• Title/Summary/Keyword: Simultaneous Model

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Effect of Ice accretion on the aerodynamic characteristics of wind turbine blades

  • Sundaresan, Aakhash;Arunvinthan, S.;Pasha, A.A.;Pillai, S. Nadaraja
    • Wind and Structures
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    • v.32 no.3
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    • pp.205-217
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    • 2021
  • Cold regions with high air density and wind speed attract wind energy producers across the globe exhibiting its potential for wind exploitation. However, exposure of wind turbine blades to such cold conditions bring about devastating impacts like aerodynamic degradation, production loss and blade failures etc. A series of wind tunnel tests were performed to investigate the effect of icing on the aerodynamic properties of wind turbine blades. A baseline clean wing configuration along with four different ice accretion geometries were considered in this study. Aerodynamic force coefficients were obtained from the surface pressure measurements made over the test model using MPS4264 Simultaneous pressure scanner. 3D printed Ice templates featuring different ice geometries based on Icing Research Tunnel data is utilized. Aerodynamic characteristics of both the clean wing configuration and Ice accreted geometries were analysed over a wide range of angles of attack (α) ranging from 0° to 24° with an increment of 3° for three different Reynolds number in the order of 105. Results show a decrease in aerodynamic characteristics of the iced aerofoil when compared against the baseline clean wing configuration. The key flow field features such as point of separation, reattachment and formation of Laminar Separation Bubble (LSB) for different icing geometries and its influence on the aerodynamic characteristics are addressed. Additionally, attempts were made to understand the influence of Reynolds number on the iced-aerofoil aerodynamics.

An Analysis of the Impact of National Fishing Port Investment on Fisheries Disaster Damage by Typhoons (국가어항 투자가 태풍으로 인한 수산재해피해에 미치는 영향 분석)

  • Kim, Eun-Ji;Bae, Hyeon-Jeong
    • The Journal of Fisheries Business Administration
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    • v.53 no.1
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    • pp.73-84
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    • 2022
  • The purpose of this study is the impact of national fishing port investment and typhoons on fisheries disaster damage. The dependent variables were the amount of damage to fishing ports, fishing boats, fisheries enhancement, external facilities, mooring facilities, functional facilities, fishing port and typhoons. The analysis period is from 2002 to 2018. Since the error term is in a simultaneous correlation, it was efficiently estimated by analyzing it with a seemingly unrelated regression (SUR) method. As a result of the analysis, external facilities have not significance to all models. Investing in mooring facilities increased the amount of damage to fishing ports for five years. Investing in functional facilities reduced the amount of damage to fishing ports and aquaculture over five years. Typhoons have significance to all models, and the amount of damage increased every time a typhoon occurred. Based on these results, as the influence of typhoons increases, it seems necessary to establish preventive measures. Timely investment and maintenance to enable the role and function of national fishing ports are considered important.

Estimation of various amounts of kaolinite on concrete alkali-silica reactions using different machine learning methods

  • Aflatoonian, Moein;Mirhosseini, Ramin Tabatabaei
    • Structural Engineering and Mechanics
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    • v.83 no.1
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    • pp.79-92
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    • 2022
  • In this paper, the impact of a vernacular pozzolanic kaolinite mine on concrete alkali-silica reaction and strength has been evaluated. For making the samples, kaolinite powder with various levels has been used in the quality specification test of aggregates based on the ASTM C1260 standard in order to investigate the effect of kaolinite particles on reducing the reaction of the mortar bars. The compressive strength, X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) experiments have been performed on concrete specimens. The obtained results show that addition of kaolinite powder to concrete will cause a pozzolanic reaction and decrease the permeability of concrete samples comparing to the reference concrete specimen. Further, various machine learning methods have been used to predict ASR-induced expansion per different amounts of kaolinite. In the process of modeling methods, optimal method is considered to have the lowest mean square error (MSE) simultaneous to having the highest correlation coefficient (R). Therefore, to evaluate the efficiency of the proposed model, the results of the support vector machine (SVM) method were compared with the decision tree method, regression analysis and neural network algorithm. The results of comparison of forecasting tools showed that support vector machines have outperformed the results of other methods. Therefore, the support vector machine method can be mentioned as an effective approach to predict ASR-induced expansion.

The Determinant of Shariah Financing in the Agricultural Sector: Evidence from Indonesia

  • ALAM, Azhar;RUSGIANTO, Sulistya;HASMARINI, Maulidyah Indira;FARHAN, Alifian Muhammad
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.4
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    • pp.287-298
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    • 2022
  • Indonesia is an agrarian country with the significant development of Shariah banking. This study aimed to estimate the effect of Third Party Funds (TPF), Non-Performing Financing (NPF), Exchange Rates (ER), and Bank Indonesia Shariah Certificates (SBIS) on the Sharia Agriculture Sector Financing in Indonesia during 2014-2020. This study used the Ordinary Least Square (OLS) technique to analyze the data. The coefficient of determination test showed that 99.19% of Sharia financing in the agricultural sector was influenced by TPF, NPF, Exchange Rate, and SBIS variables. The estimation results showed that the variables of TPF and ER significantly affected Sharia Financing for Agricultural Sector (PP). Meanwhile, the NPF and SBIS variables had no significant effect on PP. This research showed the resilience and accuracy of Islamic banking in selecting financing and can support the development of other Islamic financial instruments such as SBIS. Simultaneous test results demonstrated the existence of the estimating model. Because of the character of the Indonesian nation as an agricultural country, this study advised Sharia banking to prioritize the usage of third-party funds from the public for the agricultural industry. Sharia banking also needed to produce Islamic finance products that fit the agriculture business sector's needs.

Performing a multi-unit level-3 PSA with MACCS

  • Bixler, Nathan E.;Kim, Sung-yeop
    • Nuclear Engineering and Technology
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    • v.53 no.2
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    • pp.386-392
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    • 2021
  • MACCS (MELCOR Accident Consequence Code System), WinMACCS, and MelMACCS now facilitate a multi-unit consequence analysis. MACCS evaluates the consequences of an atmospheric release of radioactive gases and aerosols into the atmosphere and is most commonly used to perform probabilistic safety assessments (PSAs) and related consequence analyses for nuclear power plants (NPPs). WinMACCS is a user-friendly preprocessor for MACCS. MelMACCS extracts source-term information from a MELCOR plot file. The current development can combine an arbitrary number of source terms, representing simultaneous releases from a multi-unit facility, into a single consequence analysis. The development supports different release signatures, fission product inventories, and accident initiation times for each unit. The treatment is completely general except that the model is currently limited to collocated units. A major practical consideration for performing a multi-unit PSA is that a comprehensive treatment for more than two units may involve an intractable number of combinations of source terms. This paper proposes and evaluates an approach for reducing the number of calculations to be tractable, even for sites with eight or ten units. The approximation error introduced by the approach is acceptable and is considerably less than other errors and uncertainties inherent in a Level 3 PSA.

Strengthening of T-beams using external steel clamps and anchored steel plates

  • Yunus Dere;Yasin Onuralp Ozkilic;Ali Serdar Ecemis;Hasan Husnu Korkmaz
    • Steel and Composite Structures
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    • v.48 no.4
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    • pp.405-417
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    • 2023
  • In order to strengthen the reinforced concrete T-beams having insufficient shear strength, several strengthening techniques are available in the literature. In this study, three different strengthening strategies were numerically studied. First one is affixing steel plates to the beam surfaces. Second one includes tightening external steel bars vertically similar to beam stirrups. The last one is simultaneous application of these two strengthening procedures which is particularly proposed in this work. Available experimental test series in the literature were handled in the study. Finite element (FE) models of reinforced concrete beam specimens having sufficient (Beam-1) and low shear capacity (Beam-2) were created within ABAQUS environment. Strengthened beams with different techniques were also modelled to reflect improved shear capacity. FE simulations made it possible to investigate parameters that were not examined during the previous experimental studies. The results of the analyses were then compared and found consistent with the experimentally obtained data. Experimental and FEM analysis results are in agreement between 1% (closest) and 6%. (maximum). Beam-2 was stregthened with 5 new porposed methods. The rate of increase in shear strength varies between 33% and 64%. It was found that, the strengthening techniques were fairly useful in improving the shear capacity of the considered girder. The model with the proposed strengthening alternative has accomplished a higher load carrying capacity, ductility and stiffness than all of the other models.

Do Sales of an Extended Brand Affect Popularity of its Original?: Empirical Evidence from Motion Pictures and their Original Books

  • Kim, Sang-Hoon;Yi, Ji-Su;Ohm, Joyo
    • Asia Marketing Journal
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    • v.18 no.2
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    • pp.45-61
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    • 2016
  • Book adaptation has been considered an effective strategy in filmmaking. This paper examines the relationship between the box office sales and the performance of its original book focusing on category extension, especially investigating reciprocal spillover effect from a movie to the book. With empirical data, two-way causality between performance of the extension brand (i.e., movies) and that of the parent brand (i.e., books) was examined to test the existence of reciprocal spillover effect. In addition, a linear model was used to test the moderating roles of extension characteristics. The results revealed that the higher the movie's box office sales, the higher the original book's sales after movie's release. The authors also found moderation effects such that if the book has high level of brand awareness prior to movie's release, or if there is a movie tie-in version, or when the book is mentioned in movie trailer, or if the movie is released shortly after the book's publication, then the strength of spillover effect is superior. The current empirical investigation is meaningful considering it provides implications to both buyers and sellers of the extension rights, contributing to the literature of reciprocal spillover effects in category extension.

Does Natural Disasters Have an Impact on Poverty in East Java, Indonesia?

  • SANTOSO, Dwi Budi;AULIA, Dynda Fadhlillah
    • The Journal of Asian Finance, Economics and Business
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    • v.10 no.1
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    • pp.57-66
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    • 2023
  • There is a strong association between poverty levels and the probability of natural disasters. East Java, however, exhibits a distinct pattern. While the rate of poverty is declining, natural disasters are becoming more severe. Considering that East Java is an area with a high risk of natural disasters and a high poverty rate, this study aims to estimate the effect of environmental preservation and the magnitude of the impact of disasters as measured by the Disaster Risk Index (IRBI) on poverty. The 3SLS model is used on secondary data from 38 districts/cities from 2015 to 2021 as an analytical database. Based on the estimation results, there are 3 findings in this study: (i) the role of government, population development, and economic activity have a strong influence on nature conservation; (ii) nature conservation has a strong influence on disaster risk; and (iii) the disaster risk index has a strong effect on poverty. As a result, areas with a high level of disaster risk have a slower rate of poverty reduction. The role of this research is to show the need for the government's role in improving the quality of natural disaster mitigation anticipation, economic activity, and the role of the population in a sustainable manner.

Impact of Institutional and Business Distance on Subsidiary Performance: The Mediation of Subsidiary Entrepreneurship

  • Minkyoung Park;Min-Jae Lee;Taewoo Roh
    • Journal of Korea Trade
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    • v.27 no.2
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    • pp.77-95
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    • 2023
  • Purpose - This study aims to identify the importance of subsidiary entrepreneurship as a key factor when MNE attempts to invest in challenging overseas markets. Through the simultaneous consideration of institutional theory and entrepreneurship theory, this study would like to examine how Korean subsidiaries in the Middle East improve their performance locally. Design/methodology - To reflect the characteristics of emerging markets, this study conducted a survey of Korean subsidiaries in the Middle East in cooperation with KOTRA and analyzed the hypotheses using a structural equation model based on 249 valid responses. Findings - The findings of this study are as follows. First, we found that institutional and business distance would positively affect subsidiaries' entrepreneurship. The result that subsidiaries' entrepreneurship is positively affected by institutional and business distance implies that attempts to close the difference between heterogeneous markets would increase subsidiaries' innovative proactiveness, such as R&D and creative marketing strategies. Second, we confirmed that the institutional and business distance positively mediate the subsidiaries' entrepreneurship growth, leading to high performance. Therefore, Korean subsidiaries are required and prepared to establish strategies to better understand institutional and business distances in advance and reduce the liability of foreignness by conducting customized research and training programs before sending Korean expatriates to local subsidiaries in the Middle East. Originality/value - This study contributed to institutional and entrepreneurship theory by proving the traditional relationship between institutional and business distance to subsidiaries' performance and the mediation of subsidiary entrepreneurship.

Data-Driven Digital Twin for Estimating Response of Pipe System Subjected to Seismic Load and Arbitrary Loads (지진하중 및 임의의 하중을 받는 배관 시스템에 대한 응답을 추정하기 위한 데이터 기반 디지털 트윈)

  • Kim, Dongchang;Kim, Gungyu;Kwag, Shinyoung;Eem, Seunghyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.6
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    • pp.231-236
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    • 2023
  • The importance of Structural Health Monitoring (SHM) in the industry is increasing due to various loads, such as earthquakes and wind, having a significant impact on the performance of structures and equipment. Estimating responses is crucial for the effective health management of these assets. However, using numerous sensors in facilities and equipment for response estimation causes economic challenges. Additionally, it could require a response from locations where sensors cannot be attached. Digital twin technology has garnered significant attention in the industry to address these challenges. This paper constructs a digital twin system utilizing the Long Short-Term Memory (LSTM) model to estimate responses in a pipe system under simultaneous seismic load and arbitrary loads. The performance of the data-driven digital twin system was verified through a comparative analysis of experimental data, demonstrating that the constructed digital twin system successfully estimated the responses.