• Title/Summary/Keyword: maritime data

Search Result 2,397, Processing Time 0.027 seconds

Variation in Planktonic Assemblages in Asan Bay During the Winter-Spring Bloom (아산만 해역 동-춘계 대증식기의 플랑크톤 변화)

  • Park, Chul;Lee, Doo-Byoul;Lee, Chang-Rae;Yang, Sung-Ryull;Jung, Byoung-Gwan
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.13 no.4
    • /
    • pp.308-319
    • /
    • 2008
  • Temporal variations in plankton assemblages and environmental factors in Asan Bay and their relationships were examined with the data collected from February till early June, 2005. Seawater temperatures showed typical pattern of temporal change observed in temperate waters. Salinity variation was minor. Phytoplankton biomass showed two peaks, one in February only in the inner part of the bay and the other in May in the whole bay. Phytoplankton succession was clearly shown with the increase of seawater temperatures. Diatom (Bacillariophyceae) dominated in February, diatom and cryptomonads (Cryptophyceae) prevailed in May, and dinoflagellates (Dinophyceae) was most abundant in June. Spring bloom in Asan Bay occurred about one month earlier than those observed in temperate seas. Among the inorganic nutrients (N, P and Si), only silicate concentration showed a significant negative correlation with phytoplankton biomass, indicating the sink of this nutrient in the bay to be the uptake by phytoplankton. Nitrate concentration seemed to be a limiting factor in this bay during the study period. Mesozooplankton abundances showed a significant positive correlation with seawater temperatures and a significant negative correlation with phytoplankton biomass. Increase of mesozooplankton abundance followed phytoplankton increase with the time lag of about two months. This increase of zooplankton seemed to be the result of increased seawater temperatures and food.

The Effect of Participation in Survival Swimming Education on Underwater Anxiety and Water Safety Awareness of University Students (생존수영교육 참여가 대학생의 수중불안과 수상안전 의식에 미치는 영향)

  • Myung-Chul Lee;Kyung-Hun Han
    • Journal of the Korean Applied Science and Technology
    • /
    • v.40 no.6
    • /
    • pp.1201-1212
    • /
    • 2023
  • This study aimed to analyze the changes in underwater anxiety and water safety consciousness among college students through participation in survival swimming education and the relationship between these changes and various factors. To achieve this, 200 college students who were participating in survival swimming education from universities located in the Busan-Ulsan-Gyeongnam region were selected as participants using convenience sampling. Among them, a final valid sample of 191 students was utilized. Data analysis was conducted using SPSS 25.0 statistical software, including exploratory factor analysis, reliability analysis, paired sample t-test, repeated measures ANOVA. The results are as follows: Firstly, college students who participated in survival swimming education showed a decrease in post-test underwater anxiety and an increase in water safety consciousness compared to pre-test. Secondly, the interaction between the groups based on the presence or absence of swimming education experience and time showed a significant effect only in the safety education, a sub-factor of water safety consciousness. Based on these results, the effectiveness of survival swimming education for college students could be confirmed, and further directions for expanding survival swimming education in university settings could be considered.

Valuing Cultural Ecosystem Services of Coastal Beaches in Korea (연안 생태계문화서비스 경제적 가치 추정 - 전국 해수욕장을 대상으로 -)

  • Chi-Ok Oh;Miju Kim;Namhee Kim
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.30 no.1
    • /
    • pp.43-57
    • /
    • 2024
  • As coastal areas have a distinct nature with the interaction of the lands and waters, they attract people to enjoy and experience the natural environments physically and intellectually; this generates cultural ecosystem services. Coastal beaches are one of the most common coastal areas for cultural ecosystem services. The purpose of this study was to 1) estimate the economic values of cultural ecosystem services derived from coastal beaches, and 2) expand the estimated values into other beaches across the country using a benefit transfer method. We divided the values of cultural ecosystem services into five different categories based on an extensive literature review: recreation and tourism, landscape and aesthetic, educational, heritage, and inspirational values. The values of tourism and recreation, landscape and aesthetic, and educational services were estimated using the choice experiments. The attributes of the choice experiments consisted of conservation funds, litter, water quality, seascape, landscape, and biodiversity, and the data were collected through online surveys with visitors of 11 representative beaches in Korea. Heritage and inspiration services were estimated using a market goods method based on their expenditures. These values were transferred to 257 beaches across the country. Study results can be used for policy decisions on various restoration and conservation projects caused by coastal erosion and development and on the need and extent of public investments.

A Dynamic Panel Approach to Examining the Effects of Local Fiscal Expenditures on Water Quality (동태적 패널접근을 활용한 지방 재정지출의 수질개선 효과분석)

  • Hyonyong Kang;Dong Hee Suh
    • Environmental and Resource Economics Review
    • /
    • v.33 no.2
    • /
    • pp.159-178
    • /
    • 2024
  • This study aims to assess the direct and indirect impacts of local fiscal expenditures on water quality. Panel data spanning from 2010 to 2018 for 173 cities and districts in Korea are assembled, and a two-stage dynamic panel model is utilized for our estimation. The empirical findings reveal several key insights. Firstly, local fiscal expenditures on water quality are effective in ameliorating both Biological Oxygen Demand (BOD) and Total Phosphorus (T-P). Notably, the direct impact on T-P surpasses that on BOD in the short and long run. Secondly, expenditures dedicated to water quality improvement demonstrate a positive effect on local economic growth, and an inverted U-shaped relationship is observed between BOD and local economic growth. Due to the positive linkage, the indirect effect on BOD suggests, on average, a deterioration in water quality during local economic growth. Thirdly, concerning BOD, the direct effect of government expenditure on water quality improvement outweighs the indirect effect, but in the case of T-P, the indirect effect is not significant, and the total effect is solely determined by the direct impact. Despite local fiscal expenditures potentially exacerbating water quality through regional economic growth, the study finds that the direct enhancement of water quality remains a more substantial factor in the short and long run.

Evaluation of Maneuverability of Small Fishing Vessels Based on CFD Simulation under Standard Loading Condition (CFD 시뮬레이션 기반 소형 어선의 표준재화상태에 따른 조종성능 평가)

  • Sun woo Lee;Sang hyun Kim;Hye woo Kim;Hyung seok Yoon;Chang woo Song;Joo hyung Oh
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.30 no.4
    • /
    • pp.348-357
    • /
    • 2024
  • Maneuvering performance is crucial for fishing vessels, especially under operational conditions that involve frequent course changes and weight variations due to catch. Small vessel accidents account for approximately 60% of maritime incidents as of 2022, mainly attributed to collisions and stranding accidents due to insufficient maneuvering performance. Especially, accidents that occur on small vessels less than 10 tons account for about 65% of all accidents. The absence of international standards presents challenges in accurately evaluating the maneuvering performance of small vessels. In this study, a 4.99-ton small fishing vessel was selected as the target, and a 3d-cad model was created. The commercial numerical analysis program STAR-CCM+ was employed to establish a simulation environment for the vessel's maneuvring motion. Based on this standard loading conditions and weight distribution were considered, 10° / 10°, 20° / 20° zigzag tests and 35° turning test were conducted. The results revealed a tendency for decreased yaw and course-keeping performance and improved turning performance as the hull weight increased. However, in partial arrival and full load departure condition, the manoeuvering performance were relatively poor. Based on this, the need for evaluation of maneuvering and standardized criteria of maneuvering performance for safe navigation of small vessels is presented. Furthermore, it is expected that the evaluation results of maneuvering performance in this study can serve as fundamental data for establishing criteria for evaluating the maneuvering performance of small vessels.

Analysis of the Educational need of Vessel First Aid Managers for Improvement of Marine Telemedicine Service (해양 원격의료 지원 개선을 위한 응급처치 담당자의 교육요구도 분석)

  • Bo-Hwi Seo;Dae-Sik Ko
    • Journal of the Health Care and Life Science
    • /
    • v.11 no.1
    • /
    • pp.87-96
    • /
    • 2023
  • This descriptive research study aims to identify the importance and satisfaction of new advanced safety education and marine telemedicine service, and to identify the priority of educational needs for trainees who have received advanced safety reeducation. Data from 190 trainees who conducted advanced safety retraining at the MarineCom were used for the study. As a result of the study, the vital sign measurement method was selected as the top priority for the new advanced safety education, and the nervous system, circulatory system, and surgical system were selected as the top priority for the educational need by type of marine telemedicine guidance. These results suggest that there was a high demand for education on vital sign measurement methods in order to determine the appropriate first aid by grasping the overall condition of the patient in the event of an emergency. Working and monotonous daily life acted as a cause of mental and physical stress, so the incidence of patients in the nervous system, circulatory system, and surgical system was high, and compared to other systems, it was judged that the demand for education was high because the patient was related to life.

Effects of the teacher characteristics on self-directed learning mediated by students' class attitude and class satisfaction in mathematics (수학 교과에서 교사특성이 수업태도와 수업만족도를 매개로 고등학생의 자기주도학습에 미치는 영향)

  • Hyesung Park;Sungyeun Kim
    • The Mathematical Education
    • /
    • v.63 no.3
    • /
    • pp.437-450
    • /
    • 2024
  • Self-directed learning in mathematics education is crucial because it enables students to think creatively and critically while continuously improving. The purpose of this study was to examine the mediating effects of class attitude and class satisfaction in mathematics on the relationship between mathematics teacher characteristics and self-directed learning. Furthermore, the study aimed to determine whether these structural relationships differ between male and female student groups. To achieve this, the theoretical model was tested using the 9th-year data (high school 3rd grade) of the Seoul Education Longitudinal Study (SELS) 2010, comprising 2,325 students (1,187 males and 1,138 females). The results revealed that the mediating effects of mathematics class attitude and class satisfaction on the relationship between teacher characteristics in mathematics and high school students' self-directed learning were significant. At this time, the direct effect of mathematics teacher characteristics on selfdirected learning was not significant, indicating that mathematics class attitude and class satisfaction had full mediating effects. Multi-group analysis results showed no significant differences in path coefficients between male and female student groups. Based on the research findings, implications for teacher education were presented to improve high school students' self-directed learning abilities in mathematics education, focusing on the mediating effects of affective factors in the classroom.

Factors Influencing Chinese Coastal Shippers' Carrier Selection Amid the U.S.-China Trade Conflict and the COVID-19 Pandemic (미·중 무역 갈등과 팬데믹 상황에서 중국 연안 화주의 컨테이너 선사 선정 요인 분석)

  • Zhu, Xinyuan;Park, Byungin
    • Journal of Korea Port Economic Association
    • /
    • v.40 no.3
    • /
    • pp.187-210
    • /
    • 2024
  • This study examines the factors influencing container shipping carrier selection among coastal shippers in China amid the pressing external challenges posed by the U.S.-China trade conflict and the COVID-19 pandemic, during a period when China is implementing policies to open its maritime market. Using Partial Least Squares Structural Equation Modeling (PLS-SEM) to analyze survey data, the research identifies multi-modal transportation services, carrier operational capabilities, and logistics risk management as key determinants. Notably, salesperson professionalism, cargo safety, and fleet stability during peak periods emerged as critical factors for shippers. The disruptions caused by the trade conflict and the pandemic have heightened shippers' focus on risk management and transportation reliability, further emphasizing the importance of carrier service quality and operational capabilities. This study underscores the need for carriers to strengthen their risk management capacities and enhance service quality in response to shifting global conditions. Additionally, the findings suggest that policymakers should consider regulatory adjustments to mitigate uncertainties in the shipping industry. Future research should delve deeper into the long-term impacts of external shocks on carrier selection decisions.

Korean Ocean Forecasting System: Present and Future (한국의 해양예측, 오늘과 내일)

  • Kim, Young Ho;Choi, Byoung-Ju;Lee, Jun-Soo;Byun, Do-Seong;Kang, Kiryong;Kim, Young-Gyu;Cho, Yang-Ki
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.18 no.2
    • /
    • pp.89-103
    • /
    • 2013
  • National demands for the ocean forecasting system have been increased to support economic activity and national safety including search and rescue, maritime defense, fisheries, port management, leisure activities and marine transportation. Further, the ocean forecasting has been regarded as one of the key components to improve the weather and climate forecasting. Due to the national demands as well as improvement of the technology, the ocean forecasting systems have been established among advanced countries since late 1990. Global Ocean Data Assimilation Experiment (GODAE) significantly contributed to the achievement and world-wide spreading of ocean forecasting systems. Four stages of GODAE were summarized. Goal, vision, development history and research on ocean forecasting system of the advanced countries such as USA, France, UK, Italy, Norway, Australia, Japan, China, who operationally use the systems, were examined and compared. Strategies of the successfully established ocean forecasting systems can be summarized as follows: First, concentration of the national ability is required to establish successful operational ocean forecasting system. Second, newly developed technologies were shared with other countries and they achieved mutual and cooperative development through the international program. Third, each participating organization has devoted to its own task according to its role. In Korean society, demands on the ocean forecasting system have been also extended. Present status on development of the ocean forecasting system and long-term plan of KMA (Korea Meteorological Administration), KHOA (Korea Hydrographic and Oceanographic Administration), NFRDI (National Fisheries Research & Development Institute), ADD (Agency for Defense Development) were surveyed. From the history of the pre-established systems in other countries, the cooperation among the relevant Korean organizations is essential to establish the accurate and successful ocean forecasting system, and they can form a consortium. Through the cooperation, we can (1) set up high-quality ocean forecasting models and systems, (2) efficiently invest and distribute financial resources without duplicate investment, (3) overcome lack of manpower for the development. At present stage, it is strongly requested to concentrate national resources on developing a large-scale operational Korea Ocean Forecasting System which can produce open boundary and initial conditions for local ocean and climate forecasting models. Once the system is established, each organization can modify the system for its own specialized purpose. In addition, we can contribute to the international ocean prediction community.

A Study on Prioritization of HNS Management in Korean Waters (해상 위험·유해물질(HNS) 관리 우선순위 선정에 관한 연구)

  • Kim, Young Ryun;Kim, Tae Won;Son, Min Ho;Oh, Sangwoo;Lee, Moonjin
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.21 no.6
    • /
    • pp.672-678
    • /
    • 2015
  • The types of hazardous and noxious substances (HNS) being transported by sea in Korea are at about 6,000, HNS transport volume accounts for 19% of total tonnage shipped in Korea, and the increase rate of seaborne HNS trade in Korea is 2.5 times higher than the average increase rate of the world seaborne HNS trade. Reflecting this trend, HNS spill incidents have been frequently reported in Korean waters, and there are increasing social demands to develop HNS management technology for the preparedness, response, post-treatment and restoration in relation to HNS spill incidents at sea. In this study, a risk-based HNS prioritization system was developed and an HNS risk database was built with evaluation indices such as sea transport volume, physicochemical properties, toxicities, persistency, and bioaccumulation. Risk scores for human health and marine environments were calculated by multiplying scores for toxicity and exposure. The top-20 substances in the list of HNS were tabulated, and Aniline was ranked first place, but it needs to be managed not by individuals but by HNS groups with similar score levels. Limitations were identified in obtaining data of chronic toxicity and marine ecotoxicity due to lack of testing data. It is necessary to study on marine ecotoxicological test in the near future. Moreover, the priority list of HNS is expected to be utilized in the development of HNS management technology and the relevant technologies, after the expert's review process and making up for the lack of test data in the current research results.