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Studies on Changes in the Hydrography and Circulation of the Deep East Sea (Japan Sea) in a Changing Climate: Status and Prospectus (기후변화에 따른 동해 심층 해수의 물리적 특성 및 순환 변화 연구 : 현황과 전망)

  • HOJUN LEE;SUNGHYUN NAM
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.28 no.1
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    • pp.1-18
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    • 2023
  • The East Sea, one of the regions where the most rapid warming is occurring, is known to have important implications for the response of the ocean to future climate changes because it not only reacts sensitively to climate change but also has a much shorter turnover time (hundreds of years) than the ocean (thousands of years). However, the processes underlying changes in seawater characteristics at the sea's deep and abyssal layers, and meridional overturning circulation have recently been examined only after international cooperative observation programs for the entire sea allowed in-situ data in a necessary resolution and accuracy along with recent improvement in numerical modeling. In this review, previous studies on the physical characteristics of seawater at deeper parts of the East Sea, and meridional overturning circulation are summarized to identify any remaining issues. The seawater below a depth of several hundreds of meters in the East Sea has been identified as the Japan Sea Proper Water (East Sea Proper Water) due to its homogeneous physical properties of a water temperature below 1℃ and practical salinity values ranging from 34.0 to 34.1. However, vertically high-resolution salinity and dissolved oxygen observations since the 1990s enabled us to separate the water into at least three different water masses (central water, CW; deep water, DW; bottom water, BW). Recent studies have shown that the physical characteristics and boundaries between the three water masses are not constant over time, but have significantly varied over the last few decades in association with time-varying water formation processes, such as convection processes (deep slope convection and open-ocean deep convection) that are linked to the re-circulation of the Tsushima Warm Current, ocean-atmosphere heat and freshwater exchanges, and sea-ice formation in the northern part of the East Sea. The CW, DW, and BW were found to be transported horizontally from the Japan Basin to the Ulleung Basin, from the Ulleung Basin to the Yamato Basin, and from the Yamato Basin to the Japan Basin, respectively, rotating counterclockwise with a shallow depth on the right of its path (consistent with the bottom topographic control of fluid in a rotating Earth). This horizontal deep circulation is a part of the sea's meridional overturning circulation that has undergone changes in the path and intensity. Yet, the linkages between upper and deeper circulation and between the horizontal and meridional overturning circulation are not well understood. Through this review, the remaining issues to be addressed in the future were identified. These issues included a connection between the changing properties of CW, DW, and BW, and their horizontal and overturning circulations; the linkage of deep and abyssal circulations to the upper circulation, including upper water transport from and into the Western Pacific Ocean; and processes underlying the temporal variability in the path and intensity of CW, DW, and BW.

Effect of soil stabilizer on the bioavailability of arsenic in paddy soil (안정화제가 논토양 내 비소의 생물유효도에 미치는 영향)

  • Ji-Hyock Yoo;Hui-Seon Kim;Mi-jin Kim;Jung-Ok Woo;Ho-yang Choi;Sung-Chul Kim
    • Journal of Applied Biological Chemistry
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    • v.65 no.4
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    • pp.349-355
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    • 2022
  • In this study, we sought to identify a soil stabilizer that can be applied to paddy fields vulnerable to arsenic (As) pollution. To this end, we conducted a pot experiment in which we evaluated the effects of different stabilizers on the bioavailability of As in paddy soil. As candidate stabilizers, we assessed calcium superphosphate (CSP), sulfur, and steel slag, which were applied at the rates of 0.7 and 1.4, 0.1 and 0.2, and 7.0 and 14.0 Ma ha-1, respectively. On day 67 after rice transplantation, we detected significantly lower concentrations of As in the solutions of paddy soil treated with 1.4 Ma ha-1 CSP (96.9 ㎍ L-1) and 0.2 Ma ha-1 sulfur (207.2 ㎍ L-1) compared with the As concentrations in control (314.5 ㎍ L-1) and steel slag-treated (268.6-342.4 ㎍ L-1) soil. Compared with the As concentrations in control brown rice (0.16 mg kg-1), concentrations in brown rice were lowest in the pots treated with 1.4 Ma ha-1 CSP (0.09 mg kg-1). Furthermore, in response to CSP treatments, we detected increases in the weight of rice grains (50.0-50.4 g/pot) compared with the control (40.4 g/pot) and other treatments (26.9-48.1 g/pot), which we speculate could be attributed to the reduction in As toxicity to rice owing to a decline in soil solution As contents and the fertilization effect of the CSP treatment. Collectively, our findings indicate a high-level application of CSP (1.4 Ma ha-1) to paddy soil has a comparatively beneficial effect in mitigating the bioavailability of As.

Analysis of Nitrogen and Phosphorus Benthic Diffusive Fluxes from Sediments with Different Levels of Salinity (염분농도에 따른 호소 퇴적물 내 질소 및 인 용출 특성 분석)

  • Seulgi Lee;Jin Chul Joo;Hee Sun Moon;Dong Hwi Lee;Dong Jun Kim;Jiwon Choi
    • Ecology and Resilient Infrastructure
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    • v.10 no.3
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    • pp.85-96
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    • 2023
  • The study involved the categorization of domestic lakes located in South Korea into three groups based on their salinity levels: upstream reservoirs with salinity less than 0.3 psu, estuarine reservoirs with salinity ranging from 0.3 to 2 psu, and brackish lagoons with salinity exceeding 2 psu. Subsequently, the research assessed variations in the concentrations of total nitrogen (T-N) and total phosphorus (T-P) in the sediment of these lakes using statistical analysis, specifically one-way analysis of variance (ANOVA). Additionally, a laboratory core incubation test was conducted to investigate the benthic nutrient fluxes in Songji lagoon (salinity: 11.80 psu), Ganwol reservoir (salinity: 0.73 psu), and Janggun reservoir (salinity: 0.08 psu) under both aerobic and anoxic conditions. The findings revealed statistically significant differences in the concentrations of T-N and T-P among sediments in the lakes with varying salinity levels (p<0.05). Further post-hoc analysis confirmed significant distinctions in T-N between upstream reservoirs and estuarine reservoirs (p<0.001), as well as between upstream reservoirs and brackish lagoons (p<0.01). For T-P, a significant difference was observed between upstream reservoirs and brackish lagoons (p<0.01). Regarding benthic nutrient fluxes, Ganwol Lake exhibited the highest diffusive flux of NH4+-N, primarily due to its physical characteristics and the inhibition of nitrification resulting from its relatively high salinity. The flux of NO3--N was lower at higher salinity levels under aerobic conditions but increased under anoxic conditions, attributed to the impact of salinity on nitrification and denitrification. Additionally, the flux of PO43--P was highest in Songji Lake, followed by Ganwol Lake and Janggun Reservoir, indicating that salinity promotes the diffusive flux of phosphate through anion adsorption competition. It's important to consider the influence of salinity on microbial communities, growth rates, oxidation-reduction processes, and nutrient binding forms when studying benthic diffusive nutrient fluxes from lake sediments.

Levels of Physicians' Self-assessment of Life Satisfaction and Associated Factors (임상의사의 삶의 만족도 자가평가 수준과 관련 요인)

  • Jong Sun Ok;Hyeongsu Kim
    • Journal of agricultural medicine and community health
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    • v.48 no.1
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    • pp.28-40
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    • 2023
  • Objectives: This study aimed to identify the level of self-assessment of life satisfaction and various factors related to the life satisfaction of Korean physicians. Methods: This study is a secondary data analysis using the 2016 Korean physician survey Korean Physician Survey(KPS) data collected by the Research Institute for Healthcare Policy of the Korean Medical Association. The member database(DB) of the Korean Medical Association was used for sampling and the target population was formed and surveyed by using stratified quota sampling. A questionnaire was sent by E-mail as an online survey method and was conducted for a total of 7 weeks from November 21, 2016 to January 8, 2017. The final number of respondents was 8,564 (response rate 13.8%). In this study, a total of 7,228 physicians, excluding residents and public health doctors who are currently treating patients directly, were studied. Factors affecting the life satisfaction of physicians were analyzed using ordinal logistic regression analysis. Results: The physical factors positively related to the life satisfaction of physicians were those who were in their 60s, female, and thought they had good health status. As for psychological factors, stress was low. As for economic factors, satisfaction with income was high. As for social factors, the physicians lived with their families and were satisfied with the time they could spend with them. Also, the physicians were satisfied with the social respect they received as a doctors. Conclusions: Based on the results of this study, it is thought that a multifaceted approach is needed to increase the life satisfaction of physicians.

Research on the revitalization of Japanese artworks: Focus on Japan Advanced Art Museum Policy (일본의 문화경제전략과 미술품 유동성 활성화에 관한 연구 - 문화청의 선진미술관 정책 추진을 중심으로 -)

  • Chu, Min-Hee
    • Korean Association of Arts Management
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    • no.51
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    • pp.135-166
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    • 2019
  • Recently, the Japan Cultural Agency announced a plan for revitalizing the art market represented by reading museums (advanced art museums) to promote industry through strengthening the sustainability and economics of art museums. Along with these policy announcements, the Japanese cultural system and Bypyeongje are divided into pros and cons, and there has been a heightened opposition, which is now in a state where policy promotion has been temporarily suspended. The opposite reason is that it does not meet the museum's inherent purpose of preservation and lore, and the reason for favoring that commercialism can ruin the art world is that the Japanese art society is other than art museums and museums Also, it consists of non-profit organizations, art festival administration organizations, support staff, volunteers, etc., but because of the high subsidy bias, no real labor costs are paid, which means that it is virtually neglected. Also, there is a vigilance that the art society itself, which reduces its reliance on subsidies in response to social changes, can survive. Seeing that the situation is not much different from Japan, Korea is also actively discussing new establishments of the National Art Bank, performing art appraisal and evaluation functions for revitalizing art works, art loan, art trust, etc. There is. As it is difficult to solve realistic problems with subsidies from the future situation, it is difficult for us to expand investment in culture, and culture and economy are united and linked. You will find a plan to make it operational. In this regard, it is thought that the examination of the cultural and economic agency's strategy, represented by the Japanese advanced art museums, gives us a meaningful suggestion.

An Analytical Study on Rational use of Undersea Space (해저공간의 합리적 활용을 위한 분석적 연구)

  • Won-Jo Jung;Nam-Ki Park
    • Journal of Navigation and Port Research
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    • v.47 no.3
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    • pp.147-154
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    • 2023
  • This study aims to determine the necessity, role, utilization, and operation and management plan in relation to the underwater space platform where humans can newly reside. It provides a comprehensive opinion on the need for creating undersea space and operation plans based on opinions of industry-university-affiliated organizations involved in the R&D project of the Ministry of Maritime Affairs and Fisheries for the utilization of undersea space and external experts participating in marine technology development. In this study, a survey was conducted on researchers participating in the construction of a Korean submarine space platform. FGI was conducted on marine technology development experts. Results were then derived. As a result of the analysis, the need for subsea space construction was found to be high. As for the role of subsea space, the most common opinion was to develop technology for utilizing subsea space and to secure marine science research functions. It was found that the creation of subsea space would have a positive impact on the domestic industry, especially the deep-sea development industry and the shipbuilding/offshore structure industry. In terms of utilization, after the end of the seabed space test bed, the response to utilization as a marine observation base and marine ecosystem research had the highest proportion. As for expected inconvenience, discomfort in the psychological environment was the highest. Experts suggest that securing a continuous budget is most important for stable operation in the future and that securing a manpower budget is essential for itemized budgets. In addition, it was judged that it would be appropriate to establish a prior agreement from the time of the prior agreement and prepare a countermeasure before proceeding with the project in order to ensure ownership issues, consignment management issues, and cost issues when using the project after the end of the project.

A Study on the Effect of the Third-Party Award Winning Advertisement on Consumer's Pre-Purchase Intention (제 3 기관 수상(Award Winning) 광고가 소비자 구매의도에 미치는 영향에 관한 연구 - 마케팅 변수들의 조절 효과를 중심으로 -)

  • Jeon, Hoseong
    • Asia Marketing Journal
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    • v.10 no.1
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    • pp.25-64
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    • 2008
  • Third-Party awards are growing in popularity. They are the hit product of the year chosen by The Korea Economic Daily, the best 10 products of the year chosen by Sports paper, the best hit product chosen by consulting firm and the best venture company of the year chosen by Information and Communication Ministry. Then these questions may be followed. Why industry likes this type of advertisement? Does this type of advertisement influences consumers' purchase intention? And if it does, how? Many researchers have been interested in external cue of product quality by focusing research effort on brand, price, producer, warranty etc. However, important but under-explored area is the role of third-party reference for signaling product quality. This paper comes from the idea that the third-party reference may signal consumers like manufacturer brand, product brand, product price, and shop brand. We develop a related theories to address research questions and drive some research hypotheses based on the previous studies probing source credibility, attribution, and signal theory. We put more emphasis on source credibility. We conducted the research based on 3x2x2x2 between group factorial design to explore causal relationship between the third party award winning advertising(real, fictional, no) and the purchase intention of consumers exposed to other information simultaneously such as product type(experience, search), distribution channel(direct, indirect) and perceived price(high, low). Since subjects are divided into 2 groups based on the means of response without extra experimental stimulus in case of perceived price. 12 different advertisements are used for conducting this study. The results are followings. First, the source credibility of the third party goes up, consumers' purchase intention would go up. It seems that consumers think the credibility of the third-party most when they are exposed to the third party award winning advertisement. Second, the product type does moderate the relationship between the third-party award winning advertisement and purchase intention. And the type of the distribution channel also moderates this relationship. The consumers' purchase intention goes up higher when they buy experience good and there is significant difference of purchase intention when consumers are exposed to direct channel treatment condition. But, perceived price has nothing to do with the third-party winning advertisement context for raising consumer intention to buy advertised product.

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Estimation of Chlorophyll-a Concentration in Nakdong River Using Machine Learning-Based Satellite Data and Water Quality, Hydrological, and Meteorological Factors (머신러닝 기반 위성영상과 수질·수문·기상 인자를 활용한 낙동강의 Chlorophyll-a 농도 추정)

  • Soryeon Park;Sanghun Son;Jaegu Bae;Doi Lee;Dongju Seo;Jinsoo Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.5_1
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    • pp.655-667
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    • 2023
  • Algal bloom outbreaks are frequently reported around the world, and serious water pollution problems arise every year in Korea. It is necessary to protect the aquatic ecosystem through continuous management and rapid response. Many studies using satellite images are being conducted to estimate the concentration of chlorophyll-a (Chl-a), an indicator of algal bloom occurrence. However, machine learning models have recently been used because it is difficult to accurately calculate Chl-a due to the spectral characteristics and atmospheric correction errors that change depending on the water system. It is necessary to consider the factors affecting algal bloom as well as the satellite spectral index. Therefore, this study constructed a dataset by considering water quality, hydrological and meteorological factors, and sentinel-2 images in combination. Representative ensemble models random forest and extreme gradient boosting (XGBoost) were used to predict the concentration of Chl-a in eight weirs located on the Nakdong river over the past five years. R-squared score (R2), root mean square errors (RMSE), and mean absolute errors (MAE) were used as model evaluation indicators, and it was confirmed that R2 of XGBoost was 0.80, RMSE was 6.612, and MAE was 4.457. Shapley additive expansion analysis showed that water quality factors, suspended solids, biochemical oxygen demand, dissolved oxygen, and the band ratio using red edge bands were of high importance in both models. Various input data were confirmed to help improve model performance, and it seems that it can be applied to domestic and international algal bloom detection.

Introduction and Evaluation of the Production Method for Chlorophyll-a Using Merging of GOCI-II and Polar Orbit Satellite Data (GOCI-II 및 극궤도 위성 자료를 병합한 Chlorophyll-a 산출물 생산방법 소개 및 활용 가능성 평가)

  • Hye-Kyeong Shin;Jae Yeop Kwon;Pyeong Joong Kim;Tae-Ho Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1255-1272
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    • 2023
  • Satellite-based chlorophyll-a concentration, produced as a long-term time series, is crucial for global climate change research. The production of data without gaps through the merging of time-synthesized or multi-satellite data is essential. However, studies related to satellite-based chlorophyll-a concentration in the waters around the Korean Peninsula have mainly focused on evaluating seasonal characteristics or proposing algorithms suitable for research areas using a single ocean color sensor. In this study, a merging dataset of remote sensing reflectance from the geostationary sensor GOCI-II and polar-orbiting sensors (MODIS, VIIRS, OLCI) was utilized to achieve high spatial coverage of chlorophyll-a concentration in the waters around the Korean Peninsula. The spatial coverage in the results of this study increased by approximately 30% compared to polar-orbiting sensor data, effectively compensating for gaps caused by clouds. Additionally, we aimed to quantitatively assess accuracy through comparison with global chlorophyll-a composite data provided by Ocean Colour Climate Change Initiative (OC-CCI) and GlobColour, along with in-situ observation data. However, due to the limited number of in-situ observation data, we could not provide statistically significant results. Nevertheless, we observed a tendency for underestimation compared to global data. Furthermore, for the evaluation of practical applications in response to marine disasters such as red tides, we qualitatively compared our results with a case of a red tide in the East Sea in 2013. The results showed similarities to OC-CCI rather than standalone geostationary sensor results. Through this study, we plan to use the generated data for future research in artificial intelligence models for prediction and anomaly utilization. It is anticipated that the results will be beneficial for monitoring chlorophyll-a events in the coastal waters around Korea.

Research on Making a Disaster Situation Management Intelligent Based on User Demand (사용자 수요 기반의 재난 상황관리 지능화에 관한 연구)

  • Seon-Hwa Choi;Jong-Yeong Son;Mi-Song Kim;Heewon Yoon;Shin-Hye Ryu;Sang Hoon Yoon
    • Korean Journal of Remote Sensing
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    • v.39 no.5_2
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    • pp.811-825
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    • 2023
  • In accordance with the government's stance of actively promoting intelligent administrative service policies through data utilization, in the disaster and safety management field, it also is proceeding with disaster and safety management policies utilizing data and constructing systems for responding efficiently to new and complex disasters and establishing scientific and systematic safety policies. However, it is difficult to quickly and accurately grasp the on-site situation in the event of a disaster, and there are still limitations in providing information necessary for situation judgment and response only by displaying vast data. This paper focuses on deriving specific needs to make disaster situation management work more intelligent and efficient by utilizing intelligent information technology. Through individual interviews with workers at the Central Disaster and Safety Status Control Center, we investigated the scope of disaster situation management work and the main functions and usability of the geographic information system (GIS)-based integrated situation management system by practitioners in this process. In addition, the data built in the system was reclassified according to purpose and characteristics to check the status of data in the GIS-based integrated situation management system. To derive needed to make disaster situation management more intelligent and efficient by utilizing intelligent information technology, 3 strategies were established to quickly and accurately identify on-site situations, make data-based situation judgments, and support efficient situation management tasks, and implementation tasks were defined and task priorities were determined based on the importance of implementation tasks through analytic hierarchy process (AHP) analysis. As a result, 24 implementation tasks were derived, and to make situation management efficient, it is analyzed that the use of intelligent information technology is necessary for collecting, analyzing, and managing video and sensor data and tasks that can take a lot of time of be prone to errors when performed by humans, that is, collecting situation-related data and reporting tasks. We have a conclusion that among situation management intelligence strategies, we can perform to develop technologies for strategies being high important score, that is, quickly and accurately identifying on-site situations and efficient situation management work support.