• 제목/요약/키워드: Occurrence frequency

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A Study on the Risk Evaluation of Subway Flood Inundation in Urban Area (도심지역 지하철 침수 위험도 평가에 관한 연구)

  • Kun-Hak Chun;Jong-Cheol Seo ;Hyeon-Gu Choi;Ji-Min Kim
    • Journal of Wetlands Research
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    • v.25 no.2
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    • pp.83-90
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    • 2023
  • Due to climate change, the occurrence of abnormal rainfall is increasing, and the intensity and scale of damage caused by heavy rain are increasing every year. In addition, as the frequency of heavy rains becomes more frequent, heavy rains often occur continuously, resulting in large flooding damage that has never been seen before in urban area. When near rivers and coastal areas are impermeable areas, the maximum flow increases rapidly as the rainfall intensity increases, so a comprehensive flood risk evaluation is needed considering the characteristics of the basin. In this study, the flood inundation risk evaluation was analyzed by giving scores on evaluation factors as a measure to prevent inundation in subway stations. Through the flood inundation risk evaluation process considering the comprehensive evaluation index, the flood risk evaluation was conducted on five urban railway stations with a large amount of traffic and floating population that had been inundated in the past. It is judged that by comprehensively analyzing this and establishing a inundation risk grade (grade 1 to 4) to establish a flood measure suitable for the risk grade.

A study on the analysis of current status of Seonakdong River algae using hyperspectral imaging (초분광영상을 이용한 서낙동강 조류 발생현황 분석에 관한 연구)

  • Kim, Jongmin;Gwon, Yeonghwa;Park, Yelim;Kim, Dongsu;Kwon, Jae Hyun;Kim, Young Do
    • Journal of Korea Water Resources Association
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    • v.55 no.4
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    • pp.301-308
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    • 2022
  • Algae is an indispensable primary producer in the ecosystem by supplying energy to consumers in the aquatic ecosystem, and is largely divided into green algae, blue-green algae, and diatoms. In the case of blue-green algae, the water temperature rises, which occurs in the summer and overgrows, which is the main cause of the algae bloom. Recently, the change in the occurrence time and frequency of the algae bloom is increasing due to climate change. Existing algae survey methods are performed by collecting water and measuring through sensors, and time, cost and manpower are limited. In order to overcome the limitations of these existing monitoring methods, research has been conducted to perform remote monitoring using spectroscopic devices such as multispectral and hyperspectral using satellite image, UAV, etc. In this study, we tried to confirm the possibility of species classification of remote monitoring through laboratory-scale experiments through algal culture and river water collection. In order to acquire hyperspectral images, a hyperspectral sensor capable of analyzing at 400-1000 nm was used. In order to extract the spectral characteristics of the collected river water for classification of algae species, filtration was performed using a GF/C filter to prepare a sample and images were collected. Radiation correction and base removal of the collected images were performed, and spectral information for each sample was extracted and analyzed through the process of extracting spectral information of algae to identify and compare and analyze the spectral characteristics of algae, and remote sensing based on hyperspectral images in rivers and lakes. We tried to review the applicability of monitoring.

COVID-19-related Korean Fake News Detection Using Occurrence Frequencies of Parts of Speech (품사별 출현 빈도를 활용한 코로나19 관련 한국어 가짜뉴스 탐지)

  • Jihyeok Kim;Hyunchul Ahn
    • Journal of Intelligence and Information Systems
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    • v.29 no.2
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    • pp.267-283
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    • 2023
  • The COVID-19 pandemic, which began in December 2019 and continues to this day, has left the public needing information to help them cope with the pandemic. However, COVID-19-related fake news on social media seriously threatens the public's health. In particular, if fake news related to COVID-19 is massively spread with similar content, the time required for verification to determine whether it is genuine or fake will be prolonged, posing a severe threat to our society. In response, academics have been actively researching intelligent models that can quickly detect COVID-19-related fake news. Still, the data used in most of the existing studies are in English, and studies on Korean fake news detection are scarce. In this study, we collect data on COVID-19-related fake news written in Korean that is spread on social media and propose an intelligent fake news detection model using it. The proposed model utilizes the frequency information of parts of speech, one of the linguistic characteristics, to improve the prediction performance of the fake news detection model based on Doc2Vec, a document embedding technique mainly used in prior studies. The empirical analysis shows that the proposed model can more accurately identify Korean COVID-19-related fake news by increasing the recall and F1 score compared to the comparison model.

Effect of Monoculture and Mixtures on Dry Matter Yield and Feed Value of Italian Ryegrass (Lolium Multiflorum Lam.) (이탈리안 라이그라스의 단파 및 혼파 재배가 건물수량 및 사료가치에 미치는 영향)

  • Jeong Sung Jung;Bo Ram Choi;Ouk Kyu Han;Bae Hun Lee;Ki Choon Choi
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.43 no.2
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    • pp.88-94
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    • 2023
  • This study was conducted to analyze and compare the dry matter yield of Italian ryegrass (IRG) cultivated under monoculture and mixed culture system to recommend suitable varieties that can be cultivated. Italian ryegrass cultivars, Green Fram (GF, extremely early-maturing), Kowinearly (KE, early-maturing), Kowinmaster (KM, mild-maturing), and Hwasan 104 (H104, late-maturing), were used for mono or mixed cultivation. The average monthly temperature in Cheonan over the past 30 years tended to be similar, but that in November and March are judged to be abnormal weather. The dry matter yield of GF+H104 was significantly higher during harvest than that of GF (p<0.05). The dry matter yields of KE and KE+KM were significantly higher during harvest than the output standards of KE and KM. There was no significant difference between the dry matter yield of H104 and KM (p>0.05), but KM had the highest yield of 16,763.1 kg/ha. Analysis showed that the highest dry matter yield during IRG harvest was obtained under monoculture and KE+KM mixed culture. Because the occurrence frequency of abnormal weather such as drought during spring is increasing recently, it is judged that IRG cultivation using early and middle growth is necessary to prepare for abnormal weather.

A Study on the Prediction Method of Information Exchange Requirement in the Tactical Network (전술네트워크의 정보교환요구량 예측 방법에 관한 연구)

  • Pokki Park;Sangjun Park;Sunghwan Cho;Junseob Kim;Yongchul Kim
    • Convergence Security Journal
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    • v.22 no.5
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    • pp.95-105
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    • 2022
  • The Army, Navy, and Air Force are making various efforts to develop a weapon system that incorporates the 4th industrial revolution technology so that it can be used in multi-domain operations. In order to effectively demonstrate the integrated combat power through the weapon system to which the new technology is applied, it is necessary to establish a network environment in which each weapon system can transmit and receive information smoothly. For this, it is essential to analyze the Information Exchange Requirement(IER) of each weapon system, but many IER analysis studies did not sufficiently reflect the various considerations of the actual tactical network. Therefore, this study closely analyzes the research methods and results of the existing information exchange requirements analysis studies. In IER analysis, the size of the message itself, the size of the network protocol header, the transmission/reception structure of the tactical network, the information distribution process, and the message occurrence frequency. In order to be able to use it for future IER prediction, we present a technique for calculating the information exchange requirement as a probability distribution using the Poisson distribution and the probability generating function. In order to prove the validity of this technique, the results of the probability distribution calculation using the message list and network topology samples are compared with the simulation results using Network Simulator 2.

Safety Improvement of Centrally Installed "Hi-pass" Lane of Express Highway (고속도로 중앙하이패스차로 안전성 개선에 관한 연구 - 서울외곽순환고속도로 본선영업소를 중심으로 -)

  • Yoo, Bong-Seok;Lee, Soo-Beom;Park, Wan-Yong;Do, Hyun-Gu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1D
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    • pp.1-10
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    • 2010
  • Safety improvement has been a continuous challenge, especially at toll gate of express highway where traffic conflict often occurs due to frequent lane change by drivers of "Hi-pass" lane and regular "TCS" lane. As a part of research on safety at toll gate, this study videotaped traffic conflict data between vehicles using centrally located "Hi-pass" lane and regular "TCS" lane and analyzed accident risk. According to the correlation analysis of vehicle speed, relative vehicle speed, and sudden vehicle deceleration rate due to traffic conflict, when the relative vehicle speed between centrally located "Hi-pass" lane and regular "TCS" lane increases, sudden vehicle deceleration rate also increases. One of the findings is that centrally located "Hi-pass" lane at toll gate shows different location for traffic conflict, and frequency of traffic conflict and the relative vehicle speed was also different based on vehicle lane use. TA (Time to Accident) analysis shows that accident rate is high at toll gate where Hipass lane is installed in center lane, when the occurrence of sudden vehicle deceleration and deceleration time of vehicles rise for vehicles on "Hi-pass" lane. Furthermore, if the expressway entrance/exit point is closely located to toll gate, TA showed a low value. Thus, it is necessary to reduce the relative vehicle speed in order to improve safety. The Study presents reduction of the relevant vehicular speed and prevention of accidents at the centrally installed "Hi-pass" lane as an important strategy for safety improvement at toll gate.

Urban Runoff Network Flow Velocity Monitoring System Using Ubiquitous Technique and GIS (Ubiquitous 기술과 GIS를 이용한 도시배수관망 유속측정 시스템 개발)

  • Choi, Changwon;Yi, Jaeeung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.5B
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    • pp.479-486
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    • 2010
  • Reliable hydrologic data acquisition is the basic and essential requirement for efficient water management. Especially the acquisition of various stream data in a certain location is very important to construct on alarm system to response an urban flood which occurs frequently due to the effect of climate change. Although the frequency of stream inundation flood occurrence becomes low owing to the consistent stream improvement, the urban flood due to the drainage system problems such as deterioration and bad management occurs continuously. The consistent management and current status understanding of the urban drainage system is essential to reduce the urban flood. The purpose of this study is to develop the urban runoff network flow velocity monitoring system which has the capability of collecting stream data whenever, wherever and to whomever without expert knowledge using Code Division Multiple Access technique and Bluetooth near-distance wireless communication technique. The urban runoff network flow velocity monitoring system consists of three stages. In the first stage, the stream information obtained by using ubiquitous floater is transferred to the server computer. In the second stage, the current state of the urban drainage system is assessed through the server computer. In the last stage, the information is provided to the user through a GUI. As a result of applying, the developed urban runoff network flow velocity monitoring system to Woncheon-Stream in Suwon, the information necessary for urban drainage management can be managed in real time.

A Comparative Analysis of Research Trends in Korean Modern Medicine: Focusing on Two Journals of Medical School (근대의학 논문의 계량학적 방법을 통한 연구 경향 비교 분석 - 의학전문학교 학술지 2종을 중심으로 -)

  • Mijin Seo;Jisu Lee
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.34 no.4
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    • pp.29-54
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    • 2023
  • This study aimed to analyze the research trends of journal articles published by medical schools representing Korean modern. A total of 682 were selected from two journals published by Medical College in Keijo and Keijo Imperial University Medical Faculty. In results, the affiliations of authors who participated in Acta Medicinalia in Keijo included various schools and hospitals, and the authors' major was found to be similar in basic medicine and clinical medicine. In The Keijo Journal of Medicine, only school-affiliated authors participated, and 96.33% of the authors were majors in basic medicine. Co-occurrence network analysis was conducted on MeSH terms from the title of the article using MeSH on Demand, and the keyword that derived in both journals was 'erythrocytes', which analyzed the condition of red blood cells according to organs and diseases. In frequency analysis, a common area of research in both journals was the study focusing on blood and blood cells, and the study of anemia and tuberculosis, which were prevalent diseases at the time. As for comparing each journal, Acta Medicinalia in Keijo has focused on inflammatory diseases and clinical pathological studies in humans, and The Keijo Journal of Medicine has focused on anatomical studies on animals and pharmacological studies on medicines. Through this study, it was possible to identify the research topics and major keywords in two medical schools with different founding goals.

Implementation of an Automated Agricultural Frost Observation System (AAFOS) (농업서리 자동관측 시스템(AAFOS)의 구현)

  • Kyu Rang Kim;Eunsu Jo;Myeong Su Ko;Jung Hyuk Kang;Yunjae Hwang;Yong Hee Lee
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.26 no.1
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    • pp.63-74
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    • 2024
  • In agriculture, frost can be devastating, which is why observation and forecasting are so important. According to a recent report analyzing frost observation data from the Korea Meteorological Administration, despite global warming due to climate change, the late frost date in spring has not been accelerated, and the frequency of frost has not decreased. Therefore, it is important to automate and continuously operate frost observation in risk areas to prevent agricultural frost damage. In the existing frost observation using leaf wetness sensors, there is a problem that the reference voltage value fluctuates over a long period of time due to contamination of the observation sensor or changes in the humidity of the surrounding environment. In this study, a datalogger program was implemented to automatically solve these problems. The established frost observation system can stably and automatically accumulate time-resolved observation data over a long period of time. This data can be utilized in the future for the development of frost diagnosis models using machine learning methods and the production of frost occurrence prediction information for surrounding areas.

Research Trend Analysis Using Bibliographic Information and Citations of Cloud Computing Articles: Application of Social Network Analysis (클라우드 컴퓨팅 관련 논문의 서지정보 및 인용정보를 활용한 연구 동향 분석: 사회 네트워크 분석의 활용)

  • Kim, Dongsung;Kim, Jongwoo
    • Journal of Intelligence and Information Systems
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    • v.20 no.1
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    • pp.195-211
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    • 2014
  • Cloud computing services provide IT resources as services on demand. This is considered a key concept, which will lead a shift from an ownership-based paradigm to a new pay-for-use paradigm, which can reduce the fixed cost for IT resources, and improve flexibility and scalability. As IT services, cloud services have evolved from early similar computing concepts such as network computing, utility computing, server-based computing, and grid computing. So research into cloud computing is highly related to and combined with various relevant computing research areas. To seek promising research issues and topics in cloud computing, it is necessary to understand the research trends in cloud computing more comprehensively. In this study, we collect bibliographic information and citation information for cloud computing related research papers published in major international journals from 1994 to 2012, and analyzes macroscopic trends and network changes to citation relationships among papers and the co-occurrence relationships of key words by utilizing social network analysis measures. Through the analysis, we can identify the relationships and connections among research topics in cloud computing related areas, and highlight new potential research topics. In addition, we visualize dynamic changes of research topics relating to cloud computing using a proposed cloud computing "research trend map." A research trend map visualizes positions of research topics in two-dimensional space. Frequencies of key words (X-axis) and the rates of increase in the degree centrality of key words (Y-axis) are used as the two dimensions of the research trend map. Based on the values of the two dimensions, the two dimensional space of a research map is divided into four areas: maturation, growth, promising, and decline. An area with high keyword frequency, but low rates of increase of degree centrality is defined as a mature technology area; the area where both keyword frequency and the increase rate of degree centrality are high is defined as a growth technology area; the area where the keyword frequency is low, but the rate of increase in the degree centrality is high is defined as a promising technology area; and the area where both keyword frequency and the rate of degree centrality are low is defined as a declining technology area. Based on this method, cloud computing research trend maps make it possible to easily grasp the main research trends in cloud computing, and to explain the evolution of research topics. According to the results of an analysis of citation relationships, research papers on security, distributed processing, and optical networking for cloud computing are on the top based on the page-rank measure. From the analysis of key words in research papers, cloud computing and grid computing showed high centrality in 2009, and key words dealing with main elemental technologies such as data outsourcing, error detection methods, and infrastructure construction showed high centrality in 2010~2011. In 2012, security, virtualization, and resource management showed high centrality. Moreover, it was found that the interest in the technical issues of cloud computing increases gradually. From annual cloud computing research trend maps, it was verified that security is located in the promising area, virtualization has moved from the promising area to the growth area, and grid computing and distributed system has moved to the declining area. The study results indicate that distributed systems and grid computing received a lot of attention as similar computing paradigms in the early stage of cloud computing research. The early stage of cloud computing was a period focused on understanding and investigating cloud computing as an emergent technology, linking to relevant established computing concepts. After the early stage, security and virtualization technologies became main issues in cloud computing, which is reflected in the movement of security and virtualization technologies from the promising area to the growth area in the cloud computing research trend maps. Moreover, this study revealed that current research in cloud computing has rapidly transferred from a focus on technical issues to for a focus on application issues, such as SLAs (Service Level Agreements).