• Title/Summary/Keyword: co occurrence

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Current Research Trends in Entrepreneurship Based on Topic Modeling and Keyword Co-occurrence Analysis: 2002~2021 (토픽모델링과 동시출현단어 분석을 이용한 기업가정신에 대한 연구동향 분석: 2002~2021)

  • Jang, Sung Hee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.3
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    • pp.245-256
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    • 2022
  • The purpose of this study is to provide comprehensive insights on the current research trends in entrepreneurship based on topic modeling and keyword co-occurrence analysis. This study queried Web of Science database with 'entrepreneurship' and collected 14,953 research articles between 2002 and 2021. The study used R program for topic modeling and VOSviewer program for keyword co-occurrence analysis. The results of this study are as follows. First, as a result of keyword co-occurrence analysis, 5 clusters divided: entrepreneurship and innovation cluster, entrepreneurship education cluster, social entrepreneurship and sustainability cluster, enterprise performance cluster, and knowledge and technology transfer cluster. Second, as a result of the topic modeling analysis, 12 topics found: start-up environment and economic development, international entrepreneurship, venture capital, government policy and support, social entrepreneurship, management-related issues, regional city planning and development, entrepreneurship research, and entrepreneurial intention. Finally, the study identified two hot topics(venture capital and entrepreneurship intention) and a cold topic(international entrepreneurship). The results of this study are useful to understand current research trends in entrepreneurship research and provide insights into research of entrepreneurship.

Analyzing the Co-occurrence of Endangered Brackish-Water Snails with Other Species in Ecosystems Using Association Rule Learning and Clustering Analysis (연관 규칙 학습과 군집분석을 활용한 멸종위기 기수갈고둥과 생태계 내 종 간 연관성 분석)

  • Sung-Ho Lim;Yuno Do
    • Korean Journal of Ecology and Environment
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    • v.57 no.2
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    • pp.83-91
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    • 2024
  • This study utilizes association rule learning and clustering analysis to explore the co-occurrence and relationships within ecosystems, focusing on the endangered brackish-water snail Clithon retropictum, classified as Class II endangered wildlife in Korea. The goal is to analyze co-occurrence patterns between brackish-water snails and other species to better understand their roles within the ecosystem. By examining co-occurrence patterns and relationships among species in large datasets, association rule learning aids in identifying significant relationships. Meanwhile, K-means and hierarchical clustering analyses are employed to assess ecological similarities and differences among species, facilitating their classification based on ecological characteristics. The findings reveal a significant level of relationship and co-occurrence between brackish-water snails and other species. This research underscores the importance of understanding these relationships for the conservation of endangered species like C. retropictum and for developing effective ecosystem management strategies. By emphasizing the role of a data-driven approach, this study contributes to advancing our knowledge on biodiversity conservation and ecosystem health, proposing new directions for future research in ecosystem management and conservation strategies.

A Study on Safety of Hydrogen Station (수소충전소의 안전성에 관한 연구)

  • Ko, Jae-Wook;Lee, Dae-Hee;Jung, In-Hee
    • Journal of the Korean Institute of Gas
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    • v.13 no.1
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    • pp.45-51
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    • 2009
  • A safety assessment was performed through the process analysis of hydrogen station. The purpose of this study provides basic information for the standard establishment about hydrogen stations. The processes of hydrogen stations were classified by four steps (process of manufacture, compression, storage, charge). FMEA (Failure Mode and Effect Analysis) method was applied to evaluate safety. Each risk element is following; S (severity), O (occurrence), D (detection). And the priority of order was decided by using RPN (Risk Priority Number) value multiplying three factors. Scenarios were generated based on FMEA results. And consequence analysis was practiced using PHAST program. In the result of C.A, jet fire and explosion were shown as accident types. In case of leakage of feed line in PSA process, concentration of CO gas is considered to prevent CO gas poisoning when the raw material that can product CO gas was used.

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A Temperature Analysis Study of Korea and its Neighbor Regions for Temperature Specification (온도규격 설정을 위한 한반도 및 주변권역 온도분석 연구)

  • Kim, In-Soo;Kang, Chee-Woo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.1
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    • pp.55-65
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    • 2015
  • This paper describes the results of a temperature analysis of Korea and its neighbor regions for temperature specification of weapon systems to be deployed in Korea, and introduces the concept of a standard deviation frequency of occurrence which represents a frequency of yearly occurrence. On the basis of this analysis, reasonable operational temperatures for the Korea weapon systems are recommended, and the regional frequency of yearly occurrence of temperatures worse than recommended operational temperatures in each country regions are presented.

Automatic Keyword Extraction using Hierarchical Graph Model Based on Word Co-occurrences (단어 동시출현관계로 구축한 계층적 그래프 모델을 활용한 자동 키워드 추출 방법)

  • Song, KwangHo;Kim, Yoo-Sung
    • Journal of KIISE
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    • v.44 no.5
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    • pp.522-536
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    • 2017
  • Keyword extraction can be utilized in text mining of massive documents for efficient extraction of subject or related words from the document. In this study, we proposed a hierarchical graph model based on the co-occurrence relationship, the intrinsic dependency relationship between words, and common sub-word in a single document. In addition, the enhanced TextRank algorithm that can reflect the influences of outgoing edges as well as those of incoming edges is proposed. Subsequently a novel keyword extraction scheme using the proposed hierarchical graph model and the enhanced TextRank algorithm is proposed to extract representative keywords from a single document. In the experiments, various evaluation methods were applied to the various subject documents in order to verify the accuracy and adaptability of the proposed scheme. As the results, the proposed scheme showed better performance than the previous schemes.

The Knowledge Structure of Multicultural Research Papers in Korea (다문화연구의 지식구조에 관한 네트워크 분석)

  • Jang, Im-Sook;Chang, Durk-Hyun;Lee, Soo-Sang
    • Journal of Korean Library and Information Science Society
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    • v.42 no.4
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    • pp.353-374
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    • 2011
  • Analyzing research paper published from 2005 to 2010, this study aims for analysing the research paradigm on multi-culture and understanding the structural characteristics of the multicultural knowledge via scientometric. Co-word network constructed by keywords in documents and their co-occurrence relationships is a kind of mapping knowledge structure. A total of 4,521 and 1,373 papers published between 2005 and 2010 were retrieved from the KRF Registered Journals and Proposed Journals. This paper employs k-core analysis method in the field of mapping knowledge structure to analyze keyword co-occurrence network of multicultural research in Korea. And Netminer 3 is employed to visualize the networks in this paper.

DEVELOPMENT OF A PRACTICAL METHOD FOR THE ESTIMATION OF WELD INDUCED CRACK IN THICK PLATE WELDMENTS

  • Lee, Jae-Myung;Yoon, Dong-Ryul;Heo, Hee-Young;Jang, Tae-Won;Lee, Jae-Won
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.396-401
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    • 2002
  • A practical method for evaluating the possibility of the occurrence of cracking in actual thick-plate T-joint weldments is presented in this study. Systematic experiments based on the method of the design of experiment are conducted in order to investigate the crack tendency in relation to typical welding parameters such as diffusible hydrogen, restraint intensity, preheating temperature and so on. The elastic analysis using the [mite element techniques is employed to quantify the restraint intensities of the specimens. The defined restraint intensities are treated in numerical way for the sake of considering the most uncertain factor among some major factors that govern the cracking phenomena due to welding. The critical plane for judgment of the crack occurrence or crack density is presented as a function of typical welding parameters including determined restraint intensities. The results of numerical estimation by the proposed method for the experimental specimens show the usefulness as a practical tool in welding induced crack problem having extensive uncertainties.

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Relation of the Skarnized Calcareous Nodules in the Hwajeol Formation and the Deep Concealed Orebody (화절층내 석회질 단괴(團塊)의 스카른화와 심부잠두(深部潛頭) 광체와의 관계)

  • Moon, Kun-Joo
    • Economic and Environmental Geology
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    • v.24 no.4
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    • pp.335-346
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    • 1991
  • It is observed that calcareous nodules of the Hwajeol Formation are locally skarnized in the Sangdong district, in which the skarn mineralization extends 5 Km westward from the Sangdong mine area to the Hwajeolchi area. After a hidden granite beneath the Sangdong mine was discovered by exploration drillings, the exploration teams of the Sangdong mine and the Korean Mining Promotion Corporation have assumed that the skarn nodule of the Hwajeol Formation was derived from emplacement of a granite in deep place and the occurrence of hidden ore bodies below the skarn, and they have discovered high grades of tungsten orebody in the same horizon of the Sangdong ore body. Mutual genetic relatioships between epidote and garnet may be explained by following chemical reactions $Ca_2FeA_{12}$ $Si_3O_{12}(OH)+CaCO_3=Ca_3(Fe,\;Al)_2$ $SiO_{12}+1/2CO_2+1/2H^+Ca_3FeSi_3O_{12}+SiO_2+CO_2=2CaFeSi_{12}O_6+CaCO_3+1/2O_3$. It is concluded that epidote and garnet are useful as target minerals indicating a potential occurrence of deep seated hidden ore body. Since the epidote may inform the emplacement of the granite, while the garnet in the skarn nodule of the Hwajeol Formation may reflect a strong hydrothermal mineralization taking place from the depth.

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