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The purpose of this paper is to quantify the impact of Wal-Mart Supercenters (WMSs) on supermarkets’ profit margins using fluid milk in the Dallas/Fort Worth metropolitan area in the USA as a case study.

The authors develop a two-stage dynamic entry game to model market competition in the pre- and post-WMS stages, and test the theoretical model using the method of simulated moments and milk scanner data from Dallas/Fort Worth supermarkets.

The empirical findings show that the entry of WMSs accounts for an average of about 16.29-25.69 percent decline in milk profit margins of nearby, or incumbent, supermarkets. Economies of scale and chain synergies are found to be five times more significant for WMSs than for incumbent supermarkets, granting Wal-Mart a significant competitive edge.

This paper quantifies the impact of WMS’s entry on incumbent supermarkets’ profit margins through a structural model of entry. In addition, this paper assesses the effect economies of scale stemming from the ability to provide shopping convenience to consumers as well as chain economies from operating stores near each other.

The purpose of this paper is to present a new model to empirically analyze retail pricing dynamics led by the competition between retailers, using fluid milk markets of three US metropolitan areas as a case study. The research is important for Chinese public policy makers to find the reasons of retail price fluctuations and provides policy makers with the direction and rationale to intervene in retailing markets.

This paper empirically applies dynamic oligopolistic competition model using Markov switching regression. The dataset used in this study includes 58 four‐week‐ending observations covering the period from March 1996 to July 2000 for three cities, Boston, Dallas, and Seattle.

The empirical results illustrate the Markov switching regression not only successfully identifies the Markov perfect equilibrium in each market, but decomposes the retail price series into the corresponding equilibrium regimes. The forecasting power of the model is surprising so it can serve as a price monitor of the government. Additionally, the model reveals the different consumer welfare implications given different price regimes. The welfare analysis shows that consumers are most likely to be worse off through price fluctuations, while they are not always better off through a sticky (stable) price series in a market.

The first limitation of the paper is the retail price data is four‐week ending. If a cycle evolves faster within four weeks, the model would overestimate the duration and underestimate the amplitude of cycles. So the study serves as an upper bound of the reality. The second limitation is the number of regimes. More than three regimes studied in a Markov switching regression may cause a series of empirical issues. However, if we integrate several regimes into one regime, we will lose rich information about the competitiveness of the markets.

This paper is the first work to apply the dynamic pricing analysis to food industry by using fluid milk market as a case study. This paper empirically identifies four retail pricing regimes in fluid milk price series and evaluates the characteristics of the regimes.

This paper assesses the welfare implications of each pricing regime. The results show that the forecasting power of the model is strong in fluid milk retail market. Therefore, the study could serve as a price monitor to the public policymaker.

This paper presents the first study to apply dynamic oligopolistic competition model to food marketing research.

The purpose of this paper is to apply the Becker‐Murphy theory of rational addiction to the case of carbonated soft drinks. The research aims to reveal the rational addiction evidence of carbonated soft drinks and derive policy implications under this evidence. Consumers' rational addictive evidence for carbonated soft drinks provides a warning for the Chinese government to regulate the industry, due to its bad health consequences.

The authors empirically apply a time‐varying parameter model and scanner data set from 46 US cities.

Empirical results provide strong evidence that carbonated soft drinks are rationally addictive, thus opening the door to taxation and regulation. Taking rational addition into account, estimated demand elasticities are much lower than previous estimates using scanner data, which implies a limited role for taxes to curb consumption but a strong role to raise revenue to fund health promotion programs.

This is the first study to test the rational addiction nature of carbonated soft drinks, thus adding to the scarce economic literature on food addiction. Although the empirical results derived are based on soft drink consumption in the USA, China is experiencing a similar consumption increase in carbonated soft drinks as in the USA, in the examined period. Therefore, the lessons from the USA are also valuable for the public policy makers in China.

The purpose of this paper is to present an econometric model to empirically analyze the influence of production patterns and transaction style on raw milk quality. More specifically, the paper examines the effects of these institutions on both nutrition and safety aspects of raw milk quality.

Using data collected from 396 households in Inner Mongolia, this paper adopts a multiple linear regression model (OLS/FGLS) and a zero-inflated Poisson regression model to test two hypotheses proposed according to theory and descriptive analysis.

The empirical results indicate that both production pattern and transaction style significantly affect raw milk quality. Production pattern has a more significant effect on raw milk nutrition, while transaction style has a more significant effect on raw milk safety.

Current government policies focus on reducing household production and regulating private milk collection stations. From a comprehensive quality perspective, these policies are not effective in that they cannot guarantee raw milk safety and have little effect on improving raw milk nutrition. Alternatively, promoting dairy farmers' specialized cooperatives may be a more effective policy measure.

In contrast to other studies, this paper adopts a comprehensive quality perspective that examines both nutritional and safety characteristics rather than focusing on any single quality indicator, separately analyzing the factors influencing raw milk nutrition and raw milk safety. Therefore, the conclusion of this paper provides a new perspective in addressing the current raw milk quality problems facing China's dairy industry.

This paper aims to address a new iterative tuning method of PID control for robot manipulators.

This tuning method uses several properties of the robot control, such as any PD control can stabilize a robot in regulation case, the closed-loop system of PID control can be approximated by a linear system, the control torque to the robot manipulator is linearly independent of the robot dynamic.

Compared with the other PID tuning methods, this novel method is simple, systematic, and stable. The transient properties of this PID control are better than the other normal PID controllers.

In this paper, a new systematic tuning method for PID control is proposed. The paper applies this method on an upper limb exoskeleton, and real experiment results give validation of our PID tuning method.

This study aims to use a deterministic tourist walk to build a system that can identify wear particles. Wear particles provide detailed information about the wear processes taking place between mechanical components. Identification of the type of wear particles by image processing and pattern recognition is key to effective online monitoring algorithm. There are three kinds of particles that are particularly difficult to distinguish: severe sliding wear particles, fatigue spall particles and laminar particles.

In this study, an identification method is tested using the deterministic tourist walking (DTW) method. This study examined whether this algorithm can be used in particle identification. If it does, can it outperform the traditional texture analysis methods such as Discrete wavelet transform or co-occurrence matrix. Different parameters such as walk’s memory size, size of image samples, different inputting vectors and different classifiers were compared.

The DTW algorithm showed promising result compared to traditional texture extraction methods: discrete wavelet transform and co-occurrence matrix. The DTW method offers a higher identification accuracy and a simple feature vector. A conclusion can be drawn that the DTW method is suited for particle identification and can be put into practical use in condition monitoring systems.

This paper combined DTW algorithm with wear particle identification problem.

To solve the problems of short battery life and low transportation safety of logistics drones, this paper aims to propose a design of logistics unmanned aerial vehicles (UAV) wing with a composite ducted rotor, which combines fixed wing and rotary-wing.

This UAV adopts tiltable ducted rotor combined with fixed wing, which has the characteristics of fast flight speed, large carrying capacity and long endurance. At the same time, it has the hovering and vertical take-off and landing capabilities of the rotary-wing UAV. In addition, aerodynamic simulation analysis of the composite model with a fixed wing and a ducted rotor was carried out, and the aerodynamic influence of the composite model on the UAV was analyzed under different speeds, fixed wing angles of attack and ducted rotor speeds.

The results were as follows: when the speed of the ducted rotor is 2,500 rpm, CL and K both reach maximum values. But when the speed exceeds 3,000 rpm, the lift will decrease; when the angle of attack of the fixed wing is 10° and the rotational speed of the ducted rotor is about 3,000 rpm, the aerodynamic characteristics of the wing are better.

The novelty of this work comes from a composite wing design of a fixed wing combined with a tiltable ducted rotor applied to the logistics UAVs, and the aerodynamic characteristics of the design wing are analyzed.