behaviors are mixed in Living Lab cities. To that end, we conducted a simulation-based analysis of the effects of AV mixing rates on continuous signal intersections and the road network in traffic situations where AVs and HDVs were mixed at peak and non-peak driving hours. The simulation scenario was designed by classifying the traffic volume levels at peak and non-peak times and defining various AV mixing rates; we also set the driver behaviors of the AVs as either conservative or aggressive. By performing a small-scale traffic simulation, the average control delay, average stopped delay, average queue length, and average travel time of the signal intersection for each scenario were derived, and the impact of the AV mixing rate on traffic operation was analyzed. The results of the analysis show that higher AV mixing rates were associated with lower measurements of the effectiveness of signal intersections, which had a positive effect on traffic operation. This resulted in a stable and efficient improvement of the traffic flow at intersections as more vehicles passed through at the time of the allocated signal, as the AVs in the simulation could be driven at short intervehicle intervals by receiving real-time traffic information. In the traffic operation on the network, we found that the higher the AV mixing rate, the lower the average travel time, resulting in a greater effect of facilitating the traffic flow of the urban network. These simulated results indicate that higher AV mixing rates were associated with positive outcomes in terms of signal intersections and network traffic operation. We expect that this simulation can be used to establish real traffic operation plans in traffic situations where AVs are mixed at each stage of autonomous driving technology in the future.
        4,000원
        8.
        2025.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        본 연구는 MTS가 피부개선에 미친 영향에 관한 기존 연구들을 분석하여, 근거 체계를 구축하고, 주요 키워드 간 관계와 역할 및 패턴 등을 구조적으로 분석하고자 텍스트마이닝과 토픽모델링 및 단어네트워크 분석을 실시하였다. 관련 선행연구들은 MTS와 관련된 핵심 키워드와 연관 키워드를 혼합하여 전자도서관에서 검색하였으 며, 결론 부분의 Text를 수집하여 분석에 사용하였다. 분석결과는 다음과 같다. 첫 째, '피부', '효과', '실험', '관리', '개선' 등의 어휘가 주요 개념으로 확인되었다. 둘째, TF-IDF 분석에서 높은 가중치의 키워드들은 MTS의 피부 개선 효과에 관한 과학적 실험 기반 논의를 시사했다. 셋째, LDA 분석 결과, ‘과학적 검증 중심’과 ‘피부 개선 효과 중심’의 토픽2개로 나뉘었다. 넷째, 단어 네트워크에서 '피부'를 중심으로 '주름', '효과', '실험' 등이 강하게 연결되었고, '여성'과 '모공' 노드는 MTS가 여성 안면 부위 에 주로 적용됨을 나타냈다. 본 텍스트마이닝 기법은 유사 의료 미용 시술 분석에도 적용 가능하며, 향후 시계열 분석과 감성 분석을 통해 MTS 효과의 변화와 대상자 반응을 심층 탐색할 필요가 있다.
        6,100원
        14.
        2025.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Silver nanoparticles (AgNPs) are promising photocatalysts with a broad light absorption range and high catalytic activity. However, conventional synthesis methods often involve toxic chemicals, limiting their environmental applicability. In this study, we developed an eco-friendly bio-templating method to synthesize hierarchical micro/nano-structured silver (MNAg) photocatalysts that uses plant leaves, including Nelumbo nucifera (lotus leaf), Rosa sp. (rose petal), and Limonium sinuatum (statice petal), as natural templates. By modifying the leaf surfaces with citrate functional groups, AgNPs were selectively formed along the microstructures of the templates, preserving their hierarchical morphology. MNAg photocatalysts were subsequently obtained through controlled calcination, and successfully retained the microscale structure of the original template. The surface morphology, chemical composition and crystalline structure of the MNAg were characterized using scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), confirming the successful formation of hierarchical AgNPs. The optical behavior of the MNAg, characterized with diffuse reflectance spectroscopy (DRS), demonstrated broadened absorption across the visible region, which is attributed to plasmonic coupling among the densely packed AgNPs, partially interconnected along the hierarchical surface. The photocatalytic performance of the MNAg materials was evaluated for methylene blue degradation under UV-Vis illumination. The MNAg derived from lotus leaves exhibited the highest photocatalytic efficiency. This study presents a sustainable route to hierarchical Ag photocatalysts, highlighting the potential of bio-inspired nanomaterials for environmental applications.
        4,000원
        18.
        2025.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        포도 ‘My heart’의 기내증식과 기외이식 후 생장에 있어서 배양용기에 부착한 미세공극 Filter 처리가 건전한 유묘를 생 산하는데 효과적인 방법을 찾고자 실시하였다. 미세공극 Filter는 환기구 크기별로 White filter type (50.0 mm×3.5 mm)과 Green filter type (50.0 mm×7.0 mm) 으로 구분하여 밀폐 처리와 비교하였다. Shoot tip 배양에 있어서 Green filter type에서 shoot 분화율이 75%로 White filter type 77% 와 밀폐처리 80% 보다 낮았지만 투명화 shoot 발생율은 4% 로 White filter type 13.4%, 밀폐처리 24.7%에 비하여 9.4- 20.7%가 적었다. 전체 배양묘의 54.9%가 투명화 발생이 되 었을 때 Green filter type으로 90일 동안 계대 배양하고 조사 한 결과 투명화율은 11.8%로 감소하였고 분화한 shoot 수는 89개에서 915개로 증가하였다. Filter type에 따라 IBA 2.0 mg·L-1를 첨가하여 30일 동안 배양을 하였을 때 Green filter type에서 기내 발근율 100%, 뿌리 수 7.3개, 엽수 10.0개로 White filter type과 밀폐 처리보다 좋았다. 기외 이식하고 15 일 후의 유묘 생존율도 Green filter type에서 100%로 다른 처 리에 비하여 1.5-29.5% 더 높았고 초장이 11.0cm, 생체중이 1.7g 으로 가장 양호하였다. 미세공극 Green filter 처리는 포 도 ‘My heart’의 기내배양에서 shoot 투명화를 감소시키고 shoot와 뿌리 생성을 촉진시키고 기외이식 후 생장은 통계적 으로 유의하게 확인되어 건전한 유묘 생산에 효과적이었다.
        4,000원
        19.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Micro display technology has become a key element of digital innovation, gaining attention with immersive technologies like AR/VR, and advancing in fields such as education, military, and healthcare. This study aims to analyze micro display technology trends, which are increasingly important across industries, and to provide insights that help companies develop strategies for related technologies. Using the patent database, BERTopic, a recent topic modeling technique, was applied to identify key themes in micro display technology development. Time-series analysis was also conducted to examine changes in research trends over time. These findings are expected to guide companies and research institutions in setting future technology development directions and strategies.
        4,300원
        20.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Molten Salt Reactor (MSR) is considered one of the most suitable technology for micro mobile reactors due to its low operating pressure (3 ~ 5 atmospheres), which reduces weight and volume compared to pressurized water reactors (PWRs). Unlike PWRs, MSRs use molten salt as both fuel and coolant, enabling compact and transportable designs. This study outlines the conceptual design of a micro mobile MSR and establishes safety criteria for transient states. It proposes strategies for managing the primary loop, intermediate heat transfer system, and air-cooled Balance of Plant (BOP) while addressing thermal and structural constraints, such as maximum temperatures and molten salt freezing points. Control approaches for reactor output and BOP systems are analyzed, highlighting fast response and adaptability to frequent power changes. The study also compares fixed-speed and variable-speed pump operations and provides a framework for operational modes, from high-temperature standby to transport-ready conditions. These findings offer a foundation for efficient, safe, and flexible MSR deployment.
        4,000원
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