Walid Ben Omrane, Chao He, Zhongzhi Lawrence He and Samir Trabelsi
Forecasting the future movement of yield curves contains valuable information for both academic and practical issues such as bonding pricing, portfolio management, and government…
Abstract
Purpose
Forecasting the future movement of yield curves contains valuable information for both academic and practical issues such as bonding pricing, portfolio management, and government policies. The purpose of this paper is to develop a dynamic factor approach that can provide more precise and consistent forecasting results under various yield curve dynamics.
Design/methodology/approach
The paper develops a unified dynamic factor model based on Diebold and Li (2006) and Nelson and Siegel (1987) three-factor model to forecast the future movement yield curves. The authors apply the state-space model and the Kalman filter to estimate parameters and extract factors from the US yield curve data.
Findings
The authors compare both in-sample and out-of-sample performance of the dynamic approach with various existing models in the literature, and find that the dynamic factor model produces the best in-sample fit, and it dominates existing models in medium- and long-horizon yield curve forecasting performance.
Research limitations/implications
The authors find that the dynamic factor model and the Kalman filter technique should be used with caution when forecasting short maturity yields on a short time horizon, in which the Kalman filter is prone to trade off out-of-sample robustness to maintain its in-sample efficiency.
Practical implications
Bond analysts and portfolio managers can use the dynamic approach to do a more accurate forecast of yield curve movements.
Social implications
The enhanced forecasting approach also equips the government with a valuable tool in setting macroeconomic policies.
Originality/value
The dynamic factor approach is original in capturing the level, slope, and curvature of yield curves in that the decay rate is set as a free parameter to be estimated from yield curve data, instead of setting it to be a fixed rate as in the existing literature. The difference range of estimated decay rate provides richer yield curve dynamics and is the key to stronger forecasting performance.
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Chao He, Yanxi Li and Runxiang Xu
The purpose of this study is to provide a textual approach to quantify the perception of uncertainty from management side and investigate how firms manage their overseas…
Abstract
Purpose
The purpose of this study is to provide a textual approach to quantify the perception of uncertainty from management side and investigate how firms manage their overseas investment dynamics when perceiving an increase in economic policy uncertainty (EPU).
Design/methodology/approach
Using a textual analysis approach, the study evaluates firm-level perception of EPU. Based on the data from China's listed firms between 2007 and 2018, it examines the association between firm-level perception of EPU and overseas investment using probit model and fixed effects regression with robust standard error adjusted for heteroscedasticity and clustered by firm.
Findings
The study finds that the level of EPU perceived by individual firms is heterogeneous. Moreover, it finds that firm-level perception of EPU is positively associated with firms' overseas investment. When perceiving an increase in EPU, firms are more likely to invest abroad and their overseas investment is more diverse. Further analysis shows that the positive association between firm-level perception of EPU and overseas investment is weaker in firms with higher financing cost, investment irreversibility and management incentive but stronger in firms with more intensive industry competition. However, it does not find significant difference in the impact of firm-level perception of EPU on overseas investment of state-owned enterprises (SOEs) and non-state-owned enterprises (non-SOEs). The results are robust to using alternative measures of primary variables and to endogeneity concerns.
Research limitations/implications
First, although the data on outward foreign direct investment (OFDI) at the national and provincial levels are comprehensive, the data on OFDI at the firm level are still relatively scarce. As the firm-level OFDI data become available, future study could be extended to OFDI flow. Second, future study could use other information disclosed by firms to evaluate their perception of EPU from host countries and examine the impact of bilateral EPU on overseas investment. Third, by evaluating firm-level perception of uncertainty in terms of a particular type of economic policies, such as fiscal policy, monetary policy, trade policy and foreign investment policy, future study could probe the sources of EPU affecting firms' overseas investment.
Practical implications
First, although uncertainty increases the volatility of firms' investment activities, firms can recognize and seize investment opportunities in an uncertain economic environment and make profits through resource integration. Second, as the association between firm-level perception of EPU and overseas investment depends on firm and industry characteristics, firms with higher financing cost, investment irreversibility and management incentive should be more cautious when making overseas investment decisions during uncertainty times. Third, governments should increase the transparency and the stability of their economic policies to help firms plan their investment policies.
Originality/value
The study extends the literature related to EPU measurement by constructing a firm-level perception index of EPU based on firms' annual reports using a textual analysis approach. Moreover, it sheds some light on the mechanism of how firms modulate their overseas investment activities under uncertainty.
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Shijian Wang, Qiyuan He, Quanwei Liang, Jie Cui, Qing Jiang, Chang Liu, Chao He, Lang Li and Yao Chen
The study aims to examine the effect of inclusions and inherent microstructure on fatigue behavior of 34Cr2Ni2Mo steel.
Abstract
Purpose
The study aims to examine the effect of inclusions and inherent microstructure on fatigue behavior of 34Cr2Ni2Mo steel.
Design/methodology/approach
Fatigue behavior of 34Cr2Ni2Mo steel was investigated for up to 1E10 cycles.
Findings
Results showed that both inclusion and inherent microstructure have an influence on the crack initiation mechanism. Fatigue cracks mostly initiated from inclusions, whereas substrate-induced crack initiations were also observed. Fatigue life of inclusion-induced failures is mostly determined by the location of inclusions rather than the loading stress. The inherent microstructure seems to tolerate inclusions at a lower stress level in very high-cycle regime owing to the absence of internal inclusion-induced failure. For the substrate-induced crack initiations, high-density dislocations are found to be accumulated around the carbide particle-matrix interface, which may be the cause of crack initiation in the inherent structure due to strain localization.
Originality/value
The effect of inclusions and inherent microstructure on fatigue behavior of 34Cr2Ni2Mo steel up to 1E10 cycles.
Highlights
Fatigue failure occurs even at a lifetime of 5.76E9 cycles.
Surface inclusion induced premature failures.
Inherent microstructure tolerates inclusions at lower stress level.
Internal carbides promote substrate-induced crack initiations.
Fatigue failure occurs even at a lifetime of 5.76E9 cycles.
Surface inclusion induced premature failures.
Inherent microstructure tolerates inclusions at lower stress level.
Internal carbides promote substrate-induced crack initiations.
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Huiyun Shi, Lu Zhang, Boyao Song and Chao He
The development of tourism around Wolong Nature Reserve changes the local communities' ways of life. This study discusses how ecotourism affects the households' use of their…
Abstract
Purpose
The development of tourism around Wolong Nature Reserve changes the local communities' ways of life. This study discusses how ecotourism affects the households' use of their capitals, the livelihood strategies as well as illustrates the impact on the habitats in the reserve through Department for International Development’s (DFID) Sustainable Livelihood Framework (SLF) with data collected during fieldwork.
Design/methodology/approach
The study focuses on (1) Calculating Livelihood Capital Index. (2) The effects of livelihood capitals on livelihood strategy were calculated by multinomial logistic regression.
Findings
The study has yielded the following results: (1) In general, tourism promotes people's livelihood capitals. The growth in different types of households under tourism settings is ranked as full-time tourism operators > part-time tourism operators > traditional living households. (2) Tourism development mainly shifts livelihood strategies in two ways. Firstly, travel operating replaces some traditional practices that make livings; secondly, increased needs for potherbs and herbs from tourists let households enter into the hills to pick the plants more actively, which intensifies the destruction of giant panda's habitats. (3) Nine types of livelihood capitals indicators, namely farmland quality, distance between house and roads, number of laborers, average housing area, average income per person, whether family members being village cadres, and ever having received skills training shape livelihood strategies in different levels.
Originality/value
Three discussions are drawn from the study: (1) Enhancing the exploit for tourism resources to form a diversified competition. (2) Introducing herb growing to fulfill tourists' needs and improve people's livelihood in the meantime. (3) Optimizing the tourism surveillance and management system and improving the rules and regulations.
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Yajun Dai, Chang Liu, Min Zhan, Xiangyu Wang, Chao He and Qingyuan Wang
The investigations provide a basis for the optimization of the alloy 6061-T6 friction stir welding (FSW) process to improve the mechanical properties of welded joints.
Abstract
Purpose
The investigations provide a basis for the optimization of the alloy 6061-T6 friction stir welding (FSW) process to improve the mechanical properties of welded joints.
Design/methodology/approach
The local deformation of the FSW joint in tension and fatigue test were experimentally investigated by digital image correlation (DIC) technique.
Findings
The local stress-strain behaviors of the sub-regions show that the plastic strain always concentrated at the heat affected zone (HAZ) on the advancing side both in tension and high cycle fatigue and eventually leads to the final fracture. The evolution of the plastic strain at very low stress is extremely slow and accounts for most of the total fatigue life. However, the local deformation exhibits a sudden increase just before the fatigue failure.
Originality/value
Based on the experimental data, the result indicates that the HAZ is the weakest zone across the weld and the strain localization in high cycle fatigue is very harmful and unpredictable for the FSW joints.
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Min Zhan, Yajun Dai, Chang Liu, Xiangyu Wang, Lang Li, Yongjie Liu, Chao He and Qingyuan Wang
The purpose of this paper is to determine (1) the relationship between microstructure and fatigue cracking behavior and (2) effect of rolling on the process of crack initiation…
Abstract
Purpose
The purpose of this paper is to determine (1) the relationship between microstructure and fatigue cracking behavior and (2) effect of rolling on the process of crack initiation and propagation in FeCrAl alloys.
Design/methodology/approach
The qualitative and quantitative fracture studies were performed using scanning electron microscopy and the non-contact optical measurement system (IFMG5).
Findings
The results show that the formation of facets, rough facets and parallel stripes in the crack initiation and early crack propagation zones are closely related to the sensitivity of crack behavior to the microstructure of the material. Besides, the rolling process has a significant influence on the small crack initiation and propagation behavior. Quantitative analysis demonstrates that the size of the stress intensity factor and plastic zone size in the rough zone is associated with the rolling process.
Originality/value
The findings of this study have the potential to enhance the understanding of the microstructural crack formation mechanisms in FeCrAl alloys and shed light on the impact of rolling on the long-term and ultra-long fatigue behavior of these alloys. This new knowledge is vital for improving manufacturing processes and ensuring the safety and reliability of FeCrAl alloys used in nuclear industry applications.
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Debiao Meng, Shiyuan Yang, Chao He, Hongtao Wang, Zhiyuan Lv, Yipeng Guo and Peng Nie
As an advanced calculation methodology, reliability-based multidisciplinary design optimization (RBMDO) has been widely acknowledged for the design problems of modern complex…
Abstract
Purpose
As an advanced calculation methodology, reliability-based multidisciplinary design optimization (RBMDO) has been widely acknowledged for the design problems of modern complex engineering systems, not only because of the accurate evaluation of the impact of uncertain factors but also the relatively good balance between economy and safety of performance. However, with the increasing complexity of engineering technology, the proposed RBMDO method gradually cannot effectively solve the higher nonlinear coupled multidisciplinary uncertainty design optimization problems, which limits the engineering application of RBMDO. Many valuable works have been done in the RBMDO field in recent decades to tackle the above challenges. This study is to review these studies systematically, highlight the research opportunities and challenges, and attempt to guide future research efforts.
Design/methodology/approach
This study presents a comprehensive review of the RBMDO theory, mainly including the reliability analysis methods of different uncertainties and the decoupling strategies of RBMDO.
Findings
First, the multidisciplinary design optimization (MDO) preliminaries are given. The basic MDO concepts and the corresponding mathematical formulas are illustrated. Then, the procedures of three RBMDO methods with different reliability analysis strategies are introduced in detail. These RBMDO methods were proposed for the design optimization problems under different uncertainty types. Furtherly, an optimization problem for a certain operating condition of a turbine runner blade is introduced to illustrate the engineering application of the above method. Finally, three aspects of future challenges for RBMDO, namely, time-varying uncertainty analysis; high-precision surrogate models, and verification, validation and accreditation (VVA) for the model, are discussed followed by the conclusion.
Originality/value
The scope of this study is to introduce the RBMDO theory systematically. Three commonly used RBMDO-SORA methods are reviewed comprehensively, including the methods' general procedures and mathematical models.
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Boyao Song, Bingxin Liu and Chao He
The main objectives of collective forest tenure reform in China are to stimulate rural households to invest in forestry management, protect the ecosystem and improve their…
Abstract
Purpose
The main objectives of collective forest tenure reform in China are to stimulate rural households to invest in forestry management, protect the ecosystem and improve their livelihood. By constructing the unbalanced panel data of household investment, this study discusses the dynamic changes and influencing factors of household investment, which will lay a foundation for further research and provide a reference for decision-making.
Design/methodology/approach
Based on 3,500 samples from rural households in the provinces of Fujian, Hunan, Yunnan, Shaanxi, Jiangxi, Gansu, and Liaoning collected during field investigations from 2010 to 2015, this study conducts an empirical analysis of the household investment in forestry management and its factors with nonbalanced panels.
Findings
According to the analysis, the average investment in forestry management per household from 2010 to 2015 fluctuates greatly; the age of the householder, increased forestry area, subsidies, joining professional cooperatives, and forest tenure mortgage show positive effects on achieving the objectives.
Originality/value
The discussions are drawn from the study that supporting policies such as the forest tenure transfer system, professional cooperatives, financial services and subsidies should be further improved to sustain a positive in the forestry industry.
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Qing-Yun Deng, Shun-Peng Zhu, Jin-Chao He, Xue-Kang Li and Andrea Carpinteri
Engineering components/structures with geometric discontinuities normally bear complex and variable loads, which lead to a multiaxial and random/variable amplitude stress/strain…
Abstract
Purpose
Engineering components/structures with geometric discontinuities normally bear complex and variable loads, which lead to a multiaxial and random/variable amplitude stress/strain state. Hence, this study aims how to effectively evaluate the multiaxial random/variable amplitude fatigue life.
Design/methodology/approach
Recent studies on critical plane method under multiaxial random/variable amplitude loading are reviewed, and the computational framework is clearly presented in this paper.
Findings
Some basic concepts and latest achievements in multiaxial random/variable amplitude fatigue analysis are introduced. This review summarizes the research status of four main aspects of multiaxial fatigue under random/variable amplitude loadings, namely multiaxial fatigue criterion, method for critical plane determination, cycle counting method and damage accumulation criterion. Particularly, the latest achievements of multiaxial random/variable amplitude fatigue using critical plane methods are classified and highlighted.
Originality/value
This review attempts to provide references for further research on multiaxial random/variable amplitude fatigue and to promote the development of multiaxial fatigue from experimental research to practical engineering application.
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Cong Liu, Yanguo Yin, Shibang Ma, Wei Liu, Guiquan Han, Haoping Wang and Chao He
This study aims to investigate the effect of steel fibers on the mechanical and tribological properties of FeS/Cu–Bi self-lubricating materials.
Abstract
Purpose
This study aims to investigate the effect of steel fibers on the mechanical and tribological properties of FeS/Cu–Bi self-lubricating materials.
Design/methodology/approach
The microstructure of the material was characterized by scanning electron microscopy. Tests on the crushing strength, impact toughness and tribological properties of materials were conducted using a universal electronic testing machine, a 300 J pendulum impact testing machine and an M200 ring-block sliding tribometer, respectively.
Findings
The mechanical properties of the material initially increased and then stabilized with increased copper-plated steel-fiber length. When the length of the copper-plated steel fiber was 7 mm, the mechanical properties of the material reached stability. Compared with the material without a copper-plated steel fiber, its crushing strength and impact toughness increased by 32.6% and 53%, respectively. A copper-plated steel fiber with a length of 7 mm lay flat in a copper matrix can strengthen the friction interface and enrich the lubricant. Accordingly, the antifriction and wear resistance of the materials increased by 17.6% and 55%, respectively.
Originality/value
The effects of copper-plated steel fibers on the properties of FeS/Cu–Bi self-lubricating materials were clarified. This work can serve as a reference for improving material performance and its engineering applications.