• Title/Summary/Keyword: change analysis

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Keyword Network Analysis of Trends in Research on Climate Change Education (키워드 네트워크 분석을 활용한 기후변화 교육 관련 연구동향 분석)

  • Kim, Soon Shik;Lee, Sang Gyun
    • Journal of the Korean Society of Earth Science Education
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    • v.13 no.3
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    • pp.226-237
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    • 2020
  • The purpose of the research is to analyze research trends related to climate change education by network analysis based on keywords extracted from the research title. For this purpose, 62 papers were selected from Korean Citation Index(KCI) journals published from 2011 to 2020 using such keywords as "climate change" and "climate change education" in the Research Information Sharing Service. The analysis procedure consisted of selection of analysis papers, keyword extraction and purification, and keyword network analysis and visualization. Textom, Ucinet 6.0, and NetDraw were used to analyze the frequency, degree centrality, and betweenness centrality. The results of the research showed that, first, Early 'Energy and Climate Change Education' had the highest frequency of papers examining climate change education. Second, the keywords/phrases that appeared most frequently in research on climate change education were "program" "energy," "analysis," "elementary school," "elementary school," "elementary school students," "development," and "impact." Third, the analysis of the centrality of betweenness centrality showed that the index of 'program', 'primary students' and 'primary schools' were the highest, and the largest group was 'development and effect of teaching and learning programs'. Based on these results, it was concluded that future research on climate change education needs to be examined in further detail and expanded into more specific areas.

Implementation of Automatic Tool for S/W Change Impact Analysis in Railway System (철도시스템 소프트웨어 변경영향 분석을 위한 자동화 도구 개발)

  • Jo, Hyun-Jeong;Hwang, Jong-Gyu;Kim, Yong-Kyu
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.2
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    • pp.95-100
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    • 2009
  • Recent advances in computer technology have brought more dependence on software to railway systems. Hence, the safety assurance of the vital software running on the railway system is very critical task and yet, not many works have been done. While much efforts have been reported to improve electronic hardware's safety, not so much systematic approaches to evaluate software's safety. In this paper, we suggested an automated analysis tool for S/W change impact in railway system, and presented its result of implementation. The analysis items in the implemented tool had referred to the international standards in relation to the software for railway system, such as IEC 61508 and IEC 62279. In these international standards, 'change impact analysis' for railway system S/W has to be required mandatorily. The proposed tool can be utilized at the assessment stage and also the software development stage.

Factors Influencing on movement of crashed Vehicle by using EDSMAC (EDSMAC을 이용한 충돌 후 차량운동에 영향을 미치는 인자)

  • Jung, H.K.;Kang, D.M.
    • Journal of Power System Engineering
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    • v.6 no.3
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    • pp.42-48
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    • 2002
  • Velocity change of crashed vehicle has been applied to assess the safety of passenger and degree of impact severity widely. In this study, 1 D crash analysis and 2 D crash analysis were performed for velocity change of crashed vehicle with HVE 2D, and factors used for these analysis are weight, C.G, roll resistance, stiffness and brake force which influence on velocity change of crashed vehicle. According to results, the velocity change of crashed vehicle was influenced by weight, center of gravity stiffness and brake force but not roll resistance.

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Study on Soil Parameters and Two Dimensional Analysis in Slope Stability (사면안정 2차원해석과 토질정수에 관한 연구)

  • 김경진;김규문;박일철
    • Journal of the Korean Professional Engineers Association
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    • v.18 no.3
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    • pp.21-27
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    • 1985
  • Earthen mass located beneth a sloping group surface, whether natural or manmade, have a tendency to move downward and outward under the influence of gravity. Unless this tendency is suitably counteracted by the Shearing resistances within the mass, a landslide occurs. Avoiding such instabilities is a major concern of the geotechnical engineer. The shearing behavior of a soil is determined empirically, i.e., by field tests or laboratory tests. This results are applied to the slope stability analysis. The factor of safety for slope stability analysis is much more sensitive to the choice of strength parameters as interpreted from soil tests than to the choice of the computational method of analysis. This paper was investigated the influence of the change in the factor of safety due to a change in one of the parameters, relative to the total change in the factor of safety due to change in all parameters. A conclusion may be reached with respect to the required precision definition of the different variables to limit uncertainties in the factor of safety to tolerable levels.

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Spectral Mixture Analysis for Desertification Detection in North-Eastern China

  • Yoon Bo-Yeol;Jung Tae-Woong;Yoo Jae-Wook;Kim Choen
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.419-422
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    • 2004
  • This paper was carried out desertification area change detection from 1980s to 2000s per unit decade using by multitemporal satellite images (Landsat MSS, TM, ETM+). This study aims to use Spectral Mixture Analysis (SMA) to identify and classify study area. Endmembers is selected bare soil, green vegetation (GV), water body using by Minimum Noise Fraction (MNF). Endmembers used to generate increase and decrease images respective from 1980s to 1990s and from 1990s to 2000s. From the analysis of multitemporal change detection for three periods, it was apparent that the area of bare soil increased significantly, with simultaneous decrease of GV and water body. The multitemporal fraction images can be effectively used for change detection. Though there is no field survey dataset, SMA is reliable result of change detection in desertification in China.

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IPA Analysis of Agricultural Climate Adaptation Policies (농업부문 기후변화 대응정책의 IPA분석)

  • Sang-ho Lee;Jae-ho Hong
    • Journal of Agricultural Extension & Community Development
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    • v.30 no.4
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    • pp.213-227
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    • 2023
  • This paper aims to examine the farmers' perceptions of the importance and feasibility of climate change awareness and adaptive measures in agriculture, utilizing paired sample t-tests and Importance-Performance Analysis (IPA). Significant differences were found in farmers' views on the importance and urgency of climate change issues, with specific factors standing out. The IPA analysis identified key issues requiring sustained attention, including climate change magnitude, extreme weather events, livestock damage scale, pest fluctuations, and variability in flowering periods. Additionally, the study revealed significant disparities in farmers' perceptions of the importance and feasibility of adaptive measures, except for specific items related to heat indices.

OntCIA: Software Change Impact Analysis System Based on the Semantic Web (OntCIA: 시맨틱 웹 기술 기반의 소프트웨어 변경 영향분석 시스템)

  • Song Hee Seok
    • Journal of Intelligence and Information Systems
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    • v.10 no.2
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    • pp.111-131
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    • 2004
  • Software change is an essential operation for software evolution. To maintain the system competently, managers as well as developers must be able to understand the structure of the system but the structure of software is hidden to the developers and managers who need to change it. In this paper, we present a system (OntCIA) for supporting change impact analysis for rating and billing domain based on the semantic web technology. The basic idea of OntCIA is to build a domain knowledge base using an OWL ontology and RDF to implement change impact analysis system that would support the managers and software developers in finding out information about structure of large software system. OntCIA allows users to incrementally build an ontology in rating and billing domain and provides useful information in response to user queries concerning the code, such as, for example 'Find the modules which have a role for confirming new subscription'. The strengths of OntCIA are its architecture for easy maintenance as well as semantic indexing by automatic reasoning.

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Causes of Change Orders in the Military Facility Construction Projects and Suggestions for Improvement (군사시설 건설사업의 설계변경 요인분석 및 개선방향)

  • Lee, Kyoung-Han;Choi, Jong-Soo
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.3
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    • pp.263-271
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    • 2013
  • Change orders have been widespread in both the private and public construction sectors. In particular, in the case of G2B (Government to Business) contracts, adjustment of contract price and/or schedule extension is a frequent occurrence due to change orders. To uncover the causes of change orders and suggest an appropriate strategy, this study analyzed 296 cases of change orders in military facility construction projects from 2008 to 2010. The analysis revealed that the major causes of change orders are users' additional requirements (28.38%), a change of finishing materials (23.99%), and change of footing type (17.57%), in that order. Building on the results of this analysis, the authors suggest plans for practical improvements. Specific recommendations include 1) reflect user requirements at the early stage, 2) minimize the use of additional budget due to change orders, and 3) reduce the process and time for contract amendment, among others. The results of this study may provide significant implications to those involved in military construction projects, particularly project owners (i.e., the Ministry of Defense) and contractors.

Synthesis and Analysis of Ge2Sb2Te5 Nanowire Phase Change Memory Devices

  • Lee, Jun-Yeong;Kim, Jeong-Hyeon;Jeon, Deok-Jin;Han, Jae-Hyeon;Yeo, Jong-Seok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.222.2-222.2
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    • 2015
  • A $Ge_2Sb_2Te_5$ nanowire (GST NW) phase change memory device is investigated with Joule heating electrodes. GST is the most promising phase change materials, thus has been studied for decades but atomic structure transition in the phase-change area of single crystalline phase-change material has not been clearly investigated. We fabricated a phase change memory (PCM) device consisting of GST NWs connected with WN electrodes. The GST NW has switching performance with the reset/set resistance ratio above $10^3$. We directly observed the changes in atomic structure between the ordered hexagonal close packed (HCP) structure and disordered amorphous phase of a reset-stop GST NW with cross-sectional STEM analysis. Amorphous areas are detected at the center of NW and side areas adjacent to heating electrodes. Direct imaging of phase change area verified the atomic structure transition from the migration and disordering of Ge and Sb atoms. Even with the repeated phase transitions, periodic arrangement of Te atoms is not significantly changed, thus acting as a template for recrystallization. This result provides a novel understanding on the phase-change mechanism in single crystalline phase-change materials.

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An Analysis of Fishermen's Perception to Climate Change in Korea (기후변화에 대한 어업인 인식의 특성 분석)

  • Kim, Bong-Tae;Lee, Sang-Geon;Jeong, Myung-Saeng
    • The Journal of Fisheries Business Administration
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    • v.45 no.3
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    • pp.71-84
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    • 2014
  • This study indicates that 84.5% of fishermen have perceived climate change and 74.9% of fishermen have responded that frequency and intensity of the impacts of climate change are increasing. The results of regression analysis have shown that the level of fishermen experiencing the impacts of climate change differs according to individual's characteristics including age, length of experience, sea area (fishing area) and types of fisheries. About half of the respondents have shown that they are not taking any actions against the effects of climate change. The main reasons are that they either have lack of knowledge on how to respond to the impacts of climate change or have the perception that climate change is irresistible. The majority of respondents have responded that they are not aware of the government's climate change policy and emphasized that it is necessary to have effective countermeasures strengthening the provision of information about climate change policy. The result of perception survey have highlighted that it is essential for the government and the fishermen to share relevant information and to consider method of cooperation.