• Title/Summary/Keyword: data modelling

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Verification of the KMA Ocean Model NEMO against Argo Floats and Drift Buoys: a Comparison with the Up-to-date US Navy HYCOM (Argo 플로트와 표류부이 관측자료를 활용한 기상청 전지구 해양모델 (NEMO)의 검증: 최신 미해군 해양모델(HYCOM)과 비교)

  • Hyun, Seung-Hwon;Hwang, Seung-On;Lee, Sang-Min;Choo, Sung-Ho
    • Atmosphere
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    • v.32 no.1
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    • pp.71-84
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    • 2022
  • This paper describes verification results for the ocean analysis field produced by the Nucleus for European Modelling of the Ocean (NEMO) of the Korea Meteorological Administration (KMA) against observed Argo floats and drift buoys over the western Pacific Ocean and the equatorial Pacific during 2020~2021. This is confirmed by a comparison of the verification for the newly updated version of the HYbrid Coordinate Ocean Model/Navy Coupled Ocean Data Assimilation (HYCOM/NCODA) against same observations. NEMO shows that the vertical ocean temperature is much closer to the Argo floats than HYCOM for most seasons in terms of bias and root mean square error. On the other hand, there are overall considerable cold biases for HYCOM, which may be due to the more rapid decreasing temperature at the shallow thermocline in HYCOM. Conclusion demonstrated that the NEMO analysis for ocean temperature is more reliable than the analysis produced by the latest version of HYCOM as well as by the out-of-date HYCOM applied to the precedent study. The surface ocean current produced by NEMO also shows 14% closer to the AOML (Atlantic Oceanographic and Meteorological Laboratory) in situ drift buoys observations than HYCOM over the western Pacific Ocean. Over the equatorial Pacific, however, HYCOM shows slightly closer to AOML observation than NEMO in some seasons. Overall, this study suggests that the resulting information may be used to promote more use of NEMO analysis.

Assessment of INSPYRE-extended fuel performance codes against the SUPERFACT-1 fast reactor irradiation experiment

  • L. Luzzi;T. Barani;B. Boer;A. Del Nevo;M. Lainet;S. Lemehov;A. Magni;V. Marelle;B. Michel;D. Pizzocri;A. Schubert;P. Van Uffelen;M. Bertolus
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.884-894
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    • 2023
  • Design and safety assessment of fuel pins for application in innovative Generation IV fast reactors calls for a dedicated nuclear fuel modelling and for the extension of the fuel performance code capabilities to the envisaged materials and irradiation conditions. In the INSPYRE Project, comprehensive and physics-based models for the thermal-mechanical properties of U-Pu mixed-oxide (MOX) fuels and for fission gas behaviour were developed and implemented in the European fuel performance codes GERMINAL, MACROS and TRANSURANUS. As a follow-up to the assessment of the reference code versions ("pre-INSPYRE", NET 53 (2021) 3367-3378), this work presents the integral validation and benchmark of the code versions extended in INSPYRE ("post-INSPYRE") against two pins from the SUPERFACT-1 fast reactor irradiation experiment. The post-INSPYRE simulation results are compared to the available integral and local data from post-irradiation examinations, and benchmarked on the evolution during irradiation of quantities of engineering interest (e.g., fuel central temperature, fission gas release). The comparison with the pre-INSPYRE results is reported to evaluate the impact of the novel models on the predicted pin performance. The outcome represents a step forward towards the description of fuel behaviour in fast reactor irradiation conditions, and allows the identification of the main remaining gaps.

Comparing building performance of supermarkets under future climate change: UK case study

  • Agha Usama Hasan;Ali Bahadori-Jahromi;Anastasia Mylona;Marco Ferri;Hexin Zhang
    • Advances in Energy Research
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    • v.8 no.1
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    • pp.73-93
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    • 2022
  • Focus on climate change and extreme weather conditions has received considerable attention in recent years. Civil engineers are now focusing on designing buildings that are more eco-friendly in the face of climate change. This paper describes the research conducted to assess the impact of future climate change on energy usage and carbon emissions in a typical supermarket at multiple locations across the UK. Locations that were included in the study were London, Manchester, and Southampton. These three cities were compared against their building performance based on their respective climatic conditions. Based on the UK Climatic Projections (UKCP09), a series of energy modelling simulations which were provided by the Chartered Institute of Building Service Engineers (CIBSE) were conducted on future weather years for this investigation. This investigation ascertains and quantifies the annual energy consumption, carbon emissions, cooling, and heating demand of the selected supermarkets at the three locations under various climatic projections and emission scenarios, which further validates annual temperature rise as a result of climatic variation. The data showed a trend of increasing variations across the UK as one moves southwards, with London and Southampton at the higher side of the spectrum followed by Manchester which has the least variability amongst these three cities. This is the first study which investigates impact of the climate change on the UK supermarkets across different regions by using the real case scenarios.

BIM-based Lift Planning Workflow for On-site Assembly in Modular Construction Projects

  • Hu, Songbo;Fang, Yihai;Moehler, Robert
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.63-74
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    • 2020
  • The assembly of modular construction requires a series of thoroughly-considered decisions for crane lifting including the crane model selection, crane location planning, and lift path planning. Traditionally, this decision-making process is empirical and time-consuming, requiring significant human inputs. Recently, research efforts have been dedicated to improving lift planning practices by leveraging cutting-edge technologies such as automated data acquisition, Building Information Modelling (BIM) and computational algorithms. It has been demonstrated that these technologies have advanced lift planning to some degree. However, the advancements tend to be fragmented and isolated. There are two hurdles prevented a systematic improvement of lift planning practices. First, the lack of formalized lift planning workflow, outlining the procedure and necessary information. Secondly, there is also an absence of a shared information environment, enabling storages, updates and the distribution of information to stakeholders in a timely manner. Thus, this paper aims to overcome the hurdles. The study starts with a literature review in combination with document analysis, enabling the initial workflow and information flow. These were contextualised through a series of interviews with Australian practitioners in the crane-related industry, and systematically analysed and schematically validated through an expert panel. Findings included formalized workflow and corresponding information exchanges in a traditional lift planning practice via a Business Process Model and Notation (BPMN). The traditional practice is thus reviewed to identify opportunities for further enhancements. Finally, a BIM-based lift planning workflow is proposed, which integrates the scattered technologies (e.g. BIM and computational algorithms) with the aim of supporting lift planning automation. The resulting framework is setting out procedures that need to be developed and the potential obstacles towards automated lift planning are identified.

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Molybdenum release from high burnup spent nuclear fuel at alkaline and hyperalkaline pH

  • Sonia Garcia-Gomez;Javier Gimenez;Ignasi Casas;Jordi Llorca;Joan De Pablo;Albert Martinez-Torrents;Frederic Clarens;Jakub Kokinda;Luis Iglesias;Daniel Serrano-Purroy
    • Nuclear Engineering and Technology
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    • v.56 no.1
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    • pp.34-41
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    • 2024
  • This work presents experimental data and modelling of the release of Mo from high-burnup spent nuclear fuel (63 MWd/kgU) at two different pH values, 8.4 and 13.2 in air. The release of Mo from SF to the solution is around two orders of magnitude higher at pH = 13.2 than at pH = 8.4. The high Mo release at high pH would indicate that Mo would not be congruently released with uranium and would have an important contribution to the Instant Release Fraction, with a value of 5.3%. Parallel experiments with pure non irradiated Mo(s) and XPS determinations indicated that the faster dissolution at pH = 13.2 could be the consequence of the higher releases from metallic Mo in the fuel through a surface complexation mechanism promoted by the OH- and the oxidation of the metal to Mo(VI) via the formation of intermediate Mo(IV) and Mo(V) species.

A constrained minimization-based scheme against susceptibility of drift angle identification to parameters estimation error from measurements of one floor

  • Kangqian Xu;Akira Mita;Dawei Li;Songtao Xue;Xianzhi Li
    • Smart Structures and Systems
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    • v.33 no.2
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    • pp.119-131
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    • 2024
  • Drift angle is a significant index for diagnosing post-event structures. A common way to estimate this drift response is by using modal parameters identified under natural excitations. Although the modal parameters of shear structures cannot be identified accurately in the real environment, the identification error has little impact on the estimation when measurements from several floors are used. However, the estimation accuracy falls dramatically when there is only one accelerometer. This paper describes the susceptibility of single sensor identification to modelling error and simulations that preliminarily verified this characteristic. To make a robust evaluation from measurements of one floor of shear structures based on imprecisely identified parameters, a novel scheme is devised to approximately correct the mode shapes with respect to fictitious frequencies generated with a genetic algorithm; in particular, the scheme uses constrained minimization to take both the mathematical aspect and the realistic aspect of the mode shapes into account. The algorithm was validated by using a full-scale shear building. The differences between single-sensor and multiple-sensor estimations were analyzed. It was found that, as the number of accelerometers decreases, the error rises due to insufficient data and becomes very high when there is only one sensor. Moreover, when measurements for only one floor are available, the proposed method yields more precise and appropriate mode shapes, leading to a better estimation on the drift angle of the lower floors compared with a method designed for multiple sensors. As well, it is shown that the reduction in space complexity is offset by increasing the computation complexity.

SPMTool: A computer application for analysis of reinforced concrete structures by the Stringer-Panel Method - Validation of nonlinear models

  • Andre Felipe Aparecido de Mello;Leandro Mouta Trautwein;Luiz Carlos de Almeida;Rafael Alves de Souza
    • Computers and Concrete
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    • v.34 no.1
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    • pp.1-14
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    • 2024
  • The design of disturbed regions in reinforced concrete structures usually applies the well known Strut and Tie Method (STM). As an alternative, the Stringer-Panel Method (SPM), an intermediate model between STM and the Finite Element Method (FEM), consists in dividing a structure into two distinct elements: the stringers (which carry axial forces) and panels (which carry shear forces). SPM has already showed good applicability in manual calculations and computer implementations, and its most known application was SPanCAD, an AutoCAD plugin for linear and nonlinear analysis by SPM. Unfortunately, SPanCAD was discontinued by the developers, and it's not compatible with the most recent versions of AutoCAD. So, this paper aims to present a computer program that was developed as an upgrade to the latter: the Stringer Panel Modelling Tool (SPMTool), which is intended to be an auxiliary design tool and it presents improvements, in comparison to SPanCAD. It is possible to execute linear and nonlinear analysis by three distinct formulations: Modified Compression Field Theory (MCFT), Disturbed Stress Field Model (DSFM) and Softened Membrane Model (SMM). The nonlinear results were compared to experimental data of reinforced concrete elements that were not designed by SPM; these elements were also analyzed in SPanCAD. On overall, SPMTool made more realistic predictions to the behavior of the analyzed structures than SPanCAD. Except for DSFM predictions for corbels (1.24), in overall average, the ultimate load predictions were conservative (0.85 to 0.98), which is a good aspect for a design tool. On the other hand, the cracking load predictions presented overestimations (1.06 to 1.47) and higher variations (25.59% to 34.25%) and the post-cracking behavior could not be accurately predicted; for this use case, a more robust finite element software is recommended.

Meta-analysis of pancreatic re-resection for locally recurrent pancreatic cancer following index pancreatectomy

  • Shahin Hajibandeh;Shahab Hajibandeh;Daisy Evans;Tejinderjit S. Athwal
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.28 no.3
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    • pp.315-324
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    • 2024
  • The role of surgical resection in patients with recurrent pancreatic cancer is unclear. We aimed to evaluate the survival outcomes of pancreatic re-resection for locally recurrent pancreatic cancer following index pancreatectomy. A literature search was carried out in CENTRAL, EMBASE, MEDLINE, CINAHL, and Web of Science. Proportion meta-analysis model was constructed to quantify 1 to 5-year survival after pancreatic re-resection for locally recurrent pancreatic cancer. Random-effects modelling was applied to calculate pooled outcome data. Fifteen retrospective studies were included, reporting a total of 250 patients who underwent pancreatic re-resection for locally recurrent pancreatic cancer following their index pancreatectomy. Pancreatic re-resection was associated with 1-year survival 70.6% (95% confidence interval [CI], 65.0-76.2), 2-year survival 38.8% (95% CI, 28.6-49.0), 3-year survival 20.2% (95% CI, 13.8-26.7), and 5-year survival 9.2% (95% CI, 5.5-12.8). The between-study heterogeneity was insignificant in all outcome syntheses. Repeat pancreatectomy for local recurrence of pancreatic cancer in the remnant pancreas following the index pancreatectomy is associated with acceptable overall patient survival. We recommend selective re-resection of such recurrences in younger patients with favorable tumor size and location. Our findings may encourage more robust studies to be conducted in this context to provide stronger evidence.

Laryngeal Cancer Screening using Cepstral Parameters (켑스트럼 파라미터를 이용한 후두암 검진)

  • 이원범;전경명;권순복;전계록;김수미;김형순;양병곤;조철우;왕수건
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.14 no.2
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    • pp.110-116
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    • 2003
  • Background and Objectives : Laryngeal cancer discrimination using voice signals is a non-invasive method that can carry out the examination rapidly and simply without giving discomfort to the patients. n appropriate analysis parameters and classifiers are developed, this method can be used effectively in various applications including telemedicine. This study examines voice analysis parameters used for laryngeal disease discrimination to help discriminate laryngeal diseases by voice signal analysis. The study also estimates the laryngeal cancer discrimination activity of the Gaussian mixture model (GMM) classifier based on the statistical modelling of voice analysis parameters. Materials and Methods : The Multi-dimensional voice program (MDVP) parameters, which have been widely used for the analysis of laryngeal cancer voice, sometimes fail to analyze the voice of a laryngeal cancer patient whose cycle is seriously damaged. Accordingly, it is necessary to develop a new method that enables an analysis of high reliability for the voice signals that cannot be analyzed by the MDVP. To conduct the experiments of laryngeal cancer discrimination, the authors used three types of voices collected at the Department of Otorhinorlaryngology, Pusan National University Hospital. 50 normal males voice data, 50 voices of males with benign laryngeal diseases and 105 voices of males laryngeal cancer. In addition, the experiment also included 11 voices data of males with laryngeal cancer that cannot be analyzed by the MDVP, Only monosyllabic vowel /a/ was used as voice data. Since there were only 11 voices of laryngeal cancer patients that cannot be analyzed by the MDVP, those voices were used only for discrimination. This study examined the linear predictive cepstral coefficients (LPCC) and the met-frequency cepstral coefficients (MFCC) that are the two major cepstrum analysis methods in the area of acoustic recognition. Results : The results showed that this met frequency scaling process was effective in acoustic recognition but not useful for laryngeal cancer discrimination. Accordingly, the linear frequency cepstral coefficients (LFCC) that excluded the met frequency scaling from the MFCC was introduced. The LFCC showed more excellent discrimination activity rather than the MFCC in predictability of laryngeal cancer. Conclusion : In conclusion, the parameters applied in this study could discriminate accurately even the terminal laryngeal cancer whose periodicity is disturbed. Also it is thought that future studies on various classification algorithms and parameters representing pathophysiology of vocal cords will make it possible to discriminate benign laryngeal diseases as well, in addition to laryngeal cancer.

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The Research about the Water Quality Prediction at Imha Reservoir Using a WASP7 Model (WASP7 모형을 이용한 임하호 수질모의에 관한 연구)

  • Ahn, Seung-Seop;Seo, Myung-Joon;Jung, Do-Joon;Park, Ro-Sam
    • Journal of Environmental Science International
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    • v.17 no.6
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    • pp.611-621
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    • 2008
  • This study intends to provide the necessary basic data needed for predicting the water quality and examining changes in water quality on the basis of the hydrological changes: an outflow or the character of a flow by investigating the interaction of the parameters through the estimation of optimal parameters need for predicting the water quality of the dam basin and the sensitivity among those estimated parameters. Im-Ha Dam in the upstream area of the Nakdong River was selected for analysis, and the water quality survey data necessary for parameter estimation was based on the monthly water quality data (water temperature, BOD, T-N and T-P) between December 1, $2005{\sim}$November 31, 2006. K1C(the saturated growth rate of plant plankton), K1RC (endogenous respiratory quotient of plankton), KDC(deoxidized ratio), K71C(minealized ratio of dissolved organic phosphorus), K83C(mineralized ratio of dissolved organic nitrogen) have been considered as the factors of the water quality performed in this water quality simulation, that is, the most effective parameters on BOD, T-N and T-P. In the result of the analysis of the sensitivity, KDC(deoxidized ratio) was the most sensitively reacted parameter on BOD and it was K71C(mineralized ratio of dissolved organic phosphorus) and K83C(mineralized ratio of dissolved organic nitrogen) on T-N and T-P. It is considered that it will be possible to apply the most optimal parameter to an analysis of the water quality simulation at Im-Ha Ho basin in the goal year by examining the interaction of the parameters through the parameters sampling which are able to applicable to prediction of the water quality and the analysis of the its sensitivity, in the future, also the analysis on the basis of the hydrological conditions: an outflow or the character of a flow will be needed.