• Fisheries and Aquatic Sciences
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• 제26권4호
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• pp.268-281
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• 2023

Coral reef fisheries are prominent for the archipelagic countries' food sufficiency and security. Studies showed that fish abundance and biomass are affected by biophysical variables. The present study determines which biophysical variables are important predictors of fish diversity, abundance, and biomass. The study used available monitoring data from the Indonesian Research Center for Oceanography, the National Board for Research and Innovation. Data were collected from 245 transects in 19 locations distributed across the Indonesian Archipelago, including the eastern Indian Ocean, Sunda Shelf (Karimata Sea), Wallacea (Flores and Banda Seas), and the western Pacific Ocean. Principal component analysis and multiple regression model were administered to 13 biophysical metrics against 11 variables of coral reef fishes, i.e., diversity, abundance, and biomass of coral reef fishes at three trophic levels. The results showed for the first time that the covers of other fauna, coral rubbles, and soft corals were the three most important predictor variables for nearly all coral reef fish variables. Other fauna cover was the important predictor for all 11 coral reef fish variables. Coral rubble cover was the predictor for ten variables, but carnivore fish abundance. Soft coral cover was a good predictor for corallivore, carnivore, and targeted fishes. Despite important predictors for corallivore and carnivore fish variables, hard coral cover was not the critical predictor for herbivore fish variables. The other important predictor variables with a consistent pattern were dead coral covered with algae and rocks. Dead coral covered with algae was an important predictor for herbivore fishes, while the rock was good for only carnivore fishes.

• Ocean and Polar Research
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• 제45권2호
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• pp.71-87
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• 2023

Climate change causes ocean warming, ocean acidification, sea-level rise, dynamic coastal risk, change of ecosystem structure and function, and degradation of ecosystem services. Not only that, but it has negatively impacted the well-being of people, society, and culture, including food security, water resources, water quality, livelihood, health, welfare, infrastructure, transport, tourism, recreation, and so on, especially by particularly degrading indigenous communities and generating an inequitable distribution of benefits and costs. As pointed out here, these adverse impacts of climate change on the ocean have been emphasized at the international and national levels. In contrast, the ocean field has been neglected in the climate change conversation for too long. However, since the UNFCCC COP 25, the ocean has been drawn into the discussion as a solution to address climate change. Moreover, the U.S. Congress recently unveiled a bill called the 'Ocean-Based Climate Solution Act, OBCSA' that reflects the new paradigm of the international regime. The comprehensive legislative bill includes elements related to climate inequity, a blue economy, and a community-led bottom-up policy mechanism, which will have a significant bearing on the ocean-climate legal system. Therefore, this study reviews the OBCSA and deduces implications with regard to the ocean-climate legal system in Korea.

• 한국컴퓨터정보학회논문지
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• 제14권5호
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• pp.103-117
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• 2009

최근 MANET(Mobile Ad-Hoc Network)에서 보안요소를 추가한 라우팅 연구가 활발히 진행되어왔다. 그러나 기존 연구들은 secure 라우팅 또는 패킷 자체에 대한 악의적인 행위 탐지 중 어느 한 측면에 대해서만 연구가 되어왔다. 본 논문에서는 패킷 자체에 대한 악의적인 행위 및 라우팅 측면에서 보안 요소를 모두 고려한 SRPPnT(A Secure Routing Protocol in MANET based on Malicious Pattern on Node and Trust Level)를 제안한다. SRPPnT는 악의적인 행위가 이루어진 노드를 확인하여 각 노드에 대한 신뢰수준을 측정 후, 획득한 각 노드의 신뢰수준에 따라 라우팅 경로를 설정함으로써 패킷 및 라우팅 경로 설정에 대해 이루어질 수 있는 악의적인 행위를 효율적으로 대응할 수 있다. SRPPnT는 AODV(Ad-Hoc On-Demand Distance Vector Routing)를 기반으로 하였다. NS 네트워크 시뮬레이션 결과를 통해, 제안된 SRPPnT는 기존 프로토콜보다 네트워크 부하를 감소시킨 상태에서 악의적인 노드의 보다 정확하고 신속한 식별과 secure한 라우팅이 이루어짐을 확인하였다.

• Journal of Preventive Medicine and Public Health
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• 제55권2호
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• pp.153-163
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• 2022

Objectives: This study divided the factors that affect participation in health screenings into individual, household, and regional levels and conducted a multi-level analysis to identify the factors related to participation in health screenings. Methods: Participants from the 2017 Community Health Survey were classified into 2 groups (under 40 and 40 or older). A multi-level logistic regression analysis was conducted to identify the factors that affected participation in health screenings. Results: The screening rate of the participants was 69.7%, and it was higher among participants aged 40 and older (80.3%) than it was among participants younger than 40 (49.8%). At the individual level, the factors that influenced participation in health screenings included age, economic activity, smoking status, physician-diagnosed hypertension, and a moderate or high physical activity level. At the household level, the odds ratio of participation in health screenings was high for participants who lived in single-person households, lived with a spouse, earned a high monthly household income, and were not beneficiaries of national basic livelihood security. At the regional level, the odds ratio at the 95% confidence interval level of participation in health screenings was high for participants who had trust in the local community and lived in an area with a proportionally high social welfare budget. Conclusions: This study analyzed nationalwide data and confirmed that individual, household, and regional characteristics affected participation in health screenings. Therefore, policies that prioritize the improvement of regional level factors and especially household level factors are likely to be the most effective for improving the screening rate.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권6호
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• pp.1706-1727
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• 2023

Under Water Sensor Networks (UWSN) has gained attraction among various communities for its potential applications like acoustic monitoring, 3D mapping, tsunami detection, oil spill monitoring, and target tracking. Unlike terrestrial sensor networks, it performs an acoustic mode of communication to carry out collaborative tasks. Typically, surface sink nodes are deployed for aggregating acoustic phenomena collected from the underwater sensors through the multi-hop path. In this context, UWSN is constrained by factors such as lower bandwidth, high propagation delay, and limited battery power. Also, the vulnerabilities to compromise the aquatic environment are in growing numbers. The paper proposes an Energy-Efficient standalone Intrusion Detection System (EEIDS) to entail the acoustic environment against malicious attacks and improve the network lifetime. In EEIDS, attributes such as node ID, residual energy, and depth value are verified for forwarding the data packets in a secured path and stabilizing the nodes' energy levels. Initially, for each node, three agents are modeled to perform the assigned responsibilities. For instance, ID agent verifies the node's authentication of the node, EN agent checks for the residual energy of the node, and D agent substantiates the depth value of each node. Next, the classification of normal and malevolent nodes is performed by determining the score for each node. Furthermore, the proposed system utilizes the sheep-flock heredity algorithm to validate the input attributes using the optimized probability values stored in the training dataset. This assists in finding out the best-fit motes in the UWSN. Significantly, the proposed system detects and isolates the malicious nodes with tampered credentials and nodes with lower residual energy in minimal time. The parameters such as the time taken for malicious node detection, network lifetime, energy consumption, and delivery ratio are investigated using simulation tools. Comparison results show that the proposed EEIDS outperforms the existing acoustic security systems.

• Smart Structures and Systems
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• 제31권1호
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• pp.57-68
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• 2023

Bridge hangers, such as those in suspension and cable-stayed bridges, suffer from cumulative fatigue damage caused by dynamic loads (e.g., cyclic traffic and wind loads) in their service condition. Thus, the identification of damage to hangers is important in preserving the service life of the bridge structure. This study develops a new method for condition assessment of bridge hangers. The tension force of the bridge and the damages in the element level can be identified using the Bayesian optimization method. To improve the number of observed data, the additional mass method is combined the Bayesian optimization method. Numerical studies are presented to verify the accuracy and efficiency of the proposed method. The influence of different acquisition functions, which include expected improvement (EI), probability-of-improvement (PI), lower confidence bound (LCB), and expected improvement per second (EIPC), on the identification of damage to the bridge hanger is studied. Results show that the errors identified by the EI acquisition function are smaller than those identified by the other acquisition functions. The identification of the damage to the bridge hanger with various types of boundary conditions and different levels of measurement noise are also studied. Results show that both the severity of the damage and the tension force can be identified via the proposed method, thereby verifying the robustness of the proposed method. Compared to the genetic algorithm (GA), particle swarm optimization (PSO), and nonlinear least-square method (NLS), the Bayesian optimization (BO) performs best in identifying the structural damage and tension force.

• 보건행정학회지
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• 제33권4호
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• pp.411-420
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• 2023

Background: The purpose of this study was to analyze the demand and supply status of patient beds by type of medical institution, categorized into 70 clinical privilege, in order to understand the regional bed supply situation. Methods: Utilizing the 70 clinical privilege defined by the Ministry of Health and Welfare, we calculated bed demand and supply quantities from 2019 to 2021 using data from Statistics Korea and the Health Insurance Statistical Yearbook. The bed demand calculation formula was based on the detailed guidelines for the medical sector by the Korea Development Institute and the 3rd edition of bed supply basic policies announced by the Ministry of Health and Welfare. Additionally, to mitigate distorted bed supply situations caused by factors such as regional levels and patient outflows, we classified bed supply types using the population decrease index indicator published by the Ministry of Public Administration and Security. Results: Among the 70 clinical privilege, it was analyzed that a relatively balanced bed supply situation exists overall, irrespective of the type of healthcare institution. However, in medical institutions at or above the level of hospitals, regions with bed supply ratios exceeding 20% compared to demand, particularly in institutions at or above the level of general hospitals, showed a relatively high rate of demand diversion. Conclusion: We have identified the bed supply types in the 70 clinical privilege in South Korea. Based on the results of this study, we emphasize the need for bed supply policies that consider regional characteristics. It is expected that this research can serve as fundamental data for future efforts aimed at managing or rectifying bed supply imbalances on a regional basis.

• 한국환경과학회지
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• 제33권6호
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• pp.417-425
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• 2024

This study investigated the effects of various planting models on the joint cultivation of eggplant (Solanum melongena) and marigold (Tagetes erecta)to enhance sustainable rooftop urban farming. Rooftop agriculture is increasingly valued to boost the food supply and benefit the environment. Integrating such practices into urban planning is viewed as a way to sustainably manage resources and improve the food-energy-water cycle in cities. The experiment was conducted on a rooftop in Chungju, South Korea from May to August. Four different planting setups were used: central eggplant with peripheral marigold (SET), eggplant with a protective net (SIC), central marigold with peripheral eggplant (TES), and control with only eggplant (CON S). These models tested the effects of companion planting versus monoculture using a lightweight soil mix ideal for rooftops made from cocopeat and perlite and enriched with organic fertilizer. Measurements focused on soil conditions and plant health and assessed soil temperature, moisture, conductivity, plant height, width, and leaf size. The results indicated that the SET modelyielded the best growth. This setup benefited from marigold pest control properties and its ability to improve soil conditions by enhancing moisture and nutrient levels and aiding eggplant growth. These findings underscore the potential of mixed planting on rooftops and suggest that such approaches can be effectively incorporated into urban agriculture to boost yield and environmental sustainability. This study supports the idea that diverse planting methods can significantly affect plant growth and promote urban greening and food security.

• 농업과학연구
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• 제50권4호
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• pp.713-721
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• 2023

Soil acidification challenges global food security by adversely influences soil fertility and agricultural productivity. Carbonized agricultural residues present a sustainable and ecofriendly way to recycle agricultural waste and mitigate soil acidification. We evaluated the effects of organic amendments on lettuce growth and soil chemical properties in two soils with different pH levels. Carbonized rice husk was produced at 600℃ for 30 min and rice husk was treated at 1% (w·w^-1). Carbonized rice husk increased soil pH, electrical conductivity, total carbon content, and nitrogen content compared with untreated and rice husk treatments. Furthermore, this study found that lettuce growth positively correlated with soil pH, with increasing soil pH up to pH 6.34 resulting in improved lettuce growth parameters. Statistical correlation analysis also supported the relationship between soil pH and lettuce growth parameters. The study findings showed that the use of carbonized rice husk increased the constituent elements of lettuce, such as carbon, nitrogen, and phosphate content. The potassium content of lettuce followed a similar trend; however, was higher in acidic soil than that in non-acidic soil. Therefore, improving the pH of acidic soil is essential to enhance agricultural productivity. It is considered advantageous to use agricultural residues following pyrolysis to improve soil pH and agricultural productivity.

• Animal Bioscience
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• 제37권4_spc호
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• pp.786-793
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• 2024

Latin America is a culturally, geographically, politically, and economically diverse region. Agriculture in Latin America is marked by a remarkable diversity of production systems, reflecting various agroecological zones, farm sizes, and technological levels. In the last decade, the swine industry increased by 30.6%, emerging as a great contributor to food security and economic development in Latin America. Brazil and Mexico dominate the pig production landscape, together accounting for 70% of sow inventory in the region. The swine industry in Latin America is predominantly comprised of small and medium-sized farms, however, in the past 30 years, the number of pig producers in Brazil dropped by 78%, whereas pork production increased by 326%. Similar to the global pork industry, the growing demand for pork, driven by population growth and changing dietary habits, presents an opportunity for the industry with an expected growth of 16% over the next decade. The export prospects are promising, however subject to potential disruptions from global market conditions and shifts in trade policies. Among the challenges faced by the swine industry, disease outbreaks, particularly African Swine Fever (ASF), present significant threats, necessitating enhanced biosecurity and surveillance systems. In 2023, ASF was reported to the Dominican Republic and Haiti, Porcine Reproductive and Respiratory Syndrome (PRRS) in Mexico, Costa Rica, the Dominican Republic, Colombia, and Venezuela, and Porcine Epidemic Diarrhea (PED) in Mexico, Peru, the Dominican Republic, Colombia, and Ecuador. Additionally, feed costs, supply chain disruptions, and energy expenses have affected mainly the smaller and less efficient producers. The swine industry is also transitioning towards more sustainable and environmentally friendly practices, including efficient feed usage, and precision farming. Ensuring long-term success in the swine industry in Latin America requires a holistic approach that prioritizes sustainability, animal welfare, and consumer preferences, ultimately positioning the industry to thrive in the evolving global market.