• Computers and Concrete
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• 제29권 5호
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• pp.323-334
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• 2022

In order to study the axial compression performance of basalt-fiber reinforced recycled concrete (BFRRC) filled circular steel tubular short columns, the axial compression performance tests of seven short column specimens were conducted to observe the mechanical whole-process and failure mode of the specimens, the load-displacement curves and the load-strain curves of the specimens were obtained, the influence of design parameters on the axial compression performance of BFRRC filled circular steel tubular short columns was analyzed, and a practical mathematical model of stiffness degradation and a feasible stress-strain curve equation for the whole process were suggested. The results show that under the axial compression, the steel tube buckled and the core BFRRC was crushed. The load-axial deformation curves of all specimens show a longer deformation flow amplitude. Compared with the recycled coarse aggregate (RCA) replacement ratio and the basalt fiber dosage, the BFRRC strength has a great influence on the peak bearing capacity of the specimen. The RCA replacement ratio and the BFRRC strength are detrimental to ductility, whereas the basalt fiber dosage is beneficial to ductility.

• Steel and Composite Structures
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• 제45권3호
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• pp.369-388
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• 2022

Composite effect between steel and recycled aggregate concrete (RAC) in steel reinforced-RAC (SRRAC) structures can effectively improve RAC's adverse mechanical properties due to the natural defects of recycled coarse aggregate (RCA). However, the performance of SRRAC after thermal exposure will have a great impact on the safety of the structure. In this paper, firstly, the mechanical properties of SRRAC structures after high temperatures exposure were tested, including 24 SRRAC columns and 32 SRRAC beams. Then, the change rules of beams and columns performance with the maximum temperature and replacement percentage were compared. Finally, the formulas to evaluate the residual bearing capacity of SRRAC beams and columns after exposure to high temperatures were established. The experimental results show that the maximum exposure temperature can be judged by the apparent phenomenon and mass loss ratio of RAC. After high temperatures exposure, the mechanical properties of SRRAC beams and columns change significantly, where the degradation of bearing capacity and stiffness is the most obvious. Moreover, it is found that the degradation degree of compression member is more serious than that of flexural member. The formulas of residual bearing capacity established by introducing influence coefficient of material strength agree well with the experimental results.

• 한국항해항만학회지
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• 제48권2호
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• pp.78-87
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• 2024

To quantitatively assess the correlation between subsystems within a port cluster and the overall coordinated development of the port group, the current paper evaluates the coordinated development of port clusters. First, we construct an evaluation index system for the coupling and coordination of port clusters. Next, we introduce the contribution index of port subsystems, coupling degree, and coupling coordination degree functions to formulate a coupling coordination evaluation model for the port cluster. Finally, we use the Yangtze River Delta port cluster as a case study for validation, specifically using empirical data from 2012 to 2021. The findings reveal distinct phased characteristics in the coupling and coordination of port clusters in the Yangtze River Delta, marked by a notable transition from "maladjustment" to "coordination." Further, sustained high coupling values over a decade indicate a significant level of competition and cooperation among ports within the Yangtze River Delta port cluster. Over time, this competitive and collaborative dynamic has progressively evolved toward a more positive and structured direction. Lastly, it is expected that the evaluation model proposed in this paper can be extrapolated to other port clusters to gauge the extent of coordinated development, thereby facilitating horizontal comparisons and vertical analyses.

• 융합경영연구
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• 제12권3호
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• pp.1-12
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• 2024

Purpose: As a major economy attracting foreign investment, China is currently facing significant international economic pressure due to the appreciation of the RMB. Additionally, China is at a critical period of socio-economic development, where foreign direct investment (FDI) plays an indispensable role in stabilizing economic growth, adjusting industrial structure, and promoting economic transformation. Research design, data and methodology: This paper focuses on the relationship between RMB exchange rate expectations and FDI. It examines the magnitude of their relationship through empirical research using cointegration tests, Granger causality tests, and BVAR (Bayesian Vector Autoregression) analysis. Results: The comprehensive study of the empirical results in this paper concludes that there is a long-term cointegrated relationship between China's RMB exchange rate expectations and foreign direct investment, indicating that their relationship is stable in the long run. It is also found that RMB exchange rate expectations have a significantly positive impact in the short term, but this impact is not significant in the long term. Conclusions: The paper also considers the possibility of establishing a China-EU Free Trade Area in the future and offers policy recommendations regarding RMB exchange rate expectations and foreign direct investment.

• 동아시아경상학회지
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• 제12권2호
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• pp.19-28
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• 2024

Purpose: In the era of global economic integration, China's doors of openness have widened, leading to increasingly frequent economic and trade exchanges between countries. Exchange rates, as a crucial economic lever for regulating foreign markets, play a vital role in the balanced development of a nation's international trade. Therefore, the relationship between exchange rate fluctuations and foreign trade has garnered widespread attention. Research design, data and methodology: This study utilizes import and export trade data between China and five ASEAN countries from 1998 to 2019. It employs regression analysis to examine the specific impact of the real effective exchange rate of the Renminbi on China's import and export trade with these ASEAN nations. Results: The empirical analysis yields the following conclusions: Firstly, the real effective exchange rate of the Renminbi exhibits a long-term stable relationship with China's import and export trade with the five ASEAN countries. Renminbi appreciation contributes to an increase in export trade volume but is detrimental to import trade. While this conclusion may deviate from classical trade theories, it aligns with the practical realities of China's foreign trade. Secondly, the coefficients before Gross Domestic Product (GDP) all display positive values, indicating that the growth of total economic demand has a stimulating effect on China's import and export trade.

• 산경연구논집
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• 제15권5호
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• pp.17-27
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• 2024

Purpose: The renminbi (RMB) has appreciated alongside the elevation of China's economic status, leading to increased exchange rate volatility. Moreover, China's medical industry saw a surge in import and export trade volume, with trade related to epidemic prevention and control in the medical sector significantly increasing its share. The medical device trade, in particular, occupies a substantial portion of this trade. Research design, data and methodology: This paper focuses on the import and export value of medical devices in the medical industry as a case study to explore the impact of RMB exchange rate fluctuations on the import and export trade of the medical industry during the pandemic. Additionally, it investigates whether the import and export trade of the medical industry can be a contributing factor to the fluctuations in the RMB exchange rate. Results: Through an empirical study on the import and export values of medical devices in the medical industry over the past three years, as well as the RMB exchange rate, this paper establishes a VAR model and conducts a series of tests including stationarity tests and cointegration tests. Conclusions: The conclusion is that fluctuations in the RMB exchange rate have a long-term impact on China's medical industry's import and export trade.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.692-700
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• 2008

A trial was conducted to study the influence of different levels of a commercial enzyme complex on performance, nutrient availability, blood parameters, digestive tract measurements, amylase and trypsin activity of the digestive tract and gut morphology in broilers fed the typical diets in north China. There were four treatments: the control diet and the other three enzyme complex supplemented diets which were 180 mg/kg, 360 mg/kg and 720 mg/kg enzyme complex supplemented to the control diet, respectively. The birds fed the diets supplemented with 180 mg/kg and 360 mg/kg enzyme complex had better performance and nutrient availability, the activities of amylase and trypsin in the digestive tract in the two treatments were improved, the villus height and surface area of villus in the small intestine increased and the crypt depth and epithelial thickness of small intestine decreased. Relative weights of pancreas and relative weights and lengths of small intestine decreased. However, the addition of 720 mg/kg enzyme complex had no effects on these parameters and increased crypt depth and epithelial thickness of the small intestine. The data suggested that suitable supplementation of enzyme complex was beneficial for the birds, while excess enzyme complex inhibited secretion of endogenous enzyme and destroyed the structure of the small intestine.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 International Conference on Digital Policy & Management
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• pp.375-387
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• 2004

The paper presents an Integrated E-Community System (IECS) for management, decision and service, designed for the e-government project of Haishu District of Ningbo, Zhejiang, China. The project need is to promote the integration of management information and service information of communities, providing a unified platform on which different departments of the district government can share and exchange community information, government officers can analyze information and make decisions, and the outside users can access and request services. To meet the project need, the IECS consists of five parts: 1) The Central DataBase (CDB) that stores all information related with management, decision and service of communities: 2) Information Extracting Subsystem (IES) that provides functions of extracting data from data sources, transforming and loading them into the CDB for system administrators; 3) Information Management Subsystem (IMS) that provides functions of querying and sharing of information for government users, and functions of information maintenance, rights and log management for system administrators: 4) Intelligent Analysis Subsystem (IAS) that provides functions of extracting analysis related data from the CDB and loading them into the DW, and functions of multi-dimensional analysis and decision-making based on the DW and OLAP for government users; 5) Information Service Website (ISW) that provides functions of promulgating and collecting of information for government users and system administrators, and functions of browsing, querying and requesting of service information for outside users. The IECS supports management, decision and service of a government based on a unified data platform--the CDB, and ensures data security by providing different workplaces and rights for different users. In the real application, the system works well.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1755-1764
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• 2016

The application of Bacillus sp. in the biological control of plant soilborne diseases has been shown to be an environmentally friendly alternative to the use of chemical fungicides. In this study, the effects of bioorganic fertilizer (BOF) fortified with Bacillus amyloliquefaciens SQY 162 on the suppression of tomato bacterial wilt were investigated in pot experiments. The disease incidence of tomato wilt after the application of BOF was 65.18% and 41.62% lower at 10 and 20 days after transplantation, respectively, than in the control condition. BOF also promoted the plant growth. The SQY 162 populations efficiently colonized the tomato rhizosphere, which directly suppressed the number of Ralstonia solanacearum in the tomato rhizosphere soil. In the presence of BOF, the activities of defense-related enzymes in tomato were lower than in the presence of the control treatment, but the expression levels of the defense-related genes of the plants in the salicylic acid and jasmonic acid pathways were enhanced. It was also found that strain SQY 162 could secrete antibiotic surfactin, but not volatile organic compounds, to suppress Ralstonia. The strain could also produce plant growth promotion compounds such as siderophores and indole-3-acetic acid. Thus, owing to its innate multiple-functional traits and its broad biocontrol activities, we found that this antagonistic strain isolated from the tobacco rhizosphere could establish itself successfully in the tomato rhizosphere to control soilborne diseases.

• 한국항만경제학회지
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• 제26권1호
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• pp.131-143
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• 2010

본 논문은 세계 주요 컨테이너 항만의 효율성을 분석하기 위해 Containerisation International Yearbook에 수록된 컨테이너 항만 가운데 컨테이너 물동량 처리기준(2007년)으로 20대 항만을 선정하여 DEA(CCR, BCC, 규모효율성)분석을 실시하였다. 항만의 효율성에 영향을 미칠 수 있는 변수를 국내외 기존 연구를 참고하여 선정하였다. 투입변수는 선석수, 수심, 크레인수, 총면적을, 산출변수는 컨테이너 화물처리량을 선정하였다. 분석결과를 요약하면, 첫째, DEA-CCR효율성은 선전항(중국)이 1.0으로서 분석대상 항만 중 가장 효율적인 항만으로 분석되었다. 둘째, DEA-BCC효율성을 분석한 결과 싱가포르, 선전항(중국), 닝보(중국), 탄중펠레파스(말레이시아)가 효율성 1.0으로서 분석대상 항만 중 효율적인 항만으로 분석되었다. 셋째, 규모의 효율성 분석결과는 선전항(중국) 만이 2004년부터 2007년까지 4년 연속효율성 1.0으로서 분석대상 항만 중 가장 효율적인 항만으로 분석되었다.