scholarly journals Farmland lease, high-rent threat and contract instability: evidence from China

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wenjue Zhu ◽  
Krishna P. Paudel ◽  
Sean Inoue ◽  
Biliang Luo
Keyword(s):  
Theoretical Model ◽  
Large Scale ◽  
Estimation Method ◽  
Rent Control ◽  
Content Type ◽  
Land Rental ◽  
High Rent ◽  
Doubly Robust Estimation ◽  
The Stability ◽  
Doubly Robust

PurposeThe purpose is to understand why contract instability occurs when small landowners lease their land to large landholders.Design/methodology/approachThe authors develop a contract theoretical model to understand the stability problem in the farmland lease contract in China, where most landowners are small landholders.FindingsResults from the doubly robust estimation method used on randomly selected interview data from 552 households in nine provinces of China indicate that contract instability can arise endogenously when large landholders sign a contract. The authors conclude that a suitable rent control regime or contract enforcement may be necessary to promote a large-scale farmland transfer in China.Originality/valueThe authors develop a contract theoretical model and apply it to the land rental market in China. Data used are original and collected from farmers located in nine provinces of China.

Stability of jets in a shallow water layer

2015 ◽  
Vol 25 (2) ◽  
pp. 358-374 ◽  
Author(s):  
Zhanhong Wan ◽  
Saihua Huang ◽  
Zhilin Sun ◽  
Zhenjiang You
Keyword(s):  
Reynolds Number ◽  
Stability Analysis ◽  
Shallow Water ◽  
Large Scale ◽  
Bottom Topography ◽  
Bottom Friction ◽  
Rossby Number ◽  
Content Type ◽  
The Stability ◽  
Topographic Parameters

Purpose – The present work is devoted to the numerical study of the stability of shallow jet. The effects of important parameters on the stability behavior for large scale shallow jets are considered and investigated. Connections between the stability theory and observed features reported in the literature are emphasized. The paper aims to discuss these issues. Design/methodology/approach – A linear stability analysis of shallow jet incorporating the effects of bottom topography, bed friction and viscosity has been carried out by using the shallow water stability equation derived from the depth averaged shallow water equations in conjunction with both Chézy and Manning resistance formulae. Effects of the following main factors on the stability of shallow water jets are examined: Rossby number, bottom friction number, Reynolds number, topographic parameters, base velocity profile and resistance model. Special attention has been paid to the Coriolis effects on the jet stability by limiting the rotation number in the range of Ro∈[0, 1.0]. Findings – It is found that the Rossby number may either amplify or attenuate the growth of the flow instability depending on the values of the topographic parameters. There is a regime where the near cancellation of Coriolis effects due to other relevant parameters influences is responsible for enhancement of stability. The instability can be suppressed by the bottom friction when the bottom friction number is large enough. The amplification rate may become sensitive to the relatively small Reynolds number. The stability region using the Manning formula is larger than that using the Chézy formula. The combination of these effects may stabilize or destabilize the shallow jet flow. These results of the stability analysis are compared with those from the literature. Originality/value – Results of linear stability analysis on shallow jets along roughness bottom bed are presented. Different from the previous studies, this paper includes the effects of bottom topography, Rossby number, Reynolds number, resistance formula and bed friction. It is found that the influence of Reynolds number on the stability of the jet is notable for relative small value. Therefore, it is important to experimental investigators that the viscosity should be considered with comparison to the results from inviscid assumption. In contrast with the classical analysis, the use of multi-parameters of the base velocity and topographic profile gives an extension to the jet stability analysis. To characterize the large scale motion, besides the bottom friction as proposed in the related literature, the Reynolds number Re, Rossby number Ro, the topographic parameters and parameters controlling base velocity profile may also be important to the stability analysis of shallow jet flows.

A compact stair-climbing wheelchair with two 3-DOF legs and a 1-DOF base

2016 ◽  
Vol 43 (2) ◽  
pp. 181-192 ◽  
Author(s):  
Chang-Hyuk Lee ◽  
Kyung-min Lee ◽  
Jehong Yoo ◽  
In-su Kim ◽  
Young-bong Bang
Keyword(s):  
Degrees Of Freedom ◽  
Flat Surface ◽  
Estimation Method ◽  
Stable Condition ◽  
Stair Climbing ◽  
Joint Power ◽  
Content Type ◽  
Flat Surfaces ◽  
Simple Estimation ◽  
The Stability

Purpose – The purpose of this paper is to describe a compact wheelchair, which has two 3-degrees of freedom (DOF) legs and a 1-DOF base (the total DOF of the leg system is 7) for stair-climbing, and wheels for flat surface driving. Design/methodology/approach – The proposed wheelchair climbs stairs using the two 3-DOF legs with boomerang-shaped feet. The leg mechanisms are folded into the compact wheelchair body when the wheelchair moves over flat surfaces. The authors also propose a simple estimation method of stair shape using laser distance sensors, and a dual motor driving system to increase joint power. Findings – The proposed wheelchair can climb arbitrary height and width stairs by itself, even when they are slightly curved. During climbing, the trajectory of the seat position is linear to guarantee the comfort of rider, and the wheelchair always keeps a stable condition to ensure the stability in an emergency stop. Originality/value – The wheelchair mechanism with foldable legs and driving wheels enables smooth stair climbing, efficient flat surface driving and additional useful motions such as standing and tilting.

scholarly journals 300-Fold Increase in Production of the Zn2+-Dependent Dechlorinase TrzN in Soluble Form via Apoenzyme Stabilization

2014 ◽  
Vol 80 (13) ◽  
pp. 4003-4011 ◽  
Author(s):  
Colin J. Jackson ◽  
Christopher W. Coppin ◽  
Paul D. Carr ◽  
Alexey Aleksandrov ◽  
Matthew Wilding ◽  
...  
Keyword(s):  
Soluble Protein ◽  
Metal Ion ◽  
Large Scale ◽  
Computational Simulation ◽  
Active Form ◽  
Fold Increase ◽  
Soluble Form ◽  
Scale Production ◽  
Content Type ◽  
The Stability

ABSTRACTMicrobial metalloenzymes constitute a large library of biocatalysts, a number of which have already been shown to catalyze the breakdown of toxic chemicals or industrially relevant chemical transformations. However, while there is considerable interest in harnessing these catalysts for biotechnology, for many of the enzymes, their large-scale production in active, soluble form in recombinant systems is a significant barrier to their use. In this work, we demonstrate that as few as three mutations can result in a 300-fold increase in the expression of soluble TrzN, an enzyme fromArthrobacter aurescenswith environmental applications that catalyzes the hydrolysis of triazine herbicides, inEscherichia coli. Using a combination of X-ray crystallography, kinetic analysis, and computational simulation, we show that the majority of the improvement in expression is due to stabilization of the apoenzyme rather than the metal ion-bound holoenzyme. This provides a structural and mechanistic explanation for the observation that many compensatory mutations can increase levels of soluble-protein production without increasing the stability of the final, active form of the enzyme. This study provides a molecular understanding of the importance of the stability of metal ion free states to the accumulation of soluble protein and shows that differences between apoenzyme and holoenzyme structures can result in mutations affecting the stability of either state differently.

A novel and fast voltage estimation scheme for assessment of power system component outages

2014 ◽  
Vol 33 (4) ◽  
pp. 1296-1328 ◽  
Author(s):  
Seyed Masoud Fatemi ◽  
Mehrdad Abedi ◽  
Behrooz Vahidi ◽  
Sajjad Abedi ◽  
Hassan Rastegar
Keyword(s):  
Power System ◽  
Large Scale ◽  
System Analysis ◽  
Estimation Method ◽  
Load Flow ◽  
System Component ◽  
Fast Method ◽  
Transfer Matrices ◽  
Content Type ◽  
Incremental Model

Purpose – The purpose of this paper is to pursue two following main goals: first, theorizing a new concept named as equivalent bus load in order to make a promising simplification over power system analysis. Second, proposing an outstanding fast and simple approach based on introduced concept for voltage estimation after multiple component outages while satisfying required accuracy. Design/methodology/approach – Equivalent load bus theory introduces three transfer matrices that describe power system topology. Mentioned matrices could be calculated simply after system reconfiguration without matrix inversion. Using transfer matrices a large-scale power system can be modeled by a simple two-bus power system from the viewpoint of any desired bus so that load flow calculation leads to same value. The analysis of simplified power system yields to extract a new incremental model based on equivalent bus load theory that will be distinguished as an outstanding fast method for voltage estimation aim. Findings – A deep study for fast voltage estimation aim is dedicated to evaluate proposed method from the accuracy and quickness point of view and the outcomes are compared to a well-known method as Distribution Factors (DF). Results and computational times unveil that presented approach is more accurate and much faster. Originality/value – A novel and new fast voltage estimation method for assessment of power system component outages is introduced.

Decentralized fuzzy C-means robust algorithm for continuous systems

2019 ◽  
Vol 92 (2) ◽  
pp. 222-228
Author(s):  
Tim Chen ◽  
J.C.Y. Chen
Keyword(s):  
Stability Criterion ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Closed Loop ◽  
Linear Matrix ◽  
Model Description ◽  
Continuous Systems ◽  
Content Type ◽  
Fuzzy C Means ◽  
The Stability

Purpose This paper aims to address the robust controller design problem for a class of fuzzy C-means clustering algorithm that is robust against both the plant parameter perturbations and controller gain variations. Based on Takagi–Sugeno (T-S) fuzzy model description, the stability and control problems of nonlinear systems are studied. Design/methodology/approach A recently proposed integral inequality is selected based on the free-weight matrix, and the less conservative stability criterion is given in the form of linear matrix inequalities (LMIs). Findings Under the premise that the controller and the system share the same, the method does not require the number of membership functions and rules. Practical implications Furthermore, the modified controller in a large-scale nonlinear system is utilized as a stability criterion for a closed-loop T-S fuzzy system obtained by LMI, and is rearranged by a machine learning membership function. Originality/value The closed-loop controller criterion is derived by energy functions to guarantee the stability of systems. Finally, an example is given to demonstrate the results.

scholarly journals Doubly Robust Crowdsourcing

2022 ◽  
Vol 73 ◽  
pp. 209-229
Author(s):  
Chong Liu ◽  
Yu-Xiang Wang
Keyword(s):  
Large Scale ◽  
Amazon Mechanical Turk ◽  
Test Time ◽  
Fair Price ◽  
Data Points ◽  
Label Aggregation ◽  
Doubly Robust Estimation ◽  
Sheer Size ◽  
Statistical Estimation Problem ◽  
Doubly Robust

Large-scale labeled dataset is the indispensable fuel that ignites the AI revolution as we see today. Most such datasets are constructed using crowdsourcing services such as Amazon Mechanical Turk which provides noisy labels from non-experts at a fair price. The sheer size of such datasets mandates that it is only feasible to collect a few labels per data point. We formulate the problem of test-time label aggregation as a statistical estimation problem of inferring the expected voting score. By imitating workers with supervised learners and using them in a doubly robust estimation framework, we prove that the variance of estimation can be substantially reduced, even if the learner is a poor approximation. Synthetic and real-world experiments show that by combining the doubly robust approach with adaptive worker/item selection rules, we often need much lower label cost to achieve nearly the same accuracy as in the ideal world where all workers label all data points.

scholarly journals Investigating the relationship between supply chain innovation, risk management capabilities and competitive advantage in global supply chains

2018 ◽  
Vol 38 (1) ◽  
pp. 2-21 ◽  
Author(s):  
Dong-Wook Kwak ◽  
Young-Joon Seo ◽  
Robert Mason
Keyword(s):  
Risk Management ◽  
Supply Chain ◽  
Theoretical Model ◽  
Competitive Advantage ◽  
Structural Equation ◽  
Large Scale ◽  
Positive Influence ◽  
Content Type ◽  
Management Capability ◽  
Management Capabilities

Purpose The purpose of this paper is to propose and validate a theoretical model to investigate whether supply chain (SC) innovation positively affects risk management capabilities, such as robustness and resilience in global SC operations, and to examine how these capabilities may improve competitive advantage. Design/methodology/approach A theoretical model was developed from extant studies and assessed through the development of a large-scale questionnaire survey conducted with South Korean manufacturers and logistics intermediaries involved in global SC operations. The data were analysed using confirmatory factor analysis and structural equation modelling to validate the suggested model. Findings It was found that innovative SCs have a discernible positive influence on all dimensions of risk management capability, which in turn has a significant impact on enhancing competitive advantage. Therefore, this work provides evidence for the importance of SC innovation and risk management capability in supporting competitive advantage. Research limitations/implications This study contributes to providing an empirical understanding of the strategic retention of SC innovation and risk management capabilities in the SC management discipline. Furthermore, it confirms and expands existing theories about innovation and competitive advantage. Practical implications The finding provides firm grounds for managerial decisions on investment in technology innovation and process innovation. Originality/value This research is the first of its kind to empirically validate the relationships between SC innovation, risk management capabilities and competitive advantage.

Financial distress determinants among SMEs: empirical evidence from Sweden

2020 ◽  
Vol 47 (3) ◽  
pp. 547-560 ◽  
Author(s):  
Darush Yazdanfar ◽  
Peter Öhman
Keyword(s):  
Financial Crisis ◽  
Financial Distress ◽  
Large Scale ◽  
Global Financial Crisis ◽  
Binary Logistic Regression ◽  
Data Availability ◽  
Cross Sectional ◽  
Data Set ◽  
Content Type ◽  
The Global Financial Crisis

PurposeThe purpose of this study is to empirically investigate determinants of financial distress among small and medium-sized enterprises (SMEs) during the global financial crisis and post-crisis periods.Design/methodology/approachSeveral statistical methods, including multiple binary logistic regression, were used to analyse a longitudinal cross-sectional panel data set of 3,865 Swedish SMEs operating in five industries over the 2008–2015 period.FindingsThe results suggest that financial distress is influenced by macroeconomic conditions (i.e. the global financial crisis) and, in particular, by various firm-specific characteristics (i.e. performance, financial leverage and financial distress in previous year). However, firm size and industry affiliation have no significant relationship with financial distress.Research limitationsDue to data availability, this study is limited to a sample of Swedish SMEs in five industries covering eight years. Further research could examine the generalizability of these findings by investigating other firms operating in other industries and other countries.Originality/valueThis study is the first to examine determinants of financial distress among SMEs operating in Sweden using data from a large-scale longitudinal cross-sectional database.

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