• Title/Summary/Keyword: Dynamic US

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Research Progress and Development of Technology in Tourism Research: A Bibliometric Analysis

  • Zhong, Lina;Zhu, Mengyao;Sun, Sunny;Law, Rob
    • Journal of Smart Tourism
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    • v.1 no.2
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    • pp.3-12
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    • 2021
  • The interaction between technology and tourism has been a dynamic research area recently. This study aims to review the progress and development of technology in tourism research via a bibliometric analysis. We derive the source data from the Web of Science (WoS) core collection and use CiteSpace for bibliometric analysis, including countries, institutions, authors, categories, references, and keywords. The analysis results are as follows: i) The number of published articles on the role of technology in tourism has increased in recent years. ii) Technology-related articles in tourism are abundant in Tourism Management, Journal of Travel Research, and Annals of Tourism Research. iii) The countries with the most contributions are China, the US, and the UK. The most active institutions are the Hong Kong Polytechnic University, University of Central Florida, Bournemouth University, University of Queensland, and Kyung Hee University. iv) The reference analysis results identify eight extensively researched topics from the most cited papers, and the keyword burst analysis results present an emerging trend. This study identifies the effect and development of technology in tourism research. Our findings provide implications for researchers about the current research focus of technology and the future research trend of technology in the tourism field.

Bankruptcy Protection Law in US With Focus on The Bankruptcy Abuse Prevention And Consumer Act Of 2005

  • Alharthi, Saud Hamoud
    • International Journal of Computer Science & Network Security
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    • v.22 no.5
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    • pp.215-219
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    • 2022
  • Bankruptcy is one of the major areas that have attracted the interest of many researchers in the American system, particularly in terms of the laws that oversee it. It provides a plan of reorganization that enables the debtor or the proprietor to discharge liabilities to the creditors through dividing the assets to settle debts. This activity is carried out under supervision to fairly protect the interests of the creditors. Bankruptcy protection systems are dynamic and complex in nature, in line with the economic sector, ensuring the protection of affected individuals from falling into huge losses. Some bankruptcy procedures give the debtor the opportunity to stay in operation or business activity and benefit from revenues until the debt is settled. This law allows some debtors to be relived from any financial burden after the distribution of assets, even if the debt is not paid in full. In light of the above information, this research paper seeks to explore the nature of the complexity of bankruptcy protection laws, their characteristics, and the justice system that regulate them. It also sheds more light on the decision-making powers on bankruptcy cases. There are specialized courts that cover bankruptcy cases located in district courts in every state.

Elastic Deformation Induced Preload Change in Tilting Pad Journal Bearing (탄성변형으로 인한 틸팅패드 저널베어링의 예압 변화)

  • Donghyun Lee;Junho Suh
    • Tribology and Lubricants
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    • v.39 no.3
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    • pp.102-110
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    • 2023
  • This study aims to quantify the variation in the performance of a tilting pad journal bearing (TPJB) owing to the elastic deformation of its pad. To this end, we first defined a parameter, "elastic preload", and predicted the changes in the performance of the TPJB, as a function of the preload amount. We used the iso-viscosity Reynolds equation, which ignores the temperature rise due to viscous shear in thin films, and the resultant thermal deformation of the bearing structure. We employed a three-dimensional finite element model to predict the elastic deformation of the bearing pad, and a transient analysis, to converge to a static equilibrium condition of the flexible pads and journal. Conducting a modal coordinate transformation helped us avoid heavy computational issues arising from a mesh refinement in the three-dimensional finite element pad model. Moreover, we adopted the Hertzian contact model to predict the elastic deformation at the pivot location. With the aforementioned overall strategy, we predicted the performance changes owing to the elastic deformation of the pad under varying load conditions. From the results, we observed an increase in the preload due to the pad elastic deformation.

Numerical modeling and global performance analysis of a 15-MW Semisubmersible Floating Offshore Wind Turbine (FOWT)

  • Da Li;Ikjae Lee;Cong Yi;Wei Gao;Chunhui Song;Shenglei Fu;Moohyun Kim;Alex Ran;Tuanjie Liu
    • Ocean Systems Engineering
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    • v.13 no.3
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    • pp.287-312
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    • 2023
  • The global performance of a 15 MW floating offshore wind turbine, a newly designed semisubmersible floating foundation with multiple heave plates by CNOOC, is investigated with two independent turbine-floater-mooring coupled dynamic analysis programs CHARM3D-FAST and OrcaFlex. The semisubmersible platform hosts IEA 15 MW reference wind turbine modulated for VolturnUS-S and hybrid type (chain-wire-chain with clumps) 3×2 mooring lines targeting the water depth of 100 m. The numerical free-decay simulation results are compared with physical experiments with 1:64 scaled model in 3D wave basin, from which appropriate drag coefficients for heave plates were estimated. The tuned numerical simulation tools were then used for the feasibility and global performance analysis of the FOWT considering the 50-yr-storm condition and maximum operational condition. The effect of tower flexibility was investigated by comparing tower-base fore-aft bending moment and nacelle translational accelerations. It is found that the tower-base bending moment and nacelle accelerations can be appreciably increased due to the tower flexibility.

Free vibration analysis of FGM plates using an optimization methodology combining artificial neural networks and third order shear deformation theory

  • Mohamed Janane Allah;Saad Hassouna;Rachid Aitbelale;Abdelaziz Timesli
    • Steel and Composite Structures
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    • v.49 no.6
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    • pp.633-643
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    • 2023
  • In this study, the natural frequencies of Functional Graded Materials (FGM) plates are predicted using Artificial Neural Network (ANN). A model based on Third-order Shear Deformation Theory (TSDT) and FEM is used to train the ANN model. Different training methods are tested to simulate input and output dependency. As this is a parametric model, several architectures and optimization algorithms were tested. The proposed model allows us to minimize the CPU time to evaluate candidate material properties for FGM plate material selection and demonstrate their influence on dynamic behavior. Consequently, the time required for the FGM design process (candidate materials for material selection) and the geometric optimization of the FGM structure would remain reasonable. The ANN model can help industries to produce FGM plates with good mechanical properties of the selected materials. I addition, this model can be used to directly predict vibration behavior by testing a large number of FGM plates, representing all possible combinations of metals and ceramics in today's industry, without having to solve any eigenvalue problems.

The Determinants and their Time-Varying Spillovers on Liquefied Natural Gas Import Prices in China Based on TVP-FAVAR Model

  • Ying Huang;Yusheng Jiao
    • Journal of Information Processing Systems
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    • v.20 no.1
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    • pp.93-104
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    • 2024
  • China is playing more predominant role in the liquefied natural gas (LNG) market worldwide and LNG import price is subject to various factors both at home and abroad. Nevertheless, previous studies rarely heed a multiple of factors. A time-varying parameter factor augmented vector auto-regression (TVP-FAVAR) model is adopted to discover the determinants of China's LNG import price and their dynamic impacts from January 2012 to December 2021. According to the findings, market fundamentals have a greater impact on the import price of natural gas in China than overall economic demand, financial considerations, and world oil prices. The primary determinants include domestic gas consumption, consumer confidence and other demand-side information. Then, there are diverse and time-varying spillover effects of the four common determinants on the volatility of China's LNG import price at different intervals and time nodes. The price volatility is more sensitive and long-lasting to domestic natural gas pricing reform than other negative shocks such as the Sino-US trade war and the COVID-19 pandemic. The results in this study further proves the importance of domestic natural gas market liberalization. China ought to do more to support the further marketization of natural gas prices while working harder to guarantee natural gas supplies.

Optimum design of steel frames against progressive collapse by guided simulated annealing algorithm

  • Bilal Tayfur;Ayse T. Daloglu
    • Steel and Composite Structures
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    • v.50 no.5
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    • pp.583-594
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    • 2024
  • In this paper, a Guided Simulated Annealing (GSA) algorithm is presented to optimize 2D and 3D steel frames against Progressive Collapse. Considering the nature of structural optimization problems, a number of restrictions and improvements have been applied to the decision mechanisms of the algorithm without harming the randomness. With these improvements, the algorithm aims to focus relatively on the flawed variables of the analyzed frame. Besides that, it is intended to be more rational by instituting structural constraints on the sections to be selected as variables. In addition to the LRFD restrictions, the alternate path method with nonlinear dynamic procedure is used to assess the risk of progressive collapse, as specified in the US Department of Defense United Facilities Criteria (UFC) Design of Buildings to Resist Progressive Collapse. The entire optimization procedure was carried out on a C# software that supports parallel processing developed by the authors, and the frames were analyzed in SAP2000 using OAPI. Time history analyses of the removal scenarios are distributed to the processor cores in order to reduce computational time. The GSA produced 3% lighter structure weights than the SA (Simulated Annealing) and 4% lighter structure weights than the GA (Genetic Algorithm) for the 2D steel frame. For the 3D model, the GSA obtained 3% lighter results than the SA. Furthermore, it is clear that the UFC and LRFD requirements differ when the acceptance criteria are examined. It has been observed that the moment capacity of the entire frame is critical when designing according to UFC.

The Multisector Model of the Korean Economy: Structure and Coefficients (한국경제(韓國經濟)의 다부문모형(多部門模型) : 모형구조(模型構造)와 추정결과(推定結果))

  • Park, Jun-kyung;Kim, Jung-ho
    • KDI Journal of Economic Policy
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    • v.12 no.4
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    • pp.3-20
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    • 1990
  • The multisector model is designed to analyze and forecast structural change in industrial output, employment, capital and relative price as well as macroeconomic change in aggregate income, interest rate, etc. This model has 25 industrial sectors, containing about 1,300 equations. Therefore, this model is characterized by detailed structural disaggregation at the sectoral level. Individual industries are based on many of the economic relationships in the model. This is what distinguishes a multisector model from a macroeconomic model. Each industry is a behavioral agent in the model for industrial investment, employment, prices, wages, and intermediate demand. The strength of the model lies in the simulating the interactions between different industries. The result of its simulation will be introduced in the next paper. In this paper, we only introduce the structure of the multisector model and the coefficients of the equations. The multisector model is a dynamic model-that is, it solves year by year into the future using its own solutions for earlier years. The development of a dynamic, year-by-year solution allows us to combine the change in structure with a consideration of the dynamic adjustment required. These dynamics have obvious advantages in the use of the multisector model for industrial planning. The multisector model is a medium-term and long-term model. Whereas a short-term model can taken the labor supply and capital stock as given, a long-term model must acknowledge that these are determined endogenously. Changes in the medium-term can be analyzed in the context of long-term structural changes. The structure of this model can be summarized as follow. The difference in domestic and world prices affects industrial structure and the pattern of international trade; domestic output and factor price affect factor demand; factor demand and factor price affect industrial income; industrial income and relative price affect industrial consumption. Technical progress, as measured in terms of total factor productivity and relative price affect input-output coefficients; input-output coefficients and relative price determine the industrial input cost; input cost and import price determine domestic price. The differences in productivity and wage growth among different industries affect the relative price.

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Dynamic Causality and Impulse Response between Maritime Import Volume, Relative Real Effective Exchange Rate, and Regional Industrial Activity : Focusing on a Trade Port of the Jeonnam Province (해상 수입물동량, 상대적 실질실효환율, 지역경기의 동태적 인과성과 충격반응 : 전남지역의 무역항을 중심으로)

  • Kim, Chang-Beom
    • Journal of Korea Port Economic Association
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    • v.33 no.1
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    • pp.47-59
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    • 2017
  • The objective of this study is to determine the short run and long run dynamics between maritime import volume (IMV), industrial production (IP), and real effective exchange rate (REER) of the Korean Won over the REER of certain major currencies (US Dollar, Chinese Yuan, and Japanese Yen) in Korea's Jeonnam province. The Johansen and Juselius cointegration results reveal that at least one cointegration vector or long-run relationship exists. Hence, this study estimated the long run equilibrium equation, which indicates that both IP and REER are inelastic, although the former is bigger than the latter. Moreover, the dynamic causality analysis reveals short and long-run unidirectional causality from IP and REER to IMV in all three models. Further, in all the models, the results indicate short run unidirectional causality from REER to IP. In addition, the impulse response (IR) results show that the impulse of IP and REER decayed after four months. Additionally, the IR analysis results indicate that the REER of the Korean Won over the REER of Japanese Yen is the biggest with respect to the impact of relative REER on IP, which is the proxy variable of regional real income. Thus, empirical results indicated that real income and REER play an important role in determining the Jeonnam's maritime import demand behavior in the short run and long run. More importantly, substantial actions reducing unexpected fluctuation of the REER and real income based on micro and macro economic policies will increase the imported volume in the ports of the Jeonnam province.

Dynamic Predicate: An Efficient Access Control Mechanism for Hippocratic XML Databases (동적 프레디킷 : 허포크라테스 XML 데이타베이스를 위한 효율적인 액세스 통제 방법)

  • Lee Jae-Gil;Han Wook-Shin;Whang Kyu-Young
    • Journal of KIISE:Databases
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    • v.32 no.5
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    • pp.473-486
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    • 2005
  • The Hippocratic database model recently proposed by Agrawal et at. incorporates privacy protection capabilities into relational databases. The authors have subsequenty proposed the Hippocratic XML daかabase model[4], an extension of the Hippocratic database model for XML databases. In this paper, we propose a new concept that we cail the dynamic predicate(DP) for effective access control in the Hippocratic XML database model. A DP is a novel concept that represents a dynamically constructed rendition that tan be adapted for determining the accessibility of elements during query execution. DPs allow us to effectively integrate authorization checking into the query plan so that unauthorized elements are excluded in the process of query execution. Using synthetic and real data, we have performed extensive experiments comparing query processing time with those of existing access control mechanisms. The results show that the proposed access control mechanism improves the wall clock time by up to 219 times over the top-down access control strategy and by up to 499 times over the bottom-up access control strategy. The major contribution of our, paper is enabling effective integration of access control mechanisms with the query plan using the DP under the Hippocratic XML database model.