• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.7
• /
• pp.1059-1066
• /
• 2021

In Korea, the importance of marine activities is great, and automatic weather observation facilities are operating on land to investigate abnormal weather phenomena caused by industrialization; however, the number of facilities at sea is insufficient. Marine survey ships are operated to establish marine safety information, but there are many places where marine survey ships are difficult to access and operating costs are high. Therefore, a small, unmanned vessel capable of marine surveys must be developed. The sail has a significant impact on the sailing performance, so much research has been conducted. In this study, the camber effect, which is a design variable of the twin curvy sail known to have higher aerodynamic performance than existing airfoil shapes, was investigated. Flow analysis results for five cases with different camber sizes show that the lift coefficient is highest when the camber size is 9%. Curvy twin sails had the highest lift coefficient at an angle of attack of 23° because of the interaction of the port and starboard sails. The port sail had the highest lift coef icient at an angle of attack of 20°, and the starboard sail had the lowest lift coef icient at an angle of attack of 15°. In addition, the curvy twin sail had a higher lift coefficient than NACA 0018 at all angles of attack.

• Journal of the Korean Geosynthetics Society
• /
• v.21 no.2
• /
• pp.31-38
• /
• 2022

Recently, irregular torrential rainfall have frequently occurred due to abnormal climate, and landslide damage is increasing. In Korea, more than 70% of the total land is mountainous areas, appropriate measures are needed to prevent landslides by heavy rainfall. When improved soil is applied to the surface of the slope, it is possible to suppress an increase in groundwater level due to rainfall penetration and secure stability of the slope. In this study, the appropriate depth of improved soil that can confirm the increase in groundwater level and secure stability by applying improved soil to the weathered soil slope was studied. A total of three cases were analyzed for the slope of the cross-section: standard slope for weathered soil (1:1.5, 1:1.8, and 1:2.0). For rainfall conditions, referring to the regional frequency probability rainfall provided by the Water resource Management Information System, the increase in groundwater level by stage was confirmed by assuming a 500-year frequency precipitation maximum duration of 48 hours. As a result of the study, in the case of natural slopes, the slope was completely saturated before 48 hours the rainfall duration, and there was a possibility of collapse. the improvement depth in the slope of 1:1.5 was appropriate for more than 1m from the surface regardless of the rainfall duration, and in the the slope of 1:1.8 was appropriate of 1m for more than 36 hours. in the slope of 1:2.0, it was appropriate for that safety when improved soil of 0.5m for rainfall duration 48 hours or more.

• Korean Journal of Plant Resources
• /
• v.36 no.2
• /
• pp.133-171
• /
• 2023

This study was conducted to prepare basic data by analyzing the biological values and environmental factors of algific talus slope in order to respond to climate change due to the greenhouse effect, and to establish plans for forest biodiversity preserving and managing. Meteorological information was measured and the flora of vascular plants were investigated for six algific talus slope by seasonally from 2020 to 2021. As a result of the investigation, the temperature of all 6 algific talus slope was lower than that of the area where the algific talus slope was located in summer, and flora was 101 families, 350 genera, 621 species, 18 subspecies, 57 variants, 7 varieties, 703 taxa. In sum, it is judged that the algific talus slope has sufficient reasons and value to be preserved because it has excellent micrometeorological value from the cold wind blowing in summer and phytogeographical value in which various plants live in a small area. However, in spite of such an important area, the management of algific talus slope is insufficient, and the algific talus slope is damaged or the ecosystem of the algific talus slope is disturbed. Therefore, it is necessary to establish a systematic conservation and management plan by designating algific talus slope as a forest genetic resource reserve and OECM.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.13-13
• /
• 2023

디지털 기술은 오늘날 플랫폼과 디지털 트윈의 기술도입을 통해 현실 세계를 네트워크와 가상세계와의 연결이 통합되어진 가상 현실 세계의 입문 도약이다. 현실에서 가상현실의 사이의 디지털 전환(digital transformation)에는 디지털 기술과 솔루션을 비즈니스의 모든 영역에 통합하는 것이 포함된다. 이러한 디지털 전환의 핵심은 데이터에 관한 것이며, 데이터를 활용하여 가치를 창출하고 고객경험과 비즈니스 영역을 극대화하는 방식을 제공한다. 최적의 데이터를 제공하기 위한 플랫폼과 가상 현실세계 구현을 위한 디지털 트윈의 상호연계 관한 기본 개념은 데이터 수집, 데이터 분석, 데이터 시각화 및 데이터 보고와 같은 데이터 비즈니스이다. 현장 데이터는 디지털 양식을 통해 수집, 기록, 저장된다. 현장 IoT 기반 데이터(사진 및 비디오 매체 등)는 지속적으로 수집되고 종종 다른 데이터베이스에 저장되지만 지리 공간적 위치에 연결되지 않는다. 모든 디지털 발전을 조화시키고 지하수 데이터에서 더 빠른 이해를 도출하기 위해서는 디지털 트윈이 시작되어야 한다. 단일 지하수플랫폼에서 현장 조건을 시각화하고 실시간 데이터를 스트리밍하며, 과거 3D 데이터와 상호작용하여지질 또는 지화학 데이터를 선택적 사용을 위해 지하수 플랫폼과 디지털 트윈이 연계되어야 한다. 데이터를 디지털 정보모델과 연결하면 디지털 트윈에 생명을 불어넣을 수 있지만 디지털 트윈의 가치를 극대화하려면 여전히 데이터 플랫폼 서비스와 전달 방식을 선택해야 한다. 지하수 플랫폼동시성을 갖는 디지털 트윈은 정적 및 동적 데이터를 저장하는 데이터베이스 또는 크라우드 서비스에서 데이터를 가져오는 API(애플리케이션 프로그래밍 인터레이스), 디지털 트윈을 위한 호스팅 공간, 디지털 대상을 구축하는 소프트웨어, 구성 요소 간 읽기/쓰기를 위한 스크립트, chatGPT 및 API를 활용할 수 있다. 이를 통해 수집된 데이터의 실시간 양방향 통신기술인 지하수 플랫폼 기술을 활용하여 디지털 트윈을 적용하고 완성할 수 있고, 이를 지하수 분야에도 그대로 적용할 수 있다. 지하수 분야의 디지털 트윈 기술의 근간은 지하수 모니터링을 위한 관측장치와 이를 활용한 지하수 플랫폼의 구축 및 양방향 자료전송을 통한 분석 및 예측기술이다. 특히 낙동강과 같이 유역면적이 넓고 유역 내 지자체가 많아 이해관계가 다양하며, 가뭄과 홍수/태풍 등 기후위기에 따른 극한 기상이변가 자주 발생하고, 또한 보 및 하굿둑 개방 등 정부정책 이행에 따른 민원이 다수 발생하는 지역의 경우 하천과 유역에 대한 지하수 플랫폼과 디지털 트윈의 동시성 기술적용 시 지하수 데이터에 대한 고려가 반드시 수반되어야 한다.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.59 no.3
• /
• pp.206-214
• /
• 2023

Fish school monitoring technology is utilized for various purposes, such as boat fishing and resource surveys. With advancements in information and communication technology, this technology has expanded its application to remote areas. Its significance has grown in fishing sites, particularly for improving the efficiency and cost-effectiveness of set-net fishing. Set-net fishing gears are not limited to coastal areas, but are also installed in inland and remote sea regions. Consequently, fishermen require technology that allows them to quickly transmit information about approaching fish schools and enables them to perform long-term monitoring. The development of remote monitoring technology for set-net fish schools must consider crucial design factors such as communication range, transmission speed, power consumption of information modules, and operational expenses. In this study, we developed a low-power remote monitoring module for set-net fish school based on WCDMA. The module was specifically designed to minimize power consumption, allowing for communication over long distances and extended operation times in set-net fishing applications. Furthermore, we developed a web server software application that enables remote access to fish schools and provides real-time weather information. The performance of the developed module was evaluated through set-net fishing site application and experiments with moving ships on the sea. The experimental results demonstrated that the remote monitoring system, consisting of the developed low-power remote monitoring module for set-net fish school based on WCDMA and a fish finder, had an average power consumption of 4.6 W, a maximum communication range of 22.84 km, and a data transmission and reception rate of 98.79%. The maximum fish school information transmission and reception rate was 97.26%

• Journal of Broadcast Engineering
• /
• v.28 no.3
• /
• pp.285-292
• /
• 2023

Recently, the impact of fine dust on health has become a major topic. Fine dust is dangerous because it can penetrate the body and affect the respiratory system, without being filtered out by the mucous membrane in the nose. Since fine dust is directly related to the industry, it is practically impossible to completely remove it. Therefore, if the concentration of fine dust can be predicted in advance, pre-emptive measures can be taken to minimize its impact on the human body. Fine dust can travel over 600km in a day, so it not only affects neighboring areas, but also distant regions. In this paper, wind direction and speed data and a time series prediction model were used to predict the concentration of fine dust in Seoul, and the correlation between the concentration of fine dust in Seoul and the concentration in each region was confirmed. In addition, predictions were made using the concentration of fine dust in each region and in Seoul. The lowest MAE (mean absolute error) in the prediction results was 12.13, which was about 15.17% better than the MAE of 14.3 presented in previous studies.

• Journal of Korea Water Resources Association
• /
• v.56 no.6
• /
• pp.381-392
• /
• 2023

Precipitation, runoff, and evapotranspiration are changing worldwide due to climate change and human activities. Because watershed runoff is an important component of the hydrological cycle, it is important to investigate the changes in watershed runoff for water resources management. This study collected observed data of runoff, precipitation, temperature, and evapotranspiration in the Geum River basin as well as their synthetic data according to Representative Concentration Pathways (RCP) scenarios, investigated the trend of hydro-meteorological variables using the Mann-Kendall test, and quantitatively evaluated the effects of climate change and human activities on the watershed runoff using the climate elasticity approach and the Budyko framework. The results indicated that the relative contribution of climate change and human activity to changes in runoff varies from region to region. For example, the watershed with the greatest contribution from climate change and human activity were the Yongdam Dam (#3001) basin and the Daecheong Dam (#3008) basin, respectively. Future climate change showed an increase in precipitation and temperature in both RCP 4.5 and 8.5 scenarios, resulting in changes in runoff in the Geum River basin from 44.8% to 65.5%, respectively. We concluded that the effect on watershed runoff can be separated into climate change and human activities, which will be important information in establishing sustainable water resource management plans.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.1
• /
• pp.60-66
• /
• 2023

Currently, the maritime industry is focusing on developing technologies that promote autonomy and intelligence, such as smart ships, autonomous ships, and eco-friendly technologies, to enhance ship operational efficiency. Many countries are conducting research on different methods to ensure ship safety while increasing operational efficiency. This study aims to develop a real-time ship operational efficiency analysis model using data analysis methods to address the current limitations of the present technologies in the real-time evaluation of operational efficiency. The model selected ship operational efficiency factors and ship operational condition factors to compare the operational efficiency of the ship with present and classified factors to determine whether the present ship operational efficiency is appropriate. The study involved selecting a target ship, collecting data, preprocessing data, and developing classification models. The results of the research were obtained by determining the improved ship operational efficiency based on the ship operational condition factors to support ship operators.

• Journal of Life Science
• /
• v.33 no.7
• /
• pp.574-585
• /
• 2023

Sarcopenia is a leading cause of increased medical and nursing care costs among the elderly. In Korea, preventive measures for sarcopenia are mostly targeted toward the general elderly population without specific diseases. However, it is also necessary to implement measures for elderly individuals living in nursing homes and hospitals, where the prevalence of sarcopenia is high. Currently, computed tomography and/or magnetic resonance imaging are considered standard diagnostic tools. However, their complexity and time-consuming nature make them unsuitable for clinical use. The exact pathophysiological mechanisms of sarcopenia are unclear, as they involve various molecular biological pathways, including decreased exercise, protein and nutrient intake, changes in testosterone and growth hormone, and inflammation. Sarcopenia symptoms can lead to several diseases, such as osteoporosis, fractures, dementia, diabetes, and cardiovascular disease. Vitamin B deficiency is a significant factor in sarcopenia induction, with B vitamins being directly involved in energy and protein metabolism and nerve function. Vitamin B deficiency can lead to neuromuscular and neurogenic disorders, which often overlap with sarcopenia. Suboptimal intake of B vitamins, malabsorption, and anorexia are common among the elderly. This study aims to provide information on the role of water-soluble B vitamins in preventing and controlling muscle mass loss and deterioration among the elderly with sarcopenia. In addition, we discuss the potential of myokines from the B vitamin family in modulating sarcopenia.

• Journal of Navigation and Port Research
• /
• v.47 no.3
• /
• pp.128-133
• /
• 2023

In order for Aids to Navigation to provide sustainable services to users, it is possible when there is no Aids to Navigation accident. If an Aids to Navigation accident occurs, the manager should efficiently manage it to prevent the same accident. However, the current Aids to Navigation accident management only specifies the cause and type of the accident. There are no separate guidelines. Thus, the accident is recorded differently depending on the manager. Therefore, this study attempted to redefine Aids to Navigation accident. To this end, Aids to Navigation accidents that have occurred over the past 23 years (year 2000 to years 2022), IALA's Aids to Navigation information standard, S-201, and categories of accidents (traffic accidents and marine accidents) were analyzed. Causes of Aids to Navigation accidents were divided into internal and external causes. Accidents were divided into three types: Light tower accident, buoy accident, and equipment accident. By further subdividing primary items, the cause of accident was reestablished into 7 items such as mooring and bad weather and 11 items such as Light tower damage, buoy loss, and equipment breakdown. These research results can be used as basic data to provide future Aids to Navigation accident statistics.