• Title/Summary/Keyword: Quantitative research

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Stress, Social Support and Coping of Adults According to Level of Self-Efficacy (성인의 스트레스, 사회적 지원과 대처: 자기효능감 수준별 분석)

  • Young-Shin Park;Ju-Yeon Son;Ok-Ran Song
    • Korean Journal of Culture and Social Issue
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    • v.23 no.2
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    • pp.295-332
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    • 2017
  • The main purpose of this research is to analyze stress, social support and coping behavior of adults based on their level of self-efficacy. A total of 899 adults (399 male; 500 female), each with a child attending either elementary and secondary school, participated in the study. The inter-rater reliability for the open-ended questionnaire utilized in the study was 93.4%, with a Kappa coefficient of .92. The range of Cronbach α for the variables measured through a quantitative method was .87~.92. The results were as follows: First, the representative responses to the question about their most painful stress experiences were, financial difficulties, child rearing and duties of workplace. The Lower Efficacy group, compared to the Upper Efficacy group, responded much more with financial difficulties related responses. There were significant differences in the level of stress symptoms according to level of self-efficacy. The Lower Efficacy group expressed stronger levels of stress symptoms when compared to the Upper Efficacy group. Second, in terms of social support, the participants responded that they received the most help from their family members, followed by none(self), and friends. When comparing the two efficacy groups, the Upper Efficacy group responded most frequently that they received social support from their family members, whereas the Lower Efficacy group indicated none. There were significant differences in the level of relational conflicts according to the level of self-efficacy. The Upper Efficacy group showed much less conflict in parent-child relations, spousal relations and relations with their boss, compared to the Lower Efficacy group. Third, for the type of social support participants received, the most frequent response was emotional support, followed by none, and advice. Relatively, when comparing the two groups with each other, the Lower Efficacy group responded more frequently with none, whereas for the Upper Efficacy group responded more frequently with advice. There were significant differences in the amount of emotional support received according to level of self-efficacy. The Upper Efficacy group received much more emotional support from their spouses and their bosses compared to the Lower Efficacy group. Fourth, the most frequently adopted coping style to stress was self-regulation, followed by direct problem solving, and nothing(none). The most frequent response for the Upper Efficacy group was direct problem solving, whereas for the Lower Efficacy group was nothing(none). There was a significant difference in coping efficiency to stress according to level of self-efficacy. The Upper Efficacy group coped more efficiently with stress than the Lower Efficacy group.

An Experimental Study on Fine Dust Emissions near Special Modified Asphalt Pavement and Conventional Asphalt Pavement (특수개질 및 일반 아스팔트 포장체 도로변의 미세먼지 발생에 대한 실험적 연구)

  • Tae-Woo Kang;Hyeok-Jung Kim
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.3
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    • pp.282-288
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    • 2023
  • In this study, we analyzed the amount of roadside fine dust generated from newly constructed specially modified asphalt pavement and general asphalt pavement from existing roads. We collected the 1,000 g (100 g/day) of dust samples from the roadside of the express bus terminal and commercial facility area in Chungcheongnam-do's C site at three-day intervals during the summer of 2022 and 2023. The collected samples were separated from fine dust according to size in the 75-150 ㎛ range and, were separated only from Tire and Road Wear Particles through density separation. No.1-3 are general asphalt pavement section as an existing road. Fine dust and Tire and Road Wear Particles in No.1-3 were 24.27 g, 24.36 g, 0.53 g, and 0.53 g, respectively, and the quantitative results for 2022 and 2023 were similar. On the other hand, No.4-6 are newly constructed specially modified asphalt pavement section. Fine dust decreased by 14.8 % and tire and road wear particles decreased by 29.6 % in 2023 compared to 2022 in No.4-6. In addition, according to the results of thermogravimetric analysis, Tire and road wear particles in No.1-3 are tire and road components at 30 % and 70 %, respectively. And Tire and road wear particles in No.4-6 are tire and road components at 35 % and 65 % in 2023, respectively. From these results, it was confirmed that the newly constructed specially modified asphalt pavement can be effective in reducing roadside fine dust and Tire and Road Wear Particles. However, there may be some shortcomings in conclusive research results due to limited space and sample collection period. In the future, we plan to conduct various case studies.

Assessment of stream water quality and pollutant discharge loads affected by recycled irrigation in an agricultural watershed using HSPF and a multi-reservoir model (HSPF와 다중 저류지 모형을 이용한 농업지역 순환관개에 의한 하천 수질 및 배출부하 영향 분석)

  • Kyoung-Seok Lee;Dong Hoon Lee;Youngmi Ahn;Joo-Hyon Kang
    • Journal of Wetlands Research
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    • v.25 no.4
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    • pp.297-305
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    • 2023
  • The recycled irrigation is a type of irrigation that uses downstream water to fulfill irrigation demand in the upstream agricultural areas; the used irrigation water returns back to the downstream. The recycled irrigation is advantageous for securing irrigation water for plant growth, but the returned water typically contains high levels of nutrients due to excess nutrients inputs during the agricultural activities, potentially deteriorating stream water quality. Therefore, quantitative assessment on the effect of the recycled irrigation on the stream water quality is required to establish strategies for effective irrigation water supply and water quality management. For this purpose, a watershed model is generally used; however no functions to simulate the effects of the recycled irrigation are provided in the existing watershed models. In this study, we used multi-reservoir model coupled with the Hydrological Simulation Program-Fortran (HSPF) to estimate the effect of the recycled irrigation on the stream water quality. The study area was the Gwangok stream watershed, a subwatershed of Gyeseong stream watershed in Changnyeong county, Gyeongsangnam-do. The HSPF model was built, calibrated, and used to produce time series data of flow and water quality, which were used as hypothetical observation data to calibrate the multi-reservoir model. The calibrated multi-reservoir model was used for simulating the recycled irrigation. In the multi-reservoir model, the Gwangok watershed consisted of two subsystems, irrigation and the Gwangok stream, and the reactions (plant uptake, adsorption, desorption, and decay) within each subsystem, and fluxes of water and materials between the subsystems, were modeled. Using the developed model, three scenarios with different combinations of the operating conditions of the recycled irrigation were evaluated for their effects on the stream water quality.

Evaluation of Applicability of Sea Ice Monitoring Using Random Forest Model Based on GOCI-II Images: A Study of Liaodong Bay 2021-2022 (GOCI-II 영상 기반 Random Forest 모델을 이용한 해빙 모니터링 적용 가능성 평가: 2021-2022년 랴오둥만을 대상으로)

  • Jinyeong Kim;Soyeong Jang;Jaeyeop Kwon;Tae-Ho Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.6_2
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    • pp.1651-1669
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    • 2023
  • Sea ice currently covers approximately 7% of the world's ocean area, primarily concentrated in polar and high-altitude regions, subject to seasonal and annual variations. It is very important to analyze the area and type classification of sea ice through time series monitoring because sea ice is formed in various types on a large spatial scale, and oil and gas exploration and other marine activities are rapidly increasing. Currently, research on the type and area of sea ice is being conducted based on high-resolution satellite images and field measurement data, but there is a limit to sea ice monitoring by acquiring field measurement data. High-resolution optical satellite images can visually detect and identify types of sea ice in a wide range and can compensate for gaps in sea ice monitoring using Geostationary Ocean Color Imager-II (GOCI-II), an ocean satellite with short time resolution. This study tried to find out the possibility of utilizing sea ice monitoring by training a rule-based machine learning model based on learning data produced using high-resolution optical satellite images and performing detection on GOCI-II images. Learning materials were extracted from Liaodong Bay in the Bohai Sea from 2021 to 2022, and a Random Forest (RF) model using GOCI-II was constructed to compare qualitative and quantitative with sea ice areas obtained from existing normalized difference snow index (NDSI) based and high-resolution satellite images. Unlike NDSI index-based results, which underestimated the sea ice area, this study detected relatively detailed sea ice areas and confirmed that sea ice can be classified by type, enabling sea ice monitoring. If the accuracy of the detection model is improved through the construction of continuous learning materials and influencing factors on sea ice formation in the future, it is expected that it can be used in the field of sea ice monitoring in high-altitude ocean areas.

Performance Evaluation of Monitoring System for Sargassum horneri Using GOCI-II: Focusing on the Results of Removing False Detection in the Yellow Sea and East China Sea (GOCI-II 기반 괭생이모자반 모니터링 시스템 성능 평가: 황해 및 동중국해 해역 오탐지 제거 결과를 중심으로)

  • Han-bit Lee;Ju-Eun Kim;Moon-Seon Kim;Dong-Su Kim;Seung-Hwan Min;Tae-Ho Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.6_2
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    • pp.1615-1633
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    • 2023
  • Sargassum horneri is one of the floating algae in the sea, which breeds in large quantities in the Yellow Sea and East China Sea and then flows into the coast of Republic of Korea, causing various problems such as destroying the environment and damaging fish farms. In order to effectively prevent damage and preserve the coastal environment, the development of Sargassum horneri detection algorithms using satellite-based remote sensing technology has been actively developed. However, incorrect detection information causes an increase in the moving distance of ships collecting Sargassum horneri and confusion in the response of related local governments or institutions,so it is very important to minimize false detections when producing Sargassum horneri spatial information. This study applied technology to automatically remove false detection results using the GOCI-II-based Sargassum horneri detection algorithm of the National Ocean Satellite Center (NOSC) of the Korea Hydrographic and Oceanography Agency (KHOA). Based on the results of analyzing the causes of major false detection results, it includes a process of removing linear and sporadic false detections and green algae that occurs in large quantities along the coast of China in spring and summer by considering them as false detections. The technology to automatically remove false detection was applied to the dates when Sargassum horneri occurred from February 24 to June 25, 2022. Visual assessment results were generated using mid-resolution satellite images, qualitative and quantitative evaluations were performed. Linear false detection results were completely removed, and most of the sporadic and green algae false detection results that affected the distribution were removed. Even after the automatic false detection removal process, it was possible to confirm the distribution area of Sargassum horneri compared to the visual assessment results, and the accuracy and precision calculated using the binary classification model averaged 97.73% and 95.4%, respectively. Recall value was very low at 29.03%, which is presumed to be due to the effect of Sargassum horneri movement due to the observation time discrepancy between GOCI-II and mid-resolution satellite images, differences in spatial resolution, location deviation by orthocorrection, and cloud masking. The results of this study's removal of false detections of Sargassum horneri can determine the spatial distribution status in near real-time, but there are limitations in accurately estimating biomass. Therefore, continuous research on upgrading the Sargassum horneri monitoring system must be conducted to use it as data for establishing future Sargassum horneri response plans.

Utilization of Smart Farms in Open-field Agriculture Based on Digital Twin (디지털 트윈 기반 노지스마트팜 활용방안)

  • Kim, Sukgu
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2023.04a
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    • pp.7-7
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    • 2023
  • Currently, the main technologies of various fourth industries are big data, the Internet of Things, artificial intelligence, blockchain, mixed reality (MR), and drones. In particular, "digital twin," which has recently become a global technological trend, is a concept of a virtual model that is expressed equally in physical objects and computers. By creating and simulating a Digital twin of software-virtualized assets instead of real physical assets, accurate information about the characteristics of real farming (current state, agricultural productivity, agricultural work scenarios, etc.) can be obtained. This study aims to streamline agricultural work through automatic water management, remote growth forecasting, drone control, and pest forecasting through the operation of an integrated control system by constructing digital twin data on the main production area of the nojinot industry and designing and building a smart farm complex. In addition, it aims to distribute digital environmental control agriculture in Korea that can reduce labor and improve crop productivity by minimizing environmental load through the use of appropriate amounts of fertilizers and pesticides through big data analysis. These open-field agricultural technologies can reduce labor through digital farming and cultivation management, optimize water use and prevent soil pollution in preparation for climate change, and quantitative growth management of open-field crops by securing digital data for the national cultivation environment. It is also a way to directly implement carbon-neutral RED++ activities by improving agricultural productivity. The analysis and prediction of growth status through the acquisition of the acquired high-precision and high-definition image-based crop growth data are very effective in digital farming work management. The Southern Crop Department of the National Institute of Food Science conducted research and development on various types of open-field agricultural smart farms such as underground point and underground drainage. In particular, from this year, commercialization is underway in earnest through the establishment of smart farm facilities and technology distribution for agricultural technology complexes across the country. In this study, we would like to describe the case of establishing the agricultural field that combines digital twin technology and open-field agricultural smart farm technology and future utilization plans.

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A Study on the Impact of Venture Capital Investment Experience and Job Fit on Fund Formation and Investment Rate of Return (벤처캐피탈의 투자경험과 직무적합도가 펀드결성과 투자수익률에 미치는 영향력에 관한 연구)

  • Kim Dae-Hee;Ha Kyu-So
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.4
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    • pp.37-50
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    • 2023
  • Venture capital invests the necessary capital and supports management and technology in promising small and medium-sized venture companies in the early stages of start-up with promising technology and excellent manpower. It plays a role as a key player in the venture ecosystem that realizes profits by collecting the investment through various means after growth. Venture capital's job is to recruit various investors(LPs) to invest in small and medium-sized venture companies with growth potential through the formation of venture investment funds, and to collect investment as companies grow, distribute and reinvest. The main tasks of venture capitalists, which play the most important role in venture investment, are finding promising companies, corporate analysis and evaluation, investment screening, follow-up management, and investment recovery. Venture capital's success indicators are fund formation and return on investment, and venture capitalists are rewarded with annual salary, performance-based incentive, and promotion with work performance such as investment, exit, and fund formation. Compared to the recent rapidly growing venture investment market, investment manpower is insufficient, and venture capital is making great efforts to foster manpower and establish infrastructure and systems for long-term service, but research has been conducted mainly from a quantitative perspective. Accordingly, this study aims to empirically analyzed the impact of investment experience, delegation of authority, job fit, and peer relationships on fund formation and return on investment according to the characteristics of the venture capital industry. The results of these empirical studies suggested that future venture capital needs a job environment and manpower operation strategy so that venture capitalists with high job fit and investment experience can work for a long time.

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The Usefulness of 18F-FDG PET to Differentiate Subtypes of Dementia: The Systematic Review and Meta-Analysis

  • Seunghee Na;Dong Woo Kang;Geon Ha Kim;Ko Woon Kim;Yeshin Kim;Hee-Jin Kim;Kee Hyung Park;Young Ho Park;Gihwan Byeon;Jeewon Suh;Joon Hyun Shin;YongSoo Shim;YoungSoon Yang;Yoo Hyun Um;Seong-il Oh;Sheng-Min Wang;Bora Yoon;Hai-Jeon Yoon;Sun Min Lee;Juyoun Lee;Jin San Lee;Hak Young Rhee;Jae-Sung Lim;Young Hee Jung;Juhee Chin;Yun Jeong Hong;Hyemin Jang;Hongyoon Choi;Miyoung Choi;Jae-Won Jang;Korean Dementia Association
    • Dementia and Neurocognitive Disorders
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    • v.23 no.1
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    • pp.54-66
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    • 2024
  • Background and Purpose: Dementia subtypes, including Alzheimer's dementia (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD), pose diagnostic challenges. This review examines the effectiveness of 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) in differentiating these subtypes for precise treatment and management. Methods: A systematic review following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted using databases like PubMed and Embase to identify studies on the diagnostic utility of 18F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the goldstandard clinical diagnosis for dementia subtypes. Results: From 12,815 articles, 14 were selected for final analysis. For AD versus FTD, the sensitivity was 0.96 (95% confidence interval [CI], 0.88-0.98) and specificity was 0.84 (95% CI, 0.70-0.92). In the case of AD versus DLB, 18F-FDG PET showed a sensitivity of 0.93 (95% CI 0.88-0.98) and specificity of 0.92 (95% CI, 0.70-0.92). Lastly, when differentiating AD from non-AD dementias, the sensitivity was 0.86 (95% CI, 0.80-0.91) and the specificity was 0.88 (95% CI, 0.80-0.91). The studies mostly used case-control designs with visual and quantitative assessments. Conclusions: 18F-FDG PET exhibits high sensitivity and specificity in differentiating dementia subtypes, particularly AD, FTD, and DLB. This method, while not a standalone diagnostic tool, significantly enhances diagnostic accuracy in uncertain cases, complementing clinical assessments and structural imaging.

Analysis of sustainability changes in the Korean rice cropping system using an emergy approach (에머지 접근법을 이용한 국내 벼농사 시스템의 지속가능성 변화 분석)

  • Yongeun Kim;Minyoung Lee;Jinsol Hong;Yun-Sik Lee;June Wee;Jaejun Song;Kijong Cho
    • Korean Journal of Environmental Biology
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    • v.41 no.4
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    • pp.482-496
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    • 2023
  • Many changes in the scale and structure of the Korean rice cropping system have been made over the past few decades. Still, insufficient research has been conducted on the sustainability of this system. This study analyzed changes in the Korean rice cropping system's sustainability from a system ecology perspective using an emergy approach. For this purpose, an emergy table was created for the Korean rice cropping system in 2011, 2016, and 202, and an emergy-based indicator analysis was performed. The emergy analysis showed that the total emergy input to the rice cropping system decreased from 10,744E+18 sej year-1 to 8,342E+18 sej year-1 due to decreases in paddy field areas from 2011 to 2021, and the proportion of renewable resources decreased by 1.4%. The emergy input per area (ha) was found to have decreased from 13.13E+15 sej ha-1 year-1 in 2011 to 11.89E+15 sej ha-1 year-1 in 2021, and the leading cause was a decrease in nitrogen fertilizer usage and working hours. The amount of emergy used to grow 1 g of rice stayed the same between 2016 and 2021 (specific emergy: 13.3E+09 sej g-1), but the sustainability of the rice cropping system (emergy sustainability index, ESI) continued to decrease (2011: 0.107, 2016: 0.088, and 2021: 0.086). This study provides quantitative information on the emergy input structure and characteristics of Korean rice cropping systems. The results of this study can be used as a valuable reference in establishing measures to improve the ecological sustainability of the Korean rice cropping system.

AHP Analysis Research to Improve the Busan Port Ship Supplies Industry (부산항 선용품산업의 개선을 위한 AHP 분석 연구)

  • Ei Mon Khaing;Cho, Ye-hee;Ha, Myoung-shin
    • Journal of Korea Port Economic Association
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    • v.40 no.2
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    • pp.21-38
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    • 2024
  • The current situation of ports and related industries is transitioning from quantitative growth in increased cargo volume and expansion of port facilities to qualitative growth in the role of ports through the creation of high value-added. Ports are now recognized as playing an important role in economic growth and development by generating high value-added, not just by increasing the amount of cargo and expanding port facilities. This study evaluated the importance of factors affecting the improvement of the Busan Port's marine equipment industry by using the Analytic Hierarchy Process(AHP) to derive the priority of improvement measures by factor and evaluate the importance of factors affecting the marine equipment industry. The factors that should be considered when selecting improvement measures for the marine equipment industry were selected as four factors: strengthening price competitiveness, increasing government and local government interest, strengthening promotion, and establishing a global network. The main sub-factors were composed of eight detailed evaluation factors by selecting two factors for each layer. The analysis was designed by dividing the factor hierarchy for selecting improvement measures for the marine equipment industry into three levels and creating survey questions for pairwise comparison. The priority of the analysis results using AHP showed that the factor with the highest priority was strengthening price competitiveness, followed by increasing government and local government interest, establishing a global network, and strengthening promotion. According to the analysis results for the second-level sub-factors, among the factors for strengthening price competitiveness, low distribution costs and storage costs were considered most important, followed by avoiding excessive competition among marine equipment companies. Among the factors for increasing government and local government interest, improving customs procedures and tariff refund procedures were considered most important, followed by strengthening incentives from the government and Busan City. Among the factors for establishing a global network, promoting large-scale marine equipment companies was considered most important, followed by actively participating in international marine equipment-related associations. Among the factors for strengthening promotion, active use of the Internet was considered most important, followed by holding domestic and international exhibitions. Based on this study, we hope to help activate Busan Port's market by enhancing its competitiveness through revitalizing its marine equipment industry, generating water traffic, and creating new value-added.