• Title/Summary/Keyword: accuracy assessment

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A Study on the Improvement of Green Building Certification System;Focused on the contrastive analysis of domestic and foreign system (국내 친환경건축물 인증제도의 개선방향에 관한 연구;국내.외 친환경건축물 인증제도의 비교분석을 중심으로)

  • Chun, Sang-Hyun;Oh, Se-Gyu
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.382-385
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    • 2006
  • After incoming the notion of eco-friendly building, many organizations developed green building assessment programs and in the late of 2001, those programs were unified to one program, 'Green Building Certification(GBC)'. Many problems, however, arose after unification of programs and now the study to solve those problems is impending. The purpose of this study is to make suggestions to solve problems of GBC through analyzing characteristics of several abroad and well developed programs. The key points of the analysis were 1) characteristics of assessment organizations, 2) structures of programs, and 3) characteristics of assessment methods and systems. The results of the study showed that GBC didn't have any positive connections with the academia, the developer and the consumer, and did have lack of assessment efficiency and accuracy.

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A complete integrity assessment of welded connections under high and low cycle fatigue followed by fracture failure

  • Feng, Liuyang;Liu, Tianyao;Qian, Xudong;Chen, Cheng
    • Steel and Composite Structures
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    • v.43 no.4
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    • pp.465-481
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    • 2022
  • This paper presents a comprehensive integrity assessment of welded structural components, including uniform high- and low-cycle fatigue assessment of welded plate joints and fatigue-induced fracture assessment of welded plate joints. This study reports a series of fatigue and fracture tests of welded plate joints under three-point bending. To unify the assessment protocol for high- and low-cycle fatigue of welded plate joints, this study develops a numerical damage assessment framework for both high- and low-cycle fatigue. The calibrated damage material parameters are validated through the smooth coupon specimens. The proposed damage-based fatigue assessment approach describes, with reasonable accuracy, the total fatigue life of welded plate joints under high- and low-cycle fatigue actions. Subsequently, the study performs a tearing assessment on the ductile crack extension of the fatigue-induced crack. The tearing assessment diagram derives from the load-deformation curve of a single-edge notched bend, SE(B) specimen and successfully predicts the load-crack extension relation for the reported welded plate joints during the stable tearing process.

3D Geopositioning Accuracy Assessment Using KOMPSAT-2 RPC (KOMPSAT-2 RPC를 이용한 3차원 위치결정 정확도 분석)

  • Oh, Kwan-Young;Jung, Hyung-Sup;Lee, Won-Jin;Lee, Dong-Taek
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.1
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    • pp.1-9
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    • 2011
  • The objective of this paper is to improve the accuracy of the 3D geopositioning extracted from Rational Polynomial Coefficient(RPC) provide in the KOMPSAT-2 metadata files. In this paper, we developed the algorithm to adjust a RFM(Rational Functional Model), and could improve the accuracy of a RFM with this algorithm. Furthermore, when a RFM was adjusted with this algorithm, the effects of the number of GCPs on the accuracy of the adjusted RFM was tested. For accuracy assessment using adjusted RFM, 9 ground control points(GCPs) and 24 check points could be used. Results indicated that the root mean squared errors(RMSEs) of horizontal residual errors calculated 24 check points were 2.20(m). The achieved accuracy of three dimensional object-point determination was 1.72(m) in the X-dimension and 1.37(m) in the Y-dimension and 2.20(m) in the Z-dimension.

Assessment of Atmospheric Greenhouse Gas Concentration Equipment Performance (대기 중 온실가스 농도 관측 장비 성능 비교 검증)

  • Chaerin Park;Sujong Jeong;Seung-Hyun Jeong;Jeong-il Lee;Insun Kim;Cheol-Soo Lim
    • Atmosphere
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    • v.33 no.5
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    • pp.549-560
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    • 2023
  • This study evaluates three distinct observation methods, CRDS, OA-ICOS, and OF-CEAS, in greenhouse gas monitoring equipment for atmospheric CO2 and CH4 concentrations. The assessment encompasses fundamental performance, high-concentration measurement accuracy, calibration methods, and the impact of atmospheric humidity on measurement accuracy. Results indicate that within a range of approximately 500 ppm, all three devices demonstrate high accuracy and linearity. However, beyond 1000 ppm, CO2 accuracy sharply declines (84%), emphasizing the need for caution when interpreting high-concentration CO2 data. An analysis of calibration methods reveals that both CO2 and CH4 measurements achieve high accuracy and linearity through 1-point calibration, suggesting that multi-point calibration is not imperative for precision. In dynamic atmospheric conditions with significant CO2 and CH4 concentration variations, a 1-point calibration suffices for reliable data (99% accuracy). The evaluation of humidity impact demonstrates that humidity removal devices significantly reduce air moisture levels, yet this has a negligible effect on dry CO2 concentrations (less than 0.5% relative error). All three observation method instruments, which have integrated humidity correction to calculate dry CO2 concentrations, exhibit minor sensitivity to humidity removal devices, implying that additional removal devices may not be essential. Consequently, this study offers valuable insights for comparing data from different measurement devices and provides crucial information to consider in the operation of monitoring sites.

Study on Improvement of Frost Occurrence Prediction Accuracy (서리발생 예측 정확도 향상을 위한 방법 연구)

  • Kim, Yongseok;Choi, Wonjun;Shim, Kyo-moon;Hur, Jina;Kang, Mingu;Jo, Sera
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.295-305
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    • 2021
  • In this study, we constructed using Random Forest(RF) by selecting the meteorological factors related to the occurrence of frost. As a result, when constructing a classification model for frost occurrence, even if the amount of data set is large, the imbalance in the data set for development of model has been analyzed to have a bad effect on the predictive power of the model. It was found that building a single integrated model by grouping meteorological factors related to frost occurrence by region is more efficient than building each model reflecting high-importance meteorological factors. Based on our results, it is expected that a high-accuracy frost occurrence prediction model will be able to be constructed as further studies meteorological factors for frost prediction.

Accuracy of Digital Breast Tomosynthesis for Detecting Breast Cancer in the Diagnostic Setting: A Systematic Review and Meta-Analysis

  • Min Jung Ko;Dong A Park;Sung Hyun Kim;Eun Sook Ko;Kyung Hwan Shin;Woosung Lim;Beom Seok Kwak;Jung Min Chang
    • Korean Journal of Radiology
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    • v.22 no.8
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    • pp.1240-1252
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    • 2021
  • Objective: To compare the accuracy for detecting breast cancer in the diagnostic setting between the use of digital breast tomosynthesis (DBT), defined as DBT alone or combined DBT and digital mammography (DM), and the use of DM alone through a systematic review and meta-analysis. Materials and Methods: Ovid-MEDLINE, Ovid-Embase, Cochrane Library and five Korean local databases were searched for articles published until March 25, 2020. We selected studies that reported diagnostic accuracy in women who were recalled after screening or symptomatic. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random effects model was used to estimate pooled sensitivity and specificity. We compared the diagnostic accuracy between DBT and DM alone using meta-regression and subgroup analyses by modality of intervention, country, existence of calcifications, breast density, Breast Imaging Reporting and Data System category threshold, study design, protocol for participant sampling, sample size, reason for diagnostic examination, and number of readers who interpreted the studies. Results: Twenty studies (n = 44513) that compared DBT and DM alone were included. The pooled sensitivity and specificity were 0.90 (95% confidence interval [CI] 0.86-0.93) and 0.90 (95% CI 0.84-0.94), respectively, for DBT, which were higher than 0.76 (95% CI 0.68-0.83) and 0.83 (95% CI 0.73-0.89), respectively, for DM alone (p < 0.001). The area under the summary receiver operating characteristics curve was 0.95 (95% CI 0.93-0.97) for DBT and 0.86 (95% CI 0.82-0.88) for DM alone. The higher sensitivity and specificity of DBT than DM alone were consistently noted in most subgroup and meta-regression analyses. Conclusion: Use of DBT was more accurate than DM alone for the diagnosis of breast cancer. Women with clinical symptoms or abnormal screening findings could be more effectively evaluated for breast cancer using DBT, which has a superior diagnostic performance compared to DM alone.

Extraction and Accuracy Assessment of Deforestation Area using GIS and Remotely Sensed Data (GIS와 원격탐사자료를 이용한 산림전용지 추출 및 정확도 평가)

  • Lee, Gihaeng;Lee, Jungsoo
    • Journal of Korean Society of Forest Science
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    • v.101 no.3
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    • pp.365-373
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    • 2012
  • This study purposed to extract and assess the accuracy of assessment for deforestation area in Wonju city using medium resolution satellite image. The total size of deforestation area during the last nine years (2000-2008) was about 467 ha, and it was occurred annually about 52 ha. The most frequent form of deforestation was settlements (72%). Ninety percent of the size of deforestation was less than 2 ha in size. In addition, 79 percent of deforestation area was found within 500 m from the road network and within 100 m of the Forest/Non-forest boundary. This study compared the deforestation based on the administrative information (GIS deforestationI) with the deforestation (RS deforestation) extracted from the satellite imagery by vegetation indices (NDVI, NBR, NDWI). Extraction accuracy, mean-standard deviation${\times}1.5$ applied 3 by 3 filtering, showed reliable accuracy 35.47% k-value 0.20. However, error could be occurred because of the difference of land-use change and land-cover change. The actual rate of land-cover change deforestation area was 32% on administrative information. The 7.52% of forest management activities area was misjudged as deforestation by RS deforestation. Finally, the comparison of land-cover change deforestation (GIS deforestationII) with the RS deforestation accuracy, as a result NDVI mean-standard deviation${\times}2$ applied 3 by 3 filtering, showed improved accuracy 61.23%, k-value 0.23.

Climate Data Qualification for Water Quality Impact Assessment (수질영향평가의 신뢰수준 향상을 위한 기상자료의 검정)

  • Lee, Khil-Ha;Cho, Hongyeon
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.601-613
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    • 2011
  • This study is focused on a climate data integrity to improve water quality assessment due to the social development projects. The study is in an attempt to calculate both extreme ranges of weather data measurements and partly provide means to assess qualification of data which fall within the extremes at the 23 meteorological weather stations. Generally speaking, maximum temperature, minimum temperature, relative humidity, dew point temperature are in the range of reasonable accuracy. However, there found some outliers of the brightness sunshine hours in Cheonan station. Also some years in Gwangju, Seoul, Wonju, Busan, and Jeju never reach to their upper limit and perhaps the calibration of the equipment is doubtful. The users need to take cautions in using the brightness sunshine hour data in preparation of water resources planning and management by estimating evapotranspiration and river discharge, and/or growth rate of the algae (phytoplankton).

Estimation of Daily Solar Radiation at the Missing Point for Water Quality Impact Assessment in Nakdong River Watershed: Comparison of Modified Angstrom Model and Transmittance interpolation Model (수질 영향평가 신뢰수준 향상을 위한 낙동강 유역 미관측 지점에서의 일사량 추정: 수정형 Angstrom모형과 투과율모형의 비교)

  • Lee, Khil-Ha
    • Journal of Environmental Impact Assessment
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    • v.21 no.1
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    • pp.219-227
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    • 2012
  • Daily solar radiation is essential for water resources planning and environmental impact assessment. However, radiation data is not commonly available in Korea other than in big cities, and there has been no direct measurement for rural areas where water resources planning and environmental impact assessment is usually most needed. In general, missing radiation data is estimated from nearby regional stations within a certain distance, and this study compared two dominant methods (modified Angstrom equation and transmittance interpolation method) at six stations in Nakdong River watershed area. Two methods shows a similar level of accuracy but the transmittance interpolation method is likely to be superior in that there is no need for any measurement element since the modified Angstrom equation require the sunshine hour measurement. This study will contribute to improve water resource and water quality management in Nakdong River watershed.

Reliability Metrics Design and Verification for the Acquisition of Small and Mid-Sized Web Application (중소규모 웹어플리케이션 개발업체 신뢰성평가를 위한 신뢰도 메트릭의 설계 및 유효성 검증)

  • Choi, Kwoung-Hee;Rhew, Sung-Yul
    • Asia pacific journal of information systems
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    • v.16 no.3
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    • pp.193-203
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    • 2006
  • Software reliability prediction is a statistical method to put in place a timely software development practice useful for objective assessment of bidders. The current study suggests one research method that enables reliability assessment of such previous projects by studying user satisfaction and project management history. If incorporated into the existing acquisition process, the reliability assessment method will further enhance objectivity and accuracy in bidder selection process. The GQM(Goal Question Metric) paradigm was used to identify assessment metrics for bidder evaluation and questionnaires were collected from users to create user satisfaction indexes. In addition, 'weight of evidence', the most appropriate categorical method, was used to isolate attributes of each variable that may contribute to reliability assessment.