The concept of resilience has gained increasing attention amid growing urbanization and rising vulnerability to infrastructure. While various methodologies exist for evaluating the resilience of lifeline systems, few address the distinct structural features and failure modes of railway networks. This study refines existing approaches by incorporating characteristics unique to high-speed railways, with a focus on two key aspects. First, we define the structure of railway networks by identifying nodes and links, and deriving link-specific resilience criteria based on the fragility characteristics and recovery profiles of their structural components. Second, we utilize real data from the Korean railway system to quantify the performance degradation caused by component failures during seismic events. To assess the framework’s applicability, we use a simplified network and a more complex one integrating Korea’s Honam Line and Honam High-Speed Line. The framework effectively identifies critical scenarios and provides a valuable tool for decision-makers in assessing seismic risk and planning recovery for railway infrastructure.

Current portable reference equipment used to evaluate the performance of vehicle detectors can collect traffic volume and speed only for the outermost lanes in each direction. Passing vehicles on the other lanes are manually counted by reviewing the recorded videos. Consequently, only traffic volume—without vehicle speed—is used as a reference value. This method is time-consuming for comparing the performance data from the equipment with the reference data and can compromise the performance evaluation. This study aims to enhance the efficiency of vehicle detection system (VDS) performance evaluations by developing multilane portable reference equipment that can accurately collect traffic information for lanes beyond the outermost lane or for more than two lanes. This study introduced the core technologies of multilane portable reference equipment and compared and analyzed the measurement accuracy of the developed equipment against data from fixed reference equipment operated by the Intelligent Transportation System (ITS) Certification and Performance Evaluation Center, following ITS performance evaluation criteria. The data from the fixed reference equipment were considered the true values, providing a basis for evaluating the accuracy of the measurements by the developed equipment. First, the accuracy of the vehicle length was determined by driving four test vehicles, each measuring 7,085 mm in length, 24–29 times in each lane. The accuracy was calculated by comparing the vehicle length data obtained from the fixed reference equipment with the actual vehicle length. A confidence interval was established for this accuracy. To assess the accuracy of the speed and occupancy time in relation to the accuracy of the analyzed vehicle length, we evaluated the error range of the vehicle length according to variations in speed and occupancy time. This analysis was based on the following relationship equation: “vehicle length = speed × occupied time – sensor spacing.” The analysis used data from approximately 16,000 vehicles, including the speed, occupancy time, and vehicle length, collected between 8:00 am and 12:00 pm on August 8, 2024. The principle behind measuring traffic volume and vehicle speed using multilane portable reference equipment involves detecting a vehicle by analyzing the time difference between the driver and passenger tires. The vehicle speed was calculated using the installation angle of the tire detection sensor and trigonometric functions. An analysis of the measurement accuracy revealed that the traffic volume accuracy of the outermost lane (the fourth lane) was 100% during both day and night. The speed accuracy was 98.8% during the day and 97.7% at night, representing the highest performance in these metrics. Additionally, the traffic volume accuracy for the innermost lane (the first lane), as measured by the detection sensor from the third lane, was more than 99.3% at all times, with a speed accuracy exceeding 96% during the day and night, that also demonstrated excellent results. The analysis results indicated that the multilane portable reference equipment developed in this study was suitable for evaluating the VDS performance. This equipment allowed the collection of traffic volume and speed data from all lanes, rather than only the outermost lanes. This capability enabled consistent analysis for each lane and enhanced efficiency by reducing the analysis time. Additionally, this is expected to improve the reliability of the performance evaluations.

Purpose: This study applied a mixed-methods design to examine the effects of the nurse shift system improvement pilot project, organized by the Ministry of Health and Welfare, on ward nurses’ quality of life, job satisfaction, and patient safety nursing activities, as well as to explore their overall evaluation of the project through in-depth interviews. Methods: Using a mixed-methods approach, this study simultaneously conducted quantitative analyses of ward nurses’ quality of life, job satisfaction, and patient safety nursing activities, along with qualitative research through in-depth interviews to explore overall perceptions of the nurse shift system improvement pilot project. Results: Patient safety nursing activities showed a significant positive correlations with quality of life (r=.24, p=.017) and job satisfaction (r=.21, p=.038). There was also a significant positive correlation between quality of life and job satisfaction (r=.63, p<.001). As a result of the qualitative analysis, eight facilitating factors and five hindering factors related to the pilot project were identified. Conclusion: Through the research, the effectiveness of the pilot project and the factors influencing nurses were identified. Accordingly, strategies are needed to enhance patient safety nursing activities by improving nurses’ quality of life and job satisfaction in pilot project wards.

본 연구는 주요 선진국의 아동·청소년 공공 전달체계를 비교 분석하여, 한국 전달체계의 구조적 문제를 진단하고 개선 방향을 제시하였다. 분석 결과, 대부분 국가는 아동·청소년을 통합된 정책 대상으로 설정하고 있으 며, 보편주의 복지 또는 다부처 협업 모델을 통해 서비스의 효율성과 연 계성을 제고하고 있다. 반면, 한국은 부처 간 분절성과 중복, 지역 간 이 질적 운영으로 통합적 접근이 제한되고 있다. 이에 본 연구는 정책 대상 의 통합, 중앙-지방 간 역할 재정립, 법·제도 기반 정비 등 체계적이고 단계적인 전달체계 개편의 필요성을 제안하였다.

병풀(Centella asiatica)의 뛰어난 약리적 효능은 산업적 활 용을 위한 대량증식 개발의 필요성을 강력하게 뒷받침하며 이 에 대한 요구가 증가하고 있다. 본 연구는 수경재배 시스템에 서 런너를 이용한 병풀의 영양번식 시 배지 종류에 따른 생육 특성을 구명하기 위해 수행되었다. 연구 결과, 폴리우레탄폼 (PU)에서 재배된 병풀의 지상부 생체중, 런너 생체중, 건물중, 엽면적, SPAD에서 유의적으로 높은 값을 보였다. 하이드로 볼(HB) 역시 다른 배지와 비교하여 유의적으로 높은 생육 특 성을 나타냈으나, 지피 펠렛(JP)에서는 대부분 생육특성에서 가장 낮은 특성을 나타내었다. PU 배지에서 생육 증가는 뿌리 발달에 핵심적인 물리적 특성인 총 공극률과 기상률에 기인한 것으로 판단된다. 따라서 본 연구 결과는 병풀의 영양번식 및 대량생산을 위해 PU 배지가 적합할 것으로 판단된다.

A high-pressure in-situ permeation measuring system was developed to evaluate the hydrogen permeation properties of polymer sealing materials in hydrogen environments up to 100 MPa. This system employs the manometric method, utilizing a compact and portable manometer to measure the permeated hydrogen over time, following high-pressure hydrogen injection. By utilizing a self-developed permeation-diffusion analysis program, this system enables precise evaluation of permeation properties, including permeability, diffusivity and solubility. To apply the developed system to high-pressure hydrogen permeation tests, the hydrogen permeation properties of ethylene propylene diene monomer (EPDM) materials containing silica fillers, specifically designed for gas seal in high-pressure hydrogen environments, were evaluated. The permeation measurements were conducted under pressure conditions ranging from 5 MPa to 90 MPa. The results showed that as pressure increased, hydrogen permeability and diffusivity decreased, while solubility remained constant regardless of pressure. Finally, the reliability of this system was confirmed through uncertainty analysis of the permeation measurements, with all results falling within an uncertainty of 11.2 %.

저온기 엽채류 생산시 저온, 저광 등으로 인해 생육 저하 및 수량 감소가 발생한다. 저온기 근권부 가온을 통해 지상부 저 온 스트레스를 경감하고 생육 및 수량을 개선할 수 있다. 최근 루꼴라, 고수, 바질, 공심채 등 향신채소의 국내 수요가 증가하 면서, 연중 생산의 필요성이 증가하고 있다. 본 연구에서는 양 액 가온을 통한 근권부 온도 제어 효과와 지상부 생육 및 수량 에 미치는 영향을 구명하고자 수행하였다. 저온기 경남 함안 에 위치한 유리 온실에서 실험을 실시하였으며, 루꼴라, 고수, 바질, 공심채를 분무경베드에 정식하여 무처리 대조구와 양 액 가온 설정온도별 처리구(NSH20, NSH25, NSH30)를 설 정하였다. 양액 조성은 PBG 엽채류 조성을 따랐으며 재배기 간 동안 폐기 없이 표준 양액(EC 1.8, pH 5.5)으로 보충하여 사용하였다. 양액의 특성 및 이온 농도는 약 3일 간격으로 분 석하였으며, 작물의 생육 및 수확 조사는 각각 정식후 2주와 4 주차에 수행하였다. 재배 기간 동안 온실 내부의 일일 최저, 평균, 최고 온도는 각각 13.75℃, 18.66℃, 30.08℃였으며, 재 배 기간 중 온실 내 최저 온도는 9.97℃였다. 대조구의 근권부 온도는 최저 13.35℃, 평균 17.17℃로 근권부 저온으로 인한 뿌리 생육 저하, 지상부 생육 감소를 유발할 수 있다. 설정 온 도별 가온 양액을 공급한 경우 근권부 평균 온도는 NSH30는 24.61℃, NSH25는 21.41℃, NSH20는 18.62℃였다. 호냉 성 작목인 루꼴라와 고수는 근권부 온도에 따른 생육 및 수량 변화가 확인되지 않았다. 반면 호온성 작목인 바질과 공심채 는 양액 가온을 통한 근권부 온도 제어시 생육 및 수량 개선이 확인되었다. 바질은 NSH25와 NSH30 처리구에서 유사한 생 육 및 수량 개선 효과가 확인되었으며, 에너지 효율성을 고려 했을 때 양액 가온 온도를 25℃로 설정하는 것이 더 경제적인 근권부 온도 관리 방안이 될 것으로 생각된다. 반면 공심채는 NSH30에서 수량이 대조구 대비 107%, NSH25 대비 60% 증 가한 것으로 보아 양액 가온 설정 온도를 높게 유지하는 것이 적합할 것으로 생각된다.

도선사는 연안과 항만수역 위해 요소 등 현지 수로 사정에 익숙하지 않은 선 박에 승선하여 안전한 입출항을 도와 주는 선박조종 전문가이다. 우리나라 도 선사는 오랜 해상 근무 경력을 가진 노련한 대형 외항선 선장 출신이 대부분이 지만, 도선사 면허의 응시요건 등 제도의 운영 형태는 각국의 여건과 정책에 따라 다양하게 운영되고 있다. 한편, 주요 해운국인 일본은 해상근무 기피에 따른 해기사와 선장 경력자의 급격한 감소로 인해 수선법(水先法)을 개정하여 2007년부터 도선사 양성제도를 도입하여 운영하고 있다. 특히, 선장 경력이 없는 항해사, 승선경력이 없는 해 사대학 졸업생의 경우에도 양성과정을 통해 도선사가 될 수 있어 대형선의 선 장 경력자만을 대상으로 선발하여 운용 중인 우리나라와 큰 대조를 보이고 있 다. 이처럼 한·일 양국의 도선 제도는 자격요건, 선발절차 및 방법, 강제도선 제도상 상당한 차이점이 존재하고 있지만, 도선사의 민사책임과 면책 등에서는 유사한 부분도 존재한다. 이 논문에서는 한국과 일본의 도선관련 법제, 운영 실태 및 민사책임 사례를 비교법적으로 연구하여 시사점을 도출하였다. 이는 바탕으로 우리나라 도선 법 제상 미비점을 보완하기 위한 발전적 개선방안을 제시하였다.

Purpose: This study aimed to explore the experiences, essence, and structure of charge nurses operating in rotational appointment systems in tertiary hospitals. Methods: This qualitative study adopted a phenomenological approach. The participants were 11 charge nurses with rotational role experience working in tertiary hospitals in a metropolitan area. Data were collected through individual in-depth interviews lasting an average of 40~60 minutes and, conducted between July 8 and August 30, 2024. Colaizzi's phenomenological method was used for data analysis, which led to the identification of 35 themes, 14 theme clusters, and five categories. Results: The study revealed five categories: (1) ‘Taking the first step as a charge nurse,’ (2) ‘Enduring the weight of being a charge nurse,’ (3) ‘Creating my own charge nurse role,’ (4) ‘Mixed emotions returning after completing the rotation,’ and (5) ‘Ready to take the leap to the next level.’ The findings indicated that charge nurses experienced significant personal and professional growth while performing their roles. They demonstrated leadership, coordinated tasks and personnel, supported staff development, resolved issues, and facilitated communication. This role had a positive impact on both individual professional development and organizational efficiency. Despite initial feelings of anxiety and fear, charge nurses embraced challenges and contributed to improvements in organizational culture and patient safety while setting new goals for continuous growth even after completing their roles. Even in the post-term, they continued to expand their perspectives as nursing managers, increased their influence, and set new goals while pursuing ongoing growth and development. Conclusion: This study provides an in-depth understanding of the experiences of charge nurses in rotational systems in tertiary hospitals. Given the crucial role of charge nurses in the nursing leadership pipeline, it is essential to establish comprehensive hospital-wide programs to nurture leadership skills among front-line nursing managers and create supportive policies that fully enable their engagement.

본 연구는 Chat GPT 기반으로 개발한 실험자용 생성형 AI 코칭 시스템 ‘Roh-KAI(로카이)’가 인간 사용자 간 상호작용과정에서 발생하는 사회적 존재 감, 신뢰, 자기효능감의 심리적 변화를 탐색하고자 하였다. 로카이는 국제코칭연 맹(ICF)과 한국코치협회(KCA)의 윤리규정 및 핵심 역량을 반영하여 8단계 47개 질문 구조로 설계되었다. 인공지능 사용경험이 있는 성인 15명을 대상으로 주제 분석 기법을 적용한 질적 연구를 진행하였다. 분석 결과 4개의 상위 주제와 9개의 하위 주제가 도출되었다. 사회적 존재감 에서는 60%가 대화의 자연스러움을, 80%가 공감적 반응을 경험했고, 인공지능 신뢰에서는 53.3%가 공감적 경청과 이해를, 40%가 비판단적 태도를 인식했다. 자기효능감에서는 66.7%가 자기 인식 확장을, 46.7%가 실행 의지 강화를 나타 냈다. 반면 53.3%가 구조화된 프로세스의 제약을 지적했고, 33.3%가 사용자 다 양성 대응 부족을, 26.7%가 윤리적 우려를 지적하였다. 연구 결과 AI 코칭 시스 템이 공감적 상호작용과 자기성찰 촉진에는 효과적이나, 시스템의 유연성과 개 별화된 접근의 중요성을 확인하였다. 본 연구는 AI 코칭 시스템의 설계와 개선 방향에 실증적 근거를 제공하는 데 의의가 있다.

Background: The Functional Movement Screen (FMS) is widely used for movement assessment but suffers from subjective scoring that leads to inconsistent evaluations. While previous studies have focused on reliability, the validity of AI-supported assessment remains unexplored. Objectives: To evaluate the reliability and validity of an AI-based motion analysis system using MediaPipe for three FMS movements. Design: Prospective reliability and validity study with repeated measures. Methods: Thirty healthy adults (age 23.4±2.8 years) performed three FMS tests (Deep Squat, Hurdle Step, Inline Lunge) recorded on video. Three evaluators (two experienced physical therapists and one novice) assessed recordings in three phases: Phase 1 involved traditional assessment by experts only to establish criterion reference, Phase 2 had all evaluators using AI support, and Phase 3 consisted of repeated AI-supported assessment. The AI system provided real-time visual feedback of joint angles and alignment through MediaPipe skeletal tracking. Results: Criterion validity showed strong agreement between traditional expert assessment and AI-supported assessment (r=0.94, P<.05). Inter-rater reliability improved from good (ICC=0.89) to excellent (ICC=0.91) with AI support. The novice evaluator achieved immediate expert-level performance with only 0.05 points difference from experts. Intra-rater reliability was excellent for all evaluators (ICC=0.84-0.89). Conclusion: The AI-based system demonstrated strong validity and improved reliability for fundamental movement assessment. While AI support enabled novice evaluators to achieve expert-level performance immediately, it may increase sensitivity to subtle movement variations. This technology shows promise for standardizing movement screening, though current limitations restrict its application to standing movements.

Magnetic nanoparticles in nanofluid have a unique ability in that they can be influenced by an external magnetic field, making them a promising heat-exchanging fluid to meet the demands of highly efficient thermal systems. The parametric impact of the magnetic field (static and time-varying) on the heat exchanging rate of Fe3O4 nanoparticles and water-based ferrofluid was investigated in this study. The experimental setup for generating a variable frequency magnetic field and analyzing the thermal behavior of ferrofluid is presented. Temperature data was obtained as heat is transferred from heated water to the ferrofluid used as a coolant. An enhancement of the heat transfer of the magnetic nanofluid was observed when varying the magnetic field frequency, through experimental analysis. The concentration of Fe3O4 nanoparticles in the ferrofluid was varied (0.5 wt%, 1 wt%)to study the impact of nanoparticle loading on heat transfer. An alternative approach for controlling the heat exchange rate in thermal systems is proposed, utilizing the magnetic tunability of the ferrofluid.

Spirodela polyrhiza (L.) has been known as greater duckweed or great duckmeat. It is native inhabited in Korea. It is considered as a rich source of primary metabolites including protein, carbohydrates, and fats. Thus, it is considered as an alternative food source for the future. In addition, it has a strong phytoremediation capacity to remove various environmental pollutants, especially inorganic elements and pesticides. With a variety of duckweed’s application, there is an urgent need to develop a cultivation method for a sustainable supply of S. polyrhiza. In this study, an indoor vertical farm has been introduced to optimize duckweed cultivation. Indoor cultivated S. polyrhiza showed about 2-fold higher fresh weight than outdoor cultivated duckweed. Contents of inorganic elements were also significantly reduced in indoor cultivated S. polyrhiza. Especially, lead (Pb), cadmium (Cd), and arsenic (As) were approximately 10-fold decreased in indoor cultivated duckweed. On the other hand, contents of proteins and fats were significantly increased in indoor cultivated S. polyrhiza, while carbohydrates were found more in outdoor cultivated S. polyrhiza. Increasing N content in a homemade nutrition solution also enhanced fresh and dried weights of S. polyrhiza by about 1.8-fold in comparison with other commercial nutrition solutions. Proliferation rate (%) was doubled every 24 hours in this indoor vertical farm, indicating the accomplishment of a sustainable supply for S. polyrhiza. Further studies need to be undertaken to cultivate other duckweeds such as Wolffia arrhiza and Lemna minor using the same indoor farming system.

Nitrogen fertilizers are generally known to be of great help in improving crop yields, but excessive nitrogen fertilizer usage can not only destroy the environment but also negatively affect crop growth. This study aims to develop a decision-making system for optimal nitrogen fertilizer use for efficient production of Chinese cabbage (Brassica rapa), one of the major vegetables. The proposed system has the functions of detecting farmland based on satellite images, predicting cabbage yields and greenhouse gas (e.g., nitrous oxide) emissions according to nitrogen fertilizer use, and making decisions using the prediction results. To develop the proposed system, a generalized prediction model is developed using experimental data collected from South Korea, Egypt, India, Canada, Lithuania, and China, and the effectiveness of the proposed system is validated through experiments. As a result, the proposed system will enable farmers to conduct eco-friendly agricultural activities through appropriate nitrogen fertilizer use while stably maximizing productivity of Chinese cabbages.

본 연구는 암환자를 대상으로 한 원예치료 프로그램이 자율 신경계 활동에 미치는 영향을 분석하고자 하였다. 연구 대상은 항암화학요법, 방사선치료, 호르몬 치료 등의 보조 치료를 완료 한 20대부터 60대까지의 15명의 여성으로 구성되었다. 원예치 료 프로그램은 테라리움 제작과 계절을 주제로 한 꽃꽂이 활동 의 두 차례 세션으로 구성되었다. 자율신경계 지표로는 교감신 경 활성(LF), 부교감신경 활성(HF), 자율신경균형도(LF/HF), 평균 맥박수, 맥박 표준편차(SDNN)를 프로그램 실시 전과 후에 의료용 측정장비를 통해 측정하였다. 그 결과, HF는 모든 연령 층에서 증가하는 경향을 보였으며 특히 60대에서 유의미한 증 가가 나타나 부교감신경계 활성이 증가하는 것을 확인하였다. LF는 모든 연령대에서 큰 변화 없이 안정적인 수치를 보였다. LF/HF 비율은 전 연령대에서 감소하였으며, 이는 자율신경 균 형 상태의 긍정적인 효과를 의미한다. 또한 평균 맥박수는 프로 그램 후에 전반적으로 감소하였으며, 특히 고령층에서 유의미한 감소가 나타났다. 이러한 결과는 원예치료 프로그램이 암환자의 생리적 스트레스를 완화하고 자율신경계 균형 회복에 긍정적인 영향을 미칠 수 있음을 보여준다. 본 연구는 자율신경계 활동의 생리적 지표를 활용하여 원예치료의 효과를 객관적으로 입증하 고자 하였다는 점에서 의의가 있다.

2008년부터 해양환경관리법에 의해 시행되어 온 해역이용협의 및 해역이용영향평가제도가 분법되어 2025년 해양이용영향평 가법으로 시행되었다. 해양이용협의와 해양이용영향평가의 일부 대상사업에 대하여 변경되었으며, 그 중에서 일반해양이용협의 대상사 업인 해수 인·배수 사업의 특정 규모(관 지름 400 mm 이상이고, 관 길이가 150 m 이상이고, 관의 점용면적이 3,000 m2 이상)와 공유수면 을 점·사용하는 부선 설치 사업(무동력장치, 60일 이내)을 간이해양이용협의 대상으로 지정하여 기존 적용 범위를 완화하였다. 그럼에도 불구하고, 간이해양이용협의서의 작성방식, 작성자의 전문성 결여, 현황파악을 위한 해양환경자료의 부실 등과 같은 문제점이 여전히 남 아있다. 따라서, 본 논문에서는 해양이용영향평가법의 적용을 받는 과거 간이해역이용협의 대상사업의 유형을 파악하고, 간이해양이용 협의서 작성 시 문제점 분석과 함께, 개선방안을 제시하고자 하였다.

Environmental DNA (eDNA) has emerged as a promising tool for aquatic biodiversity monitoring, yet its collection in lentic ecosystems remains technically constrained by filtration capacity and field logistics. In this study, we applied a novel eDNA concentration system, QuickConcTM, to evaluate freshwater mussel diversity in lakes, and compared its performance with the conventional GF/F filtration method. Water samples were collected from four reservoirs at surface, mid, bottom, and waterside layers, and processed using both filtration techniques. Metabarcoding of mitochondrial 16S rDNA revealed that QuickConcTM captured a higher average number of amplicon sequence variants (ASVs) and exhibited greater species richness and diversity indices (Shannon and Simpson), although the differences were not statistically significant. QuickConcTM samples showed a greater capacity to detect rare taxa and to recover higher ASV richness in certain cases, suggesting its potential to enhance biodiversity resolution. Species composition remained consistent across methods, with Cristaria plicata and Sinanodonta lauta being dominant in both cases. However, slight spatial variations in species assemblages were observed between center and waterside sampling points, highlighting the influence of habitat heterogeneity on eDNA distribution. Overall, our results demonstrate that the QuickConcTM system offers a practical and efficient alternative to traditional filtration methods for eDNA-based freshwater mussel monitoring, particularly in environments with high suspended solids. The findings underline the need for adaptive sampling strategies that consider both methodological and ecological factors when designing eDNA surveys in lentic ecosystems.